The Integrated Safety Concept of the Ultra-Compact Electric Vehicle

A great opportunity for increasing range and decreasing the production costs of battery-powered vehicles is to lower vehicle weight as far as possible. To this end, designers not only can incorporate lightweight materials, but also reduce the size of the vehicle and limit the equipment installed as excellent weight-saving strategies. Since this strategy could lead to crash incompatibility, ultra-compact electric cars are subjected to enormous loads in the event of a collision with a heavier vehicle. The high structural rigidity and limited deformation paths produce a high crash pulse, with higher forces acting on occupants than are experienced in conventional vehicles. The objective of the safety task force within the Visio.M project funded by the German government was to draft, implement, and test a concept that resolves these conflicting interests and provides sufficient protection for ultra-compact vehicles. Using an analysis of the potential accident scenario involving ultracompact electric vehicles as a starting point, specific safety requirements were derived for these vehicles. To meet these requirements, a strategy for an integrated safety design was developed to reduce the occupant loads. The integrated safety concept incorporates pre-crash systems, occupant protection systems, and a carbon fiber-reinforced polymer (CFRP) monocoque, among other features, and was developed using numeric simulations. Verifiable proof of the operative function and benefit of the safety concept was provided by leveraging numerical simulation techniques, carrying out comprehensive component tests, and conducting a series of full-scale crash tests using a Visio.M prototype. In the end, the integrated safety strategy is the key to realizing a sufficient level of protection for sub-compact vehicles.