MPH-02, MPB-02, MPD-02
Drive Control
6-53
DOK-INDRV*-MP*-02VRS**-FK01-EN-P
When using a load-side encoder the velocity control loop includes the
possibility to generate the actual velocity value used for control via a "mix
factor" (see Parameter Description of P-0-1119) from the actual velocity
values of the motor encoder and the load-side encoder (see also figure
"Velocity loop").
Note:
Combining the actual values of motor encoder and load-side
encoder via a mix factor can be very advantageous for
controlling systems with a low degree of stiffness in the case
of connected load.
In the velocity control loop there is the additional possibility of making the
control performance of the velocity loop more dynamic by using the so-
called acceleration feedforward. The command value for the current
controller then, to the greatest possible extent, is directly derived from the
velocity command value. The velocity loop will then only be required for
correcting disturbances. The figure below illustrates controller
feedforward:
P-0-1126
P-0-0180
P-0-0048
DF000065v01_en.fh7
feedforward
filters
-
torque/force
and current
limitation
v
act
motor
control
velocity
loop
P-0-0048:
effective velocity command value
P-0-0180:
acceleration feedforward smoothing time constant
P-0-1126:
velocity control loop: acceleration feedforward
Fig. 6-36:
Acceleration feedforward in velocity control loop
Note:
This kind of feedforward can be advantageously used for a
very high degree of inertia and/or low encoder resolution.
The following filters are available in the velocity control loop:
•
four freely configurable 2
nd
order filters (low pass, band-stop, ...)
•
one
1
st
order low pass (PT1 element)
•
one moving average filter
Velocity Mix Factor
Acceleration Feedforward
Possibilities of Filtering
Courtesy
of
CMA/Flodyne/Hydradyne
▪
Motion
Control
▪
Hydraulic
▪
Pneumatic
▪
Electrical
▪
Mechanical
▪
(800)
426-5480
▪
www.cmafh.com
