Navigation Aid for the blind
description
Transcript of Navigation Aid for the blind
NAVIGATION AID FOR THE BLIND
P12015
This material is based upon work supported by the National Science Foundation under Award No. BES-0527358. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author and do not necessarily reflect the views of the National Science Foundation.
FACULTY GUIDE: DR. BETH DEBARTOLO
Our Engineering Team
From Left:Bob Evans Electrical EngineerDavid Sachenik Electrical EngineerJackson Lamp Computer EngineerDavid Yip Electrical EngineerBen Davidson Mechanical EngineerRob Steigerwald Industrial Systems EngineerKonrad Ahlin Mechanical Engineer
Project Description
• Creation of a device that allows a vision/hearing-impaired individual to easily navigate to a location in an unfamiliar building.
• Our device understands locations by recognizing various passive radio-frequency identification (RFID) tags that are placed by doorways, restrooms, water fountains, and other areas of interest.
• The navigation algorithm calculates and determines the quickest routes to user inputted destinations.
• Complete prototype is user friendly, comfortable, and hands free.
Project requirements
•Battery Charge time less than 8 hours
•Interchangeable Battery
•Non-visual Commands
•Generates less than 50 dB Noise
•Attachment Time less than one minute
•Impact Resistant
•Lightweight
•Reliable
Electrical Design
Central Processing Unit: • MSP430F5438A Microcontroller
Determines Heading of User: • LSM303DLH Magnetometer
Determines Location of User: • SkyeTek SkyeModule M9 RFID Reader
Power Source: • Polymer Lithium Ion Battery – 1000mAh
Electrical Design
RFID Reader Antenna: •HyperLink Wireless 8 dBi Flat Patch Antenna
User Input Device:•3x4 Numerical Matrix Keypad
Defines Locations Within Building:
• Alien-Higgs Passive RFID Tags 840-960MHz
Provides Feedback to User:• Precision Microdrives 10mm Vibration Motors 400mA
Electrical Design PCB Layout
Software Design
Two Step Navigation Process:
1.) Path Finding:• Implementation based on Dijkstra’s
Algorithm• Path is stored for use by the path
following algorithm• Re-run whenever the user wanders off
course
2.) Path Following: • Currently a work in progress• Interprets data generated by the path
finding algorithm to guide user to guide user to destination
Software Design
Management of Peripheral Devices:
• Custom Interface for Keypad• Uses a sequence of pulses to scan each column of keys
• SPI Interface for RFID Reader• Uses a packet based, request-response protocol• Current implementation can return a list of detected tag IDs• Challenging to implement, caused delays in
• I2C Interface for Magnetometer• Uses a register based protocol• Raw data needs to be converted into a heading value using
trigonometry• PWM Output for Vibration Motors
• Used to control intensity of vibrations programmatically• State base controller used to control output sequences
Mechanical Design
Main Case:• Slide allows for easy battery
access• Top cover holds keypad in
place• Main body holds PCB, RFID
reader, and battery in place
Motor Cases:• Transmits vibrations• Allows offset mass to rotate
Belt Enclosure:• Ergonomically designed• Properly secures components
Results/Demonstrations• Motor Feedback Interaction• User Keypad Inputs• RFID Tag Recognition• Magnetometer Heading• Assembly of Device