Flatness Feed-Forward Control Model Based on Neural Networks

2014 ◽  
Vol 989-994 ◽  
pp. 3386-3389
Author(s):  
Zhu Wen Yan ◽  
Hen An Bu ◽  
Dian Hua Zhang ◽  
Jie Sun

The influence on the shape of the strip from rolling force fluctuations has been analyzed. The combination of intermediate roll bending and work roll bending has been adopted. The principle of rolling force feed-forward control has been analyzed. The feed-forward control model has been established on the basis of neural networks. The model has been successfully applied to a rolling mill and a good effect has been achieved.

Metals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1066
Author(s):  
Hao Tao ◽  
Hongbo Li ◽  
Jian Shao ◽  
Jie Zhang ◽  
Yujin Liu ◽  
...  

In order to analyze the flatness control characteristics for a certain UCMW (Universal Crown Mill with Work roll shifting) cold rolling mill, combined with the actual parameters in the field, a static simulation model of the quarter roll systems of the UCMW cold rolling mill was established by the ANSYS finite element software. The bearing roll gaps under the factors of the unit width rolling force, the roll bending force and the roll shift were calculated, which reflects the shape control characteristics and has a great influence on the friction and lubrication characteristics between the roll gaps. Additionally, the shape control strategy of the process parameters in the field was put forward. The results show that, at first, the work roll shift is the most effective shape control means, while the current-used range of the intermediate roll shift cannot make full use of the roll end contour of the intermediate roll, so the intermediate roll negative shift should be considered for shape control. At second, the excessive rolling force goes against the shape control, so the rolling force of each stand should be reasonably distributed. Finally, the shape control ability of the bending force is relatively weak, so the range of the work roll bending force should be appropriately increased.


2014 ◽  
Vol 988 ◽  
pp. 257-262 ◽  
Author(s):  
Ke Zhi Linghu ◽  
Zheng Yi Jiang ◽  
Fei Li ◽  
Jing Wei Zhao ◽  
Meng Yu ◽  
...  

A 3D elastic-plastic finite element method (FEM) model of cold strip rolling for 6-high continuous variable crown (CVC) rolling mill was developed. The rolling force distributions were obtained by the internal iteration processes. The calculated error has been significantly reduced by the developed model. the absolute error between the simulated results and the actual values is obtained to be less than 10μm, and relative error is less than 1%. The developed model is significant in investigating the profile control capability of the CVC cold rolling mill in terms of work roll bending, intermediate roll bending and intermediate roll shifting.


2007 ◽  
Vol 561-565 ◽  
pp. 115-118
Author(s):  
Zheng Yi Jiang ◽  
Hai Bo Xie ◽  
L.M. Yang ◽  
Hong Tao Zhu ◽  
Dong Bin Wei ◽  
...  

Asymmetric rolling of thin strip has become important due to a significant decrease of rolling force, which contributes to obtain the extremely thin strip, to reduce the rolling passes, and to save the energy by a decrease of anneal treatment. In asymmetric rolling of thin strip, edges of work rolls may contact and deform when no or small work roll bending force is applied. Work roll edge contact forms a new deformation feature. In this paper, the effects of initial thickness of strip and friction coefficient on the rolling pressure, roll edge contact length and strip crown during asymmetric rolling of thin strip with work roll edge contact effect has been discussed, and the calculated rolling force with work roll edge contact is compared with the measured value.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Guangxu Zhang ◽  
Jiahan Bao ◽  
Wenhao Li ◽  
Zhichong Wang ◽  
Xiangshuai Meng

It is important to study the vibration of rolling mills to improve the stability of rolling production. A dynamic rolling process model is established by considering the elastic recovery of the exit strip and the influence of multiroll equilibrium, and the accuracy of the model is verified by experimental data. On this basis, based on the distribution of friction force in the deformation zone, the rolling force and rolling torque are nonlinearized. In addition, a rolling mill structure model is established by considering the structure gap and a piecewise nonlinear horizontal-vertical-torsional vibration model of the rolling mill is established by combining the structure model and dynamic rolling process model. Finally, the amplitude-frequency characteristics of the work roll under different external excitation amplitude and the dynamic bifurcation characteristics of the work roll under different gaps are analyzed. The study indicates that, by reducing excitation amplitude and structure gap, the system vibration can be reduced. The research results can provide a theoretical reference for further exploration of the coupling vibration of hot rolling mills.


2012 ◽  
Vol 572 ◽  
pp. 55-60 ◽  
Author(s):  
Peng Liu ◽  
Hong Bo Li ◽  
Zhi Qian Shen

This paper focuses on a new type of 8-roll cold rolling mill with the back-up bearing roll. Compared to the traditional 6-roll cold rolling mill, a thick-walled bearing roll is used to multi-support the intermediate roll. By the rack, the fan-shaped gears, the eccentric core shaft and the servo-cylinder, the work roll can be pushed down by this screw down device on the top of the mill; By contrast with the 4(6)-roll mill, this type of mill has some characteristics, such as: the small size of rolls, lighter weight, the fast response for the screw down. The bearing roll is fixed by the supporting blocks placed on the rolling-mill housing. So this mill has large traverse rigidity, and this is propitious to the flatness control. By different means of strip flatness adjustments, such as the intermediate roll shifting, the roll bending and the bearing roll adjusting, the strip flatness can be well controlled. The oil-gas lubrication is used in the bearings of the bearing rolls, and the changing rolls equipment is designed for this type of mill too. A series of this type of mills (as 450, 800, 1250, 1450 series) have been produced since it was developed in 1997. The mills for 1250 and 1450 series have been applied in five-stand cold rolling mill and single stand reversing mill, a rolling speed of 800m/min has been achieved.


2007 ◽  
Vol 340-341 ◽  
pp. 755-760
Author(s):  
Tadahiro Kawase ◽  
Hiroyuki Shiozaki ◽  
Toshitaka Iwauchi

During lumber rolling, a fixation device is typically installed just behind the work roll to set up the delivery thickness and to fix the thickness reduction. However, the accompanying resistance force into the fixation device can cause slippage between the roll and material, indicating a bound for the rolling conditions. Slippage can be avoided by decreasing the resistance force or by adding a pushing force on the lumber from the entry side of the rolling mill. This paper experimentally investigated the effects of these horizontal forces on the rolling force and roll torque. From these results, the roll torque was found to be directly affected by the horizontal forces, but the rolling force was not affected. Secondly, a new parameter μeq was introduced and a condition of non-slippage, in which μeq must be less than the coefficient of static friction to avoid slippage, was proposed. This condition was then used to predict and to protect against slippage by identifying when this condition was violated and then applying a horizontal force to decrease μeq.


2014 ◽  
Vol 556-562 ◽  
pp. 2337-2341
Author(s):  
Yan Ping Wang ◽  
Xin Bing Yang ◽  
Yao Hui Jin ◽  
Bao Quan Liu ◽  
Jun Sheng Wang

The calculated result of the mathematical model based on the conventional transfer function has bigger deviation than the measured. In this paper the mathematical model of the work roll bending is derived. The modeling is different from conventional modeling used many presumptions and linear processing. The modeling calculated accurately the equivalent load spring using the method of influence function. The simulation results agree well with actual data of the bending system.


2012 ◽  
Vol 572 ◽  
pp. 165-170
Author(s):  
Ru Ying He ◽  
Ting Quan Gu ◽  
Yun Feng Liu

A feed-forward control method for cold rolled strip flatness is put forward. That is to carry out feed-forward compensation to bending force of the stand, so as to mitigate the complex influence caused by changes of rolling force and tension in rolling process on strip flatness based on regular flatness feedback control which focus on the last stand, according to changes in stand rolling force, inlet tension and outlet tension measured. Result shows that this technique not only increased the flatness quality of the strip cold-rolled, but also increased the stability of cold-rolling process of thin strip when it was actually applied in a cold tandem mill.


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