Description of the Software Modules and Parameters
Parameter manual
b maXX
BM5800
Document No.: 5.16029.03
425
3
18.12
x1 position actual value
Display of the current actual position in degrees.
18.13
e1 Position error value
Current position error in degrees.
The position error is the difference between the position set value and the actual position.
The display of the parameter e1 Position deviation can be smoothed with a PT
1
filter. The
time constant of the filter is set in
. This filtering doesn't influence the position
control! At the position controller input the unfiltered position deviation is evaluated.
18.14
Kv position controller
Proportional gain of the position controller, units s
-1
.
The position controller is implemented as a P-controller.
It follows from this that with a Kv = 0 the position controller makes no contribution to the
speed set value, as any error value (e1 position controller error) is multiplied by the Kv
factor.
18.15
w2-Feedforward factor
Weighting factor for the speed feedforward at position control.
The speed feedforward is implemented as DT1 element. All changes to the position set
value are differentiated with respect to time, multiplied by the parameter w2-Feedforward
factor and smoothed subsequently with the
w2-Feedforward time constant.
From this it follows that at speed feedforward of 0 the speed feedforward makes no con-
tribution to the
speed set value total.
With speed feedforward of 1 and constant change per unit time of the position set value,
the speed feedforward provides exactly the required speed set value. In this case the po-
sition controller provides only the correction set value for tracking the angle.
A value of 1 corresponds to 100%.
18.16
Gear factor, motor:load-encoder
If a gear is available between motor and load, the gear ratio motor
:
load must be set in
this parameter. Two encoders must be used for this purpose. One for the motor con-
trol/speed control and one for the load-side position sensing for position control. For this
option bit 0 = 1 must be set in
.