Mobile Device Localization Using Temperature-Gated Barometric Filtering

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Solution Overview

Problem

Barometric pressure data is unreliable in extreme ambient conditions, leading to spurious correlations with height and building floor number, which can result in inaccurate indoor positioning of mobile devices, especially in emergency situations like fires.

Innovation Solution

A method that uses a temperature sensor to detect ambient temperature anomalies, switches to a higher sampling rate to confirm their persistence, filters barometric pressure measurements during such anomalies, and localizes the device based on the filtered data to maintain accurate floor identification.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If barometric pressure measurements are used for indoor positioning, then positioning capability is improved, but measurement precision deteriorates under extreme ambient conditions

Engineering Contradiction:
Improvepositioning reliabilityVSAvoidpressure measurement precision
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The system performs preliminary detection of temperature anomalies before they corrupt pressure measurements. By monitoring temperature at a first sampling rate and switching to a second sampling rate when anomalies are detected, the system proactively identifies extreme conditions before they affect barometric pressure readings, preventing spurious positioning data

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Temperature serves as an intermediary indicator to detect extreme ambient conditions that would otherwise directly corrupt pressure measurements. The temperature sensor acts as an early warning system, allowing the system to identify when pressure readings will become unreliable due to thermal effects on the barometric sensor

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If temperature monitoring is performed continuously at high sampling rate, then detection precision is improved, but energy consumption increases

Engineering Contradiction:
Improvetemperature anomaly detection precisionVSAvoidenergy consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The sampling rate is dynamically adjusted based on environmental conditions. The system operates at a lower first sampling rate during normal conditions to conserve energy, and switches to a higher second sampling rate only when temperature anomalies are detected, optimizing the balance between detection precision and energy consumption

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the operational parameter (sampling rate) in response to detected conditions. By monitoring temperature and switching sampling rates between two discrete levels, the system adapts its measurement precision to match the actual environmental risk, reducing energy consumption during stable conditions while maintaining high detection capability when needed

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

This approach filters out spurious barometric pressure changes caused by extreme temperature conditions, ensuring reliable floor identification and preventing life-threatening errors in emergency situations by minimizing noise in pressure measurements.

Implementation Method 1

detecting, using a temperature sensor of the mobile device at a first sampling rate, an ambient temperature anomaly

Methodology Applied
Scientific EffectTemperature sensing:

Implementation Method 2

a set of barometric ambient pressure measurements contemporaneously associated with the sequence of positions

Methodology Applied
Scientific EffectBarometric pressure measurement:

Data Source

PatentEP3611467B1Method and system for mobile device localization in extreme ambient conditions
Publication Date: 2021.04.07 MAPSTED CORP
  • EP3611467B1 patent drawingFigure 1
  • EP3611467B1 patent drawingFigure 2
  • EP3611467B1 patent drawingFigure 3

AI summary

A method and system for localizing a mobile device in extreme ambient conditions. The method, executed in a processor of the mobile device, comprises detecting, using a temperature sensor of the mobile device at a first sampling rate, an ambient temperature anomaly along an indoor route being traversed, determining, based on switching to a second sampling rate, that the ambient temperature anomaly persists over a sequence of positions along the indoor route, filtering a set of barometric ambient pressure measurements contemporaneously associated with the sequence of positions, the set obtained using a barometric pressure sensor of the mobile device, and localizing the mobile device based at least partly on the filtered set of barometric ambient pressure measurements.