Owner manual

POSITIONER 1067

E-45-

APPENDIX

As shown in the figure of the previous page, the proportional action coefficient Ks of the control system

can be calculated by way of the increase in the inflectional tangent, i. e. by way of ΔX/ΔY: manipulated

variable change)

Ks =

ΔX

ΔY

The following table lists the settings for the controller parameters depending on Tu, Tg and Ks for com-

mand and disturbance response and for an aperiodic control operation as well as a control operation

with 20% overshoot. They apply to systems with a P response, with a dead time and with a delay of the

1st order.

Parameter settings according to Chien, Hrones and Reswick :

Parameter settings

Controller

type Aperiodic control operation Control operation with

(0% overshoot) 20% overshoot

Command Disturbance Command Disturbance

P controller KP = 0,3 Kp = 0,3 Kp = 0,7 Kp = 0,7

PI controller Kp = 0,35 Kp = 0,6 Kp = 0,6 Kp 0,7

Tn = 1,2 Tg Tn = 4 • Tu Tn = Tg Tn = 2,3 • Tu

PID controller Kp = 0,6 Kp = 0,95 Kp = 0,95 Kp = 1,2

Tn = Tg Tn = 2,4 • Tu Tn = 1,35 • Tg Tn = 2 • Tu

Tv = 0,5 • Tu Tv = 0,42 • Tu Tv = 0,47 • Tu Tv = 0,42 • Tu

Tu • Ks