Fault Diagnosis Strategy of Electro-Mechanical Flight Actuator Using Fuzzy Disturbance Observer

In this paper, we study the fault diagnosis problem of electro-mechanical flight actuator (EMFA) in the presence of nonlinear terms and unknown disturbances, which leads to a new fault diagnosis method based on fuzzy disturbance observer. Firstly, the model combined with nonlinear terms and synthesized disturbances is established for EMFA. Secondly, the fuzzy logic system is employed to develop a disturbance observer thereby generating the disturbance estimations for the EMFA. After that, the stability analysis illustrates that the disturbance observer error can converge to a small range around zero. The estimation errors can be used in the fault diagnosis process and then applied to detect whether the fault has occurred. Finally, the numerical simulations and discussions are carried out to demonstrate that the effectiveness of the proposed method, which shows that the designed detect strategy can reduce the false alarm rate of fault diagnosis.