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.
Go in CLI mode, Logs, and type enable RAW. You will see the "RAW" added to the list of variable. Similar for enable MOTORS. You need a new flight to produce the new log with RAW. Then go in MP Telemetry Logs unde HUD, TLog -> Kml or Graph, Graph Log and you would need to see the logs with lines named RAW. The last column is Z axis
Thanks for the instructions on enabling Z accel logging and how to download an graph a log. Got that done with these results. Looks like no vib problem and I can now go on to attempting to tune the PIDs for Loiter.
And thanks for the links to the pages on logging. Very helpful.
Having an issue maybe someone could assist with..
Hexa seems to randomly have throttle brownouts when flying (have seen in alt-hold, and loiter) where it's hovering fine at ~50% throttle, and volts/amps seems to drop for a moment, causing the hexa to drop like a brick for a quick moment, then it raises its' throttle to try to recover. At first I thought it could have been a connection issue with the battery, but this happens with multiple packs (and when two are in parallel as well..) I have a small log attached of a flight a couple of evenings ago..
3DR Hexa frame, 880k motors
This log has 1 5000 3 cell pack, fully charged
Atto 180A sensor, not enabled during this flight, but connected
Sonar attached and enabled
Optical Flow attached, enabled, not used.
Calm, no breeze, dead on steady loiter. Loiter for most of the flight, stick input for a bit to see if it causes throttle drops
You can see throttle and altitude issues at a few points in the log, when no altitude adjustment was requested
Those are two good questions - You know the saying, "The only dumb questions are the ones not asked..."
I haven't disabled sonar, although I've had it enabled for the life of the Hexa, so it's been about a year. I'm one of the few that seems to never have an issue with the sonar, as I've got it well away from everything else, and added the ground filtering when it was installed. I'll try a quick flight with it disabled, although just as many flights have had the throttle bumps at 40-50+ feet up (where sonar should be ignored) as it has at lower 10-12 foot heights..
As for batteries, I first noticed the bumps when I switched from 3s to 4s packs. In thinking it could have been the packs, I swapped back to 3s, and have tried brand new packs that were at proper volts when purchased, and balance charged before first use (of which I almost always balance charge, for the heck of it) to no help..
It's a strange one...
Good idea - but they are all soldered quite well, no cold joints, etc..
I'm thinking if it were those connectors, it would effect one motor, and not all 6 - which leads me to think it's an APM sensor or programming issue, not the esc's or motors..
It appears that it only shoots up when trying to correct for the quick drop..
Nope, sorry - using APM 2, with case, in same position that has had very good luck in the past.
It's finally nice out again here in the Buffalo area today, and I'll have it out in a few hours for some tests..