Research On Steel Pretreatment Flow Shop Scheduling Based On Hybrid Genetic Algorithm

The ship manufacturing industry is one of the most important embodiments of national economy and technical strength. In recent years, the international market share of our country shipbuilding industry is keeping rising. China has become a world recognized shipbuilding power. But in the field of high-end shipbuilding, china is still relatively weak of technical force and manufacturing experience. Along with the rising labor costs, many shipbuilding enterprises are faced with the challenge of increasing shipbuilding cost. How to improve the efficiency of ship construction problems become the focus attention of shipbuilding enterprises, but also the effective measures to increase the competitiveness of the enterprise market. So the research of the ship manufacturing enterprise workshop scheduling problem is of great significance.This paper took the steel preparation workshop of ship manufacturing enterprises as the research object; regarded the scheduling problem as a flexible job shop scheduling which exists the process of parallel machines. In order to solve this problem, this paper designed a hybrid algorithm based on genetic algorithm and simulated annealing. The concrete research contents are as follows:First of all, this paper introduced the modern shipbuilding enterprise production mode, summarized the operation process and machining process of the steel preparation workshop, analyzed the existing scheduling methods of the steel preparation workshop and research difficulties. According to the characteristics of manufacturing enterprise, and the actual production system, the optimization of job shop scheduling problem defined us minimizing earliness/tardiness.Secondly, according to the information of the actual steel preparation production workshop, this paper established the mathematical model of the flexible job shop scheduling problem, make the minimize earliness/tardiness penalties as the target of optimization. Then we designed a hybrid genetic algorithm and its operation process in detail, which covers the chromosome encoding and decoding scheme, calculation of fitness values, constraints, genetic manipulation, annealing temperature and related content.Finally, based on the actual production data of a shipyard, the hybrid genetic algorithm designed by this paper is used for the steel preparation workshop scheduling problem, obtained the optimal scheduling sequence, the work piece machining machine selection and processing sequence, and draw the Gantt chart for optimal scheduling. At the same time, in order to verify the validity of the algorithm, imported the same data into the standard genetic algorithm(SGA) iterative calculation. After comparing the results, it proves that the proposed hybrid genetic algorithm is more effective in solving the ship preparation workshop scheduling problem.