mujoco

<mujoco>
  <worldbody>
    <body name="motor1" pos="0 0.1 0">
      <joint name="slide1" type="slide" axis="0 0 1"/>
      <geom size=".03"/>
    </body>
    <body name="motor2" pos="0 0.2 0">
      <joint name="slide2" type="slide" axis="0 0 1"/>
      <geom size=".03"/>
    </body>
    <body name="motor3" pos="0 0.3 0">
      <joint name="slide3" type="slide" axis="0 0 1"/>
      <geom size=".03"/>
    </body>
    <body name="motor4" pos="0 0.4 0">
      <joint name="joint4"/>
      <geom size=".03"/>
    </body>
  </worldbody>

  <actuator>
    <!-- DC motor back-EMF stateless damping -->
    <dcmotor name="dc_bias" joint="slide1" motorconst="2.0" resistance="0.5"/>

    <!-- DC motor velocity controller damping -->
    <dcmotor name="dc_vel" joint="slide2" motorconst="1.0" resistance="1.0" input="velocity" controller="0 5"/>

    <!-- DC motor position controller damping -->
    <dcmotor name="dc_pos" joint="slide3" motorconst="1.0" resistance="1.0" input="position" controller="10 0 5"/>

    <!-- DC motor with LuGre friction (sigma1 micro-damping) -->
    <dcmotor name="dc_lugre" joint="joint4" motorconst="0.05" resistance="2.0"
             lugre="1e4 100 0.001 0.005 0.008 0.1"/>
  </actuator>
</mujoco>