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2004 SAE World Congress

作者： Milanese, Mario Novara, Carlo Gabrielli, Paolo Tenneriello, Luigi Dipartimento de Automatica e Informatica Politecnico di Torino Italy FIAT Auto S.p.A. - Product and Process Engineering Vehicle Dynamics Active Chassis Control Italy Elasis S.C.p.A. - Fiat Group Control Systems Dept. Modeling Simulation and Control Strategies Vehicle Dynamics Italy

ISBN: (纸本)0768013194

In the paper, identification of vertical dynamics of vehicles with controlled suspensions is considered. Identification is performed from experimental data measured on a four-poster bench test of a segment C car, equipped with a CDC-Skyhook dampers control system. Vertical displacements at tires are imposed, related to different types of road profiles at different constant speeds and the following front and rear variables have been measured: chassis accelerations, wheels accelerations, chassis-wheel displacements, chassis-road displacements and control currents of the dampers. A nonlinear model in regression form is identified, having the road profile and damper control currents as inputs and chassis and wheels accelerations as outputs. The model is identified by means of a Set Membership structured identification method, which takes advantage of physical information on the structure of the system, decomposing the system in five subsystems: one represents the chassis and engine and the other ones represent the front and rear suspensions and wheels-tires. The overall high-dimensional identification problem is reduced to the identification of lower dimensional subsystems and to the estimation of their interactions and a recently proposed iterative scheme is used for its solution. A quite satisfactory overall model has been obtained, whose accuracy is documented by simulating the system with road profiles and damper control currents not used for the identification. Copyright © 2004 SAE International.

关键词： Chassis

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FUZZSAM - visualization of fuzzy clustering results by modified Sammon mapping

FUZZSAM - visualization of fuzzy clustering results by modif...

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IEEE International Conference on Fuzzy systems (FUZZ-IEEE)

作者： J. Abonyi R. Babuska Department of Process Engineering University of Veszprem Hungary Delft Center for Systems and Control Delft University of Technnology Delft Netherlands

Since in practical data mining problems high-dimensional data are clustered, the resulting clusters are high-dimensional geometrical objects, which are difficult to analyze and interpret. Cluster validity measures try to solve this problem by providing a single numerical value. As a low dimensional graphical representation of the clusters could be much more informative than such a single value, this paper proposes a new tool for the visualization of fuzzy clustering results. By using the basic properties of fuzzy clustering algorithms, this new tool maps the cluster centers and the data such that the distances between the clusters and the data-points are preserved. During the iterative mapping process, the algorithm uses the membership values of the data and minimizes an objective function similar to the original clustering algorithm. Comparing to the original Sammon mapping not only reliable cluster shapes are obtained but the numerical complexity of the algorithm is also drastically reduced. The algorithm has been applied to several data sets and the numerical results show performance superior to principal component analysis and the classical Sammon mapping based projection. The examples demonstrate that proposed FUZZSAMM algorithm is a useful tool in user-guided clustering.

关键词： Clustering algorithms Data visualization Iterative algorithms Principal component analysis Prototypes Pollution measurement Data mining Data engineering Electronic mail Shape

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Nonlinear Data Transfonnation to Improve Flow Stress Prediction Using Neural Networks

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IFAC Proceedings Volumes 2004年第15期37卷 371-376页

作者： Y.Y. Yang D.A. Linkens M. Mahfouf IMMPETUS (Institute for Microstructural and Mechanical Process Engineering: The University of Sheffield) Department of Automatic Control and Systems Engineering University of Sheffield Sheffield S1 3JD UK

This paper addresses the development of a neural network (NN) model assisted with nonlinear data transformation for flow stress prediction of an aluminium alloy. The stress-strain data were collected from a plane strain compression (PSC) test machine, which is capable of testing under a wide range of strain rates. A straightforward NN modelling failed to give satisfactory stress predictions across the whole range of the input conditions. Careful analysis of the error behaviour led to the finding that the poor performance was caused by the large variation of the strain rates. To improve the model performance, a nonlinear data transformation was adopted for the strain rate, and the flow stress prediction was improved significantly.

关键词： Neural networks modelling data transformation aluminium alloy flow stress

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State-space reconstruction and prediction of chaotic time series based on fuzzy clustering

State-space reconstruction and prediction of chaotic time se...

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IEEE International Conference on systems, Man and Cybernetics

作者： J. Abonyi B. Feil S. Nemeth R. Arva R. Babuska Department of Process Engineering University of Veszprém Hungary Delft Center for Systems and Control Delft University of Technnology Delft Netherlands

Selecting the embedding dimension of a dynamic system is a key step toward the analysis and prediction of nonlinear and chaotic time-series. This paper proposes a clustering-based algorithm for this purpose. The clustering is applied in the reconstructed space defined by the lagged output variables. The intrinsic dimension of the reconstructed space is then estimated based on the analysis of the eigenvalues of the fuzzy cluster covariance matrices, while the correct embedding dimension is inferred from the prediction performance of the local models of the clusters. The main advantage of the proposed solution is that three tasks are simultaneously solved during clustering: selection of the embedding dimension, estimation of the intrinsic dimension, and identification of a model that can be used for prediction.

关键词： Chaos State-space methods Time series analysis Clustering algorithms Predictive models Delay Performance analysis Eigenvalues and eigenfunctions Covariance matrix MIMO

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Hybrid Modelling of Aluminium Alloys Properties

Hybrid Modelling of Aluminium Alloys Properties

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The Fourth International Conference on Physical and Numerical Simulation of Materials (ICPNS’2004)

Predictive modelling of material properties is well recognised by industry now. Particular attention has been given to recrystallisation and microstructural evolution. During thermomechanical processing such as forging, rolling or extrusion, the strain, strain rate, temperature and composition are the key variables that change from one material to another and from one type of processing to another. For alloys like aluminium, changes in the deformation conditions affect the evolution of dislocation substructure and subsequent recrystallisation. The use of conventional modelling approaches, such as constitutive equations, are still popular, however, the increase in use of computational techniques such as finite elements offers increase of accuracy in the predictive capability. Other predictive numerical techniques such as neural networks and neuro-fuzzy modelling can model large amount of industrial data sets which can achieve considerable improvements over the linear regression *** paper describes a novel "hybrid" modelling approach developed for predicting the evolution of the internal state variables such as the internal dislocation density, subgrain size and misorientation between subgrains, and subsequent recrystallisation behaviour. The model is developed for constant and transient deformation behaviour over a wide temperature range for different aluminium alloys (Al, Al1%Mg, Al5%Mg, Al-11%Zn). The model predicts the evolution of the internal states, the final flow stress, the static recrystallisation behaviour, nucleation of recrystallisation and the recrystallised grain size. The data used for developing the model are based on the internal states, flow stress and the recrystallisation kinetics. The model has been tested on data which were not used during the training stage, and it showed good prediction *** hybrid modelling technique adopted in this research which combines physical equations, finite element models, adaptive numeric modelli

关键词： Hybrid modeling Aluminum alloys

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Hybrid Modelling of Aluminium Alloys Properties

Hybrid Modelling of Aluminium Alloys Properties

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The Fourth International Conference on Physical and Numerical Simulation of Materials processing (ICPNS’2004)

作者： M.F.Abbod D.A.Linkens C.M. Sellars Institute for Microstructural and Mechanical Process Engineering The University of Sheffield Department of Automatic Control and Systems Engineering Department of Mechanical Engineering Department of Engineering Materials University of Sheffield Sheffield S1 3JD UK Institute for Microstructural and Mechanical Process Engineering The University of Sheffield Department of Automatic Control and Systems Engineering Department of Mechanical Engineering Department of Engineering Materials University of Sheffield Sheffield S1 3JD UK Institute for Microstructural and Mechanical Process Engineering The University of Sheffield Department of Automatic Control and Systems Engineering Department of Mechanical Engineering Department of Engineering Materials University of Sheffield Sheffield S1 3JD UK

关键词： Hybrid modeling Aluminum alloys

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A unique paper machine drive system revamp

A unique paper machine drive system revamp

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IEEE Conference Record of 2004 Annual Pulp and Paper Industry Technical Conference

作者： West, Daniel D. Honaker, Darren Barry, Keith Corporate Process Control Sappi Fine Paper North America Box 1600 RR 3 Skowhegan ME 04976 United States TMEIC-GE Automation Systems 1501 Roanoke Blvd Salem VA 24153 United States GE Engineering Services One Community Drive Augusta ME 04330 United States

This paper will review the successful master controller revamp of Sappi Fine Paper North America's #3 Paper Machine at its Skowhegan, Maine mill. The rebuild project included upgrading the press section and increasing the speed of the paper machine by 500 FPM (150 MPM). The existing original drive system had been installed with sectional AC drives. The original drive system was becoming more difficult to maintain due to unavailability of parts and the out-of-date diagnostic system. The revamp involved the re-use of 76 existing drives and the installation of 8 new AC sectional drives. A new master controller was added with an enhanced diagnostic HMI. The new master controller architecture communicated with, controlled and diagnosed the old drives as well as the new drives. The unique combination of existing drives and new drives formed a cohesive system with all of the advantages of a new drive system. A staged installation was performed to reduce the outage time impact. The paper machine rebuild project was completed in March 2003 and has met the expectations of a successful revamp.

关键词： Papermaking machinery

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Adsorption and Self‐Assembly of Peptides on Mica Substrates†

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Angewandte Chemie 2005年第13期117卷

作者： Conor Whitehouse Jiyu Fang Amalia Aggeli Mark Bell Rik Brydson Colin W. G. Fishwick Jim R. Henderson Charles M. Knobler Robert W. Owens Neil H. Thomson D. Alastair Smith Neville Boden Centre for Self‐Organising Molecular Systems Department of Chemistry University of Leeds Leeds LS2 9JT UK Fax: (+44) 113‐343‐6452 Present address: Research and Development Division Fujirebio Inc. 51 Komiya‐cho Hachioji‐shi Tokyo 192‐0031 Japan Fax: (+81) 426‐468‐325 Department of Chemistry and Biochemistry University of California Los Angeles CA 90095‐1569 USA Institute for Materials Research School of Process Environmental and Materials Engineering University of Leeds Leeds LS2 9JT UK Department of Physics and Astronomy University of Leeds Leeds LS2 9JT UK

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Fuzzy clustering for selecting structure of nonlinear models with mixed discrete and continuous inputs

Fuzzy clustering for selecting structure of nonlinear models...

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IEEE International Conference on Fuzzy systems (FUZZ-IEEE)

作者： D. Girimonte R. Babuska J. Abonyi Dipartimento di Elettronica ed Elettrotecnica Politecnico di Bari Italy Delft Center for Systems and Control Delft University of Technnology Netherlands Department of Process Engineering University of Veszprem Hungary

A method for selecting regressors in nonlinear models with mixed discrete (categorical) and continuous inputs is proposed. Given a set of input-output data and an initial superset of potential inputs, the relevant inputs are selected by a model-free search algorithm. Fuzzy clustering is used to quantize continuous data into subsets that can be handled in a similar way as discrete data. Two simulation examples and one real-world data set are included to illustrate the performance of the proposed method and compare it with the performance of regression trees. For small to medium size problems (up to 15 candidate inputs), the proposed method works effectively. For larger problems, the computational load becomes too high.

关键词： Regression tree analysis control system synthesis Nonlinear control systems process control Clustering algorithms Computational modeling Data analysis Data mining Delay effects Principal component analysis

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Diagnostics capabilities of foundation fieldbus pressure transmitters

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Chemical engineering World 2004年第6期39卷 44-54页

作者： Szanyi, Ron Raterman, Mike Eryurek, Evren Instrum and Control Projects Section ExxonMobil Research and Engineering Plant Automat and Computing Division Fairfax VA United States ExxonMobil Research and Engineering Fairfax VA United States Emerson Process Management St. Louis MO United States

Over the past two years ExxonMobil Research and engineering group, along with Emerson process Management, have tested the self-diagnostic capabilities of pressure transmitters with FOUNDATION FIELDBUS (FF) capability while installed on a fluid catalytic cracking (FCC) unit in an operating refinery. This project involved conducting a series of tests on the ability of the devices to diagnose plugged impulse lines.

关键词： Diagnosis

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