Bahir Dar University

Institute of Technology

School of Computing and Electrical Engineering

Department Of Electrical Engineering

Semester Project on
Car Collision Avoidance System

Done by

Advisor:
Dereje Mengist [233/02]
Mr. Habtemariam A.
Getaneh Tesfu [578/01]
Getu Zenebe [368/02]

Electrical and Computing Engineering (Power and Control)

February 2014
 Declaration of Authorship
We, Dereje Mengist, Getaneh Tesfu, and Getu Zenebe , declare that this project titled, ’
Car Collision Avoidance System’ and the work presented in it are our own. We confirm
that:

 This work was done wholly or mainly to semester project at this University.

 Where any part of this project has previously been submitted for a degree or any
other qualification at this University or any other institution, this has been clearly
stated. Where we have consulted the published work of others, this is always
clearly attributed.

 Where we have quoted from the work of others, the source is always given. With
the exception of such quotations, this project is entirely our own work. We have
acknowledged all main sources of help.

Authors: Signature: Supervisor: Signature:

Mr. Habtemariam A.
Dereje Mengist

Getaneh Tesfu P. Manager: Signature:

Mr. Edemialem G.
Getu Zenebe

Date: 17/02/2014 Date: 17/02/2014

It is approved that this thesis has been written in compliance with the formatting rules
laid down by the school of the university.
Examining Committe Members Signature Date

1. Chairman −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−

2. Examiner 1 −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−

3. Examiner 2−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−

i
”The beginning of knowledge is the discovery of something we do not understand”

(Frank Herbert)
 Abstract

Car accident avoidance is a system designed to help prevent collisions with vehicles
which are stationary or traveling in the same direction. Several studies have shown that
in this project driver distraction or inattentiveness is a factor in the great majority of
car accidents. Pre-crash sensing ultrasonic sensor is used to senses the obstacle in front
of the vehicle and gives the signal to the microcontroller. Based on the received signal
from the ultrasonic sensor the system works into two ranges. At first range If an obstacle
enter in the specified range it actuates the alerting system. At the second stage if the
obstacle more near to the car and if the driver does not give a response the system itself
automatically brake the pedal of the vehicle to avoid collision both at low speeds, typical
of urban driving, and at higher speeds typical of rural roads and highways.To do this
project we follow the following methodology. First we study different literatures related
car collision avoidance system and select required materials with their specification.
After that we design power and control circuit for materials based on their specification
and develop the microcontroller program. Finally by interfacing the hardware and the
software parts we construct the prototypes of the car collision avoidance system.
 Acknowledgements
We would like to thank the following people for their helps during this project work.
First, we would like to thank our advisor Mr. Habtemariam A, who helps us by giving
different ideas and correcting our miss takes depending on our project title. Secondly,
we would like to thank Mr. Girmaw A (Research method lecturer) for his help by given
Latex software and teaching us how to write our documentation by using this template,
which makes our documentation work easy and attractive. Finally, we also extend our
heartfelt thanks to our friends and well-wishers.

iv
Contents

Declaration of Authorship i

Abstract iii

Acknowledgements iv

List of Figures vii

Abbreviations viii

Physical Constants ix

Symbols x

1 Introduction 1
1.1 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Statement of the Problem . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.3 Objective . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.3.1 General Objective . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.3.2 Specific Objective . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.4 Scope and Limitation of the Project . . . . . . . . . . . . . . . . . . . . . 3
1.5 Significance of the Project . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.6 Methodology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.7 Organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2 Literature Review 6

3 Car Collision Avoidance System Description and Overall Operation 9

3.1 The Braking System Working Principle . . . . . . . . . . . . . . . . . . . 10
3.2 The Software parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.2.1 Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.2.2 Flow Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.2.3 Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
3.2.3.1 Main Program . . . . . . . . . . . . . . . . . . . . . . . . 14
3.2.3.2 Testing Program . . . . . . . . . . . . . . . . . . . . . . . 14

v
Contents vi

3.3 Selected Materials Description . . . . . . . . . . . . . . . . . . . . . . . . 14

3.4 Motor Controlling Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
3.5 Sensor Power Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
3.6 Buzzer Power Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
3.7 LED Controlling Circuit Diagram . . . . . . . . . . . . . . . . . . . . . . . 18
3.8 Main Control Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
3.9 Testing Control Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

4 Result and Discussion 21

5 Conclusion and Recommendation 22

5.1 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
5.2 Recommendation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Bibliography 23

Required Material 24
.1 Required Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Programs 25
.2 Testing Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
.3 Main Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
List of Figures

1.1 Methodology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

3.1 CCAS Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

3.2 Braking System Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . 11
3.3 Flow Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.4 Motor Control Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
3.5 Sensor Connection Diagram . . . . . . . . . . . . . . . . . . . . . . . . . 17
3.6 Buzzer Controlling Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . 18
3.7 LED Controlling Circuit Diagram . . . . . . . . . . . . . . . . . . . . . . 18
3.8 Main Controlling Circuit Diagram . . . . . . . . . . . . . . . . . . . . . . 19
3.9 Main Controlling Circuit Diagram . . . . . . . . . . . . . . . . . . . . . . 20

vii
Abbreviations

ABS Anti-Lock Braking System

AC Alternative Current
AEB Automatic Emergency Brake
CAS Collision Avoidance System
CCAS Car Collision Avoidance System
CC Cruise Control
DC Direct Current
EEPROM Electrically Erasable Programmable Read Only Memory
FMCW Frequency Modulated Continuous Wave
IMM Interacting Multiple Models
LED Light Emitted Diode
RAM Random Access Memory

viii
Physical Constants

Gravitational acceleration g = 9.81 ms−2

Sound Speed c = 340 ms−1

ix
Symbols

a Deceleration of the car -(ms−2 )

D distance m
E Efficiency
ft feet m
g acceleration of gravity (ms−2 )
P Power W (Js−1 )
Re effective radius of wheel i m
t Time s
T brake torque at wheel Kg(m2 s−2 )
W vehicle weight Kg(ms−2 )

x
Dedicated to Our Families

xi
Chapter 1

Introduction

1.1 Background

All the greatest achievements of the history, automobiles are most probably the one
which significantly changed human life. The periodical improvement in the technology
gives human race a new height. In the later years after the number of vehicles subse-
quently increased but in the last two decades it spreads drastically in every level of the
society hence safety becomes the main concern. Road accidents account a severe threat
to the lives in both ways physical as well as financial, even after digital control of the ve-
hicle. However, due to human avoidance, circumstantial error and negligence accidents
occur. Many people lost their life every year in vehicle collision majorly due to drivers
inability to keenly observe the vehicles vicinity while driving and in traffic condition.
The increasing number of traffic accidents in recent years has assumed the dimensions of
a serious social problem, making it imperative to find effective ways of reducing traffic
accidents and fatalities. As an initial step in this direction, it is important to identify
the elements of the problem through analysis of its mechanism. Traffic accidents involve
different processes according to where the accident occurs and in what situation the
collision occurs. Of the three main elements involved in an accident, i.e., the driver,
the vehicle and the environment, the main cause of accidents has been identified as the
driver. A common mode of accident occurs when two vehicles are traveling in the same
direction, one going behind the other. A rear-end collision is said to take place when
the second vehicle rams into the rear end of the vehicle in front of it. One of the most
frequent causes of rear-end accidents is the failure of a vehicle to maintain an assured
safe distance behind another vehicle to prevent a rear end collision, should the front
vehicle suddenly stop or slow down. The assured safe distance required to prevent such
a rear-end collision depends on the reaction time of the vehicle driver before the brake

1
Chapter 1. Introduction 2

pedal is actually depressed, and the braking distance traversed by the vehicle before it
comes to a complete stop after the brake pedal has been depressed. Both of these factors
vary according to the driver-vehicle-environment conditions at the time of driving. In
order to prevent collisions, many parameters which are constantly changing during the
year or even during a trip, and which may affect the stopping distance of the vehicle,
should therefore be taken into account. These parameters include the condition of the
driver, such as the driver’s reaction time; the condition of the vehicle, such as the vehicle
load, the condition of the brake system and the tires as well as the pressure of tires;
and environmental conditions, such as road type, visibility, and skidding conditions. A
very serious type of accident frequently takes place, especially in hot climates, when the
vehicle develops a flat tire at high speed. Now a day in our country the numbers of
people that die and get serious injuries due to car accident are increasing from time to
time, special in Addis Ababa twenty up to thirty properties distraction which expected
thousands birr, four up to seven easy and series injuries on human and two up to four
deaths happen daily. Our project work is focus on this collision avoidance system. As we
know total avoidance of an accident impossible, we need to reduce further the number
of accident problems and the use of new driver assistance systems will enable us to make
significant progress in this field. The goal we have defined is to make cars capable of
sensing, identifying and take solutions for problems before it occurs. As a consequence
for the medium term, driver assistance and communication systems will both be featured
as integrated vehicle modules to reduce traffic accidents significantly. CCAS is work into
two stages at first stage if an obstacle inter in the specified area it aimed at alerting
the driver by using alarm system or LED. At the second stage if the obstacle more
near the car and the driver does not response it takes a measure by its self by making
automatic mechanical braking, here in this project micro controller based CCAS with
ultrasonic object sensor and and servo motor for automatic mechanical braking which
used to avoid forward collision both at low speeds typical of urban driving, and at higher
speeds typical of rural roads and highway.

1.2 Statement of the Problem

Usually car collision may be due to carelessness of the drivers, drunkenness of the driver,
depression and sleepiness of the driver, whatever the case it is very series problem
through out the world specially in Ethiopia. Car collision accidents are very common in
our country specially in cities. For instance as we have gotten the information from Bahir
Dar Zone Traffic Police Commission Office report from august 7,2013 to January 8,2014
indicates that there are destruction of 120 properties and 85 people face easy physical
Chapter 1. Introduction 3

injuries,14 face series injuries and death of 10 people by car accident in Bahir Dar city.
There for CCAS is very important to reduced the current car collision accidents.

1.3 Objective

1.3.1 General Objective

The objective of this project is to design a car collision avoidance system in order to
alert the drivers and automatically break the system to prevent collision.

1.3.2 Specific Objective

The specific objective of this project is the following:

• To study possible methods of collision avoidance approaches

• To develop driver alerting system

• To develop automatic breaking system

• To design micro controller based CCAS

1.4 Scope and Limitation of the Project

The scope of our project is designing the driver alerting system and automatic braking
system of the vehicle to reduced car collision then constructing the prototype.
There are some limitations in car collision avoidance system. The first one is automatic
braking system of the vehicle driving with high speed may cause other problem. The
second limitation is the sensor does not used to detect the obstacle coming from a side.
The other limitation is when the traffic become crowded the alarm may be switched ON
even though the speed of the vehicle is slow.

1.5 Significance of the Project

The main significance of this system is to reduce car collision problems. Indirectly,
economical distraction, physical disability and human death or hazard will be reduced
compare to the current condition.
Chapter 1. Introduction 4

1.6 Methodology

The methodology we follow to do our project work will be as follows

Figure 1.1: Methodology

Chapter 1. Introduction 5

1.7 Organization

This project contains five chapters. The first chapter describes the introduction part
of the project with statement of the problem and its objectives. The second chapter
describes about literatures related to the car collision avoidance system. The third
chapter explains about system description and over all operation of the CCAS. The
fourth chapter describes the result and discussion of project prototype. The fifth chapter
deals about conclusion and recommendation.
Chapter 2

Literature Review

Multiple - Sensor - Collision avoidance system for automotive applications using an IMM
approach for Obstacle tracking
A collision warning system operates, generally, in the following manner: a sensor in-
stalled at the front end of a vehicle constantly scans the road ahead for vehicles or
obstacles. If such an obstacle is found, the system determines whether the vehicle is in
imminent danger of crashing, and if so, a collision warning is given to the driver. The
sensors used, fulfill the tasks of obstacle detection and tracking, which is the basis of
collision warning sensing techniques, can be classified in three main groups:

• Optical techniques (passive infrared, laser radar and vision systems): they all suffer
from the disadvantage of being sensitive to external environmental conditions.
Passive infrared and vision cannot provide a direct measurement of distance to an
object.

• Electromagnetic techniques (microwave radars): unlike the optical techniques, they

perform well under adverse environmental conditions. Despite its relatively high
cost, FMCW radar seems to be the best technique for long-range distance mea-
surement for automotive applications. It could also be used at short and medium
range, rendering a quite flexible technique.

• Acoustic techniques (ultrasonic): well-suited in applications where only short rel-

ative distance measurements are required, because they are able to provide high
resolution for a relatively low cost. The state of the art in Systems is offering single
sensor techniques. In this work a multiple-sensor approach is adopted, merging
the functionality on both data fusion and human machine interaction level - of the
different sensors, in a way that takes advantage of the complementarily of these
sensors.[8]

6
Chapter 2. Literature Review 7

A Design and Implementation of Collision Avoidance System for Automobiles using

Embedded System
In this project, advanced ideas such as pre-crash sensing, ultrasonic sensor is used to
sense the object in front of the vehicle and gives the signal to the micro controller
unit. Based on the signal received from the ultrasonic sensor, the micro controller
unit sends a signal to the braking unit for applying the brake automatically as per
braking and throttle control logic fed in to the micro controller unit. To avoid the
collision between the vehicles during the period of running conditions and automatically
applying the brake by means of actuators, Distance measuring sensors and Electronic
control module.[6]
Automatic Warning and Brake Support
Volvo Car Corporation has focused its system development on detecting potential safety
risks at an earlier stage. This means to help preventing accidents from occurring, or
reducing their effects, simply by reducing speed and shortening the stopping distance.
First out was the Collision Warning with Brake. It allows a 15 field of view, is equipped
with long range radar and registers moving and stopping vehicles. A radar sensor is
designed to monitor the area in front of the car. If the driver does not react when the
car approaches another vehicle from behind, a red light is reflected on the windscreen
and a buzzer sounds. The brake pads are automatically placed against the discs. When
the driver brakes, the system monitors the pedal pressure, if the pressure is too light,
the braking power is amplified by the system.[4]
Automatic Emergency Brake Assist
Automatic Emergency Brake Assist is a safety system in motor vehicles designed to
ensure maximum braking power is used in an emergency stop situation. Automatic
Emergency Braking (AEB) combines advanced Driver Assist Systems and Electronic
Stability Control to slow the vehicle and potentially mitigate the severity of an impact
when a collision is unavoidable. By interpreting the speed and force with which the
brake pedal is pushed, the system detects if the driver is trying to execute an emergency
stop, and if the brake pedal is not fully applied, the system overrides and fully applies
the brakes until the Anti-lock Braking System (ABS) takes over to stop the wheels
locking up.. If the system identifies an emergency, it automatically initiates full braking
faster than any driver can move their foot if a drivers steering and braking intervention
is not enough to avoid a collision, Autonomous emergency braking with maximum brake
pressure will be applied to help mitigate the impact. This final action is realized as full
ABS braking, and it ensures maximum speed reduction.[5]
Adaptive Cruise Control and Collision Warning With Brake Support
Cruise Control (CC) is a comfort system designed to maintain a constant speed preset by
the driver. Its natural evolution is the Adaptive Cruise Control that can automatically
slow down, decreasing the throttle when approaching a slower vehicle, and keeping a
Chapter 2. Literature Review 8

safe distance. The adaptive cruise control and collision warning with brake support
integrated system allows the driver to set the vehicles speed and maintain it without
using the accelerator pedal, and uses radar sensors to detect moving vehicles ahead
and warns the driver of collision risks. Four distance settings accommodate a range of
driving styles and road conditions. The driver can set distance, speed and the time
gap between vehicles. Adaptive cruise control is a radar-based system that can monitor
the vehicle in front (up to 600 feet) and adjust the speed of the vehicle to keep it at
a preset distance behind the lead vehicle, even in most fog and rain conditions. The
system measures distance as a function of speed and can monitor the traffic ahead
while ignoring stationary objects such as road signs and telephone poles. It also can
determine how fast the vehicle is approaching the vehicle ahead. For example, when
approaching a lead vehicle at a high rate of speed, the system will activate sooner than
when approaching slower. When the preceding vehicle accelerates or leaves the path,
the system accelerates once again to the preset speed. To act on the accelerator, the
system uses the speed and distance to the preceding vehicle provided by the radar sensor.
This system automatically turns off at the low speeds typical in urban traffic, because
it cannot act on the brakes, or does so to a limited extent.[7]
Chapter 3

Car Collision Avoidance System

Description and Overall
Operation

Collision Avoidance System deals with two basic object detection modes. First one is
alarm range and another one is automatic braking system. The system, which is provided
with obstacle sensing device, gets the obstacle warning ahead of the host vehicle, and
also the distance that object has been detected. After the data received by the control
module from sensing device, it decides whether the object is in alarm range or in braking
range according to the data fed already in to the control module as per control algorithm.
Simply, as the object found within the alarm range controller actuates first LED light
for alerting the driver. if the driver doesn’t take any measurement the alarm sound is
followed. Otherwise if the object found closer than alarm range braking range controller
actuates alarm and braking for alarming as well as braking respectively. The block
diagram is shown as follow.

9
Chapter 3. System Description and Overall Operation 10

Figure 3.1: CCAS Block Diagram

If the obstacle found in the range of alarm there will be no need to apply the braking
the driver has enough distance to have a control over steering. Hence the driver can
ultimately steer the vehicle from obstacle and cannot give response and the obstacle
found within the braking range the System will not have enough distance to take steer
there for it take measure by itself by actuating the automatic braking system. As per
the circuit the signal goes to the input conditioning that may be Analogue to digital
converter from input sensor but here in our project we use Arduino uno which is already
fixed with different components including signal conditioning and processing unit. The
Arduino processes the input signal from ultrasonic sensor according to the algorithm,
which was fed in to the Ardunio. The appropriate pulses control the actuator unit, which
is gaining operation signals from the Arduino output. As per the design an ultrasonic
distance measurement sensor has been proposed as obstacle detecting sensor.

3.1 The Braking System Working Principle

One of the most desirable and important characteristics of motor vehicles is that they
should have good handling characteristics in terms of directional response to steering
inputs and performance as affected by accelerator and brake application. One of the
challenges in our project is how to design the braking system. To select the types of the
servo motor we should know the torque of the motor that used to brake the car at the
time of emergency. To calculate the torque we have follow the following assumption. By
”maximum braking performance” we mean the shortest distance to slow or stop that
can be obtained without excessive locking of the wheels in order that sufficient control
and stability prevail for holding the vehicle in the desired lane of travel. It is primarily
the dynamic aspect of the man-vehicle interface with which this study is concerned.
Chapter 3. System Description and Overall Operation 11

The braking process is viewed as a task in which the driver must control and modulate
his pedal force such that he achieves the shortest braking distance possible under the
prevailing road conditions, while further satisfying the requirement that the trajectory
of his vehicle be under reasonable control.[1]

Figure 3.2: Braking System Block Diagram

Application of a pedal force F causes the brake pedal to be displaced through a distance
X1. The pedal linkage is designed to yield a mechanical advantage of force r between
the pedal and the master cylinder piston, resulting in a displacement of the piston X2
that is less than the displacement X1. The master cylinder, with an area Am, traps
the oil in the brake line, thereby developing a hydraulic pressure, p. Since there are
frictional losses, it is common to assume a pedal efficiency, E, that is less than unity.
The relationship between line pressure and pedal force is actually nonlinear but may be
simplified for illustration purposes.

p = (r ∗ E ∗ F )/Am) (3.1)

Where

x1
r= (3.2)
x2
where
p=pressure
r=mechanical advantages of force between the pedal and master cylinder
The development of vehicle deceleration by means of brake torque follows directly when
wheel inertia is neglected and it is assumed that no sliding occurs. The deceleration of
a vehicle due t o applied brake torque can be expressed as:

(4 ∗ g ∗ T )
a= (3.3)
(W ∗ Re)
Chapter 3. System Description and Overall Operation 12

Where
There for we can calculate the torque of the motor from the above formula:

a ∗ W ∗ Re
T = (3.4)
4g
Where:
E = efficiency of the pedal
g = acceleration of gravity in (ms−2 )
Re = effective radius of wheel in m
W = vehicle weight in Kg(ms−2 )
T = brake torque at wheel in Kg(m2 s−2 )
a =deceleration of the car in (ms−2 )
Am = area of master cylinder in m2
Several studies have been made investigating the use brakes receive during normal driv-
ing. All but one of the studies were European and involved variety of driving conditions.
During a test involving four drivers over a distance of 1400 miles, it was found that only
5 percent of the stops exceeded an average deceleration of 0.3 g and that 50 percent of
all stops were made a t .09 g or lower. In a test involving 23 drivers over 300 miles of
European driving, the average of the maximum decelerations observed on a number of
different test routes varied between 0.21 g and 0.34 g, the mean being 0.26 g. The single
maximum deceleration recorded was 0.6 g. A British study (Livsey,1 960-61) involving
16 vehicles covering a wide selection of vehicle types was conducted over four different
routes , including fast main road, cross country, winding roads, and an mountain de-
scent. It was found that decelerations on all the routes were usually in the range of 0.2
g t o.3 g, and rarely exceeded 0.4 g.

3.2 The Software parts

Program
The Arduino programming language is a simplified version of C/C++. [11]

3.2.1 Algorithm

• First the ultrasonic sensor senses whether the obstacle is there or not

• If there is the obstacle the sensor send signal to the microcontroller (arduino)

• The micro controller received the coming signal then check the level of the incoming
signal depending on the distance of the obstacle location relative to the vehicle
Chapter 3. System Description and Overall Operation 13

• If the obstacle on alarm position it actuates the alarm to alert the driver

• Finally if the obstacle more near to the vehicle the microcontroller actuates both
the alarm and the ABS then the vehicle stop

3.2.2 Flow Chart

Figure 3.3: Flow Chart

Chapter 3. System Description and Overall Operation 14

3.2.3 Program

Here in our project we develop two programs both the main system and simulation part
which sensor substituted by potentiometer.

3.2.3.1 Main Program

This program is developed to run the main system which is order the the micro-controller
depend up on the income signal from the ultrasonic sensor. See Appendix B

3.2.3.2 Testing Program

This program is used to test or simulation purpose of our project work which the ultra-
sonic sensor substituting by potentio meter analog input to the micro controller,then by
varying the value of the potentio meter we observe the effect of the out put signal. See
Appendix B

3.3 Selected Materials Description

Ultrasonic sensor DU 43
The Ultrasonic sensor DU 43 is primarily designed for continuous non-contact distance
measurement in different system. It has a measuring range of 25 m (80 ft) (under opti-
mum conditions).The ideal mounting point for the sensor is directly in front of the car.
The Ultrasonic emitter in the sensor is excited electrically and sends an Ultrasonic pulse
in the direction of the surface of the obstacle. The obstacle partially reflects the pulse.
This echo is detected by the same sensor, now acting as a directional microphone, and
converted back into an electrical signal. The time between transmission and reception of
the pulse the sonic run time is directly proportional to the distance between the sensor
and the obstacle surface.[10] The distance D is determined from the velocity of sound c
and the run time t by the formula: At c = 340m/s

D=0.5*c*t
(3.5)

Servo Motor
A servomotor is a motor which forms part of a servomechanism. The servomotor is
Chapter 3. System Description and Overall Operation 15

paired with some type of encoder to provide position/speed feedback. Basically there
are three types of servo motors: AC Servo Motor, DC Servo Motor and Spindle Servo
Motor. In our project, we use DC servo motor as driver for the braking system. Dc
servo motors are normally used as prime movers in computers, numerically controlled
machinery, or other applications where starts and stops are made quickly and accu-
rately. Servo motors have lightweight, low-inertia armatures that respond quickly to
excitation-voltage changes. In addition, very low armature inductance in these servo
motors results in a low electrical time constant (typically 0.05 to 1.5 ms) that further
sharpens servo motor response to command signals. Servo motors include permanent-
magnetic, printed-circuit, and moving-coil (or shell) dc servo motors. Dc servo motor
characteristics include inertia, physical shape, costs, shaft resonance, shaft configura-
tion, speed, and weight. Although these dc servo motors have similar torque ratings,
their physical and electrical constants vary. Servo motors are small controllable motors
that lend to implementation in many applications. There are Servos with many different
speeds, sizes and torque capabilities, but all have 3 wires, power, ground and control.
Servo motors are controlled through the control line, usually a yellow or white wire. The
pulse width of the signal sent to the Servo control wire determines how the motor will
move, either clockwise or counter clockwise and it degree of rotation. Arduino UNO
Arduino is an open-source electronics prototyping platform based on flexible, easy-to-
use hardware and software. It’s intended for artists, designers, hobbyists, and anyone
interested in creating interactive objects or environments. Arduino can sense the en-
vironment by receiving input from a variety of sensors and can affect its surroundings
by controlling lights, motors, and other actuators. The microcontroller on the board
is programmed using the Arduino programming language (based on Wiring) and the
Arduino development environment (based on Processing). The Arduino board features
an Arduino UNO microcontroller operating at 5 V with 2 Kb of RAM, 32 Kb of flash
memory for storing programs and 1 Kb of EEPROM for storing parameters. The clock
speed is 16 MHz, which translates to about executing about 300,000 lines of C source
code per second. The board has 14 digital I/O pins and 6 analog input pins. There is
a USB connector for talking to the host computer and a DC power jack for connecting
an external 6-20 V power source, for example a 9 V battery, when running a program
while not connected to the host computer. Headers are provided for interfacing to the
I/O pins using 22 g solid wire or header connectors.
LED
Light Emitting Diodes or LEDs are among the most widely used of all the different types
of semiconductor diodes available today. They are the most visible type of diode that
emit a fairly narrow bandwidth of either visible light at different colored wavelengths,
invisible infra-red light for remote controls or laser type light when a forward current is
passed through them. A ”Light Emitting Diode” or LED as it is more commonly called,
Chapter 3. System Description and Overall Operation 16

is basically just a specialized type of PN junction diode, made from a very thin layer
of fairly heavily doped semiconductor material. When the diode is forward biased, elec-
trons from the semiconductors conduction band recombine with holes from the valence
band releasing sufficient energy to produce photons which emit a monochromatic (single
color) of light. Because of this thin layer a reasonable number of these photons can leave
the junction and radiate away producing a colored light output. Then we can say that
when operated in a forward biased direction Light Emitting Diodes are semiconductor
devices that convert electrical energy into light energy. we use this LED in our project
for alerting the driver at the first step.

3.4 Motor Controlling Circuit

As shown in motor circuit figure 3.4 we use dc servo motor (M) in which its rating is
depending on the required torque or force that need to compressed the brake pedal.
The brake pedal force is different depending on the types of the car. The resistance
(R1) is used limit the current entering into the switching device (Q1) which comes from
the arduino. The switch device Q1 is used to control the motor depending the given
program by making ON and OF.

(V 2 − V 1)
IQ1 = (3.6)
R1

V2= 5v from the arduino and V1=0.7v the voltage drop from the transistor and the
base current required to switch on the transistor(IQ1) is around 4 mA then the value of
the resistor R1 is around to 1k from the above equation. The diode is used prevent the
arduino from the back flow of current from the motor.
Chapter 3. System Description and Overall Operation 17

Figure 3.4: Motor Control Circuit

3.5 Sensor Power Circuit

Figure 3.5: Sensor Connection Diagram

3.6 Buzzer Power Circuit

The buzzer we used to alerting the driver has an operating voltage from 3v upto 5v with
low current rating value. Therefore we use a resistance in series to protect the buzzer
from over current flow.
Chapter 3. System Description and Overall Operation 18

Figure 3.6: Buzzer Controlling Circuit

3.7 LED Controlling Circuit Diagram

The LED is used to indicate light at first stage of alerting the driver. We connected it
to Pin 8 of the arduino with 333 of resistor protection. since the current required for
LED is around 15 mA and the current drawn by arduino is around 40 mA.

Figure 3.7: LED Controlling Circuit Diagram

Chapter 3. System Description and Overall Operation 19

3.8 Main Control Circuit

Figure 3.8: Main Controlling Circuit Diagram

Chapter 3. System Description and Overall Operation 20

3.9 Testing Control Circuit

Figure 3.9: Main Controlling Circuit Diagram

Chapter 4

Result and Discussion

To built the prototype of the system, we substitute some of the materials by other
corresponding materials. Since the ultrasonic sensor is not found, we use potentio meter
instead of the ultrasonic sensor to show the result of the prototype. We also used light
emitting diode in place of buzzer. We observed that, When the potentio meter rotates in
the first step the light emitting diode (LED) is switched ON, in real system it indicates
there is obstacle on the way of the vehicle but the distance is far. So the driver has
enough distance to take measure. When the potentio meter rotates in the next step the
light emitting diode that used in place of buzzer is switched ON which tells for the driver
the obstacle become closer to the vehicle. Again as the potentio meter rotates further
the servo motor actuates which is used to automatically brake the vehicle. This implies
that the obstacle become closer to the vehicle and the driver does not have enough time
to take measure.

21
Chapter 5

Conclusion and Recommendation

5.1 Conclusion

We have seen that car accident is the current problem in both worldwide and in our
country. We focused on, one of the common modes of accident occurs when two vehicles
are traveling in the same direction, one going behind the other. We know that total
collision avoidance is impossible but we can reduced it by small percentage. So we
try to develop a car collision avoidance system by using Ultrasonic sensor as obstacle
detector and Micro controller as processing unit of the system. We have studied different
literatures related to CCAS and select required materials with their specification. Also
we have designed power and control circuit for materials based on their specification
and developed the microcontroller program. Finally by interfacing the hardware and
the software parts we have constructed the prototypes of the car collision avoidance
system. This system has two stages, the alerting and automatic braking stage. The
alerting stage by it self it has two steps lighting and sounding stages by using LED and
buzzer respectively. This system is simple in construction and low in cost compared to
current problems finally we believe that if this system applied to the real world it will
reduced the current car collision accidents.

5.2 Recommendation

We recommended that the road transport must give a great attention to the traffic
problem. Thus they should ask the concerning body or engineers to design driver alerting
system, automatic speed control of the vehicles and automatic braking system. Then
implement the system in real application area in order to reduce traffic problems caused
by car collision.

22
Bibliography 23

Reference

1. R. G. Mortimer, L. Segel, H. Dugoff, J.D. Campbell, C.M, Jorgeson, R. W. Mur-

phy ”Brake Force Requirement Study” April 10, 1970

2. Shival Dubey and Abdul Wahid Ansari Design and Development of Vehicle anti-
collision System using Electromagnet and Ultrasonic Sensors

3. T. Nishi1, N. Yamazaki1, S. Koike2, T. Kuno3 and T. Umezaki1 Collision Avoid-

ance System Using Laser Beams

4. S.Ramesh, Ravi Ranjan, Ranjeet Mukherjee, Swarnali Chaudhuri Vehicle Collision

Avoidance System Using Wireless Sensor Networks

5. Keunsuk Lee Application of the Devantech SRF04 Ultrasonic Range Finder,2002

6. A.Nmngani, M. Akturt Review of Vehicle Collision Avoidance System, The 6th

Saudi engineering conference, Dharan, December 2002.

7. Rajarajan.R , Abdul Rahuman.S, Harish Bharath.M.A, 2011 A Design and Imple-

mentation of Collision Avoidance System (CAS) for Automobiles using Embedded
System, International Conference on Circuits, System and Simulation,2011

8. Dr. Angelos Amditis, Aris Polychronopoulos, Ioannis Karaseitanidis, Dr. George

Katsoulis, Multiple - Sensor - Collision avoidance system for automotive applica-
tions using an IMM approach for obstacle tracking, April 2008.

9. R. G. Mortimer, L. Segel, H. Dugoff, J.D. Campbell, C.M, Jorgeson, R. W. Mur-

phy Brake Force Requirement Study: Driver-Vehicle Braking Performance as a
Function of Brake System Design Variables,” April 1970.

10. hpp://www.arduino.cc/en/Booklet/Homepage
Required Material

.1 Required Materials

Table 1: List of Material Used

No Name of the Material No of Item

1 Ultrasonic sensor (RPS-150) 1
2 Microcontroller (arduino UNO) 1
3 Servo motor 1
4 Alarm 1
5 Relay 2
6 LED 1
7 BJT (Bipolar transistor) 2
8 Resistors 8
9 Operational Amplifier 1
10 Diode 1
11 Power supply 1
12 Data cable 1

24
Programs

.2 Testing Program

# include < Servo .h >

int led = 8;
int buz = 12;
int potPin = A2 ;
int val =0;
Servo myServo ;
int pos = 0;
void setup ()
{
Serial . begin (9600);
pinMode ( led , OUTPUT );
pinMode ( buz , OUTPUT );
val = analogRead ( potPin );
myServo . attach (10);
}
void loop ()
{
float distance ;
val = analogRead ( potPin );
distance = ( val *170);
if ( distance <=25 && distance >=20)
{
digitalWrite ( led , HIGH );
digitalWrite ( buz , LOW );
myServo . write ( pos );
delay ( val );
digitalWrite ( led , LOW );
digitalWrite ( buz , LOW );
myServo . write ( pos );
}
else if ( distance <20 && distance >=15)
{
digitalWrite ( buz , HIGH );
digitalWrite ( led , LOW );
myServo . write ( pos );
delay ( val );
digitalWrite ( led , LOW );
digitalWrite ( buz , HIGH );
myServo . write ( pos );

25
Appendix B. C Programs 26

delay ( val );
}
else if ( distance <15 && distance >=0)
{
digitalWrite ( buz , HIGH );
digitalWrite ( led , LOW );
myServo . write (45);
delay (5000);
digitalWrite ( led , LOW );
myServo . write ( pos );
digitalWrite ( buz , LOW );
}
else
{
digitalWrite ( led , LOW );
myServo . write ( pos );
digitalWrite ( buz , LOW );
}
}

.3 Main Program

# include < Servo .h >

int led = 8;
int buz = 12;
int trigpin = 9;
Servo myServo ;
int ecop = 11;
int pos = 0;
void setup ()
{
Serial . begin (9600);
pinMode ( trigpin , OUTPUT );
pinMode ( led , OUTPUT );
pinMode ( buz , OUTPUT );
pinMode ( ecop , INPUT );
myServo . attach (10);
}
void loop ()
{
float duration , distance ;
digitalWrite ( trigpin , LOW );
d e l a y M i c r o s e c o n d s (2);
digitalWrite ( trigpin , HIGH );
delay (25);
duration = pulseIn ( ecop , HIGH );
distance = ( duration *170);
if ( distance <=25 && distance >=15)
{
digitalWrite ( led , HIGH );
digitalWrite ( buz , LOW );
myServo . write ( pos );
Appendix B. C Programs 27

delay (5000);
}
else if ( distance <15 && distance >=10)
{
digitalWrite ( buz , HIGH );
digitalWrite ( led , LOW );
myServo . write ( pos );
}
else if ( distance <10 && distance >=0)
{
digitalWrite ( buz , HIGH );
digitalWrite ( led , LOW );
myServo . write (45);
delay (5000);
myServo . write ( pos );
digitalWrite ( buz , LOW );
digitalWrite ( buz , LOW );
}
else
{
myServo . write ( pos );
digitalWrite ( buz , LOW );
digitalWrite ( buz , LOW );
}
}