Method, Design and Implementation of a Multiuser Indoor Localization System with Concurrent Fault Detection

Thanks to the large diffusion of small wearable devices there are several systems designed for indoor localization. Among the pro- posed solutions, RF-based systems have been deeply investigated due to their flexibility and limited costs. When these systems are employed as assistive tools, they should be dependable, recognizing autonomously when they are affected by a fault. In this paper, we present a method to provide multiuser localization with concurrent fault detection. We focus on two possible sources of faults: natural hardware (e.g., empty battery, faulty components) and human-made (e.g., device not worn). The presented methodology relies on two independent measurement systems and on a model based fault detection apparatus, checking for discrepancies in the behavior of the subsystems. This method is implemented to provide dependable localization in fragile people (such as elderly or people with small impairments) dwellings. We present examples of simulations in a large environment, and an implemented case-study. The collected data confirm the validity of the approach.