tb3_loopback_simulation.launch.py

# Copyright (C) 2024 Open Navigation LLC
#
# 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.
 
"""This is all-in-one launch script intended for use by nav2 developers."""
 
import os
 
from ament_index_python.packages import get_package_share_directory
 
from launch import LaunchDescription
from launch.actions import (
    DeclareLaunchArgument,
    GroupAction,
    IncludeLaunchDescription,
)
from launch.conditions import IfCondition
from launch.launch_description_sources import PythonLaunchDescriptionSource
from launch.substitutions import LaunchConfiguration
from launch_ros.actions import Node, SetParameter
from launch_ros.descriptions import ParameterFile
 
from nav2_common.launch import RewrittenYaml
 
 
def generate_launch_description():
    # Get the launch directory
    bringup_dir = get_package_share_directory('nav2_bringup')
    loopback_sim_dir = get_package_share_directory('nav2_loopback_sim')
    launch_dir = os.path.join(bringup_dir, 'launch')
    sim_dir = get_package_share_directory('nav2_minimal_tb3_sim')
 
    # Create the launch configuration variables
    namespace = LaunchConfiguration('namespace')
    use_namespace = LaunchConfiguration('use_namespace')
    map_yaml_file = LaunchConfiguration('map')
    params_file = LaunchConfiguration('params_file')
    autostart = LaunchConfiguration('autostart')
    use_composition = LaunchConfiguration('use_composition')
    use_respawn = LaunchConfiguration('use_respawn')
 
    # Launch configuration variables specific to simulation
    rviz_config_file = LaunchConfiguration('rviz_config_file')
    use_robot_state_pub = LaunchConfiguration('use_robot_state_pub')
    use_rviz = LaunchConfiguration('use_rviz')
 
    remappings = [('/tf', 'tf'), ('/tf_static', 'tf_static')]
 
    # Declare the launch arguments
    declare_namespace_cmd = DeclareLaunchArgument(
        'namespace', default_value='', description='Top-level namespace'
    )
 
    declare_use_namespace_cmd = DeclareLaunchArgument(
        'use_namespace',
        default_value='false',
        description='Whether to apply a namespace to the navigation stack',
    )
 
    declare_map_yaml_cmd = DeclareLaunchArgument(
        'map',
        default_value=os.path.join(bringup_dir, 'maps', 'tb3_sandbox.yaml'),
    )
 
    declare_params_file_cmd = DeclareLaunchArgument(
        'params_file',
        default_value=os.path.join(bringup_dir, 'params', 'nav2_params.yaml'),
        description='Full path to the ROS2 parameters file to use for all launched nodes',
    )
 
    declare_autostart_cmd = DeclareLaunchArgument(
        'autostart',
        default_value='true',
        description='Automatically startup the nav2 stack',
    )
 
    declare_use_composition_cmd = DeclareLaunchArgument(
        'use_composition',
        default_value='True',
        description='Whether to use composed bringup',
    )
 
    declare_use_respawn_cmd = DeclareLaunchArgument(
        'use_respawn',
        default_value='False',
        description='Whether to respawn if a node crashes. Applied when composition is disabled.',
    )
 
    declare_rviz_config_file_cmd = DeclareLaunchArgument(
        'rviz_config_file',
        default_value=os.path.join(bringup_dir, 'rviz', 'nav2_default_view.rviz'),
        description='Full path to the RVIZ config file to use',
    )
 
    declare_use_robot_state_pub_cmd = DeclareLaunchArgument(
        'use_robot_state_pub',
        default_value='True',
        description='Whether to start the robot state publisher',
    )
 
    declare_use_rviz_cmd = DeclareLaunchArgument(
        'use_rviz', default_value='True', description='Whether to start RVIZ'
    )
 
    urdf = os.path.join(sim_dir, 'urdf', 'turtlebot3_waffle.urdf')
    with open(urdf, 'r') as infp:
        robot_description = infp.read()
 
    start_robot_state_publisher_cmd = Node(
        condition=IfCondition(use_robot_state_pub),
        package='robot_state_publisher',
        executable='robot_state_publisher',
        name='robot_state_publisher',
        namespace=namespace,
        output='screen',
        parameters=[
            {'use_sim_time': True, 'robot_description': robot_description}
        ],
        remappings=remappings,
    )
 
    rviz_cmd = IncludeLaunchDescription(
        PythonLaunchDescriptionSource(os.path.join(launch_dir, 'rviz_launch.py')),
        condition=IfCondition(use_rviz),
        launch_arguments={
            'namespace': namespace,
            'use_namespace': use_namespace,
            'use_sim_time': 'True',
            'rviz_config': rviz_config_file,
        }.items(),
    )
 
    bringup_cmd = IncludeLaunchDescription(
        PythonLaunchDescriptionSource(os.path.join(launch_dir, 'bringup_launch.py')),
        launch_arguments={
            'namespace': namespace,
            'use_namespace': use_namespace,
            'map': map_yaml_file,
            'use_sim_time': 'True',
            'params_file': params_file,
            'autostart': autostart,
            'use_composition': use_composition,
            'use_respawn': use_respawn,
            'use_localization': 'False',  # Don't use SLAM, AMCL
        }.items(),
    )
 
    loopback_sim_cmd = IncludeLaunchDescription(
        PythonLaunchDescriptionSource(
            os.path.join(loopback_sim_dir, 'loopback_simulation.launch.py')),
        launch_arguments={
            'params_file': params_file,
        }.items(),
    )
 
    configured_params = ParameterFile(
        RewrittenYaml(
            source_file=params_file,
            root_key=namespace,
            param_rewrites={},
            convert_types=True,
        ),
        allow_substs=True,
    )
 
    start_map_server = GroupAction(
        actions=[
            SetParameter('use_sim_time', True),
            Node(
                package='nav2_map_server',
                executable='map_server',
                name='map_server',
                output='screen',
                respawn=use_respawn,
                respawn_delay=2.0,
                parameters=[configured_params, {'yaml_filename': map_yaml_file}],
                remappings=remappings,
            ),
            Node(
                package='nav2_lifecycle_manager',
                executable='lifecycle_manager',
                name='lifecycle_manager_map_server',
                output='screen',
                parameters=[
                    configured_params,
                    {'autostart': autostart}, {'node_names': ['map_server']}],
            ),
        ]
    )
 
    # Create the launch description and populate
    ld = LaunchDescription()
 
    # Declare the launch options
    ld.add_action(declare_namespace_cmd)
    ld.add_action(declare_use_namespace_cmd)
    ld.add_action(declare_map_yaml_cmd)
    ld.add_action(declare_params_file_cmd)
    ld.add_action(declare_autostart_cmd)
    ld.add_action(declare_use_composition_cmd)
 
    ld.add_action(declare_rviz_config_file_cmd)
    ld.add_action(declare_use_robot_state_pub_cmd)
    ld.add_action(declare_use_rviz_cmd)
    ld.add_action(declare_use_respawn_cmd)
 
    # Add the actions to launch all of the navigation nodes
    ld.add_action(start_robot_state_publisher_cmd)
    ld.add_action(start_map_server)
    ld.add_action(loopback_sim_cmd)
    ld.add_action(rviz_cmd)
    ld.add_action(bringup_cmd)
 
    return ld