博客

gazebo 仿真 —URDF机器人建模

  • Post author:
  • Post category:其他


文章目录



URDF机器人建模



URDF机器人建模的介绍



URDF的概念

  • URDF（Unified Robot Description Format）,统一机器人描述格式
  • ROS中一个非常重要的机器人模型描述格式
  • 可以解析URDF文件中使用XML格式描述的机器人模型
  • ROS同时也提供URDF文件的C++解析器（可以在C++代码中直接解析- -URDF机器人模型，好处：在基于模型的计算算法中，可以在代码中调用模型的信息，方便计算）



URDF机器人模型的内容

  • 连杆 link
  • 关节 joint
  • 运动学参数 axis
  • 动力学参数 dynamics
  • 可视化模型 visual
  • 碰撞检测模型 collision



URDF机器人模型的标签说明

  • link标签

    用于描述机器人某个刚体部分的外观和物理属性（比如尺寸（size）、颜色（color）、形状（shape）、惯性矩阵（inertial matrix）、碰撞属性（collision properties）等）

    xml的格式的描述 

    <link name="<link name>">
<!-- 描述机器人link部分的外观参数, 尺寸、颜色、形状等的外观信息 -->
	<inertial>......</inertial>
	<!-- 描述link的惯性参数，主要用到机器人动力学的运算部分 -->
	<visual>......</visual>
	<!-- 描述link的碰撞属性 -->
	<collision>......</collision>
</link>

  • joint标签

    描述机器人关节的运动学和动力学属性，包括关节运动的位置和速度限制。根据关节的运动形式，可以将其分为六种类型

    关节类型 描述
    continuous 旋转关节，可以围绕单轴无限旋转
    revolute 旋转关节，类似于continuous，但是有旋转的角度限制
    prismatic 滑动关节，沿某一轴线移动的关节，带有位置极限
    planar 平面关节，允许在平面正交方向上平移或者旋转
    floating 浮动关节，允许进行平移、旋转运动
    fixed 固定关节，不允许运动的特殊关节

    xml格式的描述 

    <joint name="<name of the joint>" type="<joint type>">
	<parent link="parent_link"/>
	<child link="child_link"/>
	<!--关节的参考位置，用来校准关节的绝对位置-->
	<calibration ....../>
	<!--描述关节的物理属性，例如物理静摩擦力-->
	<dynamics damping ....../>
	<!--描述运动的一些极限值，包括关节运动的上下限位置，速度限制-->
	<limit effort ....../>
	......
</joint>

  • robot标签

    完整机器人模型的最顶层标签，< link > 和 < joint >标签必须包含在 < robot > 标签内

    xml格式描述 

    <robot name="name of the robot">
	<link>......</link>
	<link>......</link>
	<joint>......</joint>
	<joint>......</joint>
</robot>



URDF机器人建模的实现



创建URDF功能包

1.创建一个机器人建模的功能包 

#进入工作空间
cd ./catkin_ws/src/
#创建功能包
catkin_create_pkg mbot_description urdf xacro

2.创建机器人建模的功能包的文件结构 

cd ./catkin_ws/src/mbot_description
mkdir urdf
mkdir meshes
mkdir launch
mkdir config
目录名称 描述
urdf 存放机器人模型的URDF或xacro文件
meshes 放置URDF中引用的模型渲染文件，机器人外观纹理，让外观和实际更相似
launch 保存相关启动文件
config 保存rviz的配置文件、功能包的配置文件



编辑launch启动文件

cd ./catkin_ws/src/mbot_description/launch
sudo gedit display_mbot_base_urdf.launch

display_mbot_base_urdf.launch文件内容 

<launch>
   <!-- 加载的参数名字叫robot_description，具体内容是urdf相关模型的路径 -->
	<param name="robot_description" textfile="$(find mbot_description)/urdf/mbot_base.urdf" />
	<!-- 设置GUI参数，显示关节控制插件 -->
	<param name="use_gui" value="true"/>
	<!-- 运行joint_state_publisher节点，发布机器人的关节状态  -->
	<node name="joint_state_publisher" pkg="joint_state_publisher" type="joint_state_publisher" />
	<!-- 运行robot_state_publisher节点，发布tf  -->
	<node name="robot_state_publisher" pkg="robot_state_publisher" type="state_publisher" />
	<!-- 运行rviz可视化界面，保存每次打开之后的相关插件，保存到config文件夹下面 -->
	<node name="rviz" pkg="rviz" type="rviz" args="-d $(find mbot_description)/config/mbot_urdf.rviz" required="true" />
</launch>



创建URDF模型



创建小车底盘（圆柱体）

cd ./catkin_ws/src/mbot_description/urdf
sudo gedit mbot_base.urdf

mbot_base.urdf文件内容 

<?xml version="1.0" ?>
<robot name="mbot">
    <link name="base_link">
        <visual>
            <origin xyz=" 0 0 0" rpy="0 0 0" />
            <!-- link坐标位置，放在最中央 ，xyz单位是米，rpy单位是弧度-->
            <geometry>
                <cylinder length="0.16" radius="0.20"/>
            </geometry>
            <!-- 机器人的外观效果，使用圆柱体，高0.16，半径0.20 -->
            <material name="yellow">
                <color rgba="1 0.4 0 1"/>
            </material>
             <!--  通过rgba来描述颜色，颜色命名为yellow,a为1是不透明-->
        </visual>
        <!--visual指的是一些物理属性的标签 -->
    </link>




</

robot


>

查看显示的效果 

roslaunch mbot_description display_mbot_base_urdf.launch

问题描述

1.

Could not find the GUI, install the ‘joint_state_publisher_gui’ package


解决方法：

sudo apt-get install ros-melodic-joint-state-publisher-gui（melodic版本）

2.

[joint_state_publisher-1] process has died [pid 12201, exit code 1, cmd /opt/


解决方法：

urdf文件第一行前面到空格全部去掉，一般格式正确后都会有颜色的，写urdf一定要注意格式，并且将其中的注释给去掉，后面再添加相应代码的时候注意去掉注释内容

3.

RVIZ成功启动不显示模型


解决方法：

①将Fixed Frame改为base_link

②点击下方的Add按钮添加RobotModel

显示效果

在这里插入图片描述



创建左侧车轮

sudo gedit mbot_base.urdf

添加代码内容（添加到上面文件代码所留出的空白位置） 

    <joint name="left_wheel_joint" type="continuous">
    <!--   joint名字为left_wheel_joint，属性为continuous，即无限旋转-->
        <origin xyz="0 0.19 -0.05" rpy="0 0 0"/>
        <!--  坐标位置，在base_link基础上，Y偏移0.19，z偏移-0.05-->
        <parent link="base_link"/>
        <child link="left_wheel_link"/>
        <!--  主关节：base_link，上面的圆柱形车体-->
        <!--  子关节：left_wheel_link，左轮-->
        <!--  主关节最后是一个，本代码是base_link-->
        <axis xyz="0 1 0"/>
        <!--left_wheel_link绕某一个轴做旋转，指定为Y轴  -->
    </joint>
     <!--joint用来连接两个link-->
    <link name="left_wheel_link">
        <visual>
            <origin xyz="0 0 0" rpy="1.5707 0 0" />
            <geometry>
                <cylinder radius="0.06" length = "0.025"/>
            </geometry>
            <material name="white">
                <color rgba="1 1 1 0.9"/>
            </material>
        </visual>
    </link>
  <!--左轮信息-->


注意：


去掉注释

查看显示效果 

roslaunch mbot_description display_mbot_base_urdf.launch

在这里插入图片描述

查看小车主体和轮子之间的TF坐标位置

添加TF坐标，将左面robotmodel选项取消

在这里插入图片描述



创建右侧车轮

方法跟上面类似

添加内容 

    <joint name="right_wheel_joint" type="continuous">
        <origin xyz="0 -0.19 -0.05" rpy="0 0 0"/>
        <!--  坐标位置，在base_link基础上，Y偏移-0.19，z偏移-0.05，与左轮正好相反-->
        <parent link="base_link"/>
        <child link="right_wheel_link"/>
        <axis xyz="0 1 0"/>
    </joint>
    <link name="right_wheel_link">
        <visual>
            <origin xyz="0 0 0" rpy="1.5707 0 0" />
            <geometry>
                <cylinder radius="0.06" length = "0.025"/>
            </geometry>
            <material name="white">
                <color rgba="1 1 1 0.9"/>
            </material>
        </visual>
    </link>

查看显示效果 

roslaunch mbot_description display_mbot_base_urdf.launch

在这里插入图片描述



创建前后支撑轮

方法同上

添加内容 

    <joint name="front_caster_joint" type="continuous">
        <origin xyz="0.18 0 -0.095" rpy="0 0 0"/>
        <parent link="base_link"/>
        <child link="front_caster_link"/>
        <axis xyz="0 1 0"/>
    </joint>

<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>link</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>front_caster_link<span class="token punctuation">"</span></span><span class="token punctuation">&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>visual</span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>origin</span> <span class="token attr-name">xyz</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>0 0 0<span class="token punctuation">"</span></span> <span class="token attr-name">rpy</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>0 0 0<span class="token punctuation">"</span></span><span class="token punctuation">/&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>geometry</span><span class="token punctuation">&gt;</span></span>
            <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>sphere</span> <span class="token attr-name">radius</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>0.015<span class="token punctuation">"</span></span> <span class="token punctuation">/&gt;</span></span>
              <span class="token comment">&lt;!--用圆形轮子代替  --&gt;</span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>geometry</span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>material</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>black<span class="token punctuation">"</span></span><span class="token punctuation">&gt;</span></span>
            <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>color</span> <span class="token attr-name">rgba</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>0 0 0 0.95<span class="token punctuation">"</span></span><span class="token punctuation">/&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>material</span><span class="token punctuation">&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>visual</span><span class="token punctuation">&gt;</span></span>
<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>link</span><span class="token punctuation">&gt;</span></span>

<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>joint</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>back_caster_joint<span class="token punctuation">"</span></span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>continuous<span class="token punctuation">"</span></span><span class="token punctuation">&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>origin</span> <span class="token attr-name">xyz</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>-0.18 0 -0.095<span class="token punctuation">"</span></span> <span class="token attr-name">rpy</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>0 0 0<span class="token punctuation">"</span></span><span class="token punctuation">/&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>parent</span> <span class="token attr-name">link</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>base_link<span class="token punctuation">"</span></span><span class="token punctuation">/&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>child</span> <span class="token attr-name">link</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>back_caster_link<span class="token punctuation">"</span></span><span class="token punctuation">/&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>axis</span> <span class="token attr-name">xyz</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>0 1 0<span class="token punctuation">"</span></span><span class="token punctuation">/&gt;</span></span>
<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>joint</span><span class="token punctuation">&gt;</span></span>

<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>link</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>back_caster_link<span class="token punctuation">"</span></span><span class="token punctuation">&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>visual</span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>origin</span> <span class="token attr-name">xyz</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>0 0 0<span class="token punctuation">"</span></span> <span class="token attr-name">rpy</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>0 0 0<span class="token punctuation">"</span></span><span class="token punctuation">/&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>geometry</span><span class="token punctuation">&gt;</span></span>
            <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>sphere</span> <span class="token attr-name">radius</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>0.015<span class="token punctuation">"</span></span> <span class="token punctuation">/&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>geometry</span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>material</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>black<span class="token punctuation">"</span></span><span class="token punctuation">&gt;</span></span>
            <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>color</span> <span class="token attr-name">rgba</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>0 0 0 0.95<span class="token punctuation">"</span></span><span class="token punctuation">/&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>material</span><span class="token punctuation">&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>visual</span><span class="token punctuation">&gt;</span></span>
<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>link</span><span class="token punctuation">&gt;</span></span>




   



    查看显示效果
   


roslaunch mbot_description display_mbot_base_urdf.launch

 
 



    在这里插入图片描述
   



    

    

    增加传感器

   



    

    

    加入摄像头

   


cd ./catkin_ws/src/mbot_description/urdf
sudo gedit mbot_with_camera.urdf 
cd ./catkin_ws/src/mbot_description/launch
sudo gedit display_mbot_with_camera_urdf.launch  

 
 



    mbot_with_camera.urdf 文件内容
   


<?xml version="1.0" ?>
<robot name="mbot">

<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>link</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>base_link<span class="token punctuation">"</span></span><span class="token punctuation">&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>visual</span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>origin</span> <span class="token attr-name">xyz</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span> 0 0 0<span class="token punctuation">"</span></span> <span class="token attr-name">rpy</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>0 0 0<span class="token punctuation">"</span></span> <span class="token punctuation">/&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>geometry</span><span class="token punctuation">&gt;</span></span>
            <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>cylinder</span> <span class="token attr-name">length</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>0.16<span class="token punctuation">"</span></span> <span class="token attr-name">radius</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>0.20<span class="token punctuation">"</span></span><span class="token punctuation">/&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>geometry</span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>material</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>yellow<span class="token punctuation">"</span></span><span class="token punctuation">&gt;</span></span>
            <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>color</span> <span class="token attr-name">rgba</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>1 0.4 0 1<span class="token punctuation">"</span></span><span class="token punctuation">/&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>material</span><span class="token punctuation">&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>visual</span><span class="token punctuation">&gt;</span></span>
<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>link</span><span class="token punctuation">&gt;</span></span>

<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>joint</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>left_wheel_joint<span class="token punctuation">"</span></span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>continuous<span class="token punctuation">"</span></span><span class="token punctuation">&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>origin</span> <span class="token attr-name">xyz</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>0 0.19 -0.05<span class="token punctuation">"</span></span> <span class="token attr-name">rpy</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>0 0 0<span class="token punctuation">"</span></span><span class="token punctuation">/&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>parent</span> <span class="token attr-name">link</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>base_link<span class="token punctuation">"</span></span><span class="token punctuation">/&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>child</span> <span class="token attr-name">link</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>left_wheel_link<span class="token punctuation">"</span></span><span class="token punctuation">/&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>axis</span> <span class="token attr-name">xyz</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>0 1 0<span class="token punctuation">"</span></span><span class="token punctuation">/&gt;</span></span>
<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>joint</span><span class="token punctuation">&gt;</span></span>

<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>link</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>left_wheel_link<span class="token punctuation">"</span></span><span class="token punctuation">&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>visual</span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>origin</span> <span class="token attr-name">xyz</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>0 0 0<span class="token punctuation">"</span></span> <span class="token attr-name">rpy</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>1.5707 0 0<span class="token punctuation">"</span></span> <span class="token punctuation">/&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>geometry</span><span class="token punctuation">&gt;</span></span>
            &lt;cylinder radius="0.06" length = "0.025"/&gt;
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>geometry</span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>material</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>white<span class="token punctuation">"</span></span><span class="token punctuation">&gt;</span></span>
            <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>color</span> <span class="token attr-name">rgba</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>1 1 1 0.9<span class="token punctuation">"</span></span><span class="token punctuation">/&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>material</span><span class="token punctuation">&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>visual</span><span class="token punctuation">&gt;</span></span>
<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>link</span><span class="token punctuation">&gt;</span></span>

<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>joint</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>right_wheel_joint<span class="token punctuation">"</span></span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>continuous<span class="token punctuation">"</span></span><span class="token punctuation">&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>origin</span> <span class="token attr-name">xyz</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>0 -0.19 -0.05<span class="token punctuation">"</span></span> <span class="token attr-name">rpy</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>0 0 0<span class="token punctuation">"</span></span><span class="token punctuation">/&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>parent</span> <span class="token attr-name">link</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>base_link<span class="token punctuation">"</span></span><span class="token punctuation">/&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>child</span> <span class="token attr-name">link</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>right_wheel_link<span class="token punctuation">"</span></span><span class="token punctuation">/&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>axis</span> <span class="token attr-name">xyz</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>0 1 0<span class="token punctuation">"</span></span><span class="token punctuation">/&gt;</span></span>
<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>joint</span><span class="token punctuation">&gt;</span></span>

<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>link</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>right_wheel_link<span class="token punctuation">"</span></span><span class="token punctuation">&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>visual</span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>origin</span> <span class="token attr-name">xyz</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>0 0 0<span class="token punctuation">"</span></span> <span class="token attr-name">rpy</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>1.5707 0 0<span class="token punctuation">"</span></span> <span class="token punctuation">/&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>geometry</span><span class="token punctuation">&gt;</span></span>
            &lt;cylinder radius="0.06" length = "0.025"/&gt;
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>geometry</span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>material</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>white<span class="token punctuation">"</span></span><span class="token punctuation">&gt;</span></span>
            <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>color</span> <span class="token attr-name">rgba</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>1 1 1 0.9<span class="token punctuation">"</span></span><span class="token punctuation">/&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>material</span><span class="token punctuation">&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>visual</span><span class="token punctuation">&gt;</span></span>
<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>link</span><span class="token punctuation">&gt;</span></span>

<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>joint</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>front_caster_joint<span class="token punctuation">"</span></span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>continuous<span class="token punctuation">"</span></span><span class="token punctuation">&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>origin</span> <span class="token attr-name">xyz</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>0.18 0 -0.095<span class="token punctuation">"</span></span> <span class="token attr-name">rpy</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>0 0 0<span class="token punctuation">"</span></span><span class="token punctuation">/&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>parent</span> <span class="token attr-name">link</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>base_link<span class="token punctuation">"</span></span><span class="token punctuation">/&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>child</span> <span class="token attr-name">link</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>front_caster_link<span class="token punctuation">"</span></span><span class="token punctuation">/&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>axis</span> <span class="token attr-name">xyz</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>0 1 0<span class="token punctuation">"</span></span><span class="token punctuation">/&gt;</span></span>
<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>joint</span><span class="token punctuation">&gt;</span></span>

<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>link</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>front_caster_link<span class="token punctuation">"</span></span><span class="token punctuation">&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>visual</span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>origin</span> <span class="token attr-name">xyz</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>0 0 0<span class="token punctuation">"</span></span> <span class="token attr-name">rpy</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>0 0 0<span class="token punctuation">"</span></span><span class="token punctuation">/&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>geometry</span><span class="token punctuation">&gt;</span></span>
            <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>sphere</span> <span class="token attr-name">radius</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>0.015<span class="token punctuation">"</span></span> <span class="token punctuation">/&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>geometry</span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>material</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>black<span class="token punctuation">"</span></span><span class="token punctuation">&gt;</span></span>
            <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>color</span> <span class="token attr-name">rgba</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>0 0 0 0.95<span class="token punctuation">"</span></span><span class="token punctuation">/&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>material</span><span class="token punctuation">&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>visual</span><span class="token punctuation">&gt;</span></span>
<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>link</span><span class="token punctuation">&gt;</span></span>

<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>joint</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>back_caster_joint<span class="token punctuation">"</span></span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>continuous<span class="token punctuation">"</span></span><span class="token punctuation">&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>origin</span> <span class="token attr-name">xyz</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>-0.18 0 -0.095<span class="token punctuation">"</span></span> <span class="token attr-name">rpy</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>0 0 0<span class="token punctuation">"</span></span><span class="token punctuation">/&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>parent</span> <span class="token attr-name">link</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>base_link<span class="token punctuation">"</span></span><span class="token punctuation">/&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>child</span> <span class="token attr-name">link</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>back_caster_link<span class="token punctuation">"</span></span><span class="token punctuation">/&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>axis</span> <span class="token attr-name">xyz</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>0 1 0<span class="token punctuation">"</span></span><span class="token punctuation">/&gt;</span></span>
<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>joint</span><span class="token punctuation">&gt;</span></span>

<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>link</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>back_caster_link<span class="token punctuation">"</span></span><span class="token punctuation">&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>visual</span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>origin</span> <span class="token attr-name">xyz</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>0 0 0<span class="token punctuation">"</span></span> <span class="token attr-name">rpy</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>0 0 0<span class="token punctuation">"</span></span><span class="token punctuation">/&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>geometry</span><span class="token punctuation">&gt;</span></span>
            <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>sphere</span> <span class="token attr-name">radius</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>0.015<span class="token punctuation">"</span></span> <span class="token punctuation">/&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>geometry</span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>material</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>black<span class="token punctuation">"</span></span><span class="token punctuation">&gt;</span></span>
            <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>color</span> <span class="token attr-name">rgba</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>0 0 0 0.95<span class="token punctuation">"</span></span><span class="token punctuation">/&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>material</span><span class="token punctuation">&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>visual</span><span class="token punctuation">&gt;</span></span>
<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>link</span><span class="token punctuation">&gt;</span></span>
<span class="token comment">&lt;!--摄像头相关内容--&gt;</span>
<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>link</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>camera_link<span class="token punctuation">"</span></span><span class="token punctuation">&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>visual</span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>origin</span> <span class="token attr-name">xyz</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span> 0 0 0 <span class="token punctuation">"</span></span> <span class="token attr-name">rpy</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>0 0 0<span class="token punctuation">"</span></span> <span class="token punctuation">/&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>geometry</span><span class="token punctuation">&gt;</span></span>
        
            <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>box</span> <span class="token attr-name">size</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>0.03 0.04 0.04<span class="token punctuation">"</span></span> <span class="token punctuation">/&gt;</span></span>
               <span class="token comment">&lt;!--外观是个盒子模拟成摄像头，长宽高分别是0.03 0.04 0.04--&gt;</span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>geometry</span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>material</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>black<span class="token punctuation">"</span></span><span class="token punctuation">&gt;</span></span>
            <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>color</span> <span class="token attr-name">rgba</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>0 0 0 0.95<span class="token punctuation">"</span></span><span class="token punctuation">/&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>material</span><span class="token punctuation">&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>visual</span><span class="token punctuation">&gt;</span></span>
<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>link</span><span class="token punctuation">&gt;</span></span>

<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>joint</span> <span class="token attr-name">name</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>camera_joint<span class="token punctuation">"</span></span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>fixed<span class="token punctuation">"</span></span><span class="token punctuation">&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>origin</span> <span class="token attr-name">xyz</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>0.17 0 0.10<span class="token punctuation">"</span></span> <span class="token attr-name">rpy</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>0 0 0<span class="token punctuation">"</span></span><span class="token punctuation">/&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>parent</span> <span class="token attr-name">link</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>base_link<span class="token punctuation">"</span></span><span class="token punctuation">/&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>child</span> <span class="token attr-name">link</span><span class="token attr-value"><span class="token punctuation">=</span><span class="token punctuation">"</span>camera_link<span class="token punctuation">"</span></span><span class="token punctuation">/&gt;</span></span>
<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>joint</span><span class="token punctuation">&gt;</span></span>




    

     

      

       </

      

      robot

     

     

      >

     

    
   



   



    display_mbot_with_camera_urdf.launch文件内容和display_mbot_base_urdf.launch文件内容基本一致，需要修改urdf相关模型的路径
   


   <!-- 加载的参数名字叫robot_description，具体内容是urdf相关模型的路径 -->
	<param name="robot_description" textfile="$(find mbot_description)/urdf/mbot_with_camera.urdf "/>

 
 



    查看显示效果
   


roslaunch mbot_description display_mbot_with_camera_urdf.launch  

 
 



    在这里插入图片描述
   



    

    

    加入激光雷达

   


cd ./catkin_ws/src/mbot_description/urdf
sudo gedit mbot_with_laser.urdf
cd ./catkin_ws/src/mbot_description/launch
sudo gedit display_mbot_with_laser_urdf.launch

 
 



    mbot_with_laser.urdf文件内容（其他内容跟未添加传感器内容一致）
   


    <!--激光雷达配置内容-->
    <link name="laser_link">
		<visual>
			<origin xyz=" 0 0 0 " rpy="0 0 0" />
			<geometry>
				<cylinder length="0.05" radius="0.05"/>
			</geometry>
			<material name="black"/>
		</visual>
    </link>
    <joint name="laser_joint" type="fixed">
        <origin xyz="0 0 0.105" rpy="0 0 0"/>
        <parent link="base_link"/>
        <child link="laser_link"/>
    </joint>

 
 



    display_mbot_with_laser_urdf.launch文件内容和display_mbot_urdf.launch文件内容基本一致，需要修改urdf相关模型的路径
   


   <!-- 加载的参数名字叫robot_description，具体内容是urdf相关模型的路径 -->
	<param name="robot_description" textfile="$(find mbot_description)/urdf/mbot_with_laser.urdf " />

 
 



    查看显示效果
   


roslaunch mbot_description display_mbot_with_laser_urdf.launch

 
 



    在这里插入图片描述
   



    

    

    加入Kinect

   


cd ./catkin_ws/src/mbot_description/urdf
sudo gedit mbot_with_kinect.urdf
cd ./catkin_ws/src/mbot_description/launch
sudo gedit display_mbot_with_kinect_urdf.launch

 
 





    mbot_with_kinect.urdf文件内容（其他内容跟未添加传感器内容一致）
   


    <!--Kinect配置-->
    <link name="kinect_link">
        <visual>
            <origin xyz="0 0 0" rpy="0 0 1.5708"/>
            <geometry>
                <mesh filename="package://mbot_description/meshes/kinect.dae" />
                 <!--直接加载Kinect的外观纹理描述文件-->
            </geometry>
        </visual>
    </link>
    <joint name="laser_joint" type="fixed">
        <origin xyz="0.15 0 0.11" rpy="0 0 0"/>
        <parent link="base_link"/>
        <child link="kinect_link"/>
    </joint>

 
 



    display_mbot_with_kinect_urdf.launch文件内容和display_mbot_urdf.launch文件内容基本一致，需要修改urdf相关模型的路径
   


   <!-- 加载的参数名字叫robot_description，具体内容是urdf相关模型的路径 -->
	<param name="robot_description" textfile="$(find mbot_description)/urdf/mbot_with_kinect.urdf " />

 
 



    在meshes文件中创建纹理描述信息。

    

    新建文件名称： kinect.dae

    

    文件下载可以参考该链接（下载需要VIP）：

    

    

     https://download.csdn.net/download/weixin_43262513/10990016

    

    

    查看显示效果
   


roslaunch mbot_description display_mbot_with_kinect_urdf.launch

 
 





     由于无法获得kinect纹理描述信息的文件，所有就无法得到它的显示效果。
    





    

    

    检查URDF模型整体结构

   



    urdf文件夹下执行 urdf_to_graphiz+要检查的urdf文件
   


urdf_to_graphiz mbot_with_camera.urdf

 
 



    打开生成的pdf文件查看

    

    在这里插入图片描述

    

    整个内容比较多，但是有较多部分都是重复的，只有理解到一部分内容，其他的内容可以根据理解部分的内容去理解。
   



    

    

    参考链接

   



    1.

    

     URDF机器人建模 理论+实践

    

    

    2.

    

     ROS学习笔记——ROS机器人系统设计—–基础编程 day 7 2019/3/2 帅某（URDF机器人建模，urdf功能包的建立，urdf相关模型建立代码已经上传）

    

    

    3.

    

     圆柱urdf：Could not find the GUI, install the ‘joint_state_publisher_gui’ package.RVIZ成功启动不显示圆柱模型