Diane E. Gyi

INTERFACE PRESSURE AND THE PREDICTION OF CAR SEAT DISCOMFORT

The technique of interface pressure measurement has generated considerable interest in the automotive industry as a method, which could be used to predict driver discomfort during the development of prototype seat designs. Two repeated measures experiments were carried out to evaluate the practical application of the technique. The variables of foam density and posture were used to create discomfort, the whole emphasis of the work being to generate results with real-world applicability. A clear, simple and consistent relationship between interface pressure and driving discomfort was not identified. Future studies using this technique should provide information regarding such factors as gender, body mass, anthropometric data, posture and foam hardness due to the confounding nature of these variables.

Exploring the optimum posture for driver comfort

Published postural angles for driving comfort are based on theoretical calculations and not observed driving postures. An experiment was conducted to investigate observed optimum driving postures and positions of the main driving controls for comparison with available data. New guidelines for optimum postural comfort have been developed. The recommended range of postural angles should be used with care because not all people will be comfortable with the whole range as individuals. Furthermore, inter-relationships between adjacent joint angles need to be considered. The data also support a strong need for both horizontal and vertical adjustment in the steering wheel.

SEAT PRESSURE MEASUREMENT TECHNOLOGIES: CONSIDERATIONS FOR THEIR EVALUATION

Interface pressure measurement has generated interest in the automotive industry as a technique which could be used in the prediction of driver discomfort for various car seat designs, and provide designers and manufacturers with rapid information early on in the design process. It is therefore essential that the data obtained are of the highest quality, relevant and have some quantitative meaning. Exploratory experimental work carried out with the commercially available Talley Pressure Monitor is outlined. This led to a better understanding of the strengths and weaknesses of this system and the re-design of the sensor matrix. Such evaluation, in the context of the actual experimental environment, is considered essential.

Interface pressure data and the prediction of driver discomfort in road trials.

An objective measure that will predict discomfort reliably, and which can be used at an early stage in the development of a vehicle and its seating, would have the potential to reduce the prevalence of musculoskeletal problems associated with driving. This paper reports on an extended road trial study to further investigate the potential value of pressure distribution data in the prediction of reported discomfort. Road trial data were collected from three cars and then interface pressure data were recorded for each of the three seats. Clear differences were identified between the cars with respect to reports of discomfort. However, no clear relationship was found between interface pressure data and reported discomfort.

The quality of accident and health data in the construction industry: interviews with senior managers

Despite recent changes in legislation and advances towards an integrated project-wide approach, health and safety management in the construction industry is still a major problem, involving a substantial cost to business, society and individuals. A prerequisite to improving the situation and developing an effective management strategy is monitoring, providing a detailed understanding of the effectiveness of different approaches to intervention. This paper describes a feasibility study using in-depth interviews with senior managers to explore the quality of accident and health data of nine large, high profile companies from the engineering construction sector. The interview dialogue comprised a series of questions and issues to be explored on the organizations accident reporting systems (e.g. what is reported, analysis performed, computerization), unsafe act and near miss auditing (e.g. definition, validity), failure type indicators (e.g. auditing, quantification) and safety culture indicators (e.g. commitment, health). Although safety was a priority for companies, health (i.e. medicals and monitoring systems) had not been given the same consideration, especially with regard to subcontracted labour. This study shows that the validity of accident statistics as a measure of safety remains a limitation, and that there is a requirement for a consistent and integrated approach to the measurement of health and safety performance.

HADRIAN: a virtual approach to design for all

This article describes research into the area of ‘design for all’. The research addresses two common needs for designers working towards developing inclusive products and environments, namely, data on users that are accessible, valid and applicable, and a means of utilising the data to assess the accessibility of designs during the early stages of development. The approach taken is through the development of a combined database and inclusive human modelling tool called HADRIAN. Data were collected on 100 people, the majority of whom are older or have some form of impairment. These individuals provide a browsable resource spanning size, shape, capability, preferences, and experiences with a range of daily activities and transport-related tasks. This is partnered with the development of a simple, CAD-based task analysis system. Tasks are carried out by the virtual individuals in the database and accessibility issues are reported, allowing excluded people to be investigated in order to understand the problems experienced and solutions identified. HADRIAN is also being expanded to include a more accessible journey planner that provides accessibility information to both end users and transport professionals. Together, HADRIAN allows more informed choices to be made either in travelling, or in the designing of products and environments.

Virtual fitting trials in ‘design for all’

Abstract ‘Design for all’ embraces the concept of designing products and workplaces so as not to exclude significant sections of the total user population. In particular, the needs of old and disabled people are to be considered alongside the younger and able-bodied population to ensure that products that are equally appropriate for all users. This is to be contrasted with a ‘design for the disabled’ approach where the special needs of disabled people are considered in order to provide products that may only be appropriate for that section of society. Fitting trials are an established technique in ergonomics where a product or workplace is evaluated by trials (perhaps on a mock-up or prototype) using a carefully selected user group that is representative of the total target population. Typically, subject selection would be based on age, gender, size, etc., and total sample sizes limited to perhaps a few dozen. A percentage of the population accommodated by the design can then be determined by reference to a set of elemental tasks such as reaching to controls. In this research, the fitting trials are virtual in that computer modelling techniques are used to create a three-dimensional geometric model of the workplace/product and evaluation is achieved using a human model that can be varied to represent the individuals within the sample. There is a lack of anthropometric and biomechanical data relating to older and disabled people so a small-scale survey is being undertaken so that an appropriate population of computer human models can be created. Methods are being developed to allow the percentage accommodated by a design to be determined in relation to a description of tasks to be carried out. Currently, an ATM (automated teller machine) design is being used as a case study to develop these techniques. Further research will eventually be undertaken to extend the data, generalise the percentage accommodation evaluation and optimise the design in terms of percentage accommodation.

Capturing user requirements for an integrated home environment

Technology is being developed at a rapid rate such that a large proportion of the population are finding it impossible to utilize the full functionality of products. In an integrated home environment, it is vital that technology products are not only desirable but also accessible to the whole population in terms of functionality and usability. This work-in-progress paper presents the findings from the first phase of a project investigating smart user interfaces (SUIs) in the context of an integrated home environment. To gather the requirements for universal access, eight workshops were conducted focussing on the needs, attitudes and expectations of people towards smart homes. This will contribute to the development of user led design criteria for the development of a prototype universal SUI.

Using HADRIAN for eliciting virtual user feedback in 'design for all'

Abstract ‘Design for all’ is an approach to product, environment or service design that aims to maximize the usability of a particular design. However, a key concept of this approach is not to tailor designs to the user in a bespoke fashion, but rather to provide a single solution that accommodates the needs of all users, including those who are older or are disabled. In order to support the designer/design team in ‘design for all’ a computer aided design and analysis tool has been developed. The tool, known as HADRIAN, has been developed to address two critical factors. The first factor is the provision of accurate and applicable data on the target users, including a broad spectrum of size, shape, age and ability. The second factor is an efficient and effective means of utilizing the data for ergonomics evaluations during the concept stages of design. HADRIANs database and task analysis tool work in combination with the existing human modelling system SAMMIE. The system as a whole allows assessment of a design against the population in the database, providing a means to elicit some of the feedback that might be gained by real user trials at a stage in the design process when physical mock-ups and user group selection would be prohibitively time consuming and expensive.

A TASK BASED 'DESIGN FOR ALL' SUPPORT TOOL

Abstract The ‘design for all’ philosophy promotes the development of products that meet the requirements of a broader section of the population, including those who are older or disabled, to minimise the need for bespoke designs and individual customisations. Such an approach begins to meet the needs of a population containing an ever increasing proportion of these excluded groups, whilst providing opportunities to manufacturers to maximise the available market for any given product. Most design activity embodies some form of task analysis that involves identifying users and the tasks they perform. Computer based human modelling systems are becoming increasingly important in this task analysis role combined with the established ergonomics technique of fitting trials, in which a product or environment is evaluated through trials using a carefully selected user group. This research addresses the lack of existing data necessary for the accurate representation of human form and capability in the older and disabled populations for use in these modelling systems. A small-scale survey is being undertaken to collect this important information. In addition, existing modelling systems in this area rely on expert ergonomics knowledge in performing task based analysis, which in addition can be a time consuming and repetitive task. Methods are being developed to streamline this process and to place the emphasis on good design and ergonomics principles as opposed to ‘driving’ the system. These methods involve the development of a simplified process for computer based task analysis and a means of determining the percentage accommodated by any given design. Further research will eventually focus on extending the data collection, refining the task model and look at a means of suggesting design solutions in response to the analysis results.