Group Name: Robo Instructors

Group Members:

Name ID Assigned work

Zubair Iqbal 1601029 Mechanical
Ansar Abbas Khan 1601017 Electronics
Aftab Mustafa 1601041 Report writing &
Qureshi Coding

Contents:
 Component
 Robot Design
 Line Detection Mechanism
 Cost Calculation

Components:

 Sensors:
 IR LEDs/photodiodes,
potentiometer, Comparator (OP-Amp
,LM358 IC) And LEDs and resistors
 Motor Driver Circuit:
 NPN Transistors (
2N2222), Resisters and Capacitors
 Arduino
 DC Motors
 9V Battery
 Wheels
 Bovine Wheel and two simple wheels
 Connection wires:
 Button

 Robot Design

Design Motivation:
The main motivation of our project is to make
our robot follow the given line with the appropriate speed.

Shape of our robot is a little bit hexagonal type, because we thought it is unique from the
other designed robots and secondly this will keep the resistance and air friction lesser.
Our Robot is not too much bulky and not even too much smaller. It can carry all the
components.

Measurements and Calculations:

The Measurements of Our Designed robots are following:

Length of the Robot: 17cm

Width of the Robot: 11cm

Diameter of the Wheel 6cm

So,

Speed= RPM * Diameter * pi * 1m/60sec

Speed=200 * 0.06m * 3.14 * 1/60

Speed=0.628 km/h

So the Speed of the Motor is 0.628km/h, which is controllable.

Base:
The base of our robot is made of acrylic sheet. Acrylic sheet is rigid and have good
strength to resistance to sunlight and other weather effects.
It is lighter in weight as compared to other sheets.

Line Detection Mechanism of Robot:

In IR sensors
there is an IR transmitter and Photodiode. When LEDs fall light on a surface it is either
reflected or absorbed and when it is reflected from surface, photodiode catches light and
generate the voltage changes. Then these voltages are send at the input of Arduino and
Arduino reads this signals and sends this signal to Motor Driver Circuit to drive the
motor.
 In motor Driver part there are two DC motors and a circuit which help to drive the
motor to follow the line. As Arduino does not supply enough voltage and current to drive
the motor. Due to which we use a motor driver circuit to get enough voltage and current
for motor.
We are using two IR sensor, left sensor and right sensor at the front of Robot. When
both sensor’s photodiode absorb enough light and robot will move forward. If left
sensor’s photodiode does not absorb light the left motor will stop and robot will move
toward left. If right sensor’s photodiode does not absorb enough light then right motor
will stop and robot will move toward right.

Motors:
We choose 6 volt motors and it has almost 200RPM.
As already described, our main purpose is to keep the robot follow the line, so we kept
the motor of 6 Volts with RPM 200, which completes our criteria.
6 Volt is enough to control our Robot.

Battery/Cell:
We are using rechargeable cells of 9.16 Volts.
Arduino will get a voltage of 5 Volts, and we will be using Motor of 6 Volts.
This cell is having long life as it have an energy capacity of 1500 mAH.

H Bridge Circuit:
The circuit shown here is a typical four transistor H-Bridge. All the provide a safer path for
the back emf from the motor to disperse and thus it protects the corresponding bipolar
transistors from destruction. All resistors limit the base current of the corresponding
transistors. Working of this circuit is very easy to understand. When terminal D is
grounded and A is pulled to +Vcc, transistors Q1 and Q4 will be on and current passes
through the motor from left to right. When terminal B is grounded and C is pulled to +Vcc,
transistors Q3 and Q2 will be on and current passes through the motor from right to right
making the motor to rotate in the opposite direction.
 Components:
TIP 142:
The TIP 142 Transistor have the following properties:
 Collector emitter voltage (Vce) of 100V
 Continuous collector current (Ic) of 10A
 Power dissipation of 125W
 Operating junction temperature range from -65°C to 150°C
 Collector emitter saturation voltage of 2V at Ic=5A
 DC current gain of 500 at Ic=10A

Transistors:
The Arduino can only deliver 40mA at 5V on its digital pins. Most motors
necessitate further current and/or voltage to operate. A transistor can act as a digital
switch, allowing the Arduino to control loads with higher electrical requirements.
 IR Sensors:

We have used IR Sensors for the robot control purpose. IR sensor reflects
white surface while absorbs black surface. When IR rays fall on white surface, it’s
reflected back and cached by photodiodes which generates some voltage changes. When
IR light falls on a black surface, light is absorb by the black surface and no rays are
reflected back, thus photo diode does not receive any light or rays.Arduino gets 1 as
input and when senses black line arduino gets 0 as input.

Cost Calculated:
Item Quantity Price Per Item
6V DC Motors 2 PKR-320
Robot Smart Car Wheels 2 PKR-100
Metal Ball Caster Free 1 PKR-180
Wheel
9V Alkaline Battery 2 PKR-320
NPN Transistors 8 PKR-45
PNP Transistors 8 PKR-32
Arduino Nano 1 PKR-650
IR Sensor Receiver & 3 pairs PKR-42
Transmitter

Total:PKR-2895/-

Note: As this is an electrical based project, so components may burn and We have
to buy different components from local brokers and Online sources, so quantities
and prices may vary.
Timeline of Next Steps:
 Re-fabrication of PCB (As per instruction of Sir Dr.Talah Manzoor)
 Coding and Logic Building.