Proceedings of DETC’2001 2001 ASME Design Engineering Technical Conferences September 09-12, 2001, Pittsburgh, Pennsylvania, USA DETC2001/CIE-21298 APPLICATION OF VAGUE GEOMETRIC REPRESENTATION FOR SHAPE INSTANCE GENERATION OF THE HUMAN BODY Niels C.C.M. Moes ∗ Delft University of Technology Department of OCP Delft, the Netherlands Email: C.C.M.Moes@IO.TUDelft.nl Zolt ´ an Rus ´ ak Imre Horv ´ ath Delft University of Technology Department of OCP Delft, the Netherlands ABSTRACT The objective of this research is the development of a generic model for the shape of a part of the human body. A generated instance is intended to be used in the construction of a Finite Elements model. The selected product type is a sitting support. With the help of a multiple regression model the shape of the upper leg and the buttock area are statistically described. The predictive variables for this shape generation are spe- cific human body characteristics, which are uncertain and usu- ally incomplete. The actual model is a vague domain defined by a set of intersection points on the distribution vectors. The measurements of the shape and specific characteristic landmarks were done with the Microscribe scanning device and the mirror box. The results include (i) a statistical analysis of the measured subject properties, (ii) the generation of the inner closure, the outer closure, and the corresponding distribution vectors, (iii) the location indices on the distribution vectors, (iv) the statisti- cal model to generate instances. 1 Introduction This paper presents a method to generate geometric in- stances from vaguely defined anthropomorphic data. First the shape of a part of the human body will be described in vague terms based on uncertain and incomplete measurements data. Then a method is presented to derive specific geometric shape ∗ Address all correspondence to this author. instances from this vague domain. These instances form a crisp shape or a vaguely defined shape. The selection criterion was derived from a set of body characteristics. The context of this research project is the development of a Computer Aided Conceptual Design engineering ontol- ogy for the shape of consumer products (Horv´ ath, 1998) (Inte- grated Concept Advancement, ICA). The educational and sci- entific boundary conditions include various aspects such as aes- thetics, manufacturability, ergonomics, and initial shape con- figuration by speech or hand movements. This report focuses on the ergonomics aspects (ICA-E), that are considered in the development of the product shape for ergonomics optimization (CAECD) (Moes, 1999). The developed optimization procedure intensively uses Finite Elements Analysis to iteratively correct the product shape for specific features of the pressure distribu- tion and the intermediate shapes. The construction of a Finite El- ements model, that will be used for the Finite Elements Analysis in the shape modification procedures, needs a geometric model of the shape of the involved body parts, in casu the areas of the upper leg and the buttocks. In the current stage of the research the attention is mainly fo- cused on the development of the procedure as such. This means that less attention is pain to aspects like modelling errors, accu- racy and geometric modelling requirements. In the discussion section actual subjects for improvement of the procedure and the accuracy will be mentioned. For the purpose testing and practical implementation of the developed theory, methods and results the person-product inter- 1 Copyright  2001 by ASME