Research On Intelligent Optimization Method For Variable Gauge Rolling Schedule Of Ultra-heavy Plate

As an important steel product,ultra-heavy plate is widely used in various fields of national construction.In order to improve the core quality of ultra-heavy plate products,based on the existing process equipment,a variable gauge rolling method is proposed to increase the single pass reduction.In this paper,the online calculation and intelligent optimization method for the rolling schedule of the ultra-heavy plate variable gauge rolling process are carried out.The online application of the variable gauge rolling method is realized by modifying the pass schedule calculation program of the on-site rolling mill process control system.In order to improve the control precision of the variable gauge rolling process,based on the actual field data,the intelligent algorithm is used to optimize the variable gauge rolling schedule.The main contents of this paper are as follows:(1)Aiming at the calculation procedure of the conventional rolling schedule,the intelligent retrieval method is used to determine the minimum number of passes.The inverse thickness calculation method is used to calculate the initial value of the thickness distribution,and the load distribution tendency of the rolling force is increased first and then decreased to obtain a reasonable schedule data.(2)According to the characteristics of variable gauge rolling process,the using stage and strategy of variable gauge rolling are determined,and two increasing reduction methods are proposed.Considering the shape and thickness control conditions,the number of variable gauge rolling groups is determined.In order to realize the calculation of the variable thickness,the segmentation calculation of the plate is carried out.Based on the nonlinear relationship between the rolling torque and the pass reduction,and considering the torque amplification factor,Newton iteration method is used to calculate the variation of the head-to-tail reduction.And the calculation process of variable gauge rolling schedule is designed.(3)Based on the C++language programming environment of Visual Studio 2012,the variable gauge rolling schedule calculation program was integrated into the online system,and the configuration file modification tool was developed,the online variable gauge rolling schedule calculation is running.Aiming at the practical application effect of the variable gauge rolling method,same plates were rolled with the conventional rolling and variable gauge rolling methods.The actual data shows that the variable gauge rolling method can reduce head impact and reduce head torque shock.With two sets of variable gauge rolling passes,the pass reduction was increased and the number of rolling passes was reduced.(4)A case-based reasoning method is proposed for intelligent optimization of variable gauge rolling schedule allocation.The case retrieval is performed by using the primary search based on LM-BP algorithm and the quadratic matching of nearest neighbor method.The accuracy of retrieval is increased by the subjective and objective setting of the weight of feature attributes.In addition,a case modification model based on GA algorithm to improve PSO algorithm is proposed,and the actual load distribution trend is taken as the objective function to achieve further improvement of the most similar cases.Finally,the stability and convergence of the GA-PSO algorithm are verified by comparing with different optimization algorithms.