HMD Visual Indication for VR Motion Sickness

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Solution Overview

Problem

In virtual reality (VR) and augmented reality (AR) applications, users experience motion sickness due to conflicting visual and vestibular signals, and existing eye tracking systems inaccurately calculate gaze convergence distance due to noise and small angle errors, while current input methods for accessing menus are complex and difficult to use.

Innovation Solution

A method and apparatus for a head-mounted display (HMD) that superimposes a visual indication, such as a grid-like pattern, to provide orientation information, with an occlusion region matching the user's gaze point to mitigate motion sickness, and an eye tracking system that calculates gaze convergence distance using a linear function based on interpupillary distances to reduce errors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a visual indication is superimposed on the display to provide orientation information, then motion sickness is mitigated, but the visual indication may obscure the scene image and distract the user

Engineering Contradiction:
Improvemotion sicknessVSAvoidscene image visibility
Core Design Contradiction:
Object-affected harmful factorsVSLoss of information

Solution Approach 1:

The visual indication is made transparent in the foveal region (center of gaze) where the user is looking, and opaque in peripheral regions. This local differentiation allows the orientation information to be visible in peripheral vision without obscuring the scene image in the central foveal region, thus mitigating motion sickness while preserving scene visibility.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

Instead of making the visual indication opaque everywhere and using transparency as a special case, the patent inverts the approach by making the indication transparent in the foveal region and opaque elsewhere. This inversion optimizes the balance between providing orientation information and maintaining scene visibility.

Inventive Principle:
Principle #13The other way round (Inversion)

2Measurement precision

If gaze vectors from both eyes are used to calculate convergence distance, then the measurement is more comprehensive, but noise and small angle errors result in large errors in the calculated distance

Engineering Contradiction:
Improvegaze convergence distanceVSAvoiderror sensitivity
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent extracts and utilizes only the horizontal components of the gaze vectors from both eyes for calculating convergence distance, rather than using the full 3D gaze vectors. This extraction of the relevant horizontal angle information simplifies the calculation and reduces the impact of noise and errors in the vertical components and other parameters.

Inventive Principle:
Principle #2Taking out (Extraction)

3Ease of operation

If traditional input means such as touch control or voice control are used to access menus, then user input is possible, but the input methods are complex and require combination of actions that conflict with other actions

Engineering Contradiction:
Improvemenu accessVSAvoidinput method complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The system uses the user's natural gaze direction to automatically indicate menu options, eliminating the need for separate pointing or selection actions. The menu system serves itself by detecting where the user is looking and presenting relevant options, allowing selection through simple gaze dwelling without requiring complex hand gestures or voice commands.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3575929B1Eye tracking application in virtual reality and augmented reality
Publication Date: 2022.08.03 TOBII TECH AB
  • EP3575929B1 patent drawingFigure 1a~2
  • EP3575929B1 patent drawingFigure 1b~1c
  • EP3575929B1 patent drawingFigure 3~4

AI summary

A method and a corresponding apparatus for mitigating motion sickness in a virtual reality VR/augmented reality (AR) system using a head mounted display (HMD) are disclosed. The method comprises receiving data from a sensor indicating a current orientation of the HMD in real space, and superimposing a visual indication on a display of the HMD. The visual indication provides visual information to a user of the current orientation of the HMD in real space. Furthermore, methods and corresponding apparatuses are disclosed of calculating gaze convergence distance in an eye tracking system, and of gaze based virtual reality (VR)/augmented reality (AR) menu expansion.