With the development of the Internet of Things (IoT), location estimation has become an essential and key factor in various monitoring applications for the IoT. Location fingerprint localization based on Wi-Fi has gra...
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This study presents a novel system for accurately positioning underground pipelines by applying rotating permanent magnets, addressing the limitations of traditional wireless systems in effectively penetrating both th...
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This study presents a novel system for accurately positioning underground pipelines by applying rotating permanent magnets, addressing the limitations of traditional wireless systems in effectively penetrating both the pipe and surrounding soil. The system is realized with the improved fingerprintmatchingalgorithm, which is composed of a rotating structure, a permanent magnet, a magnetic sensor, an A/D module, and a positioning solution module. Under the boundary conditions, a continuous propagation model of the magnetic field is analyzed for the medium of different magnetic permeability, which is the basis of the positioning method in the pipelines. To solve the problem of difficulty in obtaining an accurate dense database, a methodology involving measurement and virtual reference points (RPs) is developed. A matching method based on cluster analysis is applied in the system to improve the matching efficiency, which includes cluster selection, coarse matching, and fine positioning. The realized prototype is used to verify the proposed approach in long metal pipelines, which have a maximum positioning error of less than 0.15 m, a mean value of 0.0974 m, and a standard deviation of 0.0106 m in a factory environment. This affirms the effectiveness of the developed system in addressing issues related to accurate pipeline localization.
With the popularity of smart mobile devices, users can rely on global positioning system (GPS) technology when they are outdoors to determine their geographic location and to use other navigation services. However, GP...
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With the popularity of smart mobile devices, users can rely on global positioning system (GPS) technology when they are outdoors to determine their geographic location and to use other navigation services. However, GPS cannot reliably obtain satellite signals indoors, GPS is not suitable for indoor positioning applications. Wi-Fi and Bluetooth are the mainstream technologies used for indoor positioning today. But these radio technologies sometimes encounter problems, such as human-shadowing effects, multiple-path delays, and radio-wave interference, which can cause serious errors in the accuracy of indoor positioning results. In addition, using wireless network signals require the setup of certain infrastructure equipment. On the other hand, there are no such problems when using positioning technology based on the Earth's magnetic field. This paper analyzes how the environment can influence magnetic field measurements from magnetometers in mobile devices and verifies that this system can be used to enable indoor positioning. This paper also proposes the use of a weighted magnetic field component and the k-nearest neighbors ( $k$ -NN) algorithm for enhanced precision in indoor positioning. Finally, the research results show that a positioning accuracy of 91.7% and an average positioning error distance of 0.76 m can be achieved with these methods. The results of experiments show that the system performance is significantly feasible.
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