Line follower mobile robot (logic based)

[meowth08]

This project is a line follower. I have already the design but I'm not sure if this really works. I am having a hard time figuring out what values of components to use. To explain briefly this project, it is composed of a sensor and an H-bridge. The sensor transmitter/receiver will be from the sensor of a trackball mouse which is sort of an infrared sensor. By the way, the track or line that it would follow would be color BLACK. Whatever suggestions/changes for the design you have would be a great help.

 

[ericgibbs]

hi m80,
Looks OK, runs in Simulation, look at this image.
I have added R6 and R7

 

[meowth08]

Hello

I already finished my line follower but I was not satisfied with the speed. There is a testing track at school and others finished it in just 34 seconds. Mine finished it in 80 seconds! That is so slow. I used a 1.5 volts battery for the driving motor. When I changed it to 3 volts (series two 1.5 volt batteries), the line follower is very fast that it goes out of track. My problem now is how to vary the input voltage into 2 or 2.5 volts maybe or make it variable from 1.5 volts to 3 volts. Any idea on how I would make the circuit design? This would be the speed control of my project.

 

[ericgibbs]

Hello

I already finished my line follower but I was not satisfied with the speed. There is a testing track at school and others finished it in just 34 seconds. Mine finished it in 80 seconds! That is so slow. I used a 1.5 volts battery for the driving motor. When I changed it to 3 volts (series two 1.5 volt batteries), the line follower is very fast that it goes out of track. My problem now is how to vary the input voltage into 2 or 2.5 volts maybe or make it variable from 1.5 volts to 3 volts. Any idea on how I would make the circuit design? This would be the speed control of my project.

hi,
You could use a diode in series with the battery, that would drop about 0.7v to 1V.

Up to 1Amp motor current, you could use a 1N400x series diode

 

[koolguy]

Hi,
Don't use Transistor for making H-BRIDGES make it simple work on sensors ...
you can use Lm298( up to 2Amps) or other motor control.

 

[4pyros]

When I changed it to 3 volts (series two 1.5 volt batteries), the line follower is very fast that it goes out of track.

That is called overshoot. You will be in a balancing act between speed and accuracy. Changing the drive voltage only will only get you so far. You may also need to look at the sensor placement and response speed of the sensors to get your over all time down. If your sensors are to close or to far from the drive wheels you may not be able to go any faster with out going off the line.

 

[meowth08]

Hi,
Don't use Transistor for making H-BRIDGES make it simple work on sensors ...
you can use Lm298( up to 2Amps) or other motor control.

the design of h bridge using transistors has been checked already by sir eric. i made it and it worked. but i'm very much open to your suggestion. i am very willing to experiment. can you teach me how to make h bridges out of lm 298?

 

[meowth08]

That is called overshoot. You will be in a balancing act between speed and accuracy. Changing the drive voltage only will only get you so far. You may also need to look at the sensor placement and response speed of the sensors to get your over all time down. If your sensors are to close or to far from the drive wheels you may not be able to go any faster with out going off the line.

'overshoot' is a new term to me sir. thanks for the info. i'll also experiment adjusting the sensors.

 

[meowth08]

ritesh kakkar,

Kindly give reasons why transistors should not be used for making h bridges. Have you seen sir eric's new blog? it's a 24 v h bridge. i see many transistors.

I think whatever components we use for as long as they meet the requirements, there's no problem.

 

[4pyros]

Transistors are fine for the small motors used in line followers. ritesh is trying to use a big motor for a robot big enough to ride on. He should not be comparing apples and oranges.

 

[meowth08]

Yes!!!

We ranked third place in a total of 20 participants in the competition of line follower race (logic based) just today. Sorry, I can't post a video.

Special thanks to Sir ericgibbs who helped in many ways.

 

[4pyros]

Good job!
Did you end up moving your sensors? how did you get it faster?

 

[meowth08]

Yes, we did a lot of testing on the sensor.. We even changed the dynamo of our line follower to make it faster. 3volts in series with 1N4001 diode is the supply for the driving motor. Luckily, it managed to stay on track. Three key to make the line follower successful:

testing

testing

and more testing...

 

[harry_electro]

Hi, i am new to this project i search the net and i found this circuit how will i connect the 5v supply. Can I use a 3 1.5v battery and connect it in series with 1n4001 diode?

 

[4pyros]

Hi, i am new to this project i search the net and i found this circuit how will i connect the 5v supply. Can I use a 3 1.5v battery and connect it in series with 1n4001 diode?

Hi Harry and welcome to the forums.
You should start a new thread for your project.
I would use a 9 volt battery and a 5 volt regulater for your logic suppy and run the motors off bigger 1.5 volt batterys.