There is a demand for worm gearboxes in diversified industrial fields that include machinery such as escalators, ribbon blenders, pulverisers, bowl mills, etc. because of their peculiar characteristics like torque and quick retardation. The most commonly occurring defects in a worm gear box are scratches that develop in the worm gear and in bearings. Early defect categorization is required to prevent a sudden breakdown that would decrease production. The defect is depicted in different cases, which include defects in the gear tooth and the outer and inner races of the bearing. In another case, the defect is considered in the gear tooth as well as the bearing. The severity is designated using the ANN. The experiments were performed under these conditions with a good worm gearbox to capture vibration response signatures. Using these values as an input to the ANN, the model is trained. Experimental results show that vibration amplitude increases with fault progression in the worm gearbox, and the trained ANN model effectively categorizes worm gearbox faults with an accuracy of 97.12%.
Scalability is a key feature of reconfigurable manufacturing systems (RMS). It enables fast and cost-effective adaptation of their structure to sudden changes in product demand. In principle, it allows to adjust a system's production capacity to match the existing orders. However, scalability can also act as a "safety buffer" to ensure a required minimum level of productivity, even when there is a decline in the reliability of the machines that are part of the machine tool subsystem of a manufacturing system. In this article, we analysed selected functional structures of an RMS under design to see whether they could be expanded should the reliability of machine tools decrease making it impossible to achieve a defined level of productivity. We also investigated the impact of the expansion of the system on its reliability. To identify bottlenecks in the manufacturing process, we ran computer simulations in which the course of the manufacturing process was modelled and simulated for 2-, 3-, 4- and 5-stage RMS structures using Tecnomatix Plant Simulation software.
Based on the rolling bearing vibration measurement principle in ISO standard, a nonlinear dynamic model of ball bearing is built and motion equations of the inner ring, outer ring, and rolling elements are derived by using Lagrange’s equation. The ball bearing model includes the influence of waviness, rotational speed, external load, arbor supporting stiffness and arbor eccentricity. Ball bearing high-speed vibration tests are performed and used to verify the theoretical results. Simulated results showed that specific waviness orders produced the principal frequencies that were proportional to rotational speed. Rotational speed mainly affected the value of the natural frequency of the bearing system, and RMS (Root Mean Square) of the full band had a great fluctuation with the increase of rotational speed. In the experiment, spectrum and RMS of 2 ƒs-30 kHz (ƒs : the rotational frequency of inner ring/arbor) under high speed could include not only the influence of rotational speed but also principal frequencies produced by waviness, which could cover the part of requirements of the standard bearing vibration measurement.
The paper presents the results of an analysis of the geometrical structure of Fe-Al intermetallic protective coatings sprayed under specified gun detonation spraying (GDS) conditions. Two barrel lengths, two powder injection positions (PIP) at the moment of spark detonation, and two numbers of GDS shots with 6.66 Hz frequency were applied as variable parameters in the GDS process. Surface profile measurements were conducted by contact profilometry with the use of the TOPO-01 system and the Mitutoyo SJ 210 profilometer. The measured parameters were used to analyze surface topography in two-dimensional (2D) and three-dimensional (3D) systems. It was assumed that roughness can be regarded as a non-stationary parameter of variance in surface amplitude which is highly dependent on the sampling rate and spraying distance. Therefore, changes in surface amplitude parameters and functional properties were analyzed across segments with a length (ln) of 1.25, 4 and 12.5 mm. The development of the geometric structure of the surface was analyzed with the RMS (Root Mean Square) fractal method, and the geometric structure of the surface stretched by several orders of magnitude was evaluated based on the correlation between roughness (Rq), segment length (ln) and fractal dimension (D). The RMS method and the calculated fractal dimension (D) supported the characterization of the geometric structure of intermetallic Fe-Al protective coatings subjected to GDS under the specified process conditions based on the roughness profiles of surface segments with a different length (ln).
Choosing the right production structure (configuration) is one of the most important steps in the process of designing a reconfigurable manufacturing system (RMS). Whether or not a production process to be executed is capable of achieving the assumed performance parameters depends, among others, on the reliability of the machines and technological devices that make up the system under design. Because the individual components of a manufacturing system have different levels of reliability, the reliability of the system as a whole depends to a large extent on the way in which they are configured. This article discusses the process of selecting the structure of a manufacturing system with changing machine reliability, which allows to accommodate these changes to maintain the stability of the production process. The focus of the study was a manufacturing system under design dedicated to the machining of body parts. The experiments were carried out using analytical methods and computer simulation methods. Simulations were performed using Enterprise Dynamics software.
PL
Wybór odpowiedniej struktury produkcyjnej (konfiguracji) stanowi jeden z ważniejszych kroków w procesie projektowania rekonfigurowalnego systemu produkcyjnego (RMS). Możliwość osiągnięcia zakładanych parametrów wydajnościowych planowanego do realizacji procesu produkcyjnego jest uzależniona m.in. od stopnia niezawodności maszyn i urządzeń technologicznych wchodzących w skład projektowanego systemu. Zróżnicowany poziom niezawodności poszczególnych elementów systemu produkcyjnego powoduje, iż niezawodność systemu jako całości w dużej mierze zależy od sposobu ich konfiguracji. W niniejszym artykule przedstawiono proces wyboru struktury systemu produkcyjnego pod kątem możliwości zachowania stabilności procesu produkcyjnego wraz ze zmianą stopnia niezawodności maszyn technologicznych wchodzących w skład systemu. Jako obiekt badań przyjęto projektowany system produkcyjny dedykowany do obróbki części klasy korpus. Badania przeprowadzono z wykorzystaniem metod analitycznych oraz metod symulacji komputerowej. Jako narzędzie symulacji wykorzystany został system Enterprise Dynamics.
The article presents the results of the aircraft Cessna 172 positioning based on navigation solutions in the GPS and EGNOS (SBAS) tracking mode. The article makes a comparison of coordinate readings of the Cessna 172 in the ellipsoidal BLh frame. The verification of the coordinates of the aircraft Cessna 172 was used to assess the reliability of the GNSS satellite technique in aviation. In a research test, the navigation data were recorded by the onboard receiver Thales Mobile Mapper during an air test performed over the military aerodrome EPDE in Dęblin. Judging by the conducted investigations, it is possible to conclude that the difference in BLh coordinates of the aircraft Cessna 172 on the basis of the GPS solution and EGNOS (SBAS) solution equals, respectively: from -0.5 m to +3 m for component B; and from -2 m to +6 m for component L; from approximately -11 m to over +1 m for component h. In addition, the paper defines factors of dilution of precision PDOP, based on the GPS and EGNOS (SBAS) solutions. The average value of the PDOP coefficient for a solution in the tracking GPS mode was 2.7, whereas in the EGNOS (SBAS) tracking mode, it was equal to 2.8.
An analysis of the condition of technical objects is carried out by diagnostic systems, the purpose of which is to detect irregularities in their operation and to prevent damages. In slide bearings, it applies to the diagnostic of friction and thermal phenomena of mating friction pairs. Among many methods of bearing diagnostics, special attention should be paid to vibration diagnostic methods based on measurements of relative vibration parameters or on absolute vibration (displacement, velocity, or acceleration of vibration). Methods of the vibration diagnostic of bearings rely on periodic or continuous measurements of relative vibration parameters of the bearing housing in relation to the rotor (in the case of slide bearings the measurements of the bearing sleeve in relation to the shaft neck) or absolute vibration parameters of the bearing housing (i.e. the sleeve in the case of slide bearing). The article presents a method of vibration diagnostics of friction phenomena that occur during the operation of slide bearings under various lubrication and load conditions. There are presented methods of analysis and the interpretation of measurement data obtained as a result of the conducted slide bearing tests on the laboratory stand. A method for assessing a technical condition of the slide bearing friction pairs is proposed.
PL
Rozpoznanie stanu obiektów technicznych jest realizowane przez systemy diagnostyczne, których celem jest wykrywanie nieprawidłowości w ich działaniu i zapobieganiu uszkodzeniom. W łożyskach ślizgowych dotyczy to diagnostyki zjawisk tarciowych i cieplnych współpracujących węzłów tarcia. Wśród wielu metod diagnostyki łożysk na szczególną uwagę zasługują metody diagnostyki drganiowej, bazujące na pomiarach parametrów drgań względnych bądź drgań bezwzględnych (przemieszczenie, prędkość lub przyspieszenie drgań). Metody diagnostyki drganiowej stanu technicznego łożysk polegają na okresowych lub ciągłych pomiarach parametrów drgań względnych obudowy łożyska względem wirnika (w przypadku łożysk ślizgowych panewki łożyska względem czopa wału) bądź parametrów drgań bezwzględnych obudowy łożyska (czyli panewki w przypadku łożyska ślizgowego). W artykule przedstawiono metodę diagnostyki drganiowej zjawisk tarciowych, jakie zachodzą podczas pracy łożysk ślizgowych przy różnych warunkach smarowania i obciążenia. Przedstawiono metody analizy i interpretacji wyników pomiarów otrzymanych w wyniku przeprowadzonych badań łożyska ślizgowego na stanowisku laboratoryjnym. Zaproponowano metodę oceny stanu technicznego węzła tarcia łożyska ślizgowego.
W artykule przedstawiono rezultaty pozycjonowania statku powietrznego Cessna 172 na podstawie rozwiązania metody PPP (ang. Precise Point Positioning) w nawigacji lotniczej. Pozycja statku powietrznego została odtworzona w programie RTKLIB w bibliotece RTKPOST w module PPPKinematic. W artykule dokonano porównania współrzędnych geocentrycznych statku powietrznego pomiędzy rozwiązaniami RTKLIB, GAPS, CSRS-PPP oraz IBGE-PPP. Ponadto w artykule przedstawiono miary niezawodności zastosowania metody PPP w nawigacji lotniczej. Średnia wartość różnicy współrzędnych geocentrycznych (x, y, z) statku powietrznego nie przekracza poziomu -1,15 m wzdłuż wszystkich osi. Rozrzut uzyskanych wyników różnicy współrzędnych (x, y, z) dla samolotu Cessna 172 na podstawie rozwiązania z programów RTKLIB, GAPS, IBGE-PPP oraz CSRS-PPP wynosi od -5,15 m do +3,17 m. Ponadto błąd RMS (ang. Root Mean Square) wynosi od 0,18 m do 1,15 m.
EN
Paper presents the results of Cessna 172 aircraft positioning based on solution of PPP (Precise Point Positioning) method in air navigation. The aircraft position was recovery using the PPP-Kinematic module in RTKPOST library in RTKLIB software package. In article, the geocentric coordinates of aircraft from RTKLIB solution were compared with products of GAPS, CSRS-PPP and IBGE-PPP programs. In addition, the measures of reliability of application the PPP method in air navigation were presented in paper. The mean value of difference of aircraft coordinates (x, y, z) was not exceeded the limit of -1,15 m along all axis. The dispersion of obtained results of difference of aircraft coordinates based on solution from RTKLIB, GAPS, CSRS-PPP and IBGE-PPP programs is between -5,15 m and +3,17 m. Moreover, the RMS (Root Mean Square) bias is between 0,18 m and 1,15 m.
The article presents the possibility of applying the differential technique RTK-OTF to recover the position of the aircraft in the post-processing mode. Within the framework of the conducted research, the authors designated the geocentric coordinates XYZ of the aircraft and compared them. In the research experiment, they used archive materials from the test flight of the aircraft Cessna 172 around the airfield in Deblin on 1 June 2010. The actual position of the aircraft Cessna 172 was recovered on the basis of GPS kinematic observations registered by the receiver Topcon HiperPro mounted on board the aircraft. In the calculations, the authors also used static GPS observations from the reference station REF1 as well as virtual reference stations VirA and VirB. The final coordinates of the aircraft Cessna 172 with three independent determinations RTK-OTF were defined in the AOSS v.2.0 programme. On this basis, they made verification of accuracy in determining XYZ coordinates of the aircraft Cessna 172. The dispersion of results for the difference in the designation of the X coordinate of the aircraft ranges from –0.19 m to +0.05 m. On the other hand, the size of the difference in the designation of Y-coordinate of the aircraft ranges from –0.07 m to +0.11 m. In addition, the dispersion of the results for the difference in the designation of the Z coordinate of the aircraft is from 0.19 m to +0.12 m.
Microsoft Rights Management Services (RMS) to system mający zapewniać ochronę i prawidłowe użytkowanie dokumentów elektronicznych. RMS pozwala na stosowanie różnej polityki dostępu do dokumentu, pozwalając na kontrolę jego obiegu i wykorzystania. System umożliwia zdefiniowanie polityki dostępu nie tylko w momencie tworzenia danego dokumentu, lecz także po jego dystrybucji. Microsoft RMS wykorzystuje szereg zaawansowanych mechanizmów kryptograficznych mających zapewnić bezpieczeństwo usługi. W niniejszej pracy została przeprowadzona analiza bezpieczeństwa usługi RMS, wskazująca na istnienie szeregu luk w ochronie dokumentów. Zaproponowane zostały metody rozwiązania podstawowych problemów, w szczególności związanych z zapewnieniem integralności danych.
EN
Microsoft Rights Management Services (RMS) is a system designed to ensure the protection and proper use of electronic documents. RMS allows to apply different access policies for documents, thus allowing to control their use in time. The system allows not only defining access policies at document creation, but also after its distribution. Microsoft RMS uses a number of advanced cryptographic mechanisms and primitives to ensure overall service security. In this paper, we have analyzed the security of RMS, indicating a number of possible gaps. The methods of solving those problems, especially those related to data integrity, have been proposed.
W artykule opisano analizę drgań lotniczego silnika tłokowego ASz-62IR-16E. Wyniki opracowano na podstawie spektrum drgań jednostki napędowe, oraz wartości skutecznych przyspieszeń drgań RMS dla określonych prędkości obrotowych. Przedstawiono sposób identyfikacji częstotliwości szczytowych wartości amplitud dla widma drgań. Omówiono również zależność prędkości obrotowych jednostki napędowej na drgania generowane przez silnik. Ustalono zakres prędkości obrotowych mających wpływ na powstawanie okresowych wymuszeń.
EN
The article describes the vibration analysis of aviation piston engine ASz-62IR-16E. The results are based on the vibration spectrum of the engines, and the effective RMS accelerations for specific speeds. The paper presents a method of identifying the frequency of peak amplitudes of vibration spectra. It also discusses the dependence of rotational speed of the drive unit to the vibrations generated by the engine. Established speed range having an impact on the formation of periodic excitations.
Manufacturing companies in the 21st century will face unpredictable, high-frequency market changes, driven by global competition. The article presents a new concept of manufacturing systems – which address these challenges - known as Reconfigurable Manufacturing Systems (RMS). The concept began in 1999 at University of Michigan and is widely developed in many scientific publications. The paper first analyses main features of RSP. The next sections are devoted to analyze basic assumptions of RMS design and technical measures of RMS. Finally, the answer for the question if the RMS has the perspective of wide industrial implementations is discussed.
The paper describes micromilling machine and implemented sensor system for microcutting operations. Sensor system can be used for cutting forces, accelerations, acoustic pressure and tool displacements measurement. Cutting forces and accelerations signals were used for cutting depth, hardness of workpiece and excitation frequency of rotating tool monitoring. Other signals obtained during experiment will be used in further work. Conclusions arising from performed experiment and further research plans are presented.
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W pracy przeanaiizowano wpływ obcięcia słowa akumulatora fazy oraz skończonej rozdzielczości przetwornika C/A na wartość skuteczną sygnału generowanego przez bezpośredni syntezer częstotliwości (DDS). Zaproponowano model matematyczny, pozwalający na wyznaczenie zakresu przestrąjania układu DDS oraz oszacowania jego parametrów, tzn. długości słowa akumulatora fazy, maksymalnego obcięcia słowa akumulatora fazy, tak aby parametry te miały wpływ na wartość skuteczną generowanego sygnału mniejszy od założonej wielkości.
EN
The paper presents influence of phase word truncation effect and finite resolution of DAC on signal's root mean square value, which is generated by Direct Digital Synthesizer (DDS). Proposed mathematical model allows to set the frequency range and parameters of DDS i.e. number of bits in phase word to achieve RMS error smaller than some assumed value.
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This paper describes a real-time classification method of power quality (PQ) disturbances based on DSP-FPGA. The proposed method simultaneously uses the results obtained in the application of a series of RMS values and the discrete Fourier transform to the power signal waveform. A series of RMS values are used for estimation of the time-related parameters of the PQ disturbances and the discrete Fourier transform is used for confirmation of the frequency-related parameters of the PQ disturbances. Without adding the computational burden, both the elementary parameters of the power signal and the type of PQ disturbance are obtained easily. A simple and effective methodology for classification of nine typical kinds of PQ disturbances is proposed in this paper. Five distinguished time-frequency statistical features of each type of PQ disturbances are extracted. Using a rule-based decision tree (RBDT), the PQ disturbances pattern can be recognized easily and there is no need to use other complicated classifiers. Finally, the method is also tested using both simulated disturbances and disturbances measured using an initial development instrument. Different experimental results show the good performance of this proposed approach. Real-time calculating time based on DSP is also taken into consideration to show the effectiveness of the proposed method.
The present paper shows particularly description of the construction of the test stand for experimental research performed in University of Applied Science Giessen and connected with the measurements of hydrodynamic friction forces in journal slide bearings by using the Acoustic Emission Method. The test stand is adapted for the friction force measurements for the low bearing load and for the high bearing load. For such test stand in the case of low and high loads the dependencies between friction forces and time can be exactly obtained. During the measurements the temperature changes are expected. The advantage of this method is the fact that oscillations of measured friction values can be executed directly from the source to the sensor, what enables us to do an "online-measurement". The Acoustic Emission Analysis is (in opposite to the aforementioned Friction Power measurement) a relative method, which means, that the absolute amount of a RMS-Value depends on the measuring chain.
The present paper determines the results of experimental research performed in Gdynia Maritime University and connected with the measurements of hydrodynamic friction forces in slide journal slide bearings by using the Acoustic Emission Method. A new method for mechanical friction force measuring was carried out at this test stand, simultaneously the friction force will be indicated by an optimized Acoustic Emission System. The friction conditions at the test were measured by two different methods. At the one hand the friction power measurement and at the other hand the Acoustic Emission Analysis. One characteristic of the friction power measurement is the rather inert reaction to the oscillations of the slide bearing. The advantage of the method is the fact that one can measure absolute values of the friction power. In opposite to that, the Acoustic Emission Analysis measures the high frequency oscillations caused by the hydrodynamic friction between the oil molecules. The advantage of this method is the fact that this oscillations can be executed directly from the source to the sensor, what enables us to do an "online-measurement". The Acoustic Emission Analysis is (in opposite to the aforementioned friction power measurement) a relative method, which means, that the absolute amount of a RMS-Value depends on the measuring chain. The results are compared and discussed with other results obtained in experiments performed in University of Applied Science Giessen.
The present paper describes the results of measurements performed in University of Applied Science Giessen and determined hydrodynamic friction forces in journal slide bearings by using the Acoustic Emission Method. It describes the use of the Acoustic Emission Analysis as an indicator of the bearing friction at slide bearings. The investigations were made at two different test stands. The test stand at Maritime University Gdynia covers the hydrodynamic operation range, the test stand at University of Applied Science Giessen the mixed friction area. The successive steps of measurements of the hydrodynamic friction forces are presented in this paper. Hardness and roughness of cooperating surfaces is in this paper particularly described. The friction values and its boundary conditions at the test were measured for the low bearing load and for the high bearing load. In both cases, the dependencies between friction forces and time are exactly obtained. During the measurements, the temperature is taken into account. The advantage of this method is the fact that these oscillations can be executed directly from the source to the sensor, what enables us to do an "online-measurement". The Acoustic Emission Analysis is (in opposite to the aforementioned friction power measurement) a relative method, which means, that the absolute amount of a RMS-Value depends on the measuring chain. The results are compared and discussed with other results obtained in experiments performed in Maritime University Gdynia.
Przedstawiono wybrane zagadnienia dotyczące nanotechnologii i nanomateriałów. Omówiono pojęcia wchodzące w skład nanonauki. Opisano budowę, właściwości, metody wytwarzania oraz przykłady zastosowania i metody badań nanomateriałów.
EN
Selected topics related to nanotechnology and nanomaterials have been presented. The concept of nanoscience was discussed. The structure, chemical properties, methods of production and examples of practical apllication and research methods were discribed.
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W niniejszej pracy przedstawiono mikroskopię sił atomowych jako zaawansowaną metodę inżynierską, dającą szerokie możliwości w nowoczesnej kontroli jakości wysokiej klasy elementów optyki, fotoniki czy półprzewodników. Ponadto silnie zaakcentowano konieczność opisu morfologii warstwy wierzchniej poprzez podanie wymiaru fraktalnego oraz długości korelacji jako zasadniczych parametrów opisujących samopodobieństwo oraz samoafiniczność powierzchni elementów technicznych. Przytaczaną metodykę poparto badaniami eksperymentalnymi, w ramach których przeprowadzono analizę fraktalną topografii powierzchni cienkiej folii stopu Heuslera typu Ni-Mn-Ga z zastosowaniem metody RMS (Root Mean Square).
EN
This paper introduces the Atomic Force Microscopy as an advanced engineering method that offers great potential in the modern, high-class quality control of optic, photonic, and semiconductor elements. Furthermore, what has been strongly emphasized is a real need to describe the morphology of a surface layer using the fractal parameter and the correlation length as fundamental parameters that describe self-similarity and self-affinity of surfaces of technical elements. The methodology shown in the paper is supported with some effects of experimental work, including fractal analysis of the topography of the surface of thin Ni-Mn-Ga type Heusler alloy with the Root Mean Square (RMS) method.
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