Vibration characterization using Gaussian laser beam

The objective of this research is to present a neural network based optical vibration sensor using a quad-cell photo-detector array. The proposed system uses a He-Ne laser source whose Gaussian beam impinges on the photo-detector array. The optical power distribution from the photo-detectors is fed to vibration monitoring system which maps the power distribution to the x-y position of the laser beam center. The vibration monitoring system uses artificial neural networks for function approximation to yield the correct mapping and estimate the x-y positions of the laser beam center which are then used for vibration characterization. An experimental setup of the system is developed and then trained using neural networks. The results obtained show the effectiveness of neural networks to estimate the vibration frequency and magnitude of a vibrating system.