Dual-Core Body Control System Based On SAE J1939 Protocol

Current automotive electronic control system is developed from separate control system to centralized control system.With general point-to-point mode,it caused the continuous increase in the number of wire-geometric growth,also make more and more difficult wiring in the limited space,to limit the expansion of automobile internal control functions,the maintenance of vehicle internal electronic unit also more complex.Fortunately,quick development of Bus Technology makes a new way for automotive electronic control system.In this thesis,we introduce the state and development trend of the automobile electronics technology,and concisely review the vehicle networks.Then studies home the principle and application of CAN-bus and LIN-bus which are used widely in the modern automobile.A automobile instrument information system based on CAN/LIN bus and 16bit & Dual-Core MCU MC9S12XDG128 producted by Motorola is developed:Among them SAE J1939 protocol is CAN network communication protocol on the senior level,it can support the distribution real-time system effectively,mainly for offering the standard system structure for communication between the ECU of vehicle;LIN protocol is used in ECUs that needing simple communication only.In the use of the XGATE(dual-core) technology,the burden of CPU can been successfully reduced,and the main CPU will respond faster to the information,while the reaction process and information processing will be extended to the Deputy CPU. This can enhence the CPU's processing capability and bus response speed.To solve the control module subsystems working alone,the low level of information sharing,Poor scalability in the China-made car.Transmission greatly simplifies wiring harness,the reliability of the system has been enhanced.The system performs functions such as digitization of instrument information,sharing with auto bus communication and information of entire car,unified scheduling of entire car, online fault diagnosis.This paper presents detailedly the hardware and software of the control system considering the existing technology and the consumption level in the future of domestic automobile.The test result shows that we succeeding in realizing the data communication and network management of SAE J1939 protocol,as well as the CAN/LIN bus gateway function,it has the meaning to guide the development of the communication of automobile in our country.