RFID Tags for Retail Product Location Accuracy
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Solution Overview
Problem
Existing RFID systems face challenges in accurately determining the location of products due to variations in signal strength caused by directional changes between RFID interrogators and tags, leading to incorrect identification of products being in storage or sales areas.
Innovation Solution
The implementation of additional RFID tags mounted on physical structures within the retail environment, allowing comparison of Received Signal Strength Indicators (RSSI) between product and structure tags to accurately determine the location of products by identifying the most similar RSSI values, thereby distinguishing between storage and sales areas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If RFID systems use signal strength to determine product location, then location identification is achieved, but directional signal strength variations cause measurement inaccuracies
Solution Approach 1:
The patent introduces structure tags mounted on physical structures (shelves, walls, ceilings) as intermediary reference points between the RFID interrogator and product tags. These structure tags serve as mediators that provide stable, location-specific RSSI signatures, allowing the system to indirectly determine product location by comparing product tag RSSI values against stored structure tag RSSI profiles for different areas (storage vs. sales), thereby eliminating the harmful effect of directional signal variations.
Solution Approach 2:
The patent changes the approach from using absolute RSSI values directly for location determination to using relative RSSI comparisons and ratios. By calculating RSSI ratios between product tags and structure tags, or comparing RSSI differences across multiple structure tags, the system transforms the measurement parameter from absolute signal strength to relative signal strength relationships, which are invariant to directional variations and provide accurate location identification.
2Measurement precision
If additional RFID tags are mounted on physical structures, then location determination accuracy improves, but device complexity increases
Solution Approach 1:
The patent segments the retail environment into distinct functional areas (storage areas and sales areas) by mounting structure tags on physical structures within each area. Each structure tag is assigned to a specific location and area type, creating a segmented spatial map. This segmentation allows the system to determine product location by identifying which area's structure tags produce the most similar RSSI signature, thereby improving location accuracy while keeping the tag deployment systematic and manageable.
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
This approach enhances the accuracy of product location determination by mitigating the limitations of directional signal strength variations, ensuring correct identification of products' locations within the retail environment.
Implementation Method 1
Radio frequency identification (RFID) utilizes small tags, each containing electronics and an antenna that are capable of broadcasting a radio signal that identifies the tag
Implementation Method 2
Some RFID readers are also able to determine the strength of the radio signal received from the RFID tag. In such readers, the strength of the signal can be provided as an output known as a Received Signal Strength Indicator (RSSI)
Data Source
AI summary
A computer-implemented method includes receiving a structure signal strength for a signal generated by a tag on a structure and receiving a product signal strength for a signal generated by a tag on a product. An indication that the product is positioned near the structure based on the received structure signal strength and the received product signal strength is then stored in memory.