FMCW Radar Object Tracking Message

This message defines the structure of an object tracking message specifically for FMCW radar systems. It includes information about object classification, position, velocity, acceleration, size, and associated covariances. The message is designed to be used as part of a larger stamped or array message.

Frame of Reference

All variables below are relative to the radar's frame of reference.

Object Classifications

The following object classifications are defined:

uint16 NO_CLASSIFICATION=0
uint16 STATIC=1
uint16 DYNAMIC=2

Additional vendor-specific classifications are permitted starting from 32000 (e.g., CAR).

Message Fields

unique_identifier_msgs/UUID uuid            # A unique ID of the object generated by the radar.

                                            # Note: The z component of these fields is ignored for 2D tracking.
geometry_msgs/Point position                # x, y, z coordinates of the centroid of the object being tracked.
geometry_msgs/Vector3 velocity              # The velocity of the object in each spatial dimension.
geometry_msgs/Vector3 acceleration          # The acceleration of the object in each spatial dimension.
geometry_msgs/Vector3 size                  # The object size in the sensor frame. 
                                            # For example length, width, and height, 
                                            # or the diameter of an ellipsoid in the x, y, z, dimensions.
uint16 classification                       # An optional classification of the object (see above).
float32[6] position_covariance              # Upper-triangle covariance about the x, y, z axes.
float32[6] velocity_covariance              # Upper-triangle covariance about the x, y, z axes.
float32[6] acceleration_covariance          # Upper-triangle covariance about the x, y, z axes.
float32[6] size_covariance                  # Upper-triangle covariance about the x, y, z axes.

Example Message

# Object classifications
uint16 NO_CLASSIFICATION=0
uint16 STATIC=1
uint16 DYNAMIC=2
uint16 CAR=32000

unique_identifier_msgs/UUID uuid            # A unique ID of the object generated by the radar.
uuid: '1234567890abcdef1234567890abcdef'     # A unique identifier for the object.

geometry_msgs/Point position                # x, y, z coordinates of the centroid of the object being tracked.
position:
  x: 5.0
  y: 2.0
  z: 0.0

geometry_msgs/Vector3 velocity              # The velocity of the object in each spatial dimension.
velocity:
  x: 10.0
  y: 0.0
  z: 0.0

geometry_msgs/Vector3 acceleration          # The acceleration of the object in each spatial dimension.
acceleration:
  x: 0.0
  y: 0.0
  z: 0.0

geometry_msgs/Vector3 size                  # The object size in the sensor frame.
size:
  x: 2.0
  y: 1.0
  z: 1.5

uint16 classification                       # An optional classification of the object (see above).
classification: CAR                        # The object is classified as a car.

float32[6] position_covariance              # Upper-triangle covariance about the x, y, z axes.
position_covariance: [0.01, 0.0, 0.0, 0.01, 0.0, 0.01]

float32[6] velocity_covariance              # Upper-triangle covariance about the x, y, z axes.
velocity_covariance: [0.01, 0.0, 0.0, 0.01, 0.0, 0.01]

float32[6] acceleration_covariance          # Upper-triangle covariance about the x, y, z axes.
acceleration_covariance: [0.01, 0.0, 0.0, 0.01, 0.0, 0.01]

float32[6] size_covariance                  # Upper-triangle covariance about the x, y, z axes.
size_covariance: [0.01, 0.0, 0.0, 0.01, 0.0, 0.01]