为了提高空间相机次镜Stewart型调整机构的定位精度, 需要完成机构的精密标定。针对6-PSS Stewart机构, 首先依据最小二乘原则, 利用驱动残差构建了参数标定模型。其次为提高标定优化问题的全局求解精度, 采用自适应路径(Variable Step Adaptive, VSA)及限界处理对单纯形布谷鸟算法进行改进, 并应用于标定优化问题求解。数值仿真表明其求解能力并优于单纯型布谷鸟算法。最后, 为保证标定的全行程有效性, 规划了包含位姿六元素的试验数据采样方法。实验结果表明, 经过该方法标定后, 位姿采样点处最大位移误差由19.97 μm降为9.68 μm, 最大转角误差由123.84″降为最大8.86″, 在非采样点处最大误差与采样点处在同一量级水平。基于上述模型、算法和采样位姿规划的标定方法可有效提高定位精度, 且标定结果在全行程区域内有效。

In order to improve the adjusting accuracy of space telescope secondary mirror Stewart mechanism, the precision calibration is necessary. For the 6-PSS Stewart adjusting mechanism, first of all, the parameter calibration model was obtained by the kinematics and the least square method. Secondly, the usually cuckoo search based on simplex(SMCS) method was modified by use of VSA and limitation bounds algorithm to improve the global accuracy of optimization problem. The better calculation ability compared to SMCS was verified by the simulation results. Finally, to ensure the validity of the whole travel distance, a test data sampling process included six elements of position and orientation was planned. Experimental results show that the displacement error at the sampling point is reduced from the maximum 19.97 μm to 9.68 μm, and the angle error is reduced by a maximum of 123.84″ to 8.86″. Similar results are also shown with good accuracy at the non-sampling points, the proposed method based on the aforementioned model can effectively improve position accuracy of the secondary mirror adjusting mechanism, and the compensation results is efficient for the whole travel distance.