Trajectory Optimization for Reusable Rocket Landing

Rocket landing process starts from the time of stage separation to the end of the vertical landing to the target area. This paper presents a homotopy-based trajectory optimization algorithm for reusable rocket landing problem. By analyzing the rocket characteristics of different phases in the landing flight process, the rocket landing optimization problem is established with the fuel-optimal target, and the dynamics equations and relevant constraints at various phases. Then, a unique homotopy optimization framework based on multiple flight phases is proposed for solving this problem. Simulation results showed that the proposed algorithm in this paper can effectively handle complex landing constraints, and also provides a feasible method to analyze the whole process of reusable rocket landing.