R%20F%20I%20G%20:%20RFID%20 %20Geometry%20Photosensing%20Wireless%20Tags%20for%20Precise%20Location%20and%20Complex%20Geometric%20Procedures

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R F I G RFID GeometryPhotosensing Wireless
Tags for Precise Location and Complex Geometric
Procedures

• Ramesh Raskar,
• Paul Dietz, Paul Beardsley, Darren
  Leigh,Jeroen van Baar

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Problem Example Tagged Books in a Library

• Id List of books in RF range

• No Precise Location Data
• (Are books in sorted order ? Which book is upside
  down ?)
• The solution RFIG

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What is RFIG?RFIG RF Id Geometry

• RFIG is a system for finding location of
  (photosensitive) RF tags using a hand-held
  projector

Photosensing Wireless Tags
LED Projector
Interactive stabilized projection
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Visual Feedback of location with Photosensing
RFID Pocket ProjectorMovie
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• Mitsubishi Electric Pocket Projector DLP based
  with R, G, B LEDs Instant on, battery-pack
  Available Now

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From RFID to RFIG
Conventional RFID Photosensing RFID Tag RFIG
System
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RFIG Operation Procedure Steps

1. RF reader initializes system projector produces
   a sequence of aiming patterns
2. Temporal signal at each tag photodiode is decoded
   at the tag, and this uniquely defines its
   position
3. Tag transmits via RF its ID, its coordinates
   (and other information, as required by the
   application)
4. Reading system processes the information and
   determines the designating pattern that the
   projector has to produce in order to help the
   user accomplish the task

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Step 1 Project Sequential Aiming PatternsStep
2 Tag Decodes its Position
Sequence example for determining x -
coordinate
Tag photodiode
Total projected area
x
1
0
1
0
0 20
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Example Complete Set of 5-bit 2D Aiming Patterns
x
y
N of illumination patterns per axis ( of
bits) For example N10, Illuminated area size
10 m gt Spatial resolution 1 cm
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Step 3 Tag Transmits ID x,y CoordinatesStep
4 Projector Provides User Feedback
Example Project green spots on items that have
to be moved to store front Project red spots on
items that need to be returned to supplier
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First Experimental Set-Up
Tag
Modified Projector
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Advantages and Limitations

• Advantages
• Enhanced functionality
• High-accuracy location determination
• Ability to communicate with tags selectively
• RF collision avoidance
• Minimal impact on tag in terms of
• Cost
• Size
• Power consumption
• Limiting requirements
• Line of sight
• Modified packaging

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Alternative RFOptical Approaches
Yoshikawa RF Systems (125 kHz)
PHOCI (Cliffton Labs)Blinking LEDs Special
Camera
RFIG
LED / CCD
long
Range
LED / RFID
short
yes
no
Battery
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RFIG Application Example Surveillance Detect
Arrangement ChangeWithout Fixed Camera and In
Any Lighting Condition
Before
After
Record coordinates of tags from one view
Compare with new coordinates from a different
view
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Application Example 3D from 2 Projector
Views(Structure from Motion)

• Two unknown projector views
• Correspondence is trivial
• Applications
• Detect 3D deformations
• Asset tracking facilitation
• Trajectory grouping

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RFIG Application Example Factory RobotsLaser
Guided Robot
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Application Examples

• Location tracking
• Hospitals, locating medicines
• Asset tracking, warehouses
• Factory automation,
• Sorting, routing, directing packaging
• Positioning products on assembly line
• Entertainment, games, motion capture
• Occlusion detection
• Railway tracks
• Occupancy in public areas
• Change detection
• Surveillance, Monitoring buildings and bridges
  structures
• Augmented reality
• Visual feedback in control rooms, HCI

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Other RFID ProjectsiGlassWare
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The iGlassware System

• The prototype instrumented glass

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The Reader
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R F I
G
R F I D
(Radio Frequency Id Geometry)
Photosensing Wireless Tags
Find tag location using handheld Projector
Simultaneous readers without RF Collision
Many geometric ops
Google search term RFIG