URDF

Introduction

URDF is a very standard format that can be exported by onshape-to-robot. Below are the specific configuration entries that can be specified when using this format.

When using this exporter, frames will be added as a dummy links attached to their body using a fixed joint

config.json entries (URDF)

Here is an example of complete config.json file, with details below:

{
    "document_id": "document-id",
    "output_format": "urdf",
    // ...
    // General import options (see config.json documentation)
    // ...

    // Override joint properties (default: {})
    "joint_properties": {
        // Default properties for all joints
        "default": {
            "max_effort": 10.0,
            "max_velocity": 6.0,
            "friction": 0.5
        },
        // Set the properties for a specific joint
        "joint_name": {
            "max_effort": 20.0,
            "max_velocity": 10.0,
            "friction": 0.1,
            "limits": [0.5, 1.2]
        },
        "wheel": {
            "type": "continuous"
        }
    },

    // Whether the collisions should be used in visual as well (default: false)
    "draw_collisions": true,
    // Use only pure shapes (when available) for collisions
    "collisions_no_mesh": true,
    // Package name (for ROS) (default: "")
    "package_name": "my_robot",
    // Additional XML file to be included in the URDF (default: "")
    "additional_xml": "my_custom_file.xml",
}

joint_properties (default: {})

Allow to specify the properties of the joints produced in the URDF output. The key should be joint names. The special default key will set default values for each joints.

Possible values are:

• max_effort: The maximum effort that can be applied to the joint (added in the <joint effort=...> tag)

• max_velocity: The maximum velocity of the joint (added in the <joint velocity=...> tag)

• friction: The friction of the joint (added in the <joint_properties friction=...> tag)

• type: Sets the joint type (changing the <joint type="..."> tag)

• limits: Override the joint limits, should be a list of two values (min, max)

draw_collisions (default: false)

If this flag is set to true, the same items that are used for collisions will be used for visuals as well. If you have pure shape approximations, this is useful for debugging purposes.

collisions_no_mesh (default: false)

If this flag is set to true, only pure shapes will be used for collisions, and not the mesh. This is useful for performance reasons.

package_name (default: “”)

If you are exporting a URDF for ROS, you can specify the package name here. This will be used in the <robot> tag.

additional_xml (default: “”)

If you want to include additional XML in the URDF, you can specify the path to the file here. This file will be included at the end of the URDF file.