自动驾驶系列（六）创建简单小车仿真模型

一、创建机器人模型描述包

cd ~/catkin_ws/src/
catkin_create_pkg  smartcar_description  urdf
mkdir urdf
cd urdf
gedit smartcar.urdf

粘贴以下内容：

<?xml version="1.0"?>
<robot name="smartcar">
  <link name="base_link">
    <visual>
      <geometry>
        <box size="0.25 .16 .05"/>
	</geometry>
	<origin rpy="0 0 1.57075" xyz="0 0 0"/>
    <material name="blue">
		<color rgba="0 0 .8 1"/>
	</material>
    </visual>
 </link>

 <link name="right_front_wheel">
    <visual>
      <geometry>
        <cylinder length=".02" radius="0.025"/>
      </geometry>
      <material name="black">
        <color rgba="0 0 0 1"/>
      </material>
    </visual>
  </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 0" xyz="0.08 0.1 -0.03"/>
    <limit effort="100" velocity="100"/>
    <joint_properties damping="0.0" friction="0.0"/>
  </joint>

  <link name="right_back_wheel">
    <visual>
      <geometry>
        <cylinder length=".02" radius="0.025"/>
      </geometry>
      <material name="black">
        <color rgba="0 0 0 1"/>
      </material>
    </visual>
  </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 0" xyz="0.08 -0.1 -0.03"/>
    <limit effort="100" velocity="100"/>
    <joint_properties damping="0.0" friction="0.0"/>
 </joint>

 <link name="left_front_wheel">
    <visual>
      <geometry>
        <cylinder length=".02" radius="0.025"/>
      </geometry>
      <material name="black">
        <color rgba="0 0 0 1"/>
      </material>
    </visual>
  </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 0" xyz="-0.08 0.1 -0.03"/>
    <limit effort="100" velocity="100"/>
    <joint_properties damping="0.0" friction="0.0"/>
  </joint>

  <link name="left_back_wheel">
    <visual>
      <geometry>
        <cylinder length=".02" radius="0.025"/>
      </geometry>
      <material name="black">
        <color rgba="0 0 0 1"/>
      </material>
    </visual>
  </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 0" xyz="-0.08 -0.1 -0.03"/>
    <limit effort="100" velocity="100"/>
    <joint_properties damping="0.0" friction="0.0"/>
  </joint>

  <link name="head">
    <visual>
      <geometry>
        <box size=".02 .03 .03"/>
      </geometry>
	  <material name="white">
		  <color rgba="1 1 1 1"/>
	  </material>
    </visual>
  </link>

  <joint name="tobox" type="fixed">
    <parent link="base_link"/>
    <child link="head"/>
    <origin xyz="0 0.08 0.025"/>
  </joint>
</robot>

可以检查urdf语法：

sudo apt install liburdfdom-tools
check_urdf smartcar.urdf

返回检查结果：

二、在rviz里查看3D模型

        在smartcar_description文件夹下建立launch文件夹，创建智能车的描述文件 base.urdf.rviz.launch，描述代码如下：

<launch>
	<arg name="model" />
	<arg name="gui" default="False" />
	<param name="robot_description" textfile="$(find smartcar_description)/urdf/smartcar.urdf" />
	<param name="use_gui" value="$(arg gui)"/>
	<node name="joint_state_publisher_gui" pkg="joint_state_publisher_gui" type="joint_state_publisher_gui" />
	<node name="robot_state_publisher" pkg="robot_state_publisher" type="robot_state_publisher" />
	<node name="rviz" pkg="rviz" type="rviz" args="-d $(find urdf_tutorial)/urdf.vcg" />
</launch>

在终端启动launch文件：

roslaunch  smartcar_description  base.urdf.rviz.launch  gui:=true

 在RVIZ界面中，手动添加，RobotModol。