1. Project Schematics Circuit Working Principle and Equations
Sight Guidance System
Mohammed Alyas , Abdulmajeed Alzahrani , Mohammed Errarheb, Adel Alaeou, Navarun Gupta
Department of Electrical and Computer Engineering, University of Bridgeport, Bridgeport, CT 06604
Abstract
Parts
The sight system is built up with ultrasonic sensors to detect objects and humans in their range, they are placed on the user body, particularly on shoulders, chest, or hand. As the sensors are used for advanced assistance, the user can be guided toward a suitable daily path and to avoid obstacles and collisions. Once it’s set the user is alarmed through sounds or vibrations. The range is expected to be implemented depending on user preference. Once the system detects an object in range it will successfully notify the user.
UNO R3 / MEGA2560 R3
Ultrasonic HC-SR04 Sensor
612 Hollow Cup Motor Vibration
400 Tie/830 Tie Point Breadboard
Jumpers
Introduction
In the United States, millions of people live with visual impairment. It affects a substantial amount of activity in daily life including walking, driving, and reading. According to World Access for the Blind, a nonprofit organization whose mission is to help blind people navigate their world more efficiently and safely, the biggest struggle blind people have is physical movement often necessitating the need for help from friends and family. Technology has also had a huge impact on improving quality of life for the visually impaired allowing them independence and freedom to rely on themselves. Unfortunately, technology has not given solutions to all of the problems people with visual impairments face especially those suffering from complete blindness. And, the integration of technology has not hit mainstream, thus, these people still have to expect help from those around them. Our proposed idea can help increase the safety movement of blind people for their daily walks. Below is the block diagram of proposed project:
Figure 3: Project parts.
Project Schematics Circuit
Figure 1: Block diagram.
Working Principle and Equations
The project consists of four ultrasonic sensors, three sensor covers three different regions: Left, right and front of the chest, and the fourth one is placed on hand only activated for extra reading accuracy. Each of these sensors is detecting objects based on the “time of flight” principle. A high frequency pulse is emitted by the sensor usually in the 20 kHz to 200 kHz range. The pulse is transmitted in a cone having 30 degrees at the apex. When the pulse hits an object it is reflected back to the sensor where the pulse is received by the receiver part of the sensor. Basically, the time between the pulse and its echo is divided by two, that is the distance to the object. The distance given by this equation: Distance = Time * Speed of Sound/2
The covered angle of 90 degrees based on the sensors positions are on the figure 2b.
Figure 4: System schematic diagram.
Project Discussion
The sensors are set on about 1.5 meters above ground surface, as well as they are adjustable depending on the height of the person and the most stable and readable point. Also, they are inclined slightly downward toward the ground where it gives the user a better walking detection. The sensors and motor vibrators are distributed separately aligning one vibrator per sensor, giving the user a better approximation of the angle that is detected. As Ultrasonic Sensors are measured by the radio/sound waves, it is not affected by lit or dark fields. One of the disadvantages of the Ultrasonic Sensor is that it is not perfectly perpendicular in front of the sensor’s transmitter and receiver where the object will not be read fast as long as the object in range is not stable. Plus, it can be caught up by bad readings from other signals which are on the same frequency.
Conclusion
Our proposed idea is an innovative and low-cost way for people suffering from complete blindness and with visually impaired to integrate into society in a safe manner. It gives them independence to walk the streets freely without fear and to navigate without assistance. By using the other senses such through vibrations, people with severe visual impairment can be alarmed when objects are in their path or when a turn needs to be made to reach their desired destination.
Figure 2.a: Ultrasonic Sensors waves reflection.
Figure 2.b: Sensors covered angles. ….