Fault detection and isolation for output feedback system based on space geometry method

In this paper, a new method of actuator fault detection and isolation in output feedback is proposed in the multiple-input multiple-output feedback system. Under the feedback control, fault source can be covered and make the fault isolation difficult. To address such an issue, the fault space is firstly segmented and the fault feature is extracted according to the space geometry theory. By this approach, the residual generator can be constructed. Secondly, in allusion to the coupling between residuals and disturbances in the feedback system, a sufficient and necessary condition for decoupling is given. Then a threshold is set to detect the fault exists or not, and the structured residual set is built to realize the relationship between residuals and faults. Consequently, the fault isolation can be achieved. Simulation results validate the feasibility and validity of the proposed algorithm.