Disturbance Observer based Sliding Mode Control for Proportional Navigation Guidance

In this paper, a disturbance observer based variable structure control technique for a non linear proportional navigation guidance law is proposed. A simple system of non linear equations for proportional navigation guidance is used in the control problem. The target acceleration information is generally not available and hence is considered as an unknown quantity to be estimated by the disturbance observer. The stability of the proposed controller is then established using Lyapunov function. The effectiveness of the new control law is proved through simulations under various target maneuvering conditions.