ROS學習記錄（二）————使用smartcar進行仿真(用.xacro文件來運行rviz)

我發現一個學習ROS系統的好網站：

創客智造
http://www.ncnynl.com/ 

這里面關於ROS的各個方面都有很詳細的介紹。

這周，不，上周我對整個ROS是絕望的，我用一個一個下午的時間在敲代碼進行這個例程的學習，可以說是費勁磨難，怎么也弄不出來，網上的各種帖子都找遍了，但沒有有個有詳細的介紹到底該怎么運行出來的，這之間，我有時以為是版本的原因，就把Ubuntu的版本從12.04換到14.04還是不行；有時以為是vim編輯器的緣故，然后，找帖子千辛萬苦的裝上，當然，還是不行++；又覺得是gazebo模擬器沒裝的原因，當然，結果和前兩個一樣，又是一場空，關鍵是生氣，“到底也要死個明白啊！”我一星期都不知道哪里出了問題！所幸的是，偶然的機會找到這么一個網站，試試的感覺去嘗試一下，發現，竟然還不錯喲！竟然能運行出來。天吶，當看到小車在轉圈的時候，我都激動的想哭。

下面是過程：

再插一句，我雖然還不太確定，但有種隱約的感覺，那就是跟版本有關系，我換了好幾個版本，之前用的易科的開發版，直接給棄了，老是出毛病，我是直接裝的華東師范大學智能機器人運動與視覺實驗室主辦2015中國ROS Summer School中制作的Ubuntu for ROS，下面是地址：

http://www.ncnynl.com/archives/201608/497.html 

切入正題：

首先，安裝urdf_tutorial，可以使用其中的例子

$ sudo apt-get install ros-indigo-urdf-tutorial

這里面需要輸入密碼：aicrobo

接着，安裝liburdfdom-tools，提供對urdf文件的檢查

$ sudo apt-get install liburdfdom-tools

可能是我網速的事兒，我感覺有點慢。因為這個過程是需要是從網上下載的，所有要保證聯網狀態才行。

接下來的步驟，就是很多帖子里面沒有提到的了，也不知道是我太笨，還是人家太聰明，我都不知道該咋弄，結果人家的帖子一下子就跳到了下一個過程了。

$ cd ~/catkin_ws/src
$catkin_create_pkg  smartcar_description  std_msgs rospy roscpp urdf

這兩個的命令的意思是找到catkin_ws下的src文件，並在這個文件夾里面進行下面的操作（第一句）；在這個文件夾（src）里面建立一個名為“smartcar_description”的文件夾（正式的叫創建硬件描述包），我們這個例程的所有的內容都要放到這個文件夾里面，並且生成一下配套的一下文件

會在home里面生成配套的文件：

smartcar_description里面就是這個樣子：

然后，就是在smartcar_description中建立urdf，launch，config三個文件夾，並在里面存放一些文件：

$cd smartcar_description //定位到這個文件夾下
$mkdir urdf
$cd urdf //生成一個叫urdf的文件夾

$mkdir launch
$cd launch //生成一個叫launch的文件夾

$cd urdf //生成一個叫config的文件夾
$mkdir config
$cd urdf
$cd ~/catkin_ws/src/urdf  //選中urdf文件夾

$touch smartcar_body.urdf.xacro //在urdf文件夾下創建一個叫smartcar_body.urdf.xacro的文件

然后呢，就是沒有什么技術含量的復制，粘貼了。

把下面的這些代碼，復制下來，然后，打開新建的smartcar_body.urdf.xacro文件，像粘貼word的一樣，粘上去，保存一下。

1.機器人主體smartcar_body.urdf.xacro

<?xml version="1.0"?>
<robot name="smartcar" xmlns:xacro="http://ros.org/wiki/xacro">
<xacro:property name="M_PI" value="3.14159"/>
<!-- Macro for SmartCar body. Including Gazebo extensions, but does not include Kinect -->
<xacro:include filename="$(find smartcar_description)/urdf/gazebo.urdf.xacro"/>
<xacro:property name="base_x" value="0.33" />
<xacro:property name="base_y" value="0.33" />
<xacro:macro name="smartcar_body">
<link name="base_link">
<inertial>
<origin xyz="0 0 0.055"/>
<mass value="1.0" />
<inertia ixx="1.0" ixy="0.0" ixz="0.0" iyy="1.0" iyz="0.0" izz="1.0"/>
</inertial>
<visual>
<geometry>
<box size="0.25 .16 .05"/>
</geometry>
<origin rpy="0 0 0" xyz="0 0 0.055"/>
<material name="blue">
<color rgba="0 0 .8 1"/>
</material>
</visual>
<collision>
<origin rpy="0 0 0" xyz="0 0 0.055"/>
<geometry>
<box size="0.25 .16 .05" />
</geometry>
</collision>
</link>

<link name="left_front_wheel">
<inertial>
<origin xyz="0.08 0.08 0.025"/>
<mass value="0.1" />
<inertia ixx="1.0" ixy="0.0" ixz="0.0" iyy="1.0" iyz="0.0" izz="1.0"/>
</inertial>

<visual>
<geometry>
<cylinder length=".02" radius="0.025"/>
</geometry>
<material name="black">
<color rgba="0 0 0 1"/>
</material>
</visual>
<collision>
<origin rpy="0 1.57075 1.57075" xyz="0.08 0.08 0.025"/>
<geometry>
<cylinder length=".02" radius="0.025"/>
</geometry>
</collision>
</link>

<joint name="left_front_wheel_joint" type="continuous">
<axis xyz="0 0 1"/>
<parent link="base_link"/>
<child link="left_front_wheel"/>
<origin rpy="0 1.57075 1.57075" xyz="0.08 0.08 0.025"/>
<limit effort="100" velocity="100"/>
<joint_properties damping="0.0" friction="0.0"/>
</joint>

<link name="right_front_wheel">

<inertial>

<origin xyz="0.08 -0.08 0.025"/>

<mass value="0.1" />

<inertia ixx="1.0" ixy="0.0" ixz="0.0" iyy="1.0" iyz="0.0" izz="1.0"/>

</inertial>

<visual>

<geometry>

<cylinder length=".02" radius="0.025"/>

</geometry>

<material name="black">

<color rgba="0 0 0 1"/>

</material>

</visual>

<collision>

<origin rpy="0 1.57075 1.57075" xyz="0.08 -0.08 0.025"/>

<geometry>

<cylinder length=".02" radius="0.025"/>

</geometry>

</collision>

</link>

 

<joint name="right_front_wheel_joint" type="continuous">

<axis xyz="0 0 1"/>

<parent link="base_link"/>

<child link="right_front_wheel"/>

<origin rpy="0 1.57075 1.57075" xyz="0.08 -0.08 0.025"/>

<limit effort="100" velocity="100"/>

<joint_properties damping="0.0" friction="0.0"/>

</joint>

 

<link name="left_back_wheel">

<inertial>

<origin xyz="-0.08 0.08 0.025"/>

<mass value="0.1" />

<inertia ixx="1.0" ixy="0.0" ixz="0.0" iyy="1.0" iyz="0.0" izz="1.0"/>

</inertial>

<visual>

<geometry>

<cylinder length=".02" radius="0.025"/>

</geometry>

<material name="black">

<color rgba="0 0 0 1"/>

</material>

</visual>

<collision>

<origin rpy="0 1.57075 1.57075" xyz="-0.08 0.08 0.025"/>

<geometry>

<cylinder length=".02" radius="0.025"/>

</geometry>

</collision>

</link>

 

<joint name="left_back_wheel_joint" type="continuous">

<axis xyz="0 0 1"/>

<parent link="base_link"/>

<child link="left_back_wheel"/>

<origin rpy="0 1.57075 1.57075" xyz="-0.08 0.08 0.025"/>

<limit effort="100" velocity="100"/>

<joint_properties damping="0.0" friction="0.0"/>

</joint>

 

<link name="right_back_wheel">

<inertial>

<origin xyz="-0.08 -0.08 0.025"/>

<mass value="0.1" />

<inertia ixx="1.0" ixy="0.0" ixz="0.0" iyy="1.0" iyz="0.0" izz="1.0"/>

</inertial>

<visual>

<geometry>

<cylinder length=".02" radius="0.025"/>

</geometry>

<material name="black">

<color rgba="0 0 0 1"/>

</material>

</visual>

<collision>

<origin rpy="0 1.57075 1.57075" xyz="-0.08 -0.08 0.025"/>

<geometry>

<cylinder length=".02" radius="0.025"/>

</geometry>

</collision>

</link>

 

 

<joint name="right_back_wheel_joint" type="continuous">

<axis xyz="0 0 1"/>

<parent link="base_link"/>

<child link="right_back_wheel"/>

<origin rpy="0 1.57075 1.57075" xyz="-0.08 -0.08 0.025"/>

<limit effort="100" velocity="100"/>

<joint_properties damping="0.0" friction="0.0"/>

</joint>

 

<link name="head">

<inertial>

<origin xyz="0.08 0 0.08"/>

<mass value="0.1" />

<inertia ixx="1.0" ixy="0.0" ixz="0.0" iyy="1.0" iyz="0.0" izz="1.0"/>

</inertial>

<visual>

<geometry>

<box size=".02 .03 .03"/>

</geometry>

<material name="white">

<color rgba="1 1 1 1"/>

</material>

</visual>

<collision>

<origin xyz="0.08 0 0.08"/>

<geometry>

<cylinder length=".02" radius="0.025"/>

</geometry>

</collision>

</link>

 

<joint name="tobox" type="fixed">

<parent link="base_link"/>

<child link="head"/>

<origin xyz="0.08 0 0.08"/>

</joint>

</xacro:macro>

 

</robot>

然后，接着把下面的幾個也按這樣的方法，創建起來。

2.gazebo屬性部分 gazebo.urdf.xacro

touch gazebo.urdf.xacro

把下面的內容粘貼上去（和上面的一樣）

<?xml version="1.0"?>  
<robot xmlns:controller="http://playerstage.sourceforge.net/gazebo/xmlschema/#controller"   

    xmlns:interface="http://playerstage.sourceforge.net/gazebo/xmlschema/#interface"   

    xmlns:sensor="http://playerstage.sourceforge.net/gazebo/xmlschema/#sensor"   

    xmlns:xacro="http://ros.org/wiki/xacro"   

    name="smartcar_gazebo">  

 

<!-- ASUS Xtion PRO camera for simulation -->  

<!-- gazebo_ros_wge100 plugin is in kt2_gazebo_plugins package -->  

<xacro:macro name="smartcar_sim">  

    <gazebo reference="base_link">  

        <material>Gazebo/Blue</material>  

    </gazebo>  

 

    <gazebo reference="right_front_wheel">  

        <material>Gazebo/FlatBlack</material>  

    </gazebo>  

 

    <gazebo reference="right_back_wheel">  

        <material>Gazebo/FlatBlack</material>  

    </gazebo>  

 

    <gazebo reference="left_front_wheel">  

        <material>Gazebo/FlatBlack</material>  

    </gazebo>  

 

    <gazebo reference="left_back_wheel">  

        <material>Gazebo/FlatBlack</material>  

    </gazebo>  

 

    <gazebo reference="head">  

        <material>Gazebo/White</material>  

    </gazebo>  

 

</xacro:macro>  

 

</robot>

接着，

3、主文件 smartcar.urdf.xacro

touch smartcar.urdf.xacro

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

    xmlns:xi="http://www.w3.org/2001/XInclude"  

    xmlns:gazebo="http://playerstage.sourceforge.net/gazebo/xmlschema/#gz"  

    xmlns:model="http://playerstage.sourceforge.net/gazebo/xmlschema/#model"  

    xmlns:sensor="http://playerstage.sourceforge.net/gazebo/xmlschema/#sensor"  

    xmlns:body="http://playerstage.sourceforge.net/gazebo/xmlschema/#body"  

    xmlns:geom="http://playerstage.sourceforge.net/gazebo/xmlschema/#geom"  

    xmlns:joint="http://playerstage.sourceforge.net/gazebo/xmlschema/#joint"  

    xmlns:controller="http://playerstage.sourceforge.net/gazebo/xmlschema/#controller"  

    xmlns:interface="http://playerstage.sourceforge.net/gazebo/xmlschema/#interface"  

    xmlns:rendering="http://playerstage.sourceforge.net/gazebo/xmlschema/#rendering"  

    xmlns:renderable="http://playerstage.sourceforge.net/gazebo/xmlschema/#renderable"  

    xmlns:physics="http://playerstage.sourceforge.net/gazebo/xmlschema/#physics"  

    xmlns:xacro="http://ros.org/wiki/xacro">  

 

  <xacro:include filename="$(find smartcar_description)/urdf/smartcar_body.urdf.xacro" />  

 

  <!-- Body of SmartCar, with plates, standoffs and Create (including sim sensors) -->  

  <smartcar_body/>  

 

  <smartcar_sim/>  
</robot>

這三個文件建立好了：

同樣，再在smartcar_description文件夾下的luanch文件夾中建立下面的文件：

$ cd ~/catkin_ws/src/launch
$ touch smartcar_display.rviz.launch

和之前一樣，把下面的代碼粘進去

<launch>  

    <param name="/use_sim_time" value="false" />  

 

    <!-- Load the URDF/Xacro model of our robot -->  

    <arg name="urdf_file" default="$(find xacro)/xacro.py '$(find smartcar_description)/urdf/smartcar.urdf.xacro'" />  

    <arg name="gui" default="false" />  
    <param name="robot_description" command="$(arg urdf_file)" />  
    <param name="use_gui" value="$(arg gui)"/>  
    <node name="arbotix" pkg="arbotix_python" type="arbotix_driver" output="screen">  
        <rosparam file="$(find smartcar_description)/config/smartcar_arbotix.yaml" command="load" /> 
        <param name="sim" value="true"/>  
    </node>  

    <node name="joint_state_publisher" pkg="joint_state_publisher" type="joint_state_publisher" >  

    </node>  

    <node name="robot_state_publisher" pkg="robot_state_publisher" type="state_publisher">  

        <param name="publish_frequency" type="double" value="20.0" />  

    </node>  

 

     <!-- We need a static transforms for the wheels -->  

    <node pkg="tf" type="static_transform_publisher" name="odom_left_wheel_broadcaster" args="0 0 0 0 0 0 /base_link /left_front_link 100" />  

    <node pkg="tf" type="static_transform_publisher" name="odom_right_wheel_broadcaster" args="0 0 0 0 0 0 /base_link /right_front_link 100" />  

 

    <node name="rviz" pkg="rviz" type="rviz" args="-d $(find smartcar_description)/urdf.rviz" />  

</launch>

 

再在smartcar_description文件夾下的config文件夾中建立下面的文件：

$ cd ~/catkin_ws/src/config
$ touch smartcar_arbotix.yaml

把下面的代碼粘進去。

port: /dev/ttyUSB0
baud: 115200
rate: 20
sync_write: True
sync_read: True
read_rate: 20
write_rate: 20

controllers: {
   #  Pololu motors: 1856 cpr = 0.3888105m travel = 4773 ticks per meter (empirical: 4100)
   base_controller: {type: diff_controller, base_frame_id: base_link, base_width: 0.26, ticks_meter: 4100, Kp: 12, Kd: 12, Ki: 0, Ko: 50, accel_limit: 1.0 }
}

在smartcar_description文件夾下，直接建立一個文件urdf.rviz

把代碼粘進去

Panels:
  - Class: rviz/Displays
    Help Height: 78
    Name: Displays
    Property Tree Widget:
      Expanded:
        - /Global Options1
        - /Status1
      Splitter Ratio: 0.5
    Tree Height: 565
  - Class: rviz/Selection
    Name: Selection
  - Class: rviz/Tool Properties
    Expanded:
      - /2D Pose Estimate1
      - /2D Nav Goal1
      - /Publish Point1
    Name: Tool Properties
    Splitter Ratio: 0.588679
  - Class: rviz/Views
    Expanded:
      - /Current View1
    Name: Views
    Splitter Ratio: 0.5
  - Class: rviz/Time
    Experimental: false
    Name: Time
    SyncMode: 0
    SyncSource: ""
Visualization Manager:
  Class: ""
  Displays:
    - Alpha: 0.5
      Cell Size: 1
      Class: rviz/Grid
      Color: 160; 160; 164
      Enabled: true
      Line Style:
        Line Width: 0.03
        Value: Lines
      Name: Grid
      Normal Cell Count: 0
      Offset:
        X: 0
        Y: 0
        Z: 0
      Plane: XY
      Plane Cell Count: 10
      Reference Frame: <Fixed Frame>
      Value: true
    - Alpha: 1
      Class: rviz/RobotModel
      Collision Enabled: false
      Enabled: true
      Links:
        {}
      Name: RobotModel
      Robot Description: robot_description
      TF Prefix: ""
      Update Interval: 0
      Value: true
      Visual Enabled: true
    - Class: rviz/TF
      Enabled: true
      Frame Timeout: 15
      Frames:
        All Enabled: true
      Marker Scale: 1
      Name: TF
      Show Arrows: true
      Show Axes: true
      Show Names: true
      Tree:
        {}
      Update Interval: 0
      Value: true
  Enabled: true
  Global Options:
    Background Color: 48; 48; 48
    Fixed Frame: /base_link
  Name: root
  Tools:
    - Class: rviz/Interact
      Hide Inactive Objects: true
    - Class: rviz/MoveCamera
    - Class: rviz/Select
    - Class: rviz/FocusCamera
    - Class: rviz/Measure
    - Class: rviz/SetInitialPose
      Topic: /initialpose
    - Class: rviz/SetGoal
      Topic: /move_base_simple/goal
    - Class: rviz/PublishPoint
      Single click: true
      Topic: /clicked_point
  Value: true
  Views:
    Current:
      Class: rviz/Orbit
      Distance: 10
      Focal Point:
        X: 0
        Y: 0
        Z: 0
      Name: Current View
      Near Clip Distance: 0.01
      Pitch: 0.465398
      Target Frame: <Fixed Frame>
      Value: Orbit (rviz)
      Yaw: 0.885398
    Saved: ~
Window Geometry:
  Displays:
    collapsed: false
  Height: 882
  Hide Left Dock: false
  Hide Right Dock: false
  QMainWindow State: 000000ff00000000fd00000004000000000000013c000002c4fc0200000008fb0000001200530065006c0065006300740069006f006e00000001e10000009b0000006400fffffffb0000001e0054006f006f006c002000500072006f007000650072007400690065007302000001ed000001df00000185000000a3fb000000120056006900650077007300200054006f006f02000001df000002110000018500000122fb000000200054006f006f006c002000500072006f0070006500720074006900650073003203000002880000011d000002210000017afb000000100044006900730070006c0061007900730100000028000002c4000000dd00fffffffb0000002000730065006c0065006300740069006f006e00200062007500660066006500720200000138000000aa0000023a00000294fb00000014005700690064006500530074006500720065006f02000000e6000000d2000003ee0000030bfb0000000c004b0069006e0065006300740200000186000001060000030c00000261000000010000010f000002c4fc0200000003fb0000001e0054006f006f006c002000500072006f00700065007200740069006500730100000041000000780000000000000000fb0000000a005600690065007700730100000028000002c4000000b000fffffffb0000001200530065006c0065006300740069006f006e010000025a000000b200000000000000000000000200000490000000a9fc0100000001fb0000000a00560069006500770073030000004e00000080000002e10000019700000003000004b00000003efc0100000002fb0000000800540069006d00650100000000000004b0000002f600fffffffb0000000800540069006d0065010000000000000450000000000000000000000259000002c400000004000000040000000800000008fc0000000100000002000000010000000a0054006f006f006c00730100000000ffffffff0000000000000000
  Selection:
    collapsed: false
  Time:
    collapsed: false
  Tool Properties:
    collapsed: false
  Views:
    collapsed: false
  Width: 1216
  X: 53
  Y: 60

最后應該是這樣子的：

然后，運行下面的指令，應該就可以了

roslaunch smartcar_description smartcar_display.rviz.launch

注：以上的所有代碼都是在一個終端里面完成的，要是不小心退出了，你可能要先找到對應的路徑才可以執行。

$ cd ~/catkin_ws/src  //尋找到src文件夾，找其他文件夾的話，以此類推。

本次參考的是：

ROS探索總結-6.使用smartcar進行仿真 - 創客智造
http://www.ncnynl.com/archives/201609/843.html

下面這個里面有弄好的文件夾，可以直接下載下來運行。

ROS探索總結-7.smartcar源碼上傳 - 創客智造
http://www.ncnynl.com/archives/201609/845.html