[ros-users] ROS Interface for AR.Drone Quadrotor

[Bill Morris]

On Sat, 2010-10-16 at 08:24 -0500, Jack O'Quin wrote: 
> On Sat, Oct 16, 2010 at 5:12 AM, Cedric Pradalier
> <cedric.pradalier at mavt.ethz.ch> wrote:
> 
> > Actually, the standard coordinate frame for flying system is with Z down
> > (it allows standard compass angle to be coherent with the X,Y motion).
> > For this reason,
> > I'm voting in favour of a Z down coordinate system for the AR-Drone.
> >
> > However, I agree that I would be suprised without  x forward, y
> > sideways, and yaw around z....
> >
> > As soon as we have velocity control on the CoaX helicopter, our control
> > will definitely be like that.
> 
> I realize that the standard aerospace orientation is "upside-down"
> compared to the standard robotics orientation as defined in REP 103.
> 
>   http://www.ros.org/reps/rep-0103.html#axis-orientation
> 
> Since the intent of the ROS community is to share code, ignoring REP
> 103 is a mistake. Your vehicle would display upside-down in rviz, for
> example.
> 
> But, note that there is already a documented exception for use with
> camera frames (and an "_optical" suffix). If it is really so important
> to use the aerospace convention, you should propose a similar
> modification to REP 103 and get approval from the whole community.
> Maybe an "_aerial" suffix would be appropriate.
> 
> To me, that seems clumsy and unnecessary. You could use standard ROS
> frame transform conventions yet still communicate with humans using
> idiosyncratic aerospace terminology.

Having a North-East-Down co-ordinate system available is pretty
important for aerial robotics. Our quadrotor used NED and interfaces
with rviz by just having an extra transform.

This thread covers some of the issues.
https://code.ros.org/lurker/thread/20100909.134929.4afb6715.en.html#i20100909.134929.4afb6715

Specifically this post by Ivan.
https://code.ros.org/lurker/message/20100910.180053.89d33794.en.html