Design and performance evaluation of a multi-axis thin-film sensor for milling process measurement

Abstract

A multi-axis sensor made of flexible, light, and sensitive PVDF (polyvinylidene fluoride) thin film is designed and fabricated for cutting force measurement in milling process. The single-layer PVDF thin film is constructed with six electrodes in a certain pattern, which has two electrodes in each pair to measure the signals due to bending moment as well as torque moment on the cutter in the process of milling. All the detected voltage signals will be calibrated by the digital signal processing unit and transmitted to the remote receiver via wireless communication. A cutting-force model is established in association with the measurement scheme that can compute the feed force, transverse force, and tangential force via the collected voltage signals from the electrodes. In experiment, the PVDF sensor is directly attached to the cutter, and the commercial dynamometer is implemented under the workpiece for synchronous measurement and comparison. As a result, the developed thin-film sensor associated with the sensing circuitry and wireless communication device as well as the cutting force model can effectively measure the important cutting force with satisfactory accuracy.