ANNOTATION MECHANISMS TO MANAGE DESIGN KNOWLEDGE IN COMPLEX PARAMETRIC MODELS AND THEIR EFFECTS ON ALTERATION AND REUSABILITY

El proyecto de investigación propuesto se enmarca dentro del área de diseño de producto con aplicaciones de modelado sólido CAD/CAM (Computer Aided Design/Computer Aided Manufacturing). Concretamente, se pretende hacer un estudio de las herramientas de anotación asociativas disponibles en las aplicaciones comerciales de modelado CAD con el fin de analizar su uso, viabilidad, eficiencia y efectos en la modificación y reutilización de modelos digitales 3D, así como en la gestión y comunicación del conocimiento técnico vinculado al diseño. La idea principal de esta investigación doctoral es establecer un método para representar y evaluar el conocimiento implícito de los ingenieros de diseño acerca de un modelo digital, así como la integración dinámica de dicho conocimiento en el propio modelo CAD, a través de anotaciones, con el objetivo de poder almacenar y comunicar eficientemente la mayor cantidad de información útil acerca del modelo, y reducir el tiempo y esfuerzo requeridos para su alteración y/o reutilización.Dorribo Camba, J. (2014). ANNOTATION MECHANISMS TO MANAGE DESIGN KNOWLEDGE IN COMPLEX PARAMETRIC MODELS AND THEIR EFFECTS ON ALTERATION AND REUSABILITY [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/45997TESI

Algorithmic Perception of Vertices in Sketched Drawings of Polyhedral Shapes

In this article, visual perception principles were used to build an artificial perception model aimed at developing an algorithm for detecting junctions in line drawings of polyhedral objects that are vectorized from hand-drawn sketches. The detection is performed in two dimensions (2D), before any 3D model is available and minimal information about the shape depicted by the sketch is used. The goal of this approach is to not only detect junctions in careful sketches created by skilled engineers and designers but also detect junctions when skilled people draw casually to quickly convey rough ideas. Current approaches for extracting junctions from digital images are mostly incomplete, as they simply merge endpoints that are near each other, thus ignoring the fact that different vertices may be represented by different (but close) junctions and that the endpoints of lines that depict edges that share a common vertex may not necessarily be close to each other, particularly in quickly sketched drawings. We describe and validate a new algorithm that uses these perceptual findings to merge tips of line segments into 2D junctions that are assumed to depict 3D vertices

Explicit Communication of Geometric Design Intent in CAD: Evaluating Annotated Models in the Context of Reusability

CAD model reusability is largely determined by a proper communication of design intent, which is usually expressed implicitly within the model. Recent studies have suggested the use of 3D annotations as a method to embed design information in the model’s geometry and make part of the design knowledge explicitly available. In this paper, we evaluate the effectiveness of this method and analyze its impact in model alteration tasks. Our goal is to determine whether annotated models provide significant benefits when performing activities that require a direct manipulation of the geometry. We present the results of a study that measured user performance in two scenarios. First, we tested whether annotations are helpful when inadequate modeling assumptions can be made by designers. Second, we evaluated annotations as tools to communicate design decisions to select the most appropriate solution to a challenge when multiple options are available. In both cases, results show statistically significant benefits of annotated models, suggesting the use of this technique as a valuable approach to improve design intent communication

CAD training for digital product quality: a formative approach with computer‑based adaptable resources for self‑assessment

As the engineering and manufacturing sectors transform their processes into those of a digital enterprise, future designers and engineers must be trained to guarantee the quality of the digital models that are created and consumed throughout the product’s lifecycle. Formative training approaches, particularly those based on online rubrics, have been proven highly efective for improving CAD modeling practices and the quality of the corresponding outcomes. However, an efective use of formative rubrics to improve performance must consider two main factors: a proper understanding of the rubric and an accurate selfassessment. In this paper we develop these factors by proposing CAD training based on self-assessment through online formative rubrics enriched with adaptable resources. We analyzed self-assessment data, such as time spent, scoring diferences between trainee and instructor or use of the adaptable resources, of fourteen diferent CAD exams. Results show that resources are more efective when used without any incentives. The comparison of assessments by quality criterion can facilitate the identifcation of issues that may remain unclear to trainees during the learning process. These results can guide the defnition of new strategies for self-training processes and tools, which can contribute to the higher-quality outcomes and CAD practices that are required in model-bases engineering environments

On the application of model-based definition strategies to the delivery of technical training

ASME 2017 12th International Manufacturing Science and Engineering Conference (MSEC2017). June 4-8, 2017, Los Angeles, CA, USAThe application of computer technology to engineering and manufacturing domains has drastically transformed the way products and systems are designed and produced. However, a major drawback of CAD/CAM/CAE systems is the steep learning curve required to understand and master their extensive and increasingly complex set of functionalities. In this paper, we present a new approach to deliver CAD training materials that is inspired by Model-Based Definition (MDB) strategies, where annotated 3D models become the center of the training process. In our system, textual 3D annotations are connected to a Product Lifecycle Management (PLM) system to provide access to interactive video tutorials which are linked to specific features of a CAD model. As a proof of concerto to validate this approach, a plugin for a commercial CAD package was developed that enhances the functionality of standard 3D annotation mechanisms and enables users to interact with the technical training materials directly within the CAD interface. New data structures were implemented to support the connection and integration with PLM systems. A group of tutorials are described to illustrate the system architecture and implementation details

A Functional Classification of Text Annotations for Engineering Design

Describing and supplementing geometric shapes (parts) and layouts (assemblies) with relevant information is key for successful product design communication. 3D annotation tools are widely available in commercial systems, but they are generally used in the same manner as 2D annotations in traditional engineering drawings. The gap between technology and practices is particularly evident in plain text annotations. In this paper, we introduce a functional classification of text annotations to provide an information framework for shifting traditional annotation practices towards the Model-Based Definition (MBD) paradigm. In our view, the current classification of dimensions, tolerances, symbols, notes, and text does not stress the inherent properties of two broader categories: symbols and text. Symbol-based annotations use a symbolic language (mostly standardized) such as Geometric Dimensioning and Tolerancing (GD&T) to provide precise information about the implications of geometric imperfections in manufacturing, whereas notes and text are based on non-standardized and unstructured plain text, and can be used to convey design information. We advocate that text annotations can be characterized in four different functional types (objectives, requirements, rationale, and intent), which should be classified as such when annotations are added to a model. The identification and definition of a formalized structure and syntax can enable the management of the annotations as separate entities, thus leveraging their individual features, or as a group to gain a global and collective view of the design problem. The proposed classification was tested with a group of users in a redesign task that involved a series of geometric changes to an annotated assembly model

A voice-based annotation system for collaborative computer-aided design

In this paper, we describe a voice-based interaction mechanism to annotate 3D models directly from a computer-aided design (CAD) modeling environment. The audio signal is captured and automatically transcribed to a textual 3D note, which is attached to the geometry and made available to other product information and business processes across the enterprise via a product data management system. Our approach provides a more natural and intuitive method to capture design and engineering knowledge that is particularly effective when large amounts of information need to be communicated. We discuss the rationale of the software architecture and the value of this modality for capturing knowledge in a collaborative engineering context. Finally, we examine the results of an experiment to validate our proposal. Our results show that 3D annotations are an effective mechanism to communicate design knowledge, which suggests the need for further developments in the areas of multimodal interaction methods and interfaces for CAD and collaborative tools

CAD 3D con SolidWorks® Tomo II: Diseño avanzado

Departament d'Enginyeria Mecànica i Construcció. Codis assignatura: EM1025, ET1028, DI1028, SIX12

A Learning Tool to Assist in Animation of Bipedal Walk Cycles

This paper studies the activity of bipedal walking with the objective of describing procedural techniques to automate this process. The main problem this paper explores is how to mathematically characterize the relationships and motion of different limbs involved in the process of walking and to represent realistic and natural walk cycles. Other issues discussed are possible variations to create different types of walk cycles. The results have been used to implement and develop a learning tool to assist students in the creation of animated walk cycles. This paper is reporting on the methods used to create a practical computer-assisted tool to show and teach students how walk cycles get affected by different parameters without having to learn every facet of their complicated 3D animation applications. The results can also be applied to many different areas of visualization, such as architectural and virtual reality environments, where human or bipedal models are involved

CAD 3D con SolidWorks® Tomo II: Diseño avanzado

Departament d'Enginyeria Mecànica i Construcció. Codis assignatura: EM1025, ET1028, DI1028, SIX12