Study of Tactile interactions for visually disabled and hearing impaired

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This is presented at our thesis progress presentation. …

This is presented at our thesis progress presentation.
Supervised by:
Prof. Dr. M.M.A. Hashem
Abu Saleh Md. Musa
Taslima Akter

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  • 1. Study of Tactile interactions for visually disabled and hearing impaired Supervised by: Prof. Dr. M.M.A. Hashem Abu Saleh Md. Musa Roll-0907013 Taslima Akter Roll-0907046
  • 2. Outline • • • • • • • • • Introduction Problem Statement Specific objectives Proposed System Architecture Software Design Hardware Design Expected Results Timeline References
  • 3. Introduction • Over 21.2 million visually impaired in USA. • Independent tactile interactions is becoming a bigger challenge. • Disablers are falling behind. • Sometimes their lives at risk. • device that aids disabled with Smartphones.
  • 4. Problem Statement • • • • Difficult to develop a single device. GPS not supporting in indoor Objects are more congested in indoor Possible Solution: • Image Processing • IR Sensors & Ultrasonic way finder • New Google Phone(code name “Project Tango”)
  • 5. Specific objectives To assist physically disabled people. To navigate for both indoor and outdoor environment. To detect objects and obstacles in navigation path. To calculate the threshold value of sensors. To calculate distance of obstacles using Rangefinder sonar sensor. To eliminate noises from the pulse information. To make a system that employs total support for visually disabled people. • To perform assistance as hear aid for disabled. • To analyze a system that employs navigational path using smartphones. • • • • • • •
  • 6. Proposed System Architecture
  • 7. Software Design • • • • • Initialization and Calibration Obtaining Range information from sensors Median Filtering Wayfinding Logic Realtime scheduling
  • 8. Initialization and Calibration • ADC and TRT kernel • determines threshold based on the height of the user. • Three calibration readings at 140ms apart • chooses median value as calibrated value. sensor threshold = sqrt(2) * calibrated value • holding the tactile sensor at a 45 degree angle
  • 9. Obtaining range information from sensors • • • • • • simultaneous use of sensor. Semaphores are used to ensure that. delay 50ms require 49ms to obtain a range reading 8-bit from ADC is converted to distance. Dis(m)=Vin*(512/5)(in/V)*0.0254(m/in) =(5/256*ADC)*512/5*0.0254
  • 10. Median Filtering • • • • • Filter of size 3 effective Two causes for Impulse noises Sudden change in ranges overestimating the distance of an object
  • 11. Wayfinding logic • Two real time tasks • Navigation logic • checks for the presence of obstacles in the fields of view • object in threshold of 2m, motor will buzz • Tactile sensor logic • checks for obstacles by calibration process • scales intensity of the vibrations proportionately with the proximity of the obstacles.
  • 12. Wayfinding Logic • • • • • Pulse duration=1/range*multiplier For Navigation Logic, Multiplier=30 & for Tactile Logic Multiplier=20
  • 13. Real-time scheduling • sensors are working independently and simultaneously. • tactile sensor logic task and ranging tasks have priority over navigation logic. • navigation logic frequency =300ms • 250ms for all the other tasks.
  • 14. Software Design
  • 15. Hardware Design • Microcontroller • Motor • Ultrasonic RangeFinder • Power • Smartphone
  • 16. External Design for Hearing impaired • Amplified Sound and vibration will indicate command generated by smartphones. • amplifier circuit will be embedded. • Mini motor vibrator will be used. • Vibration indicates navigational way.
  • 17. Expected Results • • • • • • Faster Detection of Obstacles Accuracy User Satisfaction Safety User flexibility Environment independent
  • 18. Timeline
  • 19. References • • • • • • An acoustic wayfinding device with haptic feedback for the visually impaired, http:// Real-time Mobile-Cloud Computing for Context-Aware Blind Navigation, FootPath: Accurate Map-based Indoor Navigation Using Smartphones, Ultrasonic range-finder with haptic feedback, http:// Ultrasonic Pathfinder, js2587_mg792/js2587_mg792/js2587_mg792/finalProject.html Pedestrian Smartphone-Based Indoor Navigation Using Ultra Portable Sensory Equipment, arnumber=5646697