Indoor Navigation Using Fluorescent Fixture Ballast Noise

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Solution Overview

Problem

Current navigation systems using LED ambient lighting require significant infrastructure upgrades and networking capabilities, making them impractical for widespread adoption, especially in environments with standard fluorescent light fixtures.

Innovation Solution

Utilizing the high-frequency noise signals generated by electronic ballasts in standard fluorescent light fixtures, which can be uniquely fingerprinted and used for location identification, allowing navigation without the need for network connectivity or specialized hardware.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If LED ambient lighting is used for navigation, then location identification capability is improved, but infrastructure upgrade cost and device complexity increase substantially

Engineering Contradiction:

Improvelocation identification capabilityVSAvoidinfrastructure upgrade requirement

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The fluorescent light fixtures serve dual purposes: providing ambient lighting and generating navigational signals through their inherent electronic ballast operation. The system uses the fixtures' own operational characteristics (high-frequency noise signals) for navigation without requiring additional networking capabilities or specialized hardware modifications.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The invention converts the previously problematic high-frequency noise signals and manufacturing variations in electronic ballasts into useful navigational identifiers. What was considered interference or inconsistency is now exploited as the basis for unique light fingerprinting and location identification.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

2Measurement precision

If network-connectable LED fixtures are deployed for navigation, then navigation accuracy is improved, but ease of manufacture and deployment deteriorate

Engineering Contradiction:

Improvenavigation accuracyVSAvoidfixture modification requirement

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The system works with standard fluorescent light fixtures that already exist in buildings, making the navigation solution universally applicable without requiring specialized network-connectable fixtures. The common electronic ballast technology found in standard fixtures is leveraged for navigational purposes.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

Instead of requiring proprietary networked LED fixtures, the system creates a navigational solution using copies of existing standard fluorescent fixtures with their inherent electronic ballasts. The high-frequency characteristics are measured and fingerprinted to provide navigation without needing specialized hardware.

Inventive Principle:

Principle #26Copying

3Adaptability or versatility

If high-frequency noise signals from electronic ballasts are used for fingerprinting, then adaptability to existing fixtures is improved, but signal detection difficulty increases

Engineering Contradiction:

Improvecompatibility with standard fixturesVSAvoidhigh-frequency signal detection

Core Design Contradiction:

Adaptability or versatilityVSDifficulty of detecting and measuring

Solution Approach 1:

The system uses the periodic high-frequency switching action of electronic ballasts to modulate the light output. By analyzing the periodic characteristics and frequency components of the light from multiple fixtures, the system can distinguish between them based on their unique switching patterns and manufacturing variations.

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 indoor navigation using unmodified fluorescent light fixtures, providing location identification without access to building network infrastructure, and leveraging existing lighting systems for navigation purposes.

Implementation Method 1

a electronic ballast receiving line AC voltage to drive a fluorescent light bulb

Methodology Applied

Scientific EffectElectrical to optical energy conversion: Fluorescence

Implementation Method 2

measuring light from a given fluorescent fixture in the location using a mobile light sensor

Methodology Applied

Scientific EffectLight detection: Photoelectric Effect

Data Source

PatentUS10637575B2Spatial location indoors using standard fluorescent fixtures

Publication Date: 2020.04.28 WISCONSIN ALUMNI RES FOUND

AI summary

A system for identifying the location of the mobile device uses standard fluorescent light fixtures commonly found in indoor environments and detects minor variations in the light output of those fixtures caused by normal manufacturing variation. These variations are catalogued as identifying fingerprints together with location of the light fixtures to provide for navigation.