Readme

• This package is a ROS2 driver for schunk egh 80 gripper. It provides a service to send commands to the gripper via modbus TCP communication protocol.
• The service can be used to send control commands to the 'control register' and receive status data from the 'status register'.
• The package also publishes joint states of the gripper on [schunk/schunk_egh80/joint_states], this topic can be customized through the launch file.
• The package generates the used services headers internaly. All services files are in 'srv/' directory.

Dependencies

1. std_msgs
2. sensor_msgs
3. modbuspp [header file provided with the package: Modbus TCP c++ library]

Services

1. schunk/control/schunk_egh80 (schunk_control_egh80::srv::ControlEGH80)

   This service provide multiple commands as follows:

   • connect: connects to the gripper modbus TCP server. (ip_address and device_port are obtained from a yaml file)
   • set_position: sets the opening position of the gripper. (input: percentage openning)
     • parameters:
       1. position: [float32] opening value (0-100%) of the gripper.
   • acknowledge: acknowledge error.
   • get_position: obtains the current opening position (in percentage).
   • get_status: obtains the current status of the gripper.
   • stop_gripper: stop the gripper.
   • reference: define the zero position of the gripper.
   • disconnect: disconnect the gripper modbus TCP server.

Topics

1. joint_states [sensor_msgs/msg/JointState]
   • schunk/schunk_egh80/joint_states
2. status [std_msgs/msg/UInt8]
   • schunk/schunk_egh80/status

Launch

To launch this node, use the launch.py script

ros2 launch schunk_control_egh80 egh80_driver_launch.py

ToDo:

1. provide a common yaml file in a configuration package that manages all the ros parameters and default values instead of declaring them in the launch file or in the executable.