Thursday, November 19, 2009

PID Videos

This video shows a PID Controller built using an Arduino microcontroller. The fan blows the paper and the displacement is measured using an infrared sensor.

Here a Parallax BOE bot is used to demonstrate to difference between P and PID control for robot steering.


Jay said...

is the first demonstration P control? Looks like it by the twitch. Seems like the second one overshoots the signal more but is more stable? am i correct?

I Heart Robotics said...

The first one is P control and the second one is PID control. They both need their gains tuned but give you a rough idea as to what the difference is.
If the gains were tuned better it may be difficult to tell them apart but the main difference is that P control will always have some small but finite error.

Also PID is not necessarily more stable then P control if the gains are not set correctly. Stability is a specific technical term in control theory which basically means that if you have a finite input you will have a finite output as time goes to infinity.

I'll probably write up an applied PID tutorial in the next month or two.

Anonymous said...

Well done! I never get tired of playing with control loops and watching the response.