Optimization-Based Grasp Posture Generation Method of Digital Hand for Virtual Ergonomics Assessment

Abstract

Automatically generating humanlike grasp postures of the digital hand is a key issue for the virtual ergonomic assessment of the industrial products. In this paper we propose a new optimization-based approach for generating the realistic grasp posture. As an objective function, we use the number of the contact points, the fit of the specific part of the hand surface for the feature edges of the product surface and the margin for the constraints on the joint angle limits of the figures. The experimental studies on the grasp posture generation for the digital camera indicate that more realistic grasp posture could be generated using the proposed optimization-based method than the one using our former method.

Simulating Complex Automotive Assembly Tasks using the HUMOSIM Framework

“…A number of published papers have addressed developing a realistic 3D kinematic or biomechanical human hand model for predicting grasping hand postures (Buchholz and Armstrong, 1992;Miyata et al, 2005;Pitarch et al, 2005;Choi and Armstrong, 2006;Yang et al, 2006;Endo et al, 2007;Endo et al, 2008). Various aspects of the properties of human hands are considered in these studies, such as hand anthropometry, skin stretch and bulge, finger joint movement patterns, and physiological joint constraints.…”

Theoretical Biomechanics

“…In contrast, much research has been carried out on animation techniques over the past years, mainly for use in developing computer games. Lately, these advances have been cleverly used by some ergonomics researchers to develop improved graphical and kinematics hand models for evaluating the use of products (Endo et al, 2007(Endo et al, , 2009Goussous, 2007;Kawaguchi, 2009), with good results. On the other hand, robot hand grasps have been extensively studied for years.…”

The Ease of Grasping to Evaluate Aesthetically Pleasing PET Bottle Design

“…F gravity = -F grasping and lifting (10) where F gravity is the gravity force, and F grasping and lifting is the total force required for grasping and lifting the bottle. The total force for grasping and lifting equals the sum of the individual forces generated by the thumb and fingers.…”

“…These data are obtained by employing actual models and ergonomic measurement systems. Endo et al (8)- (10) proposed a new method that employed a digital hand to assess the ergonomics of a 3D digital model. Although the optimal grasping posture was difficult to determine, the ergonomic assessment was performed by determining hand coverage and posture on product casing through the use of digital data.…”