Today's product designer is being asked to develop high quality, innovative products at an ever increasing pace. To meet this need, an intensive search is underway for advanced design methodologies that facilitate the acquisition of design knowledge and creative ideas for later reuse. Additionally, designers are embracing a wide range of 3D digital design applications, such as 3D digitization, 3D CAD and CAID, reverse engineering (RE), CAE analysis and rapid prototyping (RP). In this paper, we propose a reverse engineering innovative design methodology called Reverse Innovative Design (RID). The RID methodology facilitates design and knowledge reuse by leveraging 3D digital design applications. The core of our RID methodology is the definition and construction of feature-based parametric solid models from scanned data. The solid model is constructed with feature data to allow for design modification and iteration. Such a construction is well suited for downstream analysis and rapid prototyping. In this paper, we will review the commercial availability and technological developments of some relevant 3D digital design applications. We will then introduce three RE modelling strategies: an autosurfacing strategy for organic shapes; a solid modelling strategy with feature recognition and surface fitting for analytical models; and a curve-based modelling strategy for accurate reverse modelling. Freeform shapes are appearing with more frequency in product development. Since their ''natural'' parameters are hard to define and extract, we propose construction of a feature skeleton based upon industrial or regional standards or by user interaction. Global and local product definition parameters are then linked to the feature skeleton. Design modification is performed by solving a constrained optimization problem. A RID platform has been developed and the main RE strategies and core algorithms have been integrated into SolidWorks as an add-in product called ScanTo3D. We will use this system to demonstrate our RID methodology on a collection of innovative consumer product design examples.

Reverse innovative design - an integrated product design methodology

Feature-based product modeling is the leading approach for the integrated representation of engineering product data. On the one side, this approach has stimulated the development of formal models and vocabularies, data standards and computational ontologies. On the other side, the current ways to model features are considered problematic since it lacks a principled and uniform methodology for feature representation. This paper reviews the state of art of feature-based modeling approaches by concentrating on how features are conceptualized. It points out the drawbacks of current approaches and proposes a high-level ontology-based perspective to harmonize the definition of feature.

What are features? An ontology-based review of the literature

A method for topological entity correspondence in a replicated collaborative CAD system

The current product model consists of features and unstructured contextual connections in order to relate features. The feature modifies the previous state of the product model producing contextual connections with previously defined features. Active knowledge is applied for the adaptive modification of product model features in the case of a changed situation or event. Starting from this state-of-the-art, the authors of this paper introduced a new method to achieve higher-level and more advanced active feature driven product model definition. As part of the related research program, new situation driven model definition processes and model entities are explained in this paper. Higher-level knowledge representation in the product model is motivated by a recent trend in industrial product modeling systems towards more advanced and efficient situation-based self- adaptive model generation. The proposed model represents one of the possible future ways of product model development for product lifecycle management (PLM) systems on the global or product level of decisions. Its implementation will be new application-oriented model entity generation and representation utilizing existing modeling resources in industrial PLM systems by use of application programming interfaces (API).

Active Knowledge for the Situation-driven Control of Product Definition

Computer Aided Design (CAD) is a multi-billion dollar industry used by almost every mechanical engineer in the world to create practically every existing manufactured shape. CAD models are not only widely available but also extremely useful in the growing field of fabrication-oriented design because they are parametric by construction and capture the engineer's design intent, including manufacturability. Harnessing this data, however, is challenging, because generating the geometry for a given parameter value requires time-consuming computations. Furthermore, the resulting meshes have different combinatorics, making the mesh data inherently discontinuous with respect to parameter adjustments. In our work, we address these challenges and develop tools that allow interactive exploration and optimization of parametric CAD data. To achieve interactive rates, we use precomputation on an adaptively sampled grid and propose a novel scheme for interpolating in this domain where each sample is a mesh with different combinatorics. Specifically, we extract partial correspondences from CAD representations for local mesh morphing and propose a novel interpolation method for adaptive grids that is both continuous/smooth and local (i.e., the influence of each sample is constrained to the local regions where mesh morphing can be computed). We show examples of how our method can be used to interactively visualize and optimize objects with a variety of physical properties.

https://dl.acm.org/doi/pdf/10.1145/3072959.3073688

Interactive design space exploration and optimization for CAD models

Feature modelling is nowadays the predominant way of product modelling, in which geometric and functional information is stored in a single product model. The basic concepts of feature modelling in general, and the state of the art in commercial feature modelling systems, will be presented first. This will be followed by an overview of four major developments that solve shortcomings in such systems. First, in semantic feature modelling, it is possible to more adequately specify and maintain the meaning of features. Second, in multiple-view feature modelling, there is a specific feature model for each product development phase. Third, in collaborative feature modelling, teams of users can collaborate on the development of a product with full feature modeling functionality. Fourth, in freeform feature modelling, features with freeform shapes are made available. Some other developments are mentioned as well.

/pdf/developments-in-feature-modelling-4zsvezsdz6.pdf

Developments in Feature Modelling

Current parametric modeling systems suffer from the persistent naming problem, which is responsible for the unpredictable, sometimes stunning, behavior of such systems when re-evaluating a model, even after simple editing operations. This paper claims that the problem is an inherent difficulty of the approaches taken by current parametric modeling systems, in which various persistent naming schemes end up solving only a fraction of the problem. Instead, it is argued that the rationale behind such schemes should itself be revised. Alternative approaches to define a parametric model based on persistent parametric entities can, in fact, eliminate the flaws of using references to non-persistent geometric model entities, which is the real cause of the problem. One such approach is described here, which is able to take full advantage of parametric modeling. It provides persistent entities in the parametric definition domain, which can always be consistently referred to. Basically, it proposes the use of the names of persistent feature faces, instead of the names of boundary faces, every time a reference to a face is required in a parametric definition. Furthermore, it makes use of these feature faces names in order to identify any edge of interest on the boundary representation of the model. These edge names can then be consistently referred to in further parametric definitions. Whenever ambiguities occur, e.g. due to multiple intersections, half-spaces are automatically defined by means of references associated to the features involved, which are kept in the parametric domain. An implementation of this approach is also described, which takes care of maintaining the semantics of the parametric definition of a solid object. A number of examples illustrate how user specification of modeling operations can be transparently performed through interaction with a declarative feature model.

/pdf/a-feature-based-solution-to-the-persistent-naming-problem-2ptm8mjx08.pdf

A Feature-Based Solution to the Persistent Naming Problem

The success of feature modelling systems depends to a large extent on offering user-friendly ways for specifying and varying feature models. In this paper, several new facilities are introduced for this. Numeric and curve parameters are presented for specification and variation of freeform surface feature models. Several properties of the parameters can be defined, such as the direction of evaluation for a curve parameter. In addition to parameters present in features, other parameters can be added to a feature model, including intersection curves between features. To provide these facilities, a new three-level structure is introduced, which includes a partially evaluated model that can capture new generic model entities, including feature intersection curves. The work has been implemented in a prototype surface feature modelling system with functionality for feature class definition, feature model creation, and advanced feature model variation through the new types of parameters.

Numeric and curve parameters for freeform surface feature models

Feature modeling has simplified, improved and accelerated the Computer-Aided Design (CAD) process However, this modeling paradigm still has some serious shortcomings Firstly, its domain is currently restricted to regular and simple freeform shapes Secondly, most current feature modelers do not allow new class definitions, but instead provide design with predefined classes In this paper, we propose a method to solve these shortcomings as follows The shape domain is extended to include more general freeform features To achieve this, a generic freeform feature taxonomy is developed New feature classes can then be defined by deriving from this taxonomy, at any level of abstraction per design intent, through an object-oriented approach In particular specification of class parameters and constraints, in the new classes, is demonstrated

A Generic Taxonomy for Defining Freeform Feature Classes

This paper presents a flexible, generic mechanism to define freeform surface feature classes. The method is applicable to pre-defined and user-defined features. A feature class definition includes, firstly, declaring a feature class, and then specifying the class using attributes specific to the feature. A generic taxonomy of freeform surface features is used to facilitate class declaration. Then, the dynamic mechanism facilitates general specification of attributes. It is demonstrated that such a class definition can be consistently archived, retrieved and re-used in an application-independent manner.

Paulos J. Nyirenda

Papers

Developments in Feature Modelling

A Feature-Based Solution to the Persistent Naming Problem

Numeric and curve parameters for freeform surface feature models

A Generic Taxonomy for Defining Freeform Feature Classes

Definition of freeform surface feature classes