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CRAM iai_maps - cannot launch json_prolog and map_server (ROS melodic, kinetic)

asked 2021-05-13 01:55:05 -0500

updated 2021-05-13 18:41:03 -0500

jayess gravatar image


I try to run a launchfile mentioned in the tutorial:

I have a problem while running:roslaunch iai_maps iai_maps.launch

ERROR: cannot launch node of type [map_server/map_server]: map_server
ROS path [0]=/opt/ros/melodic/share/ros
ROS path [1]=/home/wega/catkin_ws2/src
ROS path [2]=/opt/ros/melodic/share

ERROR: cannot launch node of type [json_prolog/json_prolog_node]: json_prolog
ROS path [0]=/opt/ros/melodic/share/ros
ROS path [1]=/home/wega/catkin_ws2/src
ROS path [2]=/opt/ros/melodic/share

I'm running it on ROS melodic, Ubuntu 18.04.5 LTS (Virtual machine)I have knowrob, rosprolog, iai_maps, iai_common_msgs packages compiled in my workspace

Similar ERROR, concerning only json_prolog occurs while working on VM downloaded from:


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1 Answer

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answered 2021-05-14 04:54:40 -0500

gaya gravatar image


The tutorial that you're having problems with has a tag that it's compatible with CRAM v0.6.0 and the current default version is v0.7.0, so that tutorial is outdated. We don't maintain the tutorials in the "advanced" category, as they're for the experienced users and often about packages that are not a default part of CRAM.

Looks like you're missing dependencies. I think this error means that map_server and json_prolog are not installed. I cannot help you with installing KnowRob unfortunately, but map_server is easy:

$ sudo apt install ros-melodic-map-server

Json_prolog, which is a part of KnowRob, is not installed on the CRAM VM, as the default dependency on KnowRob has been removed a while ago. The newest version of KnowRob might use a different name for json_prolog now that I think of it. You can send an email to hawkin at uni-bremen dot de, she knows KnowRob better than I do, especially the newest version. I can only help with CRAM-specific issues.

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Asked: 2021-05-13 01:55:05 -0500

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Last updated: May 14 '21