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(solved) Configuration smooth motordirection change

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horak2084
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(solved) Configuration smooth motordirection change

Dear Guys,

we build a self balancing Scooter with 2 brushless motor and control them with 2 VESC.
We control the VESC with an Arduino Mega over PPM signal. but now we facing some problems. 

In all control modes we tested we have the problem with changing the Directory smooth.
When we want to change the directory of the motor, first the brake until the speed is nearly zero and then the vesc want to accelerate backward.
Our problem is that the delay while the motor in breaks is to long and the self balancing scooter is out of control.
It feels like the motor stops for aprox. 1 second and after this the motor begin to turn in the other direction.
For the self balancing project is this second a big problem. 

Now i want to ask if someone have a hint which parameter of the VESC could be the problem and how we solve it?
 

Best regards 

Manuel

 

horak2084
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2019-02-25 20_06_08-VESC Tool.png

TechAUmNu
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Have you tried adjusting the ramping time?

horak2084
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Hello thank you for your fast answer.

Yes we tried it but it makes no different. 
I think its not a problem of the Ramping Time, because from higher speed to nearly zero is fine. But from nearly stop to reverse it takes aprox. 1-2 seconds and in this time the motor don't move.

 

 

Here is a Link to our Motor and Appsettings, if anybody can use it to help us ;)

https://www.dropbox.com/sh/otybr4scc1iabg8/AABiiAzi4tSJKqKPtcFhl6cDa?dl=0

 

 

 

 

horak2084
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So today we did some other test and now we can confirm that, the VESC waits to change the direction until the breaking current is nearly zero.

Does anyone know how we can change this?

2019-02-26 18_58_39-VESC Tool.png

benjamin
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Have you tried using FOC? Also, are you using any sensors? For self balancing applications it is very important to use sensors, as tracking near zero speed does not work well, and the sensor implementation for BLDC is a bit broken.

horak2084
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Thank you for the useful hint!

In the FOC mod the VESC works like we expect it to do. 

marto
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This could be related to the erpm at full brake setting which is not visible in the configuration utility. I had to set this 1500 in the xml as if you didn't and you were on a hill or something slightly above 300erpm then it would keep rolling. FOC has this as default to 1500rpm which is more likely why this fix has worked.

benjamin
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You are right, I forgot to add that parameter to the setting pages. It will be fixed in version 1.07.

fpagac
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maybe adjusting the ramping time works for me, my problem has been solved in the fastest way

hill climb racing