| 1. |
- Arrouo, Gonzalo, 1981, et al.
(författare)
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Modelling of a TERFENOL-D based electric generators
- 2005
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- A linear model for an electric generator based in TERFENOL-D is developed. In order to do so, a deep study of the magnetostriction and the magnetization processes is carried out first. Secondly, mathematical expressions for the output of the generator are developed, considering two different kinds of excitations, one where the applied stress is expressed in an exponential way, and another one where it is expressed in a periodic way. A Lump Parameters Model, where the material properties are considered as constants, is analyzed. As an improvement, a second model is developed, where the material properties are considered as functions of the mechanical and magnetic solicitation of the magnetostrictive material. A comparison between both models and both inputs is realized.
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| 2. |
- Asadi, Saeed, 1987, et al.
(författare)
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Global Sensitivity Analysis of High Speed Shaft Subsystem of a Wind Turbine Drive Train
- 2018
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Ingår i: International Journal of Rotating Machinery. - : Hindawi Limited. - 1542-3034 .- 1023-621X. ; 2018
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Tidskriftsartikel (refereegranskat)abstract
- The wind turbine dynamics are complex and critical area of study for the wind industry. Quantification of the effective factors to wind turbine performance is valuable for making improvements to both power performance and turbine health. In this paper, the global sensitivity analysis of validated mathematical model for high speed shaft drive train test rig has been developed in order to evaluate the contribution of systems input parameters to the specified objective functions.Thedrive train in this study consists of a 3- phase induction motor, flexible shafts, shafts’ coupling, bearing housing, and disk with an eccentric mass.The governing equations were derived by using the Lagrangian formalism and were solved numerically by Newmark method. The variance based global sensitivity indices are introduced to evaluate the contribution of input structural parameters correlated to the objective functions. The conclusion from the current research provides informative beneficial data in terms of design and optimization of a drive train setup and also can provide better understanding of wind turbine drive train system dynamics with respect to different structural parameters, ultimately designing more efficient drive trains. Finally, the proposed global sensitivity analysis (GSA) methodology demonstrates the detectability of faults in different components.
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| 3. |
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| 4. |
- Asadi, Saeed, 1987, et al.
(författare)
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STRUCTURAL DYNAMICS OF A WIND TURBINE DRIVE TRAIN HIGH SPEED SUBSYSTEM: MATHEMATICAL MODELLING AND VALIDATION
- 2015
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Ingår i: In Proc. of the International Conference on Engineering Vibration, Ljubljana, 7 - 10 September ; [editors Miha Boltežar, Janko Slavič, Marian Wiercigroch]. - EBook. - Ljubljana: Faculty for Mechanical Engineering, 2015. - 9789616536974 ; , s. 553-562
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Konferensbidrag (refereegranskat)abstract
- The paper studies the dynamics of a wind turbine drive train high speed subsystem, both by modelling and experiments with focus on system torsional vibration and transient events which can reduce fatigue life of functional components (gearbox, bearings, shafts, couplings,others). A scaled down drive train high speed shaft test rig has been developed. Main components of the test rig are six-pole motor with variable frequency drive controller (up to 1000rpm), shafts’ disk coupling and flexible mounting structure representing gearbox housing with output high speed bearing. The test rig is equipped with measurement system comprising a set of accelerometers and displacement sensors, strain gauges and telemeter system, data acquisition hardware and software (SKFWindCon3.0). Mathematical and computational models of the test rig have been developed and went through validation tests. The system dynamic response is studied for different operational scenarios and structural parameters (run-shut down case with and without eccentric mass). The ultimate goal of the test rig is to get insight into interactionbetween internal dynamics of drive train mechanical and electrical functional components and to develop novel methods to detect, predict and prevent faults and failures in wind turbine drive trains arising due to misalignments and transient external loads.
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| 5. |
- Asadi, Saeed, 1987, et al.
(författare)
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Vibration dynamics of a wind turbine drive train high speed subsystem: Modelling and validation
- 2015
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Ingår i: ASME 2015 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, IDETC/CIE 2015, Boston, United States, 2-5 August 2015. - 9780791857182 ; 8
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Konferensbidrag (refereegranskat)abstract
- Modern wind turbines are enormous large-scale electromechanical systems. They operate in complex conditions, determined by a turbulent wind field, by possible disturbances in the electricity grid and by the behavior of sea waves for offshore turbines. Guaranteeing the structural integrity of these machines during a lifetime of 20 years is an enormous challenge. In this paper the dynamics of a wind turbine drive train high speed subsystem is studied both by modeling and experiments with focus on system torsional and flexural vibrations and transient events which can reduce fatigue life of functional components (gearbox, bearings, shafts, couplings, others). A scaled down drive train high speed shaft test rig has been developed. Main components of the test rig are six-pole motor with variable frequency drive controller (up to 1000 rpm), shafts' disk coupling and flexible mounting structure representing gearbox housing with output high speed bearing. The test rig is equipped with measurement system comprising a set of accelerometers and displacement sensors, data acquisition hardware and software (SKF WindCon3.0). Mathematical and computational models of the test rig have been developed and went through validation tests. The system kinematic and dynamic responses are studied for different operational scenarios and structural parameters (ratio of shaft bending stiffness and stiffness of mounting structures, unevenly inertia load distribution, others). The ultimate goal of the test rig is to get insight into interaction between internal dynamics of drive train functional components to be used the results obtained in developing novel methods to detect, predict and prevent faults and failures in wind turbine drive trains arising due to misalignments and transient external loads.
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| 6. |
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| 7. |
- Berbyuk, Viktor, 1953
(författare)
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BOOK REVIEW: Control of the Motion of Statically Unstable Biped Apparatus - B.A. Bordyug
- 2013
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Ingår i: Appl. Comput. Math.. ; 12:1, s. 119-
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The book "Control of the Motion of Statically Unstable Biped Apparatus" by B.A. Bordyug is a result of research done by talented scientist, Dr Bordyug. He was one of the brilliant representatives of the well-known school of Professor V.B. Larin. The book is well written. In fact, all technical results are carefully motivated in terms of signi¯cant control problems. I think that the book Control of the Motion of Statically Unstable Biped Apparatusshould attract not only the experts of the specicific area, e.g. engineers working with control design for locomotion systems, but also researchers having background in mechanics, applied mathematics, and control engineering.
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| 8. |
- Berbyuk, Viktor, 1953, et al.
(författare)
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Calculation of dynamical characteristics of human gait with below-knee prosthesis
- 2013
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Ingår i: Proceedings of 15-th International Conference on System Analysis and Information Technologies, N.D. Pankratova (Ed.), Kyiv, Ukraine, May 27-31, 2013. - 9789662748321 ; , s. 32-33
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The mathematical modeling problem of human gait with below-knee prosthesis is investigated. The kinematic, dynamic and energetic characteristics of the gait are determined based on mathematical model of human locomotor apparatus and experimental data. The experimental data of joint angles in hip, knee and ankle and reaction forces are obtained by biomechanical investigation in a sequence consisting of nearly 20 steps. The sequence of N steps reduced to double stride period and mean square domains (? -tubes) of variations of joint angles and reaction forces have been built. The stiffness characteristicsof ankle and metatarsal joints of the prosthesis device are also given from experimental investigation.The human gait with below-knee prosthesis modeling problem is formulated as a nonlinear optimal control problem with restrictions imposed both on the phase coordinates and controlling stimuli and non-differentiable energetic functional. The optimization approach based on energetic optimal principle of human locomotion is used forgait characteristics calculating.
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| 9. |
- Berbyuk, Viktor, 1953
(författare)
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Control and optimization of semi-passively actuated multibody systems
- 2002
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Ingår i: Preprints of NATO Advanced Study Institute on Virtual Nonlinear Multibody Systems, Eds.: Werner Schiehlen and Michael Valasek, Czech Technical University in Prague, June-23-July 3, 2002. ; 2, s. 40-49
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Konferensbidrag (refereegranskat)abstract
- The controlled multibody systems are under the consideration. At the lecture special emphasis is put on the study of underactuated and overactuated systems having different type of actuators (external powered drives, unpowered spring-damper like drives, etc.). Several questions are addressed about the role of inherent dynamics, and how much multibody system should be governed by external powered drives and how much by the systems inherent dynamics. The lecture consists of the following parts: introduction to the subject in question; mathematical statement of the optimal control problems that are suitable for modelling of controlled motion and optimization of semi-passively controlled multibody systems with different degrees of actuation; description of the methodology and the numerical algorithms for solution of control and optimization problems for semi-passively actuated multibody systems. The solutions of several optimal control problems for different kind of semi-passively actuated multibody systems are presented. Namely, the energy-optimal control of planar semi-passively controlled three-link manipulator robot, the energy-optimal control of closed-loop chain semi-passively actuated SCARA-like robot; optimization of the hydraulic and pneumatic drives of the multibody system modelled the human locomotor apparatus with above-knee prostheses, and others. Future perspectives in area of control and optimization problems of the semi-passively actuated multibody systems are discussed.
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| 10. |
- Berbyuk, Viktor, 1953
(författare)
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Control and optimization of semi-passively actuated multibody systems
- 2003
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Ingår i: Virtual Nonlinear Multibody Systems, Eds.: Werner Schiehlen and Michael Valasek, Kluwer Academic Publishers. ; , s. 279-295
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Tidskriftsartikel (refereegranskat)abstract
- The controlled multibody systems are under consideration. Several questions are addressed about the role of inherent dynamics, and how much multibody system should be governed by external powered drives and how much by the systems inherent dynamics. Mathematical statement of the optimal control problem that is suitable for modelling of controlled motion and optimization of semi-passively actuated multibody systems has been proposed. The methodology and numerical algorithms have been described for solving the control and optimization problems for semi-passively actuated multibody systems. Special emphasis is put on the study of controlled multibody systems having different degrees and types of actuation (underactuated and overactuated systems, external powered drives, unpowered spring-damper like drives, etc.). The solutions of energy-optimal control problems have been presented for different kinds of semi-passively actuated multibody systems (closed-loop chain semi-passively actuated robot, multibody system modelled the human locomotor apparatus with above-knee prosthesis and others).
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