Delta RMC101 User Manual
Page 41
Setup Details 2.2
Starting Up the RMC
2-13
3. Adjust the Proportional Gain
The Proportional Gain should be adjusted first to gain some control over the pressure before
continuing the tuning procedure.
Note: If negative drive causes an increase in pressure, use negative values throughout the tuning
procedure.
• Set the Proportional Gain to a small value, such as 2.
• Use an Event Step table that makes a position move with the Monitor Pressure bit set so the
axis will transition to pressure control when the Pressure Set A threshold is crossed. Use a
fairly long ramp time initially, such as 1000 msec.
• Once the axis is in pressure control, ramp the pressure between two pressures (this is best
done in Event Steps). Gradually increase the proportional gain to minimize the following
error. When you see a tendency to oscillate as the axis moves or stops, decrease the gain
10 to 30 percent.
4. Add Filter if Necessary
If the pressure feedback signal is excessively noisy, it may cause instability and will likely have
been noticed already in the previous step. Adding a filter may help. This is done using the Filter
TC parameter. See Filter TC for detailed information.
5. Adjust the Integral Gain
The Integral Gain helps get to the command pressure quickly.
• Use the same Event Step sequence as previously to ramp between two pressures. You may
want to increase the delay between the steps to more clearly see the effect of this tuning
step.
• Adjust the Integral Gain so that the pressure gets to commanded pressure quickly.
• Too much Integral Gain will cause oscillations and overshoot. If this happens, decrease the
Integral Gain.
6. Adjust the Differential Gain
Differential Gain greatly enhances performance on many hydraulic systems. Differential Gain will
tend to dampen out oscillations and help the axis track during acceleration and deceleration. This
will positively affect short, fast moves.
• Continue ramping between two pressures.
• If the drive output is always smooth, the Differential Gain can probably be increased. The
drive output should look "fuzzy." This indicates that the drive is correctly responding to the
minute errors of the axis.