关键词: 滚动时域, 动态调度, 自动物料搬运系统, 路径冲突, 晶园制造

Abstract: To resolve Overhead Hoist Transporter (OHT) conflict problems in unified Automated Material Handling Systems (AMHSs) of 300-mm wafer fabrications,a conflict free OHT path scheduling method was proposed based on rolling horizon strategy.After description of problem region,the necessary and sufficient conditions of collisions were identified and the approach to feasible alternatives was pointed out.A mathematical model was set up with an optimal objective function of minimizing the total complete time.By executing space and time conflict detection successively to the current shortest path,the conflict free path in current time window was confirmed by taking corresponding collision avoidance strategy which took less time and rescheduling based on event-driven was also conducted.The simulation experiments were designed to evaluate the proposed strategy,and results indicated that this method could detect and avoid OHT path confliction effectively.Thus the security and stability of wafer fabrication system was improved.

Key words: rolling horizon, dynamic scheduling, automated material handling systems, path confliction, wafer fabrication