ERGONOMICS, DESIGN AND COMFORT FOR THE AUTOMOTIVE INDUSTRY

The paper aims at describe the design methodology for the development of new products through a creative process, shared with different actors. The research is aimed at the development of new automotive concepts and specifically to an ergonomic and eco-friendly seat for a vehicle for future urban mobility. The application procedure is derived essentially from the study and synthesis of ergonomic principles, from which it is legitimized through laboratory tests. The ergonomic software in virtual environment has demonstrated the high level of the scientific basis, at the same time validated by full regulatory and technical compliance. The Scientific methodology goes from the concept sketches, evaluated with weighted product design techniques, to the 3D CAD and CAS models and to the Virtual Prototype immersed in the environment for Ergonomics studies; it can be applied in the automotive industry. The operating methodology was achieved through the following steps: the first step was CAD components modelling (from the sketches to the 3D parts); then, the CAS validation (the style is evaluated by dedicated tools for shapes quality); design and validation of a "configurator" of the virtual prototype (CAD/CAS Model) of the project seat (in order to set different solutions according to the specific requirements) and ergonomic validation through the use of "virtual human models", for testing comfort of different percentiles based on a sample population database. The research team have designed a seat aiming at the optimization of the postural comfort through the use of specialized software, CAS/CAD and Ergonomic Control. Thanks to the fundamental anthropometric notions it has been possible to design a profile that allows continuous contact of the manikin to fourteen cushion cylinders to ensure a uniform pressure distribution, functional to optimal comfort. It has been developed a seat which optimally accommodates the entire user population (5 percentile female - 95 percentile male). The lumbar support area was obviously connected and linked naturally to the new cervical and dorsal surface of the backrest. During the project development the sinking between virtual mannequin and fourteen cylinders/cushions for both seat and backrest has been identified, defining the dimensioning of cylindrical cushions the choice of material (polyurethane foam/pelprene). As a result, their density have been differentiated depending on the position inside the seat, in order to obtain the maximum passenger comfort without having to adjust the seat, through the knowledge of IRA parameter (Sinking Resistance Index). The particularly compact design of the seat will allow wider room for the rear passengers. The seat, fully recyclable and dismountable, will encourage recycling at end of the product life. The lightness of the structure and cushions will reduce overall weight limiting CO2 emissions. In the event of an accident the overall reduction in weight, with regard to the safety testing of future Euro NCAP crash tests, will minimize whiplash injuries. The described methodology aims at the design of the seat which combines different studies and techniques concerning materials, geometries, human-product interaction, in order to reach the best concept in terms of comfort, style, working behavior, product life cycle.