Dynamic sensing performance of a point-wise fiber bragg grating displacement measurement system integrated in an active structural control system
Journal
Sensors
Journal Volume
11
Journal Issue
12
Start Page
11605
End Page
11628
ISSN
14248220
Date Issued
2011
Author(s)
Abstract
In this work, a fiber Bragg grating (FBG) sensing system which can measure the transient response of out-of-plane point-wise displacement responses is set up on a smart cantilever beam and the feasibility of its use as a feedback sensor in an active structural control system is studied experimentally. An FBG filter is employed in the proposed fiber sensing system to dynamically demodulate the responses obtained by the FBG displacement sensor with high sensitivity. For comparison, a laser Doppler vibrometer (LDV) is utilized simultaneously to verify displacement detection ability of the FBG sensing system. An optical full-field measurement technique called amplitude-fluctuation electronic speckle pattern interferometry (AF-ESPI) is used to provide full-field vibration mode shapes and resonant frequencies. To verify the dynamic demodulation performance of the FBG filter, a traditional FBG strain sensor calibrated with a strain gauge is first employed to measure the dynamic strain of impact-induced vibrations. Then, system identification of the smart cantilever beam is performed by FBG strain and displacement sensors. Finally, by employing a velocity feedback control algorithm, the feasibility of integrating the proposed FBG displacement sensing system in a collocated feedback system is investigated and excellent dynamic feedback performance is demonstrated. In conclusion, our experiments show that the FBG sensor is capable of performing dynamic displacement feedback and/or strain measurements with high sensitivity and resolution.
Subjects
Amplitude-fluctuation Electronic Speckle Pattern Interferometry
Fiber Bragg Grating
Out-of-plane
Point-wise Displacement Sensor
Sensing System
Smart Cantilever Beam
Velocity Feedback Control
Glass Fiber
Article
Calibration
System Analysis
Calibration
Optical Fibers
Systems Integration
Type
journal article