Three-dimensional nonsingular impact angle guidance strategy with physical constraints

In this study, two nonsingular three-dimensional (3D) guidance strategies to intercept a stationary target with desired impact angles, subject to nonlinear coupled dynamics, field-of-view (FOV) limit and lateral acceleration bounds, are investigated. As a stepping stone, two novel sliding mode surfaces are designed, the convergence and boundedness of the two sliding mode surfaces can guarantee the impact-angle-constrained interception while maintaining the seeker's lock-on condition during the guidance. A novel auxiliary system is also presented to compensate for the effects caused by input saturation. In addition, the analytical achievable impact angles set is presented in terms of the initial engagement condition. Numerical simulations with various constraints, a realistic missile model and comparison study have been considered to show the feasibility and effectiveness of the proposed strategies.