To tackle challenges such as interference and poor accuracy of indoor positioning systems,a novel scheme based on ultra-wide bandwidth(UWB)technology is ***,we illustrate a distance measuring method between two UWB **...
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To tackle challenges such as interference and poor accuracy of indoor positioning systems,a novel scheme based on ultra-wide bandwidth(UWB)technology is ***,we illustrate a distance measuring method between two UWB ***,a Taylor series expansion algorithm is developed to detect coordinates of the mobile node using the location of anchor nodes and the distance between *** results show that the observation error under our strategy is within 15 cm,which is superior to existing *** final experimental data in the hardware system mainly composed of STM32 and DW1000 also confirms the performance of the proposed scheme.
In this paper, a novel RSSI-based position algorithm is proposed for Mobile ad hoc network. The proposed range-based position scheme is implemented by a blind node and several beacons. We show how to use parameters-tu...
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ISBN:
(纸本)9780819495884
In this paper, a novel RSSI-based position algorithm is proposed for Mobile ad hoc network. The proposed range-based position scheme is implemented by a blind node and several beacons. We show how to use parameters-tuning model and position-correction model to effectively compute a good estimation of the position of blind node. The results of our method in CC2431 indicate that the calculated distance is closer to the actual values and the position of the blind node can be computed in a small amount of time and that the quality of the solution is competitive with previous approaches.
Fingerprint positioning method is generally the first choice in indoor navigation system due to its high accuracy and low cost. The accuracy depends on partition density to the indoor space. The accuracy will be highe...
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Fingerprint positioning method is generally the first choice in indoor navigation system due to its high accuracy and low cost. The accuracy depends on partition density to the indoor space. The accuracy will be higher with higher grid resolution. But the high grid resolution leads to significantly increasing work of the fingerprint data collection, processing and maintenance. This also might decrease the performance, portability and robustness of the navigation system. Meanwhile, traditional fingerprint positioning method use equational grid to partition the indoor space. While used for pedestrian navigation, sometimes a person can be located at the area where he or she cannot access. This paper studied these two issues, proposed a new indoor space partition method considering pedestrian accessibility, which can increase the accuracy of pedestrian position, and decrease the volume of the fingerprint data. Based on this proposed partition method, an optimized algorithm for fingerprint position was also designed. A across linker structure was used for fingerprint point index and matching. Experiment based on the proposed method and algorithm showed that the workload of fingerprint collection and maintenance were effectively decreased, and poisoning efficiency and accuracy was effectively increased.
Real-time GNSS positioning rely mainly on pseudorange and carrier-phase. The pseudorange is not accurate because of a lot of noise and interference in environment. High-precision carrier-phase used to smooth pseudoran...
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ISBN:
(纸本)9783642373985;9783642373978
Real-time GNSS positioning rely mainly on pseudorange and carrier-phase. The pseudorange is not accurate because of a lot of noise and interference in environment. High-precision carrier-phase used to smooth pseudorange. While, when cycle slip occurs, the carrier-phase measurement is bias. Unlike Carrier observations, the Doppler observations tend to have higher continuity. In Beidou system, GEO satellites local in geostationary orbit with lower dynamic. So, we can use the small noise bandwidth to improve the accuracy of measurement. This paper analyzes the characteristics and methods of Doppler-assisted positioning the the settlement equation using the weighted least squares method. The simulation and test results show that the positioning of the reliability of the results has been improved.
Real-time GNSS positioning rely mainly on pseudorange and carrier-phase. The pseudorange is not accurate because of a lot of noise and interference in environment. High-precision carrier-phase used to smooth pseudoran...
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Real-time GNSS positioning rely mainly on pseudorange and carrier-phase. The pseudorange is not accurate because of a lot of noise and interference in environment. High-precision carrier-phase used to smooth pseudorange. While, when cycle slip occurs, the carrier-phase measurement is bias. Unlike Carrier observations, the Doppler observations tend to have higher continuity. In Beidou system, GEO satellites local in geostationary orbit with lower dynamic. So, we can use the small noise bandwidth to improve the accuracy of measurement. This paper analyzes the characteristics and methods of Doppler-assisted positioning the the settlement equation using the weighted least squares method. The simulation and test results show that the positioning of the reliability of the results has been improved.
A Non-light-of-sight (NLOS) mitigation approach based on GBSBEM was proposed in this paper. The main idea is to model the NLOS errors to the elliptical model and mitigate them with a novel method. At the first step, t...
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A Non-light-of-sight (NLOS) mitigation approach based on GBSBEM was proposed in this paper. The main idea is to model the NLOS errors to the elliptical model and mitigate them with a novel method. At the first step, the semi-minor of GBSBEM is estimated, then a way to restrain the NLOS errors with the help of the semi-minor is used. When the semi-minor can not be estimated, an optimization method based on GBSBEM pdf is presented. The method has a good effect to reduce the NLOS error, especially when the NLOS effect is notable.
Non-line-of-sight （NLOS） propagation is a major source of error for accurate time-of-arrival （TOA） location estimation. The two-step least square （LS） method, which does not need any information about the distri...
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Non-line-of-sight （NLOS） propagation is a major source of error for accurate time-of-arrival （TOA） location estimation. The two-step least square （LS） method, which does not need any information about the distribution of the NLOS error, has been studied in related researches to provide efficient location estimation of the mobile terminal （MT）. By observing the estimation of the error covariance matrix in the two-step LS method, this paper finds that the measured distances are more suitable than the initial estimated distances by maximum likelihood （ML） algorithm in NLOS environments. Moreover, by making use of the geometry relations among fixed terminals （FTs）, some measured distances which are corrupted by big NLOS errors may be reduced. Further, an iteration method can be adopted to further improve the performance of the algorithm. Accordingly, an improved algorithm based on the two-step LS method is proposed. Simulation results demonstrate that the improved algorithm has better performance than the two-step LS method and converges more quickly. Meanwhile, it is robust in different NLOS environments.
The clinical applications of capsule endoscopes have been increasing consistently since the invention of a passive capsule endoscope was made [1]. Though the capsule endoscopes are effective in detecting large lesions...
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ISBN:
(纸本)9780769539294
The clinical applications of capsule endoscopes have been increasing consistently since the invention of a passive capsule endoscope was made [1]. Though the capsule endoscopes are effective in detecting large lesions along human digestive tract, they cannot meet doctors' requirements of active control of the capsules to carefully examine small lesions. The poor precision of positioning system is one of the major hurdles blocking robots from approaching the accurate position of suspected areas. In this paper, we propose a novel algorithm to exploit the radiation patten of a radio frequency (RF) tag inside the capsule, which forms shadows or traces on a set of receiver arrays. According to the shape of the traces and the radiation pattern, the position of the radiation source, i.e. the tag inside the capsule can be calculated with our algorithm. The details of our algorithm are presented with the simulation results in the paper. With the settings under medical constraints, the degree of positioning precision in simulation is improved to less than 1cm horizontally and 2cm vertically.
We are developing advanced dedicated breast and small animal positron emission tomography (PET) systems with detectors comprising arrays of 1 x 1 x 3 mm(3) LSO crystals coupled to novel, extremely thin position-sensit...
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ISBN:
(纸本)0780392213
We are developing advanced dedicated breast and small animal positron emission tomography (PET) systems with detectors comprising arrays of 1 x 1 x 3 mm(3) LSO crystals coupled to novel, extremely thin position-sensitive avalanche photodiodes (PSAPD). This thin PSAPD is essential for achieving high crystal packing fraction for a PET system design which has 2 cm effective LSO crystal thickness, 1mm transaxial spatial resolution and 3 rum directly measured photon DOI resolution. These properties facilitate high detection efficiency and three dimensional positioning capability in the detector. With this very thin PSAPD, preliminary results indicated that we can expect I mm 3 intrinsic spatial resolution. We have observed an average of 1.1mm transaxial and 3mm DOI spatial resolution, similar to 11% energy resolution and similar to 2 ns temporal resolution. We have also implemented a position algorithm for reducing the effect of pincushioning on events detected over the face of the PSAPD.
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