Jason is travelling this week, so I'll take the helm for the next software release post.
UPDATE: the motor remapping thing was confusing everyone, so we took that out and returned to the regular motor mapping. That means that APM 2 users with Hexas and Octos should wait for the next version. APM 1 users should be fine with any frame.
NOTE: Hexa and Octo users: there have been motor mapping changes that may affect you. Please don't upgrade until we can update the documentation to reflect the changes. This should happen by the end of the day today (Feb 1).
ArduCopter 2.3 is now available in the Mission Planner. This is the next revision of the ArduCopter 2.2B6 code, which is perhaps the most tested code we've ever released (1288 comments in the thread!) and certainly in my experience the best code, too.
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 (default is 0.14, so start by turning it down to 0.1. In general tune PIDs in 25% steps).
Now that we've got solid code out there, we can turn to collecting suggested gains for standard frames, and a better guide to how to tune PIDs for your unique setups.
Here are Jason's note on the latest changes (mostly from 2.2B6)
A dampening term called STAB_D has been refined. A D term for all of the Rate based control loops has been added based on Igor's work. Landing for Baro and Sonar has been refined based on JLN's work. A slightly new approach to Loiter and Navigation is being used to try and linearize the pitch and roll for rate control. It tends to use lower gains, yet has a more assertive response in the air.
STAB_D : This is the gyro accretion dampener. This can remove small wobbles during sharp changes in angle commands. Making this too high can have a negative effect in performance and add a memory effect that can cause temporary loss in control. The in flight tuning is ranged so you are just below that effect.
If you haven't noticed before the control loops are in two stages. The first is a PI stage that converts some sort of position or angle error into a desired rate. These generally do not need to be tuned. They are more of a user preference on how fast you want the copter to perform a motion.
The second stage is the actual PID loop that needs to be tuned for the copter. This converts the desired rate into a motor command of some sort. I added a D term based on Igor's recommendation to the PI's for each rate controller. These should show up soon in the mission planner for the release. I cannot give you a concrete answer for how to tune the D terms, because they each depend on their function such as alt hold or loiter, etc.
Still, the absolute most important term is always the Rate_P term for each loop. Start tuning here.
The default PIDs are in the what flies great for a stock jDrones/3DR Quad with the purple motors in X mode.
Note the Mission Planner does not yet highlight these D terms on the main tuning page (it will soon), but you can find them and modify them on in the Parameters list.
Autolanding should now work well (see video above) and the Tri servo issue is now resolved.
The code should now compile with Arduino 1.0 (thank, Randy!), but remember that you need to use the "relaxpatch" version of Arduino in our downloads section.
[Update: we've reverted the below. See update at the top of the post]
Important for Octo users:
We've changed some of the motor orders for some more exotic airframes. We'll be updating the docs on the Wiki in a day or two to reflect this. Pat Hickey explains:
As before, the hexa plus APM2 motor setup has changed from the ordering [1, 2, 3, 4, 5, 6] to [ 5, 6, 1, 2, 3, 4 ].
The Octa V layout for APM2 is:6 42 58 13 7Motors 1 through 4 spin clockwise, and 5 through 8 spin counterclockwise.
Thanks to the whole community for the wonderful job
Great stuff, Well done all involved!
I trust this removes that anyoing inital 5sec wobble when take off ? Well I'll doon find out.
But not in downloads yet?
all 100%, quad flying like a, a, um, a flying solid thing, can't think of a solid enough word ;)
Now for the octo...
Thanks to all those testing, and thanks for the update Chris (especially the nod towards the camera control on APM2 ;)
Now it's time to break the record of 1288 comments... but now all positive i hope! :-)
Enjoy with 2.3!
Now to fix crashed quad and try auto landing :)
Yes, at the moment is not in the downloads section, then leave available here.
EDIT: remove, because there's possible error inside the motors mappings for hexa and octo frame with APM1.
just loaded 2.3 on my octo, as I always do, via MP, setup, calibrate etc etc.
Gently tested it and it flipped backwards, ive re-loaded, re-checked everything and all working fine, apart from the fact that is just tilting back no matter what i do with radio, ive had someone hold the octo and the more throttle i give, the more it just wants to flip backwards... ????
Any ideas guys ?
Thanks Marco :-)
Are you on APM2? Motor ordering changed between 2.2b6 and 2.3, as mentioned in Chris's post. I had to redo mine for the hexa X too.
Hmmm ... not good, I hope that is not a problem with the new motor mapping, because I honestly do not quite understand what was done with frame type: http://code.google.com/p/ardupilot-mega/source/list
Duran, check the motors with the test inside the CLI, move the stick and check if the motors position is corrected.