APPENDIX
The following table lists the settings for the controller parameters depending on Tu, Tg and Ks for
command 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 :
Controller
type
Aperiodic control operation
(0% overshoot)
Command
P controller
KP = 0,3
PI controller
Kp = 0,35
Tn = 1,2 Tg
PID controller
Kp = 0,6
Tn = Tg
Tv = 0,5 • Tu
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 ∆X / ∆Y
(∆Y: manipulated variable change)
Ks =
Parameter settings
Disturbance
T g
Kp = 0,3
Tu • Ks
T g
Kp = 0,6
Tu • Ks
Tn = 4 • Tu
T g
Kp = 0,95
Tu • Ks
Tn = 2,4 • Tu
Tv = 0,42 • Tu
∆X
∆Y
PH CONTROLLER 8205
Control operation with
20% overshoot
Command
T g
Kp = 0,7
Tu • Ks
T g
Kp = 0,6
Tu • Ks
Tn = Tg
T g
Kp = 0,95
Tu • Ks
Tn = 1,35 • Tg
Tv = 0,47 • Tu
E-47-
Disturbance
T g
Kp = 0,7
Tu • Ks
Tu • Ks
T g
Kp 0,7
Tu • Ks
Tu • Ks
Tn = 2,3 • Tu
T g
Kp = 1,2
Tu • Ks
Tu • Ks
Tn = 2 • Tu
Tv = 0,42 • Tu
T g
T g
T g