@inproceedings{rubio-hervas_gupta_ong_reyhanoglu_2020, title={Pay-per-flight Dynamic Pricing of UAV Operations}, DOI={10.1109/AIDA-AT48540.2020.9049171}, abstractNote={Insuring unmanned aerial vehicles (UAVs) is a relatively new concept, where not much data is available yet. We propose the combination of available data from different sources, other than past accident rates, to stochastically model the operational environment by using Gaussian process-based function approximations. A data-driven risk measure is then derived through such stochastic formulation accounting for both aleatoric uncertainties of the considered environmental factors as well as epistemic uncertainties originating from the geographical sparsity of data collection sources. The risk measure is obtained in a path-integral form which represents the operational risk associated with a defined operation in partially unknown environments. A novel pay-per-flight dynamic pricing scheme is derived from such risk measure.}, booktitle={Proceedings of the 2020 International Conference on Artificial Intelligence and Data Analytics for Air Transportation (AIDA-AT)}, author={Rubio-Hervas, J.R. and Gupta, A. and Ong, Y.-W. and Reyhanoglu, M.}, year={2020} } @article{mehndiratta_kayacan_reyhanoglu_kayacan_2020, title={Robust Tracking Control of Aerial Robots Via a Simple Learning Strategy-Based Feedback Linearization}, volume={8}, ISSN={2169-3536}, url={http://dx.doi.org/10.1109/access.2019.2962512}, DOI={10.1109/access.2019.2962512}, abstractNote={To facilitate accurate tracking in unknown/uncertain environments, this paper proposes a simple learning (SL) strategy for feedback linearization control (FLC) of aerial robots subject to uncertainties. The SL strategy minimizes a cost function defined based on the closed-loop error dynamics of the nominal system via the gradient descent technique to find the adaptation rules for feedback controller gains and disturbance estimate in the feedback control law. In addition to the derivation of the SL adaptation rules, the closed-loop stability for a second-order uncertain nonlinear system is proven in this paper. Moreover, it is shown that the SL strategy can find the global optimum point, while the controller gains and disturbance estimate converge to a finite value which implies a bounded control action in the steady-state. Furthermore, utilizing a simulation study, it is shown that the simple learning-based FLC (SL-FLC) framework can ensure desired closed-loop error dynamics in the presence of disturbances and modeling uncertainties. Finally, to validate the SL-FLC framework in real-time, the trajectory tracking problem of a tilt-rotor tricopter unmanned aerial vehicle under uncertain conditions is studied via three case scenarios, wherein the disturbances in the form of mass variation, ground effect, and wind gust, are induced. The real-time results illustrate that the SL-FLC framework facilitates a better tracking performance than that of the traditional FLC method while maintaining the nominal control performance in the absence of modeling uncertainties and external disturbances, and exhibiting robust control performance in the presence of modeling uncertainties and external disturbances.}, journal={IEEE Access}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Mehndiratta, Mohit and Kayacan, Erkan and Reyhanoglu, Mahmut and Kayacan, Erdal}, year={2020}, pages={1653–1669} } @article{navabi_davoodi_reyhanoglu_2019, title={Modeling and control of a nonlinear coupled spacecraft-fuel system}, volume={162}, ISSN={0094-5765}, url={http://dx.doi.org/10.1016/j.actaastro.2019.06.029}, DOI={10.1016/j.actaastro.2019.06.029}, abstractNote={This paper considers the nonlinear interaction of the rigid body dynamics of a spacecraft with the sloshing dynamics of the liquid propellant in its partially filled spherical tank during an orbital transfer. Fuel slosh dynamics are described by a three-dimensional two-pendulum model characterizing the first two sloshing modes, and the coupled equations of motion of the vehicle and the fuel masses are derived by means of quasi-Lagrangian equations. In addition, this paper studies active nonlinear control methods to control the attitude of the spacecraft while suppressing the sloshing of fuel. Simulations are conducted to illustrate the effectiveness of these control methods.}, journal={Acta Astronautica}, publisher={Elsevier BV}, author={Navabi, M. and Davoodi, A. and Reyhanoglu, M.}, year={2019}, month={Sep}, pages={436–446} } @inproceedings{steinbusch_reyhanoglu_2019, place={New York}, title={Robust Nonlinear Output Feedback Control of a 6-DOF Quadrotor UAV}, booktitle={2019 12th Asian Control Conference (ASCC)}, publisher={IEEE}, author={Steinbusch, A. and Reyhanoglu, M.}, year={2019} } @inproceedings{steinbusch_reyhanoglu_2019, place={New York}, title={Robust Nonlinear Tracking Control of a 2- DOF Helicopter Systems}, booktitle={Proceedings of 2019 12th Asian Control Conference (ASCC)}, publisher={IEEE}, author={Steinbusch, A. and Reyhanoglu, M.}, year={2019} } @inproceedings{steen_reyhanoglu_2019, title={Trajectory Tracking Control for a Mobile Robot on a Smooth Manifold}, booktitle={European Conference on Mobile Robots}, author={Steen, J. and Reyhanoglu, M.}, year={2019} } @inproceedings{steen_reyhanoglu_2019, place={New York}, title={Trajectory Tracking Control of a Rolling Disk on a Smooth Manifold}, booktitle={Proceedings of 2019 12th Asian Control Conference (ASCC)}, publisher={IEEE}, author={Steen, J. and Reyhanoglu, M.}, year={2019} } @inproceedings{rehan_reyhanoglu_van steen_2019, title={Trajectory tracking of a knife-edge on a flat surface}, ISBN={9783907144008}, url={http://dx.doi.org/10.23919/ecc.2019.8795750}, DOI={10.23919/ecc.2019.8795750}, abstractNote={The paper discusses trajectory tracking control of a knife-edge on a flat surface. The knife-edge has a single point of contact with the surface and it can slide on the surface without friction. A nonlinear trajectory tracking controller is designed for the knife-edge moving on a flat surface. The tracking control results show that the knife-edge successfully tracks the trajectories that satisfy a persistent excitation condition. A switching control algorithm is proposed to achieve stabilization in case the persistent excitation condition is violated. Simulation results are included to illustrate the effectiveness of the tracking control algorithm developed in the paper.}, booktitle={2019 18th European Control Conference (ECC)}, publisher={IEEE}, author={Rehan, Muhammad and Reyhanoglu, Mahmut and van Steen, Jari}, year={2019}, month={Jun} } @inproceedings{ramos-pedroza_kidambi_mackunis_reyhanoglu_2018, title={A Nonlinear Output Feedback Regulation Method for Limit Cycle Oscillation Suppression Using a Sliding Mode Observer}, ISBN={9781538613955}, url={http://dx.doi.org/10.1109/cdc.2018.8619317}, DOI={10.1109/cdc.2018.8619317}, abstractNote={A nonlinear output feedback control method is presented, which achieves asymptotic limit cycle oscillation (LCO) regulation in an aircraft wing section using synthetic jet actuators. To eliminate the standard requirement that LCO pitching and plunging rates are available for feedback, a finite-time sliding mode observer is utilized to estimate the rates using only measurements of LCO displacements. To achieve the result, a detailed mathematical model of the LCO dynamics is utilized, which includes nonlinear stiffness effects, unmodeled external disturbances, and dynamic model uncertainty, in addition to the parametric actuator uncertainty. A rigorous analysis is used to prove finite-time convergence of the estimation error, and a Lyapunov-based stability analysis is used to prove asymptotic regulation control of the LCO. Numerical simulation results are also provided which show the performance of the proposed sliding mode observer-based control design in comparison with our recently developed bank of filters-based output feedback LCO control method.}, booktitle={2018 IEEE Conference on Decision and Control (CDC)}, publisher={IEEE}, author={Ramos-Pedroza, Natalie and Kidambi, Krishna Bhavithavya and MacKunis, William and Reyhanoglu, Mahmut}, year={2018}, month={Dec} } @inbook{mackunis_reyhanoglu_kidambi_2018, place={Rijeka, Croatia}, title={Adaptive Nonlinear Regulation Control of Thermoacoustic Oscillations in Rijke-Type Systems}, ISBN={978-953-51-5729-8}, DOI={10.5772/intechopen.70683}, abstractNote={Adaptive nonlinear control of self-excited oscillations in Rijke-type thermoacoustic sys- tems is considered. To demonstrate the methodology, a well-accepted thermoacoustic dynamic model is introduced, which includes arrays of sensors and monopole-like actuators. To facilitate the derivation of the adaptive control law, the dynamic model is recast as a set of nonlinear ordinary differential equations, which are amenable to control design. The control-oriented nonlinear model includes unknown, unmeasurable, nonvanishing disturbances in addition to parametric uncertainty in both the thermo- acoustic dynamic model and the actuator dynamic model. To compensate for the unmodeled disturbances in the dynamic model, a robust nonlinear feedback term is included in the control law. One of the primary challenges in the control design is the presence of input-multiplicative parametric uncertainty in the dynamic model for the control actua- tor. This challenge is mitigated through innovative algebraic manipulation in the regulation error system derivation along with a Lyapunov-based adaptive control law. To address practical implementation considerations, where sensor measurements of the complete state are not available for feedback, a detailed analysis is provided to demon- strate that system observability can be ensured through judicious placement of pressure (and/or velocity) sensors. Based on this observability condition, a sliding-mode observer design is presented, which is shown to estimate the unmeasurable states using only the available sensor measurements. A detailed Lyapunov-based stability analysis is pro- vided to prove that the proposed closed-loop active thermoacoustic control system achieves asymptotic (zero steady-state error) regulation of multiple thermoacoustic modes in the presence of the aforementioned model uncertainty. Numerical Monte Carlo-type simulation results are also provided, which demonstrate the performance of the proposed closed-loop control system under various sets of operating conditions.}, booktitle={Adaptive Robust Control Systems}, publisher={InTech}, author={MacKunis, W. and Reyhanoglu, M. and Kidambi, K.B.}, editor={Le, Anh TuanEditor}, year={2018}, pages={161–181} } @book{reyhanoglu_2018, place={Rijeka, Croatia}, title={Computational and Experimental Studies of Acoustic Waves}, ISBN={9789535137153 9789535137160}, url={http://dx.doi.org/10.5772/65135}, DOI={10.5772/65135}, abstractNote={This book presents recent studies of acoustic wave propagation through different media including the atmosphere, Earth's subsurface, complex dusty plasmas, porous materials, and flexible structures. Mathematical models of the underlying physical phenomena are introduced and studied in detail. With its seven chapters, the book brings together important contributions from renowned international researchers to provide an excellent survey of recent computational and experimental studies of acoustic waves. The first section consists of four chapters that focus on computational studies, while the next section is composed of three chapters that center on experimental studies.}, publisher={InTech}, year={2018}, month={Jan} } @article{rehan_reyhanoglu_2018, title={Control of Rolling Disk Motion on an Arbitrary Smooth Surface}, volume={2}, ISSN={2475-1456}, url={http://dx.doi.org/10.1109/lcsys.2018.2838528}, DOI={10.1109/lcsys.2018.2838528}, abstractNote={This letter studies the motion of a vertical rolling disk on an arbitrary smooth surface in ${\mathbb {R}}^{3}$ . The disk can roll without slipping about its axis and turn about the surface normal. A global formulation for the dynamics of the rolling disk is proposed without the use of local coordinates, and the model is globally defined on the manifold without singularities or ambiguities. The theoretical results are specialized for two different surfaces; a flat surface and a spherical surface. The proposed motion planning algorithm consists of three phases and each phase is a rest-to-rest maneuver, such that the rolling disk is stationary at both the start and the end of each phase. Simulation results are included that show effectiveness of the motion planning algorithm on the smooth surfaces.}, number={3}, journal={IEEE Control Systems Letters}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Rehan, Muhammad and Reyhanoglu, Mahmut}, year={2018}, month={Jul}, pages={357–362} } @inproceedings{hoffman_reyhanoglu_2018, title={Differential Geometric Approach to Robust Control of an Oscillatory Base Robot Manipulator}, ISBN={9781509066841}, url={http://dx.doi.org/10.1109/iecon.2018.8592746}, DOI={10.1109/iecon.2018.8592746}, abstractNote={Ahstract- This paper studies the control of a robotic manipulator mounted on an oscillatory base. The system is subjected to bounded uncertainties, particularly those bounded by constants and positive non-decreasing functions. Through manifolds defining the appropriate configuration space, a Lagrangian formulation in terms of global coordinates is constructed, leading to well-defined equations of motion. A nonlinear tracking control law is designed in kind and proven to achieve semi-global asymptotic stability in spite of these disturbances. Proof of the controller performance is demonstrated through simulation.}, booktitle={IECON 2018 - 44th Annual Conference of the IEEE Industrial Electronics Society}, publisher={IEEE}, author={Hoffman, Derek and Reyhanoglu, Mahmut}, year={2018}, month={Oct} } @article{rehan_reyhanoglu_2018, title={Global Formulation and Motion Planning for a Sphere Rolling on a Smooth Surface}, volume={16}, ISSN={1598-6446 2005-4092}, url={http://dx.doi.org/10.1007/s12555-018-0011-3}, DOI={10.1007/s12555-018-0011-3}, number={6}, journal={International Journal of Control, Automation and Systems}, publisher={Springer Science and Business Media LLC}, author={Rehan, Muhammad and Reyhanoglu, Mahmut}, year={2018}, month={Oct}, pages={2709–2717} } @inproceedings{rehan_reyhanoglu_2018, title={Motion Planning for a Knife-Edge Moving on the Surface of a Torus}, ISBN={9781509066841}, url={http://dx.doi.org/10.1109/iecon.2018.8591313}, DOI={10.1109/iecon.2018.8591313}, abstractNote={This paper studies the motion planning problem for a knife-edge moving on the surface of a torus. Kinematics formulation for the knife-edge controlled by its speed along the heading direction and its turn rate about the surface normal is obtained using global coordinates so that the mathematical model has no singularities or ambiguities. A novel motion planning algorithm has been developed based on the geometry of the torus. The results of computer simulations are included to illustrate the effectiveness of the algorithm for any initial and final position/direction of the knife-edge moving on the surface of the torus.}, booktitle={IECON 2018 - 44th Annual Conference of the IEEE Industrial Electronics Society}, publisher={IEEE}, author={Rehan, Muhammad and Reyhanoglu, Mahmut}, year={2018}, month={Oct} } @book{reyhanoglu_2018, title={Nonlinear Systems - Modeling, Estimation, and Stability}, ISBN={9781789234046 9781789234053}, url={http://dx.doi.org/10.5772/intechopen.71815}, DOI={10.5772/intechopen.71815}, abstractNote={This book focuses on several key aspects of nonlinear systems including dynamic modeling, state estimation, and stability analysis. It is intended to provide a wide range of readers in applied mathematics and various engineering disciplines an excellent survey of recent studies of nonlinear systems. With its thirteen chapters, the book brings together important contributions from renowned international researchers to provide an excellent survey of recent studies of nonlinear systems. The first section consists of eight chapters that focus on nonlinear dynamic modeling and analysis techniques, while the next section is composed of five chapters that center on state estimation methods and stability analysis for nonlinear systems.}, publisher={InTech}, year={2018}, month={Jul} } @inproceedings{lambert_reyhanoglu_2018, title={Observer-Based Sliding Mode Control of a 2-DOF Helicopter System}, ISBN={9781509066841}, url={http://dx.doi.org/10.1109/iecon.2018.8592714}, DOI={10.1109/iecon.2018.8592714}, abstractNote={A sliding mode control (SMC) strategy is presented for a 2 degrees of freedom (DOF) helicopter system, which achieves asymptotic attitude regulation to desired set points as well as trajectory tracking. A rigorous Lyapunov-based analysis is provided to prove convergence to the desired set points. To overcome the practical limitations of velocity measurements, a sliding mode observer is designed to estimate the angular velocities. The convergence of the estimated velocities to the actual velocities is proven via a rigorous Lyapunov-based analysis and illustrated through computer simulations. In addition, computer simulations are presented, to demonstrate the effectiveness of the control law when applied to the complete nonlinear system dynamics. Finally, the control strategy is experimentally tested on the Quanser 2-DOF AERO helicopter. The results of the observer-based SMC strategy are compared to a conventional PID-controller.}, booktitle={IECON 2018 - 44th Annual Conference of the IEEE Industrial Electronics Society}, publisher={IEEE}, author={Lambert, Peter and Reyhanoglu, Mahmut}, year={2018}, month={Oct} } @inproceedings{lambert_reyhanoglu_2018, title={Observer-Based Sliding Mode Control of a 6-DOF Quadrotor UAV}, ISBN={9781509066841}, url={http://dx.doi.org/10.1109/iecon.2018.8592769}, DOI={10.1109/iecon.2018.8592769}, abstractNote={A sliding mode control (SMC) strategy is presented for a 6 degrees of freedom (DOF) quadrotor unmanned aerial vehicle (UAV), which achieves asymptotic position and attitude regulation. To overcome the practical limitations of velocity measurements, a sliding mode observer (SMO) is designed to estimate both the translational and rotational velocities. A rigorous Lyapunov-based analysis is provided to prove convergence to a desired set point in the presence of model uncertainties. Computer simulation results are presented, which demonstrate the effectiveness of the control law when applied to the complete nonlinear system dynamics.}, booktitle={IECON 2018 - 44th Annual Conference of the IEEE Industrial Electronics Society}, publisher={IEEE}, author={Lambert, Peter and Reyhanoglu, Mahmut}, year={2018}, month={Oct} } @article{hoffman_rehan_mackunis_reyhanoglu_2018, title={Quaternion-based Robust Trajectory Tracking Control of a Quadrotor Hover System}, volume={16}, ISSN={1598-6446 2005-4092}, url={http://dx.doi.org/10.1007/s12555-018-0112-z}, DOI={10.1007/s12555-018-0112-z}, number={6}, journal={International Journal of Control, Automation and Systems}, publisher={Springer Science and Business Media LLC}, author={Hoffman, Derek and Rehan, Muhammad and MacKunis, William and Reyhanoglu, Mahmut}, year={2018}, month={Oct}, pages={2575–2584} } @inproceedings{stebler_mackunis_ramos-pedroza_reyhanoglu_2017, place={New York}, title={A dynamic neural network-based sliding mode observer method for a class of uncertain dynamic systems}, ISBN={9781509021826}, url={http://dx.doi.org/10.1109/CCTA.2017.8062431}, DOI={10.1109/CCTA.2017.8062431}, abstractNote={A dynamic neural network (DNN)-based observer design is presented, which amalgamates an adaptive neural network-based technique with a finite-time sliding mode estimation method. The proposed observer design is motivated by practical quadrotor unmanned aerial vehicle tracking control applications, where direct sensor measurements of translational and rotational rates are not available for feedback. While sliding mode estimation strategies are well established as an effective means to compensate for bounded disturbances and dynamic model uncertainty, the proposed observer design employs a feedforward adaptive DNN-based estimation term in addition to a robust, high-gain feedback sliding mode element. The use of the DNN-based term in the estimator design is motivated by the desire to improve transient performance and reduce steady state error. In addition, the proposed sliding mode estimator design is proven to compensate for input-multiplicative parametric model uncertainty. To the best of the authors' knowledge, this is the first DNN-based sliding mode estimator result to rigorously prove asymptotic state estimation in the presence of parametric actuator uncertainty. A Lyapuov-based stability analysis is utilized to prove that the proposed DNN-based observer achieves asymptotic estimation of the quadrotor altitude and attitude rates in the presence of model uncertainty and bounded disturbances (e.g., sensor noise). Numerical simulation results are also provided to demonstrate the improved performance that is achieved by incorporating the adaptive DNN in the observer.}, booktitle={2017 IEEE Conference on Control Technology and Applications (CCTA)}, publisher={IEEE}, author={Stebler, Shane and MacKunis, William and Ramos-Pedroza, Natalie and Reyhanoglu, Mahmut}, year={2017}, month={Aug} } @inproceedings{stebler_campobasso_kidambi_mackunis_reyhanoglu_2017, title={Dynamic neural network-based sliding mode estimation of quadrotor systems}, ISBN={9781509059928}, url={http://dx.doi.org/10.23919/ACC.2017.7963344}, DOI={10.23919/ACC.2017.7963344}, abstractNote={A dynamic neural network (DNN)-based observer design is presented, which amalgamates an adaptive neural network-based technique with a sliding mode estimation method. The proposed observer design is motivated by practical quadrotor tracking control applications, where direct sensor measurements of translational and rotational rates are not available for feedback. While sliding mode estimation strategies are well established as an effective means to compensate for bounded disturbances and dynamic model uncertainty, the proposed observer design employs a feedforward adaptive DNN-based estimation term in addition to a robust, high-gain feedback sliding mode element. The use of the DNN-based term in the estimator design is motivated by the desire to improve transient performance and reduce steady state error. The DNN-based feedforward term could also offer the advantage of reducing the control effort that would be required when the proposed observer design is operating as part of a closed-loop control system. A Lyapuov-based stability analysis is utilized to prove that the proposed DNN-based observer achieves asymptotic estimation of the quadrotor altitude and attitude rates in the presence of model uncertainty and bounded disturbances (e.g., sensor noise). Numerical simulation results are also provided to demonstrate the improved performance that is achieved by incorporating the adaptive DNN in the observer.}, booktitle={2017 American Control Conference (ACC)}, publisher={IEEE}, author={Stebler, S. and Campobasso, M. and Kidambi, K. and MacKunis, W. and Reyhanoglu, M.}, year={2017}, month={May} } @book{reyhanoglu_2017, place={London}, title={Dynamical Systems: Analytical and Computational Techniques}, ISBN={9789535130154 9789535130161}, url={http://dx.doi.org/10.5772/63189}, DOI={10.5772/63189}, abstractNote={There has been a considerable progress made during the recent past on mathematical techniques for studying dynamical systems that arise in science and engineering. This progress has been, to a large extent, due to our increasing ability to mathematically model physical processes and to analyze and solve them, both analytically and numerically. With its eleven chapters, this book brings together important contributions from renowned international researchers to provide an excellent survey of recent advances in dynamical systems theory and applications. The first section consists of seven chapters that focus on analytical techniques, while the next section is composed of four chapters that center on computational techniques.}, publisher={InTech}, year={2017}, month={Mar} } @inproceedings{reyhanoglu_hoffman_2017, title={Finite-time control of a compliant base robot manipulator}, ISBN={9781509015733}, url={http://dx.doi.org/10.1109/ASCC.2017.8287365}, DOI={10.1109/ASCC.2017.8287365}, abstractNote={The control design of a two-link robotic manipulator with a translationally compliant base is investigated. The equations of motion are derived using a Lagrangian formulation. A notch-filtered finite-time control law is designed to avoid natural frequency excitation via the control input. The control algorithm's performance is then observed through simulation, aiming to demonstrate effectiveness on a benchmark robotic manipulator system.}, booktitle={2017 11th Asian Control Conference (ASCC)}, publisher={IEEE}, author={Reyhanoglu, Mahmut and Hoffman, Derek}, year={2017}, month={Dec} } @inproceedings{hoffman_reyhanoglu_2017, title={Geometric tracking control of a three-dimensional revolute joint robot}, ISBN={9781509015733}, url={http://dx.doi.org/10.1109/ASCC.2017.8287245}, DOI={10.1109/ASCC.2017.8287245}, abstractNote={This paper studies the tracking control of a three-dimensional revolute joint robot consisting of a rotating base and two rigid rotating links with bounded unstructured uncertainties to all three degrees of freedom. The configuration space of the system is considered as a direct product of three one-sphere (S1) configuration spaces to provide a global formulation. Following a Lagrangian formulation, a nonlinear tracking control law is designed in terms of global coordinates. The proposed controller is mathematically proven to provide uniformly ultimately bounded stability, and simulations demonstrate its performance.}, booktitle={2017 11th Asian Control Conference (ASCC)}, publisher={IEEE}, author={Hoffman, Derek and Reyhanoglu, Mahmut}, year={2017}, month={Dec} } @article{mcclamroch_reyhanoglu_rehan_2017, title={Knife-Edge Motion on a Surface as a Nonholonomic Control Problem}, volume={1}, ISSN={2475-1456}, url={http://dx.doi.org/10.1109/lcsys.2017.2700441}, DOI={10.1109/lcsys.2017.2700441}, abstractNote={This letter studies a new formulation for the kinematics of a knife-edge moving on an arbitrary smooth surface in ${\mathbb {R}^{3}}$ . The kinematics equations for a knife-edge, viewed as a rigid body, are constrained by the requirement that the knife-edge maintain contact with the surface. They describe the constrained translation of the point of contact of the knife-edge on the surface and the constrained attitude of the knife-edge as a rigid body. These equations for the knife-edge kinematics in ${\mathbb {R}}^{3}$ are expressed in a geometric form, without the use of local coordinates; they are globally defined without singularities or ambiguities. The kinematics equations can be expressed in several simplified forms and written as a drift-free nonlinear control system. Comments are made about interesting motion planning and path planning problems. The kinematics equations are specialized for two specific surfaces defined in ${ {\mathbb {R}}^{3}}$ , namely, a flat plane and the surface of a sphere. Results for the flat plane are compared with standard results obtained using local coordinates; results for the sphere, in contrast, require full attention to the 3-D geometry.}, number={1}, journal={IEEE Control Systems Letters}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={McClamroch, Harris and Reyhanoglu, Mahmut and Rehan, Muhammad}, year={2017}, month={Jul}, pages={26–31} } @article{kayacan_khanesar_rubio-hervas_reyhanoglu_2017, title={Learning Control of Fixed-Wing Unmanned Aerial Vehicles Using Fuzzy Neural Networks}, volume={2017}, ISSN={1687-5966 1687-5974}, url={http://dx.doi.org/10.1155/2017/5402809}, DOI={10.1155/2017/5402809}, abstractNote={A learning control strategy is preferred for the control and guidance of a fixed-wing unmanned aerial vehicle to deal with lack of modeling and flight uncertainties. For learning the plant model as well as changing working conditions online, a fuzzy neural network (FNN) is used in parallel with a conventional P (proportional) controller. Among the learning algorithms in the literature, a derivative-free one, sliding mode control (SMC) theory-based learning algorithm, is preferred as it has been proved to be computationally efficient in real-time applications. Its proven robustness and finite time converging nature make the learning algorithm appropriate for controlling an unmanned aerial vehicle as the computational power is always limited in unmanned aerial vehicles (UAVs). The parameter update rules and stability conditions of the learning are derived, and the proof of the stability of the learning algorithm is shown by using a candidate Lyapunov function. Intensive simulations are performed to illustrate the applicability of the proposed controller which includes the tracking of a three-dimensional trajectory by the UAV subject to time-varying wind conditions. The simulation results show the efficiency of the proposed control algorithm, especially in real-time control systems because of its computational efficiency.}, journal={International Journal of Aerospace Engineering}, publisher={Hindawi Limited}, author={Kayacan, Erdal and Khanesar, Mojtaba Ahmadieh and Rubio-Hervas, Jaime and Reyhanoglu, Mahmut}, year={2017}, pages={1–12} } @inproceedings{rehan_reyhanoglu_mcclamroch_2017, title={Motion planning for a knife-edge on the surface of a hyperboloid}, ISBN={9781509015733}, url={http://dx.doi.org/10.1109/ASCC.2017.8287363}, DOI={10.1109/ASCC.2017.8287363}, abstractNote={This paper presents a motion planning strategy for a knife-edge moving on the surface of a hyperboloid. First, kinematics equations for the knife-edge are developed without the use of local coordinates so that the mathematical model is globally defined and have no singularities or ambiguities. Then, a novel motion planning algorithm has been constructed using the concept of ruled surfaces. The computer simulations demonstrate the effectiveness of the algorithm for any initial and final position/direction of the knife-edge on the surface of the hyperboloid.}, booktitle={2017 11th Asian Control Conference (ASCC)}, publisher={IEEE}, author={Rehan, Muhammad and Reyhanoglu, Mahmut and McClamroch, Harris}, year={2017}, month={Dec} } @inbook{reyhanoglu_rehan_2017, title={Nonlinear Dynamics and Control of Aerial Robots}, ISBN={9789535134633 9789535134640}, url={http://dx.doi.org/10.5772/intechopen.69641}, DOI={10.5772/intechopen.69641}, abstractNote={Aerial robotics is one of the fastest growing industry and has a number of evolving applications. Higher agility make aerial robots ideal candidate for applications like rescue missions especially in difficult to access areas. This chapter first derives the complete nonlinear dynamics of an aerial robot consisting of a quadcopter with a two-link robot manipulator. Precise control of such an aerial robot is a challenging task due to the fact that the translational and rotational dynamics of the quadcopter are strongly coupled with the dynamics of the manipulator. We extend our previous results on the control of quadrotor UAVs to the control of aerial robots. In particular, we design a backstepping and Lyapunov-based nonlinear feedback control law that achieves point- to-point control of the areal robot. The effectiveness of this feedback control law is illustrated through a simulation example.}, booktitle={Aerial Robots - Aerodynamics, Control and Applications}, publisher={InTech}, author={Reyhanoglu, Mahmut and Rehan, Muhammad}, year={2017}, month={Sep} } @inproceedings{hoffman_rehan_mackunis_reyhanoglu_2017, place={New York}, title={Robust quaternion-based nonlinear output feedback control of a quadrotor hover system}, ISBN={9781509028733}, url={http://dx.doi.org/10.1109/CDC.2017.8264379}, DOI={10.1109/CDC.2017.8264379}, abstractNote={A robust nonlinear output feedback control method is presented, which achieves three degree of freedom (3-DOF) attitude control of a hover system test bed. The proposed control method formally incorporates the practical limitations in the voltage control inputs to the control actuators (i.e., the quadrotor propellers). In addition, the control law is designed to compensate for uncertainty in the hover system dynamic model, including input-multiplicative parametric uncertainty resulting from uncertain drag and friction coefficients in the propellers' dynamic model. To reduce the computational requirement in the closed-loop system, constant feedforward estimates of the input-multiplicative uncertainty are utilized in lieu of adaptive parameter estimates. Eschewing the high-gain feedback requirement that is characteristic of standard sliding mode observer methods, the proposed control method utilizes a bank of dynamic filters, which operates as a velocity estimator in the closed-loop system. A rigorous error system development and Lyapunov-based stability analysis are presented to prove that the proposed output feedback control law achieves asymptotic 3-DOF attitude control in the presence of parametric input uncertainty and unmodeled dynamics. Experimental results are provided to demonstrate the performance of the attitude control method using the Quanser 3-DOF hover system test bed.}, booktitle={2017 IEEE 56th Annual Conference on Decision and Control (CDC)}, publisher={IEEE}, author={Hoffman, Derek and Rehan, Muhammad and MacKunis, William and Reyhanoglu, Mahmut}, year={2017}, month={Dec} } @article{ramos-pedroza_mackunis_reyhanoglu_2017, title={Synthetic Jet Actuator-Based Aircraft Tracking Using a Continuous Robust Nonlinear Control Strategy}, volume={2017}, ISSN={1687-5966 1687-5974}, url={http://dx.doi.org/10.1155/2017/4934281}, DOI={10.1155/2017/4934281}, abstractNote={A robust nonlinear control law that achieves trajectory tracking control for unmanned aerial vehicles (UAVs) equipped with synthetic jet actuators (SJAs) is presented in this paper. A key challenge in the control design is that the dynamic characteristics of SJAs are nonlinear and contain parametric uncertainty. The challenge resulting from the uncertain SJA actuator parameters is mitigated via innovative algebraic manipulation in the tracking error system derivation along with a robust nonlinear control law employing constant SJA parameter estimates. A key contribution of the paper is a rigorous analysis of the range of SJA actuator parameter uncertainty within which asymptotic UAV trajectory tracking can be achieved. A rigorous stability analysis is carried out to prove semiglobal asymptotic trajectory tracking. Detailed simulation results are included to illustrate the effectiveness of the proposed control law in the presence of wind gusts and varying levels of SJA actuator parameter uncertainty.}, journal={International Journal of Aerospace Engineering}, publisher={Hindawi Limited}, author={Ramos-Pedroza, N. and MacKunis, W. and Reyhanoglu, M.}, year={2017}, pages={1–13} } @inproceedings{reyhanoglu_hoffman_2016, title={Modeling and control of a flexible-structure-mounted manipulator}, ISBN={9781509020652}, url={http://dx.doi.org/10.1109/AIM.2016.7576892}, DOI={10.1109/AIM.2016.7576892}, abstractNote={This paper studies the modeling and control problem for a robot manipulator consisting of a flexible first link and rigid second link. A nonlinear dynamical model is first derived using a Lagrangian formulation. A Lyapunov-based feedback control law is then introduced to achieve a slew maneuver of the rigid link while suppressing bending vibrations in the flexible link. The asymptotic stability of the closed-loop system is proven using LaSalle's invariance principle. Computer simulation results are included to illustrate the effectiveness of the proposed control design.}, booktitle={2016 IEEE International Conference on Advanced Intelligent Mechatronics (AIM)}, publisher={IEEE}, author={Reyhanoglu, Mahmut and Hoffman, Derek}, year={2016}, month={Jul} } @article{rubio-hervas_reyhanoglu_2016, title={Nonlinear Control of a Robot Manipulator with a Nonholonomic Jerk Constraint}, volume={18}, DOI={10.1002/asjc.1254}, abstractNote={Abstract}, number={4}, journal={Asian Journal of Control}, author={Rubio-Hervas, J.R. and Reyhanoglu, M.}, year={2016}, month={Jul}, pages={1566–1573} } @article{rubio hervas_reyhanoglu_tang_kayacan_2016, title={Nonlinear control of fixed-wing UAVs in presence of stochastic winds}, volume={33}, ISSN={1007-5704}, url={http://dx.doi.org/10.1016/j.cnsns.2015.08.026}, DOI={10.1016/j.cnsns.2015.08.026}, abstractNote={This paper studies the control of fixed-wing unmanned aerial vehicles (UAVs) in the presence of stochastic winds. A nonlinear controller is designed based on a full nonlinear mathematical model that includes the stochastic wind effects. The air velocity is controlled exclusively using the position of the throttle, and the rest of the dynamics are controlled with the aileron, elevator, and rudder deflections. The nonlinear control design is based on a smooth approximation of a sliding mode controller. An extended Kalman filter (EKF) is proposed for the state estimation and filtering. A case study is presented: landing control of a UAV on a ship deck in the presence of wind based exclusively on LADAR measurements. The effectiveness of the nonlinear control algorithm is illustrated through a simulation example.}, journal={Communications in Nonlinear Science and Numerical Simulation}, publisher={Elsevier BV}, author={Rubio Hervas, Jaime and Reyhanoglu, Mahmut and Tang, Hui and Kayacan, Erdal}, year={2016}, month={Apr}, pages={57–69} } @inproceedings{mackunis_reyhanoglu_kidambi_hervas_2016, title={Nonlinear control of thermoacoustic oscillations in Rijke-type systems}, ISBN={9788993215113}, url={http://dx.doi.org/10.1109/ICCAS.2016.7832470}, DOI={10.1109/ICCAS.2016.7832470}, abstractNote={This paper presents a robust and adaptive nonlinear controller to asymptotically regulate thermoacoustic oscillations in a Rijke-type system in the presence of dynamic model uncertainty and unknown disturbances. A mathematical model that includes unmodelled nonlinearities and parametric uncertainty is first introduced. A robust and adaptive non-linear control law is then developed to compensate for the parametric uncertainty and unmodelled nonlinearities. Results of Monte Carlo-type simulations are included to demonstrate the effectiveness of the control law.}, booktitle={2016 16th International Conference on Control, Automation and Systems (ICCAS)}, publisher={IEEE}, author={MacKunis, William and Reyhanoglu, Mahmut and Kidambi, Krishna Bhavithavya and Hervas, Jaime Rubio}, year={2016}, month={Oct} } @inproceedings{reyhanoglu_hoffman_de wit_2016, title={Nonlinear modeling and control of a two-link hybrid manipulator}, ISBN={9781509035496}, url={http://dx.doi.org/10.1109/ICARCV.2016.7838809}, DOI={10.1109/ICARCV.2016.7838809}, abstractNote={The slew maneuver problem is studied for a robot manipulator consisting of a flexible first link and rigid second link. A nonlinear dynamical model is first derived using a Lagrangian formulation. A notch-filtered finite-time control law is then introduced to achieve fast and precise slewing maneuvers without residual vibrations. The results are applied to a benchmark two-link system and a simulation example is included to illustrate the effectiveness of the proposed control technique.}, booktitle={2016 14th International Conference on Control, Automation, Robotics and Vision (ICARCV)}, publisher={IEEE}, author={Reyhanoglu, Mahmut and Hoffman, Derek and de Wit, Jop}, year={2016}, month={Nov} } @inproceedings{stebler_mackunis_reyhanoglu_2016, title={Nonlinear output feedback tracking control of a quadrotor UAV in the presence of uncertainty}, ISBN={9781509035496}, url={http://dx.doi.org/10.1109/icarcv.2016.7838569}, DOI={10.1109/icarcv.2016.7838569}, abstractNote={A nonlinear output feedback control method is presented, which achieves asymptotic altitude and attitude trajectory tracking of a quadrotor system in the presence of model uncertainty and unknown external disturbances. To address a practical scenario where velocity measurements are not available, a bank of dynamic filters is utilized, which acts as a velocity observer in the closed-loop system. A primary focus of the proposed control method is detailed development that shows how a computationally minimal strategy can be utilized to compensate for multiple sources of uncertainty without the use of adaptive parameter estimation or function approximators. A rigorous Lyapunov-based stability analysis is utilized to prove semi-global asymptotic trajectory tracking in the presence of parametric uncertainty and unmodelled external disturbances. Numerical simulation results are also provided to demonstrate the performance of the proposed control law.}, booktitle={2016 14th International Conference on Control, Automation, Robotics and Vision (ICARCV)}, publisher={IEEE}, author={Stebler, Shane and MacKunis, William and Reyhanoglu, Mahmut}, year={2016}, month={Nov} } @inproceedings{ramos-pedroza_kidambi_mackunis_reyhanoglu_2016, title={Nonlinear tracking control and structural vibration suppression for aircraft using synthetic jet actuators}, ISBN={9781509035496}, url={http://dx.doi.org/10.1109/icarcv.2016.7838797}, DOI={10.1109/icarcv.2016.7838797}, abstractNote={A synthetic jet actuator (SJA)-based control method is developed, which is rigorously proven to achieve accurate aircraft trajectory tracking control while simultaneously regulating limit cycle oscillations (LCO) in aircraft wings. To achieve the result, innovative tracking error system development is utilized along with a robust-inverse control structure. The robust-inverse control structure is utilized to compensate for the parametric uncertainty and nonlinearity inherent in the SJA mathematical model without the use of adaptive parameter estimation or function approximation schemes. After recasting the dynamics in a form amenable to control design, a nonlinear control law is developed, which achieves asymptotic trajectory tracking in the presence of external disturbances and structural disturbances due to LCO. A Lyapunov-based stability analysis is utilized to prove semi-global asymptotic trajectory tracking in the presence of LCO disturbances and parametric uncertainty in the SJA actuator model. Numerical simulation results are provided to demonstrate the capability of the proposed SJA-based control method to achieve simultaneous trajectory tracking and LCO regulation.}, booktitle={2016 14th International Conference on Control, Automation, Robotics and Vision (ICARCV)}, publisher={IEEE}, author={Ramos-Pedroza, Natalie and Kidambi, Krishna Bhavithavya and MacKunis, William and Reyhanoglu, Mahmut}, year={2016}, month={Nov} } @inproceedings{reyhanoglu_damen_mackunis_2016, title={Observer-based sliding mode control of a 3-DOF hover system}, ISBN={9781509035496}, url={http://dx.doi.org/10.1109/ICARCV.2016.7838643}, DOI={10.1109/ICARCV.2016.7838643}, abstractNote={A sliding mode control (SMC) strategy is presented for a quadrotor-based hover system, which achieves asymptotic attitude regulation in the presence of electrical and physical constraints. A sliding mode observer is employed to estimate the angular velocities. In addition, the proposed control design incorporates the input voltage constraints inherent in practical systems. A rigorous Lyapunov-based analysis is provided to prove asymptotic regulation of the hover system attitude to a desired set point. Computer simulation results are also provided, which demonstrate the capability of the control law to achieve asymptotic attitude regulation when applied to the complete nonlinear system dynamics.}, booktitle={2016 14th International Conference on Control, Automation, Robotics and Vision (ICARCV)}, publisher={IEEE}, author={Reyhanoglu, Mahmut and Damen, Remon and MacKunis, William}, year={2016}, month={Nov} } @inproceedings{damen_reyhanoglu_mackunis_hervas_2016, title={Passivity-based quaternion feedback control of a hover system}, ISBN={9788993215113}, url={http://dx.doi.org/10.1109/ICCAS.2016.7832321}, DOI={10.1109/ICCAS.2016.7832321}, abstractNote={A passivity-based quaternion feedback control strategy is presented for a hover system (quadrotor UAV test bed), which achieves asymptotic attitude regulation. The proposed control design incorporates the input voltage constraints inherent in practical UAV systems. A rigorous Lyapunov-based analysis is provided to prove asymptotic regulation of the hover system attitude to a desired set point. Computer simulation results are also provided, which demonstrate the capability of the control law to achieve asymptotic attitude regulation when applied to the complete nonlinear system dynamics.}, booktitle={2016 16th International Conference on Control, Automation and Systems (ICCAS)}, publisher={IEEE}, author={Damen, Remon and Reyhanoglu, Mahmut and MacKunis, William and Hervas, Jaime Rubio}, year={2016}, month={Oct} } @inproceedings{mackunis_reyhanoglu_kidambi_hervas_2016, title={Robust and adaptive nonlinear regulation of thermoacoustic oscillations in Rijke-type systems}, ISBN={9781509020652}, url={http://dx.doi.org/10.1109/aim.2016.7576873}, DOI={10.1109/aim.2016.7576873}, abstractNote={Nonlinear control of self-excited oscillations in a Rijke-type thermoacoustic system is considered. A commonly used thermoacoustic model with a number of monopole-like actuators is first introduced. The model is expressed in a nonlinear control-oriented form, which includes unmodeled nonlinearities and parametric uncertainty in both the thermoacoustic dynamics and in the actuator dynamics. A robust and adaptive nonlinear control law is developed to compensate for the parametric uncertainty and unmodeled nonlinearities. Challenges in the control design include input-multiplicative parametric uncertainty. This challenge is mitigated through careful algebraic manipulation in the regulation error system development along with a Lyapunov-based adaptive law. A rigorous Lyapunov-based stability analysis is used to prove that the nonlinear controller achieves asymptotic regulation of an uncertain thermoacoustic system with multiple modes.}, booktitle={2016 IEEE International Conference on Advanced Intelligent Mechatronics (AIM)}, publisher={IEEE}, author={MacKunis, William and Reyhanoglu, Mahmut and Kidambi, Krishna Bhavithavya and Hervas, Jaime Rubio}, year={2016}, month={Jul} } @article{ramos-pedroza_mackunis_reyhanoglu_2015, title={A Sliding Mode LCO Regulation Strategy for Dual-Parallel Underactuated UAV Systems Using Synthetic Jet Actuators}, volume={2015}, ISSN={1687-5966 1687-5974}, url={http://dx.doi.org/10.1155/2015/795348}, DOI={10.1155/2015/795348}, abstractNote={A sliding mode control- (SMC-) based limit cycle oscillation (LCO) regulation method is presented, which achieves asymptotic LCO suppression for UAVs using synthetic jet actuators (SJAs). With a focus on applications involving small UAVs with limited onboard computational resources, the controller is designed with a simplistic structure, requiring no adaptive laws, function approximators, or complex calculations in the control loop. The control law is rigorously proven to achieve asymptotic regulation of both pitching and plunging displacements for a class of systems in a dual-parallel underactuated form, where a single scalar control signal simultaneously affects two states. Since dual-parallel underactuated systems cannot be expressed in a strict feedback or cascade form, standard backstepping-based control techniques cannot be applied. This difficulty is mitigated through careful algebraic manipulation in the regulation error system development, along with innovative design of the sliding surface. A detailed model of the UAV LCO dynamics is utilized, and a rigorous analysis is provided to prove asymptotic regulation of the pitching and plunging displacements. Numerical simulation results are provided to demonstrate the performance of the control law.}, journal={International Journal of Aerospace Engineering}, publisher={Hindawi Limited}, author={Ramos-Pedroza, N. and MacKunis, W. and Reyhanoglu, M.}, year={2015}, pages={1–7} } @article{rubio hervas_reyhanoglu_2015, title={Controllability and stabilizability of a class of systems with higher-order nonholonomic constraints}, volume={54}, ISSN={0005-1098}, url={http://dx.doi.org/10.1016/j.automatica.2015.02.006}, DOI={10.1016/j.automatica.2015.02.006}, abstractNote={A theoretical framework is established for the control of higher-order nonholonomic systems, defined as systems that satisfy higher-order nonintegrable constraints. A model for such systems is developed in terms of differential–algebraic equations defined on a higher-order tangent bundle. A number of control-theoretic properties such as nonintegrability, controllability, and stabilizability are presented. Higher-order nonholonomic systems are shown to be strongly accessible and, under certain conditions, small time locally controllable at any equilibrium. The applicability of the theoretical development is illustrated through a third-order nonholonomic system example: a planar PPR robot manipulator subject to a jerk constraint. In particular, it is shown that although the system is not asymptotically stabilizable to a given equilibrium configuration using a time-invariant continuous feedback, it is strongly accessible and small-time locally controllable at any equilibrium.}, journal={Automatica}, publisher={Elsevier BV}, author={Rubio Hervas, Jaime and Reyhanoglu, Mahmut}, year={2015}, month={Apr}, pages={229–234} } @article{khanesar_kayacan_reyhanoglu_kaynak_2015, title={Feedback Error Learning Control of Magnetic Satellites Using Type-2 Fuzzy Neural Networks With Elliptic Membership Functions}, volume={45}, ISSN={2168-2267 2168-2275}, url={http://dx.doi.org/10.1109/tcyb.2015.2388758}, DOI={10.1109/tcyb.2015.2388758}, abstractNote={A novel type-2 fuzzy membership function (MF) in the form of an ellipse has recently been proposed in literature, the parameters of which that represent uncertainties are de-coupled from its parameters that determine the center and the support. This property has enabled the proposers to make an analytical comparison of the noise rejection capabilities of type-1 fuzzy logic systems with its type-2 counterparts. In this paper, a sliding mode control theory-based learning algorithm is proposed for an interval type-2 fuzzy logic system which benefits from elliptic type-2 fuzzy MFs. The learning is based on the feedback error learning method and not only the stability of the learning is proved but also the stability of the overall system is shown by adding an additional component to the control scheme to ensure robustness. In order to test the efficiency and efficacy of the proposed learning and the control algorithm, the trajectory tracking problem of a magnetic rigid spacecraft is studied. The simulations results show that the proposed control algorithm gives better performance results in terms of a smaller steady state error and a faster transient response as compared to conventional control algorithms.}, number={4}, journal={IEEE Transactions on Cybernetics}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Khanesar, Mojtaba Ahmadieh and Kayacan, Erdal and Reyhanoglu, Mahmut and Kaynak, Okyay}, year={2015}, month={Apr}, pages={858–868} } @article{rubio-hervas_zhao_reyhanoglu_2015, title={Nonlinear feedback control of self-sustained thermoacoustic oscillations}, volume={41}, ISSN={1270-9638}, url={http://dx.doi.org/10.1016/j.ast.2014.12.026}, DOI={10.1016/j.ast.2014.12.026}, abstractNote={Acoustic disturbances could undergo transient growth to trigger thermoacoustic instability in a combustion system with non-orthogonal eigenmodes, even with stable eigenvalues and in the presence of conventional linear controllers. In this work, nonlinear feedback control of thermoacoustic oscillations in a Rijke-type combustion system is considered. A thermoacoustic model with distributed monopole-like actuators is presented. To stabilize the thermoacoustic system, a nonlinear feedback controller is developed. It is shown that the feedback controller achieves both exponential decay of the flow disturbance energy and unity maximum transient growth. The performance of the controller is illustrated with two systems: one associated with one mode and one actuator, and the other with two modes and two actuators. The successful demonstration indicates that the developed nonlinear controller has the potential to be applied to combustion systems with multiple modes.}, journal={Aerospace Science and Technology}, publisher={Elsevier BV}, author={Rubio-Hervas, Jaime and Zhao, Dan and Reyhanoglu, Mahmut}, year={2015}, month={Feb}, pages={209–215} } @article{rubio-hervas_reyhanoglu_mackunis_2015, title={Observer-Based Sliding Mode Control of Rijke-Type Combustion Instability}, volume={34}, ISSN={1461-3484 2048-4046}, url={http://dx.doi.org/10.1260/0263-0923.34.2.201}, DOI={10.1260/0263-0923.34.2.201}, abstractNote={ Observer-based sliding mode control of combustion instability in a Rijke-type thermoacoustic system is considered. A commonly used thermoacoustic model with sensors and monopole-like actuators is linearized and formulated in a state-space form. It is assumed that the velocity or pressure sensor locations are chosen to assure the observability of the system. An observer-based sliding mode controller is then implemented to tune the actuators so that the system is asymptotically stable. The effectiveness of the controller is illustrated through a simulation example involving two modes and one sensor. The successful demonstration indicates that the observer-based feedback controller can be applied to a real combustion system with multiple modes. }, number={2}, journal={Journal of Low Frequency Noise, Vibration and Active Control}, publisher={SAGE Publications}, author={Rubio-Hervas, Jaime and Reyhanoglu, Mahmut and MacKunis, William}, year={2015}, month={Jun}, pages={201–217} } @inproceedings{hervas_reyhanoglu_mackunis_2015, title={Sliding mode control of Rijke-type thermoacoustic systems}, ISBN={9781479989478}, url={http://dx.doi.org/10.1109/RASM.2015.7154639}, DOI={10.1109/RASM.2015.7154639}, abstractNote={Observer-based feedback control of self-excited combustion oscillations in a Rijke-type thermoacoustic system is considered. A commonly used thermoacoustic model with a number of sensors and distributed monopole-like actuators is first introduced. The model is formulated as a linear time-delay system. It is shown that the velocity or pressure sensor locations can be chosen to assure the observability of the system. An observer-based sliding mode controller is then implemented to tune the actuators so that the system is asymptotically stable. The effectiveness of the controller is illustrated through a simulation example involving two modes.}, booktitle={2015 International Workshop on Recent Advances in Sliding Modes (RASM)}, publisher={IEEE}, author={Hervas, Jaime Rubio and Reyhanoglu, Mahmut and MacKunis, William}, year={2015}, month={Apr} } @inproceedings{ramos-pedroza_mackunis_reyhanoglu_2015, title={Sliding mode control-based limit cycle oscillation suppression for UAVs using synthetic jet actuators}, ISBN={9781479989478}, url={http://dx.doi.org/10.1109/rasm.2015.7154584}, DOI={10.1109/rasm.2015.7154584}, abstractNote={A sliding mode control (SMC) method is presented in this paper, which is proven to achieve asymptotic SJA-based LCO suppression without the use of adaptive laws or function approximators. In addition, the SMC-based control strategy presented here is shown to achieve suppression of both pitching and plunging displacements for a class of so-called dual-parallel underactuated systems, where a single scalar control signal simultaneously affects both states. The dual-parallel underactuated system cannot be expressed in a cascade or normal form, and hence, standard backstepping-based control approaches cannot be applied. In this paper, this difficulty is mitigated through novel algebraic manipulation in the error system development, along with innovative design of the sliding surface. A detailed model of the UAV dynamics is utilized along with a rigorous analysis to prove asymptotic regulation of the plunging displacement, and numerical simulation results are provided to demonstrate asymptotic suppression of the pitching and plunging displacements.}, booktitle={2015 International Workshop on Recent Advances in Sliding Modes (RASM)}, publisher={IEEE}, author={Ramos-Pedroza, Natalie and MacKunis, William and Reyhanoglu, Mahmut}, year={2015}, month={Apr} } @inproceedings{hervas_reyhanoglu_tang_2014, title={Automatic landing control of Unmanned Aerial Vehicles on moving platforms}, ISBN={9781479923991}, url={http://dx.doi.org/10.1109/ISIE.2014.6864588}, DOI={10.1109/ISIE.2014.6864588}, abstractNote={This paper studies the landing control problem for Unmanned Aerial Vehicles (UAVs) on an oscillating platform such as a ship deck in a rough sea. A full nonlinear mathematical model is first introduced for the UAV in an inertial frame. A Fourier transform based method is then employed for a realistic characterization of the sea motion and the ship dynamics. Finally, a landing control algorithm is developed based on the dynamics of the UAV relative to the ship. The effectiveness of the control algorithm is illustrated through a simulation example.}, booktitle={2014 IEEE 23rd International Symposium on Industrial Electronics (ISIE)}, publisher={IEEE}, author={Hervas, Jaime Rubio and Reyhanoglu, Mahmut and Tang, Hui}, year={2014}, month={Jun} } @inproceedings{zhao_reyhanoglu_2014, title={Feedback Control of Transient Growth of Thermoacoustic Oscillations}, ISBN={9781624102851}, url={http://dx.doi.org/10.2514/6.2014-3183}, DOI={10.2514/6.2014-3183}, booktitle={20th AIAA/CEAS Aeroacoustics Conference}, publisher={American Institute of Aeronautics and Astronautics}, author={Zhao, Dan and Reyhanoglu, Mahmut}, year={2014}, month={Jun} } @article{zhao_reyhanoglu_2014, title={Feedback control of acoustic disturbance transient growth in triggering thermoacoustic instability}, volume={333}, ISSN={0022-460X}, url={http://dx.doi.org/10.1016/j.jsv.2014.04.015}, DOI={10.1016/j.jsv.2014.04.015}, abstractNote={Transient growth of acoustic disturbances could trigger thermoacoustic instability in a combustion system with non-orthogonal eigenmodes, even with stable eigenvalues. In this work, feedback control of transient growth of flow perturbations in a Rijke-type combustion system is considered. For this, a generalized thermoacoustic model with distributed monopole-like actuators is developed. The model is formulated in state-space to gain insights on the interaction between various eigenmodes and the dynamic response of the system to the actuators. Three critical parameters are identified: (1) the mode number, (2) the number of actuators, and (3) the locations of the actuators. It is shown that in general the number of the actuators K is related to the mode number N as K=N2. For simplicity in illustrating the main results of the paper, two different thermoacoustic systems are considered: system (a) with one mode and system (b) that involves two modes. The actuator location effect is studied in system (a) and it is found that the actuator location plays an important role in determining the control effort. In addition, sensitivity analysis of pressure- and velocity-related control parameters is conducted. In system (b), when the actuators are turned off (i.e., open-loop configuration), it is observed that acoustic energy transfers from the high frequency mode to the lower frequency mode. After some time, the energy is transferred back. Moreover, the high frequency oscillation grows into nonlinear limit cycle with the low frequency oscillation amplified. As a linear-quadratic regulator (LQR) is implemented to tune the actuators, both systems become asymptotically stable. However, the LQR controller fails in eliminating the transient growth, which may potentially trigger thermoacoustic instability. In order to achieve strict dissipativity (i.e., unity maximum transient growth), a transient growth controller is systematically designed and tested in both systems. Comparison is then made between the performance of the LQR controller and that of the transient growth controller. It is found in both systems that the transient growth controller achieves both exponential decay of the flow disturbance energy and unity maximum transient growth.}, number={16}, journal={Journal of Sound and Vibration}, publisher={Elsevier BV}, author={Zhao, Dan and Reyhanoglu, Mahmut}, year={2014}, month={Aug}, pages={3639–3656} } @article{rubio hervas_zhao_reyhanoglu_2014, title={Linear-Quadratic-Gaussian Control of Rijke-Type Combustion Instability}, volume={5}, number={4}, journal={Mathematics in Engineering, Science and Aerospace}, author={Rubio Hervas, J. and Zhao, D. and Reyhanoglu, M.}, year={2014}, pages={445–456} } @inproceedings{hervas_reyhanoglu_tang_2014, title={Nonlinear automatic landing control of unmanned aerial vehicles on moving platforms via a 3D laser radar}, url={http://dx.doi.org/10.1063/1.4904663}, DOI={10.1063/1.4904663}, abstractNote={This paper presents a motion tracking and control system for automatically landing Unmanned Aerial Vehicles (UAVs) on an oscillating platform using Laser Radar (LADAR) observations. The system itself is assumed to be mounted on a ship deck. A full nonlinear mathematical model is first introduced for the UAV. The ship motion is characterized by a Fourier transform based method which includes a realistic characterization of the sea waves. LADAR observation models are introduced and an algorithm to process those observations for yielding the relative state between the vessel and the UAV is presented, from which the UAV's state relative to an inertial frame can be obtained and used for feedback purposes. A sliding mode control algorithm is derived for tracking a landing trajectory defined by a set of desired waypoints. An extended Kalman filter (EKF) is proposed to account for process and observation noises in the design of a state estimator. The effectiveness of the control algorithm is illustrated through a simulation example.}, publisher={AIP Publishing LLC}, author={Hervas, Jaime Rubio and Reyhanoglu, Mahmut and Tang, Hui}, year={2014} } @inproceedings{hervas_zhao_reyhanoglu_2014, title={Nonlinear feedback control of thermoacoustic oscillations in a Rijke tube}, ISBN={9781479923991}, url={http://dx.doi.org/10.1109/ISIE.2014.6864606}, DOI={10.1109/ISIE.2014.6864606}, abstractNote={Flow disturbances could undergo transient growth to trigger thermoacoustic instability in a combustion system with non-orthogonal eigenmodes. In this work, nonlinear feedback control of thermoacoustic oscillations in a Rijke-type combustion system is considered. A generalized thermoacoustic model with distributed monopole-like actuators is proposed. To stabilize the thermoacoustic system, a Lyapunov-based nonlinear controller is developed. It is shown that the nonlinear feedback controller achieves both exponential decay of the flow disturbance energy and unity maximum transient growth.}, booktitle={2014 IEEE 23rd International Symposium on Industrial Electronics (ISIE)}, publisher={IEEE}, author={Hervas, Jaime Rubio and Zhao, Dan and Reyhanoglu, Mahmut}, year={2014}, month={Jun} } @inproceedings{hervas_zhao_reyhanoglu_2014, title={Observer-based control of Rijke-type combustion instability}, url={http://dx.doi.org/10.1063/1.4904662}, DOI={10.1063/1.4904662}, abstractNote={In this work, observer-based feedback control of combustion instability in a Rijke-type thermoacoustic system is considered. A generalized thermoacoustic model with distributed monopole-like actuators is developed. The model is linearized and formulated in state-space and it is assumed that pressure sensors are the only information available for feedback. It is shown that a system of this form is observable. As a Linear-Quadratic-Gaussian (LQG) controller is implemented to tune the actuators, the system becomes asymptotically stable. The performance of the controller is evaluated with a system involving two modes. The successful demonstration indicates that the observer-based feedback controller can be applied to a real combustion system with multiple modes.}, publisher={AIP Publishing LLC}, author={Hervas, Jaime Rubio and Zhao, Dan and Reyhanoglu, Mahmut}, year={2014} } @inproceedings{hervas_reyhanoglu_2014, title={Observer-based nonlinear control of space vehicles with multi-mass fuel slosh dynamics}, ISBN={9781479923991}, url={http://dx.doi.org/10.1109/ISIE.2014.6864607}, DOI={10.1109/ISIE.2014.6864607}, abstractNote={This paper studies the problem of observer-based control of space vehicles with fuel slosh dynamics in a zero gravity environment. Multi-mass-spring models are considered for the characterization of the most prominent sloshing modes. The control objective is to control the translational velocity vector and the attitude of the spacecraft, while attenuating the sloshing modes. A full-state feedback that uses a reduced-order observer for the estimation of the slosh states is proposed to achieve the objective. The effectiveness of the proposed observer-based control law is illustrated through a computer simulation.}, booktitle={2014 IEEE 23rd International Symposium on Industrial Electronics (ISIE)}, publisher={IEEE}, author={Hervas, Jaime Rubio and Reyhanoglu, Mahmut}, year={2014}, month={Jun} } @inproceedings{hervas_kayacan_reyhanoglu_tang_2014, title={Sliding mode control of fixed-wing UAVs in windy environments}, ISBN={9781479951994}, url={http://dx.doi.org/10.1109/ICARCV.2014.7064440}, DOI={10.1109/ICARCV.2014.7064440}, abstractNote={In this paper, a fully nonlinear aircraft dynamic model in the presence of wind is introduced. Assuming the wind vortex hypothesis, the equations of motion are formulated in a novel nonlinear control system form that is affine in control input for the chosen aircraft model. A sliding mode controller is subsequently developed where the position of the throttle is used to control the air velocity and the aileron, elevator, and rudder deflections are employed to control the rest of the dynamics. It is shown that the full state converges to the desired values even in the presence of the uncertainties imposed by the wind. The applicability of the controller design is illustrated through simulations in the presence of uncertainties.}, booktitle={2014 13th International Conference on Control Automation Robotics & Vision (ICARCV)}, publisher={IEEE}, author={Hervas, Jaime Rubio and Kayacan, Erdal and Reyhanoglu, Mahmut and Tang, Hui}, year={2014}, month={Dec} } @article{rubio hervas_reyhanoglu_2014, title={Thrust-vector control of a three-axis stabilized upper-stage rocket with fuel slosh dynamics}, volume={98}, DOI={10.1016/j.actaastro.2014.01.022}, abstractNote={This paper studies the thrust vector control problem for an upper-stage rocket with fuel slosh dynamics. The dynamics of a three-axis stabilized spacecraft with a single partially-filled fuel tank are formulated and the sloshing propellant is modeled as a multi-mass–spring system, where the oscillation frequencies of the mass–spring elements represent the prominent sloshing modes. The equations of motion are expressed in terms of the three-dimensional spacecraft translational velocity vector, the attitude, the angular velocity, and the internal coordinates representing the slosh modes. A Lyapunov-based nonlinear feedback control law is proposed to control the translational velocity vector and the attitude of the spacecraft, while attenuating the sloshing modes characterizing the internal dynamics. A simulation example is included to illustrate the effectiveness of the control law.}, journal={Acta Astronautica}, author={Rubio Hervas, J.R. and Reyhanoglu, M.}, year={2014}, month={May}, pages={120–127} } @inproceedings{hervas_reyhanoglu_2013, place={New Jersey}, title={Control and stabilization of a third-order nonholonomic system}, DOI={10.1109/ICCAS.2013.6703856}, abstractNote={We study the control of a simplified model of a PPR robot manipulator subject to a third-order nonholonomic constraint. The model consists of a base body, which can translate and rotate freely in the plane, and a massless arm at the tip of which the end-effector is attached. It is assumed that two forces and a torque applied to the manipulator are available as control inputs. The objective is to control the robot end-effector movement while keeping the transverse jerk component is zero. The main result of the paper is the construction of a feedback control algorithm that transfers the manipulator from any initial equilibrium configuration to the zero equilibrium configuration in finite time. The effectiveness of the algorithm is illustrated through a simulation example.}, booktitle={Proceedings of the 2013 13th International Conference on Control, Automation and Systems (ICCAS 2013)}, publisher={IEEE}, author={Hervas, J.R. and Reyhanoglu, M.}, year={2013}, pages={17–22} } @inproceedings{hervas_reyhanoglu_2013, title={Controllability and stabilizability of higher-order nonholonomic systems}, ISBN={9781467357692 9781467357678}, url={http://dx.doi.org/10.1109/ascc.2013.6606065}, DOI={10.1109/ascc.2013.6606065}, abstractNote={This paper studies the nonlinear modeling and control problem for systems with higher-order nonholonomic constraints using tools from differential geometry. A number of control-theoretic properties such as nonintegrability, controllability, and stabilizability are first derived. The applicability of the theoretical development is illustrated through a third-order nonholonomic system example: a planar PPR robot manipulator subject to a jerk constraint. In particular, it is shown that although the system is not asymptotically stabilizable to a given equilibrium configuration using a time-invariant continuous feedback, it is strongly accessible and small-time locally controllable at any equilibrium.}, booktitle={2013 9th Asian Control Conference (ASCC)}, publisher={IEEE}, author={Hervas, Jaime Rubio and Reyhanoglu, Mahmut}, year={2013}, month={Jun} } @article{reyhanoglu_alvarado_2013, title={Estimation of debris dispersion due to a space vehicle breakup during reentry}, volume={86}, ISSN={0094-5765}, url={http://dx.doi.org/10.1016/j.actaastro.2013.01.018}, DOI={10.1016/j.actaastro.2013.01.018}, abstractNote={This paper studies the problem of the estimation of the extent of the airspace containing falling debris due to a space vehicle breakup. A precise propagation of debris to the ground is not practical for many reasons. There is insufficient knowledge of the initial state vector, ambient wind conditions, and the key parameters including the ballistic coefficients. In addition, propagation of all debris pieces to the ground would require extensive computer time. In this paper, a covariance propagation method is introduced for the estimation of debris dispersion due to a space vehicle breakup. The falling debris is simulated, and the data are analyzed to derive the probability of debris evolution in different altitude layers over time. The concept of positional probability ellipsoids is employed for the visualization of the results. Through a case study, it is shown that while the results of the covariance propagation method are in close agreement with those of the Monte Carlo method, the covariance propagation method is much more computationally efficient than the Monte Carlo method.}, journal={Acta Astronautica}, publisher={Elsevier BV}, author={Reyhanoglu, Mahmut and Alvarado, Juan}, year={2013}, month={May}, pages={211–218} } @inproceedings{reyhanoglu_alvarado_carmi_2013, title={Estimation of debris hazard areas due to a space vehicle breakup at high altitudes}, ISBN={9781467357692 9781467357678}, url={http://dx.doi.org/10.1109/ascc.2013.6606025}, DOI={10.1109/ascc.2013.6606025}, abstractNote={With the recent developments in the Commercial Space Transportation industry, there has been a surge of interest in the analyses of the debris hazard areas due to a space vehicle breakup and the risk posed to the aircraft in the national airspace system as well as to the people and the property on the ground. The focus of this paper is to study the problem of estimation of the extent of the airspace containing falling debris due to a space vehicle breakup. A precise computation of propagation of debris to the ground is not practical for many reasons. There is insufficient knowledge of the initial state vector; ambient wind conditions; and key parameters, including the ballistic coefficient distributions. In addition, propagation of all debris pieces to the ground would require extensive computer time. In this paper, a computationally efficient covariance propagation method is employed for the estimation of debris dispersion.}, booktitle={2013 9th Asian Control Conference (ASCC)}, publisher={IEEE}, author={Reyhanoglu, Mahmut and Alvarado, Juan and Carmi, Avishy}, year={2013}, month={Jun} } @article{reyhanoglu_rubio hervas_2013, title={Nonlinear modeling and control of slosh in liquid container transfer via a PPR robot}, volume={18}, ISSN={1007-5704}, url={http://dx.doi.org/10.1016/j.cnsns.2012.10.006}, DOI={10.1016/j.cnsns.2012.10.006}, abstractNote={This paper studies the point-to-point liquid container transfer control problem for a PPR robot. The robot manipulator is represented as three rigid links, and the liquid slosh dynamics are included using a multi-mass-spring model. It is assumed that two forces and a torque applied to the prismatic joints and the revolute joint, respectively, are available as control inputs. The objective is to control the robot end-effector movement while suppressing the sloshing modes. A nonlinear mathematical model that reflects all of these assumptions is first introduced. Then, Lyapunov-based feedback controllers are designed to achieve the control objective. Two cases are considered: partial-state feedback that does not use slosh state information and full-state feedback that uses both robot state and slosh state measurements or estimations. Computer simulations are included to illustrate the effectiveness of the proposed control laws.}, number={6}, journal={Communications in Nonlinear Science and Numerical Simulation}, publisher={Elsevier BV}, author={Reyhanoglu, Mahmut and Rubio Hervas, Jaime}, year={2013}, month={Jun}, pages={1481–1490} } @inproceedings{rubio hervas_reyhanoglu_2013, title={Observer-based nonlinear control of slosh in liquid container transfer via a PPR robot}, ISBN={9788993215052}, url={http://dx.doi.org/10.1109/iccas.2013.6704018}, DOI={10.1109/iccas.2013.6704018}, abstractNote={This paper studies the problem of observer-based control of slosh in liquid container transfer via a PPR robot. The control inputs for the PPR robot are two forces and a torque applied to the prismatic joints and the revolute joint, respectively. The control objective is point-to-point transfer of an open liquid container while suppressing the sloshing modes. A full-state feedback that uses a reduced-order observer for the estimation of the slosh state is proposed to achieve the objective. The effectiveness of the proposed observer-based control law is illustrated through a computer simulation.}, booktitle={2013 13th International Conference on Control, Automation and Systems (ICCAS 2013)}, publisher={IEEE}, author={Rubio Hervas, Jaime and Reyhanoglu, Mahmut}, year={2013}, month={Oct} } @inproceedings{hervas_reyhanoglu_2013, title={On the nonlinear modeling of systems with higher-order nonholonomic constraints}, ISBN={9788993215052}, url={http://dx.doi.org/10.1109/iccas.2013.6704064}, DOI={10.1109/iccas.2013.6704064}, abstractNote={This paper studies the nonlinear modeling problem for systems with higher-order nonholonomic constraints using tools from theoretical mechanics. A general control systems approach is developed for such systems. The applicability of the theoretical development is illustrated through a point mass moving on a constant-torsion space curve.}, booktitle={2013 13th International Conference on Control, Automation and Systems (ICCAS 2013)}, publisher={IEEE}, author={Hervas, Jaime Rubio and Reyhanoglu, Mahmut}, year={2013}, month={Oct} } @inproceedings{mackunis_subramanian_mehta_ton_curtis_reyhanoglu_2013, title={Robust nonlinear aircraft tracking control using synthetic jet actuators}, ISBN={9781467357173 9781467357142 9781479913817}, url={http://dx.doi.org/10.1109/cdc.2013.6759885}, DOI={10.1109/cdc.2013.6759885}, abstractNote={A robust, nonlinear tracking control strategy is presented for an aircraft equipped with synthetic jet actuators (SJA). The control law is designed to be easily implementable, requiring no observers, function approximators, or adaptive laws. By exploiting minimal knowledge of the structure of the nonlinear SJA dynamic model, a matrix decomposition technique is exploited to compensate for the input-multiplicative parametric uncertainty inherent in the SJA dynamics. The control law is shown to yield global asymptotic trajectory tracking in the presence of parametric uncertainty, actuator nonlinearity, and unknown, nonlinear external disturbances. A rigorous Lyapunov-based stability analysis is utilized to prove the theoretical result, and numerical simulation results are provided to demonstrate the performance of the proposed control law.}, booktitle={52nd IEEE Conference on Decision and Control}, publisher={IEEE}, author={MacKunis, W. and Subramanian, S. and Mehta, S. and Ton, C. and Curtis, J. W. and Reyhanoglu, M.}, year={2013}, month={Dec} } @inproceedings{rubio hervas_reyhanoglu_tang_2013, title={Thrust-vector control of a three-axis stabilized spacecraft with fuel slosh dynamics}, ISBN={9788993215052}, url={http://dx.doi.org/10.1109/iccas.2013.6704015}, DOI={10.1109/iccas.2013.6704015}, abstractNote={The thrust vector control problem is studied for an upper-stage rocket with fuel slosh dynamics. The sloshing propellant is modeled as a multi-mass-spring system. The coupled equations of motion of the spacecraft and the fuel are expressed in terms of the three dimensional spacecraft translational velocity vector, the attitude, the angular velocity, and the internal coordinates representing the slosh modes. A Lyapunov-based nonlinear feedback control law is proposed to control the translational velocity vector and the attitude of the spacecraft, while attenuating the sloshing modes. A simulation example is included to illustrate the effectiveness of the control law.}, booktitle={2013 13th International Conference on Control, Automation and Systems (ICCAS 2013)}, publisher={IEEE}, author={Rubio Hervas, Jaime and Reyhanoglu, Mahmut and Tang, Hui}, year={2013}, month={Oct} } @inproceedings{hervas_reyhanoglu_2012, place={New Jersey}, title={Control of a Spacecraft with Time-Varying Propellant Slosh Parameters}, booktitle={Proceedings of the 2012 12th International Conference on Control, Automation and Systems}, publisher={IEEE}, author={Hervas, J.R. and Reyhanoglu, M.}, year={2012}, pages={1621–1626} } @inproceedings{reyhanoglu_hervas_2012, title={Magnetic attitude control design for small satellites via slowly-varying systems theory}, ISBN={9781467324212 9781467324199 9781467324205}, url={http://dx.doi.org/10.1109/iecon.2012.6388706}, DOI={10.1109/iecon.2012.6388706}, abstractNote={This paper presents a three-axis attitude control algorithm for small satellites using only magnetic actuation. Such satellites are controllable only in two axes that are perpendicular to the local geomagnetic field vector at any point in time since the control torque can only be generated perpendicular to the geomagnetic field vector. We first model the attitude kinematics and dynamics in the geomagnetic frame in the form of an underactuated system. We then develop a three-axis magnetic attitude control algorithm using the theory of slowly-varying systems. The effectiveness of the proposed control law is illustrated through a computer simulation.}, booktitle={IECON 2012 - 38th Annual Conference on IEEE Industrial Electronics Society}, publisher={IEEE}, author={Reyhanoglu, Mahmut and Hervas, Jaime Rubio}, year={2012}, month={Oct} } @article{reyhanoglu_rubio hervas_2012, title={Nonlinear dynamics and control of space vehicles with multiple fuel slosh modes}, volume={20}, ISSN={0967-0661}, url={http://dx.doi.org/10.1016/j.conengprac.2012.05.011}, DOI={10.1016/j.conengprac.2012.05.011}, abstractNote={This paper studies the modeling and control problem for planar maneuvering of space vehicles with fuel slosh dynamics. A multi-mass–spring model is considered for the characterization of the most prominent sloshing modes. The control inputs are defined by the gimbal deflection angle of a non-throttable thrust engine and a pitching moment about the center of mass of the spacecraft. The control objective, as is typical in a thrust vector control design for a liquid upper stage spacecraft during orbital maneuvers, is to control the translational velocity vector and the attitude of the spacecraft, while attenuating the sloshing modes characterizing the internal dynamics. Subsequently, a nonlinear mathematical model that reflects these specifications is derived. Finally, Lyapunov-based nonlinear feedback control laws are designed to achieve the control objective. A simulation example is included to illustrate the effectiveness of the control laws.}, number={9}, journal={Control Engineering Practice}, publisher={Elsevier BV}, author={Reyhanoglu, Mahmut and Rubio Hervas, Jaime}, year={2012}, month={Sep}, pages={912–918} } @inproceedings{reyhanoglu_kamran_kuhara_2012, place={New Jersey}, title={Orbital and Attitude Control of a Spacecraft Around an Asteroid}, booktitle={Proceedings of the 2012 12th International Conference on Control, Automation and Systems}, publisher={IEEE}, author={Reyhanoglu, M. and Kamran, N. and Kuhara, T.}, year={2012}, pages={1627–1632} } @inproceedings{reyhanoglu_hervas_2012, title={Partial-state feedback control design for liquid container transfer with sloshing suppression}, ISBN={9781467324212 9781467324199 9781467324205}, url={http://dx.doi.org/10.1109/iecon.2012.6388703}, DOI={10.1109/iecon.2012.6388703}, abstractNote={This paper studies the sloshing suppression problem in point-to-point liquid container transfer via a planar Prismatic-Prismatic-Revolute (PPR) robot. The most prominent liquid sloshing modes are modeled using a mechanical analogy based on multiple mass-spring elements. The control inputs are two forces and a torque applied to the prismatic joints and the revolute joint, respectively. The control objective is to control the robot end-effector movement while suppressing the sloshing modes. A Lyapunov-based feedback controller is designed to achieve the control objective. In contrast to the full-state feedback controller we developed in our previous work, the partial-state feedback controller described in this paper does not use slosh state information. The effectiveness of the controller is demonstrated through a simulation example.}, booktitle={IECON 2012 - 38th Annual Conference on IEEE Industrial Electronics Society}, publisher={IEEE}, author={Reyhanoglu, Mahmut and Hervas, Jaime Rubio}, year={2012}, month={Oct} } @inproceedings{reyhanoglu_hervas_2012, title={Point-to-point liquid container transfer via a PPR robot with sloshing suppression}, ISBN={9781457710964 9781457710957 9781457710940 9781467321020}, url={http://dx.doi.org/10.1109/acc.2012.6314687}, DOI={10.1109/acc.2012.6314687}, abstractNote={This paper studies the point-to-point liquid container transfer control problem for a PPR robot. A multi-mass-spring model is considered for the characterization of the most prominent liquid sloshing modes. The control inputs are two forces and a torque applied to the prismatic joints and the revolute joint, respectively. The control objective is to control the robot end-effector movement while suppressing the sloshing modes. A nonlinear mathematical model that reflects all of these assumptions is first derived. Then, a Lyapunov-based nonlinear feedback controller is designed to achieve the control objective. Finally, a simulation example is included to demonstrate the effectiveness of the controller.}, booktitle={2012 American Control Conference (ACC)}, publisher={IEEE}, author={Reyhanoglu, M. and Hervas, J. R.}, year={2012}, month={Jun} } @article{reyhanoglu_hervas_2012, title={Robotically controlled sloshing suppression in point-to-point liquid container transfer}, volume={19}, ISSN={1077-5463 1741-2986}, url={http://dx.doi.org/10.1177/1077546312456865}, DOI={10.1177/1077546312456865}, abstractNote={ This paper studies the sloshing suppression problem in point-to-point liquid container transfer via a Prismatic–Prismatic–Revolute robot. A multi-mass–spring model is introduced for the characterization of the most prominent liquid-sloshing modes. The control inputs are two forces and a torque applied to the prismatic joints and the revolute joint, respectively. The control objective is to control the robot end-effector movement while suppressing the sloshing modes. A nonlinear mathematical model that reflects all of these specifications is first derived. Then, a Lyapunov-based nonlinear feedback controller is designed to achieve the control objective. Finally, a simulation example is included to demonstrate the effectiveness of the controller. }, number={14}, journal={Journal of Vibration and Control}, publisher={SAGE Publications}, author={Reyhanoglu, Mahmut and Hervas, Jaime Rubio}, year={2012}, month={Aug}, pages={2137–2144} } @inproceedings{mackunis_reyhanoglu_drakunov_2012, title={Robust and adaptive maximum power point tracking for standalone photovoltaic systems using a sliding mode control approach}, ISBN={9781457721199 9781457721182 9781457721175}, url={http://dx.doi.org/10.1109/iciea.2012.6360898}, DOI={10.1109/iciea.2012.6360898}, abstractNote={In this paper, a sliding mode control approach is amalgamated with an adaptive control method to develop a MPPT, which is capable of achieving accurate tracking in the presence of unmodeled, nonlinear, nonvanishing disturbances and parametric uncertainty. The maximum power operating point (MPOP) is calculated online using the power/voltage relationship of the PV power system, and the error system is developed with the objective of driving the PV array voltage to the time-varying MPOP. One of the MPPT design challenges is that the dynamic model contains input-multiplicative parametric uncertainty. This difficulty is circumvented via careful manipulation in the error system development, along with Lyapunov-based adaptive laws. A rigorous Lyapunov-based stability analysis is utilized to prove the theoretical result, and numerical simulation results are provided to demonstrate practical application of the proposed PV MPPT in the presence of a rapidly changing MPOP due to sudden fluctuations in temperature.}, booktitle={2012 7th IEEE Conference on Industrial Electronics and Applications (ICIEA)}, publisher={IEEE}, author={MacKunis, W. and Reyhanoglu, M. and Drakunov, S.}, year={2012}, month={Jul} } @article{rubio hervas_reyhanoglu_2012, title={Thrust Vector Control of an Upper-Stage Rocket with Multiple Propellant Slosh Modes}, volume={2012}, ISSN={1024-123X 1563-5147}, url={http://dx.doi.org/10.1155/2012/848741}, DOI={10.1155/2012/848741}, abstractNote={The thrust vector control problem for an upper-stage rocket with propellant slosh dynamics is considered. The control inputs are defined by the gimbal deflection angle of a main engine and a pitching moment about the center of mass of the spacecraft. The rocket acceleration due to the main engine thrust is assumed to be large enough so that surface tension forces do not significantly affect the propellant motion during main engine burns. A multi-mass-spring model of the sloshing fuel is introduced to represent the prominent sloshing modes. A nonlinear feedback controller is designed to control the translational velocity vector and the attitude of the spacecraft, while suppressing the sloshing modes. The effectiveness of the controller is illustrated through a simulation example.}, journal={Mathematical Problems in Engineering}, publisher={Hindawi Limited}, author={Rubio Hervas, Jaime and Reyhanoglu, Mahmut}, year={2012}, pages={848741} } @inproceedings{reyhanoglu_drakunov_mumme_2011, title={Feasibility of Space Vehicle Debris Hazard Airspace Stratification}, ISBN={9781600869532}, url={http://dx.doi.org/10.2514/6.2011-7182}, DOI={10.2514/6.2011-7182}, abstractNote={knowledge of the initial state vector, ambient wind conditions, and the key parameters including the maximum and minimum ballistic coecients. In addition, propagation of all debris pieces to the ground would require extensive computer time. In this paper, we study the feasibility in terms of the technical computational constraints needed to identify hazarded altitude layers at dierent times. We describe all assumptions employed along with their justication. Moreover, we demonstrate the sensitivity of the results to the values of key parameters including the maximum and minimum ballistic coecients of the vehicle debris, and ambient wind conditions.}, booktitle={AIAA SPACE 2011 Conference & Exposition}, publisher={American Institute of Aeronautics and Astronautics}, author={Reyhanoglu, Mahmut and Drakunov, Sergey and Mumme, Joern}, year={2011}, month={Sep} } @inproceedings{armstrong_drakunov_reyhanoglu_2011, title={Feedback Control of a Nonholonomic Vehicle among Moving Obstacles using Variable Structure Observer}, ISBN={9781600869440}, url={http://dx.doi.org/10.2514/6.2011-1586}, DOI={10.2514/6.2011-1586}, abstractNote={A feedback controller is developed for navigating a nonholonomic vehicle in an area with multiple stationary and possibly moving obstacles. Among other applications the developed algorithms can be used for automatic parking of a passenger car in a parking lot with complex conguration or a ground robot in cluttered environment. Several approaches are explored which combine nonholonomic systems control based on sliding modes and potential eld methods.}, booktitle={Infotech@Aerospace 2011}, publisher={American Institute of Aeronautics and Astronautics}, author={Armstrong, Stephen and Drakunov, Sergey and Reyhanoglu, Mahmut}, year={2011}, month={Mar} } @article{drakunov_reyhanoglu_2011, title={Hierarchical sliding mode observers for distributed parameter systems}, volume={17}, ISSN={1077-5463 1741-2986}, url={http://dx.doi.org/10.1177/1077546310370401}, DOI={10.1177/1077546310370401}, abstractNote={ In this work we suggest hierarchical sliding mode observers for complex systems which include distributed parameter systems and combinations of distributed parameter and lumped parameter systems, modeling, for example, an actuator dynamics. The main idea is based on the observer suggested previously for general nonlinear lumped parameter systems that is using the equivalent values of the discontinuous function to obtain additional information about the system state. Such observers can be written directly into system’s original variables without requiring the state transformation. In this paper, using a modal representation of the distributed system and the hierarchy of sliding modes, we develop a structure of such an observer for a wide class of systems described by partial differential equations or combinations of ordinary and partial differential equations. An example is presented which illustrates the proposed method. }, number={10}, journal={Journal of Vibration and Control}, publisher={SAGE Publications}, author={Drakunov, Sergey V and Reyhanoglu, Mahmut}, year={2011}, month={Sep}, pages={1441–1453} } @inbook{reyhanoglu_2011, place={Rijeka, Croatia}, title={Modeling and Control of Space Vehicles with Fuel Slosh Dynamics}, ISBN={9789533075518}, booktitle={Advances in Spacecraft Technologies}, publisher={InTech}, author={Reyhanoglu, M.}, editor={Hall, JasonEditor}, year={2011}, pages={549–562} } @inproceedings{reyhanoglu_rubio hervas_2011, place={New Jersey}, title={Nonlinear control of a spacecraft with multiple fuel slosh modes}, ISBN={9781612848013 9781612848006 9781467304573 9781612847993}, url={http://dx.doi.org/10.1109/cdc.2011.6160660}, DOI={10.1109/cdc.2011.6160660}, abstractNote={This paper studies the modeling and control problem for a spacecraft with fuel slosh dynamics. A multi-pendulum model is considered for the characterization of the most prominent sloshing modes. The control inputs are defined by the gimbal deflection angle of a non-throttable thrust engine and a pitching moment about the center of mass of the spacecraft. The control objective, as is typical in a thrust vector control design, is to control the translational velocity vector and the attitude of the spacecraft, while attenuating the sloshing modes. A nonlinear mathematical model that reflects all of these assumptions is first derived. Then, a Lyapunov-based nonlinear feedback controller is designed to achieve the control objective. Finally, a simulation example is included to demonstrate the effectiveness of the controller.}, booktitle={Proceedings of the 2011 50th IEEE Conference on Decision and Control and European Control Conference}, publisher={IEEE}, author={Reyhanoglu, Mahmut and Rubio Hervas, Jaime}, year={2011}, month={Dec} } @inproceedings{reyhanoglu_hervas_2011, title={Nonlinear control of space vehicles with multi-mass fuel slosh dynamics}, ISBN={9781424496174}, url={http://dx.doi.org/10.1109/rast.2011.5966834}, DOI={10.1109/rast.2011.5966834}, abstractNote={This paper studies the maneuvering control problem for space vehicles with fuel slosh dynamics in a zero gravity environment. Multi-mass-spring models are considered for the characterization of the most prominent sloshing modes. The control objective, as is typical for spacecraft maneuvering problems, is to control the translational velocity vector and the attitude of the spacecraft, while attenuating the sloshing modes characterizing the internal dynamics. Subsequently, a nonlinear mathematical model that reflects all of these assumptions is derived. Finally, a Lyapunov-based nonlinear feedback controller is designed to achieve this control objective. A simulation example is included to illustrate the effectiveness of the controller.}, booktitle={Proceedings of 5th International Conference on Recent Advances in Space Technologies - RAST2011}, publisher={IEEE}, author={Reyhanoglu, Mahmut and Hervas, Jaime Rubio}, year={2011}, month={Jun} } @inproceedings{mackunis_drakunov_reyhanoglu_ukeiley_2011, title={Nonlinear estimation of fluid flow velocity fields}, ISBN={9781612848013 9781612848006 9781467304573 9781612847993}, url={http://dx.doi.org/10.1109/cdc.2011.6161193}, DOI={10.1109/cdc.2011.6161193}, abstractNote={A proper orthogonal decomposition (POD)-based nonlinear estimator for fluid flow velocity fields is developed, which is capable of achieving finite-time convergence of the Galerkin coefficient estimates. Using Galerkin projection and POD-based model reduction, the incompressible Navier-Stokes equations are recast as a set of nonlinear ordinary differential equations in the Galerkin coefficients. A sliding-mode-based observer is designed to estimate the unknown time-varying Galerkin coefficients. Convergence of the estimates is proven to be achieved in finite time, and high-fidelity numerical simulation results are provided to complement the theoretical development.}, booktitle={IEEE Conference on Decision and Control and European Control Conference}, publisher={IEEE}, author={MacKunis, W. and Drakunov, S. V. and Reyhanoglu, M. and Ukeiley, L.}, year={2011}, month={Dec} } @inproceedings{reyhanoglu_hervas_2011, title={Three-axis magnetic attitude control algorithms for small satellites}, ISBN={9781424496174}, url={http://dx.doi.org/10.1109/rast.2011.5966973}, DOI={10.1109/rast.2011.5966973}, abstractNote={This paper studies the three-axis attitude stabilization problem for a nadir-pointing spacecraft using only magnetic torquers as actuators. Since magnetic control systems are relatively lightweight, require low power and are inexpensive, they are attractive for small, inexpensive satellites in low Earth orbits. In this paper we present three-axis attitude control algorithms for small satellites using only magnetic torquers in the presence of noise and investigate their performance through simulations. These algorithms combine ideas from averaging and linear quadratic regulation as well as sliding mode design. Computer simulations are included to illustrate the effectiveness of the proposed control laws.}, booktitle={Proceedings of 5th International Conference on Recent Advances in Space Technologies - RAST2011}, publisher={IEEE}, author={Reyhanoglu, Mahmut and Hervas, Jaime Rubio}, year={2011}, month={Jun} } @inbook{lynch_bloch_drakunov_reyhanoglu_zenkov_2010, title={Control of Nonholonomic and Underactuated Systems}, ISBN={9781420073645 9781420073652}, ISSN={1097-9409}, url={http://dx.doi.org/10.1201/b10384-49}, DOI={10.1201/b10384-49}, booktitle={The Control Systems Handbook, Second Edition}, publisher={CRC Press}, author={Lynch, Kevin and Bloch, Anthony and Drakunov, Sergey and Reyhanoglu, Mahmut and Zenkov, Dmitry}, year={2010}, month={Dec}, pages={42–1-42–36} } @article{reyhanoglu_ton_drakunov_2009, title={Attitude Stabilization of a Nadir-Pointing Small Satellite Using Only Magnetic Actuators}, volume={42}, ISSN={1474-6670}, url={http://dx.doi.org/10.3182/20090921-3-tr-3005.00052}, DOI={10.3182/20090921-3-tr-3005.00052}, abstractNote={Abstract Abstract Recently, there has been a surge of interest in small satellite missions due to low-cost launch opportunities. In particular, the feasibility of nonlinear techniques for the attitude control of small satellites using only magnetic actuators is becoming a topic of increasing interest in the literature. Since magnetic control systems are relatively lightweight, require low power and are inexpensive, they are attractive for small, inexpensive satellites in low Earth orbits. In this paper we present averaging-based feedback control laws that achieve three-axis stabilized nadir-pointing attitude. We propose nonlinear quaternion feedback laws. Two cases are considered; full state feedback that uses both attitude and angular velocity measurement and passivity-based feedback that does not require angular velocity information. Computer simulations are included to illustrate the effectiveness of the proposed control laws.}, number={19}, journal={IFAC Proceedings Volumes}, publisher={Elsevier BV}, author={Reyhanoglu, Mahmut and Ton, Chau and Drakunov, Sergey}, year={2009}, pages={292–297} } @article{reyhanoglu_drakunov_2009, title={Novel Three-Axis Attitude Control Algorithms for Small Satellites Using only Magnetic Actuators}, volume={134}, journal={Advances in the Astronautical Sciences}, author={Reyhanoglu, M. and Drakunov, S.}, year={2009}, pages={2279–2290} } @inproceedings{reyhanoglu_drakunov_savella_2009, place={San Diego, CA}, series={Advances in the Astronautical Sciences}, title={Planar Maneuvering of a Spacecraft with Propellant Sloshing Using Switched Feedback}, booktitle={Spaceflight Mechanics 2009}, publisher={American Astronautical Society/Univelt}, author={Reyhanoglu, M. and Drakunov, S.V. and Savella, P.}, editor={Segerman, A.M. and Lai, P.C. and Wilkins, M.P. and Pittelkau, M.E.Editors}, year={2009}, pages={2291–2302}, collection={Advances in the Astronautical Sciences} } @article{drakunov_reyhanoglu_singh_2009, title={Sliding Mode Control of DC-DC Power Converters}, volume={42}, ISSN={1474-6670}, url={http://dx.doi.org/10.3182/20090921-3-TR-3005.00043}, DOI={10.3182/20090921-3-TR-3005.00043}, abstractNote={Abstract Abstract The DC-DC power converters have extreme importance in contemporary applications. Moreover, the DC-DC power converters are the ideal candidates in numerous applications such as electric and hybrid vehicles, fuel cells and others. They have been extensively researched upon over three decades. The control of these converters has been often implemented using PWM techniques and based on discrete components and integrated circuits. On the other hand, application of DC-DC converters for electric and hybrid vehicles requires more effective and robust control techniques. The voltage and current ratings must be honored for safe operation and limited operation of converter circuit. In this paper we propose a novel method for the control of a buck-boost DC-DC converter with variable input voltage based on sliding mode control technique. We demonstrate that the proposed algorithm achieves robustness to variations of the converter load and the input voltage without additional sensors.}, number={19}, journal={IFAC Proceedings Volumes}, publisher={Elsevier BV}, author={Drakunov, Sergey V. and Reyhanoglu, Mahmut and Singh, Brij}, year={2009}, pages={237–242} } @inproceedings{reyhanoglu_drakunov_2008, title={Attitude stabilization of small satellites using only magnetic actuation}, ISBN={9781424417674}, url={http://dx.doi.org/10.1109/iecon.2008.4757936}, DOI={10.1109/iecon.2008.4757936}, abstractNote={Recently there has been a great deal of excitement over the emergence of new techniques for the attitude control of small satellites. In particular, the feasibility of nonlinear techniques for the attitude control of small satellites using only magnetic actuators is becoming a topic of increasing interest in the literature. Since magnetic control systems are relatively lightweight, require low power and are inexpensive, they are attractive for small, inexpensive satellites in low Earth orbits. Although the magnetic torques that can be applied to the spacecraft for attitude control purposes are constrained to lie in the plane orthogonal to the magnetic field vector, three-axis magnetic stabilization is still possible as the variability of the magnetic field along the considered orbit is sufficient to guarantee the stabilizability of the spacecraft. In this paper we present novel three-axis attitude control algorithms for small satellites using only magnetic torquers and investigate their performance through simulations.}, booktitle={2008 34th Annual Conference of IEEE Industrial Electronics}, publisher={IEEE}, author={Reyhanoglu, M. and Drakunov, S.}, year={2008}, month={Nov} } @inproceedings{reyhanoglu_dyer_2008, place={New Jersey}, title={Control system design and simulation of spacecraft formations}, ISBN={9781424417674}, url={http://dx.doi.org/10.1109/iecon.2008.4757939}, DOI={10.1109/iecon.2008.4757939}, abstractNote={This paper presents an effective control scheme for spacecraft formations. Modifying earlier established control design techniques, feedback laws are constructed to control translational and rotational motion of a group of spacecraft. Computer simulations are carried out to illustrate the effectiveness of the control laws. The ephemeris and attitude data generated through the simulations are used to create 3D visualizations.}, booktitle={2008 34th Annual Conference of IEEE Industrial Electronics}, publisher={IEEE}, author={Reyhanoglu, M. and Dyer, D.}, year={2008}, month={Nov} } @inproceedings{reyhanoglu_2008, title={Slewing maneuver of a flexible spacecraft using finite time control}, ISBN={9781424417674}, url={http://dx.doi.org/10.1109/iecon.2008.4758378}, DOI={10.1109/iecon.2008.4758378}, abstractNote={The slew-maneuver control problem is studied for a flexible spacecraft consisting of a rigid main body to which a long flexible appendage is attached. A nonlinear dynamical system model is first developed using a distributed parameter modeling technique. A filtered finite time control law is then introduced to achieve fast and precise slewing maneuvers without residual vibrations. The results are applied to a benchmark flexible system and a simulation example is included to illustrate the effectiveness of the proposed control technique.}, booktitle={2008 34th Annual Conference of IEEE Industrial Electronics}, publisher={IEEE}, author={Reyhanoglu, M.}, year={2008}, month={Nov} } @inproceedings{reyhanoglu_de loo_2006, title={Rest-to-rest Maneuvering of a Nonholonomic Control Moment Gyroscope}, ISBN={1424404975 1424404967}, url={http://dx.doi.org/10.1109/isie.2006.295585}, DOI={10.1109/isie.2006.295585}, abstractNote={This paper studies a restricted control moment gyroscope (CMG), which constitutes a remarkable example of a nonholonomic system that arises as a consequence of its symmetry properties. A nonholonomic control system formulation is first introduced for the restricted CMG dynamics. The geometric phase technique is then used to design a feedback control algorithm for the control of the CMG system to a desired equilibrium. The effectiveness of the feedback control algorithm is illustrated through both numerical simulations and experimental results}, booktitle={2006 IEEE International Symposium on Industrial Electronics}, publisher={IEEE}, author={Reyhanoglu, Mahmut and De Loo, Jasper}, year={2006}, month={Jul} } @inproceedings{reyhanoglu_van de loo_2006, title={State Feedback Tracking of a Nonholonomic Control Moment Gyroscope}, ISBN={1424401712}, url={http://dx.doi.org/10.1109/cdc.2006.377590}, DOI={10.1109/cdc.2006.377590}, abstractNote={This paper describes how to use a cascaded back-stepping approach to develop state feedback control laws for the tracking of a restricted control moment gyroscope (CMG), which constitutes a remarkable example of a nonholonomic system that arises as a consequence of its symmetry properties. A nonholonomic control system formulation is first introduced for the restricted CMG dynamics. The backstepping technique is then used to design a state feedback control law for the tracking of the CMG system. The paper provides detailed derivations along with numerical simulations and experimental results to illustrate the effectiveness of the tracking controller}, booktitle={Proceedings of the 45th IEEE Conference on Decision and Control}, publisher={IEEE}, author={Reyhanoglu, Mahmut and van de Loo, Jasper}, year={2006} } @inproceedings{reyhanoglu_geluk_2006, title={Switched Feedback Tracking Control of a Nonholonomic Mobile Robot}, ISBN={1424403901 142440391X}, ISSN={1553-572X}, url={http://dx.doi.org/10.1109/iecon.2006.347507}, DOI={10.1109/iecon.2006.347507}, abstractNote={This paper studies the tracking problem for a car-like nonholonomic mobile robot. A switched feedback control law is developed to achieve global tracking. The control law avoids singularities arising from coordinate transformations used to describe the robot kinematics in chained form. The paper provides a detailed derivation of the control law. Simulation examples are included to illustrate the effectiveness of the tracking controller}, booktitle={IECON 2006 - 32nd Annual Conference on IEEE Industrial Electronics}, publisher={IEEE}, author={Reyhanoglu, Mahmut and Geluk, Theo}, year={2006}, month={Nov} } @inproceedings{reyhanoglu_bommer_2006, place={New Jersey}, title={Tracking Control of an Underactuated Autonomous Surface Vessel Using Switched Feedback}, ISBN={1424403901 142440391X}, ISSN={1553-572X}, url={http://dx.doi.org/10.1109/iecon.2006.347539}, DOI={10.1109/iecon.2006.347539}, abstractNote={This paper studies the tracking problem for an underactuated autonomous surface vessel. The research extends earlier backstepping designs for underactuated systems by constructing a switched feedback control law to achieve global tracking. The control law avoids singularities arising from coordinate transformations used to describe the surface vessel dynamics in second-order chained form. The paper provides a detailed derivation of the control law. Simulation examples are included to illustrate the effectiveness of the tracking controller}, booktitle={Proceedings of IECON 2006 - 32nd Annual Conference on IEEE Industrial Electronics}, publisher={IEEE}, author={Reyhanoglu, Mahmut and Bommer, Ard}, year={2006}, month={Nov} } @article{mahindrakar_banavar_reyhanoglu_2005, title={Controllability and Point-to-Point Control of 3-DOF Planar Horizontal Underactuated Manipulators}, volume={78}, DOI={10.1080/00207170412331317422}, abstractNote={This paper presents the controllability properties of an underactuated 3R manipulator and the application of a discontinuous point-to-point control law for a three-degree-of-freedom (DOF) PPR manipulator. In the first half we present a controllability analysis at various actuator configurations of the manipulator. A novel contribution is that we use a single co-ordinate system to analyse the controllability at all the three possible configurations. In the second half we present a discontinuous feedback control law for point-to-point control of a 3 DOF PPR underactuated manipulator moving in a horizontal plane. Simulation results are presented that demonstrate the effectiveness of the controller.}, number={1}, journal={International Journal of Control}, author={Mahindrakar, A.D. and Banavar, R.N. and Reyhanoglu, M.}, year={2005}, month={Jan}, pages={1–13} } @inproceedings{reyhanoglu_2004, place={New Jersey}, title={Maneuvering control problems for a spacecraft with unactuated fuel slosh dynamics}, ISBN={078037729X}, url={http://dx.doi.org/10.1109/cca.2003.1223522}, DOI={10.1109/cca.2003.1223522}, abstractNote={This paper studies maneuvering control problems for a spacecraft with fuel slosh in a zero gravity environment. The spacecraft is represented as a rigid body and fuel slosh dynamics are included using a single vibrating mass model. Both pendulum and mass-spring analogies are considered. The control inputs are defined by a thrust along the spacecraft's longitudinal axis, a transverse body fixed force and a pitching moment about the center of mass of the spacecraft. The control objective is to suppress the slosh mode, as well as the transverse and pitch dynamics, while the spacecraft accelerates in axial direction. A nonlinear feedback controller is developed to achieve this objective.}, booktitle={Proceedings of 2003 IEEE Conference on Control Applications, 2003. CCA 2003.}, publisher={IEEE}, author={Reyhanoglu, M.}, year={2004}, month={Mar} } @article{bryson,_reyhanoglu,_2003, title={Applied Linear Optimal Control: Examples and Algorithms}, volume={56}, ISSN={0003-6900 2379-0407}, url={http://dx.doi.org/10.1115/1.1579457}, DOI={10.1115/1.1579457}, abstractNote={Preface 1. Static estimation 2. Random processes 3. Dynamic estimation - filters 4. Dynamic estimation - smoothers 5. LQ SFB follower-controllors 6. LQG follower-controllers 7. Smoothers for controlled plants 8. Time-invariant filters 9. Time-invariant LQ SFB follower-controllers 10. Time-invariant LQG follower-controllers 11. Worst case controllers 12. Robust TI LQG controllers Appendices References Index.}, number={4}, journal={Applied Mechanics Reviews}, publisher={ASME International}, author={Bryson,, AE, Author and Reyhanoglu,, M, Reviewer}, year={2003}, month={Jul}, pages={B55–B56} } @inproceedings{mahindrakar_banavar_reyhanoglu_2003, place={New Jersey}, title={Discontinuous feedback control of a 3 link planar PPR underactuated manipulator}, ISBN={0780370619}, url={http://dx.doi.org/10.1109/cdc.2001.980626}, DOI={10.1109/cdc.2001.980626}, abstractNote={In this paper we consider the synthesis of a point-to-point control law for a three degrees of freedom planar PPR underactuated manipulator moving in a horizontal plane. We apply a discontinuous feedback controller construction derived for a special class of underactuated systems. By using a coordinate transformation, we transform the system into chained form which makes it suitable for the application of the discontinuous control law. Simulation results are presented that demonstrate the effectiveness of the controller.}, booktitle={Proceedings of the 40th IEEE Conference on Decision and Control (Cat. No.01CH37228)}, publisher={IEEE}, author={Mahindrakar, A.D. and Banavar, R.N. and Reyhanoglu, M.}, year={2003}, month={Jul} } @inproceedings{reyhanoglu_2003, place={New Jersey}, title={Feedback control of an underactuated system with two unactuated degrees of freedom}, ISBN={0780370619}, url={http://dx.doi.org/10.1109/cdc.2001.980838}, DOI={10.1109/cdc.2001.980838}, abstractNote={Studies the problem of controlling a planar rigid body containing a sliding block, which represents an underactuated mechanical system with two unactuated degrees of freedom. The main result of the paper is the construction of a point-to-point discontinuous feedback controller for the system by utilizing the nonlinear coupling between the directly actuated degrees of freedom and the unactuated degrees of freedom.}, booktitle={Proceedings of the 40th IEEE Conference on Decision and Control (Cat. No.01CH37228)}, publisher={IEEE}, author={Reyhanoglu, M.}, year={2003}, month={Jul} } @article{reyhanoglu_2003, title={Mechatronic control of distributed noise and vibration: A Lyapunov approach}, volume={39}, ISSN={0005-1098}, url={http://dx.doi.org/10.1016/s0005-1098(03)00145-6}, DOI={10.1016/s0005-1098(03)00145-6}, abstractNote={Compliant actuators are essential for ensuring safety in physical human-robot interaction. A compact-sized series elastic actuator (SEA), a type of compliant actuators, was developed to guarantee high force control fidelity and low output impedance in our previous work. This study is focused on the control design of a compliant robot arm driven by the developed SEA. The control problem is formulated into a singularly perturbed form which contains a slow rigid robot dynamics and a fast SEA dynamics. To achieve high-precision tracking without serious control chattering, a second-order sliding mode control (SMC) law is proposed such that the equilibrium point of the closed-loop rigid robot dynamics has semiglobal exponential stability. A derivative-type control law is employed such that the equilibrium point of the closed-loop SEA dynamics has global exponential stability. As the SMC law developed is continuous so that the rigid robot dynamics is continuously differentiable, the singular perturbation theory is applicable to establish semiglobal practical exponential stability of the entire system. This study provides the first application of continuous SMC to robots driven by compliant actuators. Experimental results have verified a high-accuracy and high-resolution tracking performance of the robot control system.}, number={9}, journal={Automatica}, publisher={Elsevier BV}, author={Reyhanoglu, Mahmut}, year={2003}, month={Sep}, pages={1664–1666} } @inproceedings{reyhanoglu_cho_mcclamroch_2000, title={Control Problems for Planar Maneuvers of a Spacecraft with Fuel Slosh}, booktitle={Proceedings of the International Conference on Nonlinear Problems in Aviation}, author={Reyhanoglu, M. and Cho, S. and McClamroch, N.H.}, year={2000}, pages={579–584} } @article{reyhanoglu_cho_harris mcclamroch_2000, title={Discontinuous feedback control of a special class of underactuated mechanical systems}, volume={10}, ISSN={1049-8923 1099-1239}, url={http://dx.doi.org/10.1002/(sici)1099-1239(20000415)10:4<265::aid-rnc470>3.0.co;2-n}, DOI={10.1002/(sici)1099-1239(20000415)10:4<265::aid-rnc470>3.0.co;2-n}, abstractNote={We study a control problem for a special class of underactuated mechanical systems, namely for mechanical systems with several directly actuated degrees of freedom and a single unactuated degree of freedom that must be controlled through the system coupling. Specific assumptions are introduced that define this class, which includes many important models of mechanical system examples. The main result of the paper is the construction of a discontinuous nonlinear feedback controller for which the closed loop equilibrium at the origin is made ‘globally attractive’. The control construction approach is introduced in detail, and a proof of attractiveness is presented. The results are applied to control of the planar motion of a rigid body with a single unactuated internal degree of freedom. Copyright © 2000 John Wiley & Sons, Ltd.}, number={4}, journal={International Journal of Robust and Nonlinear Control}, publisher={Wiley}, author={Reyhanoglu, Mahmut and Cho, Sangbum and Harris McClamroch, N.}, year={2000}, month={Apr}, pages={265–281} } @inproceedings{cho_mcclamroch_reyhanoglu_2000, place={New Jersey}, title={Dynamics of multibody vehicles and their formulation as nonlinear control systems}, ISBN={0780355199}, url={http://dx.doi.org/10.1109/acc.2000.876955}, DOI={10.1109/acc.2000.876955}, abstractNote={We develop equations of motion for multibody vehicles that can be used for nonlinear system analysis and control design. A multibody vehicle consists of a base body that can undergo general motion in three dimensions, as well as a finite number of body interconnections that can deform relative to the base body and hence define the shape of the multibody. A Lagrangian development leads to equations of motion that are expressed in terms of the locked inertia and the mechanical connection. We show that the equations of motion can be written in terms of the base body translational and angular momentum (or equivalently the base body translational and angular velocities) and generalized coordinates for the shape. The coupling between the base body translational and rotational dynamics and the shape dynamics is made clear in this formulation. We define several fundamental categories of underactuated control problems, based on specific control actuation assumptions.}, booktitle={Proceedings of the 2000 American Control Conference. ACC (IEEE Cat. No.00CH36334)}, publisher={IEEE}, author={Cho, Sangbum and McClamroch, N.H. and Reyhanoglu, M.}, year={2000} } @inproceedings{cho_mcclamroch_reyhanoglu_2000, title={Feedback control of a space vehicle with unactuated fuel slosh dynamics}, ISBN={9781624103018}, url={http://dx.doi.org/10.2514/6.2000-4046}, DOI={10.2514/6.2000-4046}, abstractNote={We develop a mathematical model that describes the accelerating flight of a spacecraft in a fixed plane. The spacecraft is represented as a rigid body and fuel slosh dynamics are included using a common pendulum model. The control inputs are defined by a transverse body fixed force and a pitching moment about the center of mass of the spacecraft; the slosh dynamics are assumed to be unactuated. The model is placed in the form of a nonlinear control system that allows for the study of planar vehicle maneuvers. We develop a nonlinear feedback controller that stabilizes a relative equilibrium corresponding to suppression of the transverse, pitch, and slosh dynamics. This controller is a significant extension of what has been done previously, since it simultaneousl y controls both the rigid vehicle motion and the fuel slosh dynamics.}, booktitle={AIAA Guidance, Navigation, and Control Conference and Exhibit}, publisher={American Institute of Aeronautics and Astronautics}, author={Cho, Sangbum and McClamroch, M. and Reyhanoglu, Mahmut}, year={2000}, month={Aug} } @article{reyhanoglu_van der schaft_mcclamroch_kolmanovsky_1999, title={Dynamics and control of a class of underactuated mechanical systems}, volume={44}, ISSN={0018-9286}, url={http://dx.doi.org/10.1109/9.788533}, DOI={10.1109/9.788533}, abstractNote={This paper presents a theoretical framework for the dynamics and control of underactuated mechanical systems, defined as systems with fewer inputs than degrees of freedom. Control system formulation of underactuated mechanical systems is addressed and a class of underactuated systems characterized by nonintegrable dynamics relations is identified. Controllability and stabilizability results are derived for this class of underactuated systems. Examples are included to illustrate the results; these examples are of underactuated mechanical systems that are not linearly controllable or smoothly stabilizable.}, number={9}, journal={IEEE Transactions on Automatic Control}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Reyhanoglu, M. and van der Schaft, A. and Mcclamroch, N.H. and Kolmanovsky, I.}, year={1999}, pages={1663–1671} } @inproceedings{reyhanoglu_cho_mcclamroch_1999, place={New Jersey}, title={Feedback control for planar maneuvers of an aerospace vehicle with an unactuated internal degree of freedom}, ISBN={0780349903}, url={http://dx.doi.org/10.1109/acc.1999.782402}, DOI={10.1109/acc.1999.782402}, abstractNote={We study feedback control laws that enable an aerospace vehicle to perform planar maneuvers. We make several key assumptions including: (1) maneuvers are planar, (2) a complete set of vehicle control forces and moments is available, (3) the vehicle is a rigid body with a single unactuated internal degree of freedom. The control objective is to design a feedback controller so that the controlled vehicle accomplishes a given planar maneuver, that is a change in the translational velocity vector and the attitude of the vehicle, while rapidly attenuating any relative motion of the internal degree of freedom. A time-invariant discontinuous feedback law is constructed that achieves these control objectives with exponential convergence rates. The effectiveness of the proposed feedback law is illustrated through a simulation example.}, booktitle={Proceedings of the 1999 American Control Conference (Cat. No. 99CH36251)}, publisher={IEEE}, author={Reyhanoglu, M. and Cho, S. and McClamroch, N.H.}, year={1999} } @inproceedings{reyhanoglu_cho_mcclamroch_1999, place={New Jersey}, title={Feedback control of a planar manipulator with an unactuated elastically mounted end effector}, volume={4}, DOI={10.1109/ROBOT.1999.774022}, abstractNote={We study feedback control laws that can stabilize an equilibrium position of an underactuated planar PPR robot manipulator. The manipulator operates in a horizontal plane, and it consists of two actuated prismatic links, an actuated revolute link, and an unactuated end effector that is elastically mounted on the third link. The fact that the end effector is unactuated and is elastically mounted on the manipulator, and thus can be controlled only through coupling with the manipulator dynamics, provides a major obstacle to control design for this problem. The control objective is to design a feedback controller that can achieve arbitrary positioning and arbitrary attitude of the end effector while suppressing any motion of the end effector relative to the third link. A nonlinear control model is constructed for this underactuated manipulator and a time-invariant discontinuous feedback law is constructed that achieves the objectives with exponential convergence rates. The effectiveness of the proposed feedback law is illustrated through simulations.}, booktitle={Proceedings 1999 IEEE International Conference on Robotics and Automation}, publisher={IEEE}, author={Reyhanoglu, M. and Cho, S. and McClamroch, N.H.}, year={1999}, pages={2805–2810} } @inproceedings{reyhanoglu_cho_mcclamroch_1999, place={New Jersey}, title={Feedback stabilization for a special class of underactuated mechanical systems}, volume={2}, DOI={10.1109/CDC.1999.830262}, abstractNote={We study feedback controllers that can stabilize the equilibrium of a special class of underactuated mechanical systems, namely mechanical systems with several directly actuated degrees of freedom and a single unactuated degree of freedom that must be controlled through the system coupling. Theoretical controllability and stabilizability results for a large class of such underactuated mechanical systems have been developed in our previous work. Here we propose feedback controllers so that a closed loop equilibrium is globally attractive. The proposed construction procedure depends on selection of a scalar configuration variable corresponding to a directly actuated degree of freedom so that the dynamics of the unactuated degree of freedom, after a rational coordinate transformation, has a special form. The construction procedure is introduced, and a number of possible modifications are suggested. This construction procedure unifies controllers that we have developed for particular examples, including an underactuated ship, a planar rigid body containing an unactuated internal degree of freedom, a planar manipulator with an unactuated elastically mounted end effector, and an aerospace vehicle with an unactuated internal degree of freedom.}, booktitle={Proceedings of the 38th IEEE Conference on Decision and Control}, publisher={IEEE}, author={Reyhanoglu, M. and Cho, S. and McClamroch, N.H.}, year={1999}, pages={1658–1663} } @inproceedings{mcclamroch_rui_kolmanovsky_cho_reyhanoglu_1998, title={Control problems for planar motion of a rigid body with an unactuated internal degree of freedom}, ISBN={0780345304}, url={http://dx.doi.org/10.1109/acc.1998.694665}, DOI={10.1109/acc.1998.694665}, abstractNote={We study control problems for a specific mechanical system consisting of a rigid base body with an unactuated internal degree of freedom. The key assumptions are that the translational and rotational motion of the base body can be completely controlled by external forces and moments, while the internal degree of freedom is unactuated. This specific example is representative of a class of underactuated mechanical control systems that are not linearly controllable. This class of control problems presents major theoretical and practical difficulties, and such models do arise in important terrestrial and spacecraft applications. Our focus in this paper is on the simplest mechanical example in this class; it illustrates important features and difficulties associated with the class of such problems.}, booktitle={Proceedings of the 1998 American Control Conference. ACC (IEEE Cat. No.98CH36207)}, publisher={IEEE}, author={McClamroch, N.H. and Rui, Chunlei and Kolmanovsky, I. and Cho, Sangbum and Reyhanoglu, M.}, year={1998} } @inproceedings{reyhanoglu_cho_mcclamroch_kolmanovsky_1998, place={New Jersey}, title={Discontinuous feedback control of a planar rigid body with an unactuated degree of freedom}, ISBN={0780343948}, url={http://dx.doi.org/10.1109/cdc.1998.760714}, DOI={10.1109/cdc.1998.760714}, abstractNote={We study the problem of controlling a specific mechanical system consisting of a rigid base body with an unactuated internal degree of freedom. The key assumptions are that the translational and rotational motion of the base body can be completely controlled by external forces and moments, while the internal degree of freedom is unactuated. It was shown in our previous work (1998) that although the system is not asymptotically stabilizable to a given configuration using a time-invariant continuous feedback, it is strongly accessible and small-time locally controllable at any equilibrium. We construct a time-invariant discontinuous feedback law to control the system to the desired configuration with exponential convergence rates. A simulation example is included to demonstrate the results.}, booktitle={Proceedings of the 37th IEEE Conference on Decision and Control (Cat. No.98CH36171)}, publisher={IEEE}, author={Reyhanoglu, M. and Cho, Sangbum and McClamroch, N.H. and Kolmanovsky, I.}, year={1998}, month={Nov} } @article{escobar_ortega_reyhanoglu_1998, title={Regulation and tracking of the nonholonomic double integrator: A field-oriented control approach}, volume={34}, ISSN={0005-1098}, url={http://dx.doi.org/10.1016/s0005-1098(97)00155-6}, DOI={10.1016/s0005-1098(97)00155-6}, abstractNote={In this paper we show how a slight modification to the well-known field-oriented control of induction motors allows us to provide simple solutions to the problems of global regulation and tracking for the nonholonomic double integrator. Two controllers are proposed, one motivated by the well-known direct field-oriented motor control, which is a simple continuous static-state feedback that guarantees exponential convergence for all initial conditions in R3 — {x2 = x2 = 0}. To overcome the latter restriction we add a dynamic extension to transfer this (initial conditions) singularity to the controller state, hence making the stability global. This controller is a direct outgrowth of indirect field oriented motor control. In view of the well-known Brockett's condition we obviously do not ensure Lyapunov stability.}, number={1}, journal={Automatica}, publisher={Elsevier BV}, author={Escobar, G. and Ortega, R. and Reyhanoglu, M.}, year={1998}, month={Jan}, pages={125–131} } @article{reyhanoglu_1997, title={Exponential stabilization of an underactuated autonomous surface vessel}, volume={33}, ISSN={0005-1098}, url={http://dx.doi.org/10.1016/s0005-1098(97)00141-6}, DOI={10.1016/s0005-1098(97)00141-6}, abstractNote={This paper studies the problem of controlling the planar position and orientation of an autonomous surface vessel using two independent thrusters. It is first shown that although the system is not asymptotically stabilizable to a given configuration using a time-invariant continuous feedback, it is strongly accessible and small-time locally controllable at any equilibrium. Time-invariant discontinuous feedback laws are then constructed to asymptotically stabilize the system to the desired configuration with exponential convergence rates. A simulation example is included to demonstrate the results.}, number={12}, journal={Automatica}, publisher={Elsevier BV}, author={Reyhanoglu, Mahmut}, year={1997}, month={Dec}, pages={2249–2254} } @inproceedings{reyhanoglu_1997, title={Feedback control of a flexible joint robot}, ISBN={9783952426906}, url={http://dx.doi.org/10.23919/ecc.1997.7082602}, DOI={10.23919/ecc.1997.7082602}, abstractNote={This paper studies the problem of controlling a super-articulated robot manipulator with joint elasticity. A control design constraint involving generalized accelerations is first imposed for controlling the manipulator motion without storing elastic energy. A nonlinear control system formulation is then introduced to describe the constrained manipulator dynamics. Following a controllability and stabilizability analysis, a time-invariant discontinuous feedback law is constructed to control the manipulator to a desired configuration without excitation of its elastic degree of freedom. The effectiveness of the proposed feedback control law is illustrated through a simulation example.}, booktitle={1997 European Control Conference (ECC)}, publisher={IEEE}, author={Reyhanoglu, Mahmut}, year={1997}, month={Jul} } @inproceedings{mcclamroch_rui_kolmanobsky_reyhanoglu_1997, place={New Jersey}, title={Hybrid closed loop systems: a nonlinear control perspective}, ISBN={0780341872}, url={http://dx.doi.org/10.1109/cdc.1997.650599}, DOI={10.1109/cdc.1997.650599}, abstractNote={A survey of hybrid closed loop control problems that arise from the use of hybrid controllers to control smooth nonlinear systems is presented. This is a special class of hybrid closed loop systems, but they are of substantial interest in identifying the value of hybrid control as a generalization of classical control approaches for nonlinear systems.}, booktitle={Proceedings of the 36th IEEE Conference on Decision and Control}, publisher={IEEE}, author={McClamroch, N.H. and Rui, C. and Kolmanobsky, I. and Reyhanoglu, M.}, year={1997} } @inproceedings{rui_reyhanoglu_kolmanovsky_cho_mcclamroch_1997, place={New Jersey}, title={Nonsmooth stabilization of an underactuated unstable two degrees of freedom mechanical system}, ISBN={0780341872}, url={http://dx.doi.org/10.1109/cdc.1997.652490}, DOI={10.1109/cdc.1997.652490}, abstractNote={This paper studies a specific mechanical example that is representative of a class of underactuated, weakly coupled, unstable mechanical systems that are exceptionally difficult to stabilize. In particular, systems in this class are not stabilizable using static smooth feedback but are stabilizable using nonsmooth feedback. Although similar purely theoretical developments have been previously presented, we emphasize the physical basis and physical implications of the theoretical conclusions in the context of a specific example. The development in this paper is limited to a specific physical example, but the approach is applicable to a wide class of underactuated, weakly coupled, unstable mechanical systems.}, booktitle={Proceedings of the 36th IEEE Conference on Decision and Control}, publisher={IEEE}, author={Rui, C. and Reyhanoglu, M. and Kolmanovsky, I. and Cho, S. and McClamroch, N.H.}, year={1997}, month={Nov} } @inproceedings{reyhanoglu_1996, place={New Jersey}, title={Control and stabilization of an underactuated surface vessel}, ISBN={0780335902}, url={http://dx.doi.org/10.1109/cdc.1996.573439}, DOI={10.1109/cdc.1996.573439}, abstractNote={This paper studies the problem of controlling the planar position and orientation of an autonomous surface vessel using two independent thrusters. It is first shown that although the system is not asymptotically stabilizable to a given equilibrium configuration using a time-invariant continuous feedback, it is strongly accessible and small-time locally controllable at any equilibrium. Time-invariant discontinuous feedback control laws are then constructed to asymptotically stabilize the system to the desired configuration with exponential convergence rates. A simulation example is included to demonstrate the results.}, booktitle={Proceedings of 35th IEEE Conference on Decision and Control}, publisher={IEEE}, author={Reyhanoglu, M.}, year={1996}, month={Dec} } @inproceedings{reyhanoglu_1996, place={Singapore}, title={Control of a Super-Articulated Robot Manipulator with Joint Elasticity}, volume={1}, booktitle={Proceedings of the 4th International Conference on Control, Automation, Robotics and Vision}, publisher={NTU}, author={Reyhanoglu, M.}, year={1996}, pages={172–176} } @inproceedings{reyhanoglu_1996, place={New Jersey}, title={Discontinuous feedback stabilization of the angular velocity of a rigid body with two control torques}, ISBN={0780335902}, url={http://dx.doi.org/10.1109/cdc.1996.573511}, DOI={10.1109/cdc.1996.573511}, abstractNote={There has been much interest over the past decade in the problem of asymptotic stabilization of the angular velocity of a rigid body with only two torque inputs. The smooth feedback laws proposed in the literature provide asymptotic stability with nonexponential convergence rates. This paper proposes discontinuous feedback laws to achieve asymptotic stability with exponential convergence rates.}, booktitle={Proceedings of 35th IEEE Conference on Decision and Control}, publisher={IEEE}, author={Reyhanoglu, N.}, year={1996} } @inproceedings{reyhanoglu_van der schaft_mcclamroch_kolmanovsky_1996, place={New Jersey}, title={Nonlinear control of a class of underactuated systems}, ISBN={0780335902}, url={http://dx.doi.org/10.1109/cdc.1996.572793}, DOI={10.1109/cdc.1996.572793}, abstractNote={A theoretical framework is established for the dynamics and control of underactuated systems, defined as systems which have fewer inputs than degrees of freedom. Control system formulation of underactuated systems is addressed and the class of second-order nonholonomic systems is identified. Controllability and stabilizability results are derived for this class of underactuated systems. Examples are included to illustrate the results.}, booktitle={Proceedings of 35th IEEE Conference on Decision and Control}, publisher={IEEE}, author={Reyhanoglu, M. and van der Schaft, A. and McClamroch, N.H. and Kolmanovsky, I.}, year={1996}, month={Dec} } @article{kolmanovsky_reyhanoglu_mcclamroch_1996, title={Switched mode feedback control laws for nonholonomic systems in extended power form}, volume={27}, ISSN={0167-6911}, url={http://dx.doi.org/10.1016/0167-6911(95)00036-4}, DOI={10.1016/0167-6911(95)00036-4}, abstractNote={A class of nonholonomic control systems in extended power form is studied. It is demonstrated that under appropriate assumptions Lagrange's equations, including classical nonholonomic constraints, can be transformed into the extended power form. A switched mode feedback controller is used to obtain global convergence of the states of the extended power form to the origin. This feedback controller can be interpreted as a hybrid system consisting of a high level discrete event supervisor and a family of low level feedback controllers. The closed loop system exhibits finite-time responses.}, number={1}, journal={Systems & Control Letters}, publisher={Elsevier BV}, author={Kolmanovsky, Ilya and Reyhanoglu, Mahmut and McClamroch, N.Harris}, year={1996}, month={Jan}, pages={29–36} } @inproceedings{reyhanoglu_van der schaft_1996, place={Singpaore}, title={Velocity Stabilization of an Underactuated Rigid Body}, volume={3}, booktitle={Proceedings of the 4th International Conference on Control, Automation, Robotics and Vision}, publisher={NTU}, author={Reyhanoglu, M. and van der Schaft, A.J.}, year={1996}, pages={2065–2069} } @article{krishnan_mcclamroch_reyhanoglu_1995, title={Attitude stabilization of a rigid spacecraft using two momentum wheel actuators}, volume={18}, ISSN={0731-5090 1533-3884}, url={http://dx.doi.org/10.2514/3.21378}, DOI={10.2514/3.21378}, abstractNote={It is well known that three momentum wheel actuators can be used to control the attitude of a rigid spacecraft and that arbitrary reorientation maneuvers of the spacecraft can be accomplished using smooth feedback. If failure of one of the momentum wheel actuators occurs, we demonstrate that two momentum wheel actuators can be used to control the attitude of a rigid spacecraft and that arbitrary reorientation maneuvers of the spacecraft can be accomplished. Although the complete spacecraft equations are not controllable, the spacecraft equations are controllable under the restriction that the total angular momentum vector of the system is zero. The spacecraft dynamics under such a restriction cannot be asymptotically stabilized to any equilibrium attitude using a timeinvariant continuous feedback control law, but discontinuous feedback control strategies are constructed that stabilize any equilibrium attitude of the spacecraft in finite time. Consequently, reorientation of the spacecraft can be accomplished using discontinuous feedback control.}, number={2}, journal={Journal of Guidance, Control, and Dynamics}, publisher={American Institute of Aeronautics and Astronautics (AIAA)}, author={Krishnan, Hariharan and McClamroch, N. Harris and Reyhanoglu, Mahmut}, year={1995}, month={Mar}, pages={256–263} } @article{reyhanoglu_bloch_harris mcclamroch_1995, title={Control of nonholonomic systems with extended base space dynamics}, volume={5}, ISSN={1049-8923 1099-1239}, url={http://dx.doi.org/10.1002/rnc.4590050408}, DOI={10.1002/rnc.4590050408}, abstractNote={Abstract}, number={4}, journal={International Journal of Robust and Nonlinear Control}, publisher={Wiley}, author={Reyhanoglu, Mahmut and Bloch, Anthony M. and Harris Mcclamroch, N.}, year={1995}, pages={325–330} } @inproceedings{reyhanoglu_1995, place={New Jersey}, title={On the stabilization of a class of nonholonomic systems using invariant manifold technique}, ISBN={0780326857}, url={http://dx.doi.org/10.1109/cdc.1995.480515}, DOI={10.1109/cdc.1995.480515}, abstractNote={This paper presents an asymptotically stabilizing discontinuous feedback controller for a class of nonholonomic systems. The controller consists of two parts: the first part yields an invariant manifold on which all trajectories of the closed-loop system tend to the origin, and the latter part renders the invariant manifold attractive, while avoiding a discontinuity surface. The controller yields exponential stability so that the convergence can be chosen arbitrarily fast.}, booktitle={Proceedings of 1995 34th IEEE Conference on Decision and Control}, publisher={IEEE}, author={Reyhanoglu, M.}, year={1995}, month={Nov} } @inproceedings{reyhanoglu_1994, place={New Jersey}, title={A general nonholonomic motion planning strategy for Caplygin systems}, ISBN={0780319680}, url={http://dx.doi.org/10.1109/cdc.1994.411341}, DOI={10.1109/cdc.1994.411341}, abstractNote={This paper studies the kinematic path planning problem for Caplygin systems, i.e. nonholonomic systems with special symmetry properties. Such systems admit local coordinate representation in which the constraint equations are cyclic in certain variables. A nonlinear control system model describing the kinematics of a Caplygin system is first introduced. An algorithm for constructing a path between specified initial and final configurations of the system is then presented. The algorithm utilizes tools from differential geometric control theory.<>}, booktitle={Proceedings of 1994 33rd IEEE Conference on Decision and Control}, publisher={IEEE}, author={Reyhanoglu, M.}, year={1994}, month={Dec} } @article{krishnan_reyhanoglu_mcclamroch_1994, title={Attitude stabilization of a rigid spacecraft using two control torques: A nonlinear control approach based on the spacecraft attitude dynamics}, volume={30}, ISSN={0005-1098}, url={http://dx.doi.org/10.1016/0005-1098(94)90196-1}, DOI={10.1016/0005-1098(94)90196-1}, abstractNote={The attitude stabilization problem of a rigid spacecraft using control torques supplied by gas jet actuators about only two of its principal axes is considered. If the uncontrolled principal axis of the spacecraft is not an axis of symmetry, then the complete spacecraft dynamics are small time locally controllable. However, the spacecraft cannot be asymptotically stabilized to any equilibrium attitude using time-invariant continuous feedback. A discontinuous stabilizing feedback control strategy is constructed which stabilizes the spacecraft to any equilibrium attitude. If the uncontrolled principal axis of the spacecraft is an axis of symmetry, the complete spacecraft dynamics are not even assessible. However, the spacecraft dynamics are strongly accessible and small time locally controllable in a reduced sense. The reduced spacecraft dynamics cannot be asymptotically stabilized to any equilibrium attitude using time-invariant continuous feedback, but again a discontinuous stabilizing feedback control strategy is constructed. In both cases, the discontinuous feedback controllers are constructed by switching between several feedback functions which are selected to accomplish a sequence of spacecraft maneuvers. The results of the paper show that although standard nonlinear control techniques are not applicable, it is possible to construct a nonlinear discontinuous control law based on the dynamics of the particular physical system.}, number={6}, journal={Automatica}, publisher={Elsevier BV}, author={Krishnan, Hariharan and Reyhanoglu, Mahmut and McClamroch, Harris}, year={1994}, month={Jun}, pages={1023–1027} } @inproceedings{kolmanovksy_reyhanoglu_harris mcclamroch_1994, place={New Jersey}, title={Discontinuous feedback stabilization of nonholonomic systems in extended power form}, ISBN={0780319680}, url={http://dx.doi.org/10.1109/cdc.1994.411683}, DOI={10.1109/cdc.1994.411683}, abstractNote={Nonholonomic control systems in extended power form are studied. It is demonstrated that under appropriate assumptions Lagrange's equations, including classical nonholonomic constraints, can be transformed to the extended power form. A discontinuous time-invariant feedback controller is developed for the extended power form. This feedback controller provides global finite time stabilization. The controller can be interpreted as a hybrid system consisting of a high level discrete event supervisor and a family of low level feedback controllers. Implementation issues are addressed.<>}, booktitle={Proceedings of 1994 33rd IEEE Conference on Decision and Control}, publisher={IEEE}, author={Kolmanovksy, L.V. and Reyhanoglu, M. and Harris McClamroch, N.}, year={1994} } @inproceedings{reyhanoglu_al-regib_1994, place={New Jersey}, title={Nonholonomic motion planning for wheeled mobile systems using geometric phases}, ISBN={0780319907}, url={http://dx.doi.org/10.1109/isic.1994.367828}, DOI={10.1109/isic.1994.367828}, abstractNote={In this paper, we consider the motion planning problem for wheeled mobile systems with nonholonomic constraints. Such systems, in general, admit local coordinate representation in which the constraints are of Caplygin form, i.e. the constraint equations are cyclic in certain variables. We first introduce a nonlinear control system model describing the motion of a wheeled mobile system with driving and steering inputs. We then describe a motion planning approach using geometric phases. We demonstrate that this motion planning approach provides a closed-form solution to the well-known multi-trailer problem. Results of the paper are illustrated through simulations of two examples: a front-wheel-drive car and a car pulling a trailer.<>}, booktitle={Proceedings of 1994 9th IEEE International Symposium on Intelligent Control}, publisher={IEEE}, author={Reyhanoglu, M. and Al-Regib, E.}, year={1994} } @inproceedings{reyhanoglu_al-regib_1993, title={A General Motion Planning Approach for Wheeled Mobile Systems}, volume={1}, booktitle={Proceedings of the Association of Edison Illuminating Companies (AEIC) Conference}, author={Reyhanoglu, M. and Al-Regib, E.}, year={1993}, pages={308–318} } @inproceedings{mcclamroch_bloch_reyhanoglu_1993, place={New Jersey}, title={Control and stabilization of a general class of nonholonomic dynamic systems}, ISBN={0780312988}, url={http://dx.doi.org/10.1109/cdc.1993.325326}, DOI={10.1109/cdc.1993.325326}, abstractNote={This paper extends results in Bloch, Reyhanogln, and McClamroch (1992) to a more general class of nonholonomic dynamic systems that are important in applications. These nonlinear control systems are referred to as nonholonomic control systems due to certain nonintegrability assumptions which are made. The class of systems considered in this paper is characterized by general nonlinear base space dynamics that are input-output decouplable. Controllability and stabilizability results for this class of nonholonomic control systems are presented.<>}, booktitle={Proceedings of 32nd IEEE Conference on Decision and Control}, publisher={IEEE}, author={McClamroch, N.H. and Bloch, A.M. and Reyhanoglu, M.}, year={1993} } @inbook{reyhanoglu_mcclamroch_bloch_1993, title={Motion Planning for Nonholonomic Dynamic Systems}, ISBN={9781461363927 9781461531760}, url={http://dx.doi.org/10.1007/978-1-4615-3176-0_6}, DOI={10.1007/978-1-4615-3176-0_6}, booktitle={Nonholonomic Motion Planning}, publisher={Springer US}, author={Reyhanoglu, Mahmut and McClamroch, N. Harris and Bloch, Anthony M.}, year={1993}, pages={201–234} } @article{reyhanoglu_1993, title={Nonholonomic Motion Planning for Caplygin Systems}, volume={18}, number={4}, journal={Arabian journal for science and engineering}, author={Reyhanoglu, M.}, year={1993}, month={Oct}, pages={515–531} } @misc{reyhanoglu_mcclamroch_1993, title={Nonlinear attitude control of planar structures in space using only internal controls}, ISBN={9780821892015 9781470429706}, url={http://dx.doi.org/10.1090/fic/002/04}, DOI={10.1090/fic/002/04}, abstractNote={An attitude control strategy for maneuvers of an interconnection of planar bodies in space is developed. It is assumed that there are no exogeneous torques and that torques generated by joint motors are used as means of control so that the total angular momentum of the multibody system is a constant, assumed to be zero. The control strategy utilizes the nonintegrability of the expression for the angular momentum. Large angle maneuvers can be designed to achieve an arbitrary reorientation of the multibody system with respect to an inertial frame. The theoretical background for carrying out the required maneuvers is summarized.}, journal={Control of Flexible Structures}, publisher={American Mathematical Society}, author={Reyhanoglu, M. and McClamroch, N.}, year={1993}, month={Jul}, pages={91–100} } @inproceedings{reyhanoglu_al-garni_nizami_1993, title={Time-Optimal Control of Rolling Motion}, volume={1}, booktitle={Proceedings of the Association of Edison Illuminating Companies (AIEC) Conference}, author={Reyhanoglu, M. and Al-Garni, A.Z. and Nizami, J.}, year={1993}, pages={284–295} } @inproceedings{krishnan_reyhanoglu_mcclamroch_1992, place={New Jersey}, title={Attitude stabilization of a rigid spacecraft using gas jet actuators operating in a failure mode}, ISBN={0780308727}, url={http://dx.doi.org/10.1109/cdc.1992.371454}, DOI={10.1109/cdc.1992.371454}, abstractNote={The authors consider the attitude stabilization of a rigid spacecraft using control torques supplied by gas jet actuators about only two of its principal axes. First, the case where the uncontrolled principal axis of the spacecraft is not an axis of symmetry is considered. In this case, the complete spacecraft dynamics are small time locally controllable. However, the spacecraft cannot be asymptotically stabilized to an equilibrium attitude using time-invariant continuous feedback. A discontinuous stabilizing feedback control strategy is constructed which stabilizes the spacecraft to an equilibrium attitude. Next, the case where the uncontrolled principal axis of the spacecraft is an axis of symmetry is considered. In this case, the complete spacecraft dynamics are not even accessible. However, the spacecraft dynamics are strongly accessible and small time locally controllable in a reduced sense. The reduced spacecraft dynamics cannot be asymptotically stabilized to an equilibrium attitude using time-invariant continuous feedback, but again a discontinuous stabilizing feedback control strategy is considered. In both cases, the discontinuous feedback controllers are constructed by switching between one of several feedback functions.<>}, booktitle={Proceedings of the 31st IEEE Conference on Decision and Control}, publisher={IEEE}, author={Krishnan, H. and Reyhanoglu, M. and McClamroch, H.}, year={1992} } @article{bloch_reyhanoglu_mcclamroch_1992, title={Control and stabilization of nonholonomic dynamic systems}, volume={37}, ISSN={0018-9286}, url={http://dx.doi.org/10.1109/9.173144}, DOI={10.1109/9.173144}, abstractNote={A class of inherently nonlinear control problems has been identified, the nonlinear features arising directly from physical assumptions about constraints on the motion of a mechanical system. Models are presented for mechanical systems with nonholonomic constraints represented both by differential-algebraic equations and by reduced state equations. Control issues for this class of systems are studied and a number of fundamental results are derived. Although a single equilibrium solution cannot be asymptotically stabilized using continuous state feedback, a general procedure for constructing a piecewise analytic state feedback which achieves the desired result is suggested. >}, number={11}, journal={IEEE Transactions on Automatic Control}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Bloch, A.M. and Reyhanoglu, M. and McClamroch, N.H.}, year={1992}, pages={1746–1757} } @inproceedings{zhao_reyhanoglu_1992, place={New Jersey}, title={Nonlinear Control Of Wheeled Mobile Robots}, ISBN={0780307380}, url={http://dx.doi.org/10.1109/iros.1992.601928}, DOI={10.1109/iros.1992.601928}, abstractNote={Kinematic models for the description of wheeled mobile robots are introduced. The nonlinear controllabilityof these ciystems is proved. It is shown that the wheeled mobile robot cannot be asymptotically stabilized to a configuration (or position) by using time-invariant continuous feedback. A general method is proposed for the construction of openloop controllers and time-invariant discontinuous feedback controllers. Our study provides a theoretical framework which can be used for the analysis and control of wheeledmobile-robot systems.}, booktitle={Proceedings of the IEEE/RSJ International Conference on Intelligent Robots and Systems}, publisher={IEEE}, author={Zhao, Yilin and Reyhanoglu, M.}, year={1992} } @inproceedings{krishnan_mcclamroch_reyhanoglu_1992, place={New Jersey}, title={On the Attitude Stabilization of a Rigid Spacecraft Using Two Control Torques}, ISBN={0780302109}, url={http://dx.doi.org/10.23919/acc.1992.4792472}, DOI={10.23919/acc.1992.4792472}, abstractNote={The attitude stabilization problem of a rigid spacecraft using only two control torques is considered. The control torques are assumed to be generated by either gas jet actuators or momentum wheel actuators. In particular, we focus on the development of a control strategy for the following two problems which have not been considered elsewhere: the attitude stabilization of an axially symmetric spacecraft using control torques supplied by two pairs of gas jet actuators about axes spanning a two dimensional plane orthogonal to the axis of symmetry; the attitude stabilization of a spacecraft using control torques supplied by two momentum wheel actuators about axes spanning a two dimensional plane orthogonal to a principal axis. The complete dynamics of the spacecraft system fails to be controllable or even accessible in these cases. However, the spacecraft dynamics are strongly accessible and small time locally controllable in a restricted sease; but the restricted spacecraft dynamics cannot be asymptotically stabilized using any smooth C1 feedback. A nonsmooth feedback control strategy is developed for the restricted spacecraft dynamics which achieves an arbitrary reorientation of the spacecraft.}, booktitle={Proceedings of the 1992 American Control Conference}, publisher={IEEE}, author={Krishnan, Hariharan and McClamroch, Harris and Reyhanoglu, Mahmut}, year={1992}, month={Jun} } @article{reyhanoglu_mcclamroch_1992, title={Planar reorientation maneuvers of space multibody systems using internal controls}, volume={15}, ISSN={0731-5090 1533-3884}, url={http://dx.doi.org/10.2514/3.11411}, DOI={10.2514/3.11411}, abstractNote={In this paper a reorientation maneuvering strategy for an interconnection of planar rigid bodies in space is developed. It is assumed that there are no exogeneous torques, and torques generated by joint motors are used as means of control so that the total angular momentum of the multibody system is a constant, assumed to be zero in this paper. The maneuver strategy uses the nonintegrability of the expression for the angular momentum. We demonstrate that large-angle maneuvers can be designed to achieve an arbitrary reorientation of the multibody system with respect to an inertial frame. The theoretical background for carrying out the required maneuvers is briefly summarized. Specifications and computer simulations of a specific reorientation maneuver, and the corresponding control strategies, are described. I. Introduction I N this paper we develop a reorientation strategy for a system of N planar rigid bodies in space that are interconnected by ideal frictionless pin joints in the form of an open kinematic chain. Angular momentum preserving controls, e.g., torques generated by joint motors, are considered. The TV-body system is assumed to have zero initial angular momentum. Our earlier work1'2 demonstrated that reorientation of a planar multibody system with three or more interconnected bodies using only joint torque inputs is an inherently nonlinear control problem that is not amenable to classical methods of nonlinear control. The goal of this study is to indicate how control strategies can be explicitly constructed to achieve the desired absolute reorientation of the TV-body system. There are many physical advantages in using internal controls, e.g., joint torque controls, to carry out the desired multibody reorientation maneuvers. First of all, this control approach does not modify the total angular momentum of the multibody system. In addition, internal controls have obvious advantages in terms of energy conservation. Moreover, they can be implemented using standard electrical servo motors, a simple and reliable control actuator technology. The formal development in this paper is concerned with control of a multibody interconnection in space that has zero angular momentum. Although these results are formulated in a general setting, we have been motivated by several classes of specific problems. Several potential applications of our general results are now described. Manipulators mounted on space vehicles and space robots have been envisioned to carry out construction, maintenance, and repair tasks in an external space environment. These space systems are essentially multibody systems satisfying the assumptions of this paper. To carry out the desired tasks, they must be capable of performing a variety of reorientation maneuvers. Previous research on maneuvering of such space multibody systems has mainly focused on maneuvers that achieve desired orientation of some of the bodies, e.g., an end effector, whereas the orientation of some of the remaining bodies cannot be specified, at least using the methodologies employed.3"8 Using the approach suggested in this paper, maneuvers that achieve any desired reorientation for all of the}, number={6}, journal={Journal of Guidance, Control, and Dynamics}, publisher={American Institute of Aeronautics and Astronautics (AIAA)}, author={Reyhanoglu, Mahmut and McClamroch, N. Harris}, year={1992}, month={Nov}, pages={1475–1480} } @inproceedings{bloch_reyhanoglu_mcclamroch_1991, place={New Jersey}, title={Control and stabilization of nonholonomic Caplygin dynamic systems}, ISBN={0780304500}, url={http://dx.doi.org/10.1109/cdc.1991.261519}, DOI={10.1109/cdc.1991.261519}, abstractNote={A theoretical framework is established for the control of nonholonomic Caplygin dynamic systems, i.e., nonholonomic systems with certain symmetry properties which can be expressed by the fact that the Lagrangian and constraints are cyclic in certain of the variables. A model is presented in terms of differential-algebraic equations defined on a phase space. A nonlinear control system in a normal form is then introduced to completely describe the dynamics. The structure of the normal form equations allows identification of a base spaces, on which a set of decoupled controllable dynamics is defined. The emphasis of the present work is on control of the normal form equations on the complete phase space. The control system, linearized at an equilibrium, always has uncontrollable eigenvalues with zero real part, their number being equal to the number of nonintegrable constraints. However, the equilibrium is shown to be strongly accessible and small time locally controllable. Conditions for smooth asymptotic stabilization to an m-dimensional equilibrium manifold are presented.<>}, booktitle={Proceedings of the 30th IEEE Conference on Decision and Control}, publisher={IEEE}, author={Bloch, A.M. and Reyhanoglu, M. and McClamroch, N.H.}, year={1991} } @inproceedings{reyhanoglu_mcclamroch_1991, title={Controllability and Stabilizability of Planar Multibody Systems with Angular Momentum Preserving Control Torques}, ISBN={0879425652}, url={http://dx.doi.org/10.23919/acc.1991.4791547}, DOI={10.23919/acc.1991.4791547}, abstractNote={Control and stabilization properties for planar multibody systems consisting of a tree interconnection of rigid bodies are studied. A reduced system model is obtained by considering rotational motion only. It is assumed that there are no exogeneous effects and angular momentum preserving torques generated by joint motors are used as means of control. The angular momentum constant is assumed to be zero so that any set of absolute angles together with zero angular velocities can be studied as an equilibrium. The final form of the reduced system equations is obtained by a further reduction using the expression for the angular momentum constant which is regarded as a nonholonomic constraint. The reduced equations completely characterize the dynamics of the multibody system; these equations necessarily include drift dynamics. We first show that for three or more interconnected bodies, the dynamics are strongly accessible ; for two interconnected bodies, the dynamics are not accessible. We next show that for three or more interconnected bodies, (1) the dynamics are small-time locally controllable from any equilibrium solution and (2) any initial condition can be transferred to any equilibrium solution in an arbitrarily small time period. The latter result is proved by construction of the required control using the holonomy property. We then prove the nonexistence of smooth feedback stabilization to a single equilibrium solution. Comments are made about construction of a stabilizing nonsmooth feedback control.}, booktitle={1991 American Control Conference}, publisher={IEEE}, author={Reyhanoglu, Mahmut and McClamroch, N. Harris}, year={1991}, month={Jun} } @inproceedings{reyhanoglu_mcclamroch_1991, title={Reorientation of space multibody systems maintaining zero angular momentum}, url={http://dx.doi.org/10.2514/6.1991-2747}, DOI={10.2514/6.1991-2747}, booktitle={Proceedings of the Navigation and Control Conference}, publisher={American Institute of Aeronautics and Astronautics}, author={Reyhanoglu, Mahmut and Mcclamroch, N.}, year={1991}, month={Aug} } @inproceedings{bloch_reyhanoglu_1990, title={Controllability and stabilizability properties of a nonholonomic control system}, url={http://dx.doi.org/10.1109/cdc.1990.203820}, DOI={10.1109/cdc.1990.203820}, abstractNote={Controllability and stabilizability properties are examined for a control system with a nonholonomic constraint. A representative nonholonomic control system example is discussed: the control of a knife edge moving on a plane surface. This example contains the essential features of the general case. It is noted that conditions for small-time local controllability are satisfied. An explicit open loop control is then given which transfers the knife edge to a single equilibrium and an explicit stabilizing feedback control.<>}, booktitle={29th IEEE Conference on Decision and Control}, publisher={IEEE}, author={Bloch, A.M. and Reyhanoglu, M.}, year={1990} }