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The Faculty of Industrial Design at Delft University of Technology prepares students for a career as industrial designers. As well as functional and aesthetic design, technical production and commercial aspects are also important factors. The cost of production has to be taken into account in the design. Mock-ups created to evaluate ergonomic aspects are a significant cost item. These costs must be kept as low as possible yet the quality of the design has to be as high possible. The situation is complicated by the fact that the characteristics of the ‘digital humans’ used in computer-aided design often vary. Applications used in teaching must facilitate learning and the students should be able to start using them fairly quickly.
Introduction of the Jack Human Modeling and Simulation toolkit to help students work on study, graduation and research assignments. Jack is easy to use and the 3D design environment lends itself to application in an ergonomics context. Jack saves time that can be devoted to the quality of design and saves on the cost of physical prototypes.
The success of a new product is largely determined by the image it conveys, which is influenced by the design. Yet design is not the only aspect that plays a role in product development. Technical and operational aspects are at least as important in ensuring success. For who wants a product that looks good if it is user-unfriendly and fails to meet expectations?
The Delft University of Technology Faculty of Industrial Design teaches students how to incorporate design, technology and business in new products. The Faculty was established in the late 1960s and has its origins in the Interior Department of the Faculty of Architecture. Since the Faculty was established as an independent institution more than 3,200 students have graduated as Industrial Design Engineers. “The broad scope of the course prepares students for positions in design departments as well as various management roles” explains Dr Johan Molenbroek, Associate Professor of Applied Ergonomics at the Faculty. “Graduates of our Faculty are frequently employed in key leadership positions, including Director of Design, by companies such as large automotive manufacturers.”
The need for digital human models
It is Molenbroek’s job to teach students that effective design has to consider the needs of the people who will use the product. “And the people in question may differ considerably,” explains Molenbroek. “When I am introducing the students to their future profession I invite the tallest and shortest inhabitants of the Netherlands to make my point. The difference in their height is 113 centimeters, which is impressive.” This immediately makes it clear to the students that if they really want to cater for the different physical characteristics of the potential users, this cannot be done with physical prototypes at a realistic cost. Molenbroek resolutely dismisses the idea that it is possible to produce designs for the ‘average’ human being. “The average man or woman does not exist. At best an average can only be based on a single physical characteristic, such as height. Yet these people are very unlikely to have the same average weight or average lower leg length. So it makes no sense to design something for the average person. Future industrial designers are taught to consider the spread of relevant characteristics. It is more important for them to identify the people who will not be able to use the product and what alternatives these people will be offered.” This immediately illustrates the importance of using digital human models when working on course assignments. If it is not possible to quickly vary the main characteristics, a design cannot be sufficiently validated. “We work with an application developed by a member of staff. The application is based on wire models and is easy to use, but the functionality and the design parameters of the application no longer meet the requirements we set for the work produced by the students. Since we lacked the capacity to develop the application further, we looked for a replacement application.”
Short learning curve
Applications that might qualify were identified during a conference on digital human modeling, which, according to Molenbroek, brought together the leading users and suppliers. Molenbroek’s job as a professor meant that he had to impose stringent requirements. Firstly, the application had to be suitable for use in an educational environment. This meant that the learning curve had to be short, given that students are not given much time to learn how to use an application. Secondly, the Faculty also wanted to be able to embed the users of the application in its user environment, which is part the standard design environment of Delft University of Technology, so it had to be possible to quickly transfer the design environment. Thirdly, since students and researchers work on projects in all parts of the world, they needed to be able to design products for very different anthropometric characteristics of different peoples. The ‘average’ Chinese head shape is not the same as the ‘average’ Dutch head shape. So it had to be easy for the students and researchers to add measurement data – also from their own projects. And the final important requirement was that it had to be easy to manipulate the anthropometric data in order to model the different stages of a human life. “Our market research showed that the Jack Human Modeling and Simulation toolkit developed by Siemens Industry Software was the only application that met our requirements without any limitations” explained Molenbroek. “And from my point of view these requirements had to be met for virtually every user.”
The Jack Human Modeling and Simulation toolkit provides the functionality to develop digital human models with characteristics that match the characteristics of the target group. The application uses public databases that contain the latest anthropometric data. “An example of such a database with 1D and 2D measurement data can be found at www.dined.nl, which makes anthropometric data from Delft University design projects available to colleagues” explains Molenbroek. As well as having the right physical proportions, the models can also be used to examine weight-bearing variables. “For example, as well as ensuring that a person fits in their operating environment, it is also possible to see if a particular operational procedure will involve an excessively heavy load, and if the user can see everything they need to see. Movements can also be simulated with the digital models.”
Jack was installed on the two hundred computers available for design projects within the Faculty in May 2008. “To start with we got several student assistants to work with the software to gain experience,” explains Molenbroek. “CAD files and models created in the 3D design system used at the Faculty can be loaded into Jack, so we compiled a brief set of instructions on how to load design geometry.” When working on projects the students are free to determine what tools they want to use. Jack was made available in addition to the Faculty’s own application, but it was not promoted in any way. “The work now being submitted by our second-year students shows that Jack was an excellent choice,” says Molenbroek. “Most of them are making very effective use of Jack. This confirms that it is easy to learn how to use Jack and that the 3D design can quickly be applied in an ergonomics context.” Plans designed to encourage greater use of Jack in teaching and graduation projects are now being developed. The graduation projects are intensively supervised so Molenbroek wants to raise the digital ergonomic analyses to the higher level he envisaged when he introduced the Jack Human Modeling and Simulation toolkit. “We devote considerable attention to ergonomics. If we can speed up the design time we can reduce the number of physical prototypes and we can also reduce the costs. Engineering students can then devote more time to the quality of their design. We expect to achieve outstanding results with Jack in the months and years to come and look forward to publishing a report in a forthcoming issue of the Faculty newsletter” says Molenbroek.
*Johan Molenbroek, Associate Professor of Applied Ergonomics at the Delft University of Technology Faculty of Industrial Design
*Anthropometry: the study of human body measurements