Compound guidance law design based on infrared/millimetre wave detection information

For the case of air-to-surface missile with guidance system composed of infrared system and millimeter wave system against ground targets, a new design scheme of nonlinear terminal guidance law with robustness is proposed. An engagement model in the pitch plane is formulated, in which states are chosen as relative distance and relative velocity, by combining the relative relationship between missile and target, where the information is obtained directly from the infrared system and millimeter wave system. By adopting the sliding mode control, an adaptive nonlinear control law of the system is designed so that the missile can hit the target accurately with the index of optimizing the relative distance. The stability of the closed-loop system is also proven by utilizing the Lyapunov stability theory. Finally an illustrative example of attacking a ground target is given to confirm the usefulness of the proposed design scheme.