Reduced‐order simultaneous state and fault estimator based fault tolerant preview control for discrete‐time linear time‐invariant systems

Abstract

In this study, an integrated fault tolerant preview tracking control framework is proposed based on reduced-order simultaneous state and fault estimation, robust preview control and fault signal compensation. In general, this work consists of three key design parts. Firstly, the analysis and synthesis conditions of a novel reduced-order simultaneous state and fault estimator are given based on the equivalent model reconstruction and optimisation of the parametric solution. Note that such a reduced-order design method can avoid traditional output equation reduction requirement, and has a wider application scope. Secondly, the robust preview tracking control policy is constructed by integrating state-feedback, preview action, and integral operation. Relying on augmentation modelling technique, a linear quadratic preview control design problem is transformed into an equivalent augmented state-feedback control design problem. Thirdly, the fault compensation is achieved by using estimated fault to accommodate fault influence. These involved designs are performed at the H ∞ optimisation level, and thus guarantee the robust tracking performance of closed-loop systems. The effectiveness of the above conclusions is finally verified via two case studies.