1. SDP Presentation1 STEVI: Sensory Technology Enhancement for the Visually Impaired 10/20/2009 Preliminary Design Review Alex StarosielskiSignal ProcessingWeb-Developer Brendan GavinSensors / IntegrationTreasurer Charbel KobrianosSensors / IntegrationTeam Administrator Yi LinFeedback / IntegrationSlide Developments Team Vouvakis Electrical and Computer Engineering

2. SDP Presentation2 Electrical and Computer Engineering The Problem The visually impaired can not navigate without assistance. Cane People The Guide Dog

3. SDP Presentation3 Electrical and Computer Engineering Long Cane Common Solution Simple, cheap, robust and reliable Limited range Problems with obstacles above waist.

4. SDP Presentation4 Electrical and Computer Engineering Electronic Solutions Electronic Travel Aids (ETAs) Detect obstacles with sensors Typically ultrasonic Indicate obstructions to user Feedback often auditory or tactile

5. SDP Presentation5 Electrical and Computer Engineering Limitations of Existing Electronic Aids Expensive! $400 to $1000 Trouble with stairs and slopes Insufficient directivity Problems with reflections indoors Problems with absorbing objects

6. Requirement Specifications SDP Presentation6 Electrical and Computer Engineering Society NeedsEngineering ConstraintsProject Specs Form FactorHandheldSize5in x 5in x 2in (handheld) Detection Range 0 – infinityPower and price0.5-4m Detection Angle 0 – 180°User interface and signal processing20° Obstacle sizes All sizesLimitations of sensors> 3in x 3in CostFreePart, manufacturing and labor costs< $400 Battery LifeInfiniteSize, power consumption> 7 hours WeightNegligibleHardware mass< 3 lbs

7. Big Picture 7 Electrical and Computer Engineering SDP Presentation

8. 8 Electrical and Computer Engineering Proposed Solution - STEVI Sensor Fusion! Auditory & Tactile Feedback UltrasoundLaserInfrared Small ObjectsX Slanted SurfacesXX DirectionalityX ReflectionsSignal Processing Absorbent ObjectsSignal Processing

9. Block Diagram - Basic SDP Presentation9 Electrical and Computer Engineering

10. Block Diagram - Intermediate SDP Presentation10 Electrical and Computer Engineering

11. SDP Presentation11 Electrical and Computer Engineering Block Diagram – Full Function

12. SDP Presentation12 Electrical and Computer Engineering Ultrasonic Sensors 2 x Maxbotix UT Average time of flight to calculate distance Angle calculated from difference in signal return times c = speed of sound in air = 343 m/s www.sparkfun.com

13. SDP Presentation13 Electrical and Computer Engineering Laser Detect distances with triangulation Used for handling stairs, curbs, angled walls and smaller objects (1/3-inch Sony Supper HAD Color CCD Wired Mini Pinhole Camera Camera view: Setup: Sony Supper HAD www.lightinthebox.com

14. Infra Red Detect closer objects Prevents user from hitting objects while sweeping left and right www.sparkfun.com Has a viewing angle of 40 deg. 14SDP Presentation Electrical and Computer Engineering

15. SDP Presentation15 Electrical and Computer Engineering Microcontroller 3 x 28 pin ATMega88PA Features: 8kB Program Space 20 MIPs at 20 MHz 23 I/O Lines, 6-channel 10 bit ADC In-circuit programming - JTAG www.digikey.com

16. SDP Presentation16 Electrical and Computer Engineering User Feedback 3 x ROB-08449 Vibrating Motor Closer obstacle - stronger vibrations Vibrating pad location - obstacle direction Alternative Feedback - Audio Jack www.sparkfun.com

17. SDP Presentation17 Electrical and Computer Engineering Prices ComponentCost Microcontrollers (3) www.digikey.com $8 Vibrating Motors (3) www.sparkfun.com $15 IR Emitter/Detector (2) www.sparkfun.com $4 Ultrasonic Transducers (2) www.sparkfun.com $10 Laser/Camera Assembly www.allelectronics.com $140 PCB Fabrication$100 Total Cost$277 Initial Balance$500 Net Savings$223

18. SDP Presentation18 Electrical and Computer Engineering Proposed MDR Deliverables Demonstration of Ultrasonic Detection Block Diagram 2 Ultrasonic Transducers Transducer Microcontroller Vibrating Motor Array Principles of Laser Detection Laser and Camera Computer Processing

19. Gantt Chart of STEVI

20. Thank You SDP Presentation20 Electrical and Computer Engineering