Version 2.5 of the ArduCopter code is now available in the AP Mission Planner and in the downloads area!
The default PIDs are optimized for a 3DR/Jdrones quad with 850 motors and 10" props. If you're using more powerful motors/props, start by turning down Rate Roll P in 25% steps.
While some testers have reported very good flights with the default PIDs, some have reported that this release is a little "sharper" due to the DCM improvements and have found they needed to:
reduce stabilize P by 10% (i.e. 4.5 -> 4.2)
reduce stabilize D by 30% (i.e. 0.15 -> 0.10)
increase rate D from 0 to 0.001
Tuning loiter can be tricky. Refer to the discussions which will appear below for more community feedback on what parameters work best.
Please post your feedback in this discussion. For enhancement requests and bug report, please add them to the arducopter issues list. When possible please include logs (tlog and/or dataflash) and tell us whether you're using APM1 or APM2 and what version of the software you're using (presumably 2.5 but tell us anyway!).
Thanks for this release go to the developers (both in the core team but also those who have provided bug fixes through the issues list) and also the community members who participated in the previous release thread and provided some great detailed information in the form of issue reports and logs which allowed us to nail some bugs!
Tomas: I have experienced issues with Yaw and a few others have as well so you are not alone. I am still trying to nail down the cause but in my case my logs show a lot of compass interference. That doesn't necessarily mean that it is the cause of the yaw problem, but it is where I have chosen to start debugging. I am working on a compass heading filter to get rid of noise, but it is still very experimental and may prove to be a bad solution to this problem. I expect to flight test my new filter this coming weekend. I will post back then.
Do you have logs that you could share with us? That would be massively helpful in diagnosing the issue. Without logs we are just making guesses which rarely leads to a solution.
Hi Adam, I have mostly got rid of my yaw problem on my Y6 by tweaking ahrs_dcm.h as suggested by Marco.
Before I made changes I was getting up to 30 yaw (mag heading) degree error when I ramp up my motors. It is now down to less than 5 degrees without changing my physical setup. I am going to flight test right now.
I'm glad you were able to get it nailed down. I think that it is a functional fix, but I'm not sure it is the right fix for my particular problem. What you are doing by tuning that kP value is just reducing the impact the compass heading has on the overall heading calculation (if I understand it correctly). I am not interested in doing that because i feel that my compass should be reliable in the first place and I will not have to lower the weight it has on the heading if I can filter the noise effectively. I am just experimenting with this heading filter right now, but it might pan out to be something more people can take advantage of.
Ok, I find it comforting not to be alone with these issues.
Adam, I agree that the compass seems to be involved in the yaw issue. And I agree at least 100% that while it is possible to decrease the symptom by tuning compass authority down, the problem indicates that the compass calibration / decoding is not reliable in the three axis it should be able to handle.
Attaching three logs, from flight with differing parameters.
Cheers / Tomas
Yep, just to confirm my opinion, its not quite perfect yet, but i think its leaps and bounds forward.
I have slight yaw issues, and also some minor attitude glitches, but very minor. I've got rid off all my vibration damping, I tried 3 different frames and its just better than previously for me.
As you saw in my last video - without any video stabilisation, gopro just velcrod to an undamped frame, it's pretty damn tasty :)
My level of understanding now also means i might actually be able to start contributing in some areas of the code so keep posting your issues, someone will crack it, if not me.
Actually guys, I see the yaw issue in 2.4.1. Especially in waypoint execution, moving between 2 waypoints separated by large distances (150+ feet), since the waypoints are separated by large distances and with default waypoint settings, the vehicle speeds off to the waypoint (e.g. 20^ pitch)--if yaw drift occurs, the vehicle veers off fairly fast to the point I need to take it out of auto mode cause it feels like the vehicle is running away. I'm going to repeat those test in 2.5 today...
Would your copter stay on the line from the one waypoint to the other better if you were using simple mode while flying in auto?
Appeared to be worse on simple--actually I;m having issues with simple on my Y6 (all these tests were on the Y6), haven't tried the 3DR hexa since it's having alt-hold problems.
Interesting thing is my RTL works fine.
3DR hexa and custom hexa in manual flight--excellent. Very smooth, BUT my custom hexa once and awhile twitches violently on aggressive inputs--APM is not mounted on vibration dampers (todo).
ALTHOLD doesn't work on either of them--going to attempt to retune. Haven't tried the other features--considering they are likely going to fail if ALTHOLD doesn't work. Y6 is still on 4.2.1 and staying there until I figure out this...
You're not alone, welcome to the club :-)
Yes same for me, looks like it knows where to point and locks onto that, but then that heading shifts and the quad rotates to match, then back again. Last time I saw that I had a bent frame, this is a new one and 2.4 worked fine.
Same for attitude, when i tilt to go in one direction, it keeps going until i give it some opposite stick. 2.4 used to stop where it was when i release the sticks.
I have put this down to the change in what would be the right parameters, now DCM is used a lot of the settings need to be different...having some trouble dialling in the right ones though!
I too am experiencing the same issues when using advanced functions like way-points, RTL and Alt-Hold. It seems that the majority of positive comments on 2.5 are coming from users who are only flying their aircraft in a basic flight mode - up, down, circles etc. I too feel that 2.5 "flies" well using basic joystick flying. However, when using way-points and RTL and ALT-Hold including light winds, the results are not good. In fact I have been spending most of my flying using 2.4.1. I would be interested in seeing a video from Marco that is more than just 5 minutes of loiter and a coke bottle. The same for the other advanced users and testers of 2.5. Do a three way-point flight with a return to landing with momentary position hold at the way-points. This is what is needed before a release is made. Put the video up to demonstrate that these advanced functions are reliable. Then do the release. Just an opinion from someone who has bought a lot of arms, motors and props following every major release. :-)