BASIC ALGORITHMS OF INPUT SHAPING AUTOTUNING

MM (Modern Machinery) Science Journal, October 2015
MACIEJ GNIADEK1, STEFAN BROCK2

1 Poznan University of Technology, Institute of Control and Information Engineering and Amica Wronki S.A., Poznan, Poland
2 Poznan University of Technology, Institute of Control and Information Engineering, Poznan, Poland

e-mail: maciej.gniadek@amica.com.pl

Abstract
Many mechanical systems contains flexible joints. The main problem in control of these kinds of objects are oscillations. The control strategy can be supplied by signal shaping methods. One of the simplest and most effective algorithm of reference signal shaping is named input shaping. The problem of input shaping tuning can be automatized. The paper shows two basic algorithms of input shaping autotuning. Every tuning method needs the information of object’s natural oscillation frequencies and their damping. These information are extracted using object identification and Fast Fourier Transform. Algorithms were tested by simulation on simple objects and on a model of two-mass system. The research was made in Matlab/Simulink environment.
 
Keywords: input shaping, command generation, autotuning, two-mass system
 
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HYBRID BODY OF UNDERGROUND RAILWAY CAR: PATH TOWARDS REDUCED WEIGHT OF RAIL VEHICLES

MM (Modern Machinery) Science Journal, October 2015
PETR HELLER, JIRI KORINEK, LADISLAV TRISKA

Regional Technological Institute, Faculty of Mechanical Engineering,
University of West Bohemia, Pilsen, Czech Republic

 e-mail: pheller@kks.zcu.cz

Abstract
The purpose of the development of a hybrid body for underground railway cars was to achieve weight reduction and a favourable impact on operating costs, primarily due to energy savings. The present paper describes the construction sequence of a prototype body shell.

 

Keywords: underground railway, hybrid body, rail vehicles, weight savings, composite materials
 

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MODERN METHODS FOR MANUFACTURING PLANNING AND SCHEDULING

MM (Modern Machinery) Science Journal, October 2015

DOI: 10.17973/MMSJ.2015_10_201519

IVANA SIMEONOVOVA1, ALEKSANDAR GYUROV2, SIMEON SIMEONOV1

1 Brno University of Technology, Faculty of Mechanical Engineering
2 Technical University of Varna, Faculty of Mechanical Engineering

 e-mail: y78756@stud.fme.vutbr.cz

Abstract
The paper deals with modern methods which can be used for planning and scheduling of manufacturing systems. Creating of production plans, using different software products is discussed. Advanced planning and scheduling methods are used for planning and scheduling. The outputs as Gantt charts are presented. Different optimization methods are applied for schedule optimization. Production plan, for every machine is created, after applying the optimization. Scheduling by using Lekin, ‘Spreadsheets’ and Asprova is described and compared.
 
Keywords: underground railway, hybrid body, rail vehicles, weight savings, composite materials

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EXPERIMENTAL OBSERVATION OF ELASTOHYDRODYNAMICALLY LUBRICATED CONTACTS REPLENISHMENT

MM (Modern Machinery) Science Journal, October 2015

DOI: 10.17973/MMSJ.2015_10_201525

DAVID KOSTAL, PETR SPERKA, PETR SVOBODA, IVAN KRUPKA, MARTIN HARTL
 
Brno University of Technology, Faculty of Mechanical Engineering,
Institute of Machine and Industrial Design, Brno, Czech Republic

 e-mail: kostal@fme.vutbr.cz

Abstract
Starved regime of elastohydrodynamic lubrication (EHL) is usually described by smaller thicknesses of the lubrication film then fully flooded regime. This state can be caused by a number of reasons including operating conditions, lubricant supply or/and its properties. Rolling bearings contain multiple consequent elements which can increase the risk of starvation because the replenishment mechanisms are not able to recover lubricant film after each element passage. One of the main aspects in the rolling bearings is proximity of the rolling elements. Severity of the starvation increases as the mutual elements distance decreases. Lubricant which was squeezed out by rolling element need some time to replenish the gap. This paper presents experimental methods for measuring the time necessary for oil lubricant film recovery. Results obtained by these methods had been compared with existing theory. The theory describes behavior of replenishment of the central film thickness and change in the lubricant distribution across the rolling track. Both of these aspects qualitatively agree. Changes in the central film thickness during replenishment process were theoretically described as very nonlinear process which was confirmed by experiment in this paper.

Keywords: underground railway, hybrid body, rail vehicles, weight savings, composite materials

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IMPLEMENTATION OF COLD ROLLING PROCESS IN BEARING INDUSTRY

MM (Modern Machinery) Science Journal, October 2015

DOI: 10.17973/MMSJ.2015_10_201526

JAN OTOUPALIK1, ZUZANA FISEROVA1, MIROSLAV NESLUSAN2, KAMIL KOLARIK3
 
1 ZKL, a.s., Brno, Czech Republic,
2 University of Zilina, Faculty of Mechanical Engineering, Zilina, Slovak Republic
3 CTU in Prague, Prague, Czech Republic

 e-mail: jan.otoupalik@zkl.cz

Abstract
This paper deals with implementation of various strategies in production of bearings and their influence on the consecutive operations. Shaping of bearings via cold rolling in compared with conventional process usually employed in bearing industry based on machining cycles on hot rolled parts. Such aspects as structure, stress state before and after heat treatment, rings deformations after heat treatment (hardening and consecutive annealing) and cutting forces during hard turning are investigated. The results show that investigated strategies produce quite different stress state and the corresponding deformation during heat treatment. Deformations of rings due to heat treatment regime cause significant instability of cutting force components. On the other hand, influence of different strategies on stress state after heat treatment as well as hard turning is minor.

Keywords: bearing, cold rolling, residual stresses, structure

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DETERMINATION OF THE GRAIN GROWTH KINETICS AS A BASE PARAMETER FOR NUMERICAL SIMULATION DEMAND

MM (Modern Machinery) Science Journal, October 2015

DOI: 10.17973/MMSJ.2015_10_201523

JAROMIR MORAVEC
 
Technical University of Liberec, Department of Engineering Technology,
Liberec, Czech Republic

 e-mail: jaromir.moravec@tul.cz

Abstract
The grain size is an important parameter influencing not only the material brittleness and strength properties, but also the transformation processes of creep, strength, and fatigue. This present paper is therefore focused on the process description for the experimental determination of the kinetics of grain growth curves temperature dependence. These curves are then used for numerical simulations of grain coarsening in different technological applications such as welding, heat treatment, or slow cooling of large parts. Further it will be demonstrated how obtained curves can be used for the prediction of the grain size in the heat affected zone (HAZ) of multilayer heterogeneous welds of X10CrWMoVNb9-2 and 18Cr9Ni3CuNbN materials and subsequently verified by real welding experiments. The paper will also show the main benefits of using GLEEBLE simulator for verification of the grain coarsening in HAZ of realized welds.

Keywords: grain size, numerical simulation, X10CrWMoVNb9-2 steel, 18Cr9Ni3CuNbN steel, welding, Gleeble

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VIRTUAL REALITY BASED DESIGN AND CALCULATION TOOL FOR IMPROVING DYNAMICS OF MACHINE TOOLS

MM (Modern Machinery) Science Journal, October 2015

DOI: 10.17973/MMSJ.2015_10_201530

VOLKER WITTSTOCK1, MARTIN KOLOUCH2, JAN BERTHOLD1, MARKUS RICHTER3
 
1Institute for Machine Tools and Production Processes, Chemnitz University of Technology, Chemnitz, Germany,
2Fraunhofer Institute for Machine Tools and Forming Technology IWU, Chemnitz, Germany
3StarragHeckert GmbH, Chemnitz, Germany

 e-mail: jan.berthold@mb.tu-chemnitz.de

Abstract
This paper presents an extended workflow to improve the dynamic behaviour of machine tools that is fully controlled in the virtual reality environment (VR). The workflow utilizes a common platform for the visualization of results of an experimental modal analysis and the following structural dynamic modification to eliminate the weak points of the design. Based on the overlaid visualization of measured mode shapes, the calculated behaviour and the CAD-model of the machine combined with the parameter modifications in the same virtual reality environment, the VR based approach becomes a development tool that helps to immediately understand cause and effect of complex changes. The advantages of the presented approach are shown by investigating parameter modifications of an I-beam demonstrator and a machine tool.

Keywords: virtual reality, design optimization, design visualization, machine tool, structural dynamic modification

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DEVELOPMENT OF CUSTOMER LOYALTY MEASUREMENT AT CZECH COMPANIES

MM (Modern Machinery) Science Journal, October 2015

DOI: 10.17973/MMSJ.2015_10_201531

JAROSLAV NENADAL
 
VSB – Technical University of Ostrava, Department of Quality Management, Ostrava, Czech Republic

e-mail: jaroslav.nenadal@vsb.cz

Abstract
Any efficient quality management system must use permanent feedback from customers. All organizations certified against the ISO 9001 standard should measure customer satisfaction. At present, such feedback seems to be unsufficient. A customer loyalty or value for customer represent advanced values for modern organizations. Unfortunately, these values are underestimated or completely ignored at Czech organizations as only about 30 % of them are interested in some customer loyalty indicators. An article is not only focused on current state analysis of customer loyalty measurement at Czech companies. The main topic is oriented to development and launching a comprehensive approach to customer loyalty measurement. This comprehensive approach includes customer loyalty measurement through future customers intentions, effects of customers loyalty, customer loss and finally, through loyalty index. Some lessons learned related to practical implementation of this approach from Czech companies will be also presented.

Keywords: quality management system, customer loyalty, feedback, measurement, customer retention, customer loyalty, organization´s performance

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MAINTENANCE MANAGEMENT SYSTEM

MM (Modern Machinery) Science Journal, October 2015

DOI: 10.17973/MMSJ.2015_10_201532

HANA PACAIOVA, JURAJ GLATZ
Technical university of Kosice, Safety and Quality Production Department, Kosice, Slovakia

e-mail: hana.pacaiova@tuke.sk

Abstract
Maintenance Management requires acceptance of basic systems approach, i.e. implementation of company goals to management goals. Well know Maintenance management philosophies (TPM, RCM, RBI) applied in order to improve processes, often remain only on the basis of the implementation of services without the need for full integration into existing management systems. Misunderstanding the nature of maintenance management leads to inefficient step, resulting in a contradiction between the goals of management and their ability to support real goals through maintenance management.
Process approach in the management of maintenance is the basis for improvement in maintenance and hence achieving the required performance.
This article, based on practical experience, analyzes the root errors caused by maintenance management in order to apply the selected philosophy in the management of maintenance without the knowledge or lack of willingness to accept a systemic approach to maintenance management.

Keywords: risk management, TPM, RCM, FMEA, KPI

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PARALLELS BETWEEN CORPORATE SOCIAL RESPONSIBILITY AND THE EFQM EXCELLENCE MODEL

MM (Modern Machinery) Science Journal, October 2015

DOI: 10.17973/MMSJ.2015_10_201533

HELENA CIERNA, ERIKA SUJOVA
Department of Manufacturing Technology and Quality Management, Technical University in Zvolen
Faculty of Environmental and Manufacturing Technology, Zvolen, Slovak Republic
 
 
Abstract
CSR is a continued promise by companies to act ethically, to contribute to sustainable economic development, and to contribute to improvement of quality of life of its employees, their families, as well as local communities and society as a whole. Increasing demands on productivity and effectivity of business subjects rightfully result in efforts to implement better management systems, which take into consideration a number of rules and documents specific for a given field. Confirmation of this trend is implementation of other models management systems that focus on quality. One such model is a parallel interconnectivity between Corporate Social Responsibility and the EFQM Excellence Model, which our article examines in deepness. Systematic and professional application of the EFQM Excellence Model and interconnectivity with Corporate Social Responsibility fundamentals results in maximization of added value for all interested parties.

Keywords: corporate social responsibility, EFQM excellence model, business, ethics, environment

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VOLUMETRIC COMPENSATION OF THREE-AXIS VERTICAL MACHINING CENTRE

MM (Modern Machinery) Science Journal, October 2015

DOI: 10.17973/MMSJ.2015_10_201534

MICHAL HOLUB, PETR BLECHA, FRANTISEK BRADAC, ROMAN KANA
Faculty of Mechanical Engineering, Brno University of Technology, Brno, Czech Republic

e-mail: holub@fme.vutbr.cz

Abstract
This contribution assesses the possibilities of application of volumetric compensation technology on a small three-axis vertical machining centre. These machine tools are designed for machining of small workpieces with various requirements on dimensional and shape accuracy. Small machine tools do not show large volumetric deviations across the entire working space as it is seen with medium-sized and large machining centres. To test volumetric compensation, detailed measurements on a small machining centre (demonstrator) were performed prior to activation of compensation set; other verification measurements were carried out with activated compensation set. Even if volumetric compensation is deployed, it is necessary to verify the achieved results in an appropriate manner. The accomplished study will offer pertinent conclusions on the appropriateness of the technology to be deployed for selected types of workpieces.

Keywords: volumetric compensation, volumetric accuracy, machine tool, LaserTRACER, ballbar

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IMPACT OF MICROCLIMATE CONDITIONS ON THE CONTROL ROOM PERSONNEL - CASE STUDY

MM (Modern Machinery) Science Journal, October 2015

DOI: 10.17973/MMSJ.2015_10_201535

LUBOS KOTEK1, PETR TRAVNICEK2, FRANTISEK BABINEC3, PETR JUNGA2, LEISAN MUKHAMETZIANOVA1
1Brno University of Technology, Faculty of Mechanical Engineering, Institute of Production Machines, Systems and Robotics, Brno, Czech Republic
2Department of Agricultural, Food and Environmental Engineering, Faculty of Agronomy, Mendel University in Brno, Brno, Czech Republic
3RISCO – Risk Consulting Brno, Brno, Czech Republic
 
Abstract
The present contribution deals with the influence of work environment factors on the control room personnel, in particular the temperature and humidity parameters, and concentration of CO2. This contribution summarizes selected practical experience of implementing ergonomic analysis and evaluation of the impact of these parameters on the reliability of human factor in the chemical industry, power engineering and gas industry.

Keywords: ergonomics, reliability of human factor, control room, work environment, temperature, humidity, carbon dioxide

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SAFETY CULTURE AND AGILE

MM (Modern Machinery) Science Journal, October 2015

DOI: 10.17973/MMSJ.2015_10_201536

VERA PELANTOVA, JANA VITVAROVA
Technical University of Liberec, Institute of Mechatronics and Computer Engineering, Liberec, Czech Republic
 
Abstract
Agile methods, a perspective alternative to the traditional project management, extend across organisations gradually. Their introduction is, however, confronted with safety aspects which are an integral part of activities in each organisation. This article deals with the relation between agile methods and the safety culture of an organisation using a comparative study based on authors’ research performed in the Czech Republic. It presents fundamental safety aspects, which must be respected while using agile methods and how they can be reflected namely in the agile method Scrum. The article aims to explore the prerequisites for a symbiotic functioning of agile methods and safety culture and in this way to help improve the competitiveness of organisations.

Keywords: agile methods, safety culture, safety aspect, organisation management system, agile team, Scrum

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ENVIRONMENTAL REPORTING IN THE ENTERPRISE AND RELATED ISSUES

MM (Modern Machinery) Science Journal, October 2015

DOI: 10.17973/MMSJ.2015_10_201537

MIROSLAVA POLANKOVA1, FRANTISEK MANLIG1, RUZENA KRALIKOVA2
1Technical University of Liberec, Liberec, Czech Republic
2 Technical University of Kosice, Kosice, Slovakia

e-mail: miroslava.polankova@tul.cz

Abstract
The article deals with environmental reporting in the company. The environmental reporting, new trends and its benefits are describes. Environmental reporting can actively monitor, manage and gradually reduce the negative impact of companies activities on the environment. The other concepts that are closely related to reporting are also describes in the article. It's environmental communication and audit, environmental management system (EMS) and environmental management accounting (EMA). In the article is a case study from the company producing automotive components. The interconnectedness clarified issue in the context of environmental reporting are describes in the aim of the final chapter. These voluntary instruments are analyzed and evaluated using SWOT analysis. The environmental management system leads to corporate responsibility, the gradual reduction of operating costs and to the competitiveness compared with enterprises which already has this system implemented. Thanks implemented environmental system enterprise easily obtains information which is required in the environmental reporting.

Keywords: environment, accounting, audit, ecological, management

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TOPOLOGY OPTIMIZATION OF A BICYCLE PART

MM (Modern Machinery) Science Journal, October 2015

DOI: 10.17973/MMSJ.2015_10_201538

PETR ZELENY, MILOS CADEK
Technical University of Liberec, Faculty of Mechanical Engineering, KSA, Liberec , Czech Republic

e-mail: petr.zeleny@tul.cz

Abstract
The paper contains suitable methodics to obtain optimal part design due to operational (static) load cases. The subject of optimization is an upper rocker of a special mountain bike frame. To obtain optimized part design a topology optimization method combined with a numerical shape optimization was used. Optimized part was manufactured by Selective Laser Melting technology. The paper begins with introduction of part's function and its operational load. Then used optimization tools are introduced and initial conditions sensitivity demonstration is performed. Manufactured part with optimized design is shown at the end of the paper.

Keywords: topology optimization, 3D printing, SLM, FEA, MTB

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COMPARISON OF TAGUCHI'S PARTIAL CORRECTION TECHNIQUE WITH CONTROL CHARTS

MM (Modern Machinery) Science Journal, October 2015

DOI: 10.17973/MMSJ.2015_10_201539

LUBOS KOTEK1, ALES NOSEK2, ALOIS FIALA1, JIRI ZAHALKA1
1Brno University of Technology, Faculty of Mechanical Engineering, Institute of Production Machines, Systems and Robotics, Department of Quality, Reliability and Safety, Brno, Czech Republic
2Brno University of Technology, Quality Management Department, Brno, Czech Republic

e-mail: kotek.l@fme.vutbr.cz

Abstract
This article compares the most commonly used methods of statistical quality control (control charts - in our case the control chart of individual values) with the Taguchi’s method of Partial Correction. The comparison applies to an actual process of hole reaming, and a test is carried out of gradual change of setting (continuously increasing simulation deviation).

Keywords: statistical process control, control charts, Taguchi's partial correction, hole reaming, Beta correction

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PARAMETERS INFLUENCING THE PRECISION OF SLM PRODUCTION

MM (Modern Machinery) Science Journal, October 2015

DOI: 10.17973/MMSJ.2015_10_201540

PETR KELLER, RADOMIR MENDRICKY
Technical University of Liberec, Department of Manufacturing Systems and Automation, Liberec, Czech Republic

e-mail: radomir.mendricky@tul.cz

Abstract
This article focuses on production of parts by Selective Laser Melting (SLM) technology, where the prototype part is created by melting metallic powder in selective manner by means of laser – layer by layer. Due to the laser, the model is loaded with high temperatures – the high-temperature stress in the material occurs during the production and consequent cooling, resulting in undesired deformation of component's shape. This deformation may be favourably influenced by appropriate parameter settings of the production process, or by means of annealing performed after the production. This article familiarises its readers with results of research dealing with influence of production process parameter settings on the magnitude of internal material tension of the printed part, or its influence on dimension and shape precision of products manufactured by this additive technology. The produced samples were measured and their shape precision was analysed by a 3D optical digitisation method, allowing comparison of the actual part to a nominal CAD model and therefore perform shape and dimension precisions of the produced prototypes in a complex and objective manner.

Keywords: SLM, selective laser melting, geometrical accuracy, 3D optical scanner, 3D digitization

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ANALYSIS OF MEASUREMENT ACCURACY OF CONTACTLESS 3D OPTICAL SCANNERS

MM (Modern Machinery) Science Journal, October 2015

DOI: 10.17973/MMSJ.2015_10_201541

RADOMIR MENDRICKY
Technical University of Liberec, Department of Manufacturing Systems and Automation, Liberec, Czech Republic

e-mail: radomir.mendricky@tul.cz

Abstract
Currently, the conventional measuring methods in industry are more and more substituted with new methods, where the inspected component is firstly digitised by means of so called optical 3D scanners, and the inspection of dimension and shape precision is performed on the obtained virtual model. This approach bears many advantages and, in many cases, provides faster and more objective results. On the other hand, it has its restrictions – for example a problematic digitisation of detailed elements such as sharp edges or small and deep holes. Also, precision of this approach is often not possible to clearly quantify and we have to find satisfaction in various comparison tests. This article familiarises its readers with the results of research focused on analysis of precision when digitising shape elements by means of 3D scanners. Simultaneously, it provides knowledge about abilities of 3D scanners to capture detailed elements of the measured component and familiarises the readers with scanning limits for individual optical systems.

Keywords: optical measurement, laser scanner, 3D optical scanner, 3D digitization, accuracy

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