Recovery guidance for linear systems with input and state constraints

When a fixed regulator is used to stabilize a desired state trajectory (guidance law), large initial tracking errors can lead to input saturation, which can result in performance deterioration. A method to modify the guidance law for recovering state-trajectory tracking (without violating input and state constraints) is presented. Although it may be feasible to find such a satisfactory recovery guidance manoeuvre for a given initial tracking error, online development of recovery guidance manoeuvres may not be computationally tractable. A technique is developed to use precomputed recovery guidance manoeuvres (for a finite set of initial tracking errors) to generate recovery guidance manoeuvres for other initial errors