关键词: 柔性作业车间, 双层粒子群优化算法, 调度优化, 凹函数递减策略, 停滞阻止策略

Abstract:

To deal with the Flexible Job-shop Scheduling Problem (FJSP), an Improved Two-Layer Particle Swarm Optimization (ITLPSO) algorithm was proposed. First, minimization of the maximal completion time of all machines was taken as the optimization objective to establish a flexible job-shop scheduling model. And then the improved two-layer PSO algorithm was presented, in which the stagnation prevention strategy and concave function decreasing strategy were adopted to avoid falling into local optimum and to improve the convergence rate. Finally, the proposed algorithm was adopted to solve the relevant instance and the comparison with existing methods was also performed. The experimental results showed that, compared with the standard PSO algorithm and the Two-Layer Particle Swarm Optimization (TLPSO) algorithm, the optimal value of the maximum completion time was reduced by 11 and 6 respectively, the average maximum completion time was reduced by 15.7 and 4 respectively, and the convergence rate was improved obviously. The performance analysis shows that the proposed algorithm can improve the efficiency of the flexible job-shop scheduling obviously and obtain better scheduling solution.

Key words: flexible job-shop, Two-Layer Particle Swarm Optimization (TLPSO) algorithm, scheduling optimization, concave function decreasing strategy, stagnation preventive strategy