Underground Optical Fiber Position Mapping Using Earthquake Vibrations
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing underground facility position contrast system requires human intervention to apply an intentional impact to manhole lids, increasing operational effort.
Innovation Solution
Utilize earthquake vibrations applied to underground optical fibers to measure changes in scattered light intensity distribution, allowing for the estimation of facility positions without manual intervention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an intentional impact is applied to the lid of the manhole to measure scattered light intensity distribution, then the position of the manhole can be associated with the longitudinal distance of the optical fiber, but the human operation rate cannot be reduced
Solution Approach 1:
The system uses natural earthquake vibrations to automatically excite the optical fiber, eliminating the need for manual impact application. The optical fiber itself serves as both the sensing element and the object being excited, achieving self-service operation without human intervention at the measurement site
Solution Approach 2:
The system converts earthquake vibrations, which are typically considered harmful or disruptive events, into useful excitation signals for measuring the scattered light intensity distribution. By utilizing these natural vibrations, the system achieves automated position association without requiring manual operation
2Reliability
If a person is dispatched to the site to apply intentional impact, then the measurement can be performed, but the operational effort and time increase
Solution Approach 1:
The system enables continuous monitoring by utilizing ongoing earthquake vibrations rather than requiring periodic manual interventions. The measurement process becomes continuous and automated, eliminating the need for repeated site dispatches and manual operations
Solution Approach 2:
The system replaces the mechanical action of manually impacting the manhole lid with natural seismic vibrations. This substitution eliminates the need for mechanical intervention by humans while maintaining the measurement capability through the optical fiber's response to vibrations
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Reduces the human operation rate by associating underground facility positions with longitudinal fiber distances using earthquake-induced vibrations.
Implementation Method 1
measuring, when an earthquake vibration is applied to an optical fiber laid underground, a change over time in a scattered light intensity distribution in a longitudinal direction of the optical fiber
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present disclosure provides an underground facility position contrast system S, which includes: a scattered light intensity distribution measurement device 1 for measuring, when an earthquake vibration is applied to an optical fiber F laid underground, a change over time in a scattered light intensity distribution in a longitudinal direction of the optical fiber F; and an underground facility position contrast device 2 for measuring a change over time in a distortion response distribution in the longitudinal direction of the optical fiber F based on the change over time in the scattered light intensity distribution in the longitudinal direction of the optical fiber F, estimating an underground facility state of the optical fiber F based on the change over time in the distortion response distribution in the longitudinal direction of the optical fiber F, and associating the underground facility position of the optical fiber F with a longitudinal distance of the optical fiber F.