In recent years, the need for real-time estimation of cutting forces has grown in response to the increased complexity and precision of machining processes. This study proposes a method for estimating three-directional cutting forces principal, feed, and thrust by utilizing strain gauges attached to sensor bolts used to fix the tool holder in lathe machining. The sensor bolts were specially machined with three flat surfaces, each equipped with strain gauges, enabling multi-directional deformation detection. A multivariate regression model was constructed using cutting force data obtained from a dynamometer and strain outputs during cutting. The inverse estimation was realized by computing a pseudo-inverse of the regression matrix. Although initial calibration based on static loads did not yield accurate results, calibration using actual cutting data from a dynamometer significantly improved the model's accuracy. The results demonstrate the feasibility of this low-cost and minimally invasive force estimation method for practical machine tool applications.
Miyahara et al. (Wed,) studied this question.