SDF with Gazebo and ROS

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Yes, i want to connect ROS and Gazbeo. If I create ROS node in a plugin, I need to use robot_state_publiser to move joints, is that true? But robot_state_publiser can not bee launch with SDF?

Hi Darko. In my opinion, It's impossible to use robot_state_publisher for sdf file. But, I found an easier way to achieve Parallel Robot Simulation.(I can launch tf by robot_state_publisher) Firstly, you need to have an urdf file and take gazebo tag for your parallel joints e.g(Your joint description should be sdf format):

<gazebo> 
    <joint name='left_wheel_Joint2' type='revolute'>  
    <pose relative_to='left_rear_hipleg_Link'>0.119824 0 -0.0315 0 0 -0.730771</pose>  
     <parent>left_rear_hipleg_Link</parent>  
     <child>left_wheel_Link</child>  
       ......  
</gazebo>

Then launch your urdf file. Robot model can not display in rviz/rviz2 but gazebo could display rightly. It's

In addition, you joint tf can not be handled correctly in gazebo tag. The gazebo tag can only help you connect parent_link and child_link in gazebo

Hi, I am a little bit confused, /tf topic is from robot_state_publisher, from /tf i can only read messages, and I can not publish on them, is the truth? Actually, I can publish but /tf is going nowhere. And one more question, can I use gazebo_ros_control plugin to connect ROS and Gazebo, or do I need to create my plugin? Thank you very much for your help so far.

Hi Darko.I think you do not need publish /tf directly. You can try to use joint_state_publisher_gui that can publish joint_state, then /tf can be published by robot_state_publisher automatically. If /tf can not be changed as you described there may be errors about launch file or urdf.Contrarily, if /tf can be changed by joint_state_gui, there is a problem with your publisher node. I have an uncertain conjecture that tf can not be changed because joint_state not changed, your tf published by robot_state_publisher that depended joint_state,so every tf you publish is covered by joint_state pass robot_state_publisher.I am reading ros2_control and ros2_gazebo_control(ros2) source code, i think it is feasible that use gazebo_ros_control to connect ROS and Gazebo(if gazebo_ros_control could do something like ros2_gazebo_control).It could provides gazebo hard_interface for you.

No thanks, I am also in the process of studying, please forgive me if there is something wrong above