PID tuning - cannot erase bounceback | Drone Community | Page 1

rose shell Dec 3, 2022, 1:42 AM

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I've been tuning a 1S 3" toothpick with a ~70g AUW on 11000KV 1303 motors.
I eliminated bounceback by removing dynamic damping and wiggling the master slider (ended up at 1.8), and then I tried to reduce bounceback on snap rolls and flips by moving P&I. Moving it below 1 immediately made flying worse so I went up in increments of 0.05. Up until 1.5 the bounceback has been reducing, but it got worse again at 1.55 and worsened more at 1.6.
What else can I do to completely stop the quad from bouncing at the end of snap maneuvers?

rose shell Dec 3, 2022, 6:15 PM

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@austere radish I was told you're an absolute wizard! When you got time, can you pitch some tips at me? Because I'm at a total loss here

abstract furnace Dec 3, 2022, 6:16 PM

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rose shell <@134627421029662720> I was told you're an absolute wizard! When you got time, c...

My guess is he's gonna ask for BB log and DVR PepeScience

rose shell Dec 3, 2022, 6:17 PM

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Ein Moment

rose shell Dec 3, 2022, 6:32 PM

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That's the best I could get it to fly

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That's the blackbox, not sure which flights are included because the DVR doesn't capture OSD

📎 btfl_all.bbl

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This is the tune that gave me the least bounceback

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I was fiddling with the P&I gains slider, move it in any direction away from 1.5 and it flies worse

austere radish Dec 3, 2022, 6:52 PM

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abstract furnace My guess is he's gonna ask for BB log and DVR <:PepeScience:884519965913399357>

XD 😁

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@rose shell I will look into that later (after 21 o'clock CEST)

rose shell Dec 3, 2022, 6:56 PM

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Appreciated!

austere radish Dec 3, 2022, 6:57 PM

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rose shell Appreciated!

Can you make me a BB (and DVR) with stock PIDs and filters?

rose shell Dec 3, 2022, 6:58 PM

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austere radish Can you make me a BB (and DVR) with stock PIDs and filters?

It's quite unflyable with stock pids and filters >.>

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But I'll try

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I crashed it three times just because of how uncontrollable it was stock

austere radish Dec 3, 2022, 6:59 PM

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Uh okay, uhm that's not good

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Than please only stock PIDs

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What firmware version?

rose shell Dec 3, 2022, 6:59 PM

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4.3

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Stock PIDs are the problem, it only becomes somewhat good when I boost the master slider significantly

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The D gain is too small by default

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It's 3am for me, I'll be able to record more tomorrow (around midday-ish my time?)

austere radish Dec 3, 2022, 7:02 PM

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Okay, I can work with that

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I will first investigate the current logs

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Reason for 0 Feed forward?

rose shell Dec 3, 2022, 7:02 PM

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Chris Rosser

austere radish Dec 3, 2022, 7:02 PM

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XD

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The reason for my question: if you play with feed forward you can solve unflyable quads

rose shell Dec 3, 2022, 7:04 PM

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Yeah, I just follow his guide for tuning Betaflight 4.3. It worked for other two toothpicks, this one is a little tougher and it is also the lightest of the three

austere radish Dec 3, 2022, 7:04 PM

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Because ff bypasses some things in the pid loop, so we can tune D and I and resolve missing reactions or so with ff

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I will look into the logs

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Maybe I can see stuff already there

rose shell Dec 3, 2022, 7:05 PM

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~70g, 3". The first one was 3.5", 99g, also flew like shit initially but I could tune it to near-perfection following Rosser's guide, another was 150g and flew near perfectly already with stock PIDs, tuning that one was a breeze

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So I guess the default tune does not handle the large-prop-low-weight combination

austere radish Dec 3, 2022, 7:07 PM

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Tbh I suspect a frame problem (I always do XD )

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I can see most of this with a stock bb flight

rose shell Dec 3, 2022, 7:08 PM

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Sir

austere radish Dec 3, 2022, 7:08 PM

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That's why I asked XD

rose shell Dec 3, 2022, 7:08 PM

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My frame is perfect x3

austere radish Dec 3, 2022, 7:08 PM

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We will see 🤣

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So many said their frame was perfect

rose shell Dec 3, 2022, 7:08 PM

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I did tune the filters by looking at logs

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It's the cleanest I've seen them

austere radish Dec 3, 2022, 7:09 PM

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Ok good

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Oh can you list the hardware too?

rose shell Dec 3, 2022, 7:09 PM

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austere radish Dec 3, 2022, 7:09 PM

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Like frame, motors, props, esc

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Looks sexy!

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I don't like the colors, but that's preference XD

rose shell Dec 3, 2022, 7:10 PM

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I could not find that canopy in a different colour, was out of stock everywhere

austere radish Dec 3, 2022, 7:11 PM

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Print it 🤪

rose shell Dec 3, 2022, 7:11 PM

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It's injection moulded

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I don't think the files are available online for it

austere radish Dec 3, 2022, 7:11 PM

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First picture, is a wire near the gyro?

rose shell Dec 3, 2022, 7:12 PM

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No, I routed it specifically away from it

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Wires do not touch the FC

austere radish Dec 3, 2022, 7:12 PM

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Perfect

rose shell Dec 3, 2022, 7:13 PM

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Reason i picked the canopy is because it's entirely self-contained

austere radish Dec 3, 2022, 7:13 PM

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I will come back when I analyzed the logs

rose shell Dec 3, 2022, 7:13 PM

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(the VTX was flipped upside down since taking that picture, the antenna is now on the other side and away from the FC)

austere radish Dec 3, 2022, 7:13 PM

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That will be in like 2 hours approx

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Seems like you already know the basics 🙈

rose shell Dec 3, 2022, 7:14 PM

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I have tuned three other quads successfully >.>

austere radish Dec 3, 2022, 7:14 PM

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There are configurations, that are not tunable

rose shell Dec 3, 2022, 7:15 PM

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I guess

austere radish Dec 3, 2022, 7:15 PM

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Because of some combined stuff nobody can fix 😦

rose shell Dec 3, 2022, 7:15 PM

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But this is the cleanest, most solid build I've made so far, so I was surprised a little

austere radish Dec 3, 2022, 7:15 PM

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Perfect parts, perfect build, together doesn't work

rose shell Dec 3, 2022, 7:15 PM

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Yeh

austere radish Dec 3, 2022, 7:15 PM

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Yeah, I will look

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Maybe I see a big tell

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I guess this involves a lot of back and forth

rose shell Dec 3, 2022, 7:16 PM

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If everything fails, I'll just bring back FF and see how it goes, otherwise with the current tune it's perfectly flyable unless I max out the sticks with my rates

austere radish Dec 3, 2022, 7:16 PM

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Oh what rates?

rose shell Dec 3, 2022, 7:18 PM

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Uh

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Copied from Micro Drones :D

austere radish Dec 3, 2022, 7:18 PM

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XD

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One wild guess, it. And handle that rates

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But I can see if that's the case in the logs

rose shell Dec 3, 2022, 7:19 PM

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Hmm

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Alright. I'll be fast asleep in 2 hours so I'll come back and read in the morning

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Thank you for looking into it

austere radish Dec 3, 2022, 7:19 PM

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If you can, try it with max 900

rose shell Dec 3, 2022, 7:20 PM

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Sure

austere radish Dec 3, 2022, 7:20 PM

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I had a 3" which had a slight unfixable weight balance problem

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This only flew perfect with lower rates

rose shell Dec 3, 2022, 7:21 PM

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Interesting, good to know. I think you can see it in DVR, if I don't quite max out the sticks it tracks smoothly

austere radish Dec 3, 2022, 7:24 PM

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Yes I saw

austere radish Dec 3, 2022, 8:49 PM

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lets do this

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@rose shell sadly i must say, this BB is pretty much useless. No rolls, flips or full throttle punches

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https://github.com/bw1129/PIDtoolbox/raw/master/images/PID_Compensation_Animated.gif

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have you seen this?

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orange is feedforward

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in this example, you dont have enough I

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without any realy logs to look at: increase I a lot and increase D a little

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please provide a new BB with flips, rolls and full throttle punches 🙂

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filter wise, you can even decrease filters 😄

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this is FCKING clean bro

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as you already guessed correctly 😄 i dont see a mechanical issue

rose shell Dec 4, 2022, 1:06 AM

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austere radish <@181898739332415489> sadly i must say, this BB is pretty much useless. No rolls...

Going to grab a better log today. Strange because I was erasing it specifically to record for the step response tool, but I guess I got carried away

rose shell Dec 4, 2022, 2:49 AM

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austere radish https://github.com/bw1129/PIDtoolbox/raw/master/images/PID_Compensation_Animated...

That's the best visualisation a pilot could hope for

rose shell Dec 4, 2022, 4:22 AM

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Naturally it rains just as I'm about to leave the house

rose shell Dec 4, 2022, 8:52 AM

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Could not get the log, the field where I fly is one huge puddle right now. Will put this on hold till next week

austere radish Dec 4, 2022, 12:16 PM

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rose shell Could not get the log, the field where I fly is one huge puddle right now. Will ...

Okay 🙂 ping me please, when you have new data

austere radish Dec 4, 2022, 12:33 PM

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we have another problem

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yaw is fine

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pitch and roll not

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your P and I is way to high
your D is too low

2 can be better, when reducing P and I

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since its a BIIIIG overshoot AND the line is above 1 => reduce P by quite a margin

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reduce I a little

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increase D a little

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Dampening: 1.1
Tracking: 1.4
Pitch Dampening: 1.1 - 1.15

Master: 1.7

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this would be my recommended changes for now

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the scale normaly ends at 1.75 which means you overshoot by 75% in deg/s

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you are close to 3!

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gyro is clean af

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d-term is acceptable

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but you have some d-term problems (slight)

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which my because you have such high P and I terms

rose shell Dec 4, 2022, 2:59 PM

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Appreciate the input! I'll play with the logs and the step response tool whan I have another field day, the visualisation of how the three terms affect the tracking completed the picture in my head. I'll report the results once done

austere radish Dec 4, 2022, 3:18 PM

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If you recall the stabilization above 1, it the reason. Your FC fights to match deg/s but never can, because your PIDs are to cranked

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This is why I don't love, cranking the masters slider so hard first. You increase everything together

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I do it too, than reduce it by 50% so in your case 1.4. than I look at logs and fix each term one by one until its perfect with a little overshoot (1.05 or so)

rose shell Dec 10, 2022, 12:30 AM

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@austere radish For your perusal! Just got out for another tuning flight, the second arm has all the flips and rolls

📎 btfl_001.bbl

austere radish Dec 10, 2022, 12:32 AM

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Nice!

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How was the flight, did you adjust some pids?

rose shell Dec 10, 2022, 12:34 AM

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That was on stock

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Going to be adjusting it now

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Even the yaw has overcorrection

austere radish Dec 10, 2022, 12:35 AM

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yeah but acceptable

rose shell Dec 10, 2022, 12:36 AM

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So from what I see I need lower I and way more D

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P is fine I guess?

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Maybe slightly less P

austere radish Dec 10, 2022, 12:38 AM

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since you have a HIGH overshoot

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lower I

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and yes

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a lot of D

rose shell Dec 10, 2022, 12:39 AM

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Setting D max to 70 and D to 50

austere radish Dec 10, 2022, 12:39 AM

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show your current settings please

rose shell Dec 10, 2022, 12:39 AM

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They're displayed next to the graphs

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P 45, I 80, D max 40, D 30

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Could use even more D

austere radish Dec 10, 2022, 12:45 AM

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you should look at the D-Term spectral before doingt hat

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this is fine so far (old logs)

austere radish Dec 10, 2022, 12:47 AM

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rose shell

P and I are somewhat perfect

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go and decrease I a LITTLE! And increase D

rose shell Dec 10, 2022, 12:48 AM

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Yup

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By like 10 for I?

austere radish Dec 10, 2022, 12:48 AM

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like 5

rose shell Dec 10, 2022, 12:48 AM

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Maybe 5

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Yeah

austere radish Dec 10, 2022, 12:49 AM

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Roll: D = 75, Dmax = 60
Pitch: D = 90, Dmax = 62

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i would aim for a little overshoot at the start

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general undershoots results in a "laggy" feel

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overshoot by max 1.05-1.1 feels realy snappy

rose shell Dec 10, 2022, 12:50 AM

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Alright, hooking up a new battery, bb in 5 minutes

austere radish Dec 10, 2022, 12:51 AM

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i will go to sleep now 😄 sorry

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but present some Data, always look at d-term noise

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and check your motor temps after torture

rose shell Dec 10, 2022, 12:51 AM

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Alright. I think I can arrive at decent values on my own

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And these motors are always cold

austere radish Dec 10, 2022, 12:51 AM

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increasing D ALWAYS increased motors temps

austere radish Dec 10, 2022, 12:52 AM

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rose shell Alright. I think I can arrive at decent values on my own

perfect! 🙂 if not - i am here xD

rose shell Dec 10, 2022, 1:40 AM

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@austere radish D:

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Almost perfect, but now it feels more sluggish and there's some bounceback that feels... almost lazy

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I stop the turn and it moves me smoothly back 4 degrees or so over the time of about half a second

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Hmm

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This is the darker red on the step response tool

📎 btfl_001.bbl

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Same but no feedforward

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More P, less I and even more D?

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Adding 2 I to the yaw, otherwise looks perfect

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I am on the right track!

rose shell Dec 10, 2022, 2:38 AM

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It started raining, but before it did I ended up with P 100, I 30, and D in the ballpark of 100, and that flew a lot fucking better than it did last week or at any point today. And motors are still barely warm.

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Pretty sure I have achieved the PID tuning zen

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I'm dialing it in more tomorrow

rose shell Dec 10, 2022, 5:13 AM

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Log from the last flight, as I don't know if I'm going to fly again today

📎 btfl_001.bbl

austere radish Dec 10, 2022, 8:39 AM

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This looks almost perfect!

After I tuned via math, I tuned a little just by feeling.. Because I'm the end that only matters

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I will look at them log later 👍

rose shell Dec 10, 2022, 8:40 AM

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I'm heading back right now to try and tighten the P a little more, and get the good FF values

austere radish Dec 10, 2022, 9:08 AM

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Perfect!

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You can play with ff boost as well

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This will decrease the ff reaction time, but not the amplitude

rose shell Dec 10, 2022, 9:16 AM

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austere radish Perfect!

Speaking of perfect,

austere radish Dec 10, 2022, 9:16 AM

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Awesome 🎉🎉🎉🎉

rose shell Dec 10, 2022, 9:16 AM

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I'll leave the yaw be

austere radish Dec 10, 2022, 9:16 AM

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I would to

rose shell Dec 10, 2022, 9:16 AM

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Those PIDs are monstrous though

austere radish Dec 10, 2022, 9:17 AM

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Yaw is always a problem child

rose shell Dec 10, 2022, 9:17 AM

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austere radish Dec 10, 2022, 9:17 AM

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rose shell Those PIDs are monstrous though

If motors are soundings good and are only warm 🤷

rose shell Dec 10, 2022, 9:17 AM

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Yeah

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I'll keep D max where it is and bring the D term down by a bit

austere radish Dec 10, 2022, 9:17 AM

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3.5 anti gravity XD I always put that at 10

rose shell Dec 10, 2022, 9:18 AM

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I actually don't know what it does :D

austere radish Dec 10, 2022, 9:18 AM

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Try it, it becomes more floaty

rose shell Dec 10, 2022, 9:18 AM

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Hmm, but I don't really want that

austere radish Dec 10, 2022, 9:18 AM

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Basically when you let off throttle, it defines how fast the quad falls out of the air

rose shell Dec 10, 2022, 9:18 AM

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Ahh

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I need it to dive well

austere radish Dec 10, 2022, 9:19 AM

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You still can with high anti grav

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But yeah, that's preference and different for each quad

rose shell Dec 10, 2022, 9:19 AM

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Hmm

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Does it affect it when it's inverted?

austere radish Dec 10, 2022, 9:19 AM

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I am glad you finally got the PIDs perfect 🎉

austere radish Dec 10, 2022, 9:20 AM

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rose shell Does it affect it when it's inverted?

Hm?

rose shell Dec 10, 2022, 9:20 AM

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When the quad is inverted, how does anti-gravity change its behaviour?

austere radish Dec 10, 2022, 9:20 AM

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Oh, good question

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I assume it does it's thing too

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Since the FC knows it's inverted

rose shell Dec 10, 2022, 9:21 AM

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Hmm

austere radish Dec 10, 2022, 9:21 AM

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But don't quote me on that

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If you never played with that, leave it

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It's so helpful on 3" quads

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Airmode and anti grav helps letting you feel more like a 5" XD with the agility of a 3"

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For now, go and fly

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Don't get logs, just fly like 10 packs

rose shell Dec 10, 2022, 9:22 AM

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Yeah

austere radish Dec 10, 2022, 9:22 AM

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And feel how it goes

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Than adjust from there

rose shell Dec 10, 2022, 9:22 AM

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I think PIDs are perfect, FF is still pending

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So I'll go do that

austere radish Dec 10, 2022, 9:23 AM

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Get back to me when you have feelings to discuss XD

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FF will demand pid changes

rose shell Dec 10, 2022, 9:23 AM

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Ah

austere radish Dec 10, 2022, 9:23 AM

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So, I would say leave it too

rose shell Dec 10, 2022, 9:36 AM

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austere radish So, I would say leave it too

Ok, so it flies AMAZINGLY

rose shell Dec 10, 2022, 9:53 AM

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austere radish Dec 10, 2022, 9:55 AM

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This looks perfect! Locked in, smooth and jitter free! Not even a little propwash.

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As I like Chris rosser so much. I learned tuning from him XD I feel guys methods are too aggressive and lead to stuff that can't be fixed from that point on

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So you need to start over ...

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I like my method, which just brings the nature of the pid loop to the person. So they understand what they are tuning

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That part is missing from rosser imho

rose shell Dec 10, 2022, 9:57 AM

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His method works well for ~500g 5" quads that are mechanically stable :D

austere radish Dec 10, 2022, 9:57 AM

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Dunno XD I tune like I told you

rose shell Dec 10, 2022, 9:57 AM

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And to a lesser degree for builds with a similar vibe

austere radish Dec 10, 2022, 9:57 AM

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And you not don't need me anymore XD that's the best part

rose shell Dec 10, 2022, 9:58 AM

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I mean, his method worked for all my toothpicks so far except this one where it just completely fell apart

austere radish Dec 10, 2022, 9:58 AM

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That one gif, almost everytime gets the click in the person's head

rose shell Dec 10, 2022, 9:59 AM

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austere radish That one gif, almost everytime gets the click in the person's head

Yep, it's literally the only thing most people would need to understand PIDs

austere radish Dec 10, 2022, 9:59 AM

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😁👍

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And that's all you need to understand all the values

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And all you need to find the perfect tune

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Happy flying brother

rose shell Dec 10, 2022, 10:00 AM

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A massive thanks for staying along for this journey :D

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I learned heaps.

#PID tuning - cannot erase bounceback