Abstract: The current situation of the automobile industry was introduced in this paper. The fuel econormy were analyzed based on the control strategy and the simple fuzzy control strategy of PID. It is foundthat it fails to meet the requirements of energy conservation and emission reduction in some special vehicleconditions ( such as rapid acceleration, emergency braking etc.) of the simulation cycle. The controstrategy based on Fuzzy PID was researched in this paper, which was applied to the Hydraulic Hybrid Vehicle. The simulation results showed: the Fuzzy PID met the verification requirements, the important fueleconomy indexes, such as the distribution of the torque working point of the automobile engine. It isproved to be an effective control strategy under the Fuzzy PID control strategy.

Key words: Hydraulic Hybrid Vehicles, fuzzy PID, simulation verification, fuel economy