Strip steel anti-loosening system and method

Abstract

The invention provides a strip steel anti-loosening system and method, and relates to the field of metal processing. The system comprises a strip breakage detection device which is used for generating a strip breakage signal when strip breakage of strip steel is detected; the mass measuring device is used for acquiring the mass of the coiled steel coil on the coiling machine; the coiling diameter measuring device is used for acquiring the coiling diameter of the coiled steel coil on the coiling machine; the rotating speed measuring device is used for measuring the instantaneous linear speed of the steel coil; the anti-loosening controller is used for responding to the strip breakage signal and executing the following operations in each control period: acquiring the instantaneous linear speed of the current period, the output power of the coiling machine motor of the current period and the coiling diameter of the current period, and calculating the speed reduction control quantity of the current period based on the quality during strip breakage; and the coiling machine speed control device is used for executing speed reduction control on the coiling machine motor in each control period according to the speed reduction control quantity of the current period until the speed of the coiling machine motor is reduced to zero.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of metal processing, in particular to a strip steel anti-loose system and method. BACKGROUND

[0002] In the process of 20-roller rolling, especially when the rolling speed exceeds 200m / min, due to the uncertainty of the incoming material quality, the existence of defects such as cracks in the edge of the strip steel, or the too large tension difference between the operation side and the transmission side caused by personnel operation, etc., the strip steel is prone to sudden breakage. After the breakage, under the action of inertia, the strip steel that has been tightly wound on the winding side will be loose and pressed against each other to form a fold, which can only be discarded, causing waste.

[0003] In the existing anti-loose system or method, the winding machine motor is stopped by issuing a fixed slope curve to the winding machine motor frequency converter through the automatic program after the strip is broken.

[0004] However, due to different steel coil quality and speed, the inertia of the steel coil after the strip is broken is different, so the fixed slope curve deceleration scheme has the following disadvantages:

[0005] (1) The influence of the dynamic change of the steel coil mass on the inertia before the strip is broken is not considered;

[0006] (2) When the speed of the strip before the strip is broken exceeds 200m / min, the fixed deceleration acceleration cannot match the angular velocity change of different coil diameters, which is easy to cause the steel coil to be loose. SUMMARY

[0007] In order to solve the above technical problems in the prior art, the purpose of the present application is to provide a strip steel anti-loose system and method, which can dynamically adjust the deceleration mode of the winding machine motor, and ensure that the wound steel coil will not be loose due to inertia when the strip is broken.

[0008] In order to achieve the above application purpose, the present application provides a strip steel anti-loose system, comprising:

[0009] A strip breakage detection device for generating a strip breakage signal when detecting that the strip is broken;

[0010] A mass measuring device for obtaining the mass of the wound steel coil on the winding machine;

[0011] A coil diameter measuring device for obtaining the coil diameter of the wound steel coil on the winding machine;

[0012] A rotational speed measuring device for obtaining the instantaneous linear speed of the wound steel coil on the winding machine;

[0013] An anti-loose controller for responding to the strip breakage signal and performing the following operations in each control period:

[0014] acquire the instantaneous linear speed of the current period, the output power of the coiler motor of the current period, and the coiling diameter of the current period, and calculate the braking force of the current period;

[0015] and, based on the mass at the time of the strip breakage, the coiling diameter of the current period, and the braking force of the current period, calculate the deceleration control amount of the current period;

[0016] The coiler speed control device is configured to, in each control period, perform deceleration control on the coiler motor according to the deceleration control amount of the current period, until the speed of the coiler motor is reduced to zero.

[0017] According to one of the technical solutions of the present application, the strip breakage detection device is further configured to:

[0018] acquire the tension of the strip between the main rolling mill and the coiler at a set step, and determine that the strip is broken when the tension at the next moment is reduced to a preset proportion of the tension at the previous moment.

[0019] According to one of the technical solutions of the present application, the mass measurement device comprises:

[0020] a strip length measurement module configured to acquire the length of the coiled strip on the coiler;

[0021] a mass calculation module configured to calculate the mass of the coiled strip based on the length of the strip, the pre-stored mass of the original coiled strip, the length of the original coiled strip, the thickness of the strip at the previous pass, and the thickness of the strip at the current pass.

[0022] According to one of the technical solutions of the present application, the anti-swing loosening controller is further configured to:

[0023] in response to the strip breakage signal, generate a main rolling mill stop signal and transmit the signal to the control unit of the main rolling mill.

[0024] The present application also provides an anti-swing loosening method for a strip, comprising the following steps:

[0025] step a, when strip breakage is detected, generate a strip breakage signal;

[0026] step b, acquire the mass, coiling diameter, and instantaneous linear speed of the coiled strip on the coiler;

[0027] step d, in response to the strip breakage signal, perform the following operations in each control period:

[0028] acquire the instantaneous linear speed of the current period, the output power of the coiler motor of the current period, and the coiling diameter of the current period, and calculate the braking force of the current period;

[0029] and, based on the mass at the time of the strip breakage, the coiling diameter of the current period, and the braking force of the current period, calculate the deceleration control amount of the current period;

[0030] Step e, in each control cycle, according to the deceleration control amount of the current cycle, the deceleration control is performed on the coiler motor until the speed of the coiler motor is reduced to zero.

[0031] According to one of the technical solutions of the present application, the process of detecting the strip break in step a includes:

[0032] The tension of the strip between the main rolling mill and the coiler is collected with a set step size; and when the tension at the next moment is reduced to a preset proportion of the tension at the last moment, it is determined that the strip is broken.

[0033] According to one of the technical solutions of the present application, the process of obtaining the mass of the coiled strip on the coiler in step b includes:

[0034] The length of the strip of the coiled strip on the coiler is obtained;

[0035] Based on the length of the strip, the pre-stored original strip mass, the original strip length, the last pass strip thickness and the current pass strip thickness, the mass of the coiled strip is calculated.

[0036] According to one of the technical solutions of the present application, it further includes step g:

[0037] In response to the strip break signal, a main rolling mill stop signal is generated and transmitted to the control unit of the main rolling mill.

[0038] The present application provides a strip anti-swinging and loosening system and method, which has the following beneficial effects:

[0039] 1. By precisely matching the speed of the coiler motor and the deceleration acceleration of the coiled strip, the movement speed of the coiler motor and the movement speed of the coiled strip are ensured to be consistent when the strip is broken, thereby reducing the strip swinging and loosening, significantly reducing the degree of strip swinging and loosening, and greatly reducing the probability of occurrence of the swinging and loosening phenomenon, improving the stability and reliability of the strip coiling;

[0040] 2. While reducing the probability of occurrence of the swinging and loosening phenomenon, the scrap quantity caused by the strip swinging and loosening is reduced, the waste of raw materials is reduced, the time of the operator processing the scrap steel is reduced, the time cost is saved, and the utilization efficiency of human resources is improved.

[0041] 3. While reducing the probability of occurrence of the swinging and loosening phenomenon, the equipment downtime caused by processing the swinging and loosening strip is reduced, the production process is smoother, the overall production efficiency is improved, and the market competitiveness of the enterprise is enhanced. BRIEF DESCRIPTION OF DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed in the embodiments. Obviously, the drawings in the following description only represent some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without any creative effort.

[0043] Fig. 1 A flow chart of a strip anti-loose method according to an embodiment of the present application is schematically shown;

[0044] Fig. 2 A schematic diagram of cooperation between a strip break detection device, a strip length measurement module and a 20-roller mill in a strip anti-loose system according to an embodiment of the present application is schematically shown;

[0045] Fig. 3 An electrical structure diagram of a strip anti-loose system according to an embodiment of the present application is schematically shown. DETAILED DESCRIPTION

[0046] The description of the embodiments of the present application should be combined with the corresponding drawings, and the drawings should be regarded as a part of the complete description. In the drawings, the shape or thickness of the embodiments can be exaggerated and simplified or convenient for illustration. Moreover, the parts of the structures in the drawings will be described separately, and it should be noted that the elements not shown or not described in the drawings are in the form known by those skilled in the art.

[0047] The description of the embodiments herein, any reference to direction and position, is only for the convenience of description, and cannot be understood as any limitation on the scope of protection of the present application. The following description of the preferred embodiments will involve a combination of features, which can exist independently or in combination, and the present application is not particularly limited to the preferred embodiments. The scope of the present application is defined by the claims. As Figs. 1-3 indicated; DETAILED DESCRIPTION

[0049] A strip anti-loose system according to an embodiment of the present application comprises:

[0050] A strip break detection device 1 is configured to generate a strip break signal when a strip break is detected;

[0051] A mass measurement device 2 is configured to obtain the mass of a coiled strip on the coiler;

[0052] A coil diameter measurement device 3 is configured to obtain the coil diameter of the coiled strip on the coiler;

[0053] A rotational speed measurement device 4 is configured to obtain the instantaneous linear speed of the coiled strip on the coiler;

[0054] The anti-swing slack controller 5 is used to perform the following operations in each control cycle in response to the broken strip signal:

[0055] The instantaneous linear speed of the current cycle, the output power of the coiler motor of the current cycle and the coiling diameter of the current cycle are obtained to calculate the braking force of the current cycle;

[0056] And based on the mass at the time of broken strip, the coiling diameter of the current cycle and the braking force of the current cycle, the deceleration control amount of the current cycle is calculated;

[0057] The coiler speed control device 6 is used to perform deceleration control on the coiler motor according to the deceleration control amount of the current cycle in each control cycle until the speed of the coiler motor is reduced to zero.

[0058] Specifically, as shown in Figs. 2-3 The strip steel anti-swing slack system of the embodiment is used in cooperation with the existing twenty-roll cold rolling mill. The twenty-roll cold rolling mill usually has one coiler on each side of the main rolling mill. The cold rolling process of the strip steel is to send the original steel coil into the upper roller combination and the lower roller group through the uncoiler (or the feeding trolley). When the bidirectional reversible rolling method is used, the strip steel will shuttle back and forth between the two ends of the main rolling mill, and the coilers on both sides will alternately serve as the feeding and discharging to realize multi-pass reduction.

[0059] Therefore, the broken strip detection device 1, the mass measuring device 2, the coiling diameter measuring device 3, the rotational speed measuring device 4, the anti-swing slack controller 5 and the coiler speed control device 6 should correspond to the two coilers, that is, when the coiling is performed on either side of the coiler, the corresponding data can be obtained. It can be set as two groups, or in the case of one group, the two coilers can be detected respectively. The rotational speed measuring device 4 can acquire the angular speed of the coiler motor, and then calculate the instantaneous linear speed based on the coiling diameter of the steel coil.

[0060] Take one side coiler as an example:

[0061] The broken strip detection device 1 is arranged between the main rolling mill and the coiler to detect the broken strip state of the strip steel at a preset frequency. When the broken strip is detected, a broken strip signal is generated as a trigger signal to trigger the subsequent strip steel anti-swing slack mechanism.

[0062] The mass measuring device 2, the coiling diameter measuring device 3 and the rotational speed measuring device 4 and other parameter acquisition modules can obtain the mass , the instantaneous linear speed , the coiling diameter and other parameters of the coiled steel coil in real time.

[0063] The anti-swing slack controller 5 (PLC) is pre-configured with an algorithm / program for calculating the deceleration control amount based on the above parameters, and the deceleration control amount is calculated through the braking deceleration acceleration ( The curve (where negative values ​​indicate deceleration) is represented as follows: It also calculates and updates the deceleration acceleration based on the instantaneous linear velocity obtained at a set period (e.g., 0.1s). .

[0064] in, This is a correction factor, which needs to be determined based on the material. It typically ranges from 0.6 to 0.95, especially when the strip material is silicon steel. ; It is braking force ( ), It's about quality. It is the current volume diameter ( ).

[0065] The aforementioned braking force The larger the value, the greater the deceleration and acceleration. The larger; braking force The output power of the winding machine motor can be used as a reference. and the instantaneous linear velocity of the steel coil get( The upper limit is determined by the maximum power of the winding machine motor, which typically has a maximum power of 5000KW. As for quality... or roll diameter The larger the value, the greater the deceleration and acceleration. The smaller the value (because the moment of inertia increases, making it more difficult to decelerate).

[0066] The winding machine speed control device 6 can use a medium-voltage frequency converter to execute a dynamic deceleration curve (periodically updated deceleration acceleration). The motion control of the coiler motor is performed. If the steel coil is... The system is running at high speed and in the winding state. If a tape breakage occurs at this point, the system detects the breakage signal and issues a deceleration strategy, using a periodically updated deceleration acceleration. The speed is reduced. Simultaneously, the speed measuring device 4 (a combination of encoder and PLC) calculates the instantaneous linear velocity. To be used to calculate deceleration acceleration .

[0067] This implementation method uses intelligent deceleration matching to automatically calculate the most suitable deceleration control amount based on the weight of the steel coil and the current linear speed, ensuring that the coiler and the steel coil stop synchronously.

[0068] At the same time, the system can quickly respond at the moment of belt breakage, that is, after detecting the belt breakage, the system can adjust the deceleration strength in a very short time (such as 0.05s) to avoid the inertia of the steel coil continuing to rotate. The deceleration strength is dynamically adjusted according to the principle that the heavier the steel coil, the faster the speed, and the slower the deceleration, to prevent sudden braking from causing loosening. Specific implementation method two

[0070] The present embodiment is a further description of the first embodiment. In the present embodiment, the belt breakage detection device 1 is also used for:

[0071] The tension of the strip steel between the main rolling mill and the coiler is collected with a set step size; and when the tension at the next moment decreases to a preset proportion of the tension at the last moment, it is determined that the strip steel is broken.

[0072] Specifically, the belt breakage signal is generated after the belt breakage detection device 1 detects that the tension of the strip steel between the main rolling mill and the coiler suddenly drops by more than 70%. The belt breakage detection device 1 uses a tension gauge to collect the tension of the strip steel in real time when the strip steel is running normally, and takes the real-time tension of the strip steel when it is running stably as a reference value. When the tension drops by more than 70% within 1 second and lasts for more than 0.5 seconds, and at the same time, the interference working conditions such as equipment start-up, shutdown and transient load change are excluded, it is determined that the belt is broken. Specific implementation method three

[0074] The present embodiment is a further description of the first or second embodiment. In the present embodiment, the mass measurement device 2 comprises:

[0075] A strip steel length measurement module 2-1 for obtaining the length of the strip steel wound on the coiler;

[0076] A mass calculation module 2-2 for calculating the mass of the wound steel coil based on the length of the strip steel, the pre-stored original steel coil mass, the original steel coil length, the thickness of the strip steel at the last pass and the thickness of the strip steel at the current pass.

[0077] Specifically, the initial original steel coil mass and the original steel coil length are input into the anti-swing loosening controller 5 (or other control units or storage units that perform data transmission with the anti-swing loosening controller 5) by manual input. The mass of the wound steel coil on the coiler is changing in real time, so the mass can be obtained by the mass calculation module 2-2 based on the original steel coil and the original steel coil length , that is, at the current moment is equal to at the current moment represents the real-time length of the strip steel wound on one of the coilers, represents the thickness ratio of the last pass and the current pass in the rolling process. Generally, the thickness of the strip in the original coil is 2.3 mm, and the thickness required in practice is reached after rolling of two passes. For example, the thickness of the strip in the original coil is 2.3 mm, and the thickness required in the second pass process is 1.4 mm, then ).

[0078] wherein the formula The real-time length of the coiled strip is the length calculated by the strip length measurement module 2-1. The strip length measurement module can adopt an encoder installed on the non-output shaft side of the coiling motor to measure the length of the coiled coil. Specific implementation four

[0080] The present embodiment is a further description of embodiment three. In the present embodiment, the anti-swing loose controller 5 is further used to:

[0081] generate a main rolling mill stop signal in response to the strip breakage signal and transmit the main rolling mill stop signal to the control unit of the main rolling mill.

[0082] Specifically, after determining that the strip breaks, the main rolling mill needs to be stopped immediately. By generating a main rolling mill stop signal in response to the strip breakage signal and transmitting the main rolling mill stop signal to the control unit of the main rolling mill, the control unit of the main rolling mill can stop the main rolling mill according to the preset stop control mode. Specific implementation five

[0084] A strip anti-swing loose method according to the present embodiment includes the following steps:

[0085] Step a, generating a strip breakage signal when detecting strip breakage;

[0086] Step b, obtaining the mass, the coil diameter and the instantaneous linear speed of the coiled coil on the coiler;

[0087] Step c, in response to the strip breakage signal, the following operations are performed in each control period:

[0088] obtaining the instantaneous linear speed of the current period, the output power of the coiler motor in the current period and the coil diameter of the current period, and calculating the braking force of the current period;

[0089] and, based on the mass at the time of breakage, the coil diameter of the current period and the braking force of the current period, calculating the deceleration control amount of the current period;

[0090] Step d, in each control period, the deceleration control amount of the current period is used to perform deceleration control on the coiler motor until the speed of the coiler motor is reduced to zero. Sixth Embodiment

[0092] In this embodiment, which is a further illustration of the fifth embodiment, the process of detecting strip breakage in step a comprises:

[0093] The tension of the strip between the main rolling mill and the coiler is collected at a set interval, and when the tension at the next time interval is reduced to a preset proportion of the tension at the previous time interval, it is determined that the strip is broken. Seventh Embodiment

[0095] In this embodiment, which is a further illustration of the fifth or sixth embodiment, the process of obtaining the weight of the coiled strip in step b comprises:

[0096] The length of the coiled strip on the coiler is obtained.

[0097] The weight of the coiled strip is calculated based on the length of the strip, the pre-stored weight of the original strip, the length of the original strip, the thickness of the strip at the previous pass and the thickness of the strip at the current pass. Eighth Embodiment

[0099] In this embodiment, which is a further illustration of the seventh embodiment, it further comprises step g:

[0100] In response to the strip breakage signal, a main rolling mill stop signal is generated and transmitted to the control unit of the main rolling mill.

[0101] The strip anti-swing loose system and method of the present application, wherein the system comprises: a strip breakage detection device for generating a strip breakage signal when strip breakage is detected; a weight measuring device for obtaining the weight of the coiled strip on the coiler; a coil diameter measuring device for obtaining the coil diameter of the coiled strip on the coiler; a rotational speed measuring device for the instantaneous linear speed of the strip; an anti-swing loose controller for, in response to the strip breakage signal, in each control cycle: obtaining the instantaneous linear speed of the current cycle, the output power of the coiler motor in the current cycle and the coil diameter in the current cycle, and calculating the deceleration control amount of the current cycle based on the weight at the time of strip breakage; a coiler speed control device for, in each control cycle, performing deceleration control on the coiler motor according to the deceleration control amount of the current cycle until the speed of the coiler motor is reduced to zero.

[0102] In addition, it should be noted that the present application can be provided as a method, device or computer program product. Therefore, the embodiments of the present application can take the form of a completely hardware embodiment, a completely software embodiment or an embodiment combining software and hardware aspects. Moreover, the embodiments of the present application can take the form of a computer program product embodied on one or more computer usable storage media having computer-usable program code embodied thereon.

[0103] The embodiments of the present application are described with reference to the flowchart illustrations and / or block diagrams of the methods, terminal devices (systems) and computer program products according to embodiments of the present application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing terminal devices to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing terminal devices, create means for implementing the functions specified in the flowchart illustrations and / or block diagrams. Fig. 1 one or more functions specified in the flowchart illustrations and / or block diagrams. Fig. 1 one or more functions specified in the flowchart illustrations and / or block diagrams.

[0104] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing terminal devices to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means that implement the function specified in the flowchart illustrations and / or block diagrams. Fig. 1 one or more functions specified in the flowchart illustrations and / or block diagrams. Fig. 1 one or more functions specified in the flowchart illustrations and / or block diagrams. These computer program instructions can also be loaded onto a computer or other programmable data processing terminal devices, such that a series of operational steps are performed on the computer or other programmable terminal devices to create a computer implemented process so that the instructions executed on the computer or other programmable terminal devices provide steps for implementing the function specified in the flowchart illustrations and / or block diagrams. Fig. 1 one or more functions specified in the flowchart illustrations and / or block diagrams. Fig. 1 one or more functions specified in the flowchart illustrations and / or block diagrams.

[0105] It should also be noted that, in the present text, the terms "comprising", "including", or any other variant thereof are intended to cover non-exclusive inclusion, so that processes, methods, articles or terminal devices that include a series of elements not only include those elements, but also include other elements that are not explicitly listed, or other elements inherent to such processes, methods, articles or terminal devices. Without more limitations, the element defined by the phrase "including a" does not exclude the presence of additional identical elements in the process, method, article or terminal device that includes the element.

[0106] Finally, it should be noted that the above description is of preferred embodiments of the application, and that although preferred embodiments of the application have been described, numerous changes and modifications can be made to the preferred embodiments without departing from the principles of the application, and that such changes and modifications are contemplated as falling within the scope of the application. Accordingly, the appended claims are intended to embrace all such changes and modifications.

Claims

1. A strip steel anti-swinging slack system, characterized in that, The application comprises: a strip break detection device for generating a strip break signal when a strip break is detected; a mass measurement device for obtaining the mass of a coiled strip on the coiler; a coil diameter measurement device for obtaining the coil diameter of the coiled strip on the coiler; a rotational speed measurement device for obtaining the instantaneous linear speed of the coiled strip on the coiler; a spin-off prevention controller for, in response to the strip break signal, performing the following operations in each control cycle: obtaining the instantaneous linear speed of the current cycle, the output power of the coiler motor in the current cycle, and the coil diameter of the current cycle, and calculating the braking force of the current cycle; and, based on the mass at the time of the strip break, the coil diameter of the current cycle, and the braking force of the current cycle, calculating the deceleration control amount of the current cycle; a coiler speed control device for, in each control cycle, performing deceleration control on the coiler motor according to the deceleration control amount of the current cycle until the speed of the coiler motor is reduced to zero.

2. The strip steel anti-swing slack system according to claim 1, characterized in that, The strip break detection device is also used for: acquiring the tension of the strip between the main rolling mill and the coiler at a set step; and when the tension at the next moment is reduced to a preset proportion of the tension at the last moment, determining that the strip is broken.

3. The strip steel anti-swing slack system according to claim 1 or 2, characterized in that, The mass measurement device comprises: a strip length measurement module for obtaining the strip length of the coiled strip on the coiler; a mass calculation module for calculating the mass of the coiled strip based on the strip length, the pre-stored original strip mass, the original strip length, the strip thickness of the last pass, and the strip thickness of the current pass.

4. The strip steel anti-whipping system of claim 3, wherein The spin-off prevention controller is also used for: in response to the strip break signal, generating a main rolling mill stop signal and transmitting it to the control unit of the main rolling mill.

5. A method of preventing slippage of a strip steel, characterized by, The steps are as follows: Step a, generating a strip break signal when a strip break is detected; Step b, obtaining the mass, coil diameter, and instantaneous linear speed of the coiled strip on the coiler; Step c, in response to the strip break signal, performing the following operations in each control cycle: obtaining the instantaneous linear speed of the current cycle, the output power of the coiler motor in the current cycle, and the coil diameter of the current cycle, and calculating the braking force of the current cycle; and, based on the mass at the time of the strip break, the coil diameter of the current cycle, and the braking force of the current cycle, calculating the deceleration control amount of the current cycle; Step d, in each control cycle, performing deceleration control on the coiler motor according to the deceleration control amount of the current cycle until the speed of the coiler motor is reduced to zero.

6. The strip steel anti-swing slackening method according to claim 5, characterized by The process of detecting a strip break in step a comprises: acquiring the tension of the strip between the main rolling mill and the coiler at a set step; and when the tension at the next moment is reduced to a preset proportion of the tension at the last moment, determining that the strip is broken.

7. The strip steel anti-swinging method according to claim 5 or 6, characterized by The process of obtaining the mass of the coiled strip on the coiler in step b comprises: obtaining the strip length of the coiled strip on the coiler; calculating the mass of the coiled strip based on the strip length, the pre-stored original strip mass, the original strip length, the strip thickness of the last pass, and the strip thickness of the current pass.

8. The strip steel anti-swing slackening method according to claim 7, characterized by It also comprises step g: in response to the strip break signal, generating a main rolling mill stop signal and transmitting it to the control unit of the main rolling mill.

Images