检索结果-内蒙古大学图书馆

Software Sensor Design for Cement Grinding Circuits – Practical Issues

IFAC Proceedings Volumes 2004年第15期37卷 59-64页

作者： R. Lepore A. Vande Wouwer M. Remy Ph. Bogaerts Laboratoire d’Automatique Faculté Polytechnique de Morts Boulevard Dolez 3î B-7000 Morts Belgium +32 (0)65 374140 fax: +32 (0)65 374136 Université Libre de Bruxelles

Due to the lack of reliable and/or inexpensive hardware sensors in cement grinding, development of software sensors is particularly significant for control and monitoring purposes. In this study, a nonlinear distributed-parameter, full-horizon observer is designed, which allows the contents of the mill to be described in terms of hold-up and particle size distribution. When measurements are available at relatively high sampling rates and at, at least, two spatial locations along the mill, fast observer convergence is obtained. However, in practical situations where measurements can be collected at the mill outlet only and with a relatively low sampling rate, the observer convergence deteriorates, as the sampling rate decreases, performance becomes similar to an asymptotic (simulation) observer. The robustness of the software sensor can be improved by on-line identification of some time-varying parameters, such as the material grindability. These several concepts are discussed and tested in simulation based on a realistic process model. Copyright © 2004IFAC

关键词： distributed-parameter systems nonlinear models softsensing observers process control industrial production systems

来源：评论

学校读者我要写书评

暂无评论

Identification of Time-non local Models under Diffusive Representation

引用

IFAC Proceedings Volumes 2010年第21期43卷 378-385页

作者： C. Casenave CNRS LAAS 7 avenue du colonel Roche F-31077 Toulouse France Université de Toulouse UPS INSA INP ISAE F-31077 Toulouse France.

In this paper, we show how the so-called diffusive representation can be used in order to identify nonlinear Volterra models of the form H (∂ t ) X = f ( u, X ) + v . Several methods are described, all being based on a suitable parameterization of H (∂ t ) by means of its γ-symbol. Following this idea, the complex dynamic nature of H (∂ t ) can be summarized by a few parameters on which the identification of the dynamic part of the model will focus. For illustration, we implement the methods on a concrete numerical example.

关键词： Least squares identification Sampled data Operators Convolution integral Continuous time systems Dynamic systems distributed-parameter systems

来源：评论

学校读者我要写书评

暂无评论

Modeling and Control of a Flexible Spacecraft for Large-Angle Rapid Maneuvers

引用

IFAC Proceedings Volumes 1998年第21期31卷 341-346页

作者： Yong Li Beijing Institute of Control Engineering Chinese Academy of Space Technology Beijing 100080 P. R. CHINA

This paper deals with large-angle rapid slew maneuvers of a flexible spacecraft, which consists of a rigid central body and a flexible beam attached to it. Dynamic model for the spacecraft described by a coupled nonlinear hybrid system is derived. With the control torque applied to the rigid central body only, a PD control law is presented using the measurements of the attitude angle of the rigid body and its velocity. Based upon the Lyapunov method in infinite dimensional space, it is shown that implementation of the control algorithm results in the slew maneuvering with the simultaneous vibration suppression.

关键词： structure systems nonlinear models distributed-parameter systems PD controllers stability analysis

来源：评论

学校读者我要写书评

暂无评论

Backstepping-based tracking control of the vertical gradient freeze crystal growth process

引用

IFAC-PapersOnLine 2023年第2期56卷 8171-8176页

作者： Stefan Ecklebe Nicole Gehring Institute of Control Theory Technische Universität Dresden Germany Institute of Automatic Control and Control Systems Technology Johannes Kepler University Linz Austria

The vertical gradient freeze crystal growth process is the main technique for the production of high quality compound semiconductors that are vital for today's electronic applications. A simplified model of this process consists of two 1D diffusion equations with free boundaries for the temperatures in crystal and melt. Both phases are coupled via an ordinary differential equation that describes the evolution of the moving solid/liquid interface. The control of the resulting two-phase Stefan problem is the focus of this contribution. A flatness-based feedforward design is combined with a multi-step backstepping approach to obtain a controller that tracks a reference trajectory for the position of the phase boundary. Specifically, based on some preliminary transformations to map the model into a time-variant PDE-ODE system, consecutive transformations are shown to yield a stable closed loop. The tracking controller is validated in a simulation that considers the actual growth of a Gallium arsenide single crystal.

关键词： crystal growth Stefan problem distributed-parameter systems control applications state feedback backstepping

来源：评论

学校读者我要写书评

暂无评论

Vibration Control of Flexible Structures with Spatially distributed Disturbance

引用

IFAC Proceedings Volumes 2004年第14期37卷 289-294页

作者： Dunant Halim School of Mechanical Engineering The University of Adelaide SA 5005 Australia

This work introduces a novel optimal control framework for vibration control of flexible structures, taking into account the spatially distributed nature of the disturbance and structural response. The control framework is developed by introducing the concept of spatial H 2 norm for systems with spatially distributed input. This approach allows the systematic design of controllers that can perforin optimally in the situation where the disturbance occurs at varying locations over a structure. Simulation studies on a piezoelectric laminate beam are performed by designing spatial H 2 controllers for minimizing structural vibration due to a spatially varying bending moment. The simulation results show that the proposed spatial H 2 controllers can effectively reduce vibration when the bending moment disturbance is applied at various locations over the beam.

关键词： Vibration Disturbance rejection Control design Flexible structures distributed-parameter systems H 2 norm

来源：评论

学校读者我要写书评

暂无评论

A Systematic Design of Backstepping-Based State Feedback Controllers for ODE-PDE-ODE systems

引用

IFAC-PapersOnLine 2021年第9期54卷 410-415页

作者： N. Gehring Institute of Automatic Control and Control Systems Technology Johannes Kepler University 4040 Linz Austria

The backstepping design of stabilizing state feedback controllers is addressed for bidirectionally coupled ODE-PDE-ODE systems, that naturally arise for infinite-dimensional systems where actuator or sensor dynamics are taken into account. A common framework for both linear parabolic and hyperbolic partial differential equations with spatially varying coefficients is presented, that solely relies on the strict feedback form of these systems. Without imposing any limitation on the dimension of the ODEs and PDEs involved, a multi-step design algorithm is suggested, that makes use of classical concepts (such as integrator backstepping and output zeroing) known for the control of ODE systems. By that, backstepping is brought back to its ODE origins and a systematic design of backstepping controllers for ODE-PDE-ODE systems is offered, with a unified treatise for parabolic and hyperbolic PDEs.

关键词： backstepping ODE-PDE-ODE systems boundary control distributed-parameter systems state feedback parabolic systems hyperbolic systems

来源：评论

学校读者我要写书评

暂无评论

INTEGRODIFFERENTIAL APPROACH TO OPTIMAL CONTROL PROBLEMS OF ELASTIC BEAM MOTIONS

引用

IFAC Proceedings Volumes 2007年第14期40卷 153-156页

作者： G.V. Kostin V.V. Saurin Institute for Problems in Mechanics of the Russian Academy of Sciences

An approach to modeling and optimization of controlled dynamical systems with distributed elastic and inertial parameters is considered. The general method of integrodifferential relations (IDR) for solving a wide class of boundary value problems is developed and criteria of solution quality are proposed. A numerical algorithm for discrete approximation of controlled motions has been worked out and applied to design the optimal control law moving an elastic system to the terminal position and minimizing the given objective function. The polynomial control for plane motions of a homogeneous cantilever beam is investigated. The optimal control problem of beam transportation from the initial rest position to given terminal states, in which the total mechanical energy of the system reaches its minimal value, is considered. Copyright © 2002 IFAC

关键词： Approximate analysis distributed-parameter systems Optimal control

来源：评论

学校读者我要写书评

暂无评论

Time reversibility and spectral completeness via exact observability

引用

IFAC Proceedings Volumes 1999年第2期32卷 2819-2823页

作者： Kangsheng Liu Department of Applied Mathematics Zhejiang University Hangzkou 310027 China

Consider a linear system Ż ( t ) = AZ ( t ), t > 0 in a ililbert space H . When if is finite-dimensional, every state trajetory of the system has a unique backward-time continuation and the set of all finite linear combinations of the generalized eigenvectors of A is dense in H . For infinite-dimensional system, however, both time reversibility and spectral completeness can be absent. This paper reveals the two properties in several elastic systems with boundary damping by the observability method (Liu and Russell, 1998).

关键词： distributed-parameter systems reversibility eigenvectors eigenmode analysis observability vibration damping

来源：评论

学校读者我要写书评

暂无评论

Hyperbolicity of the heat equation

引用

IFAC-PapersOnLine 2019年第7期52卷 63-67页

作者： Guilherme Ozorio Cassol Stevan Dubljevic Department of Chemical and Materials Engineering University of Alberta Edmonton Alberta Canada T6G 2V4

In this manuscript, a comparison between the parabolic and hyperbolic partial differential equations for heat diffusion is studied. First, numerical results and an eigenvalue analysis for these two types of equations are shown, which help to understand the difference in the system dynamics. Then, both equations are also considered in a Stefan problem for the melting of an ice block in a one-dimensional setting. The results show that the hyperbolic partial differential equation shows a finite speed of propagation of heat and can represent the system as properly as the parabolic equation.

关键词： distributed-parameter systems Moving boundary conditions Heat flows Linear systems Eigenvalue problems

来源：评论

学校读者我要写书评

暂无评论

Optimal Control Methods in Solving Inverse Problems of Mathematical Physics for First-Order Hyperbolic systems

引用

IFAC Proceedings Volumes 2001年第6期34卷 295-299页

作者： Alexander V. Arguchintsev Irkutsk State University 1 K.Marx Street Irkutsk 664003. Russia.

The paper deals with using optimal control methods for solving inverse problems of mathematical physics. In many cases this problem can be considered as an optimal control problem in which unknown control functions are smooth elementsof initial or boundary conditions, coefficients of differential operators or right-hand sides of differential equations. A non-classic optimality condition and numerical algorithm for smooth boundary controls in semi-linear first-order hyperbolic systems are presented. The special feature of the general optimization problem for boundary conditions is non-validity of the classic optimality condition of Pontryagin's type. The suggested approach is based on special variations of admissible continuously differentiable controls. These variations can be applied for controls satisfying either restrictions of inclusion type or integral restrictions.

关键词： Inverse dynamic problem optimal control distributed-parameter systems computational methods wave equations

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：