Integrated Autopilot and Guidance for Dual Control Missiles Using Higher Order Sliding Mode Control and Observers

Abstract

An integrated Autopilot-and Guidance Algorithm is developed using Higher Order Sliding Mode Control, for interceptors steered by combination of aerodynamic lift, sustainer thrust and center of gravity divert thrusters. A smooth HOSM guidance generates flight path trajectory angular rates and attitude rate commands. The attitude rate maneuvers are aimed at producing desired aerodynamic lift and / or orienting sustainer thrust. The lateral acceleration created by the attitude maneuver is treated as a “cooperative” disturbance and accounted for by the trajectory control. SOSM autopilot design is based on nonlinear dynamic sliding manifold. Proposed algorithm also includes seeker tracker, bore sight stabilization and estimation of target lateral acceleration. The algorithm is tested using computer simulations against a ballistic maneuvering target.