The Design on Lunar Probe Soft Landing and Its Optimal Strategy

Abstract

The main research in the paper tells us an optimal control strategy of Chang’e III in the process of the lunar probe soft landing. After entering into the orbit, the process of soft landing is divided into 5 stages including deceleration, quick adjustment, obstacle, avoidance and precise obstacle. According to the Newton’s Second Theorem and coordinate transform, the equation on each stage can be established. What’s more, on the basis of the Bellman Optimality Theory and according to the maximum principle, the extremum that meets the boundary condition can be calculated. Eventually, the optimal control strategy can be obtained and the calculation of substitution will be the optimal track.