Generalized Polynomial Guidance for Terminal Velocity Control of Tactical Ballistic Missiles

Abstract

This paper proposes generalized polynomial guidance for controlling the terminal velocity vector (speed and flight path angle), which could be critical for the effectiveness of the warhead of tactical ballistic missiles. A polynomial reference trajectory satisfying the initial and terminal altitudes and flight path angles is introduced with a guidance parameter that can be chosen to change the terminal speed. A single differential equation of the speed along the reference trajectory is then derived and an iterative search method for determining the guidance parameter to satisfy the prescribed terminal speed is proposed. Numerical simulation study with various impact angle and terminal speed constraints is conducted to demonstrate the performance of the proposed guidance method for terminal velocity control. Robustness of the proposed method to drag variations is also investigated to check the feasibility of generalized polynomial guidance for a practical purpose.