Three-Dimensional Optimal Robust Guidance Law Design for Missile Using Sliding-Mode Control and SDRE Control

In this paper, a new guidance law is designed for missile against maneuvering target by integrating optimal control SDRE technique and sliding-mode control. Due to the fact thatautopilot dynamic has a very important role in success or unsuccess of engagement in terminal phase, and it can make delay in guidance commands execution, this dynamic is taken into account in state equations. The robustness of the designed guidance law against disturbances is proved by the second method of Lyapunov. The proposed guidance law does not need accurate target maneuver profile and just need the maximum value of the target maneuver. Coefficients in proposed guidance law are obtained using genetic algorithm. For investigating effectiveness of proposed guidance law, by considering different scenarios, three-dimensional missile-target engagement issimulated. Then results are compared with conventional augmented proportional navigation guidance (APNG) law. Simulation results show that the proposed guidance law has high robustness against target maneuver disturbances and also one can compromise between convergence speed, intercept time and control effort.