Disturbance Compensation Based Backstepping Control for Hypersonic Vehicle

It is known that Hypersonic Vehicle (HV) is kind of system with strong coupled and highly nonlinear characteristic. In this paper, the dynamic model of HV is divided into velocity subsystem and altitude subsystem by analyzing the longitudinal model of HV. The altitude subsystem can be further decomposed into three loops: flight-path loop, pitch loop and pitch rate one. Backstepping control method is used in the design of virtual control variableˈ and tracking differentiator (TD) is selected to compute the first derivative of virtual variable, which solves the "explosive differentiation terms" in backstepping control. The extended state observers (ESO) are used to estimate and compensate the nonlinear component caused by inner and outer disturbance during the flight of the HV. The simulation results show that the control system developed has good performance and robustness under uncertain disturbance conditions.