Actuator Fault Detection for Hypersonic Flight Vehicle Model: A Sliding Mode Observer Approach

With the aim of improving the safety and reliability of hypersonic flight vehicle, a sliding mode observer-based fault detection scheme is applied to handle the detection issue of HSV actuator faults in this paper. A dynamic linear model is first derived from original nonlinear hypersonic flight vehicle model by using Taylor’s linearization approach at equilibrium point. Secondly, the actuator fault model, reflecting stuck faults and partial loss of effectiveness faults (PLOE), is constructed. Then, a sliding mode-based fault detection observer is developed based on the linear model. At last, the designed sliding mode observer is applied to the nonlinear hypersonic flight vehicle for single-input single-style actuator fault detection. The simulation results show that stuck faults and big proportion PLOE faults can be timely and accurately detected at the fault time. Meanwhile, the detection of small proportion PLOE faults encounter some difficulties and need special attention and further investigation.