Study On Intelligent Control System Of Power Assembly For Hybrid Electric Vehicle

In order to deal with the problems of energy shortage and air pollution, the development of economical and clean vehicle has been a trend of automotive industry. Hybrid electric vehicle (HEV) known as a type of economical and clean vehicle has been regarded as a focus of development in the automotive industry. The region of engine's operation can be limited and controlled to reduce fuel consumption and emissions because of the action of electric system in the hybrid power system.In the dissertation, the power assembly of power parallel hybrid electric vehicle is researched. Under the premise of the simulation analysis using electric assist control strategy, the control strategy based on fuzzy logic is designed to ensure the optimal distribution of the driver torque request between engine and electromotor, to optimize the overall energy conversion efficiency of PHEV and to improve fuel economy and emission. By means of simulation comparison, excellent characters of fuzzy logic control strategy are confirmed. The main work is as follows:(1)First, the definition of hybrid power drive system is given, and then HEV with different layout type and HEV with different Degree of Hybridization are introduced. Based on this, the layout scheme and the type of degree of hybridization are confirmed. At last, the power flow analysis of the vehicle type being chosen is carried out.(2)ADVISOR simulation software is introduced in detail, and the modeling of HEV in ADVISOR is analyzing comprehensively. By means of a series of simulation designs and calculations, parameter selection and energy matching of the designed PHEV are completed in ADVISOR.(3)Based on the analyses for design requirements of control strategy and the analysis and comparison for the existing control strategies of PHEV, the fuzzy logic control strategy aimed at decreasing fuel consumption and emissions is presented and the block of control strategy is designed. And the simulation result shows that this strategy seems feasible and proved much better than the parallel electric assistant control strategy.(4)On the basis of analyzing the requirements of assembly controller and taking the technical requirements of hardware design into consideration, the whole scheme of hardware design for assembly controller is put forward initially. And then the whole scheme of software design for assembly controller is put forward initially, with the flow charts of assembly control strategy module and CAN node communication given. At last, the port of real-time operating system (μC/OS-II) for assembly controller is introduced in detail.