The Development of On-line Monitoring System for Micro-EDM
|Keywords:||微細放電加工;RC放電波列;波形鑑別;Micro-EDM;RC pulse trains;Pulse discriminating||Issue Date:||2006||Abstract:||
The servo feed control is important for micro electrical discharge machining (Micro-EDM) process, and the average gap voltage is commonly taken to reflect discharge condition for this purpose. A system to monitor the process of Micro-EDM is developed and implemented in this paper. The system is composed of a differential probe, a data acquisition card, a RC pulse trains discriminating program and a personal computer. From the observation of the pulse trains obtained under various machining conditions, features of different pulses are sorted, and the pulses can be classified into four types, namely, normal, arc, short, and complex. An approach to distinguish each pulse type in accordance with three pulse durations measured at three pre-determined voltage levels is proposed. The man-machine interface for easy understanding of the machining process is constructed as well. The developed system is verified by using simulated signals. Actual machining by micro wire-EDM, micro-EDM drilling and micro-EDM milling are conducted and their corresponding pulse trains are tested. It is found that the pulse trains can be successfully discriminated. The pulse trains of micro wire-EDM and micro-EDM milling are mainly normal type. The pulse type distribution varies during the process of micro-EDM drilling. It is also noted that the percentage of complex pulse increases monotonically with the depth of drilling. It starts to drop when the gap condition is deteriorated that drilling is no longer possible. Accordingly, this monitoring system is used to design the servo feed control system of micro-EDM drilling process, and it is under way.
|Appears in Collections:||機械工程學系|
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.