Developing a Wireless Connection Between the Sensor and the Conditioning Signal System in Tool Vibration Monitoring

Summary

The monitoring of tool wear in turning operations has been studied for a long time. Such monitoring, if carried out in real time, can contribute significantly for the automation of the operation, making possible higher quality standards and production rates. But the cables, used to link the sensors and the instruments of signal conditioning, make the use of this kind of system very difficult outside the laboratory plant, because they obstruct the rotation of the tool turret. The obvious solution to this problem is to use some kind of no physical connection between the sensor and the electronic processing units. In this work, the circuit used to transmit the vibration signals without cables is described together with the description of the tests done in real situations and the results obtained. The maximum error (that occurs at the maximum frequency transmitted) is about 1%, what is considered suitable for the necessities of the data processing algorithms that use this information. This error is due to the demodulation process adopted, and could be smaller if the conventional A/D converter were replaced by a pulse duration measuring unit, which is a better technical solution but also a more expensive one.