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rally2
2nd March 2013, 11:50 PM
Anyone else have to keep recalibrating the KK2.0 almost every flight?

Seems like almost every other flight I have to recalibrate the sensors. It seems to think that it is pitched back. I have to go full pitch forward just to get it to move forward a bit. It seems to do this sometimes in mid flight. Starts out OK then I notice I have to start giving it more and more front stick to keep it going forward. If I let off and let the stick go center it pitches back.

I am running 1.5 and using auto level. I haven't tried switching out of auto level in flight yet but may try it.

Thanks,

Jeremy

RandallJ
2nd March 2013, 11:58 PM
Every now and then mine gets sort of out of sorts... I just land it and let it settle for a moment and take off again.. This usually happens after I have had some minor out of control moments..

jrwperformance
3rd March 2013, 12:07 AM
Mine would do the same thing... A reboot usually fixed the issue.

spiked3
3rd March 2013, 05:52 AM
Interesting. This might explain a flight I had where it started wild wobbles, after 4 flights with no wobbles. Once the wild wobbles started, it actually got to a point where I could not descend at all, and full forward stick and it was still flying backwards. My only choice was to climb. That only works for a short while, and when someone watching LOS said it was getting pretty far away I just cut throttle, and sent a bag to pick up the pieces.

Really? this is the kind of stuff we have to put up with? Is this new to 1.6? I've always been on 1.5. I was getting ready to do the next "after total rebuild / repair" flight, but I may just bench it at this point. I am tired of rebuilding. It would be nice to get to a point where the pilot crashed and not some crap hardware component.

I have been trying really really hard to find an alternative to NAZA, but it's getting harder to do.

chatch
3rd March 2013, 06:29 AM
it's because it is in cold weather.. I have seen many kk2 mess up because of low temperatures.

try a Naze32. it is a 32-bit multiwii board that doesn't require all the "multiwii crap" that kept me away from multiwii for a while. like compiling the code myself with the correct parameters. each board comes preloaded with the latest firmware, and 99% of the time, the stock PID settings work out great.

and it's $20. http://abusemark.com/store/index.php?main_page=product_info&products_id=38

spiked3
3rd March 2013, 08:15 AM
Someone suggested an APM in another thread. That is my last attempt. It has had one flight so far with some misconfigured bl-heli ESCs (my fault maybe, although im not 100%). So i'm putting Simons on now, but in any case I was not very impressed with its first flight. It probably will end up in the pile with the Wiis Ive already tried, and replaced with a NAZA. The weather is getting better and I want to fly, not rebuild.

SO maybe someone with some coding experience can answer a question; WTF is the difference between thicker foam and a different low pass filter in code? Why is dealing with vibration so difficult? Can not the drift/baseline initialization consider vibration as well? It makes me wonder, NAZA arms with the motors spinning, hmmmmm ..... is that their secret?

Chatch, is that the controller you used on the roll/flip video just posted (daredevil stunt)? hows proximity, had a chance to try it yet? I've just about given up on trying to arrive at something that works myself.

RandallJ
3rd March 2013, 09:11 AM
Well there is a lot of video on the tube about the "Rabbit W/GPS" (http://www.goodluckbuy.com/rabbit-cf-hight-direction-fixed-flight-controllerrabbit-gps-receiver-module-combo.html) and it looks to behave a lot like a NAZA.. Might be fun to try this on a cheap bird to start..

rally2
3rd March 2013, 11:00 AM
Sorry I mistyped the version. I am on 1.5.

I have both APM 2.5 and the KK2.0. APM is nice and flys well. It's also nice to have RTL and auto land. I had it do an auto land on me yesterday when the battery went low. That was nice. It was right by me but I hadn't noticed it was low. Just came right down and everything was great.

I have been using the KK2.0 on the Honey Badger just to keep things simple and light. Have had good luck so far except for the recalibrating. It was really nice out yesterday. Mid 50's and sunny with no wind. I guess maybe it was still too cold for the KK2.0? I was warm at least.

I'll check out the Naze32. Thanks for the link.

Thanks,

Jeremy

chatch
3rd March 2013, 12:50 PM
50F should be fine. I was talking about -10F in alaska sort of cold.



Chatch, is that the controller you used on the roll/flip video just posted (daredevil stunt)? hows proximity, had a chance to try it yet? I've just about given up on trying to arrive at something that works myself.

yeah that's what i used for that video. it's locked in. I've flown all the KK boards and half a dozen nazas and it's just a different feel among them all. It seems fine for proximity, I might take out some I term for more feedback from the quad

spiked3
3rd March 2013, 01:05 PM
It was a little more than $20 - I got it and the one above it (AFRO_NAZE32 & AFRO_NAZE32_FF), $100ish shipped. This is the third time I have ordered the last damn board that I am going to try :|

chatch
3rd March 2013, 01:11 PM
if you don't like the AFRO_NAZE32_FF ill buy it off you, I need another

panzlflyer
3rd March 2013, 10:28 PM
Anyone else have to keep recalibrating the KK2.0 almost every flight?

Seems like almost every other flight I have to recalibrate the sensors. It seems to think that it is pitched back. I have to go full pitch forward just to get it to move forward a bit. It seems to do this sometimes in mid flight. Starts out OK then I notice I have to start giving it more and more front stick to keep it going forward. If I let off and let the stick go center it pitches back.

I am running 1.5 and using auto level. I haven't tried switching out of auto level in flight yet but may try it.

Thanks,

Jeremy

You really need to get it flying in Normal 1st otherwise its going to act weird.
Tune the P gains then the I gains then Autolevel.
Also remember if you use auto level and tip over a certain point it may go nuts, switch back to normal in that case.
Even the mighty Naza does that if you exceed a certain amont of degrees when in Auto level mode.
i have the Naza, Kk2and Apm, all require tuning normal first if you want a well behaved flight all the time.
btw the KK2 is a blast to fly aerobatics with!!

spiked3
3rd March 2013, 10:37 PM
"It seems to think that it is pitched back. I have to go full pitch forward just to get it to move forward a bit. It seems to do this sometimes in mid flight. Starts out OK then ...." has nothing to do with tuning.

panzlflyer
3rd March 2013, 10:41 PM
It has quite a bit to do with it.
You need to learn to fly it in normal.
The acclerometers get confused as time goes on.
But whatever, if you want a no user input system buy a Naza.

spiked3
3rd March 2013, 10:45 PM
No, dude, really, it does not. I'm not stating that as an opinion.

Maybe he described it wrong, but given that description, it has nothing to do with tuning. Accelerometers do not get confused. They may drift, but they don't get confused. And even if that is the case, unless you are writing the code to compensate for drift, tuning is not going to help. Do you even know which PID parameter affects drift and why?

panzlflyer
3rd March 2013, 11:24 PM
P is the correction rate for the current deviation from the setpoint
I is the correction for slow drift over time.
As you stated you cant get any board to fly, yet you dont want to tune despite what the designer said lol
Mine flies great but what do I know.

spiked3
3rd March 2013, 11:33 PM
Well I'll give you credit, correct answer on the parameter.
And yep, I can't get any POS to fly, my bad. However the IMUs on my IMU robots (and my NAZA) do just fine thank you. Why don't the accelerometers on a NAZA get confused?
I stand by what I said; A quad that starts out flying, then half way through a battery starts drifting excessively to the point where full stick will not hold it in position, is not a tuning issue. If you think your superior tuning skills is responsible for avoiding that, then lol as well.

panzlflyer
3rd March 2013, 11:46 PM
I found that if you go past a certain angle on the Naza it goes weird as well if using self level.
There is no doubt that Dji did their homework.
This self level issue going off the rails over time is not new, happens on Helis that have tried to use a self level setup, after doing aerobatics the sense of level is screwed up and generally results in a crash.
You wouldnt happen to have a low voltage set in an ESC? If it kicked in it could cause weird issues as the pack runs down.
I am running flashed ones so it isnt a feature.

spiked3
3rd March 2013, 11:53 PM
You wouldnt happen to have a low voltage set in an ESC? If it kicked in it could cause weird issues as the pack runs down.


That's exactly what I think I have.

But in the case of "It seems to think that it is pitched back. I have to go full pitch forward just to get it to move forward a bit. It seems to do this sometimes in mid flight. Starts out OK then ....", that is not a tuning issue, it is a configuration issue. It has nothing to do with PI (or D).

Yeah I did flash tunigy plushes, with bl-heli (no small feat) but I didnt solder in permanent connectors and when it appears it has generic firmware and not multi, which may or may not have been my fault, I'm pretty sure I picked multi, but that is not how they acted, so I trashed them and I am going to try commercial simonK's tomorrow.

rally2
4th March 2013, 12:31 AM
Hi Panzlflyer,

In this case it isn't tuning that is needed. It was tuned in manual mode and then auto level was adjusted. It flys great when I recalibrate the sensors before each flight. If I don't do it though after a couple flights it starts to pitch back. If it was tuning that needed to be done it would fly poorly all the time. It also wouldn't start out flying well and then part way through the flight start getting out of sorts.

I'm not doing any acrobatics. Just cruising around checking out the field. I am running SimonK's as well so no voltage shut off.

First time it happened I thought it was windy up about 50 ft but not on the ground. Then when I got closer to the ground I realized it was the quad not the wind.

I have another kk2.0 board I'll see if it has the same issue. I had one on another quad and it seemed to be happy all the time. It lives at the bottom of a pond now though. I think I had an ESC go out at the wrong time. Not there is a right time.

Flying Monkey
7th March 2013, 03:40 PM
I still can't understand why people fly with the auto-level turned on permanantly? Learn how to fly smooth, precise and consistant in manual mode and you'll be able to do anything! The auto-level is something to use if you get in trouble (losing video, losing control, etc). Auto-level spoils people and teaches bad habits...

spiked3
7th March 2013, 03:59 PM
I still can't understand why people fly with the auto-level turned on permanantly? Learn how to fly smooth, precise and consistant in manual mode and you'll be able to do anything! The auto-level is something to use if you get in trouble (losing video, losing control, etc). Auto-level spoils people and teaches bad habits...

I do not totally disagree with that, but put it in perspective; Why do people depend on a gyro to fly helicopters? Learn to fly without a gyro and you will be a much better pilot.

Yeah, been there (early mechanical gyros and mechanical throttle/pitch mixing), done that, got the t-shirt, it sucks. It just depends on what level a person wants to go. Auto-level would not be there if there was not a demand for it. It is a lot like an automatic transmission, 99% included on production cars, 99% not included on race cars.

I still do not think this was a post about tuning or auto level - it is a post about calibration and / or software errors. BTW, if an accelerometer loses it's orientation because of some acrobatic move prior, it is 99% probability it is a software error, don't blame the accelerometer, gravity doesn't change. Now, as far as open source having software errors, that also is 99% probability.

Flying Monkey
7th March 2013, 04:16 PM
The answer to the threads question was already answered = temperature. The KK2 uses analog gyros and ACC... susceptible to drifting calibration in the cold or hot. FC's with digital gyro and ACC don't really have this problem.

Yeah, its not the ACCs fault... but its also not a software (firmware) error either. It does however require a more sophisticated program to account for the issue... If you pitch forward 20 degrees, then yaw 90 degrees left, then you just exchanged your 20 d forward pitch for a 20 degree right roll... but how would the gyros or ACC sense this? Well, the yaw gyro senses it, but its not used by the program... probably because its subject to gyro drift and not reliable. I think FCs with magnemometers solve this... or better yet GPS input. This is the deep end as far as my current knowledge goes...

spiked3
7th March 2013, 04:25 PM
Just for fun, you can google 'kalman filter' - that is what is used to merge gyro's with magnemoters. http://en.wikipedia.org/wiki/Euler_angles is the math for merging gyros with accelerometers to avoid the mixup you described, with simple integration (calculus). If you wanted to expand your knowledge any.

Flying Monkey
7th March 2013, 04:29 PM
Just for fun, you can google 'kalman filter' - that is what is used to merge gyro's with magnemoters. http://en.wikipedia.org/wiki/Euler_angles is the math for merging gyros with accelerometers to avoid the mixup you described, with simple integration (calculus). If you wanted to expand your knowledge any.

I'm aware of the Kalman filter and Euler angles thank you :) And I am constantly expanding my knowledge. The smartest thing would be to NOT use the auto-level though... auto-level is for babies :) Or design your own firmware if you know so much... it is open-source after all.

Flying Monkey
7th March 2013, 04:34 PM
Oh, and while it doesn't relate to this problem, I do agree with panzlflyer 100%... the KK2 needs to be flown and tuned in manual to get good performance and stability. It'll fly "okay" with the stock settings, but it won't reach its potential.