Högskolan i Skövde

Few studies have presented three-dimensional car-driving postural information. This laboratory study investigated drivers' preferred postures, preferred interior dimensions and how they characterise their postures. The minimum-maximum intervals of preferred angles corresponded well with other experimental studies and were larger than intervals for comfort, strength and alertness defined on the basis of theoretical reasoning. No preferred posture differences were found between females and males; nor were differences found when comparing posture after five and twenty minutes of driving. Preferred posture was not symmetric: significant differences were found between the left and right side. Subjects characterised their posture as comfortable, relaxing and restful.

Although buttons are a frequently used type of control in car interiors, little research has been undertaken on how the usage of buttons affects the visual behaviour of the driver. In this study, the aim was to analyse the effect of push button location and auditory feedback on drivers' visual time off road and safety perception when driving in a real traffic situation. The effect of six button locations (five on the centre stack, one near the gear stick) was tested. Drivers' visual behaviour was studied in real traffic on a motorway. An eye tracking system recorded the visual behaviour of eight drivers who, in 96 repeated trials each, were instructed to press a specific button. Data analysis focused on the drivers' visual time off road and safety perception in relation to the location of the button to be pressed. Auditory feedback did not show a significant effect on visual time off road. The time off road increased significantly as the angle increased between the normal line of sight and button location for the five buttons placed on the centre stack. Results for the button located close to the gear stick, with the highest eccentricity, produced a short time off road. This unexpected finding is discussed in terms of three potential explanations: 1) the role of perceptual discrimination; 2) risk perception; and 3) motor control.

In the ANNIE project - Applications of Neural Networks to Integrated Ergonomics - BE96-3433, a tool for integrating ergonomics into the design process is developed. This paper presents some features in the current ANNIE as applied to the design of car interiors. A variant of the ERGOMan mannequin with vision is controlled by a hybrid system for neuro-fuzzy simulation. It is trained by using an Elite system for registration of movements. An example of a trajectory generated by the system is shown. A fuzzy model is used for comfort evaluation. An experiment was performed to test its feasibility and it showed very promising results.

The car interior is a complex man–machine interface. Poor interior design contributes to traffic accidents as well as discomfort and disorders in professional and long distance drivers. When buying a car comfort is for many customers an important factor. Consequently, car interior comfort besides safety is of great importance when designing cars. Comfort is a subjective feeling and hard to model mathematically. The aim of this paper is to show the feasibility with fuzzy logics to model relations between human perception, human characteristics and workplace structure. A model where drivers’ perceived comfort when handling interior controls is in relation to anthropometrics and control positions are used as illustration. A series of control reach studies in simulated car driving was used for the development of a comfort model. Combined with a human simulation program the comfort model may be used by car designers at an early stage of the design process for evaluation of design concepts aiming at reachable and manageable controls in a safe and comfortable interior. The comfort model illustrates that fuzzy logics provides a constructive way of turning qualities into mathematics.

Relevance to industry: Fuzzy logics provide the opportunity to model physical parameters from the human and the technical system together with human perceptions. Such model can be combined for instance with human simulation tool and reduce ergonomic tests in real physical environments.

Car developers use digital human modeling tools to analyze and visualize car interiors in relation to human characteristics before the vehicles are actually constructed. Developers, reviewers and users of human simulation tools often claim that such tools can reduce development time and costs. In car industry companies today, human simulation tools are used by a single or a few experts in an informal working process with insufficient documentation. To prepare for extensive, effective and efficient use of human simulation modeling tools in industry with several users within a company, the aim of this study was to design and evaluate a digital guide and documentation system to support digital human modeling applications. A participative design approach was used in developing the guide, involving human simulation tool users and managers within the General Motors Group. The system consists of two major parts: a usage guide and database. The usage guide is divided into three sections considering the professionals involved: (1) initiation of human–vehicle interaction analysis, (2) preparation and running of the digital human tool and (3) recommendation formulation and closure. The guide was connected to a database with search and print capabilities for previous and ongoing human simulation analyses. Sixteen subjects from industry and university settings evaluated the support system. Results showed that the users appreciated the guide and documentation system, in particular, the database for storing human simulation work. The guide was perceived as being especially useful for guidance in large analyses, whereas for smaller ones the subjects felt the formalized guide was too lengthy and time consuming. The use of the formalized guide is likely to reduce differences in results, within and between tool users. The support system guides the simulation tool user through an acknowledged process; it documents, stores and keeps track of ongoing and previous analyses, and facilitates the reuse of studies.