20-high mills often face various flatness problems in the production of cold-rolled stainless steel thin strips.The flatness prediction model is essential for flatness control techniques.A novel rapid prediction model...20-high mills often face various flatness problems in the production of cold-rolled stainless steel thin strips.The flatness prediction model is essential for flatness control techniques.A novel rapid prediction model for flatness in a 20-high mill is proposed based on a model coupling method capable of forecasting the flatness of cold-rolled stainless steel thin strips under symmetric and asymmetric rolling conditions.The model integrates deformation coordination equations between rolls,force and moment balance equations,strip exit transverse displacement equations,and no-load roll gap equations into a unified set of linear equations.This solution process avoids repeated iterations between the elastic deformation model of the roll system and the plastic deformation model of the strip,which is a limitation of the traditional method and significantly improves the calculation speed and stability.The accuracy of the model was verified via a ZR22B-52 Sendzimir 20-high mill.The measured and calculated flatness values highly coincided,confirming the model’s accuracy.Rolling calculations of 304 stainless steel thin strips demonstrate that the new model results are consistent with those of the traditional method.The calculation time of the new model is only approximately 0.04%-0.35%that of the traditional method.On this basis,the impact of common flatness control methods on the flatness has been analyzed.展开更多
We propose a method to measure the flatness of an object with a petal-like pattern generated by the interference of the measured orbital angular momentum(OAM)beam and the reference OAM beam which carries the opposite ...We propose a method to measure the flatness of an object with a petal-like pattern generated by the interference of the measured orbital angular momentum(OAM)beam and the reference OAM beam which carries the opposite OAM state.By calculating the difference between the petal rotation angle without/with the object,the thickness information of the object,and then the flatness information,can be evaluated.Furthermore,the direction of the object’s flatness can be determined by the petal’s clockwise/counterclockwise rotation.We theoretically analyze the relationship between the object’s thickness and petal rotation angle,and verify the proposed method by experiment.The experimental results show that the proposed method is a high precision flatness measurement and can obtain the convex/concave property of the flatness.For the 1.02 mm glass sample,the mean deviation of the flatness is 1.357×10^(-8) and the variance is 0.242×10^(-16).For the 0.50 mm glass sample,the mean deviation of the flatness is 1.931×10^(-8) and the variance is 2.405×10^(-16).Two different topological charges are adopted for the 2.00 mm glass sample,and their flatness deviations are 0.239×10^(-8)(ℓ=1)and 0.246×10^(-8)(ℓ=2),where their variances are 0.799×10^(-18)(ℓ=1)and 0.775×10^(-18)(ℓ=2),respectively.It is shown that the flatness measured by the proposed method is the same for the same sample when different topological charges are used.All results indicate that the proposed method may provide a high flatness measurement,and will be a promising way to measure the flatness.展开更多
With the increasing demand for higher-quality flatness in downstream industries,the optimization of rolling processes and parameters has become a critical area of research.The effects of rolling force and front tensio...With the increasing demand for higher-quality flatness in downstream industries,the optimization of rolling processes and parameters has become a critical area of research.The effects of rolling force and front tension adjustments on flatness were examined systematically under various rolling process conditions.By embedding the Johnson-Cook constitutive model into the ABAQUS simulation platform through a user-defined subroutine,a series of three-dimensional finite element models for different rolling scenarios were developed.Simulation results indicate that,under all four rolling process conditions,edge strain consistently exceeds center strain,with forward-driven rolling exhibiting greater edge strain than reverse-driven rolling.Along the strip thickness direction,reverse-driven rolling results in higher strain compared to forward-driven rolling.Moreover,in single roll driven rolling,the upper surface of the strip experiences higher strain than the lower surface,while the reverse trend is observed in double roll driven rolling.As the rolling force increases from 1000 to 5000 kN,the strain difference in the width and thickness directions of the strip varies significantly under double roll driven rolling and double roll reverse-driven rolling,with change slopes of 5.74×10^(-6) and-2.85×10^(-6),respectively.Double roll driven rolling effectively prevents the deterioration of flatness along the rolling direction.Furthermore,as the front tension increases from 60 to 100 MPa,double roll reverse-driven rolling significantly suppresses strain differentials in the width,thickness,and rolling directions,with change slopes of-6.73×10^(-4),1.22×10^(-5),and-1.29×10^(-5),respectively.Eventually,a predictive model is established,integrating rolling process,rolling force,and front tension,thereby providing a theoretical framework for advancing the precision and efficiency of strip rolling processes.展开更多
This paper proposes a differential-fatness-based active disturbance rejection control(ADRC)for high-speed steering control of tracked tank systems.Firstly,a high-speed steering model is established by considering the ...This paper proposes a differential-fatness-based active disturbance rejection control(ADRC)for high-speed steering control of tracked tank systems.Firstly,a high-speed steering model is established by considering the lateral component of the centrifugal force acting on the tank on the basis of modeling and analyzing the dynamic model of the low-speed steering system.Secondly,we propose a differential-flatness ADRC approach by converting the under-actuated system to a fully driven flat one.Moreover,we prove the differential flatness of the steering system,which facilitates a two-channel ADRC development.Finally,we show that both the states of the flat system and the original under-actuated system can track the reference trajectory.On the external interference condition,the system is observed to re-track the target signal within 2 s.展开更多
基金supported by the National Natural Science Foundation of China(No.U21A20118)the Natural Science Foundation of Hebei Province(No.E2023203065)the National Key Laboratory of Metal Forming Technology and Heavy Equipment,China National Heavy Machinery Research Institute Co.,Ltd.(No.S2208100.W04).Author infor。
文摘20-high mills often face various flatness problems in the production of cold-rolled stainless steel thin strips.The flatness prediction model is essential for flatness control techniques.A novel rapid prediction model for flatness in a 20-high mill is proposed based on a model coupling method capable of forecasting the flatness of cold-rolled stainless steel thin strips under symmetric and asymmetric rolling conditions.The model integrates deformation coordination equations between rolls,force and moment balance equations,strip exit transverse displacement equations,and no-load roll gap equations into a unified set of linear equations.This solution process avoids repeated iterations between the elastic deformation model of the roll system and the plastic deformation model of the strip,which is a limitation of the traditional method and significantly improves the calculation speed and stability.The accuracy of the model was verified via a ZR22B-52 Sendzimir 20-high mill.The measured and calculated flatness values highly coincided,confirming the model’s accuracy.Rolling calculations of 304 stainless steel thin strips demonstrate that the new model results are consistent with those of the traditional method.The calculation time of the new model is only approximately 0.04%-0.35%that of the traditional method.On this basis,the impact of common flatness control methods on the flatness has been analyzed.
基金supported by the National Natural Science Foundation of China(Grant No.62375140)the Open Research Fund of National Laboratory of Solid State Microstructures(Grant No.M36055).
文摘We propose a method to measure the flatness of an object with a petal-like pattern generated by the interference of the measured orbital angular momentum(OAM)beam and the reference OAM beam which carries the opposite OAM state.By calculating the difference between the petal rotation angle without/with the object,the thickness information of the object,and then the flatness information,can be evaluated.Furthermore,the direction of the object’s flatness can be determined by the petal’s clockwise/counterclockwise rotation.We theoretically analyze the relationship between the object’s thickness and petal rotation angle,and verify the proposed method by experiment.The experimental results show that the proposed method is a high precision flatness measurement and can obtain the convex/concave property of the flatness.For the 1.02 mm glass sample,the mean deviation of the flatness is 1.357×10^(-8) and the variance is 0.242×10^(-16).For the 0.50 mm glass sample,the mean deviation of the flatness is 1.931×10^(-8) and the variance is 2.405×10^(-16).Two different topological charges are adopted for the 2.00 mm glass sample,and their flatness deviations are 0.239×10^(-8)(ℓ=1)and 0.246×10^(-8)(ℓ=2),where their variances are 0.799×10^(-18)(ℓ=1)and 0.775×10^(-18)(ℓ=2),respectively.It is shown that the flatness measured by the proposed method is the same for the same sample when different topological charges are used.All results indicate that the proposed method may provide a high flatness measurement,and will be a promising way to measure the flatness.
基金supported by National Key R&D Program of China(No.2024YFB4007100).
文摘With the increasing demand for higher-quality flatness in downstream industries,the optimization of rolling processes and parameters has become a critical area of research.The effects of rolling force and front tension adjustments on flatness were examined systematically under various rolling process conditions.By embedding the Johnson-Cook constitutive model into the ABAQUS simulation platform through a user-defined subroutine,a series of three-dimensional finite element models for different rolling scenarios were developed.Simulation results indicate that,under all four rolling process conditions,edge strain consistently exceeds center strain,with forward-driven rolling exhibiting greater edge strain than reverse-driven rolling.Along the strip thickness direction,reverse-driven rolling results in higher strain compared to forward-driven rolling.Moreover,in single roll driven rolling,the upper surface of the strip experiences higher strain than the lower surface,while the reverse trend is observed in double roll driven rolling.As the rolling force increases from 1000 to 5000 kN,the strain difference in the width and thickness directions of the strip varies significantly under double roll driven rolling and double roll reverse-driven rolling,with change slopes of 5.74×10^(-6) and-2.85×10^(-6),respectively.Double roll driven rolling effectively prevents the deterioration of flatness along the rolling direction.Furthermore,as the front tension increases from 60 to 100 MPa,double roll reverse-driven rolling significantly suppresses strain differentials in the width,thickness,and rolling directions,with change slopes of-6.73×10^(-4),1.22×10^(-5),and-1.29×10^(-5),respectively.Eventually,a predictive model is established,integrating rolling process,rolling force,and front tension,thereby providing a theoretical framework for advancing the precision and efficiency of strip rolling processes.
基金supported by the National Natural Science Foundation of China(62422305,62373049).
文摘This paper proposes a differential-fatness-based active disturbance rejection control(ADRC)for high-speed steering control of tracked tank systems.Firstly,a high-speed steering model is established by considering the lateral component of the centrifugal force acting on the tank on the basis of modeling and analyzing the dynamic model of the low-speed steering system.Secondly,we propose a differential-flatness ADRC approach by converting the under-actuated system to a fully driven flat one.Moreover,we prove the differential flatness of the steering system,which facilitates a two-channel ADRC development.Finally,we show that both the states of the flat system and the original under-actuated system can track the reference trajectory.On the external interference condition,the system is observed to re-track the target signal within 2 s.
