针对紧凑式带钢生产(CSP)模式下的轧制计划编制问题,综合考虑设备能力、订单需求和相邻板坯间厚度跳跃,提出一种两阶段问题求解框架。第一阶段以最小化轧制单元数和非计划卷使用量为目标建立整数规划模型,为保证模型的求解效率,从生产实际中提炼出“优先薄板,后补非计划材”的启发式规则进行求解。第二阶段以最小化板坯间平均厚度跳跃为目标来建模,综合考虑非计划卷厚度可变的特性,提出一种多邻域结构的变邻域搜索算法进行求解。通过某CSP生产线的轧制计划编制实例验证了该模型和算法的有效性。
Aiming at the rolling scheduling problem in a compact strip production (CSP) plant, this paper provides a two-stage solution framework which takes into account the equipment capacity, the order requirement and the thickness variation between adjacent slabs. In the first stage, an integer programming model is proposed to minimize the numbers of rolling units and unplanned slabs simultaneously. To solve this model efficiently, a heuristic rule extracted from the production practice is employed so that thinner slab is entitled with higher priority and unplanned slab will be manufactured unless it is quite necessary. The model of the second stage is built to lower the thickness variation between adjacent slabs and is solved by a variable neighborhood search algorithm which considers the variable thickness values of unplanned slabs. Examples of rolling scheduling in a CSP plant testify the effectiveness of the proposed model and algorithm.