混合Jobshop炼钢-连铸重调度方法及其应用

炼钢-连铸生产过程中加工设备起、停时间经常会出现严重延迟,导致调度计划不可行. 目前人工调整,存在响应速度慢和调整结果不优化的问题. 对炼钢-连铸混合Jobshop重调度问题进行了分析,提出了正在作业炉次已分配设备不变的重调度方法. 并提出了求解策略,将原调度分解为两个子调度问题. 引入炉次操作状态参数β,建立了正在作业炉次的时间修正模型,构造了启发式方法进行求解.对于未作业炉次,建立了多目标非线性0-1 整数规划模型,构造了并行逆推启发式算法进行设备指派,采用线性规划求解各操作的开工时间.基于上述方法开发了动态调度软件应用于国内某大型钢铁企业,在缩短动态调度时间、减少钢水冗余等待时间方面取得了显著成效.

Hybrid job shop rescheduling method and its application for steelmaking-casting

In steelmaking-continuous casting(SCC) production process,starting time or finishing time is often largely delayed,which can lead to unexpected changes so that the original scheduling plan becomes unrealizable.Manual adjusting cannot response in time,which will destroy the optimality of scheduling plan.As a result,rescheduling is required to adjust the original planning and schedule in response to any unexpected changes caused by delayed time.In this paper,the rescheduling problem is firstly analyzed. The rescheduling method is presented,which does not change assigned machines of processing charge. A decomposition strategy is proposed,and the original problem is split into subproblems.This is then followed by the establishment of repairing time model that repairs starting time of the processing charges by introducing production schedule parameterβ.The establishment of a multi-objective nonlinear 0-1 integer programming model is used to solve the scheduling problem of not starting production charges, and a two-stage optimal scheduling method is proposed including the production path planning of charges and the production time scheduling.The dynamic scheduling system for SCC with the rescheduling method has been successfully applied to steel plant,efficiently reducing scheduling time and shorting the redundant waiting time for molten steel.