A New Guidance Law for Impact Angle Constraints with Time-Varying Navigation Gain

Abstract In this study, a new impact angle control guidance law is proposed against a stationary target in the three-dimensional (3D) plane. A time-varying navigation gain is derived to achieve the specific terminal angle in a longitudinal plane without phased or adding a bias term. A proportional guidance law is also adopted in the lateral plane to achieve an accurate strike. The monotonicity of the look angle and the convergence of the acceleration are analysed and proven to support the proposed method. For the proposed guidance law, estimating time-to-go or giving a switch strategy is unnecessary; the navigation is continuous, which would not result in sudden changes in control input, and is convenient to implement. Extensive simulations, including autopilot lag or real missile model, are performed to validate the efficiency of the proposed method.