1. Robot arm model¶

In this chapter a Robot arm model will be defined. Refer to Gazebo chapter for simulation. We will continue the model started in the introductory chapter on urdf. We will create a new package called scara_g3_description.

cd workspace/src/Robots

catkin_create_pkg scara_g3_description geometry_msgs urdf rviz xacro

cd scara_g3_description

mkdir launch urdf meshes rviz scripts

1.1. Joints¶

1.2. Links¶

1.3. Gripper¶

1.4. Meshes¶

1.5. Transmissions¶

A transmission macro is created:

<xacro:macro name="transmission_block" params="joint_name">
  <transmission name="tran1">

     <type>transmission_interface/SimpleTransmission</type>

     <joint name="${joint_name}">
                 <hardwareInterface>hardware_interface/PositionJointInterface</hardwareInterface>
     </joint>

     <actuator name="motor1">
      <mechanicalReduction>1</mechanicalReduction>
     </actuator>

  </transmission>
</xacro:macro>

<xacro:transmission_block joint_name="joint_name1"/>
<xacro:transmission_block joint_name="joint_name2"/>
<xacro:transmission_block joint_name="joint_name3"/>

transmission_interface/SimpleTransmission is the only interface supported. The hardwareInterface could be position, velocity, or effort interfaces. In this case we choose PositionJointInterface. The hardware interface will be loaded by gazebo_ros_control plugin. Refer to Gazebo chapter for more information about this plugin.

1.6. Gazebo¶

Refer to Gazebo chapter.