Patent Document ID: 8942961
Application ID: 13857480
Patent Flag: 1

Claim One:
1. A re-matching method of slab-order for improving slab utilization in iron and steel plants, characterized in that it comprises the steps of: Step 1: formulating a mathematical model according to information of slabs and orders, so as to quantitatively describe a re-matching problem of slab-order; Step 2: dividing the slabs and orders into groups; and Step 3: generating a new slab-order matching relationship for each group of slabs and orders by using multiple neighborhoods based tabu search algorithm on the basis of the formulated mathematical model, wherein, in Step 1, the performance measures for evaluating the matching relationship between slabs and orders are converted into an objective function, and by constructing objectives and expressing matching constraints, a mathematical model for the re-matching problem is formulated and described as follows: Min ⁢ ∑ j = 1 M ⁢ ⁢ ∑ i = 1 N ⁢ ⁢ ( c ⁢ ⁢ 1 ij + c ⁢ ⁢ 2 ij ) + u 1 ⁢ max ⁡ ( 0 , ∑ i = 1 N ⁢ ⁢ a i ⁢ x ij - A j max ) + u 2 ⁢ min ⁢ { max ⁡ ( 0 , A j min - ∑ i = 1 N ⁢ ⁢ a i ⁢ x ij ) , UW } - ∑ j = 1 M ⁢ ⁢ ∑ i = 1 N ⁢ R j ⁢ x ij + ∑ j = 1 M ⁢ P j ⁢ v ⁡ ( A j - AL j - ∑ i = 1 N ⁢ ⁢ a i ⁢ x ij ) + ∑ j ∈ H k ⁢ ⁢ max ( ∑ i = 1 N ⁢ a i ⁢ x ij - T k , 0 } wherein, M denotes set of all assignable orders, N denotes set of all assignable slabs, c 1 ij denotes cost caused by steel grade difference when an assignable slab i is assigned to an assignable order j; wherein c 2 ij denotes cutting loss cost caused by specification differences in weight, width and length when slab i is assigned to order j; wherein, u 1 denotes penalty cost caused by the redundant slab weight of the order, a i denotes weight of slab i A j max : denotes an upper limit of a required slab weight of order j; wherein, u 2 denotes the penalty cost caused by the under-fulfilled slab weight of A j min the order, denotes a lower limit of the required slab weight of order j, UW denotes a maximum value of penalty cost caused by the under-fulfilled slab weight; wherein, R j denotes priority awards related to a due date of order j, the order with a tighter due date should be given a higher priority; wherein, Pj denotes the penalty for the unfulfilled order j, A j denotes the required slab weight of order j, AL j denotes a maximal under-fulfilled slab weight of order j, function v(x) denotes that v(x)=1 when x>0, and v(x)=0 when x<0; wherein, H k denotes a set of the-orders involving the equipment units K, T k denotes a maximal capacity of the equipment units K.