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ArUco detector

Detect markers and make their results available to other tools.

Checked 2026-10-16

Open this tool in Lab

Prepare and use

  1. Open ArUco detector in the catalog and install required dependencies, including OpenCV.
  2. Connect a camera and choose it in the tool using the detector.
  3. Set the physical marker size using the units expected by the field.
  4. Show the complete marker without glare or obstruction and inspect detected IDs.
  5. For positions relative to the base, connect the robot and check camera calibration and the coordinate transform.
ArUco detector — Screen detail
ArUco detector — Screen detail

Accuracy and coordinates

Distinguish camera-relative positions from robot-base positions. Without calibration, depth estimates are inaccurate; an incorrect marker size distorts distance. No markers in frame means no markers were recognized, not proof that the image contains no objects.

Module 10 introduces markers in a teaching scene.

Buttons, fields and results

Control How to use it and what happens
Camera Selects an image source when several cameras are connected. Without cameras, No cameras available replaces the panel; add a camera through the shared Lab panel.
Dictionary Select the dictionary used to create the printed marker. A different dictionary prevents correct recognition; an ID is meaningful only together with its dictionary.
Marker size, cm Enter the measured side length of the marker in centimetres. This size affects distance calculation. Do not enter millimetres in a field labelled cm.
Ready / Loading OpenCV… / OpenCV unavailable Recognition-library status. Ready confirms that processing is available, not that a marker is present in the frame.
Camera calibrated / No calibration (depth inaccurate) Shows whether camera intrinsics are available. Without calibration, estimated depth is inaccurate; run Camera calibration for the selected camera.
Detected markers The list of detected IDs updates while the camera runs. No markers in frame means that no markers were recognised in the current frame.
relative to cam. Marker coordinates relative to the camera, shown in metres. Check units before using them in another tool.
relative to base Coordinates relative to the robot base appear when a camera transformation is available. They require a connection, configuration of the camera on the arm and correct joint positions.

This panel has no separate Detect or Start button: processing begins when a camera is available and OpenCV is ready. Show the complete marker, select the correct dictionary and check that its ID appears in the list.