Low Frequency Vibration Data Analysis via Digital Image Data of High Speed Camera

Yih-Nen Jeng, Chia-Hung Wu, Chi-Hung Chang, Tzung-Ming Yang, Hau-Chang Hung
2010 48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition   unpublished
The digital image data collected by the high speed camera are properly treated so as to extract the vibration information of an operating system. The system employs a high speed digital camera and notebook computer to pick up the digital image frames. The total gray levels within a specified square region of a digital frame are considered as a single image data at the instance. The resulting image data involves the non-sinusoidal part and is removed in terms of the fast version of the iterative
more » ... on of the iterative moving least squares method so as to avoid the Direct Current (DC) contamination to the corresponding spectrum especially in the low frequency region. The Fourier sine spectrum and spectrogram are then employed to study the embedded information. The validity of the proposed system is confirmed by examine two tests with given input frequencies. The vibration information of the gear box of a motor cycle is tested and is confirmed by an accelerometer system. As the motorcycle was operating, the operation condition can be clearly inspected by the resulting spectrum and spectrogram of the image data. This experiment shows that the image system is a potential and portable non-contact type vibration data acquisition system.
doi:10.2514/6.2010-933 fatcat:lwp2f3xbqjfnhpnlnmekpagptu