Motoros2 Hardware Interfaces

This package contains the hardware interfaces for the Yaskawa robot arm. Specifically, it was written for the MOTOMAN HC20SDTP. However, the interfaces itself are not specific to this robot model and can be used with other MOTOMAN robot arms as well. Much more important is whether the MotoROS2 driver supports the robot arm model and/or the Yaskawa Motoman robot controller. For more information, please refer to the MotoROS2 repository. Additionally, it is possible that the provided ROS2 interfaces by MotoROS2 are already sufficient for your use case. In this case, you may not need to use this package.

Components

This package provides state and command interfaces for the ros2_control framework. The following components are available:

• FTSHardwareInterface: This component is responsible for providing force-torque sensor data to the ros2_control framework. It is then possible to just use the force_torque_sensor_broadcaster to publish the force-torque sensor data for other controllers, e.g. the admittance_controller. The requirement for this component is that the force-torque sensor data is published on the /tcp_force_torque topic by the MotoROS2 driver.

• GPIOSystem: This component is responsible for providing state and command interfaces for digital input/output signals. This can be used to control external devices, such as grippers or other peripherals. The current states can be read from the /dynamic_joint_states topic. To control the digital outputs, the forward_command_controller can be used at fist. However, for more complex use cases, a custom controller may be necessary. The requirement for this component is that the services for the digital input/output signals are provided by the MotoROS2 driver (/read_single_io, /write_single_io, /read_group_io, /write_group_io).

• MotoROS2HardwareInterface: This component is responsible for providing joint state and command interfaces for the robot arm. In this way, it is possible to control the robot arm using ROS2 controllers, such as joint_trajectory_controller or admittance_controller. The requirement for this component is that the current joint states are published on the topic and /queue_traj_point service is provided by the MotoROS2 driver.

Usage

To use the hardware interfaces, you need to add the following to your URDF file:

• For the FTSHardwareInterface:

<ros2_control name="fts_hw" type="sensor" is_async="true" >
  <hardware>
    <plugin>motoros2_hw_interfaces/FTSHardwareInterface</plugin>
    <param name="fts_topic">/tcp_force_torque</param>
    <param name="force_x_name">force.x</param>
    <param name="force_y_name">force.y</param>
    <param name="force_z_name">force.z</param>
    <param name="torque_x_name">torque.x</param>
    <param name="torque_y_name">torque.y</param>
    <param name="torque_z_name">torque.z</param>
  </hardware>
  <sensor name="force_torque_sensor">
    <state_interface name="force.x"/>
    <state_interface name="force.y"/>
    <state_interface name="force.z"/>
    <state_interface name="torque.x"/>
    <state_interface name="torque.y"/>
    <state_interface name="torque.z"/>
  </sensor>
</ros2_control>

• For the GPIOSystem, please refer the corresponding file in the test directory.

• For the MotoROS2HardwareInterface:

<ros2_control name="motoros2_hw" type="system" is_async="true" >
  <hardware>
    <plugin>motoros2_hw_interfaces/MotoROS2HardwareInterface</plugin>
    <param name="queue_traj_point_srv_name">/queue_traj_point</param>
    <param name="joint_states_topic_name">/hc20sdtp_joint_states</param>
    </xacro:unless>
  </hardware>

  <joint name="joint_1_s">
    <command_interface name="position"/>
    <state_interface name="position">
      <param name="initial_value">0</param>
    </state_interface>
    <command_interface name="velocity"/>
    <state_interface name="velocity"/>
  </joint>
  <joint name="joint_2_l">
    <command_interface name="position"/>
    <state_interface name="position">
      <param name="initial_value">0</param>
    </state_interface>
    <command_interface name="velocity"/>
    <state_interface name="velocity"/>
  </joint>
  <joint name="joint_3_u">
    <command_interface name="position"/>
    <state_interface name="position">
      <param name="initial_value">0</param>
    </state_interface>
    <command_interface name="velocity"/>
    <state_interface name="velocity"/>
  </joint>
  <joint name="joint_4_r">
    <command_interface name="position"/>
    <state_interface name="position">
      <param name="initial_value">0</param>
    </state_interface>
    <command_interface name="velocity"/>
    <state_interface name="velocity"/>
  </joint>
  <joint name="joint_5_b">
    <command_interface name="position"/>
    <state_interface name="position">
      <param name="initial_value">0</param>
    </state_interface>
    <command_interface name="velocity"/>
    <state_interface name="velocity"/>
  </joint>
  <joint name="joint_6_t">
    <command_interface name="position"/>
    <state_interface name="position">
      <param name="initial_value">0</param>
    </state_interface>
    <command_interface name="velocity"/>
    <state_interface name="velocity"/>
  </joint>
</ros2_control>