enpose_tracking ROS2 node

A ROS 2 node for the Enpose 6-DoF optical marker tracking system. It connects to an Enpose sensor, streams marker poses, and republishes them as ROS messages and TF.

What it does

On startup the node connects to a sensor:

• by default it discovers sensors on the local network and connects to the first compatible one;
• alternatively, set the ip parameter to connect to a specific sensor directly.

For every detected marker it then publishes:

• a geometry_msgs/PoseStamped on markers/marker_<id>/pose (in the frame_id frame), and
• a TF transform frame_id → marker_<id>.

Every two seconds it logs the average number of poses received per second.

Until a sensor is found, the node keeps retrying discovery instead of exiting, and the two-second status log reports a warning rather than a pose rate. Connecting itself needs no retry logic: the pose stream is a self-maintaining UDP subscription, so a connected sensor that is briefly unreachable or simply sends no poses for a long time recovers on its own (the status log just reports 0.0 /s while it is idle).

Building

The build pulls in the Enpose API (tag 0.1.0) with CMake FetchContent and compiles its Rust core, so a Rust toolchain (cargo) must be on PATH.

colcon build
source install/setup.bash

Running

Connect to the first sensor found on the network:

ros2 run enpose_ros enpose_node

Connect to a specific sensor:

ros2 run enpose_ros enpose_node --ros-args -p ip:=192.168.1.42

Parameters

QoS

The pose topics default to reliable QoS. A reliable publisher is compatible with both reliable and best-effort subscribers, whereas a best-effort publisher is incompatible with reliable subscribers (they receive nothing). The default therefore works with any subscriber, including rviz regardless of its Reliability setting. Set reliability to best_effort for high-rate or lossy setups where dropping samples is preferable to retransmission. The TF (/tf) output is always reliable (the tf2_ros default).

Timestamps

The sensor reports a free-running microsecond clock with an arbitrary epoch, so its values can’t be used as ROS times directly. With use_device_timestamps (the default), the node estimates the offset between the device clock and ROS time using a one-sided minimum filter — it snaps the offset down to the lowest-latency packet seen and lets it drift up slowly (bounded by max_clock_skew_rate) to follow the relative skew of the two clocks. Each pose is then stamped by its own device timestamp plus that offset. This removes receive-side jitter and preserves the distinct capture times of frames that the library batched into a single update. Setting use_device_timestamps to false falls back to stamping each batch with the ROS receive time.