Thread Tools
This thread is privately moderated by Jack Crossfire, who may elect to delete unwanted replies.
Jul 17, 2016, 09:18 PM
Registered User
Jack Crossfire's Avatar
Thread OP
Discussion

Anti cogging 3


Revisiting the anticogging table generated a few months ago revealed a bug in its calculation. Measured again the hall sensor readout for a wide range of rotation & found the cogging was fairly consistent around the motor's entire range & power levels. A little manual tweeking just might make a table which defeats the cogging.

Calculated a new table of phase offsets to correct the cogging. This looked a lot more ordered than the previous table. With the new table applied, the rotation was a lot smoother. It still wasn't perfect, but the months had proven any other method would be inferior.

Recursively creating a new anticogging table by testing itself didn't improve the results. A plot of a complete rotation using the anticogging table didn't show any areas where an equal offset could be applied to all parts of the rotation.

Finally, making an anticogging table for the motor's entire rotation rather than a single sine wave period showed some improvement but took too much memory. It means there's some variability in the reluctance or the stiction for different parts of the rotation.


Anticogging a brushless gimbal (0 min 28 sec)
Last edited by Jack Crossfire; Jul 18, 2016 at 11:48 PM.
Sign up now
to remove ads between posts


Quick Reply
Message:
Thread Tools