Posts made by Paski

Hi,

I’m experiencing issues with axis tuning. The mechanical setup is as follows:

A motor with an integrated brake and quadrature encoder.
A coupling connects the motor to a leadscrew.
A magnetic encoder is mounted on the opposite end of the motor due to limited access to the axis.
The calibration fails, likely due to backlash or counts/step mismatch. Here are the errors I’m seeing:

Power up + 00:00:29 [warn] Error: Driver 122.0 calibration failed, measured backlash (0.639 step) is too high.
Power up + 00:00:29 [warn] Warning: Driver 122.0 failed to maintain position, tuning/calibration failed.
Power up + 00:00:25 [warn] Error: Driver 122.0 calibration failed, the measured motion was less than expected, measured counts/step is about 66.8.

Is there a way to use only the quadrature encoder for calibration to bypass the backlash issue?
How can I resolve those problems?

BR.

Hi @dc42,

I was running in standalone mode.
Thanks for the "M409 K"boards[1].drivers[0].closedLoop" command; it revealed an incompatibility with the DWC, which was resolved after an update.

BR.

@dc42
It's curious that when accessing the average error (boards[1].drivers[0].closedLoop.currentFraction.avg), the output is a value. However, for positionError, it seems to return an object.

Interestingly, both are specified as value in the object model of the DWC.

Am I correct in assuming that the real-time PID error is part of the positionError? How can i acess that?

Thanks!

Thanks in advance!

I'm attempting to calibrate an axis using the encoder position error(with 1HCL board). To achieve this, I need to access the boards[].drivers[].closedLoop.positionError parameter.

Initially, I found it located at:
boards[1].drivers[0].closedLoop.currentFraction.positionError

However, when I try to retrieve its value using boards[1].drivers[0].closedLoop.currentFraction.positionError.value with echo, it doesn't return anything.

Could someone guide me on how to properly access and read the encoder error value?