Abstract: The safety guidance of the chaser spacecraft approaching the uncontrolled rotating target spacecraft is studied in this paper. During the approach, the chaser spacecraft needs to avoid obstacles in the space and avoid collisions with accessories such as the solar panels and antennas of the target spacecraft. The relative motion equation between two spacecraft under the line of the sight coordinate system is established. The quaternion is used to describe the attitude motion of the target spacecraft. The attraction potential function is designed by setting the reference position as the gravitational source. To ensure safe approaching, the spherical safety zone and the cone safety corridor are designed, and the safety potential function is designed. The obstacle is assumed to be a sphere with a certain radius, and the obstacle potential function is designed. The attraction potential function, the safety potential function, and the obstacle potential function constitute a hybrid potential function. In order to solve the problem that there may be other local minima in the whole potential field besides the reference position, the hybrid potential function is modified to ensure that the reference position is at the lowest point of the hybrid potential function. The stability of the hybrid potential function is analyzed by Lyapunov stability theory, and the required control acceleration is derived, which makes the chaser approaches the uncontrolled rotation target spacecraft along the negative gradient of the hybrid potential function. Finally, the effectiveness of this method is verified by numerical simulation.

Key words: potential function, safe approaching, safety corridor, obstacle avoidance, uncontrolled rotating