google-deepmind · kaikwan · Apr 4, 2025 · Apr 7, 2025
diff --git a/robotiq_2f140/2f140.png b/robotiq_2f140/2f140.png
diff --git a/robotiq_2f140/2f140.xml b/robotiq_2f140/2f140.xml
@@ -0,0 +1,170 @@
+<mujoco model="robotiq_2f140">
+  <compiler angle="radian" meshdir="assets" autolimits="true"/>
+
+  <option cone="elliptic" impratio="10"/>
+
+  <asset>
+    <material name="metal" rgba="0.58 0.58 0.58 1"/>
+    <material name="silicone" rgba="0.1882 0.1882 0.1882 1"/>
+    <material name="gray" rgba="0.4627 0.4627 0.4627 1"/>
+    <material name="black" rgba="0.149 0.149 0.149 1"/>
+
+    <mesh class="2f140" scale="0.001 0.001 0.001" file="base_mount.stl"/>
+    <mesh class="2f140" file="base.stl"/>
+    <mesh class="2f140" file="driver.stl"/>
+    <mesh class="2f140" file="follower.stl"/>
+    <mesh class="2f140" file="coupler.stl"/>
+    <mesh class="2f140" scale="0.001 0.001 0.001" file="pad.stl"/>
+    <mesh class="2f140" file="spring_link.stl"/>
+  </asset>
+
+  <default>
+    <default class="2f140">
+      <general biastype="affine"/>
+      <joint axis="1 0 0"/>
+      <default class="driver">
+        <joint range="-0.8 0" armature="0.005" damping="0.1" solimplimit="0.95 0.99 0.001" solreflimit="0.005 1"/>
+      </default>
+      <default class="follower">
+        <joint range="-0.8757 0.8757" armature="0.001" solimplimit="0.95 0.99 0.001" pos="0 0.005 -0.0175" solreflimit="0.005 1"/>
+      </default>
+      <default class="spring_link">
+        <joint range="-0.8 0.29670597283" armature="0.001" stiffness="0.05" springref="-2.62" damping="0.00125"/>
+      </default>
+      <default class="coupler">
+        <joint range="0 1.57" armature="0.001" solimplimit="0.95 0.99 0.001" solreflimit="0.005 1"/>
+      </default>
+
+      <default class="visual">
+        <geom type="mesh" contype="0" conaffinity="0" group="2"/>
+      </default>
+      <default class="collision">
+        <geom type="mesh" group="3"/>
+        <default class="pad_box1">
+          <geom mass="0" type="box" pos="0 0.0457554 -0.0272203" size="0.0135 0.0325 0.00375" friction="0.7"
+            solimp="0.95 0.99 0.001" solref="0.004 1" priority="1" rgba="0.55 0.55 0.55 1"/>
+        </default>
+      </default>
+    </default>
+  </default>
+  <worldbody>
+    <body name="base_mount" pos="0 0 0.007" childclass="2f140">
+      <geom class="visual" mesh="base_mount" material="black"/>
+      <geom class="collision" mesh="base_mount"/>
+      <body name="base" pos="0 0 0.0038" quat="1 0 0 -1">
+        <inertial mass="0.777441" pos="0 -2.70394e-05 0.0354675" quat="1 -0.00152849 0 0"
+          diaginertia="0.000260285 0.000225381 0.000152708"/>
+        <geom class="visual" mesh="base" material="black"/>
+        <geom class="collision" mesh="base"/>
+        <!-- Right-hand side 4-bar linkage -->
+        <body name="right_driver" pos="0 0.030601 0.054905" quat="0 0 0.911903 0.410405">
+          <joint name="right_driver_joint" class="driver"/>
+          <geom class="visual" mesh="driver" material="gray"/>
+          <geom class="collision" mesh="driver"/>
+          <body name="right_coupler" pos="0 0.01822 0.026001" quat="1 0 0 0">
+            <inertial pos="0.000163875 0.0458404 -0.0117804" quat="0.881368 0.472423 -0.0024451 -0.000996122" mass="0.0311462" diaginertia="2.96023e-05 2.79814e-05 4.39017e-06"/>
+            <joint name="right_coupler_joint" class="coupler"/>
+            <geom class="visual" mesh="coupler" material="black"/>
+            <geom class="collision" mesh="coupler"/>
+          </body>
+        </body>
+        <body name="right_spring_link" pos="0 0.0127 0.06142" quat="0 0 -0.9135455 -0.406736">
+          <inertial mass="0.0271177" pos="0.000123012 0.0507851 0.00103969" quat="0.497203 0.502496 -0.507943 0.492221"
+            diaginertia="2.83809e-05 2.61936e-05 2.81319e-06"/>
+          <joint name="right_spring_link_joint" class="spring_link"/>
+          <geom class="visual" mesh="spring_link" material="black"/>
+          <geom class="collision" mesh="spring_link"/>
+          <body name="right_follower" pos="0 0.107454 0.01451853" quat="0.935013 -0.354613 0 0">
+            <inertial mass="0.0261503" pos="0.000119314 0.0339244 -0.021841" quat="0.545437 0.430197 -0.442938 0.566776"
+              diaginertia="1.62408e-05 1.59131e-05 2.38936e-06"/>
+            <joint name="right_follower_joint" class="follower"/>
+            <geom class="visual" mesh="follower" material="black"/>
+            <geom class="collision" mesh="follower"/>
+            <body name="right_pad" pos="0 0.012 -0.0276" quat="0.707107 -0.707107 0 0">
+              <inertial mass="0.0035" pos="0 -0.0025 0.0185" quat="0.707107 0 0 0.707107"
+                diaginertia="4.73958e-07 3.64583e-07 1.23958e-07"/>
+              <geom class="visual" mesh="pad"/>
+            </body>
+            <geom class="pad_box1" name="right_pad1"/>
+          </body>
+        </body>
+        <!-- Left-hand side 4-bar linkage -->
+        <body name="left_driver" pos="0 -0.0306011 0.054904" quat="0.410405 0.911903 0 0">
+          <joint name="left_driver_joint" class="driver"/>
+          <geom class="visual" mesh="driver" material="gray"/>
+          <geom class="collision" mesh="driver"/>
+          <body name="left_coupler" pos="0 0.01822 0.026001" quat="1 0 0 0">
+            <inertial pos="0.000163875 0.0458404 -0.0117804" quat="0.881368 0.472423 -0.0024451 -0.000996122" mass="0.0311462" diaginertia="2.96023e-05 2.79814e-05 4.39017e-06"/>
+            <joint name="left_coupler_joint" class="coupler"/>
+            <geom class="visual" mesh="coupler" material="black"/>
+            <geom class="collision" mesh="coupler"/>
+          </body>
+        </body>
+        <body name="left_spring_link" pos="0 -0.0127 0.06142" quat="0.410405 0.911903 0 0">
+          <inertial mass="0.0271177" pos="0.000123012 0.0507851 0.00103969" quat="0.497203 0.502496 -0.507943 0.492221"
+            diaginertia="2.83809e-05 2.61936e-05 2.81319e-06"/>
+          <joint name="left_spring_link_joint" class="spring_link"/>
+          <geom class="visual" mesh="spring_link" material="black"/>
+          <geom class="collision" mesh="spring_link"/>
+          <body name="left_follower" pos="0 0.107454 0.01451853" quat="0.935013 -0.354613 0 0">
+            <inertial mass="0.0261503" pos="0.000119314 0.0339244 -0.021841" quat="0.545437 0.430197 -0.442938 0.566776"
+              diaginertia="1.62408e-05 1.59131e-05 2.38936e-06"/>
+            <joint name="left_follower_joint" class="follower"/>
+            <geom class="visual" mesh="follower" material="black"/>
+            <geom class="collision" mesh="follower"/>
+            <body name="left_pad" pos="0 0.012 -0.0276" quat="0.707107 -0.707107 0 0">
+              <inertial mass="0.0035" pos="0 -0.0025 0.0185" quat="1 0 0 1"
+                diaginertia="4.73958e-07 3.64583e-07 1.23958e-07"/>
+              <geom class="visual" mesh="pad"/>
+            </body>
+            <geom class="pad_box1" name="left_pad1"/>
+          </body>
+        </body>
+      </body>
+    </body>
+  </worldbody>
+
+  <contact>
+    <exclude body1="base" body2="left_driver"/>
+    <exclude body1="base" body2="right_driver"/>
+    <exclude body1="base" body2="left_spring_link"/>
+    <exclude body1="base" body2="right_spring_link"/>
+    <exclude body1="left_driver" body2="left_spring_link"/>
+    <exclude body1="right_driver" body2="right_spring_link"/>
+    <exclude body1="right_coupler" body2="right_follower"/>
+    <exclude body1="left_coupler" body2="left_follower"/>
+  </contact>
+
+  <!--
+    This adds stability to the model by having a tendon that distributes the forces between both
+    joints, such that the equality constraint doesn't have to do that much work in order to equalize
+    both joints. Since both joints share the same sign, we split the force between both equally by
+    setting coef=0.5
+  -->
+  <tendon>
+    <fixed name="split">
+      <joint joint="right_driver_joint" coef="-0.5"/>
+      <joint joint="left_driver_joint" coef="-0.5"/>
+    </fixed>
+  </tendon>
+
+  <equality>
+    <connect anchor="0 0 0" body1="right_follower" body2="right_coupler" solimp="0.95 0.99 0.001" solref="0.005 1"/>
+    <connect anchor="0 0 0" body1="left_follower" body2="left_coupler" solimp="0.95 0.99 0.001" solref="0.005 1"/>
+    <joint joint1="right_driver_joint" joint2="left_driver_joint" polycoef="0 1 0 0 0" solimp="0.95 0.99 0.001"
+      solref="0.005 1"/>
+  </equality>
+
+  <!--
+    The general actuator below is a customized position actuator (with some damping) where
+    gainprm[0] != kp (see http://mujoco.org/book/modeling.html#position).
+    The reason why gainprm[0] != kp is because the control input range has to be re-scaled to
+    [0, 255]. The joint range is currently set at [0, 0.8], the control range is [0, 255] and
+    kp = 100. Tau = Kp * scale * control_input - Kp * error, max(Kp * scale * control_input) = 0.8,
+    hence scale = 0.8 * 100 / 255
+  -->
+  <actuator>
+    <general class="2f140" name="fingers_actuator" tendon="split" forcerange="-5 5" ctrlrange="0 255"
+      gainprm="0.3137255 0 0" biasprm="0 -100 -10"/>
+  </actuator>
+</mujoco>
diff --git a/robotiq_2f140/LICENSE b/robotiq_2f140/LICENSE
@@ -0,0 +1,23 @@
+Copyright (c) 2013, ROS-Industrial
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without modification,
+are permitted provided that the following conditions are met:
+
+  Redistributions of source code must retain the above copyright notice, this
+  list of conditions and the following disclaimer.
+
+  Redistributions in binary form must reproduce the above copyright notice, this
+  list of conditions and the following disclaimer in the documentation and/or
+  other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
+ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/robotiq_2f140/README.md b/robotiq_2f140/README.md
@@ -0,0 +1,33 @@
+# Robotiq 2F-140 Description (MJCF)
+
+Requires MuJoCo 2.2.2 or later.
+
+## Overview
+
+This package contains a simplified robot description (MJCF) of the [Robotiq 140mm
+2-Finger Adaptive
+Gripper](https://robotiq.com/products/2f85-140-adaptive-robot-gripper) developed
+by [Robotiq](https://robotiq.com/). It is derived from the [publicly available
+URDF
+description](https://github.com/ros-industrial/robotiq/tree/kinetic-devel/robotiq_2f_140_gripper_visualization).
+
+<p float="left">
+  <img src="2f140.png" width="400">
+</p>
+
+## URDF → MJCF derivation steps
+
+1. Added `<mujoco> <compiler discardvisual="false"/> </mujoco>` to the URDF's
+   `<robot>` clause in order to preserve visual geometries.
+2. Loaded the URDF into MuJoCo and saved a corresponding MJCF.
+3. Manually edited the MJCF to extract common properties into the `<default>` section.
+4. Added `<exclude>` clauses to prevent collisions between the linkage bodies.
+5. Broke up collision pads into two pads for more contacts.
+6. Increased pad friction and priority.
+7. Added `impratio=10` for better noslip.
+8. Added `scene.xml` which includes the robot, with a textured groundplane, skybox, and haze.
+9. Added hanging box to `scene.xml`.
+
+## License
+
+This model is released under a [BSD-2-Clause License](LICENSE).
diff --git a/robotiq_2f140/assets/base.stl b/robotiq_2f140/assets/base.stl
diff --git a/robotiq_2f140/assets/base_mount.stl b/robotiq_2f140/assets/base_mount.stl
diff --git a/robotiq_2f140/assets/coupler.stl b/robotiq_2f140/assets/coupler.stl
diff --git a/robotiq_2f140/assets/driver.stl b/robotiq_2f140/assets/driver.stl
diff --git a/robotiq_2f140/assets/follower.stl b/robotiq_2f140/assets/follower.stl
diff --git a/robotiq_2f140/assets/pad.stl b/robotiq_2f140/assets/pad.stl
diff --git a/robotiq_2f140/assets/spring_link.stl b/robotiq_2f140/assets/spring_link.stl
diff --git a/robotiq_2f140/scene.xml b/robotiq_2f140/scene.xml
@@ -0,0 +1,40 @@
+<mujoco model="2f140 scene">
+  <include file="2f140.xml"/>
+
+  <!-- Add some fluid viscosity to prevent the hanging box from jiggling forever -->
+  <option viscosity="0.1"/>
+
+  <statistic center="0 0 0.05" extent="0.3"/>
+
+  <visual>
+    <headlight diffuse="0.6 0.6 0.6" ambient="0.3 0.3 0.3" specular="0 0 0"/>
+    <rgba haze="0.15 0.25 0.35 1"/>
+    <global azimuth="60" elevation="-20"/>
+  </visual>
+
+  <asset>
+    <texture type="skybox" builtin="gradient" rgb1="0.3 0.5 0.7" rgb2="0 0 0" width="512" height="3072"/>
+    <texture type="2d" name="groundplane" builtin="checker" mark="edge" rgb1="0.2 0.3 0.4" rgb2="0.1 0.2 0.3"
+      markrgb="0.8 0.8 0.8" width="300" height="300"/>
+    <material name="groundplane" texture="groundplane" texuniform="true" texrepeat="5 5" reflectance="0.2"/>
+  </asset>
+
+  <worldbody>
+    <light pos="0 0 1"/>
+    <light pos="0 -0.2 1" dir="0 0.2 -0.8" directional="true"/>
+    <geom name="floor" size="0 0 0.05" type="plane" material="groundplane"/>
+    <site size="0.002" pos="0 0 0.27" name="anchor"/>
+    <body name="object" pos="0 0 0.26">
+      <freejoint/>
+      <geom type="box" size="0.015 0.015 0.015" rgba=".5 .7 .5 1" friction=".5" priority="1"/>
+      <site size="0.002" pos="0.015 0.015 0.015" name="hook"/>
+    </body>
+  </worldbody>
+
+  <tendon>
+    <spatial limited="true" range="0 0.02" width="0.001">
+      <site site="hook"/>
+      <site site="anchor"/>
+    </spatial>
+  </tendon>
+</mujoco>