The ArduPilot development team is proud to announce the release of version 3.5.2 of APM:Plane. This is a minor release with small changes.
The main reason for this release over the recent 3.5.1 release is a fix for a bug where the px4io co-processor on a Pixhawk can run out of memory while booting. This causes the board to be unresponsive on boot. It only happens if you have a more complex servo setup and is caused by too much memory used by the IO failsafe mixer.
The second motivation for this release is to fix an issue where during a geofence altitude failsafe that happens at low speed an aircraft may dive much further than it should to gain speed. This only happened if the thrust line of the aircraft combined with low pitch integrator gain led to the aircraft not compensating sufficiently with elevator at full throttle in a TECS underspeed state. To fix this two changes have been made:
- a minimum level of integrator in the pitch controller has been added. This level has a sufficiently small time constant to avoid the problem with the TECS controller in an underspeed state.
- the underspeed state in TECS has been modified so that underspeed can end before the full target altitude has been reached, as long as the airspeed has risen sufficiently past the minimum airspeed for a sufficient period of time (by 15% above minimum airspeed for 3 seconds).
Many thanks to Marc Merlin for reporting this bug!
The default P gains for both roll and pitch have also been raised from 0.4 to 0.6. This is to help for users that fly with the default parameters. A value of 0.6 is safe for all aircraft that I have analysed logs for.
The default gains and filter frequencies of the QuadPlane code have also been adjusted to better reflect the types of aircraft users have been building.
Other changes include:
- improved QuadPlane logging for better analysis and tuning (adding RATE and QTUN messages)
- fixed a bug introduced in 3.5.1 in rangefinder landing
- added TECS logging of speed_weight and flags
- improvements to the lsm303d driver for Linux
- improvements to the waf build system
Happy flying!
Comments
Awesome!
Thank you, Tridge, much appreciated. I still have one or two logs of unexplained crashes but it sounds like maybe the new code could have prevented whatever caused those too. Good stuff.
@Graham, I've replied in that old message on the RTL crash. It was caused by a failure of the Y gyro on the MPU6000. If the 3.5.x code had been used then the dual-EKF would have detected this and I believe the flight would have proceeded without problem.
@Tridge
Thank you so much.
@Anthony, we do have basic docs on all Q_* parameters here:
http://ardupilot.org/plane/docs/parameters.html#q-parameters
I've also recently documented all of the frame type options here:
http://ardupilot.org/plane/docs/quadplane-support.html#frame-setup
@Tridge: I flew 3.5.2 yesterday. Guided didn't crash my plane into the ground :) (but I didn't try to have GUIDED kick in with full flaps down, which is likely what upset it last time). Since it was a maiden in a 30kph wind (not kidding :) ), I didn't want to push my luck too far.
I'll try again (GUIDED with full flaps down) and report back later.
However, no luck with getting any RPM value http://discuss.ardupilot.org/t/ap3-5-rpm-not-returning-anything/7892
@Tridge,
Thanks for the speedy update. Very much appreciated.
Can you let me know the values for:
Q_FRAME_TYPE
Now there are many un-documented Q_ parameters. Any idea when they will have a description?
There was a unexplained crash reported a while ago (http://discuss.ardupilot.org/t/crash-at-17km-from-home/5859) that may have been overlooked on the forum. It worried me a little as it had some similarities to problems I had 2 years ago (unrealistic reported pitch angles) but which for me at least seems to have gone away.
Tridge, could you perhaps have a look at that crash log?
@Marc, I do hope it helps for you!
The forums have moved now, the new link is:
http://discuss.ardupilot.org/t/looks-like-ap3-5-guided-mode-crashed...
I will go over those logs from the point of view of the changes that have been made. Hopefully later today. If I don't reply in a couple of days then ping me :-)
Well, what are the odds, thanks Andrew, that was fast.
Just finished building my new plane after 4 days of solid work, I was going to install 3.5.1, and now I see 3.5.2 with your fix. Thanks much. Hopefully the other details and logs I gave you where we discussed the bugs, can help validate if the fix also would have handled the other weird behaviour issues I had and posted there.
If others care about the details: http://ardupilot.com/forum/viewtopic.php?f=115&t=15302
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