Development Of Vehicle Control Unit Based On GD32

The vehicle control unit(VCU)is the core of a vehicle,which coordinates and schedules the vehicle components.It plays a decisive role in power distribution,driving safety,and power economy of the vehicle.Due to the limited production capacity of foreign automotive semiconductor chips caused by the pandemic,the cost of VCU has increased significantly,leading to a reduction in production or even shutdown for some small car companies.Currently,the control core and drive module of VCU mostly use foreign semiconductor chips such as NXP and Infineon,and the model toolchain of VCU is well packaged and not open-sourced.Therefore,this project proposes a technical solution that using the domestic Giga Device GD32F450ZKT6 chip as the core of the VCU and discrete components for the drive module in hardware.In terms of software,a complete set of model toolchains is developed and the development method and process of the basic software layer is verified on the basis of the vehicle functions and usage habits.Ultimately,the hardware and basic software layer of the VCU are validated by building the vehicle model.The main research contents and conclusions are as follows:(1)Based on the functions of the vehicle,a hardware scheme for domestic substitution of the VCU was designed.Firstly,the hardware functions of the VCU were analyzed according to the vehicle signal,and the hardware schematic diagram of the VCU was modularly designed by making full use of the peripheral resources of the GD32 chip.The signal interference was fully considered in the PCB layout and wiring process and the area was reasonably divided.Ultimately,the hardware design of the VCU was finally completed.The domestic substitution solution for the hardware can reduce the cost of the VCU by 15～20% and save 20～30% of the delivery time.(2)Based on the vehicle functions and VCU hardware,a set of basic software layer module libraries for the VCU was designed.The basic software layer modules were divided into hardware abstraction layer and service layer.All modules were encapsulated into Simulink library to realize multi-platform reuse.The basic software layer and control strategy were jointly modeled to generate the vehicle model.The generated code was scheduled through the template TLC file to automatically combine the underlying code and the application layer code.Compared with manually porting the underlying code,automatically generated code can reduce the workload by 30～40%and improve software development efficiency.(3)Based on the CCP protocol and CAN bus,the online upgrade function of the VCU was designed.The code generated from the model was added to the Keil template project and compiled to generate a hex file.The BOOT program of the VCU received the hex file sent by INCA and wrote it into FLASH to complete the online upgrade.After the upgrade,the VCU’s hardware and control strategy can interact in real-time to control the vehicle.(4)Based on Simulink,the vehicle control strategy model was built,and the hardware and software of the VCU were verified by tests.Processor-in-the-loop simulation was carried out by Powerbench and the basic software layer and hardware functions of the VCU were verified.The control strategy of the vehicle was designed,including power-on and power-off strategy and vehicle fault diagnosis,functions such as forward,backward,and steering of the electric vehicle were achieved,and the real vehicle verification of the VCU was completed.Final results show that the control strategy and VCU meet the control requirements,and the vehicle operates well.