Tuning Menu - gefran ADP200 User Manual

5.12 TUNING menu

The parameters in TUNING menu allow to perform an automatic calculation of the speed gains and of the
pressure gains; then the value calculated can be copied to the working gains parameters.
Speed Loop Auto-Tuning:
The speed loop tuning is done by executing a speed profile. The profile is fixed and it starts from 500 RPM to
1500 RPM with 3s of Ramps.
During this profile, the algorithm will estimate the mechanical parameters of the system. Based on the Speed
Loop Bandwidth set on IPA 11480, the algorithm will estimate the Speed Loop Kp (IPA 12150) and Speed
Loop Ki (IPA 12152).
In order to execute the speed loop tuning:
o) the IMM must be configured, by opening valve or set properly safety valve, in "open loop circuit". This
condition means that motor can rotate with low/no pressure.
o) the Speed reference and Pressure Reference must be set as digital parameter (see 5.3). The Pressure
reference needs to be at least 50% more the pressure that is reached at 1500 RPM to avoid that during the
speed tuning procedure there are constrain due Pressure Control. (i.e. (IPA 11054) Pressure ref = 100 bar)
To enable the speed loop tuning, the operator has to switch to ON the parameter Speed Tuning En (IPA
11482). After this command, the speed profile for auto-tuning is applied and motor will move from 500 to
1500 Rpm and from 1500 to 500 Rpm. At the end of the procedure the speed comes back to the original
speed that operators has set to digital reference (IPA 11056).
The tuned parameters will be shown as:
Speed Loop Kp (IPA 12150) – that is the proportional gain
Speed Loop Ki (IPA 12152) – that is the integral gain
SLT Tau (EXP) (IPA 12140) – that is the time constant of the mechanical system
SLT Gain (EXP) (IPA 12142) – that is the gain of the mechanical system
The ratio between SLT Tau and SLT Gain gives an indication of the Inertia of the system.
Finally in order to apply the calculated value, the operator can switch to ON the parameter "Load SpL Tuned
Value" (IPA 11484) that makes a copy and paste of the tuned value to the GAIN menu. As alternative the
value can be copy and paste manually.
Pressure Loop Auto-Tuning:
The pressure loop auto tuning requires that the machines is working in "closed loop" and the system must be
in pressure. The tuning should be done in the condition where the ratio between Pressure and Speed is
higher, typically on IMM this condition is reached in the hold phase after the injection.
The operator must to take a fixed value of pressure reference (this can be done from Digital or Analog) and
to put the system in pressure. After this, the operator has to Switch ON the parameter "Press Tuning EN"
(IPA 11492). The algorithm will make a 1 Hz of pressure variation and the algorithm will calculate the value
of Pressure Loop Kp and Ki (IPA 12112, IPA 12114). The procedure requires about 6 seconds, and at the
end of the procedure the pressure reference variation is automatically disabled.
In order to make active the tuned value, the operator has to switch ON the parameter "Load PrL Tuned
Value" (IPA 11494)
Note! the automatic tuning procedure, both Speed and Pressure is based on "standard machine" and it has general
hypothesis. The operator, prior to switch On the procedure that apply the tuned parameters (IPA 11484 and 11494)
must check that value estimated are "reasonable" in the proper range. If operator is not sure about the calculated
value, repeat the procedure or proceed by changing the value manually (ref. 5.5)
When IPA 11484 and 11494 are switched ON, the tuned parameters are immediately applied. As recommendation,
this operation should be done when enable is OFF or at least operator must be ready about the change.
ADP200 Application PID-IMM User Manual Pag. 69 of 80