Wyniki wyszukiwania - Biblioteka Nauki

1

Application of an inverse data-driven model for reconstructing wheel movement signals

100%

Czop P.

|

tom Vol. 18, nr 3

491-500

EN

This paper considers a method for indirect measuring the vertical displacement of wheels resulting from the road profile, using an inverse parametric data-driven model. Wheel movement is required in variable damping suspension systems, which use an onboard electronic control system that improves ride quality and vehicle handling in typical maneuvres. This paper presents a feasibility study of such an approach which was performed in laboratory conditions. Experimental validation tests were conducted on a setup consisting of a servo-hydraulic test rig equipped with displacement, force and acceleration transducers and a data-acquisition system. The fidelity and adequacy of various parametric SISO model structures were evaluated in the time domain based on correlation coefficient, FPE and AIC criteria. The experimental test results showed that inverse models provide accuracy of inversion, ranging from more than 70% for the ARX model structure to over 90% for the OE model structure.

2

Modeling and analysis of a twin-tube hydraulic shock absorber

88%

Ferdek U. , Łuczko J.

Journal of Theoretical and Applied Mechanics

|

2012

|

tom Vol. 50 nr 2

627-638

EN

In this paper, a physical and mathematical model was created for a twin-tube hydraulic shock absorber, using oil as the working medium. To analyze the model, methods of numerical integration were incorporated. The effect of the amplitude and frequency of the excitation, as well as the parameters describing the flow rate of oil through the valves, were examined. The basic characteristics of the damping force were obtained.

PL

W pracy wprowadzono model fizyczny i matematyczny dwururowego amortyzatora hydraulicznego, w którym czynnikiem roboczym jest olej amortyzatorowy. Do jego analizy wykorzystano metody numerycznego całkowania. Zbadano wpływ amplitudy i częstości wymuszenia oraz parametrów opisujących przepływ oleju przez zawory. Wyznaczono podstawowe charakterystyki siły tłumienia.

3

Laboratory research of the controllable hydraulic damper

75%

Konieczny J. , Kowal J. , Pluta J. , Podsiadło A.

|

tom Vol. 54, iss. 3

203-221

EN

The main focus is on the hydraulic shock absorbers employed in vehicles, in the context of parameters associated with the damping force control for the given direction of action and with the energy dispersion. Two types of shock absorbers are examined: those with constant and variable parameters of damping force adjustment. Shock absorbers that were subject to research investigations included a commercially - available shock absorber with fixed parameters and an experimental absorber with variable parameters. The paper summarises the problems experienced during modelling of hydraulic shock absorbers when the equivalent damping ratio is sought. Damper properties and the methods of determining them are outlined. The laboratory tests performed on these shock absorbers are considered in more detail and relevant characteristics are provided for the sake of comparison. The reasons why shock absorbers with fixed parameters have been in widespread use for many years are now investigated, highlighting the aspects which prompt the research work on shock absorbers with variable parameters.

4

The modelling and analysis of shock absorbers with stroke-dependent damping

75%

Ferdek U.

Technical Transactions

|

2018

|

tom Vol. 115, iss. 1

163--175

EN

In order to obtain the characteristics of a damping force which depends on the amplitude and frequency of the excitation, a modification to the vehicle shock absorber is proposed in this paper. Within the range of small amplitudes, the ‘soft’ characteristics improve riding comfort, while within the resonance ranges, the increased damping force provides a higher level of ride safety. A nonlinear model of the system is introduced, taking into account various strategies of oil-flow control. Utilising numerical integration methods, the influence of excitation parameters and constructional parameters on the characteristics of the damper is investigated.

PL

W pracy zaproponowano koncepcję amortyzatora samochodowego, którego charakterystyka zależy od amplitudy i częstotliwości wymuszenia. W zakresie małych amplitud charakterystyka miękka poprawia komfort jazdy. W zakresach rezonansowych zwiększona siła tłumienia zapewnia większe bezpieczeństwo jazdy. Opracowano nieliniowy model układu uwzględniający różne strategie sterowania przepływem oleju. Wykorzystując metody numerycznego całkowania, zbadano wpływ parametrów wymuszenia oraz parametrów konstrukcyjnych na charakterystyki tłumika.

5

Application of an Inverse Data-Driven Model for Reconstructing Wheel Movement Signals

75%

Czop P.

|

nr 3

6

Fluid-structure simulation of a valve system used in hydraulic dampers

63%

Czop P. , Gąsiorek D. , Gniłka J. , Sławik D. , Wszołek G.

Modelowanie Inżynierskie

|

2012

|

tom T. 14, nr 45

197--205

EN

The aim of this paper is to develop a method for optimizing the design of a disc spring valve system by reducing the aeration and cavitation effect which negatively influences the performance of a shock absorber. A fluid structure interaction (FSI) model is used in order to modify the geometry of the valve interior and, in turn, to achieve better performance of a shock absorber. The paper analyzes the pressure distribution along theflow paths inside the valve cavity to reduce the risk of aeration and cavitation, while other important engineering aspects are omitted, e.g. durability of disc-spring valve systems as discussed in [1]. A key measure of valve improvement was chosen as deterioration of the damping force level generated by a shock absorber vs. the number of cycles during continuous cycling of the damper . The objectives of this work are as follows: (i) to present a process for reducing the complexity of the geometry of a disc spring valve system in order to perform a combined fluid-structure simulation, (ii) to show keysteps of the simulation process focusing on interactions between fluid and structure domain and to review relevant simulation results, (iii) to describe practical aspects of the simulation process, including basic parameters and boundary conditions related to the applied commercial software, (iv) to make an optimization case study to show the application scope for the simulation methodology proposed in the paper, and to confront the simulation results with experimental investigations.

7

Badania oraz modelowanie właściwości sterowanego tłumika piezoelektrycznego

51%

Knap L. , Mydłowski T. , Makowski M. , Grzesikiewicz W.

TTS Technika Transportu Szynowego

|

2012

|

tom R. 19, nr 9

2553--2562, CD

PL

W pracy przedstawiono wyniki badań eksperymentalnych tłumika piezoelektrycznego.Na podstawie badań eksperymentalnych został przyjęty model sterowanego tłumika piezoelektrycznego w postaci struktury reologicznej. Dokonano identyfikacji parametrów modelu tłumika oraz przeprowadzono weryfikację przyjętego modelu. Wyniki badań numerycznych i eksperymentalnych przedstawiono w postaci charakterystyk dyssypacyjnych. Wartości sił tłumienia zależne są głównie od wielkości szczeliny w zaworze hydraulicznym, której wielkość zmieniana jest zapomocą sterowania stosem piezoelektrycznym. W ten sposób sterując zaworem można zmieniać charakterystykę tłumika poprzez zmiany oporów przepływu między komorami tłumika hydraulicznego. Badania zostały przeprowadzone w celu opracowania konstrukcji samochodowego tłumika piezoelektrycznego, który zostanie zastosowany w zawieszaniu do redukcji drgań pojazdu.

EN

The paper presents the results of the experiments involving a piezoelectric damper. A mathematical model of a controllable piezoelectric damper has been adopted for conducting the numerical research. The model is described in the form of a rheological structure. The parameters of the damper’s model have been estimated and the adopted model has been verified. The results of the simulation and the experiments are presented in the form of dissipation characteristics. The value ofthe damping forces depends on the size of the opening in a hydraulic valve which is controlled by a piezoelectric stack. This way, by controlling the valve, one can control the characteristics of the damper by changing the resistance of the flow between the chambers of the hydraulic damper. The research has been carried out in order to develop the structure of a piezoelectric damper for cars which will be applied in a vehicle’s suspension in order to reduce its vibration. Controllable piezoelectric dampers can be used for reducing vibration in mechanical devices.

8

Analiza ćwiartkowego modelu zawieszenia pojazdu z tłumikiem hydraulicznym

51%

Ferdek U. , Łuczko J.

|

tom Vol. 2, nr 2

67-74

PL

W pracy poddano analizie jakościowej ćwiartkowy model zawieszenia pojazdu. Występujący w układzie zawieszenia tłumik hydrauliczny opisano zmodyfikowanym modelem Spencera. Na podstawie przeprowadzonych analiz wyselekcjonowano parametry mające decydujący wpływ na kształt charakterystyki tłumika. Wyznaczono również charakterystyki częstotliwościowe układu w celu zbadania wpływu istotnych parametrów modelu na wprowadzone wskaźniki jakości związane z bezpieczeństwem jazdy oraz efektywnością tłumienia drgań.

EN

The paper discusses the analysis of the quarter model of the vehicle suspension. The hydraulic damper existing in the suspension system has been described using the modified Spencer model. Based on the performed analyses, the parameters having the major impact on the shape of the damper characteristics have been chosen. Additionally, the frequency characteristics of the model have been investigated, for the purpose of researching the impact of several essential model parameters on the performance factors corresponding to the driving safety and the efficiency of the shock absorber.