On Fri, Jan 28, 2011 at 11:57 PM, abhy <
abhy.12354@gmail.com> wrote:
> 2. I have another question with AMCL. Do we need to set an initial pose
> using PoseWithCovarianceStamped message type? or does it takes a position
> initially automatically?
> When we executed rviz it sometimes shows pointcloud and sometimes not. when
> it is not then manually we have to set a position in rviz.
> Or, does it detects robot position automatically using sensor readings and
> initiates?
amcl needs an initial pose estimate. There are 2 sources for it:
* parameters: `~initial_pose_*` and `~initial_pose_*` determine the
initial distribution when amcl starts up. You might set these
parameters in a .launch file if your robot always starts in the same
location (common in simulation, not with real robots). If they're not
set, amcl takes a default distribution around the pose (0,0,0). And
when it's running, amcl periodically writes the current estimate into
those parameters, so if you restart amcl without restarting roscore,
amcl will take the last saved pose as its initial estimate.
* topic: publish a PoseWithCovarianceStamped message to `initialpose`
at any time to give amcl a pose estimate. This is most commonly done
by clicking in rviz, because it's easy to visually check the result
(e.g., by comparing rendered laser scans with the map). But you can
send this message from any node.
brian.
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