Functional Target Value Deduction using Approximate Models in conceptual Design considering Model Accuracy

摘要

In the early conceptual phase of a car its major properties are set. These include in general the car size, propulsion concept, and the group of buyers. In order to be attractive for the customer the car has to compete in various disciplines with his competitors on the market. Beside the usability, design and appearance various other properties are important to be met. These properties might be due to prescribed legal requirements, e.g. concerning safety (passenger and pedestrian safety), emissions or simply customer desired values such as handling and vibration and acoustic-behavior. Obviously the future vehicle should be as good as possible in all disciplines, however the mentioned properties have strong interaction especially with the weight (acceleration, CO_2 emission) and cost of production. In order to define an achievable and an affordable compromise of optimal sub targets for car body development the criteria size of the car, weight and cost limit have to be considered and combined with the technical possibilities as well as the engineering know how. The current paper demonstrates an approach to derive reasonable and optimal balanced functional targets for car bodies based on approximate models representative for the early design phase.