Powertrain Communication System Design of Hybrid Electric Vehicle

In the automotive system design flow, protocol design is an essential step which mainly includes message allocation, message priority assignment and message period assignment. This work provides an approach in the message period assignment through experiment and validation. The experiment and validation takes the powertrain system of hybrid electric vehicle as the platform. Under the baud rate of 500 Kbps, and take the messages from EMS (engine management system) as the example, simulations are done under different message periods. The results show that when the message EEC1 sending by EMS becomes to 100 ms, the engine speed can shake dramatically. It restricts the period of message EEC1 must be smaller than 100 ms. Messages from other ECUs in the powertrain system of hybrid electric vehicle can be selected under the experiments similar to the process of the EMS. The approach in this work can be taken as a reference for designing CAN bus protocol of hybrid electric vehicle.