检索结果-内蒙古大学图书馆

8th International Symposium on Advanced Control of Chemical processes, ADCHEM 2012

作者： Wolf, Inga J. Munoz, Diego Schmitz, Moritz Marquardt, Wolfgang AVT - Process Systems Engineering RWTH-Aachen University Aachen Germany Universidad Pontificia Bolivariana Medellin Colombia

ISBN: (纸本)9783902823052

A two-layer control algorithm is developed for a class of hybrid (discrete-continuous dynamic) systems comprising important applications such as the economically optimal operation of recipe-driven batch or continuous processes. On the upper layer, the economic optimal control problem is solved rigorously by a slow controller at a low sampling rate, whereas a fast neighboring-extremal controller updates rather than tracks the optimal trajectories to account for disturbances. Consequently, the process is steered to its operational bounds, while the optimal switching times under disturbances can be determined such that the economic potential of the process is fully exploited anytime. © 2012 IFAC.

关键词： Hybrid systems

来源：评论

学校读者我要写书评

暂无评论

A bias-eliminated subspace identification method for errors-in-variables systems

A bias-eliminated subspace identification method for errors-...

引用

8th International Symposium on Advanced Control of Chemical processes, ADCHEM 2012

作者： Liu, Tao AVT-Process Systems Engineering RWTH Aachen University Turmstrasse 46 Aachen 52064 Germany Institute of Advanced Control Technology Dalian University of Technology Dalian 116024 China

ISBN: (纸本)9783902823052

For model identification of industrial operating systems subject to noisy input-output observations, known as the error-in-variables (EIV) problem, a subspace identification method is proposed in this paper by developing an orthogonal projection approach to guarantee consistent estimation of the deterministic part of such a system. The rank condition for such orthogonal projection is analyzed in terms of the nominal state-space model structure. Using the principal component analysis (PCA), the extended observability matrix and low triangular block-Toeliptz matrix of the state-space model are analytically derived. Accordingly, the system state-space matrices can be retrieved in a transparent manner from the above matrices through linear algebra or an ordinary least-squares (LS) algorithm. A benchmark example used in the existing references is adopted to demonstrate the effectiveness and merit of the proposed subspace identification method. © 2012 IFAC.

关键词： Errors

来源：评论

学校读者我要写书评

暂无评论

Flexible Closed-Loop Iterative Learning Control for Industrial Batch processes With State Delay and Time-Varying Uncertainties

引用

IFAC Proceedings Volumes 2012年第13期45卷 225-230页

作者： Tao Liu AVT-Process Systems Engineering RWTH Aachen University Turmstrasse 46 Aachen Germany (Tel: +49 (0) 241 80-97024)

A robust closed-loop iterative learning control (ILC) method is proposed for industrial batch processes with state delay and time-varying uncertainties from cycle to cycle. Based on a two-dimensional (2D) system description of such a batch process, a closed-loop ILC scheme consisting of dynamic output feedback plus feedforward control is established to realize robust tracking of the setpoint trajectory in both the time (during a cycle) and batch (from cycle to cycle) directions. Only measured output errors of current and previous cycles are used for control design to facilitate practical implementation. A flexible 2D difference Lyapunov function that guarantees monotonical state energy decrease in both the time and batch directions is introduced to establish a sufficient condition in terms of the linear matrix inequality (LMI) for holding robust stability of the closed-loop ILC system. Correspondingly, the ILC controller can be explicitly formulated, together with an adjustable robust H infinity performance level. An illustrative example is given to demonstrate effectiveness and merits of the proposed ILC method.

关键词： Industrial batch process Iterative learning control Two-dimensional system description Linear matrix inequality Robust H infinity performance

来源：评论

学校读者我要写书评

暂无评论

A Hierarchical Distributed Economic NMPC Architecture Based on Neighboring-Extremal Updates

A Hierarchical Distributed Economic NMPC Architecture Based ...

引用

American Control Conference

作者： Inga J. Wolf Holger Scheu Wolfgang Marquardt Chair of AVT - Process Systems Engineering RWTH Aachen University D-52056 Aachen Germany

ISBN: (纸本)9781457710957

A hierarchical distributed algorithm for nonlinear optimal control is presented. The algorithm enables the change of the operating point for continuous processes in real-time by further reducing computational time especially for large-scale systems with several coupled subsystems. The algorithm is an extension of a two-layer nonlinear control architecture which provides a rigorous solution to the optimal control problem by a slow controller and a sensitivity-based update for the optimal trajectories under disturbances by a fast neighboring-extremal (NE) controller. The direct incorporation of disturbances within the fast NE controller results in a parametric QP which is split up in a set of distributed parametric QP to be solved in parallel.

关键词： Optimal control Computer architecture Economics process control Sensitivity Mathematical model Vectors

来源：评论

学校读者我要写书评

暂无评论

Robust Design of Closed-Loop Nonlinear systems with Input and State Constraints

引用

IFAC Proceedings Volumes 2012年第15期45卷 916-921页

作者： Diego A. Muñoz Wolfgang Marquardt AVT - Process Systems Engineering RWTH-Aachen University Aachen Germany Research Group on Mathematics (GMat). Universidad Pontificia Bolivariana Medellin Colombia

This work focuses on the control design for feedback linearizable nonlinear systems with unknown time-varying disturbances and uncertainty such that bounds on inputs and state constraints are not violated. Exploiting the special structure of the systems considered, controllers based on Lyapunov's direct methods are easily synthesized, which enforce asymptotic stability in the presence of bounded inputs. However, these controllers do not account explicitly for state constraints in the presence of disturbances and uncertainty. The solution of this task is addressed in this work by an optimization-based method, the so-called normal vector approach.

关键词： Feedback linearization Saturation Lyapunov methods MIMO Robustness Bounded Disturbances Uncertainty Transient stability State constraints

来源：评论

学校读者我要写书评

暂无评论

Hierarchical Economic NMPC for a Class of Hybrid systems Using Neighboring-Extremal Updates

引用

IFAC Proceedings Volumes 2012年第15期45卷 561-566页

作者： Inga J. Wolf Diego Munoz Moritz Schmitz Wolfgang Marquardt AVT - Process Systems Engineering RWTH-Aachen University Aachen Germany Research Group on Mathematics (GMat). Universidad Pontificia Bolivariana Medellin Colombia

关键词： Hierarchical control economic nonlinear model-predicitive control dynamic real-time optimization hybrid systems scheduling neighboring-extremal control parametric sensitivity analysis

来源：评论

学校读者我要写书评

暂无评论

A Bias-Eliminated Subspace Identification Method for Errors-in-Variables systems

引用

IFAC Proceedings Volumes 2012年第15期45卷 166-171页

作者： Tao Liu AVT-Process Systems Engineering RWTH Aachen University Turmstrasse 46 Aachen 52064 Germany Institute of Advanced Control Technology Dalian University of Technology Dalian 116024 P.R. China

关键词： Subspace identification Errors-in-variables system Extended observability matrix Orthogonal projection Least-squares algorithm

来源：评论

学校读者我要写书评

暂无评论

Distributed model-predictive control driven by simultaneous derivation of prices and resources

Distributed model-predictive control driven by simultaneous ...

引用

作者： Scheu, Holger Marquardt, Wolfgang AVT Process Systems Engineering RWTH Aachen University 52056 Aachen Germany

ISBN: (纸本)9783902661937

A novel distributed model predictive control method for linear discrete-time systems is considered. The method can handle coupled constraints as well as coupled objective functions. For the decomposed optimal control problems embedded in the distributed controller additional linear information on the full optimal control problem is added. On each horizon, the resulting coordinated optimal control problem is solved iteratively. Prices and resources are calculated simultaneously. A convergence analysis is presented as well as a case study for an unstable process. There, an almost optimal control sequence is achieved after only one iteration. © 2011 IFAC.

关键词： Iterative methods

来源：评论

学校读者我要写书评

暂无评论

Closed-loop step response identification for improving on-line autotuning of load disturbance rejection

Closed-loop step response identification for improving on-li...

引用

作者： Liu, Tao AVT-Process Systems Engineering RWTH Aachen University Turmstrasse 46 Aachen Germany

ISBN: (纸本)9789881725592

Based on a closed-loop step response test, a low-order model identification method is proposed to facilitate on-line controller tuning for load disturbance rejection in industrial engineering practices. By introducing a damping factor to the closed-loop step response for realizing the Laplace transform, a frequency response estimation algorithm is given in terms of the closed-loop system configuration for operation. Correspondingly, a model identification algorithm is analytically derived for obtaining a low-order process model of first-order-plus-dead-time (FOPDT). Another identification algorithm is developed for improving model fitting accuracy over a specified frequency range interested to controller tuning, specifically detailed for obtaining the most widely used FOPDT and second-order-plus-dead-time (SOPDT) models, based on a weighted least-squares fitting of the process frequency response points estimated in the specified frequency range. Using the identified models, a model-based controller design and tuning method is proposed for improving load disturbance rejection. Illustrative examples from recent references are used to demonstrate the effectiveness and merits of the proposed identification algorithms and controller tuning method. © 2011 Chinese Assoc of Automati.

关键词： Laplace transforms

来源：评论

学校读者我要写书评

暂无评论

Proper orthogonal decomposition for model reduction of linear differential-algebraic equation systems

Proper orthogonal decomposition for model reduction of linea...

引用

作者： Romijn, R.C. Weiland, S. Marquardt, W. AVT-Process Systems Engineering RWTH Aachen University Germany Dept. of Electrical Engineering Eindhoven University of Technology Netherlands

ISBN: (纸本)9783902661937

This paper presents a generalization of the model reduction method proper orthogonal decomposition to systems of differential-algebraic equations of arbitrary index. It is known that proper orthogonal decomposition generalizes the method of empirical balanced truncation for linear time-invariant systems. This property will be preserved for differential-algebraic equation systems of arbitrary index. This is important for the application of proper orthogonal decomposition in control, where the input-output behaviour should be approximated accurately, which is a well-known property of balanced-truncated systems. © 2011 IFAC.

关键词： Linear time-invariant system

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：