A simplified backstepping sliding mode controller based on adaptive control for BTT missiles

Based on backstepping sliding mode control and adaptive techniques, a novel robust adaptive control scheme is proposed for BTT missiles with unmatched uncertainties. Continuous sliding mode control with one adaptive gain parameter is used at each step of backstepping design to deal with the uncertainties. "Explosion of terms" is solved by adaptively estimating the upper bound of the derivative of the virtual control, and compensating it by sliding mode control. In this way, the controller is simplified. Meanwhile, the upper bounds of aerodynamic parameters are not required. Using Lyapunov stability theorem, the tracking error is shown to be ultimately bounded. Simulation results show the effectiveness of the proposed method.