Dual-Axis Permanent Magnet Rotation for Precise 3D Position Tracking

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Solution Overview

Problem

Existing position detection systems face challenges in accurately tracking fine movements and positions in three-dimensional spaces with high precision and reliability, especially in applications requiring mobility and harsh environments.

Innovation Solution

A position detection system that generates a time-varying magnetic field by rotating a permanent magnet simultaneously about two orthogonal axes, using a carrier assembly and drive assembly to create a unique magnetic field configuration, allowing for precise tracking of sensors or objects within a bounded volume.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a permanent magnet is rotated about a single axis, then the magnetic field varies with time, but the system cannot achieve full three-dimensional coverage and precision tracking

Engineering Contradiction:
Improveposition tracking precisionVSAvoidthree-dimensional coverage
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent applies dimensionality change by rotating the permanent magnet about two orthogonal axes (first and second axes) instead of a single axis. This dual-axis rotation creates a more comprehensive three-dimensional magnetic field distribution, enabling the sensor to accurately track positions and orientations in full 3D space with millimeter precision while maintaining system adaptability.

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

2Stability of the object's composition

If the permanent magnet is offset from the rotation axis intersection, then gyroscopic effects are reduced, but the magnetic field generation becomes more complex

Engineering Contradiction:
Improvesystem stabilityVSAvoidmagnetic field generator complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent applies asymmetry by intentionally offsetting the permanent magnet from the intersection point of the two rotation axes. The magnet is positioned at a specific offset distance along the first axis, creating an asymmetric configuration that reduces gyroscopic effects and improves system stability during rotation, while the complexity is managed through the structured dual-axis rotation mechanism.

Inventive Principle:
Principle #4Asymmetry

3Reliability

If multiple magnets are used to improve field coverage, then power consumption increases, but single magnet systems are less efficient

Engineering Contradiction:
Improvefield coverage reliabilityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies periodic action by rotating a single permanent magnet about two orthogonal axes at specific frequencies. This dual-axis rotation creates a time-varying magnetic field that periodically sweeps through three-dimensional space, providing comprehensive field coverage and reliable position tracking while consuming less power than multiple stationary magnets would require.

Inventive Principle:
Principle #19Periodic 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

Enables accurate and precise tracking of positions and orientations in three-dimensional spaces with millimeter precision, reducing power consumption and maintaining stability against gyroscopic effects, suitable for various applications including biomedical, virtual reality, and robotics.

Implementation Method 1

a permanent magnet having a center of mass. The magnetic field generator includes a drive assembly coupled to the carrier assembly and configured to act on the carrier assembly to rotate the permanent magnet simultaneously about the first axis of rotation and a second axis of rotation

Methodology Applied
Scientific EffectMagnetic field generation: Magnetism

Data Source

PatentEP3803276B1Rotating a permanent magnet in a position detection system
Publication Date: 2023.08.30 OMMO TECHNOLOGIES INC
  • EP3803276B1 patent drawingFigure 1
  • EP3803276B1 patent drawingFigure 2
  • EP3803276B1 patent drawingFigure 3

AI summary

In a general aspect, a position detection system includes a magnetic field generator configured to generate a time-varying magnetic field. The magnetic field generator includes a carrier assembly that defines a first axis of rotation and comprises a permanent magnet having a center of mass. The magnetic field generator also includes a drive assembly that is coupled to the carrier assembly and configured to act on the carrier assembly to rotate the permanent magnet simultaneously about the first axis of rotation and a second axis of rotation. The second axis of rotation intersects the first axis of rotation at an intersection that is offset from the center of mass of the permanent magnet. The position detection system additionally includes a computer device configured to determine a position of a sensor based on magnetic field measurements obtained by the sensor in the time-varying magnetic field.