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.
 
import os
 
from ament_index_python.packages import get_package_share_directory
from launch import LaunchDescription
from launch.actions import DeclareLaunchArgument
from launch.substitutions import LaunchConfiguration
from launch_ros.actions import Node
 
 
def generate_launch_description() -> LaunchDescription:
    bringup_dir = get_package_share_directory('nav2_bringup')
    params_file = LaunchConfiguration('params_file')
    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',
    )
 
    scan_frame_id = LaunchConfiguration('scan_frame_id')
    declare_scan_frame_id_cmd = DeclareLaunchArgument(
        'scan_frame_id',
        default_value='base_scan',
    )
 
    loopback_sim_cmd = Node(
        package='nav2_loopback_sim',
        executable='loopback_simulator',
        name='loopback_simulator',
        output='screen',
        parameters=[params_file, {'scan_frame_id': scan_frame_id}],
    )
 
    ld = LaunchDescription()
    ld.add_action(declare_scan_frame_id_cmd)
    ld.add_action(declare_params_file_cmd)
    ld.add_action(loopback_sim_cmd)
    return ld