ar_2020.urdf

<robot name="ar_2020">

	<!-- * * * Link Definitions * * * -->

    <link name="simple_box_base_link">
 	    <inertial>
            <origin xyz="0 0 0" rpy="0 0 0"/>
            <mass value="1.0" />
            <inertia ixx="0.0741666666667" ixy="0.0" ixz="0.0" iyy="0.0585416666667" iyz="0.0" izz="0.0260416666667"/>
        </inertial>
        <collision>
            <origin xyz="0 0 0" rpy="0 0 0"/>
            <geometry>
                <box size="0.2 0.2 0.2"/>
            </geometry>
        </collision>
        <visual>
            <origin rpy="0.0 0 0" xyz="0 0 0"/>
            <geometry>
                <!--<box size="0.8 0.8 0.2"/>-->
                <mesh filename="package://mybot_description/meshes/ar_2020_v2.dae"/>
            </geometry>
        </visual>
    </link>
    
    <gazebo reference="simple_box_base_link">
        <kp>100000.0</kp>
        <kd>100000.0</kd>
        <mu1>0.1</mu1>
        <mu2>0.1</mu2>
        <fdir1>1 0 0</fdir1>
    </gazebo>

</robot>

ar_2020_v2.dae

<?xml version="1.0" encoding="utf-8"?>
<COLLADA xmlns="http://www.collada.org/2005/11/COLLADASchema" version="1.4.1">
  <asset>
    <contributor>
      <author>Blender User</author>
      <authoring_tool>Blender 2.79.0</authoring_tool>
    </contributor>
    <created>2017-12-06T21:09:04</created>
    <modified>2017-12-06T21:09:04</modified>
    <unit name="meter" meter="1"/>
    <up_axis>Z_UP</up_axis>
  </asset>
  <library_images>
    <image id="MarkerData_2020_png" name="MarkerData_2020_png">
      <init_from>MarkerData_2020.png</init_from>
    </image>
  </library_images>
  <library_effects>
    <effect id="MarkerData_2020_png-effect">
      <profile_COMMON>
        <newparam sid="MarkerData_2020_png-surface">
          <surface type="2D">
            <init_from>MarkerData_2020_png</init_from>
          </surface>
        </newparam>
        <newparam sid="MarkerData_2020_png-sampler">
          <sampler2D>
            <source>MarkerData_2020_png-surface</source>
          </sampler2D>
        </newparam>
        <technique sid="common">
          <phong>
            <diffuse>
              <texture texture="MarkerData_2020_png-sampler" texcoord="MarkerData_2020_png"/>
            </diffuse>
            <specular>
              <color sid="specular">0 0 0 1</color>
            </specular>
          </phong>
        </technique>
      </profile_COMMON>
    </effect>
  </library_effects>
  <library_materials>
    <material id="MarkerData_2020_png-material" name="MarkerData_2020_png">
      <instance_effect url="#MarkerData_2020_png-effect"/>
    </material>
  </library_materials>
  <library_geometries>
    <geometry id="Cube-mesh" name="Cube">
      <mesh>
        <source id="Cube-mesh-positions">
          <float_array id="Cube-mesh-positions-array" count="24">0.5 0.5 -0.5 0.5 -0.5 -0.5 -0.5000001 -0.4999999 -0.5 -0.4999998 0.5000002 -0.5 0.5000002 0.4999997 0.5 0.4999997 -0.5000003 0.5 -0.5000002 -0.4999998 0.5 -0.5 0.5 0.5</float_array>
          <technique_common>
            <accessor source="#Cube-mesh-positions-array" count="8" stride="3">
              <param name="X" type="float"/>
              <param name="Y" type="float"/>
              <param name="Z" type="float"/>
            </accessor>
          </technique_common>
        </source>
        <source id="Cube-mesh-normals">
          <float_array id="Cube-mesh-normals-array" count="36">0 0 -1 0 0 1 1 0 -2.38419e-7 0 -1 -4.76837e-7 -1 2.38419e-7 -1.49012e-7 2.68221e-7 1 2.38419e-7 0 0 -1 0 0 1 1 -5.96046e-7 3.27825e-7 -4.76837e-7 -1 0 -1 2.38419e-7 -1.19209e-7 2.08616e-7 1 0</float_array>
          <technique_common>
            <accessor source="#Cube-mesh-normals-array" count="12" stride="3">
              <param name="X" type="float"/>
              <param name="Y" type="float"/>
              <param name="Z" type="float"/>
            </accessor>
          </technique_common>
        </source>
        <source id="Cube-mesh-map-0">
          <float_array id="Cube-mesh-map-0-array" count="72">0 0 1 1 0 1 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 0 0 1 1 0 1 1 0 0 1 0 0 0 0 1 0 1 1 1 0 1 1 0 1 1 0 1 1 0 1 1 0 1 1 0 1 0 0 1 0 1 1 1 0 1 1 0 1</float_array>
          <technique_common>
            <accessor source="#Cube-mesh-map-0-array" count="36" stride="2">
              <param name="S" type="float"/>
              <param name="T" type="float"/>
            </accessor>
          </technique_common>
        </source>
        <vertices id="Cube-mesh-vertices">
          <input semantic="POSITION" source="#Cube-mesh-positions"/>
        </vertices>
        <triangles material="MarkerData_2020_png-material" count="12">
          <input semantic="VERTEX" source="#Cube-mesh-vertices" offset="0"/>
          <input semantic="NORMAL" source="#Cube-mesh-normals" offset="1"/>
          <input semantic="TEXCOORD" source="#Cube-mesh-map-0" offset="2" set="0"/>
          <p>0 0 0 2 0 1 3 0 2 7 1 3 5 1 4 4 1 5 4 2 6 1 2 7 0 2 8 5 3 9 2 3 10 1 3 11 2 4 12 7 4 13 3 4 14 0 5 15 7 5 16 4 5 17 0 6 18 1 6 19 2 6 20 7 7 21 6 7 22 5 7 23 4 8 24 5 8 25 1 8 26 5 9 27 6 9 28 2 9 29 2 10 30 6 10 31 7 10 32 0 11 33 3 11 34 7 11 35</p>
        </triangles>
      </mesh>
    </geometry>
  </library_geometries>
  <library_controllers/>
  <library_visual_scenes>
    <visual_scene id="Scene" name="Scene">
      <node id="Cube" name="Cube" type="NODE">
        <matrix sid="transform">0.09000003 0 0 0 0 0.09000003 0 0 0 0 0.01065584 0 0 0 0 1</matrix>
        <instance_geometry url="#Cube-mesh" name="Cube">
          <bind_material>
            <technique_common>
              <instance_material symbol="MarkerData_2020_png-material" target="#MarkerData_2020_png-material">
                <bind_vertex_input semantic="UVMap" input_semantic="TEXCOORD" input_set="0"/>
              </instance_material>
            </technique_common>
          </bind_material>
        </instance_geometry>
      </node>
    </visual_scene>
  </library_visual_scenes>
  <scene>
    <instance_visual_scene url="#Scene"/>
  </scene>
</COLLADA>

spawn_ar_tracking.launch

<?xml version="1.0" encoding="UTF-8"?>

<launch>
    
    <arg name="x" default="0.0" />
    <arg name="y" default="0.5" />
    <arg name="z" default="0.5" />
    <arg name="roll" default="1.57"/>
    <arg name="pitch" default="0"/>
    <arg name="yaw" default="0" />
    
    <arg name="urdf_robot_file" default="$(find mybot_description)/urdf/ar_2020.urdf" />
    <arg name="robot_name" default="ar_2020" />
    
    <include file="$(find spawn_robot_tools_pkg)/launch/spawn_robot_urdf.launch">
        <arg name="x" value="$(arg x)" />
        <arg name="y" value="$(arg y)" />
        <arg name="z" value="$(arg z)" />
        <arg name="roll" value="$(arg roll)"/>
        <arg name="pitch" value="$(arg pitch)"/>
        <arg name="yaw" value="$(arg yaw)" />
        
        <arg name="urdf_robot_file" value="$(arg urdf_robot_file)" />
        <arg name="robot_name" value="$(arg robot_name)" />
    </include>
</launch>

spawn_robot_urdf.launch

<?xml version="1.0" encoding="UTF-8"?>

    <launch>
    
        <arg name="x" default="0.0" />
        <arg name="y" default="0.0" />
        <arg name="z" default="0.0" />
        <arg name="roll" default="0"/>
        <arg name="pitch" default="0"/>
        <arg name="yaw" default="0.0" />
        
        <arg name="urdf_robot_file" default="" />
        <arg name="robot_name" default="" />

        <!-- This Version was created due to some errors seen in the V1 that crashed GAzebo or went too slow in spawn -->
        <!-- Load the URDF into the ROS Parameter Server -->
        <param name="robot_description" command="cat $(arg urdf_robot_file)" />
        
        <!-- Run a python script to the send a service call to gazebo_ros to spawn a URDF robot -->
        <node name="$(arg robot_name)_urdf_spawner" pkg="gazebo_ros" type="spawn_model" respawn="false" output="screen"
        args="-urdf -x $(arg x) -y $(arg y) -z $(arg z) -R $(arg roll) -P $(arg pitch) -Y $(arg yaw) -model $(arg robot_name) -param robot_description"/>
    </launch>