Multi-loop anti-saturation robust switching control scheme for hypersonic flight vehicles

A robust switching control scheme with a multi-loop anti-saturation control structure is proposed in the presence of actuator saturation for hypersonic flight vehicles. Firstly, aiming at the obvious isolation characteristics of the movement state in frequency, the circuit design method is applied to the state variables of the hypersonic vehicle, and the reference switching systems are established to describe state variables that are seriously affected by actuator saturation, thus cutting down the design complexity of switched system and the controller parameters. Then, the events that potentially induce actuator saturation are regarded as switching signals, and then we choose the reference switching model and robust controllers, which make the system outputs track the reference model's outputs very well and ensure control input can not reach saturation state. Moreover, a detailed stability analysis is performed for such a control scheme with multiple Lyapunov functions method and linear matrix inequation (LMI). Simulation and comparison demonstrate the effectiveness of the switching control scheme. Under the actuator failure and disturbances conditions, the system state may well track the reference state and the amplitude of control input is less than the actuator limit.