A knowledge-driven framework for synthesizing designs from modular components

Creating a design from modular components necessitates three steps: Acquiring knowledge about available components, conceiving an abstract design concept, and implementing that concept in a concrete design. The third step entails many repetitive and menial tasks, such as inserting parts and creating joints between them. Especially when comparing and implementing design alternatives, this issue is compounded. We propose a use-case agnostic knowledge-driven framework to automate the implementation step. In particular, the framework catalogues the acquired knowledge and the design concept, as well as utilizes Combinatory Logic Synthesis to synthesize concrete design alternatives. This minimizes the effort required to create designs, allowing the design space to be thoroughly explored. We implemented the framework as a plugin for the CAD software Autodesk Fusion 360. We conducted a case study in which robotic arms were synthesized from a set of 28 modular components. Based on the case study, the applicability of the framework is analyzed and discussed

Design automation for customised and large-scale additive manufacturing : a case study on custom kayaks

Additive Manufacturing (AM) offers the potential to increase the ability to customise large-scale plastic components. However, a substantial amount of manual work is still required during the customisation process, both in design and manufacturing. This paper looks into how the additive manufacturing of mass customised large-scale products can be supported. Data was collected through interaction with industrial partners and potential customers in a case study regarding the customisation of kayaks. As a result, the paper proposes a model-based methodology which combines design automation with a user interface. The results point to the benefit of the proposed methodology in terms of design efficiency, as well as in terms of displaying results to the end user in an understandable format

Interactive Geometric Configuration Using Sketch-Based CAD Models

Knowledge-based geometry models reduce variant design to the input of parameter values. Especially knowledge-based CAD models that incorporate geometrical data and implemented explicit knowledge offer additional possibilities. One is interactive drag-and-drop control of geometric features. This poses new requirements for the setup of CAD models as each geometric constraint, dimension and 3D feature contributes to the variability of the model. In this paper, the authors give methodological guidance to such modeling tasks by extending the CommonKADS approach with a correlation model for CAD model entities. The guidelines are visualized for the creation of an interactive, configurable steel construction model

Reusability and Flexibility in Parametric Surface-based Models: A Review of Modelling Strategies

CAD systems are indispensable tools in the product design and development process. Through the creation of parametric 3D models,they increase productivity, enable the design of highly complex parts, improve collaboration between different work teams and reduce time to launch. Nevertheless, during the design process there are many different modelling solutions to generate any one part, and the robustness and flexibility of a model depends to a great extent on the experience of the designer. This dependence on individuals rather than methodologies has a negative impact on downstream engineering activities,as many models are not easily editable. Developing a methodology to produce flexibleand reusable 3D models is therefore key to reducing the design time of the product development process. In this paper,we review the state of the art with regardtoflexibility and reusability in parametric surface-based models. We identify gaps in the field and determine the principle aspects in CAD development workflows which influence flexibility and reusability. We aim to expand the field of knowledge and establish a foundation for future research into the development of a surface-based modelling methodology

A quantitative analysis of parametric CAD model complexity and its relationship to perceived modeling complexity

Digital product data quality and reusability has been proven a critical aspect of the Model-Based Enterprise to enable the efficient design and redesign of products. The extent to which a history-based parametric CAD model can be edited or reused depends on the geometric complexity of the part and the procedure employed to build it. As a prerequisite for defining metrics that can quantify the quality of the modeling process, it is necessary to have CAD datasets that are sorted and ranked according to the complexity of the modeling process. In this paper, we examine the concept of perceived CAD modeling complexity, defined as the degree to which a parametric CAD model is perceived as difficult to create, use, and/or modify by expert CAD designers. We present a novel method to integrate pair-wise comparisons of CAD modeling complexity made by experts into a single metric that can be used as ground truth. Next, we discuss a comprehensive study of quantitative metrics which are derived primarily from the geometric characteristics of the models and the graph structure that represents the parent/child relationships between features. Our results show that the perceived CAD modeling complexity metric derived from experts’ assessment correlates particularly strongly with graph-based metrics. The Spearman coefficients for five of these metrics suggest that they can be effectively used to study the parameters that influence the reusability of models and as a basis to implement effective personalized learning strategies in online CAD training scenarios

Geometric Variability in Parametric 3D Models: Implications for Engineering Design

Modern manufacturing companies operate in environments characterized by increasingly shorter development cycles and the need to develop highly customizable products at competitive prices. In this paper, we examine the role of parametric 3D modeling in the product development process, and highlight the importance of robustness, flexibility, and responsiveness to geometric variations, which are particularly relevant in the context of the Model-Based Enterprise (MBE). We discuss the often-inefficient parametric 3D modeling practices used in industry, their root causes and implications, and identify the detrimental effects of low-quality models on engineering design activities, specifically design changes during development, generative design algorithms, design optimization, simulation, product/part family configuration, AI-based parametric modeling, Model-Based System Engineering (MBSE), and parametric and adaptive encryption. Finally, we present future lines of research aimed at increasing the quality of parametric models

Function model-based generation of CAD model variants

A product is an artefact which fulfils a specific function. However, most design automation (DA) approaches wich are used to generate multiple alternative design concepts focus on the generation of CAD models. These neglect to represent the functional aspects of the product, and are furthermore deemed too rigid for the introductino of novel solutions. Pure function modellingappraoches on the other hand provides methods such as design rationale representation, introduction of novel solutions or instantiation of combinatorial alternative concepts, but the resulting models are insufficient for analysis. To alleviate this, a design space exploration (DSE) approach which couples function modelling and CAD is presented. The approachlinks the product’s design rationale modelled in enhanced functionmeans (EF-M) to a DA approach via the here introduced object model for function and geometry (OMFG). The resulting method is able to automatically generate CAD models of alternative concepts based on combinations of alternative design solutions defined in the function model. The approach is presented through a case study of an aircraft engine component. Sixteen different concepts are generated based on four functions with alternative solutions. In an initial computation of the effort to generate all alternative concepts, the DA aspect of the approach’s effort pays off as soon as five functions have two or more alternative solutions. Beyond the benefit of efficient instantiation of CAD models of alternative product concepts, the approach promises to provide the design rationale behind each concept, and thereby a more systematic way of exploring and evaluating alternative design concepts

A new knowledge sourcing framework for knowledge-based engineering: an aerospace industry case study

New trends in Knowledge-Based Engineering (KBE) highlight the need for decoupling the automation aspect from the knowledge management side of KBE. In this direction, some authors argue that KBE is capable of effectively capturing, retaining and reusing engineering knowledge. However, there are some limitations associated with some aspects of KBE that present a barrier to deliver the knowledge sourcing process requested by industry. To overcome some of these limitations this research proposes a new methodology for efficient knowledge capture and effective management of the complete knowledge life cycle. The methodology proposed in this research is validated through the development and implementation of a case study involving the optimisation of wing design concepts at an Aerospace manufacturer. The results obtained proved the extended KBE capability for fast and effective knowledge sourcing. This evidence was provided by the experts working in the development of the case study through the implementation of structured quantitative and qualitative analyses

Assessment of parametric assembly models based on CAD quality dimensions

[EN] An approach to convey CAD quality-oriented strategies to beginning users to create bottom-up assemblies is described. The work builds on previous efforts in the area of single part history-based, feature-based parametric modeling evaluation by defining, testing, and validating a set of quality dimensions that can be applied to MCAD assembly assessment. The process of redefining and adapting dimension descriptors and achievement levels of parts rubrics to make them applicable to assemblies is addressed, then the results of two experimental studies designed to analyze the inter-rater reliability of this approach to assembly evaluation are reported. Results suggest the mechanism is reliable to provide an objective assessment of assembly models. Limitations for the formative selfevaluation of CAD assembly skills are also identified.This work was partially supported by the Spanish grant DPI2017-84526-R (MINECO/AEI/FEDER, UE), project CAL-MBE, Implementation and validation of a theoretical CAD quality model in a Model-Based Enterprise (MBE) context. , and the ANNOTA2 project funded by Universitat Politècnica de València.Otey, J.; Company, P.; Contero, M.; Camba, JD. (2019). Assessment of parametric assembly models based on CAD quality dimensions. Computer-Aided Design and Applications. 16(4):628-653. https://doi.org/10.14733/cadaps.2019.628-653S62865316