Dressing Tool Condition Monitoring through Impedance-Based Sensors: Part 1-PZT Diaphragm Transducer Response and EMI Sensing Technique

• Published in: Sensors (Basel, Switzerland) Vol. 18; no. 12; p. 4455
• Main Authors: Junior, Pedro, D'Addona, Doriana M, Aguiar, Paulo R
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI 16-12-2018; MDPI AG
• Subjects: dressing; electromechanical impedance; EMI; grinding process; piezoelectric sensors; PZT; sensor monitoring; tool condition monitoring; EMI; piezoelectric sensors; electromechanical impedance; dressing; sensor monitoring; tool condition monitoring; grinding process; PZT
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s18124455

Low-cost piezoelectric lead zirconate titanate (PZT) diaphragm transducers have attracted increasing attention as effective sensing devices, based on the electromechanical impedance (EMI) principle, for applications in many engineering sectors. Due to the considerable potential of PZT diaphragm transducers in terms of excellent electromechanical coupling properties, low implementation cost and wide-band frequency response, this technique provides a new alternative approach for tool condition monitoring in grinding processes competing with the conventional and expensive indirect sensor monitoring methods. This paper aims at assessing the structural changes caused by wear in single-point dressers during their lifetime, in order to ensure the reliable monitoring of the tool condition during dressing operations. Experimental dressing tests were conducted on aluminum oxide grinding wheels, which are highly relevant for industrial grinding processes. From the results obtained, it was verified that the dresser tip diamond material and the position of the PZT diaphragm transducer mounted on the dressing tool holder have a significant effect on the sensitivity of damage detection. This paper contributes to the realization of an effective monitoring system of dressing operations capable to avoid catastrophic tool failures as the proposed sensing approach can identify different stages of the dressing tool lifetime based on representative damage indices.