LINE FOLLOWER ROBOT
This is my first robot which is very simple line follower. I,Anil K M,J Rajasekhar Reddy made it for out college technical festival. Later I made two other line followers using microcontrollers but I don't have the programms of it.
Working Principle:Here we used the black strip of thickness 3cm. We made the track by combining four white sheets together and pasting black strip over it. In this we are designed the robot in such a way that when black strip comes under the LDR (means the robot try to cross over the black strip) the correspond motor will become off. This happens when curved portions comes. So the other motor works and robot will take the turn.
Here the LDR resistance varies from
400ohm to 200Kohm. When robot is in White strip:
V2= (V - .2)*((1+5.6)/(1+5.6+1) V
LIMITATIONS AND PROBLEMS
Here main limitation comes onreaction time of LDR
The LDR used are very cheap so their reaction time was very slow
matching between Inertia and reaction time of LDR
If we use some good speed the robot will cross the black strip
because of reaction time of LDR and due to inertia. So the speed
should be kept optimum.
We are keepind LDR's on the bottom of the robot so the proper
lighting should be provided. Lighting should be of high intensity.
Then we get better response. We used two 2.5V bulbs. It is better to
use flourescent lamps.In black strip reflection is less.
Here you can see that the robot is going forward and taking turn.
So this should be avoid by fitting LDR in the front so that the robot
will take turn as a normal vehicle take turn.