Positioning with ArUco markers

aruco_pose package consists of two nodelets: aruco_detect detects individual ArUco-markers and estimates their poses, aruco_map detects maps of markers using aruco_detect output.

Quick start

To run a camera nodelet, markers and maps detector:

roslaunch aruco_pose sample.launch

You’re going to need cv_camera package installed.

aruco_detect nodelet

aruco_detect detects ArUco markers on the image, publishes list of them (with poses), TF transformations, visualization markers and processed image for debugging.

It’s recommended to run it within the same nodelet manager with the camera nodelet (e. g. cv_camera).

Parameters

• ~dictionary (int) – ArUco dictionary (default: 2)
  • 0 = DICT_4X4_50
  • 1 = DICT_4X4_100,
  • 2 = DICT_4X4_250,
  • 3 = DICT_4X4_1000,
  • 4 = DICT_5X5_50,
  • 5 = DICT_5X5_100,
  • 6 = DICT_5X5_250,
  • 7 = DICT_5X5_1000,
  • 8 = DICT_6X6_50,
  • 9 = DICT_6X6_100,
  • 10 = DICT_6X6_250,
  • 11 = DICT_6X6_1000,
  • 12 = DICT_7X7_50,
  • 13 = DICT_7X7_100,
  • 14 = DICT_7X7_250,
  • 15 = DICT_7X7_1000,
  • 16 = DICT_ARUCO_ORIGINAL
• ~estimate_poses (bool) – estimate single markers’ poses (default: true)
• ~send_tf (bool) – send TF transforms (default: true)
• ~frame_id_prefix (string) – prefix for TF transforms names, marker’s ID is appended (default: aruco_)
• ~length (double) – markers’ sides length
• ~length_override (map) – lengths of markers with specified ids
• ~known_tilt (string) – known tilt (pitch and roll) of all the markers as a frame

Topics

Subscribed

• image_raw (sensor_msgs/Image) – camera image
• camera_info (sensor_msgs/CameraInfo) – camera calibration info

Published

• ~markers (aruco_pose/MarkerArray) – list of detected markers with their corners and poses
• ~visualization (visualization_msgs/MarkerArray) – visualization markers for rviz
• ~debug (sensor_msgs/Image) – debug image with detected markers

Published transforms

• <camera_frame> => <frame_id_prefix><id> – markers’ poses

aruco_map nodelet

aruco_map nodelet estimates position of markers map.

Parameters

• ~map – path to text file with markers list
• ~frame_id – published frame id (default: aruco_map)
• ~known_tilt – debug image width
• ~image_width – debug image width (default: 2000)
• ~image_height – debug image height (default: 2000)
• ~image_margin – debug image margin (default: 200)
• ~dictionary (int) – ArUco dictionary (default: 2) - should be the same as dictionary parameter of aruco_detect nodelet

Map file has one marker per line with the following line format:

marker_id marker_length x y z yaw pitch roll

Where yaw, pitch and roll are extrinsic rotation around Z, Y, X axis, respectively.

See examples in map directory.

Topics

Subscribed

• image_raw (sensor_msgs/Image) – camera image (used for debug image)
• camera_info (sensor_msgs/CameraInfo) – camera calibration info (used for debug image)
• markers (aruco_pose/MarkerArray) – list of markers detected by aruco_pose nodelet

Published

• ~pose (geometry_msgs/PoseWithCovarianceStamped) – estimated map pose
• ~image (sensor_msgs/Image) – planarized map image
• ~visualization (visualization_msgs/MarkerArray) – markers map visualization for rviz
• ~debug (sensor_msgs/Image) – debug image with detected markers and map axis

Published transforms

• <camera_frame> => <map_name> – markers map pose

Running tests

Command for running tests:

catkin_make run_tests && catkin_test_results

Copyright

Copyright © 2018 Copter Express Technologies. Author: Oleg Kalachev.

Distributed under MIT License (https://opensource.org/licenses/MIT).

Changelog for package aruco_pose

0.21.1 (2020-11-17)

• First release of aruco_pose package to ROS
• Contributors: Alamoris, Alexey Rogachevskiy, Arthur Golubtsov, Ilya Petrov, Oleg Kalachev