连铸-轧制生产中带有批决策的排序问题的建模与优化方法

以长材产线为背景, 研究了炉次在连铸及轧制阶段的组批及批排序问题. 与以往将连铸、轧制分开研究不同, 本文同时考虑连铸和轧制阶段对组批及批排序的要求, 还考虑了下游工序精整机组负荷均衡生产的要求. 为该问题建立了新的混合整数规划(Mixed integer programming, MIP) 模型. 由于问题的NP-hard 属性和模型的大规模特征, 以及工业应用的实际要求, 本文提出了改进的分散搜索(Scatter search, SS) 算法用于求解该问题. 在改进的SS 算法中, 利用解的相关性质来限制搜索空间, 并将变邻域搜索策略引入, 从而结合解的多样性及邻域互补性特点, 充分发挥算法混合的优势. 实际数据的计算结果验证了改进SS 算法的有效性.

Modelling and Optimization Methods for the Sequencing Problem with Batching Decision in the Continuous-casting and Rolling Production

In this paper, we take the long steel production line as research background, and investigate the charge batching and batch sequencing problem on the continuous-caster and the rolling machine. Different from the previous research in which the casting and rolling stages are disjoined, in this study the batching and batch sequencing requirements on both stages are considered simultaneously, as well as the requirement on balanc-ing the workloads on different finishing machines downstream. A novel mixed integer programming (MIP) model is developed. Because of the NP-hardness of the problem and the huge size of MIP model, along with practical requirement for industry appli-cation, we propose an improved scatter search (SS) algorithm to solve the problem. In this algorithm, the search space is reduced by some optimal properties and the variable neighborhood search strategy is introduced such that the diversification and the com-plementary advantage of difference neighborhoods are combined and the merits of hybrid algorithms are exploited. The compu-tational results on practical data demonstrate the efficiency of the improved scatter search algorithm.