Moveit! Study notes (two): URDF

URDF

URDF (unified robot description format) unified robot description format, using xml format to describe the robot model. Among them, the linklabel describes the link information, the jointlabel describes the joint information, the transmissionlabel describes the relationship between the motor and the joint, and the gazebolabel describes the simulation information of the robotic arm. The robotlabel is the root label describing the entire robotic arm.

Base model

First build the overall structure of the robotic arm, without considering the details. The following urdf file describes the structure of a simple robotic arm model composed of three links and two revolute joints.

    <robot name="myrobot">

      <link name="link1" />
      <link name="link2" />
      <link name="link3" />

      <joint name="joint1" type="continuous">
        <parent link="link1"/>
        <child link="link2"/>
      </joint>

      <joint name="joint2" type="continuous">
        <parent link="link2"/>
        <child link="link3"/>
      </joint>

    </robot>

Complete model

    <robot name="myrobot">
    
      <link name="link1" />
      <link name="link2" />
      <link name="link3" />
   
      <joint name="joint1" type="continuous">
        <parent link="link1"/>
        <child link="link2"/>
        <origin xyz="5 3 0" rpy="0 0 0" />
      </joint>
      
      <joint name="joint2" type="continuous">
        <parent link="link2"/>
        <child link="link3"/>
        <origin xyz="-2 5 0" rpy="0 0 1.57" />
      </joint>

    </robot>