Head-Mountable Display Motion Tracking Using Optical Flow and Accelerometers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing virtual reality systems, particularly head-mountable displays (HMDs), face challenges in accurately tracking the user's head movements and maintaining a seamless virtual environment experience due to limitations in motion detection and image processing, which can lead to disorientation and reduced immersion.
Innovation Solution
The implementation of a head-mountable display system that incorporates a front-facing camera for motion sensing using optical flow detection and a hardware motion detector, such as piezoelectric accelerometers or optical fibre gyroscopes, to accurately track head movements and adjust the virtual image accordingly, ensuring a stable and immersive experience.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a camera is used to detect images of markers for tracking head movements, then the virtual environment tracking is improved, but motion detection accuracy deteriorates due to image processing limitations
Solution Approach 1:
The patent replaces the optical-mechanical camera-based marker detection system with a direct motion sensing system using accelerometers and gyroscopes. This substitution eliminates the need for complex image processing while providing more accurate and direct motion detection, resolving the contradiction between tracking accuracy and processing complexity.
Solution Approach 2:
The patent introduces motion sensors (accelerometers and gyroscopes) as intermediary devices that directly detect head movements without requiring camera-based marker tracking. These sensors act as mediators between the user's head movements and the virtual environment, providing accurate motion data while simplifying the overall system architecture.
2Reliability
If multiple detection methods are combined for motion sensing, then tracking accuracy is improved, but device complexity increases
Solution Approach 1:
The patent combines multiple motion sensing technologies (accelerometers for linear acceleration detection and gyroscopes for rotational motion detection) into a single integrated motion detection system. This merging approach enhances the reliability and accuracy of motion tracking while managing system complexity through unified sensor integration.
3Loss of information
If camera-based marker detection is used, then relative location detection is achieved, but disorientation occurs due to motion detection limitations
Solution Approach 1:
The patent replaces the indirect camera-based marker detection system with direct motion sensing using accelerometers and gyroscopes. This substitution provides more precise motion detection data, preventing spatial disorientation and maintaining accurate orientation information in the virtual environment.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution enhances the tracking of head movements within virtual environments, providing a more stable and immersive experience by accurately adjusting the virtual image in response to user head movements, thereby improving user engagement and reducing disorientation.
Implementation Method 1
a camera to capture successive images, each image being captured during a respective image capture period
Implementation Method 2
a motion sensor to detect motion of the HMD and to control operation of the detector in response to the detected motion
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
A data processing device comprises a camera configured to capture successive images, each image being captured during a respective image capture period such that respective different portions of the captured image are captured at respective different capture times within the image capture period;a detector to detect, from images captured by the camera, information indicating a relative location of a remote marker with respect to the data processing device, and to associate a timestamp with a detected relative location indicating a time at which the relative location was detected;and a motion sensor to detect motion of the data processing device and to control operation of the detector in response to the detected motion.