Ph.D. thesis is focused on the design of the method for simulation of energy demands of machine tool in operation at the stage of its development. Proposed method is developer on the basis of literature search in science and in industry. The method itself is composed of five related steps, that must be realised in the proper order in order to create a relevant energy profile of a machine tool. The output from the method are simulated data providing a course of comsumed energy and required power which are time dependent. Output data are obtained on the basis of the drive system simulation of machine tool through G-code, that is interpreted for simulation by the compiler into the matrix. It contains data necessary for controlling of machine tool, such as the required end points of the tool and required feed rates, to which is assigned a time value. G-code is partially time parametrized. It is then followed by full time parametrization through a of mathematical model of drive mechanisms and due the synergy of software for drive mechanisms control (Matlab Simulink) and software for physical simulation (MSC Adams) is processed into output data. As an input parameter figures also coefficient used as multiplier of the normal force of driving mechanisms, which is a function of feed rate. This loss function is obtained experimantally. In the context of Ph.D. thesis were conducted two experiments, used to verify the developed method. For each experiment is proceeded according to estabilished method and it is included a comparsion of simulation and measured data for various operating modes. The proposed method, described in the Ph.D. thesis, allows designers to summarize the energy demand of the proposed machine before its production. When correctly interpreted, the results of the method can serve as a basis for improving the energy profile and thereby increasing the energy efficiency of the machine tool.

Ph.D. thesis is focused on the design of the method for simulation of energy demands of machine tool in operation at the stage of its development. Proposed method is developer on the basis of literature search in science and in industry. The method itself is composed of five related steps, that must be realised in the proper order in order to create a relevant energy profile of a machine tool. The output from the method are simulated data providing a course of comsumed energy and required power which are time dependent. Output data are obtained on the basis of the drive system simulation of machine tool through G-code, that is interpreted for simulation by the compiler into the matrix. It contains data necessary for controlling of machine tool, such as the required end points of the tool and required feed rates, to which is assigned a time value. G-code is partially time parametrized. It is then followed by full time parametrization through a of mathematical model of drive mechanisms and due the synergy of software for drive mechanisms control (Matlab Simulink) and software for physical simulation (MSC Adams) is processed into output data. As an input parameter figures also coefficient used as multiplier of the normal force of driving mechanisms, which is a function of feed rate. This loss function is obtained experimantally. In the context of Ph.D. thesis were conducted two experiments, used to verify the developed method. For each experiment is proceeded according to estabilished method and it is included a comparsion of simulation and measured data for various operating modes. The proposed method, described in the Ph.D. thesis, allows designers to summarize the energy demand of the proposed machine before its production. When correctly interpreted, the results of the method can serve as a basis for improving the energy profile and thereby increasing the energy efficiency of the machine tool.

For some time now coordinate measuring machines have been an integral part of the shop floor. The goal has been to make coordinate measuring machines (CMMs) into tools that can easily be used by machinists to improve their manufacturing capabilities. The value of a CMM as a quality control tool is undisputed. Now efforts are being made to further reduce the time and cost of measurement by reducing the physical distance between machining and measuring processes. The ability to reduce that distance to zero and measure a part directly on the chip-making machine has been a goal for many years. Dimensional inspection of parts is primarily conducted by coordinate measuring machines operating on motion instructions from task planning software. The research in direct machining and control (DMAC) at BYU has identified a potential application of CMM technologies on existing machine tools. To prove that a machine tool can be controlled as a CMM with the DMAC controller, this research will integrate the software package PC-DMIS provided by Wilcox Associates, Inc. with a DMAC controller provided by Direct Controls, Inc. to conduct in-process dimensional inspection of parts as they are being machined. This process is referred to as DirectCMM because it will link the DMAC controller directly to PC-DMIS without need for post-processing. This thesis will lay the groundwork for future efforts at developing systems that utilize in-process part inspection to dynamically correct computer aided manufacturing (CAM) process plans. To aid future efforts at dynamic CAM process updating, a software interface specification will be created for passing measurement data between CMM and CAD/CAM software packages. A CMM control specification will also be created to provide a standard method for controlling coordinate measuring machines with the DMAC controller. Possible methods for dynamic CAD/CAM updating will be explored.

Machine tools accuracy has been a cornerstone in defining machining system capability and directly affecting dimensional and geometrical tolerance of machined parts. The effort for achieving higher precision and accuracy can be distinguished in two general ideas. One is to improve performance of machine tools by designing better, stiffer and more accurate machine tools. The other is to develop tools and methods for evaluating and measuring their behaviour and gain knowledge of their performance. In order to properly control the machine tool characteristics that can affect and improve their accuracy such as static stiffness and static accuracy.This thesis is aiming at establishing and further advancing the idea of loaded testing of machining systems and the concept of Elastically Linked Systems as a framework for measuring, identifying and characterising quasi-static stiffness of machine tools under loaded conditions. This will allow the creation of an improved capability profile of machining system accuracy. The focus is on the implementation of Elastically Linked Systems concept (ELS) through the Loaded Double Bar system, a measurement method that can partly simulate the process-machine interaction by reproducing forces exerted on the machine tool structure for the evaluation of system characteristics under loaded condition. This allows the qualitative and quantitative evaluation and comparison of machine tools for the purpose of accuracy enhancement, identification of weak directions with potential utilization in process planning, machine procurement and maintenance.Through two case studies, the capability to identify the effect of machine components and structure behaviour is shown. / <p>QC 20180514</p>

<p>Condition monitoring of critical machine tool components and machining processes is a key factor to increase the availability of the machine tool and achieving a more robust machining process. Failures in the machining process and machine tool components may also have negative effects on the final produced part. Instabilities in machining processes also shortens the life time of the cutting edges and machine tool.</p><p>The condition monitoring system may utilise information from several sources to facilitate the detection of instabilities in the machining process. To avoid additional complexity to the machining system the use of internal sensors is considered. The focus in this thesis has been to investigate if information related to the machining process can be extracted directly from the internal sensors of the machine tool.</p><p>The main contibutions of this work is a further understanding of the direct response from both linear and angular position encoders due the variations in the machining process. The analysis of the response from unbalance testing of turn tables and two types of milling processes, i.e. disc-milling and slot-milling, is presented. It is shown that operational frequencies, such as cutter frequency and tooth-passing frequency, can be extracted from both active and inactive machine axes, but the response from an active machine axis involves a more complex analysis. Various methods for the analysis of the responses in time domain, frequency domain and phase space are presented.</p> / QC 20100518

工具機不僅在機械產業占有一席之地，在製造業更是扮演舉足輕重的 角色，生活周遭所使用的物品，許多都是由工具機所製造。工具機產業的 核心技術，仰賴資深員工的經驗傳承，因此教育訓練是工具機廠商營運的 流程中重要的一環。傳統DEA 要求所有的投入、產出資料必須為量化的數 據，然而現實生活中有很多重要的變數難以量化，Likert 量表發明後，學 者們大量使用Likert 量表量化這些變數，但是Likert 量表尺度的公平性 是許多學者質疑的重點。模糊DEA 透過模糊理論，改善Likert 量表尺度 公平性的問題，因此本研究使用模糊DEA 進行工具機廠商教育訓練績效的 分析，並比較Likert 量表尺度下的DEA 與模糊DEA 實證結果的不同，研 究對象為民國96 年的台灣地區85 間工具機廠商。 幾項重要的實證分析結果如下： 1. 整體技術效率差者，多為訓練積極的廠商。 2. 部分規模效率差的廠商，純技術效率表現尚在中等水平，表示這些廠商 只是因為訓練較為積極，使得投入在生產規模遞減的水準。 3. 工具機產業的教育訓練普遍有浪費的現象，顯示只要投入少許資源即可 達到相當的成效，若要突破某個瓶頸，就要增加相當多的資源。 4. 整體而言使用Likert 量表尺度或是模糊DEA 的結果沒有顯著差異，但 是對於效率較佳的廠商來說，模糊DEA 具有較高的鑑別力。 / The machine tool plays an important role in not only machinery industry but also the whole manufacturing industry. Most of goods around us are made by the machine tool. The core technologies hold by experienced employees depends on training to pass down. Therefore, training is an essential process in machine tool factories. In traditional DEA, all inputs and outputs need to be numeric data. But in reality, there are many key variables are hard to be measured in numeric. After Likert scale being invented, the scholars widely use the scale to evaluate these key variables. However, there is criticism of the equity in Likert scale. Fuzzy DEA corrects this disadvantage of Likert scale with fuzzy theory. As a result, this study evaluates the training efficiency of 85 Taiwanese machine tool manufacturers in 2007 with fuzzy DEA and comparers the result between fuzzy DEA and the method of Likert scale. Some important conclusions are shown as follow: 1. Most of the inefficient DMUs are active about training. 2. Although some DMUs are bad in scale efficiency, they are fair in pure technical efficiency. It explains that these DMUs just input at decrease return to scale (DRTS) level. 3. Generally, there is waste of training in this industry. The empirical result tells us they can obtain certain effects with little input. If they want to break through some bottle neck of training effects, they have to input tremendous resources. 4. As a whole, there is no difference between the result of fuzzy DEA and the method of Likert scale. However, there is better discrimination of efficient DMUs in fuzzy DEA.

Eine Absicherung der Maschinendynamik im gesamten Arbeitsraum unter Berücksichtigung des Einflusses der Maschinensteuerung kann nur durch eine mechatronische Analyse der Werkzeugmaschine auf Gesamtsystemebene erfolgen. Derart komplexe Berechnungen erfordern allerdings die Simulation von großen Verfahrbewegungen (MKS) unter Berücksichtigung der Strukturelastizitäten (FEM) sowie der Steuerung (Controls) und sind somit vor allem multi–disziplinären Virtual Prototyping Tools vorbehalten. Die erfolgreiche multi-disziplinäre WZM–Berechnung stellt außerordentlich hohe Anforderungen an die Modellbildungsgüte der einzelnen Maschinenkomponenten inklusive der Validierung des jeweils gewählten Modellierungsansatzes bzw. Detailierungsgrades. Dieses gilt insbesondere für funktionelle Komponenten wie Linearantriebe, Kugelgewindetriebe usw., da diese nicht ohne Weiteres aus einem CAD–Baugruppenmodell abgeleitet und in das Berechnungsmodell übernommen werden können. Das zur Modellierung und Simulation notwendige Expertenwissen ist in einer vordefinierten, parametrischen Komponentenbibliothek – ähnlich einem Baukastenprinzip – implementiert.

Este trabalho trata da avaliação do desempenho de máquinas de usinagem cujas arquiteturas se baseiem em estruturas cinemáticas paralelas planas. Inicialmente analisa dois tipos distintos de arquiteturas paralelas, avaliando as suas mobilidades, possíveis formas de atuação, além de apresentar seus modelos teóricos cinemáticos e dinâmicos correspondentes. A seguir, descrevem-se no texto algumas simulações realizadas em oito modelos propostos, de modo a se observar os comportamentos das arquiteturas consideradas, quando da execução de possíveis trajetórias da ferramenta em movimento plano (2D). A seleção dos modelos e a discussão dos resultados são guiadas por índices de desempenho presentes na literatura e outros propostos ou adaptados. O trabalho discute ainda as melhores soluções, com foco nas trajetórias prédefinidas e em critérios importantes para os mecanismos de arquitetura paralela. / This dissertation concerns the performance evaluation of machine-tool with architectures based on planar parallel kinematic structures. The text starts analyzing two distinct types of parallel architectures, their mobility, feasible schemes of actuation and presents their kinematic and dynamic models. From this point, simulations are described to figure out some characteristics of chosen architectures, in eight different models, focused on execution of tool trajectories in plane motion (2D). The model selection and the discussion about obtained results are guided by performance indexes from the literature and others either proposed or adapted. The work also discusses the best solutions, for pre-defined tool trajectories and important points for mechanisms with parallel structures.

Como seguir com o crescimento da indústria, da economia e do consumo de energia de forma sustentável? No setor manufatureiro as máquinas-ferramentas são peças-chave nos processos de fabricação. Como saber se uma bomba, um motor ou outro elemento acessório é adequado para uma máquina-ferramenta específica? Normalmente, fabricantes se baseiam em sugestões dos fornecedores para selecionar tais elementos, o que resulta em um projeto ajustado pela experiência e por estimativas subjetivas, às vezes superestimando as dimensões do projeto por segurança. O objetivo deste trabalho é monitorar o consumo da energia elétrica durante a fase de uso da máquina-ferramenta, com o fim de explicar a demanda de energia em cada uma de suas tarefas, sugerindo diretrizes para o aperfeiçoamento do projeto desta nos seus componentes críticos. Esta dissertação apresenta uma cuidadosa revisão de livros e pesquisas anteriores, os quais direcionaram a etapa experimental. Assim, elegeu-se trabalhar em um centro de usinagem, o qual foi monitorado por um analisador de qualidade de energia. A metodologia experimental iniciou-se com a avaliação da eficiência energética da máquina-ferramenta em termos de fator de potência, a fim de trabalhar dentro dos parâmetros da legislação brasileira, e finalizou-se com o monitoramento do consumo de energia elétrica. Tal monitoramento foi feito em três cenários de usinagem: em vazio, a seco e com fluido, utilizando um mesmo plano de trabalho em todas as situações. Conclui-se que prognósticos de consumo de energia são possíveis se tempos e constantes do modelo apresentado são conhecidos para uma máquina-ferramenta específica, parâmetros que são influenciados pela experiência do operador. A medição do consumo de energia da máquina em vazio e com remoção permitiram conhecer o consumo de energia pela usinagem propriamente dita. Observou-se também que apenas a máquina-ferramenta consome 59% da energia total quando está usinando; as mudanças de velocidade não afetam o consumo de energia diferentemente da taxa de remoção de material; elementos auxiliares à usinagem não deterioram a eficiência energética da máquina, embora possam representar uma boa taxa percentual de gasto no consumo total; e a troca de ferramentas é mais eficiente na usinagem do que em vazio. / How to follow the growth of industry, economy and energy consumption in a sustainable way? In the manufacturing sector, the machine tools are key-parts in the processes. How can we know if a pump, an electric motor or another accessory element is adequate to a specific machine tool? Usually, the manufacturer relies on suggestions from suppliers to select those elements, resulting in a project adjusted by experience and subjective estimations, sometimes overestimating for security. The objective of the present work is to monitor the consumption of electric power during the useable phase, in order to map the energy demand in each of its tasks, thus suggesting guidelines for the improvement of the project to its critical components. This dissertation presents a thorough review of books and previous research, which has guided the experimental phase. Accordingly, it was chosen to work in a machining center, which was monitored by a power quality analyzer. The experimental methodology began with the evaluation of the energetic efficiency of the machine tool in terms of power factor, in order to work within the parameters of the Brazilian legislation, and ended up with electric energy consumption monitoring. Such monitoring was made in three machining scenarios: cutting air, cutting dry and with coolant, sing the same CNC workplan in all situations. The conclusions include that forecasting of energy consumption is possible if time and constants of the proposed model are known for a specific machine tool, parameters which are influenced by the experience gathered by the operator. The measurement of energy consumption during air cutting and removing material allowed to know the energy consumption of the machining operation itself. It was also observed that: the machine alone consumes 59% of the total energy when in operation; the energy consumption is not affected by speed changes, but by the material removal rate; auxiliary elements to the machining do not negatively affects the energy efficiency of the machine, although may represent considerable expenditure in total consumption; and, the exchange of tools is more efficient when removing material, than when air machining.

A obsolescência das Máquinas-Ferramentas (MFs) é um processo natural de envelhecimento neste tipo de equipamento. Esse processo compreende uma série de degradações tecnológicas, os quais se instalam e ocorrem em toda estrutura física de uma MF, independentemente da tecnologia utilizada. As degradações podem, no entanto, ser resultantes de vários fatores, como uso, aplicação, regime de trabalho, dentre outros. Os aspectos tecnológicos ficam mais evidentes quando se analisam as máquinas a Comando Numérico Computadorizado (CNC). Por sua vez, o CNC é um equipamento que apresenta uma evolução constante, mas que muitas vezes não pode ser facilmente incorporado às máquinas já existentes sem um processo de retrofitting anteriormente definido. Um processo de retrofitting pode ser considerado como um processo que permite aplicar incrementos tecnológicos em uma MF. Mais recentemente, diversos estudos têm apresentado tendências que fazem uma ligação entre MFs e sustentabilidade, sem, no entanto, definir ou propor modelos. Estudar os aspectos do comportamento das MFs existentes e poder aplicar recursos das novas tecnologias pode contribuir para melhorar os aspectos de sua produtividade e, por conseguinte, contribuir para uma produção mais sustentável. No entanto, isso deve ser feito a partir de uma metodologia que oriente um processo de tomada de decisão. Dessa forma, este trabalho propõe um método de referência aplicado a retrofitting de máquinas a partir da definição de coeficientes e de índices numéricos cujos resultados atuam como ferramenta orientativa a um processo de tomada de decisão. O método é aplicado a diversos tipos de MFs e os resultados indicam a viabilidade ou não de um retrofitting. / The obsolescence of Machine Tools (MT) may be defined is a natural process of aging in this type of equipment. This process comprises a series of technological degradation, which settles and occurs across the entire and physical structure of a MT, regardless of the technology used. The degradations may, however, be due to several factors such as usage, application, machining process and so on. The technology aspects are more evident when analyzing the machines Computerized Numerical Control (CNC). By the other hand the CNC is an equipment which naturally contributes with a constant evolution, but they often cant be easily incorporated into an existing machine without a procedure for retrofitting previously defined. A process of retrofitting can be defined and considered as a process incorporates technology resulting in increments of technology to a MT. However, the addressing of such process is usually applied without any models or tools within a process of decision making. More recently, several studies have shown trends making a connection between MT and sustainability without, however, defining templates for such process. The studies of all aspects of the behavior of an existing MT, even with its limitations, suggest the resources of new technologies can help to improve in general all aspects of their productivity and therefore contribute to a more sustainable production. However, this must be done from a methodology that guides the process of decision making. This decision process represents a process that results from a technological gain in a MT or not. Thus, this work proposes a reference method applied to retrofitting machines by defining a series coefficients and numerical indices whose results intends to be used as a tool for helping a decision-making process.