10S custom skate ESC: testers wanted!
- Thread starter austindavid
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sl33py
10 kW
Wow! That is cool.
besides being quieter, are there any performance or efficiency benefits of FOC? I did some light reading on FOC not really knowing the difference and it seems like in the ebike groups they were seeing a solid couple percent improvement in efficiency. better low end power but slightly less top speed (that sounds ideal for an eboard).
Thanks Vedder!
besides being quieter, are there any performance or efficiency benefits of FOC? I did some light reading on FOC not really knowing the difference and it seems like in the ebike groups they were seeing a solid couple percent improvement in efficiency. better low end power but slightly less top speed (that sounds ideal for an eboard).
Thanks Vedder!
I will try to get/find someone that can help measuring the FOC values for the RSPEC motors but that not easy yet! Does anyone have RSPEC motors (on loop?) and can get the values required for FOC measured according to this guideline ?
=> http://cache.freescale.com/files/microcontrollers/doc/app_note/AN4680.pdf?pspll=1
=> http://cache.freescale.com/files/microcontrollers/doc/app_note/AN4680.pdf?pspll=1
sl33py said:
You are right about that the top speed decreases. I did some quick experiments with field weakening, but I had to add a lot of negative d-axis current to make it go up, so in practice I think you should expect a bit lower top speed. I haven't measured the efficiency yet, but I don't think there will be much difference. Ebikes have very slow hub motors and there FOC should give more improvements than for our geared setups with tiny wheels compared to bicycle wheels. According to a thesis I read (Investigation of Issues Related to Electrical Efficiency Improvements of Pump and Fan Drives in Buildings by JOHAN ASTROM), trapezoidal commutation with proper phase advance is slightly more efficient than FOC in most situations. I don't know if it is different for bicycle hub motors or if the controllers they compared FOC to were poor, but in any case you won't see a very noticeable difference in efficiency. I think the quietness is the main benefit of FOC for our boards, and that is a big improvement for me at least.
It was a turnigy 6374 168kv motor.
Also, I tried an RC inrunner that has 1uH inductance, and there the current measurement was completely off. It did run though, drawing lots of current. The old implementation should be easier to use and configure for a wider range of motors, but we will see after I have polished the FOC implementation more.
Here is some info on FOC, there is also a PDF at the end with measurements and graphs (unfortunately in german).
http://www.sinusleistungssteller.de/en_SinusStromRegelung.html
They say system efficiency (Motor+ESC) is 4-5% better compared to an "XY-standard Hobby ESC". Overall system efficiency (Motor+ESC+Battery) is 7-8% better. Motor temps after their tests was 75C with standard commutation, 70C with FOC.
http://www.sinusleistungssteller.de/en_SinusStromRegelung.html
They say system efficiency (Motor+ESC) is 4-5% better compared to an "XY-standard Hobby ESC". Overall system efficiency (Motor+ESC+Battery) is 7-8% better. Motor temps after their tests was 75C with standard commutation, 70C with FOC.
Is there already a wiki page regarding the various configuration options for this esc?
I'm specifically interested in tuning the Vedder ESC concerning startup torque.
I have the esc working with a 6" hub motor and the startup torque is good in hybrid mode (but it doesn't sound too nice).
Also with braking I'm not yet satisfied - I have relatively soft braking - but close to standstill (maybe related
to the hybrid rpm threshold) it suddenly brakes a lot harder.
I'm specifically interested in tuning the Vedder ESC concerning startup torque.
I have the esc working with a 6" hub motor and the startup torque is good in hybrid mode (but it doesn't sound too nice).
Also with braking I'm not yet satisfied - I have relatively soft braking - but close to standstill (maybe related
to the hybrid rpm threshold) it suddenly brakes a lot harder.
Anyone managed to get good startup in sensorless?
I have connected it to large hub motor and torque is good when already moving, but from stand still it is very jittery, trying to move to both directions...
Seems like it is unable to observe the position by HF injection.
I have connected it to large hub motor and torque is good when already moving, but from stand still it is very jittery, trying to move to both directions...
Seems like it is unable to observe the position by HF injection.
Guys I need your help.
As some of you know, I lost my 2 VESCs in the hand of Marcin who did never sent them back to me after repair/replacement. I live in France, EU. Do any of you know of a VESC builder in the EU?
In the case nobody does it I might consider building my owns, since I wanted to mod it anyway. But still this delays me again.
Thanks for advance if you can help!
As some of you know, I lost my 2 VESCs in the hand of Marcin who did never sent them back to me after repair/replacement. I live in France, EU. Do any of you know of a VESC builder in the EU?
In the case nobody does it I might consider building my owns, since I wanted to mod it anyway. But still this delays me again.
Thanks for advance if you can help!
I am still having problems with large motor (MXUS 3000W V2). It spins OK if started when already spinning, but will not start from stand still when loaded, and even not always without load.
I have set Integrator limit to 400 and BEMF coupling to 0. Increasing BEMF coupling seems to have a bad effect, same with decrease of integrator limit.
By the way, here is my rotor position detection:
There is a lot of noise. Maybe that is because algorithm is optimized for lower inductance motors?
I have set Integrator limit to 400 and BEMF coupling to 0. Increasing BEMF coupling seems to have a bad effect, same with decrease of integrator limit.
By the way, here is my rotor position detection:
There is a lot of noise. Maybe that is because algorithm is optimized for lower inductance motors?
onloop
10 kW
- Joined
- Jun 24, 2013
- Messages
- 600
whitepony
10 kW
- Joined
- Feb 19, 2015
- Messages
- 663
from an aspiring vesc user to the user community: is there a way to adjust your drag in the VESC ... Im kinda looking for active belt/engine drag suppression by electric support.
was thinking about hooking up my tesseract with a single motor lightweight electrification to lift me up hills ... and then skate them down with a raw longboard feel --- or at least something as close as possible to that.
i probably really havent thought this through, but theoretically, on flat and smooth terrain, you could measure the velocity from full throttle to a stand still to determine a mixed drag of belt, motor, wheel deformation and also air of you and your particular setup ... and then add this kind of torque to the control at all times for an absolute zero drag mode. could try to substract wheel deformation & air by another run without a belt for the most natural raw longboard feel!
but for this to work, I would need to know a lot more about how to control these outrunner motors ...
was thinking about hooking up my tesseract with a single motor lightweight electrification to lift me up hills ... and then skate them down with a raw longboard feel --- or at least something as close as possible to that.
i probably really havent thought this through, but theoretically, on flat and smooth terrain, you could measure the velocity from full throttle to a stand still to determine a mixed drag of belt, motor, wheel deformation and also air of you and your particular setup ... and then add this kind of torque to the control at all times for an absolute zero drag mode. could try to substract wheel deformation & air by another run without a belt for the most natural raw longboard feel!
but for this to work, I would need to know a lot more about how to control these outrunner motors ...
chaka
1 kW
whitepony said:from an aspiring vesc user to the user community: is there a way to adjust your drag in the VESC ... Im kinda looking for active belt/engine drag suppression by electric support.
was thinking about hooking up my tesseract with a single motor lightweight electrification to lift me up hills ... and then skate them down with a raw longboard feel --- or at least something as close as possible to that.
i probably really havent thought this through, but theoretically, on flat and smooth terrain, you could measure the velocity from full throttle to a stand still to determine a mixed drag of belt, motor, wheel deformation and also air of you and your particular setup ... and then add this kind of torque to the control at all times for an absolute zero drag mode. could try to substract wheel deformation & air by another run without a belt for the most natural raw longboard feel!
but for this to work, I would need to know a lot more about how to control these outrunner motors ...
The only way I know of to accomplish this is to use really tall gearing. My personal board has a 20/32 tooth on 83mm kegels and it feels totally neutral when not on the throttle. This tall gearing paired with the VESC current control has proven to be more than satisfactory. Prior to using the VESC it would cog viciously when applying too much throttle at low speed.
whitepony
10 kW
- Joined
- Feb 19, 2015
- Messages
- 663
you just minimize the rpm of the motor by tall gearing, so you basically just reduce drag. I instead would like the VESC to actively work against setup drag as function of velocity - something that could be described by a quadratic polynomial reasonably well probably. if the drag as function of velocity or motor rpm is known, it sounds doable somehow to account for it on the control side?
Assembling question:
BOM for VESC V4.10 contains a resistor 330kOhm at R15, but R15 is not there anymore (compared with V4.7 where it was present).
Did I overlook something or was it indeed omitted in V4.10 (and just forgotten to be deleted in BOM 4.10)?
BOM for VESC V4.10 contains a resistor 330kOhm at R15, but R15 is not there anymore (compared with V4.7 where it was present).
Did I overlook something or was it indeed omitted in V4.10 (and just forgotten to be deleted in BOM 4.10)?
chaka
1 kW
Yes, it was removed in version 4.10.
Hello Guys,
last week i got one VESC PCB (V4.7) and ordered the parts from Mouser (BOM 4.7). Now i have assembled the VESC and flashed the Firmware (1.10). I can connect the VESC with the PC an can run my motor.
But the detection of the Motor paramters do not work. I get the Message (Bad detection). And when i run the motor without detection with standart parameters it runs very hard. I tried this with 2 different motors.
Outrunner with 1200kv
Inrunner 4 Poles with 2500kv
There are no Faults or flasching red Led
I hope you guys can help me.
last week i got one VESC PCB (V4.7) and ordered the parts from Mouser (BOM 4.7). Now i have assembled the VESC and flashed the Firmware (1.10). I can connect the VESC with the PC an can run my motor.
But the detection of the Motor paramters do not work. I get the Message (Bad detection). And when i run the motor without detection with standart parameters it runs very hard. I tried this with 2 different motors.
Outrunner with 1200kv
Inrunner 4 Poles with 2500kv
There are no Faults or flasching red Led
I hope you guys can help me.
chuttney1
100 W
F3-John said:
I must say 1200 Kv for Outrunner and 2500 Kv for an inrunner is very high, not useful for eboards. I am assuming you have other applications with the VESC you want to test...
Hummina Shadeeba
10 MW
im guessing the motor doesn't have enough inuduction as indicated by the high kv. You could run those on a board with good results if you used low voltage. but the esc isn't recognizing it from their low magnetism. that's my guess.
