检索结果-内蒙古大学图书馆

Sampled-data indirect adaptive control of bioreactor using affine radial basis function network architecture

JOURNAL OF DYNAMIC SYSTEMS MEASUREMENT AND CONTROL-TRANSACTIONS OF THE ASME 1997年第1期119卷 94-97页

作者： Gorinevsky, D UNIV TORONTO DEPT MECH ENGNTORONTOONCANADA

This paper considers a problem of bioreactor control, which is formulated in Anderson and Miller (1990) and Ungar (1990) as a benchmark problem for application of neural network-based adaptive control algorithms. A completely adaptive control of this strongly nonlinear system is achieved with no a priori knowledge of its dynamics. This becomes possible thanks to a novel architecture of the controller, which is based on an affine Radial Basis Function network approximation of the sampled-data system mapping. Approximation with such network could be considered as a generalization of a standard practice to linearize a nonlinear system about the working regime. As the network is affine in the control components, it can be inverted with respect to the control vector by using fast matrix computations. The considered approach includes several features, recently introduced in some advanced process control algorithms. These features-multirate sampling, on-line adaptation, and Radial Basis Function approximation of the system nonlinear-are crucial for the achieved high performance of the controller.

关键词： Radial basis function networks HIGH-PERFORMANCE adaptive control computer algorithms Data sampling ARCHITECTURE Affine Building construction Benchmark testing Controllers In-law Bioreactors ActiveX control

来源：评论

学校读者我要写书评

暂无评论

Fuzzy power control in PWM voltage-type rectifier

Fuzzy power control in PWM voltage-type rectifier

引用

IEEE International Symposium on Industrial Electronics

作者： Valouch, V Acad Sci Czech Republ Inst Elect Engn Prague 18202 Czech Republic

ISBN: (纸本)0780339363

The paper presents a fuzzy logic-based control principle of active and reactive powers in PWM voltage rectifiers. Such a PWM voltage-type rectifier, equiped with the proposed control strategy, may be used advantageously as an active filter to compensate the unsuitable power factor and/or current high harmonics of nonlinear loads connected to the mains. After the description of this control algorithm, results of simulation are presented and compared with those for the Direct Self Control (DSC) strategy of the PWM rectifiers, which is another new and promissing method, The results of the analysis and simulation performed show that the fuzzy power control method if simple and little sensitive to the changes of input filter parameters, while the number of sensors needed is relatively low. The algorithm works well even for the small values of the input filter inductance and output de capacitance, and exhibits high dynamic capabilities.

关键词： Fuzzy Rectifiers Reactive power PWM rectifiers input filter Power control computer algorithms control strategy nonlinear load active filters

来源：评论

学校读者我要写书评

暂无评论

Direct torque control of induction motor drives

Direct torque control of induction motor drives

引用

IEEE International Symposium on Industrial Electronics

作者： Buja, G Casadei, D Serra, G Univ Padua Dept Elect Engn I-35100 Padua Italy

ISBN: (纸本)0780339363

Direct Torque control (DTC) is an emerging technique for controlling the PWM inverter-fed induction motor (IM) drives. It allows the precise and quick control of the IM flux and torque without calling for complex control algorithms. In principle, moreover, it requires only the knowledge of the stator resistance. The? tutorial starts by reviewing the basic operation of an IM and of a PWM inverter using the space vector theory. The field-orientated (FO) control of an IM drive is also reviewed. Then the concept of DTC is illustrated and three DTC-based strategies [i.e. Switching Table (ST), Direct Self control (DCS), Space Vector Modulation (SVM)] are described. The ST strategy is dealt with in detail, discussing the results which can be obtained with different choices of the switching table. Problems associated with the selection of the amplitude of the hysteresis bands of the flux and torque controllers are illustrated by means of experimental data. Merits and limits of DTC: are reported and a comparison with FO control is given.

关键词： Pulse width modulation inverters computer algorithms induction motors stator resistance induction motor drives space vector Torque Torque control calls

来源：评论

学校读者我要写书评

暂无评论

Distributed link-layer control for automated highway systems

引用

JOURNAL OF DYNAMIC SYSTEMS MEASUREMENT AND CONTROL-TRANSACTIONS OF THE ASME 1997年第2期119卷 192-197页

作者： Peng, H Department of Mechanical Engineering and Applied Mechanics University of Michigan Ann Arbor MI 48109-2125

The modeling and design of a link-layer control algorithm for automated highway systems are presented in this paper. Link-layer control systems address the coordination of traffic on a stretch of highway, and serve as the intermediate layer between traffic management (ATMS) and vehicle control (AVCS) systems. The key role of the link layer control system is to use macroscopic traffic information for improved traffic flow. A distributed control algorithm is developed based on optimal control theory. The proposed control law is implemented in a simulation program which keeps track of the motions of each individual vehicles on the highway. Simulation results under three perturbed conditions-uneven traffic distribution, broken vehicle, and traffic merging-are presented.

关键词： vehicle control systems Automated highway systems Highway systems truth maintenance Freeway Advanced Vidicon Camera System (AVCS) emulator program Traffic distribution control law computer algorithms link layer Traffic Traffic flow Traffic information

来源：评论

学校读者我要写书评

暂无评论

computer algorithms FOR RADIOMETRIC MEASUREMENT OF TEMPERATURE DURING THE GALVANNEAL PROCESS

引用

METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE 1994年第3期25卷 459-462页

作者： ZENTNER, LK DEWITT, DP WHITE, DA GASKELL, DR PURDUE UNIV SCH MAT ENGN W LAFAYETTE IN 47907 USA PURDUE UNIV SCH MECH ENGN W LAFAYETTE IN 47907 USA INLAND STEEL CORP E CHICAGO IN 46312 USA

A set of computer algorithms has been developed to facilitate the measurement of temperature by radiometry during the galvannealing of steel strip. During the galvanneal process, the emissivity of the surface of the strip increases rapidly from a value of approximately 0.2 for the highly specular surface of the liquid zinc coating to a value as high as 0.8 for the surface of the diffuse intermetallic layer that is formed. Reliable noncontact measurement of temperature during galvannealing requires an approach that can accommodate and compensate for this large and rapid change in emissivity. The galvanneal process was simulated in 63 laboratory tests during which the temperature was measured by a thermocouple, and spectral radiance was measured using a dual-wavelength radiation thermometer (DWRT). The emissivity of the surface was obtained from these data. The tests were conducted at galvannealing temperatures of 753, 793, and 833 K and simulated line speeds of 60, 80, and 100 m/min. The laboratory data were used to develop a linear dual-wavelength emissivity compensation algorithm to infer the temperature of the strip to within +/-20 K. The iron content of the galvannealed layers varied in the range 5 to 13 pct, and measurements of surface roughness gave arithmetic roughness values in the range 1 to 3 mum.

关键词： Zinc coatings RADIOMETRY Ribbon Device Component noncontact measurement computer algorithms Strip steel Surfaces Thermocouple Temperature Roughness measurement hot dip galvanizing Emissivity fast-switching

来源：评论

学校读者我要写书评

暂无评论

Development of a fuzzy logic controller for dc/dc converters: Design, computer simulation, and experimental evaluation

引用

IEEE TRANSACTIONS ON POWER ELECTRONICS 1996年第1期11卷 24-32页

作者： So, WC Tse, CK Lee, YS Hong Kong Polytechnic Univ Hong Kong

The design of a fuzzy logic controller for dc/dc converters is described in this paper, A brief review of fuzzy logic and its application to control is first given, Then, the derivation of a fuzzy control algorithm for regulating dc/dc converters is described in detail, The propo11pel01-sosed fuzzy control is evaluated by computer simulations as well as experimental measurements of the closed-loop performance of simple dc/dc converters in respect of load regulation and line regulation.

关键词： line regulation closed-loop performance Fuzzy logic computer Simulation fuzzy logic controller power conversion unit computer algorithms load control Fuzzy control

来源：评论

学校读者我要写书评

暂无评论

Control for unstable nonminimum phase uncertain dynamic vehicle

引用

IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS 1996年第3期32卷 945-951页

作者： Rusnak, I RAFAEL Advanced Defense Systems Limited Israel

A control algorithm for control of Linear uncertain system is presented This algorithm is applied to the control of an unstable nonminimum phase uncertain dynamic vehicle. The algorithm is based on the state and parameters observability canonical (SPOC) form and a certainty equivalence pole placement controller. The algorithm provides single controller for the problem of the uncertain dynamic vehicle that approaches the performance of a controller designed for perfectly known parameters within the whole range of the plant's parameters uncertainty. The algorithm is globally bounded input bounded output stable and needs only the knowledge of the order of the plant. The algorithm is presented and its performance is demonstrated by simulations.

关键词： Uncertainty WELL PERFORMANCE pole assignment linear uncertain system Controllers Plant uncertain algorithms Signal controller FULL-SCALE Bounded vehicle computer algorithms

来源：评论

学校读者我要写书评

暂无评论

Operation of the unified power flow controller as harmonic isolator

引用

IEEE TRANSACTIONS ON POWER ELECTRONICS 1996年第6期11卷 776-784页

作者： Enslin, JHR Zhao, J Spee, R OREGON STATE UNIV DEPT ELECT & COMP ENGNCORVALLISOR 97331

The unified power flow controller (UPFC) is a tool in the implementation of Flexible AC Transmission Systems (FACTS), It provides for the equivalent of static VAr compensation and series injection using back-to-back force commutated converters, This paper proposes a control strategy to extend UPFC operation to allow for the isolation of harmonics due to nonlinear loads. Simulation results based on the Electromagnetic Transients Program (EMTP) are used to illustrate device performance in a power system environment. Experimental results based on a single phase laboratory implementation verify the proposed control algorithm.

关键词： Electromagnetic Transients Program harmonics control strategy flexible AC transmission systems Surgery Isolator Device Component unified power flow controller static VAr compensation computer algorithms equipment performance demand regulator

来源：评论

学校读者我要写书评

暂无评论

Searching for faint companions to nearby stars with the Hubble Space Telescope

引用

PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC 1996年第724期108卷 510-519页

作者： Schroeder, DJ Golimowski, DA JOHNS HOPKINS UNIV DEPT PHYS & ASTRONCTR ASTROPHYS SCIBALTIMOREMD 21218

A search for faint companions (FCs) to selected stars within 5 pc of the Sun using the Hubble Space Telescope's Planetary Camera (PC) has been initiated. To assess the PC's ability to detect FCs, we have constructed both model and laboratory-simulated images and compared them to actual PC images. We find that the PC's point-spread function (PSF) is 3-4 times brighter over the angular range 2 ''-5 '' than the PSF expected for a perfect optical system. Azimuthal variations of the PC's PSF are 10-20 times larger than expected for a perfect PSF. These variations suggest that light is scattered nonuniformly from the surface of the detector. Because the anomalies in the PC's PSF cannot be precisely simulated, subtracting a reference PSF from the PC image is problematic. We have developed a computer algorithm that identifies local brightness anomalies within the PSF as potential FCs. We find that this search algorithm will successfully locate FCs anywhere within the circumstellar field provided that the average pixel signal from the FC is at least 10 sigma above the local background. This detection limit suggests that a comprehensive search for extrasolar Jovian planets with the PC is impractical. However, the PC is useful for detecting other types of substellar objects, With a stellar signal of 10(9) e(-), for example, we may detect brown dwarfs as faint as M(l)=16.7 separated by 1 '' from a Cen A.

关键词： Hubble Space Telescope Micro computer Syncope Searches Point spread function Fluorocarbons NEARBY STARS SEARCHING ALGORITHM Companions Jovian planet Anomalies computer algorithms

来源：评论

学校读者我要写书评

暂无评论

Analysis of one-way reservation algorithms

引用

JOURNAL OF HIGH SPEED NETWORKS 1996年第4期5卷 347-363页

作者： Cidon, I Rom, R Shavitt, Y SUN MICROSYST INC MT VIEWCA 94043 TECHNION ISRAEL INST TECHNOL DEPT ELECT ENGNIL-32000 HAIFAISRAEL

Modem high speed networks (and ATM networks in particular) use resource reservation as a basic means of establishing communications. One-way on-the-fly reservation is a method for allocating resources for short bursts of data when regular reservation is too costly. The first of such algorithms were recently suggested by Turner. We investigate two examples that are characteristic to the way traffic streams interact in virtual circuit networks: a three node subnetwork that also acts as a 4X2 switch and a ring. For both systems we compute system throughput under homogeneous load, and compare it with the throughput when fast reservation protocols (FRP) are used. For the three node subnetwork we give an explicit expression for an upper bound.

关键词： Real-time computing computer algorithms Virtual machine systems

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：