Jung, CS Song, HK Hyun, JC 2024-01-21T15:32:10Z 2024-01-21T15:32:10Z 2021-09-05 1999-06 0959-1524 https://pubs.kist.re.kr/handle/201004/142164 A direct synthesis tuning method is proposed for the PI controller settings of unstable first-order-plus-time-delay processes. Unlike hitherto-known PI setting rules which often result in overshoots in time response or require the modification of the feedback control structure, this method ensures the overdamped response as desired while retaining the conventional PI control structure. This enhanced performance is possible by introducing a first-order set-point filter and applying simple rules for setting the values of the controller parameters without having any tuning parameters. The comparison with both conventional PI controllers and two-stage IMC method reveals that the proposed method produces not only smooth overdamped closed-loop response for set-point changes, but also fast regulatory control response for load changes. These responses are also shown to be quite robust against the uncertainties of the parameters as well as against the noise in the signal. The stability conditions for the processes having a large time delay or different ratios of time delay/time constant have been investigated as well. (C) 1999 Elsevier Science Ltd. All rights reserved. English ELSEVIER SCI LTD CONTROLLERS SYSTEMS DESIGN A direct synthesis tuning method of unstable first-order-plus-time-delay processes Article 10.1016/S0959-1524(98)00049-3 1 JOURNAL OF PROCESS CONTROL, v.9, no.3, pp.265 - 269 JOURNAL OF PROCESS CONTROL 9 3 265 269 scie scopus 000079210200006 2-s2.0-0033148385 Automation & Control Systems Engineering, Chemical Automation & Control Systems Engineering Article CONTROLLERS SYSTEMS DESIGN first-order-plus-time-delay processes