Author Options:

how the robot follows only the black line without programmed ? how the robot turns left&right according to the line? Answered



4 years ago

Self Correction !

less left light ( means turning right wise onto line )
Slows the left motor
Causing a turn left ( away from the line )


less right light ( means turning left wise onto line )
Slows the right motor
Causing a turn right ( away from the line )


4 years ago

The robot will have three ldr's which act as switches. If the robot sees 0 1 0, where 0 is background and 1 is the line, the robot will go straight. If it sees 1 1 0 or 0 1 1, they will switch the motors off accordingly to correct the path of the robot until it sees 0 1 0.


The robot views the line with some kind of photo sensor. In general there will be 3 side by side slightly further apart then the width of the line.

When the robot moves over the line one of the sensor will go dark and electronics will turn the robot towards that sensor until it is clear again .

In this way the robot can follow the line provided that:

1. there is a good contrast between the line and back ground.

2. the line does not make very sharp turns

3. the robot does not go too fast.

Sometimes the robot will use 3 sensors. 1 that sits in the middle over the line. 2 each side. This gives more accuracy and a faster response.