SDRE based adaptive optimal sliding mode control for re-entry vehicle

This paper considers the robust attitude control problem of re-entry vehicle in the presence of the parametric uncertainties and external disturbances. Based on SDRE method, an optimal sliding surface is first obtained through the minimization of a selected performance index function. Then, an adaptive sliding mode controller is designed to guarantee the reachability condition of the related optimal sliding surface. The switching gains are obtained on-line through an adaptation scheme, which eliminates the requirement of a priori knowledge of the upper bound on the lumped uncertainties. The effectiveness of the proposed strategy is verified by both theoretical analysis and simulation results.