Self-Tuning PID Control of a Polybutene Process

Design and experimental evaluation of a multivariable self-tuning PID controller

“…Next consider the design of PID controllers [18] for the augmented system given by (11). The digital PID control law to be considered in this paper is described as…”

“…Note that the parameters l i are related to only k c i : In other words, T I i and T D i are independent of l i : Thus the proposed scheme has a feature such that after selecting P i ðz À1 Þ in the generalised output (18), l i can be determined or chosen independently by considering the stability of the control system based on a priori information. For example, the Bode diagram can be utilised to determine l i : Such a design method for selecting l i is discussed in detail in Section 3.…”

“…The main motivation in this study is to extend the univariate PID control scheme [18] to multivariate control systems. Many industrial processes are inherently multivariate in nature and yet are presently controlled by multiloop PID control schemes, where the interaction among the loops is essentially ignored.…”

“…This study attempts to precisely implement this idea but in an adaptive manner, i.e. a static precompensator is estimated and implemented in an online manner followed by a separate adaptive outer loop for the design of 'p' SISO PID control loops based on the generalised minimum variance criterion [2,18]. The advantage is that the proposed technique can deal with the time-variant nature of the process and also retain the designer's intuition and insight through the relatively simple design scheme that is proposed.…”