Wyniki wyszukiwania - BazTech

1

A novel technique for driveline assembly applications

Coban H., Harrison D. K., De Silva A. K. M.

Journal of KONES

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2011

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Vol. 18, No. 4

55-63

EN

A novel technique for drivetrain assembly - Mill-Knurling and Press-Fitting (MKPF) is projected as a substitute to laser welding or bolting. This joining practice involves the press fitting of two mating surfaces, one with mill-knurled teeth and the other which is of a comparatively softer material, enabling it to stream over the teeth making a joint. This process has been applied within an automobile rear axle differential which is subjected to random torque loads. Experimental analysis and simulation has been used to evaluate the serviceable viability and the latent benefits of mill knurled joints with both laser welded and bolted joints currently used by BMW. Assumptions such as total cost of planning, research and development, total investment, total specific resources, raw material and manufacturing costs were used to evaluate mill knurling as an alternative to laser welding and bolted assemblies. The MKPF method has been successfully applied to assemble rear axle differential cases to the bevel gears. The costs, weight and size estimations are very positive in comparison to the competitive methods of laser welding and bolting. The noteworthy weight saving will strengthen the efforts by the automotive industry to reduce the emission levels of vehicles. The pitch flank deviation values which are critical for the life cycle duty of the bevel gear need to be further investigated in order to achieve comparable results with laser welding.

2

Cold forming techniques for the manufacture of steel structual sections

Macdonald M., Heiyantuduwa M., Harrison D. K.

Przegląd Mechaniczny

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2008

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nr 2

40-43

3

The exploitation of wavelet de-noising to detect bearing faults

Al-Raheem K. F., ROY A., Ramachandran K. P., Harrison D. K., Grainger S.

Journal of KONBiN

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2007

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No. 1 (3)

7-16

EN

Failure diagnosis is an important component of the Condition Based Maintenance (CBM) activities for most engineering systems. Rolling element bearings are the most common cause of rotating machinery failure. The existence of the amplitude modulation and noises in the faulty bearing vibration signal present challenges to effective fault detection method. The wavelet transform has been widely used in signal de-noising due to its extraordinary time-frequency representation capability. In this paper, we proposed new approach for bearing fault detection based on the autocorrelation of wavelet de-noised vibration signal through a wavelet base function derived from the bearing impulse response. To improve the fault detection process the wavelet parameters (damping factor and center frequency) are optimized using maximization kurtosis criteria to produce wavelet base function with high similarity with the impulses generated by bearing defects, that leads to increase the magnitude of the wavelet coefficients related to the fault impulses and enhance the fault detection process. The results show the effectiveness of the proposed technique to reveal the bearing fault impulses and its periodicity for both simulated and real rolling bearing vibration signals.

4

Research and developments in laser beam machining

Pająk P. T., De Silva A. K. M., Harrison D. K., McGeough J. A.

Zeszyty Naukowe Politechniki Poznańskiej. Budowa Maszyn i Zarządzanie Produkcją

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2005

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Nr 2

63-91

EN

This paper reviews basic relationships and parameters as well as recent trends in research and development of Laser Beam Machining (LBM), particularly emphasising on applications of novel, short and ultra-short pulsed lasers. Since laser development a lot effort has been done to improve laser performance and to limit its drawbacks. One of the main development directions are the improvement of LBM surface integrity by limitation of heat affected zone and the increase of machining accuracy particularly in micromachining. Therefore the machining needs are the main drivers for development of short and ultrashort pulsed lasers that, iasers of better beam quality, lasers of shorter wavelengths. Shorter pulses of the order of 10-15 s enable to minimise heat conduction and maximise ablation, whereas shorter wavelengths (< 300nm) are absorbed too a greater extent by the material rather than longer wavelengths. Moreover shorter wavelengths enable to produce smaller features. This paper gives also a number of various laser machining applications as well as considers modern laser beam guidance techniques.

5

Product quality monitoring using artificial neural networks

Wood C. H., Harrison D. K., Szpytko J.

Biuletyn Wojskowej Akademii Technicznej

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2004

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Vol. 53, nr 7

173-183

PL

Rozwój automatyzacji maszyn i urządzeń wymaga nowego spojrzenia na współdziałanie w układzie człowiek/operator - urządzenie. Automatyka przyczynia się do poprawy bezpieczeństwa i niezawodności układów antropocentrycznych, jednakże wiedza i umiejętności operatora są nadal istotne w procesie eksploatacji maszyn i urządzeń. Rozwijane są działania zorientowane na ciągłe monitorowanie stanu technicznego procesu typu CM (ang. Condition Monitoring). Przedmiotem artykułu są wyniki badań noża tokarki podczas operacji skrawania. Rejestrowane podczas skrawania wibracje są analizowane w odniesieniu do uzyskanej jakości obrabianej powierzchni. Jakość obrabianej powierzchni była przedmiotem klasyfikacji dla potrzeb sieci neuronowych. Na podstawie przeprowadzonych badań sformułowano korelacje pomiędzy poziomem wibracji noża skrawającego tokarki a jakością obrabianego przedmiotu. Otrzymane z badań wyniki umożliwiły opracowanie narzędzia uniemożliwiającego realizację operacji w rezultacie, której jakość obrabianej powierzchni nie będzie zadawalająca. Opracowane narzędzie wykorzystuje w procesie decyzyjnym sieci neuronowe.

EN

With the trend towards the use of automated systems apparent and the removal of direct human contact in the manufacturing of components, the expertise associated with human operators is also being eroded. While automation can reduce human errors, improve safety and economy of operation, it is felt that the loss of benefits felt due to the human expertise might be recovered. The process of condition monitoring (CM) involves monitoring the condition of a particular machine to attempt to detect the adverse changes that would indicate that the performance of the machine is failing. This paper reports the results of acquiring vibration readings during the cutting operation of a centre lathe and analysing the data off-line with a view to determining the state of the Surface Finish produced during the cutting procedure. The process of using the Artificial Neural Networks to classify the measured signature analysis data into distinguished classes of Surface Finish quality will be discussed. This is part of a body of on-going work which aims to show how automated techniques employing Artificial Intelligence are preferred if CM is to make a real impact in the manufacturing industry.

6

The identification of on-line surface finish via an ANN application

Wood C. H., Harrison D. K., Sihra T. S., Szpytko J.

Mechanics and Mechanical Engineering

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2002

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Vol. 6, nr 2

87-93

EN

In this paper, a brief description is provided of a comprehensive experiment conducted to investigate the effect of the vibration characteristics of a lathe as the tool tip is worn through repeated machining operations. The characteristics are measured as vibration spectra and visual pattern techniques are employed to detect trends in these spectra, which indicate the variance in surface finish quality. Artificial Neural Networks (ANNs) are then employed to provide a more powerful tool for feature extraction and combined with surface finish measurement taken during the cutting operation, a correlation between these two parameters is undertaken. The results show that ANNs are capable at complementing existing tool wear monitoring techniques and potentially they could be applied to a wider spectrum of condition monitoring strategies developed to date.

PL

Przedmiotem artykułu są badania relacji pomiędzy jakością powierzchni (gładkość) przedmiotu obrabianego z użyciem tokarki, a wzbudzanymi drganiami obserwowanymi na jej nożu skrawającym (dla powtarzalnych cyklicznie operacji). W rezultacie przeprowadzonych badań sformułowano relacje pomiędzy gładkością powierzchni i drganiami na nożu, które umożliwiły zastosowanie sieci neuronowych ANN do prognozowania tendencji zmian w stanie technicznym tokarki. Opracowane narzędzie ANN umożliwia prowadzenie w układzie on-line oceny jakości wykończenia powierzchni obrabianego przedmiotu.

7

An efficient information system for automated process planning

Pang J., Harrison D. K., MacDonald M.

Mechanics and Mechanical Engineering

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2002

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Vol. 6, nr 2

49-63

EN

Process planning is one of the most important components in manufacturing industry. It may be considered as a bridge between design and manufacturing. Tremendous efforts have been made to develop automated process planning systems during the last three decades. However, their effectiveness is stili far from satisfactory. Process planning is a very complicated and complex task. It not only requires a good deal of technique specific expertise and knowledge but also is very dependent on dynamic manufacturing resources. With the recent development in computer information systems, especially Artificial Intelligence (Al) and advanced modelling techniques, Computer Aided Process Planning (CAPP) has greatly benefited from the new information processing capabilities. By efficiently combining some of these techniques such as object-oriented techniques, deductive mechanisms, logic programming and fuzzy logic, an integrated and intelligent information representation is introduced to facilitate automatic process planning in this paper. It can effectively satisfy the requirements of representing the process planning information and also provide an open structure for the information exchange within the Computer Integrated Manufacturing (CIM) environment.

8

The conceptual role of 3D vision systems for the automated factory

Harrison D. K., Szpytko J., Wainwright C. E. R., Gill R.

Automatyka / Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie

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2001

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T. 5, z. 1/2

241-248

EN

Increasing international competition implies that manufacturing companies must develop their production systems to satisfy business and marketing needs. For manufacturing to be competitive requires a strategic orientation, the foundation of which must be Total Quality. This may be achieved by the development of reliable automated inspection processes. This paper considers the elements related to an archetypal automated visual inspection system and examines the component subsystem within each element.

PL

Przedmiotem artykułu jest przegląd systemów automatycznej wizualnej inspekcji pod kątem przemysłowych aplikacji dla potrzeb podejmowania decyzji eksploatacyjnych.

9

Safety in hazard goods transportation

Szpytko J., Harrison D.K.

Zagadnienia Eksploatacji Maszyn

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2000

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Vol. 35, nr 2

45-59

EN

The aim of the paper is the discussion of safety in hazard goods transportation and risk analysis, which considered aspects of road/rail en-route and marine and transportation of nuclear materials. The criteria for judging the tolerability risks have been discussed (including risk zones and risk criteria), as well as possibilities of the risk reduction of transportation of the dangerous substances. The above have been discussed mostly on the Great Britain example, as well as Polish experiences. All the risks from the major hazard aspects of the transport of dangerous substances by rail and road are only a small proportion of the total risks facing people travelling or living near railways and roads. For the rail en-route transported the risk is lower and comparable with the limits suggested for fixed instalations. In conclusion no suggestion of any methods to risk reduction has been proposed (only directions), because the criteria to the decision making are not technically based but rather socio-political. The decision making is based mostly on the numerate method to express consistently what risk society currently tolerates. Tolerable risks should be still reduced so far, as is reasonably practicable.

PL

Przedmiotem artykułu jest dyskusja zagrożeń i ryzyka w aspekcie bezpiecznego transportu materiałów niebezpiecznych. Uwagę skoncentrowano na transporcie drogowym, kolejowym i morskim oraz materiałach radioaktywnych. Sformułowano dopuszczalne obszary podejmowania ryzyka i ich kryteria pod kątem społecznego akceptowania. Przedyskutowano możliwości zwiększenia bezpieczeństwa w transporcie materiałów niebezpiecznych. Analizę stanu bezpieczeństwa przeprowadzono na przykładzie Wielkiej Brytanii oraz polskich doświadczeń. Możliwe aspekty ryzyka pochodzące od przemieszczania ładunków niebezpiecznych koleją i transportem kołowym są małe w stosunku do skali szkodliwych oddziaływań na mieszkających wzdłuż tras drogowych i kolejowych oraz podróżujących środkami transportu. Ryzyko transportu materiałów niebezpiecznych jest mniejsze niż akceptowalny poziom ryzyka dla ich stałych instalacji. Złożoność problematyki transportu materiałów niebezpiecznych uniemożliwia formułowanie metod redukcji ryzyka (sformułowano jedynie kierunki przesięwzięć), ponieważ kryteria podejmowania decyzji mają przede wszystkim aspekt socjalno-polityczny, w małym stopniu mają związek z techniką i inżynierią. Poziom ryzyka jest silnie determinowany akceptowalnością społeczną, ma charakter ewolucyjny i jest obniżany wraz ze wzrostem świadomości człowieka i jego dobrobytu.

10

A transport based case study application of object oriented software development

Wainwright Ch.E.R, Harrison D.K., Szpytko J.

Archives of Transport

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1998

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Vol. 10, iss.3-4

51-65

EN

The principle aim of software engineering is to help to produce quality software. The quality software plays a key position in each modem device, as well as transport system controlling, moreover in the device/materials handling system life cycle integration. However, conventional software development methods no longer fulfil software requirements. In this paper, a brief review of conventional software development methodologies is conducted, followed by an appraisal of Object-Oriented Technology (OOT). Many advantages of OOT are claimed over conventional development methods, yet few concrete reports exist to support these claims. To verify the existence of OOT advantages, this paper describes the application of the technology for the development of a company wide estimation and design system for fire protection systems, including goods handling and transport problem of hazardous materials. After presenting software development issues, operational results are discussed and key issues of OOT raised.

PL

Oprogramowanie pełni istotną rolę w sterowaniu nowoczesnymi urządzeniami i systemami transportowymi, a ponadto w integracji faz życia każdego urządzenia lub systemu produkcyjnego. Konwencjonalne oprogramowanie nie spełnia oczekiwań użytkownika. W artykule omówiono tradycyjne metodologie, a szczególną uwagę zwrócono na technologie zorientowane obiektowo (OOT). Technikę tę zastosowano w ocenie skuteczności i w projektowaniu systemu zabezpieczenia przeciwpożarowego, obejmującego transport mediów oraz materiałów niebezpiecznych. Powyższa aplikacja umożliwiła praktyczną jakościową ocenę techniki obiektowej.