Flips and rolls with the retardness of Attitude
« on: August 10, 2017, 01:40:29 pm »
Howzit guys,

All the way from South Africa and I have a question.

I have my 250 up and running for a while now, but need some help with tuning.

I have setup my CC3D for flips and rolls (Rattitude) and I can do them successfully, BUT, in order for them to be nice and snappy as they are, my Max Rate Limit is sitting at 720deg/s, but that makes my normal flight basically unflyable. Going down on that makes the flips too slow. As I've read, the Max Rate Limit applies to all modes, so this affects attitude as well.

I'm not proficient with Rate mode yet, but my suspicion is that if I get Rate mode down and wanna do flips, the Max Rate Limit will also make my quad sort of too twitchy to fly if my flips are set for 720deg/s.

I've also tried dialing in some expo. Started at 30% but my controls are so retarded that I can't fly. Down to 25% and it's better, but stick movement near center still feels to jelly. Down to 20% and I can fly her, but proximity flying is now downright dangerous, because trying to get out a tight spot with lots of stick action, she just pitches or rolls HEAVILY and into the ground if I'm not fast enough to correct. I don't like to let go of the sticks, I try to correct and keep to my pattern of flying.

So, my question is this, is there SOMEWHERE to disable that Max Rate Limit and just have Rattitude and at 80% switch over to Rate and then the Rate deg/s takes over to flip?
My mode transition % from Attitude to Rate is set at 95%, so I can be sure that I still have most of the stick movement to fly Attitude, but only at full stick deflection does she swap to Rate and flips, but that darn Max Rate Limit is buggering me around.

Please help!  :)
Reallac X6R
Racerstar 2205 2300kv
BL-Heli ESC's
CC3D
Matek PDB
HQ Prop V1s
Eachine TX801 VRX

f5soh

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Re: Flips and rolls with the retardness of Attitude
« Reply #1 on: August 10, 2017, 01:54:53 pm »
Hi, welcome.

Quote
my Max Rate Limit is sitting at 720deg/s, but that makes my normal flight basically unflyable.

Can you explain why ?

Please post your config file : File > Export UAV Settings

Re: Flips and rolls with the retardness of Attitude
« Reply #2 on: August 10, 2017, 02:46:34 pm »
Well, according to what I've read on the wiki pages, the Max Rate Limit deg/s applies to all modes. Even Attitude.  :)

The first setting (Attitude mode response (deg)) is the max angle she can go.
Then Rate mode response (deg/s)
Then Max Rate Limit (deg/s).

If I set my Attitude to 72, and leave the rest as default, the "quickness" of my pitch and roll movement will be determined by the max rate limit (300deg/s), but she will stop at 76deg angle as defined under attitude........ahhhhh.......  8)

Did I just solve my own problem? So If my max angle is specified under Attitude as 72deg's, and my max rate limit is 720deg/s, she will just reach 72deg's much quicker, but still not go over 72deg's? YAR!  ;D ;D ;D ;D
Reallac X6R
Racerstar 2205 2300kv
BL-Heli ESC's
CC3D
Matek PDB
HQ Prop V1s
Eachine TX801 VRX

f5soh

  • *****
  • 3767
    • LibrePilot
Re: Flips and rolls with the retardness of Attitude
« Reply #3 on: August 10, 2017, 03:04:38 pm »
Quote
Did I just solve my own problem?
I don't known...

Quote
So If my max angle is specified under Attitude as 72deg's, and my max rate limit is 720deg/s, she will just reach 72deg's much quicker, but still not go over 72deg's? YAR!

This is valid for Attitude stabilization where the max angle is limited according to the Attitude mode response value en degrees.

Re: Flips and rolls with the retardness of Attitude
« Reply #4 on: August 10, 2017, 03:41:53 pm »
Thanks.

It's a little confusing though, but I'll get there.
Reallac X6R
Racerstar 2205 2300kv
BL-Heli ESC's
CC3D
Matek PDB
HQ Prop V1s
Eachine TX801 VRX

Re: Flips and rolls with the retardness of Attitude
« Reply #5 on: August 10, 2017, 04:36:37 pm »
Once you get better flying rates look in acro+. I say this because i use it like expo. I have my rates set to 270 degrees that i fly around in altitude and ratitude and acro+. Acro plus is like ratitude in the sence that once it goes past a certain point in rotation it speeds up the degrees per sec. So on the expert stablization page i have acro + set to 65 on both.   I also have my max rate set to 1080 which is 3 whole flips per sec. Cuz im not sure how much faster it makes it but boy do i fell lt when i go to flip. I used to only be comfortable doing one flip at a time now i can do 2,3 maybe even 4 flips  in a row and feel way more cofendent. I would try it because if you get disoriented you can always flip the flight mode switch to altitude and it will level you out good luck  happy skys.

Re: Flips and rolls with the retardness of Attitude
« Reply #6 on: August 10, 2017, 06:00:40 pm »
I find that for Attitude mode, just use a really high max rate and the bank angle will follow the stick position with very little lag, and that feels good.

That works well for Rattitude too.  The only down side is that the second half of the flip (from upside down to level) will always be very quick.  I don't consider that a down side...  A quick glance at the code and it seems that all of Rattitude has apparently been converted to use the Rate mode max rate.  This would make the Attitude portion of Rattitude feel mushy.  So that's why it doesn't feel crisp now...........

(Rate mode) If you try to run the max rate too high, and your PIDs aren't tuned well enough, you will start to get "blowouts" (one or more axes aren't where they should be) at high rotational accelerations / rates.  Using and adjusting AxisLock mode instead of Rate mode can help correct for these blowouts.

Rate mode does require slower rates because a human becomes part of the feedback loop, and max rate mode flip speed is thoughtfully set with a different setting so you can have Rate mode rotate slower than other modes (Attitude).

It's been a while, but IIRC, Attitude mode with Basic "attitude estimation algorithm" does not work well for any long flights (say > 1 minute) where you are holding the same, non-neutral stick positions for a long time.  Examples: continuous circles around you where you hold roll and yaw constantly or long straight flight (think quadcopter FPV) where you hold forward pitch constantly.  You want Rate mode for these.  Of course, camera gimbals are always "Attitude mode" so you will always have small leveling issues with gimbals in the aforementioned cases.  INS13 helps for this because it partly uses the mags (in addition to the standard use of accels) to determine what is level.
« Last Edit: August 11, 2017, 05:01:50 pm by TheOtherCliff »

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Re: Flips and rolls with the retardness of Attitude
« Reply #7 on: August 10, 2017, 09:38:20 pm »
Hi icepick ,
I would agree with Wayne - once you can use rate mode , then you can fly acro+ with rates say 300-500 and acro factor up to 95% .

Nice and steady control ( with no yucky expo ) and rather speedy rolls n flips.
I find it preferable to plain rate mode for proximity flying.

Re: Flips and rolls with the retardness of Attitude
« Reply #8 on: August 11, 2017, 10:13:35 am »
@Cliff, this is how I have it setup now.

Rattitude with high max rate, but with a lower 35deg angle on Attitude (close to my FPV cam angle). I guess at 35deg, the speed should be ok for me now. Previously my angle was 72deg, which made the quad super banky, but in FPV I just see grass. :)

Thanks all for the replies.

I'll experiment with the Rattitude/max rate ect. This I will just use for when I'm flying LOS. I can manage rate okish in FPV for now, so will practise more with rate + FPV. I cannot fly rate LOS AT ALL! I suck. But FPV I can manage. Just feels more natural to me.
Reallac X6R
Racerstar 2205 2300kv
BL-Heli ESC's
CC3D
Matek PDB
HQ Prop V1s
Eachine TX801 VRX

Re: Flips and rolls with the retardness of Attitude
« Reply #9 on: August 11, 2017, 06:19:08 pm »
A quick glance at the code and it seems that all of Rattitude has apparently been converted (2014) to use the Rate mode max rate.  This would make the Attitude portion of Rattitude feel mushier.

I was about to tell you that Attitude mode max bank angle has no effect in Rattitude mode because "Mode Transition" (80% stick by default) shapes the stick feel.  The above change also brings max bank angle more into the way that the stick works and feels.  I don't know how these two settings interact.