Hidehiko Okabe

Three dimensional apparel CAD system

We aredeveloping a three dimensional ( denoted 3D, hereafter) CAD system for garments to help the process of pattern making. This is a process to create a 3D form of a garment by designing a two dimensional ( 2D, hereafter ) paper pattern that realizes the 3D form The core of the system is a simulator that estimates the 3D form of a garment put on a body from its paper pattern ( 2D~3D process ) and a developing program to obtain the 2D pattern that minimizes the energy required to deform it to the given 3D shape ( 3D ~2D process ). In both processes, the specific snisotropy of the mechanical properties of cloths is ecmsidered. In the 2D +3D process, the contact problem with body and geometrical nonlinearity are also taken into account. The preprocessor for the 2D+3D simulator is quite unique in that it converts an arbitrmy 2D paper pattern into a 3D surface, ecmaidering the topological operatiom ‘sewing’. Both the 2D~ 3D process and the 3D +2D process are formulated as nonlinear energy-minimum problems, and they are solved by our original method in about 10 minutes with our workstations. Once the 3D form is obtain~ the color pattern of a given cloth is mapped and displayed. As a consequence of the mechanical calculation, the distributions of the distortion and stress of the cloth are also visualized. Such information may contribute to the design of garments with consideration of physical attributes as well as visual beauty.

Robot hand with sensor for handling cloth

A robot hand to handle cloth is presented. In the study carried out, the authors tried to pick up a piece of cloth from a stack of cloth, to judge its thickness and to control the tension of it by the robot hand with a strain gauge sensor. The robot hand has two fingers with two degrees of freedom. One fingers tip was made from balsa wood, the other was made from balsa wood and phosphorus bronze plate with strain gauge sensor. The robot hand was attached to a robot arm and picked up a piece of cloth in cooperative motion with the robot arm. The hand was able to pick up a piece of wool cloth 0.4 mm in thickness. And it was able to pick up a piece of rayon cloth 0.2 mm in thickness in some trials by an automatic adjusting software. Sensor output was nearly in proportion to the thickness of cloth picked up. And sensor output was nearly in proportion to the tension of the cloth too.<<ETX>>