This is a work in progress. I've tried to address some fine tuning and performance issues.
Denny R. had made a comment about the inertia of bigger props causing issues. I've added a low pass filter to smooth the positive acceleration of the props to see if we can get at this issue. It may require tuning up Rate_P for a few folks, but I saw little issue in multiple flights.
Crosstrack had a small math error that decreased the resolution of it. I've fixed that and upped the default gains to get better tracking.
Made WP hit radius 1 by default. even 3m is too much for quads. (If you pass a WP you will move on to the next)
The Loiter method is tuned a little better by default, and now uses GPS offsets when flying less than 1.5m/s. Code experimentation will continue on this front. Thanks to Emile and afernan for their help!
A fix in the Z Accel startup was added to get an averaged result.
Added the ability to enter Loiter with Optflow enabled. - still a work in progress, not for everyday use just yet.
This alpha is on GIT now and is for user's who want to test code. As always, you need to use the "relaxpatch" version of Arduino you can find in the downloads section.
Update: We've found and patched some small type bugs in the latest and updated some GPS drivers in the Library. Be sure to pull the latest code and check http://apm.tridgell.net/ for the status of each build run against the SIL sim server.
I pushed a version on to GIT that addresses a number of issues.
- the low speed GPS XY calculations were incorrect and have been fixed
- Nav_Rate I term has been removed in loiter control - it's too easy to get two iterms working out of phase
- A second derivative has been added to Roll and Pitch. I found it removed wobbles nicely - Can be adjusted in the planner as STAB_D with a default of .25 (just enough)
- Smoothing has been applied to the motor commands in a way that really quiets down the alt hold pulsing without much effect on latency
- Yaw now has a dynamic constraint and I've upped the yaw gain.
- The motors output now have an LP filter on them so that the accelerate just a tad slower than the deceleration. This is a test to see if it helps big Octo's and Hexa's
- The Rate_I term is now zero'd for first five seconds after takeoff to keep balance.
- Loiter gains are lightened up a bit
- Nav_Rate_P is lower to remove back and forth sped related hunting in loiter
- Compass is enabled by default
- New I2C Library now included which should solve I2C related lockouts
- optflow is still a work in progress.
This update is based on flights today in a very windy environment.
It occurred to me that we're handling the WP nav I terms incorrectly and I reworked the WP navigation to share the same I terms from the Loiter. Even though they use different error input, etc, they turn out to both deal with wind in the same way. I have not Flown WPs with this new code, but heavily tested it in the sim and It's really rocking in hard wind. Transitions from Loiter flight and Nav flight are very smooth. Please let me know if you have luck.
This is a quick patch based on a bad crash Marco had. My theory was an I term that built up during wind that needed to be reset, but wasn't. It's a corner case but It bit Marco pretty bad. Please re-pull if you have R4 running to go to R5. And please, please be careful. This is alpha code not for general testing, but for development. Don't fly it on anything you would feel bad about crashing.
Update R7:Added an auto-land timer for RTL. If you don't change modes for 20s after the copter arrives at home, it will begin to auto-land. If you have failsafe and no GPS, you will immediately begin auto-landing.
Minor tweaks and cleanup
Made climb rate controller for landing universal for all altitude changes
Updated Loiter controller - Works great in the sim, thanks Afernan.
It seems no difference except the name changed from r8 to r9, quite surprising ;-)
there are a lot of changes done by Jason. You must follow all Jason´s as "author".
Rana, I think you're confused by the way our repository works. You need to look at all the changelogs since r8--there have been scores. We only increment the revision number when we want the testers to fly new code.
Thanks, Chris, I have seen many changes are there.
AeroSIM RC used as HIL - details on internal PID´s
I´ve got the answer from the developer (Manuel, email@example.com) about internal PID on sim.
After activating the plug-in, all internal pids continue active. To avoid that the model don´t use it it must be modified the plugin in the folloging sense:
- from the plugin: write in channels 34,35,36,37 as inputs for motors
- in the model: chage the motor voltage regulator to input that channels 3 to 37, instead the copter mix like now.
I don´t know how to do that change in the plugin. Anyone knows who wrote the "plugin_AeroSIMRC.dll"?
This is very interesting, now we have to try those who have the source code and compiled the plugin for AeroSim.
Make a new thread about this in the dev list, if you want I'll do it.
Sure Marco. Let´s do that new thread. I think is worth to try too get a reliable HIL testing. This will push strongly the development
Im very interested in hil in aerosim, since i just bought that sim..
It would be nice though if this kind of testing would be available to everyone just by using missionplanner hil firmware. Maybe those who make the HIL firmwares could put it in missionplanner under "hil special firmware"-choise or something like that.
2.1.1.r9 Hill test on AeroSim
Done a complete round of modes testing, and all is OK.
Good improvements in height control and auto performance, RTL and AUTOLAND. Need to test in real flight.
I test in flight this afternoon with my new x-quad X525... :-)
Here a video of the T3 2 rounds mission competition with the firmware ArduCopter v2.1.1 R9 connected in HIL mode with an APM v1 (APM 2560) board through the Mission Planner v1.1.19. The flight plan follows exactly the T3-2 mission.