Adaptive backstepping fault tolerant control for near space vehicles

In this paper, a novel adaptive sliding mode backstepping fault-tolerant control methodology is developed for near space vehicle attitude control system with engine fault. The proposed approach combines adaptive backstepping with sliding mode control strategies that can make the systems stable and accurately track the desired signals in the presence of external disturbances, model parameter uncertainties and engine faults. Firstly, the attitude dynamic model is introduced and a nominal adaptive backstepping control law is designed, then the engine faulty model is established. Secondly, an adaptive observe is designed to estimate both the information of fault and disturbance, which is used to update the preceding fault-tolerant control laws. Finally, the simulation results are provided to show the effectiveness of the proposed fault tolerant control scheme.