[ros-users] defining interfaces for GPS way-points and mapping

[Jack O'Quin]

On Wed, Jun 1, 2011 at 5:33 PM, Chad Rockey <chadrockey at gmail.com> wrote:
> Hi Jack,
> Eric and I are both finishing our theses and starting jobs this month, but
> we'd be willing to provide our limited input to this.  We've only worked
> with off-road mobile robots with very simple waypoints, nothing like Open
> Street Maps or Google Maps; although something like that would be great to
> see happen.

> I do like the idea of a common UTM conversion tool.

UTM conversions are fairly easy and quite useful. We've got some that
can be used. They need some cleanup, so better implementations would
be welcome.

> Another possible tool would be KML import and export to waypoints/paths,
> since this makes it easy to visualize and create paths in Google Earth/Maps.
>  For our waypoints, we would define them in KML files either by clicking in
> Google Earth or manually typing in coordinates.  Then we could feed this to
> our robot which would start following them in order or we could look at the
> path either as markers or as a polygon in Google Earth.  Even though the
> imagery data could be a meter or two off, it was still very useful when
> great precision wasn't required or we just wanted to look at the overall
> shape/order.
>
> Here is an example KML path
> file: http://code.google.com/apis/kml/documentation/kml_tut.html#paths

KML should definitely be considered. Good idea.

> Bill Morris morris at ee.ccny.cuny.edu writes:
>
> One of our projects this summer requires GPS based navigation for aerial
> robots so I'll be working on this more later in the summer. I would like
> to see GPS waypoints defined in E-Turtle and a gps_tools library for
> Fuerte.

I could imagine defining a way-point ID as a 128-bit opaque value,
able to hold a UUID if desired. The basic WayPoint message would at
least contain an ID, latitude and longitude. Maybe that's it. Lat/Long
needs to be defined unambiguously, probably using fractional degrees,
positive North and East, negative South and West.

Getting those messages defined, reviewed and agreed to in time for
E-turtle sounds difficult but possible. Should they go in some
common_msgs package? If so, which one?

 http://www.ros.org/wiki/common_msgs

If there is still design and development work to do before we know
what to standardize on, I suggest picking a repository and working
together on a general stack for mapping-related packages. We could use
the utexas-art-ros-pkg repo for that, maybe ros.org, or some other.
Perhaps it would be best to create a new repo just for this. I'll
volunteer to maintain it wherever seems best and most convenient to
the participants.

We could do both: define a standard WayPoint and WayPointID, but
create a separate repo for GPS tools.

What do y'all suggest?
-- 
 joq