One-Parameter Method for a Multiloop Control System Design

Abstract

A multiloop control system can be designed with the independent design method by assuming trial controllers with design parameters and adjusting the design parameters so as to satisfy stability and performance bounds. Various stability and performance bounds have been available and were studied for less restrictive ones. On the other hand, little attention has been paid to trial controllers even though they greatly affect the final control performances. Controllers with one design parameter are the usual choice. Here, a one-parameter method for 2 × 2 multiloop control systems is extended to higher dimensional processes in which the design parameter is the time constant of the set point response of the paired output. Control performances are compared with the well-known biggest log modulus tuning method and the sequential autotuning method.

Heuristic-based multi-scale control procedure of simultaneous multi-loop PID tuning for multivariable processes

“…In the past, several researchers used the WB column as an example for comparing the effectiveness of different multi-loop PID design methods; e.g., see [7,10,18].…”

“…Five multi-loop PID control systems tuned using different procedures are compared: (a) heuristic-based SML (SML-H), (b) optimization-based SML (SML-O), (c) dominant pole placement procedure of Zhang et al [7], (d) decentralized PI design of Chen and Seborg [18], and (e) one-parameter tuning method of Jung et al [10].…”

“…In this method there are n tuning parameters for a given n × n MIMO system. Also it is interesting to note that, Jung et al [10] proposed the so-called one-parameter tuning method based on an IMC control scheme. In this method, a multiloop control system is first designed by assuming trial controllers with certain design parameters.…”

Inter-Communicative Decentralized Multi-Scale Control (ICD-MSC) Scheme: A New Approach to Overcome MIMO Process Interactions

“…Several design methods have emerged based on the independent design approach, e.g. independent method based on effective open-loop transfer functions [11], one-parameter method [12], and method based on Nyquist stability analysis [13].…”

Decentralized identification for multivariable integrating processes with time delays from closed-loop step tests

“…Due to the existence of cross-couplings or interactions between these variables, each control loop will be affected more or less by other loops so that classical single-loop PID controller design methods become invalid. In this situation, a number of multivariable robust PID controller design methods were put forward on the basis of decentralized control structures [5,8,10,16,19]. However, all these methods required a prior multivariable model in the form of a continuous transfer function matrix with different time delays for nominal performance, whose elements can be approximated with a firstorder plus dead time (FOPDT) model or a second-order plus dead time (SOPDT) model [26].…”