Arbench

Annotation for robotics bench. A FreeCAD workbench for annotating frames of interest, exporting these w.r.t. the part frame, and exporting part information.

Installation instructions

This workbench supports versions of FreeCAD>0.16.

1. Install FreeCAD
2. If you're not on Ubuntu follow the workbench installation instructions or you can do the following on Ubuntu.
3. Custom workbenches are located in .FreeCAD/Mod/ under your home directory cd ~/.FreeCAD/Mod/
4. Either
   • Clone the repository there
   • symlink the cloned repo in there (ln -s ./ARBench ~/.FreeCAD/ARBench)
5. Start the workbench by
   1. Running FreeCAD
   2. Open a STEP file
   3. Open the ARBench workbench

Usage

1. Click a small feature e.g. a circle
2. Press the feature frame creator (cone with a magnifying glass on it icon)
3. Chose type of feature to create
4. Chose feature parameters if relevant and the offset of the frame from the feature.
5. Repeat 4 for each feature you want on each part
6. Click a part and press the export to json button (block->textfile icon)
7. Save json
8. Use the json with whatever you want. E.g. arbench_part_publisher

Freecad to Gazebo exporter

To generate SDF and URDF model from freecad assembly use python call:

freecad_exporter.export_gazebo_model(freecad_assembly_file, model_destination_folder, config)

Note: Only links and joints are generated in the SDF model. To use the model with ros, use the URDF model.

Config specification

{
    "name": "robot_name",
    "joints_limits": {"upper": 90, "lower": -90, "effort": 10, "velocity": 5},
    "transmission": {
        "type": "transmission_interface/SimpleTransmission",
        "hardware_interface": "hardware_interface/PositionJointInterface"
    },
    "joints_config": {
        "type": "position_controllers/JointGroupPositionController",
        "grouped": true
    },
    "joints_pid": {"p": 20.0, "i": 10.0, "d": 0.0, "i_clamp": 0.0},
    "root_link": "base_link",
    "ros_package": "humanoid_17dof_description",
    "sdf_only": false,
    "export": true
}

sdf_only: Export only SDF.

export: Export mesh files.

Future plans

• Extend collada exporter to export materials from assemblies.
• Create a FreeCAD workbench to interactively assign joints and export to gazebo.
• Support any valid structures of assemblies.