MONITORING AND CLASSIFICATION OF DIMENSIONAL FAULTS FOR AUTOMOTIVE BODY ASSEMBLY

Sudden process changes occurring dining automobile body assembly proce sses will influence the downstream assembly process and the functional ity and final appearance of the vehicle. Furthermore, these faults cou ld result in a decreased production rate and an increase in the cost i f sudden process changes are so serious that the production line has t o be stopped for investigation. Thus, sudden process changes should be detected and eliminated as soon as possible to prevent defective prod ucts from being produced and to reduce the cost of repairs/reworks. A monitoring algorithm is developed to detect, classify, and group proce ss changes by analyzing the dimensional data of car bodies. The result s of this monitoring algorithm can help diagnose the root causes of va riation according to the locations of measurement points, body structu re, assembly sequence, and tooling layout. Measurement data obtained f rom an optical coordinate measuring machine (OCMM) are used to demonst rate the monitoring technique.