Localization systems are the source of data that allows to evaluate elderly person’s behaviour, to draw conclusions concerning his or her health status and wellbeing, and to detect emergency situations. The article contains a description of a system intended for elderly people tracking. Two novel solutions have been implemented in the system: a hybrid localization algorithm and a method for wireless anchor nodes synchronization. The algorithm fuses results of time difference of arrival and received signal strength measurements in ultrawideband (UWB) and Bluetooth Low Energy (BLE) radio interfaces, respectively. The system allows to change the intensity of UWB packets transmission to adapt localization accuracy and energy usage to current needs and applications. In order to simplify the system installation, communication between elements of the system infrastructure instead of wire interfaces is performed over wireless ones. The new wireless synchronization method proposed in the article consists in retransmission of UWB synchronization packets by selected anchor nodes. It allows for extension of the system coverage, which is limited by the short range of UWB transmission. The proposed solution was experimentally verified. The synchronization method was tested in a laboratory, and the whole system’s performance was investigated in a typical flat. Exemplary results of the tests performed with older adult participation in their own homes are also included.

The clock frequency tolerance and instability have a big impact on positioning accuracy and precision in UWB localization systems. The paper deals with synchronization and TDOA error reduction technique relying on reference packets transmission. The method was implemented in the UWB positioning system. The paper contains description of the method, system architecture and results of performed measurements.

The paper presents an indoor mapping and UWB (ultra-wideband) anchor localization method. The method, unlike most of the solutions described it the literature uses a static LiDAR (Light Detection and Ranging) mounted on a tripod rather than a robotic platform. It can be used at an any place, where employing a robot would be difficult (e.g. private homes), but since it requires manual LiDAR placement it would be most efficient in spaces of moderate areas. The proposed concept consists in mapping the environment of system installation while performing ranging measurements with deployed UWB anchor nodes. The SLAM (Simultaneous Location and Mapping) algorithm used for map integration and device localization relies only on LiDAR results. The matching is performed in two steps by finding an initial match based on corresponding landmarks extracted from the scans (intersections of the detected wall lines) and refining the results using an Iterative Closest Point algorithm. The anchors are localized based on the ranging results and SLAM-derived device locations using a Least-Squares based optimizer. The experiments have shown that the algorithm allows to construct a comprehensive map of the environment and localize the anchors with a root mean square error of 0.34 m, which is at similar level to analogous methods described in other works. The impact of anchor localization error on the systems performance was not significant. In both static and dynamic scenarios the difference in median errors obtained using reference and mapped anchors’ locations was about 0.05 m.

Independent living of elderly persons in their homes requires support that can be provided with modern assistive technologies. Monitoring of elderly persons behaviour delivers valuable information that can be used for diagnosis and detection of health problems as well as triggering alerts in emergency situations. The paper includes a description of the ultra wideband system developed within Networked InfrasTructure for Innovative home Care Solutions (NITICS) Active and Assisted Living (AAL) project. The system can be used as a component of AAL platforms. It delivers data on users localization and has a fall detector functionality. The system also provides access to raw measurement results from Microelectromechanical Systems (MEMS) sensors embedded in the device worn by the monitored person. These data can be used in solutions intended for elderly person’s behaviour investigation. The system was investigated under laboratory conditions as well as in home environment. The detailed system description and results of performed tests are included in the article.

The EIGER¹ project proposes a global approach for the exploitation of the efficient joint use of GNSS signals and UWB positioning in order to allow permanent and reliable outdoor/indoor localization. This paper is focused on the UWB positioning subsystem designed within the project. The architecture of the system and design of the main devices are described. Results of selected laboratory tests of developed equipments are presented and discussed.

UWB positioning systems are able to provide outstanding accuracy and precision of localization. However, system performance strongly depends on the quality of reference clock oscillators installed in system devices and accuracy of anchors synchronization. The paper describes a new transmission scheme providing wireless infrastructure nodes synchronization and reduction of errors caused by tag's clock oscillator tolerance and stability. The paper contains description of the positioning system architecture and the algorithm for time difference of arrival determination. The proposed scheme was investigated, the results of simulations are included in the paper.