Dear ROS-Users,

The CCNY Robotics Lab is pleased to announce the release of two
packages for laser scan registration. canonical_scan_matcher is a
wrapper around Andrea Censi's "Canonical Scan Matcher" [1].
polar_scan_matching is a wrapper around Albert Diosi's "Polar Scan
Matching" [2].

Both packages estimate the displacement of a robot by comparing
consecutive Laser Scan messages. They can be used without providing
any estimate for the displacement of the robot between the scans. In
this way, they can serve as an odometric estimate for robots that
don't have any other odometric system. Alternatively, a displacement
estimate can be provided as input to the scan matchers, in the form of
an Imu message or a tf transform, in order to produce better (or
faster) scan matching results.

While the two scan matchers use different algorithms and parameters,
the ROS wrappers are identical in terms of topics/frames/tf's, making
the two packages interchangeable.

Documentation and usage instructions can be found at the respective wiki pages:

 * http://www.ros.org/wiki/canonical_scan_matcher
 * http://www.ros.org/wiki/polar_scan_matcher

As usual, we have provided a small demo bag file with laser data and a
launch file that can be used to view the packages in action. Each wiki
page also has a video of what the output of the demo should look like.

We hope you find the scan matchers useful, and we extend our thanks to
the authors of the original implementations.

Ivan Dryanovski
William Morris
The CCNY Robotics Lab
http://robotics.ccny.cuny.edu


[1] A. Censi, "An ICP variant using a point-to-line metric"
Proceedings of the IEEE International Conference on Robotics and
Automation (ICRA), 2008
[2] A. Diosi and L. Kleeman, "Laser Scan Matching in Polar Coordinates
with Application to SLAM " Proceedings of 2005 IEEE/RSJ International
Conference on Intelligent Robots and Systems, August, 2005, Edmonton,
Canada