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Electrical double-layer capacitors diagnosis using least square estimation method

ELECTRIC POWER SYSTEMS RESEARCH 2014年第Dec.期117卷 69-75页

作者： Oukaour, A. Omar, N. Gualous, H. Rachid, A. Van den Bossche, P. Van Mierlo, J. Univ Caen Basse Normandie EA 4253 F-50130 Octeville France Vrije Univ Brussel B-1050 Brussels Belgium Univ Picardie Jules Vernes F-80000 Amiens France

This paper deals with the electrical double-layer capacitor's (EDLC) aging diagnosis for electric and hybrid vehicles. It has been shown in the literature that the aging of EDLCs is related to the constraints undergone by the component such as EDLC voltage (V-sc) combined with the operating temperature. The results of several studies show that the best indicators of the EDLCs aging are the capacitance and the equivalent series resistance. Some experimental methods allow the identification of these parameters but they are time consuming and cannot be embedded. This study presents a new method to estimate the EDLC parameters using least square algorithm based on data measurements of input/output of the system. In order to perform the aging test, a test bench is developed. EDLCs are aged at constant temperature and constant voltage. They are placed inside a climatic chamber at 70 degrees C and polarized at 2.9 V during the aging process. To quantify the EDLC aging, the equivalent series resistance and the equivalent capacitance are measured. (C) 2014 Elsevier B.V. All rights reserved.

关键词： EDLC aging EDLC diagnosis EDLC parameters estimation EDLC modeling least square algorithm Runge-Kutta algorithm

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ARMAX Time Delay Systems Identification Based on least square Approach

ARMAX Time Delay Systems Identification Based on Least Squar...

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17th IFAC Symposium on System Identification (SYSID 2015)

作者： Bedoui, Saida Abderrahim, Kamel Gabes Univ Natl Engn Sch Gabes Res Unit Numer Control Ind Proc Route MedenineBP 6029 Gabes Tunisia

In this paper, an algorithm is developed for the identification of the time delay parameter and the dynamic parameters of autoregressive moving average with exogenous input ARMAX time delay models. This algorithm consists in constructing a linear-parameter formulation by building a generalized vector observation and using the recursive least squares approach to solve the obtained system. Simulation and experimental test results are presented to illustrate the performance of the proposed approach. (C) 2015, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.

关键词： Time Delay Systems System Identification Discrete-time least square algorithm

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Polarization Tracking in the Presence of PDL and Fast Temporal Drift

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JOURNAL OF LIGHTWAVE TECHNOLOGY 2022年第19期40卷 6408-6416页

作者： Farsi, Mohammad Hager, Christian Karlsson, Magnus Agrell, Erik Chalmers Univ Technol Dept Elect Engn SE-41296 Gothenburg Sweden Chalmers Univ Technol Dept Microtechnol & Nanosci SE-41296 Gothenburg Sweden

In this paper, we analyze the effectiveness of polarization tracking algorithms in optical transmission systems suffering from fast state of polarization (SOP) rotations and polarization-dependent loss (PDL). While most of the gradient descent (GD)-based algorithms in the literature may require step size adjustment when the channel condition changes, we propose tracking algorithms that can perform similarly or better without parameter tuning. Numerical simulation results show higher robustness of the proposed algorithms to SOP and PDL drift compared to GD-based algorithms, making them promising candidates to be used in aerial fiber links where the SOP can potentially drift rapidly, and therefore becomes challenging to track.

关键词： Signal processing algorithms Channel estimation Symbols Optical fiber dispersion Optical polarization Optical fiber amplifiers Optical fiber couplers Constant modulus algorithm hybrid algorithm least square algorithm polarization-dependent loss polarization tracking state of polarization

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A Numerical Method to Enhance the Accuracy of Mass-Spring Systems for Modeling Soft Tissue Deformations

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JOURNAL OF APPLIED BIOMECHANICS 2009年第3期25卷 271-278页

作者： Mohammadi, Hadi Univ Western Ontario Biomed Engn Grad Program London ON Canada

This technical note presents a numerical corrective technique that allows control of nonlinearity in a mass-spring system (MSS) independent of its spring constants or system topology. The governing equations of MSS in the form of ordinary differential equations or a regular function accompanied by any boundary or initial condition as known constraints, are employed to modify the results. A least-squares algorithm coupled with the finite difference method is used to discretize the basic residual function implemented in this corrective technique. This numerical solution is applicable to both static and dynamic MSS. This technique is easy to implement and has accuracy similar to that of the equivalent finite element method (FEM) solution to the same system whereas solutions are obtained in a fraction of the CPU time. The proposed technique can also be used to smooth solutions from other methods such as FEM or boundary element method (BEM).

关键词： mass-spring system finite difference method least square algorithm finite element method soft tissue mechanics

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A New and Fast Method for On-line Estimation of d and q Axes Inductances of Interior Permanent Magnet Synchronous Machines Using Measurements of Current Derivatives and Inverter DC-Bus Voltage

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IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS 2019年第10期66卷 7488-7497页

作者： Bui, Minh Xuan Rahman, M. Faz Guan, Deqi Xiao, Dan Univ New South Wales Sch Elect Engn & Telecommun Sydney NSW 2052 Australia

This paper proposes a novel on-line technique for estimation of the inductances of an interior permanent magnet synchronous machine (IPMSM) based on the measurement of dc-bus voltage of the inverter and the stator current derivatives at certain voltage vectors during each pulsewidth modulation (PWM) cycle. This technique removes the requirement for the bulky and expensive shaft-locking mechanisms and test signal injection for obtaining the machine dq inductance parameters off line. It also overcomes the problems associated with other recursive on-line techniques which take a number of PWM cycles to update the parameters. The proposed method estimates the d and q axes inductances of IPMSMs within each PWM cycle without requiring knowledge of stator resistance, rotor flux linkage, and rotor speed. It also tracks the variations of the inductances (especially the q-axis inductance), which vary significantly due to q-axis magnetic saturation and cross saturation effect of the IPMSM, with sufficient accuracy. This paper presents full analysis, system simulation, and extensive experimental studies in order to verify the accuracy, quick tracking ability, and robustness of the proposed method.

关键词： Current derivative measurement interior permanent magnet synchronous machine (IPMSM) least square algorithm on-line inductance estimation SVPWM

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One-to-one non-linear transformation for RSS-based localization with unknown transmit power

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IET COMMUNICATIONS 2021年第4期15卷 627-641页

作者： Danaee, Meysam Raees Imam Hussein Comprehens Univ Elect Engn Dept 3rd Floor 303 Tehran Iran

For most of the positioning algorithms, based on the received signal strength, the objective function of the estimator is linearized so that the conventional least square algorithm can be executed. This would necessitate using a data model containing many noisy elements which implicitly violates the least squares assumptions. To avoid this violation, an optimized data modelling would have to be set up as shown in this paper. The authors then trivially provide the solution of this new least square problem which is still a primary coarse position estimation because of ignoring the non-linear relationships existing among parameters of the estimation. To extract quantitative information from these non-linear relationships, the authors also propose two new signal space points for using Taylor-series expansion as effectively as possible in accordance of the new data model. The proposed algorithms work without any knowledge about the transmit power. The performance evaluation of the proposed idea indicates that the new suggested estimators perform significantly better than the other existing linear position estimators for a large range of noise variance and path-loss exponent values.

关键词： WSN Taylor-series expansion RSS-based localization sensor placement Optimisation techniques Signal processing and detection Wireless sensor networks optimized data modelling signal space points least square algorithm primary coarse position estimation least squares approximations positioning algorithms one-to-one nonlinear transformation wireless sensor networks Interpolation and function approximation (numerical analysis) objective function linear position estimators signal processing nonlinear relationships least square problem received signal strength

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Multiparameter Estimation of IPMSMs Using Core Loss Current Calculations in dq-Axis Equivalent Circuit Model

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IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS 2023年第2期59卷 1295-1306页

作者： Cheng, Hongfu Toulabi, Mohammad Sedigh Deshpande, Uday Kar, Narayan C. Univ Windsor Windsor ON N9B 3P4 Canada D&V Elect Ltd Toronto ON L4H 2Y7 Canada

Accurate parameter estimation is critical for high-performance modeling and control of interior permanent magnet synchronous machines (IPMSMs). Core loss effects affect the accuracy of the parameter estimation, especially in high loading conditions with saturated cores. Existing research on parameter estimation considering core loss effects generally focuses on the core loss equivalent resistance estimation;however, they require either accurate core loss experimental data or finite element analysis (FEA) model. The core loss equivalent resistance is dependent on the loading conditions, harmonics, frequency, and temperature, which increases the difficulty of accurately estimating the resistance. This article firstly proposes a direct core loss equivalent current estimation method for multiparameter estimation purposes without estimating the core loss equivalent resistance. Based on the estimated core loss equivalent currents, the dq-axis inductances equivalent currents are calculated to perform the multiparameter estimation. The proposed approach can improve the precision of the parameter estimation and the computation efficiency by calculating the core loss equivalent resistance currents without having the core loss data. The effectiveness of the proposed multiparameter estimation method is evaluated by comparing the calculated and measured torques of a laboratory 4.5 kW IPMSM in various operating conditions. The improved accuracy of the proposed method is verified by comparing it with two existing online parameter estimation methods and FEA-based offline parameter estimation results.

关键词： Core loss decoupled parameter estimation least square algorithm magnetic saturation VSI nonlinearity

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Ultrasonic Distance Measurement Method by Using the Envelope Model of Received Signal Based on System Dynamic Model of Ultrasonic Transducers

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JOURNAL OF ELECTRICAL ENGINEERING & TECHNOLOGY 2018年第2期13卷 981-988页

作者： Choe, Jin-Hee Lee, Kook-Sun Choy, Ick Cho, Whang Kwangwoon Univ Sch Robot Seoul South Korea SNUT Dept Elect & Informat Engn Seoul South Korea

In order to acquire an accurate TOF, this paper proposes a method that produces TOF by using a mathematical model for the envelope of the received signal obtained from a system dynamic model of ultrasonic transducer. The proposed method estimates the arrival time of the received signal retrospectively by comparing its wave form obtained after triggering point with its mathematical envelope model. Experimental result shows that the error due to variation of triggering point can be dramatically decreased by implementing the proposed method.

关键词： Envelope model least square algorithm System dynamic model of ultrasonic transducer Time of flight Ultrasonic distance measurement

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Damage Identification in a Plate Structure Based on Strain Statistical Moment

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ADVANCES IN STRUCTURAL ENGINEERING 2014年第11期17卷 1639-1655页

作者： Xiang, Wei Wang, Dansheng Zhu, Hongping Huazhong Univ Sci & Technol Sch Civil Engn & Mech Wuhan 430074 Peoples R China

The fourth strain statistical moment (FSSM) based damage detection method has been recently proposed by the authors and the results of numerical study demonstrated the proposed method is sensitive to local structural damage but insensitive to measurement noise for beam-type structure. In this paper, the method is extended to a plate structure. The method consists of two steps: damage localization and damage quantification. First, the damage is located by using the difference curved surfaces of FSSMs in one direction of a plate subjected to Gauss White Noise (GWN) excitation before and after damage. Then the model updating method based on least square algorithm is used to estimate the damage severities. Also, the numerical (finite element) simulations are carried out for a simply supported plate. The results demonstrate the proposed method can provide good prediction of both location and severity of damage at one or more sites, even under low damage severities and high measurement noise conditions.

关键词： damage identification fourth strain statistical moment (FSSM) finite element method thin plate least square algorithm

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Application of antenna arrays to mobile communications .2. Beam-forming and direction-of-arrival considerations

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PROCEEDINGS OF THE IEEE 1997年第8期85卷 1195-1245页

作者： Godara, LC School of Electrical Engineering Australian Defence Force Academy University of New South Wales Canberra ACT Australia

Array processing involves manipulation of signals induced on various antenna elements. Its capabilities of steering nulls to reduce cochannel interferences and pointing independent beams toward various mobiles, as well as its ability to provide estimates of directions of radiating sources, make it attractive to a mobile communications system designer. Array processing is expected to play an important role in fulfilling the increased demands of various mobile communications services. Part I of this paper showed how an array could be utilized in different configurations to improve the performance of mobile communications systems, with references to various studies where feasibility of an array system for mobile communications is considered. This paper provides a comprehensive and detailed treatment of different beam-forming schemes, adaptive algorithms tl? adjust the required weighting on antennas, direction-of-arrival estimation methods-including their performance comparison-and effects of errors on the performance of an array system, as well as schemes to alleviate them. This paper brings together almost all aspects of array signal processing. It is presented at a level appropriate to nonexperts in the field and contains a large reference list to probe further.

关键词： beam forming conjugate gradient method eigenstructure methods ESPRIT least square algorithm linear prediction method maximum entropy maximum likelihood method minimum norm mobile communications multipath arrivals MU-SIC MVDR estimator neural networks recursive least square algorithm weighted subspace fitting

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