Development of a software in the loop environment for automotive powertrain systems

In the last years the interest for hybrids vehicle increased mainly for environmental reasons. The dynamic behavior of a vehicle is then influenced by the interaction between the engine and the hybrid system. The final goal of the paper is to realize a software in the loop environment which can be utilized for the development of control strategies for hybrid vehicles. This paper presents the implementation of a simplified engine-driveline model to complete an existing vehicle dynamic model. The engine model is based on maps which are expressed as function of engine speed and load request. Particular care is devoted to the clutch model which allows describing both the situations of engaged and disengaged clutch. The driveline model also permits to change the transmission ratio between engine and wheels depending on the selected gear. The model parts are integrated, taking into account the requirement to use the model in real time simulations, coupling to the engine-driveline with a pre-existing vehicle dynamics model by means of the vehicle driving wheels. The complete vehicle-engine model is used to evaluate the differences in vehicle dynamic behavior when additional masses are added to the vehicle and the position of vehicle center of gravity is changed.