The Design And Research Of Electric Vehicle Controller Node Based On CAN Bus

With the improvement of people's living standard,Cars have become the most important means of transportation,but they also bring about energy consumption and environmental pollution,pure electric vehicle as an important direction to solve energy and environmental problems more and more attent ion.The communication between most control units of pure electric vehicles is through CAN network,and as the hub of the whole control system of electric vehicle,the information of the vehicle controller can be transmitted and processed in a timely and e ffective manner,which will affect the performance of the whole control system.Therefore,it is necessary to carry out in-depth study on the vehicle controller node CAN communication,as to ensure the timely and effective transmission of the information i n the vehicle controller.In this paper,the CAN bus scheduling algorithm is analyzed and applied to the message scheduling of the whole vehicle controller CAN node by using the pure electric vehicle controller as the object,In addition,the online updating method of the vehicle controller is studied in depth,and the online updating of the vehicle controller application is realized in a more efficient way.The main contents of this paper are as follows:(1)The communication mechanism and message scheduling strategy of CAN bus are analyzed,and a hybrid scheduling algorithm is designed based on static scheduling algorithm and dynamic scheduling algorithm,using the index way to partition coding message deadline,and the delay of low priority message is reduced on the basis of ensuring the real-time performance of high priority message transmission through hierarchical scheduling.The control system network scheduling model is established by using the Simulink/Truetime toolkit,and the simulation results show that the hybrid scheduling algorithm can reduce the delay of message,improve the real-time performance of control system.(2)In the design of the CAN Bootloader,the method of EEPROM sign bit judgment is adopted to avoid the problem of poor real-time performance of the external switch.In addition,error detection mechanism was added to the CAN Bootloader upgrade program,in the process of the vehicle controller online update timely detection and location of the error.(3)The communication framework and communication protocol of the vehicle controller are designed and the schedulable analysis is carried out.The hardware of the node CAN communication is designed,and the hybrid scheduling algorithm is applied to the design of the communication software of the vehicle controller node.the communication experimental platform is set up,using CAN Bootloader to update the whole vehicle controller application online,and communicate with VCU panel using the BMS master plate,the experiment shows that the vehicle controller application can update for rapid and effective with CAN Bootloader,The whole vehicle controller node based on the hybrid scheduling algorithm can complete the communication normally,thus verifying the feasibility of the hybrid scheduling algorithm on the whole vehicle controller node.