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Topology optimisation-based distributed estimation in relay assisted wireless sensor networks

IET CONTROL THEORY AND APPLICATIONS 2014年第18期8卷 2219-2228页

作者： Yan, Jing Chen, Cailian Luo, Xiaoyuan Liang, Hao Guan, Xinping Yang, Xian Yanshan Univ Inst Elect Engn Qinhuangdao 066004 Peoples R China Shanghai Jiao Tong Univ Dept Automat Key Lab Syst Control & Informat Proc Minist Educ China Shanghai 200240 Peoples R China Univ Waterloo Dept Elect & Comp Engn Waterloo ON N2L 3G1 Canada

This study studies a distributed estimation problem in relay assisted wireless sensor networks (WSNs). Different from most existing works, the network consists of two kinds of nodes, that is, sensor nodes (SNs) which is capable of sensing and computing and relay nodes (RNs), which is only capable of simple data aggregation. The problem of how to coordinate two kinds of nodes to facilitate distributed estimation is challenging because of their heterogeneous capability. The authors first develop a min-weighted rigid graph-based topology optimisation scheme to reduce the redundancy of communication links such that the energy consumption in the relay assisted WSN can be reduced. With the optimised topology, a consensus-based estimation algorithm is proposed for SNs and RNs, respectively. The asymptotic unbiasedness and consistency of the estimation algorithm are analysed in the presence of measurement and communication noises. The proposed method is applied to estimate the distribution of slab temperature in the hot rolling process. It is demonstrated that the topology optimisation reduces communication energy consumption, while the deployment of RNs improves temperature estimation accuracy as compared to a homogeneous WSN with SNs only.

关键词： wireless sensor networks relay networks (telecommunication) telecommunication network topology distributed estimation relay assisted wireless sensor networks WSN sensor nodes relay nodes data aggregation graph-based topology optimisation scheme communication links energy consumption estimation algorithm

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Hough transform-based large micro-motion target detection and estimation in synthetic aperture radar

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IET RADAR SONAR AND NAVIGATION 2019年第4期13卷 558-565页

作者： Zhou, Yang Bi, Daping Shen, Aiguo Wang, Xiaoping Natl Univ Def Technol Coll Elect Engn Lab 202 Hefei Anhui Peoples R China

Target vibration or rotation produces special phase modulation of synthetic aperture radar azimuth echo signals, referred to as the micro-Doppler effect, which can provide favourable information for target detection and recognition. However, the pulse repetition frequency will be lower than the azimuth bandwidth of azimuth echo signal when the micro-motion amplitude is too large, resulting in spectral aliasing, which invalidates the conventional detection and estimation algorithm. This study proposes a new target detection and estimation algorithm for large micro-motion targets. First, the authors perform time-frequency (TF) transform on the azimuth echo signals of micro-motion targets. Then extract the TF curves in the TF distribution. After modifying the analytical expression of large micro-motion target TF curves, the target detection and parameter estimation are realised by Hough transform. The algorithm proposed in this study is applicable to the detection of both large and small micro-motion targets. It is capable of detecting multiple micro-motion targets in a single range cell simultaneously and is featured with high parameter estimation precision even if there is strong noise. Simulation results and field experimental data prove the effectiveness of the proposed algorithm and its superiority compared with the inverse radon transform algorithm.

关键词： time-frequency analysis synthetic aperture radar Hough transforms Doppler radar radar signal processing radar resolution object detection Doppler effect Radon transforms parameter estimation radar imaging micromotion target detection synthetic aperture radar rotation microDoppler effect azimuth echo signal micromotion amplitude estimation algorithm micromotion target TF

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On Rate Requirements for Achieving the Centralized Performance in Distributed estimation

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IEEE TRANSACTIONS ON SIGNAL PROCESSING 2017年第8期65卷 2020-2032页

作者： El Gamal, Mostafa Lai, Lifeng Worcester Polytech Inst Dept Elect & Comp Engn Worcester MA 01609 USA Univ Calif Davis Dept Elect & Comp Engn Davis CA 95616 USA

We consider a distributed parameter estimation problem, in which multiple terminals send messages related to their local observations using limited rates to a fusion center which obtains an estimate of a parameter related to the observations of all terminals. It is well known that if the transmission rates are in the Slepian-Wolf region, the fusion center can fully recover all observations and hence can construct an estimator having the same performance as that of the centralized case. One natural question is whether Slepian-Wolf rates are necessary to achieve the same estimation performance as that of the centralized case. In this paper, we show that the answer to this question is negative. We establish our result by explicitly constructing an asymptotically minimum variance unbiased estimator that has the same performance as that of the optimal estimator in the centralized case while using information rates less than the conditions required in the Slepian-Wolf rate region. The key idea is that, instead of aiming to recover the observations at the fusion center, we design universal schemes enabling the fusion center to compute a sufficient statistic using rates outside of the Selpian-Wolf region.

关键词： Distributed learning MVUE estimation algorithm Slepian-Wolf rates universal encoding/decoding scheme

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estimation-based ILC applied to a parallel kinematic robot

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CONTROL ENGINEERING PRACTICE 2014年 33卷 1-9页

作者： Axehill, Johanna Wallen Dressler, Isolde Gunnarsson, Svante Robertsson, Anders Norrlof, Mikael Saab Aeronaut SE-58188 Linkoping Sweden Linkoping Univ Dept Elect Engn Div Automat Control SE-58183 Linkoping Sweden Lund Univ Dept Automat Control SE-22100 Lund Sweden ABB Robot SE-72168 Vasteras Sweden

estimation-based iterative learning control (ILC) is applied to a parallel kinematic manipulator known as the Gantry-Tau parallel robot. The system represents a control problem where measurements of the controlled variables are not available. The main idea is to use estimates of the controlled variables in the ILC algorithm, and in the paper this approach is evaluated experimentally on the Gantry-Tau robot. The experimental results show that an ILC algorithm using estimates of the tool position gives a considerable improvement of the control performance. The tool position estimate is obtained by fusing measurements of the actuator angular positions with measurements of the tool path acceleration using a complementary filter. (C) 2014 Elsevier Ltd. All rights reserved.

关键词： Iterative methods Learning control Robotic manipulator estimation algorithm Performance evaluation

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Design, modelling and estimation of a novel modular multi-speed transmission system for electric vehicles

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MECHATRONICS 2017年 45卷 119-129页

作者： Roozegar, M. Setiawan, Y. D. Angeles, J. McGill Univ Dept Mech Engn Ctr Intelligent Machines CIM Montreal PQ Canada

The efficiency of electric vehicles (EVs) should be improved to make them viable, especially in light of the current low energy-storage capacity of electric batteries. Research demonstrates that applying a multi speed transmission (MST) in an EV can reduce the energy consumption of the vehicle through gear shifting. However, for effective gear-shifting control in MSTs, first of all, the model of the transmission is required. Moreover, reliable methods should be employed for estimation of the unmeasurable loads and states of the system, under model-based control. This study establishes the mathematical model and estimation algorithms for a novel MST designed for EVs. The main advantages of the designed MST are simplicity and modularity. After devising the dynamics of our proposed transmission, the Kalman filter, the Luenberger obsever and neural networks (NNs) are used to estimate the states, the unknown arbitrary disturbance and the unknown clutch torque applied to the system. Simulation results demonstrate that the proposed approach is suitable for estimation purposes. Experiments were conducted using an in-house prototyped transmission testbed, to validate the simulation results and assess the estimation algorithms. (C) 2017 Elsevier Ltd. All rights reserved.

关键词： Multi-speed transmission design estimation algorithm Kalman filter Neural networks Mathematical modelling Electric vehicle

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Fault-Decoupled Instantaneous Frequency and Phase Angle estimation for Three-Phase Grid-Connected Inverters

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IEEE TRANSACTIONS ON POWER ELECTRONICS 2016年第4期31卷 2880-2889页

作者： De Donato, G. Scelba, G. Borocci, G. Capponi, F. Giulii Scarcella, G. Univ Roma La Sapienza Dept Astronaut Elect & Energet Engn I-00184 Rome Italy Univ Catania Dept Elect Elect & Comp Engn I-95127 Catania Italy

Frequency and phase angle estimation is a key aspect for grid-connected inverters that are required to guarantee low-voltage fault-ride-through capability. Over the past two decades, a number of estimation algorithms have been proposed, mostly based on the well-known phase-locked loop (PLL). It has been demonstrated that standard PLLs do not perform correctly in abnormal grid conditions, due to the oscillations produced in the frequency and phase angle estimates by the voltage harmonics. This paper introduces a new, general approach to harmonic decoupling and presents a highly intuitive and simple scheme, applying it to an alpha beta-PLL;compensation of any desired number of harmonic components is possible. Two implementations of this decoupling scheme are presented. It is shown that the performances of the resulting fault-decoupled PLLs are comparable with those of other advanced frequency and phase angle estimation structures.

关键词： estimation algorithm fault ride through frequency grid connection harmonics phase angle phase-locked loop (PLL)

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Attitude estimation Using Inertial and Magnetic Sensors Based on Hybrid Four-Parameter Complementary Filter

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IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT 2020年第7期69卷 5149-5156页

作者： Suh, Young Soo Univ Ulsan Dept Elect Engn Ulsan 44610 South Korea

A complementary filter is presented for the attitude estimation using inertial and magnetic sensors. The proposed filter is based on a new attitude representation, where 4-D parameters (a 3-D unit vector and one angle quantity) are used. The proposed representation has an intuitive interpretation and the proposed filter has a separation property (magnetic disturbance does not affect pitch and roll angle estimation). Kinematics of the 4-D parameters and other properties are investigated. The proposed filter is verified through simulation and experiments.

关键词： estimation Magnetic sensors Quaternions Magnetic separation Accelerometers Kinematics Attitude estimation complementary filter estimation algorithm inertial sensors orientation

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Blind estimation of pseudo-random codes in periodic long code direct sequence spread spectrum signals

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IET COMMUNICATIONS 2016年第11期10卷 1273-1281页

作者： Gu, Xiaowei Zhao, Zhijin Shen, Lei Hangzhou Dianzi Univ Sch Commun Engn Hangzhou 310018 Zhejiang Peoples R China

An estimation method of pseudo-random (PN) codes in the periodic long code direct sequence spread spectrum signals using a pair of spreading code and scrambling code [i.e. long scrambling code direct sequence spread spectrum (LSC-DSSS)] is investigated in this study. Via the investigation of properties of triple correlation function (TCF) of m-sequences, the existence of common peaks in the TCFs of different m-sequences is proved, and the corresponding relationship between common peaks and primitive polynomials is further investigated. Four theorems are proposed as supplements of triple correlation theory and a novel estimation algorithm of the PN codes in LSC-DSSS signals is put forward on the basis of the theorems. With certain carrier frequency and chip rate of spreading code, this algorithm first eliminates the influence of information codes through delay-and-multiply operation. Then the TCF of signal is calculated, and the two PN codes in signal are successfully estimated finally by searching and using the common peak coordinates in the TCF. Simulation results show that the proposed algorithm exhibits excellent performance in estimating PN codes in LSC-DSSS signals.

关键词： code division multiple access spread spectrum communication correlation theory random codes m-sequences polynomials estimation theory blind estimation pseudorandom code periodic long code direct sequence spread spectrum signal estimation method PN code periodic long code direct sequence spread spectrum signals spreading code scrambling code LSC-DSSS signal triple correlation function TCF m-sequences primitive polynomial triple correlation theory estimation algorithm carrier frequency spreading code chip rate information code delay-and-multiply operation

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algorithms and Schemes for Chlorophyll a estimation by Remote Sensing and Optical Classification for Turbid Lake Taihu, China

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IEEE JOURNAL OF SELECTED TOPICS IN APPLIED EARTH OBSERVATIONS AND REMOTE SENSING 2015年第1期8卷 350-364页

作者： Zhang, Fangfang Li, Junsheng Shen, Qian Zhang, Bing Wu, Chuanqing Wu, Yuanfeng Wang, Ganlin Wang, Shenglei Lu, Zhaoyi Chinese Acad Sci Inst Remote Sensing & Digital Earth Key Lab Digital Earth Sci Beijing 100094 Peoples R China Minist Environm Protect Satellite Environm Applicat Ctr Beijing 100029 Peoples R China

Monitoring chlorophyll a (CHLA) by remote sensing is particularly challenging for turbid productive waters. Although several empirical and semianalytical algorithms have been developed for such waters, their accuracy varies significantly due to variability in optical properties. In this paper, we evaluated the performance of six CHLA concentration (C-chla) estimation algorithms [e. g., two-band ratio algorithm (TBR), normalized difference chlorophyll index (NDCI), synthetic chlorophyll index (SCI), three-band algorithm (TBS), four-band algorithm (FBS), and improved four-band algorithm (IOC3M)] for a highly turbid lake based on remote sensing reflectance classification. Remote sensing reflectance was classified using the iterative k-mean clustering method. We also developed four estimation schemes (S1-S4) for the six algorithms to assess the effect of the estimation scheme on the accuracy of the algorithms. The estimation schemes were developed based on classification methods (no, soft, or hard classification) and the optimization bands used. The six algorithms performed differently for different remote sensing reflectance classes and different estimation schemes. The optimal algorithms for Classes 1, 2, and 3 were TBS, NDCI, and TBR, respectively. For the four estimation schemes, TBS and NDCI outperformed the other four algorithms. The accuracy of TBS and NDCI was higher than FBS, IOC3M, TBR, and SCI. The accuracy of all six algorithms was improved by remote sensing reflectance classification, particularly for Classes 2 and 3. Soft classification with recalibration of the bands for each class outperformed hard classification for all the three classes.

关键词： Chlorophyll a (CHLA) estimation algorithm Lake Taihu optical classification remote sensing

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Unambiguous velocity estimation method based on intra-pulse cross-correlation

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IET RADAR SONAR AND NAVIGATION 2020年第6期14卷 879-886页

作者： Zhang, Yunjian Pan, Pingping Fu, Maozhong Deng, Zhenmiao Zhang, Yixiong Liu, Hui Sun Yat Sen Univ Sch Elect & Commun Engn 135 Xingang Xi Rd Guangzhou Peoples R China Xiamen Univ Sch Informat 422 Siming South Rd Xiamen Peoples R China

In this study, by employing the intra-pulse cross-correlation (IPCC) operation, an unambiguous velocity estimation method is proposed for narrow-band long-range radars with high carrier frequency and low pulse repetition frequency. This estimation algorithm is simple and could be easily implemented in existing radar systems without changing the radar hardware or the pulse transmitting scheme. Comparing with the slow time dimension correlation algorithm, the accuracy of the proposed intra-pulse frequency domain method is greatly improved, and the brute-force search for the unknown motion parameters is also unnecessary. By first setting a small frequency offset of the IPCC operation, the unambiguous velocity region could be significantly enlarged. Using the relatively coarse but unambiguous estimates and increasing the frequency offset step by step, the IPCC is repeatedly applied to obtain more accurate estimates. Note that the estimation results of the IPCC algorithm could be used in the maximum-likelihood estimator for ambiguity resolution. The Cramer-Rao bound for the proposed algorithm is derived, and the optimal frequency offset in the sense of estimation accuracy is also analysed. Through numerical simulations for both synthetic and real radar data, the effectiveness of the proposed estimation algorithm is verified.

关键词： correlation methods maximum likelihood estimation frequency-domain analysis radar signal processing search problems unambiguous velocity region IPCC algorithm maximum-likelihood estimator estimation accuracy estimation algorithm unambiguous velocity estimation method intra-pulse cross-correlation operation narrow-band long-range radars high carrier frequency low pulse repetition frequency radar systems radar hardware pulse transmitting scheme intra-pulse frequency domain method optimal frequency offset brute-force search motion parameters Cramer-Rao bound

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