夹具的定位误差模型

Model of locating error for fixtures

建立了定位元件公差和工件定位误差之间的映射模型 .利用该映射模型 ,给定工件的位姿精度 ,进而确定定位元件的公差要求 ;而给定定位元件的公差 ,可以确定完全定位、欠定位和过定位时工件的位姿误差 .一旦工件的位姿误差确定后 。

A mapping model between the error space of locators a nd the work-piece locating error space was built up. Given the tolerance specific ation of a work-piece, the geometry design requirements can be determined for a ll the locators using the model. By the geometric tolerance of locators, the cal culating methods for the locating errors of a work-piece are developed for the deterministic positioning, over deterministic positioning and under deterministi c positioning cases. When the position and orientation errors of a work-piece a re determined, the position errors of a set of critical points on the work-piec e can be calculated to evaluate the variation of a feature.