2 different ODrives v3.4 with different motors give phase inductance out of range on devel branch

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1

I updated to the latest devel branch and now I’m getting ERROR_PHASE_INDUCTANCE_OUT_OF_RANGE for one of my motors, reading the values I get this:
Error motor 0 0
Error motor 1 6
Phase inductance motor 0 0.0002207966026617214
Phase inductance motor 1 0.0013126198900863528

And what is more strange is that my second board with the same type of motors and encoders get me this:
Error motor 0 0
Error motor 1 6
Phase inductance motor 0 0.00021768918668385595
Phase inductance motor 1 0.001135334256105125

So I think there is a bug somewhere because I don’t believe in coincidences

Where is the place where this is treated differently for motor0 and motor1?

Thank you!

2

I think it might be a software issue because before switching from master to devel I did not have this problem, I will try switching back and see if it goes away.

1 Like
3

Ok, looking into it on my setup now.

4

I’m just dumping my results here in realtime, nothing conclusive yet. I will be using the same motors in all the tests.

On ODrive v3.4 - 48V edition, with master branch, I get:

In [1]: my_odrive.motor0.phase_inductance
Out[1]: 1.062745286617428e-05

In [2]: my_odrive.motor1.phase_inductance
Out[2]: 1.087363125407137e-05

On ODrive v3.4 - 48V edition, with devel branch, I get:

In [1]: my_odrive.motor0.phase_inductance
Out[1]: 1.0702136933105066e-05

In [2]: my_odrive.motor1.phase_inductance
Out[2]: 1.0885468327614944e-05

I’m gonna switch to 24V board now.

5

I switched to master and now I get this, no hardware changes at all and both motors work

Phase inductance motor 0 0.00030777082429267466
Phase inductance motor 1 0.0003215439210180193

6

I do make 2 changes to the code accommodate my motors (I made them both on master and on devel)

  1. on the line that says if (!measure_phase_resistance(motor, motor->calibration_current, 1.0f)), change the 1.0f to 10.0f
  2. change static const float kI = 10.0f; //[(V/s)/A] to 50.0f
7

If you have a microscope, can you check if any of these cuts seems to have compromised the track going to the via?

8

These changes should be fine, at the very least they shouldn’t yield different results for the 2 channels.

9

no microscope, sorry

10

Can I call you on Skype, and maybe we can brainstorm what’s going on?

11

yes, call when ready