Optical Fiber Laying Vehicle Using Pinger-Based DAS Positioning

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Solution Overview

Problem

Existing optical fiber sensing systems face challenges in accurately determining the position where the optical fiber is laid on the seabed, leading to poor accuracy in detecting underwater targets.

Innovation Solution

An optical fiber laying vehicle equipped with a wave-transmitter to emit a pinger signal, a DAS interrogator to acquire acoustic data, and a processor to estimate the fiber's shape using acoustic data from multiple points on the seabed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If an optical fiber sensing system uses backscattered light from an optical fiber laid on the seabed to detect underwater targets, then the system can acquire underwater environmental information, but the accuracy of detecting the target position is poor because the laying position of the optical fiber cannot be accurately found

Engineering Contradiction:

Improvetarget position detection accuracyVSAvoidoptical fiber laying position information

Core Design Contradiction:

Measurement precisionVSLoss of information

Solution Approach 1:

The patent introduces a pinger signal as an intermediary acoustic signal transmitted into water to interact with the optical fiber. The DAS interrogator detects acoustic data from the pinger signal at multiple points along the optical fiber, creating a mediator between the optical fiber and the detection system that enables precise positioning without requiring prior knowledge of the fiber's laying position

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces optical-based positioning methods with acoustic-based positioning. Instead of relying on optical signals for positioning, the system uses acoustic data from the pinger signal detected by the DAS interrogator to estimate the optical fiber's shape and position, substituting the mechanical/acoustic domain for the optical domain in the positioning function

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If the optical fiber is laid on the seabed for underwater target detection, then the system can monitor vibrations and sounds, but the difficulty of accurately finding the laying position reduces the overall system effectiveness

Engineering Contradiction:

Improveunderwater target detection reliabilityVSAvoidoptical fiber laying position determination

Core Design Contradiction:

ReliabilityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent performs preliminary action by transmitting the pinger signal into water before the optical fiber sensing system operates. This preliminary acoustic signal transmission allows the system to pre-map the optical fiber's position and shape using acoustic data, establishing accurate positioning information in advance that will support reliable target detection

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback by using the acoustic data detected by the DAS interrogator to continuously estimate and update the optical fiber's shape. The system feeds back the acoustic information about the fiber's position and configuration to the control unit, which uses this feedback to maintain accurate positioning and improve detection reliability

Inventive Principle:

Principle #23Feedback

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

Precisely determines the laying position of the optical fiber by estimating its shape using acoustic data, enhancing the accuracy of underwater target detection.

Implementation Method 1

a wave-transmitter configured to transmit a pinger signal into water

Methodology Applied

Scientific EffectAcoustic wave propagation: Sound

Implementation Method 2

a DAS (Distributed Acoustic Sensing) interrogator configured to acquire, for each of a plurality of points on an optical fiber laid on a seabed, acoustic data indicating a sound resulting from the pinger signal detected at that point

Methodology Applied

Scientific EffectAcoustic detection: Sound

Implementation Method 3

A DAS (Distributed Acoustic Sensing) interrogator acquires information on vibrations and sounds conveyed to an optical fiber by using backscattered light received from the optical fiber

Methodology Applied

Scientific EffectBackscattered light detection: Light

Data Source

PatentUS20250290788A1Optical fiber laying vehicle, optical fiber sensing method, and non-transitory computer readable medium

Publication Date: 2025.09.18 NEC CORP

AI summary

An optical fiber laying vehicle according to the present disclosure includes: a wave-transmitter configured to transmit a pinger signal into water; a DAS interrogator configured to acquire, for each of a plurality of points on an optical fiber laid on a seabed, acoustic data indicating a sound resulting from the pinger signal detected at that point; at least one memory configured to store a set of instructions; and at least one processor configured to execute the set of instructions and thereby estimate a shape of the optical fiber by using the acoustic data acquired for each of the plurality of points.