Vehicle-mounted CAN bus delay optimization method

Abstract

The invention relates to a vehicle-mounted CAN bus delay optimization method, which starts from two aspects of overall optimization and local optimization at the same time, and achieves the purpose ofimproving the communication accuracy by accurately analyzing a CAN bus message transmission sequence and compensating message offset. And meanwhile, by using a coding method which can be used for most vehicle-mounted CAN bus control systems, the real-time performance of message transmission is better ensured, and the communication execution quality is improved.

Description

technical field [0001] The invention relates to the field of data transmission bus technology, in particular to a vehicle-mounted CAN bus delay optimization method. Background technique [0002] With the rapid development of modern industrial technology, today's cars are increasingly intelligent, networked and automated, more and more electronic devices are applied to cars, the unit parts of the body network are also increasing, and the information transmitted between each other The amount of information is increasing, so it is very important to choose a real-time data transmission technology. CAN bus technology adopts short-frame data transmission structure and CSMA / CD bus arbitration method. Its short-frame data structure ensures short data transmission time, while CSMA / CD arbitration method ensures fast sending of higher priority messages , so CAN bus has better real-time performance than general data transmission technology. [0003] However, as the network structure b...

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Problems solved by technology

[0003] However, as the network structure becomes more and more complex and the network load becomes higher and higher, the possibility of collision between low-priority messages and high-priority messages increases. Due to the fixed priority competition mechanism of the CAN bus, low-priority data frames Arbitration fails in bus competition, and multiple retransmissions may occur, the transmission delay of information becomes larger and uncertain, and problems such as information transmission error and information retransmission become more and more serious. The real-time and controllability of the entire network Will drop sharply, resulting in the real-time and reliability of the CAN bus network can not be guaranteed

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