文档介绍：ARTICLE IN PRESS
Control Engineering Practice ] (]]]]) ]]]–]]]
ate/conengprac
Advanced control algorithms embedded in a programmable
logic controller
Samo Gerksˇ icˇ a,Ã, Gregor Dolanca, Damir Vrancˇ ic´ a, Jusˇ Kocijana,b, Stanko Strmcˇ nika,
Sasˇ o Blazˇ icˇ c, Igor Sˇ, Zoran Marinsˇ ekd, Miha Bozˇ icˇ ekd, Anna Stathakie,
Robert Kinge, Mincho Hadjiskif, Kosta Boshnakovf
aJozˇef Stefan Institute, Ljubljana, Slovenia
bNova Gorica Polytechnic, Nova Gorica, Slovenia
cUniversity of Ljubljana, Faculty of Electrical Engineering, Ljubljana, Slovenia
dINEA ., Ljubljana, Slovenia
eComputer Technology Institute, Athens, Greece
fUniversity of Chemical Technology and Metallurgy Sofia, Sofia, Bulgaria
Received 23 April 2004; accepted 15 May 2005
Abstract
This paper presents an innovative self-tuning nonlinear controller ASPECT (advanced control algorithms for programmable logic
controllers). It is intended for the control of highly nonlinear processes whose properties change radically over its range of
operation, and includes three advanced control algorithms. It is designed using the concepts of agent-based systems, applied with the
aim of automating some of the configuration tasks. The process is represented by a set of low-order local linear models whose
parameters are identified using an online learning procedure. This bines model identification with pre- and post-
identification steps to provide reliable operation. The controller monitors and evaluates the control performance of the closed-loop
system. The controller was implemented on a programmable logic controller (PLC). The performance is illustrated on a field test
application for control of pressure on a hydraulic valve.
r 2005 Elsevier Ltd. All rights reserved.
Keywords: Control engineering; Fuzzy modelling; Industrial control; Model-based control; Nonlinear control; Programmable logic controllers; Self-
tuning regulators
1. Introduction considerable and growing market for ad