RFID Tag Grid for AGV Location Tracking
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Solution Overview
Problem
Existing safety systems for automated guided vehicles (AGVs) in industrial environments lack effective location-based information to prevent collisions and ensure personnel safety, relying on methods like laser scanners and safety edges that do not provide comprehensive protection.
Innovation Solution
An RFID system is implemented where AGVs use a processor and RFID transceiver to read and compare unique identification and position data from RFID tags arranged in a grid or pathway, allowing safe navigation and triggering faults to prevent collisions by matching data elements in a predetermined table.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If laser scanners and safety edges are used to detect people and objects, then collision protection is provided, but location-based information is not available
Solution Approach 1:
The system divides the workspace into discrete locations, each marked by an RFID tag with a unique identification. The AGV segments its navigation into discrete location transitions, reading RFID tags at each location to determine position. This segmentation enables precise location tracking while maintaining safety monitoring.
Solution Approach 2:
RFID tags serve as intermediary elements between the AGV and the workspace environment. These passive tags contain unique identifications that the AGV's RFID reader detects to determine location. The tags mediate the interaction between the vehicle and workspace, providing location-based information without requiring active sensors at each location.
2Loss of information
If RFID tags with unique identification are used to determine location, then location-based information is provided, but system complexity increases
Solution Approach 1:
The system uses inexpensive passive RFID tags that can be easily deployed throughout the workspace. These tags require no power source, have simple read-only memory for location identification, and can be replaced or repositioned as needed. The low cost and simplicity of individual tags offset the increase in overall system complexity through ease of deployment and maintenance.
Solution Approach 2:
The AGV creates a digital representation of its physical location by reading the unique identification from RFID tags and mapping it to a predetermined table of location data. This copying of location information from physical tags to digital memory enables the AGV to determine its position without complex physical sensors at each location.
3Measurement precision
If RFID tags are placed throughout the workspace to provide location information, then navigation precision is improved, but the quantity of components increases
Solution Approach 1:
The system transitions from continuous space to discrete location points by placing RFID tags at specific locations throughout the workspace. The AGV determines position by detecting which discrete location's RFID tag it is near, converting continuous navigation into discrete location transitions. This dimensional change from continuous to discrete reduces the need for dense tag placement while maintaining navigation precision.
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
The RFID system minimizes collisions and potential injuries by enabling precise location determination and control of AGVs, achieving Safety Integrity Level 2 (SIL 2) or Performance Level d (PLd) characteristics, thereby enhancing safety in industrial environments.
Implementation Method 1
upon coming into proximity of an electromagnetic field produced by an RFID transceiver or antenna, the RFID tag energizes and transmits via radio frequency waves
Data Source
AI summary
Aspects of the present invention provide an RFID system for safely controlling an auto guided vehicle, an automated robot or other moving object (“AGV”). The system may include a plurality of radio frequency identification (“RFID”) tags, and each may store a unique identification in a first memory location, a position in a second memory location and/or an instruction in a third memory location. An AGV having an RFID transceiver or antenna and a computer with a non-transitory computer-readable storage medium containing a predetermined table may read one or more of the memory locations. The table comprises a plurality of data elements with certain data elements associated with particular RFID tags. The AGV safely determines its location upon matching the one or more memory locations read with one or more data elements, or triggers a fault upon failing to match. The AGV may also predict the next RFID tag.