simple_gripper.sdf

<?xml version="1.0"?>
<sdf version="1.7">
  <!-- Note: This is the accompaning SDF file for the example demo in
       simple_gripper.cc and therefore these two files must be kept in sync.

         This file defines the model for a simple gripper having two fingers.
       The right finger is fixed to the body of the gripper. The left finger
       is attached to the main body by a prismatic joint that allows it to
       perform a grip.
         The frame of the gripper, G, has its x-axis pointing to the right
       of the gripper, its y-axis pointing "forward" (towards the fingers
       side) and, the z-axis pointing upwards. This file only defines visual
       geometry but not contact geometry, allowing the demo in
       simple_gripper.cc to add contact geometry programmatically.
  -->
  <model name="simple_gripper">
    <!-- Pose X_WG of the gripper model frame G in the world frame W. -->
    <pose>0.0555 0 0.0505 0 0 1.57</pose>
    <joint name="weld_base" type="fixed">
      <parent>world</parent>
      <child>y_translate_link</child>
    </joint>
    <link name="y_translate_link">
      <inertial>
        <mass>0.0001</mass>
        <inertia>
          <ixx>0.0001</ixx>
          <ixy>0</ixy>
          <ixz>0</ixz>
          <iyy>0.0001</iyy>
          <iyz>0</iyz>
          <izz>0.0001</izz>
        </inertia>
      </inertial>
    </link>
    <joint name="translate_joint" type="prismatic">
      <parent>y_translate_link</parent>
      <child>body</child>
      <axis>
        <xyz expressed_in="__model__">0 0 1</xyz>
        <!-- Drake attaches an actuator to all joints with a non-zero effort
             limit. We do want an actuator for this joint. -->
        <limit>
          <effort>500</effort>
        </limit>
      </axis>
    </joint>
    <link name="body">
      <pose>0 -0.049133 0 0 0 0</pose>
      <inertial>
        <mass>0.988882</mass>
        <inertia>
          <ixx>0.162992</ixx>
          <ixy>0</ixy>
          <ixz>0</ixz>
          <iyy>0.162992</iyy>
          <iyz>0</iyz>
          <izz>0.164814</izz>
        </inertia>
      </inertial>
      <visual name="visual">
        <geometry>
          <box>
            <size>0.146 0.0725 0.049521</size>
          </box>
        </geometry>
      </visual>
    </link>
    <link name="left_finger">
      <pose>0.040 0.029 0 0 0 0</pose>
      <inertial>
        <mass>0.05</mass>
        <inertia>
          <ixx>0.16</ixx>
          <ixy>0</ixy>
          <ixz>0</ixz>
          <iyy>0.16</iyy>
          <iyz>0</iyz>
          <izz>0.16</izz>
        </inertia>
      </inertial>
      <visual name="visual">
        <geometry>
          <box>
            <size>0.007 0.081 0.028</size>
          </box>
        </geometry>
      </visual>
    </link>
    <link name="right_finger">
      <pose>0.047 0.029 0 0 0 0</pose>
      <inertial>
        <mass>0.05</mass>
        <inertia>
          <ixx>0.16</ixx>
          <ixy>0</ixy>
          <ixz>0</ixz>
          <iyy>0.16</iyy>
          <iyz>0</iyz>
          <izz>0.16</izz>
        </inertia>
      </inertial>
      <visual name="visual">
        <geometry>
          <box>
            <size>0.007 0.081 0.028</size>
          </box>
        </geometry>
      </visual>
    </link>
    <joint name="weld_right_finger" type="fixed">
      <parent>body</parent>
      <child>right_finger</child>
    </joint>
    <joint name="finger_sliding_joint" type="prismatic">
      <parent>right_finger</parent>
      <child>left_finger</child>
      <axis>
        <xyz>1 0 0</xyz>
        <!-- Drake attaches an actuator to all joints with a non-zero effort
             limit. We do want an actuator for this joint. -->
        <limit>
          <effort>500</effort>
        </limit>
      </axis>
    </joint>
  </model>
</sdf>