Finite-Time Super Twisting Disturbance Observer-Based Backstepping Control for Body-Flap Hypersonic Vehicle

This paper investigates the attitude control problem for underactuated body-flap hypersonic vehicles (BFHSVs) with mixed disturbances. First, the control-oriented model for BFHSV is introduced. Then, an improved finite-time super twisting disturbance observer (STDO) is designed. Finite-time convergence of estimate error and smoother inputs are achieved. Meanwhile, a parametric command method is introduced to calculate the differential of inputs which can enhance the dynamic response of the closed-loop system. Subsequently, the virtual control signal is derived by a second-order filter to avoid the differential explosion problem. The overall stability of the closed-loop system is demonstrated by applying the Lyapunov stability theory. Finally, the performance of the proposed control scheme is evaluated through extensive and comparative numerical simulations under multiple disturbances.