scholarly journals Automatic control of the rolling mode “at an angle” on a reversing hot rolling mill

2020 ◽  
Vol 2 ◽  
pp. 99-104
Author(s):  
M.G. Ievlev ◽  
Keyword(s):  
Automatic Control ◽  
Longitudinal Axis ◽  
Rolling Process ◽  
Thick Sheet ◽  
Plate Mill ◽  
Automated Control ◽  
Quality Of Control ◽  
Sheet Width ◽  
Minimum Number ◽  
Rolling Mode

One of the most important indicators of the quality of control of the rolling process on a plate mill is the accuracy of obtaining the geometric dimensions of rolled metal, which determines the cost of metal per ton of product, in particular, the accuracy of the implementation of a given width. The sheet width exceeding the width of the initial billet, under rolling on plate mills, is obtained at the stage of breaking the width in a horizontal stand. Breakdown of the width in most cases is carried out by rolling the workpiece at an angle of to the longitudinal axis of the future sheet. However, if the rotation of the roll (slab) is not possible at the stated angle (for example, when the width of the roll is less than the distance between the rollers), then a part of the considered stage is carried out by rolling “at an angle” less than . In the process of such rolling, the dimensions of the roll along all axes and its shape in plan are changed (initially the rectangular shape takes the form of a parallelogram). The paper describes the mathematical description for one of the options for forming the width of a thick sheet when rolling “at an angle” in relation to an automated control system for the technological process of a plate mill. On the basis of the concepts describing the formation of the roll in the plan during rolling “at an angle”, the expressions were obtained that relate the parameters of the roll and the rolling mode. The problem of automatic control of the rolling mode “at an angle” is formulated. The proposed calculation of the rolling mode, which is implemented at a pace with the rolling process, provides a rectangular roll of a predetermined width for a minimum number of passes, subject to restrictions on the reduction in passes. The described approach to the automatic control of the rolling mode during rolling at the “angle” is implemented in the mathematical support of the system for calculating the rolling parameters and heat hardening of the plate mill 5000.

scholarly journals Automated control system for fire cutting units on a plate mill

2021 ◽  
Vol 1 ◽  
pp. 86-95
Author(s):  
M.G. Ievlev ◽  
◽  
G.G. Grabovsky ◽  
Keyword(s):  
Control System ◽  
Automatic Control ◽  
High Reliability ◽  
Metrological Certification ◽  
Plate Mill ◽  
Metal Consumption ◽  
Automated Control ◽  
Automated Control System ◽  
Plate Rolling ◽  
Reliability Characteristics

One of the most important indicators of a plate rolling mill efficiency is a metal consumption (cost coef-ficients) per ton of product. Reduction of metal consumption coefficients is ensured by the accuracy of the set geometric dimensions realization during the rolling, increasing the accuracy of geometric dimen-sions of the plates that are cut from the rolls on fire cutting units, as well as by operating in the minus field of tolerances on the geometric dimensions of the plates. Improving the accuracy of the geometric dimensions of the plates, cut from the rolls on the fire cutting units, is achieved through the automatic control of these units. The article describes the technical solutions, implemented in the automated con-trol system of fire cutting units (the ACS FCU) of the heat treatment department and fire cutting of a plate mill 3600. The purposes of the ACS FCU creation include an increase in accuracy and stabilization of the geometrical sizes of the work pieces cut out of plates through the automatic control; reduction of metal consumption coefficients due to the operation in the minus field of tolerances on the geometric dimensions of the work pieces; replacement of obsolete equipment with the modern one in order to in-crease the reliability of the mill equipment operation; increasing the ACS FCU service life through the use of modern equipment with high reliability characteristics; reduction of unplanned equipment down-time that may arise as a result of the ACS FCU technical means failures. The automated control system of fire cutting units has been set up, tested and put into operation; a metrological certification of the system has been carried out as well. The results of the ACS FCU testing and its subsequent operation have confirmed the system efficiency and the performance of all its intended functions. This system can be also implemented in the processes of treatment of other rolling mills, equipped with the units for the fire cutting of metal.

Experience with the Relay Procedure for Tuning Controllers in Automatic Control of Chlorination

1993 ◽  
Vol 28 (11-12) ◽  
pp. 257-261
Author(s):  
M. Truett Garrett ◽  
Zaki Ahmad ◽  
Shelly Young
Keyword(s):  
Wastewater Treatment ◽  
Automatic Control ◽  
Time Constant ◽  
Wastewater Treatment Plants ◽  
Relay Feedback ◽  
Quality Of Control ◽  
Incomplete Mixing ◽  
Long Time ◽  
Chlorine Demand

The recent requirements by U.S.E.P.A. for dechlorination and biomonitoring have increased the importance of automatic control of effluent chlorination in wastewater treatment plants. Difficulties with the Ziegler-Nichols controller tuning procedure were reported at the Kyoto Workshop, 1990. Problems are caused by the noise of incomplete mixing, a long time constant, and the disturbances of changing flow and chlorine demand. The Astrom-Hagglund relay feedback procedure provides acceptable control while data is logged to determine the controller constants. Experiences in using the procedure in existing facilities (not redesigning the mixing point) and the quality of control are presented.

Research on Transition Zones of Spherical Surface Parts in 3D Rolling Process

2014 ◽  
Vol 687-691 ◽  
pp. 3-6
Author(s):  
Da Ming Wang ◽  
Ming Zhe Li ◽  
Zhong Yi Cai
Keyword(s):  
Sheet Metal ◽  
Spherical Surface ◽  
Three Dimensional ◽  
Rolling Process ◽  
Experimental Results ◽  
Transition Zones ◽  
Spherical Surfaces ◽  
Sheet Width ◽  
Forming Precision ◽  
Roll Gap

3D rolling is a novel technology for three-dimensional surface parts. In this process, by controlling the gap between the upper and lower forming rolls, the sheet metal is non-uniformly thinned in thickness direction, and the longitudinal elongation of the sheet metal is different along the transverse direction, which makes the sheet metal generate three-dimensional deformation. In this paper, the transition zones of spherical surface parts in 3D rolling process are investigated. Spherical surface parts with the same widths but different lengths are simulated in condition of the same roll gap, and their experimental results are presented. The forming precision of forming parts and the causes of transition zones in the head and tail regions are analyzed through simulated results. The simulated and experimental results show that the lengths of transition zones of spherical surfaces in the head and tail regions are fixed values in condition of the same sheet width and roll gap.

Methodology for draft schedule design of plate rolling process with peening effect considered

2009 ◽  
Vol 223 (9) ◽  
pp. 1159-1169 ◽  
Author(s):  
C H Moon ◽  
Y Lee
Keyword(s):  
Rolling Process ◽  
Correction Method ◽  
Thickness Ratio ◽  
Reduction Ratio ◽  
Roll Force ◽  
Plate Mill ◽  
Material Thickness ◽  
Roll Torque ◽  
Plate Rolling ◽  
Ratio Correction

We propose an approach for designing a draft schedule applicable to thick plate rolling. In the proposed approach, the peening effect, i.e. thick material is rolled with a small reduction ratio, is considered fully in computing roll force and torque. To determine an initial draft schedule, we calculate material thickness at each pass and total number of passes by taking the smallest of the critical reduction ratios (reduction ratio by maximum reduction increment, reduction ratio assigned in designing a plate mill, reduction ratios by allowable roll force and roll torque). To make a final draft schedule, we then propose two ways (thickness ratio correction (TRC) method and reduction ratio correction (RRC) method) that redistribute reduction ratios predetermined in the initial draft schedule. The proposed approach has been applied to POSCO No. 2 Plate Mill. Results reveal that the reduction ratios are determined by allowable roll torque if the material being rolled is relatively thick, but reduction ratios are decided by roll force as the material thickness being rolled decreases. It has been found that the thickness ratio correction method is useful when a heavy reduction ratio is necessary in the later part of the rough rolling sequence, and obtaining a uniform microstructure over material thickness during rolling is important. Meanwhile, the reduction ratio correction method is effective if surface defect generation on the material during rolling is a concern.

scholarly journals Automated control of rolling modes on plate mills

2020 ◽  
Vol 4 ◽  
pp. 95-112
Author(s):  
M.G. Ievlev ◽  
Keyword(s):  
Control Strategies ◽  
Electricity Consumption ◽  
Rolling Process ◽  
Optimum Ratio ◽  
Technological Parameters ◽  
Automated Control ◽  
Economic Significance ◽  
Rolling Strip ◽  
Main Effect ◽  
Rolling Quality

Indicators of rolling quality and rolling process are presented, which determine the efficiency of plate mill operation. The purposes of the automated control of rolling which consist in achievement of an optimum ratio of the mentioned indicators, and division of control channels (when it’s possible) achiev-ing the best values of each indicator named above. Control of rolling modes (compression on passes, speeds, cooling) provides the main effect in indicators quality formation of hire and rolling process. The statement of the problem of automated rolling control is given. The choice of the optimized indicator in the problem of automatic rolling control is determined by its economic significance, the nature of the interrelation with the technological parameters and controls. One of the most economically significant for plate mills is the coefficient of metal consumption of the workpiece per ton of rolled product, or the yield, which depends on the accuracy of the implementation of the specified geometric dimensions of the rolling strip. The formulation of the problem of ensuring the minimum value of deviations in the thickness (width) of the strip from the specified value is given. The problem of optimization on one of three indicators of the rolling process is also formulated: the equivalent torque of the main drive, the electricity consumption for rolling and the time consumption of the rolling cycle, which are determined by the entire course of the rolling cycle, i.e. applied management strategy. The principles of solving the problem of automatic control of rolling modes are described. The rolling control strategies used in the ACS TP of plate mills are considered. Methods of constructing mathematical models for ACS TP of plate mills, as well as their adaptation, are described.

scholarly journals Effect of gripping conditions and strip oscillations on vibrations originating at cold rolling

2020 ◽  
Vol 76 (1) ◽  
pp. 54-58
Author(s):  
A. V. Kozhevnikov
Keyword(s):  
Cold Rolling ◽  
Rolling Process ◽  
Rolling Speed ◽  
Continuous Rolling ◽  
Rolling Mills ◽  
Deformation Parameters ◽  
High Dynamic ◽  
Working Rollers ◽  
Rolling Mode ◽  
Strip Length

The process of continuous rolling is subjected to non-stationarity, accompanied by oscillations of not only basic technological and power parameters, but also parameters in the hearth of deformation. Non-stationarity at the rolling accounting high dynamic of the process results in origination of negative vibration effects. To prevent the vibrations originations the rolling speed is decreased, which prevents the reaching of the designing parameters of rolling mills operation. The study of influence of non-stationarity of the rolling technological process on gripping conditions and origination of dangerous oscillations was carried out. Characteristics of rolling mode of strip of 2.0–0.45 × 970 mm dimension, accompanied by vibration was presented, as well as graphs of the strip oscillations in the process of stationary rolling and under conditions of vibrations origination presented. An assumption made, that during vibrations origination the gripping conditions of the strip by rollers are disturbed. It means that provision of the grip stationarity will decrease the risk of the vibrations originating at the rolling. The assumption was confirmed by the studies of the cold rolling at five-stand mill 1700 of Cherepovets steel-works. The calculations of the hearth of deformation parameters were made by application of an elaborated dynamic model of the rolling process. The higher probability of vibrations originating at the rolling of strips of smaller thickness explained. It was shown, that due to the strip length, the rolling of the thinner metal is accomplished at higher speeds, comparing with the rolling of thicker metal. In addition, it was shown that the friction coefficient value at that would promote increase of risk of non-stationary rolling mode originating. The support of stable friction conditions in the hearth of deformation is promoted by usage of chrome-plated working rollers and asymmetrical rolling.

scholarly journals Evaluation of modern equipment for automated control and maintenance systems for mine transport

2021 ◽  
Vol 326 ◽  
pp. 00040
Author(s):  
Georgiy Vishniakov ◽  
Evgeniy Pushkarev
Keyword(s):  
Automatic Control ◽  
Control Systems ◽  
Analytical Study ◽  
Parameter Control ◽  
Mining Equipment ◽  
Specific Group ◽  
Automated Control ◽  
Modern Equipment ◽  
Maintenance Systems ◽  
Mine Transport

The article presents the results of an analytical study of the equipment of production facilities for automatic control and maintenance of mining equipment. The analysis of the needs of enterprises in parameter control systems and the actual availability of these systems is carried out. Based on the list of parameters, conclusions are drawn about the development of modern automated control systems. The list of parameters was divided into groups to simplify data processing, as well as to be able to draw conclusions about each specific group. The solution of the problem is presented, which allows one to optimize the operation of the equipment and to avoid the occurrence of critical situations as much as possible.

Reconfiguration Analysis of a Two Degrees-of-Freedom 3-4R Parallel Manipulator With Planar Base and Platform1

2015 ◽  
Vol 8 (1) ◽  
Author(s):  
Xianwen Kong ◽  
Jingjun Yu ◽  
Duanling Li
Keyword(s):  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Euler Parameter ◽  
Operation Modes ◽  
Minimum Number ◽  
Moving Platform ◽  
Multiple Operation ◽  
Motion Characteristics ◽  
Rolling Mode ◽  
And Control

This paper deals with a 2-DOF (degrees-of-freedom) 3-4R parallel manipulator (PM) with planar base and platform—a novel PM with multiple operation modes (or disassembly free reconfigurable PM) that can use the minimum number of actuated joints. At first, a set of constraint equations of the 3-4R PM are derived with the orientation of the moving platform represented using a Euler parameter quaternion (also Euler–Rodrigues quaternion) and then solved using the algebraic geometry method. It is found that this 3-4R PM has six 2-DOF operation modes, including the two expected spherical translation mode and sphere-on-sphere rolling mode when the PM was synthesized. The motion characteristics of the moving platform are obtained using the kinematic interpretation of Euler parameter quaternions with certain number of constant zero components, which was presented in a recent paper by the first author of this paper, instead of the eigenspace-based approach in the literature. The transition configurations, which are constraint singular configurations, among different operation modes are also presented. This work provides a solid foundation to the development and control of the 2-DOF 3-4R PM with both 2-DOF spherical translation mode and 2-DOF sphere-on-sphere rolling mode.

Multiposition evaluation of the quality of a ready strip during automated control of the rolling process

2007 ◽  
Vol 48 (6) ◽  
pp. 511-515
Author(s):  
Z. G. Salikhov ◽  
O. A. Krivodubskii ◽  
R. T. Gazimov
Keyword(s):  
Rolling Process ◽  
Automated Control
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