Much progress has been made in recent years in the development of Computer-Aided Design and Computer-Aided Manufacturing (CAD/CAM) tools for engineering design, analysis, and manufacturing. Unfortunately, most of these CAD/CAM applications were constructed independently and without standardization. In essence, they automate a single aspect of design, analysis, or manufacturing and cannot be combined to form a cohesive environment, since integration among applications was not addressed during the design phase of CAD/CAM application software creation. In view of this problem, a novel approach is suggested for software integration of applications in a network environment. The distributed integration solution described in this dissertation employs a new "integration client/server" relationship, where the integration server is the core of the system, providing functions to translate or transform data between applications. The integration client consists of an interface with the server, a CAD/CAM application, and a user interface with the integrated system called the GRIM (GRaphical Interface Manager). There is only one integration server in the system, but there may be an unlimited number of clients. The solution created for distributed integration is implemented in a Computer-Aided Software Engineering (CASE) workbench, geared specifically toward the generation of integration systems. This workbench is known as the CAD/CAM CASE Workbench, and includes an integration solution as well as standard CASE tools. The integration solution contains several tools which will aid a system designer in generating integration systems for CAD/CAM applications. Included is the distributed integration solution described in this dissertation. The distributed integration solution is designed to facilitate the semi-automatic generation of an integration system. It consists of an integration server at the center of the integration system which manages the exchange of data among the integration clients. The integration clients are the CAD/CAM applications in the context of the integration system. To use the distributed integration solution, the integration system designer will customize portions of the structure charts, data dictionary, and module specifications contained in the workbench according to the needs of the applications programs and generate C-source code defining the integration system. Using the distributed integration solution, the user will be able to effect data requests for applications, using the GRIM to interact with the system. All data exchanges are request driven. In addition to the distributed integration solution, this research includes a prototype integrated system which allows data to be requested from one application, and translated to a second for display and manipulation. The prototype was tested in a distributed environment and the results are described. / Ph. D.

3-D Interactive CADAM allows for easier construction, modification, analysis, and display of 3-D geometry surfaces and wire-frames. This research forms a basis for preliminary aircraft geometric design using the CADAM system. The helicopter design program, HESCOMP, originally a batch mode program, was coupled with CADAM via the CADAM data base such that the analysis, design, and redesign of the helicopter geometry and interior equipment geometry can be accomplished interactively. HESCAD, a program which produces the helicopter preliminary design model and enables the interior equipment design process, is developed. It provides a capability to evolve rapidly and refine helicopter configurations generated automatically using output from HESCOMP or interior equipment design by graphically and numerically defining helicopter components through interactive, on line, computer graphic display devices. Helicopter 3-D wireframes are automatically produced for any HESCOMP helicopter geometry output. A method which directs CADAM to analyze the helicopter components and produce weights, centers of gravity, moments and products of inertia and to review the results of the analyses directly on the screen is provided. This research was sponsored by IBM Corporation Federal Systems Division under contract No. 417503-DE. This thesis describes and illustrates the HESCAD program. Detailed graphical results are also presented. / Master of Science / incomplete_metadata

Robots with vision capability have been taught to recognize unknown objects by comparing their shape features with those of known objects, which are stored in the vision system as a knowledge base. Traditionally, this knowledge base is created by showing the robot the set of objects that it is likely to come across. This is done with the vision system to be used and must be done in an online mode. An approach to teach the robot in an off-line mode by integrating the robot vision system and an off-line graphic system, has been developed in this research. Instead of showing the objects that the robot is likely to come across, graphic models of the objects were created in an off-line graphic system and a FORTRAN program that processes the models to extract their shape parameters was developed. These shape parameters were passed to the vision system. A program to process an unknown object placed in front of the vision system was developed to extract its shape parameters. A program that compares the parameters of the unknown object with those of the known models was also developed. The vision system was calibrated to measure the pixel dimensions in inches. In the vision system, shape parameters of the objects were found to vary with different orientations. The range of variation for each parameter was established and this was taken into consideration in the parameter comparison program. / Master of Science

This thesis introduces a program which serves as a post-processor interface between CAD AM NC and a DYNA milling machine. This program processes the CLDA TA file that is the output of the IBM System/370 APT-AC processor. The input to the APT-AC processor is an APT file, generated by passing CADAM NC data through the CADAM/ APT interface. The CLDA TA file is post-processed and instructions in DYNA language, required to machine the part on the DYNA milling machine, are created. This is achieved through different subroutines that have been written for different types of statements in the CLDA TA file. For each type of statement in the CLDA TA file, a different subroutine is accessed which processes that statement according to the requirements of the DYNA milling machine and writes the corresponding statement in DYNA language to a file. The post-processor then reads the different DYNA statements from different files and creates the complete part program in DYNA language required to machine the part. / M.S.

The purpose of this thesis is to provide a complete package for the design and three dimensional modeling display of cams. The software produced as a part of this work will operate as a module of CADAM to produce cam designs and enter the resulting cam as a CAD model and produce the graphical display of the cam. In addition to the introductory material, this thesis is divided into four sections. The section on the graphics packages used in this thesis includes a brief history and capabilities of each of the packages. The second section details the procedure to be adopted in order to design a cam. The next section details ANICAM, the program that has been developed to incorporate the design and display procedure. The fourth section of this thesis contains recommendations for further work in this area. The theoretical work in this project is a combination of original derivations and applications of the theory in the design literature. / Master of Science

<p>Piping is an essential component in buildings, and its as-built information is critical to facility management tasks. Manually extracting piping information from legacy drawings that are in paper, PDF, or image format is mentally exerting, time-consuming, and error-prone. Symbol recognition and detection are core problems in the computer-based interpretation of piping drawings, and the main technical challenge is to determine robust features that are invariant to scaling, rotation, and translation. This thesis aims to use convolutional neural networks (CNNs) to automatically extract features from raw images, and consequently, to locate and recognize symbols in piping drawings.</p> <p>In this thesis, the Spatial Transformer Network (STN) is applied to improve the performance of a standard CNN model for recognizing piping symbols, and the Faster Region-based Convolutional Neural Network (Faster RCNN) is adopted to exploit its capacity in symbol detection. For experimentation, the synthetic data are generated as follows. Two datasets are generated for symbol recognition and detection, respectively. For recognition, eight types of symbols are synthesized based on the geometric constraints between the primitives. The drawing samples for detection are manually sketched using AutoCAD MEP software and its piping component library, and seven types of symbols are selected from the piping component library. Both sets of samples are augmented with various scales, rotations, and random noises.</p> <p>The experiment for symbol recognition is conducted and the accuracies of the recognition accuracy of the CNN + STN model and the standard CNN model are compared. It is observed that the spatial transformer layer improves the accuracy in classifying piping symbols from 95.39% to 98.26%. For the symbol detection task, the experiment is conducted using a public implementation of Faster RCNN. The mean Average Precision (mAP) is 82.8% when Intersection over Union (IoU) threshold equals to 0.5. Imbalanced data (i.e., imbalanced samples in each class) led to a decrease in the Average Precision in the minority class. Also, the symbol library, the small dataset, and the complex backbone network limit the generality of the model. Future work will focus on the collection of larger set of drawings and the improvement of the network’s geometric invariance.</p>

Quality control (QC) plan is an important component of manufacturing planning for mass customization. QC planning is to determine the operational tolerances and the way to control process variation for assuring the production quality against design tolerances. It includes four phases, i.e., tolerance stack-up analysis, tolerance assignment, in-process inspection design, and the procedure of error source diagnosis & process control. Previous work has been done for tolerance stack-up modeling based on the datum-machining surface relationship graph (DMG), machining error analysis, and worst-case/statistical method. In this research, the tolerance stack-up analysis is expanded with a Monte-Carlo simulation for solving the tolerance stack-up problem within multi-setups. Based on the tolerance stack-up model and process capability analysis, a tolerance assignment method is developed to determine the operation tolerance specifications in each setup. Optimal result is achieved by using tolerance grade representation and generic algorithm. Then based on a process variation analysis, a platform is established to identify the necessity of in-process inspection and design/select the inspection methods in quality control planning. Finally a general procedure is developed to diagnose the error sources and control the process variation based on the measurements.

Fixtures accurately locate and secure a part during machining operations such that the part can be manufactured to design specifications. To reduce the design costs associated with fixturing, various computer-aided fixture design (CAFD) methods have been developed through the years to assist the fixture designer. Much research has been directed towards developing systems that determine an optimal fixture plan layout, but there is still a need to develop a CAFD method that can continue to assist designers at the unit level where the key task is identifying the appropriate structure that the individual units comprising a fixture should take. This research work details the development of a CAFD methodology (called CAFixD) that seeks to fill this hole in the CAFD field. The approach taken is to consider all operational requirements of a fixture problem, and use them to guide the design of a fixture at the unit level. Based upon a case-based reasoning (CBR) methodology where relevant design experience is retrieved and adapted to provide a new fixture design solution, the CAFixD methodology adopts a rigorous approach to indexing design cases in which axiomatic design functional requirement decomposition is adopted. Thus, the design requirement is decomposed in terms of functional requirements, physical solutions are retrieved and adapted for each individual requirement, and the design re-constituted to form a complete fixture design. Case adaptation knowledge is used to guide the retrieval process. Possible adaptation strategies for modifying candidate cases are identified and then evaluated. Case and adaptation strategy combinations that result in adapted designs that best satisfy the preferences of the designer are used as the final design solutions. Possible means of refining the effectiveness of the method include combining adaptation strategies and considering the order in which design decisions are taken.

A two-dimensional structural analysis design approach has been the universally accepted method for a small structural engineering design firm. The tools to perform the analysis have been paper and pencil, calculators and more recently personal computers with two-dimensional software. With the introduction of three-dimensional software, a major shift is occurring on how small structural engineering firms approach analysis and design. This thesis research reviews the analysis of an existing building utilizing the standard two-dimensional approach, including horizontal diaphragm-action within wood floors. This study also reviews the research performed on horizontal diaphragms and investigates the use of three-dimensional, finite element modeling (RISA-3D) for the analysis of horizontal diaphragms. It is shown that the three-dimensional model can provide results similar to the two-dimensional hand calculations. However, the thickness of the diaphragm elements has to be significantly modified for flexible diaphragm action. The experience described herein is useful for structural engineer interfacing within three-dimensional CAD systems. The thesis concludes with a discussion on the challenges facing small structural engineering firms, including computer based technologies, engineering expertise to develop contract documents and review shop drawings, and outsourcing of design services.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The use of computer resources for machinery programming with Computer Numeric Control (CNC) has become increasingly more necessary in manufacturing companies. The objective is to reduce unproductive time, to optimize programming process, to decrease possibility of error caused by manual programming and to decrease the time that the machine is not being used. Softwares employed for the programming of CNC machines, known as CAM, are programs that, among other functions, enable the automatic generation of CNC programs, through the calculus of the tool path, from the geometric representation of the available part in computer systems presented virtually. When their integration occurs, we obtain CAD/CAM systems that currently, due to the great advance of technologies, help the creation of shapes and the handling of dimensions, thus enabling the programming of several kinds of numerically-driven equipment. Due to a great array of resources offered by these programs, its cost is high. Therefore, the purchase of these programs by companies is impracticable. In addition, these companies do not need all the great array of resources to deal with low complexity geometry. By considering these aspects, the objective of this study is to develop a low-cost CAD/CAM integrated methodology to apply in fixed cycles for milling and drilling, existing in the numeric comand of machine tools. In order to analyze the technique, a system using a CAD software was designed. Through its optimization resources, routines for programming fixed cycles of a machine tool (milling) with three-axle programmable CNC were created. The results demonstrated viability of this proposal as it was possible to obtain a CAD/CAM system for specific application. / A utilização de recursos computacionais para a programação de máquinas com Comando Numérico Computadorizado (CNC) tem se tornado cada vez mais necessária nas empresas de manufatura. Esses recursos permitem a redução dos tempos improdutivos, a otimização do processo de programação, a diminuição da possibilidade de erro causado pela programação manual e do tempo de máquina parada. Os softwares utilizados para a programação de máquinas CNCs, conhecidos pela sigla CAM (Manufatura assistida por computador), são programas que, entre outras funções, possibilitam a geração automática de programas CNC através do cálculo do caminho da ferramenta, a partir da representação geométrica da peça disponível na forma virtual em sistemas computacionais de auxilio ao projeto CAD (desenho assistido por computador). Da integração desses sistemas, têm-se os sistemas CAD/CAM, que hoje, devido ao avançado grau de desenvolvimento das tecnologias, auxiliam na criação de formas e manipulação de dimensões possibilitando a programação de diversos tipos de equipamentos comandados numericamente. Devido à gama de recursos oferecida por esses programas, seu custo é elevado, o que torna sua aquisição inviável para pequenas empresas, que, muitas vezes, não necessitam de todos esses recursos por trabalharem com geometria de pouca complexidade. Levando em consideração esses aspectos, o objetivo deste trabalho é desenvolver uma metodologia de integração CAD/CAM de baixo custo para aplicação de ciclos fixos para usinagem em fresamento e furação, existentes no comando numérico de máquinas-ferramenta. Para analisar a técnica, foi desenvolvido um sistema utilizando um software de CAD, a partir do qual, através de seus recursos de otimização e automatização, foram criadas rotinas para programação dos ciclos fixos de uma fresadora CNC de 3 eixos programáveis. Os resultados demonstraram a viabilidade dessa proposta, pois foi possível obter um sistema CAD/CAM para aplicação específica.