Study On The Optimization Of Storage Location Assignment In Bearing Automated Storage/Retrieval System

With the rapid development of modern industry, the traditional storage methods can not meet the growing needs of production and distribution, and AS/RS (Automated Storage/Retrieval System) has been getting more and more applied. Faced with tens of thousands of storage locations, the optimization of storage location assignment has become the important factor of improving access efficiency and reducing costs.This paper took the unit load AS/RS of a large bearing distribution enterprise for background. On the basis of some theories at home and abroad about AS/RS, the paper did an in-depth research on Storage Location assignment. The main work in this article is as follows:According to the type and application of AS/RS in bearing distribution enterprise, this paper introduced the numbering method based on energy consuming for storage location. It proposed the function of energy consuming classification to classify all bearing products within the distribution scope.According to the proportion of each classification, it divided every storage rack for a few zones.The paper focused on the storage location assignment problem of a unit load AS/RS.In order to solve the problem of bearing corrosion in the warehouse, the paper studied the differences of humidity and temperature conditions in different storage locations. Combined with accuracy and inventory cycle of different bearing specifications, it established a minimum corrosion degree model for storage location assignment during storage process;In order to solve the problem of declining quality of unloading goods and customer satisfaction which were caused by rusty bearings,it established a model based on effective corrosion degree, which take the extent of bearings corrosion rather than traditional storage time as decision-making factor during the process of choosing unloading bearings.This model also considered the corrosion status of the same specification bearings in different storage locations in next inventory cycle. It makes unselected bearings get less corrosion and less maintenance costs during the next inventory cycle.According to the target of pursuing lower operation cost in AS/RS,the paper introduced the minimum energy consuming model, which combined with minimum corrosion degree model together as an optimization model for storage location assignment in storage process;On the other hand, the paper retained the original efficiency priority model, which combined with the model based on effective corrosion degree together as an optimization model for storage location assignment in unloading process.This model used effective corrosion degree as a constraint to ensure the quality of unloading bearings.Finally, the paper used Pareto Genetic Algorithm to solve the Multi-objective models of storage location assignment. In this article, a self-adaptive penalty function method was proposed to handle constraint in model. The introduction of the elite reservation strategy can improve the quality of the population and make algorithm have better convergence.It used filter of Pareto solutions set to save better solutions in every generation. The experiment results showed that the Pareto Genetic Algorithm has good convergence rate and search ability. It can be used for solving the models of storage location assignment and getting more than one Pareto optimal solution.