Self-deployable positioning systems for emergency situations employing uwb radio technology

Abstract

Indoor positioning systems have been widely studied in the last decade due to the need of humans for them especially in the large building such as malls, airports, hospitals...etc. Still, there is no suitable precise indoor positioning system which can be implemented for different indoor environments and situations. We should mention military urban and emergency situations. In military urban and emergency response operations, the time is a crucial issue, and a precise positioning system with a clear indoor covering is a highly prerequisite tool to enhance safety. It should be seamless, low, frugal, power efficacious, low cost and supply less meter-level accuracy. In emergency scenarios, we don't have enough flexibility and time to install all anchor nodes in a proper situation that may help to obtain an appropriate accuracy for locating a mobile station, but command centers require observing their operational forces, and rescuers demand to detect potential victims to perform proper care. The most common users for these situations are the firefighters, police, military, and civilians. The main goal of this Ph.D. dissertation is to create an accurate indoor positioning (IP) system that could be used in different indoor environments and situation, especially for the emergency situation. So, we create this system through different steps as explained below. First, we have considered the study of different radio technologies to choose the suitable radio technology called Ultra wide band (UWB) radio technology. The reasons of selection the UWB and the commercial device that implements such technology are explained in details in chapters 3 and 4. Afterward, due to some impacts of the UWB in indoor environments (see chapters 4 and 5), we continue the study of NLOS identification and mitigation methods. In these chapters, we create two different NLOS identification and mitigation methods using a commercial UWB device experimentally. The first method used two parameters extracted from the UWB device to identify the propagation channel and map information of the building that the method is experimentally done in it to mitigate the NLOS channel. The second method of NLOS identification and mitigation used three parameters extracting from the UWB device to be an input set of the Fuzzy logic technique used to identify the propagation channels. In this identification method, it is not only to identify the prorogation channel to NLOS and LOS but also to divide the NLOS channel into hard and soft channels. Then, we created a database that includes the three parameters and the distance Bias to mitigate the NLOS channel for obtaining an accurately estimated distance to be used for creating an accurate IP system. Finally, with the aim of applying our designs to mass market applications, we move to create a novel IP system using the UWB technology called anchor selection (AS). In this technique, we focus on using fewer sensors (anchor nodes) to locate a mobile station under harsh circumstances such as scenarios where the installation area of the anchor nodes is narrow and/or the installation time should be very short. The proposed approach is based on grouping anchor nodes in different sets and evaluating the positioning error of each of these groups by means of a novel mean squared error (MSE)-based methodology. A virtual node approach is also proposed to consider the case where position must be computed with only two anchor nodes.