Fiber Optic Sensor Calibration Using Bragg Grating Identification

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Solution Overview

Problem

The manual pairing of fiber optic sensors in bearing devices with calibration tables often leads to incorrect load interpretation due to manufacturing variations, resulting in mismatching and inaccurate load calculations.

Innovation Solution

An automated method and device for calibrating fiber optic sensors in bearing devices by coupling the sensor to an optical interrogator, emitting an optical signal, collecting reflected wavelengths, processing these to identify the sensor, and associating it with the correct calibration data table based on unique optical fiber digital data, eliminating the need for manual pairing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If manual pairing is used to associate fiber optic sensor with calibration table, then operation simplicity is maintained, but matching reliability deteriorates due to human error

Engineering Contradiction:

Improvematching reliabilityVSAvoidoperation complexity

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The system performs self-identification through the refraction gratings embedded in the optical fiber. The sensor automatically provides its unique identity code when illuminated by the optical interrogator, eliminating the need for manual pairing operations and thereby ensuring reliable matching between sensor and calibration table.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The manual mechanical pairing process is replaced by an optical identification system. The refraction gratings act as an optical barcode that can be automatically read and processed, substituting human-operated mechanical matching with an automated optical-electrical system.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If automated identification system is implemented, then matching reliability is improved, but device complexity increases

Engineering Contradiction:

Improvematching reliabilityVSAvoidsystem complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The optical interrogator serves multiple functions: it interrogates the fiber optic sensor for load measurements, identifies the sensor through refraction grating patterns, and retrieves the appropriate calibration table. This multi-functionality reduces the need for separate dedicated identification devices, thereby limiting the increase in system complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The refraction gratings act as an intermediary element embedded in the optical fiber that carries identification information. This intermediary enables automatic identification without requiring complex external scanning or reading devices, as the identification data is passively available through the existing optical signal path.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Measurement precision

If manual pairing is used, then device complexity is kept low, but measurement precision deteriorates due to mismatching

Engineering Contradiction:

Improveload measurement precisionVSAvoidcalibration system complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The refraction gratings are pre-encoded with unique identification information during manufacturing. This preliminary action ensures that each optical fiber carries its identity code inherently, allowing for automatic and accurate matching with the corresponding calibration table before any measurement takes place, thereby ensuring measurement precision without complex runtime calibration procedures.

Inventive Principle:

Principle #10Preliminary action

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

Ensures reliable matching between the fiber optic sensor and its calibration data, reducing mismatching and enhancing the accuracy of load calculations in bearing devices.

Implementation Method 1

the optical fiber comprising a set of refraction gratings configured to identify the optical fiber

Methodology Applied

Scientific EffectRefraction: Refraction

Implementation Method 2

The set of refraction gratings may comprise a set of Bragg refraction gratings

Methodology Applied

Scientific EffectBragg diffraction: Bragg Diffraction

Data Source

PatentUS12553795B2Device for calibrating a fiber optic sensor and associated method, sensor and bearing device

Publication Date: 2026.02.17 AB SKF SKF PATENT DEPARTMENT

AI summary

The device (2) for calibrating a fiber optic sensor in a bearing device (1), comprises an optical fiber (3) including a set (6) of refraction gratings configured to identify the optical fiber (3), the device comprising:an optical interrogator (7) configured to emit an optical signal into the optical fiber (3),collecting means (9) for collecting the reflected wavelength of each refraction grating illuminated by the optical signal,first processing means (10) to process the collected reflected wavelengths of the set (6) of refraction gratings to identify the optical fiber (3), andsecond processing means (11) to associate the identified optical fiber (3) with a calibration data table of the said fiber optic sensor.