Integrated cutting force measurement system based on MEMS sensor for monitoring milling process

Abstract

In manufacturing process, the stability of cutting state is especially important for processing quality. Monitoring cutting force is a research hotspot for a long time. In this paper, an integrated cutting force measurement system based on piezoresistive MEMS sensor for measuring axial force and torque in milling process is proposed. Based on the thin-walled cylinder and the arch structure, the stress-transforming element of composite splitted structure of conical and cylindrical shell is developed to detect cutting force. The natural frequency of the proposed element has a great improvement in strain sensing sensitivity that can satisfy most cutting situations. A piezoresistive MEMS sensor designed as sensitive component and used in the cutting force measurement system. When the elastic body was sustained cutting force, the piezoresistive MEMS sensors that arranged on the element sense the deformation and output voltage signals to reveal the change of cutting force. In order to verify the basic performance of the cutting force measurement system, static calibration and modal impact tests are carried out. The results indicate that the sensor’s original sensitivity is 2.85 × 10−2 mV/N and 2.90 mV/Nm in axial and torsional directions. Dynamic cutting tests show that the cutting force measurement system can reflect the variation of cutting status very well. It is qualified to monitor the change of axial and torsional forces in practical applications. The cutting test results indicate the measurement system scarcely reduce the workpiece surface quality in machining process.