Optimal Design of the Power Train of Vehicles: Modelling, Simulation and Optimization

Abstract

In the early stage of development of a vehicle, the design of the power train is encouraged by numerical simulations. Virtual testing of different variants and configurations of a car can be well-investigated without constructing any prototype. The mathematical models used to calculate the fuel consumption and driving power differ. Therefore, there exist different program packages to calculate these qualifying criteria of a vehicle. A standard interface between these packages and the optimization program has to be developed. Different, partly antagonistic objective functions are presented to optimize the design of the power train. The most important of the criteria are driving power and fuel consumption. The aim of development of new vehicles is to reduce the fuel consumption without loss of driving power. To fulfil these requirements it is not enough to investigate on each part of the power train separately. It is more efficient to optimize the whole system, using a mathematical model of the power train. The aim of the investigations is to find optimal characteristics of the torque converter, automatic gear transmissions, and the transmission of the rear axle differential, using mathematical methods for systematic optimization. In this paper methods are developed which can be used to optimize both model parameters and whole characteristics. The investigations are split up into the topics: mathematical description of objective functions, appropriate parameterization of characteristics, sensitivity analyses of the objective function. Some results are presentedKeywordsFuel ConsumptionPenalty TermRear AxleTorque ConverterPower TrainThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.