Robot - motors run at different speeds

Projects Discussion and Showcase Robotics
#1

It seems that the two motors in my Arduino robot run at different speeds. So with them both set to full speed (255,255), the robot does not travel in a straight line - instead it veers to the left or the right. Is this to be expected? Do I need to compensate myself in software?

I contacted Arduino about this and they sent me a replacement robot - but it behaves in exactly the same way (actually the replacement veers the other way, but it still won't go straight).

Here's a video: IMG 6833 - YouTube

Any ideas?

#2

I would describe this as normal behavior. The reason why all the sensors (like the electronic compass) are on the robot is to make course corrections.

#3

Thanks for that. I'm kind of glad if that's the case - I'd be very surprised to have received two faulty robots. But I wonder why Arduino didn't simply tell me the same thing when they saw the video...

#4

The wheels need calibration. Take a look at

Examples -> Robot_Control -> Explore -> R06_Wheel_Calibration

If you have not calibrated the wheels.

#5

does it always turn the same way ? Trying sending a different signal to each wheel.

#6

srimadh:
The wheels need calibration. Take a look at

Examples -> Robot_Control -> Explore -> R06_Wheel_Calibration

If you have not calibrated the wheels.

Amazing! This did the trick. Thank you so much. I wonder why on earth neither Arduino nor their distributor thought
of doing this...

#7