The Research And Implement Of In-vehicle Network System Based On Embedded LINUX Platform

With the rapid development of electronic technique and the continuity improvement of vehicle performance, the electronic equipments on vehicle are becoming more and more. Traditional electric systems mostly introduced point-to-point communication mode, little affiliation with them. That made the connection system complex. In order to adapt the development of the vehicle electronic equipment, the in-vehicle network system has come forth. For example, CAN bus, LIN bus and FlexRay have been applied in in-vehicle network system. Because of particular structure and stable performance of CAN bus, which applied in it is the most widely.However, there is a disadvantage of high cost in CAN bus that is applied in low level communication of body network. So now, body control network is required to solve the problem that is establishing another consistent and low-cost low level communication network standard. And then, this standard will be the assistant bus of CAN. From this, body control network would implement hierarchy and low-cost;this moment, the target of LIN bus is applying in low level communication among body network module nodes.This paper introduced the domestic and international situation and development about the in- vehicle network briefly. On the basis of familiar with CAN bus and LIN bus, considering characteristics of the embedded system, I have designed the in-vehicle network system based on embedded Linux platform.In order to managing the nodes of in-vehicle network efficiently and processing the data, I have designed the MCN(main control node) of the in-vehicle network. That is carried out by the S3C44B0X MPU of ARM7 core, and the software platform is μClinux. MCN realized the CAN device driver based on SJA1000, the whole system is more reliable and efficient. So it provides the software and hardware enviement of extending to the in-vehicle information center in the future. Besides CAN bus, this system used LIN bus into in-vehicle network, and present low cost CAN/LIN mix network architecture for vehicle. In order to cornect between CAN bus and LIN bus, I designed the CAN/LIN data exchange gateway based on PIC18F248.That is the CAN node, as well as is the LIN master node. The gateway tramform the CAN messages received from the CAN bus to LIN messages, and transmit to the LIN bus. At the same time, it tramsform the LIN messages received from the LIN bus to CAN messages, and transmit to the CAN bus. It realized data type convertion between CAN bus and LIN bus successfully.