Kinematics approaches for automated fixture reconfiguration planning

The most important task of fixture design is to locate a workpiece with the acceptable position. This paper presents a general fixture model able to characterize the state of the workpiece which is produced by the fixture locating-scheme. The fixture model is firstly proposed to discompose into the locating principle model and the locating error model. The locating principle model is used to verify the number and layout of the fixture locators/locating points whereas the locating error model formulates the relationship between the variations in the position and orientation of the workpiece and the dimensions/positions of locators. On the other hand, based on the conception of the robust design, the fixture design model is further established to improve the locating quality of the fixture. Finally, by means of some examples, a detailed discussion is made about how the analysis and optimal design of the locating-scheme is carried out.