Real-time critical safety curve and predictive control based trajectory planning for complex shaped rotating spacecraft proximity

This paper presents a real-time trajectory planning and tracking control framework for a complex-shaped chaser to approach a rotating target with complex shapes. The framework is divided into two layers: trajectory planning and tracking control. Firstly, considering the complex shapes and relative attitude constraints of the target and chaser, a real-time critical safety curve (RT-CSC) is proposed as a collision avoidance constraint combined with the rotational motion of the target. Secondly, the multi-constraint improved disturbed fluid method (MCIDFM) is proposed. The flow field velocity is designed by considering proximity time optimization under boundary and chaser thruster performance constraints. Trajectory planning is achieved by making the flow field bypass the non-convex keep-out zone formed by the RT-CSC. Then, the tracking control is implemented using a model predictive control method and the closed-loop asymptotic stability is demonstrated. Simulation results demonstrate the proposed methods’ smoothness, safety, and strong approach capabilities. Rapidity and robustness are also reflected in simulation analysis.