Vehicle architectures change and evolve in order to gear to new mobility demands, are reconfigured and renewed to cater to market demands, as opposed to the idea that the car is a mature product. Challenges to be met in the near future include:

• reduce consumption and emissions (throughout the entire life cycle);

• offer versatile, compact products with low running costs.

Vehicles must also comply with ever more stringent safety standards in line with the evolution of international regulations. At the same time, car-makers are required to make decisions and formulate strategies that reduce investments, such as standardisation of floor pans, of components and the development of modular solutions. The road map of architectures must, therefore, run parallel but separately from that of technologies so that the need for standardisation is compatible with market customisation requirements. The Mimosa Project (MIcrovettura con propulsione ecologica MOdulare e Sicura ad elevata versAtilità of impiego), for example, addresses the problem of urban passenger and goods transport, focussing on the development of compact, safe vehicles that exploit floor pan modularity to adapt to a multiplicity of environment-friendly power-units. The architecture developed in the Mimosa Project delivers maximum versatility of use, making it possible to design an entire family of micro cars (city cars, delivery vans, micro spiders, etc.) with reduced specific investments. The main leading edge of this vehicle architecture is adoption of the ‘split-frame’ layout already used in the past for other applications (sports cars, niche vehicles) but never for city cars.

In the ‘split frame’ layout, the structural function is separated from the aesthetic function in two distinct modules:

• First module: the rolling chassis. Wheelbase, track and height from the ground can be modified with minimum design changes. The chassis is solely responsible for safety, comfort and handling performance and  is also designed to house a family of ecological, alternative power-units.

• Second module: the body. This module is responsible for the aesthetic function and is connected rigidly to the supporting floorpan. The body is made of polymer aesthetic panels (low-investment technologies). The layout of the body and of mobile parts is designed to permit customisation according to various types of use (passenger transport, delivery, etc.). To demonstrate the results achieved in the project, two vehicles were constructed: a compact city car (2.5 metres in length) with electric traction, powered by lithium ion batteries, and a micro pick up, a 2.8-m long two-seater, also with electric traction powered by lithium ion batteries. Both vehicles feature front drive, guaranteed by two independent electric motors that each act on a single wheel. The differential function is furnished electronically rather than mechanically. Compared with the conventional mechanical solution, this design approach offers various advantages as regards dynamic stability control and also optimisation of the feeling of steering. The project, with MIUR funding, was carried out in cooperation with the University of Catania and GGG Elettromeccanica, a Catania-based company with long-term experience in the production of special vehicles.