A Guidance Law With Terminal Impact Angle Constraint Accounting for Missile Autopilot

Abstract

A slidingmode guidance (SMG) law is designed to intercept maneuvering targets with impact angle constrained flight trajectories under the assumption of ideal missile autopilot. Furthermore, accounting for the autopilot as secondorder dynamics, a new guidance law with terminal impact angle constraint is designed using the dynamic surface control method. Some firstorder lowpass filters are introduced into the designing process to avoid the occurrence of highorder derivatives of the line of sight (LOS) angle in the expression of the guidance law such that the guidance law can be implemented in practical applications. The proposed guidance law is effective in compensating for the secondorder autopilot lag. Simulation results show that it is able to guide a missile to impact a maneuvering target with a desired angle and a small miss distance.