Impact-angle-constrained reentry guidance law guaranteeing convergence before attainment of desired line-of-sight range

Abstract

For reentry vehicle attacking a stationary target on the ground, impact-angle-constrained guidance law guaranteeing convergence before attainment of desired line-of-sight range is studied in this paper. Initially, a novel guidance model is established, in which line-of-sight range is treated as an independent variable, describing the relative motion between the vehicle and the target. Subsequently, a guidance law with impact angle constraint is designed based on the guidance model, which is presented in the form of normal overload. Compared with traditional guidance laws, the proposed one guarantees line-of-sight angular rate converges to zero and line-of-sight angle converges to the commanding impact angle before line-of-sight range decreases to the desired value. Finally, comparisons among proportional navigation guidance, optimal navigation guidance, and the proposed guidance are carried out by numerical simulation, which demonstrate the correctness and advantage of the novel guidance model and guidance law. The guidance model and guidance law proposed in this paper provide a new way for the design of fast convergent guidance law with impact angle constraint.