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

摘要： 为有效解决300mm晶圆制造中整体式自动物料搬运系统的高空穿梭车路径冲突问题,提出基于滚动时域的高空穿梭车避碰调度策略。对问题域进行了描述,论证了冲突发生的充要条件,指出了搜索可行候选路径的途径;以任务完成时间最小为优化目标建立数学模型,通过对最短路径依次进行空间和时间冲突侦测,针对预测的碰撞,采用耗时较短的避碰策略,从而确定时域内无冲突路径的调度方案,并在时域内进行基于事件驱动的再调度。仿真实验表明,该算法能有效实现物料搬运中高空穿梭车路径冲突的检测和避碰,提高晶圆制造系统运行的安全性和稳定性。

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