基于正交设计的3-RPS并联机构精度分析与综合

摘要

To analyze the influence degree of pose parameters on pose errors,and to guarantee the accuracy requirements of 3-RPS parallel mechanism in the whole workspace,the orthogonal design method was adopted for accuracy analysis and accuracy synthesis.According to the orthogonal design method,three pose parameters of 3-RPS parallel mechanism were considered as three factors for pose errors,and the pose error values from range analysis were introduced as error sensitive indexes.The influence degree of pose parameters on pose errors were obtained through range analysis.The factors were divided into reasonable levels based on the ratio of error sensitive indexes,and then more reasonable poses from orthogonal table were provided for accuracy synthesis.Accuracy synthesis was carried out according to the orthogonal table and tolerance values of 21 geometry original errors were derived according to accuracy requirements.The result shows that： By applying the orthogonal design method in accuracy analysis and synthesis,the influence degree of pose parameters on pose errors was analyzed completely,the accuracy synthesis results ensure the accuracy requirements in the whole workspace and a reference was provided for the development of prototype.%为了分析3-RPS并联机构在整个工作空间内各个位姿参数对位姿误差的影响程度,并且使该机构在整个工作空间内都满足精度要求,利用正交设计的思想对该机构进行了精度分析与精度综合.根据正交设计的思想,把该机构的3个位姿参数看成对位姿误差有影响的3个因素,用位姿误差的极差值作为敏感系数,通过极差分析得到了位姿参数对位姿误差的影响程度.以敏感系数的比值为依据合理划分各个因素的水平数,使排列的正交表为精度综合提供更加合理的位姿,对表中的各个位姿进行精度综合,得到了给定精度要求下的21项几何原始误差的公差值.结果表明：用正交设计的思想可以分析清楚位姿参数对位姿误差的影响程度,精度综合结果使机构在整个工作空间内满足精度要求,为物理样机的研制提供了参考.