An Intercept Guidance Law with Impact-Angle-Constrained Based on Linear Gauss Pseudospectral Model Predictive Control

A nonlinear optimal guidance law with constraint on impact angle is proposed in this paper for interception of incoming high-speed ballistic missile targets. The guidance law is developed based on the recently developed linear gauss pseudospectral model predictive control (LGPMPC) method which is to solve the nonlinear optimal control problem with quadratic performance index and hard terminal constraints. The LGPMPC method combines the philosophies of linear quadrature optimal control, the Model Predictive Control and Gauss Pseudospectral Method. A design of engaging an incoming high-speed ballistic missile target with a specified impact angle in two dimensions is carried out to evaluate the performance of the proposed guidance law. In this work, the initial guess is produced by biased PN guidance law in the two dimensions. Simulation results show that the proposed guidance law has high computational efficiency in achieving ideal impact angles with high accuracy and the near-zero miss distance. And the generated lateral acceleration is small and smooth as expected. Moreover, performance of the proposed guidance law is superior to other guidance laws by comparative studies.