摘要
针对航天器近距离操作中的动态障碍物规避问题,研究了一种燃料较省、精度较高的规避动态障碍物的自适应人工势函数制导方法。首先,对于引入高斯函数形式斥力势会使势函数在收敛点处的值不为零的情况,对斥力势乘以修正项,使得在收敛点的势能为零,消除了平衡点的偏离;在规避静态障碍物的基础上,研究了规避动态障碍物的人工势函数制导。其次,根据速度与引力梯度之间的关系,设计负反馈,使引力势梯度"适应"速度的变化,研究了规避动态障碍物的自适应人工势函数制导。最后,采用精确的数学模型进行数值仿真,验证所设计的制导律的正确性和有效性,并与传统的人工势函数制导对比。仿真结果表明:采用修正势函数提高了收敛精度;自适应人工势函数制导控制脉冲作用施加更加合理,相比人工势函数而言,总速度脉冲消耗可节省30%,精度提高两个数量级。
To avoid the dynamic obstacles during spacecraft autonomous proximity operations, a fuel saving and high-accuracy adaptive artificial potential function guidance method for dynamic obstacles avoidance was presented. As for the situation that the Gaussian repulsive potential function was non-zero at the desired position, a correction term was multiplied to eliminate deviation from the equilibrium point. The guidance law of avoiding dynamic obstacles was deduced based on that of the static obstacles avoidance. Then, according to the relationship between velocity and gravity gradient, the negative feedback control was designed to make the gravity gradient adapt to the variance of velocity, and the adaptive artificial potential function guidance law for dynamic obstacles avoidance was obtained eventually. To verify the correctness and effectiveness of the guidance law, a series of numerical simulations using the precise mathematical model were carried out. The simulation results show that the corrected potential function can effectively improve the convergent precision~ and the adaptive artificial potential function guidance law makes the control pulses.more reasonable, with saving 30% of the total delta V, and is two degrees more accurate than the traditional artificial potential function guidance law.
出处
《中国空间科学技术》
EI
CSCD
北大核心
2012年第5期1-8,共8页
Chinese Space Science and Technology
基金
国家自然科学基金(11072194)资助项目
关键词
人工势函数
制导
动态障碍物
自适应
航天器
Artificial potential function Guidance Dynamic obstacles Adaptive Spacecraft
