ROS2机器人实验报告提示04➡开山⬅Nav2

Posted 2021-12-04 zhangrelay

ROS2基础部分实验内容详细描述分别在前3次提示中。涉及文档如下所示：

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本节开始，主要涉及文档如下图所示：

如果不熟悉，请看直播回放，并且依据回放中的方法进行练习，注意直播时ROS2版本为foxy，镜像中是 galactic。

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本节涉及代码在如下文件夹：

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参考：

所有代码都已调试通过，但最好按文档自学一遍，这样才能掌握。

测试案例：

. install/setup.bash

ros2 launch sam_bot_description display.launch.py

ros2 launch slam_toolbox online_async_launch.py

ros2 run tf2_tools view_frames.py

ros2 launch nav2_bringup navigation_launch.py

ros2 run nav2_costmap_2d nav2_costmap_2d_markers voxel_grid:=/local_costmap/voxel_grid visualization_marker:=/my_marker

本部分详细介绍参考钉钉直播回放和

Nav2官方教程➡First-Time Robot Setup Guide⬅搞不定

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添加激光主题查看效果。

修改一下：

 

如遇到问题独立思考。 

自主完成实验。 

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
    ])

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