Multivariable and multirate self-tuning control: a distillation column case study

Offset‐Free Inferential Feedback Control of Distillation Compositions Based on PCR and PLS Models

“…A nonlinear tray by tray dynamic model has been developed using mass and energy balances. This simulation has been validated against pilot plant tests and is well known for its use in control system performance studies [9,10]. The following assumptions are imposed: negligible vapor holdup, perfect mixing in each stage and constant liquid holdup.…”

Multirate Multivariable Self-Tuning Control of Distillation Columns Using Kalman Predictor

“…The multivariable multirate STCs derived earlier (Tham et al, 1991a;Chien et al, 1986), which are referred to as conventional multirate STC in this study, have assumed that A(q-l) and C(q-l) are diagonal matrices and they neglected the effect of reflux flow rate on the bottom product composition during the intervals between successive control actions by the bottom control loop. Thus, the above methodologies assume that the effect of intersample interactions over the control period is insignificant.…”

“…The sampling periods used in this study are 41 = 1 min, and 42 = 3 min (Tham et al, 1991a). The steady state operating conditions (Wood and Berry, 1973) are listed in Table I.…”

“…Different sampling rates are encountered in distillation columns if temperature is controlled at one end and composition at the other end or if two-point composition control is used with different analysis times for each loop. Chien et al (1986) and Tham et al (1991a) have employed conventional multirate controllers for distillation control. Tham et at.…”

Modelado, análisis y diseño de sistemas de control con muestreo no convencional.

“…Así ocurre en las aplicaciones aerospaciales (Glasson, 1982), (De la Sen et al, 1987), de robótica (Lee y Xu, 1993), (Tsao y Hutchinson, 1994), (Nemani et al, 1994), (Sun et al, 1996), (Valera, 1998), control de procesos químicos (Tham et al, 1991), (Lee et al, 1992), (Zhu y Ling, 1994) y de una variada gama de procesos, desde la molienda de cemento ( Morant, Albertos y Crespo, 1986), ( Salt, 1992) al controlador del disco duro de un ordenador (Hara y Tomizuka, 1998), (Baek y Lee, 1999).…”