m-explore-ros2/explore/launch/explore.launch.py

import os

from ament_index_python.packages import get_package_share_directory
from launch_ros.actions import Node

from launch import LaunchDescription
from launch.actions import DeclareLaunchArgument
from launch.substitutions import LaunchConfiguration


def generate_launch_description():
    ld = LaunchDescription()
    config = os.path.join(
        get_package_share_directory("explore_lite"), "config", "params.yaml"
    )
    use_sim_time = LaunchConfiguration("use_sim_time")

    declare_use_sim_time_argument = DeclareLaunchArgument(
        "use_sim_time", default_value="true", description="Use simulation/Gazebo clock"
    )

    node = Node(
        package="explore_lite",
        name="explore_node",
        executable="explore",
        parameters=[config, {"use_sim_time": use_sim_time}],
        output="screen",
    )
    ld.add_action(declare_use_sim_time_argument)
    ld.add_action(node)
    return ld