What is a Line Follower Robot?


This robot as its name suggest follows a white or a black line. The main logic behind this robot is that it follows transparent or opaque surface in which white surface reflects back light and light is absorbed by the black surface.

This logic is used by an IR sensor, which is a pair of IR transmitters and emitter. IR rays are emitted by the transmitter and the receiver receives them. If the surface is white in color it reflects back the color and the receiver starts to receive in the way which sensor produces 5v as the output of the LINE FOLLOWING ROBOT. So output gets connected to the logic circuit to move  other appliances or motor’s. Once the sensor meets the black surface no rays are reflected back, so the output will be 0 voltage.As the sensor gets on  black surface no rays are reflected back, so the output will be zero volts.

A simple line following robot doesn’t need to be programmed and works without microcontroller hence it can be made by a novice..The components used in the line following robots are  ULN 2003A IC and INFRARED SENSORS. When the infrared sensor gets on the reflective or white surface it gives an output of 5 volts.ULN 2003A consists of a high current high voltage Darlington transistor array. It acts a switch in the circuit and as soon as it receives 5v as input the output switch opens and if there is no input switch closes.

As soon  as the IR sensor produces 5va s the output the pin of the ir sensor gets connected with the ulb2003 IC input pin and it leads to the motor which starts running. Once there is no input motor stops working.