From 9853c080b0e8ed924a65a8a8b8af8ba29d428393 Mon Sep 17 00:00:00 2001
From: "Dr. Denis" <denis@stoglrobotics.de>
Date: Tue, 2 Apr 2024 13:13:17 +0200
Subject: [PATCH] Cleanup launch files and add example for .xml launch file.
 (#266)

---
 .../launch/cart_example_effort.launch.py      | 40 +++++-------
 .../launch/cart_example_position.launch.py    | 40 +++++-------
 .../launch/cart_example_velocity.launch.py    | 54 +++++-----------
 .../launch/diff_drive_example.launch.py       | 56 ++++++-----------
 .../gripper_mimic_joint_example.launch.py     | 42 +++++--------
 .../gripper_mimic_joint_example.launch.xml    | 63 +++++++++++++++++++
 .../launch/tricycle_drive_example.launch.py   | 47 ++++++--------
 7 files changed, 167 insertions(+), 175 deletions(-)
 create mode 100644 gz_ros2_control_demos/launch/gripper_mimic_joint_example.launch.xml

diff --git a/gz_ros2_control_demos/launch/cart_example_effort.launch.py b/gz_ros2_control_demos/launch/cart_example_effort.launch.py
index 2f59952f..1b7b88ad 100644
--- a/gz_ros2_control_demos/launch/cart_example_effort.launch.py
+++ b/gz_ros2_control_demos/launch/cart_example_effort.launch.py
@@ -12,52 +12,45 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import os
-
-from ament_index_python.packages import get_package_share_directory
-
-
 from launch import LaunchDescription
 from launch.actions import DeclareLaunchArgument, ExecuteProcess, IncludeLaunchDescription
 from launch.actions import RegisterEventHandler
 from launch.event_handlers import OnProcessExit
 from launch.launch_description_sources import PythonLaunchDescriptionSource
-from launch.substitutions import LaunchConfiguration
+from launch.substitutions import Command, FindExecutable, PathJoinSubstitution, LaunchConfiguration
 
 from launch_ros.actions import Node
-
-import xacro
+from launch_ros.substitutions import FindPackageShare
 
 
 def generate_launch_description():
     # Launch Arguments
     use_sim_time = LaunchConfiguration('use_sim_time', default=True)
 
-    gz_ros2_control_demos_path = os.path.join(
-        get_package_share_directory('gz_ros2_control_demos'))
-
-    xacro_file = os.path.join(gz_ros2_control_demos_path,
-                              'urdf',
-                              'test_cart_effort.xacro.urdf')
-
-    doc = xacro.parse(open(xacro_file))
-    xacro.process_doc(doc)
-    params = {'robot_description': doc.toxml()}
+    # Get URDF via xacro
+    robot_description_content = Command(
+        [
+            PathJoinSubstitution([FindExecutable(name="xacro")]),
+            " ",
+            PathJoinSubstitution(
+                [FindPackageShare("gz_ros2_control_demos"), "urdf", "test_cart_effort.xacro.urdf"]
+            ),
+        ]
+    )
+    robot_description = {"robot_description": robot_description_content}
 
     node_robot_state_publisher = Node(
         package='robot_state_publisher',
         executable='robot_state_publisher',
         output='screen',
-        parameters=[params]
+        parameters=[robot_description]
     )
 
     gz_spawn_entity = Node(
         package='ros_gz_sim',
         executable='create',
         output='screen',
-        parameters=[{'string': doc.toxml(),
-                     'name': 'cart',
-                     'allow_renaming': True}],
+        arguments=["-topic", "robot_description", "-name", "cart", "-allow_renaming", "true"],
     )
 
     load_joint_state_broadcaster = ExecuteProcess(
@@ -75,8 +68,7 @@ def generate_launch_description():
         # Launch gazebo environment
         IncludeLaunchDescription(
             PythonLaunchDescriptionSource(
-                [os.path.join(get_package_share_directory('ros_gz_sim'),
-                              'launch', 'gz_sim.launch.py')]),
+                [PathJoinSubstitution([FindPackageShare('ros_gz_sim'), 'launch', 'gz_sim.launch.py'])]),
             launch_arguments=[('gz_args', [' -r -v 3 empty.sdf'])]),
         RegisterEventHandler(
             event_handler=OnProcessExit(
diff --git a/gz_ros2_control_demos/launch/cart_example_position.launch.py b/gz_ros2_control_demos/launch/cart_example_position.launch.py
index 33e96772..933a361a 100644
--- a/gz_ros2_control_demos/launch/cart_example_position.launch.py
+++ b/gz_ros2_control_demos/launch/cart_example_position.launch.py
@@ -12,52 +12,45 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import os
-
-from ament_index_python.packages import get_package_share_directory
-
-
 from launch import LaunchDescription
 from launch.actions import DeclareLaunchArgument, ExecuteProcess, IncludeLaunchDescription
 from launch.actions import RegisterEventHandler
 from launch.event_handlers import OnProcessExit
 from launch.launch_description_sources import PythonLaunchDescriptionSource
-from launch.substitutions import LaunchConfiguration
+from launch.substitutions import Command, FindExecutable, PathJoinSubstitution, LaunchConfiguration
 
 from launch_ros.actions import Node
-
-import xacro
+from launch_ros.substitutions import FindPackageShare
 
 
 def generate_launch_description():
     # Launch Arguments
     use_sim_time = LaunchConfiguration('use_sim_time', default=True)
 
-    gz_ros2_control_demos_path = os.path.join(
-        get_package_share_directory('gz_ros2_control_demos'))
-
-    xacro_file = os.path.join(gz_ros2_control_demos_path,
-                              'urdf',
-                              'test_cart_position.xacro.urdf')
-
-    doc = xacro.parse(open(xacro_file))
-    xacro.process_doc(doc)
-    params = {'robot_description': doc.toxml()}
+    # Get URDF via xacro
+    robot_description_content = Command(
+        [
+            PathJoinSubstitution([FindExecutable(name="xacro")]),
+            " ",
+            PathJoinSubstitution(
+                [FindPackageShare("gz_ros2_control_demos"), "urdf", "test_cart_position.xacro.urdf"]
+            ),
+        ]
+    )
+    robot_description = {"robot_description": robot_description_content}
 
     node_robot_state_publisher = Node(
         package='robot_state_publisher',
         executable='robot_state_publisher',
         output='screen',
-        parameters=[params]
+        parameters=[robot_description]
     )
 
     gz_spawn_entity = Node(
         package='ros_gz_sim',
         executable='create',
         output='screen',
-        parameters=[{'string': doc.toxml(),
-                     'name': 'cart',
-                     'allow_renaming': True}],
+        arguments=["-topic", "robot_description", "-name", "cart", "-allow_renaming", "true"],
     )
 
     load_joint_state_broadcaster = ExecuteProcess(
@@ -76,8 +69,7 @@ def generate_launch_description():
         # Launch gazebo environment
         IncludeLaunchDescription(
             PythonLaunchDescriptionSource(
-                [os.path.join(get_package_share_directory('ros_gz_sim'),
-                              'launch', 'gz_sim.launch.py')]),
+                [PathJoinSubstitution([FindPackageShare('ros_gz_sim'), 'launch', 'gz_sim.launch.py'])]),
             launch_arguments=[('gz_args', [' -r -v 4 empty.sdf'])]),
         RegisterEventHandler(
             event_handler=OnProcessExit(
diff --git a/gz_ros2_control_demos/launch/cart_example_velocity.launch.py b/gz_ros2_control_demos/launch/cart_example_velocity.launch.py
index 251bdcaf..5c7753fb 100644
--- a/gz_ros2_control_demos/launch/cart_example_velocity.launch.py
+++ b/gz_ros2_control_demos/launch/cart_example_velocity.launch.py
@@ -12,52 +12,45 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import os
-
-from ament_index_python.packages import get_package_share_directory
-
-
 from launch import LaunchDescription
 from launch.actions import DeclareLaunchArgument, ExecuteProcess, IncludeLaunchDescription
 from launch.actions import RegisterEventHandler
 from launch.event_handlers import OnProcessExit
 from launch.launch_description_sources import PythonLaunchDescriptionSource
-from launch.substitutions import LaunchConfiguration
+from launch.substitutions import Command, FindExecutable, PathJoinSubstitution, LaunchConfiguration
 
 from launch_ros.actions import Node
-
-import xacro
+from launch_ros.substitutions import FindPackageShare
 
 
 def generate_launch_description():
     # Launch Arguments
     use_sim_time = LaunchConfiguration('use_sim_time', default=True)
 
-    gz_ros2_control_demos_path = os.path.join(
-        get_package_share_directory('gz_ros2_control_demos'))
-
-    xacro_file = os.path.join(gz_ros2_control_demos_path,
-                              'urdf',
-                              'test_cart_velocity.xacro.urdf')
-
-    doc = xacro.parse(open(xacro_file))
-    xacro.process_doc(doc)
-    params = {'robot_description': doc.toxml()}
+    # Get URDF via xacro
+    robot_description_content = Command(
+        [
+            PathJoinSubstitution([FindExecutable(name="xacro")]),
+            " ",
+            PathJoinSubstitution(
+                [FindPackageShare("gz_ros2_control_demos"), "urdf", "test_cart_velocity.xacro.urdf"]
+            ),
+        ]
+    )
+    robot_description = {"robot_description": robot_description_content}
 
     node_robot_state_publisher = Node(
         package='robot_state_publisher',
         executable='robot_state_publisher',
         output='screen',
-        parameters=[params]
+        parameters=[robot_description]
     )
 
     gz_spawn_entity = Node(
         package='ros_gz_sim',
         executable='create',
         output='screen',
-        parameters=[{'string': doc.toxml(),
-                     'name': 'cart',
-                     'allow_renaming': True}],
+        arguments=["-topic", "robot_description", "-name", "cart", "-allow_renaming", "true"],
     )
 
     load_joint_state_broadcaster = ExecuteProcess(
@@ -71,19 +64,12 @@ def generate_launch_description():
         output='screen'
     )
 
-    load_imu_sensor_broadcaster = ExecuteProcess(
-        cmd=['ros2', 'control', 'load_controller', '--set-state', 'active',
-             'imu_sensor_broadcaster'],
-        output='screen'
-    )
-
     return LaunchDescription([
         # Launch gazebo environment
         IncludeLaunchDescription(
             PythonLaunchDescriptionSource(
-                [os.path.join(get_package_share_directory('ros_gz_sim'),
-                              'launch', 'gz_sim.launch.py')]),
-            launch_arguments=[('gz_args', [' -r -v 4 empty.sdf'])]),
+                [PathJoinSubstitution([FindPackageShare('ros_gz_sim'), 'launch', 'gz_sim.launch.py'])]),
+            launch_arguments=[('gz_args', [' -r -v 3 empty.sdf'])]),
         RegisterEventHandler(
             event_handler=OnProcessExit(
                 target_action=gz_spawn_entity,
@@ -96,12 +82,6 @@ def generate_launch_description():
                 on_exit=[load_joint_velocity_controller],
             )
         ),
-        RegisterEventHandler(
-            event_handler=OnProcessExit(
-                target_action=load_joint_velocity_controller,
-                on_exit=[load_imu_sensor_broadcaster],
-            )
-        ),
         node_robot_state_publisher,
         gz_spawn_entity,
         # Launch Arguments
diff --git a/gz_ros2_control_demos/launch/diff_drive_example.launch.py b/gz_ros2_control_demos/launch/diff_drive_example.launch.py
index e109d769..a29796bc 100644
--- a/gz_ros2_control_demos/launch/diff_drive_example.launch.py
+++ b/gz_ros2_control_demos/launch/diff_drive_example.launch.py
@@ -12,56 +12,48 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import os
-
-from ament_index_python.packages import get_package_share_directory
-
 from launch import LaunchDescription
 from launch.actions import DeclareLaunchArgument, ExecuteProcess, IncludeLaunchDescription
 from launch.actions import RegisterEventHandler
 from launch.event_handlers import OnProcessExit
 from launch.launch_description_sources import PythonLaunchDescriptionSource
-from launch.substitutions import LaunchConfiguration
+from launch.substitutions import Command, FindExecutable, PathJoinSubstitution, LaunchConfiguration
 
 from launch_ros.actions import Node
-
-import xacro
+from launch_ros.substitutions import FindPackageShare
 
 
 def generate_launch_description():
     # Launch Arguments
     use_sim_time = LaunchConfiguration('use_sim_time', default=True)
 
-    gz_ros2_control_demos_path = os.path.join(
-        get_package_share_directory('gz_ros2_control_demos'))
-
-    xacro_file = os.path.join(gz_ros2_control_demos_path,
-                              'urdf',
-                              'test_diff_drive.xacro.urdf')
-
-    doc = xacro.parse(open(xacro_file))
-    xacro.process_doc(doc)
-    params = {'robot_description': doc.toxml(), 'use_sim_time': use_sim_time}
-
-    print(params)
+    # Get URDF via xacro
+    robot_description_content = Command(
+        [
+            PathJoinSubstitution([FindExecutable(name="xacro")]),
+            " ",
+            PathJoinSubstitution(
+                [FindPackageShare("gz_ros2_control_demos"), "urdf", "test_diff_drive.xacro.urdf"]
+            ),
+        ]
+    )
+    robot_description = {"robot_description": robot_description_content}
 
     node_robot_state_publisher = Node(
         package='robot_state_publisher',
         executable='robot_state_publisher',
         output='screen',
-        parameters=[params],
+        parameters=[robot_description]
     )
 
     gz_spawn_entity = Node(
         package='ros_gz_sim',
         executable='create',
         output='screen',
-        parameters=[{'string': doc.toxml(),
-                     'name': 'diff_drive',
-                     'allow_renaming': True}],
+        arguments=["-topic", "robot_description", "-name", "diff_drive", "-allow_renaming", "true"],
     )
 
-    load_joint_state_controller = ExecuteProcess(
+    load_joint_state_broadcaster = ExecuteProcess(
         cmd=['ros2', 'control', 'load_controller', '--set-state', 'active',
              'joint_state_broadcaster'],
         output='screen'
@@ -73,31 +65,21 @@ def generate_launch_description():
         output='screen'
     )
 
-    # Bridge
-    bridge = Node(
-        package='ros_gz_bridge',
-        executable='parameter_bridge',
-        arguments=['/clock@rosgraph_msgs/msg/Clock[ignition.msgs.Clock'],
-        output='screen'
-    )
-
     return LaunchDescription([
-        bridge,
         # Launch gazebo environment
         IncludeLaunchDescription(
             PythonLaunchDescriptionSource(
-                [os.path.join(get_package_share_directory('ros_gz_sim'),
-                              'launch', 'gz_sim.launch.py')]),
+                [PathJoinSubstitution([FindPackageShare('ros_gz_sim'), 'launch', 'gz_sim.launch.py'])]),
             launch_arguments=[('gz_args', [' -r -v 4 empty.sdf'])]),
         RegisterEventHandler(
             event_handler=OnProcessExit(
                 target_action=gz_spawn_entity,
-                on_exit=[load_joint_state_controller],
+                on_exit=[load_joint_state_broadcaster],
             )
         ),
         RegisterEventHandler(
             event_handler=OnProcessExit(
-                target_action=load_joint_state_controller,
+                target_action=load_joint_state_broadcaster,
                 on_exit=[load_diff_drive_controller],
             )
         ),
diff --git a/gz_ros2_control_demos/launch/gripper_mimic_joint_example.launch.py b/gz_ros2_control_demos/launch/gripper_mimic_joint_example.launch.py
index e4b9f82d..db0cdb7c 100644
--- a/gz_ros2_control_demos/launch/gripper_mimic_joint_example.launch.py
+++ b/gz_ros2_control_demos/launch/gripper_mimic_joint_example.launch.py
@@ -15,52 +15,45 @@
 # Author: Denis Stogl (Stogl Robotics Consulting)
 #
 
-import os
-
-from ament_index_python.packages import get_package_share_directory
-
-
 from launch import LaunchDescription
 from launch.actions import DeclareLaunchArgument, ExecuteProcess, IncludeLaunchDescription
 from launch.actions import RegisterEventHandler
 from launch.event_handlers import OnProcessExit
 from launch.launch_description_sources import PythonLaunchDescriptionSource
-from launch.substitutions import LaunchConfiguration
+from launch.substitutions import Command, FindExecutable, PathJoinSubstitution, LaunchConfiguration
 
 from launch_ros.actions import Node
-
-import xacro
+from launch_ros.substitutions import FindPackageShare
 
 
 def generate_launch_description():
-    # Launch arguments
+    # Launch Arguments
     use_sim_time = LaunchConfiguration('use_sim_time', default=True)
 
-    gz_ros2_control_demos_path = os.path.join(
-        get_package_share_directory('gz_ros2_control_demos'))
-
-    xacro_file = os.path.join(gz_ros2_control_demos_path,
-                              'urdf',
-                              'test_gripper_mimic_joint.xacro.urdf')
-
-    doc = xacro.parse(open(xacro_file))
-    xacro.process_doc(doc)
-    params = {'robot_description': doc.toxml()}
+    # Get URDF via xacro
+    robot_description_content = Command(
+        [
+            PathJoinSubstitution([FindExecutable(name="xacro")]),
+            " ",
+            PathJoinSubstitution(
+                [FindPackageShare("gz_ros2_control_demos"), "urdf", "test_gripper_mimic_joint.xacro.urdf"]
+            ),
+        ]
+    )
+    robot_description = {"robot_description": robot_description_content}
 
     node_robot_state_publisher = Node(
         package='robot_state_publisher',
         executable='robot_state_publisher',
         output='screen',
-        parameters=[params]
+        parameters=[robot_description]
     )
 
     gz_spawn_entity = Node(
         package='ros_gz_sim',
         executable='create',
         output='screen',
-        parameters=[{'string': doc.toxml(),
-                     'name': 'gripper',
-                     'allow_renaming': True}],
+        arguments=["-topic", "robot_description", "-name", "gripper", "-allow_renaming", "true"],
     )
 
     load_joint_state_broadcaster = ExecuteProcess(
@@ -79,8 +72,7 @@ def generate_launch_description():
         # Launch gazebo environment
         IncludeLaunchDescription(
             PythonLaunchDescriptionSource(
-                [os.path.join(get_package_share_directory('ros_gz_sim'),
-                              'launch', 'gz_sim.launch.py')]),
+                [PathJoinSubstitution([FindPackageShare('ros_gz_sim'), 'launch', 'gz_sim.launch.py'])]),
             launch_arguments=[('gz_args', [' -r -v 4 empty.sdf'])]),
         RegisterEventHandler(
             event_handler=OnProcessExit(
diff --git a/gz_ros2_control_demos/launch/gripper_mimic_joint_example.launch.xml b/gz_ros2_control_demos/launch/gripper_mimic_joint_example.launch.xml
new file mode 100644
index 00000000..72d5e81d
--- /dev/null
+++ b/gz_ros2_control_demos/launch/gripper_mimic_joint_example.launch.xml
@@ -0,0 +1,63 @@
+<!--
+Copyright (c) 2024, Stogl Robotics Consulting UG (haftungsbeschränkt)
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+
+
+Source of this file are templates in [RosTeamWorkspace](https://github.com/StoglRobotics/ros_team_workspace) repository.
+
+Author: Dr. Denis
+-->
+
+<launch>
+  <arg name="gui"
+       default="false"
+       description="Start RViz2 automatically with this launch file."/>
+
+  <!-- Load description and start controllers -->
+  <let name="robot_description_content" value="$(command '$(find-exec xacro) $(find-pkg-share gz_ros2_control_demos)/urdf/test_gripper_mimic_joint.xacro.urdf')" />
+
+  <node pkg="robot_state_publisher" exec="robot_state_publisher" output="both">
+    <param name="robot_description" value="$(var robot_description_content)" />
+    <param name="use_sim_time" value="true" />
+  </node>
+
+  <!-- Start Gazebo -->
+  <include file="$(find-pkg-share ros_gz_sim)/launch/gz_sim.launch.py" >
+    <arg name="gz_args" value=" -r -v 4 empty.sdf"/>
+  </include>
+
+  <node pkg="ros_gz_bridge" exec="parameter_bridge" args="
+        /clock@rosgraph_msgs/msg/Clock[ignition.msgs.Clock"
+        output="screen">
+  </node>
+
+  <!-- Create robot in Gazebo -->
+  <node pkg="ros_gz_sim" exec="create" output="screen" args="-topic /robot_description -name gripper -allow-renaming true"/>
+
+  <!-- Start Controllers -->
+  <!--joint_state_braodcaster_spawner-->
+  <node pkg="controller_manager" exec="spawner" args="joint_state_broadcaster">
+    <param name="use_sim_time" value="true" />
+  </node>
+  <!--Mobile Base Controller-->
+  <node pkg="controller_manager" exec="spawner" args="gripper_controller">
+    <param name="use_sim_time" value="true" />
+  </node>
+
+  <!-- Rviz -->
+  <node if="$(var gui)" pkg="rviz2" exec="rviz2" output="log" args="-d $(find-pkg-share $(var ros2_control_demo_description))/rrbot/rviz/rrbot.rviz">
+    <param name="use_sim_time" value="true" />
+  </node>
+
+</launch>
diff --git a/gz_ros2_control_demos/launch/tricycle_drive_example.launch.py b/gz_ros2_control_demos/launch/tricycle_drive_example.launch.py
index 3b773ddb..bfe3ce0e 100644
--- a/gz_ros2_control_demos/launch/tricycle_drive_example.launch.py
+++ b/gz_ros2_control_demos/launch/tricycle_drive_example.launch.py
@@ -12,56 +12,48 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import os
-
-from ament_index_python.packages import get_package_share_directory
-
 from launch import LaunchDescription
 from launch.actions import DeclareLaunchArgument, ExecuteProcess, IncludeLaunchDescription
 from launch.actions import RegisterEventHandler
 from launch.event_handlers import OnProcessExit
 from launch.launch_description_sources import PythonLaunchDescriptionSource
-from launch.substitutions import LaunchConfiguration
+from launch.substitutions import Command, FindExecutable, PathJoinSubstitution, LaunchConfiguration
 
 from launch_ros.actions import Node
-
-import xacro
+from launch_ros.substitutions import FindPackageShare
 
 
 def generate_launch_description():
     # Launch Arguments
     use_sim_time = LaunchConfiguration('use_sim_time', default=True)
 
-    gz_ros2_control_demos_path = os.path.join(
-        get_package_share_directory('gz_ros2_control_demos'))
-
-    xacro_file = os.path.join(gz_ros2_control_demos_path,
-                              'urdf',
-                              'test_tricycle_drive.xacro.urdf')
-
-    doc = xacro.parse(open(xacro_file))
-    xacro.process_doc(doc)
-    params = {'robot_description': doc.toxml(), 'use_sim_time': use_sim_time}
-
-    print(params)
+    # Get URDF via xacro
+    robot_description_content = Command(
+        [
+            PathJoinSubstitution([FindExecutable(name="xacro")]),
+            " ",
+            PathJoinSubstitution(
+                [FindPackageShare("gz_ros2_control_demos"), "urdf", "test_tricycle_drive.xacro.urdf"]
+            ),
+        ]
+    )
+    robot_description = {"robot_description": robot_description_content}
 
     node_robot_state_publisher = Node(
         package='robot_state_publisher',
         executable='robot_state_publisher',
         output='screen',
-        parameters=[params],
+        parameters=[robot_description]
     )
 
     gz_spawn_entity = Node(
         package='ros_gz_sim',
         executable='create',
         output='screen',
-        parameters=[{'string': doc.toxml(),
-                     'name': 'tricyle',
-                     'allow_renaming': True}],
+        arguments=["-topic", "robot_description", "-name", "tricyle", "-allow_renaming", "true"],
     )
 
-    load_joint_state_controller = ExecuteProcess(
+    load_joint_state_broadcaster = ExecuteProcess(
         cmd=['ros2', 'control', 'load_controller', '--set-state', 'active',
              'joint_state_broadcaster'],
         output='screen'
@@ -86,18 +78,17 @@ def generate_launch_description():
         # Launch gazebo environment
         IncludeLaunchDescription(
             PythonLaunchDescriptionSource(
-                [os.path.join(get_package_share_directory('ros_gz_sim'),
-                              'launch', 'gz_sim.launch.py')]),
+                [PathJoinSubstitution([FindPackageShare('ros_gz_sim'), 'launch', 'gz_sim.launch.py'])]),
             launch_arguments=[('gz_args', [' -r -v 4 empty.sdf'])]),
         RegisterEventHandler(
             event_handler=OnProcessExit(
                 target_action=gz_spawn_entity,
-                on_exit=[load_joint_state_controller],
+                on_exit=[load_joint_state_broadcaster],
             )
         ),
         RegisterEventHandler(
             event_handler=OnProcessExit(
-                target_action=load_joint_state_controller,
+                target_action=load_joint_state_broadcaster,
                 on_exit=[load_joint_trajectory_controller],
             )
         ),