Hi Sergey,
have you tested wii-esc firmware ?
Some time ago i changed all my esc from simonk to wii-esc
Actually i only use hk blueseries 40amp esc with wii-esc firmware
(Complimentary PWM)
this is the best combination i ever tested.
On my little quad i use hk blueseries 20amp.
On 04/15/2014 04:52 PM, Sergey Krukowski wrote:
Hi guys!
Last time I had a chance to work a bit with different ESCs flashed
with SimonK firmware and since it wasn't really plug and play or fast
and furious as most comments in web say - wanted to share some
experience.
First of all I tried 3 different rotorcrafts with 3 different motor
sizes with 3 different ESCs:
ST4708 360KV with 15x5.5 propeller and Turnigy Multistar 45 Amp 6S LiPo
MK3638 700Kv with 13x4.7 propeller and ZTW Spider Series 30A OPTO 4S
LiPo
CF2822 1200Kv with 10x4.7 propeller and Afro ESC 12Amp 3S LiPo
As far as the first rotorcraft was pretty large, it was pretty stable
and I didn't really noticed any weird behavior.
However both other showed very weird frame oscillations mostly in
horizontal frame positions. And there was no PID combination to find,
that would remove these oscillations (was using ahrs_int_cmpl_quat
with euler_int attitude stabilization).
The oscillations wasn't really large, didn't really impact horizontal
position stability but the overall external flight quality was
unacceptable.
The actual problem eventually was in SimonK firmware. Most of
recently released versions (well, most likely ALL available to buy
ESCs with SimonK firmware) have a poorly solved max output power
limitation depending on commutation period (most probably because of
atmega's calculation power lack). That is why on some
motor/propeller/pwm command combinations it doesn't give enough power
to motor, causing undershoot and therefore the weird oscillations I
described.
The actual solution was to increase TIMING_RANGE1 and TIMING_RANGE2
values, so the firmware can give more power on lower rpms. But it
should be care taken about that modification, because it can cause
other problems, for example motor stall.
P.S.
Right now there is an other way of the max power limitation
implemented under the tgy github, looks like it should work more
stable on different motors/props/rpms than before.
Best Regards,
Sergey
_______________________________________________
Paparazzi-devel mailing list
address@hidden
https://lists.nongnu.org/mailman/listinfo/paparazzi-devel
_______________________________________________
Paparazzi-devel mailing list
address@hidden
https://lists.nongnu.org/mailman/listinfo/paparazzi-devel