共查询到18条相似文献,搜索用时 140 毫秒
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负荷分配是轧制规程设定计算的核心,合理的负荷分配能够充分发挥轧机生产能力,稳定生产过程,提高产品质量.负荷分配发展至今,其中按目标比例分配是众多分配方法中重要方法之一.按目标比例分配的数学模型本质上是求解非线性方程组问题,对国内外各种代表性的算法进行比较分析,在此基础上提出新的算法--改进Newton法,该算法既有Newton法良好的收敛性,同时又可以避免求Jacobian逆矩阵.经仿真验证,计算速度较快,精度较高,满足在线要求. 相似文献
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提出一种带钢热连轧精轧机组负荷分配的优化计算策略,采用多目标优化算法离线计算确定精轧各机架的轧制力分配系数,采用"压下模式+轧制力模式"相结合的方式实现负荷分配在线计算。为了确定各精轧机架的轧制力分配系数,建立兼顾轧制功率最小、负荷均衡与板形良好的负荷分配多目标优化模型;为了实现负荷分配在线计算,根据压下模式负荷分配计算确定厚度分配的初始值,根据CLAD算法进行轧制力模式负荷分配迭代计算,最后采用压下模式分配计算确定的压下率分布范围对轧制力模式分配结果进行限幅处理。新方法已成功应用于梅钢1 780mm热连轧生产线,在线应用表明该方法可以有效减少操作工干预,提高带钢精轧过程的轧制稳定性。 相似文献
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为克服压下量模式负荷分配的不足,宝钢1 580 mm过程机改造项目计划开发新的轧制力模式负荷分配方法。针对传统Newton-Raphson法对初始值依赖较大和算法容易发散等不足,提出了一种轧制力模式负荷分配的改进算法。该方法以精轧各机架的压下量为优化变量,根据轧制力成比例原则建立非线性方程组,通过推导将系数矩阵变为对角阵,避免了矩阵求逆运算;为了满足各次迭代所有机架压下量修正值之和为零的约束,添加一个修正项对各机架压下量修正值进行总体协调。提出了轧制力和压下量的超限处理方案。模拟计算验证了新算法的有效性,计算速度快,收敛性好,满足在线计算要求。 相似文献
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综合等负荷函数法的逆向算法 总被引:11,自引:3,他引:8
讨论了“综合等负荷函数法”的改进,将原有正向迭,改为温度-厚度的正反向交叉迭代,并通过在迭代中过程中人为增加负荷余量和采用新的迭代参数,极大地改善了目标函数性态和算法的稳定性,为该方法的实时在线应用奠定了坚实的基础。 相似文献
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Load distribution is a key technology in strip hot rolling process, which influences the coil′s microstructure and performance. Currently, Newton Raphson algorithm is applied to load distribution of hot tandem mills in many hot rolling plants and has some serious defects such as having a strict restriction on initial iterative calculation value and requiring coefficient matrix of nonlinear equations to be nonsingular. To eliminate these defects and improve the online performance of the process control computer, Newton descendent numeric algorithm is introduced to this field to widen the initial value range and a new model named error conversion algorithm is put forth to deal with special conditions when the coefficient matrix is singular. Furthermore, considering the characteristics of load distribution, a condition of strip thickness distribution abnormality and corresponding solutions are provided which ensure that rolling parameters can be calculated normally. Simulation results show that the improved algorithm has overcome the defects of the Newton Raphson algorithm and is suitable for online application. 相似文献
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Based on rolling feature of continuous tandem cold rolling mill, such as multi-variable, strong coupling, non-linear, analyze and set the equal relative load, preventing slippage and profile well as the multi-objective optimization goal, BP neural network with self-learning function is adopted to replace traditional rolling force models and then Levenberg-Marquardt algorithm is adopted to predict the rolling force. Then use multi-objective fuzzy theory to solve the problem of multi-objective optimization of tandem cold rolling schedule. With the example of 1370mm tandem cold rolling, the rolling schedule of the common rolling, the single-object optimization design and the multi-objective fuzzy optimization design are compared with each other, optimization result shows the proposed optimization method decreases the value of three objective functions simultaneous. The performance of the optimal rolling schedule is satisfying and it is promising. 相似文献
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