TagLabel: RFID Based Orientation and Material Sensing for Automated Package Inspection

TL;DR

TagLabel integrates orientation and material sensing in a single RFID-based framework using 2 or 3 passive UHF tags. By combining phase-based phase differences (PDoA), tag occlusion, and antenna patterns with machine-learned classifiers, it achieves around 80–82% accuracy across all orientations without opening packages. The approach leverages RSSI/phase features in both absorption/reflection/scattering interactions and orientation cues, using random forests for orientation and neural networks for material classification, demonstrating practical viability with standard hardware. This work enables faster, safer, and more automated logistics screening by co-paving orientation-aware sensing with content identification.

Abstract

Modern logistics systems face increasing difficulty in identifying counterfeit products, fraudulent returns, and hazardous items concealed within packages, yet current package screening methods remain too slow, expensive, and impractical for widespread use. This paper presents TagLabel, an RFID based system that determines both the orientation and contents of packages using low cost passive UHF tags. By analyzing how materials change RSSI and phase, the system identifies the contents of a package without opening it. Using orientation inferred from phase differences, tag occlusion, and antenna gain patterns, the system selects the tag with the greatest occlusion for accurate material sensing. We evaluate two and three tag configurations, and show that both can deliver high orientation and material sensing performance through the use of machine learning classifiers, even in realistic RF environments. When combined into a unified pipeline, TagLabel achieves more than 80 percent accuracy across all package orientations. Because it requires only standard RFID hardware and offers fast scanning times, this approach provides a practical way to enhance package inspection and improve automation in logistics operations.

Figures (17)

• Figure 1: Interaction Phenomena Between RF and Materials
• Figure 2: Illustration of Phase Difference Between Tags
• Figure 3: TagLabel Data Pipeline
• Figure 4: Tag Locations for each Orientation State
• Figure 5: Tag Positions for Material Classification