A method and device for scheduling periodic messages, and a computer-readable storage medium

Abstract

The application discloses a periodic message scheduling method and device, and a computer-readable storage medium. The method includes: using the greatest common divisor to reduce the array Φ composed of the scheduling period values ​​of multiple periodic variables to obtain the array Φ r ; when Φ r When there are multiple identical elements not equal to 1 in , the elements are merged to obtain the array Φ rc , Φ rc The elements in the middle have no common divisor and no repeated elements not equal to 1; calculate Φ rc The number of elements equal to 1 in W 1 , and the maximum number of pairwise prime elements W included in the elements not equal to 1 2 , calculate the rank of the schedule W=W 1 +W 2 ;Construct the initial schedule, and adjust the distribution of each periodic variable in the initial schedule, so that the number of periodic variables in each row is less than or equal to the rank of the schedule, and schedule the periodic variables according to the adjusted initial schedule. In this application, by calculating the rank of the scheduling table, the constructed scheduling table has the best row uniformity, and the resulting variable period communication delay is the smallest.

Description

technical field [0001] The present invention relates to but not limited to the technical field of industrial automation, and specifically relates to a periodic message scheduling method and device, and a computer-readable storage medium. Background technique [0002] WorldFIP (World Factory Instrumentation Protocol) fieldbus is a real-time and scheduling fieldbus technology, which is widely used in industrial process control. Dispatch table is an important technology for WorldFIP fieldbus to realize real-time communication. The dispatch table is stored in the bus arbitrator (Bus Arbitrator, BA), and the bus arbitrator realizes the dispatch of periodic data and non-periodic data communication according to the information in the dispatch table, which is the basis for WorldFIP fieldbus network to realize real-time and deterministic communication . Such as figure 1 As shown, the WorldFIP bus scheduling table is composed of several micro-cycles in a macro-cycle. The front part...

AI Technical Summary

Problems solved by technology

It can be seen that the unevenness of the row arrangement of the schedule table will cause a delay in the periodic communication of one or more variables

When this unevenness is large, the possible periodic communication delay value is also large, and in severe cases, it will cause control logic errors in the control system with WorldFIP fieldbus as the communication network

[0004] At present, there are many methods for constructing the WorldFIP bus schedule, such as the Highest Common Factor / Lowest Common Multiple (HCF / LCM) method, the Monotonic Rate (RateMonotonic, RM) method, and the Minimum Deadline Priority (Earliest Deadline) method. First, EDF) method, delayed release (Deferred Release, DR) method, etc., but these methods all have a common problem, that is, the row uniformity of the dispatch table constructed by them is not optimal, and some methods even construct The row uniformity of the scheduling table is very poor, so it seriously affects the real-time and correctness of bus data communication

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