Magnetic Tracking System Using Dipole Beacons for Indoor Positioning

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing wireless location technologies, such as GPS and mobile phone networks, are adversely affected by multipath signaling, terrain features, and atmospheric artifacts, leading to inaccurate location determinations due to interference with electromagnetic wave propagation.

Innovation Solution

A magnetic tracking system, MagneLoc, utilizing magnetic dipole beacons that generate low-frequency magnetic fields and a map of the magnetic field in a region of interest, allowing for accurate location determination of a target using a simple algorithm that processes the magnetic field measurements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If electromagnetic wave tracking systems (GPS, mobile networks) are used to determine location, then location determination capability is provided, but accuracy is degraded due to multipath signaling and terrain interference

Engineering Contradiction:

Improvelocation determination accuracyVSAvoidmultipath signaling and terrain interference

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent replaces electromagnetic wave-based tracking systems with a magnetic field-based tracking system. Instead of using radio waves that are susceptible to multipath effects and terrain blocking, the invention uses magnetic fields generated by dipole beacons to determine target location. Magnetic fields penetrate obstacles better and are less affected by multipath signaling, thereby resolving the contradiction between providing location determination capability and maintaining accuracy in challenging environments.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the physical parameter used for tracking from electromagnetic waves to magnetic fields. By operating in the magnetic domain rather than the electromagnetic wave domain, the system achieves improved measurement precision in environments where electromagnetic waves are degraded by terrain features and multipath effects.

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If GPS satellites are used for location determination, then global coverage is achieved, but unencumbered line of sight to satellites is required

Engineering Contradiction:

Improveglobal coverage capabilityVSAvoidline of sight requirement

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent substitutes satellite-based electromagnetic wave tracking with a terrestrial magnetic field-based system using dipole beacons. This replacement eliminates the line-of-sight requirement to satellites while maintaining location determination capability in challenging environments such as mines and bore holes where satellite signals are blocked.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If magnetic field tracking is used to eliminate multipath effects, then location accuracy in challenging environments is improved, but system complexity increases

Engineering Contradiction:

Improvelocation accuracy in challenging environmentsVSAvoidmagnetic dipole beacon system complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent changes the operating domain from electromagnetic waves to magnetic fields, which inherently provides better performance in challenging environments. The system uses relatively simple magnetic dipole beacons that generate magnetic fields for tracking, achieving improved measurement precision without excessive complexity.

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

The MagneLoc system provides accurate location determination with reduced interference from masking or shielding artifacts, achieving errors less than 0.18 meters in a 10m by 11m region, and can function without unencumbered lines of sight to satellites, improving location accuracy in challenging environments.

Implementation Method 1

magnetic dipole beacons that generate low-frequency magnetic fields

Methodology Applied

Scientific EffectMagnetic field generation: Magnetic Field

Implementation Method 2

a magnetic field sensor coil located at the location of the target that generates signals responsive to the first and second magnetic fields

Methodology Applied

Scientific EffectMagnetic field detection: Magnetic Field

Data Source

PatentUS9891291B2Magnetic tracking system

Publication Date: 2018.02.13 STATE OF ISRAEL - SOREQ NUCLEAR RES CENT

AI summary

Apparatus for determining a location of a target, the apparatus comprising: first and second magnetic dipole beacons positioned at substantially a same spatial location having respectively first and second time dependent magnetic moments oriented in different directions that generate first and second magnetic fields having different time dependencies; at least one magnetic field sensor coil located at the location of the target that generates signals responsive to the first and second magnetic fields; and circuitry that receives the signals generated by the at least one sensor coil and processes the signals responsive to the different time dependencies of the magnetic fields to determine a location of the at least one sensor coil and thereby the target.