Paper:

# Monitoring and Adaptive Process Control of Wire Electrical Discharge Turning

## Mu-Tian Yan and Pai-Hung Hsieh

Department of Mechatronic Engineering, Huafan University, No.1, Huafan Rd. Shihding Dist., New Taipei City 223, Taiwan R.O.C.

This paper presents a novel pulse discriminating and control system for the identification of spark gap states, process monitoring and control of Wire Electrical Discharge Turning (WEDT). The relation between the proportion of open circuit, normal spark, arc discharge, short circuit to total sparks (defined as open circuit ratio, normal spark ratio, arc discharge ratio and short circuit ratio, respectively), ignition delay time and metal removal rate were experimentally studied and analyzed. A fuzzy logic controller was proposed to control both the arc discharge ratio and ignition delay time at optimal levels by on-line regulation of table feed-rate and pulse off-time for adaptive control optimization of WEDT. Experimental results show that the developed process monitoring and control system results in faster machining and better machining stability as compared with a conventional servo feed control scheme for the WEDT process.

*Int. J. Automation Technol.*, Vol.8, No.3, pp. 468-477, 2014.

- [1] J. Qu, A. J. Shih, and R. O. Scattergood, “Development of the cylindrical wire electrical discharge machining process, part 1: concept, design, and material removal rate,” J. of Manufacturing Science and Engineering, Vol.124, No.3, pp. 702-707, 2002.
- [2] J. Qu, A. J. Shih, and R. O. Scattergood, “Development of the cylindrical wire electrical discharge machining process, part 2: surface integrity and roundness,” J. of Manufacturing Science and Engineering, Vol.124, No.3, pp. 708-714, 2002.
- [3] A. Mohammadi, A. F. Tehrani, E. Emanian, and D. Karimi, “A new approach to surface roughness and roundness improvement in wire electrical discharge turning based on statistical analyses,” Int. J. of Advanced Manufacturing Technology, Vol.39, No.1-2, pp. 64-73, 2008.
- [4] M. J. Haddad and A. F. Tehrani, “Investigation of cylindrical wire electrical discharge turning (CWEDT) of AISI D3 tool steel based on statistical analysis,” J. of Materials Processing Technology, Vol.198, No.1-3, pp. 77-85, 2008.
- [5] M. J. Haddad, M. Tajik, A. Fadaei Tehrani, A. Mohammadi, and M. Hadi, “An experimental investigation of cylindrical wire electrical discharge turning process using Taguchi approach,” Int. J. of Material Forming, Vol.2, No.3, pp. 167-179, 2009.
- [6] M. J. Haddad, F. Alihoseini, M. Hadi, M. Hadad, A. F. Tehrani, and A. Mohammadi, “An experimental investigation of cylindrical wire electrical discharge turning process,” Int. J. of Advanced Manufacturing Technology, Vol.46, No.9-12, pp. 1119-1132, 2010.
- [7] N. Kinoshita, M. Fukui, and G. Gamo, “Control of wire-EDM preventing electrode from breaking,” Annuals of the CIRP, Vol.31, No.1, pp. 111-114, 1982.
- [8] K. P. Rajurkar and W. M. Wang, “On-line monitor and control for wire breakage in WEDM,” Annals of the CIRP, Vol.140, No.1, pp. 219-222, 1991.
- [9] K. Shoda, Y. Kaneko, H. Nishimura, M. Kunieda, and M. X. Fan, “Adaptive control of WEDM with on-line detection of spark locations,” Proc. of the 10th of Int. Symp. for Electro-Machining (ISEM-10), pp. 410-416, 1992.
- [10] M. T.Yan and Y. S. Liao, “A Self-learning fuzzy controller for wire rupture prevention in WEDM,” Int. J. of Advanced Manufacturing Technology, Vol.11, No.4, pp. 267-275, 1996.
- [11] R. Snoeys, D. Dauw, and J. P. Kruth, “Improved adaptive control system for EDM processes,” Annals of CIRP, Vol.29, No.1, pp. 97-101, 1980.
- [12] V. Garbajs and J. Peklenik, “Statistical model for an adaptive control of EDM-process,” Annals of CIRP, Vol.34, No.1, pp. 499-502, 1985.
- [13] M.Weck and J.M. Dehmer, “Analysis and adaptive control of EDM sinking process using the ignition delay time and fall time as parameter,” Annals of CIRP, Vol.41, No.1, pp. 243-246, 1992.
- [14] K. P. Rajurkar and W. M. Wang, “A new model reference adaptive control of EDM,” Annals of CIRP, Vol.38, No.1, pp. 183-186, 1989.
- [15] W. M. Wang and K. P. Rajurkar, “Modeling and adaptive control of EDM systems,” J. of Manufacturing Systems, Vol.11, No.5, pp. 334-345, 1992.
- [16] K. P. Rajurkar, W. M. Wang, and J. A. McGeough, “WEDM identification and adaptive control for variable-height components,” Annals of CIRP, Vol.43, No.1, pp. 199-202, 1994.
- [17] K. P. Rajurkar, W. M. Wang, and W. S. Zhao, “WEDM-adaptive control with a multiple input model for identification of workpiece height,” Annals of CIRP, Vol.46, No.1, pp. 147-150, 1997.
- [18] M. Boccadoro and D. F. Dauw, “About the application of fuzzy controllers in high-performance die-sinking EDM machines,” Annals of CIRP, Vol.44, No.1, pp. 147-150, 1995.
- [19] M. T. Yan and Y. S. Liao, “Adaptive control of WEDM process using the fuzzy control strategy,” J. of Manufacturing System, Vol.17, No.4, pp. 263-274, 1998.
- [20] Y. S. Liao and J. C. Woo, “Design of a fuzzy controller for the adaptive control of WEDM process,” Int. J. of Machine Tools and Manufacture, Vol.40, No.15, pp. 2293-2307, 2000.
- [21] M. T. Yan, Y. S. Liao, and C. C. Chang, “On-line estimation of workpiece height by using neural networks and hierarchical adaptive control of WEDM,” Int. J. of Advanced Manufacturing Technology, Vol.18, No.12, pp. 884-891, 2001.
- [22] M. T. Yan, “An adaptive control system with self-organizing fuzzy sliding mode control strategy for micro wire-EDM machine,” Int. J. of Advanced Manufacturing Technology, Vol.50, No.1-4, pp. 315-328, 2010.
- [23] A. Behrens and J. Ginzel, “Neuro-fuzzy process control system for sinking EDM,” J. of Manufacturing Processes, Vol.5, No.1, pp. 33-39, 2003.
- [24] T. Ishida and Y. Takeuchi, “Design and implementation of automatic discharge gap controller for a curved hole creating microrobot with an electrical discharge machining function,” Int. J. of Automation Technology, Vol.4, No.6, pp. 542-551, 2010.
- [25] M. Kita, T. Ishida, and Y. Takeuchi, “Direct measurement of electrode movement during electrical discharge machining by means of automatic discharge gap controller,” Int. J. of Automation Technology, Vol.4, No.6, pp. 552-561, 2010.
- [26] M. T. Yan, C. W. Huang, and C. J.Wang, “Development of an open architecture CNC system for a wire-EDM machine,” Materials Science Forum, Vols.505-507, pp. 481-486, 2006.

This article is published under a Creative Commons Attribution-NoDerivatives 4.0 Internationa License.