Non-contact low-frequency vibration Rapid Measurement Based on hue-height mapping

Abstract A non-contact vibration measurement system based on camera-projector system and hue-height mapping is proposed. The CCD camera acquires the color deformed fringes with red(R) green(G) blue(B) channels, which is modulated by a vibrating loudspeaker, with the aim to demodulate the information of vibrations. In order to avoid the crosstalk between RGB channels, the sampling frames from RGB space are converted to hue(H) saturation(S) intensity(I) space. By using hue information, height value of each pixel point at different sampling frames can be restored, so as to obtain the vibration curve of the loudspeaker. The experiments compare the vibrations of different frequencies at several Hertz, and different amplitudes lower than millimeter degree. The results show that this optical image system can detect low-frequency vibrations with high accurate amplitudes, and meet the basic industrial measurement requirements.