Multi-objective Optimization Research For Machine Dynamic Layout Based On Chaos Genetic Algorithm

Workshop facility layout is one of the most important research aspects in manufacturing system planning.The quality of layout has impact on material handling costs,production efficiency and safety.In the background of flexible production mode,the traditional static facility layout,which does not consider the dynamic characteristics of the market,with high cost,has difficulty in satisfying requirements of the enterprises.Therefore,it is of great practical significance to study dynamic facility layout problem.Due to the complexity and diversity of the actual layout problem,a complete set of optimization model and method for dynamic facility layout problem is very urgent.This paper devotes to research the layout problem of workshops with producing multi-variety and small-batch products,and achieves an optimized resource arrangement with the cooperation of computer technology.This paper summarizes status of domestic and foreign research about facility layout problem,mainly focus on four themes of form,model,solving algorithm and computer-aided design.The research status of dynamic facility layout problem is specifically analyzed,which laid a theoretical foundation for the later study of facility layout model and algorithm.For layout model,multi-line linear layout problem is taken as a research object.Material handling cost,facility resetting cost and area utilization rate are taken as optimization multi-objectives,and constraints are also determined.Than the mixed integer programming model of facility with unequal area in continuous plane is established.To solve this problem,this paper analyzes the basic theory,the operation process and the integration method of genetic algorithm and chaos technology,and designs an effective chaos genetic algorithm.The hybrid algorithm inherits the inversion of the genetic algorithm and the ergodicity of the chaotic search,and overcomes the problem that the genetic algorithm is easy to fall into the local optimum,which greatly improves the searching speed and global convergence.It is a very suitable algorithm for solving facility layout problems.Since it is troublesome to bring examples into the algorithm program when solving problems,an calculation tool for quick layout optimization is developed using Java language to realize computer-aided design.With this tool,adding algorithms,an example can be solved.Finally,on the basis of this tool,the facility layout problem of a machining workshop in Lanzhou is optimized.The optimization results show that the dynamic facility layout which proposed in this paper can obviously reduce production cost and improve workshop utilization.Then,the chaos genetic algorithm is compared with modified genetic algorithm,NSGA-II and ant colony algorithm to solve an same instance respectively.The feasibility and validity of the hybrid algorithm are proved.