COMPARING AND TUNING PI AND PID DIGITAL CONTROL ALGORITHMS.
Abstract
For years engineers have followed the practice of installing proportional-plus-integral (PI) controllers in the 'normal' control loops and proportional-plus-integral-plus-derivative (PID) controllers in the 'tough' control loops--usually slow loops involving temperature. The typical reason given is that the additional cost of the derivative mode could only be justified in difficult control loops. Another reason is that the PID controller is much more difficult to tune, and engineers would prefer not to undertake it unless necessary. With the advent of direct digital control systems, the increased cost of using a PID algorithm instead of a PI algorithm is negligible, and only the tuning problem remains. Perhaps automated tuning procedures will be perfected in the future to eliminate this problem, but for the present, some guidelines are needed for determining when and how PID and PI algorithms should be used. This report attempts to answer some of these questions about PI and PID algorithms. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1969
- Accession Number
- AD0688795
Entities
People
- Cecil L. Smith
- Paul W. Murrill
- Uday D. Shendrikar
Organizations
- Louisiana State University