A radio-optic method for measuring relative motion

A radio-optic methodology for in situ monitoring of vibration or relative motion of components in engineered systems is described. The technology relies on use of light-weight radio-optic components attached to or embedded in system members to measure in real time the relative motion between the members, or between the system and the medium in which it is located, due to internal or external loads. The positions of optical fiber detector elements relative to a radiation source element as a function of time is tracked, thus measuring relative position time history from which velocity and acceleration can also be determined. The technology permits determination of critical system performance characteristics and aids in determining safety of systems that are subjected to various loads. Instruments based on this technology will have the benefits of being capable of high spatial and temporal resolution, of interfering minimally with the system under investigation, of being relatively inexpensive and of being operable either continuously or intermittently as desired. Results of Monte Carlo simulations and of limited experimental verification studies are presented. (C) 2003 Elsevier B.V. All rights reserved.