OK, in summary I have a TBS discovery and I want to do a better job of setting up its odd angle arms to work with the APM. I feel like understand this would also be great for testing and adding new platforms like a spider Octa, hexa V, etc.
I've made pictures because I feel they can better convey information. Basically, I've found the angles on my non-pure X frame (not 45* spacing) from the horizontal and vertical lines. I tried do a simple edit of these values (see picture 3), but it didn't see very stable over the normal X with the same PID settings.
I also looked at how the Octa V is setup, and I'm thinking that is the best way to tackle this problem, but I don't quite understand how I might map these values out for this setup. Who wrote the V code? Could they share any insight?
Here is the normal X frame, and the rough Roll/Pitch factor that gets applied after the add_motor function by my calculations.
I then looked at the Octa V and saw how it skipped the add motor function and just wrote raw roll/pitch factors. I mapped them here to try to better understand how their placement would change my offset X.
So can I get away with my angle changes running add_motors, or do I need to find out what the real roll/pitch factors for this offset should be?
Edit: Updated pictures.
Replies
Hi Josh,
check this out, ardupirates motor mixing.
I wrote this when I made the V mixing for the arducopter/ardupirates, hope it helps.
Dani
Finally got some arms, here's what I'm getting for angles on the TBS discovery:
How do you mean it flew badly ? Did it respond to roll/pitch correctly ?
Also, where did you get the raw values ? Here's what I'm getting for these angles (67.5 -120 -67.5 120)
#1 -0.9 0.4
#2 0.9 -0.5
#3 0.9 0.4
#4 -0.9 -0.5
rounded up at one decimal
but if you measured correctly then the correct in-code angles for 2 & 4 should be more like 127.5 , -127.5
I did some more testing yesterday; putting the add_motor_raw function works just fine. I started out just emulating the X quad setup to get a baseline, and this worked as well. I will flight test the configuration in the last picture today. It felt like it had more forward pitch correction which is what I wanted.
I still am looking for any information on how one might find these raw values so we can write code for Octa spiders, Hexa V's, or other crazy designs. Anyone?
I just did more flying on the correct angle offset config, and it does not fly well. The pure X setup feels much better than the correct angle setup, and I believe this is because the "pure" setups are made to be symmetrical in nature.