Machine-vision-based electrode wear analysis for closed loop wire EDM process control

Springer Science and Business Media LLC - Tập 10 - Trang 131-142 - 2021
P. M. Abhilash1, D. Chakradhar1
1Department of Mechanical Engineering, Indian Institute of Technology Palakkad, Kerala, India

Tóm tắt

The purpose of this study was to develop a closed-loop machine vision system for wire electrical discharge machining (EDM) process control. Excessive wire wear leading to wire breakage is the primary cause of wire EDM process failures. Such process interruptions are undesirable because they affect cost efficiency, surface quality, and process sustainability. The developed system monitors wire wear using an image-processing algorithm and suggests parametric changes according to the severity of the wire wear. Microscopic images of the wire electrode coming out from the machining zone are fed to the system as raw images. In the proposed method, the images are pre-processed and enhanced to obtain a binary image that is used to compute the wire wear ratio (WWR). The input parameters that are adjusted to recover from the unstable conditions that cause excessive wire wear are pulse off time, servo voltage, and wire feed rate. The algorithm successfully predicted wire breakage events. In addition, the alternative parametric settings proposed by the control algorithm were successful in reducing the wire wear to safe limits, thereby preventing wire breakage interruptions.

Tài liệu tham khảo

Abhilash PM, Chakradhar D (2021) Chakradhar image processing algorithm for detection quantification and classification of microdefects in wire electric discharge machined precision finish cut surfaces. J Micromanuf. https://doi.org/10.1177/25165984211015410

Abhilash PM, Chakradhar D (2021) Failure detection and control for wire EDM process using multiple sensors. CIRP J Manuf Sci Technol 33:315–326. https://doi.org/10.1016/j.cirpj.2021.04.009