《鸿蒙机器人编程》4-实践课-建造自己机器人的3D模型-实训指南

建造自己机器人的3D模型课程内容： 本节主要介绍机器人仿真的相关内容，结合Rviz和Gazebo进行集成使用教学目标：掌握在Rviz中显示机器人模型掌握在Gazebo中显示机器人模型掌握如何在Gazebo中控制机器人运动一．在Rviz中显示机器人模型实现流程：第一步（准备）：新建功能包，导入依赖第二步（核心）：编写urdf文件第三步（核心）：在launch文件集成URDF与RViz第四步（结果）：在RViz中显示机器人模型1.新建功能包首先进入工作空间catkin_ws的src目录下，创建名为“spark_description”的功能包，并为其导入相关依赖$cdcatkin_ws/src/$catkin_create_pkgspark_descriptionroscpprospyurdftfgeometry_msgsstd_msgs2.编写urdf文件（用urdf构建一台极简的spark机器人模型）①进入spark_description功能包，创建urdf文件夹，用于存放urdf文件。$cdspark_description$mkdirurdf②导入机器人模型素材，在项目源代码中将meshes文件夹复制到此功能包下项目源码路径：复制到创建的功能包下：③创建urdf文件（spark_description_simple.urdf）将项目源代码中的spak_description_simple.urdf文件复制到urdf文件夹下我们首先创建一个urdf文件去描述一台极简的spark机器人，用robot标签将机器人各部分包含进来。起名为sparkbase，每部分用link标签去表示，分别用joint将各部分连接。下面是详细代码：<robotname="spark_base"> <linkname="base_footprint"/> <linkname="base_link"> <visual> <origin xyz="000" rpy="000"/> <geometry> <mesh filename="package://spark_description/meshes/spark/base/spark_base.DAE"/> </geometry> </visual> </link> <jointname="base_joint"type="fixed"> <origin xyz="000.01" rpy="000"/> <parentlink="base_footprint"/> <childlink="base_link"/> </joint> <linkname="left_wheel_link"> <visual> <origin xyz="000" rpy="000"/> <geometry> <mesh filename="package://spark_description/meshes/spark/base/left_wheel.DAE"/> </geometry> </visual> </link> <jointname="left_wheel_joint"type="continuous"> <origin xyz="0-0.1310.024" rpy="000"/> <axisxyz="010"/> <parentlink="base_link"/> <childlink="left_wheel_link"/> </joint> <linkname="right_wheel_link"> <visual> <origin xyz="000" rpy="000"/> <geometry> <mesh filename="package://spark_description/meshes/spark/base/right_wheel.DAE"/> </geometry> </visual> </link> <jointname="right_wheel_joint"type="continuous"> <origin xyz="00.1310.024"rpy="000"/> <axisxyz="010"/> <parentlink="base_link"/> <childlink="right_wheel_link"/> </joint> <linkname="spark_stack"><visual><origin xyz="000"rpy="000"/><geometry><meshfilename="package://spark_description/meshes/spark/stack/spark_stack.DAE"/></geometry></visual></link><jointname="spark_stack_joint"type="fixed"><origin xyz="000" rpy="000"/><parentlink="base_link"/><childlink="spark_stack"/></joint></robot>3.在launch文件集成URDF与RViz①创建launch文件夹，用于存放launch文件$mkdirlaunch$cdlaunch②创建launch文件将项目源代码中的spark_description_simple.launch文件复制到此launch文件夹中③导入Rviz环境，将项目源代码中的rviz文件夹复制到功能包下用urdf文件描述出机器人的基本信息后，我们就可以在rviz里面通过launch文件来启动它。launch文件中，根标签就是launch，然后定义几个在launch文件里面用到的参数。model就是机器人的模型描述文件；usegui表示是否使用gui；publishdefaultpositions表示是否发布这个位置信息。然后我们用一个param标签来将model上传到参数服务器，命名为robotdescription。launch文件的具体编写如下：<launch><argname="model"default="$(findspark_description)/urdf/teaching/spark_description_simple.urdf"/><argname="use_gui"default="false"/><argname="publish_default_positions"default="true"/><paramname="robot_description"command="$(findxacro)/xacro$(argmodel)"/><nodename="joint_state_publisher"pkg="joint_state_publisher"type="joint_state_publisher"> <paramname="use_gui"value="$(arguse_gui)"/> <paramname="publish_default_positions"value="$(argpublish_default_positions)"/> <rosparamparam="source_list">["wheel_states"]</rosparam></node><nodename="robot_state_publisher"pkg="robot_state_publisher"type="robot_state_publisher"/><nodepkg="rviz"type="rviz"name="rviz"args="-d$(findurdf_demo_rviz)/config/urdf.rviz"/></launch>4.在RViz中显示机器人模型用下列命令，启动构造好的spark机器人：$cdcatkin_ws$sourcedevel/setup.bash$roslaunchspark_descriptionspark_description_simple.launch下面是运行界面截图：二．在Gazebo中显示机器人模型实现流程：第一步（核心）：编写urdf文件第二步（核心）：编写launch文件第三步（结果）：在Gazebo中显示机器人模型1.编写urdf文件将项目源代码中的spark_description_gazebo_simple.urdf文件复制到此urdf文件夹中如何修改上面的urdf文件使机器人在Gazebo中显示？必须步骤

：在每一个<link>内添加<inertia>标签。可选步骤

：在每一个<link>内添加<gazebo>标签。将外观颜色转换成Gazebo格式；将stl文件转换成dae文件，获得更好的渲染效果；添加传感器插件。在<robot>标签内添加<gazebo>。为了防止机器人陷入障碍物，我们增加了碰撞模型标签。此标签设置了碰撞模型的位置、姿态以及碰撞几何体，以便机器人能够进行碰撞检测。具体代码如下：<robotname="spark"> <linkname="base_footprint"/> <linkname="base_link"> <inertial> <origin xyz="000"rpy="000"/> <mass value="0.916261377"/> <inertiaixx="0.001"ixy="0.0"ixz="0.0" iyy="0.001"iyz="0.0" izz="0.001"/> </inertial> <visual> <origin xyz="000" rpy="000"/> <geometry> <mesh filename="package://spark_description/meshes/spark/base/spark_base.DAE"/> </geometry> </visual> <collision> <origin xyz="000"rpy="000"/> <geometry> <mesh filename="package://spark_description/meshes/spark/base/spark_base.DAE"/> </geometry> </collision> </link> <jointname="base_joint"type="fixed"> <origin xyz="000.01" rpy="000"/> <parentlink="base_footprint"/> <childlink="base_link"/> </joint> <linkname="left_wheel_link"> <inertial> <massvalue="0.01"/> <originxyz="000"/> <inertiaixx="0.001"ixy="0.0"ixz="0.0" iyy="0.001"iyz="0.0" izz="0.001"/> </inertial> <visual> <origin xyz="000"rpy="000"/> <geometry> <mesh filename="package://spark_description/meshes/spark/base/left_wheel.DAE"/> </geometry> </visual> <collision> <origin xyz="000" rpy="000"/> <geometry> <mesh filename="package://spark_description/meshes/spark/base/left_wheel.DAE"/> </geometry> </collision> </link> <jointname="left_wheel_joint"type="continuous"> <origin xyz="0-0.1310.024"rpy="000"/> <axisxyz="010"/> <parentlink="base_link"/> <childlink="left_wheel_link"/> </joint> <linkname="right_wheel_link"> <inertial> <massvalue="0.01"/> <originxyz="000"/> <inertiaixx="0.001"ixy="0.0"ixz="0.0" iyy="0.001"iyz="0.0" izz="0.001"/> </inertial> <visual> <origin xyz="000" rpy="000"/> <geometry> <mesh filename="package://spark_description/meshes/spark/base/right_wheel.DAE"/> </geometry> </visual> <collision> <origin xyz="000"rpy="000"/> <geometry> <mesh filename="package://spark_description/meshes/spark/base/right_wheel.DAE"/> </geometry> </collision> </link> <jointname="right_wheel_joint"type="continuous"> <origin xyz="00.1310.024"rpy="000"/> <axisxyz="010"/> <parentlink="base_link"/> <childlink="right_wheel_link"/> </joint><linkname="spark_stack"><inertial><origin xyz="000" rpy="000"/><massvalue="0.224592038"/><inertiaixx="0.052467491"ixy="-0.000000000"ixz="0.001956704"iyy="0.055610919"iyz="0.000000000"izz="0.012118046"/></inertial><visual><origin xyz="000" rpy="000"/><geometry><meshfilename="package://spark_description/meshes/spark/stack/spark_stack.DAE"/></geometry></visual><collision><originxyz="000"rpy="000"/><geometry><meshfilename="package://spark_description/meshes/spark/stack/spark_stack.DAE"/></geometry></collision></link><jointname="spark_stack_joint"type="fixed"><origin xyz="000" rpy="000"/><parentlink="base_link"/><childlink="spark_stack"/></joint><transmissionname="tran1"><type>transmission_interface/SimpleTransmission</type><jointname="left_wheel_joint"><hardwareInterface>VelocityJointInterface</hardwareInterface></joint><actuatorname="motor1"><hardwareInterface>VelocityJointInterface</hardwareInterface><mechanicalReduction>1</mechanicalReduction></actuator></transmission><transmissionname="tran2"><type>transmission_interface/SimpleTransmission</type><jointname="right_wheel_joint"><hardwareInterface>VelocityJointInterface</hardwareInterface></joint><actuatorname="motor2"><hardwareInterface>VelocityJointInterface</hardwareInterface><mechanicalReduction>-1</mechanicalReduction></actuator></transmission><gazebo><pluginname="gazebo_ros_control"filename="libgazebo_ros_control.so"><robotNamespace>/</robotNamespace><robotSimType>gazebo_ros_control/DefaultRobotHWSim</robotSimType></plugin></gazebo> </robot>2.编写launch文件将项目源代码中的spark_gazebo_simple.launch文件复制到此launch文件夹中具体代码如下：<launch><!--thesearetheargumentsyoucanpassthislaunchfile,forexamplepaused:=true--><argname="paused"default="false"/><argname="use_sim_time"default="true"/><argname="gui"default="true"/><argname="headless"default="false"/><argname="debug"default="false"/><!--Weresumethelogicinempty_world.launch--><includefile="$(findgazebo_ros)/launch/empty_world.launch"><argname="debug"value="$(argdebug)"/><argname="gui"value="$(arggui)"/><argname="paused"value="$(argpaused)"/><argname="use_sim_time"value="$(arguse_sim_time)"/><argname="headless"value="$(argheadless)"/></include><!--urdfxmlrobotdescriptionloadedontheParameterServer--><paramname="robot_description"command="$(findxacro)/xacro'$(findspark_description)/urdf/teaching/spark_description_gazebo_simple.urdf'"/><nodename="joint_state_publisher"pkg="joint_state_publisher"type="joint_state_publisher"></node><!--Startingrobotstatepublishwhichwillpublishtf--><nodename="robot_state_publisher"pkg="robot_state_publisher"type="robot_state_publisher"output="screen"><paramname="publish_frequency"type="double"value="50.0"/></node><!--Runapythonscripttothesendaservicecalltogazebo_rostospawnaURDFrobot--><nodename="urdf_spawner"pkg="gazebo_ros"type="spawn_model"respawn="false"output="screen" args="-urdf-modelspark-paramrobot_description"/></launch>3.在Gazebo中显示机器人模型用下列命令，将spark机器人模型加载到gazebo：$cdcatkin_ws$sourcedevel/setup.bash$roslaunchspark_descriptionspark_gazebo_simple.launch下面是运行界面截图：三．在gazebo中实现spark机器人的运动仿真实现流程：第一步（核心）：编写urdf文件第二步（核心）：创建控制器配置文件第三步（核心）：编写launch文件第四步（结果）：启动Gazebo并发布spark_controller/cmd_vel消息控制机器人运动1.编写urdf文件将项目源代码中的spark_description_gazebo.urdf文件复制到此urdf文件夹中如何修改上面的urdf文件使机器人在Gazebo中实现运动控制？必须步骤

：向URDF文件中的joint添加<transmission>标签。向URDF文件中添加ros_control插件，并添加相应插件的controller配置文件。可选步骤：

在每一个<link>内添加<gazebo>标签。将外观颜色转换成Gazebo格式；将stl文件转换成dae文件，获得更好的渲染效果；添加传感器插件。在每一个<joint>内添加<gazebo>标签。设置适当的阻尼动力系数；添加执行器控制插件。在<robot>标签内添加<gazebo>。为了完成传动所描述的这种动力驱动，我们需要加载roscontrol这个插件。这里我们用到了gazebo里面的一个插件libgazeboroscontrol。首先要在这个gazebo标签里加上plugin插件的标签，连同设置了你的插件的名字、文件名。这里面还允许你设置机器人的命名空间，还有这个机器人的仿真的类型。具体代码如下：<robotname="spark"> <linkname="base_footprint"/> <linkname="base_link"> <inertial> <origin xyz="000"rpy="000"/> <mass value="0.916261377"/> <inertiaixx="0.001"ixy="0.0"ixz="0.0" iyy="0.001"iyz="0.0" izz="0.001"/> </inertial> <visual> <origin xyz="000" rpy="000"/> <geometry> <mesh filename="package://spark_description/meshes/spark/base/spark_base.DAE"/> </geometry> </visual> <collision> <origin xyz="000"rpy="000"/> <geometry> <mesh filename="package://spark_description/meshes/spark/base/spark_base.DAE"/> </geometry> </collision> </link> <jointname="base_joint"type="fixed"> <origin xyz="000.01" rpy="000"/> <parentlink="base_footprint"/> <childlink="base_link"/> </joint> <linkname="left_wheel_link"> <inertial> <massvalue="0.01"/> <originxyz="000"/> <inertiaixx="0.001"ixy="0.0"ixz="0.0" iyy="0.001"iyz="0.0" izz="0.001"/> </inertial> <visual> <origin xyz="000"rpy="000"/> <geometry> <mesh filename="package://spark_description/meshes/spark/base/left_wheel.DAE"/> </geometry> </visual> <collision> <origin xyz="000" rpy="000"/> <geometry> <mesh filename="package://spark_description/meshes/spark/base/left_wheel.DAE"/> </geometry> </collision> </link> <jointname="left_wheel_joint"type="continuous"> <origin xyz="0-0.1310.024"rpy="000"/> <axisxyz="010"/> <parentlink="base_link"/> <childlink="left_wheel_link"/> </joint> <linkname="right_wheel_link"> <inertial> <massvalue="0.01"/> <originxyz="000"/> <inertiaixx="0.001"ixy="0.0"ixz="0.0" iyy="0.001"iyz="0.0" izz="0.001"/> </inertial> <visual> <origin xyz="000" rpy="000"/> <geometry> <mesh filename="package://spark_description/meshes/spark/base/right_wheel.DAE"/> </geometry> </visual> <collision> <origin xyz="000"rpy="000"/> <geometry> <mesh filename="package://spark_description/meshes/spark/base/right_wheel.DAE"/> </geometry> </collision> </link> <jointname="right_wheel_joint"type="continuous"> <origin xyz="00.1310.024"rpy="000"/> <axisxyz="010"/> <parentlink="base_link"/> <childlink="right_wheel_link"/> </joint><linkname="spark_stack"><inertial><origin xyz="000" rpy="000"/><massvalue="0.224592038"/><inertiaixx="0.052467491"ixy="-0.000000000"ixz="0.001956704"iyy="0.055610919"iyz="0.000000000"izz="0.012118046"/></inertial><visual><origin xyz="000" rpy="000"/><geometry><meshfilename="package://spark_description/meshes/spark/stack/spark_stack.DAE"/></geometry></visual><collision><originxyz="000"rpy="000"/><geometry><meshfilename="package://spark_description/meshes/spark/stack/spark_stack.DAE"/></geometry></collision></link><jointname="spark_stack_joint"type="fixed"><origin xyz="000" rpy="000"/><parentlink="base_link"/><childlink="spark_stack"/></joint><transmissionname="tran1"><type>transmission_interface/SimpleTransmission</type><jointname="left_wheel_joint"><hardwareInterface>VelocityJointInterface</hardwareInterface></joint><actuatorname="motor1"><hardwareInterface>VelocityJointInterface</hardwareInterface><mechanicalReduction>1</mechanicalReduction></actuator></transmission><transmissionname="tran2"><type>transmission_interface/SimpleTransmission</type><jointname="right_wheel_joint"><hardwareInterface>VelocityJointInterface</hardwareInterface></joint><actuatorname="motor2"><hardwareInterface>VelocityJointInterface</hardwareInterface><mechanicalReduction>-1</mechanicalReduction></actuator></transmission><gazebo><pluginname="gazebo_ros_control"filename="libgazebo_ros_control.so"><robotNamespace>/</robotNamespace><robotSimType>gazebo_ros_control/DefaultRobotHWSim</robotSimType></plugin></gazebo> </robot>2.创建控制器配置文件控制器的一些参数，我们通常把它写成一个配置文件。命名为controller.yaml①在功能包下创建config文件夹，用于存放配置文件$mkdirconfig$cdconfig②将项目源代码中的controller.yaml文件复制到此config文件夹中具体代码如下：joint_state_controller:type:joint_state_controller/JointStateControllerpublish_rate:20spark_controller:type:"diff_drive_controller/DiffDriveController"left_wheel:"left_wheel_joint"right_wheel:"right_wheel_joint"wheel_separation:0.11wheel_radius:0.04publish_rate:50.0#defaultsto50pose_covariance_diagonal:[0.001,0.001,1000000.0,1000000.0,1000000.0,1000.0]twist_covariance_diagonal:[0.001,0.001,1000000.0,1000000.0,1000000.0,1000.0]cmd_vel_timeout:20.0#wetestthisseparately,giveplentyfortheothertests我们这里面将控制器的这个参数写到controller.yaml，然后我们用rosparam来将这些配置参数加载到参数服务器上。这里面控制器包括jointstatecontroller和sparkcontroller。3.创建launch文件将项目源代码中的spark_gazebo.launch文件复制到此launch文件夹中具体代码如下：<launch><!--urdfxmlrobotdescriptionloadedontheParameterServer--><paramname="robot_description"command="$(findxacro)/xacro'$(findspark_description)/urdf/teaching/spark_description_gazebo.urdf'"/><nodename="joint_state_publisher"pkg="joint_state_publisher"type="joint_state_publisher"></node><!--Startingrobotstatepublishwhichwillpublishtf--><nodename="robot_s