Adaptive Control of the WEDM Process Using a Self-Tuning Fuzzy Logic Algorithm with Grey Prediction
Resource
International Journal of Advanced Manufacturing Technology,34,527-537.
Journal
The International Journal of Advanced Manufacturing Technology
Pages
527-537
Date Issued
2005
Date
2005
Author(s)
Lee, W. M.
Liao, Y. S.
Abstract
A control system to improve the efficiency of machining a workpiece with varying thickness in the wire electrical discharge machining (WEDM) process is proposed. The abnormal ratio R ab defined by the proportion of abnormal sparks in a sampling period is taken as the controlled variable. It is allowed to reduce temporarily as the cutting thickness is changing. A gain self-tuning fuzzy control algorithm is used so that the transient situation as the cutting thickness is suddenly increasing can be suppressed immediately, and a stable performance can be achieved. In addition, the grey predictor is adopted to compensate the time-delayed R ab caused by the low-pass filter data processing. Experiments reveal that there is a slight variance in the optimal reference of R ab when the cutting thickness is larger than 20 mm, and its value is set to 55% in these cases. Three cases were tested: the constant machining parameters, the constant R ab and the proposed adaptive R ab . The results show that the cutting speed can be obviously improved by the proposed control strategy. © 2006 Springer-Verlag London Limited.
SDGs
Type
journal article