Burkert 8693 - Adjustment Rules According to Chien, Hrones and Reswick (Actuating Variable Jump Method)

176
Type 8692, 8693
english
General Rules - Appendix
3.2 Adjustment Rules according to Chien, Hrones and Reswick
(Actuating Variable Jump Method)
With this method the controller parameters are adjusted on the basis of the transient behaviour of the controlled system. An
actuating variable jump of 100 % is output. The times Tu and Tg are derived from the progress of the actual value of the control
variable.
Progress of the control variable following an actuating variable jump ΔY
Actuating variable Y
Ks⋅ΔY
Actual value
ΔX
Tu
Tg
Control variable
t
ΔY
t
Fig. 8: Progress of the control variable, actuating variable jump
Procedure
Switch controller to MANUAL (MANU) operating state →
Output the actuating variable jump and record control variable with a recorder →
If progresses are critical (e.g. danger of overheating), switch off promptly. →
Note that in thermally slow systems the actual value of the control variable may continue to rise after the controller has
been switched off.
In the following table the adjustment values have been specified for the controller parameters, depending on Tu, Tg and Ks for
reference and disturbance reaction, as well as for an aperiodic control process and a control process with a 20 % overshoot.
They apply to controlled systems with P-behaviour, with dead time and with a delay of the first order.