Site: Tokyo Metropolitan Institute of Technology
6-6, Asahigaoka, Hino-shi
Tokyo 191, Japan

Date Visited: 15 December 1995

JTEC/WTEC Attendees: L. Weiss (report author), A. Lightman, R. D. Shelton

Host:

Dr. Shuichi Fukuda

OVERVIEW

Dr. Shuichi Fukuda's research involves the development of methods that help to capture customer requirements throughout the entire product development cycle. He is particularly concerned with 3D shape generation at the earlier stages of design where rough sketches play an important role and where many trials are required. One aspect of his work that is of particular interest to this JTEC/WTEC study is research that combines CAD, 3D modeling, and virtual reality with rapid prototyping in a fashion that allows the user to "intuitively" manipulate 3D models. Dr. Fukuda has two principal goals:

  1. Develop a CAD system that allows a designer (or layman) to create and modify a topologically complex CAD model more intuitively than with conventional methods at the earlier stages of design.

  2. Develop a system that allows a designer (or layman) to easily modify a design by manipulating a physical model that is quickly created with rapid prototyping, and then by feeding this information back to the CAD system using virtual reality (VR) tools.

The CAD system that Dr. Fukuda is developing, called "Section CAD," represents objects as a collection of discrete cross-sectional descriptions. The user creates and manipulates the model using simple 2D operations on selected cross-sections. The system then propagates these changes to the rest of the model by extrusion and interpolation operations (i.e., morphing between two sections). The premise is that designers (and lay people) tend to use 2D sketches when manually creating designs and therefore would find it easier to use 2D CAD tools. This writer tried to create a complex shape with Section CAD and, indeed, found it was very easy to use.

Figure TMIT.1 depicts the system for combining CAD and virtual and physical prototyping.


Fig. TMIT.1. Schematic for combining rapid prototyping and virtual reality.

This is a very novel application that will, in essence, form a closed-loop system around the user and the physical modeler. A designer would first create an initial design with a CAD modeler such as "Section CAD." A physical model would then be built with a rapid prototyping technology such the D-MEC/Sony SCS-1000HD photolithography system (which is available in Dr. Fukuda's lab). After the prototype is built, the designer could grasp the physical object and squeeze and pull on it to distort the shape. The small deflections would be measured (using a data-glove type device) and amplified, and this information would then be used to modify the CAD model. The designer would visualize the model changes in realtime using a virtual reality display, driven from an SGI Onyx dual processor computer with Reality Engine graphics, which would further guide him or her in modifying the design.

This system is only in the early stages of development, and a complete operational system is not yet available. Dr. Fukuda expects that a complete demonstration system will be ready in about two to three years. One of the problems in developing this system is that the current resin which the researchers are using (SCR-500) is not pliable enough for this application, and alternative resins will have to be identified.

Government funding for this research is U.S. $1.5 million. Dr. Fukuda currently has six graduate students working on various aspects of this system.


Published: September 1996; WTEC Hyper-Librarian