Integrated fault estimation and tolerant control for discrete-time switched affine systems with mixed switching laws

Abstract

This study is concerned with the issues of simultaneous actuator fault estimation and the design of observer-based fault-tolerant control for a class of discrete-time switched affine systems subject to a mixed switching scheme. A mixed switching law, which is composed of constant dwell-time and state-dependent switching logic, is introduced to avoid the chattering phenomenon of augmented error switched affine system, and a discretized Lyapunov function approach is used to ensure the asymptotic stability of error systems. Then, the simultaneous fault estimation and tolerant control based state observer are studied and the corresponding design problem is transformed into resolving a multi-objective optimization for augmented error systems with H∞ performance index. Moreover, the gains of fault estimator and tolerant controller are explicitly calculated via resolving the conditions of linear matrix inequalities. Finally, a practical application of DC motor/Buck–Boost converter is illustrated to verify the effectiveness and practicability of the developed approach.