Investigation of Reusable Launch Vehicle Landing Guidance Control with Multiple Sliding Surface Technique

This paper proposes an autonomous approach and landing guidance law for a reusable launch vehicle (RLV) at the specified runway touchdown. With the full nonlinear point-mass dynamics, the multiple sliding surfaces guidance (MSSG) technique is developed for the closed-loop guidance law to guarantee a successful approach and landing (A&L) movement, which has the same advantage in the finite time convergent property as higher order sliding mode control. Its global stability is proved using Lyapunov theory. The resultant guidance law has features in on-line trajectories calculation without any off-line analysis only using the boundary conditions of the A&L phase and instantaneous states of the RLV. Therefore, it is capable of targeting different touchdown points on the runway and overcoming large initial condition errors. Simulations are provided to verify the effectiveness of the proposed law.