Adaptive nonsingular terminal sliding mode cooperative guidance law in active defense scenario

Abstract

An active defense scheme in which a ballistic missile launches a defending missile to intercept the incoming intercepting missile is considered. Compared with traditional passive evasion strategies, the active defense scheme can greatly increase the ballistic missile’s survival rate. Different from many terminal guidance laws using the line-of-sight nullifying strategy, a triangle-based guidance strategy by which the defender tries to keep itself on the line-of-sight connecting the target and the incoming intercepting missile is used to design a guidance law. With such a strategy, it is proved that the interceptor’s composite acceleration can be very small due to the acceleration cancellation in the target–interceptor line-of-sight frame and the defender–interceptor line-of-sight frame, meaning that the defender can catch the interceptor with small maneuverability. Based on this strategy, an adaptive nonsingular terminal sliding mode based cooperative guidance law is proposed treating the interceptor’s acceleration as an unknown bounded external disturbance. Simulation results show the high performance of the proposed guidance law.