The development of the off-line measurement planning system for inspection automation

Measurement by a coordinate measuring machine (CMMs) has placed the main reliance on individual tolerances based on features such as arc, circle, cone, cylinder, line, plane, sphere, etc. However, the tolerances cannot be interpreted by individual features only and must take into account relationships with other features. For this reason, measurement and inspection should be carried out based not on features, but on geometric tolerances. To inspect parts automatically with respect to geometric tolerances, an off-line system is needed to establish measurement plans and to control inspection procedures. Further, for the correct estimation of form errors of geometric tolerances, statistical determination for the number of probing points is required. In this research, we developed three modules for the off-line measurement and inspection system. They are (1) the data input module, (2) the measurement planning module, and (3) the statistical analysis module. The scope of the geometric tolerances is limited to the position tolerance. This system has been constructed based on a solid modeller called CIMCAD-3D which operates in the SUN SPARC workstation.