Line Follower Surveillance Robot

Line Follower Surveillance Robot Department of EEE, AHSANULLAH UNIVERSITY OF SCIENCE AND TECHNOLOGY, Dhaka, Bangladesh.

1. Introduction Line follower robot is a basic of all kinds of robot. A robot must follow something to do its desire works. For a line follower robot, a robot must have to follow the line given.

(b) Adafruit Motor Driver Shield: The motor driver shield is used , is designed by Adafruit where two L293D chips are used to control 4 DC motors and 74HC595N chip is used to control 2 servo motors. It has also a reset button. This motor driver shield is to be set on Arduino uno.

2. Theory Features of Motor Driver Shield: (a) Arduino Uno: The Arduino Uno is a microcontroller board based on the t he ATmega328. It has 14 digital input/output pins (of which 6 can be used as PWM outputs), 6 analog inputs, a 16 MHz ceramic resonator, a USB connection, a power jack, an ICSP header, and a reset button. It contains everything needed to support the microcontroller; simply connect it to a computer with a USB cable or power it with a AC-to-DC adapter or battery to get started.

Chipset : Two L293D & One 74HC595N chipset Provided current rate: 0.6A each chipset Analog Pin: 6 Voltage Terminals : 5v & 9v External Supplies: A 2 pin terminal blocks to supply external power to motors.

Features of Arduino Uno :

Microcontroller : ATmega328 Operating Voltage: 5V Input Voltage: 7-12 V Digital I/O Pins: 14 Analog Pins: 6 DC current per I/O pin: 40ma Flash memory: 32 kb SRAM: 2 kb Clock Speed: 16 MHz Fig : Adafruit Motor Driver Shield

3. Equipments To build this line follower robot we have used the equipments given below (a) Arduino Uno Fig : Arduino Uno

(b) Adafruit Motor Driver Shield V1 (c) Rover Chassis

(d) 2 DC motors (e) A Servo Motor : 

DM-S0090M

> We will use a sensor board which is mounted with black tape at the front of the chassis. In this sensor board we supplies 5v internally through the 5v terminal of the motor driver shield. The main purpose of this robot is to follow the given black line on a white surface. First we have to take the serial of each LDR of the sensor board of black line and white surface through arduino serial monitor using this code.

(f) LDR (g) LED (h) Jump Wires (i) Plexi Glass (j) 11.5v Li-po Battery (35c) [3 Cells 2200mAh] (k) 9V Battery (l) A Digital Camera (m) Other necessary tools

int sensePin =0; void setup() { analogReference(DEFAULT); Serial.begin(9600); } void loop() { Serial.println(analogRead(sensePin)); delay(500

4. Circuit Diagram

Then we will notice the serial of LDR like this

Fig: Circuit Diagram of Sensor board

After getting all the serials of all LDR. We can set the ranges of them. >After that we will connect one DC motor with a M1 terminal and another with M4 terminal of the motor driver shield. > Then we will connect the servo motor DM-S0090M at Ser1 terminal. > We will use 3 Cells 2200mAh Li-po Battery (35c) to give the motors enough power to operate which should be connect with the external power supply terminal. >We use enough plexi glass to decorate the whole things neatly. >Then we use Digital camera which is set on the top of the body , where the servo motor is set to be operated to press the shutter button of the camera. Fig: Diagram of a Line follower robot

5. Procedure > At first we have to create a black line with black tape on a white surface like white sheet.

> We can use check point where camera is to be snapped by the servo by using a bit black tape on the line. > After doing proper code on servo we can run this robot.

> Then we will use a rover chassis (built in 2 DC motors) as a main body of line follower robot. CODE:

#include #include

// Motor Library add // Servo's Library add

value5 = analogRead(sensePin4); // Value of LDR5

Servo myservo; {

Servo myservo2;

{if ( value1 >=1 && value1 <= 8 )

int pos = 0;

convalue1 = 0 ; //Range of serial of LDR1 on Black

int count, count2,count3;

else if ( value1 >= 9 && value1 <= 20) AF_DCMotor motor(1);

//Left MOTOR

AF_DCMotor motor2(4);

//Right MOTOR

int sensePin0 = 0;

convalue1 = 1 ;} //; //Range of serial of LDR1 on White

//Start from left sense pin

int sensePin1 = 1; int sensePin2 = 2; int sensePin3 = 3;

{if ( value2 >= 1 && value2 <= 8) convalue2 = 0 ; ; //Range of serial of LDR2 on Black

int sensePin4 = 4; int value1, value2,value3, value4, value5; int convalue1, convalue2,convalue3, convalue4,convalue5;

void setup()

else if ( value2 >=9 && value2 <= 20) convalue2 = 1 ;} //; //Range of serial of LDR2 on White

{if ( value3 >= 1 && value3 <= 15) convalue3 = 0 ; ; //Range of serial of LDR3 on Black

{ analogReference(DEFAULT); myservo.attach(9); myservo2.attach(10);

else if ( value3 >= 16 && value3 <= 25) convalue3 = 1 ;} //; //Range of serial of LDR3 on White

} {if ( value4 >= 1 && value4 <= 8)

void loop()

convalue4 = 0 ; ; //Range of serial of LDR4 on Black

{ value1 = analogRead(sensePin0); // Value of LDR1 value2 = analogRead(sensePin1); // Value of LDR2

else if ( value4 >= 10 && value4 <=20 ) convalue4 = 1 ;} //; //Range of serial of LDR4 on White

{if ( value5 >= 1 && value5 <= 4) value3 = analogRead(sensePin2); // Value of LDR3

value4 = analogRead(sensePin3); // Value of LDR4

convalue5 = 0 ; ; //Range of serial of LDR5 on Black

else if ( value5 >= 5 && value5 <= 20) convalue5 = 1 ;} //; //Range of serial of LDR5 on White

{ motor.setSpeed(120); motor2.setSpeed(60); motor.run(FORWARD); motor2.run(FORWARD);} } // We assume the position of the LDR like LDR1-LDR2-LDR3-LDR3-LDR4-LDR5

else if (convalue1==1 &&

if (convalue1==1 &&

convalue2==1 &&

convalue2==1 &&

convalue3==0 &&

convalue3==0 &&

// Straight

convalue4==1 && convalue5==1 )

//Combination 11011

convalue4==0 && // Right SHARP TURN convalue5==0 ) //Combination 11000 motor.setSpeed(120); motor2.setSpeed(100);

{ motor.setSpeed(120);

motor.run(FORWARD);

motor2.setSpeed(120);

motor2.run(BACKWARD);}

motor.run(FORWARD); motor2.run(FORWARD);}

else if ( convalue1==1 && convalue2==0 && //Left TURN


convalue3==1 &&

convalue2==0 && convalue3==0 && //Bit Left turn

convalue4==1 && convalue5==1 ) //Combination 10111

convalue4==1 && convalue5==1 ) // Combination 10011

{ motor.setSpeed(60); motor2.setSpeed(150);


motor.run(BACKWARD);


motor2.run(FORWARD);}

motor.run(FORWARD); motor2.run(FORWARD);}

else if ( convalue1==1 && convalue2==1 &&


convalue3==1 &&

convalue2==0 && convalue3==0 && //Sharp Left Turn

convalue4==0 &&

//Right TURN

convalue5==1 ) //Combination 11101


{ motor.setSpeed(150); motor2.setSpeed(60);


motor.run(FORWARD);

motor2.setSpeed(120); motor.run(BACKWARD);


motor2.run(FORWARD);} else if ( convalue1==1 && convalue2==1 && //Bit Right turn


convalue3==1 &&

convalue2==1 && convalue3==0 &&

//Bit Right turn


convalue4==1 && convalue5==0 ) //Combination 11110 { motor.setSpeed(150);

{



motor.run(FORWARD);


motor2.run(BACKWARD);} else if ( convalue1==0 && else if ( convalue1==0 &&

convalue2==0 &&

convalue2==1 &&

convalue3==0 && //Right Sharp Turn

convalue3==1 &&

convalue4==0 &&

convalue4==1 &&


//Bit Left turn








motor2.run(FORWARD);}

motor2.run(FORWARD);} else if ( convalue1==1 && else if ( convalue1==1 &&

convalue2==0 &&

convalue2==1 &&//Right Turn

convalue3==0 && //Left Sharp Turn

convalue3==1 &&

convalue4==0 &&

convalue4==0 &&







motor.run(FORWARD);

motor.run(FORWARD);


motor2.run(BACKWARD);} else if ( convalue1==0 && else if ( convalue1==0 &&

convalue2==0 &&

convalue2==0 &&

convalue3==0 && //Stop

convalue3==1 && //Left Turn

convalue4==0 &&

convalue4==1 &&


convalue5==1 )


//Combination 00111


motor2.setSpeed(0);


motor.run(FORWARD);

motor.run(BACKWARD); motor2.run(FORWARD);}

motor2.run(FORWARD);

else if ( convalue1==1 && convalue2==1 && convalue3==1 &&

//Backward

convalue4==1 && convalue5==1 ) //Combination 11111 { motor.setSpeed(120); motor2.setSpeed(120);

{ for(pos = 0; pos < 45; pos += 45) // goes from 0 degrees to 45 degrees {

// Click Down The servo

myservo.write(pos); position in variable 'pos' delay(1000);

// tell servo to go to

// waits 1s for the servo to reach the position

}

for(pos = 45; pos>=1; pos-=45) degrees to 0 degrees {

// goes from 45

// Click up the servo

myservo.write(pos); position in variable 'pos'

// tell servo to go to

delay(1500); // waits 1.5s for the servo to reach the position }

Then, to turn right side, this combination may be happened 11100, 11000, 11001, 11101, 11110 To turn right side the rpm of right motor should be less than the left motor. For sharp turn right motor should be run Backward and left motor should be run Forward at same rpm. Then, to turn left side, this combination may be happened 00111, 00011, 10011, 10111, 10000 To turn right side the rpm of left motor should be less than the right motor. For sharp turn left motor should be run Backward and right motor should be run Forward at same rpm. If there’s no line to follow, like this combination 11111

{motor.setSpeed(120);

Both motors will run Backward, to rejoin the line.

motor2.setSpeed(120); motor.run(FORWARD); We have made a checkpoint, where the LDR combination will be

delay(500);

00000

motor2.run(FORWARD);

When robot will reach the check point, the rpm of both motors will be 0 that means it’ll stop. Then the servo blade will click down to the shutter of the camera and push it over 1 second which is enough to snap a photo.

delay(500); } }

After 2.5 second both motor will run forward to follow the line. Then the whole process will be done like decrypted before.

}

}

7. Troubleshooting (a) At first we build the sensor board, then took the value of each LDR and with the value of LDR we wrote the code using the ranges of serial. But our robot did not follow the line. Then we figure it out that the light of surrounding interrupted LDR so the value was changing time to time.

6. Working Principles When we put the robot on line, the light of LED will reflect to the LDR. The rate of reflection from the black line and white surface are different. From the rate of reflection to the LDR, (the ranges were preset in the code) the motors will rotate as we coded. If we assume the reflection ranges from black line is 0 and the ranges from the white surface is 1, then to go straight it has to be : 1

1

0

1

1

LDR1 LDR2 LDR3 LDR4 LDR5

Then the rpm of both motors are same.

To solve this problem we mounted every LED and LDR with black tape very well and then we mounted the the whole sensor board. From then it followed the line perfectly.

(b) At first our robot run too slowly because we were using a battery which was unable to supply enough power to run the robot fast. Then we used Li-Po 14.5v Li-po Battery (35c) [4 Cells 2200mAh] as external power to run the motors. As we

changed the battery the value of LDR changed. So we again took the value and run the programme. And robot responded perfectly.

(c) The very next day when we were testing our robot’s performance. After completing the first Lap of our track suddenly we saw fire and smoke on the motor shield. Then we figured out that our motor shield dead.

We were using that battery directly to the motor shield to run which was excessive. Then we changed the battery again with 11.5 V Li-po (3 cells) 35c also a new motor shield. Then we used 7809 voltage regulator IC to regulate the voltage from 11.5v to 9 v.

(d) After running our robot for some times suddenly it stopped. And found that the heat of the 7809 was very high and it was already damaged.

To solve this problem we used heat-sink with a new 7809 and connect again. Then everything was going okay. (e) After that we set our camera on the top to be operated by a servo motor. But we purchased a continuous rotating servo. Which was unable to control by our code.

Then we changed the servo and bought DM-S0090M. It could be controlled easily by our code. (f) When we were running our robot with servo we found that when was operating , the brightness of the LED decreasesd. As a result the value of LDR changed so it was not running and robot also didn’t follow the line.

To solve this problem we used an extra 9V battery of 250mA to operate the Arduino and we

7. Application in Future To monitor a certain area of a city it can be used. It will capture the footage of different spot of that area which is helpful to avoid the unsocial activities by monitoring. To observe the terrorist activity it can be used as a drone in an area. To see the condition of an disastrous and dangerous area it can be used. It can be used to get footage of places where human can not access like Underground mine, Narrow Sewerage tunnel.

8. Images

SUBMITTED BY

Section : A Semester : 2.2 Group : 2 Group Member : 

Rifayet Hasan Sajol (12.01.05.014)



Chowdhury (12.01.05.017)



Shafkat Tasnim (12.01.05.037)



Md. Motiur (12.01.05.038)



Sohan Bin Anwer (12.01.05.049)

Fakrul

Rahman

Alam

Sagar

Line Follower Surveillance Robot

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