unique_multi_tb3_simulation_launch.py

# Copyright (c) 2018 Intel Corporation
#
# 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.
 
"""
Example for spawning multiple robots in Gazebo.
 
This is an example on how to create a launch file for spawning multiple robots into Gazebo
and launch multiple instances of the navigation stack, each controlling one robot.
The robots co-exist on a shared environment and are controlled by independent nav stacks.
"""
 
import os
from pathlib import Path
import tempfile
 
from ament_index_python.packages import get_package_share_directory
from launch import LaunchDescription
from launch.actions import (AppendEnvironmentVariable, DeclareLaunchArgument, ExecuteProcess,
                            GroupAction, IncludeLaunchDescription, LogInfo, OpaqueFunction,
                            RegisterEventHandler)
from launch.conditions import IfCondition
from launch.event_handlers import OnShutdown
from launch.launch_description_sources import PythonLaunchDescriptionSource
from launch.substitutions import LaunchConfiguration, TextSubstitution
 
 
def generate_launch_description() -> LaunchDescription:
    # Get the launch directory
    bringup_dir = get_package_share_directory('nav2_bringup')
    launch_dir = os.path.join(bringup_dir, 'launch')
    sim_dir = get_package_share_directory('nav2_minimal_tb3_sim')
 
    # Names and poses of the robots
    robots = [
        {
            'name': 'robot1',
            'x_pose': 0.0,
            'y_pose': 0.5,
            'z_pose': 0.01,
            'roll': 0.0,
            'pitch': 0.0,
            'yaw': 0.0,
        },
        {
            'name': 'robot2',
            'x_pose': 0.0,
            'y_pose': -0.5,
            'z_pose': 0.01,
            'roll': 0.0,
            'pitch': 0.0,
            'yaw': 0.0,
        },
    ]
 
    # Simulation settings
    world = LaunchConfiguration('world')
 
    # On this example all robots are launched with the same settings
    map_yaml_file = LaunchConfiguration('map')
    graph_filepath = LaunchConfiguration('graph')
 
    autostart = LaunchConfiguration('autostart')
    rviz_config_file = LaunchConfiguration('rviz_config')
    use_robot_state_pub = LaunchConfiguration('use_robot_state_pub')
    use_rviz = LaunchConfiguration('use_rviz')
    log_settings = LaunchConfiguration('log_settings', default='true')
 
    # Declare the launch arguments
    declare_world_cmd = DeclareLaunchArgument(
        'world',
        default_value=os.path.join(sim_dir, 'worlds', 'tb3_sandbox.sdf.xacro'),
        description='Full path to world file to load',
    )
 
    declare_map_yaml_cmd = DeclareLaunchArgument(
        'map',
        default_value=os.path.join(bringup_dir, 'maps', 'tb3_sandbox.yaml'),
        description='Full path to map file to load',
    )
 
    declare_graph_file_cmd = DeclareLaunchArgument(
        'graph',
        default_value=os.path.join(bringup_dir, 'graphs', 'turtlebot3_graph.geojson'),
    )
 
    declare_robot1_params_file_cmd = DeclareLaunchArgument(
        'robot1_params_file',
        default_value=os.path.join(
            bringup_dir, 'params', 'nav2_params.yaml'
        ),
        description='Full path to the ROS2 parameters file to use for robot1 launched nodes',
    )
 
    declare_robot2_params_file_cmd = DeclareLaunchArgument(
        'robot2_params_file',
        default_value=os.path.join(
            bringup_dir, 'params', 'nav2_params.yaml'
        ),
        description='Full path to the ROS2 parameters file to use for robot2 launched nodes',
    )
 
    declare_autostart_cmd = DeclareLaunchArgument(
        'autostart',
        default_value='false',
        description='Automatically startup the stacks',
    )
 
    declare_rviz_config_file_cmd = DeclareLaunchArgument(
        'rviz_config',
        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'
    )
 
    # Start Gazebo with plugin providing the robot spawning service
    world_sdf = tempfile.mktemp(prefix='nav2_', suffix='.sdf')
    world_sdf_xacro = ExecuteProcess(
        cmd=['xacro', '-o', world_sdf, ['headless:=', 'False'], world])
    start_gazebo_cmd = ExecuteProcess(
        cmd=['gz', 'sim', '-r', '-s', world_sdf],
        output='screen',
    )
 
    remove_temp_sdf_file = RegisterEventHandler(event_handler=OnShutdown(
        on_shutdown=[
            OpaqueFunction(function=lambda _: os.remove(world_sdf))
        ]))
 
    # Define commands for launching the navigation instances
    nav_instances_cmds = []
    for robot in robots:
        params_file = LaunchConfiguration(f"{robot['name']}_params_file")
 
        group = GroupAction(
            [
                IncludeLaunchDescription(
                    PythonLaunchDescriptionSource(
                        os.path.join(launch_dir, 'rviz_launch.py')
                    ),
                    condition=IfCondition(use_rviz),
                    launch_arguments={
                        'namespace': TextSubstitution(text=robot['name']),
                        'rviz_config': rviz_config_file,
                    }.items(),
                ),
                IncludeLaunchDescription(
                    PythonLaunchDescriptionSource(
                        os.path.join(bringup_dir, 'launch', 'tb3_simulation_launch.py')
                    ),
                    launch_arguments={
                        'namespace': robot['name'],
                        'map': map_yaml_file,
                        'graph': graph_filepath,
                        'use_sim_time': 'True',
                        'params_file': params_file,
                        'autostart': autostart,
                        'use_rviz': 'False',
                        'use_simulator': 'False',
                        'headless': 'False',
                        'use_robot_state_pub': use_robot_state_pub,
                        'x_pose': TextSubstitution(text=str(robot['x_pose'])),
                        'y_pose': TextSubstitution(text=str(robot['y_pose'])),
                        'z_pose': TextSubstitution(text=str(robot['z_pose'])),
                        'roll': TextSubstitution(text=str(robot['roll'])),
                        'pitch': TextSubstitution(text=str(robot['pitch'])),
                        'yaw': TextSubstitution(text=str(robot['yaw'])),
                        'robot_name': TextSubstitution(text=robot['name']),
                    }.items(),
                ),
                LogInfo(
                    condition=IfCondition(log_settings),
                    msg=['Launching ', robot['name']],
                ),
                LogInfo(
                    condition=IfCondition(log_settings),
                    msg=[robot['name'], ' map yaml: ', map_yaml_file],
                ),
                LogInfo(
                    condition=IfCondition(log_settings),
                    msg=[robot['name'], ' params yaml: ', params_file],
                ),
                LogInfo(
                    condition=IfCondition(log_settings),
                    msg=[robot['name'], ' rviz config file: ', rviz_config_file],
                ),
                LogInfo(
                    condition=IfCondition(log_settings),
                    msg=[
                        robot['name'],
                        ' using robot state pub: ',
                        use_robot_state_pub,
                    ],
                ),
                LogInfo(
                    condition=IfCondition(log_settings),
                    msg=[robot['name'], ' autostart: ', autostart],
                ),
            ]
        )
 
        nav_instances_cmds.append(group)
 
    set_env_vars_resources = AppendEnvironmentVariable(
        'GZ_SIM_RESOURCE_PATH', os.path.join(sim_dir, 'models'))
    set_env_vars_resources2 = AppendEnvironmentVariable(
            'GZ_SIM_RESOURCE_PATH',
            str(Path(os.path.join(sim_dir)).parent.resolve()))
 
    # Create the launch description and populate
    ld = LaunchDescription()
    ld.add_action(set_env_vars_resources)
    ld.add_action(set_env_vars_resources2)
 
    # Declare the launch options
    ld.add_action(declare_world_cmd)
    ld.add_action(declare_map_yaml_cmd)
    ld.add_action(declare_graph_file_cmd)
    ld.add_action(declare_robot1_params_file_cmd)
    ld.add_action(declare_robot2_params_file_cmd)
    ld.add_action(declare_use_rviz_cmd)
    ld.add_action(declare_autostart_cmd)
    ld.add_action(declare_rviz_config_file_cmd)
    ld.add_action(declare_use_robot_state_pub_cmd)
 
    # Add the actions to start gazebo, robots and simulations
    ld.add_action(world_sdf_xacro)
    ld.add_action(start_gazebo_cmd)
    ld.add_action(remove_temp_sdf_file)
 
    for simulation_instance_cmd in nav_instances_cmds:
        ld.add_action(simulation_instance_cmd)
 
    return ld