DSC-backstepping based robust adaptive LS-SVM control for near space vehicle's reentry attitude

Purpose - The purpose of this paper is to propose a robust control scheme for near space vehicle's (NSV's) reentry attitude tracking problem under aerodynamic parameter variations and external disturbances. Design/methodology/approach - The robust control scheme is composed of dynamic surface control (DSC) and least squares support vector machines (LS-SVM). DSC is used to design a nonlinear controller for HSV; then, to increase the robustness and improve the control performance of the controller. LS-SVM is presented to estimate the lumped uncertainties, including aerodynamic parameter variations and external disturbances. The stability analysis shows that all closed-loop signals are bounded, with output tracking error and estimate error of LS-SVM weights exponentially converging to small compacts. Findings - Simulation results demonstrate that the proposed method is effective, leading to promising performance. Originality/value - First, a robust control scheme composed of DSC and adaptive LS-SVM is proposed for NSV's reentry attitude tracking problem under aerodynamic parameter variations and external disturbances; second, the proposed method can achieve more favorable tracking performances than conventional dynamic surface control because of employing LS-SVM to estimate aerodynamic parameter variations and external disturbances.