Encoder with index/Z signal needs offset_calibration every time start up or not?

1

Hi,all
I have an encoder with index signal.I was told that I need to run “encoder offset calibration"only once,and after that just search for the index signal every boot. But I found that, I have to run “encoder offset calibration” every boot,too. If not,the motor will work only for the first time after odrivetool sent command. And after running"reboot”, errors showed like this:

重启报错1
重启报错1832×616 31.5 KB

I am confused and frustrated.

  1. What are the reasons of these errors?
    2.Does the encoder need startup_encoder_offset_calibration? If not, how can I avoid these errors? If yes, odrive may be not suitable for my project (it would be disappointing).
    I’d appreciate it if you could help me.
2

If you calibrate the offset once, and then set encoder.config.pre_calibrated=True and save config, you should not have to calibrate it again on boot.

3
  1. As Towen said, the process is:
encoder.config.use_index = True
axis.requested_state = AXIS_STATE_FULL_CALIBRATION_SEQUENCE
encoder.config.pre_calibrated = True
motor.config.pre_calibrated = True
odrv.save_configuration()

Then at boot, you run index search only and it will work.

  1. The error you’re showing (overspeed) is due to vel_limit being too low, or too low of a load on the motor for torque mode
4

Hi,Towen
Thank you for your reply.It’s good to confirm that I don’t need to run encoder_offset_calibretion every boot.

5

Hi Wetmelon,
Thank you for your reply. I configured my encoder as you said, and I mounted a gear reducer to increase the load on the motor. The motor works much better than before,though those errors still exist sometimes, but it will work normally after reboot now! I think I can solve the problem thoroughly. Thanks a lot!