Flexible manufacturing system deadlock-free scheduling method based on improved genetic algorithm

Abstract

The invention belongs to the technical field of production scheduling of flexible manufacturing systems, and particularly relates to a deadlock-free scheduling method for a flexible manufacturing system based on an improved genetic algorithm. The method comprises the following specific steps of: establishing a Petri net model of the flexible manufacturing system, determining genetic parameters, encoding and decoding, generating an initialized population, performing detecting and repairing, calculating processing time and fitness, judging whether a termination rule and genetic operation are metor not, and outputting an optimal individual; adjusting all chromosomes into control feasible chromosomes through a two-step forward looking method, and decoding the control feasible chromosomes intoa deadlock-free scheduling sequence; optimizing and improviing the genetic algorithm in the design process of the scheduling strategy. Meanwhile, in the variation process, the chromosome gene is divided into a path gene and a process gene, variation operation is conducted on the path gene and the process gene at the same time, the variation rates of the path gene and the process gene are the same, and therefore the operation steps are simple, the production efficiency is greatly improved, and the application environment is friendly.

Description

Technical field: [0001] The invention belongs to the technical field of production scheduling of a flexible manufacturing system (Flexible Manufacturing System), and in particular relates to a deadlock-free scheduling method for a flexible manufacturing system based on an improved genetic algorithm. Background technique: [0002] Flexible manufacturing plays a very important role in today's pursuit of multi-variety and small-batch production. In order to survive and develop, more and more modern enterprises regard flexible manufacturing as an effective means to improve their competitiveness. The flexible manufacturing system consists of a unified information control system, material storage and transportation system, and a set of digitally controlled processing equipment. It is an automatic manufacturing system (Flexible Manufacturing System) that can adapt to the continuous change of processing objects. The English abbreviation is FMS. The flexible manufacturing system inc...

AI Technical Summary

Problems solved by technology

However, most of the existing technologies use inefficient deadlock detection methods when dealing with deadlocks, which cannot guarantee that the repaired sequences will no longer have deadlocks during operation. Even if it can guarantee that the repaired code sequences are all feasible, but This repair method also has certain limitations, only for specific systems, such as manufacturing systems without central resources; for flexible manufacturing systems with central resources, the existing deadlock control algorithm cannot repair all infeasible code sequences, resulting in The execution efficiency of the algorithm is reduced, and it is even impossible to jump out of the local optimal value. Therefore, when performing deadlock-free scheduling on a flexible manufacturing system with central resources, it is necessary to quickly find a solution that meets the production requirements and does not fall into a local optimal value. Method for Deadlock-Free Scheduling Sequences

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