Hi Agusto,

It's pretty quick.  I just wrote a nodelet which does cloud to scan
spoofing.  It's really unstable at the moment and will be refactored and
moved soon, but if you want an example see
https://github.com/ros-pkg-git/ni/blob/master/pointcloud_to_laserscan/src/cloud_to_scan.cpp

Tully

On Tue, Dec 21, 2010 at 5:49 AM, trigal <trigal@gmail.com> wrote:

>
> Hi ros-users!
>
> I'm using ROS for developing a control of an big robot (autonomous car) and
> I have a few
> questions, regarding AMCL and sensor messages laserscan and pointcloud.
>
> I have a SICK LD-MRS400001 series laser range finder. This laser, with my
> current configuration,
> doesn't seem to have a constant angular resolution so, when I build laser
> scan messages putting all
> data inside the result, the points positions are not distributed properly,
> resulting wider or shorter
> with respect to the obstacles.
> To solve the problem I thought to use the horizontal angle of the measure
> that the lasers sends for
> every point/beam in the scan, so today I tried to create a point cloud
> instead of a laserscan message
> and everything worked fine.
> But now the problem is: how can I use this information for the AMCL
> localization?
> The laserscan data assumes that points have all the same angular distance
> (angle_increment) and I
> know there exist procedure to convert a laserscan message into a pointcloud
> message, but I couldn’t
> find a procedure to do the opposite, a mean to convert a pointcloud into
> laserscan (I do understand
> that finding the "best" laserscan based on a pointcloud is not a trivial
> matter).
> I took a look at AMCL code and I found relations with laser_pipeline that
> advised me to don't try
> to modify the node without a complete knowledge of what that code does!
>
> So again, does anyone know how I could use this range finder for the
> localization with AMCL?
>
> Best regards,
> Augusto
> --
> View this message in context:
> http://ros-users.122217.n3.nabble.com/AMCL-and-msgs-laserscan-pointcloud-tp2126040p2126040.html
> Sent from the ROS-Users mailing list archive at Nabble.com.
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-- 
Tully Foote
Systems Engineer
Willow Garage, Inc.
tfoote@willowgarage.com
(650) 475-2827