针对混合动力汽车动力系统通信需求和控制策略,提出了基于CAN总线的控制系统拓扑结构,开发了该系统的CAN总线通信协议;研究了协议中优先级分配、单帧与多帧标识、数据长度与帧编号确定和重要报文应答机制等。应用CANoe软件对3种情况下的网络总线负载率进行仿真对比并通过RMA方法对网络实时性能进行测试。结果表明,该系统网络负载低,通信实时性好,能满足控制需求。
In view of the communication requirements and control strategy of hybrid electric vehicle,a topology of control system based on CAN bus is proposed,a CAN communication protocol for the system is developed,and several issues in protocol including the allocation of priority,the identification of single and multi-frames,the confirmation of data length and frame number and the response mechanism for important messages are studied.The bus load rate in three different situations are compared by simulation with CANoe and the real-time performance of CAN is tested by rate monotonic analysis method.The results show that the system has a low bus load and good communication realtimeness,well meeting control requirements.