翻滚目标安全走廊内的碰撞可能性判断方法

在接近空间带大附件翻滚目标过程中,由于目标章动运动,空间会被划分为目标扫过的危险区与不被扫过的安全区.追踪星在目标安全区内飞行过程中,为规避航天器间的碰撞,应判断追踪星与目标安全区之间是否存在碰撞可能性.为解决这一问题,参考区域判定法思想,将判断碰撞可能性的问题转化为目标安全区与追踪星轨迹的位置判定问题.通过分析目标安全区特征与追踪星轨迹特点,分别建立锥面状的目标星安全走廊和椭球状的追踪星位置误差曲面,从而进一步将问题转化为目标星安全走廊锥面与追踪星位置误差椭球的位置判定问题.经过射影变换和平面投影过程,原锥面与椭球在不改变位置关系的前提下分别被转化为平面上圆与椭圆.利用平面曲线位置判据,判定圆与椭圆的位置关系,反推出锥面与椭球的位置关系,从而判断追踪星在目标安全走廊内飞行有无碰撞可能性.数值仿真表明,该方法可以准确判断锥面与椭球的空间位置关系,并可用于目标安全走廊内的碰撞可能性判断.

Collision possibility detection in the safe corridor of a tumbling target

In the mission of approaching to a disabled tumbling target, the space will be divided into the safe zone and the unsafe zone because of the nutation of the target. During the chaser''s flight in the safe zone of the target, the collision possibility between the target and the chaser should be determined to avoid the collision accident. To solve this problem, the region judgment method is used to transform the task into the position relation determination problem between the safe zone of the target and the trajectory of the chaser. By analyzing characteristics of the safe zone of the target as well as the trajectory of the chaser, both the conical safe corridor model of the target and ellipsoidal position error model of the chaser are established. As a result, the problem is further transformed into the issve of position relation determination between the cone and the ellipsoid. Through projective transformation and plane projection, the original cone and ellipsoid are transformed into a circle and an ellipse on the plane with the unchangeable position relation. Using the location criterion of plane curves, the position relation between the circle and ellipse would be determined, and then, the position relation between the cone and ellipsoid could be deduced, which is expected to determine whether the collision risk exists or not. Simulation experiment shows that this method is accurate to determine the position relation between the conical surface and the ellipsoidal surface, and it can be used to detect the collision possibility in the flight during the safe corridor of the target.