Contents

List of Abbreviation…………………………………………………. iii

List of Figures……………………………………………………….. iv

Photograph of the Project…………………………………………

Abstract……………………………………………………………

Chapter 1: Introduction……………………………………………….1

1.1

Objective……………………………………………..2

1.2

Introduction to ROBOTICS.………………….……...3

Chapter 2: Block Diagram……….. …………………………………..4

2.1

Block Diagram……………………………………….5

2.2

Block Diagram Description…………………………..9

Chapter 3: Circuit Details…………………………………………

3.1 Circuit Diagram….……………………………………..11

3.2 PCB Diagram…………………………………………..12

Chapter 4: Working…………………………………………………..13

4.1

Working……………………………………………..14

Chapter 5: Components Required……………………………………16

Chapter 6: Result and Conclusion………………………………….…17

6.1

Result………………………………………………...18

6.2

Conclusion…………………………………………...19

Chapter 7: Bill of Materials…………………………………………

Chapter 8: Advantage and Future Scope……………………………

8.1

Advantages………………………………………….23

8.2

Future Scope………………………………………...24

Chapter 9: Reference………………………………………….……

INTRODUCTION

1.1 OBJECTIVE

Obstacle avoidance is one of the most important aspects of mobile robotics.

Without it robot movement would be very restrictive and fragile. Obstacle

Avoiding is a task which is used for detecting the objects placed in the path

of the robot or any vehicle.

Basically it's in the form of a moving vehicle which is able to detect and

avoid potential obstacles on its path and change its direction appropriately

so that its motion stays uninterrupted.

The idea is simple and works without microcontroller . That means we can

make it without any kind of coding and the circuit allows us to use any DC

motor regardless of its power, so even high power obstacle avoiding

vehicles could be made using this circuit which are normally used in malls

and similar retail outlets.

1.2 INTRODUCTION TO ROBOTICS

Robotics is a part of todays communication. In today’s world

ROBOTICS is fast growing and interesting field . It is simplest way for

latest technology modification. Now a days communication is part of

advancement of technology , so we decided to work on ROBOTICS field ,

and design something which will make human life simpler in day today

aspect . Thus we are supporting this cause.

This project is basic stage of any automatic robot. This ROBOT has

sufficient intelligence to cover the maximum area of provided space . It has

two infrared sensors which are used to sense the obstacles coming in

between the path of ROBOT . It will move in a particular direction and

avoid the obstacle which is coming in its path .

We have used two DC motors to give motion to the ROBOT . The

constrction of the ROBOT circuit is easy and small . The electronics parts

used in the ROBOT circuits are easily available and cheap too.

2.2 BLOCK DIAGRAM DESCRIPTION:

• IR Module

It consists of IR Led, photo diode, resistors, 10K potentiometer ,

LM358IC

1)IR Led: IR Led emits light, in the range of Infrared frequency. IR

light is invisible to us as its wavelength (700nm - 1mm) is much

higher than the visible light range. Everything which produce heat,

emits infrared like for example our human body. Infrared have the

same properties as visible light, like it can be focused, reflected and

polarised like visible light.

2)Photo Diode: Photodiode is considered as Light dependent

Resistor (LDR), means it has very High resistance in absence of

light and become low when light falls on it. Photodiode is a

semiconductor which has a P-N junction, operated in Reverse Bias,

means it start conducting the current in reverse direction when

Light falls on it, and the amount of current flow is proportional to

the amount of Light. This property makes it useful for IR

detection.

3)10 K Potentiometer: A potentiometer, informally a pot, is a

three-terminal resistor with a sliding or rotating contact that forms

an adjustable voltage divider. If only two terminals are used, one

end and the wiper, it acts as a variable resistor or rheostat.

4) LM358 IC: LM358 is an operational amplifier (Op-Amp) and in

this circuit we are using it as a voltage comparator. The LM358 has

two independent voltage comparators inside it, which can be

IR sensor modules. We have used only one comparator here,

which have inputs at PIN 2 & 3 and output at PIN 1. Voltage

comparator has two inputs, one is inverting input and second is

non-inverting input (PIN 2 and 3 in LM358). When voltage at

non-inverting input (+) is higher than the voltage at inverting

input (-), then the output of comparator (PIN 1) is High. And if

the voltage of inverting input (-) is higher than non-inverting end

(+), then output is LOW.

• IC 7404

7404 is a NOT gate IC. It consists of six inverters which perform

logical invert action. The output of an inverter is the complement

of its input logic state, i.e., when input is high its output is low and

vice versa.

Fig:2.2.1 7404 IC

• L293D IC

L293D is a dual H-bridge motor driver integrated circuit (IC).

Motor drivers act as current amplifiers since they take a

low-current control signal and provide a higher-current signal. To

drive the motors this higher current signal is used. L293D contains

two inbuilt H-bridge driver circuits. In its common mode of

operation, two DC motors can be driven simultaneously, both in

forward and reverse direction. The motor operations of two

motors can be controlled by input logic at pins 2 & 7 and 10 & 15.

Input logic 00 or 11 will stop the corresponding motor. Logic 01

and 10 will rotate it in clockwise and anticlockwise directions,

respectively. Enable pins 1 and 9 (corresponding to the two

motors) must be high for motors to start operating. When an

enable input is high, the associated driver gets enabled. As a result,

the outputs become active and work in phase with their inputs.

Similarly, when the enable input is low, that driver is disabled, and

their outputs are off and in the high-impedance state.

Fig:2.2.2 L293D Motor Driver

• DC GEAR MOTOR

Geared DC motors can be defined as an extension of DC motor.

A geared DC Motor has a gear assembly attached to the motor.

The speed of motor is counted in terms of rotations of the shaft

per minute and is termed as RPM .The gear assembly helps in

increasing the torque and reducing the speed. Using the correct

combination of gears in a gear motor, its speed can be reduced to

any desirable figure. This concept where gears reduce the speed of

the vehicle but increase its torque is known as gear reduction.

Fig:2.2.3 DC Gear Motor

• IR SENSORS

Infrared sensors detect the object's distance with infrared

radiation. When the beam detects an object, the light beam returns

to the receiver with an angle after reflection. The is method of

triangulation. PIR sensors are also known as Pyroelectric Infrared

sensor, Passive Infrared sensor or IR motion sensor, which detect

the difference in temperature, thermal radiation, human body or

an animal . PIR sensor operates with the radiation of body heat .

The hotter the detected object, there will be more emission occurs

in PIR sensor.

Fig:2.2.4 IR Sensor

4.1 WORKING

In IR Module we have used IR LED as a transmitter and Photo

Diode as a receiver. It is used to detect the obstacle if obstacle

comes on the front of the IR module. Here we have used NOT

Gate as an inverter. The signal coming out from IR module is

inverted by NOT Gate and the inverting signal is sent to the

motor driver ic L293D. Robot take the left or right or the forward

movement in according to the sensing signal with the help of the

two gear motor which makes the movement of the robot .

IR module is used to detect the obstacle if obstacle comes on the

front of the IR module. The IR module send the signal to the 7404

IC or Not Gate IC. Here 7404 IC is used as an inverter. The signal

coming out from IR module is inverted by 7404 IC and the

inverting signal is sent to the motor driver IC L293D. Robot take

the left or right or the forward movement in according to the

sensing signal with the help of the two gear motor which makes

the movement of the robot smooth.

Table 5.1 Components Required

S.NO

NAME OF THE

DESCRIPTION

QUANTITY

COMPONENT

Contains infrared transmitter

and receiver with one output

pin and a preset trough

IR Sensor

which we can set sensitivity .

12 volt geared DC motor

which takes 100 revolutions

100 rpm Motor

in one minute .

It is a motor controller IC

with four input pins and four

L293D IC

output pins .

It is a NOT gate IC which

inverts the input and give it as

7404 IC

output .

Comes with radio frequency

transmitter and receiver with

an operating frequency of 27

RF Module

MHz .

Connecting Wires

Insulated copper wires

Many

6.1 RESULT

From this study, a walking robot that achieved the stated

objectives had been developed. This robot is able to produce

the basic walking movements using two gear motors. We

developed the robot with a very good intelligence which is

easily capable to sense the obstacle and by processing the

signal coming from the sensor, it is perfectly avoiding the

obstacle coming in between the path Robot take the left or

right or the forward movement in according to the sensing

signal with the help of the two gear motor which makes the

movement of the robot smooth .In future, the sensing range

can be increased by increasing the sensor quality with the

help of ultrasonic sensor or the IR signal spread all over the

provide area.

6.2 CONCLUSION

Almost all navigation robot demands the some sort of obstacle

detection, hence obstacle avoidance strategy is of most

importance. Obstacle Avoidance Robot has a vast field of

application. They can be used as services robots, for the

purpose of household work and so many other indoor

applications. Equally they have great importance in scientific

exploration and emergency rescue, there may be places that are

dangerous for humans or even impossible for humans to reach

directly, then we should use robots to help us. In those

challenging environments, the robots need to gather

information about their surroundings to avoid obstacles.

Nowadays, even in ordinary environments, people require that

robots to detect and avoid obstacles. For example, an industrial

robot in a factory is expected to avoid workers so that it won’t

hurt them. In conclusion, obstacle avoidance is widely

researched and applied in the world, and it is probable that

most robots in the future should have obstacle avoidance

function.

7. Bill of Material

Table 7.1 Bill of Material

S.NO NAME OF THE

PRICE PER

QUANTITY

TOTAL

COMPONENT

PRICE

IR Sensor

100

100 rpm motor

150

300

L293D IC

150

7404 IC

7805 IC

RF Module

150

RF Antenna

Robot Chassis

120

150

IC Base

10.

Balancing Wheel

11.

Connecting wires

12.

Battery

13.

Wheel

14.

Zero PCB

15.

Screw

Grand Total = Rs. 1,217

8.2 FUTURE SCOPE

In future, the sensing range can be increased by increasing the

sensor quality with the help of ultrasonic sensor or the IR signal

spread all over the provide area.

Performance of this robot can be improved with the help of Bump

sensors, for slow moving robots, ultrasonic range sensors for large

range up to 6m or LASER range finders.

One of the prevailing fields is the use of camera in robot,

Computer vision can be implemented for better performance.

9.1 REFERENCE

• http://www.electricaltechnology.com/motor_driverl293d

• http://www.engineersgarage.com/electronic_circuits

• “Obstacle Avoidance Robot” by K. Bhagt, S. Deshmukh,

S. Dhonde, S. Ghag, V. Waghmare

• “OBSTACLE AVOIDING ROBOT - A PROMISING

ONE” by R. Chandra Kumar, Md. S. Khan, D. Kumar, R.

Birua, S. Mondal, M. Kr. Parai

• “Obstacle Avoidance Robotic Vehicle Using Ultrasonic

Sensor, Android And Bluetooth For Obstacle Detection” by

V. Ankit, P. Jigar, V. Savan