Human factors and ergonomics

This paper presents IART, a novel inertial wearable system for automatic detection of infringements and analysis of sports performance in race walking. IART algorithms are developed from raw inertial measurements collected by a single sensor located at the bottom of the vertebral column (L5–S1). Two novel parameters are developed to estimate infringements: loss of ground contact time and loss of ground contact step classification; three classic parameters are indeed used to estimate performance: step length ratio, step cadence, and smoothness. From these parameters, five biomechanical indices customized for elite athletes are derived. The experimental protocol consists of four repetitions of a straight path of 300 m on a long-paved road, performed by nine elite athletes. Over a total of 1620 steps (54 sequences of 30 steps each), the average accuracy of correct detection of loss of ground contact events is equal to 99%, whereas the correct classification of the infringement is equal to 87% for each step sequence, with a 92% of acceptable classifications. A great emphasis is dedicated on the user-centered development of IART: an intuitive radar chart representation is indeed developed to provide practical usability and interpretation of IART indices from the athletes, coaches, and referees perspectives. The results of IART, in terms of accuracy of its indices and usability from end-users, are encouraging for its usage as tool to support athletes and coaches in training and referees in real competitions.

Keywords: Biomechanics , Inertial sensor , Judgment , Race walking , Step classification , Training improvement , User-centered design

Generally, comfort may be defined as the “level of well-being” perceived by humans in a working environment. The state-of-the-art about the evaluation of comfort/discomfort shows the need for an objective method to evaluate the “effect in the internal body” and “perceived effects” in main systems of comfort perception. Some medical studies show that each human joint has its own natural Rest Posture in which human muscles are completely relaxed or at the minimum strain level. Basing on this assumption, in other studies postural comfort curves for each Degree of Freedom of human upper and lower-limbs joints have been studied and CaMAN software has been developed to have a direct interface with these curves. In this paper, the upper limbs' postural comfort curves have been compared with the results gained by the biomechanics virtual simulation built on ANYBODY Software. A detailed study has been conducted on the upper body muscular activation during upper limbs movement with and without load. Postures have been analysed both by ANYBODY and CaMAN in order to correlate the postural (dis)comfort perception with the calculated muscular activity.

Keywords: ANYBODY software , Human Man Interface simulation , Postural comfort

Interactive multimedia applications in museums generally aim at integrating into the exhibition complementary information delivered through engaging narratives. This article discusses a possible approach for effectively designing an interactive app for museum collections whose physical pieces are mutually related by multiple and articulated logical interconnections referring to elements of immaterial cultural heritage that would not be easy to bring to the public with traditional means. As proof of this concept, a specific case related to ancient Egyptian civilization has been developed. A collection of Egyptian artifacts such as mummies, coffins, and amulets, associated with symbols, divinities, and magic spells through the structured funerary ritual typical of that civilization, has been explained through a virtual application based on the concepts discussed in the methodological section.

Keywords: Ancient Egypt , Cultural heritage exhibition , Digital heritage , Intangible heritage , Interactive devices , Multimedia , Virtual museum

Feedback through the steering wheel is known as the most important source of information to the driver. The so-called steering feeling, composed of self-aligning actions coming from tyres and suspension geometry all the way through mechanical linkages to the driver's hands, provides vital communication for intuitive driving, and it is therefore utterly important for safety and for a pleasant driving experience as well. Subtle forces and vibrations, due to the interaction between the tyre contact patch and the road surface texture, also play a role, provided they are not heavily filtered or cancelled by the power steering system. Human perception is guided by experience in order to establish correlations between steering feedback and vehicle motion in terms of straight-line stability, cornering speed, tyre adhesion and available friction, vehicle balance, and so on. A front-wheel drive car is potentially a critical vehicle from this point of view, especially when the powertrain can deliver large torque figures, and even more so if a limited-slip differential (LSD) or a similar active device is present in order to improve traction capabilities. Any difference between the two wheels in terms of tractive force can result into the so-called torque steer issue, that is to say, a "pulling" sensation on the steering wheel or a shifting of the vehicle from the desired trajectory. This paper analyses the torque steer phenomenon on an all-wheel-drive, full electric sportscar where a significant portion of the torque is transferred to the front axle. The effects of suspension kinematics and the load variation at tyre contact patch level are taken into account. For evaluating the impact of steering feedback, the VI-grade® simulation software is adopted and a test campaign on the professional driving simulator available at the University of Brescia has been carried out in order to understand the impact of steering feedback on driver perception and performance.

Keywords: Electric cars , Steering feeling , Torque steer

Additive Manufacturing is a widespread technology that may enhance product customization based on specific users' needs, as in the case of assistive devices. Many chronic physical progressively disabling diseases, but also ageing, may cause severe limitations in daily life, which can be overcome by highly customized aids. Literature shows that the active involvement of the patient in the development of assistive devices through co-design allows for their greater therapeutic effectiveness and acceptance. Therefore, this paper proposes a methodological approach for the development of inclusive assistive devices to support daily activities in persons with disabling diseases of the upper-limb. The approach integrates co-design, standardized tools, and low- and high-tech prototyping techniques and tools, which lead to significant feedbacks from patients. The patients are encouraged to interact with conceptual prototypes through direct 3D CAD modelling and touch screen devices. Assessment tests highlight the suitability of the method to achieve the expected goals.

Keywords: Additive Manufacturing , Assistive device , Co-design , Hand pathologies , Inclusive method , Occupational therapy , Parametric modelling

An innovative airport control tower concept based on the use of modern augmented reality technologies has been developed and validated by means of human-in-the-loop experiments in a simulated environment. An optical-based augmented reality interface underpins the proposed concept that consists in providing air traffic control operators in the airport control tower with complete head-up information, as opposed to the current mix of information retrieval through both head-up real view and head-down interfaces. Specific measurement of the time spent by the operator working in either head-up or head-down position, show that the proposal has a clear effect in stimulating the air traffic control operator to work in a head-up position more than in a head-down position, with positive effects on his/her situational awareness and perceived workload, especially when dealing with low visibility conditions operational scenarios.

Some literature has already demonstrated the widespread influence of human personality on product design. Nevertheless, most of the existing user experience (UX) design methods and tools do not fully exploit knowledge about user personality in selecting the best participants to maximize the effectiveness of the design efforts. This research tries to fill the gap by introducing PERSEL, the ready-to-use PERsonality-based SELector. PERSEL is a Microsoft Excel workbook, free to download, which allows expression of the objectives (needs) and assessment of the user personality; in turn, PERSEL suggests the best users to be involved in UX redesign activities and in what way, in order to get solutions answering to the needs in the best possible way. A comparison of the solutions generated by the first adoption of PERSEL in the field with those coming from the involvement of users selected without obeying any specific criterion, begins validating the research results, mainly in terms of PERSEL functioning and effectiveness.

Keywords: Human personality in product design , Mental models , User experience , User testing , UX redesign processes

In the orthodontic field, UX concerns can take an important role in boosting innovation from the designers, engineers, dentists, dental technicians and patients' points of view. In the last months, these concerns spread over the development of functional orthodontic appliances for the correction of skeletal class II malocclusions. This paper focuses on two phases: the data collection before starting the development and the evaluation of the design results. The UX concerns developed through the involvement of the Quality Function Deployment and the irMMs-based UX evaluation method 2.0, including the meQUE questionnaire 2.0. This paper describes the UX role, the related activities and the impact of its involvement in the design process.

Keywords: Functional orthodontic appliances , irMMs-based UX evaluation method 2.0 , meCUE questionnaire , Quality function deployment , User experience

The variety of human behaviors makes user-product interaction difficult to manage and foresee, especially concerning users running into problems. This research considers several interaction problems and identifies recurring behaviors. Then, it highlights the users, products and environments' aspects corresponding to each of these behaviors. This makes possible foreseeing the behavior of specific users who run into problems while interacting with specific products in specific environments. The results are used to upgrade an existing user-product interaction modeling approach in order to make it able to suggest better-focused product improvements to designers as well as alternative problem solving to different users.

Keywords: Functional mock-up for interaction , Human behavior , Interaction modeling , User-product interaction

Although the increasing use of automation in industry, manual assembly stations are still common and, in some situations, even inevitable. Current practice in manual assembly lines is to balance them using the takt-time of each workstation and harmonize it. However, this approach mostly does not include ergonomic aspects and thus it may lead to workforce musculoskeletal disorders, extended leaves, and demotivation. This paper presents a holistic human-centric optimization method for line balancing using a novel indicator the ErgoTakt. ErgoTakt improves the legacy takt-time and helps to find an optimum between the ergonomic evaluation of an assembly station and its balance in time. The authors used a custom version of the ErgoSentinel Software and a Microsoft Kinect depth camera to perform online and real-time ergonomic assessment. An optimization algorithm is developed to find the best-fitting solution by minimizing a function of the ergonomic RULA-value and the cycle time of each assembly workstation with respect to the worker's ability. The paper presents the concept, the system-setup and preliminary evaluation of an assembly scenario. The results demonstrate that the new approach is feasible and able to optimize an entire manual assembly process chain in terms of both, economic aspects of a well-balanced production line as well as the ergonomic issue of long term human healthy work.

Keywords: Assembly digitalization , Ergonomic assessment , Line balancing

Nowadays, smartphones and laptops equipped with cameras have become an integral part of our daily lives. The pervasive use of cameras enables the collection of an enormous amount of data, which can be easily extracted through video images processing. This opens up the possibility of using technologies that until now had been restricted to laboratories, such as eye-tracking and emotion analysis systems, to analyze users' behavior in the wild, during the interaction with websites. In this context, this paper introduces a toolkit that takes advantage of deep learning algorithms to monitor user's behavior and emotions, through the acquisition of facial expression and eye gaze from the video captured by the webcam of the device used to navigate the web, in compliance with the EU General data protection regulation (GDPR). Collected data are potentially useful to support user experience assessment of web-based applications in the wild and to improve the effectiveness of e-commerce recommendation systems.

Keywords: Affective Computing , Convolutional Neural Networks , Deep Learning , Gaze detection , User Experience

The paper describes the conceptual model of an emotion-aware car interface able to: map both the driver's cognitive and emotional states with the vehicle dynamics; adapt the level of automation or support the decision-making process if emotions negatively affecting the driving performance are detected; ensure emotion regulation and provide a unique user experience creating a more engaging atmosphere (e.g. music, LED lighting) in the car cabin. To enable emotion detection, it implements a low-cost emotion recognition able to recognize Ekman's universal emotions by analyzing the driver's facial expression from stream video. A preliminary test was conducted in order to determine the effectiveness of the proposed emotion recognition system in a driving context. Results evidenced that the proposed system is capable to correctly qualify the drivers' emotion in a driving simulation context.

Keywords: Driver Monitoring System , Emotion recognition , Facial expression recognition

One of the most actual and consistent drivers for the industry is sustainability, which includes three main pillars: environment, economics, and society. While numerous methods for environmental and economic sustainability assessment have been proposed, social sustainability assessment is still lacking in structured methods and tools, although human has always played a key role. Moreover, technological development is pushing the industrial world toward a new paradigm, the “Industry 4.0,” which embeds topics such as data digitalization, cyber-physical systems, and machine learning. It entails significant changes in human resources management, without reducing their importance. Humans were part of the manufacturing system from the first industrial revolution, and no automation or digitalization can be possible without humans. The industry can no longer underestimate the reasonable application of human factors and ergonomics principles to the workplace. For this purpose, the paper provides a novel transdisciplinary engineering method to measure and promote social sustainability on production sites. It exploits Internet of Things technology to support the (re)design of manufacturing processes and plants toward human-centered connected factories. To improve the workers' well-being has positive effects on their health, satisfaction, and performance. The method has been implemented in a real industrial case study within the footwear industry. The sole finishing process has been analyzed from different perspectives to solve ergonomics-related problems and implement effective improvement strategies.

Keywords: Human factors , Human-centered connected factories , Industry 4.0 , Manufacturing ergonomics , Social sustainability

Industrial process digitalisation is pervading numerous areas of production system, including sustainability. The study presents a method to affirm how the social sustainability of a company also passes through the protection of the welfare of the worker and describes a case study focused on small and medium-sized enterprises (SMEs). The method considers different aspects including the characteristics of the worker/s, the working context, and the content of the work activity. According to the objectives of social sustainability in the factory environment multifactorial variables related to the workers wellbeing have been defined. IoT system and ad-hoc questionnaires can be used to collect such variables. Following the proposed method, the results of the case study offer many in-depth insights, from the objective analysis of personal characteristics to the organisation of work, and from the application of international standards to the evaluation of psychological parameters.

Keywords: Ergonomics , Human factors , Human-centred manufacturing , Industry 4.0 , Internet of things , IoT , Social sustainability , User-centred workplace , Worker wellbeing

Especially in the footwear sector, the transition from the mass production to the mass customization increasingly requires Industry 4.0 solutions that do not reduce the human contribution to production processes but facilitate and value it to increase the job satisfaction. In this context, this paper proposes a method to (re)design the workplace according to a multiperspective ergonomic assessment. It efficaciously combines the analysis of physiological and environmental parameters by Internet-of-Things, the ergonomics risks identification by experts and the subjective evaluation of workers well-being. The method has been experimented in an Italian factory that produces customized shoes for the luxury market.

Keywords: Artisanal production , Ergonomics , Human-centered manufacturing , Workplace

In current industrial systems, automation is a very important aspect for assessing manufacturing production performance related to working times, accuracy of operations and quality. In particular, the introduction of a robotic system in the working area should guarantee some improvements, such as risks reduction for human operators, better quality results and a speed increase for production processes. In this context, human action remains still necessary to carry out part of the subtasks, as in the case of composites assembly processes. This study aims at presenting a case study regarding the reorganization of the working activity carried out in workstation in which a composite fuselage panel is assembled in order to demonstrate, by means of simulation tool, that some of the advantages previously listed can be achieved also in aerospace industry. In particular, an entire working process for composite fuselage panel assembling will be simulated and analyzed in order to demonstrate and verify the applicability and effectiveness of human-robot interaction (HRI), focusing on working times and ergonomics and respecting the constraints imposed by standards ISO 10218 and ISO TS 15066. Results show the effectiveness of HRI both in terms of assembly performance, by reducing working times and ergonomics-for which the simulation provides a very low risk index.

Keywords: Aerospace production , Ergonomics , Human-robot interaction , Simulation

In the era of Industry 4.0, automation plays a key role in improving manufacturing production processes in terms of working times, accuracy of operations, products' quality, and so on. With focus on the working tasks on composite components, drilling and riveting operations require particular attention due to the possibility of damage to the final product, especially when they are executed manually. To reduce these kinds of risks, the introduction of a robot in the working area could represent an improvement to speed up the processes and to ensure a better quality result. It is worth noting that human intervention remains necessary for carrying out a part of the sub-tasks, especially in the case of composite assembly procedures. This paper aims at presenting a case study about the drilling and riveting operations on a composite aircraft fuselage whose working cell is characterized by the coexistence of a human and a robot. Moreover, the implementation of a numerical simulation allows validating the working cycle and the adopted solutions in terms of ergonomic performance.

Keywords: aircraft fuselage assembly , composite manufacturing , ergonomics , human–robot interaction , simulation

Recent research results on human–robot interaction and collaborative robotics are leaving behind the traditional paradigm of robots living in a separated space inside safety cages, allowing humans and robot to work together for completing an increasing number of complex industrial tasks. In this context, safety of the human operator is a main concern. In this paper, we present a framework for ensuring human safety in a robotic cell that allows human–robot coexistence and dependable interaction. The framework is based on a layered control architecture that exploits an effective algorithm for online monitoring of relative human–robot distance using depth sensors. This method allows to modify in real time the robot behavior depending on the user position, without limiting the operative robot workspace in a too conservative way. In order to guarantee redundancy and diversity at the safety level, additional certified laser scanners monitor human–robot proximity in the cell and safe communication protocols and logical units are used for the smooth integration with an industrial software for safe low-level robot control. The implemented concept includes a smart human-machine interface to support in-process collaborative activities and for a contactless interaction with gesture recognition of operator commands. Coexistence and interaction are illustrated and tested in an industrial cell, in which a robot moves a tool that measures the quality of a polished metallic part while the operator performs a close evaluation of the same workpiece.

Keywords: Collaborative robotics , Depth sensing , Human-machine interface , Industrial cell , Polishing , Safe human–robot interaction

Human and robot collaboration represents an interesting development direction for traditional industrial robotic solutions. Especially for those cases where the operations are difficult to automate or burdensome for manual execution, the mutual exchange of human sensitivity and robot repeatability represents an effective approach. Nevertheless, industrial robots are poorly involved for collaborative tasks since specific safety countermeasures are required to avoid all the potential hazards. Consequently, the design and assessment of safety solutions represents a fundamental phase to estimate feasibility of industrial collaborative solutions. The presented work proposes a computer-aided approach to identify, assess and optimize the safety systems that enables the collaborative usage of industrial robots. It exploits the capabilities of virtual controller-based offline programming packages to design in advance the safety countermeasures. An initial consistency test validates the response of the selected tool with respect to the safety functionalities. Subsequently, a virtual replica of a potential industrial collaborative solution has been developed. As a result, it has been possible to mimic the behaviour of such a system with respect to Speed and Separation Monitoring collaborative method.

Keywords: Computer-aided assessment , Human-robot collaboration , Indutrial robots , Safey countermeasures , Speed and separation monitoring

An effective sensor system for monitoring the pressure distribution on a car seat would enable researches on Advanced Driver Assistance Systems (ADAS) and comfort of occupants. However, the irregularities of the seat shape or those of the occupant clothes challenge the robustness of such a sensor system. Moreover, the position identification of bodies of different percentiles by few pressure sensors is difficult. So, a higher resolution pressure pad has been developed. The number of sensors is significantly increased by means of a matrix scan strategy. Tests on the pressure pad with different occupants proves its robustness in scanning the contact area.

Keywords: Advanced Driver Assistance Systems , Car seat , Comfort , Driver monitoring , Pressure , Sensor matrix