Fibre Optic Acceleration Sensor V-Configuration

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional fibre optic acceleration sensors have limitations in frequency range, resonance frequency, temperature range, and sensitivity stability, which restrict their performance and lifespan in monitoring end-winding vibrations in harsh environments.

Innovation Solution

A fibre optic acceleration sensor design featuring a microelectromechanical system with a configuration of one input optical fibre and two output optical fibres forming acute angles at the reflecting tip, allowing for a compact size and increased sensitivity, along with a seismic mass with asymmetric design and anchor points for independent movement, enhances frequency response and temperature stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If conventional FAS configuration is used, then the sensor structure is simple, but the frequency range is limited (10 Hz to 400 Hz) and resonance frequency is low (around 600 Hz)

Engineering Contradiction:
Improvefrequency rangeVSAvoidsensor configuration
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

The optical system is segmented into one input optical fibre and two output optical fibres arranged in a V-configuration. This segmentation allows the sensor to achieve extended frequency range (up to 1000 Hz) and higher resonance frequency (around 1500 Hz) while maintaining a relatively simple overall structure that integrates well into the stator bar.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from a conventional linear or single-fibre configuration to a two-dimensional V-configuration with acute angles. This dimensional change in the optical fibre arrangement enables improved frequency response and resonance characteristics without significantly increasing structural complexity.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Temperature

If conventional FAS temperature range is used, then the sensor operates in standard conditions, but the temperature range is limited (-20°C to 100°C) and stability above 10 years is not achieved

Engineering Contradiction:
Improvetemperature rangeVSAvoidsensitivity stability
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The patent optimizes physical parameters including the acute angle configuration of optical fibres, the geometry of the seismic mass, and the anchor point arrangement. These parameter changes enable the sensor to operate reliably across an extended temperature range (-20°C to 155°C) while maintaining sensitivity stability over more than 10 years.

Inventive Principle:
Principle #35Parameter changes

3Volume of moving object

If the optical fibres are arranged at acute angles, then the sensor size is reduced and sensitivity is increased, but the alignment precision requirement increases

Engineering Contradiction:
Improvesensor sizeVSAvoidoptical fibre alignment
Core Design Contradiction:
Volume of moving objectVSManufacturing precision

Solution Approach 1:

The V-configuration with acute angles creates a compact sensor structure that is self-aligning to a degree. The geometric arrangement of the two output fibres flanking the input fibre provides inherent alignment guidance, reducing the stringency of external alignment requirements while maintaining small sensor dimensions and high sensitivity.

Inventive Principle:
Principle #25Self-service

4Speed

If the seismic mass is designed with asymmetric configuration and multiple anchor points, then the frequency response is improved, but the mechanical complexity increases

Engineering Contradiction:
Improvefrequency responseVSAvoidmechanical structure
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

The patent employs an asymmetric seismic mass configuration with non-uniform geometry and strategically positioned anchor points. This asymmetric design optimizes the frequency response and resonance characteristics (achieving around 1500 Hz) while the overall mechanical structure remains integrated and relatively simple for manufacturing.

Inventive Principle:
Principle #4Asymmetry

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 improved design achieves a broader frequency range, higher resonance frequency, extended temperature range, and prolonged lifespan, enabling superior performance and reliability in monitoring end-winding vibrations and other parameters.

Implementation Method 1

The optical portion (3) comprises one input optical fibre (11) and two output optical fibres (12)

Methodology Applied
Scientific EffectOptical fibre transmission: Optical Fibre

Implementation Method 2

the reflecting tip (5) extends towards the longitudinal axis of the input optical fibre (11)... light from the input optical fibre (11) reaches at the reflecting tip (5) and is reflected completely into at least one output optical fibre (12)

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 3

The mechanical portion (2) comprises a seismic mass (4) and a reflecting tip (5) extending therefrom... The mechanical portion (2) has at least two anchor points (8)

Methodology Applied
Scientific EffectInertial movement: Inertia

Data Source

PatentEP3380849B1Fibre optic acceleration sensor
Publication Date: 2020.01.08 MC MONITORING
  • EP3380849B1 patent drawingFigure 1~2
  • EP3380849B1 patent drawingFigure 3a~3c
  • EP3380849B1 patent drawingFigure 3d~4

AI summary

A fibre optic acceleration sensor (1) for sensoring and monitoring end-winding vibration and measuring parameters such as acceleration, force, or displacement, comprising: a mechanical portion (2), comprising a seismic mass (4) with a reflecting tip (5) extending therefrom; and an optical portion (3), comprising at least one input optical fibre (11) and at least one output optical fibre (12); wherein the reflecting tip (5) is configured to reflect light completely from the input optical fibre (11) into the output optical fibre (12). The fibre optic acceleration sensor of the present invention for sensoring and monitoring end-winding vibrations can thereby have higher sensitivity, reduced size, increased frequency range, higher resonance frequency and longer lifespan that is more superior compared to the prior art.