Line Following Robot

Hello everyone!

Many of you might be interested in robotics but you might not know how to begin your first project in robotics. If so then why don't you try the line following robot.

Line Following Robot is an autonomous robot which follows the specified track of line drawn with distinct color different from surface. A line following robot is a mobile machine employed to sense and follow the black lines that are drawn on the white surface or black or red line in white surface, white or red line in black surface. Robot must be able to detect particular line and keep following it. Robot follows a certain path controlled by a feedback mechanism.

MAKING OF LINE FOLLOWING ROBOT:

Components Required:

1.    Arduino

2.    Motors

3.    Motor driver

4.    IR Sensors

5.    Chassis

6.    Connecting Wires

7.    Power Supply

Components Overview:

DC Motor:

It is an electronic device which converts the electric energy into mechanical energy. 

They are also called actuators. They are used in a robot for rotating wheels which help the robot to move around on the arena. These motors work on the basic principle of Faraday’s Law and they can rotate in both directions.

We would be using two of these motors.

Wires :

We need to have a wire to connect motors and other parts. The wire must be able to handle the current up to 2 Amp. Different kinds of wires can be found in the market. For example, Ribbon wire, where multiple wires are attached to in ribbon like form, red and black wire. The wire also should be flexible so that it will not create any trouble during game-play.

Chassis :

Chassis is one of the most essential part of the robot on which all the durability depends. Mostly chassis are made with iron,steel or plastic. It is good to use a plastic chassis for Racer Robot. It defines the shape, size and weight of the robot so, one should pay deep attention while choosing a chassis. Similarly, chassis should be designed in such a way that it can tolerate shocks during the game-play.

Wheels:

Wheel is another  part of our robot  which defines the stability and speed of the robot.The diameter of the wheel should be chosen according to the speed you need. Grip of the tire is also an important thing. You can use any rubber materials for the increase in the grip of the tire. For instance Grip of cricket bat, bicycle tire tubes, numerous amount of hairband rubbers, etc.

Arduino Board:

It is a board that have atmega micro-controller consisting of input/output pins,power supply,etc.We have to write code in Arduino IDE in high level language,commonly  C language and then upload to the board.

IR Sensor:

Simply,IR sensor reads the color from physical world and gives the values to the user.There are two types of IR sensors i.e analog and digital sensors.Analog sensor gives analog values and digital sensor gives digital values(1 or 0).

Power supply:

Generally, 9V or 12V batteries are used to give power supply.Motors are provided with 12V or 9V whereas arduino board and sensors are provided with 5V power supply.Rechargeable batteries are preferred mostly.

How does it works?

When robot is placed on the fixed path, it follows the path by detecting the line. The robot direction of motion depends on the two sensors outputs. When the two sensors are on the line of path, robot moves forward. If the left sensor moves away from the line, robot moves towards right. Similarly, if right sensor moves away from the path, robot moves towards its left. Whenever robot moves away from its path it is detected by the IR sensor.

IR sensor consists of IR transmitter and IR receiver on a board. When the vehicle is moving on a black line, IR rays are continuously absorbed by the black surface and there is no reflected ray making output high. Whenever, the robot moves out to the white surface, it starts reflecting the IR rays and making the output low. Thus depending on the output of IR sensor micro-controller indicates the motors to change their direction.

Assembling of Line Follower Robot:

Step 1:

Get the chassis for robot.

Step 2:

If you are using caster wheel,assemble two motors and attach wheels on each motor.  

          

Otherwise use four motors and attach wheels on each motors.

Then,connect the two right motors and two left motors.

Step 3:

Connect the motors to motor driver(L293D IC) in M1 out and M2 out respectively.

Step 4:

Connect the motor driver with Arduino.

Connect four pins(for eg:4,5,6,7) of Arduino to motor driver in M1 in(4,5) and M2 in(6,7).

Step 5:

Adjust the IR sensors(normally two sensors) on the chassis.

Connect sensors and Arduino (eg:11 and 12).

Step 6:

Now write appropriate program and upload on Arduino board.

Step 7:

Attach all parts  on the chassis appropriately.

Step 8:

Give power supply to motor driver(5V or 9V or 12V) , sensors(5V) and Arduino board(5V).

Step 9:

Get the game field and test your robot.

Now your robot will follow a line as per game field and developed program in Arduino.

Applications of line follower robot:

• These robots can be used as automated equipment carriers in industries replacing traditional conveyor belts.

• These robots can also be used as automatic cars running on roads with embedded magnets.

• These can also be used at homes for domestic purposes like floor cleaning etc.

• These can be used in public places like shopping malls, museums etc to provide path guidance.

• This can also be used in defense application.

Limitations of Line Following Robot:

• Line Following Robot require 2-3 inch broad line.

• It may not move properly if the black line drawn is of low intensity.

• The IR sensors may sometimes absorb IR rays from surrounding also. As a result Robot may move in improper direction.

Programming logic:

1. Interfacing motor with Arduino:

int x,y;

//black = 0, white = 1

void setup()

{

  Serial.begin(9600);

pinMode(2,OUTPUT);   // defines the output pin

pinMode(3,OUTPUT);

pinMode(8,OUTPUT);

pinMode(9,OUTPUT);

}

void forward()

{

  digitalWrite(2,1);    // rotates the motor

  digitalWrite(3,0);

  delay(1000);            //waits for 1sec

  digitalWrite(8,0);

  digitalWrite(9,1);

  delay(1000); 

   

}

void pause()

{

  digitalWrite(2,0);

  digitalWrite(3,0);

  delay(1000); 

  digitalWrite(8,0);

  digitalWrite(9,0);

  delay(1000); 

}

void right()

{

  digitalWrite(2,1);

  digitalWrite(3,0);

  delay(1000); 

  digitalWrite(8,0);

  digitalWrite(9,0);

  delay(1000); 

}

void left()

{

  digitalWrite(2,0);

  digitalWrite(3,0);

  delay(1000); 

  digitalWrite(8,0);

  digitalWrite(9,1);

  delay(1000); 

  

}

void loop()

{

  x = digitalRead(A0);

  y = digitalRead(A1);

  if (x == 1 && y == 0)

{

      left();

      Serial.println("LEFT");

  }

  else if (x == 0 && y == 1)

{

      right();

      Serial.println("RIGHT");

  }

  else if(x == 0 && y == 0) 

{

    forward();

    Serial.println("FRONT");

  

  }

  

  else

{

    pause();

    Serial.println("PAUSE");

 }

}

2.  Interfacing sensor with Arduino:

void setup()

{

pinMode(9,INPUT);           // defines input pin

}

void loop()

{

int x=digitalRead(9);         // stores the value of sensor

}

Hope you might have created your own line following robot and have make this post beneficial and useful. So, share it among you friends too and keep innovating.