6-60
Drive Control
MPH-02, MPB-02, MPD-02
DOK-INDRV*-MP*-02VRS**-FK01-EN-P
Position Loop (with Respective Feedforward Functions)
Brief Description
The following section only describes the position loop with the respective
feedforward possibilities (velocity and acceleration feedforward).
Note:
For the description of position command value processing see
section "Velocity Control with Cyclic Command Value Input" in
chapter "Operating Modes".
The position loop merely is a proportional loop. The P-amplification can
be set via the
S-0-0104, Position loop Kv-factor
parameter.
•
The lag error is minimized by:
•
variable velocity feedforward (cf. P-0-0040) and
•
variable acceleration feedforward (cf. S-0-0348)
incl. smoothing filter.
•
Depending on the control performance that was set, a cycle time of
250 µs (advanced) or 500 µs (basic) is used for the position loop (cf.
P-0-0556, bit 2).
•
with lag distance or lagless, i.e. with velocity feedforward
•
model monitor for the lag error (see also F2028)
•
S-0-0032, Primary mode of operation
(bit 3 = 1
→
activation of lagless operation)
•
S-0-0104, Position loop Kv-factor
•
S-0-0189, Following distance
•
S-0-0348, Acceleration feedforward gain
•
P-0-0040, Velocity feedforward evaluation
•
P-0-0556, Control word of axis controller
Parameters for command value processing/filtering:
•
P-0-0042, Current position command average value filter order
•
P-0-0099, Position command smoothing time constant
•
P-0-0187, Position command processing mode
•
F2028 Excessive deviation
•
F2036 Excessive position feedback difference
•
F2037 Excessive position command difference
Functional Description
Note:
Activating the lagless operation causes a feedforward value
determined from the position command value (velocity
command value) to be added to the velocity command value
at the position loop output.
By means of the velocity feedforward it is possible to reduce the lag error
to a minimum (ideally = 0) at constant velocity.
In order to achieve a reduction of the lag error during the acceleration
process, the acceleration feedforward (cf. S-0-0348) has to be activated.
Features
Pertinent Parameters
Pertinent Diagnostic Messages
Velocity Feedforward
Acceleration Feedforward
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of
CMA/Flodyne/Hydradyne
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Motion
Control
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