Koopman Predictor-based Sliding Mode Control for Strapdown Interceptor under Divert and Attitude Control System

This paper proposes a Koopman predictor-based sliding mode control (KPSMC) method for the strapdown interceptor under the divert and attitude control system (DACS). The kinematic and dynamic equations of the strapdown interceptor are constructed firstly, including the strapdown interceptor-target relative motion equations, strongly coupled dynamic model of DACS and the mapping state of the body line-of-sight (BLOS) angle. Then, considering the mapping state of the constrained field-of-view (FOV), the Koopman predictor is established for the guidance and control systems with strong coupling and nonlinearity. Finally, the controller of the strapdown interceptor is designed by combining the Koopman predictor and the sliding mode control (SMC) theory, which simplifies the design difficulty of DACS-based controller and enhances the control capability of the BLOS angle while accomplishing the required control accuracy. The effectiveness of the proposed predictor and control law is checked by the comparison simulations, and the robustness of the proposed law is demonstrated by the Monte Carlo tests.