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Remote Bridge Deflection Measurement Using an Advanced Video Deflectometer and Actively Illuminated LED Targets
1Institute of Solid Mechanics, Beihang University, Beijing 100191, China. tianl@buaa.edu.cn.
Sensors (Basel, Switzerland)
|August 27, 2016
Summary
A new video deflectometer uses LED targets for accurate, real-time bridge deflection measurement. This contactless system works reliably in varying light conditions, aiding structural safety evaluations.
Area of Science:
- Structural Engineering
- Optical Measurement Systems
- Remote Sensing
Background:
- Accurate measurement of large-scale structure deflection is crucial for safety.
- Ambient light variations pose challenges for remote optical measurement systems.
Purpose of the Study:
- To propose an advanced video deflectometer for remote, real-time bridge deflection measurement.
- To overcome ambient light interference in deflection measurements of large structures.
Main Methods:
- Active imaging using high-brightness monochromatic LED targets and bandpass filter imaging.
- Calibration and accuracy assessment using precisely controlled LED target translations.
- Field application on the Wuhan Yangtze River Bridge for multipoint deflection monitoring.
Main Results:
- The video deflectometer demonstrated high accuracy in outdoor environments.
- Successful remote, real-time, and multipoint deflection measurement of a major bridge was achieved.
- The system showed strong robustness against ambient light changes.
Conclusions:
- The proposed video deflectometer offers a reliable solution for contactless, real-time structural health monitoring.
- This technology has significant potential for routine safety evaluations of bridges and other large structures.
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