Method of change management based on dynamic machining error propagation

In multistage machining processes (MMPs), the final quality of a part is influenced by a series of machining processes, which are complex correlations. So it is necessary to research the rule of machining error propagation to ensure the machining quality. For this issue, a change management method of quality control nodes (i.e., QC-nodes) for machining error propagation is proposed. A new framework of QC-nodes is proposed including association analysis of quality attributes, quality closed-loop control, error tracing and error coordination optimization. And the weighted directed network is introduced to describe and analyze the correlativity among the machining processes. In order to establish the dynamic machining error propagation network (D-MEPN), QC-nodes are defined as the network nodes, and the correlation among the QC-nodes is mapped onto the network. Based on the network analysis, the dynamic characteristics of machining error propagation are explored. An adaptive control method based on the stability theory is introduced for error coordination optimization. At last, a simple example is used to verify the proposed method. Supported by the National Natural Science Foundation of China (Grant No. 50875204) and the National Hi-Tech Research and Development Program of China (“863” Project) (Grant No. 2007AA00Z108)