We are in the process of making a robot with both arms by modifying the open_manipulter package. We made two arms with urdf, but the control bar is only on the left arm. How do I get control bars for both arms?

<?xml version="1.0"?>
<!-- Open_Manipulator Chain -->
<robot name="open_manipulator_chain" xmlns:xacro="http://www.ros.org/wiki/xacro">

  <!-- some parameters -->
  <xacro:property name="pi" value="3.141592654" />

  <!-- Import all Gazebo-customization elements, including Gazebo colors -->
  <xacro:include filename="$(find open_manipulator_description)/urdf/open_manipulator_chain.gazebo.xacro" />
  <!-- Import Rviz colors -->
  <xacro:include filename="$(find open_manipulator_description)/urdf/materials.xacro" />

  <!-- World -->
  <link name="world">
  </link>

  <!-- World fixed joint1-->
  <joint name="world_fixed1" type="fixed">
    <origin xyz="0 0.25 0" rpy="0 0 0"/>
    <parent link="world"/>
    <child link="link1"/>
  </joint>


  <!-- World fixed joint2-->
  <joint name="world_fixed2" type="fixed">
    <origin xyz="0 -0.25 0" rpy="0 0 0"/>
    <parent link="world"/>
    <child link="link4"/>
  </joint>

  <!-- Link 1 -->
  <link name="link1">
    <collision>
      <origin xyz="0.0 0.0 0.0" rpy="0 0 0"/>
      <geometry>
        <mesh filename="package://open_manipulator_description/meshes/chain_link1.stl" scale="0.001 0.001 0.001"/>
      </geometry>
    </collision>

    <visual>
      <origin xyz="0.0 0.0 0.0" rpy="0 0 0"/>
      <geometry>
        <mesh filename="package://open_manipulator_description/meshes/chain_link1.stl" scale="0.001 0.001 0.001"/>
      </geometry>
      <material name="grey"/>
    </visual>

    <inertial>
      <origin xyz="0 0 0" />
      <mass value="0.01" />
      <inertia ixx="0.001" ixy="0.0" ixz="0.0"
               iyy="0.001" iyz="0.0"
               izz="0.001" />
    </inertial>
  </link>

  <!-- Joint 1 -->
  <joint name="joint1" type="revolute">
    <parent link="link1"/>
    <child link="link2"/>
    <origin xyz="0.012 0.0 0.036" rpy="0 0 0"/>
    <axis xyz="0 0 1"/>
    <limit velocity="6.5" effort="1000" lower="${-pi*0.9}" upper="${pi*0.9}" />
  </joint>

  <!-- Transmission 1 -->
  <transmission name="tran1">
    <type>transmission_interface/SimpleTransmission</type>
    <joint name="joint1">
      <hardwareInterface>PositionJointInterface</hardwareInterface>
    </joint>
    <actuator name="motor1">
      <hardwareInterface>PositionJointInterface</hardwareInterface>
      <mechanicalReduction>1</mechanicalReduction>
    </actuator>
  </transmission>

  <!--  Link 2 -->
  <link name="link2">
    <collision>
      <origin xyz="0.0 0.0 0.040" rpy="0 0 0"/>
      <geometry>
        <mesh filename="package://open_manipulator_description/meshes/chain_link2.stl" scale="0.001 0.001 0.001"/>
      </geometry>
    </collision>

    <visual>
      <origin xyz="0.0 0.0 0.040" rpy="0 0 0"/>
      <geometry>
        <mesh filename="package://open_manipulator_description/meshes/chain_link2.stl" scale="0.001 0.001 0.001"/>
      </geometry>
      <material name="grey"/>
    </visual>

    <inertial>
      <origin xyz="0 0 0" />
      <mass value="0.01" />
      <inertia ixx="0.001" ixy="0.0" ixz="0.0"
               iyy="0.001" iyz="0.0"
               izz="0.001" />
    </inertial>
  </link>

  <!--  Joint 2 -->
  <joint name="joint2" type="revolute">
    <parent link="link2"/>
    <child link="link3"/>
    <origin xyz="0.0 0.0 0.040" rpy="0 0 0"/>
    <axis xyz="0 -1 0"/>
    <limit velocity="6.5" effort="1000" lower="${-pi*0.9}" upper="${pi*0.9}" />
  </joint>

  <!-- Transmission 2 -->
  <transmission name="tran2">
    <type>transmission_interface/SimpleTransmission</type>
    <joint name="joint2">
      <hardwareInterface>PositionJointInterface</hardwareInterface>
    </joint>
    <actuator name="motor2">
      <hardwareInterface>PositionJointInterface</hardwareInterface>
      <mechanicalReduction>1</mechanicalReduction>
    </actuator>
  </transmission>

  <!--  Link 3 -->
  <link name="link3">
    <collision>
      <origin xyz="0.022 0 0.122" rpy="0 0 0"/>
      <geometry>
        <mesh filename="package://open_manipulator_description/meshes/chain_link3.stl" scale="0.001 0.001 0.001"/>
      </geometry>
    </collision>

    <visual>
      <origin xyz="0.022 0 0.122" rpy="0 0 0"/>
      <geometry>
        <mesh filename="package://open_manipulator_description/meshes/chain_link3.stl" scale="0.001 0.001 0.001"/>
      </geometry>
      <material name="grey"/>
    </visual>

    <inertial>
      <origin xyz="0 0 0" />
      <mass value="0.01" />
      <inertia ixx="0.001" ixy="0.0" ixz="0.0"
               iyy="0.001" iyz="0.0"
               izz="0.001" />
    </inertial>
  </link>






  <!-- Link 4 -->
  <link name="link4">
    <collision>
      <origin xyz="0.0 0.0 0.0" rpy="0 0 0"/>
      <geometry>
        <mesh filename="package://open_manipulator_description/meshes/chain_link1.stl" scale="0.001 0.001 0.001"/>
      </geometry>
    </collision>

    <visual>
      <origin xyz="0.0 0.0 0.0" rpy="0 0 0"/>
      <geometry>
        <mesh filename="package://open_manipulator_description/meshes/chain_link1.stl" scale="0.001 0.001 0.001"/>
      </geometry>
      <material name="grey"/>
    </visual>

    <inertial>
      <origin xyz="0 0 0" />
      <mass value="0.01" />
      <inertia ixx="0.001" ixy="0.0" ixz="0.0"
               iyy="0.001" iyz="0.0"
               izz="0.001" />
    </inertial>
  </link>

  <!-- Joint 3 -->
  <joint name="joint3" type="revolute">
    <parent link="link4"/>
    <child link="link5"/>
    <origin xyz="0.012 0.0 0.036" rpy="0 0 0"/>
    <axis xyz="0 0 1"/>
    <limit velocity="6.5" effort="1000" lower="${-pi*0.9}" upper="${pi*0.9}" />
  </joint>

  <!-- Transmission 3 -->
  <transmission name="tran3">
    <type>transmission_interface/SimpleTransmission</type>
    <joint name="joint3">
      <hardwareInterface>PositionJointInterface</hardwareInterface>
    </joint>
    <actuator name="motor3">
      <hardwareInterface>PositionJointInterface</hardwareInterface>
      <mechanicalReduction>1</mechanicalReduction>
    </actuator>
  </transmission>

  <!--  Link 5 -->
  <link name="link5">
    <collision>
      <origin xyz="0.0 0.0 0.040" rpy="0 0 0"/>
      <geometry>
        <mesh filename="package://open_manipulator_description/meshes/chain_link2.stl" scale="0.001 0.001 0.001"/>
      </geometry>
    </collision>

    <visual>
      <origin xyz="0.0 0.0 0.040" rpy="0 0 0"/>
      <geometry>
        <mesh filename="package://open_manipulator_description/meshes/chain_link2.stl" scale="0.001 0.001 0.001"/>
      </geometry>
      <material name="grey"/>
    </visual>

    <inertial>
      <origin xyz="0 0 0" />
      <mass value="0.01" />
      <inertia ixx="0.001" ixy="0.0" ixz="0.0"
               iyy="0.001" iyz="0.0"
               izz="0.001" />
    </inertial>
  </link>

  <!--  Joint 4 -->
  <joint name="joint4" type="revolute">
    <parent link="link5"/>
    <child link="link6"/>
    <origin xyz="0.0 0.0 0.040" rpy="0 0 0"/>
    <axis xyz="0 -1 0"/>
    <limit velocity="6.5" effort="1000" lower="${-pi*0.9}" upper="${pi*0.9}" />
  </joint>

  <!-- Transmission 4 -->
  <transmission name="tran4">
    <type>transmission_interface/SimpleTransmission</type>
    <joint name="joint4">
      <hardwareInterface>PositionJointInterface</hardwareInterface>
    </joint>
    <actuator name="motor4">
      <hardwareInterface>PositionJointInterface</hardwareInterface>
      <mechanicalReduction>1</mechanicalReduction>
    </actuator>
  </transmission>

  <!--  Link 6 -->
  <link name="link6">
    <collision>
      <origin xyz="0.022 0 0.122" rpy="0 0 0"/>
      <geometry>
        <mesh filename="package://open_manipulator_description/meshes/chain_link3.stl" scale="0.001 0.001 0.001"/>
      </geometry>
    </collision>

    <visual>
      <origin xyz="0.022 0 0.122" rpy="0 0 0"/>
      <geometry>
        <mesh filename="package://open_manipulator_description/meshes/chain_link3.stl" scale="0.001 0.001 0.001"/>
      </geometry>
      <material name="grey"/>
    </visual>

    <inertial>
      <origin xyz="0 0 0" />
      <mass value="0.01" />
      <inertia ixx="0.001" ixy="0.0" ixz="0.0"
               iyy="0.001" iyz="0.0"
               izz="0.001" />
    </inertial>
  </link>
</robot>