Flight control for hypersonic vehicle based on quasi-continuous high-order sliding mode

This paper describes the design of nonlinear robust controller for hypersonic vehicle model which is nonlinear, multivariable, and includes uncertain parameters. Firstly, the multi-input and multi-output (MIMO) quasi-continuous high-order sliding mode controller are proposed to track the responses of the vehicle to a step change in altitude and velocity. Furthermore, based on the simulation results, the virtual control is introduced into the design of fourth-order velocity and fifth-order altitude quasi-continuous sliding mode controller in order to reduce the control chattering. The arbitrary order robust sliding mode differentiator is used to calculate the missing differential which is used in the design of controller. Finally, Simulation results show that the proposed methodology reduces the chattering and achieves excellent tracking performances in spite of parameter uncertainties.