Siemens SINUMERIK 840D sl Function Manual page 364

G2: Velocities, setpoint / actual value systems, closed-loop control
7.6 Optimization of the control
The following rules apply to making manual fine adjustments:
Monitoring
Overshoot
Excessively slow
approach
MD32810 fine adjustment
Therefore, MD32810 should be assigned as small a value as possible, with the overshoot
setting the limit during positioning. Furthermore, the initial value is only modified slightly during
fine adjustment, typically by adding or deducting 0.25 ms.
For example, if the initial value is 1.5 ms, the optimum value calculated manually is usually
within the range 1.25 ms to 1.75 ms.
In the case of axes equipped with direct measuring systems (load encoders) and strong
elasticity, you may possibly accept small overshoots of some micrometers. These can be
reduced with the help of the position setpoint filter for dynamic response adaptation (MD32910
$MA_DYN_MATCH_TIME) and for jerk (MD32410 $MA_AX_JERK_TIME), which also reduces
the axis speed.
Identical axis data within an interpolation group
All the axes within an interpolation group should have identical settings in the following data:
● MD32200 $MA_POSCTRL_GAIN (adapted using MD32910)
● MD32620 $MA_FFW_MODE
● MD32610 $MA_VELO_FFW_WEIGHT
● MD32810 $MA_EQUIV_SPEEDCTRL_TIME (or MD32800
$MA_EQUIV_CURRCTRL_TIME) (dependent on the mechanical system and drive)
● MD32400 $MA_AX_JERK_ENABLE
● MD32402 $MA_AX_JERK_MODE
● MD32410 $MA_AX_JERK_TIME
The servo gain display (K
service" is used for checking.
Non-identical axis data within an interpolation group
If identical values are not possible for the above data, the following machine data can be used
to make an adjustment:
MD32910 $MA_DYN_MATCH_TIME (time constant of dynamic response adaptation)
This allows the same servo gain value (K
364
Measure
Increase MD32810
Increasing the value slows the axis down but increases the geometric contour error
on curves; similar to reducing the position controller gain: MD32200
$MA_POSCTRL_GAIN. This can be observed on the user interface in the operating
section "Diagnostics" > "Axis service" using the computed K
Reduce MD32810
Reducing the value speeds the axis up but decreases the geometric contour error
on curves.
) of the user interface in operating section "Diagnostics" > "Axis
V
V
) to be displayed.
Function Manual, 01/2015, 6FC5397-0BP40-5BA2
value.
V
Basic Functions