使用机器人操作系统ROS 2和仿真软件Gazebo 9环境综合测试教程（三）

在完成教程（一）搭建机器人和（二）命令遥控可视化后，将仿真机器人用于更为逼真的环境，可以测试如SLAM，区域覆盖以及场馆巡逻算法，这里环境均采用aws提供模型，分别为smallhouse和bookstore，环境适用于ROS2和ROS1全部案例，但ROS1内容不做讲解，这里只简要叙述一下ROS2中调试和使用的过程。

在环境中添加机器人模型：

在launch中添加机器人需要注意如上差异，如添加一个urdf格式机器人可参考如下命令：

ros2 service call /spawn_entity 'gazebo_msgs/SpawnEntity' '{name: "urdf_ball", xml: "<?xml version=\"1.0\" ?><robot name=\"will_be_ignored\"><link name=\"link\"><visual><geometry><sphere radius=\"1.0\"/></geometry></visual><inertial><mass value=\"1\"/><inertia ixx=\"1\" ixy=\"0.0\" ixz=\"0.0\" iyy=\"1\" iyz=\"0.0\" izz=\"1\"/></inertial></link></robot>"}'

更多内容参考：https://github.com/ros-simulation/gazebo_ros_pkgs/wiki/ROS-2-Migration:-Spawn-and-delete

如果需要在制定位置插入机器人，需要查阅spawn_entity.py源码：

  
  

   
   

    
    

     
     

    
    
    
    

     
     
 # Encode xml object back into string for service call
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     

      
       entity_xml = ElementTree.tostring(xml_parsed)
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 # Form requested Pose from arguments
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     

      
       initial_pose = Pose()
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     

      
       initial_pose.position.x = float(self.args.x)
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     

      
       initial_pose.position.y = float(self.args.y)
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     

      
       initial_pose.position.z = float(self.args.z)
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     

      
       q = quaternion_from_euler(self.args.R, self.args.P, self.args.Y)
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     

      
       initial_pose.orientation.w = q[0]
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     

      
       initial_pose.orientation.x = q[1]
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     

      
       initial_pose.orientation.y = q[2]
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     

      
       initial_pose.orientation.z = q[3]
     
     
    
    
  
  
 
 

注意这里的initial_pose和表中参数的对应情况，不再赘述。

mobot加入smallhouse场景如下所示，支持多机器人！后续补充：

可以在此环境中复习，前2课所学过的全部内容。

启动文件smallhouse.launch.py代码如下：

  
  

   
   

    
    

     
     

    
    
    
    

     
     

      import os
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     

      from ament_index_python.packages import get_package_share_directory
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     

      from launch import LaunchDescription
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     

      from launch.actions import ExecuteProcess, DeclareLaunchArgument
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     

      from launch.actions import IncludeLaunchDescription
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     

      from launch_ros.actions import Node
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     

      from launch.conditions import IfCondition
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     

      from launch.launch_description_sources import PythonLaunchDescriptionSource
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     

      from launch.substitutions import LaunchConfiguration
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     

      # this is the function launch system will look for
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     

      def generate_launch_description():
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     

      
       robot_name = 'mobot'
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     

      
       world_file_name = 'smallhouse.world'
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 # full path to urdf and world file
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     

      
       world = os.path.join(get_package_share_directory(robot_name), 'worlds', world_file_name)
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     

      
       urdf = os.path.join(get_package_share_directory(robot_name), 'urdf', 'mobot.urdf')
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 # read urdf contents because to spawn an entity in 
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 # gazebo we need to provide entire urdf as string on command line
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 #small_house = launch.actions.IncludeLaunchDescription(
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 # launch.launch_description_sources.PythonLaunchDescriptionSource(
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 # os.path.join(
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 # get_package_share_directory('aws_robomaker_small_house_world'),
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 # 'launch',
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 # 'small_house.launch.py')))
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 # Spawn mobot
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     

      
       spawn_mobot = Node(
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     

      
       package='gazebo_ros',
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     

      
       node_executable='spawn_entity.py',
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     

      
       node_name='spawn_entity',
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 #node_namespace=namespace_,
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     

      
       output='screen',
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 #emulate_tty=True,
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     

      
       arguments=['-entity',
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 'mobot',
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 '-x', '3.5', '-y', '1.0', '-z', '0.1',
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 '-file', urdf
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     

      
       ]
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     

      
       )
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 #xml = open(urdf, 'r').read()
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 # double quotes need to be with escape sequence
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 #xml = xml.replace('"', '\\"')
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 # this is argument format for spwan_entity service 
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 #spwan_args = '{name: \"mobot\", xml: \"' + xml + '\"}'
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 # create and return launch description object
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 return LaunchDescription([
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 # start gazebo, notice we are using libgazebo_ros_factory.so instead of libgazebo_ros_init.so
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 # That is because only libgazebo_ros_factory.so contains the service call to /spawn_entity
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     

      
       ExecuteProcess(
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     

      
       cmd=['gazebo', '--verbose', world, '-s', 'libgazebo_ros_factory.so'],
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     

      
       output='screen'),
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 # tell gazebo to spwan your robot in the world by calling service
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 # ExecuteProcess(
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 # cmd=['ros2', 'service', 'call', '/spawn_entity', 'gazebo_msgs/SpawnEntity', spwan_args],
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 # output='screen'),
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 #small_house,
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     

      
       spawn_mobot,
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     
 
     
     
    
    
   
   

    
    

     
     

    
    
    
    

     
     

      
       ])
     
     
    
    
  
  
 
 

机器人初始位置为x: 3.5 y: 1.0 z: 0.1，参考如下文档片段：

Robot Simulation - Initial Position

Do not use (0,0,0) for the initial position as it will collide with the lounge chairs. Instead, a resonable position is (3.5,1.0,0.0).

机器人可以加载已有的ROS2功能包，如导航功能包等。

具体参考：2020年ROS机器人操作系统用户官方调查 文末的介绍。

关于环境综合测试更多截图如下所示：

smallhouse：

navigation2:

bookstore:

navigation2:

下一节将讲解如何制作一个跟随机器人～mobot-follow～

文章来源: zhangrelay.blog.csdn.net，作者：zhangrelay，版权归原作者所有，如需转载，请联系作者。

原文链接：zhangrelay.blog.csdn.net/article/details/105707950