Multi-objective Optimization Scheduling Model Based on NSGA-II Algorithm

The preparation of steelmaking-continuous casting-hot rolling production planning is a complex combinational optimization problem with multiple objectives and constraints. Based on the inductive characteristics and constraints, a multi-objective optimization model for integrated production of steelmaking, continuous casting, and hot rolling is established. In this paper, the 2nd generation of non-dominated sorting genetic algorithm (NSGA-II) is employed to make converters, continuous casters and hot mill have the lowest idle capacity, and the idle capacity of each heat, cast, and rolling unit are respectively summed as the objective function in the multiobjective optimization. According to the process features of steelmaking, continuous casting and hot rolling, the constraints in each production process is enumerated. Plug-in coding method is designed, the NSGA-II algorithm is adopted to solve the pareto front of the multi-objective optimization, and the lowest production time solution in the pareto front is selected as the final production plan. Finally, a simulation analysis is conducted on the actual project to verify the effectiveness of the algorithm, and meanwhile prove its reference value when applied to actual production scheduling problems.