gefran ADP200 User Manual page 59

Guideline about how to use the GAIN_SCH menu
The application PID-IMM for ADP200 drive allows the possibility to change the behavior of the pressure loop
gain according to the actual motor speed. This function is known as Gain-Scheduling, below are reported
some hints about how to set the parameters.
The Gain Scheduling function is useful to:
- adapt the pressure loop according to the type of hydraulic movement.
- reduce the overshoot during speed to pressure transition.
a) Adapt the pressure loop according to the type of hydraulic movement.
Aim of the PID-IMM application is to control pressure and speed in different situation, without any
information about the status of valve and/or in general about the knowledge of the hydraulic model.
An IMM machine is composed by a Machine with several hydraulic circuits that are commanded
through PLC that make the switching of valves. The information of the valve commands is not
transmitted to the drive. From the control point of view of the PID-IMM application the different
hydraulic scenario means a different hydraulic model, and so to get a robust and fast control
adaptive gains are required.
To be practices , in the IMM there is movement that requires high pressure with low speed, and vice
versa there is other condition where there is high speed with low pressure. One example of the
movement where is possible to see this effect is during the transition between injection and holding
phase.
In the following picture is reported a P/Q (pressure,flow) diagram of this movement:
ADP200 Application PID-IMM
Gain schedule block diagram
User Manual Pag. 59 of 80