METHOD OF COMPREHENSIVE DATA ANALYSIS IN DIAGNOSTICS OF COMPLEX POWER EQUIPMENT

Author(s):  
Е.А. Абидова ◽  
А.Д. Данилов ◽  
А.Е. Дембицкий ◽  
А.В. Чернов

Предложен подход к диагностике сложного и габаритного оборудования на примере определения технического состояния дизельного двигателя. Отличительной особенностью дизельного двигателя является сложность конструкции, требующая применения комплекса методов для обеспечения полноты контроля и чувствительности при выявлении дефектов на ранних стадиях развития. Описана схема обработки данных, позволяющая повысить чувствительность при диагностике за счет комплексного анализа данных различной физической природы с использованием анализа сингулярного спектра. Повышение чувствительности обосновывается путем численного моделирования и обработки результатов измерения диагностических параметров в реальных производственных условиях. В качестве показателей чувствительности рассматриваются расстояния между координатами центров кластеров параметров исправного и неисправного состояния в исходном пространстве и в пространстве главных компонент. Продемонстрировано, что предлагаемый подход обеспечивает повышение чувствительности в условиях, когда влияние дефекта на диагностические параметры сопоставимо с действием случайных факторов в объекте диагностирования. Указанное повышение качества диагностирования достигается благодаря корреляции между параметрами за счет их представления в виде траекторных матриц. Помимо повышения чувствительности при выявлении дефектов также достигается и существенное сжатие информации, которая используется для определения состояния. Преимуществом предлагаемого подхода также является наглядная визуализация результатов The article suggests an approach to the diagnosis of complex and oversized equipment by the example of determining the technical condition of a diesel engine. A distinctive feature of the diesel engine is the complexity of the design, which requires the use of a set of methods to ensure complete control and sensitivity when detecting defects at early stages of development. We describe the data processing scheme, which allows you to increase the sensitivity in diagnostics due to the complex analysis of data of various physical nature using the principal component method. The increase in sensitivity is justified by numerical modeling and processing the results of measuring diagnostic parameters in real production conditions. Distances between coordinates of centers of clusters of parameters of serviceable and faulty state in initial space and in space of principal components are considered as indicators of sensitivity. We demonstrated that the proposed approach provides increased sensitivity in conditions where the effect of a defect on diagnostic parameters is comparable to measurement errors. The indicated improvement in the quality of diagnostics is achieved due to the correlation between the parameters due to their representation in the form of trajectory matrices. In addition to increasing sensitivity when detecting defects, significant compression of information that is used to determine the state is also achieved. The advantage of the proposed approach is also the vivid visualization of the results

2019 ◽  
Vol 18 (4) ◽  
pp. 949-975 ◽  
Author(s):  
Valentin Senchenkov ◽  
Damir Absalyamov ◽  
Dmitriy Avsyukevich

The development of methodical and mathematical apparatus for formation of a set of diagnostic parameters of complex technical systems, the content of which consists of processing the trajectories of the output processes of the system using the theory of functional spaces, is  considered in this paper. The trajectories of the output variables are considered as Lebesgue measurable functions. It ensures a unified approach to obtaining diagnostic parameters regardless  a physical nature of these variables and a set of their jump-like changes (finite discontinuities of trajectories). It adequately takes into account a complexity of the construction, a variety of physical principles and algorithms of systems operation. A structure of factor-spaces of measurable square Lebesgue integrable functions, ( spaces) is defined on sets of trajectories. The properties of these spaces allow to decompose the trajectories by the countable set of mutually orthogonal directions and represent them in the form of a convergent series. The choice of a set of diagnostic parameters as an ordered sequence of coefficients of decomposition of trajectories into partial sums of Fourier series is substantiated. The procedure of formation of a set of diagnostic parameters of the system, improved in comparison with the initial variants, when the trajectory is decomposed into a partial sum of Fourier series by an orthonormal Legendre basis, is presented. A method for the numerical determination of the power of such a set is proposed. New aspects of obtaining diagnostic information from the vibration processes of the system are revealed. A structure of spaces of continuous square Riemann integrable functions ( spaces) is defined on the sets of vibrotrajectories. Since they are subspaces in the afore mentioned factor-spaces, the general methodological bases for the transformation of vibrotrajectories remain unchanged. However, the algorithmic component of the choice of diagnostic parameters becomes more specific and observable. It is demonstrated by implementing a numerical procedure for decomposing vibrotrajectories by an orthogonal trigonometric basis, which is contained in spaces. The processing of the results of experimental studies of the vibration process and the setting on this basis of a subset of diagnostic parameters in one of the control points of the system is provided. The materials of the article are a contribution to the theory of obtaining information about the technical condition of complex systems. The applied value of the proposed development is a possibility of their use for the synthesis of algorithmic support of automated diagnostic tools.


2015 ◽  
Vol 8 (1) ◽  
pp. 37-42 ◽  
Author(s):  
Aleksandrs Gasparjans ◽  
Aleksandrs Terebkovs ◽  
Anastasia Zhiravetska

Abstract A method of technical diagnostics of ship diesel engine – generator installation – is proposed. Spectral-power diagnostic parameters of the synchronous generator voltage and currents are used. The electric machine in this case is the multipurpose sensor of diagnostic parameters. A judgment on the quality of the operational processes in diesel engine cylinders and its technical condition is possible on the basis of these parameters. This method is applicable to piston compressor installations with electric drive. On the basis of such parameters as rotating torque, angular speed and angular acceleration it is possible to estimate the quality of the operating process in the cylinders of a diesel engine, the condition of its cylinder-piston group and the crank gear mechanism. The investigation was realized on the basis of a diesel-generator with linear load. The generator operation was considered for the case of constant RL load. Together with the above mentioned, the condition of bearings of synchronous machines, uniformity of the air gap, windings of the electric machine were estimated during the experiments as well. The frequency spectrum of the stator current of the generator was researched and analyzed. In this case the synchronous machine is becoming a rather exact multipurpose diagnostic sensor. The signal of non-uniformity in the operation process of diesel engine cylinders and its technical condition is the increasing of the amplitudes of typical frequencies.


2021 ◽  
Vol 5 (3 (113)) ◽  
pp. 37-45
Author(s):  
Borys Bodnar ◽  
Oleksandr Ochkasov ◽  
Mykhailo Ochkasov

The widespread introduction of information technologies in the systems that manage technical fleets, the use of maintenance and repair systems based on risk assessment, is based on the calculation of a large enough number of indicators. Modern locomotives are equipped with systems for monitoring and diagnosing technical condition. Combining these systems with the Internet of Things and Big Data technologies provides an opportunity to use completely new approaches to fleet management. At the initial stage of the construction of such systems, it is necessary to devise criteria that make it possible to automatically determine the technical condition of a locomotive and its components in order to identify the locomotive in the total fleet that requires maintenance or repair. A procedure has been proposed for calculating the technical condition index of locomotives and their components based on data from monitoring systems. The procedure is based on the formation of latent diagnostic parameters employing the principal component method and on the subsequent calculation of the weight coefficients of these parameters applying the method of hierarchy analysis. The special feature of the proposed procedure is that when calculating the index, those latent diagnostic parameters are used that are derived from the group of control parameters whose weight coefficients are computed using the method of hierarchy analysis without involving experts. This paper reports the results from calculating the informativeness of the diagnostic parameters of load, loss, input, as well as their weight coefficients. The highest information content, from 0.5 to 0.85, is demonstrated by the load parameter; the smallest (0.05‒0.26) ‒ the input parameter. The average value and the dependences of changes in the technical condition index of a hydraulic transmission during the tests have been determined. Analysis of the technical condition index makes it possible to assess the transmission's response to changes in test modes, the dynamics of changes in losses


Author(s):  
A.V. Golenishev ◽  
A.V. Nadezkin ◽  
M.E. Starchenko

Рассматриваются подходы по определению пороговых значений концентрации продуктов износа в отработанном цилиндровом масле, характеризующие переход объекта диагностирования судового крейцкопфного дизеля из одного технического состояния в другое. Показано, что существующие методики не учитывают индивидуальные особенности и техническое состояние деталей цилиндропоршневой группы. Предложено для решения задачи их трибодиагностики использовать разработанную имитационную модель, позволяющую провести моделирование процесса изнашивания цилиндровой втулки и поршневых колец судового дизеля и на основании полученных расчетов определить концентрацию продуктов износа поступивших в отработанное цилиндровое масло при различной скорости изнашивания трущихся деталей. Данные о фактической концентрации продуктов износа в отработанном цилиндровом масле в дальнейшем соотносятся с результатами моделирования, что позволяет оценить техническое состояние деталей цилиндропоршневой группы двигателя. Представлены результаты моделирования по определению пороговых значений концентрации продуктов износа в отработанном цилиндровом масле, характеризующее переход судового дизеля из исправного в несправное техническое состояние. Даны практические рекомендации по выбору пороговых значений содержания продуктов износа в отработанном цилиндровом масле для различных типов судовых крейцкопфных дизелей и условий их эксплуатации.The article examines approaches to determine the threshold values of the concentration of wear debris in used cylinder oil that characterize the transition of a ship crosshead diesel engine unit under test from one technical condition to another. It is shown that the existing methods do not take into account the individual characteristics and technical condition of the parts of the cylinder-piston group. To solve the problem of tribodiagnostics, it is proposed to use the developed simulation model, which allows modeling the wear process of the cylinder bushing and piston rings of a marine diesel engine and, based on the obtained results, determining the concentration of wear products issued in the used cylinder oil at different wear rates of the moving parts. The data on the actual concentration of wear products in the used cylinder oil are subsequently correlated with the simulation model results, which makes it possible to evaluate the technical condition of the parts of the engine cylinder-piston group. The article presents the results of modeling of threshold values determination of the concentration of wear products in used cylinder oil, that measure the transition of a marine diesel engine from a working condition to a malfunctioning technical condition. Practical recommendations are given on choosing threshold values for the concentration of wear products in used cylinder oil for various types of marine crosshead diesel engines and their operating conditions.


2017 ◽  
Vol 168 (1) ◽  
pp. 68-72
Author(s):  
Piotr BOGUŚ ◽  
Mateusz CIESZYŃSKI ◽  
Jerzy MERKISZ

The paper presents a method of classification of locomotive Diesel engine states basing on vibration signals taken from an engine body and using chosen statistical parameters calculated for the original signal and it wavelet multiresolution components. The researches presented in the paper concern estimation of an engine states before and after a general repair. The target application of the presented researches is an on-line diagnostic system which can complement standard OBD systems. To this purpose the applied methods should not base on complex analysis of some spectral, time-frequency or scalogram plots but rather on choosing single diagnostic parameters which are suitable for the fast on-line diagnostic. The results have showed the significant difference in distinguishing of engine work before and after a general repair using some chosen statistical parameters applied to vibration signals.


2021 ◽  
Vol 2061 (1) ◽  
pp. 012131
Author(s):  
O N Litskevich ◽  
A P Litskevich

Abstract This article solves the problem of a quantitative assessment of the occurrence of destruction in the intersystem interactions of the transport system and the electrical system of the seaport, in the conditions of the technological process in the seaport, which indicates its significant impact on the electrical system, as a result of which the reliability of the berthing power line is significantly reduced. The intersystem interactions that occur during the implementation of the technological process, as experience shows, are the causes of critical situations that occur at the border of areas of different physical nature, and the consequences are recorded, in the case under consideration, in the electrical system. A mathematical model describing intersystem destruction in quantitative form is presented in this paper using a logical-probabilistic model that reflects internal and external relationships. In the object under study, the destructive cause (collision) and the consequence (accumulation of electrical damage in the insulation of the cable line) are in the same object (the mooring power supply unit), and this is limited to the effects of intersystem destruction. In such a statement, the object of power supply of the technological process and equipment is considered as a composite object containing a cable line and an electric contact column. The problem being formulated is an important and relevant scientific task, which includes not only the question of identifying the causes of increased electrical wear of the power line, but also the development of methods for obtaining quantitative results, and in practical terms also involves the diagnosis of the technical condition of electrical equipment and timely preventive maintenance.


2010 ◽  
Vol 28 (No. 3) ◽  
pp. 185-191 ◽  
Author(s):  
G.G. Codină ◽  
S. Mironeasa ◽  
D. Bordei ◽  
A. Leahu

Recently, in 2005, a new method for monitoring the rheological properties of the dough on the entire technological process of bread making became available through Mixolab at an international level. This laboratory equipment has amazing possibilities for the research and development, enabling a complex analysis of flour. It allows the analysis of flour proteins quality (water absorption, stability, elasticity, weakening), the analysis of starch behaviour (gelatinisation, gelatinisation temperature, the modification of its consistency on additives addition) and the analysis of enzymatic activities (proteolytic, amylolytic). The objective of this study is to establish a relation between the alveograph, Falling Number, and Mixolab values. Sixty flours, collected around the Romanian country, were analysed simultaneously on alveograph (standard protocol), for the Falling Number, and on Mixolab ("Simulator" and the standard option "Chopin+" protocol). A selection of principal factors based on the Principal Component Analysis (PCA) was applied which allowed the building of an efficient predictive model for each parameter. There were significant correlations between most of the Alveograph parameters: maximum pressure (P), deformation energy (W), extensibility (L), alveograph ratio (P/L) and Simulator Mixolab stability. Using the Mixolab standard option "Chopin+" protocol a close association was found between some Mixolab parameters: stability and protein weakening (C2, difference of the points C1–C2 abbreviated C12) and the alveograph values (P, W). From the point of view of the correlations established with the Falling Number index, very good results were obtained with the parameters obtained with Mixolab that measures starch gelatinisation (C3, difference of the points C3–C2 abbreviated C32), amylolytic activity (C4, difference of the points C3–C4 abbreviated C34), and starch gelling (C5, difference of the points C5-C4 abbreviated C54).


2015 ◽  
Vol 236 ◽  
pp. 113-118
Author(s):  
Marcin Kluczyk ◽  
Andrzej Grządziela

The paper presents a model of dynamics of six-cylinder inline diesel engine executed in the Matlab software. The basic equations necessary to describe the forces acting during the engine operation was presented. Application of some simplifications allowed to present proposal of a mathematical model of the engine, which allows analysis of changes of forces in the crank-piston system, depending on the technical condition of the fuel system elements. Operational experience indicate that one of the most common cause of failure of the fuel system is reduced fuel charge supplied by a defective fuel injection pump. Calculations of gas forces had been replaced by the implementation into the model indication charts recorded from tests on a engine test stand. Simulation results were presented as a result of FFT spectra of modeled tangential forces.


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