Design of a New Proportional Guidance Algorithm Using Sliding Mode Control

In this paper، a new guidance law for yaw channel of homing interceptors is designed. Because of using the sliding mode theory، the nonlinear equations of motion are used and the target acceleration is considered as an uncertainty. Therefore، the precise measuring or estimating of target acceleration is not required and only the upper bound of target maneuvers is used. A sliding surface is defined using the angle rate of the interceptor target line of sight. For producing a smooth control signal and removing the chattering of the guidance commands، the discontinuous term of guidance law has been approximated with a continuous function. Adjusting the parameter of sliding term leads to decreasing the missile control effort، the time of flight and velocity loses. Simulation results in the presence of a real control system dynamics of a homing interceptor show the effectiveness and robustness of the designed guidance law against maneuvering target in comparison with the proportional navigation algorithm.