Work - Volume 68, issue s1

Authors: Mansfield, Neil J. | Walia, Kartikeya | Singh, Aditya

Article Type: Research Article

Abstract: BACKGROUND: Autonomous vehicles can be classified on a scale of automation from 0 to 5, where level 0 corresponds to vehicles that have no automation to level 5 where the vehicle is fully autonomous and it is not possible for the human occupant to take control. At level 2, the driver needs to retain attention as they are in control of at least some systems. Level 3-4 vehicles are capable of full control but the human occupant might be required to, or desire to, intervene in some circumstances. This means that there could be extended periods of time where the …driver is relaxed, but other periods of time when they need to drive. OBJECTIVE: The seat must therefore be designed to be comfortable in at least two different types of use case. METHODS: This driving simulator study compares the comfort experienced in a seat from a production hybrid vehicle whilst being used in a manual driving mode and in autonomous mode for a range of postures. RESULTS: It highlights how discomfort is worse for cases where the posture is non-optimal for the task. It also investigates the design of head and neckrests to mitigate neck discomfort, and shows that a well-designed neckrest is beneficial for drivers in autonomous mode. Show more

Keywords: Autonomous vehicles, automated driving, seating, simulator study, backrest, comfort

DOI: 10.3233/WOR-208010

Citation: Work, vol. 68, no. s1, pp. S111-S118, 2021

Authors: Moertl, Peter | Hoefler, Margit | Ewerz, Benjamin

Article Type: Research Article

Abstract: BACKGROUND: We motivate and describe a holistic comfort model to account for the impact of driver and passenger activities on their comfort experiences in vehicles. The proposed model is an expansion of existing ones and postulates two dimensions of comfort that are linked with cognitive moderation processes toward holistic experience: physiological comfort combines multiple physiological experiences such as thermal, auditory, and postural comfort and is moderated via cognitive processes of focusing or masking. On the other hand, emotional comfort reflects the experience of activities and is moderated by cognitive appraisal processes. OBJECTIVE: Using this model, we derive three …hypotheses that are examined. METHOD: In a driving simulator study, 32 participants assessed holistic and physiological comfort while driving under various conditions. RESULTS: The participant responses on various comfort questions loaded on two main principal components that closely resemble the distinction between holistic and physiological comfort. Also, the driving and non-driving activity types seemed to have a different impact on holistic versus physiological comfort as predicted by our model. Show more

Keywords: Virtual development, comfort, comfort model, holistic comfort, automotive comfort, human-systems integration

DOI: 10.3233/WOR-208011

Citation: Work, vol. 68, no. s1, pp. S119-S128, 2021

Authors: Naddeo, Alessandro | Di Brigida, Liliana | Fontana, Carlotta | Montese, Jessica | Quartuccia, Manuel | Nasti, Mario | Pisani, Matteo Maria | Turco, Vito | De Stefano, Marco | Fiorillo, Iolanda | Califano, Rosaria

Article Type: Research Article

Abstract: BACKGROUND: Nowadays, the ergonomic study of the driving position is a critical aspect of automotive design. Indeed, due to the rising needs on the market, one focus for car industries is to improve the perceived comfort related to the cars’ interior. Driving a car for a prolonged time could cause complaints in some body-regions, especially in the lumbar-sacral area. Thus, special lumbar-sacral supports for driver seat has been proposed for reducing this kind of complaints. OBJECTIVE: Development of two virtual and physical models of lumbar-sacral support for improving both the lumbar/sacral and overall perceived comfort while driving. …METHODS: Two prototypes of lumbar/sacral support have been realized: the first one was integrated into the seat, and the second one was shaped as a removable pillow (removable support). Fifty participants were asked to rate the perceived comfort in lab tests performed on a seating-buck by comparing three configurations (5 min each): a standard seat, seat with the removable support, seat with integrated support. Subjective data (by questionnaires) and objective data (interface pressure between backrest and driver) have been acquired and statistically processed. In addition, real driving tests have been performed to test the actual performance of the removable support in term of perceived comfort comparing it with the standard seat. RESULTS: Statistical correlations between subjective and objective data showed interesting results in comfort improvement through the adopted solutions. Real driving tests showed an improvement in comfort perception with the lumbar-sacral support towards the standard seat. CONCLUSIONS: Thanks to the virtual prototyping and the application of previous knowledge, coming from literature and experience, a solution for improving the overall comfort and reduce the lumbar/sacral pain while driving has been developed, tested, and assessed. Show more

Keywords: Car seat comfort, seat design, lumbar-sacral support, body-shaped pillow

DOI: 10.3233/WOR-208012

Citation: Work, vol. 68, no. s1, pp. S129-S138, 2021

Authors: Naddeo, Alessandro | Cappetti, Nicola

Article Type: Research Article

Abstract: BACKGROUND: Human-centred design asks for wellbeing and comfort of the customer/worker when interacting with a product. Having a good perception-model and an objective method to evaluate the experienced (dis)comfort by the product user is needed for performing a preventive comfort evaluation as early as possible in the product development plan. The mattress of a bed is a typical product whose relevance in everyday life of people is under-evaluated. Fortunately, this behaviour is quickly changing, and the customer wants to understand the product he/she buys and asks for more comfortable and for scientifically assessed products. No guidelines for designing a personalized …mattress are available in the literature. OBJECTIVES: This study deals with the experience of designing an innovative product whose product-development-plan is focused on the customer perceived comfort: a personalized mattress. The research question is: which method can be used to innovate or create a comfort-driven human-centred product? METHODS: Virtual prototyping was used to develop a correlated numerical model of the mattress. A comfort model for preventively assessing the perceived comfort was proposed and experimentally tested. Mattress testing sessions with subjects were organized, and collected data were compared with already tested mattresses. Brainstorming and multi-expert methods were used to propose, realize, and test an archetype of a new mattress for final comfort assessment. RESULTS: A new reconfigurable mattress was developed, resulting in two patents. The mattress design shows that personalized products can be tuned according to the anthropometric data of the customer in order to improve the comfort experience during sleep. CONCLUSIONS: A “comfort-driven design guideline” was proposed; this method has been based on the use of virtual prototyping, virtual optimization and physical prototyping and testing. It allowed to improve an existing product in a better way and to bring innovation in it. Show more

Keywords: Comfort, mattress, design, personalized product, innovation

DOI: 10.3233/WOR-208013

Citation: Work, vol. 68, no. s1, pp. S139-S150, 2021

Authors: Liu, Zhihui | Rotte, T. | Anjani, S. | Vink, P.

Article Type: Research Article

Abstract: BACKGROUND: Staggered seats are a solution for the Flying-V aircraft, where the cabin’s longitudinal axis has a 26 degrees angle with respect to the direction of flight, to compensate for an otherwise oblique sitting position. However, little is known on acceptable pitches in this staggered configuration. OBJECTIVE: The goal of this research is to evaluate the comfort of different pitches for seats that are staggered relative to the cabin’s longitudinal axis. METHODS: Two rows of staggered seats are positioned at three different pitches (27, 29 and 31 inches). 53 participants were seated in each setup. For …each, a questionnaire was completed including questions on comfort and discomfort, top view photos were taken to analyse postures and physical dimensions were recorded to define passengers’ space. RESULTS: Comfort as well as discomfort were significantly different for the three setups. The comfort at 27 inches was seen as unacceptably low. The 29 and 31-inch configurations showed to result in acceptable levels of comfort, comparable to higher-end seating layouts. There were very little complaints about space in lateral direction (elbow and seat width), showing the advantage of having your won armrest and shoulder space in the staggered configuration. Interesting was that at larger pitches more complaints were found for the seat characteristics, probably in the shorter pitch the other discomfort was overruling this. CONCLUSION: The 26-degree staggered configuration offers improvements in shoulder- and elbow-space. The results for the 29- and 31-inch are expected to allow enough design freedom for further exploration of such a configuration for the Flying-V cabin interior. Show more

Keywords: Staggered seats, oblique sitting, seat pitch, comfort, sitting postures

DOI: 10.3233/WOR-208014

Citation: Work, vol. 68, no. s1, pp. S151-S159, 2021

Authors: Liu, Yuezhi (Sean) | Zhong, Xianzhi | Ghebreiyesus, Wintta | Ji, Jiancheng | Xi, Fengfeng (Jeff)

Article Type: Research Article

Abstract: BACKGROUND: This paper outlines a method to study the interaction between the human body and the aircraft seat concerning the seat comfort. METHOD: Firstly, the human body is modeled based on biomechanics and divided into a number of body segments connected by joints according to human anatomy. The angles between the body segments are obtained by curve fitting of the existing biomechanical research data. The contact forces between the human body and the seat are modeled using pairs of bi-lateral point forces. These forces are calculated and located through the analysis of the center of gravity of each …body segment and average muscular structure of the human body. The geometry of the human and the seat is obtained from a 3D scan model or a CAD model. Secondly, the pressure distribution between the human body and the seat is modeled and calculated using the contact stress theory. The results of the two parts are combined to analyze the comfortability in relation to different postures, backrest recline angles and changing in shape and material. RESULTS: Simulations were performed and they are compared with experimental measurement and various FEM studies for validation. It is found that accuracy of this method is comparable with most FEM calculation. CONCLUSION: This method provides a new direction in cushion conform research. It is faster and convenient to use comparing to the FEM, and the result is reliable. Show more

Keywords: Bio-modeling, contact modeling, seat-human interaction, seating comfort, interface pressure distribution

DOI: 10.3233/WOR-208015

Citation: Work, vol. 68, no. s1, pp. S161-S182, 2021

Authors: Sharafkhani, Mahnaz | Argyle, Elizabeth | Cobb, Sue | Tennent, Paul

Article Type: Research Article

Abstract: BACKGROUND: Aircraft passengers’ physical activity levels are often limited during flight for extended periods of time, which can have serious impact on health, comfort, and passenger experience. However, several factors, such as limited personal space and social factors, can make movement difficult. OBJECTIVE: The study aimed to identify participant behaviour and postures during medium to long-haul flights and their effect on location and severity of physical discomfort. This work investigated how aircraft passengers’ comfort ratings changed over time and explored the association between postures and comfort ratings during flight. The study also explored the association between performing in-flight …exercises and factors limiting participants’ abilities to complete these exercises. METHOD: Twenty-nine participants sat in an aircraft simulated cabin for 180 minutes and periodically performed in-seat exercises. They also completed a questionnaire providing data on demographic information, self-reported discomfort scores for multiple areas of the body, which types of exercises participants performed, and qualitative comments about discomfort. Self-reported comfort ratings were measured at 20 min intervals and posture identification was conducted by analysing the video recordings. RESULTS: Six postures were identified, and it was observed that individual participants changed posture at least once and up to nine times during the three-hour period. Body part areas with the highest reported scores of discomfort ratings were: back of the neck, back-left shoulder, back-right shoulder, back-left buttock, and lower back. Participants reported that they had difficulty in performing recommended in-flight exercises due to limited space. CONCLUSIONS: Limited space in aircraft seating restricts passenger movement. Some body areas are more prone to discomfort. Show more

Keywords: Passenger experience, comfort, body part discomfort

DOI: 10.3233/WOR-208016

Citation: Work, vol. 68, no. s1, pp. S183-S195, 2021

Authors: Smith, Jordan | Phillips, Stephen | Bowler, Nic | Conway, Harry | Caglar, Levent

Article Type: Research Article

Abstract: BACKGROUND: A robust rail seat comfort assessment can inform the GB rail industry when procuring new seats and identify areas for comfort improvement in the refurbishment of existing seats, improving the customer experience. OBJECTIVE: To take a multifactorial approach to measuring comfort and to create a robust seat comfort assessment method for the GB rail industry. METHODS: Seat comfort assessment scores were developed by identifying seat dimensions (e.g. Seat height, seat width, seat depth), seat pad thickness and hardness requirements, seat accessories and seat attractiveness components. Scores for each seat feature were verified by conducting a …fitting trial and asking 7 participants to rank dimensions through a range of adjustment. The combined scoring of features was verified by asking 14 participants to rank seats in three configurations (<minimum comfort; minimum comfort;>minimum comfort). The seat comfort dimensions scores were then validated by ranking seven existing rail seats using the assessment method and comparing the ranks with subjective comfort ranks of 12 participants. RESULTS: The validation testing resulted in a moderate positive correlation, indicating an alignment between the seat comfort assessment method and subjective comfort scores. CONCLUSIONS: A multifactorial seat comfort assessment has been shown to be a good indicator of passenger seat comfort. Show more

Keywords: Seat comfort, seat design, rail travel, customer experience

DOI: 10.3233/WOR-208017

Citation: Work, vol. 68, no. s1, pp. S197-S208, 2021

Authors: Han, Lu | Zhang, Hechen | Xiang, Zhongxia | Shang, Jinze | Anjani, Shabila | Song, Yu | Vink, Peter

Article Type: Research Article

Abstract: BACKGROUND: The contrast between a bright computer screen and a dark ambient environment may influence comfort of the users, especially on their eyes. OBJECTIVE: The objective of this research is to identify the optimal desktop lighting for the comfortable use of the computer screen in a dark environment. METHODS: An experiment was designed where seven illumination setups were introduced for the users to perform their leisure tasks on a computer screen. Fifteen healthy subjects participated in the experiments. During each session, durations of the eye blinks, fixations and saccades of the user were recorded by an …eye tracker. His/her neck and trunk movements were recorded by a motion tracking system as well. The comfort/discomfort questionnaire, localized postural discomfort questionnaire, NASA task load index and computer user questionnaire were used to record the overall comfort/discomfort, the local perceived physical discomfort, the cognitive workload, and general/eye health problems, respectively. RESULTS: Subjective and objective measurement results indicated that users felt more comfortable with high intensity warm lights using a computer screen. We also identified that the eye fixation durations, as well as the scores of two questions in the computer user questionnaire, have significant negative correlations with comfort. On the other side, the durations of blinks and the scores of three questions in the computer user questionnaire, were significantly correlated with discomfort. CONCLUSION: The warm (3000K) and high intensity (1500 lux) light reduced the visual and cognitive fatigue of the user and therefore improve the comfort of the user during the use of a computer screen. Show more

Keywords: Light, design, eye tracking

DOI: 10.3233/WOR-208018

Citation: Work, vol. 68, no. s1, pp. S209-S221, 2021

Authors: Tang, Zhi | Liu, Zhihui | Tang, Yingte | Dou, Jinzhen | Xu, Chang | Wang, Lina

Article Type: Research Article

Abstract: BACKGROUND: More and more people choose to travel by high-speed railway. The seats in these vehicles are an important contact point and comfort of the seat cushions needs attention. OBJECTIVE: The aim of this study is to choose among three seat cushions, the one that creates most comfort for a high-speed train. METHODS: Twelve healthy volunteers were selected to participate in the experiment. Three different surface shape models of high-speed railway seat cushions were used. The Seat Pressure Distribution Index (SPD%) was calculated and analysed. A 7-point Likert scale questionnaire was applied for subjective evaluation. …RESULTS AND CONCLUSION: The evaluation is based on subjective and objective data. The results showed that the front protruding cushion made the pressure distribution more even, while the flat cushion had the smallest SPD% and the static pressure was most evenly distributed. This knowledge was beneficial for the design of comfortable high-speed railway seat cushions. Show more

Keywords: High-speed railway, seat cushion, body pressure distribution, sitting posture

DOI: 10.3233/WOR-208019

Citation: Work, vol. 68, no. s1, pp. S223-S229, 2021