197,365 research outputs found
Regeltechniek in beweging
Full text linkRegeltechniek is een relatief jong en dynamisch vakgebied. In deafgelopen decennia is waardering ontstaan voor de relatie tussenklassieke en moderne (modelgebaseerde) regeltechniek. Er isook een duidelijk toenemende aandacht voor toepassingen.Uitgaande van zijn ervaring met de regeling van nauwkeurigepositioneringssystemen betoogt Maarten Steinbuch in zijn rede,dat naast de aandacht voor modelvorming van het te regelen systeemmeer onderzoek nodig is voor de (experimentele) modelvormingvan storingen en modelonzekerheden. Deze ‘disturbance-based’ontwerpcyclus licht hij in zijn rede nader toe.Ook bepleit Maarten Steinbuch, mede gebaseerd op zijn industriëleervaring, een verdere professionalisering van de academischeorganisatie. Hij breekt een lans voor de relevantie van het praktiserenvan experimentele vaardigheden in het onderwijs en voor het belangvan een gezonde interactie tussen wetenschap en industrie
Topology Optimization of Hybrid Power Trains
No full text\u3cp\u3eTopology optimization methods for continuum systems (structural topology, shape, material) are well-established. However, these methods do not apply to non-continuum or dynamic systems with discrete components with unique characteristics as with hybrid vehicles. This chapter examines the power train topology and control design optimization problem at vehicle system level. The design space related to power train and control system optimization level is rapidly increasing with new developments in power train, auxiliary technologies, system architectures (topologies) and cyber-physical systems. The multi-objective, mixed or hybrid (continuous/discrete time) character on both coupled levels of the problem requires relative long computation time. Therefore, it requires a bi-level (nested) or simultaneous system design approach. Since, sequential or iterative design procedures fail to prove system-level optimality. In this chapter, some illustrative examples are discussed related to nested control and design optimization problems related to continuous/stepped-gear transmission shifting, power split control and/or in combination with topology optimization.\u3c/p\u3
Modelling and control of an electro-mechanically actuated pushbelt type continuously variable transmission
No full textFor analysis, control design and testing of an electro-mechanically actuated CVT, a simulation model is built. The model incorporates all major driveline components and the proposed actuation system with servo motor actuation. The clamping forces in the variator are calculated using an explicit formulation of a model based on Coulomb friction. Identification of the non-linear model using step response analysis shows resonances between 8-12 [Hz] and between 20-30 [Hz], depending on the ratio. Closed loop bandwidths that can be achieved are typically 5 [Hz] for ratio control and 20 [Hz] for slip control
Inferential iterative learning control with basis functions : application in wide format media handling
No full textThis report, Inferential Iterative Learning Control with Basis Functions: Application in Wide Format Media Handling, is a traineeship report within the Control Systems Technology Group of the faculty of Mechanical Engineering at the Eindhoven University of Technology. Research is performed at Océ Technologies B.V. in Venlo under supervision of prof. Dr. Ir. M. Steinbuch, Dr. ir. S.H. Koekebakker and Ing. S. Winteraeken. The focus of this report is on designing an intelligent media handling controller that minimizes interactions between the media loading and media positioning. Iterative Learning Control (ILC) has proven to be successful in increasing performance in industrial applications with repetitive tasks, a shortcoming of ILC is however its model and reference dependency. Basis functions were introduced to enlarge the ability to accommodate for variations in the reference and initial conditions. Performance is not always measured in a collocated fashion, in the industrial application at hand it is measured indirectly. This calls for inferential iterative learning control (IILC), where the performance increase via ILC is rendered in a non-collocated setting while stability is guaranteed by a collocated feedback loop. This report proves that the designed IILC algorithm with basis functions is robust against variations in the load and reference while achieving signicant improvements in comparison to previously developed ILC algorithm
Dr. Duane M. Jackson, Morehouse College, July 2011
No full textThis video is a conversation with Dr. Duane M. Jackson. Dr. Jackson talks about his paper, "Recall and the Serial Position Effect: The Role of Primacy and Recency on Accounting Students' Performance." Jackie Daniel, AUC Woodruff Library, is the interviewer
Dynamic modelling and robust control of a wind energy conversion system
No full textThe application of wind energy conversion systems for the production of electrical energy requires a cheap and reliable operation. Especially at high wind velocities fluctuations from the wind field result in large mechanical loads of the wind turbine. Also fluctuations in the grid voltage may yield large dynamic excitations. In order to realize a long lifetime and a reliable operation active control systems are necessary. The main goal of the study described in this thesis is to develop an approach for the design of a high performance control system for a wind turbine with variable speed. The wind turbine system under investigation has a three-bladed rotor which is connected to the generator by a transmission. The electrical conversion system consists of a synchronous generator with a rectifier, direct current transmission and an inverter. The manipulable inputs are the pitch angle of the turbine blades, the field voltage of the generator and the delay angle of the rectifier. Both the generator speed and the direct current are being measured. The control design problem at full load is to minimize fluctuations in speed and current while reducing the mechanical (fatigue) loads. The feedback system should realize this without excessive use of the input variables and must also be simple to implement. I In order to be able to design a high performance control system a high quality dynamic model is required. Much attention has been given to the. modelling of the electrical conversion system. The switching of the thyristors of the rectifier bridge results in periodic behaviour at a high frequency. In order to design a control system an averaged model has been derived through the application of Floquet theory for periodic systems. The properties of the aerodynamic transfer and of the drive train only have been approximately modelled. Deviations of these nominal models from the real system are accounted for using norm-bounded uncertainty models. Using the nominal model and the uncertainty models the control system design has been carried out. The control design problem can suitably be handled by the Linear Quadratic design method. However, instead of using the standard solution with observers, in this study the optimization theory has been applied with respect to a predefined structure of the feedback law. In this approach the order and structure of the controller can be selected as part of the problem formulation. The application to the wind turbine system shows that a high performance control system can be obtained using a relatively simple, low order multivariable feedback law. The use of frequency weighting effectively reduces the role of mechanical parasitic dynamics. Application of the multi-model principle in combination with LQ optimization theory provides a way to synthesize controllers which are robust for large (aerodynamic) changes in operating conditions. A quantitative robustness analysis shows how the design parameters of the feedback law can be adapted in order to enhance the robustness of the controller. The approach taken, involving extensive modelling combined with uncertainty models and with the use of optimization theory and robustness analysis, has been shown to result in a high performance control system. Its main characteristic is the integrated approach of the control problem, with combined control action via the mechanics and the electrical conversion system. It is recommended to apply this integrated approach also to other types of wind turbine systems.Mechanical Maritime and Materials Engineerin
"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States" By M. Carey.
No full text"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States: containing bried sketches of the moral and political character of those states.
By M. Carey, member of the American philosophical, and of the American Antiquarian Society, and author of The Olive Branch, Cindiciae Hibernicae, essays on banking, on political economy, and on internal improvement.
To which are now added the English editor's comments on the subject; together with Important Advice to Emigrants, and Cautions Against Impositions Practiced in the Outports
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Dr. Glendon Swarthout
No full textHosted by Roger M. Busfield, MSU Assistant Professor of Speech and Theater, Meet the Author is designed to introduce a general audience to a contemporary author and their work through in-depth interviews. This episode features a conversation between Dr. Glendon Swarthout, prolific author and English professor at MSU, and assistant professors Sam S. Baskett and Theodore B. Strandness
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