Method for detecting deflection of center of gravity of plate blank before charging

Abstract

The invention discloses a method for detecting deflection of the center of gravity of a plate blank before furnace charging, and belongs to the technical field of automatic control of steel rolling heating furnaces. The method comprises the steps that when a roller bed motor is in a zero-speed torque state and the plate blank is kept static on a roller bed, the torque of the roller bed motor is obtained; calculating the unit plate weight torque based on the roller way motor torque and the plate blank weight; the calculated unit plate weight torque is compared with a preset unit plate weight torque threshold value, the slab gravity center deflection degree is judged, and the slab gravity center deflection degree is graded; and when the gravity center of the plate blank deflects, the temperature of the roller bed motor is calculated in real time, and overheating protection of the roller bed motor is achieved. The method can prevent the slab from sliding in the steel charging process and the furnace wall from being mechanically damaged, has the characteristics of high applicability and low cost, and can greatly improve the safety in the production process.

Description

Technical Field

[0001] The invention relates to the technical field of automatic control of a steel rolling heating furnace, and in particular to a method for detecting the deviation of the center of gravity of a slab before loading into a furnace. Background Art

[0002] The heating furnace is an important part of the hot rolling production line of a steel plant. Its safe operation is the basis for ensuring the normal operation of hot rolling. If the center of gravity of the slab to be heated by the heating furnace is deviated, the slab may slip between the steel loader when entering the furnace, and may also slip when moving forward in the heating furnace. In severe cases, it will cause mechanical damage to the furnace wall and cause engineering accidents. In addition, the deviation of the center of gravity of the slab will cause the torque of some roller motors to increase abnormally, and the large amount of heat generated will cause the temperature of the motor to rise, which may cause damage to the motor. Therefore, the detection of the deviation of the center of gravity of the slab is an important part of ensuring safe production. However, there is currently a lack of methods for detecting the deviation of the center of gravity of the slab on the roller. Summary of the invention

[0003] The invention provides a method for detecting the deviation of the center of gravity of a slab before loading into a furnace, so as to solve the technical problem that there is a lack of a solution for detecting the deviation of the center of gravity of a slab on a roller table in current engineering.

[0004] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0005] In one aspect, the present invention provides a method for detecting the deviation of the center of gravity of a slab before loading into a furnace, comprising:

[0006] When the roller motor is in a 0-speed torque state so that the slab remains stationary on the roller, the roller motor torque is obtained;

[0007] Based on the roller motor torque and slab weight, the unit slab weight torque is calculated;

[0008] The calculated unit plate weight torque is compared with the preset unit plate weight torque threshold to determine the degree of deviation of the center of gravity of the slab and classify the degree of deviation of the center of gravity of the slab;

[0009] When the center of gravity of the slab is deviated, the roller motor temperature is calculated in real time to implement overheat protection for the roller motor.

[0010] Furthermore, the roller motor torque is obtained in the following manner:

[0011] The current value and voltage value of the roller motor are obtained through the frequency converter, and the torque of the roller motor is calculated according to the current value and voltage value of the roller motor obtained by the frequency converter;

[0012] or

[0013] The current value and voltage value of the roller motor are obtained by using the current and voltage meter provided with the roller motor, and the torque of the roller motor is calculated according to the current value and voltage value of the roller motor obtained by the current and voltage meter;

[0014] or

[0015] The roller motor torque is directly acquired through the torque sensor.

[0016] Further, the calculation of the unit plate weight torque based on the roller motor torque and the plate weight includes:

[0017] For each roller motor, calculate the average torque value within a certain period of time as its torque;

[0018] Calculate the sum of all roller motor torques;

[0019] Based on the sum of the torques of all roller motors and the slab weight, the torque per unit slab weight is calculated.

[0020] Furthermore, the calculation formula of the unit plate weight torque is:

[0021]

[0022] Among them, M T is the torque per unit plate weight; M i is the torque of the i-th roller motor, i = 1, 2, ..., x, x is the number of roller motors; sum {M1, M2, ..., M x} represents the sum of the torques of all roller motors; m is the weight of the slab.

[0023] Furthermore, the calculated unit plate weight torque is compared with a preset unit plate weight torque threshold, the degree of deviation of the center of gravity of the slab is determined and the degree of deviation of the center of gravity of the slab is graded, including:

[0024] Set four torque thresholds per unit weight that increase in sequence: M a 、M b 、M c 、M d ;

[0025] The degree of deviation of the center of gravity of the slab is determined and graded according to the following judgment rules:

[0026]

[0027] Among them, α represents the degree of deviation of the center of gravity of the slab; M T is the torque per unit plate weight.

[0028] Furthermore, when the value of α is 1, it indicates that the degree of deviation of the center of gravity of the slab is blue; when the value of α is 2, it indicates that the degree of deviation of the center of gravity of the slab is yellow; when the value of α is 3, it indicates that the degree of deviation of the center of gravity of the slab is orange; when the value of α is 4, it indicates that the degree of deviation of the center of gravity of the slab is red; among them, for the slab with a degree of deviation of the center of gravity of red, it is directly stopped from entering the furnace and the technicians are automatically notified for subsequent manual processing.

[0029] Furthermore, the calculation formula of the roller motor temperature is:

[0030]

[0031] Wherein, T is the roller motor temperature; T0 is the initial value of the roller motor temperature; K is the roller motor power coefficient; t0 is the initial time when the slab is stationary on the roller; t1 is the real time when the slab is on the roller when calculating the roller motor temperature; U is the roller motor voltage value; I is the roller motor current value; t represents the time variable; C is the heat capacity of the roller motor; A is the heat dissipation coefficient of the roller motor; S is the heat dissipation area of ​​the roller motor surface.

[0032] Furthermore, the roller motor overheat protection is implemented, including:

[0033] When the roller motor temperature is not less than the preset motor temperature threshold, the roller motor is judged to be overheated, and a "motor overheat" fault is reported and the circuit breaker trips;

[0034] When the roller motor temperature is lower than the preset motor temperature threshold, it is determined that the current roller motor is not overheated.

[0035] On the other hand, the present invention further provides an electronic device, comprising a processor and a memory; wherein the memory stores at least one instruction, and the instruction is loaded and executed by the processor to implement the above method.

[0036] In yet another aspect, the present invention further provides a computer-readable storage medium, wherein at least one instruction is stored in the storage medium, and the instruction is loaded and executed by a processor to implement the above method.

[0037] The technical solution provided by the present invention utilizes the voltage value, current value and torque of the roller motor to solve the problem of detecting the center of gravity deviation of the slab without adding a new detection device, and can also provide a motor overheating protection function, greatly improving the safety of the production process. The beneficial effects brought by it include at least:

[0038] 1. The present invention detects whether the center of gravity of the slab is skewed by the torque of the roller motor, thereby controlling the skewness of the center of gravity of the slab, preventing the slab from sliding during steel loading and mechanical damage to the furnace wall. The invention has strong applicability, low cost, and obvious effect in the heating furnace of metallurgical engineering, and greatly improves the safety of the production process;

[0039] 2. The roller motor in the application scenario of the present invention generates heat while maintaining the slab stationary. The present invention calculates the motor temperature by heat integration to achieve a motor overheat protection function. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0041] Figure 1 It is a schematic diagram of the application scenario of the present invention;

[0042] Figure 2 is a flow chart of a method for detecting the deviation of the center of gravity of a slab before loading into a furnace provided by an embodiment of the present invention;

[0043] Figure 3 It is a system block diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0044] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0045] First of all, it should be noted that in the embodiments of the present invention, words such as "exemplarily" and "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "exemplary" in the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of the word "exemplarily" is intended to present the concept in a concrete way. In addition, in the embodiments of the present invention, the meaning expressed by "and / or" can be both, or it can be either of the two.

[0046] First embodiment

[0047] This embodiment provides a method for detecting the deviation of the center of gravity of a slab before loading into a furnace. The application scenario is as follows: Figure 1As shown, it is used to detect the degree of deviation of the center of gravity of the slab on the roller table of the heating furnace to prevent mechanical damage to the furnace wall; its basic principle is: when the slab reaches the specified position, the roller table of the heating furnace is stationary, the roller motor remains energized, the inverter gives the motor a certain compensation output voltage, and adjusts the magnetic flux of the motor to make it in a 0-speed high-torque state. If the center of gravity of the slab is deflected, it will have a tendency to slide along the roller direction. At this time, the inverter will detect the speed and realize dynamic balance through vector control. In this process, the voltage and current required by the roller motor will increase, which can be adjusted by unit plate weight The degree of abnormal increase in motor torque determines the degree of deviation of the slab center of gravity. Therefore, this method collects the voltage and current values ​​of the roller motor to calculate the motor torque, or directly obtains the motor torque through a torque sensor, and compares the unit plate weight torque with the manually set unit plate weight torque threshold to determine the degree of deviation. When the roller motor is at 0 speed torque, the electric energy consumed by the roller motor is mainly converted into heat energy, causing the motor temperature to rise, which may burn the motor in severe cases. Therefore, the motor temperature can be predicted by calculating the heat generated by the motor, and a motor overheat protection function can be provided for the motor to protect the motor.

[0048] The method can be implemented by an electronic device, and the execution process of the method is as follows: Figure 2 As shown, the following steps are included:

[0049] S1, when the roller motor is in a 0-speed torque state so that the slab remains stationary on the roller, the roller motor torque is obtained;

[0050] It should be noted that when the slab reaches the designated position of the roller table of the heating furnace, the roller table motor remains powered on, and the frequency converter provides a compensation voltage to the motor to keep the motor stationary (i.e., 0-speed high-torque state), increase the motor magnetic flux and excitation current, and keep the slab stationary on the roller table. At this time, the present embodiment obtains the roller table motor torque, that is, the motor torque at 0 speed of the roller table motor, and uses this as a basis for detecting the skewness of the slab center of gravity; wherein, the roller table motor torque is obtained in the following three ways:

[0051] a) Obtain current and voltage values ​​through the frequency converter to calculate the motor torque; b) Obtain current and voltage values ​​through the matching current and voltage meter to calculate the motor torque; c) Obtain motor torque directly through the torque sensor;

[0052] Of course, other methods may be used to obtain the roller motor torque, which is not limited in this embodiment.

[0053] S2, based on the roller motor torque and the slab weight, calculates the unit slab weight torque;

[0054] Specifically, in this embodiment, the calculation process of the unit plate weight torque is as follows:

[0055] S21, when the roller motor is in a high torque state at 0 speed, the average torque of the motor within a certain period of time is obtained in real time to obtain the real-time torque of the load roller motor during the stop time of the slab on the roller;

[0056] S22, calculating the sum of the real-time torques of all load roller motors during the stop time of the slab on the roller;

[0057] S23, calculate the ratio of the sum of the real-time torques of all load roller motors during the stop time of the slab on the roller to the mass of the slab, which is used as the unit weight torque M of the slab. T , the formula is:

[0058]

[0059] Among them, M i is the torque of the i-th roller motor, i=1,2,…,x, x is the number of roller motors; sum{} represents the summation formula; m represents the weight of the slab for which the center of gravity deviation is currently being determined.

[0060] S3, comparing the calculated unit plate weight torque with a preset unit plate weight torque threshold, determining the degree of deviation of the center of gravity of the slab and grading the degree of deviation of the center of gravity of the slab;

[0061] Specifically, in this embodiment, according to the actual on-site measurement results, four unit plate weight torque thresholds are manually set: M a 、M b 、M c 、M d The skewness is divided into red, orange, yellow and blue levels. The judgment threshold can be adjusted according to customer feedback and system judgment results; the specific judgment rules are as follows:

[0062]

[0063] Among them, α represents the degree of deviation of the center of gravity of the slab; M T is the unit plate weight torque. When the value of α is 1, it means that the slab gravity center deviation level is blue level; when the value of α is 2, it means that the slab gravity center deviation level is yellow level; when the value of α is 3, it means that the slab gravity center deviation level is orange level; when the value of α is 4, it means that the slab gravity center deviation level is red level; among them, the gravity center judgment result is directly output to the automation system, and for the slab with the gravity center deviation level of red level, it is directly stopped from entering the furnace, and the technicians are automatically notified for subsequent manual processing.

[0064] S4, when the center of gravity of the slab is deflected, the roller motor temperature is calculated in real time to implement overheat protection of the roller motor;

[0065] It should be noted that when the roller motor is at 0 speed, the electric energy consumed by the roller motor is mainly converted into heat energy, which is easy to burn the motor. For this, the real-time roller motor temperature can be calculated in the form of heat integration. When the motor temperature exceeds the overheating threshold, the corresponding overheating protection process is executed. Specifically, when the center of gravity of the slab is deflected, that is, the calculated unit plate weight torque is greater than M a In this embodiment, the motor with the largest current is selected for overheat protection calculation and judgment, and the specific implementation process is as follows:

[0066] According to manual experience, given an initial value T0 of the load roller motor temperature, the power coefficient K of the load roller motor, and the heat dissipation coefficient A of the load roller motor, the calculation formula of the roller motor temperature T is:

[0067]

[0068] Among them, t0 is the initial time when the slab is stationary on the roller; t1 is the real time when the slab is on the roller when calculating the roller motor temperature; U is the roller motor voltage value; I is the roller motor current value; t represents the time variable; C is the heat capacity of the roller motor, that is, the heat required for the motor to rise 1 degree; S is the heat dissipation area of ​​the roller motor surface; Among them, the values ​​of T0, K, and A can be adjusted according to customer feedback and system judgment results.

[0069] Furthermore, the motor overheat protection judgment rule is:

[0070]

[0071] If β=1, the motor is judged to be overheated, and the "motor overheated" fault is reported and tripped. Wherein, T represents the real-time calculated roller motor temperature; T β Indicates the threshold for judging motor overheating, which can be specified manually.

[0072] In summary, this embodiment provides a method for detecting the deviation of the center of gravity of the slab before loading into the furnace. The deviation of the center of gravity of the slab is detected by the roller motor torque, thereby realizing the control of the deviation of the center of gravity of the slab, and preventing the sliding of the slab during the steel loading process and the mechanical damage of the furnace wall. At the same time, the motor temperature is calculated by heat integration to realize the motor overheating protection function. When applied to the heating furnace of metallurgical engineering, it can greatly improve the safety of the production process.

[0073] Second embodiment

[0074] This embodiment uses a practical application example to illustrate the implementation process of the present invention, and its implementation steps are as follows:

[0075] Step 1) When the slab reaches the designated position of the roller table of the heating furnace, the roller table motor remains powered on, and the inverter provides a compensation voltage to the motor to keep the motor stationary (i.e., 0-speed high-torque state), increase the motor flux and excitation current, and at this time directly obtain the real-time torque value M of the motor through the torque sensor i .

[0076] The following data application scenario is that the 12 load roller motors of the heating furnace entry roller are controlled by the same inverter. The starting time is the moment when the speed of the slab on the heating furnace entry roller is 0. The data of three slabs are used as an example for explanation. Table 1 lists the real-time torque data of the roller motor controlled by the same inverter when slabs A, B, and C are stationary on the entry roller.

[0077] Table 1 Roller motor real-time torque data

[0078]

[0079] Step 2) Calculate the unit plate weight torque. The ratio of the sum of all load roller motor torques to the slab weight is taken as the unit plate weight torque, and the calculation formula is:

[0080]

[0081] Among them, the masses m of the three slabs A, B, and C are 19260kg, 19220kg, and 19260kg respectively. The calculation results of the unit slab weight torque are shown in Table 2 below.

[0082] Table 2 Unit plate weight torque data

[0083]

[0084] Step 3) Determine the degree of slab gravity center deviation. According to the actual on-site measurement results, four unit slab weight torque thresholds of 10x10 -3 N﹒ m / kg、20x10 -3 N﹒ m / kg、30x10 -3 N﹒ m / kg, α=1, 2, 3, 4 correspond to the blue, yellow, orange, and red levels of the degree of deflection respectively. The judgment rules are:

[0085]

[0086] According to this judgment rule, slabs A, B, and C belong to the blue, blue, and yellow grades respectively. The slabs have no obvious center of gravity deviation and can enter the furnace normally. The center of gravity judgment result is directly output to the automation system, and the torque-related parameters of each slab are saved for subsequent adjustment of the threshold. If a slab with a red center of gravity deviation is found, the slab will be stopped from entering the furnace and the technicians will be automatically notified for subsequent manual processing.

[0087] Step 4) Take the motor with the largest current for overheat protection calculation. The slab stops on the furnace roller for 50 seconds. The measured motor current is shown in Table 3.

[0088] Table 3 Real-time current value of roller motor

[0089]

[0090] According to the actual situation on site and manual experience, a motor temperature initial value of 40°C, power coefficient K = 1.38, roller motor compensation voltage of 5%, motor heat capacity C of 0.161×10 6 J / K, heat dissipation coefficient A = 19.4W / (m 2 ·K), motor surface heat dissipation area S = 1.59m 2 , then the temperature calculation formula of the motor is:

[0091]

[0092] The calculated real-time temperature of the motor is always 40°C, the temperature rise does not exceed 0.1°C, the motor temperature does not exceed the motor warning temperature of 70°C, and the operation is normal.

[0093] It can be seen from the above examples that the scheme of the present invention can greatly improve the safety in the production process.

[0094] Third embodiment

[0095] This embodiment provides an electronic device, such as Figure 3 As shown, the electronic device includes: a processor and a memory; wherein the processor and the memory can be connected via a communication bus; the memory stores at least one instruction, and the instruction is loaded and executed by the processor to implement the method of the first embodiment. In addition, the electronic device may also include a transceiver, the processor and the transceiver can be connected via a communication bus, and the transceiver is used to communicate with other devices.

[0096] Next, combine Figure 3 The following is a detailed introduction to the various components of the electronic device:

[0097] Among them, the processor is the control center of the electronic device, and the electronic device may include multiple processors, each of which may be a single-core processor (single-CPU) or a multi-core processor (multi-CPU). The processor here may be a processor or a general term for multiple processing elements. For example, the processor is one or more central processing units (CPUs), or other general-purpose processors, application specific integrated circuits (ASICs), or one or more integrated circuits configured to implement an embodiment of the present invention, such as one or more microprocessors (digital signal processors, DSPs), or one or more field programmable gate arrays (field programmable gate arrays, FPGAs), or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc. The processor may execute various functions of the electronic device by running or executing software programs stored in the memory and calling data stored in the memory.

[0098] In a specific implementation, as an embodiment, the processor may include one or more CPUs, such as Figure 3 The CPU0 and CPU1 shown in the figure are, of course, only exemplary.

[0099] The memory is used to store the software program for executing the solution of the present invention, and the execution is controlled by the processor. The specific implementation method can refer to the above method embodiment and will not be repeated here.

[0100] Optionally, the memory may be a read-only memory (ROM) or other types of static storage devices that can store static information and instructions, a random access memory (RAM) or other types of dynamic storage devices that can store information and instructions, or an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital versatile discs, Blu-ray discs, etc.), a magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. The memory may be integrated with the processor or exist independently and accessed through the interface circuit ( Figure 3 (not shown) is coupled to the processor, which is not specifically limited in this embodiment of the present invention.

[0101] The transceiver may include a receiver and a transmitter ( Figure 3 The receiver is used to implement the receiving function, and the transmitter is used to implement the sending function. The transceiver can be integrated with the processor or exist independently and communicate with the electronic device through the interface circuit ( Figure 3 (not shown) is coupled to the processor, which is not specifically limited in this embodiment of the present invention.

[0102] In addition, it should be noted that Figure 3 The structure of the electronic device shown in the figure does not constitute a limitation on the device, and the actual device may include more or fewer components than shown in the figure, or combine certain components, or arrange the components differently. In addition, the technical effects achieved by the electronic device when executing the method of the first embodiment above can refer to the technical effects described in the first embodiment above, so they are not repeated here.

[0103] Fourth embodiment

[0104] This embodiment provides a computer-readable storage medium, which stores at least one instruction, and the instruction is loaded and executed by a processor to implement the method of the first embodiment. The computer-readable storage medium may be a ROM, a random access memory, a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, etc. The instructions stored therein may be loaded by a processor in a terminal to execute the method.

[0105] In addition, it should be noted that the present invention can be provided as a method, an apparatus or a computer program product. Therefore, the embodiment of the present invention can be in the form of a full or partial hardware embodiment, a full or partial software embodiment or an embodiment combining software and hardware. Moreover, when implemented using software, the embodiment of the present invention can be in the form of a computer program product implemented on one or more computer-usable storage media containing computer-usable program codes. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, the process or function described in the embodiment of the present invention is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions can be transmitted from one website site, computer, server or data center to another website site, computer, server or data center by wired (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or data center containing one or more available media sets. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a DVD), or a semiconductor medium. The semiconductor medium may be a solid state hard disk.

[0106] The embodiments of the present invention are described with reference to the flowcharts and / or block diagrams of the methods, terminal devices (systems), and computer program products according to the embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of the processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, an embedded processor, or other programmable data processing terminal device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing terminal device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0107] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing terminal device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1These computer program instructions can also be loaded onto a computer or other programmable data processing terminal device, so that a series of operation steps are executed on the computer or other programmable terminal device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable terminal device provide for implementing the process in the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0108] It should also be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. The terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or terminal device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of more restrictions, the elements defined by the sentence "including one..." do not exclude the existence of other identical elements in the process, method, article or terminal device including the elements. In addition, the term "and / or" is only an association relationship describing the associated objects, indicating that there can be three relationships, for example, A and / or B, which can represent: A exists alone, A and B exist at the same time, and B exists alone, wherein A and B can be singular or plural. In addition, the character " / " in this article generally indicates that the objects before and after are in an "or" relationship, but it may also indicate an "and / or" relationship. Please refer to the context for specific understanding. "At least one" means one or more, and "plurality" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can be represented by: a, b, c, ab, ac, bc or abc, where a, b, c can be single or plural.

[0109] In addition, it can be understood that in various embodiments of the present invention, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0110] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0111] In several embodiments provided by the present invention, it should be understood that the disclosed equipment, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of functional modules / units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point, the coupling or direct coupling or communication connection between each other shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms. The unit described as a separate component may or may not be physically separated, and the component displayed as a unit may or may not be a physical unit, that is, it may be located in one place, or it may be distributed on multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the scheme of this embodiment. In addition, each functional unit in each embodiment of the present invention can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit.

[0112] If the method is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0113] Finally, it should be noted that the above is only a preferred embodiment of the present invention. It should be pointed out that although the preferred embodiment of the present invention has been described, for ordinary technicians in this technical field, once the basic creative concept of the present invention is known, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention. Therefore, the attached claims are intended to be interpreted as including the preferred embodiment and all changes and modifications that fall within the scope of the embodiments of the present invention.

Claims

1. A method for detecting the deviation of the center of gravity of a slab before loading into a furnace, characterized in that: include: When the roller motor is in a 0-speed torque state so that the slab remains stationary on the roller, the roller motor torque is obtained; Based on the roller motor torque and slab weight, the unit slab weight torque is calculated; The calculated unit plate weight torque is compared with the preset unit plate weight torque threshold to determine the degree of deviation of the center of gravity of the slab and classify the degree of deviation of the center of gravity of the slab; When the center of gravity of the slab is deviated, the roller motor temperature is calculated in real time to implement overheat protection for the roller motor.

2. The method for detecting the deviation of the center of gravity of the slab before loading into the furnace according to claim 1, characterized in that: The roller motor torque is obtained as follows: The current value and voltage value of the roller motor are obtained through the frequency converter, and the torque of the roller motor is calculated according to the current value and voltage value of the roller motor obtained by the frequency converter; or The current value and voltage value of the roller motor are obtained by using the current and voltage meter provided with the roller motor, and the torque of the roller motor is calculated according to the current value and voltage value of the roller motor obtained by the current and voltage meter; or The roller motor torque is directly acquired through the torque sensor.

3. The method for detecting the deviation of the center of gravity of a slab before loading into a furnace according to claim 1, characterized in that: The calculation of the unit plate weight torque based on the roller motor torque and the plate weight includes: For each roller motor, calculate the average torque value within a certain period of time as its torque; Calculate the sum of all roller motor torques; Based on the sum of the torques of all roller motors and the slab weight, the torque per unit slab weight is calculated.

4. The method for detecting the deviation of the center of gravity of a slab before loading into a furnace according to claim 3, characterized in that: The calculation formula of the unit plate weight torque is: Among them, M T is the torque per unit plate weight; M i is the torque of the i-th roller motor, i = 1, 2, ..., x, x is the number of roller motors; sum {M1, M2, ..., M x } represents the sum of the torques of all roller motors; m is the weight of the slab.

5. The method for detecting the deviation of the center of gravity of a slab before loading into a furnace according to claim 1, characterized in that: The step of comparing the calculated unit plate weight torque with a preset unit plate weight torque threshold, determining the degree of deviation of the center of gravity of the plate blank and grading the degree of deviation of the center of gravity of the plate blank comprises: Set four torque thresholds per unit weight that increase in sequence: M a 、M b 、M c 、M d ; The degree of deviation of the center of gravity of the slab is determined and graded according to the following judgment rules: Among them, α represents the degree of deviation of the center of gravity of the slab; M T is the torque per unit plate weight.

6. The method for detecting the deviation of the center of gravity of a slab before loading into a furnace according to claim 5, characterized in that: When the value of α is 1, it means that the degree of deviation of the center of gravity of the slab is blue; When the value of α is 2, it means that the degree of deviation of the center of gravity of the slab is yellow; When the value of α is 3, it means that the degree of deviation of the center of gravity of the slab is orange; When the value of α is 4, it means that the degree of deviation of the center of gravity of the slab is red; Among them, for slabs with a red level of center of gravity deviation, they are directly stopped from entering the furnace and the technicians are automatically notified for subsequent manual processing.

7. The method for detecting the deviation of the center of gravity of a slab before loading into a furnace according to claim 1, characterized in that: The calculation formula for roller motor temperature is: Wherein, T is the roller motor temperature; T0 is the initial value of the roller motor temperature; K is the roller motor power coefficient; t0 is the initial time when the slab is stationary on the roller; t1 is the real time when the slab is on the roller when calculating the roller motor temperature; U is the roller motor voltage value; I is the roller motor current value; t represents the time variable; C is the heat capacity of the roller motor; A is the heat dissipation coefficient of the roller motor; S is the heat dissipation area of ​​the roller motor surface.

8. The method for detecting the deviation of the center of gravity of a slab before loading into a furnace according to claim 1, characterized in that: The method of realizing overheat protection of the roller motor includes: When the roller motor temperature is not less than the preset motor temperature threshold, the roller motor is judged to be overheated, and a "motor overheat" fault is reported and the circuit breaker trips; When the roller motor temperature is lower than the preset motor temperature threshold, it is determined that the current roller motor is not overheated.

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