The non-coherent source localization problem based on distributed sensor arrays can be formulated into a group sparsity based phase retrieval problem where only the magnitude (absolute value) of the received signals i...
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ISBN:
(纸本)9781665406338
The non-coherent source localization problem based on distributed sensor arrays can be formulated into a group sparsity based phase retrieval problem where only the magnitude (absolute value) of the received signals is available. Under such a framework, a two-dimensional localization method is proposed. Unlike traditional source localization methods, random phase errors at sensors of the distributedarray will not affect estimation results by the proposed method. Simulation results indicate that the proposed non-coherent source localization method outperforms the traditional one in the presence of large phase errors, while still maintains an acceptable accuracy in the absence of phase errors.
This paper considers the problem of tracking multiple acoustic sources in 3-D space using a distributed acoustic vector sensorarray. Unlike the existing two-stage localization approach, which estimates the direction ...
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This paper considers the problem of tracking multiple acoustic sources in 3-D space using a distributed acoustic vector sensorarray. Unlike the existing two-stage localization approach, which estimates the direction of arrival of the source at each sensor first and then triangulate a 3-D position, a particle filtering approach is developed to directly fuse the signals collected from distributedsensors. To enhance the tracking performance and constrain the computational complexity, an information filter is developed to approximate the optimal importance sampling. Since the position state of the source is linear with the velocity state, a Rao-Blackwellization step is employed to marginalize out the velocity component. In addition, the posterior Cramer-Rao bound is developed to provide a lower performance bound for the distributed tracking system. Both the numerical study and simulations show that the proposed tracking approach significantly outperforms the two-stage localization approaches for 3-D position estimation.
In the past, distributed acoustic vector sensor (AVS) arrays have been employed to localize the source in a three dimensional space. Least-squares approaches were introduced to triangulate the source position by using...
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In the past, distributed acoustic vector sensor (AVS) arrays have been employed to localize the source in a three dimensional space. Least-squares approaches were introduced to triangulate the source position by using the direction of arrival (DOA) measurements extracted at each AVS. However, such approaches: (1) cannot detect and localize multiple sources;and (2) can be seriously degraded due to inaccurate DOA estimates. In this paper, a practical scenario that the source existence and the number of sources are assumed to be unknown is considered. A random finite set (RFS) approach is developed to jointly detect and track multiple wideband acoustic sources. RFS is able to characterize the randomness of the state process (i.e., the source dynamics and the number of active sources) as well as the measurement process (i.e., DOA measurements generated by real sources and false alarms). Since the relationship between DOAs and source position is highly nonlinear, a particle filtering approach is employed to arrive at a computationally tractable approximation of the RFS densities. Simulations under different acoustic environments demonstrate the performance of the proposed approach and show a significant improvement on position estimation over the least squares approaches. (C) 2013 Elsevier B.V. All rights reserved.
Consider the problem of tracking multiple acoustic sources in three dimensional (3-D) space using a distributed acoustic vector sensor (AVS) array. Traditionally, indirect approaches are widely used, by which the dire...
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ISBN:
(纸本)9781467310680
Consider the problem of tracking multiple acoustic sources in three dimensional (3-D) space using a distributed acoustic vector sensor (AVS) array. Traditionally, indirect approaches are widely used, by which the direction of arrival (DOA) of the source at each sensor is estimated first, and the DOA estimates are then employed to intersect a 3-D position. The performance of position estimation can be seriously degraded by inaccurate DOA estimates at the first stage, and multiple source localization is impossible unless the DOA estimates can be associated to each source accurately. In this paper, a particle filtering (PF) approach is developed to directly fuse the signals collected from distributedsensors and track the 3-D positions. To enhance the tracking performance and keep the computational complexity affordable, an extended information filter is developed to achieve the optimal resampling. The simulations show that the proposed tracking approach significantly outperforms the indirect localization approaches and is able to track multiple active sources accurately.
The work presented relates to the design and construction of an inexpensive distributive load sensor. It is to be used for impact tests on samples which are in the form of flexible or deformable beams of a considerabl...
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ISBN:
(纸本)0819457396
The work presented relates to the design and construction of an inexpensive distributive load sensor. It is to be used for impact tests on samples which are in the form of flexible or deformable beams of a considerable length. The sensor compromises of forty fingers made of steel, arranged next to each other and covering a total length of about a meter. Both ends of each finger are clamped. PZT ceramic patches, which are bonded to the bottom surfaces of each finger, are used to convert the impact response into an electrical signal. An amplifier and filter were designed for each finger. The frequency range over which each finger operates is extended by the use of a Butterworth filter. An amplifier box was built containing the charge amplifier circuitry and filter of each of the forty fingers comprising the distributive sensor. Tests are performed on the distributive sensor in order to show that this simple and inexpensive distributive sensor is effective. The results are presented and discussed.
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