Methodical conception and development of innovative lightweight chassis systems, illustrated by the example of the "LEICHT" concept

Kurzfassung

In the context of future electric vehicles, new requirements and restrictions, but also larger degrees of freedom, have been revealed for vehicle concepts. To meet the revised conditions, new approaches are necessary as well as a holistic view of the vehicle and its subsystems. Those revised conditions are for example the integration of new and additional functions into the chassis, the reduction of the unsprung mass or the maximization of the packaging space that can lead to a complete redesign of the automobile. In this paper, a methodical conception and development process is presented that faces the changed boundary conditions brought by the electrification and proposes an ap-proach that is divided in 3 main phases. Based on the properties of the vehicle concept, the drive and chassis requirements are derived in phase I of the process. With conceptual design matrices, the drive properties can be determined and afterwards the drive can be dimensioned. In phase II, innovative chassis systems are conceptualized through applying different lightweight strategies. Hereby, the focus is laid on fulfilling the changed chassis requirements and on a possible integration of the drive in the chassis. After the evaluation of the innovative lightweight structures, phase III, the engineering phase, begins were the concepts are developed by means of computer aided design, simulation and multi-body dynamics. In accordance with the theoretical description of the 3 phases, the methodical approach is illustrated by presenting an innovative, electrically powered lightweight chassis concept, the “LEICHT ” - Concept, that was developed with the proposed approach. The “LEICHT” promises a significant weight reduction by integrating the motor in an intelligent way. In addition, the impact on the motor is reduced and the freedom in packaging is maximized. Through the application of the drive/chassis module on all four wheels, new possibilities for vehicle dynamics control strategy can be applied.