Hello,

I'm using Gazebo version 9.11.0 and i'm trying to load a model for my robot with mecanum wheels. I converted my mecanum wheel from Solidworks to Collada format and I obtained a *.dae file.

When I try to load it in Gazebo, the wheel doesn't fully and correctly load as you can see in the attached picture.

This picture shows how the wheel is made in Solidworks:

Why is this happening? How can I solve it? If I open the DAE file I can correctly see the wheel.

This is my code:

<?xml version="1.0"?>
<robot name="wheel" xmlns:xacro="http://www.ros.org/wiki/xacro">

  <xacro:property name="PI" value="3.1415926535897931" />

  <!-- Wheels -->
  <xacro:property name="wheel_radius" value="0.152" />
  <xacro:property name="wheel_height" value="1.115" />
  <xacro:property name="wheel_mass" value="6.5" /> <!-- in kg-->

  <xacro:macro name="cylinder_inertia" params="m r h">
    <inertia  ixx="${m*(3*r*r+h*h)/12}" ixy = "0" ixz = "0"
              iyy="${m*r*r/2}" iyz = "0"
              izz="${m*(3*r*r+h*h)/12}" />
  </xacro:macro>

  <xacro:macro name="omni_wheel" params="prefix parent *origin reflect">

    <joint name="${prefix}_wheel_joint" type="continuous">
      <parent link="${parent}"/>
      <child link="${prefix}_wheel_link"/>
      <xacro:insert_block name="origin" />
      <axis xyz="0 1 0" rpy="0 0 0" />
      <limit effort="100" velocity="100"/>
      <joint_properties damping="0.0" friction="0.0"/>
    </joint>

    <link name="${prefix}_wheel_link">
      <visual>
        <origin xyz="0 0 0" rpy="0 0 0" />
        <xacro:if value="${reflect}">
          <geometry>
            <mesh filename="package://summit_description/meshes/wheels/wheel-1.dae" />
          </geometry>
          </xacro:if>
          <xacro:unless value="${reflect}">
            <geometry>
              <mesh filename="package://summit_description/meshes/wheels/wheel-1.dae" />
            </geometry>
            </xacro:unless>
      </visual>

      <collision>
                <origin xyz="0 0 0" rpy="${PI/2} 0 0" />
        <geometry>
                    <cylinder length="${wheel_height}" radius="${wheel_radius}" />
        </geometry>
      </collision>

      <inertial>
        <mass value="${wheel_mass}" />
        <origin xyz="0 0 0" />
        <cylinder_inertia  m="${wheel_mass}" r="${wheel_radius}" h="${wheel_height}" />
      </inertial>
    </link>

    <!-- Transmission is important to link the joints and the controller (see summit_xl_control/config/summit_xl_control.yaml)-->
    <transmission name="${prefix}_wheel_joint_trans">
      <type>transmission_interface/SimpleTransmission</type>
      <joint name="${prefix}_wheel_joint" >
        <hardwareInterface>hardware_interface/VelocityJointInterface</hardwareInterface>
      </joint>
      <actuator name="${prefix}_wheel_joint_motor">
         <mechanicalReduction>1</mechanicalReduction>
      </actuator>
    </transmission>

    <gazebo reference="${prefix}_wheel_link">
        <mu1 value="1.0"/>
        <mu2 value="1.0"/>
        <kp value="10000000.0" />
        <kd value="1.0" />
        <fdir1 value="1 0 0"/>
        <turnGravityOff>false</turnGravityOff>
    </gazebo>

  </xacro:macro>
</robot>