Modelling of autoresonant control of ultrasonic transducer for machining applications

Abstract

A computer model of a non-linear ultrasonic vibrating system with the possibility of autoresonant control is presented in this paper. The system controlled consists of two modules, the first of which is an electromechanical model of an ultrasonic transducer comprising a piezoelectric transducer and a step concentrator. The second module simulates an influence from the machining process. Coefficients of the electromechanical model and its validity were estimated through an identification process based on the experiments with a real ultrasonic transducer. Further, a numerical model of the autoresonant control of this system has been developed. The autoresonant control maintains the resonant regime of oscillation by means of positive feedback, which provides transformation and amplification of the control signal. The model allows the use and comparison of three control strategies depending on the different electrical and mechanical feedback control signals. The results from simulation and from real machining experiments under different control strategies are compared and discussed.

Resonant Tuning of Langevin Transducers for Ultrasonically Assisted Machining Applications

“…From equations (1) and (4) to (7), the expressions of the strain amplitude of the piezoceramic elements and the force developed are:…”

“…LTRASONICALLY assisted machining (UAM) is implemented by superimposing a micro-scale high frequency vibration to the relative motion of a cutting tool tip to make the tool-workpiece interaction a discontinuous process [1], [2], [3]. Compared with the conventional machining process, UAM technology introduces benefits such as great reductions in machine-tool cutting force, torque, temperature, burr formation, improvement on the surface finish integrity and enhancement on the ability of machining difficult-to-cut materials [4]. Efficiency of the UAM process is mainly determined by the amplitude of the oscillations at the working end.…”

Modeling of autoresonant control of a parametrically excited screen machine

“…The counter values determine each oscillation period. The detail of converting a sinusoidal wave to a square wave is well presented in Li [22] and Voronina [23] PhD theses. The newly generated square wave can be further processed by an amplifier.…”

Experimental analysis on autoresonant control of ultrasonically assisted drilling

“…This is based on the fact that the phase lag between the vibration of the tool and the excitation force is a constant [16]. The schematic autoresonant feedback control diagram is illustrated in Fig.…”