Sliding Mode Guidance for 3D Gliding Motions with Bank Limitations

A sliding mode terminal guidance strategy is developed for an unpowered reusable launch vehicle (RLV) during the terminal area energy management (TAEM) phase. The main idea is to use the finite-time reaching phase of the sliding mode method to solve the three-dimensional (3D) guidance problem with multiple flight constraints. Firstly, the mathematical model of a RLV in the altitude domain is provided, based on which a new sliding surface is constructed to account for multiple constraints on terminal conditions and dynamic pressure profile. Subsequently, a second-order sliding mode guidance law is constructed to ensure the reaching of the sliding surface at a specific altitude. Finally, the effectiveness of the proposed guidance strategy in both nominal case and the case of bank limitations is illustrated by the numerical simulations.