A High-Order Sliding-Mode Adaptive Observer for Uncertain Nonlinear Systems

International audienceA high-order sliding-mode adaptive observer is proposed to solve the problem of adaptive estimation, i.e., the simultaneous estimation of the state and parameters, for a class of uncertain nonlinear systems in the presence of external disturbances, that does not need to satisfy a relative degree condition equal to one. This approach is based on a highorder sliding-mode observer and a nonlinear parameter identification algorithm. The practical, global and uniform asymptotic stability of the adaptive estimation error, despite the external disturbances, is guaranteed through the small-gain theorem. The convergence proofs are developed based on Lyapunov and inputto-state stability theories. Some simulation results illustrate the performance of the proposed high-order sliding-mode adaptive observer

A Robust Nonlinear Model Reference Adaptive Control for Disturbed Linear Systems: An LMI Approach

International audienceIn this paper a robust nonlinear Model Reference Adaptive Control (MRAC) is proposed for disturbed linear systems, i.e., linear systems with parameter uncertainties, and external time-dependent perturbations or nonlinear unmodeled dynamics matched with the control input. The proposed nonlinear control law is composed of two nonlinear adaptive gains. Such adaptive gains allow the control to counteract the effects of some perturbations and nonlinear unmodeled dynamics ensuring asymptotic convergence of the tracking error to zero, and the boundedness of the adaptive gains. The nonlinear controller synthesis is given by a constructive method based on the solution of Linear Matrix Inequalities (LMIs). Besides, the simulation results show that, due to the nonlinearities, the rate of convergence of the proposed algorithm is faster than the provided by a classic MRAC

Control robusto por retroalimentación de salida para sistemas con incertidumbres usando observadores via modos deslizantes de orden superior

Control robusto por retroalimentación de salida para sistemas con incertidumbres usando observadores via modos deslizantes de orden superio

Control por retroalimentacion de salida para sistemas con incertidumbres usando observadores via modos deslizantes de orden superior

Control por retroalimentación de salida para sistemas con incertidumbres usando observadores vía modos deslizantes de orden superio

A High-Order Sliding-Mode Adaptive Observer for Uncertain Nonlinear Systems

International audienceA high-order sliding-mode adaptive observer is proposed to solve the problem of adaptive estimation, i.e., the simultaneous estimation of the state and parameters, for a class of uncertain nonlinear systems in the presence of external disturbances, that does not need to satisfy a relative degree condition equal to one. This approach is based on a highorder sliding-mode observer and a nonlinear parameter identification algorithm. The practical, global and uniform asymptotic stability of the adaptive estimation error, despite the external disturbances, is guaranteed through the small-gain theorem. The convergence proofs are developed based on Lyapunov and inputto-state stability theories. Some simulation results illustrate the performance of the proposed high-order sliding-mode adaptive observer

Sensor fault diagnosis using a non-homogeneous high-order sliding mode observer with application to a transport aircraft

International audienceIn avionics and aerospace multisensor systems, reliable and early detection of individual sensor faults present substantial challenges to health monitoring designers of such systems. This study addresses the problem of sensor fault diagnosis. The proposed solution is based on a non-homogeneous high-order sliding mode observer used to estimate the faults, theoretically in finite time and in the presence of bounded disturbances. The sensor faults are estimated for the class of systems satisfying the structural property of strong observability. A key feature of the proposed solution is concerned by the effect that measurement noise could have on fault reconstruction. It is shown that the fault estimation error is bounded in the L∞-norm sense, and an upper bound is theoretically derived. The method is applied to the problem of sensor fault estimation of a large transport aircraft. Simulation results as well as a pilot experiment are presented to demonstrate the potential of the proposed method

Robust Output Tracking of a 3DOF Helicopter via High-Order Sliding Mode Observers

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Sliding-Mode Control for On-Orbit Rendezvous with a Fleeing Passive Target on a Circular Capture Trajectory

This paper deals with the design of finite-time controllers for on-orbit rendezvous and capture missions. The objective is to assess the capacity of sliding–mode controllers to control a chaser spacecraft during a capture maneuver of a fleeing passive spacecraft. The control solution is based on a variable structure approach that relies on the sliding mode control theory. More precisely, the general super-twisting algorithm is used to control the chaser’s attitude, whereas the control of the relative position between the two spacecraft is based on the simplex-based sliding mode control theory. The method is tested in a full-scaled benchmark that accurately simulates the capture mission