Laplace transform and PID controller library ?


This is my first post on this forum so sorry if it isn't written as it should be, if anything has to be changed i'd be glad to change it.

For a science project in my engineering class I choosed to build a balancing bot, all the hardware is already build and i am now writting the code to stabilize it.
My code will be based on the one shown in "Arduino robotics" published by Apress, but my plan is to improve the stabilizing process by using a PID controller (in facts a PI).
I have already found all the equations and i will soon have found the gains to use for the controller , my only problem left is to code it on my arduino board.

The board i'm using is an arduino uno SMD version.

So i wondered if anyone knew about an existing library that could be used to implement such a controller and my equations ?

PS: sorry for my poor english i'm from France.

There is a PID libraries in the libraries section of the website. There is also lots out there if you google "arduino PID".

There is also a Robotics section with a long running thread on a self balancing robot that is worth a read. Or was, at least, before you committed to your hardware design.

@marco_c: Thanks, i looked for Laplace tranform library but i didn't think to look for a PID one only , and it kinda solves my problem (sorry for the pointless thread, silly me ..)

@PaulS : In facts I did the hardware a month ago and i looked a this thread at this time (eveen though i hadn't registered yet)

my plan is to improve the stabilizing process by using a PID controller (in facts a PI).

That sounds like a good fun project. I wish we'd had toys like this to play with when I was studying this type of thing.

The 'D' (differential) element of the PID algorithm provides a damping effect and I would have thought was essential to get the system to settle.

I did not know the ‘D’ was so usefull, in facts the only reason why i choosed a PI is that it is much easier to settle but if i happen to have some spare time (won’t be easy with Diablo III lurking on my desk) i’ll try to use one.

Actually it’s not really a toy to play with since my teacher told me to build one and then did not help me at all after …