Group 9: Chill
Geordi: RFID based location
sensing
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
map and layout tags
• 2) Speech to text /
touchpad
• 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