ROS2机器人实验报告提示05➡寻路⬅Nav2
上一节,构建了有机器人和一些障碍物仿真元宇宙。
如何让机器人具备自主导航的能力呢???
先介绍偷懒的方式:
安装turtlesim3包,然后使用官方教程即可。
- sudo apt update
- sudo apt install ros-galactic-turtlebot3-gazebo ros-galactic-turtlebot3-msgs ros-galactic-turtlebot3-simulations
直接运行:
- ros2 launch nav2_bringup tb3_simulation_launch.py
查看是否报错!
如果打不开,多尝试几次!
export TURTLEBOT3_MODEL=waffle
export GAZEBO_MODEL_PATH=$GAZEBO_MODEL_PATH:/opt/ros/galactic/share/turtlebot3_gazebo/models
如上环境一定要争取配置,推荐添加到bash文件中。
更多内容参考博客相关章节或观看钉钉直播课回放。
思考题:
对比ros2 launch nav2_bringup tb3_simulation_launch.py和ros2 launch sam_bot_description display.launch.py。
实现机器人自动导航,需要哪些功能包,如何实现。
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.
-
- """This is all-in-one launch script intended for use by nav2 developers."""
-
- import os
-
- from ament_index_python.packages import get_package_share_directory
-
- from launch import LaunchDescription
- from launch.actions import DeclareLaunchArgument, ExecuteProcess, IncludeLaunchDescription
- from launch.conditions import IfCondition
- from launch.launch_description_sources import PythonLaunchDescriptionSource
- from launch.substitutions import LaunchConfiguration, PythonExpression
- from launch_ros.actions import Node
-
-
- def generate_launch_description():
- # Get the launch directory
- bringup_dir = get_package_share_directory('nav2_bringup')
- launch_dir = os.path.join(bringup_dir, 'launch')
-
- # Create the launch configuration variables
- slam = LaunchConfiguration('slam')
- namespace = LaunchConfiguration('namespace')
- use_namespace = LaunchConfiguration('use_namespace')
- map_yaml_file = LaunchConfiguration('map')
- use_sim_time = LaunchConfiguration('use_sim_time')
- params_file = LaunchConfiguration('params_file')
- autostart = LaunchConfiguration('autostart')
-
- # Launch configuration variables specific to simulation
- rviz_config_file = LaunchConfiguration('rviz_config_file')
- use_simulator = LaunchConfiguration('use_simulator')
- use_robot_state_pub = LaunchConfiguration('use_robot_state_pub')
- use_rviz = LaunchConfiguration('use_rviz')
- headless = LaunchConfiguration('headless')
- world = LaunchConfiguration('world')
-
- # Map fully qualified names 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
- # https://github.com/ros/geometry2/issues/32
- # https://github.com/ros/robot_state_publisher/pull/30
- # TODO(orduno) Substitute with `PushNodeRemapping`
- # https://github.com/ros2/launch_ros/issues/56
- remappings = [('/tf', 'tf'),
- ('/tf_static', 'tf_static')]
-
- # Declare the launch arguments
- declare_namespace_cmd = DeclareLaunchArgument(
- 'namespace',
- default_value='',
- description='Top-level namespace')
-
- declare_use_namespace_cmd = DeclareLaunchArgument(
- 'use_namespace',
- default_value='false',
- description='Whether to apply a namespace to the navigation stack')
-
- declare_slam_cmd = DeclareLaunchArgument(
- 'slam',
- default_value='False',
- description='Whether run a SLAM')
-
- 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_use_sim_time_cmd = DeclareLaunchArgument(
- 'use_sim_time',
- default_value='true',
- description='Use simulation (Gazebo) clock if true')
-
- 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_autostart_cmd = DeclareLaunchArgument(
- 'autostart', default_value='true',
- description='Automatically startup the nav2 stack')
-
- declare_rviz_config_file_cmd = DeclareLaunchArgument(
- 'rviz_config_file',
- default_value=os.path.join(
- bringup_dir, 'rviz', 'nav2_default_view.rviz'),
- description='Full path to the RVIZ config file to use')
-
- declare_use_simulator_cmd = DeclareLaunchArgument(
- 'use_simulator',
- default_value='True',
- description='Whether to start the simulator')
-
- 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')
-
- declare_simulator_cmd = DeclareLaunchArgument(
- 'headless',
- default_value='False',
- description='Whether to execute gzclient)')
-
- declare_world_cmd = DeclareLaunchArgument(
- 'world',
- # TODO(orduno) Switch back once ROS argument passing has been fixed upstream
- # https://github.com/ROBOTIS-GIT/turtlebot3_simulations/issues/91
- # default_value=os.path.join(get_package_share_directory('turtlebot3_gazebo'),
- # worlds/turtlebot3_worlds/waffle.model')
- default_value=os.path.join(bringup_dir, 'worlds', 'waffle.model'),
- description='Full path to world model file to load')
-
- # Specify the actions
- start_gazebo_server_cmd = ExecuteProcess(
- condition=IfCondition(use_simulator),
- cmd=['gzserver', '-s', 'libgazebo_ros_init.so', world],
- cwd=[launch_dir], output='screen')
-
- start_gazebo_client_cmd = ExecuteProcess(
- condition=IfCondition(PythonExpression(
- [use_simulator, ' and not ', headless])),
- cmd=['gzclient'],
- cwd=[launch_dir], output='screen')
-
- urdf = os.path.join(bringup_dir, 'urdf', 'turtlebot3_waffle.urdf')
-
- start_robot_state_publisher_cmd = Node(
- condition=IfCondition(use_robot_state_pub),
- package='robot_state_publisher',
- executable='robot_state_publisher',
- name='robot_state_publisher',
- namespace=namespace,
- output='screen',
- parameters=[{'use_sim_time': use_sim_time}],
- remappings=remappings,
- arguments=[urdf])
-
- rviz_cmd = IncludeLaunchDescription(
- PythonLaunchDescriptionSource(
- os.path.join(launch_dir, 'rviz_launch.py')),
- condition=IfCondition(use_rviz),
- launch_arguments={'namespace': '',
- 'use_namespace': 'False',
- 'rviz_config': rviz_config_file}.items())
-
- bringup_cmd = IncludeLaunchDescription(
- PythonLaunchDescriptionSource(
- os.path.join(launch_dir, 'bringup_launch.py')),
- launch_arguments={'namespace': namespace,
- 'use_namespace': use_namespace,
- 'slam': slam,
- 'map': map_yaml_file,
- 'use_sim_time': use_sim_time,
- 'params_file': params_file,
- 'autostart': autostart}.items())
-
- # 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_slam_cmd)
- ld.add_action(declare_map_yaml_cmd)
- ld.add_action(declare_use_sim_time_cmd)
- ld.add_action(declare_params_file_cmd)
- ld.add_action(declare_autostart_cmd)
-
- ld.add_action(declare_rviz_config_file_cmd)
- ld.add_action(declare_use_simulator_cmd)
- ld.add_action(declare_use_robot_state_pub_cmd)
- ld.add_action(declare_use_rviz_cmd)
- ld.add_action(declare_simulator_cmd)
- ld.add_action(declare_world_cmd)
-
- # Add any conditioned actions
- ld.add_action(start_gazebo_server_cmd)
- ld.add_action(start_gazebo_client_cmd)
-
- # Add the actions to launch all of the navigation nodes
- ld.add_action(start_robot_state_publisher_cmd)
- ld.add_action(rviz_cmd)
- ld.add_action(bringup_cmd)
-
- return ld
sam_bot_description display.launch.py
- import launch
- from launch.substitutions import Command, LaunchConfiguration
- import launch_ros
- import os
-
- def generate_launch_description():
- pkg_share = launch_ros.substitutions.FindPackageShare(package='sam_bot_description').find('sam_bot_description')
- default_model_path = os.path.join(pkg_share, 'src/description/sam_bot_description.urdf')
- default_rviz_config_path = os.path.join(pkg_share, 'rviz/urdf_config.rviz')
- world_path=os.path.join(pkg_share, 'world/my_world.sdf')
-
- robot_state_publisher_node = launch_ros.actions.Node(
- package='robot_state_publisher',
- executable='robot_state_publisher',
- parameters=[{'robot_description': Command(['xacro ', LaunchConfiguration('model')])}]
- )
- joint_state_publisher_node = launch_ros.actions.Node(
- package='joint_state_publisher',
- executable='joint_state_publisher',
- name='joint_state_publisher',
- condition=launch.conditions.UnlessCondition(LaunchConfiguration('gui'))
- )
- rviz_node = launch_ros.actions.Node(
- package='rviz2',
- executable='rviz2',
- name='rviz2',
- output='screen',
- arguments=['-d', LaunchConfiguration('rvizconfig')],
- )
- spawn_entity = launch_ros.actions.Node(
- package='gazebo_ros',
- executable='spawn_entity.py',
- arguments=['-entity', 'sam_bot', '-topic', 'robot_description'],
- output='screen'
- )
- robot_localization_node = launch_ros.actions.Node(
- package='robot_localization',
- executable='ekf_node',
- name='ekf_filter_node',
- output='screen',
- parameters=[os.path.join(pkg_share, 'config/ekf.yaml'), {'use_sim_time': LaunchConfiguration('use_sim_time')}]
- )
-
- return launch.LaunchDescription([
- launch.actions.DeclareLaunchArgument(name='gui', default_value='True',
- description='Flag to enable joint_state_publisher_gui'),
- launch.actions.DeclareLaunchArgument(name='model', default_value=default_model_path,
- description='Absolute path to robot urdf file'),
- launch.actions.DeclareLaunchArgument(name='rvizconfig', default_value=default_rviz_config_path,
- description='Absolute path to rviz config file'),
- launch.actions.DeclareLaunchArgument(name='use_sim_time', default_value='True',
- description='Flag to enable use_sim_time'),
- launch.actions.ExecuteProcess(cmd=['gazebo', '--verbose', '-s', 'libgazebo_ros_factory.so', world_path], output='screen'),
-
- joint_state_publisher_node,
- robot_state_publisher_node,
- spawn_entity,
- robot_localization_node,
- rviz_node
- ])
能否修改sam_bot_description display.launch.py,是其不仅具备SLAM还具备导航功能呢?
?_?
^_^
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