Summary:

New navigation stack SIG at http://www.ros.org/wiki/sig/Navigation and
http://www.ros.org/wiki/hydro/Planning/Navigation<http://www.ros.org/wiki/hydro/Planning/Navigation#preview>
.

Longer version:

Greetings ROS users,

I have started a new SIG for the navigation stack, specifically concerned
at the moment with plans for the Hydro release.  I realize it is a bit late
in the cycle for this, but we have a great new feature that we are eager to
release:

*Layered Costmaps
*
David Lu has modified the costmap_2d package significantly to add a modular
"layered costmap" feature. With this, multiple layers of costmaps can be
maintained separately and then combined for global or local planning. This
should allow, for instance, a static map layer which is never overwritten
by sensors, a separate layer for sonars from lasers so they don't overwrite
each other, or a special layer that tracks people and applies custom cost
functions around them.

This includes breaking changes to the C++ API for Costmap2DROS,
RecoveryBehavior, BaseLocalPlanner, and BaseGlobalPlanner. Anyone who has
written a custom RecoveryBehavior, BaseLocalPlanner or BaseGlobalPlanner
subclass will need to recompile and likely make some code changes.

The node/topic API is very similar or possibly exactly the same, so if you
are just using the nav stack instead of coding for it, you should be
unaffected. The layers code introduces a new parameter layout for
configuring the costmaps (typically under move_base). However it also
includes code to detect an old non-layered parameter set and convert it to
a nearly equivalent layered set.

*Current status
*
Currently the relevant branches on http://github.com/ros-planning/navigationare
*hydro-devel* and *layered-costmaps-catkinized*.

Soon I will merge them into *hydro-layered-costmaps* which people can test
for a bit and then I will merge it back into *hydro-devel* if it seems
ready.

The following things are still not working in the layered-costmaps code:

   - base_local_planner::TrajectoryPlannerROS (dwa_local_planner is newer
   though and works fine)
   - carrot_planner
   - rotate_recovery
   - tests in costmap_2d
   - costmap_2d_cloud executable
   - clear_costmaps service in move_base
   - clear_unknown_space service in move_base

If you have strong feelings about any of these things being supported for
hydro, please post on the SIG mailing
list<https://groups.google.com/group/ros-sig-navigation>or create a
new issue on github.

Thank you!
Dave