中文摘要：

为深入研究动平台中心点误差范围，以一种少自由度3-RPS／UPS冗余并联机构为研究对象，提出了一种改进的铰链间隙误差分析方法，分析了此并联机构球铰间隙对动平台中心点的影响，在此基础上提出了一种改进的误差分析方法，并对具有相同结构参数的3一RPS非冗余并联机构和具有冗余支链的3一RPS／UPS并联机构进行误差分析及计算，结果表明，冗余并联机构的误差空间在各方向上都比非冗余并联机构小，故冗余约束可减小误差，提高并联机构精度。

英文摘要：

The paper analyses the joint error of 3 -RPS/UPS parallel mechanism with actuation redundan cy. The effect of joint clearance on the center position of the moving platform is carried out. Then an im proved method of error analysis is proposed. The error space of the center of the moving platform on 3 RPS parallel mechanism and 3- RPS/UPS redundant parallel mechanism with the same structural parame ters is calculated and the ranges are compared. The results show that redundant constraints can reduce er rors and improve accuracy of parallel mechanism.