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Determination of ship maneuvering hydrodynamic coefficients using system identification technique based on free-running model test

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SCIENTIA IRANICA 2016年第5期23卷 2154-2165页

作者： Hajizadeh, S. Seif, M. S. Mehdigholi, H. Sharif Univ Technol Ctr Excellence Hydrodynam & Dynam Marine Vehicles Dept Mech Engn Tehran Iran

In the recent years, different mathematical models have been suggested for maneuvering of displacement vessels that are capable of estimation of vessel maneuvers with acceptable precision. These mathematical models are based on determined hydrodynamic coefficients and their accuracy depends on the known coefficients used to solve the mathematical model. system identification methods are developed to calculate these coefficients utilizing input and output data obtained from different sources. In this research, a 4.36-m model of KRISO Container Ship (KCS) displacement vessel has been manufactured by fiberglass, and the maneuver turning tests have been carried by self-propulsion method. A 3DM-GX1 sensor, together with a protractor and Global Positioning system (GPS), has been used to measure the yaw and rudder angle, position, linear accelerations, and angular velocities of the vessel in different times. The hydrodynamic coefficients in the mathematical model are determined by the Extended Kalman filter method. Then, the mathematical model is solved and different maneuvers are simulated by coefficients calculated from the experiments. Simulations are validated by model tests. The mathematical model and hydrodynamic coefficients presented in this paper can be applied for optimization of ship maneuvering performance and course control purposes. (C) 2016 Sharif University of Technology. All rights reserved.

关键词： Maneuvering Modeling Displacement hull Hydrodynamic coefficient system identification technique

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Stability Region Assessment With Mechanism-Data Driven Equivalent Impedance for Wind Power Plant

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IEEE TRANSACTIONS ON POWER ELECTRONICS 2024年第8期39卷 9355-9366页

作者： Qin, Shiyao Wang, Peng Li, Shaolin Zhao, Haoran Wang, Jinlong Luo, Jia China Elect Power Res Inst Natl Key Lab Renewable Energy Grid Integrat Beijing 100192 Peoples R China Shandong Univ Sch Elect Engn Jinan 250061 Peoples R China

Online identification of the stability region for the wind power plant (WPP) equipped with permanent magnet synchronous generators encounters two challenges: calculating high-order impedance and estimating the stability boundary of multiple parameters. To address these challenges, the mechanism-data-driven equivalent impedance for each branch of the WPP is developed, and the high-dimensional stability region boundary is established with a machine learning-based algorithm. In mechanism-driven modeling, the aggregated impedance is derived using parallel calculation. In data-driven modeling, different key parameters in wide frequency bands are modified to ensure the accuracy of the equivalent impedance. The equivalent impedance derived through the mechanism-data-driven approach deviates from the detailed impedance within +/- 1%. Regarding the stability region estimation, the fuzzy support vector machine is applied. To improve the speed of the online training of the stability region, the weighted Mahalanobis distance is employed to distinguish the importance of stability index samples. In validation, the stability regions of the power of the WPP are established. The impacts of the static var generator (SVG) on the stability performance are analyzed, and regulating the reactive power of the SVG can enhance small-signal stability. The stability region estimation and enhancement are verified through time-domain simulations and experiments in a controller-hardware-in-loop platform.

关键词： Equivalent impedance machine learning small-signal stability region system identification technique wind power generation

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A CFD Assisted Closed-loop Control system Design for the 37-element Canadian SCWR under Full Load Condition

A CFD Assisted Closed-loop Control System Design for the 37-...

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作者： Huirui Han University of Western Ontario

学位级别：硕士

A method to design the closed-loop control system for the 37-element vertical Canadian supercritical water-cooled reactor (SCWR) fuel bundle has been proposed in this study. The dynamic models used in the controller design are obtained based on the computational fluid dynamics (CFD) simulations of the fluid flow and heat transfer of the supercritical water in the SCWR fuel bundle. The Reynolds Stress Model is used in the CFD simulations. Comparisons of the supercritical water flow behaviors and heat transfer phenomenon in the single- rod channel and multi-rod channel are also carried out. The results show that there are secondary flows in the single rod channel. The maximum cladding surface temperatures in the single rod channel and the multi-rod channel are different. Therefore, the multi-rod channel is used to conduct the numerical simulations of the fluid flow and heat transfer in the Canadian SCWR and the CFD data are used to construct the control system for the SCWR. To construct the dynamic control model, the transient thermo-hydraulic behaviors of the supercritical water in the SCWR fuel bundles are predicted numerically. Step perturbances are used to generate the dynamic responses between the inputs and outputs. The linear dynamic control models are constructed by the system identification technique based on the CFD simulation data. Then, the linear dynamic models are validated by comparing the results with those from full-scale CFD simulations. Based on the linear dynamic models, the control system with two PID controllers is designed to make the SCWR return to the design condition when perturbances occur. The performance evaluation of the proposed control system is carried out by using it in a closed-loop control system for the Canadian SCWR.

关键词： SCWR CFD cladding surface temperature linear dynamic models system identification technique controllers

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Dynamic Characteristics of a New Three-Dimensional Linear Homeomorphic Saccade Model

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INTERNATIONAL JOURNAL OF NEURAL systemS 2018年第3期28卷 1750050页

作者： Zhou, Wei Zhai, Xiu Ghahari, Alireza Korentis, G. Alex Kaputa, David Enderle, John D. Univ Connecticut Dept Biomed Engn 260 Glenbrook Rd Storrs CT 06269 USA

A linear homeomorphic eye movement model that produces 3D saccadic eye movements consistent with anatomical and physiological evidence is introduced in this second part of a two-paper sequence. Central to the model is the implementation of a time-optimal neural control strategy involving six linear muscle models that faithfully represent the dynamic characteristics of 3D saccades. The muscle is modeled as a parallel combination of viscosity B-2 and series elasticity K-se, connected to the parallel combination of active-state tension generator F, viscosity element B-1, and length tension elastic element K-lt. The neural input for each muscle is separately maintained while the effective pulling direction is modulated by its respective pulley. The results demonstrate that a time-optimal, 2D commutative neural controller, together with the pulley system, actively functions to implement Listing's law during both static and dynamic simulations and provide an excellent match with the experimental data. The parameters and neural input to the muscles are estimated using a time domain system identification technique from saccade data, with an excellent match between the model estimates and the data. A total of 20 horizontal, 5 vertical and 62 oblique saccades are analyzed.

关键词： Saccades system identification technique 3D rotational dynamics oculomotor plant Listing's law main sequence diagrams time-optical control

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Pragmatic two-step homogenisation technique for ferromagnetic laminated cores

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IET SCIENCE MEASUREMENT & TECHNOLOGY 2015年第2期9卷 152-159页

作者： Henrotte, Francois Steentjes, Simon Hameyer, Kay Geuzaine, Christophe UCL Inst Mech Mat & Civil Engn B-1348 Louvain La Neuve Belgium Rhein Westfal TH Aachen Inst Elect Machines D-52056 Aachen Germany Univ Liege Inst Montefiore ACE B-4000 Liege Belgium

Electromagnetic fields and eddy currents in thin electrical steel laminations are governed by the laws of magnetodynamics with hysteresis. If the lateral dimension of the laminations is large with respect to their width, the fields and currents generated under arbitrary excitation inside a lamination can be resolved accurately by solving a one-dimensional finite element magnetodynamic problem across half the lamination thickness. This mesoscopic model is able to produce, by averaging the necessary information, a homogenised laminated core model, to be used in the macroscopic modelling of electrical devices involving ferromagnetic lamination stacks. As each evaluation of the homogenised model at the macroscale implies a finite element simulation at the mesoscale, a monolithic implementation of the homogenisation method would be extremely time-consuming. Hence the idea of this study to use system identification techniques to construct an algebraic approximation of the homogenised model, to be used as a conventional constitutive relationship in two- or three-dimensional macroscale simulations. This pragmatic two-step homogenisation approach turns out to be quite accurate and efficient in practice, and it entails no implementation in the FE code, provided the latter offers enough flexibility in the description of the material laws.

关键词： laminations ferromagnetic materials electromagnetic fields finite element analysis approximation theory magnetic cores iron alloys silicon alloys thin film devices eddy current losses ferromagnetism magnetic hysteresis electromagnetic field eddy currents pragmatic two step homogenisation technique ferromagnetic laminated cores 3D macroscale simulation material laws FE code 2D macroscale simulation homogenised model algebraic approximation system identification technique monolithic implementation mesoscale flnite element simulation ferromagnetic lamination stack electrical devices macroscopic modelling homogenised laminated core model mesoscopic model 1D finite element magnetodynamic problem arbitrary excitation hysteresis laws of magnetodynamics thin electrical steel laminations

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Performance guarantees via pole placement for a webserver hosted on a private cloud

Performance guarantees via pole placement for a webserver ho...

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European Control Conference (ECC)

作者： Saikrishna, P. S. Chandrasekar, Addarsh Pasumarthy, Ramkrishna IIT Madras Dept Elect Engn Madras Tamil Nadu India IIT Madras Dept Mech Enginnering Madras Tamil Nadu India

ISBN: (纸本)9783952426937

In this paper we apply pole placement techniques to meet the performance objectives of a web server hosted on a private cloud. The web server is modeled as a switched system with models developed for several well defined operating regions using system identification technique. We then obtain the conditions for placement of exact and regional poles in desired locations using full state feedback to guarentee performance and stability. The experiments are performed on the open source Eucalyptus based cloud setup.

关键词： cloud computing control engineering computing file servers pole assignment public domain software state feedback switching systems (control) Web server full state feedback open source Eucalyptus based cloud setup private cloud regional pole placement techniques switched system system identification technique Asymptotic stability Cloud computing Stability analysis Switches Throughput Time factors Web servers

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Stabilizing Positive Feed-Forward Control Design for a DC Power Distribution system using a Passivity-Based Stability Criterion and system Bus Impedance identification

Stabilizing Positive Feed-Forward Control Design for a DC Po...

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29th Annual IEEE Applied Power Electronics Conference and Exposition (APEC)

作者： Riccobono, Antonino Siegers, Jonathan Santi, Enrico Univ S Carolina Dept Elect Engn Columbia SC 29208 USA

ISBN: (纸本)9781479923250

DC distribution systems consist of several feedback-controlled converters interconnected to form a complex power distribution system. While the analysis and design of a single power converter and its control is well understood, in a DC distribution system the situation is different. Analyzing and designing a complex multi-converter system in such a way as to guarantee both system stability and performance is a complex problem that was not fully solved in the past. Difficulties stem from a lack of adequate analysis and design tools, limited understanding of the problem, difficulties in applying the existing stability criteria, and the need for stabilizing converter controllers. To tackle all these difficulties, this paper presents how two recently proposed tools, i.e. the Passivity-Based Stability Criterion (PBSC) and the Positive Feed-Forward (PFF) control, can be used together with a system identification technique to address system level stability issues in DC distribution systems. In particular, after the frequency-domain measurement of the system bus impedance is taken, a parametric model of the bus impedance can be obtained and used to design a stabilizing PFF control that imposes passivity of the overall bus impedance. If passivity of the overall DC bus impedance is ensured, stability is guaranteed as well. The method is experimentally validated on a system consisting of the cascade of two converters. Two series of results are presented: 1) when we have knowledge of the system model, and 2) when we treat the system as a "black-box".

关键词： control system synthesis frequency-domain analysis power convertors power distribution control power system identification power system interconnection power system stability DC power distribution system PBSC PFF black-box system complex multiconverter system feedback-controlled power converter interconnection frequency-domain measurement parametric model passivity-based stability criterion stabilizing positive feedforward control design system bus impedance system bus impedance identification system identification technique Control systems Impedance Impedance measurement Power distribution Power system stability Stability criteria

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Estimation and Robustness Analysis of Protein Networks for Cell Cycle systems

Estimation and Robustness Analysis of Protein Networks for C...

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IEEE International Conference on Control Applications Part of 2010 IEEE Multi-Conference on systems and Control

作者： Azuma, Takehito Kurata, Masachika Takahashi, Noriko Adachi, Shuichi Utsunomiya Univ Dept Elect & Elect Engn Utsunomiya Tochigi 321 Japan Keio Univ Dept Appl Phys & Physico Informat Tokyo 108 Japan

ISBN: (纸本)9781424453634

This paper proposes an estimation problem of protein networks for cell cycle and their robustness analysis. Our proposed method is explained to estimate a protein network for cell cycle based on system identification techniques. The method is based on the least-squares method for state space models. Applying the method, a 6-dimensional protein network is estimated for cell cycle to demonstrate the efficacy of our proposed method. The estimated protein network is called as 6-dimensional cell cycle system and the cell cycle system is described as nonlinear differential equations. Moreover robustness analysis and numerical simulations are performed for the cell cycle system described as nonlinear differential equations. From these results, robustness of the cell cycle system is discussed.

关键词： 6-dimensional protein network cell cycle systems cellular biophysics least squares approximations least-squares method molecular biophysics nonlinear differential equations nonlinear differential equations protein networks proteins robustness analysis state space model system identification technique

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Gradient algorithm for structural parameter estimation and nonlinear restoring forces

Gradient algorithm for structural parameter estimation and n...

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American Control Conference

作者： Garrido, R Rivero-Angeles, FJ Martinez-Garcia, JC Martinez-Guerra, R Gomez-Gonzalez, B IPN CINVESTAV Dept Automat Control Mexico City 07300 DF Mexico

ISBN: (纸本)0780383354

Civil structures undergo hysteresis cycles due to cracking or yielding when subjected to severe strong motions. Seismic instrumentation, structural monitoring and system identification techniques have been used in the past years to assess damage. The present research proposes a gradient algorithm to simultaneously identify the combined driving and nonlinear restoring forces, and structural parameters, such as damping and stiffness in a single-degree-of-freedom structure. Simulations are carried out using the El Centro (1940) and the Mexico City (1985) seismic records. Encouraging results are obtained for the identification of the parameters and the estimation of the driving and restoring forces.

关键词： gradient methods structural engineering parameter estimation condition monitoring computerised monitoring nonlinear restoring force structural parameter estimation gradient algorithm civil structure hysteresis cycle seismic instrumentation structural monitoring system identification technique driving force

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Method to update the coefficients of the secondary path filter under active noise control

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SIGNAL PROCESSING 2001年第2期81卷 381-387页

作者： Fujii, K Ohga, J Fujitsu Labs Ltd Wireless Commun Syst Lab L41 Nakahara Ku Kawasaki Kanagawa 2118588 Japan

In active noise control systems using a filtered-x algorithm, the secondary path must be identified before the coefficients of the noise control filter are updated. The secondary path, however, has an impulse response that is continually changing in practical systems. This change degrades noise reduction and the stability of the system. Therefore, the coefficients of the secondary path filter must be adjusted to actual impulse response samples at specific intervals. This paper proposes a method to update the coefficients under active noise control without feeding extra noise to the secondary source. Instead, this method uses estimation errors. The coefficients of the noise control filter generally have the different estimation errors whenever the coefficients are updated. To use the estimation error, this method implements the additional filter modeled on the overall path from a detection sensor to an error sensor, through the primary path, the control filter and the secondary path. Two different coefficient sets of the noise control filter derive two equations on this overall path. A solution of these concurrent equations naturally yields the impulse response samples of the secondary path. This paper uses a system identification technique to solve the concurrent equations. This technique is practical in that calculation errors are distributed equally over all coefficients of the secondary path filter. Finally;computer simulations explained in this paper confirm that the concurrent equation method can refresh the coefficients under active noise control. (C) 2001 Elsevier Science B.V. All rights reserved.

关键词： feedforward control filtered-x algorithm secondary path filter concurrent equations system identification technique

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