Ergonomic Product Research Articles

SELF-COMPACTING CONCRETE USE FOR CONSTRUCTION WORK ENVIRONMENT SUSTAINABILITY

Many of those working on construction sites are exposed to demanding work loads; construction workers lift and carry heavy materials and work in awkward postures. Occupational injuries and accidents due to poor ergonomics are more common in the construction industry and many times lead to human tragedies, disrupt construction processes and adversely affect the cost, productivity, and the reputation of the construction industry. In Sweden, it is reported that concrete workers have the highest relative work-related musculoskeletal injury frequency. Therefore, the use of ergonomic production methods to prevent this can have a significant human, social and financial impact. Research introduced here presents a case study of comparative analyses of ergonomic situations for concrete workers performing concrete casting processes. Three different ergonomic risk assessment methods were used to assess the physical strain, hand-arm vibration and noise affects risks involved in concrete casting work tasks. The combination of technical and managerial factors results in a system where workers are as efficient and safe as possible during their work tasks, and thus, makes the construction work environment sustainable. The aim of our research is to find practical methods to evaluate and compare two different concrete casting methods from an ergonomic perspective. The focus is on the production of cast-in-place concrete bridge constructions where the traditional concrete casting method is compared with the SCC (Self-Compacting concrete) casting method. To be able to identify work-related musculoskeletal injury risks due to concrete casting work tasks, QEC (Quick Exposure Check for musculoskeletal risks), PLIBEL (Checklist for identification for Ergonomics Hazards) and ErgoSAM (Ergonomic production technology method) methods were used. Ergonomic risks analysis methods QEC, PLIBEL and ErgoSAM have all shown capabilities to evaluate construction work activities and thus determine whether a construction work activity constitutes a musculoskeletal risk to the worker or not before any ergonomic intervention is introduced. As a result the present ergonomic risks emanating from work methods used in the traditional concrete placing can be significantly reduced with the use of self-compacting concrete (SCC) that eliminates awkward work postures, noise and hand arm vibration, thereby reducing if not eliminating musculoskeletal injuries among concrete workers during their concrete casting work tasks.

A case study of Bayesian belief networks in industrial work process design based on utility expectation and operational performance

PurposeThe primary purpose of this study is to illustrate a practical approach for industrial work process design that, in an integrative manner, captures essential concerns from different parties associated with manufacturing. It aims explicitly to incorporate utility expectation from the perspectives of operational managers, floor workers, and financial planners into the decision making process.Design/methodology/approachThrough a real industrial scenario, the case study illustrates the use of a Bayesian belief network (BBN)‐based expert system and influence diagram in work process design. What‐if analysis is performed. Statistical tests are then used to benchmark and validate the experimental results and actual data.FindingsThe results suggest that the proposed BBN framework is effective in modeling and solving the work design problem. The findings can draw meaningful insights into the adoption and capacity of BBN in the fields of ergonomics, worker health management, and performance improvement.Practical implicationsPractically, the industrial problem is to compare the new stand‐up sewing cells against the traditional sit‐down sewing layout while taking into consideration of ergonomic effect (repetitive motion injury (RMI) likelihood), floor space (SF), yield (%), and cost ($). The study illustrates the use of an expert system and influence diagram to evaluate different alternatives for ergonomic work design in production process.Social implicationsThe results of this study can potentially improve health safety management and worker ergonomics.Originality/valueThe paper is among the few systematic studies that have applied BBN and influence diagram to production ergonomics and worker health management. A methodological framework utilizing these probabilistic reasoning techniques are developed. This new framework can capture essential concerns from different parties in manufacturing.

A Method to Create Dynamic Motions of Digital Human Models and a Case Study

For ergonomic design and product evaluation, a digital human model simulation (DHMS) system is widely used in many areas. In this study, a systematic method was proposed to create dynamic motions of digital human model (DHM) in the RAMSIS software, one of the DHMS systems and a case study was implemented to create ingress and egress motions in a car mockup; a motion capture system collected the trajectory data of markers attached to the participants’ body parts. In the RAMSIS software, a digital human model, “Manikin,” was created with their anthropometric data. Also, the dynamic motions of Manikin were created by the Actor and the Character, DHMs from another DHMS system (MotionBuilder) by using the trajectory data of its joint points. In a case study, participants performed experiments to enter and exit the car mockup with 37 markers attached to their bodies for the motion capture system. Through the proposed systematic method, ingress and egress motions of its Manikin were successfully created.

Standardisation of digital human models

Digital human models (DHM) have evolved as useful tools for ergonomic workplace design and product development, and found in various industries and education. DHM systems which dominate the market were developed for specific purposes and differ significantly, which is not only reflected in non-compatible results of DHM simulations, but also provoking misunderstanding of how DHM simulations relate to real world problems. While DHM developers are restricted by uncertainty about the user need and lack of model data related standards, users are confined to one specific product and cannot exchange results, or upgrade to another DHM system, as their previous results would be rendered worthless. Furthermore, origin and validity of anthropometric and biomechanical data is not transparent to the user. The lack of standardisation in DHM systems has become a major roadblock in further system development, affecting all stakeholders in the DHM industry. Evidently, a framework for standardising digital human models is necessary to overcome current obstructions. Practitioner Summary: This short communication addresses a standardisation issue for digital human models, which has been addressed at the International Ergonomics Association Technical Committee for Human Simulation and Virtual Environments. It is the outcome of a workshop at the DHM 2011 symposium in Lyon, which concluded steps towards DHM standardisation that need to be taken.

A New Method for Selecting the Best Design

In this article the authors illustrate how individual expert ratings can be employed to prioritize specifications for use in forced rankings. Those rankings are then used to select a design with the best overall usability. The authors provide an example of this approach in the selection of a medical transport vehicle seat to produce a more ergonomic product that could improve patient outcomes and driver safety.

Ergonomic assessment of automotive assembly tasks with digital human modelling and the 'ergonomics assessment worksheet' (EAWS)

The increasing global competition and changing demographic profiles amplify the importance of efficient design of work stations and processes that considers the physical job demands and the operators’ abilities. Good ergonomic design is not restricted to the current production, but should be considered during all phases of the product life cycle. Digital human model (DHM) simulations provide good opportunities for an integrated ergonomic design, particularly during pre-production planning. This article gives an overview on DHM used in production ergonomics and highlights two new approaches to enhance current DHM applications. The editor for manual work activities (EMA) helps to speed up and optimise human movement simulation. MTMergonomics is an ergonomic risk assessment tool for industrial engineers (and ergonomists) during the planning phase of the product development process, based on MTM process languages like MTM-UAS. The ergonomic assessment worksheet (EAWS) is a tool for the holistic evaluation of physical workloads. It is implemented in digital human models like Jack and serves as an ergonomic evaluation tool within EMA and MTMergonomics. EAWS serves as a common feature to link DHM, EMA and MTMergonomics activities.

Functional design method for improving safety and ergonomics of mechanical products

In order to help companies to improve their competetiveness, it is important to develop new design methodologies. In this framework, a Functional And Robust Design (FARD) methodology dedicated to routine design of “highly productive” modular product ranges is proposed including principles of functional analysis, Design For Assembly (DFA), and techniques of modelling and simulation for ergonomics consideration. This paper focuses on the application of this original method applied to mechanical vibration and ergonomics problems of a scraper. Including biomechanical aspect in the design methodology, it is possible to identify the impact of a vibration tool on its users using numerical models of the tool coupled to a finite element model of the human hand. This method can proactively warn very early, in the design process, the risks of causing musculoskeletal disorders and facilitate an optimization of the mechanical tool. This study is a first step in a context of human-centered design.

Ergonomic factors and production target evaluation in eucalyptus timber harvesting operations in mountainous terrains.

There are several forest operations involved in Eucalyptus timber harvesting. This study was carried out during brush-cutting; tree felling, bucking, delimbing, piling and manual extraction operations, with the following objectives: a) analyzing, ergonomically, two systems of brush-cutting: one manual and the other semi-mechanized, using two different machines; b) ergonomically evaluating three different brands of pruner machines used in delimbing felled trees. c) determining the feasible target of productivity as a function of ergonomic factors relevant to establish the time of resting pauses for workers in manual and semi-mechanized timber harvesting systems in mountainous terrain. Brush-cutting, either manual or semimechanized, is an activity carried out prior to timber harvesting. It is usually a hard work, with low productivity when compared with mechanized systems. Pruner machines have been used by forest companies, due to the great possibilities to improve productivity, quality and the health of workers. Ergonomics is a discipline that promotes the adequacy of work to the physical and mental characteristics of human beings, seeking to design production systems and products considering relevant aspects, including social, organizational and environmental factors. Companies should consider the ergonomic factor in the determination of daily worker production targets.

Analysis of ergonomic furniture made of wood and sub-products from renewable forests.

The furniture ergonomic evaluation was carried out through the use of questionnaires and forms in industries. For the ergonomic product analysis, it was used the methodology "Object Ergonomics - Ergonomic System Technical Reading" (design goals and management actions), and measurements of products. The values achieved were compared with the standard dimensions, and the compliance or non-compliance of the furniture to it was assessed. In relation to the dimensions of the bed, the following variables did not comply with the norms: external and internal length, external and internal width, height and width of the sidebar and distance to the floor. The dimensions of these variables were above the recommended values. The double bed was inadequate for management actions and maintenance. Since the kitchen cabinet is a product that went through physical testing and follows national standards; the finish used is powder coating. The kitchen cabinet proved to be appropriate in all design requirements and for management actions. Both furniture pieces were inadequate, considering the difficulty for maintenance when a product or part of it was damaged. It was recommended the creation of regulatory standards for the production of safe and comfortable furniture.

The question of the ergonomic use of virtual models

The comfort and functionality between man and his surroundings are the main goals of ergonomics, making it are increasingly in the production process. Many companies have tried Virtual Reality Center (VRC) to assist the analysis and development of ergonomic products. The use of virtual models brings many benefits to the design of products, including greater flexibility, speed and quality, and facilitates the control and reporting, also integrating all stages of the project. There are still some difficulties for the deployment of these resources, like the need for more powerful computers and specialized professionals. Possibly, the VR will be indispensable to the construction in some years, becoming a tool of fundamental importance to the professionals.

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.

Human Factors and Ergonomics [review of "Human Factors and Ergonomics in Consumer Product Design: Methods and Techniques" (Karwpwski, W., Eds. et al; 2011)

This first volume (of a two-volume series) outlines how to incorporate HFs/E principles and knowledge into the design of consumer products in a variety of applications. It discusses the user-centered design process, starting with how mental workload affects everyday interactions with consumer products and what lessons may be applied to product design. The book then highlights the ever increasing role of information technology, including digital imaging, video and other media, and virtual reality (VR) applications, in consumer product design. It also explores user-centered aspect of consumer product development with discussions on user-centered versus task-based approach, articulation and assessment of user requirements and needs, interaction with design models, and eco design. With contributions from a team of researchers from 21 countries, the book covers the current state-of-the-art methods and techniques of product ergonomics. It provides an increased knowledge of how to apply the HF/E principles that ultimately lead to better product design.

Ergonomics product development of a mobile workstation for health care

The use of information and communication technologies is increasing in health care, and patient information is being transferred into electronic format. The aim of this study was to test the ergono...

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.

일상생활활동에 대한 생활시간 분석 : 서울에 거주하는 한국 성인을 대상으로

This study describes behavioral characteristics of Korean population over twenty years old in a variety of activities of daily living by analyzing the raw data of the time use survey provided by Statistics Korea (KOSTAT). Seven activities and forty four sub-activities of daily living were selected for analysis : personal care, employment, household care, family care, voluntary work and community participation, social life, recreation and leisure, and travel. In order to quantitatively understand how Korean adults spend their time for a day and how their lifestyle changes over time, we collected the time recorded by 3,673 respondents in three surveys over the past ten years (in 1999, 2004, and 2009). Then, we performed analysis of variance to compare the behavioral characteristics by user age and gender based on the mean time of each activity. The differences in behavior among user groups and over time could be used to design ergonomic products and services based on user experience, especially for universal design of housing and transportation facilities.

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.

Product Ergonomics Design Driven by Parametric Human Body Model

Considering the demands for product ergonomics design, the paper proposed a driven design method for product’s shape and structure design through the manipulation of human body models. Based on the anthropometry data, a parametric human body driving model system is established with three layers, which are structure model, dimension model and surface model. The driven design method of product ergonomics design is realized, in which human body data are directly mapped to product design parameters. The driven design method provides a rational way to utilize ergonomics design principles and guarantee higher efficiency and more reliability. The method is tested in seat design examples.

Ergonomic Products

Ergonomic Products

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.