PHASE_RESISTANCE_OUT_OF_RANGE for gimbal motor at 12v

1

I have a gimbal motor and a Odrive Micro, and I have found that at 12 volts vbus, no set of calibration parameters will give me a successful calibration. Instead I either get

PHASE_RESISTANCE_OUT_OF_RANGE
or
PHASE_INDUCTANCE_OUT_OF_RANGE

If instead I use 26v vbus with a calibration voltage of 9v, I can get a successful calibration.

Due to other limitations of my system, running my system at anything other than 12v would be a lot of refactoring. Are there any other things I can try, or am I out of luck?

2

Hi! What gimbal motor specifically is this? I’d check out this docs page: Calibration Voltage/Current — ODrive Documentation 0.6.11 documentation

Note you can also take the phase_resistance/phase_inductance values you found with the 26V vbus then use them at 12V vbus. You can set axis0.config.motor.phase_resistance and axis0.config.motor.phase_inductance, and also set axis0.config.motor.phase_resistance_valid and axis0.config.motor.phase_inductance_valid to True. As long as you’re using the same motor, running motor calibration isn’t strictly necessary between two different setups – only re-running encoder offset calibration is necessary when the motor/motor mounting changes.

3

Its a custom motor. If I calibrate it with 24v they seem to just work with 12. That being said we’ve just learned that at 12v they don’t provide the torque we need, so it looks like we’ll be running the entire system on 24.

Thanks for the tip as well about copying over the inductance and resistance. That will be very useful in the future.

4

No worries, best of luck and please let me know how else I can help in the future!