[example_9] Switch to gz_ros2_control (backport #482) (#749)

* [example_9] Switch to gz_ros2_control (#482)

* Switch from gazebo classic to gazebo

* update docs

* Use gz_ros2_control in semi-binary builds

* rm dependency conditional

Co-authored-by: Dr. Denis <[email protected]>

* Remove gazebo classic from repos file

* Add gazebo bridge node and fix some warnings (#755) (#757)

(cherry picked from commit 2587970)

Co-authored-by: Julia Jia <[email protected]>

---------

Co-authored-by: Christoph Fröhlich <[email protected]>
Co-authored-by: Dr. Denis <[email protected]>
Co-authored-by: Christoph Froehlich <[email protected]>
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>
Co-authored-by: Julia Jia <[email protected]>

Author: 4 people

README.md

@@ -55,7 +55,7 @@ The following examples are part of this demo repository:
 
    *RRBot* with an exposed transmission interface.
 
-* Example 9: ["Gazebo classic simulation"](example_9)
+* Example 9: ["Gazebo simulation"](example_9)
 
    Demonstrates how to switch between simulation and hardware.
 

doc/index.rst

@@ -286,7 +286,7 @@ Examples
    Example 6: Modular robots with separate communication to each actuator <../example_6/doc/userdoc.rst>
    Example 7: Full tutorial with a 6DOF robot <../example_7/doc/userdoc.rst>
    Example 8: Using transmissions <../example_8/doc/userdoc.rst>
-   Example 9: Gazebo classic <../example_9/doc/userdoc.rst>
+   Example 9: Gazebo <../example_9/doc/userdoc.rst>
    Example 10: Industrial robot with GPIO interfaces <../example_10/doc/userdoc.rst>
    Example 11: CarlikeBot <../example_11/doc/userdoc.rst>
    Example 12: Controller chaining <../example_12/doc/userdoc.rst>

example_9/bringup/config/rrbot_controllers.yaml

@@ -1,6 +1,6 @@
 controller_manager:
   ros__parameters:
-    update_rate: 10  # Hz
+    update_rate: 1000  # Hz
 
     joint_state_broadcaster:
       type: joint_state_broadcaster/JointStateBroadcaster

example_9/bringup/launch/rrbot_gazebo_classic.launch.py renamed to example_9/bringup/launch/rrbot_gazebo.launch.py

@@ -36,11 +36,34 @@ def generate_launch_description():
     # Initialize Arguments
     gui = LaunchConfiguration("gui")
 
+    # gazebo
     gazebo = IncludeLaunchDescription(
         PythonLaunchDescriptionSource(
-            [PathJoinSubstitution([FindPackageShare("gazebo_ros"), "launch", "gazebo.launch.py"])]
+            [FindPackageShare("ros_gz_sim"), "/launch/gz_sim.launch.py"]
         ),
-        launch_arguments={"verbose": "false"}.items(),
+        launch_arguments={"gz_args": " -r -v 3 empty.sdf"}.items(),
+    )
+
+    # Gazebo bridge
+    gazebo_bridge = Node(
+        package="ros_gz_bridge",
+        executable="parameter_bridge",
+        arguments=["/clock@rosgraph_msgs/msg/Clock[gz.msgs.Clock"],
+        output="screen",
+    )
+
+    gz_spawn_entity = Node(
+        package="ros_gz_sim",
+        executable="create",
+        output="screen",
+        arguments=[
+            "-topic",
+            "/robot_description",
+            "-name",
+            "rrbot_system_position",
+            "-allow_renaming",
+            "true",
+        ],
     )
 
     # Get URDF via xacro
@@ -52,7 +75,7 @@ def generate_launch_description():
                 [FindPackageShare("ros2_control_demo_example_9"), "urdf", "rrbot.urdf.xacro"]
             ),
             " ",
-            "use_gazebo_classic:=true",
+            "use_gazebo:=true",
         ]
     )
     robot_description = {"robot_description": robot_description_content}
@@ -67,13 +90,6 @@ def generate_launch_description():
         parameters=[robot_description],
     )
 
-    spawn_entity = Node(
-        package="gazebo_ros",
-        executable="spawn_entity.py",
-        arguments=["-topic", "robot_description", "-entity", "rrbot_system_position"],
-        output="screen",
-    )
-
     joint_state_broadcaster_spawner = Node(
         package="controller_manager",
         executable="spawner",
@@ -96,8 +112,9 @@ def generate_launch_description():
 
     nodes = [
         gazebo,
+        gazebo_bridge,
         node_robot_state_publisher,
-        spawn_entity,
+        gz_spawn_entity,
         joint_state_broadcaster_spawner,
         robot_controller_spawner,
         rviz_node,

example_9/description/gazebo/rrbot.gazebo.xacro

@@ -9,28 +9,43 @@ https://github.com/ros-simulation/gazebo_ros_demos/blob/kinetic-devel/rrbot_desc
 
     <!-- ros_control plugin -->
     <gazebo>
-      <plugin filename="libgazebo_ros2_control.so" name="gazebo_ros2_control">
+      <plugin filename="gz_ros2_control-system" name="gz_ros2_control::GazeboSimROS2ControlPlugin">
         <parameters>$(find ros2_control_demo_example_9)/config/rrbot_controllers.yaml</parameters>
       </plugin>
     </gazebo>
 
     <!-- Link1 -->
     <gazebo reference="${prefix}base_link">
-      <material>Gazebo/Orange</material>
+      <material>
+        <script>
+          <uri>file://media/materials/scripts/gazebo.material</uri>
+          <name>Gazebo/Orange</name>
+        </script>
+      </material>
     </gazebo>
 
     <!-- Link2 -->
     <gazebo reference="${prefix}link1">
       <mu1>0.2</mu1>
       <mu2>0.2</mu2>
-      <material>Gazebo/Yellow</material>
+      <material>
+        <script>
+          <uri>file://media/materials/scripts/gazebo.material</uri>
+          <name>Gazebo/Yellow</name>
+        </script>
+      </material>
     </gazebo>
 
     <!-- Link3 -->
     <gazebo reference="${prefix}link2">
       <mu1>0.2</mu1>
       <mu2>0.2</mu2>
-      <material>Gazebo/Orange</material>
+      <material>
+        <script>
+          <uri>file://media/materials/scripts/gazebo.material</uri>
+          <name>Gazebo/Yellow</name>
+        </script>
+      </material>
     </gazebo>
 
   </xacro:macro>

example_9/description/ros2_control/rrbot.ros2_control.xacro

@@ -1,14 +1,14 @@
 <?xml version="1.0"?>
 <robot xmlns:xacro="http://www.ros.org/wiki/xacro">
 
-  <xacro:macro name="rrbot_ros2_control" params="name prefix use_gazebo_classic:=^|false">
+  <xacro:macro name="rrbot_ros2_control" params="name prefix use_gazebo:=^|false">
 
     <ros2_control name="${name}" type="system">
       <hardware>
-        <xacro:if value="${use_gazebo_classic}">
-          <plugin>gazebo_ros2_control/GazeboSystem</plugin>
+        <xacro:if value="${use_gazebo}">
+          <plugin>gz_ros2_control/GazeboSimSystem</plugin>
         </xacro:if>
-        <xacro:unless value="${use_gazebo_classic}">
+        <xacro:unless value="${use_gazebo}">
           <plugin>ros2_control_demo_example_9/RRBotSystemPositionOnlyHardware</plugin>
           <param name="example_param_hw_start_duration_sec">0</param>
           <param name="example_param_hw_stop_duration_sec">3.0</param>

example_9/description/urdf/rrbot.urdf.xacro

@@ -6,7 +6,7 @@ https://github.com/ros-simulation/gazebo_ros_demos/blob/kinetic-devel/rrbot_desc
 -->
 <robot xmlns:xacro="http://www.ros.org/wiki/xacro" name="2dof_robot">
   <xacro:arg name="prefix" default="" />
-  <xacro:arg name="use_gazebo_classic" default="false" />
+  <xacro:arg name="use_gazebo" default="false" />
 
   <!-- Import RRBot macro -->
   <xacro:include filename="$(find ros2_control_demo_description)/rrbot/urdf/rrbot_description.urdf.xacro" />
@@ -25,9 +25,9 @@ https://github.com/ros-simulation/gazebo_ros_demos/blob/kinetic-devel/rrbot_desc
   </xacro:rrbot>
 
   <xacro:rrbot_ros2_control
-    name="RRBot" prefix="$(arg prefix)" use_gazebo_classic="$(arg use_gazebo_classic)"/>
+    name="RRBot" prefix="$(arg prefix)" use_gazebo="$(arg use_gazebo)"/>
 
-  <xacro:if value="$(arg use_gazebo_classic)">
+  <xacro:if value="$(arg use_gazebo)">
     <!-- Import Gazebo Classic definitions + plugin -->
     <xacro:include filename="$(find ros2_control_demo_example_9)/gazebo/rrbot.gazebo.xacro" />
     <xacro:rrbot_gazebo prefix="$(arg prefix)"/>

example_9/doc/rrbot_gazebo.png

@@ -6,34 +6,12 @@ Example 9: Simulation with RRBot
 =================================
 
 With *example_9*, we demonstrate the interaction of simulators with ros2_control. More specifically,
-Gazebo Classic is used for this purpose.
+gazebo is used for this purpose.
 
 .. note::
 
   Follow the installation instructions on :ref:`ros2_control_demos_install` how to install all dependencies,
-  Gazebo Classic should be automatically installed.
-
-  * If you have installed and compiled this repository locally, you can directly use the commands below.
-  * If you have installed it via the provided docker image: To run the first two steps of this example (without Gazebo Classic), use the commands as described with :ref:`ros2_control_demos_install`. To run the later steps using Gazebo Classic, execute
-
-    .. code::
-
-      docker run -it --rm --name ros2_control_demos --net host ros2_control_demos ros2 launch ros2_control_demo_example_9 rrbot_gazebo_classic.launch.py gui:=false
-
-    first. Then on your local machine you can run the Gazebo Classic client with
-
-    .. code-block:: shell
-
-      gzclient
-
-    and/or ``rviz2`` with
-
-    .. code-block:: shell
-
-      rviz2 -d src/ros2_control_demos/example_9/description/rviz/rrbot.rviz
-
-
-  For details on the ``gazebo_ros2_control`` plugin, see :ref:`gazebo_ros2_control`.
+  gazebo should be automatically installed. For details on the ``gz_ros2_control`` plugin, see :ref:`gz_ros2_control`.
 
 Tutorial steps
 --------------------------
@@ -55,24 +33,18 @@ Tutorial steps
 
    It uses an identical hardware interface as already discussed with *example_1*, see its docs on details on the hardware interface.
 
-3. To start *RRBot* in the simulators, open a terminal, source your ROS2-workspace and Gazebo Classic installation first, i.e., by
-
-  .. code-block:: shell
-
-    source /usr/share/gazebo/setup.sh
-
-  Then, execute the launch file with
+3. To start *RRBot* in the simulators, open a terminal, source your ROS2-workspace first. Then, execute the launch file with
 
   .. code-block:: shell
 
-    ros2 launch ros2_control_demo_example_9 rrbot_gazebo_classic.launch.py gui:=true
+    ros2 launch ros2_control_demo_example_9 rrbot_gazebo.launch.py gui:=true
 
-  The launch file loads the robot description, starts Gazebo Classic, *Joint State Broadcaster* and *Forward Command Controller*.
-  If you can see two orange and one yellow "box" in Gazebo Classic everything has started properly.
+  The launch file loads the robot description, starts gazebo, *Joint State Broadcaster* and *Forward Command Controller*.
+  If you can see two orange and one yellow "box" in gazebo everything has started properly.
 
-  .. image:: rrbot_gazebo_classic.png
+  .. image:: rrbot_gazebo.png
     :width: 400
-    :alt: Revolute-Revolute Manipulator Robot in Gazebo Classic
+    :alt: Revolute-Revolute Manipulator Robot in gazebo
 
 4. Check if the hardware interface loaded properly, by opening another terminal and executing
 
@@ -118,7 +90,7 @@ Tutorial steps
 
     ros2 launch ros2_control_demo_example_9 test_forward_position_controller.launch.py
 
-   You should now see the robot moving in Gazebo Classic.
+   You should now see the robot moving in gazebo.
 
    If you echo the ``/joint_states`` or ``/dynamic_joint_states`` topics you should see the changing values,
    namely the simulated states of the robot
@@ -135,7 +107,7 @@ Files used for this demos
 - Launch files:
 
   + Hardware: `rrbot.launch.py <https://github.com/ros-controls/ros2_control_demos/tree/{REPOS_FILE_BRANCH}/example_9/bringup/launch/rrbot.launch.py>`__
-  + Gazebo Classic: `rrbot_gazebo_classic.launch.py <https://github.com/ros-controls/ros2_control_demos/tree/{REPOS_FILE_BRANCH}/example_9/bringup/launch/rrbot_gazebo_classic.launch.py>`__
+  + gazebo: `rrbot_gazebo.launch.py <https://github.com/ros-controls/ros2_control_demos/tree/{REPOS_FILE_BRANCH}/example_9/bringup/launch/rrbot_gazebo.launch.py>`__
 
 - Controllers yaml: `rrbot_controllers.yaml <https://github.com/ros-controls/ros2_control_demos/tree/{REPOS_FILE_BRANCH}/example_9/bringup/config/rrbot_controllers.yaml>`__
 - URDF file: `rrbot.urdf.xacro <https://github.com/ros-controls/ros2_control_demos/tree/{REPOS_FILE_BRANCH}/example_9/description/urdf/rrbot.urdf.xacro>`__