Tuning a pneumatic system – Delta RMC151 User Manual
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2 Starting Up the RMC
a. Set all the gains to zero.
b. Set the Differential Gain to a small value, then issue the Hold Current Position (5)
command to put the axis in closed loop control.
c. Rotate the motor manually to get a feel for the resistance to movement (damping).
Increase the Differential Gain until the damping is significant. If the motor chatters or
oscillates, decrease the gain.
d. Continue tuning the gains in the order given in the Tuning a Position Axis topic.
2.3.10. Tuning a Pneumatic System
When tuning a pneumatic cylinder, use the basic instructions in the Tuning a Position Axis
topic, but use the order of the gains below.
Tuning Order
When using high-order gains, increasing the highest order will allow you to increase lower
order gains. However, you need to first set the lower gains to some value before you can
set the higher ones. Then, you can go back and increase the lower order gains.
The Output Filter can significantly improve control of pneumatics. Without the Output
Filter, the Differential Gain can cause the Control Output to oscillate, causing oscillation of
the axis. By using the output filter, the differential gain can be increased significantly to
help the Actual Velocity track the Target Velocity.
Suggested Tuning Order:
a. Proportional Gain
b. Output Filter
c. Differential Gain
d. Double Differential Gain
e. Triple Differential Gain
f. Double Differential Gain
g. Differential Gain
h. Proportional Gain
i. Integral Gain
j. Repeat several times.
Feed Forwards are not useful on poor systems. They may be more significant on low-
friction cylinders. If your application requires Feed Forwards, set them before setting the
Integral Gain.
The P, D, DD and TD gains typically differ from each other by an order of magnitude. For
example, the ratio of the gains to each other may be as shown below. Keep in mind that
the actual value of gains required on your system may differ significantly.
P: 10
I: 10
D: 0.1 or smaller
DD: 0.01 or smaller
TD: 0.001 or smaller
Other tips:
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