Interbotix TF Tools

This package contains various tools used manipulate the TF tree.

tf_rebroadcaster

This tool, built as a composable node, allows users to rebroadcast specific TFs from one topic to another and optionally add a prefix. For example, say that, for some reason, the user had a TF tree that was published to the topic /mobile_base/tf and instead wanted it to be published to /tf. This node, along with its configuration file (the template can found at config/tf_rebroadcaster.yaml) will allow the user to do just that.

Warning You are not be able to rebroadcast from the root namespace to other namespaces, i.e. you cannot rebroadcast from /tf to /mobile_base/tf.

Parameters

The tool takes two parameters:

Configuration File Format

# The 'frames' node contains all frames to be rebroadcasted.
# Each frame is formatted as so:
# frames:
#   PARENT_FRAME_ID:
#     child_frame_id: CHILD_FRAME_ID
#     prefix: PREFIX
# This configuration would take the transform from frame 'PARENT_FRAME_ID' to
#   frame 'CHILD_FRAME_ID', add the prefix 'PREFIX', and rebroadcast it to the
#   specified topic.
# If prefix is left as an empty string (''), no prefix will be added.
frames:
  odom:
    child_frame_id: base_link
    prefix: ''
  odom:
    child_frame_id: base_footprint
    prefix: ''

Demo Launch File

This tool comes with a launch file to demonstrate usage. It takes three launch arguments:

An example ros2 launch command would be:

ros2 launch interbotix_tf_tools tf_rebroadcaster.launch.py topic_from:="/mobile_base/tf" namespace_to:=""

You may include the tf_rebroadcaster in a ComposableNodeContainer like so:

from launch_ros.actions import ComposableNodeContainer
from launch_ros.descriptions import ComposableNode

...

tf_rebroadcaster_container = ComposableNodeContainer(
    name='container',
    namespace=namespace_to_launch_arg,
    package='rclcpp_components',
    executable='component_container',
    composable_node_descriptions=[
        ComposableNode(
            package='interbotix_tf_tools',
            plugin='interbotix_tf_tools::TFRebroadcaster',
            name='tf_rebroadcaster',
            namespace=namespace_to_launch_arg,
            parameters=[
                {
                    'filepath_config': config_launch_arg,
                    'topic_from': topic_from_launch_arg,
                },
            ],
            remappings=[('/tf', [namespace_to_launch_arg, '/tf'])],
        ),
        ComposableNode(
            ...
        ),
    ]
)