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Search Results: 1 - 10 of 192194 matches for " G. Wszo?ek "
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First-principle and data-driven model- based approach in rotating machinery failure mode detection
G. Wszoek,P. Czop
Journal of Achievements in Materials and Manufacturing Engineering , 2010,
Abstract: Purpose: A major concern of modern diagnostics is the use of vibration or acoustic signals generated by a machine to reveal its operating conditions. This paper presents a method which allows to periodically obtain estimates of model eigenvalues represented by complex numbers. The method is intended to diagnose rotating machinery under transient conditions.Design/methodology/approach: The method uses a parametric data-driven model, the parameters of which are estimated using operational data.Findings: Experimental results were obtained with the use of a laboratory single-disc rotor system equipped with both sliding and hydrodynamic bearings. The test rig used allows measurements of data under normal, or reference, and malfunctioning operation, including oil instabilities, rub, looseness and unbalance, to be collected.Research limitations/implications: Numerical and experimental studies performed in order to validate the method are presented in the paper. Moreover, literature and industrial case studies are analyzed to better understand vibration modes of the rotor under abnormal operating conditions. Practical implications: A model of the test rig has been developed to verify the method proposed herein and to understand the results of the experiments. Hardware realization of the proposed method was implemented as a standalone operating module developed using the Texas Instruments TMS3200LF2407 Starter Kit.Originality/value: The parametric approach was proposed instead of nonparametric one towards diagnosing of rotating machinery.
Advanced model structures applied to system identification of a servo- hydraulic test rig
P. Czop,G. Wszoek
Journal of Achievements in Materials and Manufacturing Engineering , 2010,
Abstract: 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.
The laboratory stand for didactic and research of a Fluidic Muscle
G. Wszoek,G. Stawarz,P. Zub
Journal of Achievements in Materials and Manufacturing Engineering , 2007,
Abstract: Purpose: The aim of this work was to design and build a laboratory stand dedicated for didactic and research purposes connected with a Fluidic Muscle. The stand is placed at the Electropneumatic and PLC controllers Laboratory [10,11,12] of the Institute of Engineering Processes Automation and Integrated Manufacturing Systems of the Faculty of Mechanical Engineering of the Silesian University of Technology, Gliwice, Poland.Design/methodology/approach: The stand was designed and visualised by utilisation of professional CAD software – CATIA and a fluidic muscle was chosen according to a MuscleSIM programme of FESTO company.Findings: The device integrates the elements which are indispensable determinant of contemporary industry and the main aim of its construction was to bring closer conceptions and ideas connected with the construction and the outworking of the fluidic muscle, problems of proportional pressure control, visualisation and control of the industrial processes as well as making possible of carrying out the investigations and experiments on these elements.Research limitations/implications: The module structure of the research stand gives possibility to make its further development by adding extra modules that can be easily mounted on plates, which will make possible the implementation of series of individual positions controlled by one PLC. Thanks to the applied system of visualisation, switching among synoptic screens is possible. The visualisation represents every separate module of the stand and so, with the help of one operator position, gives possibility to control every chosen module of the whole device.Originality/value: The mechatronic didactic and research device introduced in the paper represents the new approach to the problem of visualisation and control of the fluidic muscle and constitutes the perfect tool of the aided didactic process in the Institute’s laboratory
Laboratory support for the didactic process of engineering processes automation at the Faculty of Mechanical Engineering
J. ?wider,P. Michalski,G. Wszoek
Journal of Achievements in Materials and Manufacturing Engineering , 2006,
Abstract: Purpose: The scope of the paper is to present effects of creating the laboratory support for the didactic process of automatic control of engineering processes.Design/methodology/approach: The discussed laboratory framework is a complex system, flexible in terms of further development, operating on four basic levels: rudimental- serving general introductory classes to the subject, advanced level- suitable for specialisation classes, hardware and software for individual or team work assignments completed in the course of self-studies, semester projects, BSc and MSc. theses, and the sophisticated level designed for PhD and DSc research workers.Findings: Close cooperation with industry and practical implementation of joint research projects play a crucial role in the functioning of the laboratory framework.Practical implications: The education of modern engineers and Masters of Science in automatic control and robotics is a challenging task which may be successfully accomplished only if faced with industrial reality. Continuously advancing industrial companies demand graduates who can quickly adjust to the workflow and who can instantly utilize the knowledge and skills acquired in the complex, interdisciplinary field of mechatronics.Originality/value: The discussed laboratory framework successfully couples software and hardware, providing a complex yet flexible system open for further development, enabling teaching and research into the design and operation of modern control systems, both by means of virtual construction and testing in simulation programs, as well as on real industrial structures configured in laboratory workstations.
Didactic model of the high storage system
J. ?wider,G. Wszoek,D. Recik
Journal of Achievements in Materials and Manufacturing Engineering , 2006,
Abstract: 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 aplicationsOriginality/value: This paper describes the new didactic station with innovational steering algorithm [4, 5].
Adjustment method of parameters intended for first-principle models
P. Czop,G. Kost,D. S?awik,G. Wszoek
Journal of Achievements in Materials and Manufacturing Engineering , 2012,
Abstract: Purpose: This paper demonstrates a process of estimation phenomenological parameters of a first-principle nonlinear model based on the hydraulic damper system.Design/methodology/approach: First-principle (FP) models are formulated using a system of continuous ordinary differential equations capturing usually nonlinear relations among variables of the model. The considering model applies three categories of parameters: geometrical, physical and phenomenological. Geometrical and physical parameters are deduced from construction or operational documentation. The phenomenological parameters are the adjustable ones, which are estimated or adjusted based on their roughly known values, e.g. friction/damping coefficients. Findings: A phenomenological parameter, friction coefficient, was successfully estimated based on the experimental data. The error between the model response and experimental data is not greater than 10%.Research limitations/implications: Adjusting a model to data is, in most cases, a non-convex optimization problem and the criterion function may have several local minima. This is a case when multiple parameters are simultaneously estimated. Practical implications: First-principle models are fundamental tools for understanding, optimizing, designing, and diagnosing technical systems since they are updatable using operational measurements.Originality/value: First-principle models are frequently adjusted by trial-and-error, which can lead to nonoptimal results. In order to avoid deficiencies of the trial-and-error approach, a formalized mathematical method using optimization techniques to minimize the error criterion, and find optimal values of tunable model parameters, was proposed and demonstrated in this work.
Formulation and identification of First- Principle Data-Driven models
P. Czop,G. Kost,D. S?awik,G. Wszoek
Journal of Achievements in Materials and Manufacturing Engineering , 2011,
Abstract: Purpose: The paper consists of two parts. The first part presents and discusses a process of formulation and identification of First-Principle Data-Driven (FPDD) models, while the second part demonstrates numerical examples of identification of FPDD models.Design/methodology/approach: First-Principle (FP) model is formulated using a system of continuous ordinary differential equations capturing usually nonlinear relations among variables of the model. The considering model applies three categories of parameters: geometrical, physical and phenomenological. Geometrical and physical parameters are deduced from construction or operational documentation. The phenomenological parameters are the adjustable ones, which are estimated or adjusted based on their roughly known values, e.g. friction/damping coefficients.Findings: A few phenomenological parameters were successfully estimated from numerically generated data. The error between the true and estimated value of the parameter occurred, however its magnitude is low at level below 2%.Research limitations/implications: Adjusting a model to data is, in most cases, a non-convex optimization problem and the criterion function may have several local minima. This is a case when multiple parameters are simultaneously estimated.Practical implications: FPDD models are an excellent tool for understanding, optimizing, designing, and diagnosing technical systems since they are updatable using operational measurements. This opens application area, for example, for model-based design and early warning diagnostics.Originality/value: First-Principle (FP) models are frequently adjusted by trial-and-error, which can lead to non-optimal results. In order to avoid deficiencies of the trial-and-error approach, a formalized mathematical method using optimization techniques to minimize the error criterion, and find optimal values of tunable model parameters, was proposed and demonstrated in this work.
Off-line displacement error correction method for servo-hydraulic testers
D. Braska,M. Huchla,P. Czop,G. Wszoek
Journal of Achievements in Materials and Manufacturing Engineering , 2012,
Abstract: Purpose: This paper presents an approach towards improving the test rig performance in reproduction of random excitation to which a prototype hydraulic damper is subjected. The method is intended to be implemented as a software solution without modifications either in hardware or the settings of the servo-hydraulic tester. These are the conditions of fatigue tests when a specific signal sequence (block) is repeated until failure of the sample.Design/methodology/approach: Experimental validation of the proposed correction method was conducted using a servo-hydraulic test rig and a transfer function inverse model which was identified based on the operational data.Findings: The proposed method, both in the frequency and time domain, improves the tracking of the test signal and allows an accuracy of more than 95% to be gained using the best fit measure in the case of reproduction of coloured noise signals.Research limitations/implications: It is possible to consider more advanced model-based methods for performing off-line error correction, e.g. state-space models.Practical implications: The proposed method was validated and implemented in the LabVIEW software to automatically perform the correction of the test signal before the test. The method was validated for the test rig with and without the tested object.Originality/value: The paper proposes an off-line control strategy that improves the reproduction of the load signal in case of repeatable test sequences achieving more than 99% agreement between the applied and measured load.
The off-line programming and simulation software for the Mitsubishi Movemaster RV-M1 robot
J. ?wider,K. Foit,G. Wszoek,D. Mastrowski
Journal of Achievements in Materials and Manufacturing Engineering , 2007,
Abstract: Purpose: Contemporary robotics requires modern instruments for programming, control and supervising ofrobots’ work. It becomes necessary to strict adjust the robot in its working environment after tests on a virtualmodel of the robot and its surroundings. The aim of present work is a presentation of preliminary version ofthe system for off-line programming, simulation and remote supervision of the Mitsubishi Movemaster RV-M1robot.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 orientedmodular structure.Research limitations/implications: The code of the software has been developed in high level programmingin such manner, that allows further translation and transfer to the other system platform. Far-reaching plansinclude creation of universal form of the software, which could be applied to majority of system platforms andcan operate with different types of robots.Practical implications: Created software has presently didactic character and it is used during conduction oflaboratory classes.Originality/value: Conducted works have in view a creation of universal and modular software. Existingcommercial solutions are usually dedicated to a concrete type of robot.
Vibration analysis of mechanical systems with utilisation of GRAFSIM and CATGEN software
J. ?wider,G. Wszoek,K. Foit,P. Michalski
Journal of Achievements in Materials and Manufacturing Engineering , 2007,
Abstract: Purpose: The paper describes the method and corresponding software used for modelling and vibration analysis of mechanical systems. A s 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.
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