Accurate crown control is paramount for ensuring the quality of hot-rolled strip products.Given the multitude of influencing parameters and the intricate coupling and genetic relationships among them,the conventional ...Accurate crown control is paramount for ensuring the quality of hot-rolled strip products.Given the multitude of influencing parameters and the intricate coupling and genetic relationships among them,the conventional crown control method is no longer sufficient to meet the precision requirements of schedule-free rolling.To address this limitation,an optimization framework for hot-rolled strip crown control was developed based on model-driven digital twin(MDDT).This framework enhances the strip crown control precision by facilitating collaborative operations among physical entities,virtual models,and functional application layers.In virtual modeling,a data-driven approach that integrates the extreme gradient boosting and the improved Harris hawk optimization algorithm was firstly proposed to fit the relationship between key process parameters and strip crown,and a global-local collaborative training strategy was proposed to enhance the model adaptability to diverse working conditions.Subsequently,the influence of crucial process factors on the virtual model was examined through model responses.Furthermore,a novel optimization mode for crown control based on MDDT was established by aligning and reconstructing both the physical and virtual models,thereby enhancing the crown control precision.Finally,data trials were conducted to validate the effectiveness of the proposed framework.The results indicated that the proposed method exhibited satisfactory performance and could be effectively utilized to improve the crown control precision.展开更多
The strip flatness and crown control model is the foundation of automatic strip shape control. Considering the metal transverse flows and the inter stand second deformation, the trip flatness and crown control model h...The strip flatness and crown control model is the foundation of automatic strip shape control. Considering the metal transverse flows and the inter stand second deformation, the trip flatness and crown control model has been developed, which can be applied to CVC mills and PC mills as well as normal four-high mills. The strip flatness and crown control model has high precision, and has been successfully applied to the automatic strip shape control system reconstruction of Tangshan Ganglu 1 250 mm hot strip plant.展开更多
[ Objectives ] The paper aimed to reduce the damage of wheat crown rot caused by Fusarium graminearum on wheat production. [ Methods ] Pathogens were isolated from wheat crown rot samples collected in fields, and the ...[ Objectives ] The paper aimed to reduce the damage of wheat crown rot caused by Fusarium graminearum on wheat production. [ Methods ] Pathogens were isolated from wheat crown rot samples collected in fields, and the major pathogenic fungi were determined as F. graminearum through molecular techniques. Different fungicides were administrated at seedling stage and reviving stage to control the disease. [ Results] There were significant differences in control effects against crown rot among different fungicides. Tebuconazole ·prochloraz mixture and Carbendazim · triadimefon mixture had good control effects, while such single agents as Tebuconnazole and Difenoconazole· propicondzole had good control effects as well. [ Conclusions] Seed dressing with agents could significantly reduce the incidence rate of crown rot at seedling stage, and stem spraying at reviving stage had better control effect.展开更多
Crown feedback control is one part of the automatic shape control （ASC） system. On the basis of large simulation researches conducted, a linear crown feedback control model was put forward and applied in actual stri...Crown feedback control is one part of the automatic shape control （ASC） system. On the basis of large simulation researches conducted, a linear crown feedback control model was put forward and applied in actual strip rolling. According to its successful op- eration in the ASP 1700 hot strip mill of Angang Group for one year and also from the statistical results of several crown measurements, it can be definitely said that this control model is highly effective and shows stable performance. The control effectiveness of different gauges of strips with the feedback control is found to increase by 10%-30% compared with that without feedback control.展开更多
In order to establish precision model, a software to calculate the strip crown of four-high hot rolling mill was developedby using affecting function method according to the strip crown calculation theory. The effect ...In order to establish precision model, a software to calculate the strip crown of four-high hot rolling mill was developedby using affecting function method according to the strip crown calculation theory. The effect of work roll diameter,unit width rolling load, roll bending force, work roll crown, initial strip crown and reduction, etc, on load distributioneffect rate was simulated by using the software. The results show that the load distribution effect rate increaseswith the increase of strip width, work roll diameter, unit width rolling load, roll bending force, work roll crown,initial strip crown and reduction. Based on the simulation results, base value of load distribution effect rate andfitting coefficients of six power polynomial of load distribution effect rate modification coefficient were determinedconsidering all of the above parameters. A simplified mathematical model for calculating load distribution effect ratewas established.展开更多
基金financially supported by the National Key Research and Development Program of China(Grant No.2023YFB3710204)Guangxi Science and Technology Major Program(Grant No.AA23023028-1)+1 种基金Natural Science Foundation of Heilongjiang Province of China for Distinguished Young Scientists(Grant No.JQ2022E007)Xinjiang Production and Construction Corps Science and Technology Plan(Grant No.2023AA003).
文摘Accurate crown control is paramount for ensuring the quality of hot-rolled strip products.Given the multitude of influencing parameters and the intricate coupling and genetic relationships among them,the conventional crown control method is no longer sufficient to meet the precision requirements of schedule-free rolling.To address this limitation,an optimization framework for hot-rolled strip crown control was developed based on model-driven digital twin(MDDT).This framework enhances the strip crown control precision by facilitating collaborative operations among physical entities,virtual models,and functional application layers.In virtual modeling,a data-driven approach that integrates the extreme gradient boosting and the improved Harris hawk optimization algorithm was firstly proposed to fit the relationship between key process parameters and strip crown,and a global-local collaborative training strategy was proposed to enhance the model adaptability to diverse working conditions.Subsequently,the influence of crucial process factors on the virtual model was examined through model responses.Furthermore,a novel optimization mode for crown control based on MDDT was established by aligning and reconstructing both the physical and virtual models,thereby enhancing the crown control precision.Finally,data trials were conducted to validate the effectiveness of the proposed framework.The results indicated that the proposed method exhibited satisfactory performance and could be effectively utilized to improve the crown control precision.
基金Item Sponsored by National Natural Science Foundation of China (50534020)
文摘The strip flatness and crown control model is the foundation of automatic strip shape control. Considering the metal transverse flows and the inter stand second deformation, the trip flatness and crown control model has been developed, which can be applied to CVC mills and PC mills as well as normal four-high mills. The strip flatness and crown control model has high precision, and has been successfully applied to the automatic strip shape control system reconstruction of Tangshan Ganglu 1 250 mm hot strip plant.
基金Supported by Special Fund for Agro-scientific Research in the Public Interest(201503112)Special Project for Construction of China Agricultural Industry Research System(CARS-03)Key Technology R&D Program of Jiangsu Province(BE2013439)
文摘[ Objectives ] The paper aimed to reduce the damage of wheat crown rot caused by Fusarium graminearum on wheat production. [ Methods ] Pathogens were isolated from wheat crown rot samples collected in fields, and the major pathogenic fungi were determined as F. graminearum through molecular techniques. Different fungicides were administrated at seedling stage and reviving stage to control the disease. [ Results] There were significant differences in control effects against crown rot among different fungicides. Tebuconazole ·prochloraz mixture and Carbendazim · triadimefon mixture had good control effects, while such single agents as Tebuconnazole and Difenoconazole· propicondzole had good control effects as well. [ Conclusions] Seed dressing with agents could significantly reduce the incidence rate of crown rot at seedling stage, and stem spraying at reviving stage had better control effect.
文摘Crown feedback control is one part of the automatic shape control （ASC） system. On the basis of large simulation researches conducted, a linear crown feedback control model was put forward and applied in actual strip rolling. According to its successful op- eration in the ASP 1700 hot strip mill of Angang Group for one year and also from the statistical results of several crown measurements, it can be definitely said that this control model is highly effective and shows stable performance. The control effectiveness of different gauges of strips with the feedback control is found to increase by 10%-30% compared with that without feedback control.
基金This study was financially supported by the National Natural Science Foundation of China under the contract No.59995440the State Key Development Programming on Foundamental Research under the contract No.G2000067208-4the Natural Science Foundation of Liaoning Province under the contract No.2001101021.
文摘In order to establish precision model, a software to calculate the strip crown of four-high hot rolling mill was developedby using affecting function method according to the strip crown calculation theory. The effect of work roll diameter,unit width rolling load, roll bending force, work roll crown, initial strip crown and reduction, etc, on load distributioneffect rate was simulated by using the software. The results show that the load distribution effect rate increaseswith the increase of strip width, work roll diameter, unit width rolling load, roll bending force, work roll crown,initial strip crown and reduction. Based on the simulation results, base value of load distribution effect rate andfitting coefficients of six power polynomial of load distribution effect rate modification coefficient were determinedconsidering all of the above parameters. A simplified mathematical model for calculating load distribution effect ratewas established.
