An embedded multi-sensor system on the rotating dynamometer for real-time condition monitoring in milling

The newly developed multi-sensor system for a milling process sensor system is capable of simultaneously measuring six channels of machining signals using a rotating tool incorporating a wireless system. Furthermore, the system can be used to measure the spindle torque, T (q) ; tool vibration in the z-axis, A (z) ; tool tip temperature, T (m) and the three components of the cutting force. Cutting force signals are generated by using a cross-beam-legged transducer embedded in the standard milling tool holder. A mini accelerometer is placed under the force transducer, whereas a thermocouple is positioned under a cutting tool insert close to the cutting edge. All signals are collected and sent to the data logger system via an inductive wireless transmitter unit incorporated into the standard rotating tool holder. The calibration, verification and real experimental machining test results reveal that the sensor system is both suitable and reliable for measuring machining signals. The measured signals are found to be importantly related to changes in the flank wear state. Therefore, this system can be used for real-time tool condition monitoring in the milling process.