DYNAMIC CALIBRATION SYSTEMS AND METHODS FOR WEARABLE HEADS-UP DISPLAYS
Systems, methods and articles that provide dynamic calibration of eye tracking systems for wearable heads-up displays (WHUDs). The eye tracking system may determine a user's gaze location on a display of the WHUD utilizing a calibration point model that includes a plurality of calibration points. During regular use of the WHUD by the user, the calibration point model may be dynamically updated based on the user's interaction with user interface (UI) elements presented on the display. The UI elements may be specifically designed (e.g., shaped, positioned, displaced) to provide in-use and on-going dynamic calibration of the eye tracking system, which in at least some implementations may be unnoticeable to the user.
1 . A method of operating a wearable heads-up display device (WHUD) comprising a display and a glint detection module, the method comprising:
during regular operation of the WHUD by a user,
populating, by at least one processor, the display of the WHUD with at least one user interface (UI) element; and
detecting, by the at least one processor, a gaze location of a user based at least in part on glint information received from the glint detection module and a known location of at least one of the at least one UI element on the display.
2 . The method of claim 1 wherein populating the display of the WHUD with at least one UI element comprises populating the display with a number of UI elements that is below a threshold determined to enable accurate gaze location detection.
3 . The method of claim 1 wherein populating the display of the WHUD with at least one UI element comprises maximizing the respective distances between a plurality of UI elements displayed on the display.
4 . The method of claim 1 wherein populating the display of the WHUD with at least one UI element comprises minimizing a similarity between an angle and a length of vectors that join pairs of a plurality of UI elements displayed on the display.
5 . The method of claim 1 wherein populating the display of the WHUD with at least one UI element comprises populating the display of the WHUD with at least one animated UI element.
6 . The method of claim 1 , further comprising:
updating, by the at least one processor, an eye tracking calibration based at least in part on the detected gaze location.
7 . The method of claim 6 wherein updating an eye tracking calibration comprises generating at least one calibration point based at least in part on the detected gaze location, the at least one calibration point comprising a glint space point received from the glint detection module and a display space point that corresponds to a location of a UI element displayed on the display.
8 . The method of claim 7 wherein generating at least one calibration point comprises generating a calibration point for each UI element displayed on the display, each calibration point associated with a UI element comprising a glint space point received from the glint detection module and a display space point that corresponds to the location of the UI element on the display.
9 . The method of claim 6 wherein updating an eye tracking calibration comprises adding a calibration point to at least one parent calibration point model that comprises a plurality of calibration points to generate at least one child calibration point model.
10 . The method of claim 9 , further comprising:
fitting, by the at least one processor, a transform to the calibration points of the at least one child calibration point model.