Displacement-based dynamometer for milling force measurement

Abstract

This paper presents a novel method for measuring cutting forces during milling using a flexure-based dynamometer. The flexure displacement is measured and the force is determined by structural deconvolution. In this approach, the force is extracted from displacement by filtering the displacement signal in the frequency domain using the flexure's displacement-to-force frequency response function. It is shown that, for a range of excitation forces, the measured displacement can be used to reconstruct the force profile. First, a single degree of freedom flexure system is used to determine the excitation forces. Second, the structural deconvolution technique is applied to a multiple degree of freedom flexure system. Finally, a cutting force comparison is made between a multi-axis piezoelectric dynamometer and the reconstructed displacement-based force profile. Good agreement between measured and reconstructed forces is demonstrated.