Network-level adaptive fault diagnosis method for CAN (Controller Area Network)

Abstract

The invention relates to a bus fault diagnosis method for a CAN (Controller Area Network), particularly, a network-level adaptive fault diagnosis (NAFD) method for the CAN. The method is mainly applied to a car CAN network communication system. The method comprises model analysis and a fault diagnosis method. On the basis of a CAN bus topology model, a fault diagnosis model is established. Nodes in a CAN network are divided into test nodes and tested nodes. In a mode of carrying out diagnosis among the nodes in sequence, fault types of fault nodes are judged. The fault types of the nodes are divided into a normal state, an intermittent fault state and a permanent fault state. The fault nodes are closed through two times of diagnosis. Node state misjudgment and node resource waste resultingfrom external factor interference are avoided. Cache content in each node only comprises states of the corresponding nodes, so data volume in the network is reduced. The reliability of the CAN bus network is improved, and moreover, the performance of the network is improved.

Description

technical field [0001] The invention relates to a CAN bus fault diagnosis method, in particular to a network-level adaptive CAN bus fault diagnosis method NAFD (an Network-level Adaptive Fault Diagnosis method for controllerarea network). NAFD diagnoses intermittent faults and permanent faults of nodes through information communication between network nodes. When a node has a permanent fault, it enters the bus off state, thereby improving the reliability of the network. Background technique [0002] CAN (Controller Area Network) is an internationally standardized serial communication protocol for automobiles, and it is already a standard protocol for automobile networks. Due to its high performance and reliability, it is also widely used in industrial automation, ships, medical equipment, automobiles and other industrial occasions, providing strong support for the distributed control system to realize real-time and reliable data communication between nodes. [0003] The veh...

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Problems solved by technology

[0005] The technical problem to be solved by the present invention is that the existing CAN bus fault diagnosis method cannot accurately judge the fault type of the node in the network and the problems such as large amount of data in the network and slow diagnosis speed during diagnosis, and proposes a network-level self-adaptive CAN The bus fault diagnosis method NAFD divides the nodes in the CAN network into test nodes and measured nodes, and uses the method of sequentially diagnosing the nodes to determine the fault type of the fault node; at the same time, the cache content in each node only contains the corresponding node The state of the network reduces the amount of data in the network, thereby improving network performance

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