1,720,967 research outputs found
RF ranging based on space diversity techniques and directive antennas
No full textIn this paper, a ranging technique based on narrowband transmissions in the 2.4 GHz ISM band is discussed. Multipath mitigation techniques based on Multiple Input Multiple Output (MIMO) philosophy are considered, discussing the effect of antenna directivity on the achievable performance
Effects of antenna directivity on RF ranging when using space diversity techniques
No full textIn this paper, a ranging technique based on narrowband transmissions in the 2.4. GHz ISM band is discussed. Multipath mitigation techniques based on Multiple Input Multiple Output (MIMO) philosophy are considered, discussing the effect of antenna rotations on the achievable performance under Line of Sight conditions, and the effect of RSSI measurement uncertainty on the effectiveness of the mitigation techniques. Simulation and experimental results show that the proposed approach can effectively improve the ranging accuracy. © 2015 Elsevier Ltd
An Experimental System for Tightly Coupled Integration of GPS and AC Magnetic Positioning
No full textA Positioning System Based on Low Frequency Magnetic Fields
No full textThis paper describes the design and the realization of a low-frequency ac magnetic-field-based indoor positioning system (PS). The system operation is based on the principle of inductive coupling between wire loop antennas. Specifically, due to the characteristics of the ac artificially generated magnetic fields, the relation between the induced voltage and the distance is modeled with a linear behavior in a bilogarithmic scale when a configuration with coplanar, thus equally oriented, antennas is used. In this case, the distance between a transmitting antenna and a receiving one is estimated using measurements of the induced voltage in the latter. For a high operational range, the system makes use of resonant antennas tuned at the same nominal resonant frequency. The quality factors act as antenna gain increasing the amplitude of the induced voltage. The low-operating frequency is the key factor for improving robustness against nonline-of-sight (NLOS) conditions and environment influences with respect to other existing solutions. The realized prototype, which is implemented using off-the-shelf components, exhibits an average and maximum positioning error, respectively, lower than 0.3 and 0.9 m in an indoor environment over a large area of 15 × 12 m in NLOS conditions. Similar performance is obtained in an outdoor environment over an area of 30 × 14 m. Furthermore, the system does not require any type of synchronization between the nodes and can accommodate an arbitrary number of users without additional infrastructure
A Magnetic Ranging-Aided Dead-Reckoning Positioning System for Pedestrian Applications
No full textThis paper investigates the applicability of a developed Magnetic Positioning System (MPS) as a support for a dead-reckoning inertial navigation system (DR-INS) for pedestrian applications. The integrated system combines the complementary properties of the separate systems, operating over long periods of time and in cluttered indoor areas with partial nonline-of-sight conditions. The obtained results show that the proposed approach can effectively improve the coverage area of the MPS and the operation time with bounded errors of the DR-INS. In particular, a solution that provides bounded position errors of 1-2 m over significantly long periods of time up to 45 min, in realistic indoor environments, is demonstrated. Moreover, system applicability is also shown in those scenarios where arbitrary orientations of the MPS mobile node are considered and an MPS position estimate is not available due to less than three distance measurements
An Indoor AC Magnetic Positioning System
No full textThis paper describes the design and realization of a magnetic indoor positioning system. The system is entirely realized using off-the-shelf components and is based on inductive coupling between resonating coils. Both system-level architecture and realization details are described along with experimental results. The realized system exhibits a maximum positioning error of <10 cm in an indoor environment over a 3 × 3 m2 area. Extensive experiments in larger areas, in nonline-of-sight conditions, and in unfavorable geometric configurations, show submeter accuracy, thus validating the robustness of the system with respect to other existing solutions
A hybrid outdoor/indoor Positioning System for IoT applications
No full textMotivated by the emergence of the Internet of Things (IoT), and by the importance that location information has on many complex systems scenarios, we propose a hybrid scheme for user positioning in an urban scenario. The system uses both a Global Navigation Satellite System (GNSS) and a Magnetic Positioning System (MPS). To maintain receiver complexity and cost at a minimum, the location scheme combines the MPS technique and GNSS measurements. A Kalman filter algorithm is used as the data integration mechanism over the time axis. Results demonstrate that the use of a local MPS provides increased location coverage, without service interruptions, when the number of visible satellites is inadequate. The obtained accuracy in the indoor environment is better than meter-level, thus fulfilling the requirements of many hybrid outdoor/indoor positioning applications
Analysis of the sensitivity of AC magnetic ranging systems to environmental configurations
No full text
A simple magnetic signature vehicles detection and classification system for Smart Cities
No full textVehicle recognition is one of the main challenges in Intelligent Transportation Systems (ITS). The need to recognize the vehicle type can help insurance companies, public safety organizations, infomobility, and policy-makers in general. In this paper, we propose a vehicle recognition system based on speed estimation, vehicle length estimation and classification of the vehicle type. We developed a real time system for vehicle recognition based on four steps: a storage of the magnetic signature of the vehicle, speed estimation, estimation of the length of the vehicle and vehicle recognition. The latter has been realized through matching between the measured waveform with information in a database containing magnetic signatures of vehicles. Matching was realized using the Dynamic Time Warping (DTW) method. Experimental results involving 10 vehicles and 50 trials show successful identification of approximately 98% of the considered vehicles
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