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American control Conference

作者： Chunyu Yang Qingling Zhang Jyh-Horng Chou Yingwei Zhang Key Laboratory of Integrated Automation of Process Industry Ministry of Education Northeastern University Shenyang 110004 P.R. China Institute of Systems Science Northeastern University Shenyang 110004 P.R. China Institute of System Information and Control Engineering National Kaohsiung First University of Science and Technology I University Road Yuanchau Kaohsiung 824 Taiwan

ISBN: (纸本)9781424474264

This paper investigates the absolute stability problem for Lur'e singularly perturbed systems with multiple nonlinearities. The objective is to determine if the system is absolutely stable for any epsilon E (0, (epsilon)_(0)], where epsilon denotes the perturbation parameter and (epsilon)_(0) is a pre-defined positive scalar. Firstly, an epsilon-dependent Lyapunov function of Lur'e-postnikov form is constructed. Then, a stability criterion expressed in terms of epsilon-independent linear matrix inequalities (LMIs) is derived. Finally, an example is given to show the feasibility and effectiveness of the obtained method.

关键词： Robust stability Stability criteria control systems Lyapunov method Power system stability Power system modeling Educational institutions Nonlinear control systems control nonlinearities USA Councils

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Identification of nonlinear static processes with local polynomial regression and subset selection

Identification of nonlinear static processes with local poly...

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15th IFAC Symposium on System Identification, SYSID 2009

作者： Sequenz, Heiko Schreiber, Alexander Isermann, Rolf Institute of Automatic Control Laboratory of Control Engineering and Process Automation Technical University Darmstadt Germany

ISBN: (纸本)9783902661470

The presented method for nonlinear system identification is based on the LOLIMOT algorithm introduced by Nelles and Isermann [1996]. The LOLIMOT algorithm divides the input space by a tree-construction algorithm and interpolates the local linear models by local membership functions. Instead of assuming local linear models, the presented algorithm utilizes general local nonlinear functions, which make the algorithm more flexible. These are approximated by a multidimensional Taylor series. Since the amount of regressors grows fast with the number of inputs and the expansion order, a subset selection procedure is introduced. It reveals significant regressors and gives information about the local functional behavior. The local subset selection is implemented as a stepwise regression with replacement of regressors. Mallows' Cp-statistic is used for the subset selection algorithm and is also implemented for final model selection. The benefit of the extended algorithm lies in the higher flexibility in the local models, which results in less partitions of the input space by a similar approximation quality. © 2009 IFAC.

关键词： Membership functions

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Improved Multidisciplinary Multiobjective Collaborative Optimization Technique Based on NSGA-II Algorithm 1

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IFAC Proceedings Volumes 2010年第25期43卷 139-144页

作者： H. Li Y. Jing S. Zhang V. Ojleska T. Kolemisevska G.M. Dimirovski Key Laboratory of Integrated Automation of Process Industry Ministry of Education Northeastern University Shenyang 110004 P.R. China Northeastern University School of Information Science & Engineering Shenyang 110004 P.R. China SS Cyril and Methodius University School FEIT Institute of ASE Karpos II BB MK-1000 Skopje R. Macedonia Dogus University Computer Eng. and Control Eng. Departments TR-34722 Istanbul Turkey

The multiobjective collaborative optimization (MCO) has been widely adopted in concurrent engineering design as a good multiobjective optimization approach provided the problem of optimization results converging often to a local extremum has been taken care of. It has been demonstrated to yield useful solutions to a wide range of optimization problems under concurrent condition both technical and non-technical ones. A solution strategy for MCO that overcomes this drawback is proposed here on the grounds of genetic NSGA-II algorithm. It is an adaptive heuristic search technique that controls the distances between the individual and system's feasible region during genetic evolution. In the evolving NSGA-II based non-dominated sorting, the individual threshold of infeasibility degree is reduced gradually via genetic evolution and the individual's feasibility capacity is determined by its infeasibility degree and the threshold. It has been applied to a benchmark example of speed reducer design, and the obtained results demonstrate the proposed technique is comparably more efficient and may offer substantial advantages over the gradient-based optimization methods. Copyright © 2010 IFAC

关键词： Collaborative optimization dynamic threshold genetic algorithms multidisciplinary optimization multiobjective optimization

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Identification of Nonlinear Static processes with Local Polynomial Regression and Subset Selection

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IFAC Proceedings Volumes 2009年第10期42卷 138-143页

作者： Heiko Sequenz Alexander Schreiber Rolf Isermann Institute of Automatic Control Laboratory of Control Engineering and Process Automation Technical University Darmstadt Germany (Tel: +49-6151-16 3914

The presented method for nonlinear system identification is based on the LOLIMOT algorithm introduced by Nelles and Isermann [1996]. The LOLIMOT algorithm divides the input space by a tree-construction algorithm and interpolates the local linear models by local membership functions. Instead of assuming local linear models, the presented algorithm utilizes general local nonlinear functions, which make the algorithm more flexible. These are approximated by a multidimensional Taylor series. Since the amount of regressors grows fast with the number of inputs and the expansion order, a subset selection procedure is introduced. It reveals significant regressors and gives information about the local functional behavior. The local subset selection is implemented as a stepwise regression with replacement of regressors. Mallows’ C p -statistic is used for the subset selection algorithm and is also implemented for final model selection. The benefit of the extended algorithm lies in the higher flexibility in the local models, which results in less partitions of the input space by a similar approximation quality.

关键词： Local Regression Subset Selection LOLIMOT Identification Algorithm Multivariate Polynomials Least-Squares Estimation Automotive Emissions

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Investigating the effect of pruning on the diversity and fitness of robot controllers based on MDL2∈ during Genetic Programming

Investigating the effect of pruning on the diversity and fit...

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Congress on Evolutionary Computation

作者： M. Szymanski H. Worn Jan Fischer Institute of Process Control and Robotics Universität Karlsruhe Karlsruhe Germany Fraunhofer Institute of Manufacturing Engineering and Automation (IPA) Stuttgart Germany

In this paper we propose a new diversity measure based on the correlation of bit strings for the analysis of genetic programming (GP) experiments. The diversity measure has been applied to analyse the impact of pruning on the diversity of a population during genetic programming and its relation to the convergence time of the fitness function. To show the usability of the proposed diversity measure a GP experiment is introduced where simulated Jasmine robots have to learn a collision avoidance behaviour to find their way through a maze. A full analysis of this experiment is given with different fixed pruning strategies in respect to the population diversity and fitness. The GP has been done on behaviour-based robot controllers implemented in MDL2isin. MDL2isin has the advantage that it provides a very compact bit string representation of the control programme, which can be used for diversity analysis.

关键词： Robot control Genetic programming Convergence Shape measurement Robot programming XML process control Intellectual property Manufacturing processes Pulp manufacturing

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An adaptive weight PSO for rolling schedules multi-objective optimization of tandem cold rolling

An adaptive weight PSO for rolling schedules multi-objective...

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IEEE International Conference on automation and Logistics

作者： Yu Wang Yong Li Jianchang Liu Key Laboratory of Integrated Automation of Process Industry Ministry of Education Northeastern University Shenyang Liaoning China Department of Automatic Control Shenyang Institute of Aeronautical Engineering Shenyang Liaoning China

In this paper, an adaptive weight particle swarm optimization is proposed for multi-objective optimization. And it is applied to rolling schedules multi-objective optimization of tandem cold rolling. According to the demands of actual rolling schedules designing, power distribution, rolling energy consumption and slip rate are selected as objective functions. Then the multi-objective model of rolling schedules is established. The proposed algorithm is applied to rolling schedules optimization of tandem cold rolling. The result shows that the proposed method decreases the values of three objective functions simultaneously compared to actual rolling schedules. Furthermore the proposed algorithm has faster convergence speed than the adaptive weight approach GA.

关键词： Job shop scheduling Particle swarm optimization Optimization methods Power distribution Scheduling algorithm automation Energy consumption Logistics Laboratories Convergence

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Evolutionary optimization methods for predictive on-off control

Evolutionary optimization methods for predictive on-off cont...

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作者： Schmitz, Ulrich Haber, Robert Bars, Ruth Shell Deutschland Oil Rhineland Refinery Department for Technology and Services Ludwigshafener Strasse l D-50389 Wesseling Germany University of Applied Science Cologne Institute of Process Engineering and Plant Design Betzdorfer Str. 2 D-50679 Cologne Germany Budapest Univ. of Technology and Economics Dept. of Automation and Applied Informatics MTA-BME Control Research Group Goldmann Gy.ter 3 H-1111 Budapest Hungary

ISBN: (纸本)9783902661661

On-off control is still widely used in the industry, especially for discontinuous actuators, e.g. compressors, steam turbines or furnace burners. Exact set-point control is not possible by an on-off controller. Lower and upper limits are defined for the control signal which should not be violated. For this predictive gap control quadratic and horizon dependent cost functions are defined. Traditional numerical optimization fails with longer prediction horizons, but a genetic algorithm can be effectively applied even for long horizons.

关键词： Actuators

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Evolutionary optimization methods for predictive on-off control

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IFAC Proceedings Volumes 2009年第19期42卷 408-413页

作者： Ulrich Schmitz Robert Haber Ruth Bars Shell Deutschland Oil Rhineland Refinery Department for Technology and Services Ludwigshafener Strasse l D-50389 Wesseling Germany University of Applied Science Cologne Institute of Process Engineering and Plant Design Betzdorfer Str. 2 D-50679 Cologne Germany Budapest Univ. of Technology and Economics Dept. of Automation and Applied Informatics MTA-BME Control Research Group Goldmann Gy.ter 3 H-1111 Budapest Hungary

Abstract On-off control is still widely used in the industry, especially for discontinuous actuators, e.g. compressors, steam turbines or furnace burners. Exact set-point control is not possible by an on-off controller. Lower and upper limits are defined for the control signal which should not be violated. For this predictive gap control quadratic and horizon dependent cost functions are defined. Traditional numerical optimization fails with longer prediction horizons, but a genetic algorithm can be effectively applied even for long horizons.

关键词： predictive control on-off control discontinuous actuators genetic algorithms

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Numerical simulation of flow field in a quench oil tower

Numerical simulation of flow field in a quench oil tower

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2007 ASME Pressure Vessels and Piping Conference, PVP 2007

作者： Shuihua, Zheng Shengchang, Zhang Zengliang, Gao Zhejiang University of Technology Institute of Process Equipment and Control Engineering MOE Key Laboratory of Mechanical Manufacture and Automation Hangzhou 310032 China

ISBN: (纸本)0791842819

Towers are applied in the wide range of the petrochemical industry. The flow condition and the temperature distribution in the tower are the focus of the people's attention, which would affect function of the tower and could result in unstable operation of the tower. In this paper, the flow field in a quench oil tower is simulated based on CFD method. The DPM (Discrete Phase Model) is used to calculate and analyze flow distribution and heat transfer between gas and liquid. The numerical results such as temperature and velocity distributions below lower tray in tower are obtained. According to CFD results, modification method of improving the flow distribution is proposed. Copyright © 2007 by ASME.

关键词： Flow fields

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Research on the vibratory stress relief used to reduce residual stress of mismatch butt welds of a cylinder

Research on the vibratory stress relief used to reduce resid...

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2007 ASME Pressure Vessels and Piping Conference, PVP 2007

作者： Xin, Ren Yuan, Tian Zengliang, Gao Kangda, Zhang Zhejiang University of Technology Institute of Process Equipment and Control Engineering MOE Key Laboratory of Mechanical Manufacture and Automation Hangzhou 310032 China

ISBN: (纸本)0791842843

The residual stresses of mismatch butt welds of a cylinder were measured by the blind-hole method before and after a vibratory residual stress relief treatment. The results show that this treatment could greatly reduce the maximal butt weld residual stress of dissimilar steel from 540MPa to 119MPa. The concentrated distributions of the first and the second principal residual stresses became gentle after the vibratory residual stress relief treatment. Copyright © 2007 by ASME.

关键词： Stress analysis

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