Handheld Device Tracking in VR via Sensor Fusion

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Solution Overview

Problem

Current augmented and virtual reality systems face challenges in accurately tracking the movement of handheld electronic devices within immersive environments, particularly due to reflective surfaces and varying lighting conditions, which affect the precision of depth camera imaging.

Innovation Solution

A system that combines data from a depth camera on a head-mounted display with inertial measurement unit data from the handheld device, allowing for accurate 6DOF tracking of the device's position and orientation, and translates this data into corresponding actions within the virtual environment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a depth camera is used to track the handheld device, then the system can capture position data, but reflective surfaces and varying lighting conditions reduce measurement precision

Engineering Contradiction:
Improvetracking precisionVSAvoidlighting condition sensitivity
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent combines data from multiple sources: depth camera position data, accelerometer data, and orientation data from the handheld device. This multi-sensor fusion approach compensates for the depth camera's sensitivity to lighting conditions by relying on the inertial sensors within the handheld device, which are不受 lighting affects.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The system uses the handheld device itself as an intermediary tracking target rather than relying solely on external markers or features in the environment. The device's own sensors (accelerometer and orientation sensors) serve as intermediaries to provide reliable tracking data independent of environmental lighting conditions.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If multiple sensors are combined for tracking, then measurement precision improves, but device complexity increases

Engineering Contradiction:
Improvetracking accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The handheld device serves multiple functions: it acts as both the user interface and the tracking target. The same device contains both the sensors for navigation (accelerometer, orientation sensors) and the target features for camera tracking, eliminating the need for separate specialized tracking equipment.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The handheld device tracks itself by utilizing its own embedded sensors (accelerometer and orientation sensors) to provide position and orientation data. This self-service capability reduces system complexity by eliminating the need for external tracking infrastructure.

Inventive Principle:
Principle #25Self-service

3Reliability

If specialized tracking equipment is used, then tracking reliability improves, but the system requires additional hardware

Engineering Contradiction:
Improvetracking reliabilityVSAvoidhardware requirements
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The handheld device is designed to be self-sufficient for tracking purposes by incorporating its own sensors (accelerometer and orientation sensors). This eliminates the need for specialized external tracking equipment while maintaining reliable tracking through the device's intrinsic capabilities.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system uses the handheld device for multiple purposes: as the user interface, as the navigation sensor platform, and as the tracking target. This multi-functionality eliminates the need for separate specialized tracking hardware.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3314371B1System for tracking a handheld device in an augmented and/or virtual reality environment
Publication Date: 2019.11.20 GOOGLE LLC
  • EP3314371B1 patent drawingFigure 1
  • EP3314371B1 patent drawingFigure 2A~2B
  • EP3314371B1 patent drawingFigure 3

AI summary

A system for tracking a first electronic device, such as a handheld electronic device, in a virtual reality environment generated by a second electronic device, such as a head mounted display may include the fusion of data collected by sensors of the electronic device with data collected by sensors of the head mounted display, together with data collected by a front facing camera of the electronic device related to the front face of the head mounted display.