Phase difference technique for material classification by using tuning fork with piezoelectric resonator

Abstract

A tuning fork with piezoelectric (TFP) is an electro-mechanical device; its principle performance is based on specific frequency and limited voltage. As the principle, the device can result output significantly. This paper presents a material classification using phase difference value that is received from touching between material and modified TFP. For the modified TFP, it is customized by a millimeter needle. The frequency response method on Bode plot is used to observe the modified TFP behavior, and to select a specific frequency. The first-order model with cascade notch filters is employed to identify mathematical model of the TFP, and to verify the model by simulation. Experimentation is considered on 2 touching techniques: a shear-force type and a tapping mode type. There are hard plastic, iron, silicon rubber, vinyl eraser and hydrogel for test material. The results are described by both time series plots of input-output signals and numerical table of shifted phase. The technique can employed to classify the test materials effectively and explicitly. © (2013) Trans Tech Publications, Switzerland.