Tactile Navigation System for the Blind & Visually Impaired (VI)

Tactile Navigation System for the Blind & Visually Impaired (VI) Presented by: Tim Giguere & Tim DeBellis 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

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

Intra-Building Navigation: Concept Selection

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: Selected Concept

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: RFID Testing and Results

Intra-Building Navigation: Interface

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

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 operation dependent on customer needs. 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 • FEA models for compressive load scenarios • Servo-arms tested under bending with servo max stall torque. • Fatigue Analysis • Modified Goodman Criteria applied. • Plastic component stresses applied to research data for fatigue conditions • Vibration Analysis of Motor • 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 • 6V rechargeable NiMH 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: Sponsors: Advisor: Dr. Elizabeth DeBartolo Christian Seemayer (EE) Rob Proietti (ME) William Kelly (ME) Tim DeBellis (EE) Tim Giguere (ME) Shannon Carswell (EE) Daniel Paris (EE) Tim Garvin (CE) Daniel Stanley (CE)

Tactile Navigation System for the Blind & Visually Impaired (VI)