<?xml version="1.0" ?>
<!--
  Ignition Gazebo demo using DiffDrive as a tracked drive system

  Try sending commands:

    ign topic -t "/model/vehicle_blue/cmd_vel" -m ignition.msgs.Twist -p "linear: {x: 0.5}, angular: {z: 0.7}"

    ign topic -t "/model/vehicle_green/cmd_vel" -m ignition.msgs.Twist -p "linear: {x: 1.0}, angular: {z: -0.8}"

  Listen to odometry:

    ign topic -e -t /model/vehicle_blue/odometry

    ign topic -e -t /model/vehicle_green/odometry

-->
<sdf version="1.6">
  <world name="track_drive">

    <physics name="1ms" type="ignored">
      <max_step_size>0.001</max_step_size>
      <real_time_factor>1.0</real_time_factor>
    </physics>
    <plugin
      filename="ignition-gazebo-physics-system"
      name="ignition::gazebo::systems::Physics">
    </plugin>
    <plugin
      filename="ignition-gazebo-user-commands-system"
      name="ignition::gazebo::systems::UserCommands">
    </plugin>
    <plugin
      filename="ignition-gazebo-scene-broadcaster-system"
      name="ignition::gazebo::systems::SceneBroadcaster">
    </plugin>
    <plugin
      filename="ignition-gazebo-imu-system"
      name="ignition::gazebo::systems::Imu">
    </plugin>

    <light type="directional" name="sun">
      <cast_shadows>true</cast_shadows>
      <pose>0 0 10 0 0 0</pose>
      <diffuse>1 1 1 1</diffuse>
      <specular>0.5 0.5 0.5 1</specular>
      <attenuation>
        <range>1000</range>
        <constant>0.9</constant>
        <linear>0.01</linear>
        <quadratic>0.001</quadratic>
      </attenuation>
      <direction>-0.5 0.1 -0.9</direction>
    </light>

    <model name="ground_plane">
      <static>true</static>
      <link name="link">
        <collision name="collision">
          <geometry>
            <plane>
              <normal>0 0 1</normal>
              <size>100 100</size>
            </plane>
          </geometry>
        </collision>
        <visual name="visual">
          <geometry>
            <plane>
              <normal>0 0 1</normal>
              <size>100 100</size>
            </plane>
          </geometry>
          <material>
            <ambient>0.8 0.8 0.8 1</ambient>
            <diffuse>0.8 0.8 0.8 1</diffuse>
            <specular>0.8 0.8 0.8 1</specular>
          </material>
        </visual>
      </link>
    </model>

    <model name="vehicle_blue">
      <pose frame=''>0 2 0.071917 0 0 0</pose>
      <link name='base_link'>
          <pose frame=''>0 0 0 0 -0 0</pose>
          <inertial>
              <pose frame=''>-0.122 0 0.118 1.5707963267948966 -0 0</pose>
              <mass>13.14</mass>
              <inertia>
                  <ixx>0.10019</ixx>
                  <ixy>0</ixy>
                  <ixz>0</ixz>
                  <iyy>0.345043</iyy>
                  <iyz>0</iyz>
                  <izz>0.302044</izz>
              </inertia>
          </inertial>
          <collision name='base_link_collision'>
              <pose frame=''>-0.122 0 0.118 0 -0 0</pose>
              <geometry>
                  <box>
                      <size>0.50017 0.24093 0.139</size>
                  </box>
              </geometry>
          </collision>
          <visual name='base_link_visual'>
              <pose frame=''>-0.122 0 0.118 0 -0 0</pose>
              <geometry>
                  <box>
                      <size>0.50017 0.24093 0.139</size>
                  </box>
              </geometry>
              <material>
                <ambient>0.5 0.5 1.0 1</ambient>
                <diffuse>0.5 0.5 1.0 1</diffuse>
                <specular>0.0 0.0 1.0 1</specular>
              </material>
          </visual>
          <self_collide>0</self_collide>
          <gravity>1</gravity>
          <kinematic>0</kinematic>

          <sensor name="imu_sensor" type="imu">
            <always_on>1</always_on>
            <update_rate>1000</update_rate>
          </sensor>
      </link>

      <link name='left_track'>
          <pose frame=''>0 0.1985 0 0 -0 0</pose>
          <inertial>
              <mass>2.06</mass>
              <inertia>
                  <ixx>0.002731</ixx>
                  <ixy>0</ixy>
                  <ixz>0</ixz>
                  <iyy>0.032554</iyy>
                  <iyz>0</iyz>
                  <izz>0.031391</izz>
              </inertia>
          </inertial>
          <collision name='left_track_collision'>
              <pose frame=''>0 0 0.01855 1.5707963267948966  -0 1.5707963267948966</pose>
              <geometry>
                  <box>
                      <size>0.009728 0.018094 0.05</size>
                  </box>
              </geometry>
          </collision>
      </link>
      <joint name='left_track_j' type='fixed'>
          <child>left_track</child>
          <parent>base_link</parent>
      </joint>
      <link name='left_track_wheel1'>
          <pose frame=''>0.25 0.1985 0.01855 0 -0 0</pose>
          <inertial>
              <mass>0.5</mass>
              <inertia>
                  <ixx>0.001</ixx>
                  <ixy>0</ixy>
                  <ixz>0</ixz>
                  <iyy>0.001</iyy>
                  <iyz>0</iyz>
                  <izz>0.001</izz>
              </inertia>
          </inertial>
          <collision name='left_track_wheel1_collision'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
              <surface>
                  <friction>
                      <ode>
                          <mu>0.5</mu>
                          <mu2>3.19858</mu2>
                          <fdir1>0 0 1</fdir1>
                          <slip1>0</slip1>
                          <slip2>0</slip2>
                      </ode>
                  </friction>
              </surface>
          </collision>
          <visual name='left_track_wheel1_visual'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
          </visual>
      </link>
      <joint name='left_track_wheel1_j' type='revolute'>
          <child>left_track_wheel1</child>
          <parent>left_track</parent>
          <axis>
              <xyz>0 1 0</xyz>
              <limit>
                  <lower>-1e+16</lower>
                  <upper>1e+16</upper>
              </limit>
          </axis>
      </joint>
      <link name='left_track_wheel2'>
          <pose frame=''>0.1786 0.1985 0.01855 0 -0 0</pose>
          <inertial>
              <mass>0.5</mass>
              <inertia>
                  <ixx>0.001</ixx>
                  <ixy>0</ixy>
                  <ixz>0</ixz>
                  <iyy>0.001</iyy>
                  <iyz>0</iyz>
                  <izz>0.001</izz>
              </inertia>
          </inertial>
          <collision name='left_track_wheel2_collision'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
              <surface>
                  <friction>
                      <ode>
                          <mu>0.5</mu>
                          <mu2>3.19858</mu2>
                          <fdir1>0 0 1</fdir1>
                          <slip1>0</slip1>
                          <slip2>0</slip2>
                      </ode>
                  </friction>
              </surface>
          </collision>
          <visual name='left_track_wheel2_visual'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
          </visual>
      </link>
      <joint name='left_track_wheel2_j' type='revolute'>
          <child>left_track_wheel2</child>
          <parent>left_track</parent>
          <axis>
              <xyz>0 1 0</xyz>
              <limit>
                  <lower>-1e+16</lower>
                  <upper>1e+16</upper>
              </limit>
          </axis>
      </joint>
      <link name='left_track_wheel3'>
          <pose frame=''>0.1072 0.1985 0.01855 0 -0 0</pose>
          <inertial>
              <mass>0.5</mass>
              <inertia>
                  <ixx>0.001</ixx>
                  <ixy>0</ixy>
                  <ixz>0</ixz>
                  <iyy>0.001</iyy>
                  <iyz>0</iyz>
                  <izz>0.001</izz>
              </inertia>
          </inertial>
          <collision name='left_track_wheel3_collision'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
              <surface>
                  <friction>
                      <ode>
                          <mu>0.5</mu>
                          <mu2>3.19858</mu2>
                          <fdir1>0 0 1</fdir1>
                          <slip1>0</slip1>
                          <slip2>0</slip2>
                      </ode>
                  </friction>
              </surface>
          </collision>
          <visual name='left_track_wheel3_visual'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
          </visual>
      </link>
      <joint name='left_track_wheel3_j' type='revolute'>
          <child>left_track_wheel3</child>
          <parent>left_track</parent>
          <axis>
              <xyz>0 1 0</xyz>
              <limit>
                  <lower>-1e+16</lower>
                  <upper>1e+16</upper>
              </limit>
          </axis>
      </joint>
      <link name='left_track_wheel4'>
          <pose frame=''>-0.25 0.1985 0.01855 0 -0 0</pose>
          <inertial>
              <mass>0.5</mass>
              <inertia>
                  <ixx>0.001</ixx>
                  <ixy>0</ixy>
                  <ixz>0</ixz>
                  <iyy>0.001</iyy>
                  <iyz>0</iyz>
                  <izz>0.001</izz>
              </inertia>
          </inertial>
          <collision name='left_track_wheel4_collision'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
              <surface>
                  <friction>
                      <ode>
                          <mu>0.5</mu>
                          <mu2>3.19858</mu2>
                          <fdir1>0 0 1</fdir1>
                          <slip1>0</slip1>
                          <slip2>0</slip2>
                      </ode>
                  </friction>
              </surface>
          </collision>
          <visual name='left_track_wheel4_visual'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
          </visual>
      </link>
      <joint name='left_track_wheel4_j' type='revolute'>
          <child>left_track_wheel4</child>
          <parent>left_track</parent>
          <axis>
              <xyz>0 1 0</xyz>
              <limit>
                  <lower>-1e+16</lower>
                  <upper>1e+16</upper>
              </limit>
          </axis>
      </joint>
      <link name='left_track_wheel5'>
          <pose frame=''>-0.0358 0.1985 0.01855 0 -0 0</pose>
          <inertial>
              <mass>0.5</mass>
              <inertia>
                  <ixx>0.001</ixx>
                  <ixy>0</ixy>
                  <ixz>0</ixz>
                  <iyy>0.001</iyy>
                  <iyz>0</iyz>
                  <izz>0.001</izz>
              </inertia>
          </inertial>
          <collision name='left_track_wheel5_collision'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
              <surface>
                  <friction>
                      <ode>
                          <mu>0.5</mu>
                          <mu2>3.19858</mu2>
                          <fdir1>0 0 1</fdir1>
                          <slip1>0</slip1>
                          <slip2>0</slip2>
                      </ode>
                  </friction>
              </surface>
          </collision>
          <visual name='left_track_wheel5_visual'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
          </visual>
      </link>
      <joint name='left_track_wheel5_j' type='revolute'>
          <child>left_track_wheel5</child>
          <parent>left_track</parent>
          <axis>
              <xyz>0 1 0</xyz>
              <limit>
                  <lower>-1e+16</lower>
                  <upper>1e+16</upper>
              </limit>
          </axis>
      </joint>
      <link name='left_track_wheel6'>
          <pose frame=''>-0.1072 0.1985 0.01855 0 -0 0</pose>
          <inertial>
              <mass>0.5</mass>
              <inertia>
                  <ixx>0.001</ixx>
                  <ixy>0</ixy>
                  <ixz>0</ixz>
                  <iyy>0.001</iyy>
                  <iyz>0</iyz>
                  <izz>0.001</izz>
              </inertia>
          </inertial>
          <collision name='left_track_wheel6_collision'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
              <surface>
                  <friction>
                      <ode>
                          <mu>0.5</mu>
                          <mu2>3.19858</mu2>
                          <fdir1>0 0 1</fdir1>
                          <slip1>0</slip1>
                          <slip2>0</slip2>
                      </ode>
                  </friction>
              </surface>
          </collision>
          <visual name='left_track_wheel6_visual'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
          </visual>
          <gravity>1</gravity>
          <velocity_decay/>
          <kinematic>0</kinematic>
      </link>
      <joint name='left_track_wheel6_j' type='revolute'>
          <child>left_track_wheel6</child>
          <parent>left_track</parent>
          <axis>
              <xyz>0 1 0</xyz>
              <limit>
                  <lower>-1e+16</lower>
                  <upper>1e+16</upper>
              </limit>
          </axis>
      </joint>
      <link name='left_track_wheel7'>
          <pose frame=''>-0.1786 0.1985 0.01855 0 -0 0</pose>
          <inertial>
              <mass>0.5</mass>
              <inertia>
                  <ixx>0.001</ixx>
                  <ixy>0</ixy>
                  <ixz>0</ixz>
                  <iyy>0.001</iyy>
                  <iyz>0</iyz>
                  <izz>0.001</izz>
              </inertia>
          </inertial>
          <collision name='left_track_wheel7_collision'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
              <surface>
                  <friction>
                      <ode>
                          <mu>0.5</mu>
                          <mu2>3.19858</mu2>
                          <fdir1>0 0 1</fdir1>
                          <slip1>0</slip1>
                          <slip2>0</slip2>
                      </ode>
                  </friction>
              </surface>
          </collision>
          <visual name='left_track_wheel7_visual'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
          </visual>
      </link>
      <joint name='left_track_wheel7_j' type='revolute'>
          <child>left_track_wheel7</child>
          <parent>left_track</parent>
          <axis>
              <xyz>0 1 0</xyz>
              <limit>
                  <lower>-1e+16</lower>
                  <upper>1e+16</upper>
              </limit>
          </axis>
      </joint>
      <link name='left_track_wheel8'>
          <pose frame=''>0.0358 0.1985 0.01855 0 -0 0</pose>
          <inertial>
              <mass>0.5</mass>
              <inertia>
                  <ixx>0.001</ixx>
                  <ixy>0</ixy>
                  <ixz>0</ixz>
                  <iyy>0.001</iyy>
                  <iyz>0</iyz>
                  <izz>0.001</izz>
              </inertia>
          </inertial>
          <collision name='left_track_wheel8_collision'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
              <surface>
                  <friction>
                      <ode>
                          <mu>0.5</mu>
                          <mu2>3.19858</mu2>
                          <fdir1>0 0 1</fdir1>
                          <slip1>0</slip1>
                          <slip2>0</slip2>
                      </ode>
                  </friction>
              </surface>
          </collision>
          <visual name='left_track_wheel8_visual'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
          </visual>
      </link>
      <joint name='left_track_wheel8_j' type='revolute'>
          <child>left_track_wheel8</child>
          <parent>left_track</parent>
          <axis>
              <xyz>0 1 0</xyz>
              <limit>
                  <lower>-1e+16</lower>
                  <upper>1e+16</upper>
              </limit>
          </axis>
      </joint>

      <link name='right_track'>
          <pose frame=''>0 -0.1985 0 0 -0 0</pose>
          <inertial>
              <mass>2.06</mass>
              <inertia>
                  <ixx>0.002731</ixx>
                  <ixy>0</ixy>
                  <ixz>0</ixz>
                  <iyy>0.032554</iyy>
                  <iyz>0</iyz>
                  <izz>0.031391</izz>
              </inertia>
          </inertial>
          <collision name='right_track_collision'>
              <pose frame=''>0 0 0.01855 1.5707963267948966  -0 1.5707963267948966</pose>
              <geometry>
                  <box>
                      <size>0.009728 0.018094 0.05</size>
                  </box>
              </geometry>
          </collision>
      </link>
      <joint name='right_track_j' type='fixed'>
          <child>right_track</child>
          <parent>base_link</parent>
      </joint>

      <link name='right_track_wheel1'>
          <pose frame=''>0.25 -0.1985 0.01855 0 -0 0</pose>
          <inertial>
              <mass>0.5</mass>
              <inertia>
                  <ixx>0.001</ixx>
                  <ixy>0</ixy>
                  <ixz>0</ixz>
                  <iyy>0.001</iyy>
                  <iyz>0</iyz>
                  <izz>0.001</izz>
              </inertia>
          </inertial>
          <collision name='right_track_wheel1_collision'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
              <surface>
                  <friction>
                      <ode>
                          <mu>0.5</mu>
                          <mu2>3.19858</mu2>
                          <fdir1>0 0 1</fdir1>
                          <slip1>0</slip1>
                          <slip2>0</slip2>
                      </ode>
                  </friction>
              </surface>
          </collision>
          <visual name='right_track_wheel1_visual'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
          </visual>
      </link>
      <joint name='right_track_wheel1_j' type='revolute'>
          <child>right_track_wheel1</child>
          <parent>right_track</parent>
          <axis>
              <xyz>0 1 0</xyz>
              <limit>
                  <lower>-1e+16</lower>
                  <upper>1e+16</upper>
              </limit>
          </axis>
      </joint>
      <link name='right_track_wheel2'>
          <pose frame=''>0.1786 -0.1985 0.01855 0 -0 0</pose>
          <inertial>
              <mass>0.5</mass>
              <inertia>
                  <ixx>0.001</ixx>
                  <ixy>0</ixy>
                  <ixz>0</ixz>
                  <iyy>0.001</iyy>
                  <iyz>0</iyz>
                  <izz>0.001</izz>
              </inertia>
          </inertial>
          <collision name='right_track_wheel2_collision'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
              <surface>
                  <friction>
                      <ode>
                          <mu>0.5</mu>
                          <mu2>3.19858</mu2>
                          <fdir1>0 0 1</fdir1>
                          <slip1>0</slip1>
                          <slip2>0</slip2>
                      </ode>
                  </friction>
              </surface>
          </collision>
          <visual name='right_track_wheel2_visual'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
          </visual>
      </link>
      <joint name='right_track_wheel2_j' type='revolute'>
          <child>right_track_wheel2</child>
          <parent>right_track</parent>
          <axis>
              <xyz>0 1 0</xyz>
              <limit>
                  <lower>-1e+16</lower>
                  <upper>1e+16</upper>
              </limit>
          </axis>
      </joint>
      <link name='right_track_wheel3'>
          <pose frame=''>0.1072 -0.1985 0.01855 0 -0 0</pose>
          <inertial>
              <mass>0.5</mass>
              <inertia>
                  <ixx>0.001</ixx>
                  <ixy>0</ixy>
                  <ixz>0</ixz>
                  <iyy>0.001</iyy>
                  <iyz>0</iyz>
                  <izz>0.001</izz>
              </inertia>
          </inertial>
          <collision name='right_track_wheel3_collision'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
              <surface>
                  <friction>
                      <ode>
                          <mu>0.5</mu>
                          <mu2>3.19858</mu2>
                          <fdir1>0 0 1</fdir1>
                          <slip1>0</slip1>
                          <slip2>0</slip2>
                      </ode>
                  </friction>
              </surface>
          </collision>
          <visual name='right_track_wheel3_visual'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
          </visual>
      </link>
      <joint name='right_track_wheel3_j' type='revolute'>
          <child>right_track_wheel3</child>
          <parent>right_track</parent>
          <axis>
              <xyz>0 1 0</xyz>
              <limit>
                  <lower>-1e+16</lower>
                  <upper>1e+16</upper>
              </limit>
          </axis>
      </joint>
      <link name='right_track_wheel4'>
          <pose frame=''>-0.25 -0.1985 0.01855 0 -0 0</pose>
          <inertial>
              <mass>0.5</mass>
              <inertia>
                  <ixx>0.001</ixx>
                  <ixy>0</ixy>
                  <ixz>0</ixz>
                  <iyy>0.001</iyy>
                  <iyz>0</iyz>
                  <izz>0.001</izz>
              </inertia>
          </inertial>
          <collision name='right_track_wheel4_collision'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
              <surface>
                  <friction>
                      <ode>
                          <mu>0.5</mu>
                          <mu2>3.19858</mu2>
                          <fdir1>0 0 1</fdir1>
                          <slip1>0</slip1>
                          <slip2>0</slip2>
                      </ode>
                  </friction>
              </surface>
          </collision>
          <visual name='right_track_wheel4_visual'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
          </visual>
      </link>
      <joint name='right_track_wheel4_j' type='revolute'>
          <child>right_track_wheel4</child>
          <parent>right_track</parent>
          <axis>
              <xyz>0 1 0</xyz>
              <limit>
                  <lower>-1e+16</lower>
                  <upper>1e+16</upper>
              </limit>
          </axis>
      </joint>
      <link name='right_track_wheel5'>
          <pose frame=''>-0.0358 -0.1985 0.01855 0 -0 0</pose>
          <inertial>
              <mass>0.5</mass>
              <inertia>
                  <ixx>0.001</ixx>
                  <ixy>0</ixy>
                  <ixz>0</ixz>
                  <iyy>0.001</iyy>
                  <iyz>0</iyz>
                  <izz>0.001</izz>
              </inertia>
          </inertial>
          <collision name='right_track_wheel5_collision'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
              <surface>
                  <friction>
                      <ode>
                          <mu>0.5</mu>
                          <mu2>3.19858</mu2>
                          <fdir1>0 0 1</fdir1>
                          <slip1>0</slip1>
                          <slip2>0</slip2>
                      </ode>
                  </friction>
              </surface>
          </collision>
          <visual name='right_track_wheel5_visual'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
          </visual>
      </link>
      <joint name='right_track_wheel5_j' type='revolute'>
          <child>right_track_wheel5</child>
          <parent>right_track</parent>
          <axis>
              <xyz>0 1 0</xyz>
              <limit>
                  <lower>-1e+16</lower>
                  <upper>1e+16</upper>
              </limit>
          </axis>
      </joint>
      <link name='right_track_wheel6'>
          <pose frame=''>-0.1072 -0.1985 0.01855 0 -0 0</pose>
          <inertial>
              <mass>0.5</mass>
              <inertia>
                  <ixx>0.001</ixx>
                  <ixy>0</ixy>
                  <ixz>0</ixz>
                  <iyy>0.001</iyy>
                  <iyz>0</iyz>
                  <izz>0.001</izz>
              </inertia>
          </inertial>
          <collision name='right_track_wheel6_collision'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
              <surface>
                  <friction>
                      <ode>
                          <mu>0.5</mu>
                          <mu2>3.19858</mu2>
                          <fdir1>0 0 1</fdir1>
                          <slip1>0</slip1>
                          <slip2>0</slip2>
                      </ode>
                  </friction>
              </surface>
          </collision>
          <visual name='right_track_wheel6_visual'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
          </visual>
      </link>
      <joint name='right_track_wheel6_j' type='revolute'>
          <child>right_track_wheel6</child>
          <parent>right_track</parent>
          <axis>
              <xyz>0 1 0</xyz>
              <limit>
                  <lower>-1e+16</lower>
                  <upper>1e+16</upper>
              </limit>
          </axis>
      </joint>
      <link name='right_track_wheel7'>
          <pose frame=''>-0.1786 -0.1985 0.01855 0 -0 0</pose>
          <inertial>
              <mass>0.5</mass>
              <inertia>
                  <ixx>0.001</ixx>
                  <ixy>0</ixy>
                  <ixz>0</ixz>
                  <iyy>0.001</iyy>
                  <iyz>0</iyz>
                  <izz>0.001</izz>
              </inertia>
          </inertial>
          <collision name='right_track_wheel7_collision'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
              <surface>
                  <friction>
                      <ode>
                          <mu>0.5</mu>
                          <mu2>3.19858</mu2>
                          <fdir1>0 0 1</fdir1>
                          <slip1>0</slip1>
                          <slip2>0</slip2>
                      </ode>
                  </friction>
              </surface>
          </collision>
          <visual name='right_track_wheel7_visual'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
          </visual>
      </link>
      <joint name='right_track_wheel7_j' type='revolute'>
          <child>right_track_wheel7</child>
          <parent>right_track</parent>
          <axis>
              <xyz>0 1 0</xyz>
              <limit>
                  <lower>-1e+16</lower>
                  <upper>1e+16</upper>
              </limit>
          </axis>
      </joint>
      <link name='right_track_wheel8'>
          <pose frame=''>0.0358 -0.1985 0.01855 0 -0 0</pose>
          <inertial>
              <mass>0.5</mass>
              <inertia>
                  <ixx>0.001</ixx>
                  <ixy>0</ixy>
                  <ixz>0</ixz>
                  <iyy>0.001</iyy>
                  <iyz>0</iyz>
                  <izz>0.001</izz>
              </inertia>
          </inertial>
          <collision name='right_track_wheel8_collision'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
              <surface>
                  <friction>
                      <ode>
                          <mu>0.5</mu>
                          <mu2>3.19858</mu2>
                          <fdir1>0 0 1</fdir1>
                          <slip1>0</slip1>
                          <slip2>0</slip2>
                      </ode>
                  </friction>
              </surface>
          </collision>
          <visual name='right_track_wheel8_visual'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
          </visual>
      </link>
      <joint name='right_track_wheel8_j' type='revolute'>
          <child>right_track_wheel8</child>
          <parent>right_track</parent>
          <axis>
              <xyz>0 1 0</xyz>
              <limit>
                  <lower>-1e+16</lower>
                  <upper>1e+16</upper>
              </limit>
          </axis>
      </joint>

      <!-- Track drive -->
      <plugin filename="ignition-gazebo-diff-drive-system"
              name="ignition::gazebo::systems::DiffDrive">
        <left_joint>left_track_wheel1_j</left_joint>
        <right_joint>right_track_wheel1_j</right_joint>
        <left_joint>left_track_wheel2_j</left_joint>
        <right_joint>right_track_wheel2_j</right_joint>
        <left_joint>left_track_wheel3_j</left_joint>
        <right_joint>right_track_wheel3_j</right_joint>
        <left_joint>left_track_wheel4_j</left_joint>
        <right_joint>right_track_wheel4_j</right_joint>
        <left_joint>left_track_wheel5_j</left_joint>
        <right_joint>right_track_wheel5_j</right_joint>
        <left_joint>left_track_wheel6_j</left_joint>
        <right_joint>right_track_wheel6_j</right_joint>
        <left_joint>left_track_wheel7_j</left_joint>
        <right_joint>right_track_wheel7_j</right_joint>
        <left_joint>left_track_wheel8_j</left_joint>
        <right_joint>right_track_wheel8_j</right_joint>
        <wheel_separation>0.493</wheel_separation>
        <wheel_radius>0.09047</wheel_radius>
      </plugin>

    </model>

    <model name="vehicle_green">
      <pose frame=''>0 -2 0.071917 0 0 1.5707963267948966</pose>
      <link name='base_link'>
          <pose frame=''>0 0 0 0 -0 0</pose>
          <inertial>
              <pose frame=''>-0.122 0 0.118 1.5707963267948966  -0 0</pose>
              <mass>13.14</mass>
              <inertia>
                  <ixx>0.10019</ixx>
                  <ixy>0</ixy>
                  <ixz>0</ixz>
                  <iyy>0.345043</iyy>
                  <iyz>0</iyz>
                  <izz>0.302044</izz>
              </inertia>
          </inertial>
          <collision name='base_link_collision'>
              <pose frame=''>-0.122 0 0.118 0 -0 0</pose>
              <geometry>
                  <box>
                      <size>0.50017 0.24093 0.139</size>
                  </box>
              </geometry>
          </collision>
          <visual name='base_link_visual'>
              <pose frame=''>-0.122 0 0.118 0 -0 0</pose>
              <geometry>
                  <box>
                      <size>0.50017 0.24093 0.139</size>
                  </box>
              </geometry>
              <material>
                <ambient>0.5 1.0 0.5 1</ambient>
                <diffuse>0.5 1.0 0.5 1</diffuse>
                <specular>0.0 1.0 0.0 1</specular>
              </material>
          </visual>
          <self_collide>0</self_collide>
          <gravity>1</gravity>
          <kinematic>0</kinematic>
          <sensor name="imu_sensor" type="imu">
            <always_on>1</always_on>
            <update_rate>1000</update_rate>
          </sensor>
      </link>

      <link name='left_track'>
          <pose frame=''>0 0.1985 0 0 -0 0</pose>
          <inertial>
              <mass>2.06</mass>
              <inertia>
                  <ixx>0.002731</ixx>
                  <ixy>0</ixy>
                  <ixz>0</ixz>
                  <iyy>0.032554</iyy>
                  <iyz>0</iyz>
                  <izz>0.031391</izz>
              </inertia>
          </inertial>
          <collision name='left_track_collision'>
              <pose frame=''>0 0 0.01855 1.5707963267948966 -0 1.5707963267948966</pose>
              <geometry>
                  <box>
                      <size>0.009728 0.018094 0.05</size>
                  </box>
              </geometry>
              <surface>
                  <friction>
                      <ode>
                          <mu>0.5</mu>
                          <mu2>3.19858</mu2>
                          <fdir1>0 0 1</fdir1>
                          <slip1>0</slip1>
                          <slip2>0</slip2>
                      </ode>
                  </friction>
                  <contact>
                      <collide_bitmask>0</collide_bitmask>
                  </contact>
              </surface>
          </collision>
      </link>
      <joint name='left_track_j' type='fixed'>
          <child>left_track</child>
          <parent>base_link</parent>
      </joint>
      <link name='left_track_wheel1'>
          <pose frame=''>0.25 0.1985 0.01855 0 -0 0</pose>
          <inertial>
              <mass>0.5</mass>
              <inertia>
                  <ixx>0.001</ixx>
                  <ixy>0</ixy>
                  <ixz>0</ixz>
                  <iyy>0.001</iyy>
                  <iyz>0</iyz>
                  <izz>0.001</izz>
              </inertia>
          </inertial>
          <collision name='left_track_wheel1_collision'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
              <surface>
                  <friction>
                      <ode>
                          <mu>0.5</mu>
                          <mu2>3.19858</mu2>
                          <fdir1>0 0 1</fdir1>
                          <slip1>0</slip1>
                          <slip2>0</slip2>
                      </ode>
                  </friction>
              </surface>
          </collision>
          <visual name='left_track_wheel1_visual'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
          </visual>
      </link>
      <joint name='left_track_wheel1_j' type='revolute'>
          <child>left_track_wheel1</child>
          <parent>left_track</parent>
          <axis>
              <xyz>0 1 0</xyz>
              <limit>
                  <lower>-1e+16</lower>
                  <upper>1e+16</upper>
              </limit>
          </axis>
      </joint>
      <link name='left_track_wheel2'>
          <pose frame=''>0.1786 0.1985 0.01855 0 -0 0</pose>
          <inertial>
              <mass>0.5</mass>
              <inertia>
                  <ixx>0.001</ixx>
                  <ixy>0</ixy>
                  <ixz>0</ixz>
                  <iyy>0.001</iyy>
                  <iyz>0</iyz>
                  <izz>0.001</izz>
              </inertia>
          </inertial>
          <collision name='left_track_wheel2_collision'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
              <surface>
                  <friction>
                      <ode>
                          <mu>0.5</mu>
                          <mu2>3.19858</mu2>
                          <fdir1>0 0 1</fdir1>
                          <slip1>0</slip1>
                          <slip2>0</slip2>
                      </ode>
                  </friction>
              </surface>
          </collision>
          <visual name='left_track_wheel2_visual'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
          </visual>
      </link>
      <joint name='left_track_wheel2_j' type='revolute'>
          <child>left_track_wheel2</child>
          <parent>left_track</parent>
          <axis>
              <xyz>0 1 0</xyz>
              <limit>
                  <lower>-1e+16</lower>
                  <upper>1e+16</upper>
              </limit>
          </axis>
      </joint>
      <link name='left_track_wheel3'>
          <pose frame=''>0.1072 0.1985 0.01855 0 -0 0</pose>
          <inertial>
              <mass>0.5</mass>
              <inertia>
                  <ixx>0.001</ixx>
                  <ixy>0</ixy>
                  <ixz>0</ixz>
                  <iyy>0.001</iyy>
                  <iyz>0</iyz>
                  <izz>0.001</izz>
              </inertia>
          </inertial>
          <collision name='left_track_wheel3_collision'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
              <surface>
                  <friction>
                      <ode>
                          <mu>0.5</mu>
                          <mu2>3.19858</mu2>
                          <fdir1>0 0 1</fdir1>
                          <slip1>0</slip1>
                          <slip2>0</slip2>
                      </ode>
                  </friction>
              </surface>
          </collision>
          <visual name='left_track_wheel3_visual'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
          </visual>
      </link>
      <joint name='left_track_wheel3_j' type='revolute'>
          <child>left_track_wheel3</child>
          <parent>left_track</parent>
          <axis>
              <xyz>0 1 0</xyz>
              <limit>
                  <lower>-1e+16</lower>
                  <upper>1e+16</upper>
              </limit>
          </axis>
      </joint>
      <link name='left_track_wheel4'>
          <pose frame=''>-0.25 0.1985 0.01855 0 -0 0</pose>
          <inertial>
              <mass>0.5</mass>
              <inertia>
                  <ixx>0.001</ixx>
                  <ixy>0</ixy>
                  <ixz>0</ixz>
                  <iyy>0.001</iyy>
                  <iyz>0</iyz>
                  <izz>0.001</izz>
              </inertia>
          </inertial>
          <collision name='left_track_wheel4_collision'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
              <surface>
                  <friction>
                      <ode>
                          <mu>0.5</mu>
                          <mu2>3.19858</mu2>
                          <fdir1>0 0 1</fdir1>
                          <slip1>0</slip1>
                          <slip2>0</slip2>
                      </ode>
                  </friction>
              </surface>
          </collision>
          <visual name='left_track_wheel4_visual'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
          </visual>
      </link>
      <joint name='left_track_wheel4_j' type='revolute'>
          <child>left_track_wheel4</child>
          <parent>left_track</parent>
          <axis>
              <xyz>0 1 0</xyz>
              <limit>
                  <lower>-1e+16</lower>
                  <upper>1e+16</upper>
              </limit>
          </axis>
      </joint>
      <link name='left_track_wheel5'>
          <pose frame=''>-0.0358 0.1985 0.01855 0 -0 0</pose>
          <inertial>
              <mass>0.5</mass>
              <inertia>
                  <ixx>0.001</ixx>
                  <ixy>0</ixy>
                  <ixz>0</ixz>
                  <iyy>0.001</iyy>
                  <iyz>0</iyz>
                  <izz>0.001</izz>
              </inertia>
          </inertial>
          <collision name='left_track_wheel5_collision'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
              <surface>
                  <friction>
                      <ode>
                          <mu>0.5</mu>
                          <mu2>3.19858</mu2>
                          <fdir1>0 0 1</fdir1>
                          <slip1>0</slip1>
                          <slip2>0</slip2>
                      </ode>
                  </friction>
              </surface>
          </collision>
          <visual name='left_track_wheel5_visual'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
          </visual>
      </link>
      <joint name='left_track_wheel5_j' type='revolute'>
          <child>left_track_wheel5</child>
          <parent>left_track</parent>
          <axis>
              <xyz>0 1 0</xyz>
              <limit>
                  <lower>-1e+16</lower>
                  <upper>1e+16</upper>
              </limit>
          </axis>
      </joint>
      <link name='left_track_wheel6'>
          <pose frame=''>-0.1072 0.1985 0.01855 0 -0 0</pose>
          <inertial>
              <mass>0.5</mass>
              <inertia>
                  <ixx>0.001</ixx>
                  <ixy>0</ixy>
                  <ixz>0</ixz>
                  <iyy>0.001</iyy>
                  <iyz>0</iyz>
                  <izz>0.001</izz>
              </inertia>
          </inertial>
          <collision name='left_track_wheel6_collision'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
              <surface>
                  <friction>
                      <ode>
                          <mu>0.5</mu>
                          <mu2>3.19858</mu2>
                          <fdir1>0 0 1</fdir1>
                          <slip1>0</slip1>
                          <slip2>0</slip2>
                      </ode>
                  </friction>
              </surface>
          </collision>
          <visual name='left_track_wheel6_visual'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
          </visual>
          <gravity>1</gravity>
          <velocity_decay/>
          <kinematic>0</kinematic>
      </link>
      <joint name='left_track_wheel6_j' type='revolute'>
          <child>left_track_wheel6</child>
          <parent>left_track</parent>
          <axis>
              <xyz>0 1 0</xyz>
              <limit>
                  <lower>-1e+16</lower>
                  <upper>1e+16</upper>
              </limit>
          </axis>
      </joint>
      <link name='left_track_wheel7'>
          <pose frame=''>-0.1786 0.1985 0.01855 0 -0 0</pose>
          <inertial>
              <mass>0.5</mass>
              <inertia>
                  <ixx>0.001</ixx>
                  <ixy>0</ixy>
                  <ixz>0</ixz>
                  <iyy>0.001</iyy>
                  <iyz>0</iyz>
                  <izz>0.001</izz>
              </inertia>
          </inertial>
          <collision name='left_track_wheel7_collision'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
              <surface>
                  <friction>
                      <ode>
                          <mu>0.5</mu>
                          <mu2>3.19858</mu2>
                          <fdir1>0 0 1</fdir1>
                          <slip1>0</slip1>
                          <slip2>0</slip2>
                      </ode>
                  </friction>
              </surface>
          </collision>
          <visual name='left_track_wheel7_visual'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
          </visual>
      </link>
      <joint name='left_track_wheel7_j' type='revolute'>
          <child>left_track_wheel7</child>
          <parent>left_track</parent>
          <axis>
              <xyz>0 1 0</xyz>
              <limit>
                  <lower>-1e+16</lower>
                  <upper>1e+16</upper>
              </limit>
          </axis>
      </joint>
      <link name='left_track_wheel8'>
          <pose frame=''>0.0358 0.1985 0.01855 0 -0 0</pose>
          <inertial>
              <mass>0.5</mass>
              <inertia>
                  <ixx>0.001</ixx>
                  <ixy>0</ixy>
                  <ixz>0</ixz>
                  <iyy>0.001</iyy>
                  <iyz>0</iyz>
                  <izz>0.001</izz>
              </inertia>
          </inertial>
          <collision name='left_track_wheel8_collision'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
              <surface>
                  <friction>
                      <ode>
                          <mu>0.5</mu>
                          <mu2>3.19858</mu2>
                          <fdir1>0 0 1</fdir1>
                          <slip1>0</slip1>
                          <slip2>0</slip2>
                      </ode>
                  </friction>
              </surface>
          </collision>
          <visual name='left_track_wheel8_visual'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
          </visual>
      </link>
      <joint name='left_track_wheel8_j' type='revolute'>
          <child>left_track_wheel8</child>
          <parent>left_track</parent>
          <axis>
              <xyz>0 1 0</xyz>
              <limit>
                  <lower>-1e+16</lower>
                  <upper>1e+16</upper>
              </limit>
          </axis>
      </joint>

      <link name='right_track'>
          <pose frame=''>0 -0.1985 0 0 -0 0</pose>
          <inertial>
              <mass>2.06</mass>
              <inertia>
                  <ixx>0.002731</ixx>
                  <ixy>0</ixy>
                  <ixz>0</ixz>
                  <iyy>0.032554</iyy>
                  <iyz>0</iyz>
                  <izz>0.031391</izz>
              </inertia>
          </inertial>
          <collision name='right_track_collision'>
              <pose frame=''>0 0 0.01855 1.5707963267948966 -0 1.5707963267948966</pose>
              <geometry>
                  <box>
                      <size>0.009728 0.018094 0.05</size>
                  </box>
              </geometry>
              <surface>
                  <friction>
                      <ode>
                          <mu>0.5</mu>
                          <mu2>3.19858</mu2>
                          <fdir1>0 0 1</fdir1>
                          <slip1>0</slip1>
                          <slip2>0</slip2>
                      </ode>
                  </friction>
                  <contact>
                      <collide_bitmask>0</collide_bitmask>
                  </contact>
              </surface>
          </collision>
      </link>
      <joint name='right_track_j' type='fixed'>
          <child>right_track</child>
          <parent>base_link</parent>
      </joint>

      <link name='right_track_wheel1'>
          <pose frame=''>0.25 -0.1985 0.01855 0 -0 0</pose>
          <inertial>
              <mass>0.5</mass>
              <inertia>
                  <ixx>0.001</ixx>
                  <ixy>0</ixy>
                  <ixz>0</ixz>
                  <iyy>0.001</iyy>
                  <iyz>0</iyz>
                  <izz>0.001</izz>
              </inertia>
          </inertial>
          <collision name='right_track_wheel1_collision'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
              <surface>
                  <friction>
                      <ode>
                          <mu>0.5</mu>
                          <mu2>3.19858</mu2>
                          <fdir1>0 0 1</fdir1>
                          <slip1>0</slip1>
                          <slip2>0</slip2>
                      </ode>
                  </friction>
              </surface>
          </collision>
          <visual name='right_track_wheel1_visual'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
          </visual>
      </link>
      <joint name='right_track_wheel1_j' type='revolute'>
          <child>right_track_wheel1</child>
          <parent>right_track</parent>
          <axis>
              <xyz>0 1 0</xyz>
              <limit>
                  <lower>-1e+16</lower>
                  <upper>1e+16</upper>
              </limit>
          </axis>
      </joint>
      <link name='right_track_wheel2'>
          <pose frame=''>0.1786 -0.1985 0.01855 0 -0 0</pose>
          <inertial>
              <mass>0.5</mass>
              <inertia>
                  <ixx>0.001</ixx>
                  <ixy>0</ixy>
                  <ixz>0</ixz>
                  <iyy>0.001</iyy>
                  <iyz>0</iyz>
                  <izz>0.001</izz>
              </inertia>
          </inertial>
          <collision name='right_track_wheel2_collision'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
              <surface>
                  <friction>
                      <ode>
                          <mu>0.5</mu>
                          <mu2>3.19858</mu2>
                          <fdir1>0 0 1</fdir1>
                          <slip1>0</slip1>
                          <slip2>0</slip2>
                      </ode>
                  </friction>
              </surface>
          </collision>
          <visual name='right_track_wheel2_visual'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
          </visual>
      </link>
      <joint name='right_track_wheel2_j' type='revolute'>
          <child>right_track_wheel2</child>
          <parent>right_track</parent>
          <axis>
              <xyz>0 1 0</xyz>
              <limit>
                  <lower>-1e+16</lower>
                  <upper>1e+16</upper>
              </limit>
          </axis>
      </joint>
      <link name='right_track_wheel3'>
          <pose frame=''>0.1072 -0.1985 0.01855 0 -0 0</pose>
          <inertial>
              <mass>0.5</mass>
              <inertia>
                  <ixx>0.001</ixx>
                  <ixy>0</ixy>
                  <ixz>0</ixz>
                  <iyy>0.001</iyy>
                  <iyz>0</iyz>
                  <izz>0.001</izz>
              </inertia>
          </inertial>
          <collision name='right_track_wheel3_collision'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
              <surface>
                  <friction>
                      <ode>
                          <mu>0.5</mu>
                          <mu2>3.19858</mu2>
                          <fdir1>0 0 1</fdir1>
                          <slip1>0</slip1>
                          <slip2>0</slip2>
                      </ode>
                  </friction>
              </surface>
          </collision>
          <visual name='right_track_wheel3_visual'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
          </visual>
      </link>
      <joint name='right_track_wheel3_j' type='revolute'>
          <child>right_track_wheel3</child>
          <parent>right_track</parent>
          <axis>
              <xyz>0 1 0</xyz>
              <limit>
                  <lower>-1e+16</lower>
                  <upper>1e+16</upper>
              </limit>
          </axis>
      </joint>
      <link name='right_track_wheel4'>
          <pose frame=''>-0.25 -0.1985 0.01855 0 -0 0</pose>
          <inertial>
              <mass>0.5</mass>
              <inertia>
                  <ixx>0.001</ixx>
                  <ixy>0</ixy>
                  <ixz>0</ixz>
                  <iyy>0.001</iyy>
                  <iyz>0</iyz>
                  <izz>0.001</izz>
              </inertia>
          </inertial>
          <collision name='right_track_wheel4_collision'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
              <surface>
                  <friction>
                      <ode>
                          <mu>0.5</mu>
                          <mu2>3.19858</mu2>
                          <fdir1>0 0 1</fdir1>
                          <slip1>0</slip1>
                          <slip2>0</slip2>
                      </ode>
                  </friction>
              </surface>
          </collision>
          <visual name='right_track_wheel4_visual'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
          </visual>
      </link>
      <joint name='right_track_wheel4_j' type='revolute'>
          <child>right_track_wheel4</child>
          <parent>right_track</parent>
          <axis>
              <xyz>0 1 0</xyz>
              <limit>
                  <lower>-1e+16</lower>
                  <upper>1e+16</upper>
              </limit>
          </axis>
      </joint>
      <link name='right_track_wheel5'>
          <pose frame=''>-0.0358 -0.1985 0.01855 0 -0 0</pose>
          <inertial>
              <mass>0.5</mass>
              <inertia>
                  <ixx>0.001</ixx>
                  <ixy>0</ixy>
                  <ixz>0</ixz>
                  <iyy>0.001</iyy>
                  <iyz>0</iyz>
                  <izz>0.001</izz>
              </inertia>
          </inertial>
          <collision name='right_track_wheel5_collision'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
              <surface>
                  <friction>
                      <ode>
                          <mu>0.5</mu>
                          <mu2>3.19858</mu2>
                          <fdir1>0 0 1</fdir1>
                          <slip1>0</slip1>
                          <slip2>0</slip2>
                      </ode>
                  </friction>
              </surface>
          </collision>
          <visual name='right_track_wheel5_visual'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
          </visual>
      </link>
      <joint name='right_track_wheel5_j' type='revolute'>
          <child>right_track_wheel5</child>
          <parent>right_track</parent>
          <axis>
              <xyz>0 1 0</xyz>
              <limit>
                  <lower>-1e+16</lower>
                  <upper>1e+16</upper>
              </limit>
          </axis>
      </joint>
      <link name='right_track_wheel6'>
          <pose frame=''>-0.1072 -0.1985 0.01855 0 -0 0</pose>
          <inertial>
              <mass>0.5</mass>
              <inertia>
                  <ixx>0.001</ixx>
                  <ixy>0</ixy>
                  <ixz>0</ixz>
                  <iyy>0.001</iyy>
                  <iyz>0</iyz>
                  <izz>0.001</izz>
              </inertia>
          </inertial>
          <collision name='right_track_wheel6_collision'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
              <surface>
                  <friction>
                      <ode>
                          <mu>0.5</mu>
                          <mu2>3.19858</mu2>
                          <fdir1>0 0 1</fdir1>
                          <slip1>0</slip1>
                          <slip2>0</slip2>
                      </ode>
                  </friction>
              </surface>
          </collision>
          <visual name='right_track_wheel6_visual'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
          </visual>
      </link>
      <joint name='right_track_wheel6_j' type='revolute'>
          <child>right_track_wheel6</child>
          <parent>right_track</parent>
          <axis>
              <xyz>0 1 0</xyz>
              <limit>
                  <lower>-1e+16</lower>
                  <upper>1e+16</upper>
              </limit>
          </axis>
      </joint>
      <link name='right_track_wheel7'>
          <pose frame=''>-0.1786 -0.1985 0.01855 0 -0 0</pose>
          <inertial>
              <mass>0.5</mass>
              <inertia>
                  <ixx>0.001</ixx>
                  <ixy>0</ixy>
                  <ixz>0</ixz>
                  <iyy>0.001</iyy>
                  <iyz>0</iyz>
                  <izz>0.001</izz>
              </inertia>
          </inertial>
          <collision name='right_track_wheel7_collision'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
              <surface>
                  <friction>
                      <ode>
                          <mu>0.5</mu>
                          <mu2>3.19858</mu2>
                          <fdir1>0 0 1</fdir1>
                          <slip1>0</slip1>
                          <slip2>0</slip2>
                      </ode>
                  </friction>
              </surface>
          </collision>
          <visual name='right_track_wheel7_visual'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
          </visual>
      </link>
      <joint name='right_track_wheel7_j' type='revolute'>
          <child>right_track_wheel7</child>
          <parent>right_track</parent>
          <axis>
              <xyz>0 1 0</xyz>
              <limit>
                  <lower>-1e+16</lower>
                  <upper>1e+16</upper>
              </limit>
          </axis>
      </joint>
      <link name='right_track_wheel8'>
          <pose frame=''>0.0358 -0.1985 0.01855 0 -0 0</pose>
          <inertial>
              <mass>0.5</mass>
              <inertia>
                  <ixx>0.001</ixx>
                  <ixy>0</ixy>
                  <ixz>0</ixz>
                  <iyy>0.001</iyy>
                  <iyz>0</iyz>
                  <izz>0.001</izz>
              </inertia>
          </inertial>
          <collision name='right_track_wheel8_collision'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
              <surface>
                  <friction>
                      <ode>
                          <mu>0.5</mu>
                          <mu2>3.19858</mu2>
                          <fdir1>0 0 1</fdir1>
                          <slip1>0</slip1>
                          <slip2>0</slip2>
                      </ode>
                  </friction>
              </surface>
          </collision>
          <visual name='right_track_wheel8_visual'>
              <pose frame=''>0 0 0 1.5707963267948966 -0 0</pose>
              <geometry>
                  <cylinder>
                      <length>0.09728</length>
                      <radius>0.09047</radius>
                  </cylinder>
              </geometry>
          </visual>
      </link>
      <joint name='right_track_wheel8_j' type='revolute'>
          <child>right_track_wheel8</child>
          <parent>right_track</parent>
          <axis>
              <xyz>0 1 0</xyz>
              <limit>
                  <lower>-1e+16</lower>
                  <upper>1e+16</upper>
              </limit>
          </axis>
      </joint>

      <!-- Track drive -->
      <plugin filename="ignition-gazebo-diff-drive-system"
              name="ignition::gazebo::systems::DiffDrive">
        <left_joint>left_track_wheel1_j</left_joint>
        <right_joint>right_track_wheel1_j</right_joint>
        <left_joint>left_track_wheel2_j</left_joint>
        <right_joint>right_track_wheel2_j</right_joint>
        <left_joint>left_track_wheel3_j</left_joint>
        <right_joint>right_track_wheel3_j</right_joint>
        <left_joint>left_track_wheel4_j</left_joint>
        <right_joint>right_track_wheel4_j</right_joint>
        <left_joint>left_track_wheel5_j</left_joint>
        <right_joint>right_track_wheel5_j</right_joint>
        <left_joint>left_track_wheel6_j</left_joint>
        <right_joint>right_track_wheel6_j</right_joint>
        <left_joint>left_track_wheel7_j</left_joint>
        <right_joint>right_track_wheel7_j</right_joint>
        <left_joint>left_track_wheel8_j</left_joint>
        <right_joint>right_track_wheel8_j</right_joint>
        <wheel_separation>0.493</wheel_separation>
        <wheel_radius>0.09047</wheel_radius>
      </plugin>

    </model>

  </world>
</sdf>
