空间相机偏流调整旋转轴系的设计与精度分析

Design and accuracy analysis for drift adjusting rotary axes of space camera

为提高空间相机的摄影精度和偏流角的控制精度,应用刚度较强的外筒机座平面作为轴系止推轴承轨道平面,设计了双径向与轴向复合约束力封闭式旋转轴系结构,其结构具有质量轻、转动灵活、回转精度高等特点。讨论了影响轴系旋转精度的诸多误差因素,如轴向窜动误差,角度摆动误差等,并定量分析了构成轴系零件的形位误差引起旋转轴系在回转运动中的晃动误差。通过对轴系晃动误差的检测,验证了所选用的轴系精度为3.8″,满足了总体技术指标在5″以内的要求。

The drift adjusting rotary axes of space camera mainly provides the angular motion control of the camera in the horizontal direction, and performs the real-time control of azimuthal drift to realize the image motion compensation in the photo-taking process. The drift adjusting rotary axes determine to a large extent the photo-taking accuracy and the drift control accuracy of a camera. For the utilization of the plane of highly rigid external pedestal as the orbital plane of the thrust bearing, and the adoption of composite enclosed design in both radial and axial directions, the structure of rotary axes features light mass, free rotation and high rotational accuracy. A number of factors having effect on the accuracy of rotary axes, such as radial runout and angular swing, are discussed, and a quantitative analysis has also been made for the axial shaking error resulting from the form and position errors of the rotary axis components. The measured shaking error of the rotary axes indicated that the accuracy of the axes selected is 3.8', and satisfies the general technical specification of being within 5'.