| In recent years,driven by innovative technologies such as the Internet of things,5G and AI,semiconductor applications in various industries have been expanding.Semiconductor chips,as the cornerstone of the information technology industry,play a crucial role in information security and national economy.Since 2015,China has been the largest semiconductor consumer in the world,while its self-sufficiency rate can only reach 12%,which seriously restricts the development of China’s information industry.Semiconductor manufacturing requires cooperation between semiconductor processing systems and material handling systems to ensure the execution of production plans.Therefore,the automatic material transportation system has become an indispensable part of semiconductor manufacturing.In this thesis,an AGV scheduling and path planning problem in automated material transport system with AGVs as the transport tool in semiconductor production workshop are studied.Two main problems,the path planning and the collision avoidance of AGVs,are studied and a two-stage optimization algorithm is improved.Firstly,the mathematical modeling method and a task assignment method based on task urgency are used to assign all material handling tasks to the AGVs,and the initial paths of all AGVs are obtained based on AGV walking rules.Then,the collision nodes in the initial paths are detected and adjusted by using collision avoidance strategy to obtain the global non-collision AGV scheduling scheme.Furthermore,the layout and material handling tasks of the production workshop under different production scales are constructed based on the real semiconductor production,and the efficiency and stability of the algorithm are demonstrated by instances.Finally,with the consideration of input-output,sensitivity analysis is done on the effect of the number of AGVs in the semiconductor workshop on the completion time of the handling tasks,and suggestions on the number of AGVs in the workshop are given. |
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