基于多目标遗传算法的柔性加工线平衡优化

Optimization of Line Balancing for Flexible Machining Lines Based on Multiobjective Genetic Algorithm

摘要:

针对柔性加工线平衡问题，提出了生产线平衡的同时得到工位配置、操作分配与排序的方法.分析了操作间的优先关系约束、操作同工位约束和由机床性能、装夹方式、工件姿态决定的工位对操作限制的约束以及工位能力约束，以机床数量、生产线节拍、生产线平衡率为优化目标，建立了优化模型.设计了多目标遗传算法，采用启发式种群生成方法和解码方法，应用帕累托分级和共享函数法对可行解适应度值进行评价，保证解的分布性和均匀性.该方法应用于缸体生产线实例，获得了满意的非支配解集及多个线平衡方案，验证了方法可行有效.

Abstract:

To solve line balancing problems for flexible machining line, a method was proposed, which can provide optimal stations configuration and operations assignment and sequence. After analyzing precedence constraint, clustering constraint and station constraint decided by machine capability, setups and workpiece orientation, a mathematical model was constructed, in which three objectives were considered simultaneously: number of machines, cycle time, line balancing rate. The multiobjective genetic algorithm (MOGA) was presented. A heuristic population generation and a heuristic decoder were designed. The Pareto ranking method and the sharing function method were employed to evaluate the individuals’ fitness, which guaranteed the dispersity and uniformity of the solutions. A case study for cylinder block machining line was carried out, and multiple optimal solutions were obtained by the MOGA. The computational results demonstrate the feasibility and effectiveness of the proposed algorithm.