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.
What're you PID about Loiter mode?
Hi Baloon, I tested with Marco's PIDs as default and just tuned RATE P and R so far. Attention the flight was made with 0 wind today (first day in about 2 weeks now ! Great timing).
Here's my param file :
Thank you for you parameters, Next afternoon i will test 2.4 too.
I just ordered a complete board from you. Please put the version in it that will work for hexa.
The frame is a S-606 from Infinity Hobby. Good frame. 600 mm from motor to motor.
Cobra 2217's, 960 KV, 10 by 4.5 props from Innovative Designs.
Nice flight by the way.
Hi Tom, sorry but you must be making some confusion here. I don't sell boards :) I'm just a user. Thanks
Rui, to lower the canal swing decrease Stab_P and increases slightly Rate_P and Rate_I if you want more command rate smoother.
Unfortunately, the little quad require long tuning.
I'm uploading the video I made to my heavy X8 with 2.4, flown in Stabilize, should be online in about an hour.
For this video I used soft enough flight parameters.
Hey Marco, where's your video? :)
5 minutes and is here... :P
You have done a really good flight with the v2.4 and it is very stable and you are very lucky with the perfect weather conditions.
Just had a short flight using stabilise and alt_hold (sonar). There was a pretty gutsy wind and it was getting dark, but my showleds don't mind darkness ;-)
My hexa flew fine on default pid's. Much better then version 2.1 but I'm not sure it felt as crisp as 2.0.49. I kinda had to stay on top of the hexa, couldn't let go of the sticks in my small garden. But that might have been due to the wind also. It is rather turbulent in my small garden. I would not have flown my 450 size heli in this wind, don't think I could have kept it under control.
Alt_hold was fine too, though only used rather briefly, it kept it's altitude nicely, better then I manually could.
More testing tomorrow at the flying field, but I'm feeling positive about this one !
Could you tell me, is it any change about the default motors mapping for hexa & octo plus frame (2.4), like the last time (2.3).
ArduCopter V2.4 Final - Smooth flight with my heavy X8:
Sorry for the drunk filmer, is the same of yestarday (LOL).
This is my first attempt with the new incoming release of ArduCopter V2.4 and my heavy X8, need better tuning and for this reason I have not pushed hard but i think is a good starting point.
This large quad was designed to shoot videos quite soft, so do not pretend to do aerobatics, flying to clean.
I enclose the parameters used in this video.
I await your comments, always welcome, and waiting your video (flying please).
"Led pattern" by u4eake