Effects of the Differences in Driving Behavior on Fuel Economy and Emission Characteristics during Vehicle Simulator Execution 2018-01-1768

Around the world, fuel economy and emission regulations for vehicles have become increasingly stringent year by year. In Europe, the real driving emission (RDE) testing was introduced for evaluating the emission at driving the road-going vehicles after September 2017. In order to effiency produce the actual vehicles, Each automobile manufacturer introduce the “Hardware In the Loop Simulator” (HILS) and “Engine In the Loop Simulator” (which is called the EILS or the extended HILS [1, 2]), which is combined with HILS and an actual engine. However, if the driver model used in the vehicle simulation (HILS, extended HILS) does not correctly simulate actual human driving behaviors, the model vehicle performances will differ from the actual vehicle performance.

The fuel economy and emission characteristics are affected by the differences of the driver model control logic during the execution of vehicle simulation. In this study, we constructed new driver model, which is simulated the human driving behaviors, on HILS and extended HILS. The new driver model was adopted the logic of the pedal operation, which has three elements (quickness, frequency, and holding) [3, 4]. Next, we checked the driving behavior of new driver model by using the chassis dynamometer and actual vehicle operated by driving robot installed this model. In this test result, vehicle driving behaviors by new driver model was exactly similar the human driving behaviors. And, new driver model could be easily operated, even if the vehicle conditions, driving conditions, human driving behavior changed.

At extended-HILS operating, emission characteristics, estimated by adopted of the conventional driver model or the new driver model, are different. It was found that these different driving operations affected the control of emission suppressors such as exhaust gas recirculation (EGR). Therefore, they might cause differences in the fuel economy and emission characteristics between the vehicle simulation/development process and actual-vehicle evaluation process.