Hot-Rolling Batch Planning Problem of Round Bar with Roller Capacity

Considering the feature of roller capacity with dynamics change in round bar production, a hot-rolling batch planning problem is studied. Firstly, the problem is formulated as a different capacities vehicle routing problem (DCVRP). And then, a mathematic model is built with two optimization objectives, minimization for total set-up time and maximization for utilization of roller. Secondly, an algorithm based on constraint satisfaction technique is present with variable selection rules and value selection rules for billet selecting, grouping and sequencing, and constraint propagation for searching-space reducing and rolling-unit partitioning. Meanwhile, the current capacity of online roller is updated dynamically during the solving process of algorithm. Finally, comparing results indicated that the proposed model and algorithm are effective and efficient.

Research and Application of Integrated Scheduling Management System of Steelmaking-Casting-Rolling Based on Heat Process Model

by studying steelmaking-casting-rolling production process, a mathematical model of integrated batch planning is established innovatively to minimize processing costs of whole line and computed by an intelligent optimization ant algorithm. On the premise of utilizing and coordinating capacity of steelmaking and rolling, the mathematical model of integrated batch planning can create integrated batch planning to combine steelmaking-casting-rolling closely according to each process constraint conditions and optimization objective. Furthermore, another mathematical model of job scheduling based on heat process model is proposed to not only guarantee the logistics balance between continuous casting and hot rolling, but also acquire the highest ratio of DHCR and lowest energy consumption.