def generate_launch_description():
# Get the launch directory
bringup_dir = get_package_share_directory('amazon_robot_bringup')
# Create the launch configuration variables
namespace = LaunchConfiguration('namespace')
use_namespace = LaunchConfiguration('use_namespace')
rviz_config_file = LaunchConfiguration('rviz_config')
# Declare the launch arguments
declare_namespace_cmd = DeclareLaunchArgument(
'namespace',
default_value='navigation',
description=('Top-level namespace. The value will be used to replace the '
'<robot_namespace> keyword on the rviz config file.'))
declare_use_namespace_cmd = DeclareLaunchArgument(
'use_namespace',
default_value='false',
description='Whether to apply a namespace to the navigation stack')
declare_rviz_config_file_cmd = DeclareLaunchArgument(
'rviz_config',
default_value=os.path.join(bringup_dir, 'rviz', 'amazon_robot_default_view.rviz'),
description='Full path to the RVIZ config file to use')
# Launch rviz
start_rviz_cmd = Node(
condition=UnlessCondition(use_namespace),
package='rviz2',
executable='rviz2',
name='rviz2',
arguments=['-d', rviz_config_file],
output='screen')
namespaced_rviz_config_file = ReplaceString(
source_file=rviz_config_file,
replacements={'<robot_namespace>': ('/', namespace)})
start_namespaced_rviz_cmd = Node(
condition=IfCondition(use_namespace),
package='rviz2',
executable='rviz2',
name='rviz2',
namespace=namespace,
arguments=['-d', namespaced_rviz_config_file],
output='screen',
remappings=[('/tf', 'tf'),
('/tf_static', 'tf_static'),
('/goal_pose', 'goal_pose'),
('/clicked_point', 'clicked_point'),
('/initialpose', 'initialpose')])
exit_event_handler = RegisterEventHandler(
condition=UnlessCondition(use_namespace),
event_handler=OnProcessExit(
target_action=start_rviz_cmd,
on_exit=EmitEvent(event=Shutdown(reason='rviz exited'))))
exit_event_handler_namespaced = RegisterEventHandler(
condition=IfCondition(use_namespace),
event_handler=OnProcessExit(
target_action=start_namespaced_rviz_cmd,
on_exit=EmitEvent(event=Shutdown(reason='rviz exited'))))
# 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_rviz_config_file_cmd)
# Add any conditioned actions
ld.add_action(start_rviz_cmd)
ld.add_action(start_namespaced_rviz_cmd)
# Add other nodes and processes we need
ld.add_action(exit_event_handler)
ld.add_action(exit_event_handler_namespaced)
return ld
def generate_launch_description():
# Get the launch directory
bringup_dir = get_package_share_directory('nav2_bringup')
# Names and poses of the robots
robots = [{
'name': 'robot1',
'x_pose': 0.0,
'y_pose': 0.5,
'z_pose': 0.01
}, {
'name': 'robot2',
'x_pose': 0.0,
'y_pose': -0.5,
'z_pose': 0.01
}]
# Simulation settings
world = LaunchConfiguration('world')
simulator = LaunchConfiguration('simulator')
# On this example all robots are launched with the same settings
map_yaml_file = LaunchConfiguration('map')
params_file = LaunchConfiguration('params_file')
bt_xml_file = LaunchConfiguration('bt_xml_file')
rviz_config_file = LaunchConfiguration('rviz_config')
log_settings = LaunchConfiguration('log_settings', default='true')
# Declare the launch arguments
declare_world_cmd = DeclareLaunchArgument(
'world',
default_value=os.path.join(bringup_dir, 'worlds', 'world_only.model'),
description='Full path to world file to load')
declare_simulator_cmd = DeclareLaunchArgument(
'simulator',
default_value='gazebo',
description='The simulator to use (gazebo or gzserver)')
declare_map_yaml_cmd = DeclareLaunchArgument(
'map',
default_value=os.path.join(bringup_dir, 'maps',
'turtlebot3_world.yaml'),
description='Full path to map file to load')
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_bt_xml_cmd = DeclareLaunchArgument(
'bt_xml_file',
default_value=os.path.join(
get_package_share_directory('nav2_bt_navigator'), 'behavior_trees',
'navigate_w_replanning_and_recovery.xml'),
description='Full path to the behavior tree xml file to use')
declare_rviz_config_file_cmd = DeclareLaunchArgument(
'rviz_config',
default_value=os.path.join(bringup_dir, 'rviz',
'nav2_namespaced_view.rviz'),
description='Full path to the RVIZ config file to use')
# Start Gazebo with plugin providing the robot spawing service
start_gazebo_cmd = ExecuteProcess(
cmd=[simulator, '--verbose', '-s', 'libgazebo_ros_factory.so', world],
output='screen')
# Define commands for spawing the robots into Gazebo
spawn_robots_cmds = []
for robot in robots:
spawn_robots_cmds.append(
IncludeLaunchDescription(
PythonLaunchDescriptionSource(
os.path.join(bringup_dir, 'launch',
'spawn_robot_launch.py')),
launch_arguments={
'x_pose': TextSubstitution(text=str(robot['x_pose'])),
'y_pose': TextSubstitution(text=str(robot['y_pose'])),
'z_pose': TextSubstitution(text=str(robot['z_pose'])),
'robot_name': robot['name'],
'turtlebot_type': TextSubstitution(text='waffle')
}.items()))
# Define commands for launching the navigation instances
nav_instances_cmds = []
for robot in robots:
namespaced_rviz_config_file = ReplaceString(
source_file=rviz_config_file,
replacements={'<robot_namespace>': ('/' + robot['name'])})
group = GroupAction([
# TODO(orduno)
# Each `action.Node` within the `localization` and `navigation` launch
# files has two versions, one with the required remaps and another without.
# The `use_remappings` flag specifies which runs.
# A better mechanism would be to have a PushNodeRemapping() action:
# https://github.com/ros2/launch_ros/issues/56
# For more on why we're remapping topics, see the note below
# PushNodeRemapping(remappings)
# Instances use the robot's name for namespace
PushRosNamespace(robot['name']),
IncludeLaunchDescription(
PythonLaunchDescriptionSource(
os.path.join(bringup_dir, 'launch',
'nav2_tb3_simulation_launch.py')),
launch_arguments={
# TODO(orduno) might not be necessary to pass the robot name
'namespace': robot['name'],
'map_yaml_file': map_yaml_file,
'use_sim_time': 'True',
'params_file': params_file,
'bt_xml_file': bt_xml_file,
'autostart': 'False',
'use_remappings': 'True',
'rviz_config_file': namespaced_rviz_config_file,
'use_simulator': 'False'
}.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'], ' behavior tree xml: ', bt_xml_file]),
LogInfo(condition=IfCondition(log_settings),
msg=[
robot['name'], ' rviz config file: ',
namespaced_rviz_config_file
])
])
nav_instances_cmds.append(group)
# A note on the `remappings` variable defined above and the fact it's passed as a node arg.
# A few topics have fully qualified names (have a leading '/'), these need to be remapped
# to relative ones so the node's namespace can be prepended.
# In case of the transforms (tf), currently, there doesn't seem to be a better alternative
# for multi-robot transforms:
# https://github.com/ros/geometry2/issues/32
# https://github.com/ros/robot_state_publisher/pull/30
# Create the launch description and populate
ld = LaunchDescription()
# Declare the launch options
ld.add_action(declare_simulator_cmd)
ld.add_action(declare_world_cmd)
ld.add_action(declare_map_yaml_cmd)
ld.add_action(declare_params_file_cmd)
ld.add_action(declare_bt_xml_cmd)
ld.add_action(declare_rviz_config_file_cmd)
# Add the actions to start gazebo, robots and simulations
ld.add_action(start_gazebo_cmd)
for spawn_robot_cmd in spawn_robots_cmds:
ld.add_action(spawn_robot_cmd)
for simulation_instance_cmd in nav_instances_cmds:
ld.add_action(simulation_instance_cmd)
return ld