Closed-loop trajectory optimization for precision landing on small bodies considering tracking guidance

Since the dynamics parameters of the small bodies and the initial state of the lander are uncertain, an optimization method considering the closed-loop tracking guidance is presented. Firstly, the dynamics for landing on small bodies is constructed and the optimal problem is analyzed. Then, the feedback guidance law is designed by use of the Linear Quadratic Regulator. The closed-loop sensitivity matrix equations are derived, and the performance index with weighted fuel consumption and sensitivity is constructed. Then, the trajectory considering the closed-loop tracking guidance is obtained by solving the constructed optimal problem. The simulation results show that the presented method can reduce position and velocity errors and meet the requirements for precision landing on small bodies.