Tactile Navigation System for the Blind Visually Impaired

Tactile Navigation System for the Blind & Visually Impaired (VI) Presented by: Tim Giguere & Tim De. Bellis Shannon Carswell & Tim Garvin

� Objective: Develop a device to aid the VI and blind in navigation throughout a building using a tactile interface. � Issues Faced: ◦ Campus and Classroom navigation ◦ Predominate use of memory for navigation ◦ Current market technology unreliable and expensive � This is a combination of two Senior Design Projects: ◦ Intra-Building Navigation ◦ Tactile Interface Problem Statement

Intra-Building Navigation: Functional Decomposition

Intra-building Navigation: Concept Generation Navigate Building Input Destination Keypad Voice Braille Automaticread schedule Read Location of User RFID GPS IR Ultrasound Generate Directions Compass Map Piece by Piece Direct. Compass and Map Interface Directions Sound Digital Display Tactile Display Braille Display Track Location RFID GPS IR Ultrasound Verify Location Tag Id’s GPS Location Ultrasound Readings IR Signature

Intra-Building Navigation: Concept Selection Step #1 Screening RFID IR Web Dog (REF) 2 RFID tags RFID and IR Aug. GPS RFID and Compass Availability of parts + + + D + + - + Distance 0 0 0 + 0 Cost of parts + + - + + 0 + Size + + + + Accuracy + + 0 + + Ease of Integration + + + + Cost of upkeep + + + + Sum + 's 6. 00 6. 0 0 4. 00 6. 00 5. 00 6. 00 Sum 0's 1. 00 1. 0 0 2. 00 1. 00 Sum -'s 0 0 1 0 Selection Criteria A T U M Net Score 6 6 3 6 6 4 6 Rank 1 1 3 1 1 2 1 Continue? YES NO DATUM YES NO YES

Intra-Building Navigation: Concept Selection

Intra-Building Navigation: Selected Concept � RFID Technology ◦ Place passive tags throughout the building to identify locations ◦ Use the reader to track location of user ◦ Develop navigation algorithm to produce directions between user and desired location � Compass ◦ Provide initial bearing to produce accurate directions

Intra-Building Navigation: RFID Testing and Results Test Procedure: ◦ Initial Read Range USB Power Supply ◦ Surface ◦ Height Placement ◦ Engineering Specifications Accurate Directions Repeatability ◦ Directions ◦ Location Identification Latency Mean Learning Time

Intra-Building Navigation: Interface

Intra-Building Navigation: Navigation �‘Hybrid’ Algorithm ◦ Graph Traversal ◦ Area Navigation A B C

�Develop a tactile interface that blind and VI individuals can use as a personal navigator �Device operation: ◦ Destination Input ◦ Entry to Internal Map comparison ◦ Directional information relay to user via tactile means �Device needs. operation dependent on customer System Integration

Customer Needs

Housing Structure Top and Side walls constructed from HDPE and Garolite plastic. Bottom is rapid-prototyped at RIT Brinkman Lab. Directionality Servo-driven tactile pegs Tactile pegs made of HDPE Proximity Vibration Motor Controlled by pulse width module to output 2 second vibrations Mechanical System Design

� Stress Analysis � Fatigue Analysis � Vibration Analysis of Motor ◦ FEA models for compressive load scenarios ◦ Servo-arms tested under bending with servo max stall torque. ◦ Modified Goodman Criteria applied. �Plastic component stresses applied to research data for fatigue conditions ◦ Issue of human exposure levels. ◦ 5 m/s^2 max for exposure time allowed. ◦ From testing, motor reaches between 25 and 55 minutes of constant exposure Mechanical System Design Analysis

� Built around an 8 -bit PIC C -based microcontroller. � Motors controlled by PIC and driven by BJT network. � Keypad continuously polled in software, user entry stored in variable length string � String will eventually compared to internal map to provide directional info � 6 V rechargeable Ni. MH battery Electrical System Design

� Individually test components for functionality � Prototype system using PIC development kit � Create ‘front end’ user inputs � Move design to PCB � Verify power levels Electrical System Design Strategy

Tactile Team: Navigation Team: Christian Seemayer (EE) Shannon Carswell (EE) Rob Proietti (ME) Daniel Paris (EE) William Kelly (ME) Tim Garvin (CE) Tim De. Bellis (EE) Daniel Stanley (CE) Tim Giguere (ME) Sponsors: Advisor: Dr. Elizabeth De. Bartolo