[ros-users] navigation stack bare minimums
Mike Purvis
mpurvis at clearpathrobotics.com
Tue Jun 8 14:36:08 UTC 2010
>
> If you're doing a lot of multi-robot navigation and you want the robot's to
> be aware of each other's positions, you'll probably need a map frame. You
> don't necessarily need to run a map_server, but you will need to have your
> localization source, whether that be GPS, camera-based localization, or
> other, publish a transform from the map frame to the odom (or if you don't
> have odom, base_link) frame of your robot. In the case where you don't have
> a map_server... you'd still set the "static_map" parameter on the
> global_costmap to be false.
This is very helpful, thanks.
With the parameters that you posted, you should no longer receive this
> error. Can you take a look at the parameters you have set with "rosparam
> dump" to make sure that the parameters for the global_costmap are being set
> correctly? They should fall under the move_base_node/global_costmap/
> namespace.
>
Okay, yes, I've played with the namespaces, and I believe all of the pieces
are now seeing the proper parameters. Thanks for the tip about rosparam
dump.
I have a few remaining questions about global_costmap and local_costmap. I
have the navigation stack talking to my simulator, but when I send a goal, I
get the following output:
[ WARN] 1276006631.337854000: The goal sent to the navfn planner is off the
global costmap. Planning will always fail to this goal.
[ WARN] 1276006631.425825000: The goal sent to the navfn planner is off the
global costmap. Planning will always fail to this goal.
[ WARN] 1276006631.704455000: The robot's start position is off the global
costmap. Planning will always fail, are you sure the robot has been properly
localized?
[ WARN] 1276006631.825804000: The goal sent to the navfn planner is off the
global costmap. Planning will always fail to this goal.
[ WARN] 1276006631.904408000: The robot's start position is off the global
costmap. Planning will always fail, are you sure the robot has been properly
localized?
[ERROR] 1276006631.949307000: Aborting because a valid plan could not be
found. Even after executing all recovery behaviors
Now, I'm using raw UTM coordinates for my position, so the numbers are
large. My odometry messages (and corresponding transforms) look like so:
header:
seq: 4657
stamp: 1276006871180577039
frame_id: odom
child_frame_id: base_link
pose:
pose:
position:
x: 596506.594977
y: 4956355.18823
z: 0.0
orientation:
x: 0.0
y: 0.0
z: 0.922148700667
w: 0.386835590217
covariance: [0.0 ...
And my goal, accordingly, was sent like so:
rostopic pub /clearpath/robots/0/move_base_simple/goal
geometry_msgs/PoseStamped '{ header: { frame_id: "odom" }, pose: { position:
{ x: 596505, y: 4956355 }, orientation: { x: 0, y: 0, z: 0.62, w: 0.78 } }
}'
publishing and latching message. Press ctrl-C to terminate
Now, I've tried to center the global costmap over this region, like so:
global_costmap:
global_frame: odom
robot_base_frame: base_link
update_frequency: 5.0
static_map: false
rolling_window: true
width: 100
height: 100
origin_x: 596500
origin_y: 4956350
map_type: costmap
Is this a correct approach? Alternatively, I could put a local origin in my
odometry and tf broadcasters. Would that be better? Or is there something
else entirely?
Thanks again.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.ros.org/pipermail/ros-users/attachments/20100608/44c9073f/attachment-0003.html>
More information about the ros-users
mailing list