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The article focuses on a design and experimental verification of continuous nonlinear systems control based on a new control structure based on a linear reference model. An application of Lyapunov’s second method ensures its asymptotic stability conditions. The basic idea in the development of the control structure consists of utilizing additional information from a newly introduced state variable. The structure is applied for angular speed control of an induction motor (IM) drive representing a higher-order nonlinear system. The developed control algorithm helps to achieve the zero steady-state control deviation of the IM drive angular speed. Simulations and experiments performed in various operating states of the IM drive confirm the advantages of the new control structure. Except for set dynamics, the method ensures that the system is stable, invariant to disturbances, and is robust against variations of the parameters. When comparing the obtained control structure of the IM control with the classical vector control, the proposed control structure is simpler. In addition, the proposed control structure is linear, robust against variation in important parameters and invariant against external disturbances. The main advantage over conventional control techniques consists of the fact that the controller design does not require any exact knowledge of the system parameters and, moreover, it does not suffer from system stability problems. The method will find a wide applicability not only in the field of AC controlled drives with IM but also generally in control of industry applications.
Pavol Fedor; Daniela Perdukova; Peter Bober; Marek Fedor. New Stable Non-Vector Control Structure for Induction Motor Drive. Applied Sciences 2021, 11, 6518 .
AMA StylePavol Fedor, Daniela Perdukova, Peter Bober, Marek Fedor. New Stable Non-Vector Control Structure for Induction Motor Drive. Applied Sciences. 2021; 11 (14):6518.
Chicago/Turabian StylePavol Fedor; Daniela Perdukova; Peter Bober; Marek Fedor. 2021. "New Stable Non-Vector Control Structure for Induction Motor Drive." Applied Sciences 11, no. 14: 6518.
This paper presents a simple turn-on and turn-off angles adjustment method to increase the efficiency of small-size switched reluctance motor (SRM) in wide speed and torque range. The simplicity of the control algorithms allows building a variable speed drive without a high-performance microcontroller and FPGA or ASIC. The firing angles calculation uses a second-order polynomial and look-up table. An increase in efficiency is demonstrated on the finite element analysis (FEA) model of SRM which was verified against measurement on an experimental test bench. Measured efficiency maps have a flat top for the investigated motor. Therefore, the angle jittering due to limited position sensor precision and 50 µs processor cycle time have a small impact on motor efficiency. The evaluation of the angle adjustment method and comparison with measurements identifies which part of the FEA model is crucial for the one-to-one implementation of the angle adjustment formulas obtained from simulation to the motor control algorithm.
Peter Bober; Želmíra Ferková. Firing angle adjustment for switched reluctance motor efficiency increasing based on measured and simulated data. Electrical Engineering 2021, 1 -12.
AMA StylePeter Bober, Želmíra Ferková. Firing angle adjustment for switched reluctance motor efficiency increasing based on measured and simulated data. Electrical Engineering. 2021; ():1-12.
Chicago/Turabian StylePeter Bober; Želmíra Ferková. 2021. "Firing angle adjustment for switched reluctance motor efficiency increasing based on measured and simulated data." Electrical Engineering , no. : 1-12.
The presented research background is a car body manufacturer’s request to test the car body’s components welded from dissimilar steel sheets. In view of the vehicle crew’s protection, it is necessary to study the static and dynamic behavior of welded steels. Therefore, the influence of laser welding on the mechanical and dynamical properties, microstructure, microhardness, and welded joint surface roughness of interstitial free CR180IF and dual-phase DP600 steels were investigated. Static tensile tests were carried out by using testing machine Zwick 1387, and dynamic test used rotary hammer machine RSO. Sheet steel was tested at different strain rates ranging from 10−3 to 103 s−1. The laser welds’ microstructure and microhardness were evaluated in the base metal, heat-affected zone, and fusion zone. The comprehensive analysis also included chemical analysis, fracture surface analysis, and roughness measurement. The research results showed that the strain rate had an influence on the mechanical properties of base materials and welded joints. The dynamic loading increases the yield stress more than the ultimate tensile strength for the monitored steels, while the most significant increase was recorded for the welded material.
Mária Mihaliková; Kristína Zgodavová; Peter Bober; Anna Špegárová. The Performance of CR180IF and DP600 Laser Welded Steel Sheets under Different Strain Rates. Materials 2021, 14, 1553 .
AMA StyleMária Mihaliková, Kristína Zgodavová, Peter Bober, Anna Špegárová. The Performance of CR180IF and DP600 Laser Welded Steel Sheets under Different Strain Rates. Materials. 2021; 14 (6):1553.
Chicago/Turabian StyleMária Mihaliková; Kristína Zgodavová; Peter Bober; Anna Špegárová. 2021. "The Performance of CR180IF and DP600 Laser Welded Steel Sheets under Different Strain Rates." Materials 14, no. 6: 1553.
One of the common problems of organizations with turn-key projects is the high scrap rate. There exist such traditional methods as Lean Six Sigma (LSS) and DMAIC tools that analyze causes and suggest solutions. New emerging intelligent technologies should influence these methods and tools as they affect many areas of our life. The purpose of this paper is to present the innovative Lean Six Sigma method for the Small Mixed Bathes (SMB) production system. The standard set of LSS tools is extended by intelligent technologies such as artificial neural networks (ANN) and machine learning. The proposed method uses the data-driven quality strategy to improve the turning process at the bakery machine manufacturer. The case study shows the step-by-step DMAIC procedure of critical to quality (CTQ) characteristics improvement. Findings from the data analysis lead to a change of measurement instrument, training of operators, and lathe machine set-up correction. However, the scrap rate did not decrease significantly. Therefore the advanced mathematical model based on ANN was built. This model predicts the CTQ characteristics from the inspection certificate of the input material. The prediction model is a part of a newly designed process control scheme using machine learning algorithms to reduce the variability even for input material with different properties from new suppliers. Further research will be focused on the validation of the proposed control scheme, and acquired experiences will be used to support business sustainability.
Kristina Zgodavova; Peter Bober; Vidosav Majstorovic; Katarina Monkova; Gilberto Santos; Darina Juhaszova. Innovative Methods for Small Mixed Batches Production System Improvement: The Case of a Bakery Machine Manufacturer. Sustainability 2020, 12, 6266 .
AMA StyleKristina Zgodavova, Peter Bober, Vidosav Majstorovic, Katarina Monkova, Gilberto Santos, Darina Juhaszova. Innovative Methods for Small Mixed Batches Production System Improvement: The Case of a Bakery Machine Manufacturer. Sustainability. 2020; 12 (15):6266.
Chicago/Turabian StyleKristina Zgodavova; Peter Bober; Vidosav Majstorovic; Katarina Monkova; Gilberto Santos; Darina Juhaszova. 2020. "Innovative Methods for Small Mixed Batches Production System Improvement: The Case of a Bakery Machine Manufacturer." Sustainability 12, no. 15: 6266.
In the modern high-performance drive applications, a high-precision and efficient control of the induction motor depends on the accuracy of parameter values. However, the motor parameters may change due to the winding temperature fluctuations, flux saturation and skin effect. Any discrepancy between the values of the motor’s actual parameters and the ones used for the design of the controllers may result in degradation of the drive performance. In this work, a new identification method of hardly measurable internal quantities of the induction motor, such as components of the magnetic flux vector and electromagnetic torque, is outlined. Commonly, the measurable quantities of the induction motor like stator currents, stator voltage frequency and mechanical angular speed are used to determine a feedback effect of the rotor flux vector on the vector of the stator currents of induction motor. Based on this feedback, it is also possible to identify the actual value of the rotor resistance, which may alter during the induction motor operation. This has a significant impact on the precision of the identified quantities as well as on the master control of the induction motor. Stability of the identification structure is guaranteed by the position of roots of characteristic equation of its linear transfer function. Simulation and experimental results are given to highlight the quality, effectivity, feasibility, and robustness of the proposed identification method, which is working reliably within the whole range of the motor angular speed.
Daniela Perdukova; Petr Palacky; Pavol Fedor; Peter Bober; Viliam Fedak. Dynamic Identification of Rotor Magnetic Flux, Torque and Rotor Resistance of Induction Motor. IEEE Access 2020, 8, 142003 -142015.
AMA StyleDaniela Perdukova, Petr Palacky, Pavol Fedor, Peter Bober, Viliam Fedak. Dynamic Identification of Rotor Magnetic Flux, Torque and Rotor Resistance of Induction Motor. IEEE Access. 2020; 8 (99):142003-142015.
Chicago/Turabian StyleDaniela Perdukova; Petr Palacky; Pavol Fedor; Peter Bober; Viliam Fedak. 2020. "Dynamic Identification of Rotor Magnetic Flux, Torque and Rotor Resistance of Induction Motor." IEEE Access 8, no. 99: 142003-142015.
In this paper, a comparison of the simple firing angle modulation method (FAM) and the more advanced torque sharing function (TSF)-based control of switched reluctance motor (SRM) is presented. The off-line procedure to tailor and optimize the parameters of chosen methods for off-the-shelf SRM is explained. Objective functions for optimization are motor efficiency, torque ripple, and integral square error. The off-line optimization uses a finite element method (FEM) model of the SRM. The model was verified by measurement on the SRM. Simulation results showed that FAM has comparable efficiency to TSF, but has a much higher value of torque ripple. The presented off-line procedure can be used for single or multi-objective optimization.
Peter Bober; Želmíra Ferková. Comparison of an Off-Line Optimized Firing Angle Modulation and Torque Sharing Functions for Switched Reluctance Motor Control. Energies 2020, 13, 2435 .
AMA StylePeter Bober, Želmíra Ferková. Comparison of an Off-Line Optimized Firing Angle Modulation and Torque Sharing Functions for Switched Reluctance Motor Control. Energies. 2020; 13 (10):2435.
Chicago/Turabian StylePeter Bober; Želmíra Ferková. 2020. "Comparison of an Off-Line Optimized Firing Angle Modulation and Torque Sharing Functions for Switched Reluctance Motor Control." Energies 13, no. 10: 2435.
The purpose of the present study is three-fold. Firstly, it attempts to describe the bake hardening (BH) behavior of selected interstitial free (IF) and dual phase (DP) steels. Secondly, it predicts the BH behavior of the IF DX 51D and DP 500 HCT 590X plates of steel, and thirdly studies material failure prevention in scholarly sources. The research is aimed at investigating the increasing steel strength during the BH of these two high-strength sheets of steel used for outer vehicle body parts. Samples of steel were pre-strained to 1%, 2%, and 5% and then baked at 140–220 °C for 10 to 30 min. The BH effect was determined from three factors: pre-strain, baking temperature, and baking time. Research has shown that increasing the yield strength by the BH effect is predictable. Therefore, the number of experiments could be reduced for the investigation of BH effect for other kinds of IF and DP steels. The literature study of the hailstone failure reveals that the knowledge of BH steels behavior helps to calculate the steel supplier´s failure mode effect analysis (FMEA) risk priority number.
Mária Mihaliková; Kristína Zgodavová; Peter Bober; Andrea Sütőová. Prediction of Bake Hardening Behavior of Selected Advanced High Strength Automotive Steels and Hailstone Failure Discussion. Metals 2019, 9, 1016 .
AMA StyleMária Mihaliková, Kristína Zgodavová, Peter Bober, Andrea Sütőová. Prediction of Bake Hardening Behavior of Selected Advanced High Strength Automotive Steels and Hailstone Failure Discussion. Metals. 2019; 9 (9):1016.
Chicago/Turabian StyleMária Mihaliková; Kristína Zgodavová; Peter Bober; Andrea Sütőová. 2019. "Prediction of Bake Hardening Behavior of Selected Advanced High Strength Automotive Steels and Hailstone Failure Discussion." Metals 9, no. 9: 1016.
The article deals with the impact of a different number of poles of 6/4 and 12/8 switched reluctance machines on torque ripple at selected method of motor control. Compared switched reluctance motors have the same basic dimensions (stator outer diameter, length, air gap, rotor outer diameter) and operate at the same saturation of the magnetic circuit. Motor models are created in the ANSYS EM (ANSYS Maxwell) program. The motors are controlled by the direct torque control method. The very control is simulated in ANSYS Simplorer. Used in the control schemes are FEM motor models. At the end of the article, the influence of the number of poles on the torque ripples at different speeds, loads, and stator pole embraces is compared.
Želmíra Ferková; Ľuboš Suchý; Peter Bober. Comparison of 6/4 and 12/8 switched reluctance motor models using direct torque control with torque lookup table. Electrical Engineering 2019, 102, 75 -83.
AMA StyleŽelmíra Ferková, Ľuboš Suchý, Peter Bober. Comparison of 6/4 and 12/8 switched reluctance motor models using direct torque control with torque lookup table. Electrical Engineering. 2019; 102 (1):75-83.
Chicago/Turabian StyleŽelmíra Ferková; Ľuboš Suchý; Peter Bober. 2019. "Comparison of 6/4 and 12/8 switched reluctance motor models using direct torque control with torque lookup table." Electrical Engineering 102, no. 1: 75-83.
IT service desk is a complex service that IT service company provides to its customers. This article provides a methodology which uses discrete-event simulation to help IT service management to make decision and to plan service strategy. Simulation model considers learning ability of service desk agents and growth of knowledge database of the company. Model shows how the learning curve influences the time development of service desk quality and efficiency. This article promotes using simulation to define quantitative goals for the service desk improvement.
Peter Bober. Simulation for IT Service Desk Improvement. Quality Innovation Prosperity 2014, 18, 47 -58.
AMA StylePeter Bober. Simulation for IT Service Desk Improvement. Quality Innovation Prosperity. 2014; 18 (1):47-58.
Chicago/Turabian StylePeter Bober. 2014. "Simulation for IT Service Desk Improvement." Quality Innovation Prosperity 18, no. 1: 47-58.
Peter Bober. LESSON LEARNED FROM USING INTERACTIVE TRAINING SOFTWARE FOR STATISTICAL PROCESS CONTROL. QUALITY AND LEADING INNOVATION´2014 2014, 1 .
AMA StylePeter Bober. LESSON LEARNED FROM USING INTERACTIVE TRAINING SOFTWARE FOR STATISTICAL PROCESS CONTROL. QUALITY AND LEADING INNOVATION´2014. 2014; ():1.
Chicago/Turabian StylePeter Bober. 2014. "LESSON LEARNED FROM USING INTERACTIVE TRAINING SOFTWARE FOR STATISTICAL PROCESS CONTROL." QUALITY AND LEADING INNOVATION´2014 , no. : 1.
The purpose of this paper is to contribute to learning, knowledge creation and knowledge transfer for building organization innovability by integrating the management systems in the SIMPRO-IMS web based environment. The paper content consists of the interpretation of role-play simulation, role-play simulation process description, methodology, and the employment of role-play simulation outcomes, as well as the discussion of the knowledge thus obtained. Primary the model of the SIMPRO-Q education environment has been developed and tested during a period of 15 years in several industrial organizations as well as service organizations such as Higher Education Institution (HEI) and Healthcare Organization (HCO). The newest version SIMPRO-IMS has recently been developed to support a need of integration of management systems and information archiving. With the last development, SIMPRO-IMS web based environment, processes of five ISO systems are integrated for parallel development, implementation, auditing, maintaining and leading. SIMPRO-IMS provides management with the apparatus necessary to realize a systematic and verifiable approach to the creation and control of IMS documentation. At the same time contributes to the preservation of organization memory in response to the growing challenges of globalization and digitalization. The research is limited by the complexity of a real system and possible empiric results verification. The results achieved are verified when people really overcome the resistance to change. This can be assessed thoughtfully only after some period of time. Another limitation is presented by measurability of real enhancement achieved in quality, safety and environmentality of production, and business continuity and social responsibility of an organization. Development and progress in the methodology of SIMPRO-IMS web based environment is encoded in upgrading the SIMPRO database by processes of the environmental management, occupational health & safety management, information security management, energy management, service management, business continuity management and social responsibility management into one cohesive system with a holistic set of documentation, policies, procedures and processes, and a preserving knowledge for learning, new knowledge creation and knowledge transfer for building organization innovability.
Kristína Zgodavová; Peter Bober. An Innovative Approach to the Integrated Management System Development: SIMPRO-IMS Web Based Environment. Quality Innovation Prosperity 2012, 16, 1 .
AMA StyleKristína Zgodavová, Peter Bober. An Innovative Approach to the Integrated Management System Development: SIMPRO-IMS Web Based Environment. Quality Innovation Prosperity. 2012; 16 (2):1.
Chicago/Turabian StyleKristína Zgodavová; Peter Bober. 2012. "An Innovative Approach to the Integrated Management System Development: SIMPRO-IMS Web Based Environment." Quality Innovation Prosperity 16, no. 2: 1.
The purpose of the presentation is to provide the generalized knowledge about an innovative teaching approach to the design and development of the Integrated Management System (IMS) in web-based environments using Role Play Simulation (RPS).
Kristina Zgodavova; Matus Horvath; Pavol Palfy; Peter Bober; Milos Horvath. Integrated Management Systems web-based collaborative learning: (Interactive lesson presentation). 2012 15th International Conference on Interactive Collaborative Learning (ICL) 2012, 1 -3.
AMA StyleKristina Zgodavova, Matus Horvath, Pavol Palfy, Peter Bober, Milos Horvath. Integrated Management Systems web-based collaborative learning: (Interactive lesson presentation). 2012 15th International Conference on Interactive Collaborative Learning (ICL). 2012; ():1-3.
Chicago/Turabian StyleKristina Zgodavova; Matus Horvath; Pavol Palfy; Peter Bober; Milos Horvath. 2012. "Integrated Management Systems web-based collaborative learning: (Interactive lesson presentation)." 2012 15th International Conference on Interactive Collaborative Learning (ICL) , no. : 1-3.
The aim of this paper is to show the how to get new knowledge and skills through solving production relocation situations in a continuously changing global environment. The used methods model and simulate the related risks, using web based learning environment of Quality Management Role Play Simulation (SIMPRO-Q). The presented methods are applicable also in engineering education. During simulations, the role-players make both quantitative and qualitative decisions regarding management of critical situations during production relocation. Experiences from relocation production project in industry are discussed at the end of the paper.
Lubomir Lengyel; Kristina Zgodavova; Peter Bober. Modeling and Simulation of Relocation of a Production in SIMPRO-Q Web Based Educational Environment. International Journal of Advanced Corporate Learning (iJAC) 2012, 5, 26 .
AMA StyleLubomir Lengyel, Kristina Zgodavova, Peter Bober. Modeling and Simulation of Relocation of a Production in SIMPRO-Q Web Based Educational Environment. International Journal of Advanced Corporate Learning (iJAC). 2012; 5 (1):26.
Chicago/Turabian StyleLubomir Lengyel; Kristina Zgodavova; Peter Bober. 2012. "Modeling and Simulation of Relocation of a Production in SIMPRO-Q Web Based Educational Environment." International Journal of Advanced Corporate Learning (iJAC) 5, no. 1: 26.
Allocation of specific cutting plans and their scheduling to individual cutting machines presents a combinatorial optimization problem. In this respect, various approaches and methods are used to arrive to a viable solution. The paper reports three approaches represented by three discreet optimization methods. The first one is back-tracing algorithm and serves as a reference to verify functionality of the other two ones. The second method is optimization using genetic algorithms, and the third one presents heuristic approach to optimization based on anticipated properties of an optimal solution. Research results indicate that genetic algorithms are demanding to calculate though not dependant on the selected objective function. Heuristic algorithm is fast but dependant upon anticipated properties of the optimal solution. Hence, at change of the objective function it has to be changed. When the scheduling by genetic algorithms is solvable in a sufficiently short period of time, it is more appropriate from the practical point than the heuristic algorithm. The back-tracing algorithm usually does not provide a result in a feasible period of time.
Peter Bober. Comparison of Different Approaches to the Cutting Plan Scheduling. Quality Innovation Prosperity 2011, 15, 1 .
AMA StylePeter Bober. Comparison of Different Approaches to the Cutting Plan Scheduling. Quality Innovation Prosperity. 2011; 15 (1):1.
Chicago/Turabian StylePeter Bober. 2011. "Comparison of Different Approaches to the Cutting Plan Scheduling." Quality Innovation Prosperity 15, no. 1: 1.
The global objective of the paper is to introduce a new Statistical Process Control (SPC) education technology using an interactive control chart simulator. The basis is the contemporary experience in teaching at universities and in training for the practice and from there resulting observation, that especially the regular students often lack practical knowledge about the production process while managers lack deeper insight into the SPC theory. A possibility to eliminate this deficiency is a practical activity where individuals attain knowledge and skills through personal or hands-on experiences. Function of the simulator is to enable the student to resolve typical situations encountered in the SPC. This paper presents learning objectives, the SPC simulator concept, its functions, and the manner of its use in education.
Peter Bober; Kristina Zgodavova. Educational web tool for Statistical Process Control. 2011 14th International Conference on Interactive Collaborative Learning 2011, 460 -464.
AMA StylePeter Bober, Kristina Zgodavova. Educational web tool for Statistical Process Control. 2011 14th International Conference on Interactive Collaborative Learning. 2011; ():460-464.
Chicago/Turabian StylePeter Bober; Kristina Zgodavova. 2011. "Educational web tool for Statistical Process Control." 2011 14th International Conference on Interactive Collaborative Learning , no. : 460-464.