It is well understood that optical fibre quality can be affected by the conditions present during fibre drawing. fibre tension , drawing speed, furnace temperature, the atmosphere within the ddrawing zone, viscosity of the glass, pre-form neck down shape and vibration in the drawn fibre are all factors which may affect the drawing process, and consequently the properties of the optical fibre. Most of these factors can be affected by the behaviour of the drawing furnace. Therefor monitoring furnace condition and predicting furnace decay are very important to the optical fibre manufacturing process. However, furnace conditions are very complicated and cannot be described by traditional mathematical models. In order to implement condition monitoring more effectively, the effects of process parameters and vibrations on the porperties and geometry of germanium-doped silica-core single-mode fibre, the subject of the current study were investigated by experiments and literature survey. These results can be used to determine the optimum processing conditions and select feature parameters for a condition monitoring system. Sources of vibration were analysed in order to provide information on which subsequent work to minimise vibrations on the drawn fibre could be based. The feature parameters which relate to furnace decay were extracted from the selected drawing parameters and are presented in this thesis. A new non-contact tension measurement system was devised. Different kinds of neural networks and their application in the furnace condition monitoring systems were investigated and the results are reported. A neural network software with fast training speed and a data exchange interface was developed to meet the needs of this furnace monitoring system. This thesis oresents a novel on-line condition monitoring system for drawing furnaces in the optical fibre drawing process. This system utilises the feature parameters extracted from drawing parameters and a neural network as the learning and decision making component. It can monitor the performance of the drawing process and give a pre-warning when furnace decay occurs or drawing parameters exceed the allowed working range. Hence, fibre properties can be enhanced, the production yield can be improved and machine utilities can be increased. This system has been used on a production optical fibre drawing tower at Pirelli Cables Limited and a high success rate for recognising furnace condition was achieved.

This study investigated a methodology for an on-line condition monitoring of tool wear during milling. Based on a comprehensive literature survey, a novel method called 'feature filtered fuzzy clustering' is proposed and developed. Different from the existing fuzzy clustering techniques used for the condition monitoring of machine faults and tool awear, this method can make a realistic identification and classification of tool wear under various cutting conditions by the classification of the features on which the effects of cutting conditions were removed. To realise this method, the relationships between the cutting conditions and the features under three pre-defined wear states corresponding to three clustering centres (initial, normal, severe) were established by experiemnts, which were undertaken under the conditions defined by experiemental design, and non-linear multiple regression analysis. During experiments, a sensor fusion strategy was applied in order to get information from different aspects of the milling process. A mathematical model for fuzzy clustering based on the conception of distance has been verified by experiments using inserts both with artificially created flank wear and accelerated natural flank wear during milling in a CNC tool. In order to obtain appropriate features, the effectiveness of applying different physical parameters, i.e. cutting forces, power consumption of the spindle motor, AE RMS and AE pseudo ring-down count, for monitoring of tool wear has been investigated. Employing data fusion approach and its effect on the classification results has been investigated. Also the feasibility of applying Fourier and Walsh transforms to cutting force signals during monitoring of tool wear has been investigated.

The research presented herein embodies three subject area specifically aimed at the investigation and application of the spiral geometry. These areas are: the derivation of a spiral coordinate system in E2; the formulation of a new metric suitable for spiral pipe structures; the numerical simulation of an incompressible viscous fluid flowing through spiral pipe structures. The spiral coordinate system is first derived and then proven admissible using differential geometry. Validation is achieved using the spiral coordinate system as an alternative transformation for mapping from Cartesian to Polar coordinates for the solution domain of the general wave equation from a square to a circular elastic membrane. Problems associated with curves that do not possess natural-parameterisation in terms of arc-length, and as such cannot use the standard form of the Frenet-Serrat formulae, are solved with the derivation of a generalized metric. This metric is presented and proven for use on an arbitrary shaped pipe of class 'n' and is especially suited for spiral pipe structures. The associated Christoffel symbols of the second kind are also derived and presented in association with the generalized metric for use with the tensorial form of the Navier-Stokes and continuity equations. Finally, the spiral coordinates system is extended into E3 for two types of pipe; the spiral conic and the spiral parabolic. The Continuity and Navier-Stokes equations are numerically solved for an incompressible viscous Newtonian fluid for these pipe structures with various inlet conditions and geometric constraints. A correlation is made with these solutions and solutions found for the helical pipe structure, the nearest equivalent to the spiral found in the open literature.

No description available.

The aim of the study described in this thesis is to investigate the application of expert system technology to acrylic fibre production, with a particular emphasis on knowledge acquisition requirements. In doing so, it is intended to provide an understanding of the requirements and appropriate techniques for the effective application of expert systems in the process industries; The scope of the study is limited to process fault administration which involves detecting, diagnosing arid correcting abnormalities in process operation. A methodology is provided for the systematic development of expert systems within the defined area of application. An important phase in the development methodology is that of expert system specification. This involves an analysis of expert behaviour and the specification of expert system functionality: In order to assist system specification, generic knowledge types and human expert activities have been identified within the context of process fault administration. Knowledge acquisition is discussed in terms of the requirements during each phase of the proposed development methodology. A detailed review is given of the available techniques for knowledge acquisition and an assessment is presented of the most appropriate techniques to apply during each phase of the methodology. A new knowledge acquisition technique is described. The technique is designed to record knowledge of process operation and process fault diagnosis. It is based on a hierarchical decomposition of the process in terms of process objectives. Two complementary forms of knowledge representation are produced: a hierarchy diagram which shows the dependency relationships between individual process objectives and a task statement table which provides a more. detailed explanation of the objectives. Finally, three. case studies are described in which the techniques described in the thesis were applied and developed.

The aim of this research was to understand and solve problems associated with the integration of a Machine Planner within a product model environment. This work was carried out in conjunction with other researchers, pursuing parallel integration issues related to pre-production proving and product data representation. Product data representations of component level planned, processes and feature level process data have been explored as sub-sets of -a product data model to aid integration. Geometric queries on a cell decomposition solid, model. have been explored as a means of providing feature geometric interaction data, while the dimensional interactions between features have also been addressed. Product data representations have been modelled using a prototype software tool, providing an environment for the exploration of the integration of a Machine Planner using a feature based design approach. Necessary Machine Planning functions have been implemented, using the ADA programming language, to explore the integrating capability of the product model environment, concentrating on the use of a prismatic benchmark component. Using the experimental implementation, setup and operation plans have been produced and machining part programs generated from product model representations of variants on the benchmark component. These have been successfully machined using a3 axis vertical machining centre. Such experiments, as well as others in conjunction with co-researchers, have shown that a product data model can provide a common base of data for the integration of a range of design and manufacturing activities.

An important element for the integration of CAD/CAM is the representation and handling of data used during the design and manufacturing activities. The use of features and product modelling techniques bring a better handling of this data and provide CAD/CAM with an excellent platform for integration. The thesis explores the use of a predefined set of features in a product modelling environment for the design and machining of rotational components. Theword features in this research implies a set of functional, geometrical and technological information with a unique form. Those features are pre-defined and comprise of a limited number of elements which carry the information related to design and manufacturing activities. The thesis is divided into three main parts. The first part contains a review of topics related to the research e. g. group technology, component features, CAD/CAM and also contains a literature survey of related research works. In the second part the "features" are defined and presented. Also the product modelling environment is explained and the basic rule based procedures which are used to automatize the operation planning activities are presented. In the last part a description of the case-studies used for automatic NC code generation is presented followed by a discussion of the results. Lastly, the conclusions are drawn and ideas for further work presented.

Building contractors are unhappy about the existing post-tender use of the bills of quantities, particularly the way in which data produced by the estimator may be independently produced again or amended to a suitable format by other management functions. This research aimed at proposing better formats and presentations for the estimating data in order to reduce the repetition and re-work involved in the post-tender use of estimating data, hence to reduce the complexities in data flow in building contractor organizations. The work was primarily carried out for the Sri Lankan industry. To establish the scale and nature of the problem, past work on the format and presentation of estimating data and its current management was studied through literature, interviews and discussions with professionals in ten case studies. Proposals were formulated defining; an efficient classification and coding system, a well defined library structure, a new format to the contractor's copy of the estimate, and effective uses of the computer. The main proposal was to split the unit rate into its components and to provide a breakdown of resource requirements for each bill item. The documents prepared in two test projects were used to demonstrate the feasibility of the proposals in the earlier case studies, and feedback was obtained on the use and extent of use of the improved estimate in post-tender works. A live project was undertaken to investigate the practicability of implementing of the proposals. Finally, an independent survey, without disclosing the results derived from test projects, case studies and the live project was carried out to assess the acceptability of the proposals in the whole industry. All practical work was undertaken in Sri Lanka. The main conclusions derived from these works are; Any research that would investigate the contractor's efficient post-tender use of estimates hould be addressed to contractor organisations; and any proposal that would improve the contractor's data management should be based on contractor's presentation of the estimate. Although the contractors widely use the estimate in their management functions, the full potential is not obtained throughout the contract. Substantial re-work exists in the use of estimate in contractor's post-tender works. The average extent of use of the estimating data was measured at 50% the other 50% of data required re-work. Proposals presented in this research would increase the extent of use of the estimate, hence improve the contractor's data management. The new average extent of use of estimating data (after the introduction of proposals) derived from case studies was 75%. This new average, when compared with the earlier average (50%) showed a 50% possible improvement in the extent of use of estimate in the industry. Test projects, the live project and the independent survey, all showed that the proposals are not only feasible and practicable to implement in contractor organizations, but also acceptable in the whole industry as solutions which would improve the extent of use of the estimate and reduce the complexity of data flow in contractor organizations. The significance of these conclusions is that any contractor organization can adopt the proposals to improve their management because not only has their practicability been investigated but also their acceptability in the whole industry in Sri Lanka as a solution to data complexities is established. The conclusionsa re also of value to other countries.

No description available.

The complexity of enterprise engineering processes requires the application of reference architectures as means of guiding the achievement of an adequate level of business integration. This research aims to address important aspects of this requirement by associating the formalism of reference architectures to various life cycle phases of integrating manufacturing systems (IMS) and enabling their use in addressing contemporary system engineering issues. In pursuit of this aim, the following research activities were carried out: (1) to devise a framework which supports key phases of the IMS life cycle and (2) to populate part of this framework with an initial combination of architectures which can be encapsulated into a computer-aided systems engineering environment. This has led to the creation of a workbench capable of providing support for modelling, analysis, simulation, rapid-prototyping, configuration and run-time operation of an IMS, based on a consistent set of models associated with the engineering processes involved. The research effort concentrated on selecting and investigating the use of appropriate formalisms which underpin a selection of architectures and tools (i. e. CIM-OSA, Petrinets, object-oriented methods and CIM-BIOSYS), this by designing, implementing, applying and testing the workbench. The main contribution of this research is to demonstrate that it is possible to retain an adequate level of formalism, via computational structures and models, which extend through the IMS life cycle from a conceptual description of the system through to actions that the system performs when operating. The underlying methodology which supported this contribution is based on enacting models of system behaviour which encode important coordination aspects of manufacturing systems. The strategy for demonstrating the incorporation of formalism to the IMS life cycle was to enable the aggregation into a workbench of knowledge of 'what' the system is expected to achieve (i. e. 'problems' to be addressed) and 'how' the system can achieve it (i. e possible 'solutions'). Within the workbench, such a knowledge is represented through an amalgamation of business process modelling and object-oriented modelling approaches which, when adequately manipulated, can lead to business integration.