Research on a Head Pursuit Interception Guidance Law based on Sliding Mode Control

In intercept hypersonic target,the traditional chase mode guidance law requires missile to be faster and more flexible than the target. To solve this problem,this paper designs a head pursuit interception guidance law. First of all,the missile and target motion model in the head pursuit methods is established and analyzed. The head pursuit methods require the missile to fly in front of the target,and the missile speed is smaller than the target speed. Then, according to the sliding mode control theory, the angle between the target velocity vector and the line of sight is set as the sliding surface,and the missile is controlled to always fly in the direction of the target speed. So the sliding mode guidance law is obtained. The analysis finds that the guidance law requires a small speed and is insensitive to the target maneuver. The simulation results show that the guidance law requires low overload and has high precision.