Title :
Relay based gain and phase margins PI controller design
Author :
De Arruda, Gustavo H M ; Barros, Péicles R.
Author_Institution :
Dept. de Engenharia Eletrica, Univ. Fed. da Paraiba, Joao Pessoa, Brazil
Abstract :
An iterative procedure for achieving gain and phase margin specifications for a PI controller is presented. The iteration scheme is based on the use of two relay tests applied to the closed loop system. The first relay test is standard and it is used here to obtain the gain margin of the closed loop system at each iteration step. The second one is applied to the closed loop system such that a limit cycle is developed at the loop gain crossover frequency. Under this condition it is possible to obtain an estimate of the phase margin of the loop transfer function. The procedure is applied to a PI controller tuning in a heat exchanger in laboratory scale using desired gain and phase margin specifications
Keywords :
closed loop systems; control system synthesis; frequency estimation; frequency response; heat exchangers; iterative methods; limit cycles; relay control; transfer functions; tuning; two-term control; PI controller design; PI controller tuning; closed loop system; frequency estimation; gain margin specification; heat exchanger; iterative procedure; laboratory scale; limit cycle; loop gain crossover frequency; loop transfer function; phase margin specification; relay tests; Closed loop systems; Frequency locked loops; Laboratories; Limit-cycles; Phase estimation; Relays; System testing; Temperature control; Transfer functions; Tuning;
Conference_Titel :
Instrumentation and Measurement Technology Conference, 2001. IMTC 2001. Proceedings of the 18th IEEE
Conference_Location :
Budapest
Print_ISBN :
0-7803-6646-8
DOI :
10.1109/IMTC.2001.928265
