ArduCopter 2.6 released!

Paul Emous June 22, 2012 at 12:37am

Hi All,

I just upgraded to 2.6 and facing some minor issues as well. The drone (DJI F450 Frame) is very wobblely and aggrasive. But I know I can tune this using the Pid. However. Normally If I had my troggle on 50% (centred) the drone wouldnt take off.

Now after arming putting the stick up for its first test flight, I nearly lost it because it started flying. How can I lower its output?

Bruce Jones June 21, 2012 at 11:38pm

Over the last 4 days I've probably gone through 20 or so batteries with my tricopter with an APM2 running the latest 2.6 software. All-in-all it's been a really great experience. Last night especially was a ton of fun. I was using Flight Planner and flying all kinds of fun waypoint formations. It was great! And then tonight happened.

I went to the same location today as yesterday, had the exact same setup, nothing different except batteries were charged up. I took off and everything seemed fine in stable mode, so I switched to auto thinking the simple waypoint plan I'd just loaded would be quick and easy. Instead my tri headed off towards nowheresville like a rocket. After a couple shocked seconds the tri had probably flown 500 meters away and up to a height of 100 meters. I switched to RTL (which had worked so nicely the last couple days) and the craft veered 90° but kept on going. I switched to alt hold and luckily it stuck. I then slowly worked it back while trying to get my heart rate down and wondering just far the range is on my Spektrum system.

I reloaded the waypoints, checked to make sure they were loaded, triple checked all I could on the computer and tried again. Similar response. I did this 4 times, each time almost loosing the tri. I was pretty upset, I mean this had worked flawlessly 20 hours prior.

Then I remembered that even though I had added a keychain camera to the front of my tri yesterday, it's battery had been dead and I wasn't able to use it. I recharged it before my outing today. Could this little thing have caused such a big problem?

Innocuous looking little thing, eh? Well it's evil. I took it off and bingo, I flew just fine. It was mounted probably 8cm in front of and below the front of the APM2, but caused a lot of grief. Later I looked at the flight logs. Here's where it thought I was flying:

Nice little jaunt over the Atlantic and France, and wow, high-earth orbit! The camera obviously has RF or magnetic issues with the FC. Or the FC is über sensitive to noise.

I'm kind of nervous what will happen when I mount my GoPro.

So then I flew happily for a bit. I've been having issues with my yaw - not debilitating, just irritating. And enough to prevent any decent AP. So I tried to get a video of the problem. Here it is, not good because it was a bit breezy and I was trying to fly while holding the camera, but you'll get the idea. In the video I try to make 3 different small clock-wise yaw rotations. Watch the rear motor on the servo, it's all over the place.

If anybody's working on the yaw problem, maybe this will help.

So after flying 5 4S batteries (17-18 minutes each!!!!) I was out of 4Ss and switched to a 3s. I took it up, checked out stab mode, then switched to alt hold. IMMEDIATELY all 3 motors shut off and I crashed about 20 meters. When it hit the ground the 1 motor came back on again and started tearing itself up. I did some major damage to my tri and won't be flying it again for a while.

Has anyone else experienced anything like this? I really don't want to blame the FC when there are so many things I can do wrong. But the fact that all 3 motors went out at the same time makes me believe it's not a motor or ESC issue. When it hit the ground the lights on the APM2 were on and one motor started spinning so I don't think it was a battery connection issue (and the connection was good and tight). I'm not sure what else that leaves. And no, unfortunately there was no log file saved from that. I checked right away and that last flight didn't seem to get written properly to the onboard uSD card (at least I couldn't see it , and my laptop with the 3DR radio had run out of juice an hour before.

I really want to fly this combo again. But now I'm gun-shy. If this had come down on somebody it would have been bad news. And I really hate rebuilding.

Developer

Marco Robustini June 21, 2012 at 11:37pm

Auto mission and yaw:

Council to include this define in the config if you want a better precision during waypoint mission, especially when the quad arrives on each waypoint.
This also allows you to move the yaw throughout the mission directing an hypothetical cam in the desired direction without compromising the mission.
I personally think that the direction of the nose should be completely independent, especially if you want to take pictures or video.

#define AUTO_YAW YAW_HOLD

Many users have asked me the flight parameters of my quad, they will post here in the week.

Bests, Marco

steve June 21, 2012 at 8:16pm

I'm using Planner 1.1.93 mav 1.0 and with the new config screens I'm not sure about my loiter or yaw settings. First I noticed in section ArduCopter Config that my loiter P=0, I=0 and IMAX 30 but when I go to other section ArduCopter Pids I see other settings for loiter which are 2.4 | .08 | .4 | IMAX 30.

And regarding YAW, for the first time I tried to take off in ACRO mode to try and tune that and it quickly does a fast yaw even though it is very good in stable mode. SO I checked my Rate Yaw and it's .13 | .0 | .002 | IMAX 50

and in stabilize Yaw it is 8 | .01 | IMAX 8

Is this right or is my acro spin caused by something else?

Moderator

Dean Wynton June 21, 2012 at 7:39pm

Rate mode is best tuned in Acro mode as it only uses the gyros, once you have it behaving quite well in this mode you can switch into stab mode and tune that, at least thats how I do it? I wouldn`t recommend this method for anyone that is not comfortable flying though? as a badly tuned acro mode can be a handful. If you go too high with rate p it will actually make the machine less responsive and have a delayed reaction to input...

Stab mode use both the accelerometers and gyros, Stab p is for tuning the accelerometers

Developer

Adam Rivera June 21, 2012 at 11:41am

Question for anyone: I would not consider myself a "PID beginner", but I can always use more tips and tricks from other experienced users. My question is this, Given that the Stab P gain could change the way that the RATE P/I gains behave, how can you decouple them for the purpose of tuning? I have tried several strategies and the one I use most often is below.

1. Set Stab P to 1 so it is not a affecting the desired rate at all.
2. Fiddle with Rate_P until the fast oscillation is visible and then reduce a little so it goes away
3. Increase Stab P for more responsive controls

The problem is at number 3. If you increase the Stab P, the desired rate increases which increases the rate error which seems to induce fast oscillations again. Am I on track here? How do you find the balance between the two terms? Right now I have my copter pretty well tuned, but I feel that I stumbled upon functional gains rather than fully understood the process.

Manfred Dickgiesser June 21, 2012 at 11:12am

T-Rex 450 hovering with APM2 2.6.

To hover T-Rex 450 in stabilize, I need to have always a little right roll input through the RC. I don’t like to trim it through the RC.

It feels like the APM2 wants to level 100% horizontal.

No Heli hovers at a 100% horizontal attitude, because it needs always to counter act the thrust of the Tail Rotor. This is the difference to hovering with a Quad.

I flew the T-Rex 450 before with “HeliCommand” and it had a provision to ‘trim’ the horizontal attitude, called “neutral roll attitude” in decrees (see picture) 4 is the default good for 450 size Heli. On my big one (1200 size) it’s 2.

How can I overcome the left drift without trimming the RC?

I tried to trim the Swash more to the right, but of course no success as expected.

ultrojo June 21, 2012 at 9:35am

quad x650 frame + 10" props + apm2 + turnigy 18a plush + stock motor + version 2.6 newfirmware report.

YAW turns very slow... And if it pointing rudder stick to the east litle bit , it drift 10-20 degrees to the left (just yaw)... i have to pointing stick to the faster with long travel to the right, then the quad yaw to the right slowly...

How to solve this issue?

thanks.

Mie Must June 21, 2012 at 8:55am

Hi, Im having a problem when I upload the 2.6 firmware to my APM1. Having difficulties when ARM and DISARMED the motors. Sometime it worked and sometime didnt. When i switched back n downgrade to 2.5 firmware everything seem to be ok again. Is the 2.6 firmware developed to suit APM2 and not APM1?

Rui Manuel Cravo Marques June 21, 2012 at 3:01am

Hello. Having made about 20/25 flights without any problem or strange reaction since version 2.5.4, I would like to give some suggestions that solved some of my problems. This are not rules, just suggestions :

1 - use an external uBEC instead of the an ESC BEC. uBECs are much more reliable and efective since they use a switching regulator instead of regulating voltage via heat dissipation (linear BEC from ESC). However, you should separate it as far as you can from your RX since it may cause interference.

2 - Don't trust the servo connectors from the BEC to provide power to the board. Solder the red and black wires comming from the BEC to the power rail from APM (red = 5v || black = ground). I had a loose connector wich aparently was ok, but it was not, causing some strange power losses.

3 - Also to prevent bad connections, after you have aligned all the signal wires comming from the ESCs to connect to the APM, put some duct tape around all the aligned connectors in a way you have a single big connector, that will prevent that a "rogue" connector comes loose, and it's easier for you to analyze if they are all well connected.

4 - Yes. It's true, don't trust bullet connectors that come soldered from factory. Most of them come loose easilly. Preferebly solder the motor wires directlly to the ESC wires, or, if you still want to use bullet connectors (like I do), redo the solders from factory, and put some heat shrinking tube around the connection to absorb vibrations and keep it together.

5 - If you're using an APM1 + Oilpan, make sure to verify if the oilpan is well attached to the APM, because after a rough landing or a crash, the boards may separate a bit and you don't notice, causing sensor reading problems and strange behaviours.

6 - For some versions now, the STAB I parameter comes by default at 0.100. I remember some time ago Marco advised to lower it or put it to 0 since the I term was already integrated in the software. I don't know why it still comes by default at 0.100 but in my oppinion should come at 0.0. This term was giving me strange twitchings. Instead I use a RATE I term of 0.015 (may not be adequate to everyone but try values from 0.010 to 0.020), and yes, even with a COG away from the center, I get a leveled flight, not when I take off, but after 2 or 3 seconds in flight.

7 - Very important. Don't use cheap propellers. You may not notice but they brake in mid flight leading to strange crashes, wich you may think were from a motor or ESC. Choose good nylon APC props or the carbon reinforced ones. The carbon reinforced ones, are stiffer but break much easily than the APC ones when they touch something.

Happy flights everyone.

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ArduCopter 2.6 released!

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