PL
 |
EN
Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 14

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  semi-active control
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
1
Content available Semi-active vibration control of horizontal seat suspension by using magneto-rheological damper
Maciejewski Igor, Krzyżyński Tomasz, Pecolt Sebastian, Chamera Sebastian
Journal of Theoretical and Applied Mechanics
|
2019
|
Vol. 57 nr 2
411--420
EN
In this paper, the modelling process and control strategy of a semi-active seat suspension with a magneto-rheological damper (MR) is presented. The proposed system should protect operators of working machines against vibration in the horizontal direction. The control algorithm mimics the desired force that might be introduced into the seat suspension actively. The model parameters are determined experimentally as a function of the control current. The elaborated system is tested by using an electro-hydraulic shaker that generates vibrations for the semi-active seat suspension with the seated human body. Power spectral densities and transmissibility functions are presented as the results of simulations and measurements. In addition, transmissibility factors and maximum relative displacements of the suspension are evaluated for both the conventional passive seat suspension and the semi-active system with an MR damper.
2
Content available remote Vibration Control of a Seat Suspension System by Using Magnetorheological Damper
Maciejewski I., Pecolt S., Krzyżyński T.
Machine Dynamics Research
|
2018
|
Vol. 42, No. 2
61--71
EN
In this paper, the modelling process and control strategy of the semi-active seat suspension with magneto-rheological damper (MR) is presented. The proposed system should protect the working machines operators against vibration in horizontal direction. The control algorithm mimics the desired force that might be actively introduced into the seat suspension. The model parameters are determined experimentally as a function of the control current. The elaborated system is tested by using the electro-hydraulic shaker that generates vibrations of the semi-active seat suspension with seated human body. The power spectral densities and the transmissibility functions are presented as the results of simulations and measurements. In addition, the transmissibility factors and the maximum relative displacements of suspension are evaluated for both the conventional passive seat suspension and the semi-active system with MR damper.
3
Content available A semi-active control of lateral vibrations of the overhung rotor using dampers with the magneto-rheological fluid
Michajłow M., Konowrocki R., Szolc T.
Vibrations in Physical Systems
|
2016
|
Vol. 27
273--280
EN
In the paper there is proposed an algorithm of an efficient semi-active control of steady-state periodic lateral vibrations of the overhung rotor-shaft system. This algorithm has been developed using fundamentals of the Optimal Control Theory. In the considered system the control is realized by means of the linear dampers with the magneto-rheological fluid built in the bearing housing. The computational example demonstrates possibilities of the applied approach resulting in an additional reduction of out-of-resonance and near-resonance harmonic oscillation amplitudes in comparison with an analogous passive control.
4
Content available Semi-active vibration control using a rotary magnetorheological damper - experimental verification
Pręgowska A., Konowrocki R., Szolc T.
Pomiary Automatyka Robotyka
|
2013
|
R. 17, nr 2
487-491
EN
From all kinds of vibrations, torsional ones are very important as naturally associated with fundamental rotational drive system motion. The aim of this paper is to present semiactive control of torsional vibrations of the working machine drive systems, which is performed using a rotary damper with the magnetorheological fluid. The main purpose of this research is minimization of vibration amplitudes in order to increase fatigue durability of the most responsible machine elements. The special control strategies are proposed for steady-state torsional vibrations suppression. The semi-active control method is based on a principle of on-line selection of optimum damping coefficient values, which is realized by application of the magnetorheological fluid. The analysis performed in the paper combines experimental verification using the laboratory test rig with theoretical computations. This experiment was designed in the form of the laboratory drive system co-operating with two asynchronous motors generating properly programmed driving and retarding electromagnetic torques.
PL
Drgania skrętne są jednym z najważniejszych rodzajów drgań, ponieważ są naturalnie związane z podstawowym ruchem roboczym wielu maszyn i urządzeń. Prezentowany artykuł jest poświęcony półaktywnemu sterowaniu drganiami skrętnymi napędu maszyny roboczej przy wykorzystaniu obrotowych tłumików z cieczą magnetoreologiczną o zmiennych właściwościach dyssypacyjnych. Głównym celem prezentowanych badań jest zmniejszenie poziomu amplitudy drgań skrętnych w celu zwiększenia trwałości zmęczeniowej najbardziej odpowiedzialnych elementów maszyny roboczej. Półaktywne sterowanie sprowadza się do wyznaczenia optymalnej wartości współczynnika tłumienia, który jest realizowany przy wykorzystaniu właściwości filmu z cieczy magnetoreologicznej. Teoretyczna koncepcja sterowania została doświadczalnie zweryfikowana za pomocą stanowiska doświadczalnego w postaci laboratoryjnego układu napędowego, na którym zmienne napędowe i oporowe momenty wymuszające są generowane odpowiednio przez silnik i hamownicę asynchroniczną.
5
Content available On the semi-active control method for torsional vibrations in electro-mechanical systems by means of rotary actuators with a magneto-rheological fluid
Pręgowska A., Konowrocki R., Szolc T.
Journal of Theoretical and Applied Mechanics
|
2013
|
Vol. 51 nr 4
979--992
EN
The aim of this paper is to present a method of the semi-active control of torsional vibrations in a working machine drive system by means of rotary actuators with a magneto-rheological fluid. The simple open-loop control strategy is proposed for a mechanical system vibrating in steady-state operating conditions. This semi-active control approach is based on the principle of optimum viscous damping and frictional properties realized by the magneto-rheological fluid, where its respective parameters are determined by the applied control electric currents. The analysis is performed theoretically by means of structural electro-mechanical models of the considered drive system as well as experimentally using a laboratory test rig in the form of a rotor-shaft system co-operating with two asynchronous motors generating property programmed driving and retarding electro-magnetic torques.
6
Content available remote Vibration control of the rotating machine geared drive system using linear actuators with the magneto-rheological fluid
Michajłowicz M., Konowrocki R., Szolc T.
Vibrations in Physical Systems
|
2012
|
Vol. 25
279--284
EN
In this paper there is proposed a semi-active control technique based on the linear actuators with the magnetorheological fluid (MRF) connecting the drive system planetary gear housing with the immovable rigid support. Here, control damping torques are generated by means of the magneto-rheological fluid of adjustable viscosity. Such actuators can effectively suppress amplitudes of severe transient and steady-state rotational fluctuations of the gear housing position and in this way they are able to minimize dangerous oscillations of dynamic torques transmitted by successive shaft segments in the entire drive system. The general purpose of the considerations is to control torsional vibrations of the real power-station coal-pulverizer geared drive system driven by means of the asynchronous motor. The investigations have been carried out using the experimental test rig based on the real object, where the measurement results were compared with analogous theoretical ones obtained by the use of computer simulations.
7
Content available remote Experimental verification of the semi-active control concepts for torsional vibrations of the electro-mechanical system using rotary magneto-rheological actuators
Pręgowska A., Konowrocki R., Szolc T.
Vibrations in Physical Systems
|
2012
|
Vol. 25
329--334
EN
In the paper semi-active control of torsional vibrations of the rotating machine drive system driven by an electric motor is performed by means of rotary actuators with the magneto-rheological fluid. The main purpose of these studies is a minimisation of vibration amplitudes in order to increase the fatigue durability of the most responsible elements, assure possibly precise motion of the driven machine working tool as well as to reduce a generated noise level. For suppression of steady-state torsional vibrations excited by dynamic external torques generated by the motor and by the driven object there are proposed control strategies based on a principle of optimum current damping coefficient values realized by the magneto-rheological fluid. The theoretical control concepts are experimentally verified using the laboratory test rig in the form of drive system co-operating with two asynchronous motors generating properly programmed driving and retarding electromagnetic torques.
8
Content available remote On the semi-active control of carrying structures under a moving load
Pisarski D., Bajer C. I.
Vibrations in Physical Systems
|
2010
|
Vol. 24
325--330
EN
In this paper we address a group of recent research focused on the semi active control problems in carrying structures systems subjected to a travelling load. The magnitude of the moving force is assumed to be constant by neglecting inertial forces. The response of the system is solved in modal space. The optimal control problem is stated and it is solved by using of Pontryagin Maximum Principle. Switching control method is verified by numerical examples. The controlled system widely outperforms passive solutions. Due to its simplicity in practical design, the presented solution should be interesting to engineers.
PL
W pracy przedstawiono wyniki badań półaktywnego sterowania w układach nośnych poddanym obciążeniom ruchomym. Obciążenie zostało przedstawione jako bezinercyjne. Odpowiedź układu została wyznaczona w reprezentacji modalnej. Sformułowano zadanie sterowania optymalnego. Uzasadniono zastosowanie sterowań typu bang-bang opierając się na Twierdzeniu o Maksimum Pontryagina. Proponowana metoda sterowania została zweryfikowana na podstawie przykładów numerycznych. Wykazano przewagę układów sterowanych nad układami tłumienia pasywnego. Opracowana strategia sterowania jest prosta w implementacji i może być atrakcyjnym rozwiązaniem dla inżynierów.
9
Content available Właściwości wibroizolacyjne semi-aktywnego układu zawieszenia siedziska z tłumikiem magneto-reologicznym
Maciejewski I.
Pomiary Automatyka Kontrola
|
2009
|
R. 55, nr 9
727-730
PL
W pracy zaprezentowano wyniki badań symulacyjnych oraz pomiarów eksperymentalnych układu zawieszenia siedziska operatora maszyny roboczej. Właściwości wibroizolacyjne zawieszenia poprawiono poprzez semi-aktywne sterowanie siłą tłumika magneto-reologicznego, który rozprasza szkodliwą dla zdrowia człowieka energię drgań mechanicznych. Zastosowany w układzie zawieszenia regulator generuje elektryczny sygnał sterujący, proporcjonalny do prędkości bezwzględnej ruchu siedziska. W celu porównania wyników badań symulacyjnych i eksperymentalnych wykorzystano przebiegi gęstości widmowych mocy przyspieszenia drgań siedziska oraz jego funkcje przenoszenia przy wymuszeniach o charakterze losowym.
EN
The object of simulation and experimental research is the visco-elastic passive seat suspension with an air-spring, hydraulic shock-absorber and scissors guidance mechanism. Passive seat suspension amplifies the vibration amplitude at low frequency range of excitation signal (the resonance effect) [6]. In order to help the working machine operator against vibration, the vibro-isolation properties of conventional seat suspension are improved by using the magneto-rheological damper. A controllable force of the magneto-rheological damper dissipates a harmful energy vibration for the human bodies. This paper studies the vibration isolation characteristics of semi-active damping control strategy, which are based on sky-hook control [9]. The control strategy named "sky-hook" simulates a passive damper hooked to an imaginary inertial reference point. Therefore, the controller applied in suspension system generates the electrical control signal, which is proportional to absolute velocity of the seat motion. The dynamical behaviour of conventional passive and semi-active seat suspension are compared on the basis of seat effective amplitude transmissibility factor [3, 4] and conflicted suspension travel [10]. As the results of computer simulation and experimental research the power spectral densities of seat acceleration and the transmissibility functions are presented for random excitation.
10
Content available remote Analogies between Shunted Piezoceramics and Mechanical Damping Elements
Neubauer M.
Machine Dynamics Problems
|
2009
|
Vol. 33, No. 2
79-91
EN
Piezoelectric shunt damping is an emerging field of research. In this technique the electrodes of a piezoceramics are connected to an electrical shunt. Due to the piezoelectric effect, some part of the kinetic energy of the mechanical host structure is converted into electrical energy. The electrical network is designed with the aim to maximize the energy dissipation, which yields a damping effect for the mechanical system. Various electrical shunts like inductance-resistance networks, negative capacitances and switching networks are commonly used for this purpose. In this paper, the effective damping performances of piezoelectric shunt damping with various electrical networks are evaluated. A comparison with viscous damping and dry friction demonstrates the analogies with mechanical damping elements.
11
Content available remote Analysis of Oscillations of Vehicle Suspension with Magnetorheological Dampers
Mitura A., Warmiński J.
Machine Dynamics Problems
|
2008
|
Vol. 32, No. 1
64-72
EN
Analysis of vehicle's vibrations, modelled by a two-degree-of-freedom system, is presented in this paper. The suggested quarter-car model is investigated in two variants: (I) with a conventional suspension composed of a linear spring and a bilinear damper, (II) a system with semi-active suspension, realized by magnetorheological damper (MR). For description of MR damping force, as functions of velocity and input current Bouc-Wen model is used. An open loop control, based on abstract sky-hook and ground-hook models and MR damping, is used for a vehicle oscillations reduction. Obtained vehicle body acceleration, a suspension deflection and a tyre displacement are compared for two considered variants of suspension. Advantages of semi-active vehicle suspension are emphasised.
12
Content available remote Effectiveness of mass damper and composite mass damper for control of wind-excited vibration
Lewandowski R., Grzymisławska J.
Archives of Civil Engineering
|
2005
|
Vol. 51, nr 4
485-513
EN
It is the purpose of this paper to study the effectiveness of the passive, active and semi-active versions of the conventional and composite tuned mass damper systems to reduce vibrations of building structures exposed to strong winds. The possibility of using the semi-active control system is of particular interest because the semi-active dampers have several attractive features such as simplicity, reliability and low power requirement. The parameters of the passive version of composite mass damper are determined in such a way that the ratio of vibration reduction of the main mass is approximately equal for both types of passive dampers. The LQR method and the Lyapunov method are used to determine the active and semi-active control forces. Several remarks concerning the effectiveness of considering dampers are formulated on the basis of extensive numerical simulations.
PL
W pracy analizuje się efektywność tradycyjnych oraz tzw. złożonych masowych tłumików drgań używanych do redukcji drgań konstrukcji budowlanych wywołanych działaniem silnych wiatrów. Analizuje się efektywność tłumików traktowanych jako pasywne, aktywne i półaktywne eliminatory drgań. W szczególności rozważa się możliwość użycia układu półaktywnej regulacji, ponieważ tłumiki półaktywne posiadają kilka atrakcyjnych właściwości takich jak prostota, niezawodność oraz małe zapotrzebowanie na energię. Parametry pasywnego złożonego tłumika drgań są wyznaczane w ten sposób, że względna redukcja drgań masy głównej dla dwóch rozważanych typów tłumików pasywnych jest w przybliżeniu równa. Do wyznaczenia siły aktywnej i półaktywnej regulacji posłużono się metodami LQR oraz Lyapunova. Na podstawie wyników obszernych symulacji numerycznych sformułowano szereg uwag dotyczących efektywności rozważanych tłumików drgań.
13
Experimental Identification of a Magnetorheological Damper Model to Compare Semi-Active Control Strategies of Vehicle Suspensions
Sireteanu T., Stancioiu D., Giuclea M., Stammers C. W.
Mechanika / Akademia Górniczo-Hutnicza im. St. Staszica
|
2003
|
T. 22, z. 3
433-438
EN
The efficiency of various semiractive control strategies of vehicle suspensions equipped by magnetorheological fluid dampers (MRD) are compared. The parametric model of the damper dynamie behaviour is developed by an inverse method employing genetic algorithms. The model parameters are determined using the measured damping characteristics for a set of constant control current values and harmonie imposed motion. The model is validated on the data measured for variable control current and different types of damper toading. Taking into account the good agreement between predicted and measured data, the obtained model is used to compare by numerical simulation the efficiency of two semi-active control strategies (balance logic, sky-hook) used to improve the vehicle comfort.
14
Content available remote Application of optimum control for suppression of semi-active mechanical systems vibration
Wittbrodt E., Hein R.
Vibrations in Physical Systems
|
2002
|
Vol. 20
298--299
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.