Add MoMo robot

[manavthakkar]

This PR adds momo robot urdf along with the scad files for collision approximation. MoMo is a mecanum wheeled robot developed at the Institut für Technische Logistik - Hamburg, Germany.

When i drag and drop the momo_urdf in this urdf web viewer, everything works perfectly, but when i use the onshape-to-robot-bullet, the wheels are missing.

[Gregwar]

Hello,

Thanks for your PR!

Here are some remarks:

There are unfixed parts. You used "groups" to attach x/y/z axises, which is not supported by onshape-to-robot.

Instead, you should consider one of the following:
- Use the composite part "frame" (you have to click on the composite button to enable it, see below)
- Simply add a mate connector called "frame_something", without using a separate body

The robot is not loading entirely in pyBullet, because of mesh sizes.

Here is what I changed:

• Set joint type to continuous
• Ignored inner parts and connectors
• Enabled meshes simplification and merge, with a limit to 1M

{
    "url": "https://cad.onshape.com/documents/0f7ba08d49760d832652e76c/w/f802382a554ac4e5d967eb06/e/176c79e9883e5c00c7190ba1",
    "output_format": "urdf",
    "use_scads": true,
    "simplify_stls": true,
    "merge_stls": true,
    "max_stl_size": 1,

    "joint_properties": {
        "*wheel*": {
            "type": "continuous"
        }
    },

    "ignore": {
        "Aluminium_profile*": "all",
        "*Connector*": "all"
    }
}

MuJoCo support

Here is a suitable configuration for MuJoCo

{
    "url": "https://cad.onshape.com/documents/0f7ba08d49760d832652e76c/w/f802382a554ac4e5d967eb06/e/176c79e9883e5c00c7190ba1",
    "output_format": "mujoco",
    "use_scads": true,

    "joint_properties": {
        "*": {
                "actuated": false,
                "range": false
        },
        "*_wheel": {
           "actuated": true,
           "type": "velocity",
           "limits": [-16, 16],
           "kv": 5.0
        }
    }
}

momo.mp4

[manavthakkar]

Thanks for the feedback!

I added the mate connectors with name "frame_something", without using separate bodies, and updated the configuration file for the urdf, and added momo_mujoco with the configuration that you provided.