cart_pole.urdf

<?xml version="1.0"?>

<robot xmlns="http://drake.mit.edu"
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 name="CartPole">

  <mujoco>
    <compiler discardvisual="false"/>

    <option timestep="0.01">
    </option>
  </mujoco>

  <link name="world">
    <!-- <visual> -->
    <!--   <origin xyz="0 0 -5" rpy="0 0 0" /> -->
    <!--   <geometry> -->
    <!--     <box size="1000 1000 10" /> -->
    <!--   </geometry> -->
    <!--   <material> -->
    <!--     <color rgba="0.93 .74 .4 1" /> -->
    <!--   </material> -->
    <!-- </visual> -->
  </link>

  <link name="cart">
    <inertial>
      <origin xyz="0 0 .25" rpy="0 0 0" />
      <mass value="10" />
      <inertia ixx="1" ixy="0" ixz="0" iyy="1" iyz="0" izz="1" />
    </inertial>
    <visual>
      <origin xyz="0 0 0" rpy="0 0 0" />
      <geometry>
        <box size=".4 .1 .1" />
      </geometry>
      <material>
        <color rgba="0 1 0 1" />
      </material>
    </visual>
  </link>

  <link name="pole">
    <inertial>
      <origin xyz="0 0 -.5" rpy="0 0 0" />
      <mass value="1" />
      <inertia ixx="1" ixy="0" ixz="0" iyy="1" iyz="0" izz="1" />
    </inertial>
    <visual>
      <origin xyz="0 0 -.25" rpy="0 0 0" />
      <geometry>
         <cylinder length=".5" radius=".01" />
      </geometry>
      <material>
        <color rgba="1 0 0 1" />
      </material>
    </visual>
    <visual>
      <origin xyz="0 0 -.5" rpy="0 0 0" />
      <geometry>
         <sphere radius=".05" />
      </geometry>
      <material>
        <color rgba="0 0 1 1" />
      </material>
    </visual>
  </link>

  <joint name="x" type="prismatic">
    <parent link="world" />
    <child link="cart" />
    <origin xyz="0 0 0" />
    <axis xyz="1 0 0" />
  </joint>

  <joint name="theta" type="continuous">
    <parent link="cart" />
    <child link="pole" />
    <origin xyz="0 0 0" />
    <axis xyz="0 -1 0" />
  </joint>

  <transmission type="SimpleTransmission" name="cart_force">
    <actuator name="force" />
    <joint name="x" />
    <mechanicalReduction>1</mechanicalReduction>
  </transmission>
</robot>