Design of guidance law with precise impact angle and time control

Spatial-temporal constrained guidance is a method that simultaneously meets impact angleand time constraints. To address the problem of missile terminal guidance, a spatial-temporal constrained guidance law with precise control capability is designed in this paper. First, based on the time-to-go estimation of the optimal impact angle constrained guidance law, a varying-gain impact angle constrained guidance law whose time-to-go can be precisely predicted is inversely derived without any small angle approximation. Second, an impact-time error feedback term is added to the above guidance law to obtain the singularity-free spatial-temporal guidance law for simultaneous precise control of impact angleand time. Third, by introducing the remaining trajectory length as an independent variable, the proposed spatial-temporal guidance law is extended to practical scenarios with missile speed variation. Finally, the effectivenessand advantages of the proposed guidance law are verified through several numerical simulations.