hri_person_manager is a ROS node, part of the ROS4HRI framework. It aggregates information about detected faces, bodies and voices into consistent persons, and exposes these detected persons with their links to their matching face, body, voice.

The aggregation relies on additional ROS nodes to provide candidate 'matches' between persons and/or body parts. For instance a face recogniser, that would publish candidate matches between faces and unique persons.

hri_person_manager is part of the ROS4HRI framework, and follows the ROS REP-155.

• Boost Graph library
• libhri and hri_msgs

Compile & install the node like any standard ROS node (eg, use catkin build).

It can be installed manually, by running the following set of commands:

$ cd ros_ws/src
$ git clone https://github.com/ros4hri/hri_person_manager.git
$ cd hri_person_manager
$ mkdir build && cd build
$ cmake -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=/opt/ros/noetic .. && make && make install

(of course, replace the INSTALL_PREFIX by your desired prefix)

This node subscribes to the /humans/candidate_matches topic (of type hri_msgs/IdsMatch.msg and creates a probablisitic graph with each detected features (face, body, voice) or persons. Features are considered to be linked if the likelihood of their connection is above the humans/match_threshold parameter.

It then looks for a partition of that graph such that:

• each subgraph is connected
• each subgraph has at most one feature of each type
• the overall likelihood of associations is maximised

See doc/ALGORITHM.md for details.

• /humans/match_threshold (float, default: 0.5): the minimum level of likelihood to consider a face/body/voice to belong to a given person.

• /humans/reference_frame (string, default: map): persons' TF frames are published with respect to reference_frame. Typically, faces/bodies/voices frames are published wrt to their respective sensors frame. hri_person_manager instead publishes TF frames of humans in reference_frame. reference_frame is usually a 'static' frame (eg map), so that if the person moves out of view of the robot (and therefore, its position can not be updated anymore), it 'stays' where it was last seen.

• /humans/robot_reference_frame (string, default: base_link): used to compute the distance between a person and the robot. Ideally, a frame attached to the robot, at ~people head height.

• /humans/proxemics/{personal,social,public}_distance (float, default: 1.2m for personal_distance, 3.6m for social_distance, 20m for public_distance): defines the range of the 3 main proxemics zone: the personal space goes from 0m to personal_distance, the social space from personal_distance to social_distance, and the public space from social_distance to public_distance. Persons detected beyond the public_space distance are not published. Set public_distance to 0m to ignore the maximum public space distance and always publish all the people.

• ~features_from_matches (bool, default: true): if set to true, features appearing in a candidate_matches message are assumed to be currently tracked, and are added to the features-person graph. If set to false, only features published on /humans/*/tracked are considered tracked, and candidate_matches for untracked features will be ignored.

• /humans/persons/tracked (type: hri_msgs/IdList): list of the persons currently tracked (ie seen or heard)

• /humans/persons/known (type: hri_msgs/IdList): list of the persons that were or are tracked at some point

• /humans/persons/in_{personal,social,public}_space (type: hri_msgs/IdList): list of persons currently tracked and in the corresponding proxemics space (cf parameters above for the distnace ranges of each zone)

• /humans/persons/<person id>/...: refer to the REP-155 for the list of topics and their semantics

In addition to the standard REP-155 topics, hri_person_manager also publishes proxemics:

• /humans/persons/in_{personal|social|public}_space (type: hri_msgs/IdsList): list of the persons currently in each proxemics zone (based on the ranges defined in the parameter section above)
• /humans/persons/<person id>/proxemic_space (type: std_msgs/String): one of unknown, personal, social, public (based on the ranges defined in the parameter section above)

• /humans/graph (type: std_msgs/String): a graph of the current probablisitic 'feature associations' network, in GraphViz format. Useful for debugging and can be plotted using the GraphViz tool.