Design of Missile Mid-Course Guidance for Constrained Impact Angle

This research develops a mid-course guidance law, which enables a constrained impact angle at the engagement, in response to the needs of modern missile design. To achieve this goal and share the workload with the terminal guidance, the mid-course guidance has to regulate the missile to a specific target location and a specific flight angle for a specific time-to-go. Therefore, conventional mid-course guidance laws are inadequate in this case. The proposed guidance law achieves this goal by recursively updating the target dynamics for the mid-course guidance, and applying optimal controls with frequently updated control parameters. Simulation results demonstrate the importance and effectiveness of the proposed method. In a simulation case, the interception missile is 100 kilometers away from the target missile, the flight speed of the two missiles are 1200 m/s and 800 m/s, respectively, and the requested impact angle is 150°. The proposed method achieves the positioning error and flight-path-angle error of 791 meters and 0.56°, at the end of mid-course guidance. When working with the previously developed terminal guidance, the miss distance and impact-angle error are 0.002m and 0.001° at the end of the engagement.