On simulating human reach motions for ergonomics analyses

Abstract

Many existing job analysis tools for ergonomics have concentrated on the potential adverse effects of force, posture, and repetition, as these appear to be traditionally recognized risk factors in the workplace. Recent investigations have indicated that this pragmatic approach may be overly simplistic, and thus miss prediction of risk factors associated with certain motions.This article reviews some of the research under way in the University of Michigan's Human Motion Simulation Laboratory to develop a set of human motion prediction models. To produce these models, over 37,000 motions of 100 men and women from 18 to 78 years in age have been measured with a motion capture system. The motions are typical of people reaching and moving light to moderate load objects while either seated or standing. A 17-link kinematics model has been developed to resolve the dynamics of the motions.Thus far, initial motion algorithms have been developed that capture well over 95% of the between participant repeatability. Advantages and limitations of the methods and data being used are discussed and illustrated.

Research on Outfitting Virtual Assembly based on Ergonomics

“…Chaffin expounded that the digital human model has been increasingly used in industrial design system and ergonomic methods can evaluate the reachability of assembly design to reduce production cost and improve the comfort level of operation [1,2]. T. DUKIC et al proposed to add human model to the virtual assembly process, considering that the multifaceted ergonomic factors and methods can improve the authenticity of virtual simulation [3].Dan Lämkull et al added virtual human into virtual assembly simulation, and by comparing with the actual operation result, concluded that digital human model can improve the operational posture and tooling design of the work, and can get better assembly sequence by forming a benign feedback process [4].Shiguang Qiu et aldecomposed the virtual human movement into three kinds of movement, the original motion, fine motor and transient motion, realize the rapid generation of virtual people virtual human posture movement through hybrid control method of virtual human applied in the DMSP interactive assembly maintenance simulation system, which shows that the method can improve the generation efficiency of the virtual human movement [5].…”

Ergonomics Contribution in Maintainability

“…Where D is mass per unit volume (g/cm 3 ), m is the mass of body segment (g or kg), V is the volume of water displaced (g/cm 3 ), W is the weight of the body segment (N) and g is gravitational acceleration constant (m/sec 2 ). 2 ) x x Segment Density (g/cm 3 ).…”

“…Digital Human Modelling (DHM) techniques have been introduced to test, validate and improve the working instructions, improve both the design of workers' task and of the product, taking human as the center of the work design system [3,4,5,6,7]. A human centric approach allows validating the workspace design, assessing the accessibility of an assembly design, reducing the production cost, and the risk of MSDs as well.…”

Interactive virtual evaluation for interface design

“…Chaffin (2002) demonstrated the successful use of digital human models to analyze and improve workplace design. If digital prototyping technologies and the methodology of ergonomics evaluation can be combined, it will be able to implement human-system interaction virtually at the early stage of the design and fulfill the concept of human-centered design.…”