Cogging Compensation
The Cogging Compensation feature allows a user to remove the effects of cogging from their motor. Cogging is an undesirable component (magnetic force) in the motor between the permanent magnets and the windings.
The Cogging Compensation feature needs to be configured and then the user will run a teach algorithm. The teach will move the motor at a very slow speed (1 rpm) and record any difference in current at each position. After processing the data, it will then create a cogging compensation lookup table that will adjust the current feed forward based on position.
If you are not using modulo on your cogging compensation table, then you will need to first move the axis to the Teach Start Position which is simply a position slightly before your cogging compensation table minimum value.
Limitations
The cogging teach (AXIS#.IL
"Instruction list"
This is a low-level language and resembles assembly.COGCOMP.TEACH.MOVE) must be run in position mode and the axis must be enabled. Additionally, when modulo is disabled, the user must move the axis to the Teach Start Position. This is necessary because additional travel (usually minimal) beyond the expected cogging compensation table range is needed to get up to speed and to stop afterwards.
AKD1G Keyword Equivalents
|
AKD1G Keyword |
AKD2G Keyword |
|---|---|
|
COGCOMP.TEACH |
AXIS#.IL.COGCOMP.TEACH.MOVE |
|
COGCOMP.V |
AXIS#.IL.COGCOMP.TEACH.V |
|
COGCOMP.RANGELOW |
|
|
COGCOMP.RANGEHIGH |
|
|
COGCOMP.CORRECTIONVALUE |
|
|
COGCOMP.SAVE |
Typical Uses of Cogging Compensation
The Cogging Compensation feature could be used on motors that exhibit large amounts of cogging or applications that move at slower speeds.
Cogging Compensation Keywords
AXIS#.IL.COGCOMP.TEACH.POSSTART
AXIS#.IL.COGCOMP.MOVETOSTART.MOVE
AXIS#.IL.COGCOMP.MOVETOSTART.V
