Impact-Angle-Control Guidance Law with Terminal Constraints on Curvature of Trajectory

This paper presents an impact-angle-control guidance law with terminal constraints on the curvature of the missile trajectory. The formulation takes into account nonlinear kinematics and time-varying velocity, allowing for more general cases in which the flight path angle may not be small throughout the entire trajectory. The proposed optimal guidance law aims to minimize the change rate of pseudo-curvature, which is defined as a curvature with weighting factors based on the flight-path angle and range to go. The analysis shows that the trajectories generated by this nonlinear guidance law have a simple polynomial form with respect to downrange. Numerical simulations demonstrate that the cost function parameter can be used to shape the trajectories along the downrange