Research on Flatness Feed-Forward Control for Cold Rolled Strip

2012 ◽  
Vol 572 ◽  
pp. 165-170
Author(s):  
Ru Ying He ◽  
Ting Quan Gu ◽  
Yun Feng Liu
Keyword(s):  
Control Method ◽  
Rolling Force ◽  
Rolling Process ◽  
Thin Strip ◽  
Rolled Strip ◽  
Feed Forward ◽  
Feed Forward Control ◽  
Strip Flatness ◽  
Cold Rolled ◽  
The Stability

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.

An Automatic Control Strategy of Strip Width in Cold Rolling

2014 ◽  
Vol 1004-1005 ◽  
pp. 1221-1225
Author(s):  
Ji Lai Yu ◽  
Ting Quan Gu ◽  
Jian Guo Wang
Keyword(s):  
Cold Rolling ◽  
Automatic Control ◽  
Control Strategy ◽  
Rolling Force ◽  
Rolling Process ◽  
Strip Width ◽  
Rolled Material ◽  
Feed Forward Control ◽  
The Stability ◽  
Hot Rolled

This paper proposes an automatic control strategy of the strip width in cold rolling process. The prediction model for the exit strip width of each stand is established. In addition to the strip width variation of the incoming hot-rolled material between the measured and the pre-set values, the variations of the rolling force, tension, bending force and the roll shift amount of each stand are utilized to model and forecast the stand exit width deformation. Then, the model can be used to determine the compensation values of the different profile adjustment mechanism and the exit strip width can be controlled in high accuracy. In this way, the effect of the strip width variation of the incoming hot-rolled material and the fluctuation of the stand rolling process parameters on the exit strip width can be eliminated. Moreover, the feed-forward control of the strip width can reduce the incidence of abnormal situation, such as the strip breakage and off-tracking ,and improve the stability of the cold rolling process.

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
Keyword(s):  
Neural Networks ◽  
Rolling Mill ◽  
Rolling Force ◽  
Work Roll ◽  
Control Model ◽  
Good Effect ◽  
Feed Forward ◽  
Force Fluctuations ◽  
Feed Forward Control ◽  
Roll Bending

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.

scholarly journals Mass Imbalance Compensation Control for Stabilized Platform Based on UKF Identification

2018 ◽  
Vol 198 ◽  
pp. 01005
Author(s):  
WeiMing Zhang ◽  
ZeLin Shi
Keyword(s):  
Mean Squared Error ◽  
Unscented Kalman Filter ◽  
Parameters Estimation ◽  
Feed Forward ◽  
Mass Imbalance ◽  
Feed Forward Control ◽  
Nonlinear Compensation ◽  
The Stability ◽  
Stabilized Platform ◽  
Platform System

Due to the mass imbalance about the center of rotation, the stability of stabilized platform system degrades with carrier’s disturbances. Various feed-forward control methods are provided by reaserchers to solve this problem, however these methods are not well applied because the eccentricity of stabilized platform could not be measured directly. The dynamics model of a typical 2-axis stabilized platform is given. The eccentricity vector is identified through Unscented Kalman Filter(UKF) algorithm. Imbalance torque is precisely observed so that the real-time nonlinear compensation for mass imbalance is achieved through a feed-forward loop. The simulation result indicates that the Root Mean Squared Error (RMSE) of parameters estimation is 0.024 after convergence. the LOS stabilization with carrier’s 2.5Hz vibration is 0.04 rad/s, which improves 78% compared to conventional feed-back control.

Finite Element Analysis of Thin Strip Profile in Asymmetric Cold Rolling Considering Work Roll Crossing and Shifting

2014 ◽  
Vol 1061-1062 ◽  
pp. 515-521 ◽  
Author(s):  
Abdulrahman Aljabri ◽  
Zheng Yi Jiang ◽  
Dong Bin Wei
Keyword(s):  
Finite Element ◽  
Cold Rolling ◽  
Finite Element Model ◽  
Rolling Force ◽  
Element Model ◽  
Work Roll ◽  
Rolling Process ◽  
Thin Strip ◽  
Asymmetric Rolling ◽  
Element Analysis

Cold rolled thin strip has received a great deal of attention through technological and theoretical progress in the rolling process, as well as from researchers who have focused on some essential parameters of strip such as its shape and profile. This paper describes the development of a 3-D finite element model of the shape of thin strip during cold rolling to simulate the cold rolling of WCS (work roll crossing and shifting) in asymmetric rolling. This finite element model considers the asymmetrical rolling parameters such as variations in the diameters of the rolls and the crossing angle as the work roll shifts on the strip during cold rolling. The shape and profile of the strip are discussed in the asymmetrical and symmetrical rolling conditions, while the total rolling force and distribution of stress are discussed in the case where the roll cross angle and axial shifting roll changes. The results can then be used to control the shape and profile of thin strip during rolling.

Determining and Optimizing of Guide Rolls Motion Track in Cold Ring Rolling Process

2006 ◽  
Vol 532-533 ◽  
pp. 141-144 ◽  
Author(s):  
Zhi Chao Sun ◽  
He Yang ◽  
Lan Yun Li
Keyword(s):  
Functional Relationship ◽  
Rolling Force ◽  
Rolling Process ◽  
Initial Position ◽  
Ring Rolling ◽  
Software Environment ◽  
Cold Ring Rolling ◽  
The Stability ◽  
Ring Rolling Process ◽  
And Control

Guide rolls play an important role in controlling both the ring circularity and the stability of cold ring rolling process. However, it is difficult to predict and control the motion of the guide rolls due to the complexity of process associated with the coupled effects of multi-factors. In this paper, a reasonable controlling model of the guide rolls is proposed, and the functional relationship between the motion track of the guide rolls and their setup parameters and process ones is established, by which the guide rolls motion track can be determined. On this basis, a 3D-FE simulation model for cold ring rolling is developed under the ABAQUS software environment and the effects of the initial position and motion track of the guide rolls on the forming stability, ring circularity, rolling force, and oscillating are investigated. Taking the forming stability and ring circularity as objects, the optimum initial position and motion track of the guide rolls are obtained.

scholarly journals Feed-forward control of elastic-joint industrial robot based on hybrid inverse dynamic model

2021 ◽  
Vol 13 (9) ◽  
pp. 168781402110381
Author(s):  
Mei Zaiwu ◽  
Chen Liping ◽  
Ding Jianwan
Keyword(s):  
Dynamic Model ◽  
Analytical Model ◽  
Control Method ◽  
Data Driven ◽  
Parameter Uncertainties ◽  
Inverse Dynamic ◽  
Inverse Dynamic Model ◽  
Feed Forward ◽  
Elastic Joint ◽  
Feed Forward Control

A novel feedforward control method of elastic-joint robot based on hybrid inverse dynamic model is proposed in this paper. The hybrid inverse dynamic model consists of analytical model and data-driven model. Firstly, the inverse dynamic analytical model of elastic-joint robot is established based on Lie group and Lie algebra, which improves the efficiency of modeling and calculation. Then, by coupling the data-driven model with the analytical model, a feed-forward control method based on hybrid inverse dynamics model is proposed. This method can overcome the influence of the inaccuracy of the analytical inverse dynamic model on the control performance, and effectively improve the control accuracy of the robot. The data-driven model is used to compensate for the parameter uncertainties and non-parameter uncertainties of the analytical dynamic model. Finally, the proposed control method is proved to be stable and the multi-domain integrated system model of industrial robot is developed to verify the performance of the control scheme by simulation. The simulation results show that the proposed control method has higher control accuracy than the traditional torque feed-forward control method.

Review on Main Drive Torsional Vibration and Roller Coupling Vibration of Rolling Mill

2020 ◽  
Vol 14 ◽  
Author(s):  
Xiao-bin Fan ◽  
Bin Zhao ◽  
Yu Jiang ◽  
Bing-Xu Fan
Keyword(s):  
Rolling Mill ◽  
High Speed ◽  
Control Method ◽  
Hot Spot ◽  
Rolling Process ◽  
Coupling Vibration ◽  
Non Linear ◽  
Roll System ◽  
The Stability ◽  
Rolling Mill Vibration

Background: Rolling mill vibration has become one of the most widespread and unsolved problems in rolling industry, which is called "Ghost" vibration. The research on the starting mechanism, vibration characteristics and vibration suppression measures of high-speed tandem rolling mill has always been a hot spot and difficult point in the field of rolling at home and abroad. However, up to now, the research on rolling mill vibration has not formed a relatively complete and widely accepted theoretical system, experimental means and solutions. In production, vibration is often controlled by experience and test, which has high cost and low efficiency. Methods: In this paper, the research history and achievements of vibration phenomena, vibration mechanism, stability of rolling process and vibration control theory of high-speed tandem rolling mill in recent years are summarized. The aim is to reveal the mechanism of rolling mill vibration in continuous rolling process, the mechanism of rolling mill non-linear vibration instability and its changing law, and to explore the optimization of rolling process and the control method of rolling mill structure so as to improve the rolling process. Results: The evolution of non-linear random torsional / bending vibration and its transfer mechanism to the space coupling vibration of the roll system, the unsteady dynamic friction characteristics of the rolling interface and the mechanism of induced roll chatter, and the non-linear random dynamic behavior of the space coupling vibration of the roll system are revealed. Conclusion: The stability of rolling process can realize the research and development of high-end products considering the stability of rolling process, and also provide reference for further research by industry experts.

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