Multi-Frequency Sensor Assembly for Strain and Proximity Detection

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Solution Overview

Problem

Existing non-contact sensor assemblies face challenges in accurately detecting strain and proximity of targets in complex stress environments, particularly in uniaxial, biaxial, and complex stress scenarios, due to limitations in permeability fluctuations and vibration compensation.

Innovation Solution

A sensor assembly with a drive element and sensor elements that apply a drive signal with multiple frequency components to generate a magnetic flux through a target, allowing for strain detection and proximity measurement using output signals from both the drive and sensor elements, with additional circuitry for digital signal processing and vibration compensation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a single frequency drive signal is used, then the device complexity is low, but the measurement precision for both strain and proximity deteriorates

Engineering Contradiction:
Improvestrain detection precisionVSAvoidsignal processing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies periodic action by using a multi-frequency drive signal comprising first and second frequency components. The first frequency component generates magnetic flux for strain detection while the second frequency component generates magnetic flux for proximity detection. This periodic multi-frequency approach allows simultaneous measurement of both strain and proximity without requiring separate measurement systems, thereby improving measurement precision while managing device complexity through systematic signal separation.

Inventive Principle:
Principle #19Periodic action

2Measurement precision

If magnetic flux level varies, then the response to target movement is enhanced, but the stability of strain measurement deteriorates

Engineering Contradiction:
Improveproximity detection precisionVSAvoidmagnetic flux stability
Core Design Contradiction:
Measurement precisionVSStability of the object's composition

Solution Approach 1:

The patent uses periodic action with distinct frequency components where the first frequency component is dedicated to strain measurement and the second frequency component is dedicated to proximity measurement. By separating the measurement functions into different frequency domains, the system allows the magnetic flux level to vary for proximity detection without compromising strain measurement stability, as each frequency component can be independently processed and analyzed.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent applies segmentation by dividing the drive signal into separate frequency components with distinct functions. The first frequency component handles strain measurement while the second frequency component handles proximity measurement. This segmentation allows independent optimization of each measurement function and enables the system to maintain stable strain measurements even when overall magnetic flux levels vary due to target movement.

Inventive Principle:
Principle #1Segmentation

3Measurement precision

If separate measurements are used for strain and proximity, then the measurement precision for each parameter is maintained, but the device complexity increases

Engineering Contradiction:
Improvedual parameter measurement precisionVSAvoidsensor assembly complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies universality by designing a single sensor assembly that performs multiple functions through a multi-frequency drive signal. The same drive element and sensor elements used for strain detection are also utilized for proximity detection by employing different frequency components. This multi-functional approach enables simultaneous measurement of both strain and proximity parameters without requiring separate dedicated sensor systems, thereby maintaining measurement precision while reducing overall device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

Enables precise determination of strain parameters and proximity in various stress environments, improving measurement accuracy and stability by maintaining a constant magnetic flux level through the target, while compensating for vibrations effectively.

Implementation Method 1

applying a drive signal to a drive element in a sensor assembly having a drive element and one or more sensor element so that responsively to the drive signal the drive element generates a magnetic flux that travels through a target

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

Changes in inductivity and resistance resulting from permeability fluctuations of a target under stress can be observed for detection of stresses and strain of the target

Methodology Applied
Scientific EffectMagnetic permeability fluctuation: Magnetic Field

Data Source

PatentEP2938984B1Proximity and strain sensing
Publication Date: 2018.02.21 GENERAL ELECTRIC CO
  • EP2938984B1 patent drawingFigure 1
  • EP2938984B1 patent drawingFigure 2
  • EP2938984B1 patent drawingFigure 3

AI summary

There is set forth herein a method comprising applying a drive signal to a drive element in a sensor assembly having a drive element and one or more sensor element so that responsively to the drive signal the drive element generates a magnetic flux that travels through a target, determining a strain of the target using a picked up output signal picked up by the one or more sensor element. In one embodiment, a sensor assembly can be employed for detecting a proximity of the target using a picked up output signal picked up by e.g., the drive element. In one embodiment, a drive signal can have a plurality of frequency components.