嫦娥五号表取采样臂载相机成像位姿与覆盖

Imaging posture and coverage of Chang’e 5 surface sampling manipulator cameras

嫦娥五号探测器成功实现了中国首次地外天体采样返回。月面工作过程中,表取采样机械臂上的臂载相机获取了大量的图像数据,结合嫦娥五号四自由度表取采样机械臂,利用几何法描述了其逆运动学,针对臂上远摄相机和末端近摄相机2种形式的臂载相机,提出了单目运动相机的成像位姿确定方法,并分析了不同成像位姿图像对表取采样区的视场覆盖,建立了非图像化的多图像交叠评估原则。根据嫦娥五号月面表取采样臂载相机图像,进行了成像位姿与视场覆盖仿真分析,并通过地形重建对结果进行了验证。结果表明该方法可确定大范围运动的臂载相机所获得的图像的交叠联系,通过成像位姿与图像特征相结合,可为区域地形重建等多图像联合应用提供支持。

The Chang’e 5 explorer successfully realized China’s first lunar sample-return mission. Lots of images were acquired by the cameras mounted on the surface sampling manipulator in the process of lunar surface exploration. The inverse kinematics of the 4 degrees of freedom manipulator of Chang’e 5 was discussed with the geometric method. The imaging posture determination approach for the two types of monocular motion cameras mounted on the manipulator--far camera and near camera was proposed. For the sampling area, the coverage of the field of view under different imaging posture was analyzed. Furthermore, the principle of multi-image overlapping evaluation without image was established. Then the imaging posture and image coverage were simulated based on the manipulator camera motion information, and the simulation results were verified through terrain reconstruction. The results indicate that the approach can be used to establish the overlapping connection of multi-images acquired by the manipulator camera in widespread motion, and can be used in multi-image joint applications such as topographic reconstruction with the help of imaging posture.