ArduPlane 2.50 released
I'm delighted to announce the release of ArduPlane 2.50 for your flying pleasure. This release has a lot of advances to some of the core ArduPlane code, and should be a big improvement for many people.
Perhaps the most important change in this release is the new DCM code that does acceleration correction based on the GPS. This improvement is based on work by Bill Premerlani which really advances the state of the art for attitude estimation on small microcontroller based autopilots. The improvement in attitude estimation is very noticable in flight, resulting in significantly more accurate control. Many thanks to Bill for his patience in working with Jon Challinger and myself to bring this improvement to ArduPlane.
Other significant improvements include:
- updates to the barometer driver to sample the pressure and temperature much more rapidly, leading to better altitude estimation
- updates to the AP_AnalogSource driver to be interrupt driven, allowing us to sample all analog sources much more rapidly. For ArduPlane this improves the airspeed sensor on the APM2 a lot.
- updates to the waypoint completion logic, to use a "finish line" algorithm. This prevents the problem of circling around a waypoint when we miss it by more than the waypoint radius. The waypoint is now considered complete when we pass a line that is perpendicular to the track, and passing through the target waypoint.
- improvements to the AP_Mount code, allowing for control of roll/pitch/yaw stabilisation via EEPROM variables that can be set over MAVLink. This allows you to setup the mount once, and it will resume operation as soon as you boot. These changes also fix a number of bugs in the AP_Mount code, so it AP_Mount hasn't worked for you, please try again. Many thanks to Greg Fletcher and Amilcar Lucus for the AP_Mount improvements.
- Lots of improvements to the ArduPlane parameter documentation. This documentation should be the first place you look when trying to understand ArduPlane configuration parameters. Many thanks to Andreas Antonopoulos for his great work on generating these wiki docs based on the source code markup.
- New LAND_PITCH_CD parameter to control the landing pitch when not under airspeed control. Thanks to Jeff Taylor for fixing this!
- New SCALING_SPEED parameter that allows you to set the base speed for scaling PIDs. Previously we assumed a standard speed of 15 m/s, which is too low for fast aircraft. By adjusting SCALING_SPEED you can have the same set of PIDs for both airspeed and non-airspeed flight control.
There is one change in this release which may require some re-tuning. We were using the wrong value for time delta when using the PID controller for navigation roll. This has been fixed by making the PID library calculate the delta time internally, but it means that existing HDG2RLL_I and HDG2RLL_D values will be incorrect. I have fixed the defaults, but if you have your own settings for these, you will need to drop HDG2RLL_I by a factor of 5, and raise HDG2RLL_D by a factor of 5 to get the same result as for the previous release.
Thanks to everyone who has contributed to this release!
For the next release the plan is to concentrate on improved stabilisation and navigation controllers, based on the great work being done by Jon Challinger.
Happy flying!
Replies to This Discussion
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Permalink Reply by Andre S on -
Uhhh.. IMHO "increase X by a factor of 5" usually refers to a multiplication by 5, whereas "decrease X by a factor of 5" usually refers to a division by 5. No addition or subtraction! Not sure I understand your line of thought, Spag.
I would also be interested if these changes _only_ affect HDG2RLL (and not for example those RLL2SERV ones). Should maybe have a look at the git diffs but maybe Andrew could confirm quickly?
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Permalink Reply by spagoziak on -
I've noticed a new option in advanced params--AHRS_GPS_GAIN. The description text in the Mission Planner says this is used to determine how much of the GPS is used to control the plane's attitude.
Since upgrading to 2.5 this morning, I've been watching my HSI in the mission planner slowly wander all over the place. The plane itself hasn't moved; it's sitting in a rack on the table. Yet the HSI says the plane is rolled 90 degrees left and pitched 50 degrees up. Ha--and during the time I've typed this out, now I'm -35 degrees (and diving).
2.4 held solid and true wherever it was placed. Is this new behavior expected and ok? i was excited to try out the cool new stuff Trige described above, but this HSI business and having to wait 20 minutes for 3D lock gives me great apprehension to test it on the wing!
spag
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Permalink Reply by spagoziak on
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Any thoughts on this, folks? I downgraded back to 2.4 right away and normal behavior was restored.
Doesn't anyone else's HSI float around aimlessly while the plane is stationary? I'd love the benefit of good new ides in the code, but the floating horizon thing has me a bit reluctant to proceed :(
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DeveloperPermalink Reply by Andrew Tridgell on -
Do you have a tlog showing this behaviour?
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Permalink Reply by Andke on -
-be sure you did not move the aircraft while booting (while it was calibrating)
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Permalink Reply by Jake Stew on -
HSI? If you've got a HSI in MP then you're doing something really wrong. Try reinstalling.
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Permalink Reply by Andy on -
same problem here but during flight it does the job but at the ground hmmm it is a strange behavior...
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3D RoboticsPermalink Reply by Chris Anderson on -
Can you try erasing your EEPROM (CLI: Setup/Erase) and going through the config process again?
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Permalink Reply by spagoziak on
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I definitely don't move it on boot (at least on the bench), with the way I have it powered. Andi, hearing that the lazy floating horizon is also happening to you but still flies well is very reassuring. At one point to hold the plane to what it thought was level, I'd have had to bank 90 degrees right and pitch down a bit!
Chris, I'll definitely blast the EEPROM on my next attempt to push 2.5 up.
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