LibrePilot Forum

Users => Vehicles - MultiRotors => Topic started by: 12many on April 03, 2016, 04:23:03 am

Title: Custom frame setup using Paparazzi RotorcraftMixing docs
Post by: 12many on April 03, 2016, 04:23:03 am

Hi,

I'm trying so set up a unique frame design.  I found a reference to http://wiki.paparazziuav.org/wiki/RotorcraftMixing in another post here and have been using that for reference.  There's one thing I can't understand though.

In the example, as I understand it the rotor coordinate input matrix appears to be defined like this:


      [R1x  R2x  R3x  R4x  R5x  R6x  ...]
A =   [R1y  R2y  R3y  R4y  R5y  R6y  ...]
      [R1d  R2d  R3d  R4d  R5d  R6d  ...]


However, when I look at the graphic and the values in the given example, it appears that the rotors have been swapped left/right.  I.e. I'd expect that since R1 is in the lower-right quadrant, it's values would have (+,-) values but they have (-,-) values, leading me to believe that either the signs on the Y axis have been transposed or the graphic is indicating the rotors in the wrong places.

Or most probably I'm confused.  (The 90-degree rotation of the graphic doesn't help!)  So I'm hoping to get clarification.
Can someone confirm that my above matrix definition is correct?  Or am I doing something else wrong?

Thanks in advance!

And by the way thanks also for resurrecting things from the ashes of OP.  This is my first post here.  Reading the forum comments the energy is positive and I look forward to contributing somehow someday.
 :)

Title: Re: Custom frame setup using Paparazzi RotorcraftMixing docs
Post by: 12many on April 05, 2016, 08:00:11 am

Hello?  Can anyone help?

Title: Re: Custom frame setup using Paparazzi RotorcraftMixing docs
Post by: f5soh on April 05, 2016, 08:26:54 am

Search for "paparazzi" here in forum, take a look here:
https://forum.librepilot.org/index.php?topic=338.msg2397#msg2397

Title: Re: Custom frame setup using Paparazzi RotorcraftMixing docs
Post by: 12many on April 05, 2016, 08:29:47 am

Thanks f5 that looks like exactly what I needed.  I don't know how I missed that!

+1  :)

Title: Re: Custom frame setup using Paparazzi RotorcraftMixing docs
Post by: 12many on April 05, 2016, 08:46:23 am

For anyone who happens to stumble on this thread, it looks like I was making the mistake of assuming the diagram is looking at your multicopter from the top down in a Cartesian sense like we were all taught in geometry, which resulted in the flipped Y coordinate.

It all makes much more sense if you think of the diagram as looking at the vehicle from the bottom up.  I have yet to confirm this but it does seem to sync everything up in my head much better.

I'll know soon enough, if my bird decides up is down I'll try to come back and correct this thread.