Anchor Graph Repositioning for Augmented Reality Drift Control

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Solution Overview

Problem

Augmented reality devices experience anchor point drift due to sensor errors and computational inaccuracies, leading to substantial visual distortions when simulating large objects or objects far from the device, especially in mixed-reality systems.

Innovation Solution

A computing system generates and repositions anchor graphs by detecting changes in anchor positions, maintaining fixed edge lengths and angles, and combining disjoint anchor graphs to maintain accurate virtual object positioning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If anchor points are used to track physical environment features, then virtual objects can be positioned in the physical environment, but anchor point drift occurs due to sensor errors causing visual distortions

Engineering Contradiction:
Improveanchor point position accuracyVSAvoidvisual distortion
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The system segments the anchor graph into multiple disjoint anchor graphs, each representing a subset of anchors. This segmentation allows independent optimization and repositioning of each subset, reducing the propagation of errors across the entire graph and minimizing cumulative drift effects.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system performs preliminary repositioning of anchor graphs by detecting changes in anchor positions and applying transformations to maintain fixed edge lengths and angles. This preliminary correction prevents drift accumulation before it causes significant visual distortions in the augmented reality display.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If anchor graphs are repositioned to correct drift, then positioning accuracy improves, but computational complexity increases

Engineering Contradiction:
Improvevirtual object placement accuracyVSAvoidcomputational complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

By dividing the anchor graph into multiple smaller disjoint graphs, the system reduces the computational complexity of each individual graph processing operation. Each subset can be repositioned and optimized independently with fewer computational resources, while still achieving overall positioning accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system applies partial repositioning actions by focusing computational effort only on detected drift issues in specific anchor subsets rather than reprocessing the entire anchor graph. This selective approach reduces unnecessary computations while maintaining positioning accuracy where needed.

Inventive Principle:
Principle #16Partial or excessive action

3Area of stationary object

If multiple disjoint anchor graphs are combined, then coverage of physical environment increases, but error propagation between graphs occurs

Engineering Contradiction:
Improveenvironment coverageVSAvoidposition accuracy
Core Design Contradiction:
Area of stationary objectVSMeasurement precision

Solution Approach 1:

The system maintains disjoint anchor graphs as separate segments that only combine at verified overlap regions. This segmentation strategy allows extensive environment coverage through multiple graphs while isolating errors to specific segments, preventing error propagation across the entire combined graph.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system uses shared anchors in overlap regions as intermediary reference points when combining disjoint anchor graphs. These intermediary anchors serve as stable reference points that anchor the transformation between graphs, reducing error propagation by providing a common reference frame for graph integration.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3776470B1Anchor graph based positioning for augmented reality
Publication Date: 2025.08.27 MICROSOFT TECHNOLOGY LICENSING LLC
  • EP3776470B1 patent drawingFigure 1A
  • EP3776470B1 patent drawingFigure 1B
  • EP3776470B1 patent drawingFigure 2

AI summary

A computing system, including at least one imaging sensor configured to collect imaging data of a physical environment. The computing system may further include a processor configured to generate, based on the imaging data, a first anchor graph including a first plurality of anchors connected by a first plurality of edges. Each anchor of the first plurality of anchors may indicate a respective estimated position in the physical environment. The processor may be further configured to detect a change in the estimated position of at least one anchor of the first plurality of anchors relative to the at least one imaging sensor. Based on the change in the estimated position, the processor may reposition the first anchor graph relative to the at least one imaging sensor. Estimated lengths of the first plurality of edges and estimated angles between the first plurality of edges may remain fixed.