Passive RFID Tag Catcher Mode for Adjacent Tag Localization
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Solution Overview
Problem
Existing RFID systems face challenges in unambiguously identifying tags in a crowded environment and fail to detect adjacent tags within a limited radius, limiting their performance and accuracy.
Innovation Solution
A passive RFID tag equipped with peripheral circuits that can switch between standard and catcher modes, allowing it to receive and process echoes from adjacent tags, determine their distance, and store their identification within a specified radius, enhancing tag identification and localization capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a readable machine is used to identify tags in a crowded environment, then tag identification capability is provided, but the ability to unambiguously identify a specific tag among numerous tags is limited
Solution Approach 1:
The patent introduces an intermediary tag (the first tag) that acts as a mediator between the readable machine and the second tag. The first tag receives the polling command, determines it's not addressed to it, switches to catching mode, and catches the echo from the second tag. This intermediary enables indirect tag identification without requiring the readable machine to directly communicate with each tag, improving identification accuracy in crowded environments.
Solution Approach 2:
The patent replaces the traditional mechanical/protocol-based anti-collision identification system with an acoustic/echo-based detection mechanism. Instead of relying on complex anti-collision protocols where tags sequentially respond, the system uses echo catching where the first tag listens for and captures the echo signal from the second tag, determining distance and identity through the echo timing and characteristics.
2Adaptability or versatility
If existing RFID tags are used, then basic identification is provided, but the capability to pick up signals from adjacent tags is missing
Solution Approach 1:
The patent implements dynamic functionality in RFID tags by enabling them to switch between standard mode and catching mode. The first tag dynamically changes its operational state based on the received polling command - when it determines the command is not addressed to it, it switches to catching mode to capture echoes from adjacent tags. This dynamic adaptability allows tags to perform multiple functions (standard identification and adjacent tag detection) depending on environmental conditions.
3Reliability
If anti-collision protocol is initiated to identify tags, then collision resolution is achieved, but the process is time-consuming and reduces identification efficiency
Solution Approach 1:
The patent applies preliminary action by having the first tag proactively switch to catching mode before the actual echo exchange occurs. The first tag receives the polling command, determines it's not addressed to it, and preemptively switches to catching mode, preparing the receiving circuits in advance. This preliminary preparation eliminates delays that would occur if the tag had to switch modes after detecting the need to catch echoes, thereby improving identification speed while maintaining reliability.
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 the identification of adjacent tags within a predefined radius, filters out tags outside this radius, and boosts the performance of RFID readers by providing a compacted identification message and localized tag information, improving the accuracy and efficiency of tag identification.
Implementation Method 1
said RFID tag A determining a distance (D.t2t) between the RFID tag A and the RFID tag B based on a total timing (TT) equal to t3 minus t1
Data Source
AI summary
A method and RFID tag for locating RFID tags. A passive RFID tag A receives a polling command transmitted from a RFID reader and addressed to another passive RFID tag B. The RFID tag A determines that the polling command is not addressed to the RFID tag A and consequent1y, at time t1, switches the RFID tag A to a catching mode for catching echos from other tags. The RFID tag A receives at time t3>t1 an echo of a message sent by the RFID tag B to the RFID reader. The RFID tag A determines a distance (D.t2t) between the RFID tag A and the RFID tag B based on t3 minus t1. The distance D.t2t does not exceed a specified radius limit and the identification of the RFID tag B and the distance D.t2t are stored in a database within the RFID tag A.