Indoor and underground orientation and navigation by using the barometer sensor

Elizaveta Karpakova, 3. Sem. Geoinformation Master mit Kaatz, Richter und Zimmermann (Geoality GbR), … und Prof. Dr. Roland-M. Wagner

Droidcon 2012, Berlin, Urania, 14.3.2012

Overview

1. Problem statement for indoor orientation & navigation

2. Application example: (Berlin) Underground

3. Approach with Barometer

4. Data-collection

5. Analysis

6. Conclusion

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Problem statement for indoor orientation

Do you need an (outdoor) navigator?

1992: no

2012: yes

GPS is not usable for indoor orientation and positioning, other sensors are needed

Challenge: Change! More Change in indoor environment, e.g. fairs, cons

Some privacy aspects, e.g. indoormaps only for welcomed visitors and not for everybody in the net; => local infrastructure

Additional indoor information needed, e.g. pics, contact, time, location => e-flyer

An early project is: openfloormap.org

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Application example: (Berlin) Underground

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CC-At-By Ingo http://www.flickr.com/photos/30184910@N06

Undergrounds are used by million people every day

Many are tourists and need permanent orientation & navigation

Orientation needed also between stairs and stations

Frequent users might be interested e.g. for a wake-up app

Only a few underground operators offer an (open) interface

Approach with Barometer

Cell-id Positioning in Undergrounds allows to define the line and a position between 4-6 stations

Underground stations have different altitudes due to crossings and surface

Barometer / pressure measurement is robust and does not require much energy

Moving train pressure changefor station counting

Only deltas are needed

Absolute altitudecalculation with weather service

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Data-collection

Specialized app to capture the context

Which line?

Which direction

Walking / Stairs

Train movement

Capturing of all smartphone available sensor data

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https://play.google.com/store/apps/details?id=de.geoality.activitys

Analysis: Characteristics I

Multiple underground train stations with filter

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Filtered Pressure

Sensor Pressure

Analysis: Characteristics II

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Underground Station

Pressure changes due to tunnel effects

Conclusion

Cellid positioning offers the underground line and an interval between 4-6 stations, which is not suficient

Acceleration and pressure changes are characteristic enough to count stations

Pressure Delta between (multiple) stations can additional be used for absolute positioning

Very robust for determination of levels (underground stairs, buildings)

Currently only two android devices available (Xoom, Galaxy Nexus)

Apps, Data and Bachelor Thesis available

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