The Notices and Disclaimers for Ocean Worlds Autonomy Testbed for Exploration Research and Simulation can be found in README.md in the root directory of this repository.

Contains the lander semantic and kinematic descriptions (SRDF and URDF), the moveit path planner and the gazebo trajectory feeder, and common code related to the lander. The package also contains the definition and implementation of several arm services

• Requirements
• Usage
  • Calling Arm Operations using RQT Service Caller
  • Calling Arm Operations using ROS Command Line Interface
• MoveIt Setup Assistant
• Misc Information
  • Common Code
  • Package History

To compile and run this package you need to have the following dependencies:

• ros-melodic-destkop-full
• ros-melodic-joint-trajectory-controller

First run the simulation using any of the available OceanWATERS launch configurations:

roslaunch ow atacma_y1a.launch  # other options:
                                # * europa_terminator.launch
                                # * europa_terminator_workspace.launch

This will start the simulation, as well as loads available services to to control the arm, you can interact with the exposed services using any of the two methds described below:

When OceanWATERS sim is launched by default it starts an instance of rqt_gui that has the Service Caller plugin enabled. You can use the service caller interface to invoke the different arm services that are exposed by the simulation. Find the rqt_gui window then select the Service Caller tab. Using the drop down menu, select the service that you want to invoke (for example/arm/dig_circular or /arm/guarded_move), configure the service arguments, as shown below:

Finally, press the Call button to invoke the service as configured.

Alternatively to using the RQT Service Caller gui interface, you may interact with the services using the rosservice command line tool. While the simulation is running, start a new terminal and source OceanWATERS workspace. Then, invoke the services using their respective commands as listed below:

• Stow

rosservice call /arm/stow "{}"

• Unstow

rosservice call /arm/unstow "{}"

• Deliver Sample

rosservice call /arm/deliver_sample \
  "{use_defaults: true,
    x: 0.0, y: 0.0, z: 0.0}"

• Dig Linear

rosservice call /arm/dig_linear \
  "{use_defaults: true,
    x: 0.0, y: 0.0, depth: 0.0,
    length: 0.0, ground_position: 0.0}" 

• Dig Circular

rosservice call /arm/dig_circular \
  "{use_defaults: true,
    x: 0.0, y: 0.0, depth: 0.0,
    parallel: false, ground_position: 0.0}"

• Grind

rosservice call /arm/grind \
  "{use_defaults: true,
    x: 0.0, y: 0.0, depth: 0.0,
    length: 0.0,
    parallel: false, ground_position: 0.0}" 

• Guarded Move

rosservice call /arm/guarded_move \
  "{use_defaults: true,
    x: 0.0, y: 0.0, z: 0.0,
    direction_x: 0.0, direction_y: 0.0, direction_z: 0.0,
    search_distance: 0.0}"

Note: Some of the exposed arm services take a number of arguments, the examples provided here show running these service using default values. For more info on the arguments of each of the services above, refer to the message declaration in the .srv files.or use rossrv utility as shown here (replacing "foo" with the desired service name):

rossrv show -r foo

The moveit setup assistant can now be easily launched using the command:

roslaunch ow_lander setup_assistant.launch

Once the assistant is launched call the Load Files to load the current configuration. The following image shows a screenshot of a successfully loaded lander configuration:

There are various reasons why you may need to re-run the setup assistant:

• Update the links collision matrix: this should be reconfigured again whenever links count, their shape or size changes or there was a change in the number of joints or their types.
• Define new arm/antenna poses or revise existing ones.

All the motion planning services have been converted into ROS Actions. With ROS actions we can dynamically interact with the arm while performing any of the above mentioned tasks and also receive real-time feedback about the end effector's position.

The ROS Action server scripts, as well as client scripts to test the actions, are found in the scripts directory.

include/ow_lander/lander_joints.h contains joint names as they appear in the URDF and related code. Please prefer this header over writing similar code yourself to keep all our code consistent. If the lander is modified to change the number of joints or any joint names, this header must be updated as well.

• A major overhaul of this package was done after switching from JointPositionController to JointTrajectoryController for arm services. Nonetheless, this revised version is more comptabile with the file generated by the setup_assistant with few manual edits. Refer to PR: Oceanwater 518 switch to using effort controllers joint trajectory controller for complete track of the set of changes.

• A force torque (FT) sensor was added to the arm on the distal pitch joint. For more information refer to the the following PRs Oceanwater 614 implement a force torque sensor for the lander arm and refer to the related wiki page Lander Simulation / Force Torque Sensor

• ROS Action support was added to the package. For more information refer to Oceanwater 534 implement current arm services as rosaction