An impact angle constraint integral sliding mode guidance law for maneuvering targets interception

An integral sliding mode guidance law (ISMGL) combined with the advantages of the integral sliding mode control (SMC) method is designed to address maneuvering target interception problems with impact angle constraints. The relative motion equation of the missile and the target considering the impact angle constraint is established in the longitudinal plane, and an integral sliding mode surface is constructed. The proposed guidance law resolves the existence of a steady-state error problem in the traditional SMC. Such a guidance law ensures that the missile hits the target with an ideal impact angle in finite time and the missile is kept highly robust throughout the interception process. By adopting the dynamic surface control method, the ISMGL is designed considering the impact angle constraints and the autopilot dynamic characteristics. According to the Lyapunov stability theorem, all states of the closed-loop system are finally proven to be uniformly bounded. Simulation results are compared with the general sliding mode guidance law and the trajectory shaping guidance law, and the findings verify the effectiveness and superiority of the ISMGL.