A new combined actuator fault estimation and accommodation for linear parameter varying system subject to simultaneous and multiple faults: an LMIs approach

This paper proposes a novel fuzzy observer scheme-based active fuzzy fault-tolerant tracking control (FFTTC) combined with a parallel distributed compensation control law for a linear parameter varying system subject to actuator faults and noise measurement. This system consists of a doubly fed induction generator-based wind energy conversion system described by a Takagi–Sugeno fuzzy model. The developed scheme is able to force system states to track their desired reference signal in finite time and obtain a better dynamic response and performance. A fuzzy state observer is also developed to simultaneously estimate the generator states and the actuator faults. Based on the obtained online fault estimation information, the FFTTC will be reconfigured to compensate for the fault impact. The closed-loop stability is established based on a Lyapunov function. Sufficient conditions are formulated for the existence of fuzzy fault-tolerant control parameters in the form of linear matrix inequalities (LMIs), which can be easily solved by means of a standard YALMIP toolbox. The fuzzy observer and fuzzy fault-tolerant tracking control gains can be computed based on the solutions of a set of LMIs. Computer simulations were performed using the MATLAB/Simulink environment to highlight the performance and robustness of the proposed design procedure with respect to actuator fault occurrences.