Research On Pneumatic-Fuel Hybrid Vehicle And Control Strategy

Facing the increasing demand of automobile year by year,the serious oil shortage problem and air pollution.The development of new energy vehicle has become the inevitable choice to get out of many difficulties at present.In this paper,one kind of parallel pneumatic fuel hybrid vehicles with front and rear clutches is presented.Pneumatic engine has high torque in low speed,while internal combustion engine is high efficient in high speed.This hybrid vehicle combine the advantages of pneumatic engine and ice combustion engine.The main contents of this paper are as follows:First,the pneumatic engine is one of the power sources of the pneumatic fuel hybrid vehicle.The research of the pneumatic engine is the foundation and important part of the whole vehicle control strategy of the hybrid electric vehicle.Based on the self-modified pneumatic engine,the measurement and control platform of the pneumatic engine is built.The dynamic performance,working characteristic and control method of the pneumatic engine are studied through the pneumatic engine characteristic experiment.The control method of pneumatic engine based on valve phase optimization is presented,and the calibration test of valve phase of pneumatic engine is completed.Secondly,the architecture of pneumatic fuel hybrid vehicle power system is preSented,and the simulation models of key power components,including internal combustion engine,pneumatic engine,compressed gas tank and so on,are established.It provides platform for the research of control strategy of pneumatic-fuel hybrid vehicle power system.Thirdly,based on the rule-based control strategy and the equivalent fuel consumption minimum control strategy,the steady-state energy management strategy of pneumatic fuel hybrid vehicle is proposed,which is used to Which is used for selection the working mode,division of the shift position of Transmission,torque allocation three tasks in power system.Based on the simulation model of pneumatic fuel hybrid electric vehicle.The simulation test of given urban conditions is carried out to verify that the energy management strategy proposed in this paper,which can effectively improve the fuel economy of the vehicle.Finally,there are torque fluctuations in the process of working mode switching of pneumatic fuel Hybrid Electric vehicle.To solve this problem,a coordinated torque control strategy is proposed.The main contents include aerodynamic engine control strategy based on dynamic response torque predictive torque compensation,internal combustion engine control strategy based on slope control and clutch state control strategy.The simulation experiment with coordinated control strategy and the simulation experiment without coordinated control strategy are carried out respectively.By comparing the simulation results,it is verified that the coordination torque control strategy in this paper can effectively improve the smoothness of vehicle working mode switching process.