Optimal guidance for guided projectile with impact angle constraint

To improve the damage effect of guided projectile, not only miss distance is required to be the minimum, but also the projectile is required to attach the target with a specific angle. Since the guided projectile has no seeker and cannot carry on the terminal guidance, it is necessary to achieve a specific terminal attack angle by optimizing the trajectory of the projectile. Firstly, for the trajectory optimization problems with complex nonlinearities, and multiple constraints, such as state constraint, control input constraint and boundary constraint, this paper utilizes the Gauss pseudospectral method. Then, with the optimal trajectory as a standard trajectory, linear quadratic regulator (LQR) method is designed as the optimal tracking law to achieve the tracking for the standard trajectory. The simulation results show that the optimal guidance proposed in this paper can achieve the specific terminal attack angle with a small miss distance.