chapter 1

CHAPTER ONE

1.0

INTRODUCTION

Technology is the making, modification, modification, usage usag e and knowledge of tools, machines, techniques, crafts, systems, methods of organization in order to solve a problem, problem, improve a preexisting solution to the problem, achieve a goal or perform a specific function. It can also be referred to the collection of such tools, machinery, modifications, arrangements and procedures. Technologies significantly affect human as well as other animal species' ability to control and adap adaptt to to thei theirr natu natura rall env envir iron onm ments ents.. The The term term can can eith either er be a p p l i e d g e n e r a l l y o r t o specific areas: exampl examples es include

construction

information information technology. Visual impairment is

technology,

medical technology, and

the loss of vision (of a person) or a

significant limitation of visual capability resulting from either

disease,

trauma,

or

congenital or degenerative conditions that cannot be corrected by conventional means, such

as

refractive refractive

correction,

medication,

or surgery. The following following terms are used to

describe the different levels of visual impairment: Partially sighted which occurs as a result of some type of visual problems. Low vision generally refers to a severe visual impairment, not necessarily necessarily limited to distance vision. Low vision applies to all individuals individuals who are unable to read the newspaper at a normal viewing viewing distance, even with the aid of eyeglasses or contact lenses. This can also be divided into two levels: Myopic - unable to see distant objects clearly, commonly called nearsighted or short- sighted, Hyperopic - unable to see close objects clearly, commonly called far-sighted or long-sighted. Blindness is a total or  partial inability to see due to some some physiological or neurological deficits. The levels of  blindness are scaled according to the extent extent of vision loss. los s. A situation where one is unable to see forms or sense light is referred to as total blindness. The following are a few eye disorders which can lead to visual impairments; retinal degeneration, albinism, cataracts, and

glaucoma, muscular problems that result in visual disturbances, corneal disorders, diabetic retinopathy, congenital disorders, and infection. For a visually impaired person to navigate an environment without human assistance, the person must have adequate information about the travel path and also be able to detect obstacles with with in his/her navigation range. Without any form of assistance, most visually impaired people have to stress their other senses mostly the ears in an attempt to detect any possible obstacles in their path. Visually impaired individuals have a very important goal of moving through unfamiliar spaces or situations without any form of aid. For easy movement in both familiar and unfamiliar environments, there are various various

methods methods d e v i s e d to aid aid visually visually

impaired impaired

individua individuals, ls,

examples of these methods are the use of walking canes, use of guide dogs which assist in navigation or by the help of another human with perfect sight. However, some of these methods have their shortcomings in terms of their efficiency. For example, the ordinary walking stick is unable to detect obstacles in its path except by direct contact with the obstacle. Also, the use of guide dogs is limited to environments the dog has been trained to navigate and any deviation from this trained environment will be dangerous to the individual. Human guides can be a letdown at times because the guide might not be available at the time his help is needed. This impedes the movement of the visually impaired person. All these shortcomings of some of the existing aids are the reason for developing an electronic walking aid that can help the visually impaired to navigate any environment without straining their other sense organs or depend on human guide. This is achieved through implementation of design which which is capable of detecting obstacles in the navigation path and indicates the direction of the obstacles to prevent the user of the walking aid from coming in contact with the obstacles and hence preventing accidents.

1.1 BACKGROUND OF THE STUDY

Vision is the most important part of human physiology as 83% of information human being gets from the environment is via sight. The 2011 statistics by the World Health Organization (WHO) estimates that there are 285 million people in world with visual impairment, 39 billion of which are blind and 246 with low vision. The traditional and oldest mobility aids for persons with visual impairments are the walking cane (also called white cane or stick) and guide dogs. The most important drawbacks of these aids are necessary skills and training phase, range of motion and very little information conveyed. With the rapid advances of modern technology, both in hardware and software front have brought potential to provide intelligent navigation capabilities. Recently there has been a lot of Electronic Travel Aids (ETA) designed and devised to help the blind navigate independently and safely. Also high-end technological solutions have been introduced recently to help blind persons to navigate independently. Many blind guidance systems use ultrasound because of its immunity to the environmental noise. Another reason why ultrasonic is  popular is that the technology is relatively inexpensive, and also ultrasound emitters and detectors are small enough to be carried without the need for complex circuit. Blind people have used canes as mobility tools for centuries, but it was not until after World War I that the white cane was introduced.

1.2

STATEMENT OF THE PROBLEMS

Many blind persons use the white stick to help their daily movement. The stick helps them to detect obstructions around them and to avoid them from danger. The function of the common walking stick usually used by the blind is limited. Therefore, there is need to develop a new walking stick that can detect any obstacles before the user hit it with the end of the stick.

1.3

AIMS AND OBJECTIVES OF THE RESEARCH

The objective of this project is to develop a smart walking stick that can sense obstacles around the visually impaired person. The walking stick will be able to sense different distances between the user and the obstacles for up to 120 cm long. In addition, the objective of this project is also to help the movement of blind person in their daily activities. Nevertheless, this project also targets to develop a low cost, study and robust walking stick.

This project will fulfill the following objectives;

1. To design an assistive technology for visually impaired people which can detect obstacles and provide alternative ways 2. To alarm the user through speech (earphone/headphone) and vibration to determine the obstacles direction sources. 3. To build low cost blind navigation using Arduino with 1sheeld to connect to smartphone.

1.4 SIGNIFICANCE OF THE STUDY 

To enhance the mobility of blind people.



Protecting blind people from possible hazard



Less costly product will be affordable for many people.



The system can be used both indoor and outdoor navigation.



Blind person’s location can be track ed ed whenever needed which will ensure additional safety.



Detects obstacles and alerts the blind person through vibration alert and speech output.

1.5 DEFINITION OF TERMS

Ultrasonic Sensor: Ultrasonic sensor provides a very low-cost and easy method of distance

measurement. This sensor is perfect for any number of applications that require you to perform measurements between moving or stationary objects. Naturally, robotics applications are very  popular but you'll also find this product to be useful in security systems or as an infrared replacement if so desired. Microcontroller (ATMEGA328):A microcontroller (sometimes abbreviated µC, uC or MCU) is

a small computer on a single integrated circuit containing a processor core, memory, and  programmable input/output input/output peripherals. peripherals. Vibration: a movement back and forth, or an emotion sensed by another person. An example of a

vibration is vibration is the feeling of two cymbals being. Sensor: a mechanical device sensitive to light, temperature, radiation level, or the like, that

transmits a signal to a measuring or control instrument. Visualization: Visualization is Visualization is the process of representing abstract business or scientific data as

images that can aid in understanding the meaning  of  of the data Blind: the state or condition of being unable to see because of injury, disease, or a congenital

condition. Obstruction: something that obstructs, blocks, or closes up with an obstacle or obstacles; obstacle

or hindrance:

1.6 CHAPTER SUMMARY

Chapter one covers the introduction, background, statement of problem, aims and objectives, significance of the study, scope and limitations of the study and definition of terms. Chapter two covers the literature review and the review of related works. Chapter three covers the methods of data collection and the materials used for the work. Chapter four covers the implementation, implementation, Results and analysis of project. Chapter five covers the conclusion, summary summary and recommendation recommendation

CHAPTER TWO 2.0 LITERATURE REVIEW

Traditionally ultrasonic walking stick is the most popular, simplest tool for detecting obstacles due to its low cost, portability. It enables user to effectively scan the area in front and detect obstacles on the ground like holes, steps, walls, uneven surfaces, downstairs etc .but it can only  be used to detect obstacles up to knee-level. Its detection range is limited up to 1-2 feet only. Certain obstacles (e.g. protruding windowpanes, raised platforms, a moving vehicle, horizontal  bars) cannot be detected until they are dangerously close to the person. person. Even dog guides guides are very capable to guide these persons but they are unable to detect potentially hazardous obstacles at head level. Several solutions have been proposed in the recent years to increase the mobility and safety of visually impaired persons. It uses sonar technology to identify the position of user by mounting ultrasonic ultrasonic modules on ceiling at regular intervals. intervals. This system is portable, easy to operate and is not affected by environmental changes. However, this system is limited only for indoor navigation navigation because it requires detailed detailed interior map of the building. Another real-time technology developed to alert visually impaired user by the presence of static / dynamic obstacles in a few meters surrounding, which works without depending on any Smartphone, uses camera for background motion detection. This system is robust to complex camera and  background motion and does not required any prior knowledge about the obstacle size, shape or  position. This camera-based camera-based image processing system can be a better option but it requires lot  processing power power and hence system system becomes bulky, bulky, costly and and it must be transportable. transportable.

2.1 REVIEW OF RELATED LITERATURES

Voice operated outdoor navigation system for visually impaired persons done by Somnath and Ravi (2012). Uses a stick equipped with ultra-sonic sensors, GPS and audio output system. The

stick contains GPS which will have SD memory card which used to store different locations.

The user  can set the location by voice and the GPS will guide the person to his/her distention. This system will also provide the speed and the remaining distance to reach the distention. When the ultra-sonic sensors detect any obstacle directly the voice system will activate the caution voice. This system can be classified as a low cost system affordable by the user. In addition to that, it can provide a voice guide for the user with greatest possible accuracy. The system uses the ARM processor which has more memory space, so that the operating speed is high. However, this system cannot operate indoors because there will be no signal for the GPS system. The accuracy of the GPS signal need to be improved because it only can be controlled within 5 meters radios. Finally, the blind person needs to be trained on the

system so that he or she can use it effectively.

“Blind  “Blind  audio Guidance system”  system”  is based on embedded system, uses ultrasonic sensor for distance measurement, IR sensor for object detection and AVR sound system for  audio instructions. The main functions of this system are environment recognition and path detection. Ultrasonic sensors receive visual information and this visual information is transformed into auditory information. To represent the information about the position of obstacles audio components

of

intensity,

frequency,

binaural

phase

difference are used. This signal

transformation system reduces the training time required to use a white cane. However, only issue of this system is the difficulty to know one’s location one’s location globally.

Another study in the same field to help blind people uses the  pulse echo technique in order to  provide a warning sound when detecting the obstacles. This technique is used by the United States military for locating the submarines. They used pulse of  ultrasound range from 21 KHz to 50 KHz which hit the hard surface to generate echo pulses. By calculating the difference  between signals transmit time and signal receiving time we can  predict the distance between the

user and the obstacles. This system is very sensitive in terms of detecting the obstacles. It has a detection range up to 3 meters and a detection angle 0 to 45 degree. However, this system requires more power to operate because of the transmitter and receiver circuits. So, this system needs to be re-designed to operate with less power consumption. Anon, N.D.

Another study done by Jayant, Pratik and Mita, ( 2012) proposed a smart smart cane assisted assisted mobility for the visually impaired. The system is based on normal ultrasonic sensors and ATMEL microcontroller. It operates with two rechargeable  battery (7.4v) it can be rechar recharged ged using USB cable or AC adaptor. The control unit is programed using ATMEL AVR  microcontroller ATMEGA328P microcontroller. Once any obstacles are detected vibration and  buzzer will start start in order to warn the user. This system is a non-complex system to use. It has the ability to cover a distance up to 3 meters and has the rechargeable feature of the battery. Also, this system can be folded in small piece so that the user can carry it easily. However, this system has only one direction detection coverage and it is inaccurate in detecting the obstacles.

All the studies which had been reviewed show that, there are many techniques of making a smart sticks for blind people. However, the study conclusion shows that, using the ultrasonic sensors would be an efficient solution to detect the obstacles with maximum range of 10cm and 45 degree degree coverage

CHAPTER THREE METHODOLOGY

3.1 DEFINITION OF METHODOLOGY METHODOLOGY

Research methodology is the study of how to perform scientific research. It is part of any analysis or research that is used to find out about the type of data that is to  be maintain, how it is found, how it is operate and how it is recorded. With this structured system analysis and design methodology which is internationally accepted software engineering model, I was able to achieve a wonderful hardware design which is one of main purpose of embarking on this project.

3.2 MATERIALS USED 3.2.1 Ultrasonic Range Sensor

Ultrasonic Sensor Ultrasonic sensors (also known as transceivers when they both send and receive) work on a principle similar to radar or sonar which evaluate attributes of a target by interpreting the echoes from radio or sound waves respectively. Ultrasonic sensors sensors generate high frequency sound waves and evaluate the echo which is received back by the sensor. Sensors calculate the time interval  between sending the signal and receiving the echo to determine the distance to an object. This technology can be used for measuring: wind speed and direction (anemometer), fullness of a tank and speed through air or water. For measuring speed or direction a device uses multiple detectors and calculates the speed from the relative distances to particulates in the air or water. To measure the amount of liquid in a tank, the sensor measures the distance to the surface of the fluid. Further applications include: humidifiers, sonar, medical ultra sonography, burglar alarms and non-destructive testing. Systems typically use a transducer which generates sound waves in the ultrasonic range, above 18,000 hertz, by turning electrical

energy into sound, then upon receiving the echo turn the sound waves into electrical energy which can be measured and displayed. The technology is limited  by the shapes of surfaces and the density or consistency of the material. For example foam on the surface of a fluid in a tank could distort a reading.

Ultrasonic Sensor 3.2.2 Microcontroller (Promini Arduino)

The Arduino Pro Mini is an ATmega168 based microcontroller board. The board comes with built-in arduino bootloader. It has 14 digital input/output pins (of which 6 can be used as PWM outputs), 8 analog inputs, an on-board resonator, a reset button, and holes for mounting pin headers. The board can be connected to the PC using USB port and the board can runs on USB power. There are two version of the Pro Mini. One runs at 3.3V and 8 MHz, the other at 5V and 16MHz

Diagram of an Arduino pro mini

Arduino Pro Mini DETAILS

Microcontroller

ATmega168

Operating Voltage

3.3V or 5V

Input Voltage

3.35 -12 V (3.3V model) or 5 - 12 V (5V model)

Digital I/O Pins

14 (of which 6 provide PWM output)

Analog Input Pins

8

DC Current per I/O Pin

40 Ma

Flash Memory

16 KB (of which 2 KB used by  bootloader)

SRAM

1 KB

EEPROM

512 bytes

Clock Speed

8 MHz (3.3V model) or 16 MHz (5V model)

Arduino Pro Mini PINOUT

RAW

For supplying a raw (regulated) voltage to the board

VCC

The regulated 3.3 or 5 volt supply

GND

Ground pins

RX

Used to receive TTL serial data

TX

Used to transmit TTL serial data Digital I/O pins. These pins can also be

2 and 3

configured to trigger an interrupt on a low value, a rising or falling edge, or a change in value

3, 5, 6, 9, 10, and 11

Digital I/O pins. They can also be configured to provide 8-bit PWM output Digital I/O pins. They can also be

10, 11, 12 and 13

configured as SPI pins; 10 - (SS), 11 - (MOSI), 12 - (MISO) and 13 - (SCK)

A0 to A3

Analog input pins Analog input pins. They can also be

A4 and A5.

used as IIC pins; A4 - (SDA) and A5 –  A5 –  (SCL).  (SCL).

A6 and A7

Analog input pins

Reset

The microcontroller microcontroller can be reset by

 bringing this pin low

3.2.3 Voltage Regulator

This is the basic LM7805 voltage regulator, a three-terminal positive regulator with a 5V fixed output voltage. This fixed regulator provides a local regulation, internal current limiting, thermal shut-down control, and safe area protection for your project. Each one of these voltage regulators can output a max current of 1.5A. The

LM7805,

like

most

other

regulators,

is

a

three-pin

IC.

Pin 1 (Input Pin): The Input pin is the pin that accepts the incoming DC voltage,

which the voltage regulator will eventually regulate down to 5 volts. Pin 2 (Ground): Ground pin establishes the

ground for the regulator.

Pin 3 (Output Pin): The Output pin is the regulated 5 volts DC.

Diagram of LM7805

3.2.4 BUZZER 

The Piezo buzzer produces sound based on reverse of the piezoelectric effect. The generation of pressure variation or strain by the application of electric  potential across across a piezoelectric piezoelectric material material is the underlying underlying principle. principle. These These buzzers

can be used to alert a user of an event corresponding corresponding to a switching action, counter signal or sensor input. They are also used in alarm circuits. The buzzer produces a same noisy sound irrespective of the voltage variation applied to it. It consists of piezo crystals between two conductors. When a  potential is applied across these crystals crystals they push on one conductor and pull on the other. This, push and pull action, results in a sound wave. Most buzzers  produce sound in the range 2 to 4 kHz.

Diagram of Buzzer

3.2.5 LED

LED A light-emitting diode (LED) is a semiconductor light source. LEDs are used as indicator lamps in many devices, and are increasingly used for lighting. When a light-emitting diode is forward biased (switched on), electrons are able to recombine with holes within the device, releasing energy in the form of photons.

Diagram of LEDS

3.2.6 VIBRATOR MOTOR

A vibrating motor is essentially a motor that is improperly balanced. In other words, there is an off-centered weight attached to the motor's rotational shaft that causes the motor to wobble. The amount of wobble can be changed by the amount of weight that you attach, the weight's distance from the shaft, and the speed at which the motor spins.

3.2.1 INSTRUMENT FOR DATA COLLECTION

Data collection  can be defined as any collection of data either by interview

method or by reference to written text which enables the software developer to have the necessary information required in the development of aparticular software and also to enable him updates his database. The data may be in the form of text, numbers, or encoded graphics. There are two methods of collecting data which are:



Primary Data Collection

The idea of the proposed system came into existence because of a short visit to a  blind school. It was seen that the individuals were given training to walk with a stick along a fixed path every day with a person to guide each of them. The inception of the project was marked by the conversations held with the blind  people in the school and their staff. The data collected was indicative of the facts and miseries of their daily life. The visual disability made them incapable of doing any kind of simple chores independently. This laid us to research on the already existing technologies and conduct literature survey. The existing systems as highlighted above had some disadvantages so we have tried to design a system which aims to eliminate few of the disadvantages.



Secondary Data Collection

information obtained through through secondary sources which include data collected collected for  published

and unpublished

journals, books , magazines etc it also

include

information gotten from the internet that were not originally collected by the researcher . Data collection of this type, however lack originality because of high

 probability of information being out of date out and might not suit the need at hand. The method of data collection used for the success of this research 

Reference to written text



Website research



Library research



Reference to Written Text

Reference was also made to some existing documents; some materials were also downloaded from internet for reviewing the work. 

Website Research:

Different document on the World Wide Web (www) were reviewed to find information, which was essential in writing the chapters and software design. 

Library Research:

Book, journals and magazines were reviewed to collect all necessary information, which were also used in writing this seminar work.

CHAPTER FOUR TESTING

The following tests were carried out to determine the different responses of the components that make make up the th e Navigation Navigation auxiliary auxiliary for the visually impaired impaired

Obstruction Detection Test

With the ultrasonic transmitter (TX) fixed on

the model model board and the

ultrasonic receiver (RX), the microcontroller is connected along with LED, the Motor vibrator and the Buzzer to indicate the distance and presence of an obstacle respectively if any

is detected.

These components components are powered

from the 5V supply of the voltage regulator. An obstacle was put in front of the sensor, and it was observed that the LED turned on when the obstacle was  put in front also the vibrator vi brator motor vibrates and the buzzer blew and alarm to alert the presence of an obstacle.

Light Detection Test

The light dependent resistor is connected to a 100K resistor in a voltage divider network. The LDR is a variable resistor that has high resistance in low light conditions and low resistance in welllit situations. The LEDs are connected to a transistor that is switched on when the voltage divider network (LDR included) generates the voltage required to turn on the LEDs. This circuit arrangement was taken to a dark room with low light intensity, and it was observed that the LEDs were turned on and when the fluorescent tubes of the room were turned on, the LEDs LEDs turned off. This indicates indicates that that the LED LEDss are turned on based b ased on the intensity of light detected by the LDR circuit.

CHAPTER FIVE

EXPECTATION

The ultrasonic stick system is mainly aiming at novel approach towards designing and developing a blind walking stick in order to assist blind person to move on different surface and in different path. By the means of creating fusion between visual sensing technologies, object finding technology and the voice guidance technology.

CONCLUSION

The advancement of walking stick for the blind can be implemented using several ways of distance measurement detection. Ultrasonic range sensor and infrared sensor are examples of sensors that are appropriate for the system. However, ultrasonic range sensor is more suitable to be implemented due to several factors. The ultrasonic range sensor is used in this project because it is small, light in weight and consumer less power compared to infrared sensor. It also is less affected by some materials or by colour. The infrared sensor is easily affected by sunlight and dark materials. Besides, it is capable of detecting objects within 100cm. The ultrasonic sensors used in this project are placed at above-knee and belowknee positions to detect the obstacles in the user path. This method is very helpful for the blind especially when they are moving alone for outdoor activities