Anybody had any success with APM2.0 and a Tricopter? after much messing around with PID`s I can get it to RTL in a fashion 70% of the time but once it gets bak to Launch it tends to lose it bearings and dissapear in another direction and I have to switch into stabilize mode before it crashes and the same with loiter it will hold the height most of the time but never the position, somebody please help..
Any follow-up on this? I'm just finishing up a tricopter build and would love to put my brand new APM2 on it. But if there's a 30% chance of a crash I might try something different.
Hi Bruce, although this post was only a month ago, I have been studying the apm code and hardware in detail... And have learnt alot in the process, it was just a case of adjusting some settings and this can be tricky to learn, but there are a few of us on here that understand the process and would be happy to help... Here are a couple of videos, as proof that perservering and mainly understanding can acheive.
Also when I first started I was using 2.5.4 firmware and there were problems with the compass and the gyros were not scaled properly causing slow response to error, this has been resolved in the latest firmware release
OK, those videos convinced me to give it a try - I'll be setting up the electronics in the next day or so. Anything I should keep in mind while finishing the build or before the maiden flight, other than using the latest version of the software?
Thanks for the update. I was kind of wondering what I was going to do with my fancy new APM2 if I didn't put it on the tri.
Is it a homebuild or a kit? either way I would suggest keeping the apm2.0 as far away from the main power and esc`s as they can cause interference, of course still keeping the apm at the center of gravity and not so far away that it is inconveinient. I have mine 55mm away but you could get away with less I think?
It's the Tim Nilson Delrin kit. I was going for as clean a build as possible, so right now my ESCs are in the middle deck of the central plates, directly underneath where the FC would go. Maybe I should give up my addiction to the clean look and move the ESCs out on the arms.
To keep balance, I'd still have to put the battery on the bottom underneath everything. That's going to be about 3-4 cm below the FC. I could put a thin aluminum shield above the battery. Or maybe under the FC.
The main thing you want to avoid is electromagnetic interference, if you can test for this you might get your clean build? the top of my battery is 120mm away from the board, this isnt needed it was just the way I built it. Try putting everything as you want it then connect to mission planner so you can see magnectic field on the tuning screen then connect main battery, it should go up just a tiny bit hardly noticeable if it goes up alot you will need to move things around, the arm motors and hold the craft down then gently throttle up and watch the magnectic field again if it goes up too much it means interference..
Or if the compass moves when you are not moving the craft.
EMI is not an easy customer and putting the aluminium shield there probably will have no effect. There are ways of reducing it but none are simple, the best way is distance..
Just went out for my APM2 maiden tonight. I posted more detailed results in another thread, but thanks for the help here.
My biggest problem was with the GPS. I'm wondering a bit if that's an EMI problem too. I may try some experiments totally moving the battery and receiver away from the APM2 board to see if that helps.
Thanks again! I had fun out there tonight.
No, I haven't seen those. Do you have a link to them?
I didn't do any tuning tonight at all, just wanted to verify that everything was working at a baseline level. Actually came away happier than expected. Tri specific PIDs would be gravy!
Thanks for that pointer. I just downloaded your config file and compared it to mine - interesting. In general, it seems like you're making the craft a bit less aggressive than the stock params? For example all of your NAV_* params are much less than the defaults. All the SPEED_MAX params too.
Unfortunately it's rainy here today so I won't get to try flying with your params. Hopefully tomorrow.
One more noob question - are all of the parameters defined or explained in the documentation or one place in the source code somewhere? I can't seem to find it.