Group 9: ChillGeordi: RFID based location sen

sing

Brian Loo (bloo)

Geeta Shroff (gshroff)

Zane Starr (zcs)

Product Overview

• Indoor navigation system – When GPS not available

• Mapping application on desktop

• Map database loaded stored on device

• RFID tagged path read by device

• Communicated to user via text to speech software on device

Architecture• 1) Admin to create ma

p and layout tags• 2) Speech to text / tou

chpad• 3) RS322 / Wi-fi• 4) RFID GEN 2

State Diagram• Admin creates map• User inputs request

for a location• Device determines

location• Device fetches map

and plans path accordingly to tags being read.

• User follows instructions from device

State Diagram (PDA, Map GUI)

State Diagram (RFID)

Use cases

• Location assisted shopping

• Visually impaired location sensing

• Shortest path for couriers

• Directed tours

– One user per device

Use Error scenario• Low Battery• RFID tag not found in

database• Unable to read RFID

• Unable to understand user’s voice command

• Unable to connect with DB server

• Unable to plan path

• Device turns off• Ignore tag until next

tag is found• Move reader closer to

RFID• Inform user, revert to

using touch screen• Try 3 times, then

revert to using local version of DB

• Inform user, ask for another destination

Fundamental Risks

– SOFTWARE• Inaccurate route

planning– Unwanted

(impossible) paths in graph generation

• Device Driver handling capacity

– Multiple tags may collide

– HARDWARE• RFID sensor

– Identifying a sensor to integrate into project

• Maintenance & Infrastructure

– Price of RFID sensors & tags

– RFID's falling off walls

• Latency – Slow reading of RFID

tags

Ancillary Risks

– SOFTWARE• Software response time

– path planning, voice output/input

• Voice to text/ text to voice implementation

– Revert to touchscreen

– HARDWARE• RFID sensor

– Unable to get usable range

• Antennae – Size of usable

antennae

• Portability – Size of device

– Power of Sensors

Mitigations

• Inaccurate route planning

• Multiple tags colliding

• Software latency (path planning)

• Environmental( Signal attenuation)

• Price of RFID sensors & tags

• Portability (Power for sensors)

• Next hop path generation

• Not a problem for GEN 2 tags

• Astar algorithm (pruning)

• Insulated backing- aware of surrounding materials

• Passive tags are cheap

• Depends on sensor

END