Blindness can be defined as a state if being sightless whereby both eyes suffer from complete loss of vision, this disability is mostly caused by diabetes, macular degeneration, traumatic injuries, infections, glaucoma etc. As of 2012, World Health Organizati0n (WHO) has estimated that about 285 million people worldwide are visually impaired; in which 39 million are blind while the other 246 million suffer from low vision. Research shows that 90% of the blind are unable to travel alone, 3% depends on their pets while the remaining 7% make use of walking aids.

Introduction

The main purpose of this project is to design a device that will serve as a medium of communication between the blind person and his environments, the device should be made up of an assembly of several sensors which will enable it to detect obstacles and give details about the environmental condition around the user.

Blindness has been existing since old age, ever since then, walking stick has been in use for mobility purposes. In February 2000, World Health Organization (WHO) stated that "If additional resources are not urgently mobilized and efforts are not made to curb this trend of blindness, by 2020 the global burden of blindness can double". They had also estimated that approximately 50% of the world's blind people suffer from Cataract while majority of the remaining are blind due to conditions that include; Glaucoma, Trachoma, Onchocerciasis (also known as river blindness) and other conditions of childhood blindness.

Safety and confidence of the blind is very important and could be increased using devices that gives signals to find the direction of an obstacle-free path an in unfamiliar or changing environment. Some of them also depend on their pets and guide dogs for mobility. However, guide dogs are very expensive and needs to be looked out for. Due to the development of modern technology, many different devices has been designed using electronic components in order to assist the blind navigate through their environment, such devices include the smart canes, eye-mates, white sticks etc. They are commonly referred to as electronic travel aids or mobility aids.
Several researchers have introduced devices that use sensor technology and laser technology to improve the guidance and safety of the blind and visually challenged people, different ideas and methodologies had been used to design systems or devices relating to this topic, developers had put effort to help the visually impaired people feel safe, secured and comfortable whenever they are going out to public places or even in their homes. These devices has been called different names such as; Smart canes, navigation aid, smart guide and the likes. These devices are continously improved upon by adding new ideas for the purpose of it serving as a second eye, helping them to walk independently.

Why G.E.S?

The loss of vision is often accompanied by loss of independence. The visually impaired, in particular totally blind people are unable to take advantage of different services. The lack of social interactions, human contact and limited mobility are some of the problems faced by these people. This project is primarily aimed at easing the problems of mobility for these particular set of people.
In mobility, the geographical location and safe paths are key elements, avoiding all obstacles and people that may be coming directly opposite them, avoiding hazards in form of fire and drowning. This project will tackle these problems. Enhanced mobility will invariably increase their independence. These problems were arrived at based on statistics and personal experience.

Design & Methodology

       Block diagram of the G.E.S 

         Flow chart of the G.E.S

The Guidance and Emergency System for the Blind comprises of seven (8) units interfaced together which include:

• Ultrasonic Sensing Unit
  An Ultrasonic sensor is a device that can measure the distance between it and another object by using ultrasound waves. The device operates by sending out an ultrasound wave at frequency of about 40 KHz listening for that sound wave to be reflected back, the device then record the time elapsed between the sound wave being generated and the sound wave that is bounced back using it to calculate the distance between the sensor and the object.

• G S M Unit
  The GSM Module that will be used for this project is the SIM800 modem. It is so called because it has a SIM800 GSM chip and RS232 interface that enables easy connection with the computer or laptop using the USB to Serial connector. The purpose of the G S M module in this project is to send an emergency message to a predefined number when the holder of the system is in trouble, mostly in case of fire outbreak or when in a moist environment. This whole process is made possible through the program that will be loaded on the microcontroller.

• G P S Unit
  GPS stands for Global Positioning System, it enables one to easily obtain the position information anywhere in the world. The purpose of this unit is to locate the current position or location of the holder of the system during emergency, this module is linked with the G S M unit such that when the coordinate of the location is determined, the G S M module automatically sends these coordinates to a predefined number indicating that the holder of the system is in danger or needs help.

• Microcontroller Unit
  A Microcontroller is a tiny computer on a single chip, it can also termed as a control device Similar to a computer, the Microcontroller is made with a variety of peripherals such as the input & output units, memory, timers, serial data communications and most of all, it is programmable.
  As related to this project work, i will use the ATMEGA 8 microcontroller because it is not difficult to program, the microcontroller is responsible for the control of all other components interfaced with it. This unit is the decision making unit of the Guidance and Emergency System for the Blind. The unit is interfaced conveniently with the G S M unit, G P S unit, Ultrasonic Sensing Unit, Smoke detection Unit and the Power Supply Unit.

• Smoke Sensing Unit
  The (MQ-2) smoke sensor is a device that senses smoke, as a typical indicator of fire. The mode of operation is through a small amount of radioactive material between two electrically charged plates, which ionizes the air and causes current to flow between the plates. When smoke enters the chamber, it disrupts the flow of ions, thus reducing the flow of current and sends signals to the microcontroller which activates the Buzzer.

• Power Supply Unit
  The power supply unit comprises of a 12V, 2 A DC battery, a 1 microfarad capacitor and a 5V regulator (7805). The power supply unit was designed for the purpose of providing sufficient voltage to all other units of the system. The Circuit diagram of the power supply unit is shown in the figure below.

• Buzzer Unit
  A buzzer or beeper is an audio signaling device, which may be mechanical, electromechanical, or piezoelectric. It is used to give out audio signals, it comprises of a coil and a moving electrical contact. When the coil is energized, the contact is pulled toward the coil, but this breaks the circuit and the contact rapidly moves back to its original position giving out a loud buzzig sound. The essence of the buzzer in this project is to give a feedback signal to the user, indicating that there is an obstacle ahead.

• Humidity Sensing Unit
  Humidity sensor, also known as Hygrometer is usually incorporated with two different functionalities; it senses and measures the moisture content and temperature of an environment. The purpose of this sensor is for humidity sensing in order to indicate moist environment, preventing the user from slipping or falling into water.

This research work is a personal project i've been working on for a couple of weeks now and i've found out that similar projects had been done in the past. This is my own version, a different approach and modification of already existing ideas. My intention for this project is to fabricate a prototype that can be developed and reproduced so it can serve as support for the visually challenged/blind people.
The assembly of all the above mentioned components had been simulated using Proteus simulation program and the result is shown below.

From the diagram above, the GSM and GPS modules were not directly connected to the microcontroller, this is because the output voltage of the microcontroller is too low and will not be able to power these modules, therfore a voltave regulator was introduced into the circuit in order to increase the voltage going into the GSM and GPS module for proper funcionality.

Limitation

The GES is designed as a support system for the blind, it is not 100% efficient as no system can operate with efficiency of 100%. The system still has some limitations, the limitation i've identified here is that it won't be able to detect overhead obstacles as well as obstacles that the upper body region are liable to come across.

Note:

Images whose sources were not indicated were personally designed by me.

References

Reference 1

Reference 2

Reference 3

[4]. M. F. Saaid, A. M. Mohammad, and M. S. A. M. Ali, “Smart cane with range notification for blind people,” Proc. - 2016 IEEE Int. Conf. Autom. Control Intell. Syst. I2CACIS 2016, no. october, pp. 225–229, 2017.

[5]. M. S. R. Tanveer, M. M. A. Hashem, and M. K. Hossain, “Android assistant EyeMate for blind and blind tracker,” 2015 18th Int. Conf. Comput. Inf. Technol. ICCIT 2015, pp. 266–271, 2016.

[6]. N. B. James, “Navigati0n Aidin ng Stick for the Visuall ly Impaired,” no. iv, pp. 1254–1257, 2015.

[7]. Y. Niitsu, T. Taniguchi, and K. Kawashima, “Detection and notificati0n of dangerous obstacles and places for visually impaired persons using a smart cane,” 2014 7th Int. Conf. Mob. Comput. Ubiquitous Networking, ICMU 2014, pp. 68–69, 2014.

[8]. N. Agarwal, A. Iyer, S. Naidu, and S. Rodrigues, “Electronic guidance system for the visually impaired - A framew0rk,” Proc. - Int. Conf. Technol. Sustain. Dev. ICTSD 2015, pp. 2–6, 2015.

[9]. M. Varghese, S. S. Manohar, K. Rodrigues, V. Kodkani, and S. Pendse, “The smart guide cane: An enhanced walking cane for assisting the visually challenged,” Proc. - Int. Conf. Technol. Sustain. Dev. ICTSD 2015, v0l. 1, pp. 0–4, 2015.

[10]. R. K. Megalingam, A. Nambissan, A. Thambi, A. Gopinath, and K. Megha, “Sound- and Touch-Based Smart Cane: Better Walking Experience for Visually Challenged,” Adv. Intell. Syst. Comput., vol. 308 AISC, no. VOLUME 1, pp. 589–595, 2015.

[11]. L. D. Dunai, I. L. Lengua, I. Tortajada, and F. B. Simon, “Obstacle detectors for visually impaired people,” 2014 Int. Conf. Optim. Electr. Electron. Equipment, OPTIM 2014, no. 1975, pp. 809–816, 2014.