Verification of in-line data capture and processing in dimensional management systems in car body assembly

Car body manufacture and assembly involves a complex set of operations which require a major capital investment for production tooling. This applies particularly to the manufacture of body panels and their assembly in the "body-in-white" phase. High technology computer controlled co-ordinate measuring machines (:CMM) are traditionally used to confirm the dimensional integrity of both the car body subassemblies and the complete car body and to assist in improving the production tooling to obtain dimensionally accurate products. The paper considers the need for the replacement of CMM based methodologies with laser based optical measurement technology. This is required in order to produce quickly a statistically reliable measurement of the body sub-assembly dimensions. The cost of measuring car bodies and the speed of co-ordinate measuring machines suggests that CMMs are not able to provide the required speed of measurement to control adequately car body sub-assembly dimensions. The conducted experiments conclude that properly designed laser based optical measuring systems provide the required speed of data capture smd data processing capacity necessary to increase the required sample rate to a level capable of controlling the production process and to assure dimensional accuracy of the car bodies.