Simulation of Demos

[erencandural]

Hello,

I've been studying the packages and trying out the demos in the LBR-Stack, specifically the Pose Control in lbr_demos_advanced_cpp. My question is, is it possible to run the demos without an actual robot. That is, can we simulate the robots as digital twins instead?
I've followed the steps, skipping the first one, in the Pose Controller example and simply replaced sim:=false with sim:=true:

ros2 launch lbr_bringup bringup.launch.py \ sim:=true\ ctrl:=lbr_joint_position_command_controller \ model:=iiwa7 # [iiwa7, iiwa14, med7, med14]

However, I don't see any movement in the Gazebo simulation. Is it simply not possible without an actual robot or is there something wrong with my way of thinking?

On a similar note, when I follow the lbr_bringup, I face the same problem; the robot model is loaded but I can't do path planning as I would following the MoveIt tutorials.
ros2 launch lbr_bringup bringup.launch.py \ model:=iiwa7 # [iiwa7, iiwa14, med7, med14] \ sim:=true # [true, false] \ rviz:=true # [true, false] \ moveit:=true # [true, false]

When I add the Motion Planning panel, I'm faced with the following error

[rviz2-8] Warning: class_loader.impl: SEVERE WARNING!!! A namespace collision has occurred with plugin factory for class rviz_default_plugins::displays::InteractiveMarkerDisplay. New factory will OVERWRITE existing one. This situation occurs when libraries containing plugins are directly linked against an executable (the one running right now generating this message). Please separate plugins out into their own library or just don't link against the library and use either class_loader::ClassLoader/MultiLibraryClassLoader to open.
[rviz2-8] at line 253 in /opt/ros/humble/include/class_loader/class_loader/class_loader_core.hpp
[rviz2-8] [ERROR] [1725375138.956735071] [moveit_ros_visualization.motion_planning_frame]: Action server: /recognize_objects not available
[rviz2-8] [INFO] [1725375138.976150870] [moveit_ros_visualization.motion_planning_frame]: MoveGroup namespace changed: / -> . Reloading params.
[rviz2-8] [WARN] [1725375138.991135752] [rcl.logging_rosout]: Publisher already registered for provided node name. If this is due to multiple nodes with the same name then all logs for that logger name will go out over the existing publisher. As soon as any node with that name is destructed it will unregister the publisher, preventing any further logs for that name from being published on the rosout topic.
[rviz2-8] [ERROR] [1725375149.008694913] [rviz2]: Could not find parameter robot_description and did not receive ```
robot_description via std_msgs::msg::String subscription within 10.000000 seconds.
[rviz2-8] Error: Error document empty.
[rviz2-8] at line 100 in ./urdf_parser/src/model.cpp
[rviz2-8] Failed to parse robot description using: urdf_xml_parser/URDFXMLParser
[rviz2-8] [INFO] [1725375159.032092561] [moveit_rdf_loader.rdf_loader]: Unable to parse URDF
[rviz2-8] [ERROR] [1725375159.070748971] [moveit_ros.planning_scene_monitor.planning_scene_monitor]: Robot model not loaded

I also see the warning "NO PLANNING LIBRARY LOADED" in the Motion Planning panel and I can't see any joints in the Joints section. Is it simply my understanding of this system that's wrong or is it something possible but I'm not able to simulate the robot?

[mhubii]

Hi @erencandural, sorry for the late response.

Simulation and real system are compatible if the loaded controller exists for simulation and the real system. Some of the demos only run on the real hardware.

As for the moveit error, I am assuming you use your custom rviz launch? Since this repository puts the move group under a namespace, there might be some errors when things aren't configured the right way.

[mhubii]

related to #172