Siemens SINUMERIK 840D Function Manual page 80

G2: Velocities, setpoint / actual value systems, closed-loop control
2.6 Optimization of the control
MD32910 $MA_DYN_MATCH_TIME (time constant of dynamic response adaptation)
This allows the same servo gain value (K
Different servo gain display values (K
● The gear ratios do not match in one or several axes.
● The feedforward control setting data does not match.
Setting the equivalent time constant of the current control loop (MD32800)
The activation of the torque feedforward control filter is performed with:
MD32620 $MA_FFW_MODE = 4
The same rules and recommendations apply to setting the time constant of the current control
loop MD32800 $MA_EQUIV_CURRCTRL_TIME as to the speed feedforward control.
Limitation to stiff machines
Experience has shown that this expenditure is only worthwhile in the case of very stiff
machines, and requires appropriate experience. The elasticities of the machine are often
excited due to the injection of the torque so strongly that the existing vibrations neutralize the
gain in contour accuracy.
In this case, it would be worth trying the function "Dynamic Stiffness Control" (DSC) as an
alternative:
MD32640 $MA_STIFFNESS_CONTROL_ENABLE = 1
Note
The following conditions apply to use of DSC:
● In the NC, no actual value inversion (MD32110 $MA_ENC_FEEDBACK_POL = -1) must be
parameterized. Actual-value inversion in the drive (SINAMICS parameter p0410) is
permissible.
● The function must be activated for all axes that are in an interpolation relationship (path
motion or coupling) (MD32640 = 1).
● If one of the axes is parameterized as a simulated axis (MD30130 $MA_CTRLOUT_TYPE
= 0, MD30240 $MA_ENC_TYPE = 0), DSC cannot be applied. In this case, the function
must be deactivated for all axes that are in an interpolation relationship (MD32640 = 0).
Exception error condition
An exception error condition may occur if p1192 is set for a non-existing measuring system
and DSC is activated!
For service situations in which an additional measuring system has to be disabled and DSC
is active, it must be assured that p1192 is also adapted.
80
CAUTION
) to be displayed.
V
) usually point to the following:
V
Function Manual, 06/2019, A5E47437747B AA
Axes and spindles