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2nd International Conference on Measurement, Instrumentation and Automation (ICMIA 2013)

作者： Zhu Shengjie Feng Xinhuan Wuhan Univ Sch Resources & Environm Sci Wuhan 430072 Peoples R China Wuhan Univ Sch Comp Wuhan 430072 Peoples R China

ISBN: (纸本)9783037857519

Naturally, for the mountain mapping, the communication system's power is limited, As a matter of fact, the stations should be built as high as possible in order to eliminate the terrain shielding and radiate to the farther areas, however the number of users or other aspects also counts, In this paper, we introduced new methods to locate the modified location for the base stations in the mountain areas, and with this method, we use less stations to cover the most areas in the given situation. For a random mountain terrain, the coverage rate of this model is as high as 95.1%.

关键词： Mountain Mapping Field Communication positioning algorithm Mapping equipment

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Real-time implementation of camera positioning algorithm based on FPGA & SOPC 7

Real-time implementation of camera positioning algorithm bas...

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7th International Symposium on Advanced Optical Manufacturing and Testing Technologies (AOMATT) - Optical Test and Measurement Technology and Equipment

作者： Yang Mingcao Qiu Yuehong Chinese Acad Sci Xian Inst Opt & Precis Mech Xian 710119 Peoples R China Univ Chinese Acad Sci Beijing 100049 Peoples R China

ISBN: (纸本)9781628413571

In recent years, with the development of positioning algorithm and FPGA, to achieve the camera positioning based on real-time implementation, rapidity, accuracy of FPGA has become a possibility by way of in-depth study of embedded hardware and dual camera positioning system, this thesis set up an infrared optical positioning system based on FPGA and SOPC system, which enables real-time positioning to mark points in space. Thesis completion include: (1) uses a CMOS sensor to extract the pixel of three objects with total feet, implemented through FPGA hardware driver, visible-light LED, used here as the target point of the instrument. (2) prior to extraction of the feature point coordinates, the image needs to be filtered to avoid affecting the physical properties of the system to bring the platform, where the median filtering. (3) Coordinate signs point to FPGA hardware circuit extraction, a new iterative threshold selection method for segmentation of images. Binary image is then segmented image tags, which calculates the coordinates of the feature points of the needle through the center of gravity method. (4) direct linear transformation (DLT) and extreme constraints method is applied to three-dimensional reconstruction of the plane array CMOS system space coordinates. using SOPC system on a chip here, taking advantage of dual-core computing systems, which let match and coordinate operations separately, thus increase processing speed.

关键词： positioning algorithm Feature point extraction Match point mark

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Optimal KNN positioning algorithm via Theoretical Accuracy Criterion in WLAN Indoor Environment

Optimal KNN Positioning Algorithm via Theoretical Accuracy C...

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IEEE Global Telecommunications Conference (GLOBECOM 2010)

作者： Xu, Yubin Zhou, Mu Meng, Weixiao Ma, Lin Harbin Inst Technol Commun Res Ctr Harbin 150001 Peoples R China

ISBN: (纸本)9781424456383

This paper proposes the optimal K nearest neighbors (KNN) positioning algorithm via theoretical accuracy criterion (TAC) in wireless LAN (WLAN) indoor environment. As far as we know, although the KNN algorithm is widely utilized as one of the typical distance dependent positioning algorithms, the optimal selection of neighboring reference points (RPs) involved in KNN has not been significantly analyzed. Therefore, in order to fill this gap, the optimal KNN positioning algorithm based on the best TAC is introduced. And this algorithm is beneficial to construct the reliable WLAN indoor positioning system and provide the efficient location based services (LBSs). The relationship among theoretical expectation accuracy, unit interval of neighboring RPs and dimensions of target location region is also revealed. Furthermore, the feasibility and effectiveness of optimal KNN positioning algorithm are verified based on the experimental comparisons respectively in the regular office room, straight corridors, static positioning and dynamic tracking situations.

关键词： accuracy criterion WLAN positioning algorithm radio fingerprint expectation error

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The Optimization of RSSI-Neural network positioning algorithm 4

The Optimization of RSSI-Neural network positioning algorith...

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4th International Conference on Instrumentation and Measurement, Computer, Communication and Control (IMCCC)

作者： Zhang Xuhui Gao Baojiang Liu Yukun Wang Juan Chang Huimin Harbin Univ Sci & Technol Higher Educ Key Lab Measuring & Control Technol & Harbin Peoples R China

ISBN: (纸本)9781479965755

This paper optimized the RSSI neural network positioning algorithm. In-depth analysis of the principles of the Kalman filter and using the Kalman filter to filter the Received Signal Strength Indicator (RSSI) value. Analysis the structure of back propagation neural network and optimized the structure of the RSSI-neural network algorithm. MATLAB simulation verified the optimization algorithm has higher accuracy and more robustness.

关键词： RSSI BP BP neural network Kalman filter positioning algorithm

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Semi-supervised positioning algorithm in Indoor WLAN Environment

Semi-supervised Positioning Algorithm in Indoor WLAN Environ...

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81st IEEE Vehicular Technology Conference (VTC Spring)

作者： Ying, Xia Lin, Ma Zhang Zhongzhao Yao, Wang Harbin Inst Technol Commun Res Ctr Harbin 150006 Peoples R China Qiqihar Univ Sch Commun & Elect Engn Qiqihar Peoples R China Minist Publ Secur Key Lab Police Wireless Digital Commun Harbin Peoples R China

ISBN: (纸本)9781479980888

In Wireless Local Area Network (WLAN) positioning system, the most popular solution for RSS-based positioning is the fingerprinting architecture. In this paper, we present a novel algorithm, known as Semi-supervised Discriminant Embedding (SDE), to reconstruct a radio map by using real-time signal-strength values received at random points. Instead of deploying dense reference points, our approach takes advantage of less labeled data and partial unlabeled data to transform into lower-dimensional feature signals. Through solving the objective functions optimization, with strong discriminative features in Receive Signal Strength (RSS) are retained in the low-dimensional space. We conducted experiments in our office area with a realistic WLAN environment. Compared to the traditional methods, the experimental results show that the proposed algorithm has considerable accuracy improvement in the same positioning environment. Furthermore, the results also show the size of training samples can be greatly reduced in the proposed algorithm in order to achieve the similar accuracy of traditional approaches. That is, the cost of collecting fingerprints in the offline stage and calibrating database in the online stage are thus reduced.

关键词： Wireless local area network (WLAN) Fingerprinting Semi-supervised discriminant embedding (SDE) Dimensional reduction positioning algorithm

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Research on Location Fingerprint Based WiFi positioning algorithm

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电脑学刊 2017年第5期28卷 162-177页

作者： Maoyuan Huang Shaobo Wu Yinglei Li

Existing WiFi signals are utilized to carry out indoor positioning, and received signal strength RSSI is usually selected as a positioning feature parameter. An RSSI positioning algorithm is divided into a range-based positioning algorithm and a range-free positioning algorithm. The range-based positioning algorithm calculates a distance by utilizing an indoor transmission loss model and is lager in dependency on an indoor model; and the range-free positioning algorithm adopts a location fingerprint algorithm, a fingerprint database is established by only needing to measure RSSI values, each fingerprint is in only correspondence to one location information, information of an unknown location can be estimated by matching the unknown location fingerprint and the fingerprint database, and realization is simple. This article studies the positioning principle of the location fingerprint algorithm, indicates influence factors which may generate errors in the positioning process, comprehensively and deeply analyzes sources of the errors and also indicates the limitation of the existing location estimation algorithm. This article presents a k-means and WKNN based location fingerprint algorithm. According to the location fingerprint algorithm, the fingerprint database is preliminarily established by measuring collected RSSI values for many times and solving a mean and then is trained by utilizing k-means clustering analysis, and some fingerprints with very small similarity are removed; and actually measured fingerprints are matched with the fingerprint database after being trained, so that the accuracy of the fingerprint database is improved, the search space of matching is reduced, and the influence of the fingerprint database on a positioning result is reduced. In the location estimation stage, a new weight coefficient calculation method is introduced, the location accuracy of WKNN is improved.

关键词： clustering fingerprint k-means positioning algorithm RSSI WiFi WKNN WLAN

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Two-point magnetic field positioning algorithm based on rotating magnetic dipole

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MEASUREMENT 2021年 174卷 109059-109059页

作者： Lin, Pengfei Zhang, Ning Lin, Chunsheng Chang, Ming Xu, Lei Naval Univ Engn Coll Weaponry Engn Wuhan 430033 Peoples R China

The detection and localization of magnetic targets based on magnetic field signals have become a research hotspot in recent years. In this study, a magnetic field model is established for the rotating propeller, which is regarded as a magnetic dipole. Moreover, a positioning algorithm of two-point shaft-rate magnetic field is proposed according to the rotating magnetic dipole. In addition, the positioning accuracy of the algorithm and the influence of some factors such as uneven magnetic distribution of magnetic dipole and measurement noise on the accuracy are analyzed. The simulation results indicate that the positioning accuracy increases with the increase in the circular trajectory radius of magnetic moment when there is an uneven magnetic distribution. The error caused by measurement noise increases with the increase in the distance between the measurement point and magnetic dipole source. Finally, the feasibility of the algorithm is verified through experiments.

关键词： Rotating magnetic dipole positioning algorithm Magnetic field

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A Fine-Tuned positioning algorithm for Space-Borne GNSS Timing Receivers

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SENSORS 2020年第8期20卷 2327-2327页

作者： Chen, Xi Wei, QiHui Zhan, YaFeng Ma, TianYi Tsinghua Univ Natl Res Inst Informat Sci & Technol Beijing 100084 Peoples R China Tsinghua Univ Dept Elect Engn Beijing 100084 Peoples R China

To maximize the usage of limited transmission power and wireless spectrum, more communication satellites are adopting precise space-ground beam-forming, which poses a rigorous positioning and timing requirement of the satellite. To fulfill this requirement, a space-borne global navigation satellite system (GNSS) timing receiver with a disciplined high-performance clock is preferable. The space-borne GNSS timing receiver moves with the satellite, in contrast to its stationary counterpart on ground, making it tricky in its positioning algorithm design. Despite abundant existing positioning algorithms, there is a lack of dedicated work that systematically describes the delicate aspects of a space-borne GNSS timing receiver. Based on the experimental work of the LING QIAO (NORAD ID:40136) communication satellite's GNSS receiver, we propose a fine-tuned positioning algorithm for space-borne GNSS timing receivers. Specifically, the proposed algorithm includes: (1) a filtering architecture that separates the estimation of satellite position and velocity from other unknowns, which allows for a first estimation of satellite position and velocity incorporating any variation of orbit dynamics;(2) a two-threshold robust cubature Kalman filter to counteract the adverse influence of measurement outliers on positioning quality;(3) Reynolds averaging inspired clock and frequency error estimation. Hardware emulation test results show that the proposed algorithm has a performance with a 3D positioning RMS error of 1.2 m, 3D velocity RMS error of 0.02 m/s and a pulse per second (PPS) RMS error of 11.8ns. Simulations with MATLAB show that it can effectively detect and dispose outliers, and further on outperforms other algorithms in comparison.

关键词： GNSS timing receiver space-borne positioning algorithm LING QIAO

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Impact of event positioning algorithm on performance of a whole-body PET scanner using one-to-one coupled detectors

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PHYSICS IN MEDICINE AND BIOLOGY 2018年第5期63卷 055008-055008页

作者： Surti, S. Karp, J. S. Univ Penn Dept Radiol Philadelphia PA 19104 USA Univ Penn Dept Phys & Astron Philadelphia PA 19104 USA

The advent of silicon photomultipliers (SiPMs) has introduced the possibility of increased detector performance in commercial whole-body PET scanners. The primary advantage of these photodetectors is the ability to couple a single SiPM channel directly to a single pixel of PET scintillator that is typically 4 mm wide (one-to-one coupled detector design). We performed simulation studies to evaluate the impact of three different event positioning algorithms in such detectors: (i) a weighted energy centroid positioning (Anger logic), (ii) identifying the crystal with maximum energy deposition (1st max crystal), and (iii) identifying the crystal with the second highest energy deposition (2nd max crystal). Detector simulations performed with LSO crystals indicate reduced positioning errors when using the 2nd max crystal positioning algorithm. These studies are performed over a range of crystal cross-sections varying from 1 x 1 mm2 to 4 x 4 mm(2) as well as crystal thickness of 1 cm to 3 cm. System simulations were performed for a whole-body PET scanner (85 cm ring diameter) with a long axial FOV (70 cm long) and show an improvement in reconstructed spatial resolution for a point source when using the 2nd max crystal positioning algorithm. Finally, we observe a 30-40% gain in contrast recovery coefficient values for 1 and 0.5 cm diameter spheres when using the 2nd max crystal positioning algorithm compared to the 1st max crystal positioning algorithm. These results show that there is an advantage to implementing the 2nd max crystal positioning algorithm in a new generation of PET scanners using one-to-one coupled detector design with lutetium based crystals, including LSO, LYSO or scintillators that have similar density and effective atomic number as LSO.

关键词： PET positioning algorithm spatial resolution contrast one-to-one coupled detector

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Enhanced positioning algorithm of ARPS for Improving Accuracy and Expanding Service Coverage

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SENSORS 2016年第8期16卷 1284-1284页

作者： Lee, Kyuman Baek, Hoki Lim, Jaesung Ajou Univ Dept Comp Engn 206 World Cup Ro Suwon 16499 South Korea Ajou Univ Dept Mil Digital Convergence 206 World Cup Ro Suwon 16499 South Korea

The airborne relay-based positioning system (ARPS), which employs the relaying of navigation signals, was proposed as an alternative positioning system. However, the ARPS has limitations, such as relatively large vertical error and service restrictions, because firstly, the user position is estimated based on airborne relays that are located in one direction, and secondly, the positioning is processed using only relayed navigation signals. In this paper, we propose an enhanced positioning algorithm to improve the performance of the ARPS. The main idea of the enhanced algorithm is the adaptable use of either virtual or direct measurements of reference stations in the calculation process based on the structural features of the ARPS. Unlike the existing two-step algorithm for airborne relay and user positioning, the enhanced algorithm is divided into two cases based on whether the required number of navigation signals for user positioning is met. In the first case, where the number of signals is greater than four, the user first estimates the positions of the airborne relays and its own initial position. Then, the user position is re-estimated by integrating a virtual measurement of a reference station that is calculated using the initial estimated user position and known reference positions. To prevent performance degradation, the re-estimation is performed after determining its requirement through comparing the expected position errors. If the navigation signals are insufficient, such as when the user is outside of airborne relay coverage, the user position is estimated by additionally using direct signal measurements of the reference stations in place of absent relayed signals. The simulation results demonstrate that a higher accuracy level can be achieved because the user position is estimated based on the measurements of airborne relays and a ground station. Furthermore, the service coverage is expanded by using direct measurements of reference stations for user p

关键词： accuracy enhancement re-estimation positioning algorithm virtual measurement dilution of precision

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