An e-quality control model for multistage machining processes of workpieces

To track and control the changes of process quality attributes in multistage machining processes (MMPs), an e-quality control (e-QC) model is proposed. The e-QC model is defined as a quality information service node with e-formalizing technology, whose input/output and intermediate process (that is IPO) are known to other nodes, and its implemention in MMPs is provided. In order to establish the e-QC model, a measuring network is constructed to acquire the original quality data, and the changes of process quality attributes are monitored and diagnosed by the integrated quality analysis tools attached to the e-QC, which can be tracked by information template network in real time. Furthermore, a hierarchical control method is adopted to coordinate e-QCs, in which the quality loss and adjusting cost are used to quantify the opportunities for e-QCs to improve process quality. At last, a prototype is developed to verify the proposed methods. Supported by the National Basic Research Program of China (“973”) (Grant No. 2005CB724106) and the National High-Tech Research and Development Program of China (“863”) (Grant No. 2007AA00Z108)