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Due to increasing trends of miniaturization, components with microscale features are in high demand. Accordingly, manufacturing and measurement of small components as small as a few microns became new challenges. Micro milling and femtosecond laser machining are the most common in use cutting operations providing high accuracy and productivity. Micro milling has unique features different from traditional milling including high ratio of tool size to feature size, and constant ratio of tool edge radius to tool size [1]. Due to the mentioned differences, low stiffness of the micro mill and the complexity of the cutting mechanism at the macroscale, selection of cutting parameters are difficult [2]. Therefore, process performance in micro milling, which affects surface quality and tool life, depends on the selected cutting parameters. Also, for measuring micro components, the available dimensional control systems in the market are atomic force microscopes (AFMs) and a combination of coordinate measuring machines (CMMs) and vision systems. These are confined to the scopes of nanoscale and macroscale parts, respectively. It is difficult to justify the high cost and large size of these systems for measurement of mesoscale/microscale features and components and dimensional verification of miniature parts with 3D features. Therefore, a new cost-effective way is needed for measuring components and features in these scales. Additionally, lack of advanced CAD/CAM software for micro laser machining providing constant velocity along the tool path, is the main problem in femtosecond laser machining. In this thesis, to address the mentioned challenges, different software packages are presented to improve micro machining productivity, to provide an accurate and cost effective way of micro scanning and to bring CAD/CAM capability for micro laser machining. / Graduate / 0548 / abdolreza.bayesteh@gmail.com

The mass customisation manufacturing (MCM) paradigm has created a problem in manufacturing control implementation, as each individual customer has the potential to disrupt the operations of production. The aim of this study was to characterise the manufacturing effects of customers’ decisions in product configuration, in order to research steady state control requirements and work-in-process distributions for effective MCM operations. A research method involving both analytic and empirical reasoning was used in characterising the distributed control environment of manufacturing systems involved in MCM. Sequences of job arrivals into each manufacturing system, due to customers’ decisions in product configuration, were analysed as Bernoulli processes. A customer model based on this analysis captured the correlation in product configuration decisions over time. Closed form analytic models were developed from first principles, which described the steady state behaviour of flow controlled manufacturing systems under generalised clearing policy and uncorrelated job arrival sequences. Empirical analysis of data sets achieved through discrete event simulation was used in adjusting the models to account for more complex cases involving multiple job types and varying correlation. Characteristic response surfaces were shown to exist over the domains of manufacturing system load and job arrival sequence correlation. A novel manufacturing flow control method, termed biased minimum feedback (BMF) was developed. BMF was shown to posses the capability to distribute work-in-process within the entire manufacturing facility through work-in-process regulation at each manufacturing system, so as to increase the performance of downstream assembly stations fed from parallel upstream processing stations. A case study in the production of a configurable product was used in presenting an application for the models and methods developed during this research. The models were shown to be useful in predicting steady state control requirements to increase manufacturing performance. / Thesis (Ph.D.)-University of KwaZulu-Natal, Durban, 2013.

The complexity of Field-Programmable Gate Array (FPGAs) logic blocks have undergone constant evolution to the point where both the basic soft logic blocks that implement combinational logic and the fixed-function hard blocks contain complex interconnects, hierarchy and modes. The goal of this thesis is to both support that complexity and enable future architecture exploration of even increased complexity and new kinds of hard functionality. To accomplish this, a Computer-Aided Design (CAD) flow that can map a user circuit to an FPGA with these complex blocks is needed. We propose a new language that can describe these complex blocks and a new area-driven tool for the packing stage of that CAD flow. The packing stage groups components of a user circuit into the complex blocks available on the FPGA. We conduct experiments to illustrate the quality of the packing tool and to demonstrate the newly-enabled architecture exploration capabilities.

The complexity of Field-Programmable Gate Array (FPGAs) logic blocks have undergone constant evolution to the point where both the basic soft logic blocks that implement combinational logic and the fixed-function hard blocks contain complex interconnects, hierarchy and modes. The goal of this thesis is to both support that complexity and enable future architecture exploration of even increased complexity and new kinds of hard functionality. To accomplish this, a Computer-Aided Design (CAD) flow that can map a user circuit to an FPGA with these complex blocks is needed. We propose a new language that can describe these complex blocks and a new area-driven tool for the packing stage of that CAD flow. The packing stage groups components of a user circuit into the complex blocks available on the FPGA. We conduct experiments to illustrate the quality of the packing tool and to demonstrate the newly-enabled architecture exploration capabilities.

One of the key points to reduce the world dependence on fossil fuels and the emissions of greenhouse gases is the use of renewable energy sources. Recent studies showed that wind energy is a significant source of renewable energy which is capable to meet the global energy demands. However, such energy cannot be harvested by today’s technology, based on wind towers, which has nearly reached its economical and technological limits. The major part of the atmospheric wind is inaccessible to the conventional wind turbines and wind at higher altitude is the major source of potential energy which has not been fully exploited yet. The thesis paper has presented a study aimed to devise a new class of wind generator based on extracting energy from high altitude wind.A brief theoretical study is presented to evaluate the potential of an innovative high altitude wind power technology which exploits a tethered airfoil to extract energy from wind at higher altitude. Among the various concepts proposed over last few decades, a kite power system with a single kite is selected for the design purpose.The designed ground station is an improvisation over existing prototypes with an energy reservoir for having a continuous power output. A flywheel is used as the energy storage system which stores the extra energy during traction phases and supplies it during recovery phases and thus giving a continuous power generation regardless of the kite’s motion and keeping the rotor speed in a permissible range defined by the design constraints. Manufacturability of the structure, availability of the components, safety and maintenance criteria have been taken into account while building the ground station CAD model.A dynamic simulation model is developed to investigate the power transmission system of the kite power unit which reflects the torque, speed and power behaviour of the modelled ground station driveline. The functionality of the designed model for the selected concept is tested with several numerical and graphical examples.

Electronic Design Automation (EDA) tools are today very capable computer programs supporting electronic engineers with the design of printed circuit board (PCB). All tools have their strengths and weaknesses; when choosing the right tool many factors needs to be taken into consideration aside from the tools themselves. Companies need to focus on the product and revenues for a business to be viable. Depending on the knowledge and strengths of the company, the choice of tools varies. The decision should be based on the efficiency of the tools and the functions necessity for the company rather than the price tags. The quality and availability of support for the tools, training costs, how long will it take to put the tool in operation and present or future collaboration partners is equally important factors when deciding the right tool. The absence of experience and knowledge of the current tool within a company is a factor which could affect important operation; therefore it is important to provide training and education on how to use the tool to increase its efficiency. Providing training and education can be a large expense, but avoids changes within and makes the business competitive. The choice of EDA tool should be based on the employed engineer’s current knowledge and experience of the preferred tool. If the employed engineer’s knowledge and experience varies too much, it might be preferable to make a transition to one of the tool by training and education. Product lifecycle management (PLM) is a data management system and business activity management system which focuses on the lifecycle of a product. To manage the lifecycle of a product it is necessary to split the lifecycle into stages and phases for a more manageable and transparent workflow. By overseeing a product’s entire lifecycle there are benefits which affects many areas. PLM greatest benefits for EDA are collaboration across separate groups and companies by working together through a PLM platform, companies can forge strong design chains that combine their best capabilities to deliver the product to the customers. This report is a study on evaluating which EDA suits the company with consideration of the employed engineer’s demands, requests and competence. The interests in PLM made the company suggest a short theory study on PLM and EDA benefits.

CADSYN (Computer Aided Design SYNthesis) is a visual, interactive computer program working under Computer Aided Design (CAD) enviroment, which accomplishes the synthesis and analysis of planar four-bar mechanisms. The synthesis tasks are motion generation, path generation and function generation. During synthesis, the dyadic approach is utilized which introduces vector pairs and complex number algebra to model the motion. The possible solutions can be limited for link dimensions, the center circle point curves within a certain region, transmission angle characteristics, branch and order defects. The designed mechanism can be analyzed for velocity, acceleration and transmission angle and any of the data can be exported to Excel&reg / for further analysis. The software is designed to provide the user maximum feasible number of solutions. In four multiply separated position synthesis, if there is flexibility in the value(s) of one or any number of input parameter(s), designer can obtain different Burmester curves by changing those parameter(s). Designer can also simulate the kinematics of the mechanism by using drawing functions that are available from the CAD iv enviroment at any time. Drawing parts in the design plane can be attached to any link of the mechanism and can be simulated throughout the motion as part of the link it is attached. As a whole, this computer program is designed to satisfy the needs of mechanism designers while working in CAD enviroment.

Seit einigen Jahren hat sich Mathcad als universelle Mathematiksoftware an vielen Universitäten, Instituten und in Unternehmen bewährt. An der Professur Maschinenelemente der TU Chemnitz wird Mathcad derzeit u.a. bei der Entwicklung einer vollkommen neuartigen Riemenscheibenkupplung für PKW-Kältemittelverdichter eingesetzt. Hierfür wurde ein mathematisches Modell entwickelt, mit dem sich die Bauteilbelastungen sowie die dynamischen Vorgänge in der Kupplung simulieren lassen. Bei der Analyse und Optimierung solcher technischen Systeme besteht häufig der Wunsch, die Bewegung der Bauteile und die wirkenden Kräfte direkt in Mathcad dreidimensional zu visualisieren, ohne dass dafür ein CAD-System benötigt wird. Im Vortrag werden benutzerfreundliche Funktionen präsentiert und anhand einiger Beispiele live vorgeführt, mit denen dies möglich ist. Des Weiteren wird gezeigt, wie diese Funktionen bei der Entwicklung der genannten Riemenscheibenkupplung eingesetzt wurden.