Allen-Bradley Kinetix 5100 2198-E1004-ERS, Руководство пользователя, Страница: 207 / 500

Rockwell Automation Publication 2198-UM004A-EN-P - October 2019
207
Modes of Operation
Chapter 10
Gain Adjustment of the Position Loop
There are two types of gain adjustment for the position loop: auto and manual.
Auto adjustment
is when the servo drive provides an auto tuning function so you
can easily complete the gain adjustment.
For a detailed description, refer to Autotuning on page 170 .
Manual adjustment
is when you must manually set the speed control unit ID189
and ID191 (P2.004 and P2.006) before you set the position control unit, since a
speed loop is included in the position loop. After you manually set the speed
control unit, you must then manually set the parameters Position Proportional
Gain ID185 (P2.000) and Velocity Feedforward Gain ID187 (P2.002).
There are two types of gain:
1.
Proportional gain: a larger gain increases the response bandwidth of
position loop.
2.
Feed forward gain: reduces the deviation of phase delay.
The position loop bandwidth should not be larger than the speed loop
bandwidth.
In counts, the region around the commanded position where integral gain is
active. If the position error is greater than the Position Loop Izone, the integrator
is reset.
When you set the value of position control gain (KPP, ID185/P2.000) too high,
the bandwidth for the position loop is increased and the phase margin is reduced.
Meanwhile, the motor rotates and vibrates in the forward and reverse directions.
In this case, you have to decrease KPP until the rotor stops vibrating. When the
fp
KPP = 2 × π × fp
Where:
fv = response bandwidth of
speed
loop (Hz)
fp = response bandwidth of
position
loop (Hz)
Example: If the desired position bandwidth is 20 Hz, then
adjust the KPP (ID185, P2.000) to 125 (2 × π × 20 Hz = 125).
fv
4
≤
Position Feed
Forward Gain
ID187 (P2.002)
Position
Control Gain
ID185 (P2.000)
Max.
Speed Limit
ID160 (P1.055)
Speed Command
Position Control Unit
Position
Command
Position
Loop Izone
ID654 (P2.123)
Integrator
ID235 (P2.053)
Di
ffer
entiator
Position Counter Encoder
Smooth Constant
of Position Feed
Forward Gain
ID188 (P2.003)
Changing Rate
of Position
Control Gain
ID186 (P2.001)
Gain switching
condition and
method selection
ID212 (P2.027)
+ + +
+
+
+
–