3D gliding guidance for an unpowered RLV in the TAEM phase

A sliding mode guidance strategy is developed for an unpowered reusable launch vehicle (RLV) during the terminal area energy management (TAEM) phase. The 3-DOF guidance model of a RLV in the domain of altitude is firstly provided, based on which a new sliding surface is constructed to account for multiple constraints on terminal conditions and dynamic pressure profile during flight. A second-order sliding mode guidance law is then developed to ensure the reaching of the sliding surface at a specific altitude. The simulation results confirm the effectiveness of the proposed method.