6UPS并联机构静态误差的矢量法标定

Calibration of a 6UPS Parallel Machine by Vector Method

分析了不同误差对并联机构的影响,通过对机构进行位姿误差分析,建立了采用并联机构运动学反解模型的矢量法误差求解模型;研究了常用的机构标定方法及相应的测量工具,使用激光干涉仪完成了误差测量实验,并按照矢量法误差模型对测量结果进行了分析计算,使用多组姿态数据的不同组合进行误差计算,并对误差影响区域及区域重心进行拟合处理,获得了优化的机构静平台、动平台铰链的位置误差数据。使用位置误差数据可以获得更好的补偿效果。

Based on the error analysis of orientation and position of a platform, a general error model was established. The commonly used methods of parallel machine parametrical calibration and corresponding measuring tool were studied. The model used by different calibration methods were studied, especially the vector method of kinematics model. The practical calibration experiments that were abided by the vector method were performed. After the experiments, all of the structural parameters of the machine were obtained; they included the positions of all the joint centers of legs at the static and motion platform, and the positions of cutter at the motion platform. Using different groups of the orientations and positions of the platform, many structural parameters can be obtained. The influence space and its center were calculated. These optimizing error data will obtain better compensation in motion control.