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2024 | Buch

32nd International Conference on Organization and Technology of Maintenance (OTO 2023)

herausgegeben von: Tomislav Keser, Naida Ademović, Eleonora Desnica, Ivan Grgić

Verlag: Springer Nature Switzerland

Buchreihe : Lecture Notes in Networks and Systems

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SUCHEN

Über dieses Buch

This book presents papers submitted at 32nd International Conference on Organization and Technology of Maintenance (OTO 2023) held on December 12, 2023, at Osijek, Republic of Croatia.

The objective of this conference is to promote, standardize, and support efforts to gain new knowledge in areas that are intimately tied to technical and social systems and where maintenance of any kind is of utmost importance. By bringing together experts from various fields, this conference aims to foster collaboration and the exchange of ideas, ultimately leading to advancements in both technical and social systems. Additionally, it seeks to create a platform for discussing best practices and innovative approaches in maintenance, ensuring the sustainability and efficiency of these systems in the long run. Furthermore, the upkeep of technological and social systems, along with their accessibility and dependability, significantly influences the long-term sustainability and economic feasibility of their functioning. Periodic and condition-based maintenance are integral components of the various systems, influencing their operational efforts and outcomes. By providing a space for professionals to exchange ideas and experiences, this platform facilitates the identification and implementation of cutting-edge maintenance strategies. Moreover, it recognizes the importance of addressing emerging challenges such as digitalization and environmental impact in order to ensure the continued effectiveness of these systems.

Conference topics will address maintenance challenges in the areas of machine design, maintenance technologies in general, organization and management of maintenance proposals and procedures, quality management in system maintenance, information systems, product life cycle management, design for maintainability, material and structural properties, diagnosis and prediction of failures and breakdowns, design optimization for maintenance, analysis of maintenance efficiency and cost-effectiveness, civil, mechanical and electrical engineering, etc.

Inhaltsverzeichnis

Frontmatter
Analysis of the Impact of Smartphone on the Environment Using the LCA Method

Today’s industrial production has a great impact on the environment all over the world. The constant increase in the world’s population has a great impact on the expanding industries in the world. Maintenance, eco-design and life cycle analysis are important concepts related to sus-tainability and environmental protection. Life cycle refers to everything associated with the product at all stages of its life, from the extraction of raw materials to the disposal or recycling of the product. The mobile phone was chosen as a representative in accordance with the global development of the relevant industry and the desire to show its impact on the environment using the LCA (Life cycle assessment) method. The concepts of sustainable development, recyclability and eco-indicators were explained and some concepts and tools were presented to show how can mobile phones industry reduce the impact and con-tribute to the environment and sustainability.

Jure Marijić, Marko Vilić, Ivan Grgić, Mirko Karakašić, Željko Ivandić, Domagoj Komarčić
Lean Smart Maintenance for Machine Tools

The Lean Smart Maintenance concept has been developed to provide an optimal and targeted maintenance strategy. By implementing this concept, manufacturing companies can achieve an efficient maintenance program for their CNC machines, which is a crucial component in ensuring the continued operation and the overall success of the manufacturing process. Moreover, maintenance resources are minimized as maintenance measures are performed more effectively. Both planned and unplanned shutdowns are considered. In this paper, the focus is on a comprehensive consideration of maintenance in a SAP-based, medium-sized company with an inhomogeneous machine park and the digital networking of all departments. The data-based model follows a centralized approach from the maintenance technician’s mobile device, over the warehouse management of the maintenance to sales information with the use of advanced planning and scheduling software.

Josip Florian Strutz, Tomislav Saric, Katica Simunovic, Ivan Samardzic
Advanced Construction Materials Based on Concrete to Protect the Living Space from Non-Ionizing Radiation

This paper presents measurements of the reflection and transmission coefficient of electromagnetic waves through concrete and two concrete-based composites: concrete with steel fibers and concrete with carbon fibers with the aim of enhancing the attenuation of electromagnetic waves passing through concrete and concrete composites. The frequency range for which the measurements were carried out extends from 30 MHz to 18 GHz and includes most of the existing stationary (and mobile) radiation EM sources in the environment in which the general population moves (FM, DVBT2, 2G - 5G mobile radio systems, stationary radar border area control systems). The measurement results show that as the thickness of the concrete increases, the transmission through concrete and concrete composites decreases (parameter S12 decreases). Furthermore, composites with carbon fibers partially reduce, while those with steel fibers significantly reduce, the transmission of EM waves through such composites. The reduction of parameter S12 by composites with steel is up to 52 dB (at a frequency of 2.9 GHz) for a block thickness of 100 mm. It is important to emphasize that in the case of composites with steel fibers, the influence of the fibers on the transmission parameters is more significant than the thickness of the sample. The reason for this is the increase in electrical conductivity of composites with steel fibers due to the increased proportion of conductive components in the concrete.

Vanja Mandrić, Slavko Rupčić, Davor Vinko, Ivica Dominković
Analysis of the Structure of Agricultural Machinery Repair Workshops - A Case Study

Modern agricultural production implies the use of highly sophisticated machines. Their high reliability, efficiency, and operational life depend to a large extent on high-quality and timely regular preventive maintenance measures. Unfortunately, during exploitation, the machines will break down, and we attempt to restore them to their correct state with a high-quality, quick, and cheap repair. To achieve high-quality and efficient maintenance and repair, good work organization, necessary facilities, devices, and tools, as well as qualified and educated workers are essential. In the work, an audit of two central repair facilities for the repair of agricultural machinery was carried out to verify their advantages and disadvantages about the organization of maintenance and repair of machinery. The results of the research indicate the absence of diagnostics, maintenance planning, a longer time interval for the procurement of standard spare parts (3–5 days) in workshop 1, while in workshop 2 the only deficiency is manifested in the absence of maintenance planning.

Željko Barač, Tomislav Jurić, Ivan Plaščak, Monika Marković, Antonija Kojić, Denis Ćosić
Maintenance of Agricultural Machinery in the Company Jerković d.o.o.

The aim of this study is to examine the actual state of maintenance of agricultural machinery at Jerković d.o.o. The research results indicate that daily and weekly maintenance is carried out almost entirely according to the instructions for handling and maintenance. Technical protection and garage storage of the machines are per-formed adequately. However, to improve maintenance practices, machine operators need to be educated on the latest technologies.

Denis Ćosić, Željko Barač, Tomislav Jurić, Ivan Plaščak, Josip Damjan
Bridging the Physical and Virtual Worlds: A Hand Tracking Gesture Recognition System for XR Applications

Extended reality (XR) is a term that encompasses augmented reality (AR), virtual reality (VR), and mixed reality (MR). These technologies allow users to interact with digital content in immersive and realistic ways. One of the challenges of XR is to provide natural and intuitive ways to control and manipulate the virtual environment. This paper presents the development of a gesture recognition system for hand tracking in extended reality technologies (XR) and its practical applications. The system uses a gesture definition language that allows the user to create custom gestures based on the hand skeleton model. The system was implemented using the Oculus Quest 2 device and the Oculus SDK in the Unity game engine and is compatible with all devices that support hand tracking. The gesture recognition system was implemented using a three-bone thumb and little finger model that is compatible with all hand models that contain four bones. The implementation of this gesture recognition system in XR has several benefits, including increased immersion, improved interaction with virtual objects, and reduced physical fatigue compared to traditional input methods such as controllers or keyboards. This system provides users with a more intuitive and natural way to interact with their virtual environment. Overall, this work demonstrates the feasibility and potential of integrating gesture recognition into XR technologies and its ability to enhance user experience and interaction. The system presented in this work can serve as a foundation for future developments in this area, with potential applications in gaming, education, healthcare, and other fields.

Matija Fumić, Časlav Livada
Transmission of Electromagnetic Waves Through a Clay Material

This paper deals with the simulation calculation of transmission (S21) and reflection (S22) parameters in a material parametrically based on clay (brick). The electromagnetic parameters of the clay that are the subject of the study are: relative permittivity εr, loss tangent tan δ and electrical conductivity σ, while the only structural parameter is the thickness d of the sample. The values of all considered parameters are within the range of data from available literature and values that could occur due to external causes (e. g. an increase in clay moisture leads to an increase in electrical conductivity). The simulation model was carried out with the software tool ANSYS HFSS and validated with a laboratory measurement model. The laboratory model consists of a circular waveguide with an inner diameter of 150 mm and a total length of 700 mm, which is excited by 52 mm long probes placed 50 mm from the last wall of the waveguide. The lower cut-off frequency of this measurement system is 1.173 GHz, so all results (simulation and measurement) are limited by this lower cut-off frequency of the waveguide. All simulation calculations were performed for three clay sample thicknesses: 18 mm, 36 mm and 54 mm. These calculations were made with the aim of determining brick composites that have high attenuation of electromagnetic EM waves (low transmission parameter and high reflection parameter) in order to reduce the strength of EM fields inside the object made of such bricks. The measured results were used to verify the simulation model.

Vanja Mandrić, Slavko Rupčić, Davor Vinko, Domagoj Bilandžija
Opening Doors and Drawers by a UR5 Robot with Force Control

Robots capable of automatically opening and closing articulated objects such as doors and drawers have broad potential applications in households, healthcare facilities, and industrial environments. Drawers can be opened and closed by pulling or pushing along the axis of translation, while doors can be opened by rotating around the axis of rotation. When a robot’s motion path deviates from the ideal trajectory required for opening and closing, its action can cause various damages due to excessive lateral forces. In this paper, we address the problem of force control in robotic manipulation of doors and drawers. The goal of force control is to minimize lateral forces when opening and closing doors and drawers. At the same time, position control is performed in the direction of the ideal trajectory. A force-torque sensor attached to a robot can monitor all forces in 3D space. We conduct experiments on opening and closing the doors and drawers using a UR5 robot with and without force control, and analyze the force response while monitoring the success of the actions performed. With this study, we provide insight into the usefulness of force control in opening and closing doors and drawers by a robot.

Jana Dukić, Lukrecia Vulić, Valentin Šimundić, Petra Pejić, Robert Cupec
Maintaining Mobile Communication in Distress and Emergency Situations

This paper provides an overview of the technical aspects of the application of amateur radio stations in maintaining mobile communication in distress and emergency situations. Ultra-high frequencies (UHF) were selected for radio communication testing. Testing was performed at a frequency of 446 MHz, which is covered by the PMR446 (Private Mobile Radio) standard. Handheld radios were used to test communication in urban conditions. Given the high attenuation of electromagnetic waves in urban areas due to concrete and steel reinforced concrete buildings, special attention is paid to testing communication in urban areas. The quality and range of communication using non-directional and directional antennas as well as with simplex repeaters are presented in the paper. The obtained measurement results of quality and range of communication in urban conditions are analyzed and interpreted. General conclusions are given on the capabilities of amateur radio handheld stations and additional equipment such as antennas and simplex repeaters for maintaining communication in distress and emergency situations in urban conditions.

Tomislav Barić, Hrvoje Glavaš
Testing the Quality of CNC Plasma Thermal Cutting in Accordance with the HRN EN 1090-2 Standard for the Production of Steel Structures

The paper briefly explains the development of the EN 1090 standard through the theoretical part where the general data of the standard is presented, and in the practical part one of the requirements of the standard is analyzed where its application to thermal cutting of steel sheets is shown. It is necessary to provide a standard in which the basic characteristics of the semi-finished product (microstructure of the material) are changed only up to the permitted limits, because changes greater than the permitted greatly affect the behavior of the components during the next steps in the production process.

Miroslav Duspara, Ivan Dunđer, Marija Stoić, Josip Cumin, Antun Stoić
Automated Titration of SO2 in the Winery Environment: Conceptual Design and Proof of Concept

The wine production industry competes every day for better product quality, same time lowering production costs. As product quality strongly relies on winemaker expertise and quality of raw materials, lower production costs are tightly related to the automation level of whole production process. One of parameter that significantly influences on the wine quality is sulphur-oxide based compound in its free form which is measurable using process so called titration of SO (sulphur oxide titration). Currently the state of titration measurement automation highly correlates to the scale of production and only the biggest winemakers have some sort of automated titration devices. Such devices are not suitable for small or medium winemakers due their high costs, either of purchase of measurement services. This paper proposes, make conceptual development and evaluate functionality for an automated titration device for SO compounds in winemaking industry which is suitable for small and medium winemakers and does not break their banks. The concept elaborates and deduce setup for distributed wine supplying, conditioning of the measurement device and metrology of the measurement.

Tomislav Keser, Robert Miling, Davorin Miličević, Damir Blažević
RS485 Network Design and Maintenance in Food Processing Industry: A Winery Application

The communication networks are widely in use in every aspect of our life, making our environment compliable to the ever-present IoT oriented technocratic society. Good and quality communication enables reliable and representative data transportation service which provides interoperability of various data-processing systems. Majority of industrial processes have some sort of communication topologies used for interconnection of various subsystems, required by their specific operation principles, and often works in harsh and electrically and mechanically unpleasant environment. Presence of electromagnetic noises, electric discharges, strong and high alternating magnetic fields, mechanical and chemical stresses, also environmentally caused impacts on data transportation scheme, cause data corruption and lowers availability and reliability of such network. This paper deals with the problem of design, implementation and verification of RS485 based communication network for multi-nodal data exchange in winery cellars. The wine cellar represents exceptionally harsh environment in aspects of environmental chemical and electrical related conditions. The paper proposes optimal topology among multi-nodal communication devices for an experimental cellar setup, and develop communication protocol for efficient data exchange. Furthermore, a strategy for successful maintenance is also presented through in-protocol and nodal-oriented topology integration.

Ivana Kovačević, Tomislav Matić, Tomislav Keser, Robert Miling
IoT in Smart Chromodynamic Plants Gardening

The present economy of food production follows the trends of constant increase of its production. From year to year, better yields in crop production and efficient management of nutrient supply in flowers are expected. The environmental aspects that affect the well-being of flowers are well known, but the dynamics in the efficiency of nutrient ingestion efficiency and photocatalytic sugar production is something that has only been known relatively recently and has now become manageable. The efficiency of photocatalysis of floral nutrients is highly dependent on the photon-based energy source, or light, and its plant-specific conformal light spectrum. Generally, bluish and reddish tinted visible light sources are suitable for efficient plant growth, making the system more efficient overall (lower energy consumption and other requirements). Such systems are often referred to as chromodynamic plant growth systems. This paper presents an IoT-based system that leverages knowledge of chromodynamic plant growth control. The development and validation challenges are presented and explained. Proposals to solve the challenges are also presented to make the whole system Internet-enabled, chromodynamically controlled, and energy efficient. The systems presented show that chromodynamics validates the horticultural premise of nutrient uptake efficiency, in addition to energy efficiency and the trend toward networking everything based on IoT principles.

Željko Juric, Tomislav Keser, Ivor Plander, Mario Levanić
Unmanned Aerial Vehicle Mapping of River Flow for Water Resources Management

Unmanned aerial vehicle surveying of the riverbed enables detailed mapping of the river flow, which is useful for various purposes such as flood management, ecosystem monitoring and geological processes. Unmanned aerial vehicles are used to collect data on water height, flow velocity and bed shape, creating precise maps of river systems. This process can be fast, efficient and safe for operators, and is therefore increasingly used in scientific research and water resource management.Riverbed surveying can be done with a LiDAR (Light Detection and Ranging/Laser scanning) camera which collects visual data on the condition of the riverbed, such as changes in shape, erosion and sedimentation. LiDAR cameras, also known as side-scan sonar, use sound signals to collect data on the depth and shape of the riverbed and create a precise 3D map of the riverbed. This process enables a detailed analysis of the river system and is useful for water resource management and environmental protection.The paper will give an overview of the methods and technologies that are currently relevant for the implementation of such recordings. Also, future work will be presented, as well as the advantages and challenges of such a project from an economic and technological point of view.

Marina Peko, Dominika Crnjac Milić, Ivan Vidaković
Development of a Device for Maintaining the Temperature of the Tendons During the Period of Recovery

The development of a device for maintaining the temperature of tendons during recovery on a tensile test device is an area of research that has gained attention in biomechanics. Preconditioning is a critical phase in which tendons are subjected to cyclic loading to simulate in vivo conditions. However, this process can alter the mechanical properties of the tendon and impact test results. Maintaining the temperature of tendons during the recovery phase can help reduce the effects of preconditioning and improve the accuracy of test results. The device developed for this purpose is composed of a heating element, temperature sensors, a water pump and a controller unit. It can maintain the temperature of tendons at $$33\,^\circ {\text{C}}$$ 33 ∘ C , which is the average temperature in the human knee. The use of this device has shown promising results in reducing the variability of tensile test results, simulating the real conditions in the human body and improving the reproducibility of tests.

Ivan Grgić, Mirko Karakašić, Željko Ivandić, Jure Marijić, Marko Vilić
Maintenance of Automobiles and Motorcycles Through Prism of OBD II Diagnostic Tools

The automotive maintenance is often based on the sensor electrical information. The sensor data can be measured directly by the means of multimeters or oscilloscopes, or it can be read through OBD-II communication port.OBD-II protocol is the standardized communication protocol, and it is used for vehicle diagnostic. The development of this protocol and devices begun back in 1968, and to this day many features have been developed and integrated in the modern diagnostic devices. Service codes and sensor values are often processed under common codes, and sometimes it is difficult to detect the cause of malfunction through common error codes. For this purpose, most automotive manufacturers use their own communication lines and can give more insight into engine malfunction. Besides malfunction detection in workshops, the OBD-II devices are more and more used for vehicle annual inspection (MOT) during annual vehicle registration renewal. This paper gives an overview of existing OBD 2 devices on the market (in 2023 year), and their technical possibilities with regard to automotive maintenance technologies. Introduction gives short historical introduction of OBD technology, second chapter gives basic OBD-II pinout, basic protocols and basic engine error codes. The third chapter gives an overview of technical data for the commercially available OBD-II hardware modules. Fourth chapter gives overview of application in the field of maintenance technologies.

Josip Cumin, Daniel Novoselović, Dejan Marić, Tomislav Šolić
Construction of Variable Sheet Metal Hand Bending Tool

Automotive chassis is made from deep drawn and stamped sheet metal pieces. Corrosive resistance of the chassis is maintained by the means of galvanizing technology in synchronization with the usage of modern coatings.During time, the coating can be chipped off - especially on the chassis underbody (e.g. from gravel or rocks). In such places corrosion quickly develops and the sheet metal deteriorates. This chassis needs to be repaired in order to prolong vehicle lifetime. The body repair is performed by cutting-out the corroded segments and replacing it by welding. For the modern cars, the sheet metal parts are easily obtainable in the specialized stores, but there is problem of finding sheet metal parts for “oldtimer” vehicles. In such cases, the sheet metal parts are required to be custom tailored with the basic tools and excellent problem-solving and manufacturing skills. This paper brings the idea of adjustable (modular) hand-bending tool for the bending of sheet metal segments, so that they could be custom tailored to the car chassis damaged place.

Josip Cumin, Hrvoje Vorel, Miroslav Duspara, Hrvoje Glavaš
Cost-Effectiveness of an Automatic Lubrication System for Bearings

Improper lubrication is a leading cause of bearing failures, accounting for half of all instances. Lubricating bearings with grease or oil forms a protective film that prevents direct metal-to-metal contact, reducing friction and overheating, and prolonging the bearing’s lifespan. Lubrication also acts as a barrier against foreign particles and wear. In this study, an analysis of automatic lubrication in a milling plant was carried out and compared to manuel lubrication. A milling factory with 22 roller mills with a total production capacity of 450 tons/day is considered. It is calculated that the failure of eight bearings in each mill roller due to lubrication issues results in a substantial cost of $39,000 over a two-year period. The Automatic lubrication system named “SmartLub” regulates lubricant quantity, timing, and application points, ensuring optimal lubrication. The choice of the oil pump was determined by considering both the viscosity of the oil and the head loss within the piping system utilized. By adhering to calculated frequencies, the system extends bearing service life to four years. Furthermore, the manual system reduces labor costs by $400 per roller mill every two years, while unplanned downtimes caused by lubrication issues are minimized. The automatic system eliminates the need for bi-monthly one-day shutdowns in the conventional lubrication systems, saving a total of six days per year. With an estimated lifespan of 20 years, the system achieved a payback period of 1.23 years, demonstrating its cost-effectiveness and long-term benefits. Overall, automation in bearing lubrication enhances machine efficiency, reduces spare parts and maintenance costs, and ensures optimal lubrication in the grain milling sector. Its implementation leads to extended bearing lifespan, reduced downtime, and improved profitability.

Serkan Yildiz, Murat Apakhan, Muharrem Hilmi Aksoy
Combining DOE and EDAS Methods for Multi-criteria Decision Making

Most existing Multi-Criteria Decision Making (MCDM) methods can only be used to rank readily available choices. After the first ranking has been completed, some of the options are discarded and others may arise, then it will be necessary to start the ranking over again. This study proposes a new method that can quickly rank alternatives in this situation. The proposed method is a combination of the Design of the Experimental method (DOE) and Evaluation based on the Distance from Average Solution (EDAS) method, hence it will be referred to as the DOE-EDAS method. The new aspect of this proposed method is to build a relationship between the scores of the options and the criteria. This relationship is called the regression equation. Using this regression equation, it is possible to quickly calculate the scores for alternatives (after an alternative is discarded or an alternative is added) and rank them. The method has been applied to multi-criteria decision-making in some specific cases. The results demonstrate the effectiveness of this method.

Do Duc Trung, Nguyen Xuan Truong, Hoang Tien Dung, Aleksandar Ašonja
Testing the Durability of the Color of Façade Materials

The paper presents a problem of discoloration of facade materials. 10 different materials, including acrylic resins and paints, cement mortars, and synthetic membranes were tested in accelerated weather conditions to obtain their colors’ durability. The climatic conditions were generated by the accelerated weathering tester, QUV. The research on color durability was made with the Minolta CM-700d spectrophotometer. The research was divided into two stages. In the first stage, three factors, including moisture spray, condensation, and UVA acted on the materials, while in the second stage, only UVA radiation acted on the materials. Materials differ in discoloration results. For acrylic and cement one combination of climate conditions (with an indication of moisture) seem to be the driving discoloration factor. In the case of membranes, UVA is no less color damaging. Only in a few materials, including all cement ones, the discoloration was so big, that inexperienced observers can see them.

Piotr Kosiński, Agata Jodko
Dimensional Measuring System with Temperature Compensation

This paper presents the development and creation of a system for measuring length with temperature compensation. The measuring system serves for the final dimensional control of the quality of the product. It is a necessary condition to ensure the conformity of the product with the dimensional values given in the technical drawing. The solution for the case of the product condition with temperature expansion is a measuring system, which has integrated temperature compensation. This means that every time, in addition to the measurement, it also measures the temperature of the product and takes into account the appropriate correction factor for the calculation of the actual value. This allows user to obtain standardized measurement results independent of the temperature of the product at the time of measurement.

Nemanja Zujić, Djordje Dihovicni
3D Printing Technology: Materials, Application and Current Trends in Process Improvement

Additive manufacturing, or 3D printing, is production technology for manufacturing parts, especially parts with complex geometry or complex structures. It opens different possibilities in part mass optimization, rapid prototyping as well as sustainable production and waste minimization. It is applicable in different fields such as mechanical engineering, civil engineering, medicine, food industry and so on. Manufactured parts from additive manufacturing can be very diversive depending on used technology and applied material. On qualitative features of 3D printed part can be influenced through various segments of additive manufacturing production from 3D modeling (optimizing model for 3D printing), 3D models slicing and production parameters adjustments (from the applied slicing software), 3D printer settings and used printing technology (applied material and used printing technology such as FDM or SLA, etc.) to 3D part post process treatment. This paper describes current 3D printing technologies, materials and methods for achieving functional 3D printed parts.

Ivan Palinkas, Eleonora Desnica, Jasmina Pekez, Aleksandar Rajic, Milan Rackov
Characteristics, Manufacturing, and Testing Methods of Polymer Gears: Review

During the years, numerous studies have been conducted to maximize gear performance and optimize gear mass, as vital elements of the power transmission. Because of this need, as well as overcoming the problems associated with the use of metal gears (noise, wear, high cost), gears made of polymer materials were taken into consideration. This paper aims to provide a review of the relevant literature, focusing on the parameters which affect the lifetime of polymer gears. The polymer materials that are currently used in gears manufacturing are: Polyether ether ketone (PEEK), polyoxymethylene (POM), nylon, polymethyl methacrylate (PMMA), polyamide 66 (PA66) (in this form and with additives), and others. An overview of the different manufacturing processes of polymer gears with guidelines for their application is given. Also, an account of the performance tests of polymer gears, which were conducted on devices specially developed for the needs of experiments, is given. The analysis of the test results showed that the lowest noise level is with PA gears, wear is maximum for ABS and minimum for POM gears. The future goal of the research is to evaluate the parameters of polymer gears, by comparing their performance with classic metal gears, which would enable the use of polymer gears for a wide range of engineering applications.

Ana Marković, Lozica Ivanović, Blaža Stojanović
Energy Efficiency Enhancement in a Small Industrial Facility

Small industrial utilities, connected to the distribution grid, can cause various disturbances that need to be eliminated or mitigated. Due to the complexity of the system and the large number of motors, industrial consumers may have problems with the voltage deviations caused by the excessive amount of reactive energy which is a natural consequence of their operation and construction. Since industrial consumers have to pay for both active and reactive power delivered from the grid, the goal is to reduce those costs as well as to reduce feeder loadings. Delivered energy can be reduced by installing compensation devices or by connecting photovoltaic power plant, which would produce active and reactive energy at the point of consumption. This paper analyzes the power flows and voltage conditions of a small industrial facility in three scenarios: the basic scenario, the second scenario with built-in compensation devices and in the third scenario with integrated photovoltaic power plant. For all three scenarios, power flow analysis is performed and results are presented in the form of tables and graphically.

Ružica Kljajić, Zorislav Kraus, Krešimir Fekete, Predrag Marić
Comparative Study of Single-Input and Dual-Input PSS in Multi-machine System

To meet growing demand for electricity, power systems are operating near their operating limits. Due to technical limitations, the transmission lines are close to their transmission capacity and with different dynamic characteristics interaction can occur between the parts of a single power system or between interconnected power systems. Such interactions can result in low-frequency oscillations that further limit the transmission capacity of the system. Low-frequency oscillations can be reduced by increasing the damping torque of the synchronous generators. The most efficient way to increase damping torque is to implement power system stabilizers in the generator excitation circuit. In this paper, single-input and dual-input PSS are implemented in IEEE 14-Bus test system and their influence on the small-signal stability is compared. PSS location is determined by participation analysis, while tuning of the PSS is performed using the pole placement method. For the different tuning parameters, the system performance was analyzed in both time-domain and S-domain for single-input and dual-input PSSs implementations.

Tomislav Košorog, Muharem Mehmedović, Predrag Marić, Ružica Kljajić
Creation and Maintenance of Public Real Estate Records - Business Models in Croatia

The paper briefly describes the Croatian real estate registration system, its subjects and basic processes, and points to the insufficient correlation of official real estate records with current state, which for years has been a major obstacle to the growth of business, the realization of investments, as well the management of states and other public assets. The unsettled state of public real estate records creates legal uncertainty for citizens, private investors, public and state institutions. This problem is also expressed in other countries of Southeast Europe. Defining real estate is a complex technical task that results in the materialization of boundaries between cadastral parcels as the basic record of the real estate and their recording in the selected coordinate system. This work in Croatia is entrusted to private geodetic companies whose activity is regulated by law through public tenders. Preparation of tenders on behalf of the Government of the Republic of Croatia (for works related to public real estate) is carried out by the State Geodetic Administration, and for private investors and entrepreneurs, works are regulated under market conditions. The paper investigates business model for more efficient creation and maintenance of public real estate registers - with special reference to the economic position of geodetic activity, and in the conclusion proposes measures to overcome this situation.

Milan Ivanović, Franjo Ambroš, Vedran Stojnović
Preventive Maintenance of Hydraulic Press Using Magnetic Testing

This paper presents the application of magnetic testing as one of the non-destructive methods within the preventive maintenance activities of technical systems. Magnetic testing is performed on a hydraulic press. This research aims to timely detect potential defects in the technical system, the hydraulic press, to prevent large-scale failures.

Ljiljana Radovanović, Borivoj Novaković, Mića Djurdjev, Luka Djordjević
Diagnostics of Journal Fluid-Film Bearing Failure Using a Data Manager System – Case History

The journal fluid-film bearing is a vital part of a rotary machine, which has a high load-carrying capacity. Babbitt bearings are commonly used to support the shafts of high-speed machines. Severe damage to the babbitt layer can lead to damage of the shaft journal. Fluid-film bearings installed in high-speed machines are exposed to damage due to the action of various mechanisms. It is very important to diagnose bearing damage at an early phase to prevent the possible failure of the machine. A machine monitoring system of shaft vibrations and bearing temperatures is very useful for early diagnosis of machine bearing condition. In this paper, a practical example of diagnostics of journal fluid-film bearing failure in a gear unit using a specialized data manager system is given. The bearing damage was confirmed by inspections performed during the downtime of the gear unit. Based on the visual investigation, the most likely primary cause of bearing damage was electrical pitting.

Marko Katinić, Pejo Konjatić, Mirko Karakašić, Danko Glavaš
Predicting the Specific Gravity of Must During Fermentation Using Machine Learning Models

In this article, the process of fermentation in winemaking is investigated. The authors analyze fermentation data and propose several machine learning models to assess the effectiveness of ongoing fermentation processes based on measurements of specific gravity and temperature. To evaluate the performance of each model, various metrics such as R-squared, Mean Squared Error, Root Mean Squared Error, and Maximum Absolute Error are employed. The results suggest that the models have the potential to predict fermentation outcomes in winemaking and provide winemakers with a valuable tool to optimize the process and ensure high-quality wine production.

Ivana Kovačević, Mihaela Orić, Ivana Hartmann Tolić, Emmanuel Karlo Nyarko
Importance of Blackbody in Everyday Infrared Thermography

Infrared thermography is a method of detecting thermal radiation, which is then associated with corresponding temperature values. Infrared thermal infrared cameras, like other measuring devices, must undergo a factory and periodic calibration process. The calibration is performed using blackbodies. This paper analyzes the practical application of the blackbody in the calibration of infrared thermal camera. Two infrared thermal cameras Flir E6 and Hikmicro M30 were calibrated with a Voltcraft IRS -350 blackbody. The calibration results are presented in tabular form, while the effect of the blackbody uncertainty on the overall measurement uncertainty is presented in graphical form. Since blackbodies are prohibitively expensive for most thermographers due to their price, calibration guidelines are provided to users when a blackbody is not available and the accuracy of the camera needs to be verified.

Hrvoje Glavaš
The 5S Method and Its Strategic Determinants Within the Organization of Production Plants

Racing for the global advantage, companies have been paying increasing attention to workplace design, employee safety, workplace satisfaction, labor productivity and product quality. One of the methods that can help them achieve these goals is the 5S method, which is also considered a management tool for better organization and management of the workplace. Although the 5S method is applicable to a wide range of workplaces, using published research results, this paper provides a comprehensive overview of its challenges and benefits in manufacturing companies. They are analyzed and synthesized in a new way and special attention is paid to the method steps and its implementation. The paper points to a wide scope of the method application as companies have to meet various standards and present certificates that guarantee the safety and quality of manufactured products. Since managers are constantly trying to find ways to obtain and maintain them, one of the objectives of this paper is to provide an overview and critical evaluation of existing published research results that show the impact of the method application on increasing the product quality, the production process, health and safety. The methods from the qualitative methodological framework were used and research results that contribute to the scientific discourse related to the results that can be achieved by applying the 5S method in the organization of production plants were presented.

Dominika Crnjac Milić
The Impact of Electric Car Charging on the Power Grid

In recent years, the number of electric vehicles has been growing rapidly in the European Union, and in the world in general. Electric cars are more efficient than fossil fuel cars, they have better driving characteristics, and most importantly: they do not emit gas while driving. There are still some challenges related to electric cars. Energy storage - batteries - are still under development to increase the range of cars. An even bigger challenge is the car charging infrastructure - charging stations of increasing capacity are being installed to shorten charging times. The growing number of charging stations brings new challenges, and an important question is what impact car charging stations have on the power quality. The paper presents a detailed analysis of the impact of electric car charging stations on the power quality in the distribution power grid.

Zvonimir Klaić, Filip Đaković, Mario Primorac, Krešimir Fekete
Investigation of the Improvement of the Wheat Endosperm Hardness Assessment Method by Improved Construction of the Grain Cutting Knife

The majority of bread wheat varieties in Croatia belong to the group of falsely hard “red, or winter wheat” characterized by the so-called “marbling” of the grain, i.e. the alternation of glassy and floury zones in the endosperm, which significantly complicates the precision of the standard method of deter-mining the share of glassy grains according to Pohl, ICC method standard 129. Recent research has shown that by improving the construction of the knife (by changing the angle and cutting intensity (the so-called “new knife”), a much clearer “cleaner” cut is obtained, which makes it possible to determine the degree of glassiness of the grain with greater accuracy, especially for the transitional or marmorated endosperms. Guided by this hypothesis, the degree of glassiness of extremely glassy, extremely floury and two transitional (marmorated) types of grains, cut with the “old knife” (standard device) and the “new” knife on the same instrument. The obtained results show that the obtained values for the degree of glassiness do not differ significantly between the old and new knife for extremely glassy and extremely floury wheat, while for marbled grains the measurement values differ significantly between individual evaluators and between different types of endosperm hardness, especially in the area of medium values for grain glassiness (80–20). The conclusion of the research is that when determining the values for grain glassiness of marbling-early hybrids of bread wheat in Croatia, the application of the “new knife” will give significantly more precise and accurate values and facilitate the visual assessment of endosperm glassiness.

Vinko Krstanović, Kristina Habschied, Krešimir Mastanjević
Computer Network Design for Office Building Environment

This paper presents an example of designing a computer network for a business building. When creating the project documentation, care was taken to ensure that it complies with current standards and the Rulebook on technical conditions for the electronic communication network of commercial and residential buildings. The technical description explains what structured cabling is, describes the importance of following its rules and standards, and defines the ways of marking all the equipment used in the creation of this computer network. Furthermore, an overview of all equipment with its characteristics is presented in detail. The logical scheme defines the so-called vertical network, i.e., the backbone, that is, it shows how each individual part of the active equipment inside the building is connected, how the communication cabinets are connected between the floors, and how the network switches and routers inside the communication cabinets are connected to each other. For each socket and cable, a unique label is defined, this creates a horizontal office network. This is the main part of structured cabling, where the precise definition of each individual part of the computer network provides the basis for safe and stable network operation, the possibility of easy upgrades in the future, and the elimination of possible difficulties that may arise. Application of the quality of service (QoS) on the network will be considered is the and recommendations given to avoid undesirable congestion during the flow of data by properly planning the QoS rules, such as packet marking and traffic shaping.

Damir Blažević, Tomislav Keser, Matko Mance
An Advanced Tactile-Haptic Controller for Smart Home

A smart home philosophy strongly relies on a technical principle of automatization almost every aspect of today’s way of living. Sole automation of does not only manage system processes in household, or living environment in general, but all adjacent systems and corresponding subsystems which helps to maintain system-in-whole in operational state. From control of environmental temperature, air conditioning, lighting, utility control, etc., all existing “smart” systems predominantly control actuation part of smart home. Very miniscule “smart” systems do manage and serve human-machine interaction part of it and, if are made “smart”, they rely on solutions that utilizes some sort of existing ICT technologies that are mainly optimized for communication and visual presentation, not for in-situ smart home interaction. This paper deals with the problem of development of a tactile-haptic solution for control of smart home specific subsystem and that utilize IoT platform, giving feel and user experience similar to traditional one in form of an advanced switch with regulation ability. Tactile commanding with haptic feedback is presented and applied in smart home temperature regulation. Finally, an IoT platform solution is developed, tactile-haptic relation investigated with optimal solution established, and its functionality is verified as well as is proven in real time environment.

Miloš Radić, Tomislav Keser, Damir Blažević
Improving Maintenance Planning with the Help of Information Technologies

In this paper, the processing of preventive maintenance work orders with the MP2 Professional information system is presented and a cost analysis is performed. In addition, the purchasing of spare parts and material in this system is described. It was found that the implementation of the information system can improve maintenance planning for planned preventive maintenance tasks (Tasks and Instructions module in the information system), which are organized and performed on a planned basis with prepared documentation, as well as for corrective maintenance tasks (Requests module - Call-in requests and On-site requests), which are performed after a failure. The purchasing process has also been improved with the help of the information system, as certain documents can be generated or automatically created from previous documents. In addition to the ability to generate certain documents (e.g. preventive maintenance work orders, quotation requests, requisitions, purchase orders), it is possible to obtain various reports and graphical representations useful for both maintenance technicians and management.

Sanda Simunovic, Tomislav Saric, Andrijana Milinovic, Iva Samardzic
Backmatter
Metadaten
Titel
32nd International Conference on Organization and Technology of Maintenance (OTO 2023)
herausgegeben von
Tomislav Keser
Naida Ademović
Eleonora Desnica
Ivan Grgić
Copyright-Jahr
2024
Electronic ISBN
978-3-031-51494-4
Print ISBN
978-3-031-51493-7
DOI
https://doi.org/10.1007/978-3-031-51494-4