Revisiting the Ziegler–Nichols process dynamics characterization

✍ Scribed by Tomislav B. Šekara; Miroslav R. Mataušek

• Book ID: 104027190
• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 312 KB
• Volume: 20
• Category: Article
• ISSN: 0959-1524
• DOI: 10.1016/j.jprocont.2009.08.004

✦ Synopsis

The Ziegler-Nichols process dynamics characterization is based on the estimation of the ultimate gain k u and ultimate frequency x u . The angle u of the tangent to the Nyquist curve at the frequency x u is introduced, as an additional parameter in the frequency domain. The essential dynamic characteristics of the process can be captured by using the tangent rule, proposed here as an extension of the Ziegler-Nichols approach. The validity of the tangent rule is confirmed by using the PID controller optimization on a test batch consisting of stable, integrating and unstable processes, including dead-time. Parameters k u , x u and u can be determined from the sustained oscillations, using the phase-locked loop identifier module.