RFID Antenna Assembly for Metal-Substrate Inventory Tracking

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Solution Overview

Problem

Existing inventory tracking systems face challenges in accurately tracking and locating articles stored on metal substrates within cabinets, particularly in environments where RFID tag interrogation is hindered by metal surfaces, such as in medical incubators.

Innovation Solution

An inventory tracking system comprising a cabinet with a holder and metal substrates, each equipped with an RFID read antenna assembly and an electrical connector arrangement that establishes and breaks connections between the antenna and an RFID tag interrogator, ensuring effective RFID tag interrogation even on metal substrates, using high permeability layers and a retention mechanism to maintain alignment and signal strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If RFID tag interrogation is performed on metal substrates, then tracking and locating inventory can be achieved, but signal strength is reduced and interrogation accuracy deteriorates

Engineering Contradiction:
ImproveRFID tag interrogation reliabilityVSAvoidMetal substrate interference
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A non-conductive layer is introduced between the RFID tag and the metal substrate to act as an intermediary that reduces the harmful electromagnetic interference from the metal while allowing the RFID signal to pass through effectively

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The electromagnetic parameters of the substrate are modified by adding a non-conductive layer with specific dielectric properties, changing the electromagnetic field distribution and reducing signal attenuation caused by the metal substrate

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If direct contact with inventory is required for tracking, then accurate identification can be achieved, but operational efficiency and safety are reduced

Engineering Contradiction:
ImproveInventory identification accuracyVSAvoidInventory tracking efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The mechanical contact-based identification system is replaced with a non-contact RFID electromagnetic field-based system, allowing rapid bulk interrogation of multiple tags simultaneously without physical contact or line-of-sight requirements

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Device complexity

If RFID antenna assembly is mounted directly to metal substrate, then structural simplicity is achieved, but signal interference increases

Engineering Contradiction:
ImproveAntenna mounting structure complexityVSAvoidRFID signal strength
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

A non-conductive mounting structure serves as an intermediary between the RFID antenna assembly and the metal substrate, providing mechanical support while electrically isolating the antenna from the interfering metal surface

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The mounting structure uses composite materials combining non-conductive properties for electrical isolation with mechanical properties for structural support, optimizing both signal performance and structural integrity

Inventive Principle:
Principle #40Composite materials

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

Enables fast and accurate tracking and location of inventory within cabinets, maintaining signal strength and reducing the need for direct contact, while accommodating metal substrates and ensuring efficient operation in controlled environments like incubators.

Implementation Method 1

the at least one antenna assembly comprising at least one antenna coil and a high permeability layer

Methodology Applied
Scientific EffectMagnetic field concentration: Magnetic Reluctance

Implementation Method 2

the at least one antenna assembly comprising at least one antenna coil

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP4193294B1A storage system
Publication Date: 2024.07.24 SATO HLDG CORP
  • EP4193294B1 patent drawingFigure 1~2
  • EP4193294B1 patent drawingFigure 3~4
  • EP4193294B1 patent drawingFigure 5a~5b

AI summary

An inventory tracking system (10) for use in tracking articles (12) received in a cabinet (14) comprises at least one RFID read antenna assembly (100), an RFID tag interrogator (30), and an electrical connector arrangement (24). The cabinet comprises a receptacle (16), a holder (18) arranged in the receptacle and at least one metal substrate (20) received in the holder. The metal substrate is configured to receive at least one article carrying an RFID tag. The RFID read antenna assembly is mountable to the metal substrate, the antenna assembly comprising at least one antenna coil (102) and a high permeability layer (104). The RFID tag interrogator is configured to interrogate the RFID tag of the, or each, article received by the at least one metal substrate. The electrical connector arrangement has complementary components (26, 28) carried by the holder and the metal substrate for establishing, and breaking, an electrical connection between the interrogator and the at least read antenna assembly.