A portable mid-range localization system using infrared LEDs for visually impaired people

A versatile indoor/outdoor pedestrian guidance system with good mobility is necessary in order to aid visually impaired pedestrians in indoor and outdoor environments. In this paper, distance estimation methods-for portable wireless localization systems are verified. Two systems of a fixed active beacon and a receiver using an ultrasound time-of-flight method and a differential infrared intensity method are proposed. The infrared localization system was appropriate for the goal of this study. It was possible to use the infrared intensity method to generate a uniform signal field that exceeded 30 m. Valid distance estimations which were within 30 m of coverage indoors and within 20 m of coverage outdoors were made, Also, a pocket-sized receiver which can be adapted to a smartphone was found to be suitable for use as a portable device. (C) 2014 Elsevier B.V. All rights reserved.