Human factors and ergonomics

Multimodal interfaces are proved to increase the input\output bandwidth for a more efficient interaction in 3D activities. This work presents a novel framework designed to simplify the configuration procedures and to provide a high level of flexibility in multimodal interfaces. We propose an innovative system architecture to decouple input and output configuration from the application level and a multimodal engine designed to manage and synchronize the different inputs. The flexibility of the system is ensured by the use of a hierarchical XML-based configuration structure. This framework can be applied to test the advantage of multimodal interfaces in VRAD applications and provides tools to explore the synergy of different input\output techniques. © The Eurographics Association 2007.

Design for Usability (DFU) is a well known concept in computer science, since it refers to an important topic for the Human-Computer-Interaction research community. In the industrial design field this term is not so widely employed although the product usability is considered one of the most important factors for a product to be successful on the market. The importance of usability addresses the relationship between the interface of a product and its users. The success of several products on the market depends on complex interfaces, which require the user's intense interaction. Often such devices, which the designer sees as being extremely efficient, are too complex and incomprehensible to the user. Usability should be one of the peculiar aims of the design, and thus assessed throughout the design itself. It should work on the assumption that final users should be involved during all the phases of the development of a product. The present study proposes a methodology of participatory design based on the user-product interaction in a virtual environment, and developed by involving users in the definition of the interface of an interactive product for household use.

Keywords: Participatory design , Usability , Virtual reality

The whole of trading enterprises with many average/big saling-centres forms what is today commonly known as Large Organized Distribution (LOD). The main risks regarding the people working in the LOD are: MM, repetitive motion of upper limbs, fixed postures, unfavourable microclimatic conditions and, moreover, the probability of labour accidents. In order to analyse the risks due to MM and false postures, we have used the ergonomic software "Classic Jack" distributed by EAI-UGS, which has beeen very helpful to find out the most dangerous labour operations (e.g. charging and discharging of goods, fragmentation and reassembling of manufactures, goods-shelving, branding and labelling). We have, then, suggested a programme of health surveillance that includes a medical examination, eventual x-Ray exams, specialized examination and a posturologic visit. This posturologic visit has got an olistic diagnostics approach, whose research after the causes that could be responsible for the checked diseases concerns not only the damaged area, but also other parts of the body (ocular system, auditive system, podalic system, masticatory apparatus). © PI-ME, Pavia 2005.

Keywords: Health surveillance , Large organized distribution

In this work the Authors propose a methodology based on the use of an ergonomic software in alternative to the traditional methods to evaluate muscular-skeletal diseases caused by incongruous postures or conditions of mechanical overload. This methodology allows to simulate, in a virtual environment, both a workplace and a digital human model whose behaviours are similar, from a kinematical and a dynamical point of view, to that ones of a real person. Through the simulation in a virtual environment of an operation of Manual Material Handling (MMH) in a pharmaceutics industry, the Authors have evaluated, in real time, the strengths and the reaction-moments in the axial, sagittal and lateral plane on the L4 and L5 lumbar vertebras and on the shoulder of the workers. In the work the single movements carried out by the operator are analysed using manikins of different percentiles. The results are compared with the ones coming from the use of the traditional methods to evaluate muscular skeletal disease. © PI-ME, Pavia 2005.

Keywords: Digital human models , Ergonomics , Manual material handling , Virtual simulations

An important but neglected aspect of virtual prototyping is the interaction between human and digital prototype. This is an essential issue when tests about ergonomics or product safety are required. This paper presents an approach to evaluate product ergonomics and safety based on the use of virtual human and simulations where the human model interacts with the virtual prototype. Two case studies that can demonstrate the validity of the approach are described. The first concerns the instruments and external visibility of a car; geometric model of the interior and a commercial virtual human have been used. We defined a test methodology and several simulations have been made, varying anthropometry and workplace adjustments. The results obtained are images that represent what the virtual human sees and permit to evaluate the validity of design solutions. The second case study regards the ergonomics design of a riveting system and consists of the simulation of operator's tasks using a virtual workstation and a virtual human. The results are the joint angles that define the posture of the operator and permit one to analyse task comfort. This work has been carried out to demonstrate that virtual humans are an important tool to improve virtual prototyping functionalities and, above all, to increase ergonomics and safety of products. Moreover, the second case study demonstrates also that this methodology is today necessary not only in big industry, but in small-medium enterprises too. © 2005 Taylor & Francis Group Ltd.

Keywords: Ergonomics , Safety , Simulation , Virtual human , Virtual prototype

This work deals with the definition of a virtual approach to the ergonomic analysis of the installation of a bulky technical product. Both the weight and the size could create difficulties to the users managing it during the transport, unpacking, and installation phases. This study is developed over two steps: the first step regards the execution of laboratory tests to carry out a physical description of the movement required to manage the product. Based on the results of the first step, in the second phase a virtual simulation of the movement required for the product installation is realized. Once terminated both the physical and the virtual tests, the results from the two models are compared to verify the correspondence of the virtual model with the real one through the comparison of a typical ergonomic parameter for lifting task that is the measure of the forces on the L4 and L5 inter-vertebral disk of the subject executing the test. The objectives of the work are the validation of the results of the physical test and the virtual analysis, to demonstrate the feasibility of pre-prototype tests by using a simulacrum (made of polystyrene) of an industrial product instead of a real prototype, and, finally, the use of human manikin software for the study of ergonomics of the mounting and maintenance operations. Copyright © 2005 SAE International.

This paper presents a computer-aided design (CAD)-based system for ergonomics analyses of motorcycles, which includes three-dimensional models of vehicle configurations and equipment, three-dimensional human models of various anthropometries and evaluative techniques to assess reach and postures. The system is based on a modular structure that integrates an established top-down computer-aided design framework for motorcycle design, a widely used anthropometric database and specific behavioural criteria defined by an experimental procedure correlating driving postures and vehicle configurations. As a result, vehicle designers are able to use a single analysis tool to prognosticate and assess postural comfort, from the earliest stages of the design process. In the paper, issues in vehicle design with reference to ergonomics assumptions and posture evaluations by a computerized system are discussed.

In the fields of industrial design and car manufacturing the creation of 3D curves plays a fundamental role within the design process: it allows the improvement of the visual appeal of artifacts, it enhances ergonomics and the product's commercial competitiveness through product differentiation. When flexibility and intuition are to be privileged it is fundamental to achieve natural, intuitive, mathematically correct, creation and modification of surfaces. The scientific aim of this research is the development of an innovative metaphor to modeling of 3D curves which maintains the natural expertise of the designer. The major contribution of this paper is the capability of the system to create and modify the curve naturally, without mathematical artifices, within the limits set by the use of Bezier curves. The proposed metaphor combines the benefits of two acknowledged techniques referred to as the Digital Tape Drawing and the Eraser Pen, which allow the real-time modification of the curve. The integrated adoption of tangible interfaces and innovative mathematical tools, combined with the adoption of semi-immersive environment and lightweight interaction devices, delivers intuitive curve creation for free-form modeling within the virtual scene. The paper describes the details of the algorithm developed and it highlights its strengths during the styling phase. © 2004 ACM.

Keywords: 3D curve generation , Computer aided styling (CAS) , Virtual environments

A Reverse Engineering- (RE) and Rapid Prototyping- (RP) based approach to (he development of a joystick handgrip with ergonomic features has been elaborated. The integration of Time Compression Techniques and Computer Aided Tools lead to a time-saving procedure for the design of a product whose ergonomic quality directly descends from users' sensations of comfort. The CAD model availability throughout the progressive steps of product development ensured all the potentialities of Concurrent Engineering, while Computer Aided Engineering (CAE) simulation on the definitive geometry allowed to close the Computer Integrated loop to the manufacturing process.

Keywords: Computer Aided Engineering , Design for Manufacturing , Ergonomics , Product Development , Reverse Engineering

This research activity was developed in order to build an innovative analytical model of a two wheels vehicle for the simulation of a confort test bench. This model should predict the reaction forces transmitted between the vehicle and the rider in the interface points (grip handles, saddleback, footrest). FEM modelization of a Piaggio's scooter (Hexagon 180cc, 2 strokes) mainframe and its accesories was performed and validated experimentally through a modal eigenvalues and shapes comparison (MAC). Furthrmore a multibody system of the rear suspension was developed, describing the whole vehicle with both flexible and rigid bodies. The dynamic behaviour of this suspension system was validated experimentally (since a test bench was realized) in both the cases of a shaker excitation and of the engine running at different speeds (2500/3500 rpm). The final aim was to obtain a good agreement in the comparison between the experimental results and the virtual simulation of the scooter running on a confort test bench. This useful methodology could be used in order to predict, from the early design stage, the ride comfort of a scooter. Copyright © 2001 ATA, SAE International and SAE of Japan.

This paper outlines new trends in geometric modelling, showing how systems are moving from a geometry-based approach to a physically-based approach. The possibility to simulate the actual behaviour of a product is at the basis of Virtual Prototypes that are becoming a common practice in today's product development process. As a consequence, also interaction modalities and techniques have to be improved in order to satisfy new system requirements and functionalities. The research work described in this paper shows how haptic interaction techniques represent an evolution of current interaction technologies providing intuitive and realistic modalities for interacting with virtual applications. In particular, the paper describes a research work we have carried out integrating haptic technologies together with physically-based modelling and simulation techniques. © 2001 Springer Science+Business Media New York.

Keywords: Haptic interaction , Human-computer interaction , Non-rigid material modelling , Physically-based modelling , Virtual prototyping