@james_pattison . Yah . Please do a technical performance comparison between two flight stacks . I would like to get a clear, neutral perspective so that I can choose the right one . THANKS .
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Some personal opinions on flight performance. I have flown both PX4 and ArduPilot on the same vehicle as I tried out the two flight stacks for a university drone team.
When well tuned, PX4 and Ardupilot vehicles fly almost equally well. But PX4’s lack of Autotune and InFlight Knob Tuning makes tuning a PX4 vehicle more challenging. PX4’s Airframe-specific Presets seems user-friendly, but is in fact counterproductive as the preset gains are specific to a certain payload and propulsion setup. PX4’s “Wind Problem” is not systemic, it only manifests when the Position Controller is not well tuned.
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Hi! I just finished building a quadcopter which is relatively large to carry a gopro and I’ll mainly be using it for photography. I currently have the Arducopter software on it and the loiter isn’t too great since it wobbles which meses with the footage. I have tried autotune but unfortunately the wind randomly comes which leads to that failing. I have a couple questions.
- If I do get auto tune to work, will the quad fly much better?
- Is PX4 software better for loiter? (I have a Pixhawk flight controller)
- My center of gravity is not perfectly centered since I need the gopro a little further so the legs don’t get in the shot. Could this be what is causing the wobble? The reason I ask is because the wobble is not in the direction where the CG is a bit off, it is in the other direction.
Thank you so much!!
Make a new thread under Copter 3.6 and give exact details of technical specs and post a link to a log.
I dont think PX4 will be any better without the same type of tuning and fixes, but I believe Ardupilot Copter will give you more in the long run and be more rewarding (since you already nearly finished)
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Hello,
We just update the process for copter tuning on the wiki. You should start by this. The instructions are very detailed on each steps.
Thanks for your response! I’ve created a new thread here: Drone wobbles a lot in Loiter mode
It also has a link to logs and a photo. Any help would be much appreciated! Thanks!
Hi, can you please send me a link to which tuning steps you are referring to? Is it advanced tuning? If so, I am unable to access that page for some reason. No matter what laptop I am on, when I click on advanced tuning, the screen just won’t load.
I think @khancyr intended this page:
http://ardupilot.org/copter/docs/tuning-process-instructions.html
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Indeed 
Px4 is more dev oriented and functionnal up to a point, to test exotic configurations arducopter environment can be paradoxically a better shot
Using mission planner advanced settings and fiddling with all the various firmwares needs some time but allows you to launch the trial and error process all as well provided you have suficient workshop hours behind you
Basically PX4 is more business oriented and with less advanced dev support in the end
I have not seen the Airbus drone challenge final config in flight thought, did I miss something 
?
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Yeah you missed something. The Airbus drone couldn’t fly on PX4. The controls laws just are not there. Chris Anderson had to swallow his pride, call up an Ardupilot expert who came in, dumped Ardupilot on it, and had it flying inside of a day. Mind you, he never mentioned that part publicly.
I have a friend working for a commercial company that is using PX4. Apparently it’s a bit of a basket case, and he would love to be able to throw Ardupilot on there. But the management just doesn’t get it.
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I wouldn’t have stated it if it wasn’t solid info. But I don’t have the time to dig into it right now for you. But the info is out there if one really wants to looks for it.
Just go to DIYdrones and look up the blog posts about this project. Of course he won’t mention what exactly happened. My info comes from insiders. But you can read between the lines.
The Ardupilot expert who was brought in and that Rob mentioned was Joe Aletky, you can get more info by searching for him and diydrones.
That plane, by the way, is featured on ardupilot.org home page slider. It’s the second image, you can get to it by clicking on the right arrow, clicking on the image will yield more information. Or just here.
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Google or your favorite search engine, along with link following, is your friend 
:
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First test build and initial fumblings at smaller scale, with Chris A. involvement.
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Joe Aletky takes over, his post on the successful initial flight of the cargo drone, with help from @tridge and others here . (On the now more or less defunct diydrones site.)
From the first link:
“Our friend, and well known UAS expert, Chris Anderson stopped by to integrate a 3D Robotics PX4 into a small-scale Zelator over the weekend.”
Video is worth a thousand words, especially at 1:20 or so…
Perhaps it’s worth adding that Joe Aletky was and is a gentleman and diplomat.
And for completion sake’s, video of successful flight referred earlier, here and here. More than 3 years ago, time flies! (Pun intended). And original design.
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This is also all based on some insider info.
Ah, I thought it was Joe, but wasn’t 100% sure. Thanks Olivier.
Just my 2 cents, stick with ardupilot as your OS, either NUTTX or CHIBIOS. Both work really well for me flying traditional helis (TRext 600/700). My 600 runs NUTTX, my 700 runs CHIBIOS (for no particular reasons other than to always be able to test the latest firmware versions of both). I went through the same questions in the beginning myself, but I found that you get much better help from the community running ardupilot over PX4. In fact, I couldnt find anyone that knew PX4 when I needed help. This forced me to learn ardupilot (arducopter in particular) and havent looked back since!
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Good point about community support.
Actually, and I just noticed that this is featured right on our home page.
Hello RCers
I work on an academic project in which we use a drone in order to map radiation. I took over the project from another group. The drone is using pxhawk 1 hardware and PX4 firmware. For enhaced stability during mapping a optical flow (px4flow) is used. Further there is some external control of the FC via mavlink messages comming in an also the resulting data are sent via mavlink to the FC in order to sent it via telemetry to a modified GC software.
When setting up the whole system it’s not possible to get the optical flow to work. (Actually not even sure whether it worked before or it was just a “placebo-effect”… Therefore I am considering to use ArduPilot. Can you give me some info on how easy it might be to send positions and payload data to ArduPilot in order to fly to that position and forward the payload data via telemetry to GC software (we used to use mavlink)?
Thanks in advance!
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Ardupilot supports 99% of the mavlink commands that PX4 supports.
So maybe you do not need to change anything other than the firmware.
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I have no expertise in this but you might look into the Computer Vision category of PX4 or your Pixhawk 1’s bootloader needs updating, if it actually has a 2MB capability, to have the appropriate or updated drivers within the firmware.
Good luck.