Mechanical Vibration Analysis Using an Optical Sensor

Abstract

A laser-based contactless displacement measurement system developed at the National Optics Institute is used for data acquisition to analyze the mechanical vibrations exhibited by vibrating structures and machines. The analysis of these vibrations requires a number of signal processing operations which include the determination of the system conditions through a classification of various observed vibration signatures and the detection of changes in the vibration signature in order to identify possible trends. This information is also combined with the physical characteristics and contextual data (operating mode, etc.) of the system under surveillance to allow the evaluation of certain characteristics like fatigue, abnormal stress, life span, etc., resulting in a high level classification of mechanical behaviours and structural faults according to the type of application. The aim of this paper is to introduce the problem, the instrumentation, and the requirements in terms of statistical signal processing.