The PID control algorithm is the basis for industrial process control. On this site is some basic information about PID control.

The following pages are accessible from the links on this page:

Description is a brief description of the PID algorithm

Tutorial is a six page description of some of the details of the PID algorithm, its components, and how to tune the algorithm.

Code is a two page discussion of two different methods of implementing the PID algorithm in computer code. Rather than any particular programming language, the pages show the program in English and algebra, easily translated into any programming language.