A Survey on Device-free Indoor Localization and Tracking in the Multi-resident Environment

Abstract

Indoor device-free localization and tracking can bring both convenience and privacy to users compared with traditional solutions such as camera-based surveillance and RFID tag-based tracking. Technologies such as Wi-Fi, wireless sensor, and infrared have been used to localize and track people living in care homes and office buildings. However, the presence of multiple residents introduces further challenges, such as the ambiguity in sensor measurements and target identity, to localization and tracking. In this article, we survey the latest development of device-free indoor localization and tracking in the multi-resident environment. We first present the fundamentals of device-free localization and tracking. Then, we discuss and compare the technologies used in device-free indoor localization and tracking. After discussing the steps involved in multi-resident localization and tracking including target detection, target counting, target identification, localization, and tracking, the techniques related to each step are classified and discussed in detail along with the performance metrics. Finally, we identify the research gap and point out future research directions. To the best of our knowledge, this survey is the most comprehensive work that covers a wide spectrum of the research area of device-free indoor localization and tracking.

Effects of Positioning of Multi-Sensor Devices on Occupancy and Indoor Environmental Monitoring in Single-Occupant Offices

“…The research publications on various occupancy monitoring technologies such as visual cameras, ultrasound sensors, and PIR sensors have continuously increased in recent years [2,33]. Besides the technologies primarily designed for occupancy detection, it is Energies 2021, 14, 6296 4 of 23 possible to use indoor environmental sensors such as CO 2 , temperature, and humidity to detect occupants [39,40].…”

“…Besides the technologies primarily designed for occupancy detection, it is Energies 2021, 14, 6296 4 of 23 possible to use indoor environmental sensors such as CO 2 , temperature, and humidity to detect occupants [39,40]. Every occupancy sensing technology has its advantages, disadvantages, and limitations in different conditions [33].…”

“…PIR sensors have been preferred for occupancy detection in various applications due to low cost, low power consumption, simplicity, and no need for maintenance [28,33]. These sensors are stated to provide better information about occupancy than several other common sensors, including ultrasound and CO 2 sensors [17].…”

“…The influence of occupants on energy use in office spaces is relatively strong, thus, there is a high potential to avail from occupancy and environmental monitoring [31]. PIR sensors are among the most common sensor types used for occupancy detection in buildings [32,33]. The objective of this study is to examine how sensor positioning affects the performance of PIR sensors for occupancy detection in single-occupant offices.…”

Lab-Based Evaluation of Device-Free Passive Localization Using Multipath Channel Information

“…For many applications, the person or object, which is supposed to be localized, is typically equipped with a transponder, leading to the term active or cooperative localization. In addition, radar-like approaches, also referred to as device-free passive localization (DFPL) [ 4 , 5 , 6 ], can use the Channel Impulse Response (CIR) of the communication channel to identify signal reflections and the associated path lengths, enabling a passive localization of reflecting objects. For the work presented, we emphasize the utilization of commonly available radio technologies originally intended for the interconnection of devices.…”