Wyniki wyszukiwania - Biblioteka Nauki

1

Rodzaje ekranów akustycznych w Polsce

100%

Wszołek G.

|

tom nr 7

43-45

PL

W ostatnich latach w bardzo szybkim tempie nasze drogi są wyposażane w ekrany akustyczne, których podstawowym zadaniem ma być tłumienie lub ograniczenie rozprzestrzeniania się hałasu komunikacyjnego. Wzrost świadomości dotyczącej zagrożenia hałasem spowodował lawinę informacyjną, a także pojawienie się dużej ilości firm zajmujących się problemami walki z tym zagrożeniem.

2

Analiza układu zaworu dyskowego amortyzatora samochodowego

63%

Wszołek G. , Śliwa P.

|

tom nr 1

8-10

PL

Przedstawiono weryfikacje modelu numerycznego układu zaworu dyskowego, używanego w amortyzatorach motoryzacyjnych. Podano wyniki badań i symulacji, proponując ich wykorzystanie do analizy wpływu parametrów konstrukcyjnych na wytrzymałość dysków zaworowych.

EN

The aim of this paper was to validate a numerical model of a disc valve system used in automotive shock absorbers. Results of investigations and simulations enable better to understand influence of design parameters and their contribution to strength of a valve system.

3

Advanced model structures applied to system identification of a servohydraulic test rig

63%

Czop P. , Wszołek G.

|

tom Vol. 41, nr 1-2

96-103

EN

Purpose: This paper deals with a method for the parametric system identification of a nonlinear system to obtain its parametric representation using a linear transfer function. Such representation is applicable in off-line profile correction methods minimizing the error between a reference input signal and a signal performed by the test rig. In turn, a test signal can be perfectly tracked by a servo-hydraulic test rig. This is the requirement in massive production where short test sequences are repeated to validate the products. Design/methodology/approach: A numerical and experimental case studies are presented in the paper. The numerical study presents a system identification process of a nonlinear system consisting of a linear transfer function and a nonlinear output component, being a static function. The experimental study presents a system identification process of a nonlinear system which is a servo-hydraulic test rig. The simulation data has been used to illustrate the feasibility study of the proposed approach, while the experimental data have been used to validate advanced model structures under operational conditions. Findings: The advanced model structures confirmed their better performance by means of the model fit in the time domain. Research limitations/implications: The method applies to analysis of such mechanical and hydraulic systems for which measurements are corrupted by residual harmonic disturbances resulting from system nonlinearities. Practical implications: The advanced model structures are intended to be used as inverse models in off-line signal profile correction. Originality/value: The results state the foundation for the off-line parametric error cancellation method which aims in improving tracking of load signals on servo-hydraulic test rigs.

4

Didactic model of the high storage system

51%

Świder J. , Wszołek G. , Reclik D.

|

2006

|

tom Vol. 16, nr 1-2

199--206

EN

Purpose: The continuous progress in Computer Integrated Manufacturing (CIM) field with automatic storing systems is broadening the range of education process for engineers in future. This document describes the newest didactic station integrated witch a Modular Production System (MPS) model [1, 2, 3]. It is a module of high storage. This arrangement is the perfect didactic item for students. Design/methodology/approach: The main reason, why the laboratory position, we have mentioned, has been created is brodening the students knowlegde’s range. To achive this task the warehouse has been made from really industrial elements. All manipulator’s axis were building from different types of transmissions. Findings: During the work with warehouse there has been prepared the new algorithm which controlls the linear drive. Besides that there has been created brand new standards in engineers education, which are based on the described warehouse. Research limitations/implications: The main target of the didactic activity of Institute of Engineering Processes Automation and Integrated Manufacturing Systems is broden the loboratory base. That’s the reason why now there already has been building another laboratory position, which is based on Fanuc manipulator. Practical implications: The algorithm of Pneu-Stat steering hasn’t been finished yet, but when it has been done it can be used in industrial aplications. Originality/value: This paper describes the new didactic station with innovational steering algorithm [4, 5].

5

Simplified and advanced models of a valve system used in shock absorbers

51%

Czop P. , Sławik D. , Śliwa P. , Wszołek G.

|

tom Vol. 33, nr 2

173-180

EN

Purpose: The aim of this paper is to develop a model of a valve system applicable for strain and stress prediction. Design/methodology/approach: The analytical and numerical approaches are presented to provide an overview for available methods and prediction accuracy. Findings: An equivalent numerical model of a disc valve system of different complexity was developed and discussed. Research limitations/implications: It is important to provide a model functionality allowing for calculation of disc stacks supported by a coil spring and stack settings having the opening limiter. Disc stack stress and opening characteristics vs. applied pressure may be determined with simplified analytically derived model and full 2D model including almost all significant forces and moments in a stack of circular plates. An advantage of a simplified disc stack model is possibility of its implementation in an environment supporting matrix operations, e.g. Matlab. Practical implications: A valve system has to withstand the cyclic pressure load across the piston. The number of discs, their diameters and thicknesses directly affect durability of a valve system. Damper force and valve durability expressed in life-cycles are the optimization criteria considering during selection and tuning of a valve system. Originality/value: A new valve system was developed in two versions, i.e. simplified and advanced. The model allows durability prediction at the design stage reducing the testing costs of low-performance valve systems.

6

The off-line programming and simulation software for the Mitsubishi Movemaster RV-M1 robot

51%

Świder J. , Foit K. , Wszołek G. , Mastrowski D.

|

tom Vol. 20, nr 1-2

499-502

EN

Purpose: Contemporary robotics requires modern instruments for programming, control and supervising of robot's work. It becomes necessary to strict adjust the robot in its working environment after tests on a virtual model of the robot and its surroundings. The aim of present work is a presentation of preliminary version of the system for off-line programming, simulation and remote supervision of the Mitsubishi Movemaster RV-M1 robot. Design/methodology/approach: The robot installed in institute's laboratory has been used in research work. Attention has been focused on creating of universal software, which could be developed in the future. Findings: In result of carried work a first version of the software has been developed. It has network oriented modular structure. Research limitations/implications: The code of the software has been developed in high level programming in such manner, that allows further translation and transfer to the other system platform. Far-reaching plans include creation of universal form of the software, which could be applied to majority of system platforms and can operate with different types of robots. Practical implications: Created software has presently didactic character and it is used during conduction of laboratory classes. Originality/value: Conducted works have in view a creation of universal and modular software. Existing commercial solutions are usually dedicated to a concrete type of robot.

7

Optimization of pneumatic actuators with the use of design for Six Sigma methodology

51%

Król A. , Wszołek G. , Czop P.

|

tom Vol. 47, nr 2

205--210

EN

Purpose: The first aim of this paper is to optimize pneumatic actuator behavior using a structured approach to define and control system factors in order to achieve targeted output values. The second aim is to present a structured optimization process supported by Measurement System Analysis (MSA) and Design of Experiment (DOE) tools in practical applications. Design/methodology/approach: A complete approach for optimizing an unknown system with a structured approach known from DFSS methodology is used in the practical example of pneumatic actuators. DFSS methodology requires a detailed project definition, but ensures good quality of measurement data and a well-prepared optimization process supported by known DOE tools. Findings: The structural approach for system optimization known from DFSS methodology provides a good fit for the optimization of a pneumatic actuator to achieve specified targets. Teams working on system optimization not only set the parameters but also gather a large amount of valuable information about how the mentioned system works, and what the main factors influencing the final results are. The gathered knowledge can be used to create a robust design with the lowest possible cost. Research limitations/implications: The results obtained from Measurement System Analysis and Design of Experiment are valid only for chosen factors and, importantly, only in the range used in both statistical methods. Extrapolation outside the statistical model boundaries is forbidden. Therefore a critical aspect is to agree within the project team on the correct factors and their levels. Practical implications: The optimization of pneumatic actuators can be achieved by a structured approach consisting mainly of project definition, measurement system analysis and final optimization through DOE tools to achieve given targets for displacement and time simultaneously. Originality/value: First Time Through optimization of a pneumatic actuator system as an example of any system treated as a black box, meaning a system with an unknown relationship between input and output. Design for Six Sigma methodology presented in a practical approach.

8

Design and development of seal components fatigue tester

51%

Czop P. , Sławik D. , Wszołek G. , Związek M.

|

tom Vol. 30, nr 1

67-74

EN

Purpose: The aim of the paper is research and development concerning a fatigue tester of shock absorber seal systems. Design/methodology/approach: Analytical approach has been applied to get an understanding of a heat exchange process. The mathematical model has been formulated and validated based on the available measurements. Numerical simulation has been carried out to illustrate a heat exchange process performance. Findings: It is possible to control a seal temperature and mechanical friction related to the rod movement into the seal at the specified velocity. The model accuracy is sufficient to perform sensitivity analysis and optimize the design. Research limitations/implications: The components of a fatigue tester have to withstand the significant temperature differences in the range ~30;+140*C, e. g. hydraulic hoses, fittings, and pumps. Practical implications: We combine the analytical and experimental approach to provide customized and reliable engineering solution in the area of damper component seal development. A typical seal has a lip-like design protecting the moving parts against the leakage. It can be tested in a shock absorber or externally with use of a customized test rigs. Seal tests inside a shock absorber have numerous disadvantages. A shock absorber temperature rises during longer tests and cooling phase is required. This dramatically increases tests duration performed with the use of an expensive general-purpose hydraulic testing machinery. A compressed air or water jacket is used to accelerate the cooling process. Nevertheless, there are limitations related to the physics behind the cooling process. A seal component fatigue tester allows to perform the seal component tests out of the shock absorber. Originality/value: A new testing method provides possibility to quantify the main contributors of seal usage.

9

Application of off-line error correction method software to reproduce random signals on servo-hydraulic testers

51%

Braska D. , Czop P. , Sławik D. , Wszołek G.

Journal of Achievements in Materials and Manufacturing Engineering

|

2010

|

tom Vol. 40, nr 1

41-49

EN

Purpose: This paper presents an approach towards improving the test rig performance for road signals used in automotive shock absorber tests. The goal is to develop a method for correction of the test signal profile in the off-line mode. The method is intended to be implemented as a software solution without any changes either in hardware or the settings of the servo-hydraulic tester. Design/methodology/approach: A two-stage validation of the proposed correction method was conducted using a servo-hydraulic test rig and its first-principles model. The model is capable of capturing key dynamical properties over a wide operating range while being only moderately complex. Both simulation and experimental performance results are presented and discussed. Findings: The proposed method, both in the frequency and time domain, improves the tracking of the test signal by 10-20% and allows an accuracy of more than 90% to be gained using the best fit measure in the case of reproduction of white noise signals. Research limitations/implications: It is possible to consider more advanced model-based methods for performing off-line error correction. These methods can be used if an accuracy close to 100% is expected. Practical implications: The result of the investigations is the algorithm implemented in the LabView software to automatically perform the correction of the test signal before the test. Originality/value: The paper proposes a modern approach towards the validation process by applying a simulation environment. This ensures the involvement of arbitrary disturbance models to investigate key parameters of the correction method without expensive and time-consuming experimental validation. The developed model can be extended to a model of a shock absorber to simulate full interaction between the servo-hydraulic test rig and the tested product.

10

Vibration analysis of mechanical systems with utilisation of GRAFSIM and CATGEN software

45%

Świder J. , Wszołek G. , Foit K. , Michalski P. , Jendrysik S.

Journal of Achievements in Materials and Manufacturing Engineering

|

2007

|

tom Vol. 23, nr 1

23-30

EN

Purpose: The paper describes the method and corresponding software used for modelling and vibration analysis of mechanical systems. As an example the study on the modelling of a vibrating system in a form of a passenger car was discussed with determination of the characteristics describing its vibrations and resonance zones. Design/methodology/approach: The software described in the article uses the matrix hybrid graphs method and matrix block diagrams method for making analysis of mechanical systems vibrations. For numerical calculations the system is represented in the form as a matrix block diagram, and is analysed in detailed way in the Matlab-SIMULINK environment. Findings: Numerical software packages give possibility to analyse vibrations of mechanical systems or of their parts exposed to kinematic and dynamic excitations. Research limitations/implications: Time responses of the vibrations of the passenger car system model evoked by various types of excitations are presented, as well as the amplitude-frequency -phase characteristics (a-f-p). Originality/value: The paper constitutes the source of information into the theory and practice of mechanical vibrations as well as professional computer software as a tool enabling the determination of the time responses and the a-f-p characteristics of machine and equipment parts.

11

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

45%

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

|

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.

12

Metoda wyznaczania charakterystyk zmęczeniowych zaworów dyskowych

45%

Wszołek G. , Czop P. , Jakubowski D. , Śliwa P. , Świder J.

|

tom nr 1

5-7

PL

Przedstawiono koncepcję badań zmęczeniowych zaworów dyskowych stosowanych w amortyzatorach samochodowych. Opisano tester mechaniczny do jednoczesnego wykonania większej liczby testów.

EN

The paper presents a concept of fatigue tests of disc valves used in automobile shock absorbers. A mechanical tester for simultaneous testing of more samples was presented and discussed.