An embedded system for aiding navigation of visually impaired persons

Visually impaired individuals find navigation difficult as they often lack the much needed information for bypassing obstacles and hazards in their path. In order to help blind people navigate safely and quickly, an obstacle detection system using ultrasonic sensors and USB camera-based visual navigation has been considered. The proposed system detects obstacles up to 300 cm via sonar and sends audio feedback to inform the person about their location. In addition, a USB webcam is connected with eBox 2300 (TM) Embedded System for capturing the field-of-view of the user, for finding the properties of the obstacle in particular, in the context of this work, locating a human being. Identification of human presence is based on face detection and cloth texture analysis. The major constraints for these algorithms to run on the Embedded System are small image frame (160 x 120) having reduced faces, limited memory and very less processing time available to achieve real-time image-processing requirements. Prototype of an electronic travel aid device has been developed and experimentally verified on blind-folded persons to analyse the device performance in a laboratory set-up.