tf2_lookup_server

Additional requirements:

• Eigen3, e.g. via sudo apt install libeigen3-dev

colcon build --packages-select tf2_lookup_server && source install/setup.bash

Nodes

tf2_lookup_server_node

Requests can be made for looking up instantaneous transforms, or a transform that is calculated as the average over a window.

Uses tf2_msgs/action/LookupTransform:

• target_frame, source_frame, source_time: as usual
• timeout: either a timeout for one-shot lookups, or the duration of a lookup window (can be negative for averaging into the past)
• target_time, fixed_frame: unused
• advanced: if true, averages over duration specified by timeout

ros2 run tf2_lookup_server tf2_lookup_server_node

Additional parameters:

• buffer_duration (default: 10.0): duration (s) of TF buffer
• hz (default: 50): lookup loop frequency

Examples

Lookup server test client

cd test
python3 lookup_client_test.py request.json

An example of querying the lookup_server. request.json is configured for a lookup from pelvis to head, averaged over the next few seconds until the timeout duration has elapsed.