A Finite time convergent guidance law with terminal angle constraint considering missile autopilot

Taking into consideration the autopilot dynamics, a finite-time convergent guidance law with terminal attack angle constraint, is designed for homing missiles to intercept maneuvering targets. The approach taken here is based on the existing finite-time 2-sliding mode control theory. Firstly, the constraint problem of terminal attack angle is transformed to that of terminal line-of-sight(LOS) angle, and an exact observer is employed to estimate the target maneuvers in finite time. Then, it is proved that, the guidance law has the ability to achieve the design requirement of zero miss distance and the anticipant terminal attack angle in finite time. Compared with the previous work, this guidance law is robust to target maneuvers, and can compensate for the effects of missile autopilot dynamics effectively, and the information required in it is easy to obtain in practice. Simulation results show the benefits of the design.