Auto Servo Tuning (Ast) For The Robot Axes - Siemens SINUMERIK 840D sl Commissioning Manual

Commissioning
5.7 Controller data
Example 1
The default setting for both parameters in axis 1 is as follows:
MA_MAX_AX_JERK = 1 rev./s
MA_AX_JERK_TIME = 0.1s
For handling movements, the parameters can be changed as follows, for example:
MA_MAX_AX_JERK = 3 U/s
MA_AX_JERK_TIME = 0.25s
The higher jerk limit results in increased productivity. The increased excitation of the natural
frequencies is compensated with a stronger filter. The contour deviation is not the main focus of
handling tasks.
Example 2
The default setting for both parameters in axis 1 is as follows:
MA_MAX_AX_JERK = 1 rev./s
MA_AX_JERK_TIME = 0.1s
Very high feed rates are applied for tape layering. Nevertheless, great importance is attached to
contour accuracy. A possible parameter assignment would be in this case:
MA_MAX_AX_JERK = 0.5 rev./s
MA_AX_JERK_TIME = 0.05s
5.7.4

Auto Servo Tuning (AST) for the robot axes

With SINUMERIK 840D sl Auto Servo Tuning (AST), an optimal controller setting can be
automatically determined for a feed axis. This optimal controller setting is relative to the
measured dynamic response of the axis in a specific operating point (= pose + payload). The
dynamic response of the robot axes can change very dramatically depending on the pose and
the payload. This is not taken into consideration by AST, however.
• If AST is carried out in a "dynamically disadvantageous" pose, e.g. with the robot arm
extended, this can lead to an unstable condition of the speed control loop when the robot
arm is retracted.
• If AST is carried out in a "dynamically advantageous" pose, e.g. with the robot arm retracted,
this can lead to an unstable condition of the speed control loop when the robot arm is
extended.
The use of AST on the robot arm is only possible in individual cases, assuming the working area
is extremely limited. For automatic controller optimization, the robot should be positioned
approximately in the center of the working area.
If you perform the controller parameterization for an individual axis with AST, the interpolation
behavior of the axis group is changed at first. To correct the interpolation behavior, you must
equalize the parameterization of the setpoint channel in all axes (see Section Interpolating
special axes (Page 65)).
After a controller optimization by AST, the newly determined controller parameters are written
to the active data set. When you provide a different data set as 0 for the optimization by AST, you
must switch over the active data set before the optimization via the PLC.
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SINUMERIK Run MyRobot /Direct Control
Commissioning Manual, 07/2020, A5E45238414B AD