Vehicle Positioning with Marker Correction for Visual-SLAM Drift

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Solution Overview

Problem

In dynamic environments like factories and warehouses, where backgrounds vary frequently, it is challenging to accurately determine the current position of a moving body using pre-created maps, as the position calculated by Visual-SLAM methods becomes increasingly erroneous over time due to cumulative errors in relative positioning.

Innovation Solution

A positioning apparatus comprising a first calculator for relative positioning, a storage apparatus for marker information, and a corrector that uses extracted markers to calculate and correct the position and attitude of a moving body, reducing errors by aligning the relative attitude with the direction of the passageway when the angular difference is within a threshold.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If Visual-SLAM method is used for positioning, then wireless transmitters are not required, but cumulative errors increase over time reducing positioning accuracy

Engineering Contradiction:
Improvepositioning system complexityVSAvoidpositioning accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent introduces markers as intermediary objects placed in the environment to serve as reference points for the imaging device. These markers enable the system to calculate absolute position and attitude information, acting as a mediator between the imaging device and the environment, thereby correcting cumulative errors without requiring complex wireless transmitter infrastructure

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system implements feedback by continuously detecting markers and correcting position/attitude deviations. The correction unit uses marker-based absolute position information to feedback-adjust the Visual-SLAM calculated positions, preventing error accumulation and maintaining long-term positioning accuracy

Inventive Principle:
Principle #23Feedback

2Measurement precision

If markers are used for correction, then positioning accuracy is improved, but the system requires pre-disposed markers in the environment

Engineering Contradiction:
Improvepositioning accuracyVSAvoidsystem deployment ease
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The system employs self-service by using the imaging device's own captured images to detect markers and calculate position information. The imaging device serves itself for positioning by processing images it captures, eliminating the need for external positioning infrastructure while maintaining accuracy through marker-based correction

Inventive Principle:
Principle #25Self-service

3Reliability

If GPS positioning is used outdoors, then global localization is achieved, but positioning fails indoors where satellite signals are blocked

Engineering Contradiction:
Improvepositioning availabilityVSAvoidenvironmental adaptability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent creates a universal positioning system that functions in both indoor and outdoor environments. By combining Visual-SLAM with marker-based correction using standard imaging devices, the system replaces GPS for indoor applications while maintaining comparable accuracy, achieving multi-environment functionality without requiring specialized sensors

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

Data Source

PatentEP3905213B1Positioning apparatus and moving body
Publication Date: 2023.04.26 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP3905213B1 patent drawingFigure 1
  • EP3905213B1 patent drawingFigure 2~3
  • EP3905213B1 patent drawingFigure 4~6

AI summary

A first calculator calculates a relative position and a relative attitude of a vehicle based on images captured by an image capturing apparatus mounted on the vehicle. A second calculator extracts one marker from an image captured by the image capturing apparatus, and calculates an absolute position and an absolute attitude of the vehicle based on the position and the attitude of the one extracted marker. A corrector corrects the relative position and the relative attitude based on the absolute position and the absolute attitude to generate a corrected position and a corrected attitude of the vehicle. When an angular difference between a traveling direction of the vehicle having the corrected position and the corrected attitude, and the direction of the passageway is smaller than a predetermined threshold, the corrector corrects the relative attitude based on the direction of the passageway, instead of the absolute attitude.