Detailed Description
2.5 Optimization of the control
Velocities, Setpoint/Actual-Value Systems, Closed-Loop Control (G2)
Function Manual, 08/2005 Edition, 6FC5397-0BP10-0BA0
2-65
MD32810 fine adjustment
Experience has shown that 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 must have identical settings in the following data:
MD32200 $MA_POSCTRL_GAIN
MD32620 $MA_FFW_MODE
MD32610 $MA_VELO_FFW_WEIGHT
MD32810 $MA_EQUIV_SPEEDCTRL_TIME (or MD32800
$MA_EQUIV_CURRCTRL_TIME)
MD32400 $MA_AX_JERK_ENABLE
MD32402 $MA_AX_JERK_MODE
MD32410 $MA_AX_JERK_TIME
The servo gain display (K
V
) in the axis service screen form is used for checking.
If identical values are not possible for the above data,
machine data:
MD32910 $MA_DYN_MATCH_TIME
can be used to make an adjustment.
This allows the same servo gain value (K
V
) to be displayed;
however, this rarely occurs.
Different servo gain values (K
V
) usually point to the following:
• The gear ratios do not match in one or several axes.
• The feedforward control setting data do not match.
• The jerk filter setting data is incorrect at some point.
Automatic switchover when changing the position-control cycle
Previously, if the position-control cycle (MD10050 $MN_SYSCLOCK_CYCLE_TIME)
changed or the acceptance time of the speed setpoints was modified in order to increase the
servo gain (K
V
) (MD10082 $MN_CTRLOUT_LEAD_TIME), or dynamic stiffness control was
enabled (MD32640 $MA_STIFFNESS_CONTROL_ENABLE), the adjustment of
MD32810 $MA_EQUIV_SPEEDCTRL_TIME had to be repeated,
as the optimum value changed significantly.
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