ACRO bug (fixed in 2.9.1b): while doing flips in ACRO mode, if you switch to Stabilize while inverted your throttle will go to minimum. To regain throttle control you need to switch back to ACRO then back to Stabilize again (i.e. switch to stabilize twice). You never lose control of roll/pitch/yaw.
Loiter/AltHold/Auto/RTL bug: if you switch into these modes with throttle at zero motors will go to minimum until you raise the throttle.
Auto mode altitude bug (fixed in 2.9.1b): setting a waypoint altitude greater than 320m over home altitude may wrap around and instead be interpreted as a low altitude.
ArduCopter 2.9 is now in the mission planner and the downloads area!
The major improvement is we use inertial navigation to improve altitude hold. This increased reliance on the accelerometers means you must do some additional set-up before flying:
3. If upgrading from 2.8.1, modify the throttle and altitude PID values:
Here is the list of major changes (a more detailed list can be found in the release notes):
As per usual PIDs are optimised for the 3DR/jDrones quad with 850 motors and 10" props. If you're using more powerful motors/props and are seeing bad flight behaviour in stabilize, start by turning down Rate Roll P in 25% steps.
Special thanks to our testing team lead Marco and the dedicated bunch on the 2.8.1 release thread who put their copters at risk while testing the pre-release version. Some of their videos are here: 1 2 3 4 5 6 7 8
Please feel free to report issues you find in the discussion below and/or add them to the issues list.
No problem Jeff,
ACRO_BAL_PITCH of 0
ACRO_BAL_ROLL of 0
ACRO_P of 4.5 to 9 (202.5 deg/s to 405 deg/s)
ACRO_TRAINER,1 (0 if you want to do flips but you can't do loops yet)
Let me know how it goes!
I am not a beginner. I am used to fly helis from 100 to 600 size. Quad is so relaxing, so stable. I can tell you Acro mode with 0 setting would be very hard to a beginner to start in this mode. You guys did a nice job allowing those kind of configuration. People should read about the updates from this new firmware instead whine about it. I can tell. I have 3 boards here and I am using 2.7, 2.8 and the new 2.9. 2.9 is far better. Just flew my 2.7 and I dont like it anymore. Cheerz!
This is because you have switched to loiter (Alt Hold) while you are going up. Because you are increasing altitude when AltHold is switched in you get an error build up. Alt hold is quiet aggressive at correcting altitude errors and quickly drops the motors to bring the copter back to the desired altitude. The motors aren't completely stopped but it does sound like it.
I am glad you are enjoying it. We still have some improvements to come!
Stock settings on the loiter.
As I mentioned, I've tried using both P and I terms to eliminate the behavior, but didn't get it to work.
Setup is a fairly stout quad. Aluminum arms, G10 fiberglass center plates. DT-750 motors that have been rewound for about 880kv and 10x4.7 props. The stock tune seems to be pretty close. I've increased acro_P gain to 0.155 acro_I is at 0.14, and acro-D at 0.005. All other settings are as stock. Hover is at about 45% of stick. It's a bit heavier than I'd like, I need to put it on a diet.
Alt hold is amazing compared to 2.8.1, loiter from a hover is awesome...I just love flying the thing...but when I loiter from speed it takes a long time to stabilize to a point. It's nerve wracking to see...I'll try to get some video if I can.
I've noticed the same on my quad...I thought it was the motor stopping momentarily, but figured it out when I walked over to it and tried to lift it from a hover...the slightest lift resulted in almost zero throttle (I think 13% is the default minimum?). then I pushed on it to try to send it to the ground...that was fun. It resisted strongly! I recommend it to all to try...but be careful!
After I figured out it wasn't a problem it was fun to abuse it!
Thanks for understanding. I hope I didn't come across as complaining too much...it just took me by surprise.
I did read the release notes, but I just overlooked this one. It's still confusing to me when I read it, but with a new understanding, I can see how it documents the change.
You guys are doing good work. The firmware and software have improved dramatically since the first time I tried to use this board...after hours and hours of tuning I got disgusted and put the board aside and went back to my trusty KK board. I had some time over Christmas and thought, I'll try this again...tuning happened fast! The difference was night and day.
I'm pby not a good enough pilot to give you the feedback you'd like on the full acro mode, but I can say, it's a dramatic improvement from the first time I tried it. I'd do what I can to give you feedback though.
I have noticed though, that I tend toward liking a more aggressive tune...
In the original 2.9 release video from DaveC he pushed it down with his hand to demonstrate how quickly and strongly it resists. We asked him to swap that scene out for the bit where he pushes it with a broom 'cuz it's definitely dangerous!