RAISE Walker: A Smart Geofencing Information System for Visually Impaired People

Abstract

This paper presents an affordable, integrated platform designed to significantly enhance urban navigation and quality of life for individuals with visual impairments. The system architecture is built around a dedicated mobile application and a portable, tactile external keyboard, which together form a cohesive, low-cost user interface (evaluated using Blindfolded Sighted Participants, or BSPs, in this study). The device accepts operational commands through both voice recognition and simple physical button presses. Its core functionality focuses on delivering contextual, real-time location, and transportation intelligence. The system leverages geofencing features to provide real-time alerts using Text-to-Speech (TTS) concerning pre-saved points of interest as the participant moves through the city. The application’s design parameters are derived from real visually impaired user requirements, prioritizing independence by providing comprehensive environmental awareness. Geofencing information and voice control are achieved using Speech-to-Text (STT). The application also processes open General Transit Feed Specification (GTFS) static data feeds, customizable by the user, which allows it to present all future arrival times of a vehicle, the location of the nearest stop for a specific line, and complete future scheduling information. The RAISE Walker platform enables participants to configure Web Map Services (WMS) to define environmental alerts based on publicly available layers, such as Vertical Maximum Intensity (VMI), temperature, and carbon monoxide presence. Additionally, it can read public safety messages from Telegram channels, converting them into TTS updates that play at scheduled times. The combination of the smart keyboard, capable of detecting large obstacles using dedicated Time-of-Flight (ToF) sensors, and bone-conduction headphones ensures straightforward interaction without inhibiting the ability to perceive ambient environmental sounds. Furthermore, the application is optimized to run entirely in the background with the smartphone in its secure location, which reduces theft risks and improves convenience. We describe in detail the main architectural features and operational capabilities of the integrated iOS application and its touch-sensitive hardware interface. The system performance was verified through practical evaluations, focusing on the accuracy of sensor-based obstacle detection, the provision of real-time location-aware geo-warnings, and the integration of public transportation applications. Combining these technical results with direct feedback from participants, we provide a clear proof of concept for the RAISE Walker platform as a comprehensive tool for autonomous urban navigation.