Human factors and ergonomics

Current practices about selection, assessment and management of QUAs (Quiet Urban Areas) in EU Countries, though regulated by the EU Directive 49/2002/EC on Environmental Noise (commonly abbreviated END), appear to be extremely fragmented and inhomogeneous. In fact, each country during past years adopted a set of strategies strictly related to their specific contexts. Proposing a solution to overcome the lack of harmonized methodologies for QUAs is the main aim of QUADMAP (QUiet Areas Definition and Management in Action Plans) project. The results of the project will facilitate urban planners to apply standard procedures for identification, delimitation and prioritization of QUAs. The project has a high level of demonstrativeness guaranteed by the fact that the proposed methodology will be tested on a number of case study areas. In particular, it will be tested on a set of pilot cases in Italy, Spain, and The Netherlands. The project started on 2011, September the 1st and lasts three years. At the beginning of 2013 the first version of the harmonized methodology has been defined. The project partners have being testing the procedures making up such a methodology since February 2013 in all pilot cases. The proposed methodology and an overview of the available results in pilot areas selected in the city of Firenze are presented in this paper.

Keywords: Environmental noise directive , Noise , Quiet areas , Soundscape

Mixed prototyping (MP) is an emerging approach for usability testing, thanks to its multimodal environment, which is able to involve sight, hearing and touch thus improving the ability to analyze the inter-relationships between the physical form and the behavior of the industrial products. This paper presents a method to perform usability tests in a mixed reality (MR) environment for analyzing human performance in target acquisition tasks while interacting with household appliances. The proposed method is based on the use of different kinds of digital and physical prototypes and, moreover, it introduces an experimental physical archetype for mixed prototyping that contributes to increase the efficiency of the usability evaluation process. Through this archetype the design of a user interface can be easily changed by the adoption of plug-and-play moving components (knobs and buttons) that allow to model in a few seconds any kind of control panel for washing machines, thus reducing the prototyping costs and enlarging the variety of MR interfaces that can be evaluated. The paper proposes also a validation of the use of the physical archetype through a case study in which three different control panel alternatives have been evaluated in a competitive usability study. The competitive testing allows to gather user behaviors with a broad range of design options before the development of a new control panel refined through iterative design. Experimental results show that the proposed method based on the physical archetype can be an effective support to improve the usability of the product interface. © 2012 Elsevier B.V.

Keywords: Design review , Interaction design , Mixed prototyping , Usability test

Traffic calming devices on urban streets, such as elevated pedestrian crossings, speed bumps and roundabouts, are increasingly used, therefore bus passengers on-board comfort assessment is an actual problem. In order to measure vibrational on-board comfort for public transport standing passengers related to traffic calming, an acquisition system called ASGCM (Autonomous System for Geo-referenced Comfort Measurements) has been developed, taking as a reference the European regulations on rail transports. Thanks to ASGCM, each measurement of vibration, on-ground velocity and acceleration is linked with geographical information resulting from a GPS, so a map of a comfort index, as well as statistical surveys and correlation between on-board comfort and traffic calming, can be directly obtained using a Geographic Information System (GIS), querying a centralized remote database developed ad-hoc. A large number of experimental tests has been performed in order to define a vibrational comfort index and to collect a large statistics that allows a significant comparison between different infrastructures and their characterization. The proposed technique can also be useful for diagnostics purposes, such as vehicles comparison and vehicle and road maintenance state monitoring.

Traffic calming devices on urban streets, such as elevated pedestrian crossings, speed bumps and roundabouts, are increasingly used, therefore bus passengers on-board comfort assessment is an actual problem. In order to measure vibrational on-board comfort for public transport standing passengers related to traffic calming, an acquisition system called ASGCM (Autonomous System for Geo-referenced Comfort Measurements) has been developed, taking as a reference the European regulations on rail transports. Thanks to ASGCM, each measurement of vibration, on-ground velocity and acceleration is linked with geographical information resulting from a GPS, so a map of a comfort index, as well as statistical surveys and correlation between on-board comfort and traffic calming, can be directly obtained using a Geographic Information System (GIS), querying a centralized remote database developed ad-hoc. A large number of experimental tests has been performed in order to define a vibrational comfort index and to collect a large statistics that allows a significant comparison between different infrastructures and their characterization. The proposed technique can also be useful for diagnostics purposes, such as vehicles comparison and vehicle and road maintenance state monitoring.

The paper describes a methodological approach specifically developed to capture and transform the qualitative User Experience (UX) of a consumer product into quantitative technical specifications. Merging the potentialities of Virtual Prototypes (VPs) and Digital Mock-Ups (DMU), a flexible design scenario is built to interpret users' desires. Visual, sound and haptic stimuli are reproduced in order to let users live a realistic multisensory experience interacting with the virtual replica of the product. Parametric models are defined to acquire users' preferences while optimization algorithms are used to transform them into technical specifications. The aim of the approach is to propose a robust technique to objectify users' desires and enable their direct and active participation within the product development process. The methodology is derived merging insights coming from four case studies as well as indications available in literature. Specifically the paper describes how to design the multisensory UX with household appliance doors and drawers with a specific focus on the haptic/force feedback objectification. © 2013 The Design Society.

Keywords: Experience design , Haptic feedback , Human in the loop , User centred design , Virtual reality

In recent years, the production of consumer goods has exceeded that of industrial products. This has led to changes in the areas of design and production. The target users of industrial products (in the Business to Business-B2B market) are industries that decide to purchase a product on the basis of its technical features, functions and performance. Differently, the target users of consumer products (in the Business to Consumer-B2C market) are the consumers who choose a product driven by other aspects, besides features and functions, such as the perceived value, the expected benefits, the emotions elicited, as well as features and functions. This has brought a paradigm shift in the design process. And in fact, the design of consumer products is increasingly focusing on the so-called user experience. The designer must not design only the product, but also the user experience in relation to its use. The resulting product should have a high perceived value and generate positive emotions in the consumer. These factors make a successful product on the market. Therefore, the role of the designer is designing the products and the perceptual aspects of their use, that is, designing the user experience and deriving from that the products' specifications. Consequently to that, the design process has changed in the last years. In fact, the user is now at the center of the design process, named user-centered design. Being the new focus the target users, the evaluation of their interaction with the new designed products is expected to be rigorous and systematic. An efficient approach has proved to be one in which the validation is made up by involving users in the early stages of the product design. Since typically at the level of the concept the product, or a prototype that is comparable with it at the perceptual level, is not available, it is not possible to make a thorough validation of its use with users. However, new methodologies of Virtual Prototyping allow us to simulate multisensory user interaction with product concepts early in the design process. This chapter introduces the use of interactive Virtual Prototyping (iVP) methodology for the design of the user experience with the concept of a new product. Interactive components of new products and their behavior are simulated through functional models, and users can experience them through multisensory Virtual Reality (VR) technologies.

This chapter presents a methodology that the authors developed for the evaluation of a novel device based on haptic guidance to support people with disabilities in sketching, hatching, and cutting shapes. The user's hand movement is assisted by a sort of magnet or spring effect attracting the hand towards an ideal shape. The haptic guidance device has been used as an input system for tracking the sketching movements made by the user according to the visual feedback received from a physical template without haptic assistance. Then the device has been used as an output system that provides force feedback capabilities. The drawn shape can also be physically produced as a piece of polystyrene foam. The evaluation methodology is based on a sequence of tests, aimed at assessing the usability of the device and at meeting the real needs of the unskilled people. In fact, the system has been evaluated by a group of healthy and unskilled people, by comparing the analysis of the tracking results. The authors have used the results of the tests to define guidelines about the device and its applications, switching from the concept of "test the device on unskilled people" to the concept of "testing the device with unskilled people."

Haptic perception constitutes an important component of our everyday interaction with many products. At the same time, several studies have, in recent years, demonstrated the importance of involving the emotions in the user-product interaction process. The present study was designed to investigate whether haptic interactions can affect, or modulate, people's responses to standardized emotional stimuli. 36 participants completed a self-assessment test concerning their emotional state utilizing as a pointer either a PHANToM device simulating a viscous force field while they moved the stylus, or else a stylus with no force field. During the presentation of the emotional pictures, various physiological parameters were recorded from participants. The results revealed a significant difference in the self-reported arousal associated with the pictures but no significant difference in the physiological measures. The behavioural findings are interpreted in terms of an effect of the haptic feedback on participants' perceived/interpreted emotional arousal. These results suggest that haptic feedback could, in the future, be used to modify participants' interpretation of their physiological states. © 2013 IEEE.

Keywords: Affective Haptics , Emotions , Haptic Interactions & Design , Physiology

Several activities of the product development process as for example ergonomic analyses, usability testing, and what is defined as User Experience - UX- design in general require humans to be involved as testers. In order to achieve a good effectiveness degree, these tests must be performed on prototypes as much as possible similar to the final product, and this is costly and sometimes difficult to obtain during the development process. This is especially true at the earliest stages of the process. Functional mock-up - FMU - methods and tools can be of great help, because they allow technological aspects of the products, as electronics, hydraulics, mechanics, etc. to be represented and managed in a simple and effective way. Mathematical equations allow product behavior to be determined, due to input values representing the application environment of the product. At the moment, an FMU model is great in simulating product behavior from the technological point of view, but concerns about user interaction issues are left apart. The research described in this paper aims at widening the coverage of FMU to user-product interaction issues. The goal aims at evaluating the possibility of substituting real users with a characterization of them, and to model and simulate interaction in a homogeneous way together with all the other product aspects. All of this makes the research activities very challenging, and the result is a sort of FMU-assisted interaction modeling. As an evolution of what is generally recognized as hardware and software-in-the-loop, this methodology will be referred as human-in-the-loop. © 2013 Springer-Verlag Berlin Heidelberg.

Keywords: Functional Mock-Up , Interaction , User Experience

The paper describes an application based on low cost Virtual Reality technologies whose aim is to help designers in testing some functional aspects of their product concepts without the need of building physical mockups. In particular the application allows the designers to test aspects related to the usage of products. A case study that enables designer to verify the ergonomics aspects of the interactive Virtual Prototype (iVP) of a commercial refrigerator has been implemented. The iVP is based on a three-dimensional scale representation of the product and the use of a low cost user interface as input/output device. The paper describes the implementation of the iVP and the results of some preliminary user study that has been performed in order to validate the visuo/haptic interaction approach. © Springer-Verlag London 2013.

Several studies in the field of Emotional Engineering have focused on studying new methods to design products that elicit positive emotions in the future consumers, focusing on the study of the visual perception of the products. A typical application of Emotional Engineering (E-E) is in the product design domain, where the design of new products tends to be validated even with respect to emotional responses, well before releasing the final product design. This paper proposes a new method and process for product design that is driven by the validation of emotional aspects, elicited by multi-sensory experience with products, more in line with the E-E perspective. Copyright © 2013 by ASME.

Main purpose of this work is to show how easy and economics an ergonomic/comfort based approach, in re-design a manual assembly workplace, can be; authors, using a new comfort/ergonomic evaluation criterion, analyzed a workstation and identified the critical issues under ergonomic/comfort point of view and finally gave several guidelines to re-design the workplace, implementing minor modification, and improve work-safety, work-quality and productivity. The postural analysis was performed by non-invasive and especially inexpensive methods, based on cameras and video-recorder use and by photogrammetric analysis; DELMIA® DHM software has been used to perform all simulations; comfort analysis was performed by the software developed by researchers of Departments of Industrial Engineering of Salerno: CaMAN®. The test case is an automatic assembly machine that has been modeled and used for virtual postural analysis. Main results of this work can be found in a very good numerical/experimental correlation between acquired/simulated postures and real ones, and on the powerful use of an objective comfort evaluation method, based on biomechanics and posture analysis, for giving to designers the guidelines to re-design a workplace and a work-cycle. This kind of approach seemed to be very powerful in re-designing the work-place and in re-scheduling the work time-sheet because it allowed to improve an ergonomic corrective action with minor costs for company. Obtained results demonstrated the validity of re-design hypotheses through the increase of all comfort indexes and the improvement of workstation/operator productivity. © (2014) Trans Tech Publications, Switzerland.

Keywords: Comfort evaluation criteria , Digital human modeling , Ergonomics , Not-invasive postural analysis , Re-design

We developed a wearable device to improve lower limb sport training. The presented system consists of a pair of spandex shorts which embed a processor unit, 2 accelerometers and 2 vibro motors. The accelerometers are located in proximity to the knees and measure tri-axial accelerations. We present a novel method to compute and correct asymmetry of lower limbs during training. The user performs an initial calibration phase which sets the accelerometer reference frames. While running, the system continuously refines the calibration using principal component analysis to take in account occasional shorts assessments. The system activates a corrective vibro feedback on the specific leg according to an asymmetry metric based on: (i) foot ground impact, (ii) phase error between legs, (iii) transversal knee movements. User tests demonstrated that the device is ergonomic to wear, easy to use and the corrective vibro feedback is appreciated during the training.

Keywords: Asymmetry correction , Lower limb rehabilitation , Sport training , Vibro feedback , Wearable training device

The environmental impact reduction and the growing world energy demand have generated a strong interest to smart home all over the world. Indeed, thanks to the recent developments in Information and Communication Technologies (ICT) and Internet of Things (IoT), it is possible to create smart home system by making several objects installed at home cooperate each other and offering new services to end users. However, smart home system design is not a trivial task: the increasing embedded intelligence of smart devices is generating a huge quantity of data, which needs to be properly structured and managed, and the related services must be designed and personalized according to the specific users' needs. This paper defines a methodology to support smart home system design and improve smart home information management by selection, aggregation and classification of relevant data, and their correlation to smart home services. The methodology implementation shows how it can support the design of services able to bring benefits to the subjects involved. It also represents the first step towards the creation of a standard by data management and device interoperability for smart home systems' design.

Keywords: Device interoperability , Information management , Product-service systems , Service design , Smart home system design

This paper deals with the simulation of material texture by means of electro-tactile stimuli, which directly derive from real material properties. The research presents a novel tactile display by its hardware and software system architecture and the elaboration procedure to generate the stimulating signals, and validates the adopted simulation strategy by experimental testing. The tactile system elaborates data from scans of real material samples and generates electrical stimuli to reproduce roughness and texture coarseness sensations. It also adds a coherent sound feedback to improve the realism of the simulation. The research defines also an experimental protocol based on the theory of Psychophysics to carry out system calibration and tests with users. The scope is to validate the proposed tactile system as a new tool for material simulation, which can be adopted for material virtual prototyping in several fields (product design, textile and clothing, gaming and entertainment, virtual museum, rehabilitation, etc.). Experimentations have been carried out to measure the users' response to our different material classes (wood, paper, rubber and textile fabric). Experimental results concern how good the adopted simulation approach is and the analysis of the human tactile perception simulated by the system. Main findings relate to the system performance and the users' response in terms of signal recognition and material class discrimination. © 2013 Springer-Verlag London.

Keywords: Haptics , Material simulation , Material texture , Tactile system

The psycho-physical state of a driver has been widely recognized as the crucial point in any issue concerning the development of models headed to improve the vehicle safety, either inherent and active, so much so that almost all the new in-vehicle technology, currently developing at a rapid rate, introduces devices to continuously monitor the driver. This paper describes the architecture of a real time, performance-based, driver monitoring system able to detect the decrease in driver performances due to driver distraction, fatigue, sleepiness and alcohol or drugs ingestion. The system processes the instantaneous lateral position of the vehicle on the road. This allows to work out an index of the lane keeping precision by means of the lateral position standard deviation (SDLP). This latter and the road environment complexity has been processed by a fuzzy inference system that has, as an output, a score reflecting the driver's ability to maintain adequate lane-tracking movements for a given road scenario. Fuzzy membership functions and inference rules has been based and optimized on data obtained on 12 subjects performing driving simulation under both baseline condition and two different cognitive overload situations induced by different secondary tasks, one with visual distraction, the other characterized by a pure cognitive load, respectively. Aim of the work is to attain to a black-box type devices that could both provide warnings or reminding in case of risky driving and encourage the driver to improve his behavior. Advantages would also come for parents of novice drivers promptly alerted for improper driving and even for the car insurance companies that could reward safe drivers.

Keywords: Cognitive load , Drive simulator , Fuzzy logic , Safe driving

Smart home grids require that their control devices are both usable and acceptable. The assessment of device usability and acceptability is often neglected due to the cost of prototyping solutions to be submitted to end-user during the different stages of the design process. In this context, the present paper describes a structured User-Centered Design (UCD) approach to develop usable control devices. It exploits advanced Tangible Augmented Reality (TAR) technique to represent the achieved design solution and perform usability testing without increasing development time and costs.

Keywords: Human-Computer Interaction , Smart Home , Tangible Augmented Reality , Virtual Prototyping

Nowadays, economical, technical and ergonomic factors have a great importance on the design of the agricultural tractors. The paper illustrates the use and the management of heterogeneous product information (manual measurements and drafts, 2D drawings, technical documentation, photos), advanced CAD modeling tools and digital human models, for the redesign and the ergonomic optimization of an agricultural tractor's driver cab. The project development has been organized using a top-down approach in a collaborative environment. At first, a manual measurement with gauges allowed to realize a technical draft of the whole agricultural tractor and of each component part of the driver cab. Then a main skeleton has been created in Catia V5 environment in order to specify all the datum elements necessary to model each sub-assembly of the tractor. Cabin, platform, engine, tires, seat, dashboard and controls have been organized separately and modeled considering the details related to the manual measurements and to the technical standards. Once obtained the 3D CAD model of the tractor, an opportune questionnaire was prepared and a test campaign was carried out with real operators in order to define the more critical control devices within the driver cab, as regards to usability and ergonomic issues. An "Ergonomics' Evaluation Index" (EEI) was defined taking into account the posture angles of the operator and the Rapid Upper Limb Assessment analysis tool available in the "Ergonomics Design & Analysis" module of Catia V5 based on the use of a digital human model. The index was validated comparing the results of tests carried out using virtual manikins of different percentiles performing a specific driving task, with the results of tests carried out by real operators, of the same percentiles, performing the same driving task. Critical values of the EEI obtained during some driving tasks in virtual environment, suggested to modify the shape and the position of some control devices in order to optimize the ergonomics of the driver cab. The adoption of the top-down modeling based approach allowed each change on a singular component part to be automatically propagated on the whole assembly, making easy the changes on the virtual prototype. Copyright © 2012 by ASME.

The preventive knowledge of serviceability times is a critical factor for the quantification of after-sales services costs of a vehicle. Predetermined motion time system are frequently used to set labor rates in industry by quantifying the amount of time required to perform specific tasks. The first such system is known as Methods-time measurement (MTM). Several variants of MTM have been developed differing from each other on their level of focus. Among them MTM-UAS is suitable for processes that average around 1-3 min. However experimental tests carried out by the authors in Elasis (Research Center of FIAT Group) demonstrate that MTM-UAS is not the optimal approach to measure serviceability times. The reason is that it doesn't take into account ergonomic factors. In the present paper the authors propose to correct the MTM-UAS method including in the task analysis the study of human postures and efforts. The proposed approach allows to estimate with an "acceptable" error the time needed to perform maintenance tasks since the first phases of product design, by working on Digital Mock-up and human models in virtual environment. As a byproduct of that analysis, it is possible to obtain a list of maintenance times in order to preventively set after-sales service costs. © 2012 Springer-Verlag.

Keywords: Digital humans , Ergonomics , MTM-UAS , Predetermined time analysis , Virtual maintenance , Work measurement

This paper presents a computer-Aided environment to analyze postures and movements in order to ergonomically validate the design of potentially any device a man or woman may have to deal with. The proposed environment integrates virtual prototyping techniques with Digital Human Modeling and Motion Capture techniques to determine fatigue, stress and risk for workersâTM health. We considered a vertical refrigerated display unit as case study to analyze the interaction of supermarket staff filling the shelves with goods with the main goal determining the suitability of operatorsâTM working condition and, eventually, providing a feedback to the design step. The paper, after a brief description of the state of the art of the Motion Capture system and Digital Human Modeling, presents the architecture of the integrated environment developed and the working paradigm. At last preliminary results of the experimentation as well benefits and the limits of the outcomes achieved so far in the automation of ergonomics in machines design are presented. Copyright © 2012 by ASME.