Human factors and ergonomics

Car driver and occupants monitoring is important for safety and comfort. The systems using vision sensors for monitoring the line of sight can be integrated with pressure sensors embedded in the seats to identify critical Out of Position conditions. A new modular car seat is here proposed to monitor the pressure distribution on different significant regions. The solution improves the limitations of existing technologies embedded in seats. The proportional and fast measurement enables online complex evaluations, while the layout reduces the risk of errors. The experiments proved the effectiveness of the prototype.

Keywords: Car seat pressure , Driver monitoring , Driver profiling , Intelligent vehicle , Modular car seat , Occupant classification , Safety system , Seat regions , Weight scale system

There is a looming shortage of well-trained professionals in the wood construction workforce. To challenge this shortage, we developed a simulated learning environment that leverages a novel Virtual Reality (VR) system to train novice workers in wooden wall construction. A comprehensive task analysis was first used to best identify training requirements. Then, a virtual building site was modeled and a 3D video tutorial was implemented using a VR Head-Mounted Display (HMD). To evaluate the effectiveness of this tool, participants who learned via the VR training tool were compared with participants who instead only had simple 2-D instructional video training. VR training resulted in better retention, task performance, learning speed, and engagement than the video training counterpart, maintaining system usability. This demonstrates that VR is a viable training tool for the construction sector and can produce benefits beyond those of traditional video training.

Keywords: Human-computer interaction , Virtual reality , Virtual training , Workforce development

This paper describes the final assessment of a student with SLD who uses compensatory tools to verify the effectiveness of the strategies adopted to support the construction of an inclusive assessment environment. The proposed case study is part of long-term research conducted by the University of Macerata. New technologies for analyzing emotional feedback based on the analysis of facial expressions collected from both students and professors during the exam supported the observation. Results show how the application of the emotional recognition system allows researchers to reflect on the evaluation process, on the teacher's perception about compensatory tools and, more generally, on accommodation exams strategies for students with DSA.

Keywords: Emotional feedback , Evaluation strategies , Inclusive university teaching , University students Dyslexia

In the last years, museums have begun to apply new technological solutions to manage their exhibits in a more open, inclusive, and creative way, to improve the visitors' experience to respond to the need to expand the audience. The main goal is to face the increasing competition in an economy referred to as the “Experience Economy”. To this end, Augmented Reality technology seems to represent a good solution for museum guide systems, to improve visitors' learning and enjoyment. In this context, the present paper proposes a museum guide system based on Spatial Augmented Reality powered by dynamic projection. The paper describes the overall HW and SW system architecture and reports in detail the developed process adopted to design and implement a museum guide and entertainment application, in the context of the “Studiolo of Federico da Montefeltro” in the Ducal Palace of Urbino. A preliminary survey has been carried out, which involved a total of 79 subjects, aimed at investigating the quality of visitor's experience, aroused by the proposed application, in terms of the “Four Experience Realms” defined by Pine & Gilmore (1998). Results suggest that the proposed application can be used to stage experiences that satisfy the visitors and may help to enable museums into the Experience Economy.

Keywords: Cultural heritage , Dynamic projection , Experience economy , Museum guide , Spatial augmented reality

This paper introduces a new recommendation system for museums able to profile the visitors and propose them the most suitable exhibition path accordingly, to improve visitors' satisfaction. It consists of an interactive touch screen totem, which implements a USB camera and exploits Convolutional Neural Network to perform facial coding to measure visitors' emotions and estimate their age and gender. Based on the detected level of emotional valence, the system associates visitors with a profile and suggests them to visit a selection of five works of art, following a specific itinerary. An extensive experimentation lasting 2 months has been carried out at the Modern Art Museum “Palazzo Buonaccorsi” of Macerata. Results evidence that the proposed system can create an interactive and emotional link with the visitors, influencing their mood in the Pre-Experience phase and in the subsequent Post-Experience phase. In particular, they highlight that the proposed system, which aims at acting as emotional leverage, has been able to improve the positiveness of the emotions experienced by the visitors.

Keywords: Affective computing , Cultural heritage , Emotion recognition , Facial expression recognition

Virtual museum systems, based on different X-reality technologies, has begun to spread, as they represent decisive tools to promote exhibitions and reaching out to audiences. Although budgetary considerations have so far limited the choice of technologies a wide range of possible technological options are available today at low cost. This paper provides the results of an empirical study, with the aim to determine the most appropriate technologies to satisfy the visitors' expectation and maximise their likelihood to repeat and recommend the experience. The study focuses on the comparison of the performance of five VM systems for visualise digital reproduction of archaeological finds, based on different technologies (i.e., PC desktop, holographic display, 3D stereoscopic projection, head mounted display and mobile Augmented Reality). The results provide useful insight for the development of VM systems, in order to maximize the visitor experience in terms of presence and ability to activate an experience economy perspective.

Keywords: Augmented reality , Mixed reality , Presence , Virtual Museum , Virtual reality , Visitor experience , X-Reality technologies

With the advent of future vehicles, passengers expect to travel in comfort, and the free leg space between facing-seats could be an issue due to the unsuitability for all people, according to their anthropometric variability. A previous investigation survey showed the need to increase the leg-space between facing seats and, if installed, to improve the surface of the table placed in between. So, four different distances between seat-pans front edges of facing seats have been set-up and tested (44 cm, 51 cm, 58 cm, 65 cm) with a table in between. 13 couples of participants with different heights took part to experiments. The aim was to investigate the relationship between facing-seat distances and passenger wellbeing in terms of postural comfort and social interaction. Postural comfort has been analysed through optical tracking (for postural angles overtime) and questionnaires (perceived comfort). Social interaction feelings have been investigated with questionnaires. Experiment results showed the suitable distance could be 51 cm keeping the same table surface; otherwise, the 65 cm one could be ideal changing the table surface. Relevance to industry: With the advent of autonomous driving, vehicle manufacturers and designers are working hard to define new paradigms of public transportation in terms of seat layout, passenger wellbeing and interiors' design. This paper contributes to increasing the general knowledge on the effects of distance between facing seats on postural comfort and social interaction.

Keywords: Occupant comfort , Passenger satisfaction , Seats' layout , Social interaction , Vehicle seat

Remaining seated for extended periods increases the risk health issues and discomfort perception. Consequently, the seat-pan design is crucial and could be mainly influenced by two factors: pressure distribution and seat contour. For seat pan discomfort, the lower average pressure is accompanied by less discomfort. Moreover, a seat contour with a large contact area is correlated with more comfort. Thus, a shaped cushion had been accurately designed (Virtual Prototype) and realized (Physical Prototype) aiming to translate the pressure distribution due to interaction between seat and buttock in a geometric shape, suitable for the international population (including P5 females and P95 males). With this shape, the pressure should be more uniform and lower, the contact area at interface bigger, and the perceived comfort higher. Both Virtual and Physical Prototype design had been described in this paper through a repeatable and straightforward approach. Also, experiments had been performed to validate the hypothesis through a comparison with a standard flat cushion. Results showed the goal of the design had been reached: the shaped cushion scored less pressure distribution and higher contact area than the flat cushion.

Keywords: Design methodology , Product modelling / models , Prototype manufacturing method , Surface modelling , User centred design

This study aimed to analyse the discomfort threshold (that could be linked to sensitivity or sensation) of different regions in hand and elbow to support hand-held devices' design. Indeed, there are no studies regarding the hand and elbow discomfort threshold or sensitivity. To overcome these literature gaps, the discomfort threshold of hand and elbow were recorded at 24 spots by pushing a cylinder with a diameter of 10 mm until the participants reported not to be longer comfortable. Experiments were performed with 24 participants, 13 females and 11 males. The results showed the map of discomfort threshold (or sensitivity) for the hand and elbow. The olecranon, situated at the ulna's upper (proximal) end, one of the two bones in the forearm, could withstand more pressure than the elbow area surrounding it. The fingertips and the area close to the metacarpals were most sensitive (lower discomfort threshold).

Keywords: Discomfort , Human centred design , Localized contact , Pressure , Upper limbs

A proper seat is crucial not only for preventing health issues but also for the (dis)comfort perception. In the design of a seat, the seat pan's geometric shape, either in or under the cushion, plays a vital role as it constrains the deformation of the foam it supports. The contact area and pressure distributions between the foam and the human body, closely associated with (dis)comfort, are influenced by those constrained deformations. In this paper, using a comparative study, the aim is to determine if opportunely shaped seat pans are better than a standard flat pan regarding postural comfort and pressure distribution. Two cushions with the same type of foam but two different seat pans were used in the comparison. The first seat pan is the standard one used in current aircraft seats and the second is a shaped seat pan, which was designed following the mean buttock-thigh shape of an international population (including P5 females and P95 males). Twenty-two international participants (11 males and 11 females, with BMI between 16 and 30) took part in the blind experiment. Results indicated that the cushion with shaped seat pan performed better as it led to less postural comfort, a larger contact area and more uniform pressure distribution. Also, 64% of participants favored the cushion with the shaped seat pan as they felt it was more comfortable and suitable for the buttock shape.

Keywords: Comfort , Human-center-design , Pressure map , Seat-pan

Various aspects related to comfort are described in this special issue. Some papers are focused on the environment, like smell, temperature, light, acoustics, space and some on an artefact touching the human, like the floor angle, the seat, a bed and light. However, in this special issue also topics like modelling and behavior get more attention.

Keywords: comfort , ICC2019 , main findings , model , Review

BACKGROUND: Selecting the most suitable questionnaire(s) in comfort research for product design is always a challenge, even for experienced researchers. OBJECTIVE: The objective of this research is to create a list of Preferred Comfort Questionnaires (PCQ) for product design to help researchers in the selection of questionnaires for comfort research. METHODS: Fifteen questionnaires that are often used in comfort research for product design were selected as candidate questionnaires. During the Second International Comfort Congress (ICC 2019), 55 researchers and practitioners working in the field of comfort joined together in a workshop to rate these questionnaires individually as well as rank them in groups based on their experience. The criteria of rating and ranking included easiness to answer, easiness for data interpretation, time needed to complete, the need for prior training, as well as mapping the applicable design phases and field of application. RESULTS: The elicited responses related to each questionnaire were analyzed. For comfort research in five proposed application fields and four design phases, the preferred questionnaires were highlighted and categorized into four categories: preferred questionnaire, suitable for less prior training, suitable for fast completion and generally applicable, which led to a list of PCQ for product design. CONCLUSION: We expect that the PCQ list can be used as a useful instrument to help researchers in selecting questionnaires for comfort research in product design.

Keywords: Comfort , discomfort , product design , questionnaire , research

Human–robot collaboration (HRC) solutions are replacing classic industrial robot due to the possibility of realizing more flexible production systems. Collaborative robot systems, named cobot, can work side by side with humans combining their strengths. However, obtaining an efficient HRC is not trivial; indeed, the potential advantages of the collaborative robotics increase as complexity increases. In this context, the main challenge is to design the layout of collaborative workplaces facing the facility layout problem and ensuring the safety of the human being. To move through the high number of safety standards could be very tiring and unproductive. Therefore, in this work a list of key elements, linked to reference norms and production needs, characterizing the collaborative workplace has been identified. Then, a graph-based approach has been used in order to organize and easily manage this information. The management by means graphs has facilitated the implementation of the acquired knowledge in a code, developed in Matlab environment. This code aims to help the designer in the layout organization of human–robot collaborative workplaces in standards compliance. The paper presents the optimization code, named Smart Positioner, and the operation is explained through a workflow diagram.

Keywords: Facility layout problem , Human–robot collaboration , Knowledge-based approach , Optimization criteria

The fourth industrial revolution is promoting the Operator 4.0 paradigm, originating from a renovated attention towards human factors, growingly involved in the design of modern, human-centered processes. New technologies, such as augmented reality or collaborative robotics are thus increasingly studied and progressively applied to solve the modern operators' needs. Human-centered design approaches can help to identify user's needs and functional requirements, solving usability issues, or reducing cognitive or physical stress. The paper reviews the recent literature on augmented reality-supported collaborative robotics from a human-centered perspective. To this end, the study analyzed 21 papers selected after a quality assessment procedure and remarks the poor adoption of user-centered approaches and methodologies to drive the development of human-centered augmented reality applications to promote an efficient collaboration between humans and robots. To remedy this deficiency, the paper ultimately proposes a structured framework driven by User eXperience approaches to design augmented reality interfaces by encompassing previous research works. Future developments are discussed, stimulating fruitful reflections and a decisive standardization process.

Keywords: Augmented reality , Human factors , Human-centered design , Human–robot collaboration , Human–robot interaction , User eXperience

Nowadays companies have to face a competitive market that requires small volumes with a high level of customisations. In this context, assembly quality and timeliness is crucial. To guarantee flexibility and personalization, manual operations still have a crucial role for a lot of manufacturing sectors, so that workers' conditions and ergonomics are important factors to achieve a better product quality and overall cost reduction. Ergonomics evaluation in manufacturing is a challenging and expensive activity that requires a transdisciplinary approach, to merge technical and social sciences to finally have a consolidated and reliable evaluation. This paper compared two digital human simulations tools offered by Siemens Tecnomatix: Jack and Process Simulate. They were applied on the same industrial case study, concerning the hood assembly of an agricultural machine, comparing results on ergonomics reports and usage time. Results confirmed the advantage of adopting a digital approach to predict the human effort and ergonomic risk related to a series of tasks. At the same time, they showed the major strengths and weaknesses of the two analysed tools and defined how they can be successfully adopted by companies. The paper finally provided guidelines to drive companies in choosing the best tool according to their needs.

Keywords: Digital human simulations , Digital manufacturing , Ergonomics , Human-centered design , Transdisciplinary engineering

Virtual reality (VR) offers a promising set of technologies to digitally simulate industrial processes and interaction between humans and machines. However, the use of immersive VR simulations is still limited in industry due to the uncertainty of benefits in respect with traditional digital tools, and the lack of structured methodologies to effectively implement immersive virtual simulations in practice. This paper deals with the application of VR to create virtual manufacturing simulations with the aim to design assembly lines in compliance with factory ergonomics. It proposes a methodology to allow the virtualization and simulation of assembly tasks using a combination of VR tools by replicating, or rather anticipating, what would happen at the shop floor. The adopted tools are Unity 3D for virtual environment generation, HTC VIVE to immerse the user in the virtual factory layout, Xsens as tracking system, and Leap Motion for gesture recognition. The paper also compares the new VR-based procedure with a more traditional desktop-based digital simulation on industrial cases. Results show that the new methodology is more precise to detect the operator's comfort angles and more powerful to predict process criticalities and optimize factory layout design. At the same time, it is less sensitive to errors during ergonomic assessment related to the expert's subjectivity during the analysis. © 2020, Springer-Verlag London Ltd.

Keywords: Human-centered design , Industrial ergonomics , Virtual manufacturing , Virtual reality

In recent years Human-Robot Collaboration (HRC) has become a strategic research field, considering the emergent need for common collaborative execution of manufacturing tasks, shared between humans and robots within the modern factories. However, the majority of the research focuses on the technological aspects and enabling technologies, mainly directing to the robotic side, and usually neglecting the human factors. This work deals with including the needs of the humans interacting with robots in the design in human-robot interaction (HRI). In particular, the paper proposes a user experience (UX)-oriented structured method to investigate the human-robot dialogue to map the interaction with robots during the execution of shared tasks, and to finally elicit the requirements for the design of valuable HRI. The research adopted the proposed method to an industrial case focused on assembly operations supported by collaborative robots and AGVs (Automated Guided Vehicles). A multidisciplinary team was created to map the HRI for the specific case with the final aim to define the requirements for the design of the system interfaces. The novelty of the proposed approach is the inclusion of typically interaction design tools focusing in the analysis of the UX into the design of the system components, without merely focusing on the technological issues. Experimental results highlighted the validity of the proposed method to identify the interaction needs and to drive the interface design.

Keywords: Human Factors , Human-Robot Collaboration , Human-Robot Interaction , Industrial Ergonomics , User eXperience

Product and process digitalization is pervading numerous areas in the industry to improve quality and reduce costs. In particular, digital models enable virtual simulations to predict product and process performances, as well as to generate digital contents to improve the general workflow. Digital models can also contain additional contents (e.g., model-based design (MBD)) to provide online and on-time information about process operations and management, as well as to support operator activities. The recent developments in augmented reality (AR) offer new specific interfaces to promote the great diffusion of digital contents into industrial processes, thanks to flexible and robust applications, as well as cost-effective devices. However, the impact of AR applications on sustainability is still poorly explored in research. In this direction, this paper proposed an innovative approach to exploit MBD and introduce AR interfaces in the industry to support human intensive processes. Indeed, in those processes, the human contribution is still crucial to guaranteeing the expected product quality (e.g., quality inspection). The paper also analyzed how this new concept can benefit sustainability and define a set of metrics to assess the positive impact on sustainability, focusing on social aspects. © 2021 by the authors.

Keywords: Augmented reality , Humancentered design , Model-based design , Product development , Quality inspection , Social sustainability