@article{wang_wu_wu_li_2025, title={A multiple Lyapunov function-based switching anti-windup design for linear systems under asymmetric input constraints and its application to aero-engines}, volume={2}, ISSN={["1464-5319"]}, DOI={10.1080/00207721.2025.2464018}, journal={INTERNATIONAL JOURNAL OF SYSTEMS SCIENCE}, author={Wang, Ke and Wu, Fen and Wu, Di and Li, Pengyuan}, year={2025}, month={Feb} }
 @article{jin_chen_xie_wu_2024, title={Degradation Prediction of PEMFC Based on Data-Driven Method With Adaptive Fuzzy Sampling}, volume={10}, ISSN={["2332-7782"]}, url={https://publons.com/wos-op/publon/56938553/}, DOI={10.1109/TTE.2023.3296719}, abstractNote={Durability is one of the concerns in the large-scale application of proton exchange membrane fuel cells (PEMFC). The objective of this paper is to propose a data-driven approach to achieve long-term prediction. Echo state network-cycle reservoir with jump (ESN-CRJ) is an extended network based on state echo network (ESN). ESN model is used to extract state information in reservoir and transmitted to CRJ for voltage prediction of stack. In addition, an adaptive fuzzy sampling (AFS) method is adopted to sample the training data in this paper. The degradation phenomenon is realized in the stack voltage drop, the place where the voltage drop is rapid contains more degradation information, which needs to be extracted more by the prediction model. Experimental results show that the ESN-CRJ with AFS can be an improvement of 22.02% in long-term prediction under the static current. Under the quasi-dynamic current, the long-term prediction accuracy can be an improvement of 25.06%. Consequently, the proposed approach can achieve well performance in the remaining useful life prediction.}, number={2}, journal={IEEE TRANSACTIONS ON TRANSPORTATION ELECTRIFICATION}, author={Jin, Jiashu and Chen, Yuepeng and Xie, Changjun and Wu, Fen}, year={2024}, month={Jun}, pages={3363–3372} }
 @article{zhu_xu_wu_chen_zhou_2024, title={Fault Estimation for a Class of Markov Jump Piecewise-Affine Systems: Current Feedback Based Iterative Learning Approach}, volume={11}, ISSN={["2329-9274"]}, url={https://publons.com/wos-op/publon/67964044/}, DOI={10.1109/JAS.2023.123990}, abstractNote={In this paper, the issues of stochastic stability analysis and fault estimation are investigated for a class of continuous-time Markov jump piecewise-affne (PWA) systems against actuator and sensor faults. Firstly, a novel mode-dependent PWA iterative learning observer with current feedback is designed to estimate the system states and faults, simultaneously, which contains both the previous iteration information and the current feedback mechanism. The auxiliary feedback channel optimizes the response speed of the observer, therefore the estimation error would converge to zero rapidly. Then, sufficient conditions for stochastic stability with guaranteed <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$H$</tex> <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</inf> performance are demon-strated for the estimation error system, and the equivalence relations between the system information and the estimated information can be established via iterative accumulating representation. Finally, two illustrative examples containing a class of tunnel diode circuit systems are presented to fully demonstrate the effectiveness and superiority of the proposed iterative learning observer with current feedback.}, number={2}, journal={IEEE-CAA JOURNAL OF AUTOMATICA SINICA}, author={Zhu, Yanzheng and Xu, Nuo and Wu, Fen and Chen, Xinkai and Zhou, Donghua}, year={2024}, month={Feb}, pages={418–429} }
 @article{jin_wang_chen_xie_wu_wen_2024, title={Modeling and energy management strategy of hybrid energy storage in islanded DC micro-grid}, volume={106}, ISSN={["1432-0487"]}, url={https://publons.com/wos-op/publon/67769837/}, DOI={10.1007/s00202-024-02376-x}, number={5}, journal={ELECTRICAL ENGINEERING}, author={Jin, Jiashu and Wang, Zhewei and Chen, Yuepeng and Xie, Changjun and Wu, Fen and Wen, Yinghan}, year={2024}, month={Apr} }
 @article{xu_zhu_wu_ahn_2024, title={Sampled-Data Control for Buck-Boost Converter Using a Switched Affine Systems Approach}, volume={71}, ISSN={["1558-0806"]}, url={https://publons.com/wos-op/publon/65286850/}, DOI={10.1109/TCSI.2024.3369037}, abstractNote={This paper focuses on the sampled-data control for a DC-DC buck-boost converter, which is modeled as a class of continuous-time switched affine systems (SASs). The controller of the closed-loop system, in which both the control inputs and switching signals are sampled-data-dependent, is designed to ensure convergence of the system state to a specified region. This region comprises multiple ellipsoids centered around some shifted points that need to be determined, which can better characterize the convergence region under non-uniform sampling intervals. By introducing a switching multi-shifted-point-dependent Lyapunov functional, sufficient conditions are derived to ensure practical stability of the presented SASs. The proposed design scheme generalizes the switching quadratic Lyapunov function based method, and provides a smaller and more accurate invariant set. Moreover, the method is extended to SASs with uncertainties, and the corresponding robust stability conditions are provided. Finally, the superiority of the proposed approach is demonstrated through a case study of a DC motor driven by a buck-boost converter.}, number={7}, journal={IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS I-REGULAR PAPERS}, author={Xu, Xiaozeng and Zhu, Yanzheng and Wu, Fen and Ahn, Choon Ki}, year={2024}, month={Feb} }
 @article{jin_chen_xie_wu_2023, title={Remaining useful life prediction of PEMFC based on the multi-input cycle reservoir with jump network}, volume={48}, ISSN={["1879-3487"]}, url={https://publons.com/wos-op/publon/59643387/}, DOI={10.1016/j.ijhydene.2022.12.170}, abstractNote={In recent years, fuel cells have attracted more and more attention in the energy field. However, accurate evaluation of durability is one of the key aspects of large-scale commercial application of fuel cells. The data-driven method has good fitting performance for predicting remaining useful life (RUL) at complex and nonlinear systems. In this paper, Cycle Reservoir with Jump with multi-inputs and multi-outputs (MIMO-CRJ) is proposed to further improve the fitting speed and reduce the complexity of the system which improved the structure of echo state network (ESN). Different from the previous method that only uses voltage to predict the voltage, this paper considers stack current, temperature and pressure, reactant flow rate in fuel cell operation as input variables, and extracts more degradation information to predict the voltage trend. Experimental results show that MIMO-CRJ has better performance than Cycle Reservoir with Jump with single -inputs and single-output (SISO-CRJ) and ESN networks under both static and quasi-dynamic current conditions.}, number={34}, journal={INTERNATIONAL JOURNAL OF HYDROGEN ENERGY}, author={Jin, Jiashu and Chen, Yuepeng and Xie, Changjun and Wu, Fen}, year={2023}, month={Apr}, pages={12844–12860} }
 @article{wang_li_wu_sun_2023, title={Switching Anti-Windup Synthesis for Linear Systems With Asymmetric Actuator Saturation}, volume={54}, ISSN={["2168-2275"]}, url={https://publons.com/wos-op/publon/53494828/}, DOI={10.1109/TCYB.2023.3264913}, abstractNote={This article proposes a switching anti-windup strategy for linear, time-invariant (LTI) systems subject to asymmetric actuator saturation and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mathcal{L}_{2}$</tex-math> </inline-formula> -disturbances, the core idea behind which is to make full use of the available range of control input space by switching among multiple anti-windup gains. The asymmetrically saturated LTI system is converted to a switched system with symmetrically saturated subsystems, and a dwell time switching rule is presented to govern the switching between different antiwindup gains. Based on multiple Lyapunov functions, we derive sufficient conditions for guaranteeing the regional stability and weighted <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mathcal{L}_{2}$</tex-math> </inline-formula> performance of the closed-loop system. The switching anti-windup synthesis that designs a separate anti-windup gain for each subsystem is cast as a convex optimization problem. In comparison with the design of a single anti-windup gain, our method can induce less conservative results since the asymmetric character of the saturation constraint is fully utilized in the switching anti-windup design. Two numerical examples, and an application to aeroengine control (the experiments are conducted on a semiphysical test bench), demonstrate the superiority and practicality of the proposed scheme.}, number={6}, journal={IEEE TRANSACTIONS ON CYBERNETICS}, author={Wang, Ke and Li, Pengyuan and Wu, Fen and Sun, Xi-Ming}, year={2023}, month={Apr} }
 @article{wang_wu_sun_2023, title={Switching Anti-windup Control for Aircraft Engines}, volume={70}, ISSN={["1557-9948"]}, url={https://publons.com/wos-op/publon/48750088/}, DOI={10.1109/TIE.2022.3163464}, abstractNote={In this article, we propose a switching anti-windup scheme for the aircraft engine control. The linear engine model with asymmetric saturation is first transformed into a switched system, each subsystem of which is subject to symmetric saturation. A state-dependent switching logic is presented to orchestrate the switching among multiple anti-windup compensators. We then establish the sufficient condition to guarantee the regional stability and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\mathcal {L}_{2}$</tex-math></inline-formula> performance of the resulting closed-loop system. This condition is less conservative since the non-symmetric nature of the saturation nonlinearity can be fully exploited in the control design. Optimization algorithms are further developed for the anti-windup gain design. The theoretical aspect of the proposed method is analyzed rigorously, and the effectiveness is validated through experiments performed on a semi-physical test bed.}, number={2}, journal={IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS}, author={Wang, Ke and Wu, Fen and Sun, Xi-Ming}, year={2023}, month={Feb}, pages={1830–1840} }
 @article{ban_zhang_wu_2022, title={Advanced controller synthesis for fuzzy parameter varying systems}, volume={359}, ISSN={["1879-2693"]}, url={https://publons.com/wos-op/publon/35537552/}, DOI={10.1016/j.jfranklin.2020.12.038}, abstractNote={A novel nonlinear time-varying model termed as the fuzzy parameter varying (FPV) system is proposed in this research, which inherits both advantages of the conventional T-S fuzzy system in dealing with nonlinear plants and strengths of the linear parameter varying (LPV) system in handling time-varying features. It is, therefore, an attractive mathematical model to efficiently approximate a nonlinear time-varying plant or to serve as a type of time-varying controller. Using the full block S-procedure, sufficient stability conditions have been derived in the form of linear matrix inequalities (LMIs) to test quadratic stability of the open-loop FPV system. Moreover, sufficient conditions have been derived on synthesizing both state feedback and dynamical output feedback fuzzy gain-scheduling controllers that can stabilize the FPV system. An inverted pendulum with a variable length pole is utilized to demonstrate advantages of the FPV system compared to the conventional T-S fuzzy system in representing a practical time-varying nonlinear plant and to validate the controller synthesis conditions.}, number={2}, journal={JOURNAL OF THE FRANKLIN INSTITUTE-ENGINEERING AND APPLIED MATHEMATICS}, author={Ban, Xiaojun and Zhang, Hongyang and Wu, Fen}, year={2022}, month={Jan}, pages={762–785} }
 @article{chen_zhu_wu_zhao_2022, title={Fault Estimation Observer Design for Markovian Jump Systems With Nondifferentiable Actuator and Sensor Failures}, volume={53}, ISSN={["2168-2275"]}, url={https://publons.com/wos-op/publon/55434491/}, DOI={10.1109/TCYB.2022.3169290}, abstractNote={This article addresses the simultaneous actuator and sensor fault estimation (FE) problem for a class of Markovian jump systems (MJSs) with nondifferentiable actuator failures. In order to overcome the difficulties brought by the nondifferentiable actuator failures, we construct an extended vector composed of states, sensor faults, and disturbances, where the derivatives of actuator failures are not required in this augmented system. Then, two novel observer-based approaches are developed for the augmented descriptor system to cope with the FE problem. The first one is a reduced-order FE observer, where the actuator failures can be estimated by the algebraic input reconstruction strategy. The second one refers to an iterative learning observer (ILO) design method, which can obtain the accurate FE result by integrating the estimations in the iterative processes. The two proposed FE observer design methods can avoid the sliding surface switching problem produced by sliding-mode observers in the area of MJSs. Finally, a practical example of the F-404 aircraft engine system is presented to show the validity of the proposed FE observer design techniques.}, number={6}, journal={IEEE TRANSACTIONS ON CYBERNETICS}, author={Chen, Liheng and Zhu, Yanzheng and Wu, Fen and Zhao, Yuxin}, year={2022}, month={May} }
 @article{huang_ban_wu_huang_2021, title={Design of magnetic levitation self-learning control system based on Q-network,基于Q网络的磁悬浮自学习控制系统设计}, volume={25}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85116752013&partnerID=MN8TOARS}, DOI={10.15938/j.emc.2021.09.015}, number={9}, journal={Dianji yu Kongzhi Xuebao/Electric Machines and Control}, author={Huang, T. and Ban, X.-J. and Wu, F. and Huang, X.-L.}, year={2021}, pages={132–139} }
 @article{wang_tan_wu_wang_2021, title={Fault-Tolerant Attitude Control for Rigid Spacecraft Without Angular Velocity Measurements}, volume={51}, ISSN={["2168-2275"]}, url={https://publons.com/wos-op/publon/20130703/}, DOI={10.1109/TCYB.2019.2905427}, abstractNote={In this paper, a fault-tolerant control scheme is proposed for the rigid spacecraft attitude control system subject to external disturbances, multiple system uncertainties, and actuator faults. The angular velocity measurement is unavailable, which increases the complexity of the problem. An observer is first designed based on the super-twisting sliding mode method, which can provide accurate estimates of the angular velocity in finite time. Then, an adaptive fault-tolerant controller is proposed based on neural networks using the information from the observer. It is shown that the attitude orientations converge to the desired values exponentially. Finally, a simulation example is utilized to verify the effectiveness of the proposed scheme.}, number={3}, journal={IEEE TRANSACTIONS ON CYBERNETICS}, author={Wang, Xianghua and Tan, Chee Pin and Wu, Fen and Wang, Jiandong}, year={2021}, month={Mar}, pages={1216–1229} }
 @article{cheng_wu_wu_lu_chen_cao_2021, title={Modeling and Control of Drill-String System With Stick-Slip Vibrations Using LPV Technique}, volume={29}, ISSN={["1558-0865"]}, url={https://publons.com/wos-op/publon/21316796/}, DOI={10.1109/TCST.2020.2978892}, abstractNote={In this article, a systematic linear parameter-varying (LPV) model and a gain-scheduled control methodology for drill-string systems are proposed to analyze drill-string dynamics and suppress stick-slip vibrations, finally achieving efficient drilling. First, the changing length of drill string over the entire drilling process is emphasized and the corresponding LPV model is presented by combining the existing multi-degree-of-freedom (DOF) drill-string model, so as to capture length-varying effect. Then, we construct a generalized gain-scheduled control structure based on the H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> framework and gain-scheduling technique. Procedures for obtaining original and reduced gain-scheduled controllers are designed. Using the measured top drive speed and drill-string length in real time, the gains of the proposed controllers are automatically scheduled, enforcing satisfactory tracking and disturbance rejection performances. Finally, simulations and comparisons between our model and finite-element method-based model and our control method and existing active damping controller are carried out. The simulation results illustrate the effectiveness of the proposal.}, number={2}, journal={IEEE TRANSACTIONS ON CONTROL SYSTEMS TECHNOLOGY}, author={Cheng, Jun and Wu, Min and Wu, Fen and Lu, Chengda and Chen, Xin and Cao, Weihua}, year={2021}, month={Mar}, pages={718–730} }
 @article{jin_chen_xie_zhu_wu_2021, title={Remaining useful life prediction of PEMFC based on cycle reservoir with jump model}, volume={46}, ISSN={["1879-3487"]}, url={https://publons.com/wos-op/publon/55434490/}, DOI={10.1016/j.ijhydene.2021.09.233}, abstractNote={Accurate prognosis of limited durability is one of the key factors for the commercialization of proton exchange membrane fuel cell (PEMFC) on a large scale. Thanks to ignoring the structure of the PEMFC and simplifying the prognostic process, the data-driven prognostic approaches was the commonly used for predicting remaining useful life (RUL) at present. In this paper, the proposed cycle reservoir with jump (CRJ) model improves the ESN model, changes the connection mode of neurons in the reservoir and speeds up the linear fitting process. The experiment will verify the performance of CRJ model to predict stacks voltage under static current and quasi-dynamic current conditions. In addition, the reliability of the CRJ model is verified with different amount of data as the training and test sets. The experimental results demonstrate that the CRJ model can achieve better effect in the remaining useful life prognosis of fuel cells.}, number={80}, journal={INTERNATIONAL JOURNAL OF HYDROGEN ENERGY}, author={Jin, Jiashu and Chen, Yuepeng and Xie, Changjun and Zhu, Wenchao and Wu, Fen}, year={2021}, month={Nov}, pages={40001–40013} }
 @article{xue_wu_yuan_2021, title={Robust consensus for linear multi-agent systems with structured uncertainties}, volume={94}, ISSN={["1366-5820"]}, url={https://publons.com/wos-op/publon/27992509/}, DOI={10.1080/00207179.2019.1612096}, abstractNote={This paper addresses a robust H∞ consensus problem for linear multi-agent systems subject to structured uncertainty and external disturbances under the leaderless framework. A distributed dynamic output-feedback protocol is proposed, which utilises not only relative output information of neighbouring agents but also relative state information of neighbouring controllers. Through model transformations, the robust H∞ consensus control problem of multi-agents network is reduced to a set of independent H∞ stabilisation problems for single linear subsystems. For robust H∞ consensus, it is shown that the analysis and full state-feedback synthesis conditions for such subsystems can be formulated as linear matrix inequality (LMI) optimisation problems. On the other hand, the synthesis condition for dynamic output-feedback protocol is formulated as non-convex bilinear matrix inequality (BMI) optimisation problem. An iterative LMI algorithm is then presented to solve the resulting BMI optimisation problem. An example of multiple mass-spring-damper systems has been used to demonstrate theoretical results.}, number={3}, journal={INTERNATIONAL JOURNAL OF CONTROL}, author={Xue, Xiangming and Wu, Fen and Yuan, Chengzhi}, year={2021}, month={Mar}, pages={675–686} }
 @article{xie_han_wu_zhu_2020, title={H-infinity observer-controller synthesis approach in low frequency for T-S fuzzy systems}, volume={14}, ISSN={["1751-8652"]}, url={https://publons.com/wos-op/publon/41342508/}, DOI={10.1049/iet-cta.2019.0242}, abstractNote={For the output feedback control problem of continuous-time T–S fuzzy systems with unknown premise variables, an observer–controller design method in the low-frequency domain is proposed. First, an observer–controller structure is given, the unknown premise variables are limited by Lipschitz conditions. Then, the system stability conditions are obtained by the negativeness of eigenvalues' real parts. To achieve better control performance of the system in low frequency, the index for attenuating the unknown low-frequency disturbance is guaranteed by generalised Kalman–Yakubovich–Popov lemma. Then, the stability and robustness conditions are converted into linear matrix inequality forms, which can be solved directly by a convex optimisation technique. Finally, several simulation examples carried out to show the effectiveness of the proposed method.}, number={5}, journal={IET CONTROL THEORY AND APPLICATIONS}, author={Xie, Wen-Bo and Han, Zhao-Kun and Wu, Fen and Zhu, Song}, year={2020}, month={Mar}, pages={738–749} }
 @inbook{xue_yuan_wu_2020, title={Robust output feedback control of linear state-delayed systems using dynamic IQCs}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85126413410&partnerID=MN8TOARS}, DOI={10.1016/B978-0-12-820599-0.00016-1}, booktitle={Control Strategy for Time-Delay Systems: Part I: Concepts and Theories}, author={Xue, X. and Yuan, C. and Wu, F.}, year={2020}, pages={383–412} }
 @inproceedings{xue_wu_2019, title={A Novel Distributed Output-Feedback Adaptive Consensus Protocol for Linear Multi-Agent Systems}, volume={2019-July}, url={https://ieeexplore-ieee-org.prox.lib.ncsu.edu/document/8865858}, DOI={10.23919/ChiCC.2019.8865858}, abstractNote={This paper addresses the adaptive H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> consensus problem for linear multi-agent systems subject to external disturbances. A novel fully distributed adaptive dynamic output feedback control protocol is proposed, which utilizes relative output information of neighboring agents, relative state information of neighboring controllers and time-varying coupling weight for each node. Sufficient analysis conditions are derived using Lyapunov method. Moreover, H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> adaptive output-feedback consensus synthesis conditions are formulated as linear matrix inequalities, which can be solved efficiently via convex optimization. This is achieved by using a novel adaptive protocol structure. A numerical example has been used to demonstrate the advantage of theoretical results.}, booktitle={2019 38th Chinese Control Conference (CCC)}, author={Xue, X. and Wu, F.}, year={2019}, month={Jul}, pages={6026–6031} }
 @article{xue_yuan_wu_2019, title={Convexified H-infinity output-feedback consensus synthesis for linear multi-agent systems}, volume={13}, ISSN={["1751-8652"]}, url={https://publons.com/wos-op/publon/27992510/}, DOI={10.1049/iet-cta.2018.5337}, abstractNote={This study addresses the consensus problem for linear multi‐agent systems subject to external disturbances under the leaderless framework. A novel distributed dynamic output feedback control protocol is proposed, which utilises not only relative output information of neighbouring agents but also relative state information of neighbouring controllers. Through model transformation, the consensus control problem of multi‐agents network is reduced to a set of independent stabilisation subproblems for n ‐dimensional linear systems. Sufficient analysis conditions are derived using the Lyapunov method. An important contribution of this work lies in that the leaderless output‐feedback consensus synthesis conditions are convexified without introducing any conservatism and formulated as linear matrix inequalities, which can be solved efficiently via convex optimisation. This is achieved by using a novel dynamic output‐feedback controller structure. A numerical example has been used to demonstrate the advantage of theoretical results.}, number={11}, journal={IET CONTROL THEORY AND APPLICATIONS}, author={Xue, Xiangming and Yuan, Chengzhi and Wu, Fen}, year={2019}, month={Jul}, pages={1619–1628} }
 @article{ren_ban_wu_huang_2019, title={Fuzzy learning controller design of 2-DOF flight attitude simulator,二自由度飞行姿态模拟器的模糊强化学习控制}, volume={23}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85076486999&partnerID=MN8TOARS}, DOI={10.15938/j.emc.2019.11.016}, number={11}, journal={Dianji yu Kongzhi Xuebao/Electric Machines and Control}, author={Ren, L.-W. and Ban, X.-J. and Wu, F. and Huang, X.-L.}, year={2019}, pages={127–134} }
 @article{long_wu_2019, title={Iterative-Learning-Control-Based Tracking for Asteroid Close-Proximity Operations}, volume={42}, ISSN={["1533-3884"]}, url={https://publons.com/wos-op/publon/27992511/}, DOI={10.2514/1.G003884}, abstractNote={No AccessEngineering NotesIterative-Learning-Control-Based Tracking for Asteroid Close-Proximity OperationsJiateng Long and Fen WuJiateng LongBeijing Institute of Technology, 100081 Beijing, People’s Republic of China*Ph.D. Candidate, School of Aerospace Engineering; .Search for more papers by this author and Fen WuNorth Carolina State University, Raleigh, North Carolina 27695†Professor, Department of Mechanical and Aerospace Engineering; (Corresponding Author).Search for more papers by this authorPublished Online:2 Jan 2019https://doi.org/10.2514/1.G003884SectionsRead Now ToolsAdd to favoritesDownload citationTrack citations ShareShare onFacebookTwitterLinked InRedditEmail About References [1] Kawaguchi J. 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T., “Hybrid Cartesian and Orbit Element Feedback Law for Formation Flying Spacecraft,” Journal of Guidance, Control, and Dynamics, Vol. 25, No. 2, 2002, pp. 387–393. doi:https://doi.org/10.2514/2.4893 JGCODS 0731-5090 LinkGoogle Scholar[19] Kumar K., “Attitude Dynamics and Control of Satellites Orbiting Rotating Asteroids,” Acta Mechanica, Vol. 198, Nos. 1–2, 2008, pp. 99–118. doi:https://doi.org/10.1007/s00707-007-0508-y AMHCAP 0001-5970 CrossrefGoogle Scholar Previous article FiguresReferencesRelatedDetailsCited byPassivity-Based Iterative Learning Control for Spacecraft Attitude Tracking on SO(3)Xiaoyu Lang and Anton de Ruiter11 February 2022 | Journal of Guidance, Control, and Dynamics, Vol. 45, No. 4Saturated Adaptive Relative Motion Coordination of Docking Ports in Space Close-Range RendezvousIEEE Transactions on Aerospace and Electronic Systems, Vol. 56, No. 6Neural Network Augmented Intelligent Iterative Learning Control for a Nonlinear SystemSimultaneous Learning Optimization of Hamiltonian Systems and Trajectory Tracking Around an AsteroidAsuto Taniguchi, Satoshi Satoh and Katsuhiko Yamada13 December 2019 | Journal of Guidance, Control, and Dynamics, Vol. 43, No. 2Quaternion-based adaptive attitude control of asteroid-orbiting spacecraft via immersion and invarianceActa Astronautica, Vol. 167 What's Popular Volume 42, Number 5May 2019 CrossmarkInformationCopyright © 2018 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved. All requests for copying and permission to reprint should be submitted to CCC at www.copyright.com; employ the eISSN 1533-3884 to initiate your request. See also AIAA Rights and Permissions www.aiaa.org/randp. TopicsAsteroidsAstronomyCelestial Coordinate SystemCelestial MechanicsControl TheoryFeedback ControlGuidance, Navigation, and Control SystemsPlanetary Science and ExplorationPlanetsSolar PhysicsSpace Science and TechnologySpacecraft GuidanceSpacecraft Guidance and Control KeywordsIterative Learning ControlAsteroidsSpacecraft TrajectoriesFeedback ControlNumerical SimulationSolar RadiationConvergence AnalysisRight AscensionSolar SystemOrbital InclinationAcknowledgmentsJ. Long would like to thank the support of the Graduate Technological Innovation Project of Beijing Institute of Technology 2017CX10028 and the China Scholarship Council for sponsoring this research. The authors greatly appreciate the Associate Editor and anonymous reviewers for their patient and rigorous review with high standards, which are of significant benefit for the quality improvement of this paper.PDF Received12 June 2018Accepted18 November 2018Published online2 January 2019}, number={5}, journal={JOURNAL OF GUIDANCE CONTROL AND DYNAMICS}, author={Long, Jiateng and Wu, Fen}, year={2019}, month={May}, pages={1195–1203} }
 @article{hao_duan_chen_wu_2019, title={New Controllability Conditions for Networked, Identical LTI Systems}, volume={64}, ISSN={["1558-2523"]}, url={https://publons.com/wos-op/publon/27992508/}, DOI={10.1109/TAC.2019.2893899}, abstractNote={A new necessary and sufficient condition for the controllability of networked linear time-invariant systems is derived, where the network topology is general and the nodes have identical higher dimensional dynamics. The condition is easier to verify, explicitly illustrating how the network topology, node-system dynamics, external control inputs, and inner interactions altogether affect the controllability of the whole networked system. Furthermore, the controllability of the specified Cartesian product networks is revisited, revealing that the necessity of the controllability criterion established in the work presented by Chapman et al., does not hold. In view of this, a modified, necessary, and sufficient condition is established. The effectiveness of the conditions is demonstrated using several examples.}, number={10}, journal={IEEE TRANSACTIONS ON AUTOMATIC CONTROL}, author={Hao, Yuqing and Duan, Zhisheng and Chen, Guanrong and Wu, Fen}, year={2019}, month={Oct}, pages={4223–4228} }
 @article{zhu_wu_karimi_lu_2019, title={Special issue on advanced analysis and control design of switching linear parameter-varying systems and its applications}, volume={233}, ISSN={["2041-3041"]}, url={https://publons.com/wos-op/publon/19523793/}, DOI={10.1177/0959651818819594}, abstractNote={As the linear parameter-varying (LPV) system has a large range of parameter variations, it is very difficult to achieve satisfactory control performance for the whole range of parameter variation merely through a constant controller. An effective approach to ensure the desired control performance is to divide the whole parameter range into some sub-ranges, and each sub-range corresponds to a controller. The desired performance can be satisfied via the switching of controllers belonging to different sub-ranges. Accordingly, the LPV control issues involved with certain switching properties (e.g. nondeterministic or stochastic) have received increasing interests within recent decades, and a quite large number of useful results have been reported assuming the switching signals with nondeterministic (e.g. average dwell time (ADT), persistent dwell time) or Markov stochastic properties. However, about some applications in practice, various non-ideal situations might occur, for instance, the exact values of scheduling parameters may not be valid to adapt to controller parameters owing to sensor drift and noise; the system states are not measurable completely for the desired controllers/filters in that a full knowledge of the state vector is rarely available; the various complex dynamics such as model uncertainty, time delays, and faults often exist in the practical systems, all of which bring new challenges and opportunities for theoretical researchers and applied practitioners alike. In terms of the above discussion on motivations, eight papers are chosen in this special issue from a large number of submissions via a normative peer-review process. These collections contain both theoretical and application-oriented studies for showcasing emerging innovative ideas and technologies, to address various unresolved issues and challenges in the field of hybrid LPV control systems. The main contributions of these studies are briefly provided as follows. First, considering the switched LPV systems with nondeterministic switching properties in the continuous-time domain, Zhao et al. investigate the issue of HN fault-tolerant control for a class of continuous-time switched LPV systems with actuator failures by the multiple discretized parameterdependent Lyapunov functions approach. The proposed Lyapunov technique avoids the Zeno behavior produced by the parameter and state-dependent switching approach. A new switching strategy is established depending on the parameter, state, and dwelltime (DT), which eliminates the assumption on the finite number of switching for any finite time. An application to a turbofan engine is illustrated to verify the utility of the obtained results. Next, Ren et al. address the input–output finite-time stability and finite-time boundedness for a class of continuous-time switched LPV systems with ADT switching based on an eventtriggered communication scheme. An asynchronous switching strategy is considered when deriving the sufficient conditions of stability and boundedness in finite time, and the design of parameter-dependent asynchronous controllers is performed by resolving a group of linear matrix inequalities. The effectiveness of the proposed methods is demonstrated via a numerical example. Furthermore, Ren et al. discuss the finite-time non-fragile full-order controller design issue for a class of continuous-time switched LPV systems based on the multiple Lyapunov function approach. Finally, under the ADT switching, Wang et al. study the HN filter design problem for a class of continuous-time switched LPV systems with both time-varying state and parameter delays. An improved reciprocally convex inequality is used to deal with the terms of delays, and the multiple Lyapunov function method is employed to derive the stability condition with less conservatism, which ensures the existence of novel parameterdependent filters with a guaranteed HN performance. Turning to the field of switched LPV systems with Markov stochastic switching properties, Shen et al. deal with the passive gain-scheduling filtering problem for a class of discrete-time Markov jump LPV systems in the presence of random occurring fading channels. The description of mode information between the system and the presented filter is made via a hidden Markov model. The sufficient conditions are obtained to ensure the existence of an available passive gain-scheduling filter with the aid of the stochastic analysis theory. Besides, Wang et al. concern with the issue of stochastic finite-time HN filtering issue for a class of continuous-}, number={1}, journal={PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART I-JOURNAL OF SYSTEMS AND CONTROL ENGINEERING}, author={Zhu, Yanzheng and Wu, Fen and Karimi, Hamid Reza and Lu, Bei}, year={2019}, month={Jan}, pages={3–4} }
 @inbook{yuan_wu_2019, title={ℋ<sub>∞</sub> consensus synthesis of multiagent systems with nonuniform time-varying input delays: A dynamic IQC approach}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85083277523&partnerID=MN8TOARS}, DOI={10.1016/B978-0-12-814928-7.00005-6}, booktitle={Stability, Control and Application of Time-Delay Systems}, author={Yuan, C. and Wu, F.}, year={2019}, pages={99–122} }
 @article{yuan_duan_wu_2018, title={Almost output regulation of LFT systems via gain-scheduling control}, volume={91}, ISSN={["1366-5820"]}, url={https://publons.com/wos-op/publon/9848639/}, DOI={10.1080/00207179.2017.1309573}, abstractNote={Output regulation of general uncertain systems is a meaningful yet challenging problem. In spite of the rich literature in the field, the problem has not yet been addressed adequately due to the lack of an effective design mechanism. In this paper, we propose a new design framework for almost output regulation of uncertain systems described in the general form of linear fractional transformation (LFT) with time-varying parametric uncertainties and unknown external perturbations. A novel semi-LFT gain-scheduling output regulator structure is proposed, such that the associated control synthesis conditions guaranteeing both output regulation and L2 disturbance attenuation performance are formulated as a set of linear matrix inequalities (LMIs) plus parameter-dependent linear matrix equations, which can be solved separately. A numerical example has been used to demonstrate the effectiveness of the proposed approach.}, number={5}, journal={INTERNATIONAL JOURNAL OF CONTROL}, author={Yuan, Chengzhi and Duan, Chang and Wu, Fen}, year={2018}, pages={1161–1170} }
 @inproceedings{dong_yuan_wu_2018, title={COOPERATIVE DETERMINISTIC LEARNING-BASED TRAJECTORY TRACKING FOR A GROUP OF UNICYCLE-TYPE VEHICLES}, volume={3}, url={https://publons.com/wos-op/publon/19523792/}, DOI={10.1115/DSCC2018-9003}, abstractNote={A cooperative deterministic learning based state feedback control algorithm is proposed in this paper for joint tracking control and learning/identification for a group of identical nonholonomic vehicles. Specifically, this algorithm is able to model the unknown nonlinear dynamics of the nonholonomic vehicle, and use it for trajectory tracking control with cooperative deterministic learning (DL) theory. In addition, cooperative DL grants every vehicle in the system the ability of knowledge learning not only along the trajectory of its own, but also along the trajectories of all other vehicles as well. It is shown using Lyapunov stability theory that with cooperative DL, the closed-loop system is guaranteed to be stable, with all vehicles tracking its own reference trajectories, and the radial basis function (RBF) neural network (NN) weights of all agents converge to the same constants.}, booktitle={ASME Dynamic Systems and Control Conference (DSCC)}, author={Dong, X. and Yuan, C. and Wu, F.}, year={2018} }
 @article{waghela_bryant_wu_2018, title={Control design in cyber-physical fluid-structure interaction experiments}, volume={82}, ISSN={["0889-9746"]}, url={https://publons.com/wos-op/publon/19523794/}, DOI={10.1016/j.jfluidstructs.2018.06.018}, abstractNote={Cyber-physical fluid dynamics is a hybrid experimental–computational approach to study fluid–structure interaction (FSI). It enables on-the-fly changes to structure inertia, damping, stiffness, and even kinematic constraints by replacing traditional elastically-mounted structures with actuators and a controller. The control design plays a central role in matching the closed-loop dynamics of the cyber-physical structure (CPS) to those of the desired structure. Control designs based on traditional proportional–integral–derivative (PID) and post-modern H∞ control are presented. The controllers are synthesized to match the linearized desired structural dynamics (or the input–output response) but no assumption of linearity is levied on the fluid behavior. To quantify the matching of input–output response, a CPS deviation index is defined based on H∞ norms. To evaluate and compare the performance of the control designs, two well-known FSI instabilities are considered, galloping and aeroelastic flutter. These FSI instabilities represent convenient test cases because they can be analyzed with linear aerodynamic models. Comparing the critical instability flow velocity and oscillation frequency of the CPS with different control designs and the desired mechanical structure demonstrates that the internal structure of the controller is crucial to fully matching the response of the desired structure. H∞ model-matching control with admittance causality is found to be the most adept control design for the CPS.}, journal={JOURNAL OF FLUIDS AND STRUCTURES}, author={Waghela, R. and Bryant, M. and Wu, F.}, year={2018}, month={Oct}, pages={86–100} }
 @article{yuan_wu_2018, title={Cooperative output regulation of multi-agent systems with switched leader dynamics}, volume={49}, ISSN={["1464-5319"]}, url={https://publons.com/wos-op/publon/19523797/}, DOI={10.1080/00207721.2018.1454537}, abstractNote={In this paper, the cooperative output regulation problem for heterogeneous multi-agent systems is addressed by considering a switched leader dynamics. The switched leader dynamics consists of multiple linear models and a switching rule governing the switches among them. A switched leader is capable of generating various sophisticated reference signals for more complicated multi-agent coordination tasks. A novel distributed hybrid impulsive switching control scheme is proposed to achieve cooperative output regulation. Distributed switching stability is established using the average dwell-time technique with multiple Lyapunov functions. Moreover, the associated distributed control synthesis conditions are formulated in terms of linear matrix inequalities plus linear matrix equations. As a result, both switching rules for the leader and distributed switching protocols for the followers can be jointly synthesised via efficient semi-definite programming. An example has been used to demonstrate the effectiveness of the proposed approach.}, number={7}, journal={INTERNATIONAL JOURNAL OF SYSTEMS SCIENCE}, author={Yuan, Chengzhi and Wu, Fen}, year={2018}, pages={1463–1477} }
 @article{yuan_wu_2018, title={Cooperative state estimation of multi-agent systems subject to bounded external disturbances}, volume={49}, ISSN={0020-7721 1464-5319}, url={http://dx.doi.org/10.1080/00207721.2018.1482380}, DOI={10.1080/00207721.2018.1482380}, abstractNote={This paper deals with the problem of cooperative state estimation of general linear multi-agent systems subject to heterogeneous bounded external disturbances. This problem specifies the objective that each agent estimates its own state by using only relative information from its neighbours. Because of the existence of external disturbances, the problem is challenging especially when stringent exact estimation performance is desired. To this end, two cooperative estimation protocols are proposed, including the discontinuous nonlinear protocol for exact state estimation and the continuous nonlinear protocol for estimation with bounded errors. The overall network stability and convergence properties are analysed using the Lyapunov function method. A simulation example has also been used to demonstrate the effectiveness of the proposed results.}, number={9}, journal={International Journal of Systems Science}, publisher={Informa UK Limited}, author={Yuan, Chengzhi and Wu, Fen}, year={2018}, month={Jun}, pages={1985–1996} }
 @inproceedings{xue_wu_2018, title={Distributed Consensus Control for General Uncertain Linear Multi-Agent Systems}, volume={2018-July}, url={http://dx.doi.org/10.23919/chicc.2018.8482686}, DOI={10.23919/chicc.2018.8482686}, abstractNote={This paper addresses the consensus problem for uncertain linear multi-agent systems with distributed state feedback protocol based on relative information of the neighboring agents. The agents share identical nominal linear time-invariant (LTI) dynamics subject to structured uncertainty. Through model transformation, the robust consensus control problem of high dimensional network reduced to scaled H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> control problems of a set of independent n-dimensional linear systems. Sufficient analysis conditions are provided for the robust consensus of uncertain multi-agents with H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> bound. Moreover, control synthesis condition is established as linear matrix inequalities (LMIs) and can be solved efficiently. Simulation study on a multi-agent system demonstrates the advantage of theoretical results.}, booktitle={2018 37th Chinese Control Conference (CCC)}, author={Xue, Xiangming and Wu, Fen}, year={2018}, month={Jul}, pages={7007–7012} }
 @inproceedings{yuan_wu_2018, title={H∞ Consensus Control of Multi-Agent Systems Subject to Diverse Time-Varying Input Delays via Dynamic Output Feedback}, volume={2018-June}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85052592091&partnerID=MN8TOARS}, DOI={10.23919/ACC.2018.8430878}, abstractNote={In this paper, we address the problem of leader-following dynamic output-feedback consensus control of general linear multi-agent systems with diverse time-varying input delays under the integral quadratic constraint (IQC) framework. A novel exact-memory distributed delay controller structure is proposed, which utilizes not only the relative estimation state information from neighboring agents, but also the local real-time information of time delays and the associated dynamic IQC-induced states from the agent itself for feedback control. Based on this, the distributed consensus problem can be decomposed into the H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> stabilization subproblems for a set of independent linear fractional transformation systems, whose dimensions are equal to that of a single agent plant plus the associated local IQC dynamics. Furthermore, new delay control synthesis conditions for each subproblem are fully characterized as linear matrix inequalities, such that the optimal H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> distributed consensus control solution can be synthesized effectively via convex optimization. A numerical example is used to demonstrate the proposed approach.}, booktitle={Proceedings of the American Control Conference}, author={Yuan, C. and Wu, F.}, year={2018}, pages={3672–3677} }
 @inproceedings{ban_zhang_wu_2018, title={STABILITY ANALYSIS AND CONTROLLER DESIGN FOR FUZZY PARAMETER VARYING SYSTEMS BASED ON FUZZY LYAPUNOV FUNCTION}, volume={1}, url={https://publons.com/wos-op/publon/19523791/}, DOI={10.1115/DSCC2018-8996}, abstractNote={The fuzzy parameter varying (FPV) system is a mathematical model proposed to handle nonlinear time-varying dynamical systems encountered in engineering, which has some essential advantages in handling time-varying models. In this article, a new relaxation approach is proposed for the analysis and controller design of the FPV system. Different from the current results on the FPV system, the proposed approach employs the fuzzy Lyapunov function and full block S-procedure to reduce the conservatism in analysis. Furthermore, the relaxation technique proposed in this article can be also used in solving controller synthesis problem effectively. As a result, a design procedure of non-PDC output feedback gain-scheduling controller is provided to ensure asymptotic stability of the closed-loop FPV system. A numerical example is provided to illustrate the proposed method.}, booktitle={ASME Dynamic Systems and Control Conference (DSCC)}, author={Ban, X. and Zhang, H. and Wu, F.}, year={2018} }
 @inproceedings{lian_chakrabortty_wu_duel-hallen_2018, title={Sparsity-Constrained Mixed H 2 /H ∞ Control}, volume={2018-June}, ISBN={9781538654286}, url={http://dx.doi.org/10.23919/acc.2018.8431378}, DOI={10.23919/ACC.2018.8431378}, abstractNote={We propose an algorithm for designing sparsity-constrained controllers for linear time-invariant systems with model uncertainties using a mixed H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> objective. We first improve a previously proposed descent algorithm for mixed H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> control using a modified Zoutendijk's method. Thereafter, we impose a sparsity constraint on this design by combining it with a greedy gradient support pursuit (GraSP) method. The proposed algorithm guarantees a predetermined level of sparsity while maintaining acceptable H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> performance as well as H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> robustness to uncertainties in the open-loop model. The effectiveness of the proposed method is illustrated through simulations.}, booktitle={Proceedings of the Annual American Control Conference (ACC)}, publisher={IEEE}, author={Lian, Feier and Chakrabortty, Aranya and Wu, Fen and Duel-Hallen, Alexandra}, year={2018}, month={Jun}, pages={6253–6258} }
 @article{zhang_ban_wu_2018, title={Stability analysis and controller design for a novel nonlinear system: Fuzzy parameter varying system}, volume={34}, ISSN={["1875-8967"]}, url={https://publons.com/wos-op/publon/19523795/}, DOI={10.3233/jifs-18190}, abstractNote={The novel fuzzy parameter varying system is proposed to deal with nonlinear time-varying models. It has the advantages of the T-S fuzzy system and the linear parameter varying system. It provides a new idea for solving nonlinear time-varying control problem. In this paper, some sufficient condition s are provided to guarantee the globally asymptotically stable of the equilibrium and to synthesize a T-S state feedback control law which can stabilize the closed loop fuzzy parameter varying system. Numerical simulations verify the effectiveness of our results.}, number={6}, journal={JOURNAL OF INTELLIGENT & FUZZY SYSTEMS}, author={Zhang, Hongyang and Ban, Xiaojun and Wu, Fen}, year={2018}, pages={4387–4395} }
 @article{yuan_wu_2017, title={Almost output regulation of switched linear dynamics with switched exosignals}, volume={27}, ISSN={["1099-1239"]}, url={https://publons.com/wos-op/publon/13939914/}, DOI={10.1002/rnc.3735}, abstractNote={Summary For systems with switched linear dynamics and affected by persistent switched exosignals, we propose a new hybrid control approach to achieve not only closed‐loop stability but also tracking and/or rejection of persistent references/disturbances generated by multiple exosystems, namely, output regulation. It is assumed that both controlled plant and exosystem are described by switched linear models. The proposed hybrid controller/output regulator is specified as a switching impulsive system, where the controller states will undergo impulsive jumps at each switching instant. Based on the average dwell time switching technique, it has been shown how to completely reduce the synthesis problem of the hybrid controller to a set of linear matrix equations and linear matrix inequalities. Both continuous‐time and discrete‐time cases are discussed. To demonstrate its usefulness, the proposed hybrid control method has been applied to solve the output regulation problem for a mechanical system. Copyright © 2017 John Wiley & Sons, Ltd.}, number={16}, journal={INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL}, author={Yuan, Chengzhi and Wu, Fen}, year={2017}, month={Nov}, pages={3197–3217} }
 @inproceedings{yuan_wu_duan_2017, title={COOPERATIVE OUTPUT REGULATION OF MULTI-AGENT SYSTEMS WITH SWITCHED LEADER DYNAMICS VIA SMOOTH SWITCHING}, volume={2}, url={https://publons.com/wos-op/publon/13842065/}, DOI={10.1115/dscc2017-5055}, abstractNote={This paper deals with the leader-following cooperative output regulation problem for heterogeneous multi-agent systems by considering a switched leader dynamics. The switched leader dynamics is composed by multiple linear models and a switching rule governing the switches among them, which is capable of generating more diverse and sophisticated reference signals so as to enhance the multi-agent system’s capability in coping with more complicated coordination tasks. A novel distributed switching control scheme, namely, the smooth switching control strategy, is proposed to achieve cooperative output regulation performance. Distributed switching stability of the overall network is established using multiple Lyapunov functions from the switching control theory. Moreover, under the proposed design framework, the overall cooperative switching output regulation problem can be decomposed into several independent switching stabilization subproblems, and the associated switching control synthesis conditions for each subproblems are formulated as a set of linear matrix inequalities (LMIs) plus linear algebraic equations. As a result, stabilizing switching rules for the leader and distributed switching protocols for the follower agents can be jointly synthesized via semi-definite programming. A numerical example has been used to demonstrate the effectiveness of the proposed approach.}, booktitle={ASME Dynamic Systems and Control Conference (DSCC)}, author={Yuan, C. and Wu, Fen and Duan, C.}, year={2017} }
 @article{yuan_wu_2017, title={Consensus for multi-agent systems with time-varying input delays}, volume={48}, ISSN={["1464-5319"]}, url={https://publons.com/wos-op/publon/13939910/}, DOI={10.1080/00207721.2017.1363927}, abstractNote={This paper addresses the consensus control problem for linear multi-agent systems subject to uniform time-varying input delays and external disturbance. A novel state-feedback consensus protocol is proposed under the integral quadratic constraint (IQC) framework, which utilises not only the relative state information from neighbouring agents but also the real-time information of delays by means of the dynamic IQC system states for feedback control. Based on this new consensus protocol, the associated IQC-based control synthesis conditions are established and fully characterised as linear matrix inequalities (LMIs), such that the consensus control solution with optimal H∞ disturbance attenuation performance can be synthesised efficiently via convex optimisation. A numerical example is used to demonstrate the proposed approach.}, number={14}, journal={INTERNATIONAL JOURNAL OF SYSTEMS SCIENCE}, author={Yuan, Chengzhi and Wu, Fen}, year={2017}, pages={2956–2966} }
 @article{yuan_wu_2017, title={Delay Scheduled Impulsive Control for Networked Control Systems}, volume={4}, url={https://publons.com/wos-op/publon/13939915/}, DOI={10.1109/TCNS.2016.2541341}, abstractNote={This paper presents a new design approach for networked control systems under the integral quadratic constraint (IQC) framework. Two types of network induced time-varying delays, that is, measurement delay and actuation delay, are considered. A novel delay scheduled impulsive (DSI) controller is proposed, which utilizes both plant state and the IQC dynamic state, as well as the real-time network-induced delay information for gain scheduling feedback control. Robust £ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> stability analysis of the resulting impulsive closed-loop system is performed using dynamic IQCs combined with a clock-dependent storage function. Based on the analysis results, the synthesis conditions for the proposed DSI controller are established as a finite number of linear matrix inequalities by specifying a piecewise linear storage function, which can be solved effectively via convex optimization. Finally, an application to a dc motor system demonstrates the effectiveness and advantages of the proposed design approach.}, number={3}, journal={IEEE Transactions on Control of Network Systems}, author={Yuan, C. and Wu, F.}, year={2017}, pages={587–597} }
 @article{liu_wu_ban_2017, title={Dynamic Output Feedback Control for Continuous-Time T-S Fuzzy Systems Using Fuzzy Lyapunov Functions}, volume={25}, ISSN={["1941-0034"]}, url={https://publons.com/wos-op/publon/13939916/}, DOI={10.1109/tfuzz.2016.2598852}, abstractNote={A novel relaxation approach is proposed for the analysis and dynamic output feedback control of continuous-time Takagi–Sugeno (T–S) fuzzy systems using fuzzy Lyapunov functions. Previous relaxation methods for T–S fuzzy systems have some drawbacks in relaxing quadratic functions depending on normalized fuzzy weighting functions. They often introduce conservatism or lead to computational difficulty in analysis and control synthesis. Different from previous works, the proposed approach employs linear fractional transformation mechanism and full-block <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$S$</tex-math></inline-formula> -procedure to reduce the conservatism in analysis. Furthermore, the relaxation technique proposed in this paper can be used in solving the controller synthesis problem effectively. As a result, a design procedure of a nonparallel distributed compensation output feedback controller, which ensures asymptotic stability and optimizes <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">${\mathcal L}_2$</tex-math></inline-formula> gain performance of the closed-loop systems, is provided. Several examples have been used to illustrate the advantages and efficiency of the proposed method extensively.}, number={5}, journal={IEEE TRANSACTIONS ON FUZZY SYSTEMS}, author={Liu, Yang and Wu, Fen and Ban, Xiaojun}, year={2017}, month={Oct}, pages={1155–1167} }
 @article{yuan_wu_2017, title={Exact-memory and memoryless control of linear systems with time-varying input delay using dynamic IQCs}, volume={77}, ISSN={["1873-2836"]}, url={https://publons.com/wos-op/publon/13939904/}, DOI={10.1016/j.automatica.2016.11.015}, abstractNote={Input delay is an important type of actuator nonlinearity in control systems. In this paper, we will address the output-feedback control synthesis problem for linear systems with time-varying input delay under the integral quadratic constraint (IQC) framework. A new exact-memory control scheme is first proposed, which consists of a standard linear output-feedback control law and an internal delay loop. The delay loop is embedded in the controller structure so as to reproduce the input delay behavior of the plant. By using quadratic Lyapunov functions incorporated with dynamic IQC multipliers, the resulting dynamic output-feedback delay control synthesis problem is fully characterized by a set of linear matrix inequalities (LMIs), which are convex on all design variables including the scaling factors associated with the IQC multipliers. Moreover, the corresponding result on memoryless control is also derived for the case when the plant input-delay information is not available for feedback control. An application to network systems has been used to illustrate the effectiveness and usefulness of the proposed approach.}, journal={AUTOMATICA}, author={Yuan, Chengzhi and Wu, Fen}, year={2017}, month={Mar}, pages={246–253} }
 @article{liu_ban_wu_lam_2017, title={Gain-scheduling control of T-S fuzzy systems with actuator saturation}, volume={32}, ISSN={["1875-8967"]}, url={https://publons.com/wos-op/publon/11941261/}, DOI={10.3233/jifs-16546}, abstractNote={This paper presents a gain-scheduling output feedback control design method for T-S fuzzy systems with actuator saturation. Different from existing control design methods for T-S fuzzy systems, the basic idea of the proposed approach is to transform the T-S fuzzy model with saturation nonlinearity into the form of linear fractional transformation (LFT). Instead of commonly used fuzzy controllers, a gain-scheduled output feedback controller in the LFT form is introduced to stabilize the saturated T-S fuzzy system with guaranteed H∞ performance. The problem of establishing regional stability and performance of the closed-loop nonlinear system are tackled by using robust control techniques. As a result, the conservatism introduced by dealing with the quadratic terms of normalized fuzzy weighting functions can be avoided. The proposed controller synthesis problem is cast as a convex optimization in terms of linear matrix inequalities (LMIs) and can be solved efficiently. An example of balancing the inverted pendulum with bounded actuation is provided to illustrate the effectiveness of the proposed design method.}, number={3}, journal={JOURNAL OF INTELLIGENT & FUZZY SYSTEMS}, author={Liu, Yang and Ban, Xiaojun and Wu, Fen and Lam, H. K.}, year={2017}, pages={2579–2589} }
 @inproceedings{hao_duan_wu_2017, title={Necessary and Sufficient Conditions for the Controllability of Chain- shape Networks}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85032182832&partnerID=MN8TOARS}, DOI={10.23919/ChiCC.2017.8028580}, abstractNote={This paper focuses on the controllability of chain-shape networks, where the nodes are multi-input/multi-output (MIMO) linear time-invariant (LTI) systems with higher-dimensional states. The necessary and sufficient conditions for the controllability of undirected and directed chain networks are established, respectively. The conditions are easier to verify, which explicitly show the effects of the node-system dynamics, external control inputs and inner interactions on the controllability of the whole networked system. Moreover, some necessary conditions are further derived, which are more straightforward and intuitive. The effectiveness of the conditions is demonstrated through several examples.}, booktitle={2017 36th Chinese Control Conference (CCC)}, author={Hao, Y. and Duan, Z. and Wu, F.}, year={2017}, month={Jul}, pages={7737–7742} }
 @article{rui_zhang_wang_wu_2017, title={New Developments in Multibody System Dynamics and Its Applications 2015}, volume={9}, ISSN={["1687-8140"]}, url={https://publons.com/wos-op/publon/13939886/}, DOI={10.1177/1687814017695685}, abstractNote={Multibody system dynamics is nowadays a widely used toolbox in the development of modern engineering science and technology. It provides powerful dynamic design theories, computational and analytical methods, as well as test technologies for innovative engineering applications. In order to systematically show the important effects of multibody system dynamics on the development of modern science and technology, and to strengthen the academic exchanges in the research field of multibody system dynamics and its applications, we organised the annual Special Collection ‘New Developments in Multibody System Dynamics and Its Applications 2015’, which is the third one of this Special Collection first started from 2013, for the Journal Advances in Mechanical Engineering. The present Special Collection contains 12 papers selected from the contributions coming from several countries. The 12 papers selected for this Special Collection are devoted to the following topics: the modelling, simulation and analysis of a passive dynamic walking robot with flat feet; the test technique for eliminating the accelerometer’s mass effects from frequency response functions using sensitivity analysis; the formulation for automatic deduction of overall transfer equation for branch systems using the transfer matrix method for multibody systems; the modelling, simulation and analysis for an offshore wind turbine installed on a floating spar platform using a hybrid method of finite element multibody system; the application of the transfer matrix method for multibody systems to dynamics analysis of a reinforced concrete shear wall structure during earthquakes; the modelling and simulation of the lifting operation of an offshore supply vessel; the dynamics modelling and simulation of industrial robot subject to constraint using Udwadia–Kalaba equation; the modelling and simulation of the drilling system considering fluid–solid coupling using absolute nodal coordinate formulation; the experimental study and numerical simulation of multi-impact phenomena exhibited during the collision of a sphere onto a steel beam; the application of semi-analytical finite strip transfer matrix method to the buckling analysis of thin-walled members; and the dynamics modelling and simulation of a self-synchronisation vibrating pile driver system. Thus, the general fundamental theories and several key engineering applications are covered representing the state of the art of recent intensive and extensive research activities in the field of multibody system dynamics to a certain extent. The guest editors hope that this Special Collection will provide some valuable information and guidance for scientists and engineers working on multibody system dynamics and its applications in modern engineering science and technology.}, number={3}, journal={ADVANCES IN MECHANICAL ENGINEERING}, author={Rui, Xiaoting and Zhang, Chuanzeng and Wang, Shimin and Wu, Fen}, year={2017}, month={Mar} }
 @inproceedings{ban_liu_huang_wu_2017, title={OUTPUT FEEDBACK CONTROL FOR FUZZY SYSTEMS SUBJECT TO ACTUATOR SATURATION BASED ON FUZZY LYAPUNOV FUNCTIONS}, volume={1}, url={https://publons.com/wos-op/publon/13939864/}, DOI={10.1115/dscc2016-9879}, abstractNote={In this paper, a novel fuzzy gain-scheduling output feedback control method is presented for T-S fuzzy systems subject to actuator saturation. To deal with saturation nonlinearity, the dead-zone function of control input is treated as an additional controller input. With the help of set conclusion condition, the controller can be synthesised based on fuzzy Lyapunov functions to guarantee the exponential stability of the closed-loop system in a larger region and a better L2 gain performance. Moreover, the full block S-procedure, which is widely used in robust control theory, is introduced to relax the synthesis conditions for T-S fuzzy systems to reduce the conservatism caused by quadratic terms in the conditions. Finally, a numerical example is provided to illustrates the effectiveness of the proposed control method.}, booktitle={ASME Dynamic Systems and Control Conference (DSCC)}, author={Ban, X. and Liu, Y. and Huang, X. and Wu, Fen}, year={2017} }
 @inproceedings{hongyang_xiaojun_wu_xianlin_2017, title={Piecewise Lyapunov Function Based Stability Analysis of Fuzzy Parameter Varying Systems}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85032230883&partnerID=MN8TOARS}, DOI={10.23919/ChiCC.2017.8028024}, abstractNote={The fuzzy parameter varying (FPV) system is a novel kind of nonlinear time-varying model with advantages in handing nonlinear time-varying systems than the general T-S fuzzy model. Few researches have been conducted on the stability analysis of FPV systems, except for some results derived based on the quadratic Lyapunov function. In this study, stability analysis of the FPV system is conducted on the basis of a piecewise Lyapunov function and some stability conditions are derived and formulated in terms of Linear matrix inequalities (LMIs), which can be efficiently solved by some numerical algorithms. Numerical simulations demonstrate the effectiveness of our results and also indicate that our conditions are less conservative comparing to the results derived from the quadratic Lyapunov function.}, booktitle={2017 36th Chinese Control Conference (CCC)}, author={Hongyang, Z. and Xiaojun, B. and Wu, F. and Xianlin, H.}, year={2017}, month={Jul}, pages={4245–4250} }
 @article{oduola_li_duan_qian_wu_dougherty_2017, title={Time-Based Switching Control of Genetic Regulatory Networks: Toward Sequential Drug Intake for Cancer Therapy}, volume={16}, ISSN={["1176-9351"]}, url={https://publons.com/wos-op/publon/9848611/}, DOI={10.1177/1176935117706888}, abstractNote={As cancer growth and development typically involves multiple genes and pathways, combination therapy has been touted as the standard of care in the treatment of cancer. However, drug toxicity becomes a major concern whenever a patient takes 2 or more drugs simultaneously at the maximum tolerable dosage. A potential solution would be administering the drugs in a sequential or alternating manner rather than concurrently. This study therefore examines the feasibility of such an approach from a switched system control perspective. Particularly, we study how genetic regulatory systems respond to sequential (switched) drug inputs using the time-based switching mechanism. The design of the time-driven drug switching function guarantees the stability of the genetic regulatory system and the repression of the diseased genes. Simulation results using proof-of-concept models and the proliferation and survival pathways with sequential drug inputs show the effectiveness of the proposed approach.}, journal={CANCER INFORMATICS}, author={Oduola, Wasiu Opeyemi and Li, Xiangfang and Duan, Chang and Qian, Lijun and Wu, Fen and Dougherty, Edward R.}, year={2017}, month={May} }
 @article{yang_wu_zhang_2017, title={Tracking control of hybrid systems with state-triggered jumps and stochastic events and its application}, volume={11}, ISSN={["1751-8652"]}, url={https://publons.com/wos-op/publon/13939865/}, DOI={10.1049/iet-cta.2016.1086}, abstractNote={This study addresses the tracking control problem for a class of hybrid systems with both state-triggered jumps and stochastic events. The outputs of the plant are required to follow exactly the time-varying reference trajectories which are generated by the corresponding hybrid system. Since the jump times of the plant do not coincide with those of the references, the tracking error in terms of Euclidean distance will exhibit 'peaking phenomena', and is not suitable for this kind of situation. By invoking a novel definition of the tracking error which is insensitive to state-triggered jumps and stochastic events, sufficient conditions for asymptotic stability are obtained. Exploiting the asymptotic stability criteria and the proposed non-Euclidean measure of the tracking error, the tracking control problem of a simplified flexible single-link robotic arm is successfully solved by the hybrid controller.}, number={7}, journal={IET CONTROL THEORY AND APPLICATIONS}, author={Yang, Ting and Wu, Fen and Zhang, Lixian}, year={2017}, month={Apr}, pages={1024–1033} }
 @article{liu_ban_wu_lam_2016, title={A Gain-Scheduling Control Approach for Takagi-Sugeno Fuzzy Systems Based on Linear Parameter-Varying Control Theory}, volume={138}, ISSN={["1528-9028"]}, url={https://publons.com/wos-op/publon/11941207/}, DOI={10.1115/1.4031914}, abstractNote={Due to the universal approximation capability of Takagi–Sugeno (T–S) fuzzy models for nonlinear dynamics, many control issues have been investigated based on fuzzy control theory. In this paper, a transformation procedure is proposed to convert fuzzy models into linear fractional transformation (LFT) models. Then, T–S fuzzy systems can be regarded as a special case of linear parameter-varying (LPV) systems which proved useful for nonlinear control problems. The newly established connection between T–S fuzzy models and LPV models provides a new perspective of the control problems for T–S fuzzy systems and facilitates the fuzzy control designs. Specifically, an output feedback gain-scheduling control design approach for T–S fuzzy systems is presented to ensure globally asymptotical stability and optimize H∞ performance of the closed-loop systems. The control synthesis problem is cast as a convex optimization problem in terms of linear matrix inequalities (LMIs). Two examples have been used to illustrate the efficiency of the proposed method.}, number={1}, journal={JOURNAL OF DYNAMIC SYSTEMS MEASUREMENT AND CONTROL-TRANSACTIONS OF THE ASME}, author={Liu, Yang and Ban, Xiaojun and Wu, Fen and Lam, H. K.}, year={2016}, month={Jan} }
 @inproceedings{yuan_wu_2016, title={A New Hybrid LFT Control Method for Missile Autopilot Design}, volume={2016-August}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84987858685&partnerID=MN8TOARS}, DOI={10.1109/chicc.2016.7554273}, abstractNote={This paper presents a new hybrid gain-scheduling control method for missile autopilot design. The nonlinear missile dynamics is first converted to a switched linear fractional transformation (LFT) model for controller design and synthesis purpose. Then, by using multiple Lyapunov functions and average dwell time (ADT) techniques, a new hybrid gain-scheduling autopilot is designed, which consists of a switching dynamic output-feedback LFT controller and a controller state jump dynamics. The associated control synthesis conditions guaranteeing weighted ℒ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> stability are formulated in terms of a finite number of linear matrix inequalities (LMIs), which can be solved effectively via convex optimization without parameter-space gridding. Nonlinear simulation studies show the effectiveness of the proposed approach.}, booktitle={2016 35th Chinese Control Conference (CCC)}, author={Yuan, C. and Wu, Fen}, year={2016}, month={Jul}, pages={5852–5857} }
 @article{wu_song_ren_2016, title={A Nonlinear Gain-Scheduling Compensation Approach Using Parameter-Dependent Lyapunov Functions}, volume={138}, ISSN={["1528-9028"]}, url={https://publons.com/wos-op/publon/13939868/}, DOI={10.1115/1.4031845}, abstractNote={This paper addresses the gain-scheduling control design for nonlinear systems to achieve output regulation. For gain-scheduling control, the linear parameter-varying (LPV) model is obtained by linearizing the plant about zero-error trajectories upon which an LPV controller is based. A key in this process is to find a nonlinear output feedback compensator such that its linearization matches with the designed LPV controller. Then, the stability and performance properties of LPV control about the zero-error trajectories can be inherited when the nonlinear compensator is implemented. By incorporating the exosystem, nominal input, and measured output information into the LPV model, the LPV control synthesis problem is formulated as linear matrix inequalities (LMIs) using parameter-dependent Lyapunov functions (PDLFs). Moreover, explicit formulae for the construction of the nonlinear gain-scheduled compensator have been derived to meet the linearization requirement. Finally, the validity of the proposed nonlinear gain-scheduling control approach is demonstrated through a ball and beam example.}, number={1}, journal={JOURNAL OF DYNAMIC SYSTEMS MEASUREMENT AND CONTROL-TRANSACTIONS OF THE ASME}, author={Wu, Fen and Song, Xun and Ren, Zhang}, year={2016}, month={Jan} }
 @inproceedings{boker_yuan_wu_chakrabortty_2016, title={Aggregate control of clustered networks with inter-cluster time delays}, volume={2016-July}, url={https://publons.com/wos-op/publon/13939901/}, DOI={10.1109/acc.2016.7526506}, abstractNote={We address a control problem for networks that have multiple dense clusters with sparse interconnection structure. By making use of the time-scale separation properties of such networks, we design state-feedback controllers at the cluster level to guarantee stability in the presence of time varying delays in the inter-cluster feedback channels. Applying results from singular perturbation theory, we show that when these individual controllers are implemented on the actual network model, the closed-loop response is close to that obtained from the approximate models, provided that the clustering is strong and the time delay is below the maximum limit. The design procedure is demonstrated by a simulation example.}, booktitle={2016 american control conference (acc)}, author={Boker, A. M. and Yuan, C. Z. and Wu, F. and Chakrabortty, Aranya}, year={2016}, pages={5340–5345} }
 @inproceedings{oduola_li_duan_qian_wu_dougherty_2016, title={Analysis and Control of Genetic Regulatory Systems with Switched Drug Inputs}, url={https://publons.com/wos-op/publon/9848641/}, DOI={10.1109/bhi.2016.7455952}, abstractNote={Because cancer usually involves multiple genes and pathways, combination therapy is considered as a promising approach for cancer treatment. However, when multiple drugs are taken by a patient simultaneously, toxicity becomes a concern. A potential solution is to give the drugs sequentially rather than simultaneously. In this study, we try to explore the feasibility of such an approach. Specifically, this study investigates the response of genetic regulatory networks to sequential (switched) drug inputs. The switching mechanism is based on the combination of a state-dependent and time-driven switching function. The design of the switching strategy ensures that the genetic regulatory network will be stabilized and satisfies a decay rate performance index. Simulation results using a mTOR pathway model show the effectiveness of the proposed method.}, booktitle={IEEE-EMBS International Conference on Biomedical and Health Informatics (BHI)}, author={Oduola, W. and Li, X. and Duan, C. and Qian, L. and Wu, Fen and Dougherty, E.R.}, year={2016}, pages={533–536} }
 @article{yuan_wu_2016, title={Dynamic IQC-Based Control of Uncertain LFT Systems With Time-Varying State Delay}, volume={46}, ISSN={["2168-2275"]}, url={https://publons.com/wos-op/publon/656391/}, DOI={10.1109/tcyb.2015.2503741}, abstractNote={This paper presents a new exact-memory delay control scheme for a class of uncertain systems with time-varying state delay under the integral quadratic constraint (IQC) framework. The uncertain system is described as a linear fractional transformation model including a state-delayed linear time-invariant (LTI) system and time-varying structured uncertainties. The proposed exact-memory delay controller consists of a linear state-feedback control law and an additional term that captures the delay behavior of the plant. We first explore the delay stability and the L <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> -gain performance using dynamic IQCs incorporated with quadratic Lyapunov functions. Then, the design of exact-memory controllers that guarantee desired L <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> -gain performance is examined. The resulting delay control synthesis conditions are formulated in terms of linear matrix inequalities, which are convex on all design variables including the scaling matrices associated with the IQC multipliers. The IQC-based exact-memory control scheme provides a novel approach for delay control designs via convex optimization, and advances existing control methods in two important ways: 1) better controlled performance and 2) simplified design procedure with less computational cost. The effectiveness and advantages of the proposed approach have been demonstrated through numerical studies.}, number={12}, journal={IEEE TRANSACTIONS ON CYBERNETICS}, author={Yuan, Chengzhi and Wu, Fen}, year={2016}, month={Dec}, pages={3320–3329} }
 @inproceedings{yuan_wu_2016, title={Dynamic IQC-based Analysis and Synthesis of Networked Control Systems}, volume={2016-July}, url={https://publons.com/wos-op/publon/13939900/}, DOI={10.1109/acc.2016.7526507}, abstractNote={This paper presents a new control design approach for networked control systems under the integral quadratic constraint (IQC) framework. In order to apply the IQC and dissipation theory, the networked control system with network-induced time-varying delays is first transformed to an equivalent linear fractional transformation (LFT) model. As such, dynamic IQCs can be used to capture the input-output behavior of the delay nonlinearities. Then, a novel full-information feedback control law is proposed, which utilizes both plant states and the IQC dynamic states, as well as the network-induced delay amounts, as feedback information. Robust ℓ2 stability analysis of the resulting closed loop is performed via dynamic IQCs. Based on the analysis results, the synthesis conditions for the proposed full-information feedback controller are established in a linear matrix inequality (LMI) form, which can be solved effectively using existing convex optimization algorithms. Finally, a servo motor control system is used to demonstrate the effectiveness of the proposed IQC-based control design scheme.}, booktitle={American Control Conference}, author={Yuan, C. and Wu, Fen}, year={2016}, pages={5346–5351} }
 @inproceedings{yuan_wu_2016, title={H<sub>∞</sub> state-feedback control of linear systems with time-varying input delays}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85010764272&partnerID=MN8TOARS}, DOI={10.1109/cdc.2016.7798332}, abstractNote={In this paper, we will address the state-feedback control synthesis problem for linear systems with time-varying input delays under the integral quadratic constraint (IQC) framework. A new exact-memory control scheme is first proposed, which consists of a standard linear state-feedback control law and an internal delay loop. The delay loop is embedded in the controller structure so as to reproduce the input delay behavior of the plant. With this controller structure, the resulting delay control synthesis problem is fully characterized by a set of linear matrix inequalities (LMIs), which are convex on all design variables including the scaling factors associated with the IQC multipliers. The corresponding results on memoryless state-feedback control are also derived for cases when input-delay information is not available for feedback control. A numerical example has been used to illustrate the effectiveness of the proposed approach.}, booktitle={2016 IEEE 55th Conference on Decision and Control, CDC 2016}, author={Yuan, C. and Wu, Fen}, year={2016}, pages={586–591} }
 @article{yuan_liu_wu_duan_2016, title={Hybrid Switched Gain-Scheduling Control for Missile Autopilot Design}, volume={39}, ISSN={["1533-3884"]}, url={https://publons.com/wos-op/publon/9848610/}, DOI={10.2514/1.g001791}, abstractNote={This paper presents a new hybrid switched gain-scheduling control method for missile autopilot design via dynamic output feedback. For controller design purpose, the nonlinear missile plant model is first converted to a switched linear fractional transformation system. Then, the new hybrid switched gain-scheduling autopilot is designed, which consists of a switching dynamic output–feedback linear fractional transformation controller and a supervisor enforcing a controller state reset at each switching time instant. The proposed hybrid control scheme is shown to provide a systematic yet simple framework for missile autopilot design. Specifically, the control synthesis conditions that guarantee weighted stability performance are formulated in terms of a finite number of linear matrix inequalities, which can be solved effectively via convex optimization without parameter-space gridding. Furthermore, stringent controlled performance and strong robustness against parameter perturbations are achieved using this new control approach, whereas no parameter variation information is required for both controller synthesis and implementation. The advantages of the proposed design approach over existing methods will be shown through nonlinear simulations for the missile autopilot design over a wide range of operating conditions.}, number={10}, journal={JOURNAL OF GUIDANCE CONTROL AND DYNAMICS}, author={Yuan, Chengzhi and Liu, Yang and Wu, Fen and Duan, Chang}, year={2016}, month={Oct}, pages={2352–2363} }
 @article{yuan_wu_2016, title={Hybrid almost output regulation of linear impulsive systems with average dwell-time}, volume={20}, ISSN={["1878-7460"]}, url={https://publons.com/wos-op/publon/13939871/}, DOI={10.1016/j.nahs.2015.11.001}, abstractNote={This paper deals with the hybrid almost output regulation problem for a class of linear systems with average dwell-time impulses. The proposed hybrid output regulator is constructed as a linear impulsive system that undergoes synchronous impulses with the controlled plant. Lyapunov-based sufficient conditions of the output regulability and weighted L2 performance for the linear impulsive systems are first derived. Based on the analysis results, the hybrid synthesis problem is formulated in terms of linear matrix equations plus a set of linear matrix inequalities (LMIs). With this hybrid synthesis scheme, both flow and jump dynamics of the hybrid regulator can be jointly designed by solving a convex optimization problem in minimizing the weighted L2 gain from the perturbation signal to the error output. A numerical example is used to demonstrate the proposed approach.}, journal={NONLINEAR ANALYSIS-HYBRID SYSTEMS}, author={Yuan, Chengzhi and Wu, Fen}, year={2016}, month={May}, pages={82–94} }
 @article{duan_wu_2016, title={New results on switched linear systems with actuator saturation}, volume={47}, ISSN={["1464-5319"]}, url={https://publons.com/wos-op/publon/9848631/}, DOI={10.1080/00207721.2014.911386}, abstractNote={This paper further studies the analysis and control problems of continuous-time switched linear systems subject to actuator saturation. Using the norm-bounded differential inclusion description of the saturated systems and the minimal switching rule, a set of switched output feedback controllers is designed to minimise the disturbance attenuation level defined by the regional L2 gain over a class of energy-bounded disturbances. The synthesis conditions are expressed as bilinear matrix inequalities, and can be solved by numerical search coupled with linear matrix inequality optimisation. Compared to the previous method based on polytopic differential inclusion, the proposed approach has good scalability and potentially renders better performance. Numerical examples are provided to verify the effectiveness of the proposed approach.}, number={5}, journal={INTERNATIONAL JOURNAL OF SYSTEMS SCIENCE}, author={Duan, Chang and Wu, Fen}, year={2016}, month={Apr}, pages={1008–1020} }
 @article{zhang_liang_ban_wu_2016, title={Nonlinear time-varying model: Fuzzy parameter varying system}, volume={20}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85000866197&partnerID=MN8TOARS}, DOI={10.15938/j.emc.2016.11.012}, number={11}, journal={Dianji yu Kongzhi Xuebao/Electric Machines and Control}, author={Zhang, H.-Y. and Liang, Y. and Ban, X.-J. and Wu, F.}, year={2016}, pages={86–91} }
 @article{ban_wu_2016, title={Output feedback control of linear fractional transformation systems subject to actuator saturation}, volume={47}, ISSN={["1464-5319"]}, url={https://publons.com/wos-op/publon/13939860/}, DOI={10.1080/00207721.2015.1110213}, abstractNote={In this paper, the control problem for a class of linear parameter varying (LPV) plant subject to actuator saturation is investigated. For the saturated LPV plant depending on the scheduling parameters in linear fractional transformation (LFT) fashion, a gain-scheduled output feedback controller in the LFT form is designed to guarantee the stability of the closed-loop LPV system and provide optimised disturbance/error attenuation performance. By using the congruent transformation, the synthesis condition is formulated as a convex optimisation problem in terms of a finite number of LMIs for which efficient optimisation techniques are available. The nonlinear inverted pendulum problem is employed to demonstrate the effectiveness of the proposed approach. Moreover, the comparison between our LPV saturated approach with an existing linear saturated method reveals the advantage of the LPV controller when handling nonlinear plants.}, number={15}, journal={INTERNATIONAL JOURNAL OF SYSTEMS SCIENCE}, author={Ban, Xiaojun and Wu, Fen}, year={2016}, pages={3646–3655} }
 @inproceedings{yuan_wu_duan_2016, title={ROBUST GAIN-SCHEDULING OUTPUT FEEDBACK CONTROL OF STATE-DELAYED LFT SYSTEMS USING DYNAMIC IQCS}, volume={3}, url={https://publons.com/wos-op/publon/9848638/}, DOI={10.1115/dscc2015-9686}, abstractNote={This paper is concerned with the robust gain-scheduling output feedback control problem for a class of linear parameter-varying systems with time-varying state delay. The controlled plant under consideration is described as a linear fractional transformation (LFT) model of scheduling parameters. Dynamic integral quadratics (IQCs) are employed to characterize the input-output behavior of the state-delay nonlinearity. The robust stability and the L2-gain performance are first analyzed using quadratic Lyapunov function. Then, the design of dynamic output-feedback controllers robust against the plant state-delay nonlinearity and gain-scheduled by parameters is examined. The synthesis conditions of such robust gain-scheduling controllers are formulated in terms of linear matrix inequalities (LMIs) plus a line search, which can be solved effectively using existing algorithms. A numerical example has been used to demonstrate the effectiveness and advantages of the proposed approach.}, booktitle={ASME Dynamic Systems and Control Conference (DSCC)}, author={Yuan, C. and Wu, Fen and Duan, C.}, year={2016} }
 @article{yuan_wu_2016, title={Robust H-2 and H-infinity switched feedforward control of uncertain LFT systems}, volume={26}, ISSN={["1099-1239"]}, url={https://publons.com/wos-op/publon/13939903/}, DOI={10.1002/rnc.3380}, abstractNote={This paper presents a new robust switched feedforward control scheme for a class of uncertain systems described in a standard linear fractional transformation form. First, the analysis conditions for switching stability are derived by using a piecewise Lyapunov function incorporated with the min-switching control technique. Based on the analysis results, the synthesis conditions are then formulated as a special type of bilinear matrix inequalities, which can be solved by means of linear matrix inequalities and line search. Both robust and feedforward control problems are considered. The proposed robust switched control scheme outperforms existing robust feedforward control approaches for uncertain systems based on single quadratic Lyapunov function, and leads to less conservative control design. Numerical examples will be used to illustrate the effectiveness and advantages of the proposed results. Copyright © 2015 John Wiley & Sons, Ltd.}, number={9}, journal={INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL}, author={Yuan, Chengzhi and Wu, Fen}, year={2016}, month={Jun}, pages={1841–1856} }
 @inbook{yuan_duan_wu_2016, title={Robust H<sub>∞</sub>switching control of polytopic parameter-varying systems via dynamic output feedback}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85017617021&partnerID=MN8TOARS}, DOI={10.1007/978-3-319-33590-2_4}, booktitle={Automotive Air Conditioning: Optimization, Control and Diagnosis}, author={Yuan, C. and Duan, C. and Wu, F.}, year={2016}, pages={53–72} }
 @article{yuan_wu_2016, title={Robust switching output-feedback control of time-varying polytopic uncertain systems}, volume={89}, ISSN={["1366-5820"]}, url={https://publons.com/wos-op/publon/13939902/}, DOI={10.1080/00207179.2016.1154607}, abstractNote={The problem of designing a globally optimal robust output feedback controller for time-varying polytopic uncertain systems is a well-known non-convex optimisation problem. In this paper, new sufficient conditions for both robust H2 and H∞ switching output-feedback control syntheses are proposed in terms of bilinear matrix inequalities (BMIs) under the multiple Lyapunov function framework. This set of synthesis conditions is further reduced to a special type of BMIs, which can be solved effectively using linear matrix inequality optimisation plus a line search. The associated robust output-feedback controller is constructed as a switching-type full-order dynamic output-feedback controller, consisting of a family of linear time-invariant subcontrollers and a min-switching logic. The proposed approach features the important property of computational efficiency with stringent performance. Its effectiveness and advantages have been demonstrated through extensive numerical studies.}, number={11}, journal={INTERNATIONAL JOURNAL OF CONTROL}, author={Yuan, Chengzhi and Wu, Fen}, year={2016}, pages={2262–2276} }
 @inproceedings{yuan_duan_wu_2015, title={Almost Output Regulation of Discrete-Time Switched Linear Systems}, volume={2015-July}, url={https://publons.com/wos-op/publon/9848643/}, DOI={10.1109/acc.2015.7171961}, abstractNote={In this paper, we propose a new hybrid control approach for almost output regulation of a class of discrete-time switched linear systems with average dwell time (ADT). Both controlled plant and exosystem are described by switched linear systems. The proposed hybrid controller is constructed as a switching impulsive system, where the controller states will undergo impulsive jumps at each switching instant. By using the ADT technique incorporated with multiple quadratic Lyapunov functions, the hybrid synthesis conditions for almost output regulation with asymptotic stability and weighted ℋ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> performance are formulated as a set of linear matrix equations and linear matrix inequalities (LMIs), which can be solved effectively. The proposed hybrid control method has been demonstrated through a numerical example.}, booktitle={American Control Conference}, author={Yuan, C. and Duan, C. and Wu, Fen}, year={2015}, pages={4042–4047} }
 @inproceedings{yang_wu_liu_huang_2015, title={An Optimization-Based Approach for Prosthesis Dynamic Modeling and Parameter Identification}, volume={1}, ISBN={9780791857243}, url={http://dx.doi.org/10.1115/dscc2015-9637}, DOI={10.1115/dscc2015-9637}, abstractNote={In this paper, we propose an effective approach to model the prosthetic leg dynamics for amputees wearing active-transfemoral prosthesis (ATP) which is self-powered. To accommodate unexpected effects of thigh on knee joints, the dynamic prosthesis model has been derived using both the thigh-knee-shank and the knee-shank configurations. Correlated with the amputee’s walking data, a nonlinear optimization problem is then formulated to identify the model parameters and the gains of the PD controller which is used to control the input torque for the ATP, while reducing measurement errors of the data. Moreover, the identified models are validated by comparing the predicted dynamics with experimental measurements. The advantages of proposed method in terms of simplicity, flexibility, and accuracy are demonstrated by the high correlation coefficients and the low root-mean-square errors.}, booktitle={Volume 1: Adaptive and Intelligent Systems Control; Advances in Control Design Methods; Advances in Non-Linear and Optimal Control; Advances in Robotics; Advances in Wind Energy Systems; Aerospace Applications; Aerospace Power Optimization; Assistive Robotics; Automotive 2: Hybrid Electric Vehicles; Automotive 3: Internal Combustion Engines; Automotive Engine Control; Battery Management; Bio Engineering Applications; Biomed and Neural Systems; Connected Vehicles; Control of Robotic Systems}, publisher={American Society of Mechanical Engineers}, author={Yang, Ting and Wu, Fen and Liu, Ming and Huang, He (Helen)}, year={2015}, month={Oct} }
 @article{yuan_wu_2015, title={Asynchronous switching output feedback control of discrete-time switched linear systems}, volume={88}, ISSN={["1366-5820"]}, url={https://publons.com/wos-op/publon/13939890/}, DOI={10.1080/00207179.2015.1016454}, abstractNote={In this paper, the problem of dynamic output-feedback control synthesis is addressed for discrete-time switched linear systems under asynchronous switching. The proposed hybrid controller consists of a standard dynamic output-feedback switching control law and an impulsive reset law induced by controller state jumps. Using the average dwell time technique incorporating with multiple quadratic Lyapunov functions, the switching control synthesis conditions for asymptotic stability with guaranteed weighted ℓ2-gain performance are derived as a set of linear matrix inequalities (LMIs). The proposed hybrid synthesis scheme advances existing design methods for output-feedback asynchronous switching control of switched linear systems in two important aspects: LMI formulation of the synthesis problem; and arbitrary order of the controller state. A numerical example is used to illustrate the effectiveness and advantages of the proposed design technique.}, number={9}, journal={INTERNATIONAL JOURNAL OF CONTROL}, author={Yuan, Chengzhi and Wu, Fen}, year={2015}, month={Sep}, pages={1766–1774} }
 @article{ban_wu_2015, title={Gain scheduling output feedback control of linear plants with actuator saturation}, volume={352}, ISSN={["1879-2693"]}, url={https://publons.com/wos-op/publon/13939866/}, DOI={10.1016/j.jfranklin.2015.06.005}, abstractNote={From a gain-scheduling perspective, we will study the output feedback control problem for linear systems with some of control channels subject to actuator saturation. This includes the scenario of all actuator saturation as a special case. A feedback controller, expressed in the form of linear fractional transformation, is proposed to guarantee regional stability of the closed-loop system and provide disturbance/error attenuation measured in L2 gain. The resulting synthesis condition is formulated as linear matrix inequalities (LMIs) and can be solved efficiently. Moreover, explicit formulas are derived to calculate controller gains, which reduces the computational cost compared to the method of directly solving the LMI-based condition. Numerical examples are provided to demonstrate the proposed saturation control approach.}, number={10}, journal={JOURNAL OF THE FRANKLIN INSTITUTE-ENGINEERING AND APPLIED MATHEMATICS}, author={Ban, Xiaojun and Wu, Fen}, year={2015}, month={Oct}, pages={4163–4187} }
 @article{yuan_wu_2015, title={Hybrid Control for Switched Linear Systems With Average Dwell Time}, volume={60}, ISSN={["1558-2523"]}, url={https://publons.com/wos-op/publon/13939872/}, DOI={10.1109/tac.2014.2322941}, abstractNote={This technical note presents a hybrid control scheme for the output-feedback control of switched linear systems with average dwell time. The proposed hybrid controller consists of a standard switching output-feedback control law and a supervisor enforcing a reset rule for the switching controller states at each switching instant. This hybrid control scheme provides an efficient and systematic way for designing average dwell time switched linear control systems in the sense that the boundary condition can be incorporated into the synthesis problem in a convex formulation. Specifically, both full-order and reduced-order controllers with guaranteed stability and optimal weighted H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> performance will be solved by linear matrix inequality (LMI) optimizations. Simulation studies are included to illustrate the effectiveness of the proposed approach.}, number={1}, journal={IEEE TRANSACTIONS ON AUTOMATIC CONTROL}, author={Yuan, Chengzhi and Wu, Fen}, year={2015}, month={Jan}, pages={240–245} }
 @article{rui_pfeiffer_zhang_wang_wu_2015, title={Preface}, volume={7}, ISSN={["1687-8140"]}, url={https://publons.com/wos-op/publon/27327657/}, DOI={10.1177/1687814015604802}, number={9}, journal={ADVANCES IN MECHANICAL ENGINEERING}, author={Rui, Xiaoting and Pfeiffer, Friedrich G. and Zhang, Chuanzeng and Wang, Shimin and Wu, Fen}, year={2015}, month={Sep} }
 @inproceedings{liu_wu_ban_2015, title={Robust Fault Detection Filter Design for Linear Uncertain Systems with Unknown Inputs}, volume={2015-July}, url={https://publons.com/wos-op/publon/13939863/}, DOI={10.1109/acc.2015.7170846}, abstractNote={In this paper, a robust fault detection filter design method for uncertain systems in linear fractional transformation (LFT) formulation with unknown inputs is proposed. The basic idea is to convert the complicated ℋ-/ℋ <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</inf> problem to an easier ℋ <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</inf> model following problem. Moreover, two major improvements have been made in this research. First, the uncertain systems in LFT formulation are studied. This class of uncertain models is capable of approximating complex nonlinear dynamics. Second, a more general form of filter is employed to achieve a better fault detection and disturbance rejection performance. It involves the widely used observer-based filter as a special case. With structured uncertainties, it has been shown the robust fault detection filter design can be solved by a convex optimization condition in terms of linear matrix inequalities (LMIs). An illustrative design example is used to demonstrate the effectiveness and better performance of the proposed approach.}, booktitle={American Control Conference}, author={Liu, Y. and Wu, Fen and Ban, X.}, year={2015}, pages={886–891} }
 @inproceedings{yuan_wu_duan_2015, title={Robust switching output feedback control of discrete-time linear polytopic uncertain systems}, volume={2015-September}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84946567808&partnerID=MN8TOARS}, DOI={10.1109/chicc.2015.7260096}, abstractNote={This paper presents a new switching control approach for robust output feedback control of a class of discrete-time linear systems subject to polytopic time-varying uncertainties. The proposed robust switching controller, which stabilizes the closed-loop system with a pre-specified H <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</inf> performance level, consists of a family of dynamic output feedback controllers (of an arbitrary state order) and a switching law (the relaxed min-switching strategy). Both stability analysis and control synthesis conditions are derived using a piecewise quadratic Lyapunov function. The switching law combined with the controller gain matrices are jointly synthesized by solving a convex linear matrix inequality (LMI) based optimization problem. An academic example has been used to demonstrate the effectiveness and advantages of the proposed approach.}, booktitle={Chinese Control Conference, CCC}, author={Yuan, C. and Wu, Fen and Duan, C.}, year={2015}, pages={2973–2978} }
 @article{yuan_wu_2015, title={Switching control of linear systems subject to asymmetric actuator saturation}, volume={88}, ISSN={["1366-5820"]}, url={https://publons.com/wos-op/publon/13939870/}, DOI={10.1080/00207179.2014.942884}, abstractNote={In this paper, we study the saturation control problem for linear time-invariant (LTI) systems subject to asymmetric actuator saturation under a switching control framework. The LTI plant with asymmetric saturation is first transformed to an equivalent switched linear model with each subsystem subject to symmetric actuator saturation, based on which a dwell-time switching controller augmented with a controller state reset is then developed by using multiple Lyapunov functions. The controller synthesis conditions are formulated as linear matrix inequalities (LMIs), which can be solved efficiently. Simulation results are also included to illustrate the effectiveness and advantages of the proposed approach.}, number={1}, journal={INTERNATIONAL JOURNAL OF CONTROL}, author={Yuan, Chengzhi and Wu, Fen}, year={2015}, month={Jan}, pages={204–215} }
 @inproceedings{yuan_wu_2014, title={A switching control approach for linear systems subject to asymmetric actuator saturation}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84907929465&partnerID=MN8TOARS}, DOI={10.1109/ChiCC.2014.6895600}, abstractNote={In this paper, we study the saturation control problem for linear time-invariant (LTI) systems subject to asymmetric actuator saturation under a switching control framework. The LTI plant with asymmetric saturation is first transformed to an equivalent switched linear model with each subsystem subject to symmetric actuator saturation, based on which a switching controller robust against arbitrary switching is then designed by using a common Lyapunov function approach. The controller synthesis conditions are formulated in terms of linear matrix inequalities (LMIs). The application to an inverted pendulum is also given to illustrate the effectiveness and advantages of the proposed approach.}, booktitle={Proceedings of the 33rd Chinese Control Conference, CCC 2014}, author={Yuan, C. and Wu, F.}, year={2014}, pages={3959–3964} }
 @article{duan_wu_2014, title={Analysis and control of switched linear systems via dwell-time min-switching}, volume={70}, ISSN={["1872-7956"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84902185903&partnerID=MN8TOARS}, DOI={10.1016/j.sysconle.2014.05.004}, abstractNote={This paper addresses analysis and switching control problems of switched linear systems. To this end, a mixed time-driven and state-dependent switching strategy is proposed. It guarantees an average dwell time even when all subsystems are unstable. The switching rule and its associated switching output feedback controllers are designed to stabilize the switched system and satisfy a weighted L2 gain performance. The proposed analysis and switching control approach could refrain frequent switches commonly observed in min-switching based designs. The effectiveness of the proposed approach has been illustrated through a spherical inverted pendulum example.}, journal={SYSTEMS & CONTROL LETTERS}, author={Duan, Chang and Wu, Fen}, year={2014}, month={Aug}, pages={8–16} }
 @article{duan_wu_2014, title={Analysis and control of switched linear systems via modified Lyapunov-Metzler inequalities}, volume={24}, ISSN={["1099-1239"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84890789707&partnerID=MN8TOARS}, DOI={10.1002/rnc.2886}, abstractNote={SUMMARY This paper addresses analysis and switching control problems of continuous/discrete‐time switched linear systems. A particular class of matrix inequalities, the so‐called Lyapunov–Metzler inequalities, will be modified to provide conditions for stability analysis and output feedback control synthesis under a relaxed min‐switching logic. The switching rule combined with switching output feedback controllers will be designed to stabilize the switched system and satisfy a prespecified gain performance. The proposed analysis and switching control approach could refrain frequent switches commonly observed in min‐switching based designs. The effectiveness of the proposed approach will be illustrated through numerical examples. Copyright © 2012 John Wiley & Sons, Ltd.}, number={2}, journal={INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL}, author={Duan, Chang and Wu, Fen}, year={2014}, month={Jan}, pages={276–294} }
 @article{yuan_wu_2014, title={Analysis and synthesis of linear hybrid systems with state-triggered jumps}, volume={14}, ISSN={["1878-7460"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84901363822&partnerID=MN8TOARS}, DOI={10.1016/j.nahs.2014.05.002}, abstractNote={This paper investigates first the stability and L2-gain problems for a class of linear hybrid control systems with state-triggered jumps by using an extended Lyapunov-like function (ELF) technique. The obtained results are then applied to facilitate the joint design of a hybrid controller (linear controller plus reset law) for a continuous-time linear time-invariant (LTI) plant. The hybrid H∞ synthesis conditions are expressed in linear matrix inequalities (LMIs) with two line search parameters. An inverted pendulum example is used to illustrate the effectiveness of the proposed approach.}, journal={NONLINEAR ANALYSIS-HYBRID SYSTEMS}, author={Yuan, Chengzhi and Wu, Fen}, year={2014}, month={Nov}, pages={47–60} }
 @inproceedings{zhang_yang_wu_2014, title={Control for discrete-time fuzzy Markov jump systems with mode-dependent antecedent parts}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84907328154&partnerID=MN8TOARS}, DOI={10.1109/ISIE.2014.6864978}, abstractNote={This paper is concerned with the control problem for a class of discrete-time fuzzy Markov jump systems (MJSs). Unlike the common assumption in the existing literature, the antecedent parts of fuzzy rules are mode-dependent, i.e., the premise variables and/or their fuzzy partitions can be different in different modes. Based on a fuzzy-basis-dependent and mode-dependent Lyapunov function, the existence conditions of the desired mode-dependent state feedback controller are derived such that the closed-loop system is stochastically stable and achieves a guaranteed performance in the H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> sense. Two examples, including a practical example of robot arm, are used to demonstrate the applicability of the obtained theoretical results.}, booktitle={IEEE International Symposium on Industrial Electronics}, author={Zhang, L. and Yang, T. and Wu, F.}, year={2014}, pages={2306–2311} }
 @article{yang_wu_2014, title={Control of Polynomial Nonlinear Systems Using Higher Degree Lyapunov Functions}, volume={136}, ISSN={["1528-9028"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84894656093&partnerID=MN8TOARS}, DOI={10.1115/1.4026172}, abstractNote={In this paper, we propose a new control design approach for polynomial nonlinear systems based on higher degree Lyapunov functions. To derive higher degree Lyapunov functions and polynomial nonlinear controllers effectively, the original nonlinear systems are augmented under the rule of power transformation. The augmented systems have more state variables and the additional variables represent higher order combinations of the original ones. As a result, the stabilization and L2 gain control problems with higher degree Lyapunov functions can be recast to the search of quadratic Lyapunov functions for augmented nonlinear systems. The sum-of-squares (SOS) programming is then used to solve the quadratic Lyapunov function of augmented state variables (higher degree in terms of original states) and its associated nonlinear controllers through convex optimization problems. The proposed control approach has also been extended to polynomial nonlinear systems subject to actuator saturations for better performance including domain of attraction (DOA) expansion and regional L2 gain minimization. Several examples are used to illustrate the advantages and benefits of the proposed approach for unsaturated and saturated polynomial nonlinear systems.}, number={3}, journal={JOURNAL OF DYNAMIC SYSTEMS MEASUREMENT AND CONTROL-TRANSACTIONS OF THE ASME}, author={Yang, Shuowei and Wu, Fen}, year={2014}, month={May} }
 @inproceedings{duan_wu_2014, title={Dwell-time min-switching for discrete-time switched linear systems}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84911498907&partnerID=MN8TOARS}, DOI={10.1109/ecc.2014.6862224}, abstractNote={This paper addresses analysis and switching control problems of discrete-time switched linear systems. A mixed time-driven and state-dependent switching strategy is proposed to guarantee an average dwell time even when all subsystems are unstable. The switching rule and its associated switching output feedback controllers are designed to stabilize the switched system and achieve a disturbance attenuation performance. The proposed analysis and switching control approach could refrain frequent switches commonly observed in min-switching based designs. The effectiveness of the proposed approach is illustrated through a numerical example.}, booktitle={2014 European Control Conference, ECC 2014}, author={Duan, C. and Wu, Fen}, year={2014}, pages={2540–2545} }
 @inproceedings{liu_ban_wu_lam_2014, title={Dynamie output feedback controller design for T-S fuzzy plants with actuator saturation using linear fractional transformation}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84912571024&partnerID=MN8TOARS}, DOI={10.1109/fuzz-ieee.2014.6891617}, abstractNote={In this paper, a systematic synthesis method for Takagi-Sugeno fuzzy dynamic output feedback controller is proposed for T-S fuzzy plants with actuator saturation. By using the deadzone function, both the T-S fuzzy plant with actuator saturation and the T-S fuzzy dynamic output feedback controller are transformed into the form of linear fractional transformation (LFT). Within the framework of LFT, the issue of stability as well as Hoo performance is cast as a convex optimization problem which can be approached by solving a set of linear matrix inequalities. A numerical example is presented to illustrate the effectiveness of the proposed method.}, booktitle={IEEE International Conference on Fuzzy Systems}, author={Liu, Y. and Ban, X. and Wu, Fen and Lam, H.K.}, year={2014}, pages={2125–2132} }
 @inproceedings{ban_wu_huang_2014, title={Gain scheduling output feedback control of linear plants with partial actuator saturation}, volume={19}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84929783494&partnerID=MN8TOARS}, DOI={10.3182/20140824-6-za-1003.00328}, booktitle={IFAC Proceedings Volumes (IFAC-PapersOnline)}, author={Ban, X. and Wu, F. and Huang, X.}, year={2014}, pages={9486–9491} }
 @inproceedings{yuan_wu_2014, title={Hybrid synthesis for almost asymptotic regulation of linear impulsive systems with average dwell time}, volume={2015-February}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84931846546&partnerID=MN8TOARS}, DOI={10.1109/CDC.2014.7040120}, abstractNote={This paper deals with the hybrid output regulation problem for a class of linear impulsive systems with average dwell time. The hybrid regulator is constructed as a linear impulsive system that undergoes synchronous impulses with the controlled plant, and the hybrid synthesis conditions are formulated in terms of two matrix equations plus a set of linear matrix inequalities (LMIs). With the proposed hybrid synthesis scheme, both continuous-time and discrete-time dynamics of the hybrid regulator can be jointly synthesized by solving a convex optimization problem of minimizing the weighted ℒ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> gain from the perturbation signal to the error output. A numerical example is used to demonstrate the proposed approach.}, number={February}, booktitle={Proceedings of the IEEE Conference on Decision and Control}, author={Yuan, C. and Wu, F.}, year={2014}, pages={4691–4696} }
 @inproceedings{yuan_wu_2014, title={Output feedback reset control of general MIMO LTI systems}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84911471986&partnerID=MN8TOARS}, DOI={10.1109/ecc.2014.6862225}, abstractNote={This paper presents a systematic Lyapunov-based approach for output-feedback reset control of linear time-invariant (LTI) systems with a general multiple-input multiple-output (MIMO) configuration. The reset controller consists of a base linear controller and a reset law that enforces resets to the controller states. Based on the extended Lyapunov-like function (ELF) technique, the reset controller with guaranteed exponential stability and weighted L <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> -gain performance is synthesized by solving a set of linear matrix inequalities (LMIs) with linear search over two scalar variables. A numerical example is used to illustrate the effectiveness of the proposed approach.}, booktitle={2014 European Control Conference, ECC 2014}, author={Yuan, C. and Wu, Fen}, year={2014}, pages={2334–2339} }
 @article{a reset controller design method for mimo linear systems_2013, url={https://publons.com/wos-op/publon/13939861/}, journal={33RD CHINESE CONTROL CONFERENCE (CCC)}, year={2013} }
 @inproceedings{li_wu_wang_2013, title={A reset controller design method for MIMO linear systems}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84890502865&partnerID=MN8TOARS}, booktitle={Chinese Control Conference, CCC}, author={Li, L. and Wu, F. and Wang, X.}, year={2013}, pages={2132–2136} }
 @inproceedings{song_ren_wu_2013, title={Gain-scheduling compensator synthesis for output regulation of nonlinear systems}, url={https://publons.com/wos-op/publon/13939899/}, DOI={10.1109/acc.2013.6580791}, abstractNote={This paper addresses the gain-scheduling output regulation synthesis problem for nonlinear systems. For gain-scheduling control, the linear parameter-varying (LPV) model is obtained from nonlinear plant by plant linearization about zero-error trajectories upon which an LPV controller is synthesized. In practical engineering application, a key issue is to find a nonlinear output feedback compensator related to the designed LPV controller which can guarantee that the closed-loop system of nonlinear plant and compensator linearizes to the interconnection of LPV model and LPV controller. So the stability and performance about the zero-error trajectories can be inherited when the nonlinear compensator is implemented. By incorporating equilibrium input and measured output into the auxiliary LPV model, the compensator synthesis problem is reformulated as linear matrix inequalities (LMIs) which can be solved efficiently using the interior-point method. Consequently the proposed output feedback compensator can satisfy the linearization requirement. Finally, the validity of the proposed approach is demonstrated through a ball and beam design example.}, booktitle={American Control Conference}, author={Song, Xun and Ren, Zhang and Wu, Fen}, year={2013}, pages={6078–6083} }
 @article{duan_wu_2013, title={NEW RESULTS ON CONTINUOUS-TIME SWITCHED LINEAR SYSTEMS WITH ACTUATOR SATURATION}, volume={2}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84902382010&partnerID=MN8TOARS}, DOI={10.1115/dscc2013-3789}, abstractNote={This paper further studies the analysis and control problems of continuous-time switched linear systems subject to actuator saturation. Using the norm-bounded differential inclusion (NDI) description of the saturated systems and the minimal switching rule, a set of switched output feedback controllers is designed to minimize the disturbance attenuation level defined by the regional ℒ2 gain over a class of energy-bounded disturbances. The synthesis conditions are expressed as bilinear matrix inequalities (BMIs) and can be solved by numerical search coupled with linear matrix inequality (LMI) optimization. Compared to the previous method based on polytopic differential inclusion (PDI), the proposed approach has good scalability and potentially renders better performance. Numerical examples are provided to verify effectiveness of the proposed approach.}, journal={ASME 2013 DYNAMIC SYSTEMS AND CONTROL CONFERENCE, VOL 2}, author={Duan, Chang and Wu, Fen}, year={2013} }
 @article{wu_hays_2013, title={Nonlinear gain-scheduling output-feedback control for polynomial nonlinear systems subject to actuator saturation}, volume={86}, ISSN={["1366-5820"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84883553969&partnerID=MN8TOARS}, DOI={10.1080/00207179.2013.792001}, abstractNote={This paper investigates nonlinear gain-scheduling control approaches for a class of polynomial nonlinear systems, containing an output-dependent vector field with input saturation. Using the polytopic differential inclusion and norm-bounded differential inclusion (NDI) of saturation and dead-zone functions, the nonlinear plants are transformed into systems with measurable parameters. For the polytopic differential inclusion description, a quasi-linear parameter varying (quasi-LPV) output-feedback controller will be sought for saturation control. On the other hand, the NDI model leads to a nonlinear fractional transformation (NFT) output-feedback controller for saturated nonlinear systems. The quasi-LPV and NFT output-feedback control synthesis conditions are derived in the forms of output-dependent matrix inequalities. They can be reformulated as sum-of-squares (SOS) optimisations and solved efficiently using SOS programming. The proposed nonlinear gain-scheduling saturation control approaches will be demonstrated using the Van der Pol equation.}, number={9}, journal={INTERNATIONAL JOURNAL OF CONTROL}, author={Wu, Fen and Hays, Scott}, year={2013}, month={Sep}, pages={1607–1619} }
 @article{duan_wu_2013, title={Robust Switched Filtering for Time-Varying Polytopic Uncertain Systems}, volume={135}, ISSN={["1528-9028"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84886400875&partnerID=MN8TOARS}, DOI={10.1115/1.4025027}, abstractNote={This paper studies the problem of designing robust switched filters for time-varying polytopic uncertain systems. The synthesis conditions for a set of filters under a min-switching rule are derived to guarantee globally asymptotical stability with optimized robust H∞ performance. Specifically, the conditions are expressed as bilinear matrix inequalities (BMIs) and can be solved by linear matrix inequality (LMI) optimization techniques. The proposed approach utilizes a piecewise quadratic Lyapunov function to reduce the conservativeness of robust filtering methods based on single Lyapunov function, thus better H∞ performance can be achieved. Both continuous and discrete-time robust filter designs are considered. To simplify filter implementation, a method to remove redundancy in min-switching filter members is also introduced. The advantages of the proposed robust switching filters are illustrated by several examples.}, number={6}, journal={JOURNAL OF DYNAMIC SYSTEMS MEASUREMENT AND CONTROL-TRANSACTIONS OF THE ASME}, author={Duan, Chang and Wu, Fen}, year={2013}, month={Nov} }
 @inproceedings{yuan_wu_2013, title={Robust control of switched linear systems via min of quadratics}, volume={1}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84902456381&partnerID=MN8TOARS}, DOI={10.1115/dscc2013-3715}, abstractNote={In this paper, we will investigate the robust switching control problem for switched linear systems by using a class of composite quadratic functions, the min (of quadratics) function, to improve performance and enhance control design flexibility. The robustness is reflected in two prospectives including the ℋ ∞ performance and arbitrary switching of subsystems. A hysteresis min-switching strategy is employed to orchestrate the switching among a collection of controllers. The synthesis conditions for both state feedback and output feedback control problems are derived in terms of a set of linear matrix inequalities (LMIs) with linear search over scalar variables. The proposed min function based approach unifies the existing single Lyapunov function based method and multiple Lyapunov function based method in a general framework, and the derived LMI conditions cover the existing LMI conditions as special cases. Numerical studies are included to demonstrate the advantages of the proposed control design approach.}, booktitle={ASME 2013 Dynamic Systems and Control Conference, DSCC 2013}, author={Yuan, C. and Wu, Fen}, year={2013} }
 @article{wu_cai_2013, title={Switching fault-tolerant control of a flexible air-breathing hypersonic vehicle}, volume={227}, ISSN={["2041-3041"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84877865979&partnerID=MN8TOARS}, DOI={10.1177/0959651812453914}, abstractNote={In this paper, we will apply a switching fault-tolerant control approach to an air-breathing hypersonic vehicle subject to time-varying actuator and sensor faults. The faults under consideration include loss of effectiveness of the actuators and sensors. Possible fault scenarios are categorized into different fault cases based on the fault type and its location. For each case, a parameter-dependent (or constant gain) fault-tolerant control controller is designed to stabilize the faulty system with an optimal controlled performance. The synthesis condition of each local fault-tolerant control law is formulated in terms of linear matrix inequalities. To achieve both local optimal performance and switching stability, Youla parameterization of each individual local fault-tolerant control controller is performed and the result is applied to the closed-loop system. The quadratic stability of a fast switching closed-loop system is guaranteed by a common Lyapunov function. Simulation results based on the non-linear flexible hypersonic vehicle model and fault-tolerant linear-parameter-varying controllers are presented and the reults of these studies demonstrate the effectiveness of the proposed switching fault-tolerant control approach for application to a hypersonic vehicle.}, number={I1}, journal={PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART I-JOURNAL OF SYSTEMS AND CONTROL ENGINEERING}, author={Wu, Fen and Cai, Xuejing}, year={2013}, month={Jan}, pages={24–38} }
 @inproceedings{yang_wu_2012, title={Feedback design for saturated polynomial nonlinear systems via higher order lyapunov functions}, volume={2}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84885921896&partnerID=MN8TOARS}, DOI={10.1115/dscc2012-movic2012-8644}, abstractNote={In this work, we develop a new control design approach to deal with saturated polynomial nonlinear systems by using higher order Lyapunov functions. By combining power transformation with Sum-of-Squares (SOS) techniques, we can augment the systems with more state variables representing higher order combinations of the original ones. Then, the search of higher order Lyapunov functions for original systems can be recast to the design of quadratic Lyapunov functions for augmented systems. By computing for higher order Lyapunov functions using norm-bounded differential inclusion (NDI) LMI conditions, the flexible representations of augmented systems can help us to achieve better performance than quadratic based method. Two examples illustrate the improvements to enlarge the region of attraction and to improve the ℋ∞ performance for nonlinear systems subjected to saturation nonlinearity, respectively.© 2012 ASME}, booktitle={ASME 2012 5th Annual Dynamic Systems and Control Conference Joint with the JSME 2012 11th Motion and Vibration Conference, DSCC 2012-MOVIC 2012}, author={Yang, S. and Wu, Fen}, year={2012}, pages={645–652} }
 @article{ban_deng_wu_huang_2012, title={Fuzzy gain-scheduling output feedback controller design for saturated linear plants}, volume={19}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84874307874&partnerID=MN8TOARS}, number={6}, journal={Journal of Harbin Institute of Technology (New Series)}, author={Ban, X.-J. and Deng, Z.-Q. and Wu, F. and Huang, X.-L.}, year={2012}, pages={79–86} }
 @inproceedings{ban_wu_2012, title={Gain scheduling output feedback controller design for saturated linear plants}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84873541215&partnerID=MN8TOARS}, booktitle={Chinese Control Conference, CCC}, author={Ban, X. and Wu, F.}, year={2012}, pages={89–94} }
 @inbook{hughes_wu_2012, title={LPV H∞ control for flexible hypersonic vehicle}, volume={9781461418337}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84877843144&partnerID=MN8TOARS}, DOI={10.1007/978-1-4614-1833-7_16}, booktitle={Control of Linear Parameter Varying Systems with Applications}, author={Hughes, H.D. and Wu, F.}, year={2012}, pages={413–444} }
 @article{duan_wu_2012, title={Output-feedback control for switched linear systems subject to actuator saturation}, volume={85}, ISSN={["1366-5820"]}, url={https://publons.com/wos-op/publon/9848633/}, DOI={10.1080/00207179.2012.691611}, abstractNote={Abstract This article is devoted to the output-feedback ℋ∞ control problem for switched linear systems subject to actuator saturation. We consider both continuous- and discrete-time switched systems. Using the minimal switching rule, nonlinear output feedbacks expressed in the form of quasi-linear parameter varying system are designed to satisfy a pre-specified disturbance attenuation level defined by the regional ℒ2 (ℓ2)-gains over a class of energy-bounded disturbances. The conditions are expressed in bilinear matrix inequalities and can be solved by line search coupled with linear matrix inequalities optimisation. A spherical inverted pendulum example is used to illustrate the effectiveness of the proposed approach. Keywords: switching controloutput-feedback controlactuator saturationlinear matrix inequalities Acknowledgements This work is supported in part by NASA Grant NNX07AC40A and NSF Grant 1200242.}, number={10}, journal={INTERNATIONAL JOURNAL OF CONTROL}, author={Duan, Chang and Wu, Fen}, year={2012}, pages={1532–1545} }
 @inproceedings{switching control synthesis for discrete-time switched linear systems via modified lyapunov-metzler inequalities_2012, url={https://publons.com/wos-op/publon/9848644/}, DOI={10.1109/ACC.2012.6314959}, abstractNote={This paper addresses the switching control synthesis problem of discrete-time switched linear systems. A particular class of matrix inequalities, the so-called Lyapunov-Metzler inequalities is modified to provide conditions for stability analysis and output feedback control synthesis under a relaxed min-switching logic. The switching rule combined with switching output feedback controllers are designed to stabilize the switched closed-loop system and satisfy a pre-specified ℓ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> gain performance. The proposed switching control approach is to reduce the high frequency switches commonly observed in min-switching strategy based designs. The effectiveness of the proposed approach is illustrated through a numerical example.}, booktitle={American Control Conference}, year={2012} }
 @article{zheng_wu_2011, title={Adaptive control design for uncertain polynomial nonlinear systems with parametric uncertainties}, volume={25}, ISSN={["0890-6327"]}, url={https://publons.com/wos-op/publon/13939825/}, DOI={10.1002/acs.1215}, abstractNote={In this paper, we will develop an adaptive ℋ︁∞ control approach for a class of polynomial nonlinear systems with parametric uncertainties. Motivated by the dissipation theory and the vector projection technique, we propose a nonlinear adaptive ℋ︁∞ controller and its associated parameter adaptation law. The proposed adaptive control strategy is capable of identifying unknown parameter values quickly and minimizing the effect of estimation error. To further improve adaptive controlled performance, the Lyapunov function will be relaxed from quadratic to higher-order forms and the controller gains are generalized from constant to parameter-dependent. All of the synthesis conditions are formulated in the framework of polynomial/constant linear matrix inequalities and solvable using available software packages. Copyright © 2010 John Wiley & Sons, Ltd.}, number={6}, journal={INTERNATIONAL JOURNAL OF ADAPTIVE CONTROL AND SIGNAL PROCESSING}, author={Zheng, Qian and Wu, Fen}, year={2011}, month={Jun}, pages={502–518} }
 @article{zheng_wu_2011, title={Generalized nonlinear H-infinity synthesis condition with its numerically efficient solution}, volume={21}, ISSN={["1099-1239"]}, url={https://publons.com/wos-op/publon/13939826/}, DOI={10.1002/rnc.1682}, abstractNote={Abstract In this paper, we will first derive a general synthesis condition for the output‐feedback ℋ︁ ∞ control of smooth nonlinear systems. Computationally efficient ℋ︁ ∞ control design procedure for a subclass of smooth nonlinear systems with polynomial vector field is then proposed by converting the resulting Hamilton‐Jacobi‐Isaacs inequalities from rational forms to their equivalent polynomial forms. Using quadratic Lyapunov functions, both the state‐feedback and output‐feedback problems will be reformulated as semi‐definite optimization conditions and locally tractable solutions can be obtained through sum‐of‐squares (SOS) programming. The proposed nonlinear ℋ︁ ∞ design approach achieves significant relaxations on the plant structure compared with existing results in the literature. Moreover, the SOS‐based solution algorithm provides an effective computational scheme to break the bottleneck in solving nonlinear ℋ︁ ∞ and optimal control problems. The proposed nonlinear ℋ︁ ∞ control approach has been applied to several examples to demonstrate its advantages over existing nonlinear control techniques and its usefulness to engineering problems. Copyright © 2010 John Wiley & Sons, Ltd.}, number={18}, journal={INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL}, author={Zheng, Qian and Wu, Fen}, year={2011}, month={Dec}, pages={2079–2100} }
 @article{cai_wu_2011, title={Multiobjective fault detection and isolation for flexible air-breathing hypersonic vehicle}, volume={22}, ISSN={["1004-4132"]}, url={https://publons.com/wos-op/publon/13939824/}, DOI={10.3969/j.issn.1004-4132.2011.01.006}, abstractNote={An application of the multiobjective fault detection and isolation (FDI) approach to an air-breathing hypersonic vehicle (HSV) longitudinal dynamics subject to disturbances is presented. Maintaining sustainable and safe flight of HSV is a challenging task due to its strong coupling effects, variable operating condi- tions and possible failures of system components. A common type of system faults for aircraft including HSV is the loss of effective- ness of its actuators and sensors. To detect and isolate multiple actuator/sensor failures, a faulty linear parameter-varying (LPV) model of HSV is derived by converting actuator/system compo- nent faults into equivalent sensor faults. Then a bank of LPV FDI observers is designed to track individual fault with minimum error and suppress the effects of disturbances and other fault signals. The simulation results based on the nonlinear flexible HSV model and a nominal LPV controller demonstrate the effectiveness of the fault estimation technique for HSV.}, number={1}, journal={JOURNAL OF SYSTEMS ENGINEERING AND ELECTRONICS}, author={Cai, Xuejing and Wu, Fen}, year={2011}, month={Feb}, pages={52–62} }
 @inproceedings{new results on output feedback disturbance attenuation of saturated linear systems_2011, booktitle={2011 39th Chinese Control Conference (CCC)}, year={2011}, month={Jul} }
 @inproceedings{wu_2011, title={New results on output feedback disturbance attenuation of saturated linear systems}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-80053079939&partnerID=MN8TOARS}, booktitle={Proceedings of the 30th Chinese Control Conference, CCC 2011}, author={Wu, F.}, year={2011}, pages={287–292} }
 @inproceedings{hays_wu_2011, title={Nonlinear robust H<inf>∞</inf> control with state-dependent scaling}, volume={1}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84881411710&partnerID=MN8TOARS}, DOI={10.1115/dscc2011-5994}, abstractNote={This paper addresses the design of nonlinear robust H∞ controllers for nonlinear uncertain systems with polynomial vector field and norm bounded uncertainties. We derive state-dependent matrix inequalities, using Lyapunov’s direct method, that stabilize the nonlinear systems and guarantee robust performance using nonlinear state-feedback control. The state-dependent synthesis conditions incorporate state-dependent scaling to minimize the ℒ2 gain of the disturbance/output. Sum-of-squares (SOS) optimization is applied to solve the resulting synthesis condition with optimized ℒ2 gain for the nonlinear system, without requiring an iterative approach. Finally, a design example of nonlinear Van der Pol equation is presented.}, booktitle={ASME 2011 Dynamic Systems and Control Conference and Bath/ASME Symposium on Fluid Power and Motion Control, DSCC 2011}, author={Hays, S. and Wu, Fen}, year={2011}, pages={581–588} }
 @inproceedings{duan_wu_2011, title={Output Feedback Control for Continuous-Time Switched Linear Systems Sub- ject to Actuator Saturation}, volume={1}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84881432759&partnerID=MN8TOARS}, DOI={10.1115/dscc2011-5925}, abstractNote={This paper is devoted to output feedback ℋ∞ control problem for continuous-time switched linear systems subject to actuator saturation. Using minimal switching rule, nonlinear output feedbacks, expressed in the form of quasi-linear parameter varying system are designed to satisfy a pre-specified disturbance attenuation level defined by the regional ℒ2 gains over a class of energy-bounded disturbances. The synthesis condition is further simplified and can be solved through efficient LMI optimizations. The proposed switched control approach is also illustrated by a simple example.}, booktitle={ASME 2011 Dynamic Systems and Control Conference and Bath/ASME Symposium on Fluid Power and Motion Control}, author={Duan, C. and Wu, Fen}, year={2011}, month={Oct}, pages={449–456} }
 @inproceedings{hughes_wu_2010, title={H <inf>∞</inf> LPV state feedback control for flexible hypersonic vehicle longitudinal dynamics}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84867798596&partnerID=MN8TOARS}, DOI={10.2514/6.2010-8281}, booktitle={AIAA Guidance, Navigation, and Control Conference}, author={Hughes, H. and Wu, F.}, year={2010} }
 @inproceedings{resilient control design for polynomial nonlinear systems with controller gain variations_2010, url={https://publons.com/wos-op/publon/13939867/}, DOI={10.1109/ACC.2010.5531280}, abstractNote={In this paper, we consider the resilient (non-fragile) controller design problem for polynomial nonlinear systems. The designed state feedback controller is capable of tolerating some level of controller gain variations. Based on the Lyapunov stability theorem and S-procedure, the synthesis condition will be formulated in polynomial but bilinear form of Lyapunov function and the controller gain jointly. An iterative scheme will be proposed to separate the joint search of two variables and convert the bilinear condition to linear form. Sum-of-Squares (SOS) programming will be utilized to obtain the tractable solution and gradually augment the Lyapunov function and the nonlinear control law to higher order polynomial forms so that the robust margin of control gain is optimized. An examples will be used to materialize the design scheme and demonstrate the improved robust stability margin against the controller gain variations.}, booktitle={American Control Conference}, year={2010} }
 @article{cai_wu_2010, title={Robust fault detection and isolation for parameter-dependent LFT systems}, volume={20}, ISSN={["1099-1239"]}, url={https://publons.com/wos-op/publon/13939822/}, DOI={10.1002/rnc.1468}, abstractNote={Abstract In this paper, we consider robust fault detection and isolation (FDI) problems for faulty linear systems with linear fractional transformation (LFT) parameter dependency and propose an observer‐based solution by using multiobjective optimization techniques. To simplify the design process, a general faulty LFT system will be constructed from the standard LFT description by converting actuator/system component faults into sensor faults first. Then a bank of parameter‐dependent FDI filters will be designed to identify each fault. Each FDI filter will generate a residual signal to track an individual fault with minimum error and to suppress the effects of disturbances, time‐varying parameters and other fault signals. The design of LFT parameter‐dependent FDI filters, as a multiobjective optimization problem, will be formulated in terms of linear matrix inequalities (LMIs) and can be solved efficiently. A numerical example is used to demonstrate the proposed fault detection and isolation approach for LFT systems with different parametric structures. Copyright © 2009 John Wiley & Sons, Ltd.}, number={7}, journal={INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL}, author={Cai, Xuejing and Wu, Fen}, year={2010}, month={May}, pages={764–776} }
 @article{cai_wu_2010, title={Robust parameter-dependent fault-tolerant control for actuator and sensor faults}, volume={83}, ISSN={["1366-5820"]}, url={https://publons.com/wos-op/publon/13939821/}, DOI={10.1080/00207179.2010.481024}, abstractNote={In this article, we study a robust fault-tolerant control (FTC) problem for linear systems subject to time-varying actuator and sensor faults. The faults under consideration are loss of effectiveness in actuators and sensors. Based on the estimated faults from a fault detection and isolation scheme, robust parameter-dependent FTC will be designed to stabilise the faulty system under all possible fault scenarios. The synthesis condition of such an FTC control law will be formulated in terms of linear matrix inequalities (LMIs) and can be solved efficiently by semi-definite programming. The proposed FTC approach will be demonstrated on a simple faulty system with different fault levels and fault estimation error bounds.}, number={7}, journal={INTERNATIONAL JOURNAL OF CONTROL}, author={Cai, Xuejing and Wu, Fen}, year={2010}, pages={1475–1484} }
 @inproceedings{cai_wu_2010, title={Switching fault-tolerant control by Youla parametrization}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-78650236432&partnerID=MN8TOARS}, booktitle={Proceedings of the 29th Chinese Control Conference, CCC'10}, author={Cai, X. and Wu, F.}, year={2010}, pages={4099–4104} }
 @inproceedings{a multiobjective solution approach to fault detection and isolation of lpv systems_2009, url={https://publons.com/wos-op/publon/13939839/}, DOI={10.1115/DSCC2008-2154}, abstractNote={In this paper, we consider the fault Detection and isolation (FDI) problem for faulty linear parameter-varying (LPV) systems subject to disturbances and propose a observer-based solution by using multiobjective optimization techniques. To simply the design process, a general faulty LPV system will be constructed from standard LPV description by converting actuator/system component faults into sensor faults at first. Then a bank of LPV FDI filters will be designed to identify each fault. Each FDI filter could generate a residual signal to track individual fault with minimum error and suppressing the effects of disturbances and other fault signals. The design of FDI filters will be formulated as multiobjective optimization problems in terms of linear matrix inequalities (LMIs) and can be solved efficiently. Two numerical examples are also presented to demonstrate the proposed fault detection and isolation approach on both LPV and LTI systems.}, booktitle={ASME Dynamic Systems and Control Conference (DSCC)}, year={2009} }
 @inproceedings{cai_wu_2009, title={A Robust Fault Tolerant Control Approach for LTI Systems with Actuator and Sensor Faults}, url={https://publons.com/wos-op/publon/13939841/}, DOI={10.1109/ccdc.2009.5191903}, abstractNote={In this paper, we study a robust fault-tolerant control (FTC) problem for linear systems with time varying actuator and sensor faults and propose an parameter-dependent solution by using L <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> gain optimization techniques. Using estimated faults from a fault detection and isolation (FDI) scheme, parameter-dependent robust FTC gain will be scheduled by fault magnitude to stabilize and optimize the faulty system under all possible fault scenarios. The synthesis condition of such a FTC control law will be formulated as linear matrix inequalities (LMIs) and can be solved efficiently by semi-definite programming techniques. A numerical example is used to demonstrate the proposed fault-tolerant control approach for a simple faulty systems with different fault levels and fault estimation error bounds.}, booktitle={Chinese Control and Decision Conference (CCDC)}, author={Cai, X. and Wu, Fen}, year={2009}, pages={890–895} }
 @inproceedings{computationally efficient nonlinear h-infinity control designs for a rigid body spacecraft_2009, url={https://publons.com/wos-op/publon/13939840/}, booktitle={ASME Dynamic Systems and Control Conference (DSCC)}, year={2009} }
 @article{wu_zheng_lin_2009, title={Disturbance attenuation by output feedback for linear systems subject to actuator saturation}, volume={19}, ISSN={["1099-1239"]}, url={https://publons.com/wos-op/publon/6609261/}, DOI={10.1002/rnc.1306}, abstractNote={Abstract In this paper, we study the problem of disturbance attenuation by output feedback for linear systems subject to actuator saturation. A nonlinear output feedback, expressed in the form of a quasi‐linear parameter‐varying system with state‐dependent scheduling parameter, is constructed that leads to the attenuation of the effect of the disturbance on the output of the system. The level of disturbance attenuation is measured in terms of the restricted ℒ︁ 2 gain and the restricted ℒ︁ 2 –ℒ︁ ∞ gain over a class of bounded disturbances. Copyright © 2008 John Wiley & Sons, Ltd.}, number={2}, journal={INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL}, author={Wu, Fen and Zheng, Qian and Lin, Zongli}, year={2009}, month={Jan}, pages={168–184} }
 @article{zheng_wu_2009, title={Lyapunov Redesign of Adaptive Controllers for Polynomial Nonlinear Systems}, ISBN={["978-1-4244-4523-3"]}, ISSN={["2378-5861"]}, url={https://publons.com/wos-op/publon/13939830/}, DOI={10.1109/acc.2009.5160128}, abstractNote={In this paper, we study adaptive control redesign problem of polynomial nonlinear systems with matching parametric uncertainties. By transforming the system into its corresponding error dynamics, we will develop an adaptive control scheme in attenuating the effect of the unknown parameters on the controlled output, which is composed of tracking errors and control efforts. To achieve better controlled performance, the Lyapunov functions will be relaxed from quadratic to higher order and the resulting controller gain is generalized from constant to parameter dependent. The synthesis conditions of adaptive control will be formulated as polynomial matrix inequalities and are solvable by recast the resulting conditions into a Sum of Squares (SOS) optimization problem, from which the adaptive control law as well as the parameter adaptation law are derived with zero tracking and parameter estimation errors. An example is provided to demonstrate effectiveness of the proposed adaptive control redesign approach.}, journal={2009 AMERICAN CONTROL CONFERENCE, VOLS 1-9}, author={Zheng, Qian and Wu, Fen}, year={2009}, pages={5144–5149} }
 @article{zheng_wu_2009, title={Nonlinear H-infinity Control Designs with Axisymmetric Spacecraft Control}, volume={32}, ISSN={["1533-3884"]}, url={https://publons.com/wos-op/publon/13939834/}, DOI={10.2514/1.40060}, abstractNote={In this paper, we study nonlinear control of a spacecraft symmetric about its principal axis with two control torques. Using a computationally efficient H ∞ control design procedure, attitude stabilization and command tracking problems of the axisymmetric spacecraft are solved locally. The proposed nonlinear H ∞ control approach uses higher order Lyapunov functions and reformulates the difficult Hamilton―Jacobian―Isaacs inequalities as semidefinite optimization conditions. Sum-of-squares programming techniques are then applied to obtain computationally tractable solutions, from which nonlinear control laws will be constructed. The nonlinear H ∞ control designs for spacecraft are capable of exploiting the most suitable forms of Lyapunov functions for performance improvement.}, number={3}, journal={JOURNAL OF GUIDANCE CONTROL AND DYNAMICS}, author={Zheng, Qian and Wu, Fen}, year={2009}, pages={850–859} }
 @article{dong_wu_2009, title={Online Switching Control of LFT Parameter-Dependent Systems}, volume={131}, ISSN={["1528-9028"]}, url={https://publons.com/wos-op/publon/12915968/}, DOI={10.1115/1.3023140}, abstractNote={To improve controlled performance and expand gain-scheduling control capability, we propose a switching control approach of linear fractional transformation parameter-dependent systems using multiple Lyapunov functions combined with online control techniques. At each switching instant, a gain-scheduled controller working for the next switching interval will be designed online. The switching control synthesis condition is formulated as linear matrix inequalities and can be solved efficiently, upon which the controller will be constructed. The online switching control scheme is demonstrated using an uninhabited combat aerospace vehicle problem.}, number={2}, journal={JOURNAL OF DYNAMIC SYSTEMS MEASUREMENT AND CONTROL-TRANSACTIONS OF THE ASME}, author={Dong, Ke and Wu, Fen}, year={2009}, month={Mar} }
 @article{zheng_wu_2009, title={Regional stabilisation of polynomial non-linear systems using rational Lyapunov functions}, volume={82}, ISSN={["1366-5820"]}, DOI={10.1080/00207170802627267}, abstractNote={In this article, we propose a new non-linear stabilisation approach based on the popular linear parameter-varying control techniques. The regional state-feedback control problem of polynomial non-linear systems will be studied using rational Lyapunov functions of states. By bounding the variation rates of each state, the domain of attraction will be embedded in the region specified by the non-linear vector field. As a result, the state-feedback stabilisation conditions will be formulated as a set of polynomial matrix inequalities and can be solved efficiently by sum-of-squares programming. The resulting Lyapunov matrix and state-feedback gains are typically state-dependent rational matrix functions. This approach is also extended to a class of output-dependent non-linear systems where the stabilising output-feedback controller can be synthesised using rational Lyapunov functions of outputs. Finally, several examples will be used to demonstrate the proposed stabilisation approach and clarify the effect of various choices of Lyapunov function forms and state constraints.}, number={9}, journal={INTERNATIONAL JOURNAL OF CONTROL}, author={Zheng, Qian and Wu, Fen}, year={2009}, pages={1605–1615} }
 @article{regional stabilisation of polynomial non-linear systems using rational lyapunov functions_2009, url={https://publons.com/wos-op/publon/6609233/}, DOI={10.1115/1.802908.PAPER52}, abstractNote={Study of hydrogen adsorption on activated carbon storage was carried out experimentally and theoretically. Adsorption isotherms were measured at temperature-pressure range respectively from 113–293 K and 0–12.5 MPa. A lattice theory based adsorption model, modified by adsorption potential and maximum surface concentration, was used to determine the interaction energies among adsorbed hydrogen molecules. Dynamic storage tests were performed under pressures 10.5 MPa and 5.2 MPa at ambient temperature, thermal effect was evaluated by temperature and the flow rate of the storage system. Results show that molecular interaction energies evenly changed with the surface coverage at low temperature region but drastically at a higher temperature, and the charging or discharging the system under higher pressures or higher flow rates caused stronger temperature fluctuations. However, the storage system almost simultaneously reached the highest or lowest temperature under different charge and discharge pressures. Conclusions were drawn that heat transfer enhancement measures inhibiting the temperature fluctuation in initial charge and discharge states were necessary, and lowering down the storage temperature was also vital to enhancing the affinity of hydrogen molecules as well as limiting the influence from the thermal effect.}, journal={International Journal of Control}, year={2009} }
 @inproceedings{lu_wu_2009, title={Switching-Based Fault-Tolerant Control for an F-16 Aircraft with Thrust Vectoring}, url={https://publons.com/wos-op/publon/13939911/}, DOI={10.1109/CDC.2009.5400385}, abstractNote={Thrust vectoring technique enables aircraft to perform various maneuvers not available to conventional-engined planes. This paper presents an application of switching control concepts to fault-tolerant control design for an F-16 aircraft model augmented with thrust vectoring. Two controllers are synthesized using a switching logic, and they are switched on a fault parameter. During normal flight conditions, the F-16 aircraft relies on no vectored thrust and the elevator. The thrust vectoring nozzle is only turned on in the presence of elevator failures. Two elevator fault scenarios, lock and loss of effectiveness, are considered. Nonlinear simulation results show that the switching control can guarantee the stability and performance of the faulted system.}, booktitle={IEEE Conference on Decision and Control}, author={Lu, B. and Wu, F.}, year={2009}, pages={8494–8499} }
 @article{dong_wu_2008, title={Almost output regulation for parameter-dependent linear fractional transformation systems}, volume={2}, ISSN={["1751-8652"]}, url={https://publons.com/wos-op/publon/13939793/}, DOI={10.1049/iet-cta:20070087}, abstractNote={An important problem of output regulation for linear fractional transformation (LFT) systems is considered. This problem is mainly concerned about tracking and/or rejection of persistent signals produced by some external generator. Necessary and sufficient solvability condition for LFT systems as two linear matrix equations, which is an extension of the existing output regulation results for the linear time invariant and nonlinear systems will be presented. On the basis of the analysis condition, the LFT almost output regulation problem of approximately tracking/rejecting persistent signals will be studied by minimising the ℒ2 gain from perturbation of the signal to error output. Its synthesis condition will be formulated as two matrix equations plus a set of linear matrix inequalities. An example will be used to demonstrate the proposed approach.}, number={3}, journal={IET CONTROL THEORY AND APPLICATIONS}, author={Dong, K. and Wu, F.}, year={2008}, month={Mar}, pages={200–209} }
 @inproceedings{xuejing_fen_2008, title={Constrained distributed RHC based on vector Lyapunov functions and comparison model}, volume={9 PART B}, url={https://publons.com/wos-op/publon/13939792/}, DOI={10.1115/IMECE2007-42096}, abstractNote={In this paper, we propose a distributed receding horizon control (RHC) algorithm for a class of constrained and dynamically interconnected systems with stability and performance guarantees. For weak coupling between subsystems, a vector Lyapunov function off-line is derived and will be used as terminal cost for distributed RHC. Moreover, comparison models will be used to predict subsystem states over future horizon. An example is provided to demonstrate the control design procedure.}, booktitle={ASME International Mechanical Engineering Congress and Exposition (IMECE)}, author={Xuejing, C. and Fen, W.}, year={2008}, pages={873–882} }
 @inproceedings{zheng_wu_2008, title={Nonlinear output feedback H-infinity control for polynomial nonlinear systems}, url={https://publons.com/wos-op/publon/13939790/}, DOI={10.1109/ACC.2008.4586655}, abstractNote={In this paper, we propose a computational scheme of solving the output feedback H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">infin</sub> control problem for a class of nonlinear systems with polynomial vector field. The output feedback control design problem will be decomposed into a state feedback and an output estimation problems. Resorting to higher order Lyapunov functions, two Hamilton-Jacobian-Isaacs (HJI) inequalities are first formulated as semi-definite optimization conditions. Sum-of-squares (SOS) programming techniques are then applied to obtain computationally tractable solutions, from which a nonlinear control law will be constructed. The closed-loop system is asymptotically stabilizable by the nonlinear output feedback control and achieves good H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">infin</sub> performance under the exogenous disturbances.}, booktitle={American Control Conference}, author={Zheng, Q. and Wu, F.}, year={2008}, pages={1196–1201} }
 @inproceedings{hughes_wu_2008, title={Optimal control for spacecraft large angle maneuvers using H <inf>∞</inf> linear varying parameter control techniques}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-78651082551&partnerID=MN8TOARS}, booktitle={AIAA Guidance, Navigation and Control Conference and Exhibit}, author={Hughes, H.D. and Wu, F.}, year={2008} }
 @inproceedings{chen_wu_2008, title={Output feedback RHC for constrained linear systems}, volume={9 PART B}, url={https://publons.com/wos-op/publon/13939789/}, DOI={10.1115/IMECE2007-42110}, abstractNote={In this paper, we address the problem of synthesizing output feedback control law for constrained linear systems. For lack of state information, the plant states will be estimated by an observer. Using the Lyapunov function of estimated plant and controller states, the constrained output feedback control problem will be formulated and solved in terms of linear matrix inequalities (LMIs). The quadratic cost function is minimized over control policies to yield an output feedback control strategy subject to input/output constraints. Both infinite-horizon and finitehorizon receding horizon control (RHC) are considered in the paper. Closed-loop stability and feasibility of RHC are guaranteed by off-line constrained control designs. The simulation results show that finite-horizon RHC provides better performance upper bound than infinite-horizon RHC.}, booktitle={ASME International Mechanical Engineering Congress and Exposition (IMECE)}, author={Chen, Y. and Wu, F.}, year={2008}, pages={889–896} }
 @article{zheng_wu_2008, title={Output feedback control of saturated discrete-time linear systems using parameter-dependent Lyapunov functions}, volume={57}, ISSN={["1872-7956"]}, url={https://publons.com/wos-op/publon/6609235/}, DOI={10.1016/j.sysconle.2007.12.011}, abstractNote={In this paper, we present a new output feedback control approach for discrete-time linear systems subject to actuator saturations using parameter-dependent Lyapunov functions. The saturation level indicator serves as a scheduling parameter. The resulting nonlinear controller is expressed in a quasi-LPV (linear parameter-varying) form, and the stabilization and disturbance attenuation problems are formulated and solved as finite-dimensional linear matrix inequality (LMI) optimization problems. Our approach is less conservative than a single quadratic Lyapunov function method. Specifically, the proposed output feedback control law asymptotically stabilizes the open loop system with a larger domain of attraction and achieves better disturbance attenuation under energy and magnitude bounded disturbances.}, number={11}, journal={SYSTEMS & CONTROL LETTERS}, author={Zheng, Qian and Wu, Fen}, year={2008}, month={Nov}, pages={896–903} }
 @inproceedings{zheng_wu_2008, title={State feedback and output feedback control of polynomial nonlinear systems using fractional Lyapunov functions}, volume={9 PART B}, url={https://publons.com/wos-op/publon/13939791/}, DOI={10.1115/IMECE2007-42147}, abstractNote={In this paper, we will study the state feedback control problem of polynomial nonlinear systems using fractional Lyapunov functions. By adding constraints to bound the variation rate of each state, the general difficulty of calculating derivative of nonquadratic Lyapunov function is effectively overcome. As a result, the state feedback conditions are simplified as a set of Linear Matrix Inequalities (LMIs) with polynomial entries. Computationally tractable solution is obtained by Sum-of-Squares (SOS) decomposition. And it turns out that both of the Lyapunov matrix and the state feedback gain are state dependent fractional matrix functions, where the numerator as well as the denominator can be polynomials with flexible forms and higher nonlinearities involved in. Same idea is extended to a class of output dependent nonlinear systems and the stabilizing output feedback controller is specified as polynomial of output. Synthesis conditions are similarly derived as using constant Lyapunov function except that all entries in LMIs are polynomials of output with derivative of output involved in. By bounding the variation rate of output and gridding on the bounded interval, the LMIs are solvable by SOS decomposition. Finally, two examples are used to materialize the design scheme and clarify the various choices on state boundaries.}, booktitle={ASME International Mechanical Engineering Congress and Exposition (IMECE)}, author={Zheng, Q. and Wu, F.}, year={2008}, pages={897–905} }
 @inproceedings{zheng_wu_2007, title={Improving nonlinear control performance with a hybrid control strategy}, url={https://publons.com/wos-op/publon/13939819/}, DOI={10.1109/CDC.2007.4434383}, abstractNote={To overcome inadequate performance behavior of nonlinear stabilizing control law derived from standard backstepping design, we propose a hybrid control approach to robustly stabilizing polynomial nonlinear systems in a global sense as well as improving the system performance in a local region. Specifically, we keep using backstepping controller in large space until the state trajectories entering a small region around the origin. Within the bounded region the states will be treated as parameter variables and the nonlinear system is reasonably represented as an LPV system. The construction of LPV state feedback control law together with the states/region boundedness characterization are expressed as semi-definite programming problems, and solved using SOS programming techniques. As shown by an example, the proposed hybrid controller not only maintains the system robustness but also enhances the performance by providing smaller L <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> gain and faster convergence rate.}, booktitle={IEEE Conference on Decision and Control}, author={Zheng, Q. and Wu, F.}, year={2007}, pages={3208–3213} }
 @article{wu_lin_zheng_2007, title={Output feedback stabilization of linear systems with actuator saturation}, volume={52}, ISSN={["1558-2523"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-33847366126&partnerID=MN8TOARS}, DOI={10.1109/TAC.2006.886498}, abstractNote={The note presents a method for designing an output feedback law that stabilizes a linear system subject to actuator saturation with a large domain of attraction. This method applies to general linear systems including strictly unstable ones. A nonlinear output feedback controller is first expressed in the form of a quasi-LPV system. Conditions under which the closed-loop system is locally asymptotically stable are then established in terms of the coefficient matrices of the controller. The design of the controller (coefficient matrices) that maximizes an estimate of the domain of attraction is then formulated and solved as an optimization problem with LMI constraints}, number={1}, journal={IEEE TRANSACTIONS ON AUTOMATIC CONTROL}, author={Wu, Fen and Lin, Zongli and Zheng, Qian}, year={2007}, month={Jan}, pages={122–128} }
 @inproceedings{output feedback stabilization of linear systems with actuator saturation_2007, url={https://publons.com/wos-op/publon/6609234/}, DOI={10.1109/ACC.2005.1470494}, abstractNote={The paper presents a method for designing output feedback laws that stabilize a linear system subject to actuator saturation with a large domain of attraction. This method applies to general linear systems including strictly unstable ones, and is presented in both continuous-time and discrete-time setting. A nonlinear output feedback controller is first expressed in the form of a quasi-LPV system. Conditions under which the closed-loop system is locally asymptotically stable are then established in terms of the coefficient matrices of the controller. The design of the controller (coefficient matrices) that achieves a large domain of attraction is then formulated and solved as an optimization problem with LMI constraints.}, booktitle={American Control Conference}, year={2007} }
 @inproceedings{wu_zheng_lin_2007, title={Output feedback stabilization of saturated LFT systems}, url={https://publons.com/wos-op/publon/13939812/}, DOI={10.1109/ICCA.2007.4376915}, abstractNote={In the paper, we will extend our recent results on output feedback control of LTI systems with actuator saturation to an important class of systems which have linear fractional parameter dependency. A nonlinear output feedback controller is first expressed in the form of a quasi-LPV system. Conditions under which the closed-loop system is locally asymptotically stable are then established in terms of the coefficient matrices of the controller. The design of the controller (coefficient matrices) that achieves a large domain of attraction is then formulated and solved as an optimization problem with LMI constraints.}, booktitle={IEEE International Conference on Control and Automation}, author={Wu, F. and Zheng, Q. and Lin, Z.}, year={2007}, pages={3015–3020} }
 @article{dong_wu_2007, title={Robust and gain-scheduling control of LFT systems through duality and conjugate Lyapunov functions}, volume={80}, ISSN={["1366-5820"]}, url={https://publons.com/wos-op/publon/13939811/}, DOI={10.1080/00207170601080213}, abstractNote={In this paper, we study stability and performance properties of linear fractional transformation (LFT) parameter-dependent systems using duality theory and tools from convex analysis. A pair of conjugate functions, the convex hull and the maximum of a family of quadratic functions, are used for analysis and synthesis of LFT systems. Sufficient synthesis conditions for both robust state feedback and gain-scheduling output feedback control problems are formulated as a set of linear matrix inequalities (LMIs) with linear search over scalar variables. Finally, a numerical example is used to demonstrate the advantages of the proposed approaches.}, number={4}, journal={INTERNATIONAL JOURNAL OF CONTROL}, author={Dong, K. and Wu, F.}, year={2007}, month={Apr}, pages={555–568} }
 @article{wu_chen_2007, title={Robust receding horizon control for constrained linear fractional transformation parameter-dependent systems}, volume={1}, DOI={10.1049/ict-cta:20060305}, number={5}, journal={IET Control Theory and Applications}, author={Wu, Fen and Chen, Y.}, year={2007}, pages={1423–1430} }
 @article{wu_chen_2007, title={Robust receding horizon control for constrained linear fractional transformation parameter-dependent systems}, volume={1}, ISSN={1751-8644 1751-8652}, url={http://dx.doi.org/10.1049/iet-cta:20060305}, DOI={10.1049/iet-cta:20060305}, abstractNote={A robust receding horizon control (RHC) scheme is proposed for parameter-dependent linear systems with linear fractional parameter dependency and input–output constraints. The cost function is defined over a moving finite horizon as the quadratic performance for future parameter trajectories. The robust stability of the proposed RHC scheme is guaranteed using a parameter-dependent control Lyapunov function as the terminal penalty term, which is available through off-line synthesis procedure. Moreover, it is shown that the domain of attraction will be enlarged and the controlled performance of the RHC scheme will be gradually improved as the upper bound of performance is monotonically decreasing on-line. Both off-line robust control synthesis and on-line RHC computation are formulated and solved using linear matrix inequality optimisation techniques.}, number={5}, journal={IET Control Theory & Applications}, publisher={Institution of Engineering and Technology (IET)}, author={Wu, F. and Chen, Y.}, year={2007}, month={Sep}, pages={1423–1430} }
 @article{robust receding horizon control for constrained uncertain lft systems with bounded disturbance_2007, url={https://publons.com/wos-op/publon/7424381/}, journal={Ninth Iasted International Conference on Control and Applications}, year={2007} }
 @inproceedings{a gain-scheduling control approach to stabilization of lti systems with generalized saturation input_2006, url={https://publons.com/wos-op/publon/13939815/}, DOI={10.1109/ACC.2006.1657433}, abstractNote={In this paper, we will present a gain-scheduling control method for designing output feedback laws that stabilize a linear system subject to generalized saturation input, which is composed of N(N ges 1) bends piecewise linear concave/convex functions. By exploiting the connection between one bend piecewise linear function and standard saturation function and expressing saturation on convex hull of linear functions, the design of output feedback control law will be solved as an optimization problem with LMI constraints. This approach will then be extended to multiple bends piecewise linear functions, by treating the multiple bends piecewise linear function as the convex combination of several one bend piecewise linear functions. This work will broaden the scope of gain-scheduling control approach to larger class of practical engineering problems}, booktitle={American Control Conference}, year={2006} }
 @inproceedings{zheng_wu_2006, title={A gain-scheduling control approach to stabilization of LTI systems with generalized saturation input}, volume={2006}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-34047236743&partnerID=MN8TOARS}, booktitle={Proceedings of the American Control Conference}, author={Zheng, Q. and Wu, F.}, year={2006}, pages={4528–4533} }
 @inproceedings{gain-scheduled control of lft systems through duality and conjugate lyapunov functions_2006, url={https://publons.com/wos-op/publon/13939816/}, DOI={10.1109/ACC.2006.1657163}, abstractNote={In this paper, we study stability and performance properties of linear fractional transformation (LFT) parameter-dependent system using duality theory and tools from convex analysis. A pair of conjugate functions, the convex hull and the maximum of a family of quadratic Lyapunov functions, are used for analysis and synthesis LFT systems. A sufficient synthesis condition for gain-scheduled output feedback control problem is formulated as a set of linear matrix inequalities (LMI) with linear search over scalar variables. Finally, an example is used to demonstrate the advantages of the proposed approach.}, booktitle={American Control Conference}, year={2006} }
 @inproceedings{dong_wu_2006, title={Gain-scheduled control of LFT systems through duality and conjugate lyapunov functions}, volume={2006}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-34047235176&partnerID=MN8TOARS}, booktitle={Proceedings of the American Control Conference}, author={Dong, K. and Wu, F.}, year={2006}, pages={2921–2926} }
 @article{wu_dong_2006, title={Gain-scheduling control of LFT systems using parameter-dependent Lyapunov functions}, volume={42}, ISSN={["1873-2836"]}, url={https://publons.com/wos-op/publon/13939837/}, DOI={10.1016/j.automatica.2005.08.020}, abstractNote={In this paper, we propose a new control design approach for linear fractional transformation (LFT) systems using parameter-dependent Lyapunov functions. Instead of assuming parameter dependency in LFT fashion, we consider general parameter-dependent controllers to achieve better closed-loop performance. Using full-block multipliers, new LPV synthesis conditions have been derived in terms of finite number of linear matrix inequalities (LMIs). Both continuous- and discrete-time cases are discussed. A ship steering example has been used to demonstrate advantages and benefits of the proposed approach.}, number={1}, journal={AUTOMATICA}, author={Wu, F and Dong, K}, year={2006}, month={Jan}, pages={39–50} }
 @inproceedings{dong_wu_2006, title={Online switching control designs of LFT systems}, url={https://publons.com/wos-op/publon/12917142/}, DOI={10.1109/CDC.2006.376986}, abstractNote={In this paper, we propose a switching control approach for linear fractional transformation (LFT) parameter dependent systems using multiple Lyapunov functions with online optimization techniques to improve performance and enhance control design flexibility. A gain-scheduled controller working for the next switching interval is designed at each switching time. A bumpless transfer compensator is also designed to minimize the jump of output caused by switching. The control synthesis conditions for both online switching controller and bumpless transfer compensator are formulated as linear matrix inequalities (LMI). Finally, the online switching control scheme is applied to an uninhabited combat aerospace vehicle (UCAV) problem}, booktitle={IEEE Conference on Decision and Control}, author={Dong, K. and Wu, F.}, year={2006}, pages={4075–4080} }
 @inproceedings{output regulation for parameter-dependent lft systems_2006, url={https://publons.com/wos-op/publon/13939817/}, DOI={10.1109/ACC.2006.1657651}, abstractNote={In this paper, we consider an important problem, output regulation, for linear fractional transformation (LFT) systems. This problem is mainly concerned about perfect tracking and/or rejection of persistent signals produced by some external generator. We present a necessary and sufficient solvability condition in terms of two linear matrix equations. Our result is consistent with the existing output regulation conditions for LTI and nonlinear systems. Based on the analysis condition, the synthesis problems, of both full information and output feedback controllers was solved. An example was used to demonstrate the proposed output regulation approach.}, booktitle={American Control Conference}, year={2006} }
 @article{lu_wu_2006, title={Probabilistic robust linear parameter-varying control of an F-16 aircraft}, volume={29}, ISSN={["1533-3884"]}, url={https://publons.com/wos-op/publon/13939818/}, DOI={10.2514/1.22495}, abstractNote={O PERATIONAL capability at high angles of attack, especially near and at post stall regimes, is critical for next generation fighter aircrafts and uninhabited aerial vehicles [1]. However, significantly large levels of modeling uncertainty are inevitably encountered inflight control design for those regimes. The sources of uncertainty include variations in mass, inertia, and center of gravity positions, uncertainty in the aerodynamic data, etc. [2]. The maneuverability at high angles of attack poses a challenging control problem that requires guaranteeing both robust stability and robust performance in the presence of large parameter variations. Traditional robust control techniques, like H1 and -synthesis, have been proven to be capable of producing robust uncertaintytolerant controllers for next generation aircrafts [2,3]. However, those techniques focus on deterministic worst-case robust analysis and synthesis, which often lead to overly conservative stability bound estimate and high control effort. Moreover, a large number of conventional deterministic problems in robustness analysis and synthesis are shown to be NP-hard. To reduce conservatism and computational complexity, one approach is to shift the meaning of robustness from its usual deterministic sense to a probabilistic one [4]. In contrast to traditional robust control techniques, only a probabilistic solution is given, and a certain risk-level should be accepted. However, such a system may be viewed as being practically robust from an engineering point of view. Algorithms derived in the probabilistic context are based on uncertainty randomization and usually called randomized algorithms, which may be divided into two families: methods based on statistical learning theory [5], and sequential methods based on subgradient iterations [6–8] or ellipsoid iterations [9,10]. The former can deal with nonconvex synthesis problems; however, it resorts to randomized search over the controller parameters to find a candidate solution. On the other hand, the sequential methods are formulated based on convex problems, thus avoiding the controller randomization issue [4]. The probabilistic robust control approach is still in the stage of algorithm development and improvement, and has not been explored in depth for flight control. The number of implementation of probabilistic techniques is therefore rather restricted. In the late 90s, Marrison and Stengel designed a linear quadratic regulator to control the nonlinear longitudinal dynamics of a hypersonic aircraft [11]. Recently, Wang and Stengel designed a robust flight control system for the high-incidence research model problem by combining stochastic robustness with nonlinear dynamic inversion [12]. Their work was based on statistical learning theory, and controllers were searched by using generic algorithms to minimize stochastic robustness cost functions. In our earlier paper, we applied an ellipsoid algorithm to design anH1 controller for a linearized F-16 longitudinal model [13]. Good stability and performance robustness have been achieved at the chosen flight condition. The motivation for this research is twofold. First, the probabilistic control design method for linear time-invariant plants in [13] is generalized to linear parameter-varying (LPV) systems. This generalization is very important because of the relevance of LPV systems to nonlinear systems. TheLPVcontrol synthesis condition is known to be formulated as a convex problemwith a set of parameterdependent linear matrix inequalities (LMIs) [14–16]. Second, the current state of the art does not allow accurate aerodynamicmodeling in the high angle of attack region. Because of its random nature, uncertainty in the aerodynamic data can be characterized using a statistical model, which can be handled effectively by the promising probabilistic robust control approach. Note that the study in this note focuses on the robustness issue with respect to the aerodynamic uncertainty at high angles of attack, and the results would be easily generalized to other parametric uncertainties, such as variations in mass and inertial properties. Because of the convex formulation of LPV control synthesis, the sequential method is more suitable for dealing with uncertainties and designing probabilistic robust LPV controllers. An ellipsoid algorithm with a stopping rule proposed by Oishi [10] is used to determine feasible solutions to LMI synthesis conditions. The paper is organized as follows. In Sec. II, the ellipsoid algorithm is presented, which either gives a probabilistic solution with high confidence or detects that there is no deterministic solution in an approximated sense. Section III first provides a brief overview of robust control problem of an uncertain LPV system, and then discusses the computational issues when the algorithm is applied to the robust LPV control problem. In Sec. IV, a robust LPV controller is designed for an F-16 aircraft with large aerodynamic uncertainty, and the robust performance is tested through nonlinear simulations. Finally, the paper concludes with a summary in Sec. V.}, number={6}, journal={JOURNAL OF GUIDANCE CONTROL AND DYNAMICS}, author={Lu, Bei and Wu, Fen}, year={2006}, pages={1454–1460} }
 @article{lu_wu_kim_2006, title={Switching LPV control of an F-16 aircraft via controller state reset}, volume={14}, url={https://publons.com/wos-op/publon/13663937/}, DOI={10.1109/TCST.2005.863656}, abstractNote={In flight control, the design objective and the aircraft dynamics may be different in low and high angle of attack regions. This paper presents a systematic switching LPV control design method to determine if it is practical to use for flight control designs over a wide angle of attack region. The approach is based on multiple parameter-dependent Lyapunov functions. A family of LPV controllers are designed, and each of them is suitable for a specific parameter subspace. The state of the controller is reset to guarantee the stability requirement of the Lyapunov function when the switching event occurs. Two parameter-dependent switching logics, hysteresis switching and switching with average dwell time, are examined. The proposed switching LPV control scheme is applied to an F-16 aircraft model with different design objectives and aircraft dynamics in low and high angle of attack regions. The nonlinear simulation results using both switching logics are compared.}, number={2}, journal={IEEE Transactions on Control Systems Technology}, author={Lu, B. and Wu, F. and Kim, S.W.}, year={2006}, pages={267–277} }
 @inproceedings{gibson_buckner_choi_wu_2005, title={Confidence interval networks for bounding model uncertainty: Experimental evaluations on an active magnetic bearing system}, volume={2005}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-33744973555&partnerID=MN8TOARS}, DOI={10.1109/SMCIA.2005.1466966}, abstractNote={Robust control techniques require bounds on model uncertainties to provide closed-loop stability in the face of unmodeled dynamics and parameter variations. To guarantee stability, it is customary to choose uncertainty bounds (weighting functions) that are somewhat arbitrary and overly conservative, usually at the expense of controller performance. In this paper, an intelligent approach for estimating additive uncertainty bounds associated with linear, time invariant models is presented. Confidence interval networks (CINs) provide a non-parametric method for identifying bounds on modeling error for use as uncertainty weighting functions. The CIN is a "soft-computing" variation of the model error modeling (MEM) technique, a parametric approach based on recursive least squares. By combining these methods with the "hard computing" aspects of H/sub /spl infin// control, the size of the uncertainty model is optimized, thus improving performance while maintaining robust stability. A multivariable, flexible-rotor active magnetic bearing system is used to experimentally demonstrate the benefits of intelligent uncertainty identification.}, booktitle={SMCia/05 - Proceedings of the 2005 IEEE Mid-Summer Workshop on Soft Computing in Industrial Applications}, author={Gibson, N.S. and Buckner, G.D. and Choi, H. and Wu, F.}, year={2005}, pages={160–165} }
 @article{wu, title={Convexified robust control approach and its application to actuator saturation control}, DOI={10.1109/cca.2004.1387534}, abstractNote={We study a convexified robust control problem and its application to actuator saturation control. It has been shown that the robust control synthesis condition becomes convex under a special controller structure. Moreover, for this class of robust control problem, the gain-scheduling control based on scaled small-gain condition does not provide any performance improvement over convexified robust controllers. Based on this observation, a convexified robust control synthesis framework with stringent performance and computational efficacy is proposed. The convexified robust control approach is very useful to develop saturation control schemes in convex form.}, journal={Proceedings of the 2004 IEEE International Conference on Control Applications, 2004.}, publisher={IEEE}, author={Wu, Fen} }
 @article{wu_yildizoglu_2005, title={Distributed parameter-dependent modeling and control of flexible structures}, volume={127}, ISSN={["1528-9028"]}, url={https://publons.com/wos-op/publon/13939814/}, DOI={10.1115/1.1898240}, abstractNote={In this paper, distributed parameter-dependent modeling and control approaches are proposed for flexible structures. The distributed model is motivated from distributed control design, which is advantageous in reducing control implementation cost and increasing control system reliability. This modeling approach mainly relies on a central finite difference scheme to capture the distributed nature of the flexible system. Based on the proposed distributed model, a sufficient synthesis condition for the design of a distributed output-feedback controller is presented using induced L2 norm as the performance criterion. The controller synthesis condition is formulated as linear matrix inequalities, which are convex optimization problems and can be solved efficiently using interior-point algorithms. The distributed controller inherits the same structure as the plant, which results in a localized control architecture and a simple implementation scheme. These modeling and control approaches are demonstrated on a non-uniform cantilever beam problem through simulation studies.}, number={2}, journal={JOURNAL OF DYNAMIC SYSTEMS MEASUREMENT AND CONTROL-TRANSACTIONS OF THE ASME}, author={Wu, F and Yildizoglu, SE}, year={2005}, month={Jun}, pages={230–239} }
 @inproceedings{wu_zheng_lin_2005, title={Disturbance attenuation for linear systems subject to actuator saturation using output feedback}, volume={2005}, url={https://publons.com/wos-op/publon/13939768/}, DOI={10.1109/CDC.2005.1583379}, abstractNote={In this paper, we study the problem of disturbance attenuation by output feedback for linear systems subject to actuator saturation. A nonlinear feedback control law, expressed in the form of a quasi-LPV system with state dependent scheduling parameter, is constructed that leads to the attenuation of the effect of the disturbance on the output of the system. The level of disturbance attenuation is measured in terms of the restricted L <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> gain and the restricted L <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> to L <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</inf> gain over a set of bounded disturbances.}, booktitle={IEEE Conference on Decision and Control}, author={Wu, F. and Zheng, Q. and Lin, Z.}, year={2005}, pages={7546–7551} }
 @inproceedings{gain-scheduling control of lft systems using parameter-dependent lyapunov functions_2005, url={https://publons.com/wos-op/publon/13939813/}, DOI={10.1109/ACC.2005.1470020}, abstractNote={In this paper, we propose a new control design approach for linear fractional transformation (LFT) systems using parameter-dependent Lyapunov functions. Instead of designing a controller with LFT parameter dependency, we consider general parameter-dependent controllers to achieve better closed-loop performance. Using full-block multipliers, new LPV synthesis conditions have been derived in terms of finite number of LMIs. A ship steering example has been used to demonstrate advantages and benefits of the proposed approach.}, booktitle={American Control Conference}, year={2005} }
 @article{wu_yang_packard_becker, title={Induced L/sub 2/-norm control for LPV system with bounded parameter variation rates}, DOI={10.1109/acc.1995.531398}, abstractNote={A linear, finite-dimensional plant, with state-space parameter dependence, is controlled using a parameter-dependent controller. The parameters whose values are in a compact set, are known in real time. Their rates of variation are bounded and known in real time also. The goal of control is to stabilize the parameter-dependent closed-loop system, and provide disturbance/error attenuation as measured in induced L/sub 2/ norm. The authors' approach uses a parameter-dependent Lyapunov function, and solves the control synthesis problem by reformulating the existence conditions into an semi-infinite dimensional convex optimization. The authors propose finite dimensional approximations to get sufficient conditions for successful controller design.}, journal={Proceedings of 1995 American Control Conference - ACC'95}, publisher={American Autom Control Council}, author={Wu, Fen and Yang, Xin Hua and Packard, A. and Becker, G.} }
 @article{lu_wu_kim_2005, title={Linear parameter-varying antiwindup compensation for enhanced flight control performance}, volume={28}, ISSN={["1533-3884"]}, url={https://publons.com/wos-op/publon/13663943/}, DOI={10.2514/1.4952}, abstractNote={Actuator saturation is one of the major issues of flight control in the high angle-of-attack region. This paper presents a saturation control scheme for linear parameter varyjing (LPV) systems from an antiwindup control perspective. The proposed control approach is advantageous from the implementation standpoint because it can be thought of as an augmented control algorithm to the existing control system. Moreover, the synthesis condition for an antiwindup compensator is formulated as a linear matrix inequality (LMI) optimization problem and can be solved efficiently. We have applied te LPV antiwindup controller to an F-16 longitudinal autopilot control system design and compared it with the thrust vectoring control scheme. The nonlinear simulations show that an LPV antiwindup controller improves flight quality and offers advantages over thrust vectoring in a high angle-of-attack region.}, number={3}, journal={JOURNAL OF GUIDANCE CONTROL AND DYNAMICS}, author={Lu, B and Wu, F and Kim, SW}, year={2005}, pages={494–505} }
 @inproceedings{zheng_wu_2005, title={Output feedback control of saturated linear systems using parameter-dependent lyapunov functions}, volume={74 DSC}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-33645655983&partnerID=MN8TOARS}, DOI={10.1115/IMECE2005-81152}, abstractNote={In this paper, we present an output feedback control approach for discrete-time linear systems subject to actuator saturations using parameter-dependent Lyapunov functions. The saturation level indicator serves as a scheduling parameter. The resulting nonlinear controller is expressed in a quasi-LPV form and the controller synthesis problem is formulated and solved as an optimization problem with LMI constraints. Our approach is less conservative than a single quadratic Lyapunov function method. The proposed output feedback control law asymptotically stabilizes the open loop system with a larger domain of attraction and achieves better performance under energy and magnitude bounded disturbances.}, number={1 PART A}, booktitle={American Society of Mechanical Engineers, Dynamic Systems and Control Division (Publication) DSC}, author={Zheng, Q. and Wu, F.}, year={2005}, pages={49–58} }
 @inproceedings{wu_lin_zheng_2005, title={Output feedback stabilization of linear systems with actuator saturation}, volume={5}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-23944519137&partnerID=MN8TOARS}, booktitle={Proceedings of the American Control Conference}, author={Wu, F. and Lin, Z. and Zheng, Q.}, year={2005}, pages={3385–3390} }
 @inproceedings{richards_chow_wu_2005, title={Performance characterization of IP network-based control methodologies for DC motor applications - Part II}, volume={2005}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-33749660799&partnerID=MN8TOARS}, DOI={10.1109/IECON.2005.1569283}, abstractNote={For part I see ibid., p.Z002490-Z002495. Using a communication network, such as an IP network, in the control loop is increasingly becoming the norm. This process of network-based control (NBC) has a potentially profound impact in areas such as: teleoperation, healthcare, military applications, and manufacturing. However, limitations arise as the communication network introduces delay that often degrades or destabilizes the control system. Four methods have been introduced in Part I of these two companion papers that alleviate the IP network delays to provide stable real-time control. Part II of these papers defines a performance measure for a case study on a DC motor with a networked proportional-integral (PI) speed controller with various network delays and noise levels. Simulation results show that NBC combined with these techniques can successfully maintain system stability. This allows for control of real-time applications.}, booktitle={IECON Proceedings (Industrial Electronics Conference)}, author={Richards, T. and Chow, M.-Y. and Wu, F.}, year={2005}, pages={2411–2416} }
 @inproceedings{wu_gopalarathnam_kim_2005, title={Post-stall aerodynamic modeling and gain-scheduled control design}, volume={4}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-29744459020&partnerID=MN8TOARS}, DOI={10.2514/6.2005-6169}, abstractNote={A multidisciplinary research e.ort that combines aerodynamic modeling and gain-scheduled control design for aircraft flight at post-stall conditions is described. The aerodynamic modeling uses a decambering approach for rapid prediction of post-stall aerodynamic characteristics of multiple-wing con.gurations using known section data. The approach is successful in bringing to light multiple solutions at post-stall angles of attack right during the iteration process. The predictions agree fairly well with experimental results from wind tunnel tests. The control research was focused on actuator saturation and .ight transition between low and high angles of attack regions for near- and post-stall aircraft using advanced LPV control techniques. The new control approaches maintain adequate control capability to handle high angle of attack aircraft control with stability and performance guarantee.}, booktitle={Collection of Technical Papers - AIAA Guidance, Navigation, and Control Conference}, author={Wu, F. and Gopalarathnam, A. and Kim, S.}, year={2005}, pages={3248–3262} }
 @inproceedings{lu_wu_2005, title={Probabilistic robust control design for an F-16 aircraft}, volume={3}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-29744449760&partnerID=MN8TOARS}, DOI={10.2514/6.2005-6080}, abstractNote={The uncertainty in the aerodynamic modeling at high angle of attack presents challenges to control designers. In this paper, we investigates the applicability of an ellipsoid-based randomized algorithm to design a probabilistic robust H1 controller for a tactical aircraft. With a stopping rule, this algorithm can always stop to either give a probabilistic solution or detect no solution in an approximation sense if all parameters are specifled appropriately. We have applied this algorithm to design a dynamic output feedback controller for an F-16 longitudinal autopilot system, and the simulation result shows that the performance of the closed-loop system is improved compared with that controlled by the nominal controller.}, booktitle={Collection of Technical Papers - AIAA Guidance, Navigation, and Control Conference}, author={Lu, B. and Wu, F.}, year={2005}, pages={2387–2395} }
 @inproceedings{wu_dong_2005, title={Robust and gain-scheduled H-2 synthesis for LFT parameter-dependent systems}, url={https://publons.com/wos-op/publon/13939766/}, DOI={10.1109/ACC.2005.1470402}, abstractNote={In this paper, we solve the robust H/sub 2/ synthesis problem for linear fractional transformation (LFF) systems affected by white noise disturbances. Using an intermediate matrix, we develop robust and gain-scheduling control synthesis conditions in linear matrix inequality (LMI) forms. The newly proposed robust H/sub 2/ control approach has been applied to several examples, and demonstrated less conservative performance than other control designs based on robust H/sub /spl infin// method.}, booktitle={American Control Conference}, publisher={IEEE}, author={Wu, Fen and Dong, Ke}, year={2005} }
 @article{wu_prajna_2005, title={SOS-based solution approach to polynomial LPV system analysis and synthesis problems}, volume={78}, DOI={10.1080/002071270500114865}, number={8}, journal={International Journal of Control}, author={Wu, Fen and Prajna, S.}, year={2005}, pages={600–611} }
 @article{wu_prajna_2005, title={SOS-based solution approach to polynomial LPV system analysis and synthesis problems}, volume={78}, ISSN={["1366-5820"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-27744447853&partnerID=MN8TOARS}, DOI={10.1080/00207170500114865}, abstractNote={Abstract Based on sum-of-squares (SOS) decomposition, we propose a new solution approach for polynomial linear parameter-varying (LPV) system analysis and control synthesis problems. Instead of solving matrix variables over positive cone, the SOS approach tries to find a suitable decomposition to verify the positiveness of given polynomials. The complexity of the SOS-based numerical method is polynomial of the problem size, and is computationally attractive. This approach also leads to more accurate solutions to LPV systems than most existing relaxation methods. Several examples have been used to demonstrate benefits of the SOS-based solution approach.}, number={8}, journal={INTERNATIONAL JOURNAL OF CONTROL}, author={Wu, F and Prajna, S}, year={2005}, month={May}, pages={600–611} }
 @inproceedings{wu_prajna_2004, title={A new solution approach to polynomial LPV system analysis and synthesis}, url={https://publons.com/wos-op/publon/13939848/}, DOI={10.23919/ACC.2004.1386764}, abstractNote={Based on sum-of-squares (SOS) decomposition, we propose a new solution approach for polynomial LPV system analysis and control synthesis problems. Instead of solving matrix variables over a positive definite cone, the SOS approach tries to find a suitable decomposition to verify the positiveness of given polynomials. The complexity of the SOS-based numerical method is polynomial of the problem size. This approach also leads to more accurate solutions to LPV systems than most existing relaxation methods. Several examples have been used to demonstrate benefits of the SOS-based solution approach.}, booktitle={American Control Conference}, publisher={IEEE}, author={Wu, Fen and Prajna, S.}, year={2004} }
 @article{wu_lu_2004, title={Anti-windup control design for exponentially unstable LTI systems with actuator saturation}, volume={52}, ISSN={["1872-7956"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-2642584795&partnerID=MN8TOARS}, DOI={10.1016/j.sysconle.2004.02.007}, abstractNote={In this paper, a new saturation control technique in the framework of anti-windup compensation is developed for exponentially unstable linear time-invariant systems subject to input nonlinearities. The proposed control algorithm guarantees regional stability in the existence of input saturation, and provides less conservative performance than most existing anti-windup schemes. Moreover, an explicit form of anti-windup controller with its order no more than the order of the plant is derived. An inverted pendulum example is used to demonstrate the advantages of the newly proposed anti-windup control technique.}, number={3-4}, journal={SYSTEMS & CONTROL LETTERS}, author={Wu, F and Lu, B}, year={2004}, month={Jul}, pages={305–322} }
 @inproceedings{lu_wu_2004, title={Control design of switched LPV systems using multiple parameter-dependent Lyapunov functions}, url={https://publons.com/wos-op/publon/13939772/}, DOI={10.23919/ACC.2004.1384517}, abstractNote={For a linear parameter-varying (LPV) plant with a large parameter variation region, it is often conservative to design a single LPV controller over the entire parameter space. This paper studies the control design of switched LPV systems using multiple parameter-dependent Lyapunov functions to improve performance and enhance design flexibility. Two autonomous switching logics, hysteresis switching and switching with average dwell time, are discussed. The control synthesis conditions for both switching logics are formulated, which are generally non-convex but can be convexified under certain conditions. The proposed switched LPV control schemes are applied to a magnetic bearing problem to demonstrate its advantages over existing LPV control approach.}, booktitle={American Control Conference}, author={Lu, Bei and Wu, Fen}, year={2004} }
 @inproceedings{wu_2004, title={Convexified robust control approach and its application to actuator saturation control}, volume={2}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-17744392063&partnerID=MN8TOARS}, booktitle={Proceedings of the IEEE International Conference on Control Applications}, author={Wu, F.}, year={2004}, pages={1189–1194} }
 @article{wu_soto_2004, title={Extended anti-windup control schemes for LTI and LFT systems with actuator saturations}, volume={14}, ISSN={1049-8923 1099-1239}, url={http://dx.doi.org/10.1002/rnc.943}, DOI={10.1002/rnc.943}, abstractNote={Abstract In this paper, the popular anti‐windup control scheme will be extended in two important directions. The first scenario is the control of LTI systems subject to actuators with both magnitude and rate constraints. The second case of extension is LFT systems with input saturations. Based on the extended Circle criterion, we will develop convex anti‐windup control synthesis conditions in the form of LMIs for each class of systems. The explicit anti‐windup controller formula are also provided to facilitate compensator construction. The effectiveness of proposed anti‐windup control schemes will be demonstrated using a flight control example. Copyright © 2004 John Wiley & Sons, Ltd.}, number={15}, journal={International Journal of Robust and Nonlinear Control}, publisher={Wiley}, author={Wu, Fen and Soto, Marco}, year={2004}, month={Oct}, pages={1255–1281} }
 @inproceedings{prajna_papachristodoulou_wu_2004, title={Nonlinear control synthesis by sum of squares optimization: A Lyapunov-based approach}, volume={1}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-16244409837&partnerID=MN8TOARS}, booktitle={2004 5th Asian Control Conference}, author={Prajna, S. and Papachristodoulou, A. and Wu, F.}, year={2004}, pages={157–165} }
 @article{wu_bei_2004, title={On convexified robust control synthesis}, volume={40}, ISSN={["1873-2836"]}, url={https://publons.com/wos-op/publon/13939773/}, DOI={10.1016/j.automatica.2004.01.010}, abstractNote={In this paper, we study a convexified robust control problem and its relation to gain-scheduling control. It reveals that the robust control synthesis condition becomes convex under a special plant structure. Moreover, for this class of robust control problems, the gain-scheduling control approach from scaled small-gain theorem will not provide any performance improvement over convexified robust controllers. Based on this observation, a convexified robust control synthesis framework with stringent performance and computational efficacy is proposed.}, number={6}, journal={AUTOMATICA}, author={Wu, F and Bei, L}, year={2004}, month={Jun}, pages={1003–1010} }
 @article{lu_wu_2004, title={Switching LPV control designs using multiple parameter-dependent Lyapunov functions}, volume={40}, ISSN={0005-1098}, url={http://dx.doi.org/10.1016/j.automatica.2004.06.011}, DOI={10.1016/j.automatica.2004.06.011}, abstractNote={In this paper we study the switching control of linear parameter-varying (LPV) systems using multiple parameter-dependent Lyapunov functions to improve performance and enhance control design flexibility. A family of LPV controllers is designed, each suitable for a specific parameter subregion. They are switched so that the closed-loop system remains stable and its performance is optimized. Two switching logics, hysteresis switching and switching with average dwell time, are examined. The control synthesis conditions for both switching logics are formulated as matrix optimization problems, which are generally non-convex but can be convexified under some simplifying assumptions. The hysteresis switching LPV control scheme is then applied to an active magnetic bearing problem.}, number={11}, journal={Automatica}, publisher={Elsevier BV}, author={Lu, Bei and Wu, Fen}, year={2004}, month={Nov}, pages={1973–1980} }
 @inproceedings{lu_wu_kim_2004, title={Switching LPV control for high performance tactical aircraft}, volume={2}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-19644374551&partnerID=MN8TOARS}, booktitle={Collection of Technical Papers - AIAA Guidance, Navigation, and Control Conference}, author={Lu, B. and Wu, F. and Kim, S.W.}, year={2004}, pages={1169–1179} }
 @inproceedings{anti-windup control for unstable lti systems_2003, url={https://publons.com/wos-op/publon/13939769/}, DOI={10.1109/ACC.2003.1239755}, booktitle={American Control Conference}, year={2003} }
 @article{computationally efficient algorithm for frequency-weighted optimal h-infinity model reduction_2003, url={https://publons.com/wos-op/publon/13939771/}, journal={Asian Journal of Control}, year={2003} }
 @article{wu_jaramillo_2003, title={Computationally efficient algorithm for frequency-weighted optimal H<inf>∞</inf> model reduction}, volume={5}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-1442303325&partnerID=MN8TOARS}, DOI={10.1111/j.1934-6093.2003.tb00126.x}, abstractNote={ABSTRACT In this paper, a frequency‐weighted optimal H ∞ model reduction problem for linear time‐invariant (LTI) systems is considered. The objective of this class of model reduction problems is to minimize H ∞ norm of the frequency‐weighted truncation error between a given LTI system and its lower order approximation. A necessary and sufficient solvability condition is derived in terms of LMIs with one extra coupling rank constraint, which generally leads to a non‐convex feasibility problem. Moreover, it has been shown that the reduced‐order model is stable when both stable input and output weights are included, and its state‐space data are given explicitly by the solution of the feasibility problem. An efficient model reduction scheme based on cone complementarity algorithm (CCA) is proposed to solve the non‐convex conditions involving rank constraint.}, number={3}, journal={Asian Journal of Control}, author={Wu, Fen and Jaramillo, J.J.}, year={2003}, pages={341–349} }
 @article{wu_2003, title={Distributed control for interconnected linear parameter dependent systems}, volume={150}, ISSN={["1350-2379"]}, url={https://publons.com/wos-op/publon/13939849/}, DOI={10.1049/ip-cta:20030706}, abstractNote={Stability analysis and performance control problems for a class of interconnected parameter-dependent systems with linear fractional parameter dependency are considered. The time and spatially varying parameters are assumed measurable in real-time for controller use. The distributed controller inherits the spatial structure of the plant, which is implementable through parallel computation. The stability of the interconnected parameter-dependent systems is established using a distributed Lyapunov function. Moreover, the synthesis condition of distributed parameter-dependent control gain is formulated as a convex optimisation in the form of a linear matrix inequality. An explicit distributed controller formula is also provided by exploiting the connection between the continuous and the discrete interconnected system descriptions.}, number={5}, journal={IEE PROCEEDINGS-CONTROL THEORY AND APPLICATIONS}, author={Wu, F}, year={2003}, month={Sep}, pages={518–527} }
 @inproceedings{wu_soto_2003, title={Extended LTI Anti-Windup Control with Actuator Magnitude and Rate Saturations}, volume={3}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-1542348680&partnerID=MN8TOARS}, booktitle={Proceedings of the IEEE Conference on Decision and Control}, author={Wu, F. and Soto, M.}, year={2003}, pages={2786–2791} }
 @inproceedings{wu_soto_2003, title={Extended LTI anti-windup control with actuator magnitude and rate saturations}, volume={3}, url={https://publons.com/wos-op/publon/13939770/}, DOI={10.1109/CDC.2003.1273046}, abstractNote={In this paper, we study the saturation control of actuators with both magnitude and rate constraints using anti-windup control scheme. Based on extended circle criterion, we develop convex anti-windup control synthesis condition in the form of linear matrix inequalities (LMIs). The effectiveness of proposed anti-windup control scheme is demonstrated using a flight control example.}, booktitle={IEEE Conference on Decision and Control}, author={Wu, F. and Soto, M.}, year={2003}, pages={2786–2791} }
 @article{tan_grigoriadis_wu_2003, title={H(infinity) and L(2)-to-L(infinity) gain control of linear parameter-varying systems with parameter-varying delays}, volume={150}, ISSN={["1350-2379"]}, url={https://publons.com/wos-op/publon/13939782/}, DOI={10.1049/ip-cta:20030708}, abstractNote={The analysis and state-feedback synthesis problems for linear parameter-varying systems with parameter-varying time delays are addressed. It is assumed that the state-space data and the time delays are dependent on parameters that are measurable in real-time and vary in a compact set with bounded variation rates. We explore the stability, L2 gain performance and L2 - to- L∞ gain performance for these systems using parameter-dependent Lyapunov functionals. In addition, the design of parameter-dependent state-feedback controllers that guarantee stability and desired induced norm performance are examined. Both analysis and synthesis conditions are formulated in terms of linear matrix inequalities that can be solved via efficient interior-point algorithms.}, number={5}, journal={IEE PROCEEDINGS-CONTROL THEORY AND APPLICATIONS}, author={Tan, K and Grigoriadis, KM and Wu, F}, year={2003}, month={Sep}, pages={509–517} }
 @inproceedings{lu_wu_kim_2003, title={LPV antiwindup compensation for enhanced flight control performance}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85087595411&partnerID=MN8TOARS}, DOI={10.2514/6.2003-5495}, abstractNote={In this paper, we propose a saturation control scheme for linear parameter-varying (LPV) systems from an antiwindup control perspective. The proposed control approach is advantageous because it can be thought of as an augmented control algorithm from the existing control system. Moreover, the synthesis condition for an antiwindup compensator is formulated as a linear matrix inequality (LMI) optimization problem and can be solved efficiently. We have applied the LPV antiwindup controller to an F-16 longitudinal autopilot control system design to enhance aircraft safety and improve flight quality in a high angle of attack region.}, booktitle={AIAA Guidance, Navigation, and Control Conference and Exhibit}, author={Lu, B. and Wu, F. and Kim, S.}, year={2003} }
 @article{wu_2003, title={Robust quadratic performance for time-delayed uncertain linear systems}, volume={13}, ISSN={["1099-1239"]}, url={https://publons.com/wos-op/publon/13939845/}, DOI={10.1002/rnc.720}, abstractNote={Abstract In this paper, the analysis and control synthesis problems were studied for a general class of uncertain linear systems with variable time delay. It is assumed that the structured time‐varying parametric uncertainties enter the system state‐space description in a linear fractional fashion. The generic quadratic performance metric encompasses many types of dynamic system performance measure. In the context of delay‐independent stability, it was shown that the analysis and state‐feedback synthesis problems for such time‐delayed uncertain systems can be formulated equivalently as linear matrix inequality (LMI) optimization problems using the mechanism of full block multipliers. However, the solvability condition to output‐feedback problem was given as bilinear matrix inequality (BMI), which leads to a non‐convex optimization problem. A numerical example is provided to demonstrate the advantages of newly proposed control synthesis condition for time‐delayed uncertain systems over existing approaches. Copyright © 2002 John Wiley & Sons, Ltd.}, number={2}, journal={INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL}, author={Wu, F}, year={2003}, month={Feb}, pages={153–172} }
 @article{tan_grigoriadis_wu, title={State-feedback control of LPV sampled-data systems}, DOI={10.1109/cdc.1999.827966}, abstractNote={We address analysis and state-feedback synthesis problems for linear parameter-varying (LPV) sampled-data control systems. We assume that the state-space matrices of the plant and the sampling interval depend on parameters that are measurable in real-time and vary in a compact set with bounded variation rates. We explore criteria such as the stability, the energy-to-energy gain (induced L/sup 2/ norm) and the energy-to-peak gain (induced L/sup 2/-to-L/sup /spl infin// norm) of such sampled-data LPV systems using parameter-dependent Lyapunov functions. Based on these analysis results, the sampled-data state-feedback control synthesis problems are examined. Both analysis and synthesis conditions are formulated in terms of linear matrix inequalities (LMIs) that can be solved via efficient interior-point algorithms.}, journal={Proceedings of the 38th IEEE Conference on Decision and Control (Cat. No.99CH36304)}, publisher={IEEE}, author={Tan, K. and Grigoriadis, K.M. and Wu, Fen} }
 @inproceedings{wu_yildizoglu_2002, title={A distributed parameter dependent control design for a flexible beam problem}, volume={4}, url={https://publons.com/wos-op/publon/13939853/}, DOI={10.1109/ACC.2002.1025278}, abstractNote={This paper considers the analysis and synthesis of a distributed parameter dependent controller designed for a parameter-varying spatially interconnected system. It is assumed that the distributed linear parameter varying system depends on spatial varying parameters in linear fractional manner. The controller takes a similar structure as the system. Since the dependence is in linear fractional form, the. controller synthesis condition is characterized in terms of linear matrix inequalities, which are convex optimization problems for which efficient computation techniques are readily available. This distributed control approach is demonstrated on a flexible beam problem with nonuniform cross-section geometry.}, booktitle={American Control Conference}, author={Wu, F. and Yildizoglu, S.E.}, year={2002}, pages={3174–3179} }
 @inproceedings{wu_chandler_sparks_banda_2002, title={Autonomous munitions cooperative classification}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84896813639&partnerID=MN8TOARS}, booktitle={1st UAV Conference}, author={Wu, F. and Chandler, P.R. and Sparks, A. and Banda, S.}, year={2002} }
 @inproceedings{wu_2002, title={Delay-dependent induced ℒ<inf>2</inf> norm analysis and control for LPV systems with state delays}, volume={70}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0242551161&partnerID=MN8TOARS}, booktitle={American Society of Mechanical Engineers, Dynamic Systems and Control Division (Publication) DSC}, author={Wu, F.}, year={2002}, pages={597–602} }
 @inproceedings{wu_yildizoglu_2002, title={Distributed parameter dependent modeling and control of flexible structures}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-78249262311&partnerID=MN8TOARS}, DOI={10.1115/IMECE2002-39321}, abstractNote={In this paper, distributed parameter-dependent modeling and control approaches are proposed for flexible structures. This modeling approach mainly relies on a central finite difference scheme to capture the distributed nature of the flexible system. The distributed model is motivated from distributed control design, which is advantageous for reduced control implementation cost and control system reliability. The displacements at each discretized node are assumed measurable in real-time for controller use. Based on the proposed distributed model, sufficient conditions for analysis and synthesis of a distributed output-feedback controller are presented using the induced L2 norm as the performance criterion. The controller synthesis condition is characterized in terms of linear matrix inequalities (LMIs), which are convex optimization problems and can be solved efficiently using available software. The distributed controller inherits the same structure as the plant, which results in a localized control architecture and a simple implementation. The simulation results of a distributed controller is provided.}, booktitle={ASME International Mechanical Engineering Congress and Exposition, Proceedings}, author={Wu, F. and Yildizoglu, S.E.}, year={2002}, pages={127–135} }
 @article{goh_wu, title={Duality far robust ℋ/sub 2/ performance analysis}, DOI={10.1109/cdc.1996.574302}, abstractNote={In this paper, the criterion of Paganini (1995) is reformulated in terms of the existence of analytic scalings, and the dual optimization problem, with no duality gap, is derived. Our derivation of the dual formulation of the /spl Hscr//sub 2/ robustness problem is partly motivated by the work of Jonsson (1996) and Jonsson and Rantzner (1995). In contrast to Jonsson (1996), which addresses duality for robust performance analysis of the induced /spl Lscr//sub 2/ norm type, the work here considers an additional /spl Hscr//sub 2/ norm element. Similar to the primal criterion of Paganini (1995), the dual formulation is convex, and may be computed via either gridding or basis functions, using LMI algorithms.}, journal={Proceedings of 35th IEEE Conference on Decision and Control}, publisher={IEEE}, author={Goh, Keat-Choon and Wu, Fen} }
 @inproceedings{wu_2002, title={Improving robust control performance through on-line optimization}, volume={5}, url={https://publons.com/wos-op/publon/13939857/}, DOI={10.1109/ACC.2002.1024510}, abstractNote={In this paper, a new receding horizon control (RHC) scheme is proposed for a general class of uncertain linear systems with structured parametric uncertainties and linear input/output constraints. The cost function is defined over a moving finite horizon as the "worst-case" quadratic performance for all admissible uncertainties. The robust stability of proposed RHC scheme is guaranteed by imposing terminal penalty term using a control Lyapunov function (CLF), which is available through off-line synthesis procedure. Moreover, it is shown that the controlled performance of the proposed RHC scheme will be gradually improved as the upper bound of performance is monotonically decreasing as time goes by.}, booktitle={American Control Conference}, author={Wu, F.}, year={2002}, pages={3747–3752} }
 @inproceedings{wu_kim_2002, title={LPV controller interpolation for improved gain-scheduling control performance}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85085403511&partnerID=MN8TOARS}, DOI={10.2514/6.2002-4759}, abstractNote={In this paper, a new gain-scheduling control design approach is proposed by combining LPV (linear parameter-varying) control theory with interpolation techniques. The improvement of gain-scheduled controllers can be achieved from local synthesis of Lyapunov functions and continuous construction of a global Lyapunov function by interpolation. It has been shown that this combined LPV control design scheme is capable of improving closed-loop performance derived from local performance improvement. The gain of the LPV controller will also change continuously across parameter space. The advantages of the newly proposed LPV control is demonstrated through a detailed AMB controller design example.}, booktitle={AIAA Guidance, Navigation, and Control Conference and Exhibit}, author={Wu, F. and Kim, S.}, year={2002} }
 @inproceedings{wu_jaramillo_2002, title={Numerical algorithm for model reduction of polytopic uncertain linear systems}, volume={3}, url={https://publons.com/wos-op/publon/28294470/}, DOI={10.1109/ACC.2002.1023818}, abstractNote={In this paper we study a numerical algorithm for model reduction problem of polytopic uncertain linear systems. The polytopic system has its state-space data contained in a convex polytope, a situation that often arises. The problem we are trying to solve is to find a lower order polytopic uncertain linear system with a guaranteed induced /spl Lscr//sub 2/ norm error. A sufficient solvability condition was provided in terms of LMIs with one extra coupling rank constraint, which generally leads to a non-convex feasibility problem. To deal with this problem, a cone complementarity algorithm is developed, although only local convergence is guaranteed.}, booktitle={American Control Conference}, author={Wu, F. and Jaramillo, J.}, year={2002}, pages={1748–1752} }
 @article{tan_grigoriadis_wu_2002, title={Output-feedback control of LPV sampled-data systems}, volume={75}, ISSN={["0020-7179"]}, url={https://publons.com/wos-op/publon/13939844/}, DOI={10.1080/00207170110101775}, abstractNote={In this paper, we address the analysis and the output-feedback synthesis problems for linear parameter-varying (LPV) sampled-data control systems with potentially variable sampling rates. We assume that the state-space matrices of the plant and the sampling interval depend on parameters that are measurable in real-time and vary in a compact set with bounded variation rates. We explore criteria such as the stability, the energy-to-energy gain (induced L 2 norm) and the energy-to-peak gain (induced L 2 -to- L X norm) of such sampled-data LPV systems using parameter-dependent Lyapunov functions. Based on these analysis results, the corresponding sampled-data output-feedback control synthesis problems are examined. Both analysis and synthesis conditions are formulated in terms of linear matrix inequalities (LMIs) that can be solved via efficient interior-point algorithms.}, number={4}, journal={INTERNATIONAL JOURNAL OF CONTROL}, author={Tan, K and Grigoriadis, KM and Wu, F}, year={2002}, month={Mar}, pages={252–264} }
 @article{wu_packard_balas_2002, title={Systematic gain-scheduling control design: A missile autopilot example}, volume={4}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0036760092&partnerID=MN8TOARS}, DOI={10.1111/j.1934-6093.2002.tb00362.x}, abstractNote={ABSTRACT The missile autopilot was designed using linear parameter‐varying (LPV) control techniques. The controller provides exponential stability guarantee and performance bound in terms of induced L 2 norm for the missile plant. The systematic gain‐scheduling approach is motivated by the recent development in LPV control theory and provides a well founded and systematic procedure for high performance missile autopilot design problem.}, number={3}, journal={Asian Journal of Control}, author={Wu, F. and Packard, A. and Balas, G.}, year={2002}, pages={341–347} }
 @article{wu_2001, title={A generalized LPV system analysis and control synthesis framework}, volume={74}, ISSN={["1366-5820"]}, url={https://publons.com/wos-op/publon/13939784/}, DOI={10.1080/00207170010031495}, abstractNote={In this paper, a new approach for linear parameter-varying (LPV) system analysis and control synthesis is proposed. This unified framework combines two seemingly diversified methods in systematic gain-scheduling, LPV control theory, and extends the applicability of full block S -procedure to a general class of LPV systems. An example is used to demonstrate the proposed general LPV design approach, and to show its relative merits compared to other systematic gain-scheduling control techniques.}, number={7}, journal={INTERNATIONAL JOURNAL OF CONTROL}, author={Wu, F}, year={2001}, month={May}, pages={745–759} }
 @inproceedings{wu_2001, title={Delay-dependent induced ℒ<sub>2</sub> norm analysis and control for LPV systems with state delays}, volume={2}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-1542411721&partnerID=MN8TOARS}, booktitle={ASME International Mechanical Engineering Congress and Exposition, Proceedings}, author={Wu, F.}, year={2001}, pages={1549–1554} }
 @inproceedings{wu_2001, title={Distributed control for distributed linear parameter varying systems}, volume={3}, url={https://publons.com/wos-op/publon/28294471/}, DOI={10.1109/ACC.2001.946128}, abstractNote={Considers stability analysis and performance control for distributed systems with time and spatial varying parameters. The distributed linear parameter-varying (LPV) system depends on the parameters in linear fractional transformation form. The parameters are assumed measurable in real-time for controller use. By adopting and preserving the spatial structure of the plant, the controller will have localized architecture, which can be implemented using parallel processors. Using full block multipliers, the stability property of the distributed parameter varying systems is guaranteed, by a structured Lyapunov function. Moreover, it is shown that the distributed LPV control algorithm can be determined through convex optimization as linear matrix inequalities.}, booktitle={American Control Conference}, author={Wu, F.}, year={2001}, pages={2498–2502} }
 @inproceedings{wu_2001, title={Distributed control for distributed linear parameter varying systems}, volume={3}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0034846963&partnerID=MN8TOARS}, booktitle={Proceedings of the American Control Conference}, author={Wu, F.}, year={2001}, pages={2498–2502} }
 @article{wu_2001, title={LMI-based robust model predictive control and its application to an industrial CSTR problem}, volume={11}, ISSN={["0959-1524"]}, url={https://publons.com/wos-op/publon/13939836/}, DOI={10.1016/S0959-1524(00)00052-4}, abstractNote={In this paper, robust model predictive control (MPC) is studied for a class of uncertain linear systems with structured time-varying uncertainties. This general class of uncertain systems is useful for nonlinear plant modeling in many circumstances. The controller design is characterizing as an optimization problem of the “worst-case” objective function over infinite moving horizon, subject to input and output constraints. A sufficient state-feedback synthesis condition is provided in the form of linear matrix inequality (LMI) optimizations, and will be solved on-line. The stability of such a control scheme is determined by the feasibility of the optimization problem. To demonstrate its usefulness, this robust MPC technique is applied to an industrial continuous stirred tank reactor (CSTR) problem with explicit input and output constraints. Its relative merits to conventional MPC approaches are also discussed.}, number={6}, journal={JOURNAL OF PROCESS CONTROL}, author={Wu, F}, year={2001}, month={Dec}, pages={649–659} }
 @article{wu_grigoriadis_2001, title={LPV Systems with parameter-varying time delays: analysis and control}, volume={37}, ISSN={["1873-2836"]}, url={https://publons.com/wos-op/publon/13939788/}, DOI={10.1016/S0005-1098(00)00156-4}, abstractNote={In this paper, we address the analysis and state-feedback synthesis problems for linear parameter-varying (LPV) systems with parameter-varying time delays. It is assumed that the state-space data and the time delays are dependent on parameters that are measurable in real-time and vary in a compact set with bounded variation rates. We explore the stability and the induced L2 norm performance of these systems using parameter-dependent Lyapunov functionals. In addition, the design of parameter-dependent state-feedback controllers that guarantee desired L2 gain performance is examined. Both analysis and synthesis conditions are formulated in terms of linear matrix inequalities (LMIs) that can be solved via efficient interior-point algorithms.}, number={2}, journal={AUTOMATICA}, author={Wu, F and Grigoriadis, KM}, year={2001}, month={Feb}, pages={221–229} }
 @inproceedings{switching lpv control design for magnetic bearing systems_2001, url={https://publons.com/wos-op/publon/13939847/}, DOI={10.1109/CCA.2001.973835}, abstractNote={In this paper, a new LPV control design approach is proposed for magnetic bearing (AMB) systems. The motivation of gain-scheduled control for AMB is based on the fact that rotor dynamics have strong dependency on its rotating speed. However, previous study has shown that standard LPV control design was conservative due to large variations of rotor speed. The improvement of gain scheduled controller can be achieved from two aspects: introduce the bound for rotor variation rate into the control synthesis stage; design multiple LPV controllers over different operating ranges and provide a switching scheme for stability guarantee. These features will be demonstrated through a detailed AMB controller design example. This design procedure can also be extended to high-performance control of turbo-machinery problems.}, booktitle={IEEE International Conference on Control Applications (CCA)}, year={2001} }
 @inproceedings{wu_2001, title={Switching LPV control design for magnetic bearing systems}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0035692191&partnerID=MN8TOARS}, booktitle={IEEE Conference on Control Applications - Proceedings}, author={Wu, F.}, year={2001}, pages={41–46} }
 @inproceedings{an unified framework for lpv system analysis and control synthesis_2000, url={https://publons.com/wos-op/publon/13939781/}, DOI={10.1109/CDC.2001.914637}, abstractNote={A new approach for linear parameter varying (LPV) system analysis and control synthesis is proposed. This unified framework combined two seemingly diversified methods in systematic gain-scheduling: the LPV control theory, and an extended applicability of the full block S-procedure to general LPV systems.}, booktitle={IEEE Conference on Decision and Control}, year={2000} }
 @inproceedings{wu_2000, title={An unified framework for LPV system analysis and control synthesis}, volume={5}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0034444789&partnerID=MN8TOARS}, booktitle={Proceedings of the IEEE Conference on Decision and Control}, author={Wu, F.}, year={2000}, pages={4578–4583} }
 @article{wu_grigoriadis_packard_2000, title={Anti-windup controller design using linear parameter-varying control methods}, volume={73}, ISSN={["1366-5820"]}, url={https://publons.com/wos-op/publon/13939835/}, DOI={10.1080/002071700414211}, abstractNote={In this paper, we seek to provide a systematic anti-windup control synthesis approach for systems with actuator saturation within a linear parameter-varying (LPV) design framework. The closed-loop induced L2 gain control problem is considered. Different from conventional two-step anti-windup design approaches, the proposed scheme directly utilizes saturation indicator parameters to schedule accordingly the parameter-varying controller. Hence, the synthesis conditions are formulated in terms of linear matrix inequalities (LMIs) that can be solved very efficiently. The resulting gain-scheduled controller is non-linear in general and would lead to graceful performance degradation in the presence of actuator saturation non-linearities and linear performance recovery. An aircraft longitudinal dynamics control problem with two input saturation non-linearities is used to demonstrate the effectiveness of the proposed LPV anti-windup scheme.}, number={12}, journal={INTERNATIONAL JOURNAL OF CONTROL}, author={Wu, F and Grigoriadis, KM and Packard, A}, year={2000}, month={Aug}, pages={1104–1114} }
 @inproceedings{wu_2000, title={Fixed-structure robust CMC momentum manager design for the international space station}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84894492239&partnerID=MN8TOARS}, booktitle={AIAA Guidance, Navigation, and Control Conference and Exhibit}, author={Wu, F.}, year={2000} }
 @article{tan_grigoriadis_wu_2000, title={Output-feedback control of LPV sampled-data systems}, DOI={10.1109/acc.2000.879258}, abstractNote={In this paper, we address the output-feedback synthesis problems for linear parameter-varying (LPV) sampled-data control systems with potentially variable sampling rates. We assume that the state-space matrices of the plant and the sampling interval depend on parameters that are measurable in real-time and vary in a compact set with bounded variation rates. The sampled-data output-feedback control synthesis problems are examined for criteria such as the energy-to-energy gain (induced L/sup 2/ norm) and the energy-to-peak gain (induced L/sup 2/-to-L/sup /spl infin// norm) using parameter-dependent Lyapunov functions. The synthesis conditions are formulated in terms of linear matrix inequalities (LMI) that can be solved via efficient interior-point algorithms.}, journal={Proceedings of the 2000 American Control Conference. ACC (IEEE Cat. No.00CH36334)}, publisher={IEEE}, author={Tan, Kan and Grigoriadis, K.M. and Wu, Fen}, year={2000} }
 @inproceedings{tan_grigoriadis_wu_2000, title={Output-feedback control of LPV sampled-data systems}, volume={5}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0034540006&partnerID=MN8TOARS}, booktitle={Proceedings of the American Control Conference}, author={Tan, Kan and Grigoriadis, Karolos M. and Wu, Fen}, year={2000}, pages={3687–3691} }
 @article{wu_2000, title={Robust H/sub 2/ performance of uncertain linear systems with bounded parameter variations}, DOI={10.1109/acc.2000.878723}, abstractNote={In this paper, the robust H/sub 2/ performance analysis problem was addressed for uncertain linear systems with structured time-varying uncertainties, which have bounded variation rates specified by an integral quadratic constraint (IQC). The analysis condition for robust H/sub 2/ performance was first formulated as a matrix inequality with multipliers. Consequently, a computational scheme with mixed features of basis function parameterization and gridding has been proposed to convert the analysis condition into linear matrix inequalities (LMI), which can be solved efficiently.}, journal={Proceedings of the 2000 American Control Conference. ACC (IEEE Cat. No.00CH36334)}, publisher={IEEE}, author={Wu, Fen}, year={2000} }
 @inproceedings{wu_2000, title={Robust quadratic performance analysis and synthesis for time-delayed uncertain linear systems}, url={https://publons.com/wos-op/publon/13939780/}, DOI={10.1109/ACC.2000.878630}, abstractNote={In this paper, the analysis and control synthesis problems were studied for a class of uncertain linear systems with variable time delay. It is assumed that the structured time-varying parametric uncertainties enter the system description in a linear fractional fashion. The generic quadratic performance metric encompasses many types of dynamic system performance measure. Using the mechanism of full-block scaling, it was shown that the analysis and state-feedback synthesis conditions for such time-delayed uncertain systems can be formulated as linear matrix inequality (LMI) optimization problems, which in turn is solvable using efficient interior-point algorithms.}, booktitle={American Control Conference}, publisher={IEEE}, author={Wu, Fen}, year={2000} }
 @inproceedings{wu_grigoriadis_1999, title={LPV-based control of systems with amplitude and rate actuator saturation constraints}, volume={5}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0033284293&partnerID=MN8TOARS}, booktitle={Proceedings of the American Control Conference}, author={Wu, Fen and Grigoriadis, Karolos M.}, year={1999}, pages={3191–3195} }
 @inproceedings{tan_grigoriadis_wu_1999, title={State-feedback control of LPV sampled-data systems}, volume={4}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0033324978&partnerID=MN8TOARS}, booktitle={Proceedings of the IEEE Conference on Decision and Control}, author={Tan, Kan and Grigoriadis, Karolos M. and Wu, Fen}, year={1999}, pages={3894–3899} }
 @inproceedings{wu_grigoriadis_packard_1998, title={Anti-windup controller synthesis via linear parameter-varying control design methods}, volume={1}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0000605915&partnerID=MN8TOARS}, DOI={10.1109/ACC.1998.694688}, abstractNote={We provide a novel, systematic anti-windup control synthesis approach for systems with actuator saturation using a linear parameter-varying (LPV) design framework. The closed-loop induced L/sub 2/ gain control problem is considered. Different from previous two-step design schemes, the proposed approach directly utilizes saturation indicator parameters to schedule accordingly the parameter varying controller. Hence, the synthesis conditions are formulated in terms of linear matrix inequalities (LMIs) that can be solved very efficiently. The resulting gain-scheduled controller is nonlinear in general and would lead to graceful performance degradation in the presence of actuator saturation nonlinearities.}, booktitle={Proceedings of the American Control Conference}, author={Wu, F. and Grigoriadis, K.M. and Packard, A.}, year={1998}, pages={343–347} }
 @inproceedings{anti-windup controller synthesis via linear parameter-varying control design methods_1998, url={https://publons.com/wos-op/publon/55434495/}, booktitle={American Control Conference}, year={1998} }
 @article{goh_wu_walsh_1997, title={Control design for nonlinear process models using linear robust control methods: An FCCU example}, volume={21}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0000242468&partnerID=MN8TOARS}, DOI={10.1016/s0098-1354(97)87567-9}, number={SUPPL.1}, journal={Computers and Chemical Engineering}, author={Goh, K.-C. and Wu, F. and Walsh, S.}, year={1997} }
 @article{goh_wu_1997, title={Duality and basis functions for Robust ℋ<inf>2</inf>-performance analysis}, volume={33}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0031271442&partnerID=MN8TOARS}, DOI={10.1016/S0005-1098(97)00103-9}, number={11}, journal={Automatica}, author={Goh, K.-C. and Wu, F.}, year={1997}, pages={1949–1959} }
 @inproceedings{integrated h-infinity plant/controller design via linear matrix inequalities_1997, url={https://publons.com/wos-op/publon/13939874/}, booktitle={Proceedings of the IEEE Conference on Decision and Control}, year={1997} }
 @inproceedings{wu_1997, title={LMI-based robust model predictive control evaluated on an industrial CSTR model}, url={https://publons.com/wos-op/publon/13939858/}, DOI={10.1109/CCA.1997.627724}, abstractNote={In this paper, robust model predictive control (MPC) is studied for a general class of uncertain linear systems with structured time-varying uncertainties. The controller design is characterized as an optimization problem of the "worst-case" objective function over infinite moving horizon, subject to input and output constraints. A sufficient state-feedback synthesis condition is provided in the form of linear matrix inequality (LMI) optimization, and can be solved online. The stability of such a control scheme is determined by the feasibility of the optimization problem. To demonstrate its usefulness, this robust MPC technique is applied to an industrial continuous stirred tank reactor (CSTR) problem with explicit input and output constraints. Its relative merits to conventional MPC approaches are also discussed.}, booktitle={IEEE International Conference on Control Applications (CCA)}, publisher={IEEE}, author={Wu, Fen}, year={1997} }
 @inproceedings{wu_grigoriadis_1997, title={LPV systems with parameter-varying time delays}, url={https://publons.com/wos-op/publon/13939787/}, DOI={10.1109/CDC.1997.657569}, abstractNote={In this paper, we address the analysis and state-feedback synthesis problems for linear parameter-varying (LPV) systems with parameter-varying time delays. It is assumed that the state-space data and the time delays depend on parameters that are measurable in real-time and vary in a compact set with bounded variation rates. We explore the delay-dependent stability and the induced L/sub 2/ norm performance of these systems using parameter-dependent Lyapunov functionals. In addition, the state-feedback control synthesis problem is examined when a variable state delay or input delay is present. Both analysis and synthesis conditions are formulated in terms of linear matrix inequalities (LMIs) that can be solved via efficient interior-point algorithms.}, booktitle={Proceedings of the IEEE Conference on Decision and Control}, publisher={IEEE}, author={Wu, Fen and Grigoriadis, K.M.}, year={1997} }
 @article{wu_goh_walsh_1997, title={Robust H<inf>2</inf> performance analysis for a high-purity distillation column}, volume={21}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0043235609&partnerID=MN8TOARS}, DOI={10.1016/s0098-1354(97)87496-0}, number={SUPPL.1}, journal={Computers and Chemical Engineering}, author={Wu, F. and Goh, K.-C. and Walsh, S.}, year={1997} }
 @article{wu_1997, title={Solutions to frequency weighted optimal H/sub /spl infin// model reduction problem}, DOI={10.1109/acc.1997.609606}, abstractNote={A frequency weighted optimal H/sub /spl infin// model reduction problem for linear time-invariant (LTI) systems is considered. The objective of this class of model reduction problems is to minimize the H/sub /spl infin// norm of the frequency weighted truncation error between a given LTI system and its lower order approximation. A necessary and sufficient solvability condition is derived in terms of LMIs with one extra coupling rank constraint, which generally leads to a non-convex feasibility problem. Moreover, it has been shown that the reduced-order model is stable when both stable input and output weights are included.}, journal={Proceedings of the 1997 American Control Conference (Cat. No.97CH36041)}, publisher={IEEE}, author={Wu, Fen}, year={1997} }
 @inproceedings{duality for robust h-2 performance analysis_1996, url={https://publons.com/wos-op/publon/13939786/}, booktitle={Proceedings of the IEEE Conference on Decision and Control}, year={1996} }
 @article{wu_1996, title={Induced L(2) norm model reduction of polytopic uncertain linear systems}, volume={32}, url={https://publons.com/wos-op/publon/13939850/}, DOI={10.1016/0005-1098(96)00109-4}, number={10}, journal={Automatica}, author={Wu, F.}, year={1996}, pages={1417–1426} }
 @article{induced l(2)-norm control for lpv systems with bounded parameter variation rates_1996, url={https://publons.com/wos-op/publon/13939831/}, journal={International Journal of Robust and Nonlinear Control}, year={1996} }
 @article{wu_yang_packard_becker_1996, title={Induced L<inf>2</inf>-norm control for LPV systems with bounded parameter variation rates}, volume={6}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0030286689&partnerID=MN8TOARS}, DOI={10.1002/(sici)1099-1239(199611)6:9/10<983::aid-rnc263>3.0.co;2-c}, abstractNote={A linear, finite-dimensional plant, with state-space parameter dependence, is controlled using a parameter-dependent controller. The parameters whose values are in a compact set, are known in real time. Their rates of variation are bounded and known in real time also. The goal of control is to stabilize the parameter-dependent closed-loop system, and provide disturbance/error attenuation as measured in induced L2 norm. Our approach uses a bounding technique based on a parameter-dependent Lyapunov function, and then solves the control synthesis problem by reformulating the existence conditions into a semi-infinite dimensional convex optimization. We propose finite dimensional approximations to get sufficient conditions for successful controller design.}, number={9-10}, journal={International Journal of Robust and Nonlinear Control}, author={Wu, F. and Yang, X.H. and Packard, A. and Becker, G.}, year={1996}, pages={983–998} }
 @inproceedings{adaptive control of full information problem_1995, url={https://publons.com/wos-op/publon/13939852/}, DOI={10.1109/ACC.1995.532232}, abstractNote={Considers the adaptive output tracking problem in a state feedback configuration, with induced /spl Lscr//sub 2/ norm tracking objective. The authors' scheme does not guarantee the convergence of the estimated parameter, but the updated parameter vector /spl Theta/ is kept in the prescribed parameter set.}, booktitle={American Control Conference}, year={1995} }
 @inproceedings{yang_wu_packard_1995, title={Adaptive control of full information problem}, volume={5}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0029203664&partnerID=MN8TOARS}, booktitle={Proceedings of the American Control Conference}, author={Yang, Xin H. and Wu, Fen and Packard, Andy}, year={1995}, pages={3371–3372} }
 @phdthesis{wu_1995, title={Control of Linear Parameter Varying Systems}, url={https://www.proquest.com/docview/304157733?pq-origsite=gscholar&fromopenview=true&sourcetype=Dissertations%20&%20Theses}, DOI={10.13140/RG.2.2.10966.77127}, year={1995}, month={May} }
 @inproceedings{lpv control design for pitch-axis missile autopilots_1995, url={https://publons.com/wos-op/publon/13939832/}, DOI={10.1109/CDC.1995.478672}, abstractNote={The missile pitch-axis autopilot is designed using linear parameter-varying (LPV) control theory. The controller guarantees quadratic stability and bounded induced L/sub 2/-norm performance for the missile plant. Our approach is motivated by gain-scheduling methodology and provides a well founded and systematic procedure for high performance missile autopilot design.}, booktitle={Proceedings of the IEEE Conference on Decision and Control}, year={1995} }
 @inproceedings{wu_packard_balas_1995, title={LPV control design for pitch-axis missile autopilots}, volume={1}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0029514204&partnerID=MN8TOARS}, booktitle={Proceedings of the IEEE Conference on Decision and Control}, author={Wu, Fen and Packard, Andy and Balas, Gary}, year={1995}, pages={188–193} }
 @inproceedings{wu_packard_1995, title={LQG control design for LPV systems}, volume={6}, url={https://publons.com/wos-op/publon/13939846/}, DOI={10.1109/ACC.1995.532776}, abstractNote={A parameter-dependent output-feedback control problem is considered. The parameter is assumed to be measurable in real-time, so that the controller can depend causally on its value. The performance objective is the expectation of a quadratic integral cost function. In one case, a Kalman filter based on the time-varying parameter value is implemented in real-time, and a "worst-case" state-feedback controller is designed in place of the optimal regulator. This is necessary since the optimal regulator depends acausally on the system model, which is time-varying and not known a priori in this problem. Another one is to use the solutions of two Riccati inequalities directly. Our paper derives computable bounds on the guaranteed performance for both cases, and proposes an "one-step" scheme to reduce these bounds.}, booktitle={American Control Conference}, author={Wu, Fen and Packard, Andy}, year={1995}, pages={4440–4444} }
 @inproceedings{wu_packard_1995, title={LQG control design for LPV systems}, volume={6}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0029203308&partnerID=MN8TOARS}, booktitle={Proceedings of the American Control Conference}, author={Wu, Fen and Packard, Andy}, year={1995}, pages={4440–4444} }
 @inproceedings{optimal lqg performance of linear uncertain systems using state-feedback_1995, url={https://publons.com/wos-op/publon/13939873/}, DOI={10.1109/ACC.1995.532775}, abstractNote={In this paper the state-feedback control problem for linear uncertain systems is considered. The performance objective is the expectation of a quadratic integral cost function, and the "worst-case" state-feedback controllers is designed to accommodate uncertain parameter. We give computable bounds for such performance. For an LTI system, our bounds are the square of /spl Hscr//sub 2/ norm of the system actually.}, booktitle={American Control Conference}, year={1995} }
 @inproceedings{control of linear fractional transformations_1993, url={https://publons.com/wos-op/publon/13939785/}, DOI={10.1109/CDC.1993.325342}, abstractNote={Presents a solution to a parameter-dependent control synthesis problem with L/sub 2/ induced norm performance objectives. The design problem is reformulated into a convex optimization problem which can be solved with efficient new algorithms.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>}, booktitle={Proceedings of the IEEE Conference on Decision and Control}, year={1993} }
 @inproceedings{wu_packard_poolla_1993, title={RECURSIVE METHODS FOR MODEL VALIDATION}, url={https://publons.com/wos-op/publon/13939892/}, DOI={10.23919/ACC.1993.4792815}, abstractNote={We consder a class of time-domain model validation problems as treated in [6]. As shown in that paper, these model validation problems reduce to an associated extension problem. In this paper we offer recursive algorithms for the solution of these extension problems. These algorithms can be employed, via the reduction in [6], for on-line model validation.}, booktitle={Proceedings of the American Control Conference (ACC)}, author={Wu, Fen and Packard, Andy and Poolla, Kameshwar}, year={1993}, pages={104–106} }
 @inproceedings{yi_wu_1990, title={Study of constant value thresholds of FDI in strapdown inertial navigation}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0025530297&partnerID=MN8TOARS}, booktitle={Conference Proceedings - Symposium Gyro Technology}, author={Yi, Guang-qu and Wu, Fen}, year={1990} }