AGV Grid Navigation Markers Using Angled 1D Codes

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Solution Overview

Problem

Current navigation systems for driverless transport vehicles, such as grid navigation systems using RFID or two-dimensional graphic codes, are costly, especially in large areas, and require expensive sensor devices for reading navigation information.

Innovation Solution

The use of marking elements with multiple one-dimensional graphic code patterns, each aligned at an angular offset, allowing a sensor device to switch and read navigation information reliably from any direction, utilizing inexpensive one-dimensional code readers and enabling correction maneuvers for accurate positioning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If two-dimensional graphical code patterns are used for navigation markers, then navigation information can be read from any direction, but the sensor device becomes significantly more expensive

Engineering Contradiction:
Improvereading direction independenceVSAvoidsensor device cost
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent divides the navigation marker into multiple one-dimensional code patterns arranged at different angular positions (e.g., 0°, 45°, 90°, 135°). Each one-dimensional pattern is simple to read, but collectively they provide omnidirectional readability. The sensor device reads the appropriate pattern based on its approach angle, achieving direction independence without requiring complex two-dimensional code readers.

Inventive Principle:
Principle #1Segmentation

2Device complexity

If a single one-dimensional code pattern is used, then the sensor device is inexpensive, but the vehicle cannot reliably read navigation information when approaching from arbitrary directions

Engineering Contradiction:
Improvesensor device costVSAvoidreading direction coverage
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent introduces angular asymmetry by positioning multiple one-dimensional code patterns at different orientations around the marker. This asymmetric arrangement ensures that regardless of the vehicle's approach direction, at least one code pattern will be oriented favorably for reading. The evaluation device selects the appropriate pattern based on the detected approach angle, maintaining low-cost sensor hardware while achieving omnidirectional functionality.

Inventive Principle:
Principle #4Asymmetry

3Reliability

If RFID transponders are embedded in the ground for navigation, then reliable position determination is achieved, but the system cost increases significantly for large operational areas

Engineering Contradiction:
Improveposition determination reliabilityVSAvoidsystem cost
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces expensive RFID transponders with inexpensive graphical code patterns that can be printed or applied as stickers on the ground. These code patterns are much cheaper to manufacture and install, especially over large areas. The code patterns serve the same navigation function by providing position and orientation information that the evaluation device can process to determine vehicle location reliably.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Data Source

PatentEP3578923B1Navigation system
Publication Date: 2021.08.04 SICK AG
  • EP3578923B1 patent drawingFigure 1
  • EP3578923B1 patent drawingFigure 2
  • EP3578923B1 patent drawingFigure 3~4

AI summary

A navigation system for an automated guided vehicle (AGV) comprises a set of marker elements arranged in a grid pattern on the ground, in which navigation information is encoded; a sensor device to be arranged on the AGV for reading navigation information from the marker elements; and an evaluation device connected to the sensor device for generating control signals for the AGV based on the read navigation information. Each marker element has at least two graphic code patterns, each implemented as a one-dimensional code pattern and comprising a code applied along a scanning direction, wherein the scanning directions of the at least two graphic code patterns are oriented offset from each other by an angular offset.