Research On Pure Electric Vehicle Conreol Strategy And Controller

In order to alleviate the energy crisis and environmental pollution,new energy vehicles that serve as alternative product of internal combustion engine vehicles have triggered widespread attention.The development of new vehicles such as pure electric vehicles(PEV),hybrid electric vehicles(HEV)and fuel cell vehicles(FCV)is an inevitable trend to realize the healthy and sustainable development for automotive industry.The industrialization of pure electric vehicles has become an important strategic goal for enterprises.Meanwhile,there is an urgent need for three key technologies: vehicle control technology,motor control technology and battery technology.Vehicle controller that is core component for electric vehicle has an important impact on performance of vehicles.The paper focused on CAN communication network and vehicle controller strategy for pure electric vehicle.CAN bus network topology structure is defined for vehicle communication network.The reserved PGN range is redesigned according to the function requirement of each communication node.The content of each node's message data field is defined according to “SLOT” structure.The DBC file of vehicle communication protocol edited by db++ Editor is transformed into the Simulink model by using rapid prototype tool.The CAN bus input signals include BMS,MCU information.The driving torque algorithm of “basic torque and compensating torque” is proposed based on vehicle control software structure.The driving mode is divided into power mode and economic mode with respective basic torque MAP.The compensation torque is optimized based on ANFIS toolbox.The vehicle control strategies are developed based on Simulink/Stateflow platform,including vehicle working mode strategy,torque analysis strategy,torque smoothing strategy,torque arbitration strategy,motor control command,gear management strategy,VCU power up/down strategy,high voltage power up/down strategy,vehicle fault diagnosis strategy,etc.The braking mode is divided into motor braking mode,mechanical braking mode and combined braking mode.Braking energy is regenerated when motor participated in the braking process.The input signals included digital signals,analog signals and CAN input signals.Cruise/Simulink co-simulation is built to verify the accuracy and reliability of the vehicle control strategy in the paper.The model of electric vehicle is built based on Cruise software,and the vehicle control strategy is built based on Matlab.The compared co-simulation tasks with control strategy and without control strategy are built under NEDC cycle condition,full load acceleration condition and climbing performance condition.The simulation results showed that the vehicle control strategy can effectively identify the driver's intention to select appropriate driving mode and provide torque compensation,which improve the dynamic performance of electric vehicle.Meanwhile,the control strategy can reduce battery consumption to increase endurance mileage and improve economic performance through off-line co-simulation.