Relocalization Using Gravity Vectors and Magnetic Descriptors

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Solution Overview

Problem

Conventional 3D imaging and mixed reality systems face challenges in real-time relocalization and scene recognition, particularly in indoor environments where image gradients are not always present, leading to false alignments and increased computational intensity.

Innovation Solution

The system employs gravity vectors and magnetic descriptors to align features with the virtual environment, utilizing pre-calibrated camera intrinsic parameters to correct for distortion, and a regression forest approach for efficient feature matching and pose estimation, allowing for faster and more accurate relocalization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional 3D imaging systems use image gradients for feature alignment, then feature matching can be performed, but false alignments occur in indoor environments where image gradients are not present

Engineering Contradiction:
Improvealignment accuracyVSAvoidenvironmental adaptability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent changes the parameter used for feature alignment from image gradients to gravity vectors and magnetic descriptors. This parameter change enables reliable feature matching in indoor environments where image gradients are absent, as gravity vectors and magnetic descriptors provide consistent reference frames regardless of lighting conditions or image content.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces gravity vectors and magnetic descriptors as intermediary elements that mediate between the camera and the environment. These intermediaries provide a stable reference system that is independent of image content, enabling accurate alignment in diverse indoor environments without relying on image gradients.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If the system tests multiple pose hypotheses for relocalization, then accurate positioning can be achieved, but computational intensity increases

Engineering Contradiction:
Improvepositioning accuracyVSAvoidcomputational energy
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent performs preliminary alignment using gravity vectors and magnetic descriptors before testing pose hypotheses. This preliminary action constrains the search space by pre-establishing the correct orientation and position, thereby reducing the number of pose hypotheses that need to be tested while maintaining positioning accuracy.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent segments the relocalization process into distinct stages: first aligning features using gravity vectors and magnetic descriptors, then testing pose hypotheses within the constrained framework. This segmentation allows the system to achieve accurate positioning with reduced computational energy by handling different aspects of the problem separately and efficiently.

Inventive Principle:
Principle #1Segmentation

3Reliability

If the system rebuilds the virtual environment for each revisit, then accurate scene representation is achieved, but processing time increases

Engineering Contradiction:
Improvescene representation accuracyVSAvoidprocessing time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent uses gravity vectors and magnetic descriptors to create a lightweight copy or representation of the environment's spatial structure that can be quickly compared across different visits. Instead of rebuilding the entire virtual environment, the system copies and matches key spatial references, achieving accurate scene representation with significantly reduced processing time.

Inventive Principle:
Principle #26Copying

4Measurement precision

If the system uses pre-calibrated camera intrinsic parameters for distortion correction, then alignment accuracy improves, but device complexity increases

Engineering Contradiction:
Improvealignment precisionVSAvoidcalibration requirements
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent performs camera calibration and distortion correction parameters determination in advance, before actual use. This preliminary action stores the necessary correction data, allowing the system to achieve high alignment precision during operation without requiring complex real-time calibration procedures, thereby reducing operational device complexity.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS10803365B2System and method for relocalization and scene recognition
Publication Date: 2020.10.13 OCCIPITAL INC
  • US10803365B2 patent drawing
  • US10803365B2 patent drawing
  • US10803365B2 patent drawing

AI summary

A system configured to improve the operations associated with generating virtual representations of physical environments to recognize the physical environments and/or relocalize within the virtual representations in a substantially real time system. In some cases, the system may use a first pre-training phase of descriptors and/or split nodes of regression forests using features common across various scenes to learn general image appearance, and a second training phase of descriptors and/or leaf nodes of regression forests to learn scene specific features. The system may align the features using an orientation vector, correct for camera perspective and lens distortion of the features as well as learn robust illumination invariant features from real and synthetic data.