Fixed-time Sliding Mode Disturbance Observer-Combined Fault Detection Strategy for Electro-Mechanical Flight Actuators

In this paper, we investigate the fault detection problem for the electro-mechanical flight actuator (EMFA) which is subject to nonlinear factors and unknown disturbances. Thence, it establishes a fault detection scheme combining fixed-time sliding mode disturbance observer. Firstly, we formulate the EMFA model, while the effects of nonlinear factors and lumped disturbances are taken into consideration. Next, the sliding mode disturbance observer is developed to provide estimations of nonlinear factors and lumped disturbances in a timely way for EMFAs. The stability analysis show that the disturbance observer errors can converge to a small range around the origin. After that, the generated estimation errors are employed in the course of testing the malfunctions, thereby detecting whether the fault exists. Finally, the simulation results are given to illustrate the effectiveness and performance of the designed strategy.