Line following robot STUDENT REPORT in this project, we develop the line following robot

In order for the robot to move on the right orbit, it is necessary to have a sensor, which is re-sponsible for distinguishing the guide line and the background color of the moving trajec

Ho Chi Minh City University of Technology and Education

Faculty for High Quality Training Automation and Control Engineering Technology

Line Following Robot

La Gia Bao Hoang Duong Trinh Nguyen Anh Hao

J anuary 6th, 2021

1.1 Introducing of line following robot 1

1.2 Objective of Study 2

1.3 General operating principles 2

1.4 Application of line following robot 2

2 Hardware design and software design 4 2.1 Hardware design 4

2.1.1 Idea frame 4

2.1.2 Select electronic appliances 5

2.1.3 Cost estimation 10

2.1.4 Circuit Diagram 10

2.2 Software design 11

2.2.1 A algorithm idea 11

2.2.2 Working principle of Sensor 12

2.2.3 Working principle of Line following robot 12

2.2.4 Code 13

3.2 Running results and review 19

3.2.1 Running results 19 3.2.2 Review 19

4.1 Advantage 20 4.2 Disadvantage 20 4.3 Future work 20

In this project, we develop the line following robot Module L298N is chosen as the main

controller.Arduino uno R3 is the brain which control the robot.We use Closed Loop control

and PID control for this project.Dynamic PID control algorithm has been proposed to improve

the navigation reliability of the wheeled mobile robot which uses differential drive locomotion

system The experimental results show that the dynamic PID algorithm can be performed

under the system real-time requirements

List of Figures

2.1 Line following car 4

2.2 Arduino Uno R3 5

2.3 Module L298N 6

2.4 Sensor 7

2.5 Motor V1 8

2.6 Wheel 9

2.7 Li-po battery 9

2.8 Block diagram 11

2.9 Working principle of sensor 12

2.10 Working principle of line following robot 13

3.1 Our line following car 18

List of Tables

2.1 Parameter of Arduino Uno R3 5

2.2 Parameter of module L298N 6

2.3 Parameter of sensor 7

2.4 Parameter of motor V1 8

2.5 Parameter of Wheel V1 8

2.6 Parameter of li-po battery 9

2.7 Details of Price of components 10

2.8 Table of Circuit Diagram 10

Assignment of work

Member Private work Work in pairs Work together

Nguyen Quoc Vinh Write code Present, write report

Le Tran Vu Hoang Design in Solidworks

Trinh Nguyen Anh Hao Design PowerPoint

Hoang Duong Buying electronic appliance

Chapter 1

Overview

1.1 Introducing of line following robot

Automation is a combination of many fields such as mechanics, control, information

tech-nology and mechatronics These fields come together into systems that automate and,

more-over, automate the entire manufacturing process Automation companies play an increasingly

important and essential role to meet economic development goals, especially in today’s

fast-moving work process It asks a highly qualified human resource to operate In the world

today, there are many types of robots: Large-scale such as: Machine arms in production lines,

automatic production systems In addition are robots capable of moving, doing dangerous

jobs to replace humans, robots to help the elderly, sales robots etc In this project I do the

line of detection robots, compared to the above robots Just a small, simple robot, but this

is the foundation for me to make air conditioners, more useful in the process of learning and

doing of me after this A line follower robot is basically a robot designed to follow a line or

path already pre determined by the user This line or path may be as simple as a physical black

straight line on the floor or complex line: circle, the round number eight,zigzag In order to

detect these lines, we use sensor system, it can be individual sensors connected together or

expansive vision systems with many sensors The choice of these schemes is the key to decide

the speed, the accuracy in line detection

1.2 Objective of Study

We looked up reference on the internet And they did complete this project better than us We

tried to do a robot must be capable of following a line:

• The robot must be capable of following a line

• It must be multitasking ,should be capable of taking various degrees of turns

• The robot must also be capable of following a line even if it has breaks

• It must allow calibration of the line’s darkness threshold

• The robot must be insensitive to environmental factors such as lighting and noise

1.3 General operating principles

The robot moves in a predetermined trajectory thanks to a guide, the two-wheel system is

driven by two DC electric motors through a control circuit and a power circuit Often the

guides will have a different color from the background color of the moving trajectory In

order for the robot to move on the right orbit, it is necessary to have a sensor, which is

re-sponsible for distinguishing the guide line and the background color of the moving trajectory

In order for the robot to move in the right trajectory, it is necessary to have a sensor, which

is responsible for distinguishing the guide line and the background color, bringing the

corre-sponding electrical signal to the control circuit The control circuit is responsible for receiving

feedback from the sensor, thereby controlling the speed and direction of rotation of two DC

electric motors so that the car always sticks and moves according to the guide.[1]

1.4 Application of line following robot

It is applied in technology detection lines such as automatic movement during transportation

From the industrial point of view, line following robot has been implemented in semi to fully

autonomous plants In this environment, these robots functions as materials carrier to deliver

products from one manufacturing point to another where rail, conveyor and gantry solutions

are not possible Apart from line following capabilities, these robots should also have the

ca-pability to navigate junctions and decide on which junction to turn and which junction ignore

This would require the robot to have 90 degree turn and also junction counting capabilities

To add on to the complexity of the problem, sensor positioning also plays a role in optimizing

the robots performance for the tasks mentioned earlier Line-following robots with pick-

and-placement capabilities are commonly used in manufacturing plants These move on a

speci-fied path to pick the components from specispeci-fied locations and place them on desired locations

The control principle is still inertia, but the robot path is detected

Chapter 2

Hardware design and software design

2.1 Hardware design

2.1.1 Idea frame

In this project, we had a lot of ideas such as buying frame or designing a new frame Then

we decided to make a new frame We used Solidworks to do that The first, we thought about

using screw to connect electronic appliances but it took a lot of time So we decided use glue

to connect them Because it’s very convenient and simple We have referenced but we used

module L298N and Arduino Uno R3 so we can’t stack it We designed a long frame to put

on electronic appliances During the process, we had a problem We forgot about position of

the sensor To repair it, we used Solidworks to design two plates mica And then, we used

glue to connect sensor with frame Because we used a long frame so two wheels were not

unbalanced, so we used multi-purpose wheel to balance

Figure 2.1: Line following car

2.1.2 Select electronic appliances

Arduino

Nowadays, we have many Arduino such as Arduino Mega R3, Arduino nano V3, Arduino

Leonardo, but in this project we choose Arduino Uno R3.Uno is a great option It has

many feature which we need for this project

Table 2.1: Parameter of Arduino Uno R3

Flash memory 32KB (ATmega328) with 0,5kb used by the bootloader

This is a picture which we used Solidworks to draw model Arduino Uno R3

Figure 2.2: Arduino Uno R3

Module L298N

Module L298N can control 2 DC motors or 1 stepper motor Because we used two wheels so

we need 4 holes located at 4 corners and L298N provided it for us It is very convenient for

us And we know there is an anti-heat heatsink for the IC, helping the IC to control the peak

current of 2A The L298N IC is attached to the on-board diodes to help protect the

micropro-cessor against the induced currents from starting or turning off the engine It is very useful

Table 2.2: Parameter of module L298N

Driver L298N integration of two H-bridge circuits

Power dissipation 20W (when temperature T = 75 ° C)

This is a picture which we used Solidworks to draw model L298N

Figure 2.3: Module L298N

We decided used 5 sensors We began with TCRT5000 but it is difficult because one TCRT5000

has one sensor Then we used The 5-leds bar line detector It is very convenient It is designed

to detect black and white lines On the sensor bar there are 5 infrared sensors pointing to the

ground to detect the line

Table 2.3: Parameter of sensor

Sensor 5 line detection sensors

This is a picture which we used Solidworks to draw model sensor

Figure 2.4: Sensor

We discussed between motor V1 and motor GA25 12V620RPM Motor GA25 12V620RPM

make from metal so it is better than motor V1 but it is more expensive than motor V1 We

reference on the internet and motor V1 is not bad It is very suitable for this project So we

decided to use motor V1 because this line following car is simple

Table 2.4: Parameter of motor V1

Electrical current consumption 110 ∼140mA

This is a picture which we used Solidworks to draw model Motor

Figure 2.5: Motor V1

Wheel

In this project, we used 2 types: wheel V1 and multi-purpose wheel Because our design

needs from 3 wheels to 4 wheels to balance so we used 3 wheels If we used 4 wheels V1, it

would be difficult to code Using 3 wheels is easy It is the same as 2 wheels

Table 2.5: Parameter of Wheel V1 Diameter of wheel 66mm

These are two picture which we used Solidworks to draw model wheel

Figure 2.6: Wheel

Battery

According assistant Mr Cuong, Li – po battery ( lithium polymer battery ) is very good They

are light weight and have improved safety It can refresh so we just buy one time We used 2

batteries for this project

Table 2.6: Parameter of li-po battery

2.1.3 Cost estimation

The details of price of components used in project is given below

Table 2.7: Details of Price of components

We reference on the internet and then we assembled electronic appliances completely This is

our circuit diagram

Table 2.8: Table of Circuit Diagram

2.2 Software design

2.2.1 A algorithm idea

When the vehicle is operating, the sensor will collect information and convert it into an

elec-trical signal to the microcontroller The received value will be compared with the preset value

Based on the value of the sensor sent, determine the relative deviation between the orbit of the

robot and the desired trajectory, then compare that deviation into levels Based on the

devia-tion levels, adjust the speed of the left and right wheels to return the robot to the fund religion

Specifically, to turn left the robot’s right wheel speed is one value faster than the left one

correspond to the deviation levels (need to test many times), and vice versa This method is

simple, but the robot runs unstable, sometimes very fast, sometimes slowly, Stability is highly

dependent on the robot’s motor and mechanical construction To overcome this drawback, by

applying a position controller PID mind robot

Figure 2.8: Block diagram

2.2.2 Working principle of Sensor

One sensor head will emit infrared rays If there are no obstacles, the infrared will continue

The other end is the receiver that won’t get anything, it will return -1 In the case of an

obstacle, the infrared rays are reflected back, the receiver will obtain and return the value

0 In the case of a dark surface, the infrared rays will absorb all the returned infrared rays

enough so the receiver returns 1

Figure 2.9: Working principle of sensor

2.2.3 Working principle of Line following robot

If line is centered in front of robot, line following robot goes forward When the center sensor

is high and the remaining sensor is low the center sensor is will always be on the line and as

line is black in color

If line is right of center, the robot turns right When the right sensor is high, the remaining

sensor is low and the center sensor is will always be on the line and as line is black in color

If no line is detected, circle unit is found

If line is left of center, beside of the robot, it turns left When the left sensor is high and the

remaining sensor is low the center sensor is will always be on the line and as line is black in

#define ENB 11

void read_sensor_values(void); // doc gia tri cam bien

void calculate_pid(void); // tinh PID

void motor_control(void); // kiem soat dong co

void dung();

void chay_thang();

void setup()

{

pinMode (ENA, OUTPUT);

pinMode (ENB, OUTPUT);

pinMode (In1, OUTPUT);

pinMode (In2, OUTPUT);

pinMode (In3, OUTPUT);

pinMode (In4, OUTPUT);

if (( sensor[1] == 0) && (sensor[2] == 0)

&& (sensor[3] == 0) && (sensor[4] == 0) && (sensor[5] == 1)) // trai

error = -4;

else if (( sensor[1] == 0) && (sensor[2] == 0)

&& (sensor[3] == 0) &&

(sensor[4] == 1) && (sensor[5] == 1))

error = -3;

else if (( sensor[1] == 0) && (sensor[2] == 0) && (sensor[3] == 1)

&& (sensor[4] == 1)

&& (sensor[5] == 1))

&& (sensor[4] == 1) && (sensor[5] == 0))

error = -1;

else if (( sensor[1] == 0) && (sensor[2] == 0) && (sensor[3] == 1) &&

(sensor[4] == 0) && (sensor[5] == 0)) // giua line

error = 0;

else if (( sensor[1] == 0) && (sensor[2] == 1)

&& (sensor[3] == 1) && (sensor[4] == 0)

&& (sensor[5] == 0)) error = 1;

else if (( sensor[1] == 1) && (sensor[2] == 1)

&& (sensor[3] == 1) && (sensor[4] == 0) && (sensor[5] == 0))

error = 2;

else if (( sensor[1] == 1) && (sensor[2] == 1)

&& (sensor[3] == 0) && (sensor[4] == 0) && (sensor[5] == 0))

error = 3;

else if (( sensor[1] == 1) && (sensor[2] == 0)

&& (sensor[3] == 0) && (sensor[4] == 0) && (sensor[5] == 0))

I = I + error; // sai so truoc do cong sai so hien tai

D = error - previous_error; // sai so hien tai tru sai so truoc do

PID_value = (Kp * P) + (Ki * I) + (Kd * D);

previous_error = error;

PID_phai = gia_tri_ban_dau + PID_value;

PID_trai = gia_tri_ban_dau - PID_value;

PID_phai = constrain(gia_tri_ban_dau - PID_value, 0, 170);

PID_trai = constrain(gia_tri_ban_dau + PID_value, 0, 170);

analogWrite(ENA, PID_phai);

analogWrite(ENB, PID_trai);

}

Chapter 3

Results

Although there are many controversies and disagreements, we did completely this project

Robot completed on schedule Rugged and safe hardware during heavy travel The circuit

inspection part still had errors, but was promptly corrected During the project, we had 2

trou-bles Firstly,when finished assembling the parts together and loading the code The car was

on, but the wheels were not working Secondly, Vehicle was not stable, has much fluctuation

But we fixed it The idea of making a hybrid robot car was inspired by the team from F1

racing And we did it complete Many groups in class buy frame in the store but we designed

it We can control speed by using code

Figure 3.1: Our line following car