The idea that leverages RFID labels for location determination and direction guidance

Suk chan Kang

Outline

Motivation Why RFID for this idea? Components Feature Prototype Trinetra System RFID Shelf/Rack Label for location determination RFID Label orientation and its direction coordinate The guidance from different source The absolute and local direction coordinate Sample RFID deployment file format Procedure for the direction guidance (1-6) Toy simulator (1-2) Toy simulator simulation procedure(1-6) Conclusion

Motivation

Impressed by guidance style of old treasure map Cost-effective, convenient direction guidance for the destination Better independence for the user, without bothering the store clerks Synergy effect when used with other devices like bar code reader to discriminate

between different products

Go straight by 10 walks.Turn to the right.Go straight by 15 walks.Turn to the left.Go straight by 10 walks.

Dig it !!

Why RFID for this idea?

Relatively higher cost than that of bar-code Baracoda’s IDBlue RFID-scanning pen has only 4cm-long

reading distance ! However

Basic, cheap RFID tag does suffice for this idea No requirement of line-of-sight reading of the tags

Components

RFID label deployment data file indigenous for each store Item database of the store that matches the items and their RFID shelf label Smart phone Passive RFID label Passive RFID reader Micro phone Bluetooth headset Speech-to-text software to issue the commands Text-to-speech software to inform the user of the resulting messages

Feature

RFID-based aisle and shelf-level guidance and identification Immunity for re-stocking and relocation

Most information is in the file to be stored in smart phone Only needs to reconfigure the matching between items and their position (in

the form of RFID number) in deployment file whenever the store updates its item data base

Can guide the user again even if the user happens to deviate from the desired routing

Prototype Trinetra System

RFID Shelf/Rack Label for location determination

RFID Shelf/Rack Label for location determination

RFID Label orientation and its direction coordinate

Every RFID Label is intuitively assigned its own indigenous local orientation in 12 division format

The direction coordinate of 12 division of a RFID label varies RFID by RFID

The direction which points at 12 o’clock is the direction of the side that RFID label faces

12

6

39

9

3

126

The guidance from different source

Rack

destination

3

9

612

9

3

126

Go to the 11 o’clockdirection !

Go to the 4 o’clockdirection !

View from the ceiling

The same destination, different direction guidance, depending on the user’s position

The absolute and local direction coordinate

The smart phone software should know the relation between the absolute coordinate and the local coordinate

This information is specified in RFID deployment file as the item “fdir”

12 (North)

6 (South)

39

In this example, the local 12 o’clock points

3 o’clock direction in absolute coordinate

9

3

126

Absolute 12 divisioncoordinate

Local 12 divisioncoordinate

Sample RFID deployment file format

#sNode x y fdir attri Enb Wnb SnbNnb

[sNode begin]sNode0 100 100 3 Norm 1 -1 15 -1sNode1 150 100 6 Norm 2 0 16 -1sNode2 200 100 9 Hole 3 1 17 -1sNode3 250 100 3 Norm 4 2 18 -1……….sNode75 100 350 3 Norm 76 -1 90 60sNode76 150 350 12 Norm 77 75 91 61sNode77 200 350 9 Norm 78 76 92 62[sNode end]*Fdir: The orientation that this RFID tag’s 12 o’clock faces, in absolute direction coordination*Attri: Attribute. Hole or Normal*Enb: East neighbor RFID tag id number -1 means no neighbor in that direction*Wnb: West neighbor RFID tag id number -1 means no neighbor in that direction*Snb: South neighbor RFID tag id number -1 means no neighbor in that direction*Nnb: North neighbor RFID tag id number -1 means no neighbor in that direction

Procedure for the direction guidance (1)

1. Check and download a up to the date RFID label deployment file for a shop when entering the shop

Brand new RFID deployment file

Procedure for the direction guidance (2)

2. Search for the item over the item data base of the store and get the RFID number of the destination where the items are waiting for the user The user can use speech to text software for conveniently issue the

command to smart phone

“Orange juice” “RFID 100”

Procedure for the direction guidance (3)

3. Set the RFID taken in procedure 2 to the destination

“Set destination 100”

Procedure for the direction guidance (4)

4. Identify where the user is now, by reading the nearest RFID label around the user

“RFID 9 is nowset to your position”

Procedure for the direction guidance (5)

5. Let the smart phone tell the user the routing The software in the smart phone will use “shortest path algorithm” such as

that of dijkstra The smart phone will guide you to the destination in piece wise manner The direction would be of 12 division format The distance would be of the multiple of unit distance such as “5 walks” or

“10 hops”

“Turn to the 7 o’clock”“Go straight by 10 walks”“Turn …”

“Tell me the rouging”

Procedure for the direction guidance (6)

6. Iterate 4 to 5 until the user gets to the destination successfully Even If the user would ever deviates, it is alright because the smart phone

will suggest a new shortest path from where the user is now, to the destination

Toy simulator (1)

Simulates the previous procedure from (3) to (6) Written in C++ by using Qt 3.3.4 library on Linux Platform Uses Dijkstra’s shortest path algorithm You can see the demo “avi” format file and source file at this

address: (please click!) You can compile it on Linux or Cygwin by typing:

>make clean; >qmake; >make clean;

Please just invoke “./rfidguidance &”

Toy simulator (2)

Speech to text input

Text to speech output

User

Routing line

Destination

Routing hop list

Local direction clock

Rack

RFID label

Absolute directionclock

Toy simulator simulation procedure(1)

Speech to text input commanded:“set destination 85”

Text to speech output message tells:“Node 85 is now destination”

Node 0

Node 85(not shown)

Toy simulator simulation procedure(2)

The direction for guidance routing at this label is 9 o’clock when compared with the short hand

The short hand points at theside this RFID label faces

“Go to the 9’oclock direction by 8 hops”

Absolute direction clockalways points atthe absolute 12’oclock(It does not move)

Toy simulator simulation procedure(3)

“Go to the 9’oclock direction by 2 hops”

When the user seems tohave deviated, the userhas only to tell “showrouting” again

Node 85

Toy simulator simulation procedure(4)

“Go to the 3’oclock direction by 5 hops”

Toy simulator simulation procedure(5)

“Go to the 0’oclock direction by 1 hops”

The direction forguidance routing at this label (84) and the side this label faces are the same

Toy simulator simulation procedure(6)

“You have alreadyreached your destination !!”

Conclusion

RFID label based location determination and direction guidance

Better degree of freedom for the user, not disturbing the store clerk

Relatively robust for physical re-stocking and relocation