Adaptive Sliding Mode Observer Design Research Articles

Adaptive sliding mode observer design for semi-Markovian jump systems through dynamic event-triggered mechanism

This paper deals with the problem of network-based sliding mode observer design and stabilization for nonlinear semi-Markovian jump systems. To design the observer, an event-triggering condition relies on network framework is proposed based on the system output measurement that transmitted through communication channel. Relying on the estimated state, an integral sliding surface is proposed and corresponding sliding mode controller is constructed to guarantee finite-time reachability of predefined sliding surface. In the analysis of sliding mode dynamics and error dynamics, it is considered that the transition rate information suffer from more generally uncertain cases, especially for the type that the mode jumping information from mode to others are totally unknown. Even so, sufficient conditions are developed to ensure stochastic stability of the overall closed-loop system. Finally, a numerical example is provided to verify the effectiveness of the established method.

Integrated fault tolerant tracking control for rigid spacecraft using fractional order sliding mode technique

In this study, the integrated fault estimation (FE) and fault tolerant control (FTC) design problem is investigated for the attitude system of a rigid spacecraft with inertia uncertainty, Lipschitz nonlinearity, external disturbance and multiple type actuator faults. An adaptive sliding mode observer design approach, which does not require the known upper bound of generalized perturbation, is proposed to obtain the estimation of unknown actuator faults. On this basis, a fault tolerant attitude tracking control scheme is developed for the faulty rigid spacecraft attitude system by combining the fractional order sliding mode control and backstepping control with adaptive fuzzy approximation technique. The stability of faulty closed loop attitude system under the designed FTC strategy is analyzed using Lyapunov approach. Finally, simulation results are given to show the superiority of the proposed integrated FE and FTC compared with some existing results.

An H∞non‐fragile observer‐based adaptive sliding mode controller design for uncertain fractional‐order nonlinear systems with time delay and input nonlinearity

AbstractIn this paper the problem of non‐fragile adaptive sliding mode observer design is addressed for a class of nonlinear fractional‐order time‐delay systems with uncertainties, external disturbance, exogenous noise, and input nonlinearity. An H∞ observer‐based adaptive sliding mode control considering the non‐fragility of the observer is proposed for this system. The sufficient asymptotic stability conditions are derived in the form of linear matrix inequalities. It is proven that the sliding surface is reachable in finite time. An illustrative example is provided which corroborates the effectiveness of the theoretical results.

Adaptive Sliding Mode Observer Design for a Class of T–S Fuzzy Descriptor Fractional Order Systems

This paper investigates the problem of sliding mode observer (SMO) design for Takagi-Sugeno (T-S) fuzzy descriptor fractional order systems (FOSs) with fractional order $0<; \alpha <; 1$. First, an SMO is designed for the T-S fuzzy descriptor FOS. Then, a fuzzy fractional order integral-type sliding surface is constructed. By utilizing the fuzzy sliding surface, the assumption that all local input matrices are identical in most existing results about sliding mode control (SMC) for T-S fuzzy systems, can be removed. Then, a new sufficient condition is proposed in terms of linear matrix inequalities (LMIs), which guarantees the admissibility of the sliding mode dynamics. Moreover, adaptive SMC strategy is used such that the reachability condition can be guaranteed. Finally, three examples are given to verify the effectiveness of our results.

Adaptive sliding mode observer design for a class of uncertain systems

SUMMARYState feedback method is quite popular in control engineering field. However, some popular properties of state feedback approach cannot be used while any of the system states cannot be obtained beforehand. Therefore, this paper proposes a new observer design for a class of uncertain systems through sliding mode control theory. Based on strictly positive real concept, the stability of the equivalent error system is verified. Further, by using the generalized matrix inverse approach, the proposed switching term can drive the error states to zero, and it ensures the global reaching condition of the sliding mode of the error system. Moreover, the presented sliding mode observer is proposed to possess the invariance property to the uncertainty and/or external disturbance. Furthermore, the developed sliding mode observer is extended to release the limitation of knowing the bounds of the lumped perturbations in advance. That is, not only a new sliding mode observer but also a new adaptive sliding mode observer is proposed in this paper. Finally, three examples are illustrated to demonstrate the validity of the proposed sliding mode observer and the proposed adaptive sliding mode observer. Copyright © 2014 John Wiley &amp; Sons, Ltd.