扰动环境下火星精确着陆自主轨迹规划方法

An autonomous trajectory planning method of Mars landing powered-descent in the disturbed environment is proposed based on the sequential convex programming method with the consideration of free terminal time. Firstly, considering the free terminal time, a trajectory planning problem without disturbance is established. Secondly, based on the robust Tube-MPC and the linear feedback control law, we establish a series of replanning problems of landing trajectory under the disturbed environment. The feasibility of the replanning problems is analyzed, and the necessary conditions for the feasibility of the preplanning problem are given to provide a reference for selection of control parameters. The autonomous trajectory planning framework for Mars precise landing under the disturbed environment is then proposed. Thirdly, considering the free terminal time, the flight time domain is mapped to the unit time, and a sub-problem of sequence optimization is established. The sub-problem is linearly approximated, and the sequential convex programming is employed to solve it. It is proved that the convergent solution of the approximation problem is a KKT solution of the original problem. Finally, numerical simulation is carried out to verify the effectiveness of the method.