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Connect 4 vesc with can-bus, motors stuttering

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oyvinla
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Connect 4 vesc with can-bus, motors stuttering

Hi, I'm trying to connect 4 vesc controllers over the can-bus interface and run them synchronous. I have removed the resistor on the two vescs in the middle, leaving the first and fourth with a resistor. But the issue is that the motors are not running very well, they are stuttering and locking up. 

 

I have tried and successfully runned two and two, but not 3 and 4 together.

 For me it seems like there is a communication problem when running more than two vesc controllers over can-bus. Has anyone successfully gotten 4 vesc to run synchronous?

 

I'm using the standard single vesc from trampa boards.

 

Thanks

 

frank
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Did you only connect CAN H and CAN L? No other interconnections in between the 4 Units?

oyvinla
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Yes, only CAN H and CAN L

 

Here is a picture of the setup:

VESC.png

 

Thanks

frank
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Are they in current control mode? You could try the setup with all wheels in the air. 4 wheels down on the ground create a mechanical coupling and depending on the mode that can cause issues. If you use a speed controller the ESCs would start to work against each other, due to tolerances in the system. Basically one motor would try to speed another one up and that motor then tryies its best to work against that. Tiny differences then build up fast....

oyvinla
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They are in speed control mode, and when testing, all 4 wheels have been running freely in the air. 

frank
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Speed control will likeley cause issues with the wheels down. Did you detect each motor separately and did you use the latest BETA VESC-Tool?

https://vesc-project.com/node/2859