Design And Research Of Vehicle Controller For Hybrid Electric Vehicles

Hybrid vehicle is a combination of traditional fuel vehicle and pure electric vehicle.Because of its unique power structure,it reduces the exhaust emissions of fuel vehicle and avoids the endurance of pure electric vehicle.It is the main development direction in the future stage.As the control core of the hybrid vehicle,the vehicle controller can ensure the safety and reliable operation of the vehicle and rationally allocate the power system resources.Therefore,the design of the vehicle controller with good performance has positive and practical significance for improving the dynamic performance and safety of the vehicle.Based on the analysis of the power system structure and working mode of the hybrid vehicle,combining with the control demand analysis of the ParallelSeries hybrid electric vehicle,the overall architecture of the vehicle controller is designed.By using the TC275 multi-core microcontroller as the core,the hardware circuit of the vehicle controller such as power management module,A/D,D/A module,digital input and output circuit and CAN/Flex Ray hybrid bus module is designed.At the same time,the signal conditioning circuits such as filter circuit and isolation circuit are designed to improve the anti-interference ability and stability of the vehicle controller.The Flex Ray bus is used as the power system data transmission bus to improve the transmission speed of the bus.The CAN/Flex Ray bus gateway is designed to realize the conversion and management of Flex Ray and CAN bus data.Design the software architecture of hardware driver layer,VCU abstraction layer,system layer and application layer,each layer is independent of each other,only exchange data and enhance the portability of application layer software.of the power system and the driver's power demand,optimize working mode and design switching rule of power system working states based on torque and speed of vehicle,design the power distribution strategy of the engine,motor and generator under different working modes.The control strategy model is established and simulated in Simulink.Simulation results show that the control strategy can effectively control the vehicle's power system.Design a multi-mode control strategy includes start/reverse mode,drive mode,and braking/sliding mode,which optimizes the threshold strategy of mode switching and avoids frequent switching among the modes.According to the state of the power system and the driver's power demand,optimize working mode and design switching rule of power system working states based on torque and speed of vehicle,design the power distribution strategy of the engine,motor and generator under different working modes.The control strategy model is established and simulated in Simulink.Simulation results show that the control strategy can effectively control the vehicle's power system.