A-Line Follower Robot, as the name suggests, is an automated guided vehicle, which follows a visual line embedded on the floor or ceiling. Usually, the visual line is the path in which the line follower robot goes and it will be a black line on a white surface but the other way (white line on a black surface) is also possible. Certain advanced Line Follower Robots use the invisible magnetic field as their paths.

Large line follower robots are usually used in industries for assisting the automated production process. They are also used in military applications, human assistance purpose, delivery services etc.

Line follower Robot is one of the first robots that beginners and students would get their first robotic experience with. In this project, we have designed a simple Line Follower Robot using Arduino and some other components.

Step 1: Components Required:

1. Arduino UNO (or Arduino Nano)

2. L293D Motor Driver IC [You can buy module or you can make yourself]

3. Geared Motors x 2

4. IR Sensor Module x 2 [You can buy module or you can make yourself]

5.Connecting Wires

6. Power supply

7. Battery Connector

Step 2: Working of Arduino Line Follower Robot:

In this project, I have designed an Arduino based Line Follower Robot. The working of the project is pretty simple: detect the black line on the surface and move along that line.

As mentioned, we need sensors to detect the line. For line detection logic, we used two IR Sensors, which consists of IR LED and Photodiode. They are placed in a reflective way i.e. side – by – side so that whenever they come into proximity of a reflective surface, the light emitted by IR LED will be detected by Photodiode.

When the robot moves forward, both the sensors wait for the line to be detected. For example, if the IR Sensor 1 in the above image detects the black line, it means that there is a right curve (or turn) ahead.
Arduino UNO detects this change and sends signal to motor driver accordingly. In order to turn right, the motor on the right side of the robot is slowed down using PWM, while the motor on the left side is run at normal speed.

Similarly, when the IR Sensor 2 detects the black line first, it means that there is a left curve ahead and the robot has to turn left. For the robot to turn left, the motor on the left side of the robot is slowed down (or can be stopped completely or can be rotated in opposite direction) and the motor on the right side is run at normal speed.
Arduino UNO continuously monitors the data from both the sensors and turns the robot as per the line detected by them.