The concept of mass producing custom products, though extremely beneficial to the commercial, and retail industries, does come with some limitations. One of these is the occurrence of bottlenecks in the materials handling systems associated with reconfigurable manufacturing systems tasked with achieving the goal of mass customisation manufacturing. This specific problem requires the development of an intervention system for rerouting parts and materials waiting in line, around bottlenecks and/or work flow disruptions, to alternative destinations. Mobile robots can be used for the resolution of bottlenecks, and similar disruptions in work flow, in these situations. Embedding autonomy into mobile robots in a manufacturing environment, releases the higher level production management systems from routing of parts and materials. The principle of the inverted pendulum has recently become popular in mobile robotics applications, and is being implemented in research projects around the world. The use of this principle produces a two-wheeled mobile robot that is able to actively stabilise itself while in operation. The dissertation is focused on the research, design, assembly, testing and validation of a two-wheeled autonomous materials handling robot for application in reconfigurable manufacturing systems. This robot should be dynamically or statically stable during different phases of operation. The mechatronic engineering approach of system integration has been used in this project in order to produce a more reliable robotic system. The application of the inverted pendulum principle requires that a suitable control strategy be formulated. It also necessetates the ues of sensors to track the state of the robot. Control engineering theory was used to develop an optimal control strategy that is robust enough to cope with varying payload characteristics. The Kalman filter is employed as state estimation measure to improve sensor data. For a mobile robot to be deemed autonomous, one of the requirements is that the robot should be able to navigate through its environment without colliding with obstacles in its path, and without human intervention. A navigation system has been designed, through field specific research, to enable this. The robot is also required to communicate with remote computers housing production management systems as well as with mobile robots that form part of the same materials handling system. Performance analysis and testing proves the feasibility of a mobile robot system. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2010.

Mechatronics encompass a holistic approach to the design, development, production, maintenance and disposal of complex engineering systems, products and processes. The control and modelling of the manufacturing process are carried out in a networked environment allowing for realistic real time control and simulation. This is achieved through the declarative definition of Computer Integrated Manufacturing (CIM) components, the standardisation of CIM interfaces and the object-orientated approach to model development and data management. The development ofthe Modular Mechatronic CIM control system is aimed at intelligently scheduling, controlling and monitoring manufacturing processes in realtime over Internet capable networks. Modular Mechatronics is an alternative design approach that requires the decomposition of a project into separate modules, identifiable by their individual mechatronic functionality. Modular Mechatronic control for Internet manufacturing produces an efficient and effective solution for CIM processes. This approach allows a remote user to monitor and control CIM processes in real time over the Internet allow for a supervisory control structure to control and manage these processes. The modular mechatronic design approach has been applied to the development of the CIM Internet control system, to optimise the overall function ofthe CIM system. A flexible, low cost Modular Mechatronic design approach was used to develop the CIM architecture and computer interface network, which served as the backbone of the Modular Mechatronic CIM control system. The modular designed control system was used to control CIM components in real time over the Internet. The Modular Mechatronic building block development allows for future integration of other CIM components. / Thesis (M.Sc.Eng.)-University of Natal, Durban, 2002.

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ABSTRACT MODELING A MODERN MARBLE PROCESSING PLANT BY USING PETRI NET Keser, &Ouml / zge M. Sc., Department of Mining Engineering Supervisor: Prof Dr. NeS&rsquo / e &Ccedil / elebi Co-Supervisor: Prof Dr. Tevfik G&uuml / yag&uuml / ler December 2003, 110 pages All developing countries need sufficient raw material resources to develop and to guarantee their future. Considering Turkish natural resources, marble has a great importance because of its demand on the market, reserve amount and quality. However, some effort is required to improve the existing marble production and processing efficiency. Petri nets (PNs) are the information models that control the flow for concurrent and synchronous systems. In this regard, PN application can be useful. However, its application is limited to the complex systems and no application of PN is available in mining sector. iii In this sense, this study aims to examine the applicability of PN to mining. This study examines the production system in order to optimize the process in case of two different types of marble product orders. Three case studies are applied to examine benefits and difficulties in implementation of PN to a marble processing plant. The study shows that PN can successfully be used as a tool for the optimization of total production time, simulation and modeling of the system. It provides to see the sequence of the processes, their time, remaining time of each transition and optimum total production times. The difficulties of PN implementation are found out as the determination of each path in the reachability graph, matrix representation with large quantity of place, etc.

In this study, we consider a capacity allocation problem in flexible manufacturing systems. We assume time and tool magazine capacities on the Numerical Controlled (NC) machines and limited number of available tools. Our problem is to allocate the available capacity of the NC machines to the required demand of the operations, so as to maximize the total weight of operation assignments. We formulate the problem as a Mixed Integer Linear Program and show that it is NP-hard in the strong sense. We solve the moderate-sized problems optimally by the available Integer Programming software. We also develop Lagrangean relaxation based upper bounds and several heuristic procedures. Our computational results have revealed that the Lagrangean upper bounds are very close to optimal solutions and the heuristic procedures produce near optimal solutions in very small solution times even when the problem sizes are large.

Manufacturing industry has made extensive use of simulation as a means of trying to model the impact of variability on manufacturing system behavior and to explore various ways of coping with change and uncertainty. Simulation helps find optimal solutions to a number of problems at both design and application stages of Flexible Manufacturing Systems (FMS&rsquo / s) serving to improve the &ldquo / flexibility&rdquo / level The flexibility requirement of FMS necessitates the dissemination of every activity that concerns production, throughout all the levels of a company forcing almost every level of employee face with simulation software, either in terms of preparing models, modifying runs or evaluating results. This problem of inadequate capability of personnel to utilize simulation effectively can be overcome through the design of custom interfaces and integration of simulation software with everyday-use programs. This research mainly focuses on realizing the modeling and simulation of FMS&rsquo / s by the use of the existing system in Middle East Technical University, Mechanical Engineering Department, Computer Integrated Manufacturing Laboratory as a test-bed. Additionally, the means of integration of simulation with auxiliary programs is demonstrated. The models developed throughout the study using ARENA&reg / are used to come up with different scenarios of production. Sample results and decisions about production issues that can be attained through the use of simulation are provided. The described model creation procedures, the generated models, and result assessments are expected to act as a guideline for other simulations regarding FMS&rsquo / s.

Microelectronic systems packaging involves layout dimensions of the order of microns. During manufacturing, process variations will cause parameters to deviate from their nominal values. As a result, the manufactured circuit may no longer meet the specifications it is designed to satisfy. When producing high volume of electronics, assembly yield becomes very important. This is where tolerance margins of the design parameters play an important role. This means that the performance specifications should be satisfied if the process variations are within the given tolerance margin of design parameters. Research has been done on circuit level design for manufacturability methods. The main objective of the research is to study the layout level DFM methods for signal integrity issues and embedded Rf passive components and use design centering methodology to improve the output yield value. In this dissertation, emphasis is also laid on taking care of the regression error while calculating the yield value. With the developed method, the number of design iteration cycles to maximize yield is significantly reduced.

Transfer of information between CAD models and downstream manufacturing process planning software typically involves redundant user interaction. Many existing tools are process-centric and unsuited for selection of a "best process" in the context of existing concurrent engineering design tools. A computer based Feature-Recognition (FR) process is developed to extract critical manufacturing features from engineering product CAD models. FR technology is used for automating the extraction of data from CAD product models and uses wire-frame geometry extracted from an IGES neutral file format. Existing hint-based feature recognition techniques have been extended to encompass a broader range of manufacturing domains than typical in the literature, by utilizing a combination of algorithms, each successful at a limited range of features. Use of wire-frame models simplifies product geometry and has the potential to support rapid manufacturing shape evaluation at the conceptual design stage. Native CAD files are converted to IGES neutral files to provide geometry data marshalling to remove variations in user modelling practice, and to provide a consistent starting point for FR operations. Wire-frame models are investigated to reduce computer resources compared to surface and solid models, and provide a means to recover intellectual property in terms of manufacturing design intent from legacy and contemporary product models. Geometric ambiguity in regard to what is ?solid? and what is not has plagued wire-frame FR development in the past. A new application of crossing number theory (CNT) has been developed to solve the wire-frame ambiguity problem for a range of test parts. The CNT approach works satisfactorily for products where all faces of the product can be recovered and is tested using a variety of mechanical engineering parts. Platform independent tools like Extensible Mark-up Language are used to capture data from the FR application and provide a means to separate FR and decision support applications. Separate applications are composed of reusable software modules that may be combined as required. Combining rule-based and case-based reasoning provides decision support to the manufacturing application as a means of rejecting unsuitable processes on functional and economic grounds while retaining verifiable decision pathways to satisfy industry regulators.

Bibliography: leaves 172-184. / xx, 278 leaves : ill. (chiefly col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / An analytical approach to the integrated problems of designing the dynamic cellular manufacturing systems layout concurrently with its material flow (handling) requirements, in such a manner that minimises the material handling within the system. The proposed strategy encourages the design of a dynamic layout to identify simultaneously the machine groups, economical machine distribution, and intracell and intercell layouts. / Thesis (Ph.D.)--University of Adelaide, Dept. of Mechanical Engineering, 2001?