Cs. Cox et al., QUICKTUNE - A RELIABLE AUTOMATIC STRATEGY FOR DETERMINING PI AND PPI CONTROLLER PARAMETERS USING A FOPDT MODEL, Control engineering practice, 5(10), 1997, pp. 1463-1472
Citations number
10
Categorie Soggetti
Controlo Theory & Cybernetics","Robotics & Automatic Control
It is well known that many complex processes are often satisfactorily
controlled by means of simple two-term (PI) and three-term (PID) contr
ollers. However, for those processes which use PI and PID loops, the t
ask of 'tuning' can be a very time-consuming and expensive operation.
Consequently, any help offered to the process operator to ease this te
dious task and at the same time produce consistent behaviour is very d
esirable. This paper presents a CAD software package that automaticall
y determines the necessary PI parameters for two-term operation, ident
ifies those situations where PI is not appropriate, and in these cases
designs an alternative pPI strategy. The original software used the Z
iegler-Nichols empirical settings, but this paper considers a range of
options which (in theory) should realise a less oscillatory response.
All of the strategies considered are based on a first-order-plus-dead
time (FOPDT) plant model. The paper also introduces a new set of tunin
g relationships which, despite their simplicity, appear to realise a c
onsistent, sensibly damped step response, much superior to the Ziegler
-Nichols values. The paper concludes by considering two 'real applicat
ions', namely, flow and pH control, which illustrate the quality of th
e performance achievable using the CAD software. Copyright (C) 1997 El
sevier Science Ltd.