RFID Reader Location via Pseudo Tag Triangulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for determining the location of hand-held RFID terminals in warehousing applications are either time-consuming and prone to operator error or expensive, and require additional radio receivers to process signal strength for triangulation, which increases complexity and cost.
Innovation Solution
A system using pseudo RFID tags with progressively weaker signals and shorter ranges, allowing the RFID reader to determine its location without time of flight measurements or signal strength calculations, by triangulating based on the range and transmitter identification of pseudo tag signals from multiple transmitters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If barcoding or RFID tagging key locations is used to determine hand-held terminal location, then the approach is effective and cheap, but it is time consuming and subject to operator error
Solution Approach 1:
The hand-held terminal automatically determines its own location by receiving pseudo-tag signals from multiple transmitters and performing triangulation calculations, eliminating the need for operator intervention to scan location codes. This self-service mechanism resolves the contradiction by making the system both automatic (reducing time consumption) and based on existing RFID infrastructure (maintaining cost-effectiveness).
Solution Approach 2:
The system uses multiple transmitters broadcasting pseudo-tag signals that enable rapid triangulation calculation, accelerating the location determination process from manual scanning to automatic real-time tracking. This accelerates productivity while maintaining cost-effectiveness by using existing RFID hardware.
2Extent of automation
If GPS receiver is fitted to hand-held terminal to determine location, then location can be determined automatically, but it is expensive and loses satellite signal in warehouses with metal roofs
Solution Approach 1:
The system creates a simulated GPS-like positioning infrastructure using pseudo-tag signals from multiple transmitters within the warehouse environment. Instead of relying on external satellite signals that are blocked by metal roofs, the system copies the triangulation principle used by GPS but implements it using local RFID transmitters, achieving automatic location determination at low cost and without signal loss issues.
Solution Approach 2:
Pseudo-tag signals act as intermediaries between the transmitters and the hand-held terminal, enabling location determination without requiring direct line-of-sight to external satellites. These intermediary signals are generated locally within the warehouse using existing RFID infrastructure, providing automatic location tracking that works reliably indoors without GPS's signal loss problems or high cost.
3Measurement precision
If additional radio receiver is added to process beacon signals for triangulation, then location determination is enabled, but device complexity and cost increase
Solution Approach 1:
The hand-held terminal's existing RFID reader is made multi-functional by enabling it to receive and process pseudo-tag signals in addition to its primary function of reading RFID tags on products. This universal approach allows the same hardware to perform both traditional RFID reading and location determination through triangulation, eliminating the need for additional dedicated radio receivers and reducing device complexity while maintaining location precision.
Solution Approach 2:
The location determination function is merged with the existing RFID reader functionality. The same antenna and signal processing circuits used for reading product RFID tags are also used to receive pseudo-tag signals from transmitters for triangulation-based location calculation. This merging of functions eliminates the need for separate hardware components, reducing device complexity and cost while achieving accurate location determination.
Data Source
Figure 1
Figure 2A~2B
Figure 3
AI summary
The system comprises a plurality of transmitters having a known reference point. Each transmitter includes a circuit for transmitting a sequence of unique RFID pseudo tag signals. Each unique RFID pseudo signal in the sequence has a unique range of transmission. Each unique RFID pseudo tag in the sequence has a tag identification indicating the range of transmission of the pseudo tag signal and a transmitter identification value indicating the transmitter from which the pseudo tag signal was transmitted. An RFID reader receives the unique RFID pseudo tag signals and distinguishes between each received unique RFID pseudo tag signal . A location calculator calculates the location of the RFID reader based on the range of transmission indicated in the tag identification and the location obtainable from the transmitter identification value of the unique RFID pseudo tags received by the RFID reader.