One of the main outcomes of the CADANS project is a SolidWorks Add-In for 3D anthropometric design which we refer to as the CADANS Plugin. This CAD Add-In enables the designer/developer to create near-body products like helmets, headsets, glasses, masks and so on with optimized ergonomics and based on actual human models. Many other systems only provide mannequins that are simplified beyond the accuracy needed to make well-fitting products. The CADANS project instead is based on mathematical models derived from 3D scans and holds all the advantages of statistics whilst designing in CAD. The add-in is made for Solidworks and supports versions 2014 to 2017.
This plugin supports the product designer by providing a variety of functions:
- for generating easy to use B-spline based mannequins of any percentile or measurement desired;
- for analyzing variations within the population and visualizing extremes;
- for predicting an individual’s head-shape based on simple 1D measurements;
- for clustering of the population into various sizing systems based in the 3D data;
- for designing mass-customized CAD-designs parametrically attached to the mannequins;
- and possibly many more uses.
Supported Design Types
After discussions with industry, the CADANS consortium has identified four design categories. These categories have also been implemented in the CADANS plugin:
- One size fits all: Create one design, based on the entire specified target population, with maximal coverage in terms of fit. Example: cars, desks, seats, …
- Sizing system: The population is divided into a number of sub-groups, called clusters, based on their similarity in 3D shape and size. A specific design is made for each of the sub-groups, providing the best fit coverage of individuals in that group. (example: clothing, helmets, shoes and other sizing systems)
- Mass customization: Starts with a general design based on a population average. As soon as specific dimensions of a client are known, the average manikin is replaced with a client specifi manikin and the design is updated accordingly to provide optimal fit for the specific client.
- Individualized design: Creating a design for a specific individual from start to end based on a client-specific design manikin derived from the clients dimensions.
The CADANS-plugin provides functionality for generating and updating the necessary design manikins throughout the CAD-design process. In addition, the plugin provides, via the SolidWorks parametric engine, functionality to automatically update the CAD-drawing from one design manikin to another as needed by the design types 'Sizing system' and 'Mass customization'.
The CADANS-plugin consists of a number of architectural components:
- CADANS Database: a repository structure is used for access to the 3D design manikins. In such a repository, there are typically a number of related data sets. In CADANS, each 'data set' consists of a collection of individuals, forming a population, where each individual is described with a set of measurements (lengths, circumferences, meta-data such as gender, birth, age) and a 3D geometric description (multi-patch B-spline surface or polygonal representation). For data set storage the HDF5-format is used and the repositories are stored in XML.
- CADANS Core: On top of the database-layer, we have the statistical processing core which has been implemented in C#.NET. The Core consists out of five modules. The IO-module, on the one hand, communicates with the database layer to load in population data, and on the other hand, also is responsible for storing CADANS related settings along with each SolidWorks project that makes use of CADANS functionality. The Data Structures-module is central to the Core and provides convenient access to all the population data in the form of anthropometric tables and 3D geometric descriptions. The statistics-module is used for summarizing data (means, standard deviations, percentiles), for calculation of 3D statistical shape models (from which the design manikins are extracted), and for regression models. The clustering-module is used for building sizing systems, based on standard k-medoids clustering and a newly introduced constrained k-medoids clustering that is especially suited for sizing systems with convenient size charts. Finally, the design methodology-module combines the capabilities of the other modules and provides this to the interfaces for the four design types.
- CADANS Interface: The interface provides the link between SolidWorks and the capabilities of the CADANS Core. It is implemented in VB.NET. The interface provides a user-friendly graphical user interface, in the form of a wizard, that guides the designer though the different stages of the design process for each of the four design types. The interface also takes care of the construction of the design manikins within SolidWorks and their replacement while keeping the parametric link with the CAD drawing.