Help with multiwii quadcopter

[GTiDon]

Headfree is the simple mode as I wrote above. I switched to megapirate so im also out of touch with the multiwii terminology. They are different.

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[Peter]

Pass through is only used for planes and means that it just passes the stick values on to the servos, so no stabilisation.

Head adj has something to do with the nose direction and return to home. So when you a GPS.

[kaos]

Got my replacement motor. Now, it is much better. Gee, one bad motor out of the box for a person to start his 1st every quad. Not good.

but I have to say it is still pretty touchy than cp heli on throttle though. Able to hover without slamming down to the floor. But I do noticed one thing, the pitch and roll response is very crisp, while the yaw control is very very slow. I have the rc rate at 0.5 for P/R, 0.8 for yaw , still the yaw control seems very very slow and unresponsive. Is this normal for quad?
roll: 6.3 0.03 9
picth: 6.5 0.03 9
yaw: 25 0.244 18

rate: p/r: 0.5 yaw: 0.8
thr expo: 0.5
rc rate: 0.5 rc expo: 0.2

level: 8.0 0.04 90
anything pop up in your eyes?

[jhsa]

in multicopters it is normal the yaw to be slow. But how slow is very slow?

[kaos]

errrh, slow is slower than normal, not as fast as fast.
put it this way, I can't do a piro in my garage, by the time it turns 360 degree I will be crashing. to turn the head, it takes more than one to two seconds to do it.
on a heli, I can turn 45 degree in a snap, but this it will kind of slowly turn 45 degree, and slowly turn back when stick is back. for pitch and roll, it is snappy - zip zip!

[jhsa]

Quads are quite bad for yaw speed.. don't expect it to be any close to what an heli can do
Maybe you can increase the yaw rate. Props play a big roll as well.. I haven't be following the multiwii for a while, but will again as soon as I finish modding my radios.. Have to rebuild my quad. My tricopter is grounded as well. needs a very good maintenance check. it's now 2 years old and last time I flew it I had all 3 motors stopping for a fraction of a second in flight and then starting again. that was weird and I couldn't reproduce the problem again.. So, I grounded it The tri is running multiwii 1.7 which is quite old. My quad is running 1.9.
I guess that in a few weeks I will update my multiwii knowledge again..

João

[Crucial]

I had to increase the yaw rate too. Mine was very slow responding before that.

[kaos]

I have tried yaw PID: 25 0.244 80~100 does not seem to make much difference. or there is some where else I can increase the yaw rate without changing the pitch/roll rate?
this is my 1st multicopter, when I was hovering in the garage, I was thinking: hmm this thing needs a different way of flying, I can fly this thing as a disc, control it to go any direction just by pitch and roll, basically no head or tail, just a disc with a reference of the 'head' for the 'cyclic' stick orientation. And you can pretty much do flips /rolls in any direction. Again, this is just a newbie's thought.

[GTiDon]

My yaw slow too on my CRIUS board. Just living with it at the moment. My first board was a KK and that yawed much more responsive on the same quad. So it must be settings related.

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[Peter]

The P of 25 is very high and will counteract your sticks. Normal value is 4 or 8. With a rate of .8 it will compensate for it, leaving 20% of 25. Try low P values with high rates.

Your rc rate is also low. Like this (0.5) you get half of normal response. I fly with 1.8 and a dual rate on a switch. But dual rate is only for my pitch and roll. I keep yaw at 100%. I think you could go as far as 3.5 for rc rate. Nice acrobatic
The rate for pitch and roll can go down if you put the rc rate up. In that way it works mostly on the yaw.

I like tricopters for their yaw response. But after some tuning of quads can do it enough.

[kaos]

thx. GTIDon and Peter. I will definitely try those setting. I am a little afraid to go to that number because my 1st bad motor as 1st time set up, the 1st couple min, just a little movement on the stick the quad just flipped like a fish just pulled on the bank belly up.
I was telling myself, wow, this thing is sensitive. now my motor is normal, I will try those numbers. LIke I said I have NO experience with quad before. thx for the suggestion that i have a direction to go by.
hopefully I will have a vid to show you how it flies soon. (a wk or 2 may be)

By the way, I use 2200mah 3S , during the trial hover/set up it lasted only about 6-7 min. that sounds normal?
The total weight is around 976g with one 3S battery. 18A ESC and 4 1000kv motor. 10x4.5 props.

[jhsa]

A 2200mA battery lasts about 4 and a half minutes on my quad and 5 and half minutes on my tri.. but they are both a bit heavier than yours

[kaos]

good, then I am about right on the bulk part. I will eventually put 2 3S 2200mah batt in it to do real fly, may be that will give me another 4 min or so.

[kaos]

I think you could go as far as 3.5 for rc rate. Nice acrobatic

Ok, now i know 3.5 is the max rc rate. Gee, multiwii people is like er9x people - Nerdish. why can't they just use plain numbers 0-100 for all the settings.
still remember I was messed up for a long while by the throttle number from -100 to 100 when switching to er9x, 0 is not 0.

with my 0.8 rate, the roll and pitch is quite crisp already, I would imagine at 3.5 that thing will flip/roll like a rotating cork screw.

[gohsthb]

But 0 is 0! It's just not in the same place as zero on other controllers.
-Gohst

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[jhsa]

-100, 0, 100 makes more sense to me..
0 to the left, 50 at center and 100 to the right, doesn't make much sense but I'm weird

[kaos]

-100 0 100 makes sense for servos. yes

But 0 throttle is not 0 throttle, it is 50% throttle. there is no negative throttle. or there is! ? may be turning the other direction!
The 1st model I used with er9x was a heli, expecting 0 with 0 throttle, end up with 50% throttle at bottom stick in norm mode and the heli almost shot through my garage roof when I lift it. Took me 2 wks to figure out it is from -100 to 100.
now I still need to do a little calculation when setting my heli throttle at 70% mid stick that is 40 in er9x, 80% is 60.

But 0 is 0! It's just not in the same place as zero on other controllers.

I know it is not in the same place, it is at Nerdish territory.

[jhsa]

what about on a 3D heli? zero pitch should be at around half stick, right?
Note - I know nothing about setting up a heli.. yet

[kaos]

It is. heli pitch at mid stick is 0, negative pitch is below midstick in ID mode, postive pitch is above mid stick. that is why heli can fly inverted.

[jhsa]

exactly, then zero on the middle of the throttle stick is correct in this case that's zero pitch with max pitch on 100 and -100

[kaos]

no, because in heli ID mode, the pitch is -100% 0% +100% but throttle is also on the same stick. the throttle is a V curve, 100% 0% 100%, throttle is totally reversed below mid point. This is the same reason why TH% does not work for heli throttle in ID mode at all. In ID mode the bottom stick is 100% throttle, mid stick is 0% and top stick is again 100%. There have been several discussion on changing TH% , THs using ch output instead of stick position to be useable for all throttle control including heli. THs is not too bad, hardly any time you would put the left stick (mode 2) all the way down for long. but TH% is completely not usable below mid stick in ID mode.
When developer has time, I will bring this up again, if the developer ever has time with what is going on
TH%/s is a minor issue compare to other things, I can live without TH% and by program THs with ch output the THs can work with heli's V throttle curve.

[jhsa]

true. I do agree with u on linking the timer triggers to the channel output. I think open9x already does it..

[GTiDon]

What motors are you using? That failed?

About the rates, is it the P rate referred to earlier? Mine gets stable at 3.8 and im only doing easy level flying. Every quad has its own configuration so if you find you have to increase closer or beyond 3.5 then there is nothing wrong.

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[kaos]

GTiDon:
It was the left front motor (X configuration). They are 1000Kv motor.
http://www.infinity-hobby.com/main/prod ... ts_id=6157

Yep, I read about those numbers could change with different setup. I also pulled the built in BEC for motors from the board (Flyfun 20A with 2A BEC), now only use my ext switching BEC. those 4 ESC's BEC are linear.
I read Peter was refering to RC rate max at 3.5 ?? mine was set at 0.5/0.8 May be that is why the yaw rate was so low. I definitely will increase the rc rate then put a dual rate on tx for pitch and roll as Peter suggested.

Just a question. I know once I can fly it, not for long I will flip the quad. (if I don't crash it on the maiden) how different to flip a quad from flipping a heli? do you do a quick full ail push and back or move the ail slowly and wait it to flip? I have seen the quads flips in a snap. don't know how that is done.

By the way, you need change your signature. you already gutted all those out and replaced with SKY9X board.

[GTiDon]

I think I read wrong then. Mixed up rc rate with P rates.
I use the same style motors. (930kv version) Out of 10 ordered. 1 of them had a bent shaft. Just replaced its shaft and it was good.
I also have not flipped yet. I think you might not be able to in stabilised mode? Just guessing because megapirate has a maximum bank setting.

If its going to flip you would need to throttle up. Quick full tilt stick. The flight controller has a strange feel if you used to heli. Eg pushing forward 20 degrees will keep the quads attitude at a 20 degree bank. It wont keep tilting.


I only managed a 90% high speed forward acceleration and brake. But then I had a prop strike the ground.

[kaos]

thx, I will find out in the next few days how this quad will fly.
and yes, I would imagine to flip it, acro mode is the right mode. I will be doing acro and stable to begin with. then figure out alt hold and GPS thing. Already had my baro covered from light and has a cover over the control board to keep blade wash out of it.

As for GPS mode. My guess is when you turn the CB on initially, that is when the Board will set the 'home' GPS? then when switch to GPS position hold, it should hold the position at the spot when you flip to GPS hold? and GPS return home should be whereever the qaud is and fly back to 'home' when the quad CB is initialized? or there is a setting needs to be set for home?

[kaos]

Ha, Ha.
Peter:
thx for the dual rate tip. It works perfect. I just try it today, not even after fine tuning. the quad is flying like it should. (as far as I can tell by hovering around garage). It made tons of difference.

I put 50% Dual rate of ail/ele in Tx and 30% expo as a guess start. and put these in CB
ROLL: 6.3 0.03 7
pitch: 6.5 0.03 7 rate 2.5
yaw: 7.0 0.03 18 rate 2.5

level: 7.0 0.04 10
thr mid: 0.5 thr expo: 0.5
RC rate 1.0 RC expo 0.0
Thr PID att: 0.1

(I tried RC rate at 2.0, wow almost flipped it when trying to lift it. )
and it flies/hovers similar to a heli now. the yaw rate is much better.

I am a little puzzled that my acro mode seems to be more 'stable' than level/stable mode.

Here is quick video showing what I tried today. I know I have to do more fine tuning.
but the stable mode take off is not stable as acro so is during the hovering. or may be I am just not used to the something else to control my flying mdoel.

Oops, vid still loading. I will post it when it is done.
here is the vid: http://www.youtube.com/watch?v=Ctm08P-V-ro

[GTiDon]

Looking good:)
Did you save level position? Needed for stabilised mode.

You look ready to go outside! Dont waste too much time fine tuning indoors, it suddenly becomes a different beast in the wind and needs to be tuned accordingly.

A nice feature I think is the virtual fence. You can set it not to fly further than X amount of meters from start point. I have lost orientation a couple of times and lost the quad downwind and could not bring it back. So much technology in there, its a little flying science vessel.

For tuning I also read of a feature, when you have LEDs conencted it can flash according to how its oscilating. That can really aid tuning!

I have a small ducted fan, Im tempted to try fit it on for forward thrust. Could be interesting.

[kaos]

save level position? where is that? never read about that. could you elaborate on that?
I thought level/stable fly is just turning on the level box and the, acc sensor will aid the stabilization.
so my acro mode now is without any thing turned on, (gyro is on automatically I assume), and stable mode is by checking the 'level' box without checking 'baro'. and my altitude hold mode is adding baro to the stable mode.
I turn on the mag only on GPS hold and GPS return to home. Am I doing this right? or should I turn on the mag for stable mode as well?

as for virtual fence, is that a mega pirate thing or just multiwii? I know mega pirate has way point function but not multiwii.

do you have a link for that led flashing thing?

[Peter]

The mag is used for stabilisation of yaw drift. And can be used with level mode.
The level/acc must be calibrated. Place it level and click acc calib in the GUI or in the menu of the android app. There is a stock combi also. When still not right, you can trim it by disarming, full throttle, and using roll and pitch stick. 10 ticks will do something.

Looking at your video I see you have a good start!
I cannot see your sticks, but it does not seem so stable. It should hover by itself, without much corrections. Your d values are very low. Could be the cause.

But I see that you have a dji flamewheel or clone. These are notorious for vibration.
what you could try is setting the Low Pass Filter to a low value. I have one that only flies really well when put at 20HZ.
Try it and feel the difference. You could also try the MMGYRO option.

The new dev release also has a new mode horizon. A mix between acro and level. Sticks center and it is in level and goes proportional to acro when the sticks are going from center. Full acro at full stick. Have to test it yet but seems great.
Especially for getting the hang of flipping I had to balance a lot of props
The alt hold is also much better in the dev version.

I had my copter once at rc rate of 3 with a lot of expo. Hard to fly, but multiple flips a second!