In-Dressing Acoustic Map by Low-Cost Piezoelectric Transducer

The main difficulty in the grinding process is to identify the correct moment to dress the grinding wheel. Therefore, the cutting tool (grinding wheel) must be monitored. In this context, an innovative technique was developed in this article to obtain an image from the surface of the grinding wheel during the dressing process, based on acoustic images acquired through a piezoelectric diaphragm or piezoelectric buzzer. To this end, scratches (faults) are made on a grinding wheel, after which tests are performed at various dressing depths, and signals are collected by an acoustic emission (AE) sensor and a piezoelectric diaphragm. Based on these signals, frequency bands are evaluated to obtain acoustic images that would accurately and clearly represent the scratches imprinted on the grinding wheel. Finally, the performance of the two sensors (AE sensor and piezoelectric diaphragm) are compared, and the results are analyzed in light of the dressing conditions under study. The results indicate that the piezoelectric diaphragm is as efficient in obtaining acoustic maps of the grinding wheel surface as the AE sensor and in some machining conditions, it provides superior results to those obtained when monitoring the tool with the AE sensor.