Smart cutting tool integrated with optical fibre sensors for cutting force measurement in turning

Real-time cutting force measurement is significant important to monitor tool condition and machining process. Although commercial dynamometers are available for a range of machining applications, there is a lack of multi-point and low-cost measuring methods suitable for detecting cutting forces in harsh machining environments. In this paper, a smart cutting tool integrated with optical fibre sensors is firstly presented for cutting force measurements in turning. Fibre Bragg grating (FBG) sensors are employed to acquire cutting force information on cutting tools. Compared with electrical and piezoelectric sensors, the proposed smart cutting tool has unique advantages such as electromagnetic interference immunity, explosion proof, ability to measure multiple cutting forces in the same and simplified data acquisition device with a long-distance signal transmission, enabling it to work in harsh machining environments. In addition, the proposed smart tool brings little effect on the structure and characteristics of machine tools due to FBG’ small size and lightweight. This paper investigates the operating principle of the sensory cutting tool theoretically and validates it using finite element simulations. A prototype of the proposed device was developed and tested. Static calibration, dynamic identification experiment and comparative cutting tests were conducted to evaluate its performances. Experimental results have shown that the cutting forces acquired by the developed smart tool are in good agreements with the results obtained by the reference commercial dynamometer. The proposed smart cutting tool has the potential to provide a new solution to the real-time measurement and monitoring of multi-point cutting forces in turning processes.