Approach and landing guidance based on sliding mode control and input-to-state stability

This paper presents a new guidance law based on sliding-mode control and input-to-state stability (ISS) for approach and landing of a reusable launch vehicle (RLV). According to the idea of reference-trajectory guidance, the sliding mode surface is chosen to be a linear combination of the reference-trajectory tracking error and its rate, and a guidance law is designed to make the dynamics of the sliding mode surface be ISS with respect to bounded uncertainties. Then, by introducing class KL-like function, it is proved that the influence of uncertainties on reference-trajectory tracking error can be close to zero by adjusting the guidance parameters. The numerical simulation confirms the effectiveness of the proposed design approach.