一种含平行四边形支链的3自由度并联机构姿态精度综合与装配工艺设计

ORIENTATION ACCURACY SYNTHESIS AND ASSEMBLY PROCESS DESIGN OF A3-DOF PARALLEL KINEMATIC MACHINE WITH PARALLELOGRAM STRUTS

以含平行四边形支链的3平动自由度并联机构主模块为对象,通过误差建模揭示出影响这种机构末端姿态精度因素。利用灵敏度分析结果,将精度综合归结为一类有约束线性规划问题,并据此提出两种可以有效抑制末端姿态误差的装配工艺方案。

The method to control the uncompensatable pose error of a class of 3-DOF parallel kinematic machines with parallelogram struts is investigated. The error mapping function is formulated which allows the geometric errors affecting the orientation accuracy of the moving platform to be found. It is observed that the orientation error is uncompensatable and the results of accuracy synthesis show that it is impossible to control such error by allocating the manufacturing tolerances to each related components since they are too tight to be realized. Consequently, two schemes are proposed that allow the orientation pose error to be effectively minimized by adding an adjustable bush between two components of the carriages.