I hear what you are saying but there is an issue with the esc that pulses motors in a certain scenario causing an electronically induced wobble. Motors starting and stopping all over the place.
Nothing to do with trucks.
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Huh. Ok. Lemme ask My electronics Guy Don He may have an idea. Hes 55 and has military through intel and beyond of firmware and pcb design. He’s a genius but not a boarder at all. Hes been studying this board code and different escs now for a year I bring him. Trying to Learn But Im a woodworker first. See the Divide is Dons to scared to ride one of these. So He only knows what I tell him. I gotta get him and his mind linked here. His resume is freaking intimidating!. 30 years or more of nothing but firmware and pcb hardware design. Just Never thought about esc for skateboards. Knows every single component on every esc. And every tab and drop down on vesc tool. Everything. Intestsed him over the phone when he wasnt aware. And I mean hed never seen vesc tool and for 20 minutes I said whats this whats that etc. He knew…100%. Of whats in there. And didnt know what vesc tool was. So Soon as we close this Gap. Yukovic actually has more time alive on earth than vedder and friesen have combined in esk8. And hes spent it on firmware and pcb hardware designs of all kinds. He’s like a wozniak genius. True electronics Yoda. Hes worked on spaceships amd stuff though. No fair experience!!!. Hahaha. Ill run this by him and see what he says. I gotta drop motor amps and get him on a board. Hes all Im not getting on one of those your crazy!!!. Hahaha. I said u made it run!!!. To which he said so. Your welcome. Have fun not me!!!. If he ridez one he can feel the mistakes with his knowledge. And boom!!. Epiphanys everywhere. Prob is he is older amd really cant afford to do it. Srry for ramblim. Ill ask Don.
Hey guys,
Do you know if something is being done on new firmware and if there is a possibility to have this duty cycle issue solved? If there is any beta versions out there, count on me to test it as I can’t help on coding, so I just can volunteer myself to test it. Thank you.
You’d need to ask Benjamin on the VESC forum. The fixes have been submitted but they have not been merged.
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What was the issue in layman’s terms?
The main one is detailed in the third post at the top of this thread
Sorry I dident explain very well.
what was the issue in the software that causes the lock up?
I don’t think it was ever figured out. Last I recall it had symptoms that would appear to be some sort of bug in the commutation algorithm.
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I did already on the 5.02 beta firmware thread. But no reply yet! Still not gave up and I bet he can solve it quickly.
Originally thinking it was a communication issue, but it was proven not to be the case. It is something related with duty cycle control mode on the FW itself. Still don’t know what.
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It’s already solved, he simply needs to click “Merge” which he’s not done.
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That is cool! Where did you see the pull request?
I will test it our right away. I was trying to make a custom app to get rid of this issue and I can send a command after throttle is released for 1s it force shuts down the controllers, but this is bringing other issues special with high loads because sometimes it takes longer to stop the inertia. So, definitely looking forward to get the locking issue solved!
I think we are talking about two separate issues, my fault
This issue I haven’t seen a fix for. When you said “Duty Cycle Issue” I thought you meant the other duty cycle issue. My fault.
Unfortunately this issue keeps happening without any solutions on the short term. Not sure what to do more.
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Have you tried mixing control modes? One motor run duty cycle and the others current control, may need a bit of programming to integrate all
Set the duty cycle on motor 1, set the current on all other models using a PID controller so that the current of all other motors is close to the duty cycle controles motor, this way the load is shared between them
Thinking a bit on this, the problem probably is the slight different Kv between motors, so the duty cycle doesn’t correspond to the same rpm on all motors, if this is true the approach os setting the same duty is fundamentally flawed and won’t work and isn’t VESC fault, a solution as I suggested above may work
edit: Another idea would be to mess with the PID controller of all but one VESC, set them to be forgiving and let the duty run outside the exact set duty, one would be strict and lock the duty, and the other would be allowed to stay near the set point, but not on it, I’m a bit rusty on the control background but can look it up if you want to test
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This is interesting! Can it be achieved by canbus?
The second idea I didn’t understood very well.
If I use PID speed controller, I have no issues with locking at full speed, but the machine behavior is not smooth as for duty cycle.
The different drive modes probably not, but tunning the PID of the other motors yes
Probably making a mess due to wording, when I’m saying PID, I’m not referring to PID speed control, each mode has a PID controller to get to the target value, you will set the mode as duty cycle on the main VESC and leave everything as default on it
On the slave ones you would mess with the internal PID controller, I don’t even know if just changing the values on the VESC tool would work or you need to dive into the code
@Deodand could say better if it makes sense and if is possible
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Thanks for the suggestion.
I would like to not go into custom firmware, so if this could be achieved with standard ones would be great.
I like the idea of having one master being duty cycle controlled and the others just aiding in current control but I need to achieve this using canbus.
Still, the best mode for this is current control, but with light loads, I have zero control on the acceleration and the motors just speed up. I have also variable load, so even if I keep the throttle % fixed, when removing the load, it will just go crazy on speed.
I wish the plans for acceleration control by Benjamin could be released. This will be the perfect system for this applications and also for any 4 wheel drive or any other applications with multiple motors where they need to rotate at different speeds and with variable loads.
If someone can make this happens, let us know and I bet a lot of people will be swaping to this mode right away.
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Agree on the acceleration control, always wanted that, so the board could be tame on flat and smooth ground and still have plenty of torque off road
I’m thinking the way to do it right now is with an external microcontroller
Connected to the main VESC via UART to get the current duty and motor current and use that that to set the current in a chain of CAN connected VESCs via either ppm or also uart
This will be interesting to allow the main controller to send jus the throttle input to the slave, and having the slave in any control you want. May just an extra selection box os the vesctool where you select “independent control mode” of “throttle forwarding”
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