That is about the same setup I also use without problems. The only possible solution I see is to svn update KnowRob to make sure you have the latest version and do a rosmake --pre-clean knowrob.
If this runs without errors and the segfault remains, another option is to use the .deb packages for KnowRob (which are available for Natty and Electric, only some newer features might be missing). If you have installed ROS using the Ubuntu package manager, you can just execute 'sudo apt-get install ros-electric-knowrob' and you should get the binary packages of KnowRob installed. You'll maybe need to remove the SVN version from your ROS_PACKAGE_PATH so that the binary version is used.
You can also try to run 'rosrun rosprolog rosprolog mod_vis' and then launch the visualization canvas. This would rule out problems related to the knowrob_tutorials package
Can you please post more information on your system? Operating system, version, Knowrob version (debian packages or SVN?), Java version (with ' java -version').
Thank you for your replay. I use Ubuntu 11.04, ROS Electric, SVN Knowrob, and java version "1.6.0_26" Java(TM) SE Runtime Environment (build 1.6.0_26-b03) Java HotSpot(TM) Server VM (build 20.1-b02, mixed mode). Regards Ahmed
The first option has the same problem, and I do not have more knowledge about the second option, Please if you can provide me more information about it. Thanks a lot.
Thank you for your answer, but I have the same problem. Please if you can provide me more information or links about the main requirements of visualisation_canvas and how to create prolog ROS packages that can be accessed by rosrun rosprolog rosprolog pkg-name. Thanks a lot.
http://ias.in.tum.de/kb/wiki/index.php/Loading_files_and_ROS_packages describes how to load Prolog and OWL files. For rosprolog, the most important is to have a file prolog/init.pl in your package that initializes everything (load prolog modules, parse OWL files etc). It will be called by rosprolog.
Thank you very much.