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Holding torque in "Duty Cycle" mode

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Petja
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Holding torque in "Duty Cycle" mode

Hello everybody!  I faced a problem: when I use control type "Duty Cycle" and throttle (control type ADC) has full stop position, driver draw current nearly 0.1A (sometimes generate 0.1A). This current creates holding torque.

https://ibb.co/PY8y6tn

But I want to ride free-wheel on my bike. I saw the answer by Benjamin in this topic:

https://vesc-project.com/comment/1514#comment-1514

 Is it really impossible to fix this in "Duty Cycle" mode?

The same problem is about remote, which I want to use in "Duty Cycle" mode like on this picture:

https://ibb.co/nQ5FJy9

I have holding torque in middle position of throttle now.

pf26
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Imagine you use DutyCycle mode, and allow for free riding when the throttle is released. What will happen upon riding, say 20 km/h, and then gently applying throttle ? The VESC will now impose a low duty corresponding to your throttle position, ie much lower than the one corresponding to your current speed. So it will brake (very) hard, depending on your max current setting...

DutyCycle mode requires strong correlation between throttle position and vehicle speed at all time.  I think CurrentControl is better suited for Ebike, possibly with the addition of cruisecontrole button ?

david
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I agree with pf26, torque control is the way to go on almost all applications except maybe multirotors although I haven't tried that one yet ;-)

pf26
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DutyCycleControl is nice since it controls speed very well. CurrentControl (or TorqueControl) allows to control accelerations but results in crazy speeds when there is no load applied to the motor. Maybe you could try "SpeedControl"  with low PID settings so as to make it soft enough to react a bit similar to torque control (requiring large throttle to get some accelerations).

Petja
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DutyCycleControl is nice since it controls speed very well. CurrentControl (or TorqueControl) allows to control accelerations but results in crazy speeds when there is no load applied to the motor. Maybe you could try "SpeedControl"  with low PID settings so as to make it soft enough to react a bit similar to torque control (requiring large throttle to get some accelerations).

Thank for answers!

Yes, that's my problem, I control motor without load (still not assemble my vehicle). Can you give some links/threads how to tune VESC in "SpeedControl"?

pf26
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Just like tuning any PID speed controller.. this is very dependent on your system (inertia, motor torque vs current...)