3-D Integrated Guidance and Control for Strapdown Interceptor under Divert and Attitude Control System

A three-dimensional (3D) integrated guidance and control (IGC) law for divert and attitude control system (DACS) based strapdown interceptor subjected to strong couplings and complex constraints is proposed in this paper. The 3D kinematic and dynamic equations reflecting the couplings of the interceptor are constructed by combining the characteristics of DACS and strapdown seeker. An improved IGC model is established by employing the proposed adaptive fixed-time prescribed performance function (AFTPPF). This model takes into account the boundary, terminal and convergence time constraints of strapdown interceptor, along with the mismatched unknown uncertainties. An IGC law is developed within the high-order multi-dimensional sliding mode control (SMC) framework, integrating the AFTPPF to handle the complex constrains without computational singularities and the extended disturbance observer (EDO) for uncertainty estimations. Finally, the stability and performance of the proposed control method are proved.