Motor error current limit violation

1

Hi guys,

I was running the ODrive in position control and checking the stability under different loads. The motor I’m using is T-motor P80 III kv120. When I keep on increasing the weights, ODrive starts giving motor_error “MOTOR_ERROR_CURRENT_LIMIT_VIOLATION” when set/measured current reaches 70A.

I have set the ODrive configuration as follows;

In [6]: odrv0.axis1.motor.config.current_lim
Out[6]: 120.0

In [7]: odrv0.axis1.motor.config.requested_current_range
Out[7]: 120.0

ODrive shows instability when set/measured current reaches the 70A as shown in the attached image.

result1
result11913×761 48.7 KB

Is it due to the shunt conductance? and if so do I need to change shunt resistors?

Thanks and stay safe.

2

Does this happen at every weight, or are you increasing the weight until it goes unstable? You’ll probably need softer PID gains once you hit a certain weight…

3

I was busy with some design work in our project last few days and today I got time to redo the experiment again with different loads.

I figured out the issue. The ODrive works great and it seems clever in identifying motor getting overheated. The system goes unstable when motor gets overheated due to the high current close to its peak.

Thank you so much your support.

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