robot.urdf.xacro

<?xml version="1.0"?>
<!--
DH for UR5:
a = [0.00000, -0.42500, -0.39225,  0.00000,  0.00000,  0.0000]
d = [0.089159,  0.00000,  0.00000,  0.10915,  0.09465,  0.0823]
alpha = [ 1.570796327, 0, 0, 1.570796327, -1.570796327, 0 ]
q_home_offset = [0, -1.570796327, 0, -1.570796327, 0, 0]
joint_direction = [-1, -1, 1, 1, 1, 1]
mass = [3.7000, 8.3930, 2.2750, 1.2190, 1.2190, 0.1879]
center_of_mass = [ [0, -0.02561, 0.00193], [0.2125, 0, 0.11336], [0.11993, 0.0, 0.0265], [0, -0.0018, 0.01634], [0, 0.0018,0.01634], [0, 0, -0.001159] ]
-->
<robot name="universal_robot">

  <property name="pi" value="3.14159265" />

<!-- Inertia parameters -->
  <property name="base_mass" value="4.0.0" /> <!-- Invented number, only matters for simulator -->
  <property name="shoulder_mass" value="3.7000" />
  <property name="upper_arm_mass" value="8.3930" />
  <property name="forearm_mass" value="2.2750" />
  <property name="wrist_1_mass" value="1.2190" />
  <property name="wrist_2_mass" value="1.2190" />
  <property name="wrist_3_mass" value="0.1879" />

  <property name="shoulder_cog" value="0.0 0.00193 -0.02561" />
  <property name="upper_arm_cog" value="0.0 -0.024201 0.2125" />   <!-- 0.11336 - 0.089159 =  -->
  <property name="forearm_cog" value="0.0 0.0265 0.11993" />       <!-- 0.119 is not half of 0.39225, is this really correct? -->
  <property name="wrist_1_cog" value="0.0 0.110949 0.01634" />     <!-- 0.0018 + 0.10915 = 0.110949 -->
  <property name="wrist_2_cog" value="0.0 0.0018 0.11099" />       <!-- 0.01634 + 0.09465 = 0.11099-->
  <property name="wrist_3_cog" value="0.0 0.001159 0.0" />

<!-- Kinematic model -->
  <property name="shoulder_height" value="0.089159" />  
  <property name="shoulder_offset" value="0.13915" />  <!-- shoulder_offset - elbow_offset + wrrist_1_offset = 0.10915 -->
  <property name="upper_arm_length" value="0.42500" />
  <property name="elbow_offset" value="0.130" />       <!-- CAD measured -->
  <property name="forearm_length" value="0.39225" />
  <property name="wrist_1_length" value="0.100" />     <!-- CAD measured -->
  <property name="wrist_2_length" value="0.09465" />
  <property name="wrist_3_length" value="0.0823" />

  <property name="shoulder_radius" value="0.060" />   <!-- manually measured -->
  <property name="upper_arm_radius" value="0.054" />  <!-- manually measured -->
  <property name="elbow_radius" value="0.060" />      <!-- manually measured -->
  <property name="forearm_radius" value="0.038" />    <!-- manually measured -->
  <property name="wrist_radius" value="0.035" />      <!-- manually measured -->

<!-- Collision model -->
  <property name="base_collision_length" value="0.160" />      <!-- manually measured -->
  <property name="shoulder_collision_length" value="0.200" />  <!-- manually measured -->
  <property name="shoulder_collision_offset" value="0.035" />  <!-- manually measured -->
  <property name="elbow_collision_length" value="0.200" />     <!-- manually measured -->
  <property name="elbow_collision_offset" value="0.035" />     <!-- manually measured -->




  <link name="base_link" >
    <inertial>
      <mass value="${base_mass}" />
      <inertia ixx="1.0" ixy="0.0" ixz="0.0" iyy="1.0" iyz="0.0" izz="1.0"/>
    </inertial>
  </link>

  <joint name="shoulder_pan_joint" type="revolute">
    <parent link="base_link" />
    <child link = "shoulder_link" />
    <origin xyz="0.0 0.0 ${shoulder_height}" rpy="0.0 0.0 0.0" />
    <axis xyz="0.0 0.0 1.0" />
    <limit lower="${-2.0 * pi}" upper="${2.0 * pi}" effort="10.0" velocity="${pi}"/>
    <dynamics damping="0.1" friction="0.1"/>
  </joint>
  
  <link name="shoulder_link">
    <visual>
      <geometry>
        <cylinder length="${base_collision_length}" radius="${shoulder_radius}"/>
      </geometry>
      <origin xyz="0.0 0.0 ${base_collision_length / 2.0 - shoulder_height}" rpy="0.0 0.0 0.0" />
    </visual>
    <collision>
      <geometry>
        <cylinder length="${shoulder_height}" radius="${shoulder_radius}"/>
      </geometry>
      <origin xyz="0.0 0.0 ${-shoulder_height/2.0}" rpy="0.0 0.0 0.0" />
    </collision>
    <inertial>
      <mass value="${shoulder_mass}" />
      <inertia ixx="1.0" ixy="0.0" ixz="0.0" iyy="1.0" iyz="0.0" izz="1.0"/>
      <origin xyz="${shoulder_cog}" rpy="0.0 0.0 0.0" />
    </inertial>
  </link>

  <joint name="shoulder_lift_joint" type="revolute">
    <parent link="shoulder_link" />
    <child link = "upper_arm_link" />
    <origin xyz="0.0 ${shoulder_offset} 0.0" rpy="0.0 ${pi / 2.0} 0.0" />    
    <axis xyz="0.0 1.0 0.0" />
    <limit lower="${-2.0 * pi}" upper="${2.0 * pi}" effort="10.0" velocity="${pi}"/>
    <dynamics damping="0.1" friction="0.1"/>
  </joint>

  <link name="upper_arm_link">
    <visual>
      <geometry>
       <mesh filename="package://ur5_description/meshes/UpperArm.dae" />
      </geometry>
      <origin xyz="0.0 0.0 0.0" rpy="0.0 0.0 0.0" />
    </visual>
    <collision>
      <geometry>
        <cylinder length="${upper_arm_length}" radius="${upper_arm_radius}"/>
      </geometry>
      <origin xyz="0.0 0.0 ${upper_arm_length/2.0}" rpy="0.0 0.0 0.0" />
    </collision>
    <inertial>
      <mass value="${upper_arm_mass}" />
      <inertia ixx="1.0" ixy="0.0" ixz="0.0" iyy="1.0" iyz="0.0" izz="1.0"/>
      <origin xyz="${upper_arm_cog}" rpy="0.0 0.0 0.0" />
    </inertial>
  </link>

  <joint name="elbow_joint" type="revolute">
    <parent link="upper_arm_link" />
    <child link = "forearm_link" />
    <origin xyz="0.0 ${-elbow_offset} ${upper_arm_length}" rpy="0.0 0.0 0.0" />
    <axis xyz="0.0 1.0 0.0" />
    <limit lower="${-2.0 * pi}" upper="${2.0 * pi}" effort="10.0" velocity="${pi}"/>
    <dynamics damping="0.1" friction="0.1"/>
  </joint>

  <link name="forearm_link">
    <visual>
      <geometry>
        <cylinder length="${forearm_length}" radius="${forearm_radius}"/>
      </geometry>
      <origin xyz="0.0 0.0 ${forearm_length/2.0}" rpy="0.0 0.0 0.0" />
    </visual>
    <collision>
      <geometry>
        <cylinder length="${forearm_length}" radius="${forearm_radius}"/>
      </geometry>
      <origin xyz="0.0 0.0 ${forearm_length/2.0}" rpy="0.0 0.0 0.0" />
    </collision>
    <inertial>
      <mass value="${forearm_mass}" />
      <origin xyz="${forearm_cog}" rpy="0.0 0.0 0.0" />
      <inertia ixx="1.0" ixy="0.0" ixz="0.0" iyy="1.0" iyz="0.0" izz="1.0"/>
    </inertial>
  </link>

  <joint name="wrist_1_joint" type="revolute">
    <parent link="forearm_link" />
    <child link = "wrist_1_link" />
    <origin xyz="0.0 0.0 ${forearm_length}" rpy="0.0 ${pi / 2.0} 0.0" />
    <axis xyz="0.0 1.0 0.0" />
    <limit lower="${-2.0 * pi}" upper="${2.0 * pi}" effort="10.0" velocity="${pi}"/>
    <dynamics damping="0.1" friction="0.1"/>
  </joint>

  <link name="wrist_1_link">
    <visual>
      <geometry>
        <cylinder length="${wrist_1_length}" radius="${wrist_radius}"/>
      </geometry>
      <origin xyz="0.0 ${wrist_1_length/2.0} 0.0" rpy="${-pi/2.0} 0.0 0.0" />
    </visual>
    <collision>
      <geometry>
        <cylinder length="${wrist_1_length}" radius="${wrist_radius}"/>
      </geometry>
      <origin xyz="0.0 ${wrist_1_length/2.0} 0.0" rpy="${-pi/2.0} 0.0 0.0" />
    </collision>
    <inertial>
      <mass value="${wrist_1_mass}" />
      <origin xyz="${wrist_1_cog}" rpy="0.0 0.0 0.0" />
      <inertia ixx="1.0" ixy="0.0" ixz="0.0" iyy="1.0" iyz="0.0" izz="1.0"/>
    </inertial>
  </link>

  <joint name="wrist_2_joint" type="revolute">
    <parent link="wrist_1_link" />
    <child link = "wrist_2_link" />
    <origin xyz="0.0 ${wrist_1_length} 0.0" rpy="0.0 0.0 0.0" />
    <axis xyz="0.0 0.0 1.0" />
    <limit lower="${-2.0 * pi}" upper="${2.0 * pi}" effort="10.0" velocity="${pi}"/>
    <dynamics damping="0.1" friction="0.1"/>
  </joint>

  <link name="wrist_2_link">
    <visual>
      <geometry>
        <cylinder length="${wrist_2_length}" radius="${wrist_radius}"/>
      </geometry>
      <origin xyz="0.0 0.0 ${wrist_2_length/2.0}" rpy="0.0 0.0 0.0" />
    </visual>
    <collision>
      <geometry>
        <cylinder length="${wrist_2_length}" radius="${wrist_radius}"/>
      </geometry>
      <origin xyz="0.0 0.0 ${wrist_2_length/2.0}" rpy="0.0 0.0 0.0" />
    </collision>
    <inertial>
      <mass value="${wrist_2_mass}" />
      <origin xyz="${wrist_2_cog}" rpy="0.0 0.0 0.0" />
      <inertia ixx="1.0" ixy="0.0" ixz="0.0" iyy="1.0" iyz="0.0" izz="1.0"/>
    </inertial>
  </link>

  <joint name="wrist_3_joint" type="revolute">
    <parent link="wrist_2_link" />
    <child link = "wrist_3_link" />
    <origin xyz="0.0 0.0 ${wrist_3_length}" rpy="0.0 0.0 0.0" />
    <axis xyz="0.0 1.0 0.0" />
    <limit lower="${-2.0 * pi}" upper="${2.0 * pi}" effort="10.0" velocity="${pi}"/>
    <dynamics damping="0.1" friction="0.1"/>
  </joint>

  <link name="wrist_3_link">
    <visual>
      <geometry>
        <cylinder length="${wrist_3_length}" radius="${wrist_radius}"/>
      </geometry>
      <origin xyz="0.0 ${wrist_3_length/2.0} 0.0" rpy="${-pi/2.0} 0.0 0.0" />
    </visual>
    <collision>
      <geometry>
        <cylinder length="${wrist_3_length}" radius="${wrist_radius}"/>
      </geometry>
      <origin xyz="0.0 ${wrist_3_length/2.0} 0.0" rpy="${-pi/2.0} 0.0 0.0" />
    </collision>
    <inertial>
      <mass value="${wrist_3_mass}" />
      <origin xyz="${wrist_3_cog}" rpy="0.0 0.0 0.0" />
      <inertia ixx="1.0" ixy="0.0" ixz="0.0" iyy="1.0" iyz="0.0" izz="1.0"/>
    </inertial>
  </link>
  
  <joint name="ee_fixed_joint" type="fixed">
    <parent link="wrist_3_link" />
    <child link = "ee_link" />
    <origin xyz="0.0 ${wrist_3_length} 0.0" rpy="0.0 0.0 ${pi/2.0}" />    
  </joint>

  <link name="ee_link">
    <visual>
      <geometry>
        <cylinder length="0.01" radius="${wrist_radius * 1.25}"/>
      </geometry>
      <origin xyz="0.0 0.0 0.0" rpy="0.0 ${-pi/2.0} 0.0" />
    </visual>
    <collision>
      <geometry>
        <cylinder length="0.01" radius="${wrist_radius * 1.25}"/>
      </geometry>
      <origin xyz="0.0 0.0 0.0" rpy="0.0 ${-pi/2.0} 0.0" />
    </collision>
  </link>
  


  <!-- Extra links for collision model -->
  <joint name="shoulder_collision_joint" type="fixed">
    <parent link="upper_arm_link" />
    <child link = "shoulder_collision_link" />
  </joint>
  <link name="shoulder_collision_link">
    <collision>
      <geometry>
        <cylinder length="${shoulder_collision_length}" radius="${shoulder_radius}"/>
      </geometry>
      <origin xyz="0.0 ${-shoulder_collision_offset} 0.0" rpy="${-pi / 2.0} 0.0 0.0" />
    </collision>
  </link>

  <joint name="elbow_collision_joint" type="fixed">
    <parent link="upper_arm_link" />
    <child link = "elbow_collision_link" />
  </joint>
  <link name="elbow_collision_link">
    <collision>
      <geometry>
        <cylinder length="${elbow_collision_length}" radius="${elbow_radius}"/>
      </geometry>
      <origin xyz="0.0 ${-elbow_collision_offset} ${upper_arm_length}" rpy="${pi / 2.0} 0.0 0.0" />
    </collision>
  </link>

  <gazebo reference="universal_robot">
    <material>Gazebo/Blue</material>
  </gazebo>

</robot>