kakou19:
Can you explain exactly how PID works or post some pseudo code please. Im a bit confused...
If you really want to understand PID - I suggest that you take Udacity's CS373 class; in it, PID is described and implemented (in Python) in a way that makes it very clear how it works and why. This is only one small portion of the course, though; you can't just jump to that part and hope to understand it (unless you have a good grounding in the earlier parts of the course). Depending on your skill levels, the course may be considered from "easy" to "very difficult" (the latter being true if your understanding of linear algebra and probability/statistics is low to non-existant) - but in the end is well worth the struggle.
On a similar note:
Udacity recently announced that they have brought back the original AI course that Stanford ran last fall/winter (I am contemplating enrolling in it - I was in it last fall, and had to drop out halfway through due to personal issues - I am so glad they brought it back!)...