18 research outputs found
Design and experimental validation of a piezoelectric actuator tracking control based on fuzzy logic and neural compensation
This work proposes two control feedback-feedforward algorithms, based on fuzzy logic in combination with neural networks, aimed at reducing the tracking error and improving the actuation signal of piezoelectric actuators. These are frequently used devices in a wide range of applications due to their high precision in micro- and nanopositioning combined with their mechanical stiffness. Nevertheless, the hysteresis is one the main phenomenon that degrades the performance of these actuators in tracking operations. The proposed control schemes were tested experimentally in a commercial piezoelectric actuator. They were implemented with a dSPACE 1104 device, which was used for signal generation and acquisition purposes. The performance of the proposed control schemes was compared to conventional structures based on proportional-integral-derivative and fuzzy logic in feedback configuration. Experimental results show the advantages of the proposed controllers, since they are capable of reducing the error to significant magnitude orders.The authors wish to express their gratitude to the Basque Government, through the project EKOHEGAZ (ELKARTEK KK-2021/00092), to the DiputaciĂłn Foral de Ălava (DFA), through the project CONAVANTER, and to the UPV/EHU, through the project GIU20/063, for supporting this work
Energy-efficient Reactive and Predictive Connected Cruise Control
In this paper, we propose a framework for the longitudinal control of
connected and automated vehicles traveling in mixed traffic consisting of
connected and non-connected human-driven vehicles. Reactive and predictive
controllers are proposed. Reactive controllers are given by explicit feedback
control laws. In predictive controllers, the control input is optimized in a
receding-horizon fashion, which depends on the predictions of motions of
preceding vehicles. Beyond-line-of-sight information is obtained via
vehicle-to-vehicle (V2V) communication, and is utilized in the proposed
reactive and predictive controllers. Simulations utilizing real traffic data
are used to show that connectivity can bring significant energy savings.Comment: 18 pages, 12 figures, submitted to Transportation Research Part C:
Emerging Technologie
Type-2 Takagi-Sugeno-Kang Fuzzy Logic System and Uncertainty in Machining
RĂSUMĂ: Plusieurs mĂ©thodes permettent aujourdâhui dâanalyser le comportement des Ă©coulements
qui rĂ©gissent le fonctionnement de systĂšmes rencontrĂ©s dans lâindustrie (vĂ©hicules aĂ©riens,
marins et terrestres, gĂ©nĂ©ration dâĂ©nergie, etc.). Pour les Ă©coulements transitoires ou
turbulents, les méthodes expérimentales sont utilisées conjointement avec les simulations
numĂ©riques (simulation directe ou faisant appel Ă des modĂšles) afin dâextraire le plus
dâinformation possible. Dans les deux cas, les mĂ©thodes gĂ©nĂšrent des quantitĂ©s de donnĂ©es
importantes qui doivent ensuite ĂȘtre traitĂ©es et analysĂ©es. Ce projet de recherche vise Ă
amĂ©liorer notre capacitĂ© dâanalyse pour lâĂ©tude des Ă©coulements simulĂ©s numĂ©riquement
et les Ă©coulements obtenus Ă lâaide de mĂ©thodes de mesure (par exemple la vĂ©locimĂ©trie
par image de particules PIV ).
Lâabsence, jusquâĂ aujourdâhui, dâune dĂ©finition objective dâune structure tourbillonnaire
a conduit Ă lâutilisation de plusieurs mĂ©thodes eulĂ©riennes (vorticitĂ©, critĂšre Q,
Lambda-2, etc.), souvent inadaptées, pour extraire les structures cohérentes des écoulements.
Lâexposant de Lyapunov, calculĂ© sur un temps fini (appelĂ© le FTLE), sâest rĂ©vĂ©lĂ©
comme une alternative lagrangienne efficace à ces méthodes classiques. Cependant, la
mĂ©thodologie de calcul actuelle du FTLE exige lâĂ©valuation numĂ©rique dâun grand nombre
de trajectoires sur une grille cartésienne qui est superposée aux champs de vitesse
simulés ou mesurés. Le nombre de noeuds nécessaire pour représenter un champ FTLE
dâun Ă©coulement 3D instationnaire atteint facilement plusieurs millions, ce qui nĂ©cessite
des ressources informatiques importantes pour une analyse adéquate.
Dans ce projet, nous visons Ă amĂ©liorer lâefficacitĂ© du calcul du champ FTLE en
proposant une méthode alternative au calcul classique des composantes du tenseur de
dĂ©formation de Cauchy-Green. Un ensemble dâĂ©quations diffĂ©rentielles ordinaires (EDOs)
est utilisé pour calculer simultanément les trajectoires des particules et les dérivées premiÚres
et secondes du champ de déplacement, ce qui se traduit par une amélioration de
la précision nodale des composantes du tenseur. Les dérivées premiÚres sont utilisées
pour le calcul de lâexposant de Lyapunov et les dĂ©rivĂ©es secondes pour lâestimation de
lâerreur dâinterpolation. Les matrices hessiennes du champ de dĂ©placement (deux matrices
en 2D et trois matrices en 3D) nous permettent de construire une métrique optimale
multi-échelle et de générer un maillage anisotrope non structuré de façon à distribuer efficacement
les noeuds et Ă minimiser lâerreur dâinterpolation.----------ABSTRACT: Several methods can help us to analyse the behavior of flows that govern the operation
of fluid flow systems encountered in the industry (aerospace, marine and terrestrial
transportation, power generation, etc..). For transient or turbulent flows, experimental
methods are used in conjunction with numerical simulations ( direct simulation or based
on models) to extract as much information as possible. In both cases, these methods
generate massive amounts of data which must then be processed and analyzed. This
research project aims to improve the post-processing algorithms to facilitate the study
of numerically simulated flows and those obtained using measurement techniques (e.g.
particle image velocimetry PIV ).
The absence, even until today, of an objective definition of a vortex has led to the
use of several Eulerian methods (vorticity, the Q and the Lambda-2 criteria, etc..), often
unsuitable to extract the flow characteristics. The Lyapunov exponent, calculated on a
finite time (the so-called FTLE), is an effective Lagrangian alternative to these standard
methods. However, the computation methodology currently used to obtain the FTLE
requires numerical evaluation of a large number of fluid particle trajectories on a Cartesian
grid that is superimposed on the simulated or measured velocity fields. The number of
nodes required to visualize a FTLE field of an unsteady 3D flow can easily reach several
millions, which requires significant computing resources for an adequate analysis.
In this project, we aim to improve the computational efficiency of the FTLE field
by providing an alternative to the conventional calculation of the components of the
Cauchy-Green deformation tensor. A set of ordinary differential equations (ODEs) is
used to calculate the particle trajectories and simultaneously the first and the second
derivatives of the displacement field, resulting in a highly improved accuracy of nodal
tensor components. The first derivatives are used to calculate the Lyapunov exponent
and the second derivatives to estimate the interpolation error. Hessian matrices of the
displacement field (two matrices in 2D and three matrices in 3D) allow us to build a
multi-scale optimal metric and generate an unstructured anisotropic mesh to efficiently
distribute nodes and to minimize the interpolation error. The flexibility of anisotropic
meshes allows to add and align nodes near the structures of the flow and to remove
those in areas of low interest. The mesh adaptation is based on the intersection of the
Hessian matrices of the displacement field and not on the FTLE field
Computer Aided Verification
This open access two-volume set LNCS 11561 and 11562 constitutes the refereed proceedings of the 31st International Conference on Computer Aided Verification, CAV 2019, held in New York City, USA, in July 2019. The 52 full papers presented together with 13 tool papers and 2 case studies, were carefully reviewed and selected from 258 submissions. The papers were organized in the following topical sections: Part I: automata and timed systems; security and hyperproperties; synthesis; model checking; cyber-physical systems and machine learning; probabilistic systems, runtime techniques; dynamical, hybrid, and reactive systems; Part II: logics, decision procedures; and solvers; numerical programs; verification; distributed systems and networks; verification and invariants; and concurrency
Aeronautical engineering: A continuing bibliography with indexes (supplement 250)
This bibliography lists 420 reports, articles, and other documents introduced into the NASA scientific and technical information system in February, 1990. Subject coverage includes: design, construction and testing of aircraft and aircraft engines; aircraft components, equipment and systems; ground support systems; and theoretical and applied aspects of aerodynamics and general fluid dynamics
Computer Aided Verification
This open access two-volume set LNCS 11561 and 11562 constitutes the refereed proceedings of the 31st International Conference on Computer Aided Verification, CAV 2019, held in New York City, USA, in July 2019. The 52 full papers presented together with 13 tool papers and 2 case studies, were carefully reviewed and selected from 258 submissions. The papers were organized in the following topical sections: Part I: automata and timed systems; security and hyperproperties; synthesis; model checking; cyber-physical systems and machine learning; probabilistic systems, runtime techniques; dynamical, hybrid, and reactive systems; Part II: logics, decision procedures; and solvers; numerical programs; verification; distributed systems and networks; verification and invariants; and concurrency
The Fifth Annual Thermal and Fluids Analysis Workshop
The Fifth Annual Thermal and Fluids Analysis Workshop was held at the Ohio Aerospace Institute, Brook Park, Ohio, cosponsored by NASA Lewis Research Center and the Ohio Aerospace Institute, 16-20 Aug. 1993. The workshop consisted of classes, vendor demonstrations, and paper sessions. The classes and vendor demonstrations provided participants with the information on widely used tools for thermal and fluid analysis. The paper sessions provided a forum for the exchange of information and ideas among thermal and fluids analysts. Paper topics included advances and uses of established thermal and fluids computer codes (such as SINDA and TRASYS) as well as unique modeling techniques and applications
JTIT
kwartalni
Proceedings of the Twentieth Annual Biochemical Engineering Symposium
The 20th Annual Biochemical Engineering Symposium was held at Kansas State University on April 21,1990. The objectives of the symposium were to provide: (i) a forum for informal discussion of biochemical engineering research being conducted at the participating institutions and (ii) an opportunity for students to present and publish their work.
Twenty-eight papers presented at the symposium are included in this proceedings. Some of the papers describe the progress of ongoing projects, and others contain the results of completed projects. Only brief summaries are given of the papers that will be published in full elsewhere. The program of the symposium and a list of the participants are included in the proceedings.
ContentsCell Separations and Recycle Using an Inclined Settler, Ching-Yuan Lee, Robert H. Davis and Robert A. Sclafani
Micromixing and Metabolism in Bioreactors: Characterization of a 14 L Fermenter, K.S. Wenger and E.H. Dunlop
Production, Purification, and Hydrolysis Kinetics of Wild-Type and Mutant Glucoamylases from Aspergillus Awamori, Ufuk Bakir, Paul D. Oates, Hsiu-Mei Chen and Peter J. Reilly
Dynamic Modeling of the Immune System, Barry Vant-Hull and Dhinakar S. Kompala
Dynamic Modeling of Active Transport Across a Biological Cell: A Stochastic Approach, B.C. Shen, S.T. Chou, Y.Y. Chiu and L.T. Fan
Electrokinetic Isolation of Bacterial Vesicles and Ribosomes, Debra T.L. Hawker, Robert H. Davis, Paul W. Todd, and Robert Lawson
Application of Dynamic Programming for Fermentative Ethanol Production by Zymomonas mobilis, Sheyla L. Rivera and M. Nazmul Karim
Biodegradation of PCP by Pseudomonas cepacia, R. Rayavarapu, S.K. Banerji, and R.K. Bajpai
Modeling the Bioremediation of Contaminated Soil Aggregates: a Phenomenological Approach, S. Dhawan, L.E. Erickson and L.T. Fan
Biospecific Adsorption of Glucoamylase-I from Aspergillus niger on Raw Starch, Bipin K. Dalmia and Zivko L. Nikolov
Overexpression in Recombinant Mammalian Cells: Effect on Growth Rate and Genetic Instability, Jeffrey A. Kern and Dhinakar S. Kompala
Structured Mathematical Modeling of Xylose Fermentation, A.K. Hilaly, M.N. Karim, I. C. Linden and S. Lastick
A New Culture Medium for Carbon-limited Growth of Bacillus thuringiensis, W. -M. Liu and R.K. Bajpai
Determination of Sugars and Sugar Alcohols by High Performance Ion Chromatography, T. J. Paskach, H.-P. Lieker, P.J. Reilly, and K. Thielecke
Characterization of Poly-Asp Tailed B-Galactosidase, M.Q. Niederauer, C.E. Glatz, l.A. Suominen, C.F. Ford, and M.A. Rougvie
Computation of Conformations and Energies of cr-Glucosyl Disaccharides, Jing Zepg, Michael K. Dowd, and Peter J. Reilly
Pentachlorophenol Interactions with Soil, Shein-Ming Wei, Shankha K. Banerji, and Rakesh K. Bajpai
Oxygen Transfer to Viscous Liquid Media in Three-Phase Fluidized Beds of Floating Bubble Freakers, Y. Kang, L.T. Fan, B.T. Min and S.D. Kim
Studies on the Invitro Development of Chick Embryo, A. Venkatraman and T. Panda
The Evolution of a Silicone Based Phase-Separated Gravity-Independent Bioreactor, Peter E. Villeneuve and Eric H. Dunlop
Biodegradation of Diethyl Phthalate, Guorong Zhang, Kenneth F. Reardon and Vincent G. Murphy
Microcosm Treatability of Soil Contaminated with Petroleum Hydrocarbons, P. Tuitemwong, S. Dhawan, B.M. Sly, L.E. Erickson and J.R. Schluphttps://lib.dr.iastate.edu/bce_proceedings/1019/thumbnail.jp