Document-Driven Design for Distributed CAD Services in Service-Oriented Architecture

Current computer-aided design (CAD) systems only support interactive geometry generation, which is not ideal for distributed engineering services in enterprise-to-enterprise collaboration with a generic thin-client service-oriented architecture. This paper proposes a new feature-based modeling mechanism—document-driven design—to enable batch mode geometry construction for distributed CAD systems. A semantic feature model is developed to represent informative and communicative design intent. Feature semantics is explicitly captured as a trinary relation, which provides good extensibility and prevents semantics loss. Data interoperability between domains is enhanced by schema mapping and multiresolution semantics. This mechanism aims to enable asynchronous communication in distributed CAD environments with ease of design alternative evaluation and reuse, reduced human errors, and improved system throughput and utilization

Analyzing and Implementing a Feature Mapping Approach to CAD System Interoperability

Interoperable information exchange between computer-aided design (CAD) systems is one of the major problems to enable information integration in a collaborative engineering environment. Although a significant amount of work has been done on the extension and standardization of CAD data formats as well as the cooperation of CAD systems in both academy and industry, these approaches are generally low-level and narrowly targeted. Lack of fundamental study of interoperability and generic solution to this problem is the major issue. Our intention of this research is to design a solution of CAD feature interoperability as generic as possible based on a theoretical foundation of language types. In this paper, we present a fundamental model of semantic features and feature mapping process based on the type theory. We implement and demonstrate our approach for automated feature exchange between commercial CAD systems

Revisiting the design intent concept in the context of mechanical CAD education

[EN] Design intent is generally understood simply as a CAD model¿s anticipated behavior when altered. However, this representation provides a simplified view of the model¿s construction and purpose, which may hinder its general understanding and future reusability. Our vision is that design intent communication may be improved by recognizing the multifaceted nature of design intent, and by instructing users to convey each facet of design intent through the better-fitted CAD resource. This paper reviews the current understanding of design intent and its relationship to design rationale and builds on the idea that communication of design intent conveyed via CAD models can be satisfied at three levels provided that specialized instruction is used to instruct users in selection of the most suitable level for each intent.Otey, J.; Company, P.; Contero, M.; Camba, J. (2018). Revisiting the design intent concept in the context of mechanical CAD education. Computer-Aided Design and Applications. 15(1):47-60. https://doi.org/10.1080/16864360.2017.1353733S476015

Data structures for context responsive modeling in architecture

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Architecture, 2008.Includes bibliographical references (leaf 39).Context plays important roles in architecture design, any feelings we implement, or any existing conditions that we try to address in a design process intents emerge. Understanding the relationships between elements in a given design context and how they affect decision making for new ideas is crucial in understand how a design comes into form. By capturing this context responsiveness, we can capture the design knowledge into computers for different kinds of automated processes. Parametric modeling tools and scripting interfaces in modern ... ways to model data. The objects we create from these tools could potentially used in various computation processes and allow designers to interact with slight reconfigurations, they could help designers to capture design knowledge My thesis will try to use computation concepts such as Object Orient of technology to allow modeling software to model parametric objects in a way that provides flexible interfaces amongst parametric object, script, and designers. Then I will propose a context responsive to address the questions of how to capture design in a more effective way.by Si Li.S.M

A Contribution to Conveying Quality Criteria in Mechanical CAD Models and Assemblies through Rubrics and Comprehensive Design Intent Quantification

Esta investigación examinó el uso de rúbricas de ensamblaje, describiendo su evolución a partir de rúbricas de piezas, y estudió cómo afectan a la autoevaluación de los estudiantes. También se valoró la evaluación de los estudiantes por los instructores, encontrando que, mientras que las rúbricas de ensamblaje fueron parcialmente comprendidas y utilizadas de manera eficiente por los estudiantes, éstas fueron usadas con más éxito por los instructores. En esta investigación se han abordado estrategias diseñadas para mejorar la comunicación de la intención de diseño en modelos CAD, acrecentando así su calidad, con directrices dirigidas a evaluar su eficiencia. Es evidente que se necesitan métricas dirigidas hacia la instrucción de la intención de diseño, ya que la intención de diseño transferida a través de modelos CAD puede realizarse en tres etapas con criterios contradictorios que deben ser equilibrados para llegar a la mejor estrategia de modelado. La investigación ha incluido el desarrollo de un método de validación que demuestra que las rúbricas son dispositivos útiles para garantizar una comunicación consistente de la intención de diseño, y son fundamentales no sólo para evaluar, sino también para comunicar las expectativas del instructor. En esta investigación se examinó cómo definir claramente las cualidades de la intención de diseño para permitir una más fácil evaluación de un ensamblaje CAD. Para todas las dimensiones de la rúbrica, se encontró más concordancia y correlación entre instructores que entre instructores y estudiantes. Existe una correlación moderada/fuerte entre los instructores para las dimensiones de la validez, completitud, concisión y claridad, mientras que existe una ligera correlación para las dimensiones de consistencia e intención del diseño. En segundo lugar, las rúbricas también pueden ser descritas como estáticas o dinámicas. Las rúbricas estáticas, existen sólo en papel, no proporcionan retroalimentación inmediata al educando. Las rúbricas dinámicas realizan cálculos que proporcionan observaciones de evaluación inmediatas al usuario. Además, pueden adaptarse a situaciones específicas dependiendo de la capacidad del usuario. Las rúbricas electrónicas son ideales para rúbricas dinámicas, y permiten el uso y desarrollo de rúbricas adaptativas y adaptables, como se describe a continuación. En tercer lugar, las rúbricas deben ser adaptables lo que debería hacerlas fácilmente comprensibles y fáciles de usar, y adaptativas. Las rúbricas de evaluación se usan cuando un experto determina el progreso pedagógico de un educando, mientras que las rúbricas formativas son empleadas por los propios estudiantes, para trazar su progreso e identificar las deficiencias escolares para las que necesitan apoyo. Las rúbricas se deben refinar y mejorar de forma continuada, en un proceso iterativo y colaborativo, hasta que se alcance un acuerdo satisfactorio, tanto entre evaluadores como entre evaluadores y alumnos. Por ello, se desarrollaron mapas de aserciones que ilustran el modo en que la estrategia de expansión-contracción adapta las rúbricas al progreso del aprendiz de CAD, a la vez que ayudan a comprender las diferentes dimensiones de la rúbrica. Basándose en los experimentos con las rúbricas de ensamblajes, es evidente que las pequeñas diferencias entre los instructores sugieren que la rúbrica de ensamblajes propuesta es lo suficientemente sofisticada como para proporcionar una evaluación acumulativa imparcial del desempeño del alumno. En consecuencia, se puede afirmar con confianza que los evaluadores pueden usarse indistintamente sin sacrificar la precisión. Sin embargo, la rúbrica de ensamblaje posee una eficacia finita para producir una autoevaluación formativa de las habilidades de ensamblaje CAD para nuevos alumnos.This research examined the use of assembly rubrics, described how they evolved from parts rubrics, and studied how they affect student self-evaluation. Instructor assessment of students was also evaluated, finding that while the assembly rubrics were partially understood and effectively used by the students, they were more successfully utilized by the instructors. Strategies designed to improve design intent communication in CAD models, in order to enhance their quality, with guidelines targeted to evaluate efficiency, have been addressed with this research. It is apparent that metrics directed toward the instruction of design intent are needed, since design intent transferred through CAD models can be performed at three stages with competing tradeoffs that must be balanced to arrive at the best modeling strategy. Research included the development of a validation approach that reflects that rubrics are valuable devices to expedite consistent design intent communication, and are vital not only for evaluation, but also for the communication of instructor expectations. This research examined how to clearly define qualities of design intent to enable easier CAD assembly assessment. It has been found that there is more inter-rater agreement and correlation between instructors than between instructors and students, for all rubric dimensions. There is strong to moderate correlation between instructors for the dimensions of validity, completeness, conciseness, and clarity, while slight correlation exists for the dimensions of consistency and design intent. Secondly, rubrics can also be described as being either static or dynamic. Static rubrics, existing in paper form only, do not provide immediate feedback to the learner. Dynamic rubrics perform calculations that provide immediate evaluative observations to the user. Besides, they can be independently adapted to specific situations depending on the capability of the user. Electronic rubrics are ideally suited for dynamic rubrics, and permit the use and development of both adaptable and adaptive rubrics, as described next. Thirdly, rubrics need to be adaptable which should make them easily understood and user-friendly, and adaptive (rubric can change itself, depending on the usage pattern). Evaluative rubrics are used when an expert determines the pedagogical progress of a learner, while formative rubrics are employed by the learners themselves, in order to chart their progress and identify scholastic deficiencies that are in need of remediation. Rubrics must be continually refined and improved, in an iterative, collaborative process, until satisfactory agreement is attained, both between raters, but also between raters and learners. Thus, assertions maps were developed, illustrating how the expand-contract strategy adapts the rubrics to CAD trainee progress, while assisting the understanding of the different rubric dimensions. Based on the assembly rubric experiments, it is apparent that the small differences between instructors suggests that the proposed assemblies rubric is sufficiently sophisticated to furnish an unbiased accumulative assessment of student performance. Accordingly, it can be confidently stated that raters can be used interchangeably without sacrificing accuracy. However, the assembly rubric possesses finite efficacy to produce formative self-evaluation of CAD assembly skills for new learners.Aquesta investigació examinà l'ús de rúbriques de acoblament, descrivint la seua evolució a partir de rúbriques de peces, i estudià cóm afecten a la autoavaluació dels estudiants. També es va valorar la avaluació dels estudiants per els instructors, trobant que, mentre que les rúbriques de acoblament van ser parcialment compreses i fetes servir de manera eficient per els estudiants, van ser usades amb mes èxit per els instructors. En aquesta investigació s'han abordat estrategues dissenyades per a millorar la comunicació de la intenció de disseny en models CAD, creixentat així la seua qualitat, amb directrius dirigides a avaluar la seua eficiència. Es evident que es necessiten mètriques dirigides cap a la instrucció de la intenció de disseny, ja que la intenció de disseny transferida a través de models CAD pot realitzar-se en tres etapes amb criteris contradictoris que deuen ser equilibrats per a arribar a la millor estratègia de modelatge. La investigació ha inclòs el desenvolupament de un mètode de validació que demostra que las rúbriques son dispositius útils per a garantir una comunicació consistent de la intenció de disseny, i son fonamentals no només per a avaluar, però també per a comunicar les expectatives de l'instructor. En aquesta investigació s'examinà com definir clarament les qualitats de la intenció de disseny per a permetre una mes fàcil avaluació de un acoblament CAD. Per a totes les dimensions de la rúbrica, es va trobar mes concordança i correlació entre instructors que no pas entre instructors i estudiants. Existeix una correlació moderada/fort entre els instructors per a les dimensions de la validesa, completesa, concisió i claredat, mentre que existeix una lleugera correlació per a les dimensions de consistència i intenció del disseny. En segon lloc, les rúbriques també poden ser descrites com estàtiques o dinàmiques. Les rúbriques estàtiques, existeixen sòls en paper, no proporcionen retroalimentació immediata a l'educand. Les rúbriques dinàmiques realitzen càlculs que proporcionen observacions de avaluació immediates al usuari. A mes, poden adaptar-se a situacions específiques dependent de la capacitat de l'usuari. Les rúbriques electròniques son ideals per a rúbriques dinàmiques, i permeten l'ús i desenvolupament de rúbriques adaptatives i adaptables, como es descriu a continuació. En tercer lloc, les rúbriques deuen ser adaptables, el que deuria ferles fàcilment comprensibles i fàcils d'usar, i adaptatives. Les rúbriques d'avaluació se usen quant un expert determina el progrés pedagògic de un educand, mentre que les rúbriques formatives son fetes servir per els propis estudiants, per a traçar el seu progrés i identificar les deficiències escolars para a les que necessiten suport. Les rúbriques es deuen refinar i millorar de forma continuada, en un procés iteratiu i col·laboratori, fins que se arriba a un acord satisfactori, tant entre avaluadors como entre avaluadors i alumnes. Por això, es desenvoluparen mapes de assercions que il·lustren el mode en que la estratègia de expansió-contracció adapta les rúbriques al progres del aprenent de CAD, a la vegada que ajuden a comprendre les diferents dimensions de la rúbrica. Basant-se en els experiments amb les rúbriques de acoblaments, es evident que les xicotetes diferencies entre els instructors suggereixen que la rúbrica de acoblaments proposta es lo suficientment sofisticada com per a proporcionar una avaluació acumulativa imparcial del acompliment de l'alumne. En conseqüència, es pot afirmar amb confiança que els avaluadors poden usar-se indistintament sense sacrificar la precisió. No obstant, la rúbrica de acoblaments posseeix una eficàcia finita per a produir una autoavaluació formativa de les habilitats de acoblament CAD per a nous alumnes.Otey, JM. (2017). A Contribution to Conveying Quality Criteria in Mechanical CAD Models and Assemblies through Rubrics and Comprehensive Design Intent Quantification [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/94627TESI

Constraint-Enabled Design Information Representation for Mechanical Products Over the Internet

Global economy has made manufacturing industry become more distributed than ever before. Product design requires more involvement from various technical disciplines at different locations. In such a geographically and temporally distributed environment, efficient and effective collaboration on design is vital to maintain product quality and organizational competency. Interoperability of design information is one of major barriers for collaborative design. Current standard CAD data formats do not support design collaboration effectively in terms of design information and knowledge capturing, exchange, and integration within the design cycle. Multidisciplinary design constraints cannot be represented and transferred among different groups, and design information cannot be integrated efficiently within a distributed environment. Uncertainty of specification cannot be modeled at early design stages, while constraints for optimization are not embedded in design data. In this work, a design information model, Universal Linkage model, is developed to represent design related information for mechanical products in a distributed form. It incorporates geometric and non-geometric constraints with traditional geometry and topology elements, thus allows more design knowledge sharing in collaborative design. Segments of design data are linked and integrated into a complete product model, thus support lean design information capturing, storage, and query. The model is represented by Directed Hyper Graph and Product Markup Language to preserve extensibility and openness. Incorporating robustness consideration, an Interval Geometric Modeling scheme is presented, in which numerical parameters are represented by interval values. This scheme is able to capture uncertainty and inexactness of design and reduces the chances of conflict in constraint imposition. It provides a unified constraint representation for the process of conceptual design, detailed design, and design optimization. Corresponding interval constraint solving methods are studied

An automated method mapping parametric features between computer aided design software

This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University LondonEnterprise efficiency is limited by data exchange. A product designer might specify the geometry of a product with a Computer Aided Design program, an engineer might re-use that geometry data to calculate physical properties of the product using a Finite Element Analysis program. These different domains place different requirements on the product representation. Representations of product data required for different tasks is dependent on the vendor software associated with those tasks, sharing data between different vendor programs is limited by incompatibility of the vendor formats used. In the case of Computer Aided Design where the virtual form of an object is modelled, no standard data format captures complete model data. Common data standards transfer model surface geometry without capturing the topological elements from which these geometries are constructed. There are prescriptive data representations to allow these features to be specified in a neutral format, but little incentive for vendors to adopt these schemes. Recent efforts instead focus on identifying similar feature elements between different vendor CAD programs, however this approach relies on onerous manual identification requiring frequent revision. This research develops methods to automate the task of mapping relationships between different data format representations. Two independent matching techniques identify similar CAD feature functions between heterogeneous programs. Text similarity and object geometry matching techniques are combined to match the data formats associated with CAD programs. An efficient search for matching function parameters is performed using a genetic algorithm that incorporates semantic data matching and geometry data matching. A greedy semantic matching algorithm is developed that compares with the Doc2vec short text matching technique over the API dataset tested. A SVD geometric surface registration technique is developed that requires fewer calculations than an equivalent Iterative Closest Point method