Adaptive backstepping sliding mode control for BTT missiles with control input constraints

Concerning with robust control of a bank-to-turn(BTT)missile in the presence of unmatched uncertainties and control input saturation,an adaptive backstepping sliding mode controller is designed.The upper bound of uncertainties is adaptively estimated at each step of the backstepping design,and continuous sliding mode control with norm switching function is used.To ensure the stability under control input saturation, control saturation is explicitly accounted in the design of real control.Using the Lyapunov stability theorem, the tracking error is shown to be ultimately bounded.Simulation results show the good dynamic characteristics and robustness of the proposed method in the presence of aerodynamic dispersion and control input saturation.