Smart Cane Project (IIT Gandhinagar)

Shashank  Agarwal, Prateek Nyati, &  Akshay Jain

Abstract

Out of all sense organs which humans have, 85% of the physical input data from environment come through “Eyes”. Nearly 37 million of world’s population is blind, and hence deprived of one of the most  important and informative asset “Eyes”.  Our main motivation was from our visit to Blind People Association situated (BPA) in our City, Ahmedabad. We noticed that normal blind canes used by blinds have certain limitations like detecting pot-holes,  stairs, distant objects, above knee obstacles  etc. at the same time currently available sensor equipped canes in India are very costly and unaffordable by Indian people. We took a lot of inputs from disable people at BPA and came up with the idea of developing a economical sensor equipped cane capable of assisting blind to navigate easily. Our final design is quite cheaper than existing alternatives and warns the person via vibratory and auditory signals.

Introduction/Background

Our goal was to build a smart cane which can help blind people in navigation and make it available at much cheaper prices without compromising with the functionalities by minimizing its maintenance and operating cost. For the purpose, we many times visited BPA Ahmedabad and performed Consumer Needs Analysis to come up with something which fits their need with as much accuracy as we can.

Result of Needs Assessment:

1. Potholes detection is the first priority. This was a bit surprising for us!
2. Fold ability of cane is necessary.
3. Head level obstacle detection is necessary.
4. Vibratory feedback is preferred over auditory.

This helped us a lot in actually identifying the problem statement.

Problem Statement:

• To make a smart cane which can help blind people in navigation.
• To make it available at much cheaper prices without compromising with the functionalities.
• Minimizing its maintenance and operating cost.

Design and Development

Methods Brainstormed:

• Design with multiple sensors for detecting position of obstacles.
• Design with an I.R. sensor for detecting potholes.
• Telescopic  cane design.
• With adjustable sensor angle.
• Position of batteries.
• Using cylindrical pipes as cane

Problems Faced and their Solutions

• Design with multiple sensors gave slow feedback.
• Designed with only 2 sensors.
• I.R. sensor for potholes were insensible towards black objects
• Used ultrasonic sensor
• Ultrasonic sensor had large cone angle
• Mechanically reduced cone angle
• Telescopic design was having wiring problems
• Used hinge for folding.
• cylindrical pipes were difficult to use with hinge
• Used pipes with square cross section

• The cane is mounted with two ultrasonic sensors one near the handle and one at the bottom.
• Upper ultrasonic sensor sends ultrasonic waves that after reflecting from any object get
• received by the detector of the sensor.
• The time taken between emission and detection of the ultrasound waves is measure of the distance of the obstacle from the sensor.
• The distance is processed in the microcontroller to provide appropriate output in form of
• vibrations through vibrator mounted inside the handle.
• The lower ultrasound detects variation in the distance between sensor and the ground level.
• If the distance between the sensor and the ground level increases above certain threshold that it is an indication of the pothole in the region ahead.
• Similarly if this distance increase above certain threshold than it is an indication of a stone or staircase. Microcontroller again processes this information to give proper output to the user indicating     the possibility of pothole.
• Cells placed inside the cane to minimize size of box outside cane.
• Center of mass near handle of the cane to prevent fatigue due to added weight.
• Vibratory  & auditory feedback for distinguishing between pot holes & front obstacles

Salient Features of Final Design:

• Easy to fold and carry.
• Detachable Sensor & Controller modules.
• Indoor & Outdoor modes for setting detection range.
• Pencil cells as power source because of its easy availability in market and low cost.
• Cells placed inside the cane to minimize size of box outside cane.
• Center of mass near handle of the cane to prevent fatigue due to added weight.
• Taken care of energy efficiency of the cane to reduce frequent need to replace cells.
• Vibratory & Auditory feedback for distinguishing between pot holes & front obstacles

Future Line of Action:

• Giving the smart cane to few blind people to get their feedback about it.
• Implementing any modifications as insisted by blind people in their feedback.
• Developing marketable product  by using standard hardware materials, PCB’s etc.

Evaluation

The final device was evaluated to assess durability, client ease of use, device effectiveness and safety. Durability was assessed during the design phase. Ease of use was assessed by observation and actual testing by the client. Detailed accuracy analysis and input optimization was done and addressed through redesign.

Acknowledgement

We’d like to thank Blind People Association Ahmedabad, our institute IIT Gandhinagar and Prof. Girish Singhal  for assisting us throughout the project. It was a huge learning and an eye-opening experience. We’d also like to thank the people from BPA for giving constructive feedback and advice for our device.