Time-varying sliding mode guidance with impact angle constraints against nonmaneuvering targets

In this paper, a time-varying sliding model control (TVSMC) based guidance law against nonmaneuvering targets is proposed with impact angle constraints. The algorithm is first designed for constant-speed interceptors to attack stationary and constant-velocity targets, and the global robustness of the system is ensured. Then, an adaptation strategy, adaptive time-varying sliding model control (ATVSMC), is adopted to deal with unknown but bounded disturbances by adjusting the switching gain online. Stability analysis of the closed loop system is obtained through Lyapunov theory. Finally, numerical simulation results are presented to verify the effectiveness and robustness of the proposed guidance law.