Empowering the Blind: Contactless Activity Recognition with Commodity Software-Defined Radio and Ultra-High-Frequency...

Area of Science:

• Assistive Technology
• Radio Frequency Identification (RFID)
• Computational Electromagnetics

Background:

• Existing assistive technologies for the visually impaired have limitations in real-time environmental sensing.
• Current radio frequency identification (RFID) systems primarily focus on identification rather than detailed environmental interaction.
• The integration of software-defined radio (SDR) offers potential for advanced RFID functionalities.

Purpose of the Study:

• To develop a novel computational RFID system to aid blind individuals.
• To enhance RFID capabilities for transmitting sensed information beyond basic identification.
• To enable real-time contactless activity monitoring for improved navigation and assistance.

Main Methods:

• Utilized software-defined radio (SDR) with coherent detection for a computational RFID system.
• Employed battery-less ultra-high-frequency (UHF) tag arrays within a Gen2 RFID framework.
• Developed an SDR reader to manage multiple tags with Gen2 preambles on a single transceiver.

Main Results:

• Demonstrated real-time detection of movement and walking direction within a four-meter range.
• Successfully managed multiple tags using Gen2 preambles on a single SDR transceiver.
• Characterized the influence of system parameters on RFID operational efficiency.

Conclusions:

• The developed RFID system offers a practical and affordable solution for blind individuals.
• This technology advances contactless activity monitoring and pseudo-localisation capabilities.
• The system provides a foundation for future innovations in assistive technology for the visually impaired.