Design of guidance law for passive homing missile using sliding mode control

This paper deals with a new passive homing guidance law for a stationary or a slowly moving target using sliding mode control technique. The proposed guidance law is designed in such a way of increasing the target observability. In addition, it can control a terminal impact angle to maximize warhead effect. The main idea is that we design the nonlinear sliding surface which makes an oscillatory missile motion along the desired impact angle frame so that the proposed guidance law introduces the LOS angle oscillation continuously. And then the enhanced target observability is achieved by comparing with the other conventional guidance laws such as the proportional navigation guidance. On the nonlinear sliding surface, lateral miss distance, velocity and acceleration command are converged to zero at terminal time. In addition, the proposed guidance law is robust with respect to autopilot lag and uncertainty. Finally, the performance of proposed guidance law is evaluated and demonstrated by number of simulations.