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Motor cogging

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blox11
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Motor cogging

Hi, I wanted to ask for help with a specific issue I am having. Basically the motor stutters/cogs up and vibrates loudly in certain situations such as: large accelerations, large throttle values, switching from Hall sensors to sensorless mode, reaching certain speeds (usually around top speed). It's a brushless direct drive hub motor for an e-bike, and I haven't experienced this problem with other controllers before. It can happen in both sensored and sensorless mode and at any speed, but it doesn't always happen. I've changed many settings, especially the ERPM values for sensorless and Hall interpolation and nothing seems to have had any effect.

 

Any help would be appreciated

frank
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Did you use the latest VESC-Tool? You can try to adjust the resistance value by+-5% in Motor Settings / FOC.

On the same page you can also try to adjust T to 500uS. T is in the lower box.. After that you click on Calc Apply Old and write the motor configuration to the ESC.

 

blox11
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Hi frank,

Do you believe the calculated values for the motor are bad? The biggest problem especially seems to be the transitioning from sensored to sensorless and running in sensored mode in general. Sensorless is usually quite smooth. Also, I am using a Flipsky 75100 esc so the firmware is still the last version. But I am on the latest version of vesc tool, yes. I don't know if this makes a difference or not

frank
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This unit has FW issues, but it is an illegal FW since it is not publicly released under the GPL, as required by the GPL. So it is hard to see what is wrong there.

blox11
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Really? What issues does it have, if I may ask?

Also, do the settings for temperature compensation under sensorless still work, even though I am only transitioning from sensored instead of pure sensorless from the start?

frank
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The issue is that the FW is kept locked away, although it is GPL licensed. So the community has no insight and it is legally in the scope of Copyright violation © Benjamin Vedder and contributors.

I think there is are some glitches in the HW design and maybe also software. The temperature seams to be measured incorrectly for example.

blox11
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Ok, I understand. I did not know about this before.

Would the change in resistance at different temperatures cause my issues? My motor does not have a thermistor installed at the moment, but I do know there is a massive difference in temperature as well as resistance at the beginning vs end of a ride.