Automatic landing of Crew Exploration Vehicles (CEVs) using hybrid memory-based approach

Precise landing is vital to the safe operation of Crew Exploration Vehicles (CEVs). This work investigates a new control method for automatic landing of CEV under varying and uncertain operation conditions. Hybrid memory-based control algorithm is developed to achieve attitude tracking of CEV with high precision. The salient feature of this method is that it does not involve direct nonlinearity cancellation, or on-line estimation of upper bounds on uncertainties, making it easier and more feasible for design and implementation as compared with most existing methods. It is shown that with the proposed control scheme external disturbances and coupled uncertain dynamics due to uncertain flight conditions are effectively compensated. Both theoretic analysis and simulation studies confirm the effectiveness of the proposed method.