Study On Bus Status Informantion Acquisition And Processing System Based On SAE J1939Protocol

The important control signals of vehicle electronic control unit (ECU) are transmitted byCAN-bus. And it’s very important how to acquire, save and analyze from CAN-bus directly.Not only conducive to the driver to obtain driving information easily, to improve vehiclehandling, but also ease of the investigation and analysis of vehicle accidents and provide agood reference standard for bus intelligent and the best optimization of the operatingparameters. SAE J1939protocol is a application layer protocol, which is used widely forbuses, trucks and other large vehicles. The protocol has clearly specified addressconfiguration, naming, communication and packet transmission priority of vehicle interiorECU (Electronic Control Unit).The bus network technology application status and SAE J1939protocol specific contentof the communication are analyzed.USB CAN interface card with the CAN controllerPHILIPS SJA1000and transceiver PHILIPS CTM8251T is selected as the hardware of thesystem.System PC software used Visual C++6.0tools to realize the message information SAEJ1939bus data acquisition.According to the specific requirements of SAE J1939applicationlayer protocol, the PGN and SPN database is established. By analyzing the message IDaddress and parameter data and calling the corresponding analytical procedures to parse themessage, the main parameters during vehicle operation are shown, such as vehicle speed,engine speed and percentage torque and other information.Simultaneously, using ADO access technology, the database query and managementfunctions are achieved. For SAE J1939protocol updates, user could real-time query andediting friendly.The experiments show that the system can meet the design requirements. The system iscompared with CANcase XL equipment to do experiments to verify the system reliability andaccuracy.