Digital human modelling for virtual fitting trials

A recognised difficulty with the conventional use of Digital Human Modelling (DHM) systems is that they typically use percentile data to describe anthropometry and joint constraints. Hence any model is a synthesis of the set of data rather than a representation of any particular human. Implicit in this is that an acceptable degree of correlation exists between body dimensions whereas it has long been known that only weak correlations exist. The consequences are obvious in that products are designed/evaluated against models of humans that do not exist. An alternative approach is to use pre-defined families of manikins that together ‘enclose’ and represent the necessary diversity of human form. In the real world, rather than the digital world, ergonomists use real people in ‘fitting trials’. These people might be selected on the basis of the need for diversity covering the range of anthropometry that is thought necessary for the product evaluation but the practical considerations rarely allow an exhaustive evaluation. This paper describes an amalgam of the two approaches where the anthropometry and other aspects of more than 150 people has been collected experimentally. This data is used within the HADRIAN system as discrete sets of data rather than as the basis for a percentile representation. i.e. the data is maintained as sets relating to each individual and used to construct digital models of individuals. This is combined with a task description language that is used to drive the product or workplace evaluation in a way that is analogous to a physical fitting trial. The approach is being used within AUNT-SUE (Accessibility and User Needs in Transport – Sustainable Urban Environments) a wide–ranging research project looking at exclusion in public transport systems. The use of the HADRIAN approach is illustrated through a focus on the creation of a journey planner that meets the needs of a diverse range of people including the elderly and disabled.