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Nonlinear system identification with multiple and correlated scheduling variables *

IFAC Proceedings Volumes 2013年第32期46卷 319-324页

作者： Lei Chen Biao Huang Fei Liu Key Laboratory of Advanced Process Control for Light Industry (Ministry of Education) Institute of Automation Jiangnan University Wuxi 214122 P.R. China Department of Chemical and Materials Engineering University of Alberta Edmonton AB T6G 2G6 Canada

This paper is concerned with identification of nonlinear systems with multiple and correlated scheduling variables. Multiple auto regressive exogenous (ARX) models are identified on different process operating conditions, and a normalized exponential function as the probability density function associated with each of the local ARX models taking effect is then used to combine all the local models to represent the complete dynamics of a nonlinear system. The parameters of the local ARX models and the exponential functions are estimated simultaneously under the framework of the expectation maximization (EM) algorithm. A numerical example is applied to demonstrate the proposed identification method.

关键词： System identification Nonlinear process Multiple models Expectation maximization algorithm Multiple scheduling variables

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Realizability of n-port resistive networks with 2n terminals

Realizability of n-port resistive networks with 2n terminals

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Asian control Conference

作者： Michael Z. Q. Chen Chanying Li Kai Wang Zhiqiang Zuo Minghui Yin Guanrong Chen Department of Mechanical Engineering University of Hong Kong Hong Kong China School of Automation Nanjing University of Science and Technology Nanjing China Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing China Tianjin Key Laboratory of Process Measurement and Control School of Electrical Engineering and Automation Tianjin University Tianjin China Department of Electronic Engineering City University of Hong Kong Hong Kong China

In this paper, we consider the realizability problem of n-port resistive networks containing 2n terminals. A necessary and sufficient condition for any real symmetric matrix to be realizable as the admittance of an n-port resistive network containing 2n terminals is obtained. The condition is based on the existence of a parameter matrix. We then focus on a three-port resistive network containing six terminals. A necessary and sufficient condition is derived for any real symmetric matrix to be realizable as the admittance of a three-port resistive network containing six terminals and at most five positive elements, whose topological structure is properly restricted.

关键词： Symmetric matrices Ports (Computers) Admittance Educational institutions Resistors Joining processes Passive networks

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Autonomous dynamic hand gesture recognition in industrial settings

Autonomous dynamic hand gesture recognition in industrial se...

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IADIS International Conference ICT, Society and Human Beings 2012, IADIS International Conference e-Commerce 2012, Part of the IADIS Multi Conference on Computer Science and Information Systems 2012, MCCSIS 2012

作者： Ziegler, Jens Döring, Randy Pfeffer, Johannes Urbas, Leon Department of Process Control Systems Engineering Institute of Automation Dresden University of Technology Dresden Germany

ISBN: (纸本)9789728939755

In this paper we present a robust and reliable system for interaction with mobile devices using dynamic hand gestures. While other approaches rely on remote computation our system is wearable, lightweight and unobtrusive. It is usable in industrial settings where touch-based interaction is inconvenient and resource efficiency is important. The recognition algorithm is based on Hidden-Markov-Models and optimized for fixed-point arithmetic available in low-cost embedded controllers. The system is highly reliable providing recognition rates significantly higher than the design target of 90 % for an alphabet of 10 gestures. The evaluation of the resulting solution has yielded an effectiveness of 97 % and mean execution times of less than one second. These performance figures are sufficient to consider the presented system an effective and energy efficient alternative to systems that depend on remote computation. It provides autonomous and reliable interaction for single-handed operation of mobile devices in rough industrial settings. © 2012 IADIS.

关键词： Hidden Markov models

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A soft sensor development for the estimation of benzene content in catalytic reformate

A soft sensor development for the estimation of benzene cont...

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35th International Convention on Information and Communication Technology, Electronics and Microelectronics, MIPRO 2012

作者： Ujević Andrijić, Željka Karlović, Romano Žeželj, Boris Faculty of Chemical Engineering and Technology Department of Measurement and Process Control Zagreb Croatia Rijeka Refinery Process Automation Kostrena Croatia

ISBN: (纸本)9789532330724

As vehicle emission standards become more stringent, there is an increasing need for continual monitoring of benzene content in gasoline. Since the on-line analyzers are often unavailable, and laboratory analyses are infrequently obtained, soft sensors for the estimation of benzene content of light reformate are developed. Soft sensors are developed using system identification methods. Experimental data is acquired from the refinery distributed control system (DCS) and include continuously measured variables and analyzer assays available on-line. In the present work, the development of a Finite Impulse Response (FIR) model, an Output Error (OE) model and an Auto-Regressive Model with Exogenous Inputs (ARX) model are presented. To overcome the problem of selecting the best model parameters by trial and error, genetic algorithm was used. Based on developed soft sensors, it is possible to entirely replace on-line analyzers with soft sensors by embedding the model in a DCS on-site. © 2012 MIPRO.

关键词： Benzene

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Beyond bag of words: Image representation in sub-semantic space 13

Beyond bag of words: Image representation in sub-semantic sp...

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21st ACM International Conference on Multimedia, MM 2013

作者： Zhang, Chunjie Wang, Shuhui Liang, Chao Liu, Jing Huang, Qingming Li, Haojie Tian, Qi School of Computer and Control Engineering University of Chinese Academy of Sciences 100049 Beijing China Key Lab of Intell. Info. Process Institute of Computing Technology Chinese Academy of Sciences Beijing 100190 China School of Computer National Engineering Research Center for Multimedia Software Wuhan University 430072 Wuhan China National Laboratory of Pattern Recognition Institute of Automation Chinese Academy of Sciences Beijing China School of Software Dalian University of Technology Liaoning China Department of Computer Sciences University of Texas San Antonio TX 78249 United States

ISBN: (纸本)9781450324045

Due to the semantic gap, the low-level features are not able to semantically represent images well. Besides, traditional semantic related image representation may not be able to cope with large inter class variations and are not very ro- bust to noise. To solve these problems, in this paper, we propose a novel image representation method in the sub- semantic space. First, examplar classifiers are trained by separating each training image from the others and serve as the weak semantic similarity measurement. Then a graph is constructed by combining the visual similarity and weak se- mantic similarity of these training images. We partition this graph into visually and semantically similar sub-sets. Each sub-set of images are then used to train classifiers in order to separate this sub-set from the others. The learned sub-set classifiers are then used to construct a sub-semantic space based representation of images. This sub-semantic space is not only more semantically meaningful but also more reli- Able and resistant to noise. Finally, we make categorization of images using this sub-semantic space based representation on several public datasets to demonstrate the e®ectiveness of the proposed method. Copyright © 2013 ACM.

关键词： Image representation

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Undo the codebook bias by linear transformation for visual applications 13

Undo the codebook bias by linear transformation for visual a...

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21st ACM International Conference on Multimedia, MM 2013

作者： Zhang, Chunjie Zhang, Yifan Wang, Shuhui Pang, Junbiao Liang, Chao Huang, Qingming Tian, Qi School of Computer and Control Engineering University of Chinese Academy of Sciences 100049 Beijing China National Laboratory of Pattern Recognition Institute of Automation Chinese Academy of Sciences Beijing China Key Lab of Intell. Info. Process Institute of Computing Technology Chinese Academy of Sciences Beijing 100190 China College of Computer Science and Technology Beijing University of Technology 100124 Beijing China School of Computer National Engineering Research Center for Multimedia Software Wuhan University 430072 Wuhan China Department of Computer Sciences University of Texas at San Antonio San Antonio TX 78249 United States

ISBN: (纸本)9781450324045

The bag of visual words model (BoW) and its variants have demonstrate their effectiveness for visual applications and have been widely used by researchers. The BoW model first extracts local features and generates the corresponding codebook, the elements of a codebook are viewed as visual words. The local features within each image are then encoded to get the final histogram representation. However, the codebook is dataset dependent and has to be generated for each image dataset. This costs a lot of computational time and weakens the generalization power of the BoW model. To solve these problems, in this paper, we propose to undo the dataset bias by codebook linear transformation. To represent every points within the local feature space using Euclidean distance, the number of bases should be no less than the space dimensions. Hence, each codebook can be viewed as a linear transformation of these bases. In this way, we can transform the pre-learned codebooks for a new dataset. However, not all of the visual words are equally important for the new dataset, it would be more effective if we can make some selection using sparsity constraints and choose the most discriminative visual words for transformation. We propose an alternative optimization algorithm to jointly search for the optimal linear transformation matrixes and the encoding parameters. Image classification experimental results on several image datasets show the effectiveness of the proposed method. Copyright © 2013 ACM.

关键词： Linear transformations

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Two-Degree-of-Freedom Helicopter Closed-loop Identification through a Cascade controller

Two-Degree-of-Freedom Helicopter Closed-loop Identification ...

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7th International Conference on MEMS, NANO and Smart Systems (ICMENS 2011)

作者： Ghalei, Pouya Fatehi, Alireza Arvan, Mohamadreza Advanced Process Automation and Control (APAC) Research Group K.N. Toosi University of Technology Tehran Iran Electrical Engineering Department Malek-Ashtar University of Technology Tehran Iran

ISBN: (纸本)9783037853122

Input-Output data modeling using multi layer perceptron networks (MLP) for a laboratory helicopter is presented in this paper. The behavior of the two degree-of-freedom platform exemplifies a high order unstable, nonlinear system with significant cross-coupling between pitch and yaw directional motions. This paper develops a practical algorithm for identifying nonlinear autoregressive model with exogenous inputs (NARX) and nonlinear output error model (NOE) through closed loop identification. In order to collect input-output identifier pairs, a cascade state feedback (CSF) controller is introduced to stabilize the helicopter and after that the procedure of system identification is proposed. The estimated models can be utilized for nonlinear flight simulation and control and fault detection studies.

关键词： Twin rotor helicopter MLP neural network NARX NOE Cascade State Feedback controller

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New criteria of reachable set estimation for time delay systems subject to polytopic uncertainties

New criteria of reachable set estimation for time delay syst...

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7th IFAC Symposium on Robust control Design, ROCOND'12

作者： Zuo, Zhiqiang Chen, Yinping Wang, Yijing Chen, Michael Z.Q. Tianjin Key Laboratory of Process Measurement and Control School of Electrical Engineering and Automation Tianjin University Tianjin 300072 China Department of Mechanical Engineering University of Hong Kong Hong Kong Hong Kong

ISBN: (纸本)9783902823038

The problem of reachable set estimation for linear systems subject to both time delay and polytopic uncertainties is considered in this paper. Our aim is to find a set as small as possible to bound the states starting from the origin by inputs with peak values. The Lyapunov-Krasovskii functional together with free-weighting matrix technique are proposed to derive some sufficient conditions for the existence of an ellipsoidal bound to estimate the states. This method eliminates the conservatism generated by Jensen's inequality and obtains a much tighter reachable set bound. In addition, the number of variables to be determined is smaller than the previous result based on the maximal Lyapunov functional. Finally, an example illustrates the merits of our proposed results. © 2012 IFAC.

关键词： Linear systems

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The effect of control parameters to the quality of small-scale wood pellet combustion

The effect of control parameters to the quality of small-sca...

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TAPPI International Bioenergy and Bioproducts Conference 2012, IBBC 2012

作者： Ruusunen, M. Korpela, T. Björkqvist, T. University of Oulu Control Engineering Laboratory Department of Process and Environmental Engineering P.O. BOX 4300 90014 Oulu Finland Tampere University of Technology Department of Automation Science and Engineering P.O. BOX 692 33101 Tampere Finland

ISBN: (纸本)9781622768424

The target is to clear out control variables and requirements for clean small-scale wood pellet combustion (th). Experimental runs were carried out in the form of design of experiments (DOE) with two commercial 15 kW pellet burners, namely a horizontal gas-burner and a conventional horizontal burner in a 20 kW commercial pellet boiler. Analysed variables were fuel power, draught, air flow, and fuel feed period, and researched variables were CO, O2 and efficiency. The target was to identify and characterise separately the magnitude and direction of the effect of each factor. After process identification and variable optimisation, the results shows strong influence of the studied control parameters on the efficiency and the emissions. The effects and interactions between different process variables were rather similar with both burners. The major effects for CO levels were fuel feed and additionally draught affected in case of wood gas combustion. Additionally, the effects on combustion efficiency is described by draught, air feed and fuel feed period. Furthermore, the fuel feed period affected the excess air level in case of direct combustion principle. It was noticed, however, that the combustion properties and optimal parameter values vary significantly between the two cases.

关键词： Fuels

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A soft sensor development for the estimation of benzene content in catalytic reformate

A soft sensor development for the estimation of benzene cont...

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Proceedings of the International Convention MIPRO

作者： Željka Ujević Andrijić Romano Karlović Boris Žeželj Department of Measurement and Process Control Faculty of Chemical Engineering and Technology Zagreb Croatia Process Automation Rijeka Refinery Kostrena Croatia

关键词： Mathematical model Finite impulse response filter Predictive models Autoregressive processes Data models Estimation Adaptation models

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