“A Smart Navigation and Safety System for the visually challenged
The Walk-Bot is a navigational device designed for the visually impaired. It is supposed to be worn around the waist of the user and is capable of detecting objects at any level of human movement in front of him/her.
There are 2 ultrasonic sensors present on the device: one in the front and one at an angle of 45 degrees upwards. A third infrared sensor is placed at an angle of 45 degrees towards the bottom because the ultrasonic waves have a tendency to get reflected by flat surfaces at particular angles resulting in inaccurate measurements.
The raw input from these sensors is then processed by the microprocessor using trigonometry to obtain distances 29.3% more accurately.
Walk-Bot is equipped with a gyroscope(compass) which can detect slight changes in inclination of the device and compensate for such disruptions.
The user receives feedback through a buzzer and vibration motor, both operating at varying frequency to denote closeness. It also has a panic button.
THE SENSORS:
Walk-Bot has 3 different distance sensors placed at an angle of 45 degrees to each other:
Ultrasonic Sensors: There are 2 ultrasonic sensors present on the device: one in the front and one at an angle of 45 degrees upwards. They work on the principle of SONAR(i.e. the reflection of sound waves) to measure the distance of the obstacle in front of them.
Infrared Sensor: This is the third sensor which is placed at an angle of 45 degrees towards the bottom. This sensor has been used at the bottom instead of the ultrasonic sensor because the ultrasonic waves have a tendency to get reflected by flat surfaces at particular angles resulting in inaccurate measurements.
PROCESSING THE DATA: The raw input from these sensors is then processed by the microprocessor using trigonometry to obtain much more refined and usable data. THIS IS THE MOST IMPORTANT FEATURE OF WALK-BOT AS IT ENABLES US TO FIND THE DISTANCE OF THE OBSTACLE FROM THE USER 29.3% MORE ACCURATELY THAN THE DISTANCE OF THE OBSTACLE FROM THE SENSOR ITSELF.
WARNING THE USER: Supposed to be worn on the waist, the device has two different methods of warning the user of obstructions : 1.Buzzer: The walk-bot has a buzzer which operates at varying frequencies to denote the proximity of the obstruction. In other words, it will warn the user by increasing the number of beeps as the obstacle gets closer. 2.Vibrating Motor: The walk-bot has also been equipped with a vibrating motor along with the buzzer for people who are not only visually but also audially challenged.
ERGONOMIC MAINTENANCE: Walk-Bot is equipped with a gyroscope(compass) which can detect slight changes in inclination of the device, i.e., it can sense whether the user is wearing the device in the correct manner or not and warn him/her accordingly. If the device is not perfectly parallel to the ground, the trigonometric calculations can become inaccurate. To solve this problem, information from the gyroscope can be utilized to compensate for the inclination and calculate the accurate distances. “