Ergonomic Product Design Research Articles

Postmen activity’s analysis

This study examines the postmen activity and the bag used in their task, which should transport the weight without affecting the locomotor system and the attitude of the worker. Studies were conducted on the activity of the postmen and transportation of loads, analyzing functional and ergonomic aspects of load distribution, as well as surveys with users, which made it possible to verify and prove the problems presented. Thus, the following work was developed in order to demonstrate the importance of applying an ergonomic product design.

Re-Inventing Anthropometry for Design of Ear-Mounted or Ear-Coupled Products

Anthropometry of the external ear provides basic data for ergonomic design of products that must fit the ear. However, many published documents on ear anthropometry present unclear descriptions, il...

손 치수 측정을 위한 3차원 반자동 측정 방법 개발

Measurement protocols for hand anthropometry have been studied for ergonomic product design. The present study developed a 3D semi-automatic measurement protocol (3D-SAMP) which semi-automatically measures various hand dimensions using a 3D scanner. The 3D-SAMP was compared with the conventional direct measurement method (DMM) to examine its effectiveness. The 3D-SAMP consists of (1) fabricating a plaster cast of the hand, (2) placing landmarks on the plaster hand, (3) scanning the plaster hand with a 3D scanner, (4) identifying automatically the positions of the landmarks on the digital hand, and (5) extracting automatically hand anthropometric measurements (lengths, widths, thicknesses, and circumferences). An evaluation experiment conducted in the study found the 3D-SAMP preferred to the DMM in terms of reliability (the number of dimensions exceeding the variability criteria SD=2 mm and CV=5% : 3D-SAMP =2 and DMM=24) and ease of measurement (3D-SAMP=5.2 and DMM=4.3 out of 7). The 3D-SAMP can be applied to ergonomic design of a hand-held product.

자연스러운 동작 분석을 통한 냉장고 Half Guard 조립체의 인간공학적 개선

Ergonomic product design considering users' natural use motion is of importance to improve the usability and satisfaction of a product. A five-step process of product design was developed in the present study by measuring and analyzing users' natural product-use motion with a motion capture system. The developed process was applied to ergonomic design improvement of a half guard installation part of refrigerator; new guard designs (diagonal and arc shape) were developed with the process and evaluated in terms of validity during the development as two measures (task satisfaction and similarity of natural motion). According to the evaluation result, the satisfaction at putting in- and out-task of new guard designs (<TEX>$6.3{\pm}0.5$</TEX> points) was significantly higher than that of existing guard designs (<TEX>$3.3{\pm}1.0$</TEX> points); the difference between natural motion and product-use motion in new guard designs (<TEX>$1.0{\pm}0.3cm$</TEX>) was significantly less than that of existing guard designs (<TEX>$2.0{\pm}0.2cm$</TEX>). The proposed process of natural motion analysis and product design is applicable to ergonomic product design and evaluation.

An Analysis of Natural Motion for Product Design: Refrigerator Half-Guard Installation Part Design

Ergonomic product design which considers users' natural-use motion is of importance to improve the usability and satisfaction of a product. A five-step process of product design was developed in the present study by measuring and analyzing users' natural product-use motion with a motion capture system. The developed process was applied to the ergonomic design improvement of a half-guard installation component of a refrigerator; new guard designs (diagonal and arc shape) were developed with the process and evaluated in terms of validity during the development as two measures (task satisfaction and similarity of natural motion). According to the evaluation result, the satisfaction at putting in- and out-task of new guard designs (diagonal and arc shape; 6.3 + 0.5 points) was significantly higher than that of existing guard designs (3.3 + 1.0 points); the difference between natural motion and product-use motion in new guard designs (1.0 + 0.3 cm) was significantly less than that of existing guard designs (nipper and rectangular shape; 2.0 + 0.2 cm). The proposed process of natural motion analysis and product design is widely applicable to ergonomic product design and evaluation.

Determination of Bicycle Handle Diameters considering Hand Anthropometric Data and User Satisfaction

Ergonomic product design considering both anthropometric variability and user preference is required for harmonizing the target users and products. In this study, bicycle handle diameters for three size categories were determined by considering anthropometric variability and preference. To design the bicycle handles, a four-step process was applied: (1) define anthropometric data, (2) develop size chart, (3) define a design equation, and (4) determine design values. In the first step, the 1988 US Army data was chosen as anthropometric data for the design target population. In the second step, to develop a size chart of bicycle handle, hand length and circumference were selected as key dimensions by principal component analysis on six representative hand dimensions. Next, a size chart of three categories (small: 175.5 mm, medium: 186.7 mm, and large: 196.2 mm) were derived by K-means clustering analysis for hand length and circumference. In the third step, the design equation accounting geometrical relationship between the sizes of two key dimensions and diameters of bicycle handle was adopted from a relevant existing research. In the last step, design values (40.9 mm, 43.5mm, and 45.7 mm) for each size category were calculated by inputting the sizes of the key dimensions to the design equation. To evaluate user satisfaction level of the bicycle handles, a user testing of three handle prototypes was conducted for 17 participants with various hand sizes. The test results showed that satisfaction scores for each hand group were significantly higher at the corresponding size category.

Development of a 3D Semi-Automatic Measurement Protocol for Hand Anthropometric Measurement

Measurement protocols for hand anthropometry have been studied for ergonomic product design. The present study developed a 3D semi-automatic measurement protocol (3D-SAMP) which semi-automatically measures various hand dimensions using a 3D scanner. The 3D-SAMP was compared with the conventional direct measurement protocol (DMP) to examine its effectiveness. The 3D-SAMP consists of (1) fabricating a plaster cast of the hand, (2) placing landmarks on the plaster hand, (3) scanning the plaster hand with a 3D scanner, (4) automatically identifying the positions of the landmarks on the digital hand, and (5) automatically extracting hand anthropometric measurements (lengths, widths, thicknesses, and circumferences). An evaluation experiment was conducted and found the 3D-SAMP preferred to the DMP in terms of reliability, efficiency, and ease of measurement.

Isometric elbow flexion efforts and related effort perception

Objective discomfort criteria have to be implemented into digital human models used for ergonomic design of products. However, only a few attempts have been performed to associate subjective effort...

WORKSPACE OF DIGITAL HUMAN LOWER EXTREMITIES

This paper presents an applicable formula for determining the workspace of digital human lower extremities. The digital human model has over 100 degrees of freedom (DOF): 94 in the upper body, 14 in the lower extremities, 5 in the neck, 4 in the eyes, and 25 for each hand. The Jacobian row rank deficiency criteria are implemented to determine the singular surfaces that finally form the workspace. The use of this digital human model for determining workspace offers several advantages over direct measurement: (1) the workspace can be visualized in real-time based on offline computation, (2) the workspace can be used for the ergonomic design of products in the virtual prototyping stage, and (3) the calculated workspace includes complete information about the envelope and inside characteristics.

Development of a digital human model generation method for ergonomic design in virtual environment

A group of digital human models (DHMs) representing the target population under consideration is used to design products and workplaces in virtual environment. The present study proposes a two-step method which generates a group of DHMs in various sizes to properly accommodate the designated level of the human size variability of the target population. In the first step, a designated number of pairs of stature and weight within a specified accommodation range are generated from the bivariate normal distribution of stature and weight of the target population. In the second step, for each pair of stature and weight, the sizes of the DHM body segments are determined using hierarchical regression models and corresponding prediction distributions of individual values. The proposed generation method was applied to the 1988 US Army anthropometric survey data and then implemented to a web-based system for passenger car interior design. This web-based generation system is capable of generating a group of DHMs as nationality, gender, accommodation percentage, and the number of DHMs required is specified. Relevance to industry A digital human simulation system has been used as an effective tool for ergonomic design and evaluation of products and workplaces in virtual environment. The human model generation method proposed in the present study is of use to efficiently generate a group of human models representing the target population.

Multi-resolution description of three-dimensional anthropometric data for design simplification

Three-dimensional (3D) anthropometry can provide rich information for ergonomic product design with better safety and health considerations. To reduce computational load and model complexity in product design when using 3D anthropometric data, wavelet analysis is adopted in this paper to establish multi-resolution mathematical description of 3D anthropometric data. A proper resolution can be selected for design reference according to the application purpose. To examine the approximation errors under difference resolutions, 510 upper head, whole head, and face samples of Chinese young men have been analyzed. Descriptives of approximation errors under different resolutions are presented. These data can be used as resolution selection guide. The application of the multi-resolution method in product design is illustrated by two examples. Relevance to industry: multi-resolution description of 3D anthropometric data would facilitate the analysis of and design with 3D anthropometric data to improve fitting comfort. The error data under different resolutions provide important reference for resolution selection.

Refraction effect analysis of using a hand-held laser scanner with glass support for 3D anthropometric measurement of the hand: A theoretical study

Three-dimensional (3D) anthropometric measurement provides much more surface information for ergonomic product design and safety considerations than traditional parameter measurement approaches such as using a caliper. However, some challenges remain for 3D measurement, such as measurement uncertainty introduced by shadow areas and involuntary movement of the body. For 3D anthropometric hand measurement with a laser scanner, the problems are more significant. The traveling laser light is prone to be blocked by the fingers due to the structure of the hand. Additionally, the palm and/or fingers are difficult to hold still without a support, even for a few seconds. In a previous study, a method was proposed for using a handheld portable laser scanner with a glass support. However, during scanning, the spatial relationship between the laser scanner and supporting glass could have a large range of variance, which would increase the uncertainty of the glass refraction errors. In this paper, the general principle of laser scanning through glass is discussed in detail through a ray tracing method. It is found that in most cases no virtual images exist. Then a concept of ‘deduced virtual image’ is put forward and four strategies to calculate coordinates of a measured point are discussed. These strategies are compatible with scanning without through glass in calculating coordinates of a measured point.

Analysis of Alignment Influence on 3-D Anthropometric Statistics

Three-dimensional (3-D) surface anthropometry can provide much more useful information for many applications such as ergonomic product design than traditional individual body dimension measurements. However, the traditional definition of the percentile calculation is designed only for 1-D anthropometric data estimates. The same approach cannot be applied directly to 3-D anthropometric statistics otherwise it could lead to misinterpretations. In this paper, the influence of alignment references on 3-D anthropometric statistics is analyzed mathematically, which shows that different alignment reference points (for example, landmarks) for translation alignment could result in different object shapes if 3-D anthropometric data are processed for percentile values based on coordinates and that dimension percentile calculations based on coordinate statistics are incompatible with those traditionally based on individual dimensions.

Development of a hierarchical estimation method for anthropometric variables

Most regression models of anthropometric variables use stature and/or weight as regressors; however, these ‘flat’ regression models can produce large errors in estimation for anthropometric variables having low correlations with the regressors. A novel method was proposed which estimates anthropometric variables in a hierarchical manner based on the geometric and statistical relationships between the variables. This hierarchical estimation method first constructs estimation structures by analyzing the dimensional characteristics and geometric relationships of the anthropometric variables and then develops regression models based on the estimation structures. The hierarchical estimation method was applied to 60 anthropometric variables (selected for the design of an occupant package layout in a passenger car) by using the 1988 US Army anthropometric survey data. The hierarchical regression models showed a 55% increase in adjusted R 2 and a 31% decrease in SE on average when compared with corresponding flat regression models. Relevance to industry Regression models of anthropometric variables are of use in ergonomic design of products and workplaces when necessary body measurements are unavailable. The proposed hierarchical estimation method can be applied effectively to establish regression models of anthropometric variables, which have better statistical performance and geometrical meaning.

Development and Application of a Generation Method of Human Models for Ergonomic Product Design in Virtual Environment

A group of digital human models with various sizes which properly represents a population under consideration is needed in the design process of an ergonomic product in virtual environment. The present study proposes a two-step method which produces a representative group of human models in terms of stature and weight. The proposed method first generates a designated number of pairs of stature and weight within an accommodation range from the bivariate normal distribution of stature and weight of the target population. Then, from each pair of stature and weight, the method determines the sizes of body segments by using ‘hierarchical’ regression models and corresponding prediction distributions of individual values. The suggested method was applied to the 1988 US Army anthropometric survey data and implemented to a web-based system which generates a representative group of human models for the following parameters: nationality, gender, accommodation percentage, and number of human models.

Surveying the dimensions and characteristics of Korean ears for the ergonomic design of ear-related products

Six hundred male and female Korean subjects aged 17–89 were selected for this study. Four different points of the outer ear—the lengths of the pinna, the ear connection point, the earhole and the lobule thickness—were measured and analyzed along with demographic data, including age, stature and weight. The results showed that age, sex and different ethnic populations were determinants of ear dimensions as exemplified by the length of the pinna which increases as age increases ( r=0.689). The primary objective of this study was to provide product designers with the anthropometric dimensions of Korean ears and recommend appropriate solutions for the ergonomic design of ear-related products. Based on the results of this study, it is recommended that the change in body parts due to aging be considered in the application of anthropometric data when designing such products. Relevance to Industry Limited research has been done on the dimensions of ears although an extensive amount of research has been conducted on other parts of the human body. The findings of this study, therefore, can be used as a basis for researching and producing ergonomically designed ear-related products.

Ergonomics in product design: safety factor

The aim of this paper is to give a number of methodological and theoretical indicators concerning the contribution of ergonomists to the execution of design projects of new products. Within the context of a design project, the present work therefore describes the studies and ergonomic analyses that can be undertaken during each phase of the design process from a design model based on concurrent engineering. Encompassing the design of the driving cabin of the new generation of high-speed trains (TGV-NG), this paper, through the ergonomic study of a number of technical sub-systems of this product, illustrates the advisory role of the ergonomist who, within the collective design process, ensures that the specific nature of the “human factor” is fully integrated into the design approach. Thus, throughout the design process, the ergonomist is called upon both to advise the designer on the characteristics of the target users and, on the basis of a “desirable future activities” approach, to help him or her assess the consequences of the design choices made. Ergonomics is described consequently, as an innovation and safety factor.

A Motion Modification Algorithm for Memory-Based Human Motion Simulation

Simulating human motions in the virtual CAD world is important in the computerized ergonomic design of products and workplaces. The present study introduces a novel, memory-based approach for simulating realistic human motions and presents a motion modification algorithm. in this novel approach, realistic human motions are simulated by modifying existing motion samples stored in a motion database. The proposed motion modification algorithm was found to be able to simulate human motions accurately. The memory-based motion simulation approach has advantages over existing simulation models as it can simulate qualitatively different types of motions on a single platform, predict motions of different styles, and continually learn new motions.

Planning and implementing a library ergonomics program: case study at Queens College Library, the City University of New York

The impact of computer technology on libraries is changing the face of information services and how these services are delivered. It is significant that human interaction with computers prevails all service‐oriented institutions, especially libraries where circulation, reference, and technical services are fully automated and depend on computers for information access and retrieval via patron files and online public access catalogs. Libraries spend lots of time on implementing and upgrading electronic services and library functions. However, the human factors are generally overlooked. This article will provide a systematic way to address employee safety and health issues in the library through background readings, library ergonomics in literature, current technologies on ergonomic product design and a case study of ergonomics program implementation at Queens College Library, the City University of New York.

ISO 9000, service quality and ergonomics

This paper addresses some ergonomic issues in the ISO 9000‐based quality assurance. Ergonomics ‐ the study of human factors in engineering and design of systems is briefly touched on. Then, outlines of ISO 9001 and ISO 9004 quality system models are provided, and all 20 requirements requirements of the current ISO 9001:9004 standard are presented in an ergonomic light. Subsequently, human factors in the documentation and implementation of a quality system are illustrated. The relevance of ergonomic studies in the development of service systems is addressed. Finally, a blueprint for an ergonomic assurance system, defined as a set of interrelated resources and processes that function in order to achieve objectives related to ergonomic design and use of products and processes, is provided.