git commit -m "first commit"

mir_robot/diff_drive_controller/test/wheel.xacro

@@ -0,0 +1,43 @@
+<?xml version="1.0"?>
+<robot xmlns:xacro="http://www.ros.org/wiki/xacro">
+  <xacro:macro name="wheel" params="name parent radius thickness *origin">
+    <link name="${name}_link">
+      <inertial>
+        <origin xyz="0 0 0" rpy="0 0 0"/>
+        <mass value="1"/>
+        <inertia ixx="0.2" ixy="0" ixz="0" iyy="0.2" iyz="0" izz="0.2"/>
+      </inertial>
+      <visual>
+        <origin xyz="0 0 0" rpy="0 0 0"/>
+        <geometry>
+          <cylinder radius="${wheel_radius}" length="${thickness}"/>
+        </geometry>
+      </visual>
+      <collision>
+        <origin xyz="0 0 0" rpy="0 0 0"/>
+        <geometry>
+          <cylinder radius="${wheel_radius}" length="${thickness}"/>
+        </geometry>
+      </collision>
+    </link>
+
+    <joint name="${name}_joint" type="continuous">
+      <parent link="${parent}_link"/>
+      <child link="${name}_link"/>
+      <xacro:insert_block name="origin"/>
+      <axis xyz="0 0 1"/>
+    </joint>
+
+    <!-- Transmission is important to link the joints and the controller -->
+    <transmission name="${name}_joint_trans" type="SimpleTransmission">
+      <actuator name="${name}_joint_motor"/>
+      <joint name="${name}_joint"/>
+      <mechanicalReduction>1</mechanicalReduction>
+      <motorTorqueConstant>1</motorTorqueConstant>
+    </transmission>
+
+    <gazebo reference="${name}_link">
+      <material>Gazebo/Red</material>
+    </gazebo>
+  </xacro:macro>
+</robot>