Control Theory

Hi all,

After getting the camera tracking and moving the robot according to the servo values, I’m trying to fine-tune the tracking algorithm. After reading Kevin’s post, where he mentioned control theory, it interested me on the topic. (

Can anyone point me to a reference on control theory, or explain the basic concepts? (Maybe with some code examples on the topic of the camera, or even pseudocode)

Thanks, is always a good starting place, in this case it is an extremely well documented, and laid out way of looking at it, with a brief history, as well as the mathemetical reasoning behind it:

Thanks, sorry, I forgot about wikipedia, sheepish, does anyone have any other sources of information? hopefully Maybe some snippets of code?

Again, thanks,

I should have mentioned in that other posting that these types of control algorithms are known as feed-forward or feedforward control algorithms (as opposed to feedback control). Control theory is a huge and wonderous topic and any time spent understanding the subject will not be time wasted.


Kevin, or others
Can you reccomend a good book or other refrence that would be a good starting point to learn this, as I am a computer networking major I dont get to take classes like control theory and cant afford the time nor cash to take the classes at the moment. But I am very intrested in the topics, I have researched PID control some but would like any more information I can get. :slight_smile:

I have taken a couple control courses in college, and they all tend to be pretty academic, which would have been pretty punishing entering into my current position as an on site trouble shooter in the automation industry. However, on my first day, my boss gave me an excellent book, actually written by a long time employee at the company I work for, Danaher Motion.

It assumes you have a bit of a understanding of control theory already, so perhaps this is the SECOND book you’d buy if you’re looking for good practical application and understanding of tuning parameters in the field.

Compare prices on this book:

Read Amazon’s Reviews:
Control System Design: A Practical Guide
George Ellis is a pretty smart cookie and I found this book to be highly readable. I can’t say that about a lot of technical books.


I can recommend Nise’s Control Systems Engineering]( I also have Levine’s Control System Applications]( and Control System Handbook](*, *but I’m not sure I’d recommend these books as they’re for control theory geeks (a good percentage of the latter book is pretty esoteric and over my head). A good supplemental book is Schaum’s Feedback and Control Systems]( If I were you, I’d spend some time on the web, which has a wealth of control theory information. If you have access to a copy of MATLAB or Mathematica, there are many interactive demos available at the Mathworks and Wolfram Research web sites. I would also go over the the LabVIEW forum and ask Danny Diaz if he can help you find some control theory apps for LabVIEW. There is also a freeware MATLAB-like application called Scilab, that may have interactive control theory applications. These nifty interactive control theory applications are great for helping you develop your physical intuition of how things behave in the real world.


If you click on the advanced search option here on CD and search on

Closed loop feedback

selecting ‘search titles only’ you will find a bunch of posts from previous years. most are locked so you cant reply to them, but lots of good info there.

PID stands for “proportional intergral differential”. In motion terms that corresponds to a control system that looks at “position, velocity and acceleration” of where you are compaired to where you want to be.