Relative Positioning via Sensor Fusion for AR Tracking

Solution Overview

Problem

In collaborative multi-user augmented reality applications, traditional systems face challenges in aligning tracking maps across user devices due to significant communication delays and computational resource constraints, especially when devices initiate applications at different locations and orientations, leading to inconsistent virtual object placement and drifting objects.

Innovation Solution

A system that determines relative position data by combining distance and movement data from multiple timestamps using sensor fusion, allowing for efficient computation of 6-DoF transformations between user devices, thereby eliminating the need for aligning tracking maps and reducing latency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If traditional systems exchange and align tracking maps across user devices, then virtual object placement consistency is improved, but communication delays increase significantly

Engineering Contradiction:

Improvevirtual object placement consistencyVSAvoidcommunication delays

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent extracts only the essential relative position information (distance and movement data) from the complete tracking maps, rather than transferring the entire tracking map. This allows devices to align virtual objects without exchanging large amounts of data, significantly reducing communication delays while maintaining placement consistency.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent segments the tracking map alignment process into two parts: each device maintains its own complete tracking map locally, while only sharing compressed relative position data. This segmentation allows full functionality to be preserved while minimizing communication overhead.

Inventive Principle:

Principle #1Segmentation

2Manufacturing precision

If traditional systems align tracking maps from multiple user devices, then virtual object placement consistency is improved, but computational resources required increase significantly

Engineering Contradiction:

Improvevirtual object placement consistencyVSAvoidcomputational resources

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent extracts only the essential relative position information (distance and movement data) from the complete tracking maps, rather than transferring the entire tracking map. This allows devices to align virtual objects without exchanging large amounts of data, significantly reducing communication delays while maintaining placement consistency.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of having each device exchange and process complete tracking maps to achieve alignment, the patent inverts the approach: each device computes its own tracking map independently and only shares the difference (relative position) with others. This inversion dramatically reduces the computational burden on each device.

Inventive Principle:

Principle #13The other way round (Inversion)

3Measurement precision

If tracking maps are shared across multiple user devices, then alignment accuracy is improved, but communication bandwidth requirements increase

Engineering Contradiction:

Improvealignment accuracyVSAvoidcommunication bandwidth

Core Design Contradiction:

Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent extracts only the essential relative position information (distance and movement data) from the complete tracking maps, rather than transferring the entire tracking map. This allows devices to align virtual objects without exchanging large amounts of data, significantly reducing communication delays while maintaining placement consistency.

Inventive Principle:

Principle #2Taking out (Extraction)

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 approach enables reliable and efficient alignment of tracking maps with lower computational requirements, reducing latency and improving scalability, ensuring consistent virtual object placement across user devices.

Implementation Method 1

distance measurements may be determined based on a time of flight (ToF) measurement of an ultra-wideband (UWB) signal

Methodology Applied

Scientific EffectTime of flight: Time of Flight

Implementation Method 2

an antenna array for determining a signal's angle of arrival

Methodology Applied

Scientific EffectAngle of arrival:

Data Source

PatentUS11722845B2System for combining sensor data to determine a relative position

Publication Date: 2023.08.08 ADOBE INC

AI summary

A first device determines relative position data representative of a position of one or more other user devices relative to the first device. To determine relative position data between the first device and a second device, the first device determines a distance between the first device and the second device at a plurality of timestamps. Additionally, the first device determines movement data at each timestamp from one or more device sensors. The movement data at each corresponding timestamp may reflect movement of the first device and/or the second device between a prior timestamp and the corresponding timestamp. The first device computes relative position data for the second device by combining the distance measurements and movement data over the plurality of timestamps, for instance, through a process of sensor fusion. By computing the relative position data, the first device may determine a transformation that can be used to convert between a coordinate system of the second device and the coordinate system of the first device.