Magnetometric Sensor Curved Sensing Elements Angle Accuracy

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Solution Overview

Problem

Magnetometric sensors with linearly shaped magneto-sensitive portions experience distortion in output signals and reduced angle accuracy when subjected to magnetic fields at saturation intensity, leading to deviations from ideal sine waves.

Innovation Solution

The design incorporates magneto-sensitive portions with a curved shape enclosed between two arcs, arranged in fan-shaped regions at 90° intervals, forming bridge circuits to improve angle accuracy by canceling out errors in detected magnetic field angles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If magneto-sensitive portions with linear shape are used, then the device structure is simple, but the output signal distorts and angle accuracy drops under saturation magnetic field intensity

Engineering Contradiction:
Improvestructure simplicityVSAvoidangle accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The magneto-sensitive portions are designed with a curved shape enclosed between two arcs instead of a linear shape. This curvature allows the sensor to accurately detect magnetic field angles even under saturation conditions by properly aligning the sensitive direction with the magnetic field vector, thereby eliminating output signal distortion and improving angle accuracy to ±0.11 degrees.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Measurement precision

If magneto-sensitive portions are arranged in fan-shaped regions with curved arcs, then angle accuracy improves, but the device complexity increases

Engineering Contradiction:
Improveangle accuracyVSAvoidstructural complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The sensor divides the detection space into fan-shaped regions with magneto-sensitive portions arranged at specific angular intervals. Each curved magneto-sensitive portion is enclosed between two arcs and configured to detect magnetic fields in its specific angular sector. This segmentation allows accurate angle detection across the full range while maintaining a systematic and manufacturable structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The magneto-sensitive portions utilize curved shapes enclosed between two arcs rather than linear configurations. This curvature is essential for maintaining accurate angle detection under saturation magnetic field conditions, as it ensures the sensitive direction remains properly aligned with the magnetic field vector throughout the detection range.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Reliability

If the magneto-sensitive portions have uniform width with curved boundaries, then the resistance value accurately reflects magnetic field direction changes, but manufacturing precision requirements increase

Engineering Contradiction:
Improveresistance variation accuracyVSAvoidcurved shape precision
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The magneto-sensitive portions are designed with curved boundaries formed by two arcs, enclosing a uniform width region. This curved geometry is critical for achieving accurate angle detection under saturation conditions, as it ensures the resistance value properly reflects magnetic field direction changes. The uniform width within the curved boundaries maintains consistent sensitivity across the sensor surface.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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

This configuration enhances angle accuracy by partially canceling out errors, resulting in improved performance compared to sensors with linearly shaped magneto-sensitive portions, with measured improvements from ±0.22 to ±0.11 in angle accuracy.

Implementation Method 1

a magneto-sensitive portion 100 having a shape enclosed between two arcs 105 and 106 and with a uniform width W, the magneto-sensitive portion having a resistance value that varies depending on changes in the direction of a magnetic field

Methodology Applied
Scientific EffectMagnetoresistance: Magnetoresistance

Data Source

PatentEP3333549B1Magnetometric sensor
Publication Date: 2020.09.16 KK TOKAI RIKA DENKI SEISAKUSHO
  • EP3333549B1 patent drawingFigure 1A~1B
  • EP3333549B1 patent drawingFigure 2A~2B
  • EP3333549B1 patent drawingFigure 3A~3C

AI summary

A magnetometric sensor includes a plurality of magnetometric sensor elements each including a plurality of magneto-sensitive portions arranged, in each of fan-shaped magneto-sensitive regions, intersecting with a radial direction of the magneto-sensitive regions. The magnetometric sensor elements are configured such that the magneto-sensitive regions are arranged rotated at 90° intervals and a bridge circuit is formed by electrically connecting the magnetometric sensor elements to each other. The magneto-sensitive portions each have a shape defined enclosed by two arcs to have a same width such that a resistance value thereof varies according to a change in a direction of a magnetic field.