Research on the Characteristics of Vehicle Emission by Engine Dynamometer

In the light of the vehicle dynamics,theory the driving mode of vehicle was calculated to speed and torque of engine.Based on this calculation,one heavy-duty engine was chosen to carry out engine emission test of running mode simulation.The differences between on-board emission and engine-approval emission was analyzed,and the characteristics of the on-road emission of heavy-duty vehicle were found out.The result indicates that on-road emission is very different from engine-approval emission,and the emission factor in high-speed mode is lower than the one in low-speed mode.