Navigation System based on Near-Field Communication for Blind and Visually Impaired Subjects

Since ancient times, navigation has been a fundamental need for individuals, becoming even more central with the development of Global Positioning System (GPS), as well as other indoor localization techniques. Though they effectively represent landmarks for modern society, not all the navigation systems provide accessibility to people who cannot access smartphones, such as blind and visually impaired subjects. In fact, for those people, navigating is a significant challenge, which demands for reliable and efficient navigational aids in terms of sensitivity and resolution for precise guidance. Thus, this thesis fills this gap by developing an innovative electronic system that is based on Near Field Communication (NFC) technology, integrating a reader mounted on the tip of a walking stick with passive tags strategically placed along predefined paths. This setup enables blind and visually impaired individuals to navigate safely and accurately by acknowledging the unique identifiers collected from the tags, providing a real-time mapping of their location. Throughout the development of such a device, several considerations have been conducted, starting from the study of the magnetic coupling between two antennas in an NFC fashion. In this regard, electromagnetism and communication theories have been resumed in order to get a better comprehension of how the system could have been reliable in terms of speed and range during the coupling phase, ensuring a precise interaction between reader and tags. The chosen integrated circuits acting respectively as reader and tag, offered the trade-off between performance and costs that is required for a large-scale system, allowing the realization of the device with the Microcontroller Unit and its dedicated firmware. Once the system was fully designed, PCB prototypes have been manufactured for the reader, geometrically compliant with the tip of the cane, and for the tags, optimizing their space occupation along the path. This study allowed the system to be feasible and cost-effective, emerging as a refined navigational aid for blind and visually impaired people that has the potential to be fully integrated in modern infrastructure, both indoor and outdoor.