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

Abstract

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.

Tool Condition Monitoring in Grinding Operation Using Piezoelectric Impedance and Wavelet Transform

“…An industrial single-point dresser of a natural diamond was used for the dressing operation. The experiment was conducted following the approaches reported by references [4,9,15,16]. Each trial consisted of single dressing passes (grinding wheel and dresser diamond tip interface).…”

“…The diamond's worn area was measured using computer-aided design (CAD) software. Figure 1 shows the experimental setup and the DAQ system used in the present study, based on the approach reported in [9]. As a transducer, a low-cost PZT piezoelectric diaphragm, model 7BB-20-6, from MURATA Inc. (Smyrna, GA, USA), was used.…”

“…More recently, the electromechanical impedance (EMI) method has taken place in the field of grinding process monitoring based on lead titanate zirconate (PZT) piezoelectric transducers. Preliminary applications have shown the potential of the EMI method for detecting damage in single point dressing tools, as reported in references [4,9,10]. On the other hand, it is well-known that the EMI method has been commonly used for different structural health monitoring (SHM) applications [11][12][13].…”

“…Proposed system configuration based on reference[9] using wavelet analysis for tool condition monitoring.…”

A Novel Ultrasound Technique Based on Piezoelectric Diaphragms Applied to Material Removal Monitoring in the Grinding Process

“…The ceramic is coated with a thin metallic film (usually silver) that acts as an electrode [12]. The PZT diaphragms can operate in both active and passive configurations and have an average cost of a few cents versus the high average cost of AE sensors, which range from hundreds to thousands of dollars [18]. In addition, they are compact, flexible, lightweight and simple acoustic components widely used in various electronic devices to produce sound (alarm, ringing and beep) [12,19].…”