A noise-robust vibration signal extraction method utilizing intensity optical flow

A noise-robust intensity optical flow (IOF) method was developed by leveraging the linear relationship between the vibrating displacement and optical intensity variation. By identifying measurement points with signal variance of regions of interest, this method fuses all the signals from these points into one integrated signal, and then decomposes it into various vibration mode signals and noise components. As a result, the vibration signals can be obtained with significant improvement of signal-to-noise ratio. Compared with existing advanced methods, our method is straightforward to perform better measured accuracy but preserve computationally efficient, even at the kilohertz level. Simulations and experiments are demonstrated to verify the capability and accuracy of this simple but effective method. The results show that the proposed method yields a correlation coefficient of 99.75 % with the identification results and a speed increase of > 30 % in contrast to the phase optical flow method.