Non-destructive dynamic optimal scheduling method for CAN bus

Abstract

The invention provides a CAN bus oriented non-destructive dynamic optimal scheduling method. An identifier of a CAN bus arbitration field is encoded by means of three segments, namely, a task segment, a competition segment and an auxiliary segment, wherein the competition segment is encoded by adopting a segmentation method based on an absolute deadline, and can be dynamically updated. Priorities are compared via the three segments; for messages whose priorities are the same in the task segment, the priorities in the competition segment are compared again; and for the messages whose priorities are the same in the competition segment, the priorities in the auxiliary segment are further compared. According to the CAN bus oriented non-destructive dynamic optimal scheduling method provided by the invention, the flexibility of a system is increased, the bus time is reasonably distributed and occupied, the real-time performance of the system is improved, and the system is enabled to be more reliable and has the characteristic of simple debugging.

Description

Technical field [0001] The invention relates to a non-destructive dynamic optimization scheduling method for CAN bus. Background technique [0002] CAN is a serial data communication bus developed by Bosch in 1985 in order to solve the data transmission between many test instruments and control units on automobiles. It has been widely used in distributed real-time control of automobiles, industry, and building automation. field. The static scheduling algorithm in CAN network control system is very suitable for message scheduling in deterministic hard real-time systems, but the static scheduling algorithm is only suitable for systems with fixed system time characteristics, and cannot flexibly adapt to system changes, and it is difficult to make full use of system resources. [0003] At present, there have been researches on the dynamic scheduling optimization of CAN bus. The paper "Research on Flexible Time Triggering CAN Bus Information Dynamic Scheduling" published by Guan Changj...

AI Technical Summary

Problems solved by technology

Static scheduling algorithm in CAN network control system is very suitable for message scheduling in deterministic hard real-time systems, but static scheduling algorithm is only suitable for systems with fixed system time characteristics, and cannot flexibly adapt to system changes, making it difficult to make full use of system resources

[0003] At present, there have been researches on the dynamic scheduling optimization of CAN bus. Guan Changjiao et al. published a paper "Research on Dynamic Scheduling of CAN Bus Information Triggered by Flexible Time", and Liu Chao et al. , Yang Jie, etc. published the paper "Stochastic Dynamic Priority Scheduling of Aperiodic Information in CAN Bus", etc., but the above scheduling strategies have defects in algorithm complexity, network resource overhead, etc.

The invention proposes a new non-destructive dynamic optimal scheduling method of CAN bus, which solves the problems of low communication efficiency and network utilization of static scheduling algorithms, and ensures the real-time and reliability of messages

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