Abstract
Requirements of recent automotive electrical and electronic systems are remarkable due to the increased development of luxury equipment. Also the numbers of actuators in the vehicle and their electrical power consumption have increased heavily. The increase in electrical energy consumptions causes inferior fuel economy in general. In addition the alternator and battery size also might become larger than the acceptable size to provide enough electrical energy in the vehicle. On the other hand, in the design process, it is difficult to estimate the optional energy management without optimization technology in early concept planning stage, because there are many subsystems inside a vehicle. Also the possibility for saving money and time of a development depends on the concept planning. The optimization technique has been desired for long time. The purpose of this paper is to study the simulation technique for optimization vehicle system at the concept planning step. The simulation technique is taken into account not only simple co-simulation between electrical and mechanical domain but also whole detailed vehicle system (E.g. EPS System and Fuel Estimation). In this study, some components such as battery, alternator, starter, engine, EPS, and other electrical components, have been modeled by simulation model language VHDL-AMS. They simulated well the real power-net voltage variation with sufficient accuracy (within 5% error) in practical use (-25deg C to ambient temperature). The EPS system simulation was applied not only to the domains of electrical and mechanical but also the EPS ECU model. The simulation which employed real ECU software, was validated by real vehicle data with an accuracy of 1.25% error. Finally, the simulation shows the fuel consumption dependence on power consumptions of electrical loads with an accuracy of 0.6% error.
Keywords: Multi-Domain simulation, VHDL-AMS, Modeling, EPS System, Estimating Fuel Consumption System