OCCUPATIONAL APPLICATIONSThis contribution provides a framework for modeling user-product interactions (in CAD) for in-depth ergonomic analysis of product design, using digital human models. The framework aims to be applicable to a wide range of different products while being suitable for designers - especially those who do not have specialized ergonomic expertise or training in human behavior - by providing an intuitive, standardized, and time-efficient modeling procedure. The framework contains 31 elementary affordances, which describe mechanical dependencies between product geometries and human end effectors. These elementary affordances serve as a tool for interaction modeling. Additionally, the paper provides a taxonomy of elementary affordances, which can be used to formalize / abstract the nature of user-product interactions and to describe them as elementary affordances. Furthermore, an implementation of the interaction-modeling framework is presented in a CAD environment and provides an example of how the framework could be used in terms of a computer aided ergonomics tool.
Keywords: CAD; Ergonomics; affordance; digital human model; user product interaction; user-centered design.
TECHNICAL ABSTRACTBackground Digital human models (DHM) have not yet reached their full potential for proactive virtual assessment of ergonomics in engineering and industrial design. Modeling the interaction between user and product often is time demanding, cumbersome, unstandardized, or embedded insufficiently in the computer aided engineering environment. Existing interaction-modeling frameworks either address the simulation of occupational processes, are limited to a specific use cases, or offer insufficient usability.Purpose We present a framework for interaction modeling, its methodic background, as well as its implementation. The framework aims to provide ergonomic analyses of product designs, while being suitable for designers who do not have specific ergonomic knowledge or training in human behavior.Methods To resolve these partly contradictable demands, we utilize affordances, which serve as a tool for interaction modeling. We hypothesize, that many interaction concepts existing in human technology interaction can be reduced to a relatively small set of elementary affordances. We developed a taxonomy of elementary affordances to deduce elementary affordances from empirical interaction data.Results We present the resulting taxonomy, as well as the resulting 31 elementary affordances, which describe mechanical dependencies between product geometries and human end effectors. The identified elementary affordances are implemented as affordance features in a CAD environment (Siemens NX) and result in an interaction-modeling framework. A brief application example regarding the functionalities of the framework is presented.Conclusions The introduced framework demonstrates how the integration of interaction modeling into the computer aided engineering environment can be achieved in a comprehensible and straightforward way. The resulting simplicity and accessibility may constitute one key factor to help exploit the potential of DHM simulation as a computer aided ergonomics tool in engineering and industrial design.