Improving Mobility for the Visually Impaired: A Wearable Indoor Positioning System Based on Visual Markers

This article presents an indoor positioning system based on camera and ultrasonic sensors mounted on a pair of glasses that is specifically designed for visually impaired individuals. The proposed system incorporates a recognition algorithm that is able to recognize certain color-coded markers with a detectable range of 15 m in real time on a quad-core embedded processor. In addition, microultrasonic transducers are implemented to detect obstacles in front of the glasses. The positioning system and obstacle detection can be adjusted to work independently or in parallel. The sensor data are then transmitted to a mobile phone to be processed. The results show that the proposed system is able to recognize markers and detect obstacles with low complexity and power consumption.