The Research Of The CAN Communication Technology In The Electric Vehicle Battery Management Systems

The traditional automotive used harness connections manner to achieve theconnection between the electrical signal within the automotives. With the growingamount of information and the number of nodes in the automotive, this willinevitably lead to the constantly increased number of wires, wiring increasinglydifficult, and the cost will improve, which also hampered the car’s reliabilitycommunication. CAN bus was originally developed specifically for solving theserial communication of passenger cars. It has been widely applied in the controlcommunication network system of the car, this because of its higher real-timeprocessing capabilities, higer reliability for working in strong electromagneticinterference and well detection error capacity.This thesis conducts in-depth study on the CAN communication technology of“the battery management system of JAC TOJOY pure electric vehicles”. We mainlyto achieve the data communication between the master control unit, the acquisitionunit, and the high-voltage unit in the battery management system.This thesis carried out in-depth study of the CAN bus scheduling algorithm,proposed an improved MTS scheduling algorithm. This algorithm uses recursivepartitioning method and the idea of priority boost, effectively solve the fairnessproblem, largely alleviate priority inversion phenomenon. System selects theFreescale MCU that comes with MSCAN as CAN controller, completed thehardware circuit design of CAN communication. We have formulated a specificapplication layer protocol of communication network based on SAE J1939, andwritten the underlying driver. Finally, we real-time monitored the batterymanagement system data through the PC monitoring software, it verify thereliability and timeliness of the CAN communication system in this paper.