Impact Time Control Guidance Law Design

By combining the Lyapunov stability theorem with the proportional navigation guidance (PNG) law, a novel guidance law which can control the impact time is proposed. This paper treats the impact time control problem as the impact time error regulation problem. The impact time error is defined by the difference between the desired time and the estimated time-to-go.The Lyapunov candidate function is introduced concerning the impact time error, and the control parameter is proposed to satisfy the Lyapunov stability theorem. The impact time error will go to zero before the desired time, and the singularity issue of the acceleration command has been analyzed. Numerical simulations are carried out to prove the effectiveness of the proposed guidance law.