View
217
Download
0
Category
Preview:
Citation preview
7/27/2019 Final Write Up_1
1/26
BLIND MANS SUPPORT
ABSTRACT
Our group made this device to help and developed miniaturized, wearable sensor device
that will enhance the safety of persons who are visually impaired. The device warns the users
when they are about to hit an obstacle at head level and on their path. The sensor which uses two
ultrasonic transducers for obstacle localization which is attached at the users cup and the other
sensor can be worn at the wrist.
Care of each developer was performed in making this device to optimize the functionality
of the work in terms of accuracy and detection.
7/27/2019 Final Write Up_1
2/26
BLIND MANS SUPPORT
CHAPTER I
INTRODUCTION
This project deals with creating a device that will help visually impaired people so that
they will have an additional security and comfort in doing their everyday task. This device is
made of ultrasonic transducers, dc vibrating motor that will give signals when there is a possible
collision and an arduino compatible board.
The ultrasonic sensor releases short burst of ultrasonic sound wave and then outputs a
pulse as soon as a returning echo is detected. The distance range detectable by the ultrasonicsensor (US-100) is 2cm350cm but we have set this to 100cm or 1m. As soon as an obstacle is
detected the ultrasonic sensor will send signals to the arduino board and this will read the data
and will drive the dc vibrating motor to vibrate and to the buzzer to give signal to the visually
impaired user that he/she is about to hit an obstacle.
1.1BACKGROUND OF STUDY
It is estimated that half a million of people in the Philippines are blind and this is number
is very surprising. By far, the leading cause of blindness among adults in the Philippines is
cataract accounting for around 400,000 cases. The treatment for cataract is simple and effective
but it is not readily available and affordable for those who are living in some rural areas and
remote places.
One hundred children lose their sight every week and almost half of these are either
treatable or preventable. Poor nutrition, measles and premature birth are the leading causes of
blindness of children.
7/27/2019 Final Write Up_1
3/26
BLIND MANS SUPPORT
This are certain facts that presents the state and numbers of visually impaired individuals
in the Philippines and even it is treatable by the help of modern technology and medicine, not all
individuals have the ability to have their proper treatment.
Some untreated visually impaired individuals uses canes, dog guide and some are just
handled and guided by their relative. But the two things mentioned have certain limitations in
preventing collisions. Using canes does not protect individuals in obstacles at head level while
some dog guide users experience traumatic incidences.
Being visually impaired is a difficult situation, so our group developed this device as an
additional help to those who are visually impaired and to give them the assurance of secured
walk outside and to protect them from head level obstacles.
1.2DESCRIPTION OF THE PROJECT
This device will protect individuals with head level obstacles and obstacles on their path.
With respect to existing Electronic Travel Aids, this device is minimalistic and can be
comfortably worn by individuals. This device adds protection to individuals who uses canes
because cane cannot protect blind users against head level obstacles such as tree branches, etc.
The device will be worn using cup and the other sensor is attached to the individuals
wrist and the circuit board can be attached to the users arm. As opposed to Electronic Travel
Aids using ultrasonic sensors, infrared lights and GPS technology, this device provides a
feedback just enough to ensure that the user can avoid a potentially painful collision. ETAs
using infrared lights is cheap but not that accurate specially when walking outside with the
presence of lights. GPS technology was also used in other travel aids but this is too expensive for
individuals who are living in remote places.
The device we made is affordable by the individuals in rural and remote places but the
accuracy and functionality of the device is same with some existing travel aids.
7/27/2019 Final Write Up_1
4/26
BLIND MANS SUPPORT
1.3FUNCTIONS
The main function of the device is to give signal to the visually impaired users when an
obstacle is on their path. The sensor is attached to the users cup to protect the wearers head
against collision.
The device we made is divided into two systems that work like human body. The heart of
the device us the ultrasonic sensor that would be used as a distance detector, the sensor releases
sound waves and then sends a pulse as soon as a returning echo is detected. As the returning
echo was detected, it will be sent to the arduino compatible board. The arduino compatible board
is primarily made up of Atmel Mega 328, and this serves as the brain of the system. The arduino
reads the data sent by the sensor and when the sensor detects a possible obstacle, this will send
enough signals to energize the dc vibrating motor and buzzer to give an alarm to the user.
1.4ON OUR FIRST PROJECT
This project deals with creating a device that will help visually impaired people so that
they will have an additional security and comfort in doing their everyday task. This device is
made of ultrasonic transducers, op amp, decade counter and earphone that will give signals
when there is a possible collision at head and eye level obstacles.
The ultrasonic sensor releases short burst of ultrasonic sound wave and then outputs a
pulse as soon as a returning echo is detected. The distance range detectable by the device is 2cm
350cm. As soon as an obstacle is detected the ultrasonic sensor will send signals to the receiver
transducer. The 40 kHz ultrasonic signal are converted into 40 kHz electric signals by the
receiver and amplified by transistor T3 and T4. The device have a decade counter IC4017 to
make 40 kHz be converted to 4 kHz signal which is fed to op-amp IC741 which is wired as an
earphone amplifier to give signal to the visually impaired user.
7/27/2019 Final Write Up_1
5/26
BLIND MANS SUPPORT
The main function of the device is to give signal to the visually impaired users when an
obstacle is on their path. The sensor is attached to the users eyeglass to protect individuals head
and eye against collision.
The main part of the device is the ultrasonic sensor (US-100), this works at the frequency
of 40 kHz and it is temperature compensated so it gives an accurate signal even there is a change
with the environment temperature. The ultrasonic sensor is divided into two parts the transmitter
which emits 40 kHz sound and receiver which receives 40 kHz sound and converts it into
electrical variation of the same frequency.
The device also has certain transistors T1 and T2 which serves as a 40 kHz oscillator.
When there is an obstruction detected in front of ultrasonic transmitter, some signals will be
reflected back and sensed by the ultrasonic receiver. This 40 kHz ultrasonic signal will be
converted into 40 kHz electrical signals by the receiver and then amplified by transistors T3 and
T4.
To make an audible sound out of 40 kHz electric signal, we put a decade counter IC4017
(IC1) which is a frequency divider which is connected at the output of the amplifier. This
CMOS IC4017 divides the input frequency by 10 so the 40 kHz signal becomes 4 kHz, which is
enough to have an audible range of sound. This 4 kHz signals are then fed to op-amp IC741
(IC2), which is wired as an earphone amplifier.
This device is powered with a 9V DC rechargeable battery which is also attached to a
case together with the circuit board. With this device it can give an enough signal that will enable
the user to avoid head and eye level obstructions.
Due to the unwanted results because we cannot set the detected area the ultrasonic sensor
continuously sends data to the decade counter and op-amp which results for a continuous output
of sound alarm that might irritates the user. So we have decided to make some research to make
this device a more user-friendly. Then we come up to the idea of using microcontroller to make
this a user friendly and more accurate device.
7/27/2019 Final Write Up_1
6/26
BLIND MANS SUPPORT
1.5INNOVATIONS ADDED
The innovation added to this device is the usage of two ultrasonic sensors instead of
using one to help protect the user more. We also make an arduino compatible board instead of
buying a kit which causes for almost Php1000.00+ (the original arduino board) though there are
available compatible boards in the market like the Gizduino which causes Php 600.00+ it is still
not that good for us because we want to make this device affordable so we have decided to make
one compatible board for this project since there are lot of references and sources on the net
showing tutorials on making compatible boards.
We have use an arduino compatible board to minimize the use of other components and
to maintain the minimalistic look of the device so that the device will be small and more
comfortable to wear by the user. Arduino board is use not just to drive with the latest technology
but to explore its ability in this project.
On the first project, which is composed of some capacitors, transistors and integrated
circuit this is eliminated with our second project, so that we could make this device more
minimalist.
With the sensor used, we created this device using Ultrasonic Sensor also known as sonar
instead of concentrating on Infrared LED lights though it is cheaper but we do not want to
sacrifice the accuracy of the distance range. Infrared LED lights has a smaller scale of detectable
distance and not so accurate specially when walking outside with the presence of lights.
The device is composed of two sensors with different alarm signals to help the user easily
determine where the obstacle is. The first sensors alarm is a dc vibrating motor; we got one from
our scrap Nokia 5310 phone. This is attached to the users wrist with the ultrasonic sensor.
The second sensor uses a buzzer as alarm. We have use a buzzer because our major focus
on making this device is to protect head level injuries. And this alarm signal will easily detected
by the user since it has an audible sound output. We have also attached two LED lights just to
7/27/2019 Final Write Up_1
7/26
BLIND MANS SUPPORT
determine if the device really works. The green LED indicates a power on the device and the red
LED lights when an obstruction is detected at head level.
This device is supplied with a 9V rechargeable battery attached to the case together with
the circuit board. With this device we believe that it can help visually impaired people lessen
their worries walking outside and doing their everyday task.
7/27/2019 Final Write Up_1
8/26
BLIND MANS SUPPORT
CHAPTER II
SCHEMATIC DIAGRAMS
FIRST PROJECT
ORIGINAL CIRCUIT
ORIGINAL DEVICE
7/27/2019 Final Write Up_1
9/26
BLIND MANS SUPPORT
INNOVATED DEVICE
Block Diagram
Ultrasonic Sensor (US-100)
Innovated Circuit
40KHz
OSCILLATOR
40KHz
AMPLIFIER
FREQUENCY
DIVIDER
AF
AMPLIFIER
EAR
PHONE
TX
1
RX
1
7/27/2019 Final Write Up_1
10/26
BLIND MANS SUPPORT
SECOND PROJECT
ORIGINAL CIRCUIT
DIY ARDUINO BOARD
- Source: Gizduino facebook page
7/27/2019 Final Write Up_1
11/26
BLIND MANS SUPPORT
7/27/2019 Final Write Up_1
12/26
BLIND MANS SUPPORT
ORIGINAL DEVICE
DC Vibrating Motor with Arduino
Original Program Sketch
- Source: M ake Magazine
7/27/2019 Final Write Up_1
13/26
BLIND MANS SUPPORT
7/27/2019 Final Write Up_1
14/26
BLIND MANS SUPPORT
INNOVATED CIRCUIT
Arduino Compatible Board
7/27/2019 Final Write Up_1
15/26
BLIND MANS SUPPORT
INNOVATED DEVICE
- Two Ultrasonic Sensor, Vibrating Motor, LED and Buzzer connection with ArduinoCompatible Board
7/27/2019 Final Write Up_1
16/26
BLIND MANS SUPPORT
PROGRAM SKETCH
7/27/2019 Final Write Up_1
17/26
BLIND MANS SUPPORT
2.1 COMPARISON OF ORIGINAL AND INNOVATED DEVICE
On the first project we have done, we change the infrared LED to ultrasonic
sensor to make this more accurate. Infrared LED is cheaper but detects a shortdistance unlike ultrasonic sensor although Infrared is used in obstacle detection it
is not recommended to use as proximity detection with exact range. The ultrasonicsensor (US -100) is temperature compensated therefore it is accurate even the
temperature outside changes.
The alarm signal could be hear through an earphone we didnt use buzzer
with this application because we think that it is more applicable to use outside so
that other people wont be affected with the noise given by the buzzer.
But because of the inconsistencies of this device, we have come up to the
idea that we need to upgrade this device through the use of microcontrollers. Wehave use arduino compatible board with ATMega 328, two ultrasonic sensor, dcvibrating motor and buzzer.
The original device with arduino is just a vibrating motor and the other
diagram shows an ultrasonic sensor interface with arduino. We have used this twoto develop our device.
This resulted to make our device more efficient, accurate and user friendly.
The device gives an alarm to the user once it detects an obstacle with a range of
100cm (1m). The two ultrasonic sensor is connected to the buzzer and vibratingmotor to give an alarm. While the two LED lights mounted at the casing indicatesthat the sensor at the users cup functions green LED light indicates that the sensor
work and the RED indicates that an obstacle of 1m is detected.
7/27/2019 Final Write Up_1
18/26
BLIND MANS SUPPORT
CHAPTER III
DIAGRAM AND COMPONENT LIST
FIRST PROJECT
3.1 PCB LAYOUT
3.2 PCB COMPONENT PLACEMENT GUIDE
7/27/2019 Final Write Up_1
19/26
BLIND MANS SUPPORT
3.3 COMPONENT LIST
3.4 COMPONENT PRICE LIST
7/27/2019 Final Write Up_1
20/26
BLIND MANS SUPPORT
SECOND PROJECT
3.1 PCB LAYOUT
3.2 PCB COMPONENT PLACEMENT GUIDE
7/27/2019 Final Write Up_1
21/26
BLIND MANS SUPPORT
3.3 COMPONENT LIST
3.4 COMPONENT PRICE LIST
7/27/2019 Final Write Up_1
22/26
BLIND MANS SUPPORT
CHAPTER IV
DOCUMENTATIONS
ON OUR FIRST PROJECT
7/27/2019 Final Write Up_1
23/26
BLIND MANS SUPPORT
ON OUR SECOND PROJECT
7/27/2019 Final Write Up_1
24/26
BLIND MANS SUPPORT
7/27/2019 Final Write Up_1
25/26
BLIND MANS SUPPORT
FINISH PROJECT WITH CASING
7/27/2019 Final Write Up_1
26/26
BLIND MANS SUPPORT
CHAPTER V
CONCLUSION AND RECOMMENDATIONS
We are thankful that our project was finished after the trial and errors that we have taken.
With this project we learned a lot of things about electronics; applications of decade counter and
op-amps, how does ultrasonic sensor functions, what is atmega328 and arduino. We have learned
also that the C language/programming we have could be applied in a lot of things.
Therefore our group concludes that these two devices could really help visually impaired
individuals to lessen their worries about walking outside and in doing their everyday task. The
second device is minimalistic and functional in all aspects.
This device could still be developed and be more functional. They can still add someadditional features like GPS to locate blind people and a lot more. And if this device be
developed more we could say that this device will really help and make the life of visually
impaired people easier.
Recommended