We present a design method to create close-fitting customized covers for given three-dimensional (3D) objects such as cameras, toys and figurines. The system first computes clustering of the input vertices, then generates multiple convex hulls using the results. It then outputs a cover geometry to set union operation of these hulls, and the resulting intersection curves are set as seam lines. However, as some of the regions created are not necessarily suitable for flattening, the user can design seam lines by manual drawing and erasing. The system flattens the patches of the target cover geometry after segmentation, allowing the user to obtain a corresponding 2D pattern and sew the shapes in with actual fabric. This paper's contribution lies in its proposal of a clustering method to generate multiple convex hulls, i.e., a set of convex hulls that individually cover part of the input mesh and together cover all of it. The method is based on vertex clustering to allow handling of mesh models with poor vertex connectivity such as those obtained by 3D scanning, and accommodates conventional meshes with multiple connected components and point-based models with no connectivity information. Use of the system to design actual covers confirmed that it functions as intended.
We have defined an XML schema of polishing case data, which are composed of material specifications, processing conditions, polishing material, machine specifications and evaluation results. More than one hundred parameters are dominant. Polishing processes are repeated during the variation of the associated parameters until the specified surface property is obtained. The structure of the case data becomes more complicated than that of arc welding, as polishing phenomena are not made clear physically and chemically. Thus, we proposed an effective method and examined it through case inquiries and evaluated it to be applicable as a manufacturing supporting method.
This paper is intended to report an effectiveness of micro-structuring for anti-slip surface. The experimental set-up developed in the present work enables us to measure friction force between elastic body sample on a substrate surface under dry and wet conditions. The substrates of unsaturated polyester were grooved with pitch ranging from 12 μm to 1500 μm. The maximum value of friction coefficient is obtained on 300 μm pitch of grooves in the tested conditions. The Stribeck curves show that appropriate pitch of grooves allows the specific value of ηV/p minimizing friction coefficient to become larger. This result indicates that the micro-structures limit the decrease in friction coefficient with sliding speed. Some sensory tests show sub-millimeter scale of structure does not change undesirably tactile impression, while it maintains high friction coefficient under wet condition.
In Service Engineering, a basic structure of a service that satisfies customer requirements is designed through phases of “development of functional structures” and “embodiment of functions.” In the phase of embodiment, it is important, for the purpose of enhancing the quality of a design solution, to acquire a lot of knowledge from other service cases. In Service Engineering, service functions are represented by “verb-noun approach” which may leads a different expression of the same functions, and this makes exploring entities that realize a function difficult. In this paper, to describe service functions with a unified representation, the “input-output approach” of functional modeling is introduced in service design, and service design knowledge base is constructed based on the input-output functions. The result of the verification shows that the proposed method is useful to unify service function representation and effective to manage service design knowledge in the embodiment phase.
The role of aesthetic design is increasing in the development of industrial products with growing maturity of product functions. Designers are required to reflect consumer preference in aesthetic design under the consideration of use and function. Effective techniques which enable designers to identify preference and need of customers are indispensable. This study thus aims to construct a design support system which identify them and provide ideas to a designer at an early stage in the design process. In the identification of consumer preference, it is necessary to expose vague consumer preference. The design support system also aims to reduce a burden to consumers for a preference survey and extract consumer preference by using rough sets and the genetic algorithm. The use of rough sets works well for effective analysis from small amount of data, and can extract preference rules of consumers. Furthermore, the constructed system is able to automatically create multiple design solutions by reflecting the consumer preference rules on design solutions created by a designer, and to display the created solutions to the designer.
Sketching activity plays an important role in design concept generation. Many researchers have asserted that design is an iterative process of reflective interaction between thinking design concepts within designers' mind and externalizing them in verbal and drawing expression. Superposition of drawing is a typical operation in concept generation. Designers gradually shape an image by superposing, while concepts are gradually clarified. This paper proposes a knowledge-based sketch tool which manages a draw layer that is a unit of superposition and associates it with expressed design concepts. The sketch tool incorporates a concept network model, which integrates verbal and drawing expression. The tool automatically organizes alternatives of design concepts as well as alternatives of drawing so as to help a designer easily compare with each other and flexibly change an alternative. Those features facilitate designers to reflect the verbal and drawing expression. Its prototype is implemented by a knowledge-based design support framework named DRIFT which we have been developing. An example of coffee maker design is demonstrated in order to show the facility of the proposed tool.
Surface texture is one of the important standards for the industry. National Measurement Institute of Japan (NMIJ) currently provides surface texture calibration services. In this study, the authors developed a new instrument for traceable measurement of surface texture equipped with laser interferometer. The new surface texture measuring instrument directly measures displacement of stylus by using laser interferometer in order to make surface texture measurement traceable to the national standards. Measurement path of laser interferometer is kept in vacuum to eliminate effects of air fluctuation and stabilize measurement conditions. The main frame of the surface texture measuring instrument is made of ceramics and glass ceramics to protect the instrument from thermal effects. A calibration item is measured as a movable stage of this instrument moves along the horizontal plane. To validate calibration capability, the groove depth standard and the roughness standard were measured with both the new surface texture measuring instrument and the NMIJ's conventional calibration system, and the two measurement results were compared with each other. Uncertainties of depth and roughness measurements taken with the new surface texture measuring instrument are found smaller than those of the NMIJ's conventional system, which demonstrates calibration capability of the new surface texture measuring instrument.
This paper proposes a novel method of generating a 3D virtual nail model from multiple camera image data based on the GFFD deformation method. 3D virtual nail models for individuals can be generated easily and rapidly with considerably low cost. The outline of the whole procedures is as follows. First, we take three pictures of an individual's nail. Second, we extract feature points of the nail in each image, which is arranged on the outline and surface of the nail. Third, we obtain the corresponding 3D positions of the feature points using a stereo computing method. Finally, we deform the 3D generic virtual nail model into an individual's one with GFFD based on the obtained 3D positions of the feature points. We made some experiments to evaluate whether the errors of the restored nail shape model is within the acceptable error range. By comparing the restored nail model with the model obtained by scanning the nail with a 3D digitizer, we evaluated the accuracy of the restored model. The result of the experiment shows that we can get individual nail models with sufficient accuracy.