ros - shivamvats/notes GitHub Wiki

Set use_sim_time to true only if there is a clock server publishing the simulated time. Otherwise, your nodes will keep waiting for the time to be published. use_sim_time=True typically only when using gazebo or running a ros-bag.

Note: use_sim_time=true can screw up rviz.

• Keeps track of the relative transformations between joints.
• There are alternatives as well: KDL.
• RViz needs this to visualize the robot. Hence, even if you are not using TF, make sure it is being published if you need to visualize stuff on RViz.

This is a ROS package that subscribes to /joint_states (for joint state) and robot_description (for the URDF) to commpute its FK (think KDL tree) and publish the transforms via TF (at /tf).

• To check if a urdf file is valid and visualize the link connections (tree), run check_urdf xyz.urdf.
• To get a graphical diagram/tree of the robot links run urdf_to_graphiz xyz.urdf