能量最优的航天器连续动态避障轨迹规划

Spacecraft Continuous Dynamic Obstacle Avoidance Trajectory Planning with Optimal Energy

针对传统脉冲避障算法在航天器轨迹规划应用中存在对瞬时推力依赖性强且燃料消耗量大的问题,提出能量最优的连续动态避障算法。该算法首先基于线性相对运动方程与有限时间的能量最优模型,建立了相对运动能量最优模型,同时验证了模型最优性;其次将动态障碍物的y向运动误差偏移与正态分布概率引入避碰安全距离模型,修正了追踪航天器动态避障的范围,确定了安全距离矢量长度,增强了规避障碍的可靠性;最后通过障碍物速度矢量与追踪器航天器速度矢量夹角确定动态避障点方向,减少燃料消耗的同时提高了避障的有效性、准确性。通过仿真验证,该算法可以自适应选取规避障碍点,有效规避动态障碍;工质燃料消耗较小,有效延长航天器在轨寿命。

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.