Virtual Prototyping

Virtual prototyping is based on the application of Virtual Reality projection systems and interactive devices, to present three-dimensional digital models of products and work systems in a realistic form. Thereby, different characteristics of a prototype can be evaluated and corrected in an early stage of the development process. The more realistic the presentation of the digital model is, the lower is the number of physical models (e.g., of wood, plastics, or metal) that need to be prepared, allowing to save the expenditures for their preparation.

The range of application is manifold, covering, e.g., the design of vehicles, aircrafts, buildings, interiors, production systems, or consumer products (Davies, 2002). Of special importance is that it allows practicing a participative design approach (Haines & Wilson, 1998). That is, employees from different departments (e.g., management, engineering, marketing) and potential end-users and customers joint in front of a large projection screen. They inspect the digital model from different viewpoints, zoom into details, and make their comments. Moreover, commonly different functions of the prototype are visualized, for example the doors of a car can be opened or the seats in an aircraft cabin can be set to a backward leaning position. In sum, this greatly facilitates the communication between the different partners involved in the development process.

Checking the criteria for an ergonomic design presupposes that the Virtual Environment provides functionalities that exceed a mere visualization of the prototype. The most important element is an adequate representation of the user or employee, respectively, with small and large body dimensions (5th percentile female and 95th percentile male), e.g., to check the leg- and elbowroom or the accessibility of pedals and the steering wheel in vehicles. For this purpose, human models are used, for example Ramsis. In addition, actual subjects can be integrated in the model in the form of 3D body scans.

The evaluation of ergonomic aspects requires - beyond that - the examination of body postures, viewing conditions, reach envelopes, and comfort zones. If the body posture is relatively static (e.g., in drivers' workplaces) these aspects can be visualized by additional geometries, but environments with a dynamic body posture (e.g., maintenance of a machine tool) require a complex animation of the human model.

By means of so-called Head-Mounted Displays, the evaluator is put in the user's or employee's place, respectively, in such a way that different aspects of the prototype can be experienced subjectively, for example the viewing conditions from the driver's perspective. Moreover, new interactive devices like data gloves and haptic feedback systems provide additional opportunities. They allow, e.g., simulating the operation of control elements.

The examination of criteria at an early stage results in an improved quality, an acceleration of the development process, and a reduction of development costs. Moreover, Virtual Prototyping assists in the realization of 'prospective ergonomics' (Laurig, 1984) and 'participatory design' (Haines & Wilson, 1998) concepts.

If the evaluation requires complex models and animations and/or a realistic interaction with the prototype, the expenditures for hard- and software are quite substantial. On the other hand, standard applications can be realized using conventional Personal Computers with high-performance graphics boards. Thus, Virtual Prototyping is absolutely affordable even for small and medium-sized enterprises (Gude, 2004a, 2004b).

Davies, R.C. (2002). Applications of system design using virtual environments. In K. M. Stanney (ed.), Handbook of Virtual Environments (pp. 1079-1100). Mahwah, NJ: Lawrence Erlbaum Associates.

Gude, D. (2004a). VR-Anwendungen im Design. In R. Bruder (Hrsg.), Ergonomie und Design (S. 155-163). Stuttgart: Ergonomia-Verlag.

Gude, D. (2004b). Prospektive Ergonomie beim Gesundheitsschutz am Arbeitsplatz – Unterstützungspotential virtueller Realität. Zentralblatt für Arbeitsmedizin, Arbeitsschutz und Ergonomie, 54(9), 326-334.

Laurig, W. (1984). Prospektive Ergonomie - Utopie oder Wirklichkeit? Arbeitgeberverband der Metallindustrie Köln (Hrsg.). Schriftenreihe Arbeitswissenschaft des AGV Metall, Nr. 9. Köln.

Haines, H.M. and Wilson, J.R. (1998). Development of a framework for participatory ergonomics. HSE contract research report 174. Suffolk: HSE Books.

PDF-files of Gude (2004a) and Gude (2004b) are available in Selected publications.