Research And Implementation Of Deterministic CAN Communication Scheduling In BMS System

CAN bus as the current mainstream automotive network,it has the characteristics of fast speed,short data.It is widely used in the automotive field,industrial controlling,aerospace and other fields.In the automotive network,CAN bus has become the preferred communication network for powertrain,engine controlling,etc.with its higher speed and fault tolerance.CAN network message's transmission of real-time as a key point of automotive network's security,it is of great significance to establish and optimize the vehicle network system by studying its messages' scheduling methods,the concrete realizations and application plans.Based on the introduction of CAN communication protocol and battery management system,this paper focuses on the dynamic scheduling mechanism of CAN network message set.Based on the basic theory of scheduling and the current situation of domestic and foreign research,this paper designs the frame identifier ID for segmentation and dynamically encodes the variable segment.The dynamic segmentation scheme is designed by using the double-partition coding algorithm based on exponential function and equal-difference series function,which uses the "earliest deadline"(EDF)dynamic scheduling method to design the message identifier ID dynamic allocation scheme.On the basis of this,the conclusion is given that the message set satisfies the schedulability in the scheduling mechanism of this paper,and the condition of the schedulability of the message set is strengthened by using the general judgment conclusion of CAN network message set schedulability;At the same time,it analyzes the communication model of the highest priority message which may be the worst blocked in the case of network load.Then we use the CANoe semi-physical simulation experiment platform in this paper,to verify the dynamic mechanism and scheduling algorithm.BMS communication node is realized by hardware and software,real node as simulation platform,CAN network's real-time communication simulation is realized by combining virtual node,and dynamic scheduling algorithm is given to realize the flow and mechanism in CAN bus.The research of this topic provides the applicationscheme of dynamic scheduling algorithm in CAN network.At the same time,the partition coding scheme based on power function improves the coding ability of the identifier compared with the conventional partition coding scheme(such as the average partition),which makes the system have higher resolution of the deadline of the highest priority message,The worst response time of the message is reduced and the real-time nature of CAN network message transmission is improved.