Comment by Dragonslayer for First, is this really your formating in the yaml files? There should be indentations. Then i miss definition like the API discribes (http://wiki.ros.org/range_sensor_layer), its not the same as laser scan, similar: sonar_layer: topics: ["/sonar"] no_readings_timeout: 1.0 Further I would look at this posts, -> post ->link text

Sonar usually isnt used with amcl. amcl is made for 360° 2d laserscans and a map. For this approach sonar has much to little datapoints and sonar is noisy. In the navigation stack its just used for move_base to detect obstacles in the local_costmap. I have seen the obstacle layer given to global_costmap as well though, but I dont see a good reason for this, and it still only relates to move_base. amcl doesnt see the costmaps but only the mapservers /map (might be updateable though) and "compares" to /laserscan. You should see obstacles in the local_costmap visualization in rviz, thats where the interpreted sonar data is published.