Abstract: Aiming at the problem that the traditional pulse obstacle avoidance algorithm has strong dependence on the instantaneous thrust and large fuel consumption in the applications of spacecraft trajectory planning, a continuous dynamic obstacle avoidance algorithm with optimal energy is proposed. The algorithm firstly establishes a model of relative motion with optimal energy based on a linear relative motion equation and a finite time energy optimal model, and at the same time verifies the optimality of the model. Secondly, it introduces the y direction motion error offset of the dynamic obstacles and the normal distribution probability into the collision avoidance safe distance model, corrects the range of tracking spacecraft dynamic obstacle avoidance, determines the length of the safe distance vector, and enhances the reliability of avoiding obstacles. Finally, the angle between the obstacle speed vector and the tracker spacecraft speed vector is used to determine the direction of the dynamic obstacle avoidance point, which reduces the fuel consumption and improves the effectiveness and accuracy of the obstacle avoidance. Through simulation verification, the algorithm can adaptively select the obstacle avoidance points and effectively avoid the dynamic obstacles; and the working fluid fuel consumption is small, effectively extending the spacecraft on orbit life.

Key words: Trajectory planning, Linear relative motion, Optimal energy, Dynamic obstacle avoidance, Finite time constraint