Robust Tension Control of Strip for 5-Stand Tandem Cold Mills

Tandem cold rolling process is a nonlinear complex system with external and internal uncertainties and significant disturbances. The improvement in the quality of the final output depends on the control strategy of centerline thickness and interstand tension. This paper focuses on interstand tension control problem in 5-stand tandem cold rolling mills. Tension dynamics can be described by a nominal model perturbed by parametric uncertainties. In order to overcome the model uncertainties and external disturbances, suboptimalH∞andμcontrollers are proposed and the Hankel-norm approximation is used to reduce the order ofμcontroller. The performance of the proposed controllers is demonstrated by some simulations.

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A Setup Calculation Method of Application Platform for Process Сontrol System of Tandem Cold Rolling Mills

Materials Science Forum ◽

10.4028/www.scientific.net/msf.850.494 ◽

2016 ◽

Vol 850 ◽

pp. 494-501 ◽

Cited By ~ 1

Author(s):

Jin Shan Chen ◽

Chang Sheng Li

Keyword(s):

Control System ◽

Process Control ◽

Cold Rolling ◽

Calculation Method ◽

Process Control System ◽

Rolling Mills ◽

Tandem Cold Rolling ◽

Cold Rolling Mills ◽

Calculation Module

Setup calculation function of the process control system for tandem cold rolling mills not only determinates the dimension accuracy of finished strip materials directly, but also affects the control of surface quality of strip materials. In the present work, an attempt was made to develop a new setup calculation method for tandem cold rolling mills to maximize the throughput and improve the surface quality of strips. Based on the application platform for level-2 process control system, the modular design method was adopted, and then the setup calculation function was developed. And four functional modules consisting of preset preparation module (PPM), basic setup calculation module (BSCM), dynamic setup calculation module (DSCM), and adaptive calculation module (ACM) were developed. The preset data from PPM were used in equipment of level-1 process control system, and the purposes of BSCM was to achieve high quality of products, reduce off thickness deviation and achieve stable rolling at maximum possible rolling speed for raising productivity. In order to minimize off error of preset and actual data, DSCM was provided. Thanks to the design of ACM, accuracy of mathematical model can be effectively improved on line. Ultimately, the precise model on setup calculation method for cold tandem rolling of strip steels was established, and then it was put into practical production. Statistics analysis showed that the measured data was in excellent agreement with the model, and exactly, the relative deviations on rolling force and delivery thickness of strips were less than 3.67% and 0.42%, respectively. The new setup calculation method has high precision and good generalization capability.

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Experimental methodology for tinplate rolling on a laboratory mill

E3S Web of Conferences ◽

10.1051/e3sconf/201911001001 ◽

2019 ◽

Vol 110 ◽

pp. 01001 ◽

Cited By ~ 1

Author(s):

Iryna Karmazina ◽

Volodymyr Kukhar ◽

Elena Balalayeva ◽

Alla Larkina ◽

Valentina Kashintseva

Keyword(s):

Cold Rolling ◽

Experimental Research ◽

Rolling Process ◽

Optimal Combination ◽

Experimental Methodology ◽

Rolling Mills ◽

Steel Base ◽

Cold Rolling Mills ◽

Deformation Modes

The review of cold rolling mills used for the production of tinplate and thin tinplate in the world is presented. World tinplate production is characterized by the desire to reduce the thickness of its steel base. In connection with the variety of tinplate rolling mills, peculiarities of the deformation conditions of thin tinplate, complexity of the technological process and theoretical prediction of the rolling process indices, especially in terms of the theoretical model universality, as well as paucity of existing practical data, the necessity of experimental research is substantiated. Experimental research methodology of energy and force modes for tinplate and thin tinplate rolling for different cold rolling mills: five-, six- and seven-stand, was developed. Deformation modes have been developed that allow simulating the process of continuous cold rolling of tinplate with a thickness of 0.16 mm and 0.28 mm in five-, six- and sevenstand mills, respectively. The technical characteristics of industriallaboratory equipment involved in experimental research are presented. The results of the chemical composition and mechanical properties investigation of the initial blank are presented. Experimental research of energy and force modes for tinplate rolling at different parameters of cold rolling mills using the developed methodology will determine their optimal combination, as well as justify the choice of rolling equipment in terms of energy efficiency of the rolling process and the quality of the strip.

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