Vibration and passenger comfort

The problems of maintaining the well-being of passengers travelling by public transport are complex. They include psychological, physical and organisational considerations all of which may interact to provide an overall, individual comfort reaction. Since it is a fundamental feature of vehicle design, the paper considers the effects of vehicular vibration on passenger comfort. The results of a series of questionnaire investigations to examine both the qualitative and quantitative effects of vibration are reported.     

Questionnaire surveys of passenger comfort

This paper discusses the quantitative assessment of data obtained from questionnaire surveys. Examples are adduced from surveys carried out from Swansea. After discussing the validity of information derived in this way, general methods of assessment are described. The paper continues with a detailed examination of questionnaire methods of the subjective assessment of environmental stimuli, and concludes with examples of the pitfalls which may be inherent in such assessment.     

Techniques available for the assessment of passenger comfort

This paper considers the many techniques which are available to the ergonomist for the assessment of passenger comfort. It is argued that the initial question to be answered asks whether the system as a whole is to be investigated or whether specific aspects of the journey are under consideration. If the answer is the former, then a questionnaire technique is suggested. If an investigation of a more specific nature is required, then consideration should be given to whether it is to be conducted in the 'field' using passengers, in the 'field' using subjects, or in the laboratory. Techniques such as rating scales, observation, paired comparison, and the semantic differential are described, although many other laboratory based techniques are available.     

The thematic structure of passenger comfort experience and its relationship to the context features in the aircraft cabin

This paper describes passenger comfort as an experience generated by the cabin interior features. The findings of previous studies are affirmed regarding a set of 22 context features. Passengers experience a certain level of comfort when these features impact their body and elicit subjective perceptions. New findings characterise these perceptions in the form of eight themes and outline their particular eliciting features. Comfort is depicted as a complex construct derived by passengers' perceptions beyond the psychological (i.e. peace of mind) and physical (i.e. physical well-being) aspects, and includes perceptual (e.g. proxemics) and semantic (e.g. association) aspects. The seat was shown to have a focal role in eliciting seven of those themes and impacting comfort through its diverse characteristics. In a subsequent study, a group of aircraft cabin interior designers highlighted the possibility of employing the eight themes and their eliciting features as a framework for design and evaluation of new aircraft interiors.     

The effect of 17-inch-wide and 18-inch-wide airplane passenger seats on comfort

The pitch and width of airline seats are crucial factors on the comfort of passengers. The aim of this study is to measure the comfort feeling of passengers regarding different widths and together with data from a previous study, to offer suggestions on the aircraft interior design. 311 participants were recruited and were asked to sit in 17-inch-wide and 18-inch-wide aircraft seats in a Boeing 737 fuselage for 10 min, respectively. Questionnaires on psychological comfort and overall discomfort, as well as an additional questionnaire on the discomfort of different body parts, were used to evaluate the comfort and discomfort experience of participants. Experiment results indicated that the comfort scores were significantly higher, and the discomfort scores were significantly lower for sitting in the 18-inch-wide seats than that of sitting in the 17-inch-wide seats. It was also found that rather than the buttock, the shoulders, knees, lower legs and feet contributed significantly to the reduction in overall discomfort by providing more space for movements. Regarding anthropometric measurements, participants with smaller hip-breadth felt more comfort while sitting the 18-inch-wide seat, which highlights the importance of the freedom of movement. By synthesizing the results of a previous study on the relations of the seat pitch and comfort, it was found that given the same amount of additional floor area, widening the seat is more effective on comfort than increasing the pitch.Relevance to industry: This discovery might be useful for the airline industry for a more effective and efficient usage of floor area.     

Identifying and analyzing critical factors impacting on passenger comfort employing a hybrid model

With the increase in air travel, comfort is becoming an important issue with which airlines differentiate themselves in a competitive market. Passengers are paying more attention to their comfort experience during flights. However, passenger comfort is affected by various factors that result from the complex cabin system. Besides, the factors have interrelations between one another. How to identify the key factors and comb through their interrelations to improve passenger comfort efficiently is a critical problem in cabin design. To solve this problem, a hybrid model is proposed to identify the key factors and discuss the interrelation between them based on the questionnaire data. First, factor analysis is conducted to segment complex influencing factors into groups and to extract the most important factors. Decision Making Trial and Evaluation Laboratory (DEMATEL) method and fuzzy set theory are combined in the next analysis, considering both the interrelation between factors and the fuzziness of subjective comfort perception concurrently. It forms a structural model and then visualizes the causal relationships among factors through a causal diagram. The results of an empirical study show that the proposed model is capable of identifying the critical factors that affect passenger comfort effectively and could offer a priority of factors to improve passenger comfort.     

The influence of backrest angles on the passenger neck comfort during sleep in the economy class air seat without head support

The purposes of this study were to characterize the influence of seat back angle variations on the neck comfort of sleeping passengers without a pillow and provide suggestions for the design of economy-class seats. In this study, 17 subjects were subjected to a sleep experiment to test the effect of the backrest angle on head and neck rotation and the fatigue level of the neck muscles. The results showed that a reclined backrest (positioned at 110°) caused greater rotation of the head and neck and greater fatigue of the neck muscles than a vertical backrest. Additionally, the higher was the subject's head extended above the top of the backrest, the more complicated the head and neck rotation was and the more intense the stretching of muscles was. We conclude that, when sleeping in a sitting position without head support, passengers were more likely to experience neck muscle fatigue with the reclined backrest than with the vertical backrest. Passenger height was also found to be an important factor contributing to head and neck fatigue. On the basis of the experimental results, we offer suggestions for the design of backrests to improve passengers' sleeping experience. Our research and suggestions provide a new path for innovation in the design of economy-class seats and could help to improve the travel experience.     

Predicting passenger seat comfort and discomfort on the basis of human,context and seat characteristics: a literature review

Abstract

This literature review focused on passenger seat comfort and discomfort in a human–product–context interaction. The relationships between anthropometric variables (human level), activities (context level), seat characteristics (product level) and the perception of comfort and discomfort were studied through mediating variables, such as body posture, movement and interface pressure. It is concluded that there are correlations between anthropometric variables and interface pressure variables, and that this relationship is affected by body posture. The results of studies on the correlation between pressure variables and passenger comfort and discomfort are not in line with each other. Only associations were found between the other variables (e.g. activities and seat characteristics). A conceptual model illustrates the results of the review, but relationships could not be quantified due to a lack of statistical evidence and large differences in research set-ups between the reviewed papers.

Practitioner Summary: This literature review set out to quantify the relationships between human, context and seat characteristics, and comfort and discomfort experience of passenger seats, in order to build a predictive model that can support seat designers and purchasers to make informed decisions. However, statistical evidence is lacking from existing literature.     

A guide to thermal comfort

This guide provides a simple design procedure for dealing with the requirements for a comfortable thermal environment. From the expected activity level and clothing insulation of the people concerned, a subjective temperature is calculated which will provide thermal comfort. This subjective temperature is a combination of physical parameters of the environment, ie, air and mean radiant temperatures, and air speed. A heating system must be designed to that the parameters combine to give the optimum subjective temperature. The guide also considers other possible sources of discomfort, and gives acceptable limits for them.     

Possibilities to improve the aircraft interior comfort experience

Comfort plays an increasingly important role in the interior design of airplanes. Although ample research has been conducted on airplane design technology, only a small amount of public scientific information is available addressing the passenger's opinion. In this study, more than 10,000 internet trip reports and 153 passenger interviews were used to gather opinions about aspects which need to be improved in order to design a more comfortable aircraft interior. The results show clear relationships between comfort and legroom, hygiene, crew attention and seat/personal space. Passengers rate the newer planes significantly better than older ones, indicating that attention to design for comfort has proven effective. The study also shows that rude flight attendants and bad hygiene reduce the comfort experience drastically and that a high comfort rating is related to higher "fly again" values.     

Virtual optimisation of car passenger seats: Simulation of static and dynamic effects on drivers’ seating comfort

The virtual investigation of static and dynamic effects on seating comfort requires the application of an adequate human model. An appropriate seat model considering static and dynamic properties of the structure, the foam and the trim is needed to perform an optimisation for a lower load level on the driver. The evaluation of the seating comfort must be divided into a static and a dynamic part. For the computation of the relevant physical quantities with the human model CASIMIR and a detailed seat model, the finite-element solver ABAQUS (ABAQUS Inc., http://www.abaqus.comwww.abaqus.com) is used.

To reflect a real driving situation, in the first step the human model is adapted to the right posture, which is given by the inclination of the cushion and the backrest. The seating process is then computed by the load due to gravity. The static comfort is mainly evaluated by the seat pressure distribution. Results such as the H-point and the meat-to-metal value can give additional important informations for the ergonomic and structural design of the seat. As the model reflects the nonlinear properties and the finite-element solver considers the effects out of finite displacements and contact, a good correlation with measurement is achieved.

The dynamic simulation is carried out by a unit excitation of the seat slides at the clamping points. To consider frequency-dependent properties of foam, structure and the human body, the computation uses an implicit solver. Therefore the model is linearised after the nonlinear static seating process.

Dynamic comfort is evaluated by the seat-transfer function. The presented numerical method leads to a good correlation with the measurements. Superposing the results with real excitation signals enables the estimation of the dynamic loads as muscle or intervertebral disc forces on the driver.

Altogether this method, in an early state of the development enables the user to optimise a car passenger seat structure due to the static and dynamic comforts. Considering boundary conditions as higher load amplitudes and accelerations, the advantages of virtual development can also be applied for construction vehicle seats.

Relevance to Industry

The present method allows the evaluation of static and dynamic comforts in a virtual phase of seat development. Besides the reduction of time and costs, the application of the simulation enables the testing of new materials and ways of construction with low investment.     

A tool to assess the comfort of wearable computers

Wearable computer comfort can be affected by numerous factors, making its assessment based on one value with one scale inappropriate. This paper presents a tool that measures wearable comfort across six dimensions: emotion, attachment, harm, perceived change, movement, and anxiety. The dimensions for these comfort rating scales were specifically developed for wearable equipment assessment by applying multidimensional scaling to a comfort term association matrix developed using the results of groupings of wearable computer comfort terms. Testing the scales on four different types of wearable computer showed that the scales can be used to highlight differences in comfort between different types of technology for different aspects of comfort. An intraclass correlation of .872 suggested that the scales were used with a high level of reliability. A second study showed that modifications made to a wearable computer resulted in improvements in comfort, although they were not significant (p > .05). A potential application for this research is as an aid to designers and researchers for assessing the wearability, in terms of comfort, of wearable computer devices and to determine the effectiveness of any modifications made to the design of a wearable device.     

Vehicle noise and the passenger

Little effort has been put into studying the noise climate inside passenger vehicles. This paper shows that noise levels in motor cars and heavy goods vehicles are unacceptable to the passenger at typical cruising speeds. It is suggested that one factor responsible for this state of affairs is the lack of criteria for acceptable noise levels. Research into the subjective response to noise in motor vehicles, both on the road and in the laboratory, is described. The importance of very low frequencies is shown in determining levels of comfort, as well as the difficulties in accurately reproducing in-vehicle noise in the laboratory. A tentative criterion is given for acceptable noise levels in passenger vehicles and work is described which, it is hoped, will lead to a more precise measure of subjective rating.     

Using a cool spot to improve the thermal comfort of glassmakers

Glassmakers monitoring a rolled plate process suffered discomfort from the high temperature environment. This was caused by the radiant heat emitted by the furnaces and associated equipment surrounding the glassmakers' working area, combined with a high air temperature. The glassmakers are responsible for monitoring the glass rolling machine to ensure that the product is manufactured to specification, and to prevent the molten glass sticking to the rollers. This study improved their thermal comfort by the construction of a cool area. They were also brought nearer to the rolling machine. This, with the addition of a cooler environment, improved their monitoring performance. The cool spot was constructed using glass and aluminium radiant heat shields, air curtains and low velocity cooling air.     

改善室内环境舒适度的一种新型控制方法

室内环境舒适度直接影响着在室人员的健康和工作效率,需要进行有效的控制以保证其舒适性。论文以某办公室为研究对象,提出一种基于同策蒙特卡罗自适应控制方法对建筑物内空调系统、加湿器、除湿器、照明系统和通风系统等设备优化控制,调节室内温湿度、照度和CO₂浓度提高室内舒适感。建立了有关影响室内环境舒适度的因素的状态变化的数学模型,并利用实验数据验证模型,同时与PID和模糊控制算法进行了仿真对比分析。结果表明：在同时控制影响室内环境的多个因素时,同策蒙特卡罗控制方法能够较好的跟踪实际情况,且该方法稳态误差较小,收敛速度较快。     

How the Kano model contributes to Kansei engineering in services

Recent studies show that products and services hold great appeal if they are attractively designed to elicit emotional feelings from customers. Kansei engineering (KE) has good potential to provide a competitive advantage to those able to read and translate customer affect and emotion in actual product and services. This study introduces an integrative framework of the Kano model and KE, applied to services. The Kano model was used and inserted into KE to exhibit the relationship between service attribute performance and customer emotional response. Essentially, the Kano model categorises service attribute quality into three major groups (must-be [M], one-dimensional [O] and attractive [A]). The findings of a case study that involved 100 tourists who stayed in luxury 4- and 5-star hotels are presented. As a practical matter, this research provides insight on which service attributes deserve more attention with regard to their significant impact on customer emotional needs.

Statement of Relevance: Apart from cognitive evaluation, emotions and hedonism play a big role in service encounters. Through a focus on delighting qualities of service attributes, this research enables service providers and managers to establish the extent to which they prioritise their improvement efforts and to always satisfy their customer emotions beyond expectation.     

How the Kano model contributes to Kansei engineering in services

Recent studies show that products and services hold great appeal if they are attractively designed to elicit emotional feelings from customers. Kansei engineering (KE) has good potential to provide a competitive advantage to those able to read and translate customer affect and emotion in actual product and services. This study introduces an integrative framework of the Kano model and KE, applied to services. The Kano model was used and inserted into KE to exhibit the relationship between service attribute performance and customer emotional response. Essentially, the Kano model categorises service attribute quality into three major groups (must-be [M], one-dimensional [O] and attractive [A]). The findings of a case study that involved 100 tourists who stayed in luxury 4- and 5-star hotels are presented. As a practical matter, this research provides insight on which service attributes deserve more attention with regard to their significant impact on customer emotional needs. STATEMENT OF RELEVANCE: Apart from cognitive evaluation, emotions and hedonism play a big role in service encounters. Through a focus on delighting qualities of service attributes, this research enables service providers and managers to establish the extent to which they prioritise their improvement efforts and to always satisfy their customer emotions beyond expectation.     

The hackers' comfort

A survey of present-day installations reveals that users perceive their comfort to coincide with the absence of security. To the extent that security is enforced, e.g. by the use of passwords, the user flouts all reasonable rules for dealing with these passwords. Matters are not improved when it is up to the system to issue passwords. The reason for present-day insecurity in run-of-the-mill installations is in the conflict between user friendliness as advertised and perceived by the user on the one hand, and security requirements on the other hand. There always seem to be good arguments to deal lightly with security where security, erecting barriers, is seen to be at variance with user friendliness.