Add simple universal launch file.

Author: livanov93

ur_description/launch/view_ur.launch.py

@@ -0,0 +1,85 @@
+import os
+import xacro
+import yaml
+from ament_index_python.packages import get_package_share_directory
+from launch import LaunchDescription
+from launch_ros.actions import Node
+
+def load_file(package_name, file_path):
+    package_path = get_package_share_directory(package_name)
+    absolute_file_path = os.path.join(package_path, file_path)
+
+    try:
+        with open(absolute_file_path, 'r') as file:
+            return file.read()
+    except EnvironmentError:  # parent of IOError, OSError *and* WindowsError where available
+        return None
+
+
+def generate_launch_description():
+
+    # set ur robot
+    robot_name = 'ur5e'
+
+    # <robot_name> parameters files
+    joint_limits_params = os.path.join(get_package_share_directory('ur_description'), 'config/' +
+                                       robot_name, 'joint_limits.yaml')
+    kinematics_params = os.path.join(get_package_share_directory('ur_description'), 'config/' +
+                                     robot_name, 'default_kinematics.yaml')
+    physical_params = os.path.join(get_package_share_directory('ur_description'), 'config/' +
+                                   robot_name, 'physical_parameters.yaml')
+    visual_params = os.path.join(get_package_share_directory('ur_description'), 'config/' +
+                                 robot_name, 'visual_parameters.yaml')
+
+    # common parameters
+    # If True, enable the safety limits controller
+    safety_limits = False
+    # The lower/upper limits in the safety controller
+    safety_pos_margin = 0.15
+    # Used to set k position in the safety controller
+    safety_k_position = 20
+
+    # Get URDF via xacro
+    robot_description_path = os.path.join(get_package_share_directory('ur_description'), 'urdf', 'ur.xacro')
+
+    robot_description_config = xacro.process_file(robot_description_path,
+                                                  mappings={'joint_limit_params': joint_limits_params,
+                                                            'kinematics_params': kinematics_params,
+                                                            'physical_params': physical_params,
+                                                            'visual_params': visual_params,
+                                                            'safety_limits': str(safety_limits).lower(),
+                                                            'safety_pos_margin': str(safety_pos_margin),
+                                                            'safety_k_position': str(safety_k_position)}
+                                                  )
+
+    robot_description = {'robot_description': robot_description_config.toxml()}
+
+    robot_description_semantic_config = load_file(robot_name + '_moveit_config', 'config/' + robot_name + '.srdf')
+    robot_description_semantic = {'robot_description_semantic' : robot_description_semantic_config}
+
+    # We do not have a robot connected, so publish fake joint states
+    joint_state_pub_node = Node(
+        package='joint_state_publisher',
+        executable='joint_state_publisher'
+    )
+
+    # Publishes tf's for the robot
+    robot_state_pub_node = Node(
+        package='robot_state_publisher',
+        executable='robot_state_publisher',
+        output='screen',
+        parameters=[robot_description]
+    )
+
+    # RViz
+    rviz_config_file = get_package_share_directory(
+        'ur_description') + "/cfg/view_robot.rviz"
+    rviz_node = Node(package='rviz2',
+                     executable='rviz2',
+                     name='rviz2',
+                     output='log',
+                     arguments=['-d', rviz_config_file],
+                     parameters=[robot_description, robot_description_semantic]
+                     )
+
+    return LaunchDescription([rviz_node, robot_state_pub_node, joint_state_pub_node])