Optical Fiber Vibration Analysis for Pole Position Mapping

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing optical fiber sensing systems struggle to accurately estimate the position of poles on which optical fibers are suspended, particularly when the fibers are aerially laid over utility poles or steel towers, due to the lack of precise methods for correlating DAS coordinates with real-world coordinates, and existing methods are inefficient or inaccurate.

Innovation Solution

A position evaluation apparatus and method that estimates the position of poles by analyzing characteristic vibrations using a phase difference signal from an optical fiber, calculating a difference degree of vibration characteristics between neighboring points, and integrating this data over time to improve estimation accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the DAS measures vibration point position using DAS coordinate (length from DAS to vibration point), then the position can be measured, but the location does not agree with real-world coordinate when extra length section exists on poles

Engineering Contradiction:

Improveposition measurement accuracyVSAvoidcoordinate system correspondence

Core Design Contradiction:

Measurement precisionVSLoss of information

Solution Approach 1:

The patent introduces an intermediary coordinate transformation process that converts DAS coordinates to real-world coordinates by calculating the position of poles and extra length sections. This intermediary transformation layer resolves the mismatch between DAS measurement coordinates and real-world coordinates, enabling accurate position correspondence without changing the fundamental DAS measurement mechanism.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Measurement precision

If hammering is performed on pole positions to calibrate DAS coordinates with real-world coordinates, then position correspondence can be established, but a large number of steps are required and it is not applicable to difficult-to-vibrate poles

Engineering Contradiction:

Improvecoordinate correspondence accuracyVSAvoidcalibration process complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent enables the system to automatically identify pole positions and extra length sections by analyzing vibration characteristics from the DAS data itself, without requiring external calibration actions like hammering. The system uses the existing vibration signals to self-determine the coordinate transformation parameters, eliminating the need for complex manual calibration procedures.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent replaces the mechanical calibration method (hammering poles to generate vibration for position identification) with a signal processing approach that analyzes existing vibration characteristics. This substitution eliminates the need for physical interaction with poles and reduces calibration complexity while maintaining accuracy.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If vibration is caused on a pole for calibration, then position information can be obtained, but the vibration propagates to optical fibers on both sides causing the vibrating section to spread

Engineering Contradiction:

Improvepole position detection accuracyVSAvoidvibration propagation to adjacent sections

Core Design Contradiction:

Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

The patent replaces mechanical vibration generation (hammering) with signal processing of existing vibration data. By analyzing the characteristics of naturally occurring or induced vibrations in the optical fiber, the system can identify pole positions without introducing additional mechanical vibrations that would propagate to adjacent sections.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

The solution enables precise estimation of pole positions by correlating DAS coordinates with real-world coordinates, enhancing the accuracy of pole position estimation and reducing the need for inefficient manual methods.

Implementation Method 1

an optical fiber sensor inputs coherent pulse light to an optical fiber, and receives backscattering light of the pulse light from the optical fiber

Methodology Applied

Scientific EffectBackscattering: Scattering

Implementation Method 2

the optical fiber sensor detects a phase difference of backscattering light occurring at two points on the optical fiber

Methodology Applied

Scientific EffectPhase difference detection: Interference

Data Source

PatentUS12535353B2Position evaluation apparatus, position evaluation method, and non-transitory computer readable medium

Publication Date: 2026.01.27 NEC CORP

AI summary

An apparatus includes memory and processor configured to: input, from a sensor, a signal indicating a characteristic vibration occurring at each position of an optical fiber, and estimate, based on the input signal, an aerial section in which the optical fiber being aerially laid over a pole is present; calculate, based on the input signal, sensing data indicating a vibration characteristic of each position of the optical fiber being present in the aerial section, and calculate a difference degree of the sensing data between two neighboring points of the optical fiber; and temporally integrate the difference degree, calculate a time average of the difference degree, estimate, based on a time average value of the difference degree, a position of the pole and a position of an extra length section of the optical fiber, and output an estimation result of positions of the pole and the extra length section.