cps_loki_bringup/launch/robot_localization.launch.py

# Copyright 2022 Factor Robotics
#
# 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 launch import LaunchDescription
from launch.substitutions import Command, FindExecutable, PathJoinSubstitution
from launch_ros.actions import Node
from launch_ros.substitutions import FindPackageShare
from ament_index_python.packages import get_package_share_directory
from launch_ros.actions import LifecycleNode
from launch_ros.descriptions import ParameterValue
from launch.substitutions import LaunchConfiguration

from launch.substitutions import LaunchConfiguration, PythonExpression
from launch.actions import DeclareLaunchArgument, GroupAction, SetEnvironmentVariable

def generate_launch_description():

    namespace = LaunchConfiguration('namespace')
    use_sim_time = LaunchConfiguration('use_sim_time')

    declare_namespace_cmd = DeclareLaunchArgument(
        'namespace',
        default_value='',
        description='Top-level namespace')

    declare_use_sim_time_cmd = DeclareLaunchArgument(
        'use_sim_time',
        default_value='false',
        description='Use simulation (Gazebo) clock if true')

    robot_localization_node = Node(
       package='robot_localization',
       executable='ekf_node',
       name='ekf_filter_node',
       output='screen',
       parameters = [ PathJoinSubstitution(
                [
                    FindPackageShare("cps_loki_bringup"),
                    "config",
                    "ekf.yaml"
                ]
            ) ,
            {'use_sim_time': LaunchConfiguration('use_sim_time')}
            ],
        namespace=namespace
    )

    return LaunchDescription([
        robot_localization_node
    ])