Too small throttle area

General topics and discussions about the VESC and its development.
Quezacotl
Posts: 24
Joined: 05 Apr 2017, 11:06
Location: Finland

Too small throttle area

Postby Quezacotl » 05 Apr 2017, 12:02

Hello!

I just got my VESC working. I bought it somewhere, did not build. It's working as it should.
I'm using it on my electric bike. I made my own battery packs, 36V.
I'm using hall sensor throttle for speed adjustment. 5V sensor, output made 3V3 with voltage divider. Output connected to ADC(the middle pin).
The motor runs on sensorless mode. It has hall sensors, but it works just fine without. So i haven't wired the hall sensors.

The problem is that the throttle effective area is too narrow. Speed adjust is between 26% - 36%, while under 26% is nothing and 36-100% is full power.
The throttle area and BLDC tool "ADC" tab percentage area are consistent.
Any advice?

And another problem, i can't get HC-06- bluetooth-module to communicate with VESC. I have tried to connect with Android phone using "VESC connect lite" and "VESC connect pro" that i found on Play store. They don't find anything. Other apps are able to connect to the HC-06. I have tried 9600 and 115200 baud.
As i have understood, all i have to do is "ADC and UART" or just "UART" enabled and baud rate set on the BLDC tool?

buran
Posts: 12
Joined: 28 Jan 2017, 18:02
Location: Russia

Re: Too small throttle area

Postby buran » 05 Apr 2017, 13:49

There are some "mapping" settings in ADC application - you can remap your input voltage in custom diapason.
For example map 0-5V to 2-3V, so resolution of throttle will be higher.
Have you tried to use this?

And what mode have you used in ADC app? Current control or duty control?
For me current controlled ADC worked much more predictable than duty control.

rew
Posts: 937
Joined: 25 Mar 2016, 12:29
Location: Delft, Netherlands.

Re: Too small throttle area

Postby rew » 05 Apr 2017, 14:17

On my bike, I have ADC-in linked to current control. I display the current throttle setting on the display.

Somehow, with throttle 0-25% (after remapping the voltages)..... the current setpoint remains at zero. My bike runs acceptable, but your mention of "26%" makes me think it might be the same problem.

Quezacotl
Posts: 24
Joined: 05 Apr 2017, 11:06
Location: Finland

Re: Too small throttle area

Postby Quezacotl » 05 Apr 2017, 15:00

@buran: By mapping, you mean the minimum and maximum voltage? Yea i have tried playing with it, but i haven't got it any better. Should i try something like 0-10V values? Hmm.. maybe that's the key. I only tried to reduce it.
I tried with both, but no difference. Or well, the duty mode was slightly worse. Not it's current mode.

@rev: 25% or 26%, around there.

EDIT: I tried 0-10V but no difference.

And actually i took a ride with this controller for the first time just now, and i found out that it cuts off randomly when i give full throttle straight away. And after a kilometer, even with careful little throttle, it cuts off within few seconds.
The battery level was still good when i got home and plugged USB in, something like 37V. Well not good, but decent.

artteth
Posts: 28
Joined: 22 Jul 2016, 00:28
Location: Belarus

Re: Too small throttle area

Postby artteth » 05 Apr 2017, 17:51

Quezacotl wrote:@buran: By mapping, you mean the minimum and maximum voltage? Yea i have tried playing with it, but i haven't got it any better. Should i try something like 0-10V values? Hmm.. maybe that's the key. I only tried to reduce it.
I tried with both, but no difference. Or well, the duty mode was slightly worse. Not it's current mode.

@rev: 25% or 26%, around there.

EDIT: I tried 0-10V but no difference.

And actually i took a ride with this controller for the first time just now, and i found out that it cuts off randomly when i give full throttle straight away. And after a kilometer, even with careful little throttle, it cuts off within few seconds.
The battery level was still good when i got home and plugged USB in, something like 37V. Well not good, but decent.


hall throttle can work from 3.3v so you can connect it to 3.3v and direct to adc without any voltage dividers
adjust min and max voltages in adc tab 0 throttle should be at the beginning full at the end (green strip at the bottom of adc tab)
what mode you use bloc or foc?

Quezacotl
Posts: 24
Joined: 05 Apr 2017, 11:06
Location: Finland

Re: Too small throttle area

Postby Quezacotl » 05 Apr 2017, 19:12

@artteth: Okay, thanks. Now it's working great! I hooked the hall throttle directly to 3V3, and tuned settings; 0,60V - 2,60V. And mode as "duty cycle". Now it works for almost the whole area.
The visual bar says 14% as default, and i need to pull the throttle only to about 17% and it starts. So i have now effective area 17% - about 100% :D

I have used BLDC because it feels more reliable. I have tried FOC occasionally if i could get it better.
I get more dropouts with FOC than BLDC.

I don't have any idea what could be behind those dropouts :cry:

EDIT:
@rew: Can you share your motor-related settings, since you have most likely quite similar setup than i have?

User avatar
Ecyclist
Posts: 30
Joined: 24 Jun 2017, 01:26
Location: San Diego, CA

Re: Too small throttle area

Postby Ecyclist » 24 Jun 2017, 04:42

I found tutorial on how to set up throttle on VESC.
https://endless-sphere.com/forums/viewt ... 2#p1298912
Enjoy.


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