Robust Fault-Tolerant Control using on-line control re-allocation with application to aircraft

This paper investigates the design problem of robust fault-tolerant control (FTC) by using online control re-allocation for a class of uncertain systems and its application to flight tracking control. The design procedure consists of two parts: robust fault-tolerant baseline controller design, and realization of a control re-allocation scheme. The baseline controller is obtained by an iterative LMI method, which not only stabilizes the uncertain system but also provides sufficient robustness to allow for an effective operation of the fault detection and diagnosis (FDD) subsystem in the event of actuator failures. The re-allocation scheme redesigns an optimal control law without requiring reconfiguration of the baseline controller, and compensates for actuator saturation via cascaded generalized inverse (CGI) method. Simulation results show the effectiveness of the proposed approach.