how to control eccentricity problem in hot rolling mill

Roll Eccentricity Control for Strip Rolling Mills . Awtm/ia Abstract An in depth review of the roll eccentricity control design problem is provided which encompasses a number of recent novel design contributions and includes experimental results from two separate steel tandem cold rolling mill installations A unifying approach to eccentricity control nables the diverse range of published

Loop monitoring and assessment of hot strip mill control

The object of the thesis work was to test assessment and monitoring tools for the control of a hot strip rolling mill. Two control system were also evaluated, work roll bending control and gap control. The eﬀectiveness of a ﬁlter, that is used within the control to remove the eﬀect of …

HOT ROLLING PRACTICE – An Attempted Recollection

motors. These are known as mill stands. The layout of a rolling mill varies, from a simple single stand mill to several stands positioned either side by side or in a line. A mechanism, commonly called a roller table, directs the work piece to the rolls, and another roller table for …

Seamless steel pipe produces eccentricity (uneven ...

Finished steel pipe Cold drawn steel pipe can also cause eccentricity problems due to perforation: Any factor that destroys the geometrical correctness of the deformation zone formed by the roll, the head and the guide plate will increase the uneven thickness of the capillary wall. (1) Head.

methods to control eccentricity in forged rolls

Jul 01, 1987· Awtm/ia Abstract: An in-depth review of the roll eccentricity control design problem is provided which encompasses a number of recent, novel, design contributions and includes experimental results from two separate steel, tandem cold rolling mill installations.

Roll Eccentricity Control for Strip Rolling Mills ...

Awtm/ia Abstract: An in-depth review of the roll eccentricity control design problem is provided which encompasses a number of recent, novel, design contributions and includes experimental results from two separate steel, tandem cold rolling mill installations. A unifying approach to eccentricity control ~nables the diverse range of published ...

Cascade Control for Hydraulic Automatic Gauge Control of ...

Automatic gauge control of hot rolling mills is completed by multi stands. The gauge control of hot strip finishing mills is an important process of the iron and steel industry, and the quality and qualified rate are decided by automatic control level directly. The highly-complex control system presents a challenge for the controller design, which

The Hot Rolling Process - California Steel

The Hot Rolling Process The primary function of the Hot Strip Mill is to reheat semi-finished steel slabs of steel nearly to their melting point, then roll them thinner and longer through 12 successive rolling mill stands driven by motors totaling 77,000 hp, and finally coiling up the lengthened steel sheet for transport to the next process.

Thickness Control for a Steel Beam - MATLAB & Simulink Example

Rolling Stand Model. Figures 1 and 2 depict the process of shaping a beam of hot steel by compressing it with rolling cylinders. Figure 1: Beam Shaping by Rolling Cylinders. Figure 2: Rolling Mill Stand. The desired H shape is impressed by two pairs of rolling cylinders …

Control device for a continuous hot-rolling mill ...

A control device for the purpose of achieving highly precise rolled material. The response and robust stability of the rolled material tension and looper height are specified, and a controller is designed so that the rolling mill main motor and looper operate in concert to suppress variations in rolled material tension, thereby achieving stable optimum control which is responsive to the ...

Strip Thickness Control of Cold Rolling Mill with Roll ...

In rolling mill, the accuracy and quality of the strip exit thickness are very important factors. To realize high accuracy in the strip exit thickness, the Automatic Gauge Control (AGC) system is used. Because of roll eccentricity in backup rolls, the exit thickness deviates periodically. In this paper, we design PI controller in outer loop for the strip exit thickness while PD controller is ...

LQG Regulation: Rolling Mill Case Study - MATLAB ...

LQG Regulation: Rolling Mill Case Study Overview of this Case Study. This case study demonstrates the use of the LQG design tools in a process control application. The goal is to regulate the horizontal and vertical thickness of the beam produced by a hot steel rolling mill.

(PDF) Hot rolling mill hydraulic gap control (HGC ...

These studies had concentrated to improve the mill stretch design and the rolling speed control in order to accomplish fine thickness with respect to the compensation of the roll eccentricity and ...

US4905491A - Unwind/rewind eccentricity control for ...

A method of rolling material in a rolling mill in which the material is directed from an unwind coil of the material to the mill and/or to a rewind coil of the material from the mill, the material being under tension as it is directed to and from the mill. The directing process has at least one cyclic disturbance which ordinarily causes cyclic changes in the tension of the material and in the ...

Upgrading of Hot Finishing Mill to 4-Stands, and ...

an overview of the hot finisher mill after the upgrade, and describes the new control technology and hot rolling pro-cess control system that were introduced. 2. GENERAL DESCRIPTION The hot rolling mill of the Fukui Works went into service in May, 1983 as a world-class facility, equipped with large rolling stands capable of producing wide ...

quality, a powerful controller is need- Rolling mill simulator

Rolling mill simulator A new platform for testing, analysis and optimization of cold rolling mills. Axel Brickwedde, Frank Feldmann, Nicolas Soler The cold rolling of flat metal products especially in tandem or multi-stand mills is a highly complex process where …

A Review on Chatter Analysis in Cold Rolling process

Sources of chatter in rolling mill Table 1: Chatters reasons. S.No Reasons of Chatters 1 Due to problems in drive systems: Misalignment of gears (Excitation proportional to speed)Tooth engagement, Gear defects 2 Roll ripples/ Unbalance or eccentricity of rolls/ Speed of rolls 3 Periodic grinding of rolls 4 Friction conditions lead to excitation

Application of CDM to MIMO systems: Control of hot rolling ...

250 ICASE: The Institute of Control, Automation and Systems Engineers, KOREA Vol. 3, No. 4, December, 2001 Application of CDM to MIMO Systems: Control of Hot Rolling Mill Young-Chol Kim and Myung-Joon Hur Abstract: This paper deals with a design problem of a decentralized controller with a strongly connected two -input two -output mul- tivariable system.

The Engineering Design of Rolling Mill - A&L Alluminio e Leghe

A Cold Rolling Mill rolls, in subsequent short passes(due to the relative thick material), coiled strip from a thickness of up to 8 mm (coming from Hot Rolling Mill) down to 0.2 mm; the mill is designed with high rolling force and power capability and …

Strip Thickness Control of Cold Rolling Mill with Roll ...

been developed for hot or cold mill processes. The Brit-ish Iron and SteelResearch Association (B1SRA) AGC method based on the gaug meter principle and the feede forward AGC method using the delivery time of the strip have been widely utilized in steel rolling mills [3]. Strip products thickness precision is an important quality parameter.

Online Monitoring System Design for Roll Eccentricity in ...

The key equipme nt in hot/cold tand em rolling mills is the ﬁnishing mill g roup, which usually consists o f 7 mill stands in hot rolling and 5 mill stands in cold rolling.

Rolling mill strip thickness controller - John Lysaght ...

Method and apparatus for eccentricity correction in a rolling mill: : Smith, Jr. et al. 72/11: 3543549: ROLLING MILL CONTROL FOR COMPENSATING FOR THE ECCENTRICITY OF THE ROLLS: : Howard: 72/8

Characteristic analysis and optimal control of the ...

rolling set-up model mill to maximize the throughput of the mill. In research on the control system, Geddes [9]and Geddes and Postlethwaite [10] discussed the H∞ loop-shaping method from thread to full speed and studied multi-variable control systems using Η∞ design by simulation. Pittner et al. [11] and Pittner and Simaan [12]designedthe

How To Control Eccentricity Problem In Hot Rolling Mill

Roll Eccentricity Control for Strip Rolling Mills A design of automation systems for the competi tive summary of the background to the control ofproduction of metal strip products thickness in rolling mills is described in an The thickness control problem is further earlier paper by Edwards (1987) exacerbated by the fact that tolerances are For a single stand mill, control is commonly

Non-circular grinding of backup rolls to reduce rolling ...

The steel mills built in the 1960s and 1970s and even later are looking for cost-effective means to meet the new demands. This study discusses a method of reducing the force variation in the milling stand. Typically a rolling mill consists of 1–7 rolling stands. There are usually two, three or …

Rolling of Metals: Process and Principles (With Diagram)

The rolling process is shown in Fig. 2.1: Rolling is done both hot and cold. It is accomplishes in rolling mills. A rolling mill is a complex machine having two or more working rollers, supporting rollers, roll stands, drive motor, reducing gear, flywheel, coupling gear etc. Rollers may be plain or grooved depends upon the shape of rolled product.

Method of measuring and compensating roll eccentricity of ...

an off-line eccentricity identification method which is performed when there is no plate rolling through the mill and with the top work roll and the bottom work roll in tight contact, said off-line eccentricity identification method determining the eccentricity values of N first points which equally divide a circumference of the top backup roll ...

FAULT DIAGNOSIS OF ROLL SHAPE UNDER THE SPEED …

find both eccentricity magnitude and eccentricity location in the roll as shown in Fig.10. But, as shown in Fig.12, not only magnitude of eccentricity but also location of eccentricity in the roll is obtained. 4.2 Simulations with Field Data Fig.13 shows a simplified multi-stand hot rolling system. The rolling system consists of seven stands.

Application of Singular Perturbation Control Technology in ...

improve the competitiveness model of hot rolling production line of steel products, study and solve the quality problem of the thickness accuracy has become very necessary. In this paper, a new method for thickness control is proposed, which is based on the singular perturbation control technology. II.

Polynomial LQG control of back-up-roll eccentricity gauge ...

It is a strength of the polynomial systems viewpoint, that such modifications are not usually too severe as will be seen in the sequel for the eccentricity control problem. The control of a rolling mill requires the output gauge to be regulated in the face of eccentricity and input hardness disturbances using measured roll-force.

Advanced Process and Quality Control in Hot Rolling Mills ...

3.1 Key Feature of Process Control: Detection of Periodic Defects Rolls and rollers are the most heavily used parts of a rolling mill. Due to wear from contacting hot material with great force, their lifetime is limited. Although rolls are refurbished in the roll shop regularly, they occasionally crack before the end of the usual production cycle.

Thickness Control for a Steel Beam - MATLAB & Simulink ...

The eccentricity disturbance is modeled as white noise w_e driving a band-pass filter Fe. The input thickness disturbance is modeled as white noise w_i driving a low-pass filter Fi. Feedback control is necessary to counter such disturbances. Because the roll gap delta cannot be measured close to the stand, the rolling force f is used for feedback.

CiteSeerX — ROLL ECCENTRICITY CONTROL WITH THE FORCE …

CiteSeerX - Document Details (Isaac Councill, Lee Giles, Pradeep Teregowda): The Force Feed Forward (FFF) System is the only hot strip mill AGC system in the world today which does not incorporate the BISRA principle for gage control. Instead, using a revolutionary control algorithm, FFF has proven in five installations in North and South America, that steelmakers need not replace their ...