Carma-platform v4.2.0
CARMA Platform is built on robot operating system (ROS) and utilizes open source software (OSS) that enables Cooperative Driving Automation (CDA) features to allow Automated Driving Systems to interact and cooperate with infrastructure and other vehicles through communication.
Multiple object tracker

This is the main Node in the package; it does the actual object tracking. It wraps the multiple_object_tracking library in a ROS 2 interface and composes the individual tracking steps into a cohesive pipeline. Check out the library's documentation for details on the specific pipeline steps. For our purposes, we need to be concerned only with the node's inputs and outputs. It receives incoming carma_cooperative_perception_interfaces/DetectionList.msg messages from various sources (CARMA Platform and connected remote actors), and sends out carma_cooperative_perception_interfaces/TrackList.msg messages. This Node fuses the data from the incoming DetectionList.msg messages to form the outgoing TrackList.msg messages' data.

Node behavior

The multiple_object_tracker_node Node executes a multiple object tracking pipeline at a specific frequency, which the execution_frequency_hz parameter defines. Between executions, the Node listens for incoming DetectionList.msg messages on the ~/input/detections topic, queueing received detections for processsing. The tracking pipeline executes the following steps on each iteration:

  1. temporal alignment
  2. detection-to-track scoring
  3. detection-to-track association
  4. unassociated detection clustering
  5. track maintenance
  6. detection-to-track fusion

The tracker Node outputs a list of confirmed tracks after executing the pipeline.

Subscriptions

Topic Message Type Description
~/input/detections carma_cooperative_perception_interfaces/DetectionList.msg Incoming detections

Publishers

Topic Message Type Frequency Description
~/output/tracks carma_cooperative_perception_interfaces/TrackList.msg Parameter-defined Tracked objects from the pipeline. Note: The track list contains only confirmed tracks.

Parameters

Topic Data Type Default Value Required Read Only Description
~/execution_frequency_hz float 2.0 No No Tracking execution pipeline's execution frequency (in Hertz)

Services

This Node does not provide services.

Actions

This Node does not provide actions.