Magnetometer Rotation Detection in User-Borne Devices

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Solution Overview

Problem

Current systems for tracking and determining the location of user-borne devices with magnetic objects can only detect movements in five degrees of freedom, as rotations about axes with rotationally symmetric magnetic fields are not detectable, limiting their functionality and application fields.

Innovation Solution

A user-borne device with a magnetic object having a magnetization direction oriented such that rotations about three orthogonal axes are detectable, allowing for tracking and control of trigger events in at least six degrees of freedom without additional magnetic objects, enhancing functionality and reducing manufacturing costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a magnetic object with rotationally symmetric magnetic field is used, then the device can be manufactured with simpler structure and lower cost, but rotation about the symmetry axis cannot be detected, limiting tracking to five degrees of freedom

Engineering Contradiction:
Improverotation detection capabilityVSAvoidmagnetic object structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies asymmetry by orienting the magnetization direction of the magnetic object at a specific angle (e.g., 45 degrees) relative to its longitudinal axis, creating an asymmetric magnetic field distribution. This asymmetric configuration enables the magnetometers to detect rotations about all three orthogonal axes, achieving six degrees of freedom tracking capability while maintaining a single magnetic object structure

Inventive Principle:
Principle #4Asymmetry

2Measurement precision

If additional magnetic objects are added to enable rotation detection about three axes, then tracking capability improves to six degrees of freedom, but manufacturing cost and device complexity increase

Engineering Contradiction:
Improvetracking capabilityVSAvoidnumber of magnetic objects
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent implements multi-functionality by designing a single magnetic object with a specifically oriented magnetization direction that serves multiple purposes: it enables detection of rotations about all three orthogonal axes (six degrees of freedom) while also maintaining location tracking capability. This universal approach eliminates the need for multiple separate magnetic objects or additional sensors

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

Solution Approach 2:

The patent changes the magnetic field parameters by orienting the magnetization direction at a specific angle (e.g., 45 degrees) relative to the longitudinal axis of the magnetic object. This parameter change transforms the magnetic field distribution from rotationally symmetric to asymmetric, enabling full six-degree-of-freedom tracking with a single magnetic object

Inventive Principle:
Principle #35Parameter changes

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 improved tracking and location determination of user-borne devices in six degrees of freedom, integrating additional functions and extending application fields while reducing the need for extra magnetic objects, thus lowering production costs.

Implementation Method 1

The magnetic object (110) has a magnetization direction (120). The magnetic object (110) is configured to create a magnetic field (115) associated with the magnetization direction (120)

Methodology Applied
Scientific EffectMagnetic field: Magnetic Field

Data Source

PatentEP4375813A1Detection of a rotation of a magnet in a user-borne device with a plurality of magnetometers
Publication Date: 2024.05.29 ADVANCED MAGNETIC INTERACTION (AMI)
  • EP4375813A1 patent drawingFigure 1
  • EP4375813A1 patent drawingFigure 2A~3
  • EP4375813A1 patent drawingFigure 4A~4B

AI summary

A user-borne device (100) comprises a housing (101) and a magnetic object (110) coupled to the housing (101). The magnetic object (110) has a magnetization direction (120) and the magnetic object (110) is configured to create a magnetic field (115) associated with the magnetization direction (120). The magnetization direction (120) is oriented with respect to the magnetic object (110) such that a rotation of the magnetic object (110) about a first rotation axis (112), a second rotation axis (114) and a third rotation axis (116) is detectable based on magnetic field measurements with a plurality of magnetometers (300). The first rotation axis (112), the second rotation axis (114) and the third rotation axis (116) are orthogonal with respect to each other. The user-borne device (100) is configured to control at least one trigger event based on a rotation of the magnetic object (110) about the first rotation axis (112), the second rotation axis (114) and/or the third rotation axis (116).