the 9th COE Postdoctoral and Doctoral
Researchers Technical Presentation

ALTAIR:
Automatic user location systemusing Active IR-tag

Background
Ubiquitous computing expands working area


To Maximize the mobility↓
Location system should be prepared for

Muneyuki Sakata
Image Processing Laboratory
2004/12/22

Expected utilities
of location systemWhich section → which commodity
Counter → accounting
 Storage → commodity check Hospital Which bed → which patient Nurse station → desk work / meeting Moving in a group → doctor’s round

Dynamic monitoring and accumulating
multiple workers’ location
is desirable utility.

Locating yourself : Get navigation, Footprint
Collaborating with others : Provide navigation

To acquire user’s location
Outdoor → GPSIndoor→ ??

Objective

Spatiotemporal location information
implies the worker’s activity
 StoreGathering and transmitting information anywhere,anytimeUser location system for indoors
Requirements
High accuracyex.) in front of which desk, which part of the roomDon’t disturb daily work Automatic tracking and identification
 Smaller user’s equipmentsSimple infrastructure

ALTAIR(Automatic Location Tracking system using Active IR-tag)

Related work
Autonomous positioning system(Konishi at al.,Tokyo University)○ No sensor in environment
× Large user’s system / Accumulative error

Easy Living
ActiveBat(AT&T,1997)(Microsoft,2000)

Using Radio Wave and Ultrasound(Active Bat (AT&T))

Automatic locating and identification~0.5m accuracy
Simple infrastructure
ALTAIR uses

○ High positioning accuracy
× Too many sensors are needed

Image processing using camera image(Easy Living (Microsoft))○ User has no devices
× Need some action to identify user

Wireless LAN IR-tag IR wide-angle camera
(Konishi at el., 2001)

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Proposed Method“Roll-call” strategy

IR tracking
 IR wide-angle camera+ IR marker(IR-tag)

Identify user

A・System makes IR-tag of a user
who needs to be identified blink.
・Detects the blinking IR-tag using
image sequence from camera
・Associates the user
with the blinking IR-tag

 Sparse set up with limited
number of sensors
 Stably extract the marker
from IR image

Control lighting patternof IR-tag via network
 “Roll-call” strategy

System (user’s system)
Wireless LANIR-LEDs

Repeat as if making a “roll call”,
and system can automatically
identify all users.

LightingSystem(one section)
IR wide-angle camera

・PDA(Zaurus,Sharp)
・Wireless LAN・PIC・IR-LEDs

PIC

Tracks lights
of all IR-tags
 Calculates IR-tags’
positions Detects blinking IR-tag

PDA

Local Location-Manager(LLM):
Merges information from cameras
Sequentially instructs IR-tags of all users to blink
Updates user location and identification
System(servers)

Sample application
RoomTime, User-ID , Room ,Position(x,y)
set of data

User nameTrace the user’s movequeryDatevisualization inputTime2

Automatic detectionof entering / leaving a section

ssddreACAAP’s M

LLM

ectConn’s IPAddre ss

Sample Application

Area 2

Area 1
LLM= Local Location Manager
AP = Access Point

Movie

Future Work
Some experiments

Verification of Prototype system Rate of tracking user
 Visible angle of IR-tag

Sample applications
Analyze user’s location from various aspects
Linking to other data resource Video Streaming, Meeting log,
Output of other devices…

Summary
In order to make maximize of ability ofubiquitous computing,
dynamic monitoring and accumulating user’s
location are considerable.
I proposed automatic user location systemusing active IR-tag and made a prototypesystem.
In my future work, I’ll make some experiments
to verify the prototype and make some
applications using the location system

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