Modeling and tool trajectory monitoring of an ultrasonic elliptical vibration tool

The vibration trajectory of an ultrasonic elliptical vibration cutting tool is critical for its performance in vibration-assisted cutting/texturing. The shape and amplitude of vibration trajectories will significantly affect the surface quality, tool life, and material removal mechanism. The tool trajectories are often unregulated in current practice due to the difficulties in direction measurement during cutting. In this paper, an analytical model based on the feedback signals from piezoelectric plate sensors has been proposed for the prediction of tool vibration trajectory. The proposed model calculates the elliptical vibration trajectory considering the mode superposition of two orthogonal resonant modes and the measured sensor amplitudes and phase angles. The relationship between the excitation voltage and frequency and the model parameters were studied and calibrated. Experiments were conducted to evaluate the model accuracy and to verify the feasibility of online prediction of the tool trajectory.