Research On In-vehicle CAN Network Management And Communication Technology Based On IPv6

The rapid development of automotive electronic technology and the continuousexpansion of users both lead to a highly improved level of automobile electronization and anincreasing tendency of the electronic control units(ECUs) in the vehicles as well. These unitsconstitute a large in-vehicle networks with high complexity while they make great difficultiesto effective management, control and fault diagnosis. If the ECUs break down, thecommunication between the electronic units and the on-board electronic devices under itscontrol can not be reliably guaranteed, which resulted in the existence of potentiallydangerous during driving process. The Controller Area Networks(CAN) has been widely usedin automotive electronics and many other fields by virtue of its quality of real-time, reliabilityand flexibility among various common fieldbuses. It is becoming more and more important totake effective management of the increasing and expansive in-vehicle CAN nodes.This article improved the pre-existing measure of logical strcture establishment andproposed a new CAN network management mechanism upon the basis of CAN technologystandards and OSEK/VDX specifications. By utilizing the Direct Network Management(DNM) that provided by the OSEK NM, the CAN network management platform has beenimplemented based on the in-vehicle gateway. And the grouping management and themerging mechanism of CAN nodes have been achieved as well. Experiment result indicatesthat this kind of network management mechanism can rapidly establish the stable logicalstructure in the network, and it provides the credible operating platform for remote faultdiagnosis and some further applications. The self-made nodes used in the experiments areconsist of PIC series singlechips from Microchip Corp. and PCA82C250CAN transceiverfrom Philips Corp. The peripheral control circuit adopts relays and L298N chips to controlCAN devices of a car. The ARM9is used as a hardware development board to implement thein-vehicle gateway. The development of the gateway software layer is achieved by Linuxkernel development technology. The ARM gateway integrates CAN module, WLAN module,GPS module and some other necessary parts, which provides the accesses to various networksand devices.In order to implement the interconnection and compatibility between CAN nodes andexternal terminals, each CAN node should be assigned an IP address. Since IPv4meets theaddresses exhaustion problem that can not adapt to the increasing requirment of nodeaddresses and mobile feature of in-vehicle gateway, the promoting IPv6should be taken intoconsideration. A mapping table from node IDs to IP addresses can be maintained on the gateway. In the view of external hosts, different address means different devices and functions.And these addresses can be access directly to achieve specific functions. The gatewayexecutes protocol conversion aiming at management datagrams from upper applications, andagents the data forwarding process of the lower nodes. This mechanism hides the hardwarefeatures and architectural differences of interconnecting nodes, and also lays the technicalfoundation of remote management, state control and fault diagnosis.Utilize the CAN analysis toolkit ZLGCANTest to collect and analyze operating datafrom CAN buses. CAN network remote management platform is used to monitor and analyzethe grouping/merging processes, logical structure establishment and network operating status.Experiment results indicate that the logical strcture can be rapidly built, the efficiency of CANnetwork management has been improved. And heterogeneous nodes can achieve directcommunication based on the gateway, real-time information interaction is implemented aswell, which provides effective data support and credible efficiency guarantee.