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1

An approach in determining the critical level of degradation based on results of accelerated test

Hoang Anh D., Vintr Zdenek, Valis David, Mazurkiewicz Dariusz

Eksploatacja i Niezawodność

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2022

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Vol. 24, no. 2

330--337

EN

Nowadays, systems are more complex and require high reliability for their components, especially critical system components. Therefore, to avoid serious damage, system are often replaced before the actual failure. The replaced parts are considered to have “soft failure”, and the limit in which the parts are replaced is known as the critical level of the degradation process. Determining the appropriate value of the critical level for a product is an important problem in their exploitation, as well as for predicting the Mean Time to Failure (MTTF) or Remaining Useful Lifetime (RUL) of this product based on the degradation data by the mathematical models. In this article, an approach in determining the critical levels based on failure data from an accelerated test is introduced. This approach is applied with the degradation process of Light-Emitting Diodes (LED) in an accelerated test and a type of Wiener process-based model is used to predict the MTTF or RUL of LED based on their degradation data and the found critical level.

2

Method for assessing the impact of rainfall depth on the stormwater volume in a sanitary sewage network

Kozłowski Edward, Kowalski Dariusz, Kowalska Beata, Mazurkiewicz Dariusz

Archives of Civil and Mechanical Engineering

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2022

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Vol. 22, no. 1

art. no. e8, 2022

EN

Sanitary sewage network is relatively rarely considered as the cause of urban floods. Its hydraulic overload can result not only in flooding, but also sanitary contamination of subcatchments. Stormwater is the main reason for this overload. In contrast to the stormwater or combined sewer system, these waters infiltrate into the network in an uncontrolled way, through ventilation holes of covers or structural faults and lack of tightness of manholes. Part of stormwater infiltrates into the soil, where it leaks into pipelines. This greatly hinders assessing the quantity of stormwater influent into the sanitary sewer system. Standard methods of finding correlation between rainfall and the intensity of stormwater flow are ineffective. This is confirmed, i.a. by the studies performed in an existing network, presented in this paper. Only when residuals analysis was performed using the ARIMA and ARIMAX methods, the authors were able to develop a mathematical model enabling to assess the influence of rainfall depth on the stormwater effluent from the sewage network. Owing to the possibility of using the rainfall depth forecasts, the developed mathematical model enables to prepare the local water and sewerage companies for the occurrence of urban floods as well as hydraulic overload of wastewater treatment plants.

3

Integrating advanced measurement and signal processing for reliability decision-making

Kozłowski Edward, Antosz Katarzyna, Mazurkiewicz Dariusz, Sęp Jarosław, Żabiński Tomasz

Eksploatacja i Niezawodność

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2021

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Vol. 23, no. 4

777--787

EN

An advanced milling machine multi-sensor measurement system as a condition monitoring tool was presented. It was assumed that the data collected from the 3-axis force and torque sensor can be used as a new approach and an alternative to the typical vibration signal based health monitoring and remaining useful life prediction (RUL), when integrated with machine learning techniques that are regarded as a powerful solution. Measurement system integration with the proposed signal processing method based on decision trees with different types and levels of wavelets for the cutter reliability decision-making process was presented together with proving their ability to trace the tool condition accurately. Prediction errors achieved with the use of different signal sources and data processing methods were presented and compared.

4

Framework of machine criticality assessment with criteria interactions

Jasiulewicz–Kaczmarek Małgorzata, Antosz Katarzyna, Żywica Patryk, Mazurkiewicz Dariusz, Sun Bo, Ren Yi

Eksploatacja i Niezawodność

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2021

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Vol. 23, no. 2

207--220

EN

Criticality is considered as a fundamental category of production planning, maintenance process planning and management. The criticality assessment of machines and devices can be a structured set of activities allowing to identify failures which have the greatest potential impact on the company’s business goals. It can be also used to define maintenance strategies, investment strategies and development plans, assisting the company in prioritizing their allocations of financial resources to those machines and devices that are critical in accordance with the predefined business criteria. In a criticality assessment process many different and interacting criteria have to be taken into consideration, despite the fact that there is a high level of uncertainty related to various parameters. In addition, not all assessment criteria are equally important. Therefore, it is necessary to determine the weight of each criterion taking into account different requirements of machine criticality process stakeholders. That is why a novel model of a machine criticality assessment is proposed in this paper. The model extends the existing methods of assessing machines criticality, taking into account not only the importance of machine criticality assessment criteria, but also possible interactions between them.

5

Assessment model of cutting tool condition for real-time supervision system

Kozłowski Edward, Mazurkiewicz Dariusz, Żabiński Tomasz, Prucnal Sławomir, Sęp Jarosław

Eksploatacja i Niezawodność

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2019

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Vol. 21, no. 4

679--685

EN

Further development of manufacturing technology, in particular machining requires the search for new innovative technological solutions. This applies in particular to the advanced processing of measurement data from diagnostic and monitoring systems. The increasing amount of data collected by the embedded measurement systems requires development of effective analytical tools to efficiently transform the data into knowledge and implement autonomous machine tools of the future. This issue is of particular importance to assess the condition of the tool and predict its durability, which are crucial for reliability and quality of the manufacturing process. Therefore, a mathematical model was developed to enable effective, real-time classification of the cutting blade status. The model was verified based on real measurement data from an industrial machine tool.

PL

Dalszy rozwój inżynierii produkcji, w szczególności obróbki skrawaniem, wymaga poszukiwania nowych innowacyjnych rozwiązań technologicznych. Dotyczy to w szczególności zaawansowanego przetwarzania danych pomiarowych pochodzących z systemów diagnostycznych i monitorujących. Rosnąca ilość danych gromadzonych przez wbudowane systemy pomiarowe wymaga opracowania skutecznych narzędzi analitycznych, aby efektywnie przekształcać dane w wiedzę i wdrażać autonomiczne obrabiarki przyszłości. Kwestia ta ma szczególne znaczenie dla oceny stanu narzędzia i przewidywania jego trwałości, które są kluczowe dla niezawodności i jakości procesu produkcyjnego. Dlatego opracowano nowy model matematyczny, którego zadaniem jest skuteczna klasyfikacja stanu ostrza narzędzia skrawającego realizowana w czasie rzeczywistym. Opracowany model został zweryfikowany na podstawie rzeczywistych danych pomiarowych z przemysłowej obrabiarki.

6

Komputerowy system monitorowania stanu złączy taśm przenośnikowych

Mazurkiewicz Dariusz

Mechanizacja i Automatyzacja Górnictwa

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2006

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R. 44, nr 4

14-22

PL

W przedsiębiorstwach stosujących w swoich systemach transportowych przenośniki taśmowe dąży się budowy układów o wysokiej wydajności i niezawodności, przy jednoczesnym zapewnieniu sprawnego przeniesienia transportowanego materiału na duże odległości. Prowadzi się w tym celu szereg prac badawczych w zakresie nowych konstrukcji, rozwiązań układów napędowych, nowych typów taśm, czy odpowiednich modeli reologicznych do ich obliczeń. Nieco mniej miejsca poświęca się trwałości połączeń taśm przenośnikowych, co wynika między innymi z ograniczonych możliwości wpływania na trwałość złącza, jak i z trudności badawczych i eksploatacyjnych związanych z przeciwdziałaniem zerwaniu takich połączeń. Od dwóch lat w Katedrze Podstaw Inżynierii Produkcji Politechniki Lubelskiej prowadzone są prace badawcze nad komputerowym systemem pomiarowym do monitorowania stanu złączy taśm przenośnikowych. System taki od ponad roku pracuje w kopalni LW "Bogdanka".Niniejszy artykuł prezentuje dotychczasowe wyniki badań laboratoryjnych i pomiarów w warunkach rzeczywistych. Przedstawia również ideę przekształcenia aktualnego systemu monitorującego taśmociąg w układ wspomagający sterowanie pracą przenośnika w celu wydłużenia okresu trwałości złączy.

EN

The enterprises applying the belt conveyors to their transport systems are aimed at design high efficient and reliable systems providing at the same time for functional long distance transport of materials. To achieve this aim the research has been carried out on new constructions, driving systems, new types of belts and suitable rheological models to calculate and design them. It has been devoted a little bit less of attention to durability of useful life of belt joints; it results among other things from limited opportunities of influence on joints durability as well as research and trials difficulties regarding prevention of break of such joints. The research into a measuring computer system for monitoring of joints conditions of conveyor belts has been doing for two years in the Department of Basis of Production Engineering in the Technical University in Lublin. Such a system has been working for more than one year in the "Bogdanka" coal mine.This paper presents the results of current laboratory tests and measurements under real existing conditions. It has been also shown an idea how to transform the present conveyor monitoring system into a system supporting control of con-veyors in order to extend the life of joints.