A Guidance Law with Both Impact Time and Impact Angle Constraints Based on Circular Guidance

A circular guidance-based guidance law that can meet both the impact time and impact angle constraints is studied in this paper. The establishment of the proposed guidance law consists of two parts. First, a guidance law considering only the impact angle and miss-distance is derived based on the circular guidance. Since the trajectory contains only circular and straight parts, the time-to-go can be calculated precisely instead of being estimated. Then, a fixed-time convergent controller is introduced to eliminate the impact time error regardless of the initial errors. Besides, the guidance parameters can be solved analytically. Simulation results verify the effectiveness of the proposed guidance law.