Design of variable structure guidance law with constraints on impact angle for anti-ship missile

In order to achieve the tactical mission of attacking the target on the appointed direction, the characteristics of maneuver target was analyzed, and a variable structure guidance law with constraints on impact angle, based on the 3-D relative motion model of missile and target, was presented in the point of view of engineering application. The guidance law is simple and can be implemented conveniently with little target information. In the guidance law, the distance between missile and target, and their relative velocity, which is difficult to measure, were substituted by estimation values. The estimation errors, the target´s velocity, and the target´s maneuver acceleration are all treated as bounded disturbance. And all these disturbances can be successfully restrained by choosing the appropriate parameters of guidance law. The performance of the guidance system was analyzed theoretically, and the numerical simulation result shows the validity and effectiveness of the proposed guidance law.