无人月球探测器缓冲着陆抛投试验视觉测量系统

针对无人月球探测器缓冲着陆运动抛投试验中对探测器缓冲着陆过程中三维姿态、三维速度等运动参数和缓冲着陆机构缓冲行程的测量,设计了基于计算机视觉的抛投试验测量系统。首先,在探测器主体结构上喷绘若干对顶角标志,并用全站仪测量出这些标志的空间坐标。然后,用高速摄像机采集探测器缓冲着陆过程的序列图像。最后,利用单目视觉的方法对标志的空间坐标及探测器的序列图像进行处理得到上述参数。该系统硬件设备简单,软件操作方便。理论分析和实验验证均表明,采用该系统测量探测器运动参数,其姿态角测量精度优于4′,运动速度测量精度约为0.02m/s,探测器缓冲行程精度约为4mm,完全满足无人月球探测器缓冲着陆运动试验中的测量精度要求。

Vision measuring system for soft-landing drop test of unmanned lunar explorer

A measuring system based on computer vision was developed to measure the movement parameters of a unmanned lunar explorer at a soft-landing test, such as the 3D pose, 3D velocity of explorer and the working strobe of snubber. Firstly, some opposite-vertical-angle marks were painted on the surface of the explorer, and their 3D coordinates were measured by a high-precision total station. Then, a series of images were taken by a high speed digital camera during the soft-landing test of explorer. Finally, the above parameters could be obtained by processing serial images of the explorer and 3D coordinates of the marks with the mono-vision method. The system is compact and easy to be operated. The theoretical analysis and experiments for the measurement precision of the system were performed. The results indicate that accuracies of pose angle, velocity and working strobe in measurements are 4', 0.02 m/s and 4 mm, respectively,which can satisfy the requirements of movement parameter measurements in the soft-landing tests for unmanned lunar explorers.