Positioning method and device for ladle turret position of continuous casting machine

Abstract

The application provides a positioning method and device for a ladle rotary table position of a continuous casting machine. A frequency converter is used to control the rotation of a rotary motor of the ladle rotary table. A programmable logic controller is used to collect the instantaneous speed value of the frequency converter through a field bus at a fixed cycle. The instantaneous rotation distance of the ladle rotary table in the current cycle is calculated according to the instantaneous speed value and the fixed cycle. The instantaneous rotation distance from the start of rotation to the current time is accumulated to obtain the actual rotation distance of the ladle rotary table. The actual rotation distance is compared with a preset deceleration position distance value. A deceleration instruction is sent to the frequency converter according to the comparison result, so that the ladle rotary table is switched from high-speed rotation to low-speed rotation. The actual rotation distance is compared with a preset casting position distance value. A stop instruction is sent to the frequency converter according to the comparison result, so that the ladle rotary table is stopped at the casting position. The problem that the rotation positioning of the ladle rotary table cannot be accurately positioned is solved.

Description

Technical Field

[0001] This application relates to the field of continuous casting machine production technology, and in particular to a method and device for positioning the ladle turret of a continuous casting machine. Background Technology

[0002] In the continuous casting process, molten steel is typically transferred from the ladle to the tundish and then poured into the crystallizer for casting. The ladle turret, as a key piece of equipment for carrying and transferring the ladle, needs to rotate to a specific position to achieve precise alignment between the ladle nozzle and the tundish receiving position, thereby ensuring the normal and stable pouring of molten steel. Therefore, precise control of the ladle turret's rotational position is a fundamental requirement for ensuring the continuity and stability of continuous casting production.

[0003] In related technologies, frequency converters are typically used to control the forward and reverse rotation and fast and slow rotation of the ladle turntable, and encoders or proximity switches are used to obtain the "deceleration position" and "casting position" signals of the turntable, thereby achieving positioning control.

[0004] However, when the ladle turret rotates while carrying a heavy molten steel ladle, its mechanical structure experiences severe vibrations. These vibrations can easily cause signal distortion or loss from detection components such as encoders or proximity switches, making it impossible to accurately determine the turret's actual position. If the ladle turret cannot be accurately positioned, it will directly cause a misalignment between the ladle nozzle and the tundish receiving position, preventing the ladle nozzle from opening properly for pouring. In severe cases, this can lead to production accidents such as billet lying down or pouring stopping. Therefore, improving the accuracy of the ladle turret's rotational positioning is a crucial issue that needs to be addressed to ensure the stable and smooth operation of continuous casting production. Summary of the Invention

[0005] This application provides a method and device for positioning the ladle turret of a continuous casting machine, which can effectively solve the problem of inaccurate positioning during ladle turret rotation.

[0006] The first aspect of this application provides a method for positioning the ladle turret of a continuous casting machine, including: The rotary motor of the large bag turntable is controlled by a frequency converter. The instantaneous speed value of the frequency converter is acquired at fixed intervals via a fieldbus through a programmable logic controller. Based on the collected instantaneous rotational speed value and the fixed period, the instantaneous rotational distance of the large bag rotary table within the current period is calculated; The actual rotation distance of the large bag turntable is obtained by summing the instantaneous rotation distance from the start of rotation to the current moment; The actual rotation distance is compared with the preset deceleration position distance value; Based on the comparison result of the actual rotation distance reaching the deceleration position distance value, the programmable logic controller sends a deceleration command to the frequency converter to switch the large package rotary table from high-speed rotation to low-speed rotation. The actual rotation distance is compared with the preset casting position distance value; Based on the comparison result of the actual rotation distance reaching the distance value of the casting position, the programmable logic controller sends a stop command to the frequency converter to stop the ladle rotary table at the casting position.

[0007] The rotation of the ladle turret's rotary motor is controlled by a frequency converter. A programmable logic controller (PLC) collects the instantaneous speed value of the frequency converter via a fieldbus at fixed intervals. Based on the collected instantaneous speed value and the fixed interval, the instantaneous rotation distance of the ladle turret within the current cycle is calculated. The actual rotation distance of the ladle turret is obtained by accumulating the instantaneous rotation distances from the start of rotation to the current moment. This actual rotation distance is compared with preset deceleration position distances and casting position distances. Based on the comparison result of the actual rotation distance reaching the deceleration position distance, the PLC sends a deceleration command to the frequency converter to switch the ladle turret from high-speed rotation to low-speed rotation. Finally, based on the comparison result of the actual rotation distance reaching the casting position distance, the PLC sends a stop command to the frequency converter to stop the ladle turret at the casting position. This improves the accuracy of the rotation positioning of the ladle turret in the continuous casting machine.

[0008] Optionally, it also includes: displaying the operating status, rotation speed, and actual rotation distance of the ladle rotary table in real time through a host computer monitoring system, and receiving modification instructions for the deceleration position distance value or the casting position distance value through the human-machine interface of the host computer monitoring system.

[0009] The operating status, rotation speed, and actual rotation distance of the ladle turret are displayed in real time through the host computer monitoring system. Modification commands for the deceleration position distance or casting position distance value are received through the human-machine interface of the host computer monitoring system, thereby improving the visualization of the rotation and positioning process of the ladle turret of the continuous casting machine and the convenience of parameter adjustment.

[0010] Optionally, it also includes: calculating the deviation between the actual position of the ladle rotary table after it stops and the casting position, comparing the deviation with a preset allowable error range, and issuing an alarm through the host computer monitoring system based on the comparison result that the deviation exceeds the allowable error range.

[0011] By calculating the deviation between the actual position of the ladle turret after it stops and the casting position, and comparing the deviation with the preset allowable error range, an alarm is issued through the host computer monitoring system based on the comparison result that the deviation exceeds the allowable error range, thereby improving the monitoring capability of the ladle turret positioning accuracy.

[0012] Optionally, the step of acquiring the instantaneous speed value of the frequency converter via the programmable logic controller through the fieldbus at fixed intervals includes: reading real-time speed data from the frequency converter via the PROFIBUS-DP fieldbus and storing the real-time speed data in the data block of the programmable logic controller.

[0013] Real-time speed data is read from the frequency converter via PROFIBUS-DP fieldbus and stored in the data block of the programmable logic controller, thereby improving the reliability of instantaneous speed value acquisition and the convenience of data management for the rotary table.

[0014] The second aspect of this application provides a positioning device for the position of the ladle turret of a continuous casting machine, used to implement the positioning method for the position of the ladle turret of the continuous casting machine described in the first aspect, the device comprising: A programmable logic controller, comprising a data acquisition module, a distance calculation module, and a logic control module; A frequency converter, wherein the frequency converter is communicatively connected to the programmable logic controller via a fieldbus; A rotary motor, which is electrically connected to the frequency converter and connected to the mechanical transmission mechanism of the large-bag rotary table through a reduction gearbox; The data acquisition module is used to acquire instantaneous speed values ​​from the frequency converter at fixed intervals via the fieldbus; The distance calculation module is used to calculate the instantaneous rotation distance based on the instantaneous rotation speed value and the fixed period, and to accumulate the instantaneous rotation distance to obtain the actual rotation distance; The logic control module is used to compare the actual rotation distance with the preset deceleration position distance value and the casting position distance value, and send a deceleration command or a stop command to the frequency converter through the fieldbus according to the comparison result.

[0015] By setting up an electrical connection between the frequency converter and the rotating motor, and the rotating motor connected to the mechanical transmission mechanism of the ladle turret via a reduction gearbox, and by setting up a programmable logic controller (PLC) including a data acquisition module, a distance calculation module, and a logic control module, the accuracy of the rotational positioning of the ladle turret in the continuous casting machine is improved. The data acquisition module collects instantaneous speed values ​​from the frequency converter at fixed intervals via a fieldbus. The distance calculation module calculates the instantaneous rotational distance based on the instantaneous speed values ​​and the fixed intervals, and accumulates them to obtain the actual rotational distance. The logic control module compares the actual rotational distance with preset deceleration position distance values ​​and casting position distance values, and sends deceleration or stop commands to the frequency converter via the fieldbus based on the comparison results.

[0016] Optionally, it also includes a host computer monitoring system, which is communicatively connected to the programmable logic controller. The host computer monitoring system is used to provide a human-machine interface to display the rotation status, rotation speed, and actual rotation distance of the large package rotary table.

[0017] By setting up a host computer monitoring system that communicates with the programmable logic controller, the rotation status, rotation speed, and actual rotation distance of the large package rotary table can be displayed using the human-machine interface provided by the host computer monitoring system, thereby improving the visualization of the rotation and positioning process of the large package rotary table.

[0018] Optionally, the host computer monitoring system is also used to receive input parameter modification instructions through the human-machine interface, and send the modified deceleration position distance value or the casting position distance value to the programmable logic controller.

[0019] The system receives parameter modification commands through the human-machine interface of the host computer monitoring system and sends the modified deceleration position distance value or casting position distance value to the programmable logic controller, thereby improving the convenience of adjusting the deceleration position and casting position parameters during the rotation positioning of the ladle rotary table.

[0020] Optionally, the host computer monitoring system further includes an alarm module, which is used to issue an alarm signal when the deviation between the actual stop position of the ladle rotary table and the casting position exceeds a preset threshold.

[0021] By setting up an alarm module in the host computer monitoring system, an alarm signal is issued when the deviation between the actual stop position of the ladle rotary table and the casting position exceeds a preset threshold, thereby improving the monitoring capability of the positioning accuracy of the ladle rotary table.

[0022] Optionally, the programmable logic controller (PLC) program is implemented using a modular programming approach, including a main program module, the data acquisition module, the distance calculation module, and the logic control module. The main program module is used to sequentially call the data acquisition module, the distance calculation module, and the logic control module.

[0023] By adopting a modular programming approach to implement the programmable logic controller (PLC) program, the main program module is configured to call the data acquisition module, distance calculation module, and logic control module in sequence, thereby improving the development efficiency and maintainability of the PLC program.

[0024] Optionally, the fieldbus is a PROFIBUS-DP bus.

[0025] By specifically configuring the fieldbus as a PROFIBUS-DP bus, the reliability of data transmission during the rotation and positioning of the large package rotary table is improved.

[0026] As can be seen from the above technical solution, this application provides a positioning method and device for the ladle turret of a continuous casting machine. The method involves controlling the rotation of the ladle turret's rotary motor via a frequency converter; collecting the instantaneous rotation speed value of the frequency converter via a fieldbus at fixed intervals using a programmable logic controller (PLC); calculating the instantaneous rotation distance of the ladle turret within the current cycle based on the collected instantaneous rotation speed value and the fixed cycle; accumulating the instantaneous rotation distance from the start of rotation to the current moment to obtain the actual rotation distance of the ladle turret; comparing the actual rotation distance with a preset deceleration position distance value; based on the comparison result of the actual rotation distance reaching the deceleration position distance value, sending a deceleration command to the frequency converter via the PLC to switch the ladle turret from high-speed rotation to low-speed rotation; comparing the actual rotation distance with a preset casting position distance value; and based on the comparison result of the actual rotation distance reaching the casting position distance value, sending a stop command to the frequency converter via the PLC to stop the ladle turret at the casting position. It can effectively solve the problem of inaccurate positioning of the rotary table for large packages. Attached Figure Description

[0027] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the positioning method for the ladle turret of the continuous casting machine in an embodiment of this application; Figure 2This is a schematic diagram of the control system configuration in the positioning method of the ladle turret of the continuous casting machine in the embodiments of this application; Figure 3 This is a schematic diagram of PROFIBUS-DP data communication in the positioning method of the ladle turret of the continuous casting machine in the embodiments of this application. Detailed Implementation

[0029] The embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described below do not represent all embodiments consistent with this application. They are merely examples of systems and methods consistent with some aspects of this application as detailed in the claims.

[0030] To solve the problem of inaccurate positioning on the rotary table for large packages, see [reference needed]. Figure 1 This application provides a method for positioning the ladle turret of a continuous casting machine, comprising: S100: The rotary motor of the large package rotary table is controlled by a frequency converter.

[0031] Specifically, see Figure 2 After the operator issues a rotation command on the host computer or local control box, the command is transmitted to the frequency converter through the programmable logic controller (PLC). The frequency converter drives the rotary motor, which in turn drives the large package rotary table to rotate through mechanical transmission mechanisms such as reduction gearboxes.

[0032] S200: The instantaneous speed value of the frequency converter is acquired at fixed intervals via a fieldbus through a programmable logic controller.

[0033] It should be understood that in step S200, the PLC acts as the master station and the frequency converter as the slave station, exchanging data at high speed and reliably via the fieldbus. The PLC internally sets a timer interrupt (e.g., every 100ms), and upon each interrupt, reads the instantaneous speed value V of the frequency converter via the fieldbus. This process corresponds to... Figure 2 "Data Acquisition Module" and Figure 3 PROFIBUS-DP data communication.

[0034] In some embodiments, acquiring the instantaneous speed value of the frequency converter via a fieldbus at fixed intervals through a programmable logic controller includes: reading real-time speed data from the frequency converter via a PROFIBUS-DP fieldbus and storing the real-time speed data in the data block of the programmable logic controller.

[0035] It should be understood that PROFIBUS-DP is a high-speed, reliable fieldbus protocol widely used in industrial automation. In this invention, the PLC (such as CPU315-2 DP) acts as the PROFIBUS-DP master, and the frequency converter acts as the slave. They are connected via a dedicated PROFIBUS cable, forming a configuration as follows: Figure 3 The PROFIBUS-DP data communication network is shown. The OP270 panel connects to a PLC (such as a CPU315-2 DP) via the MPI (Multi-Point Interface) protocol, enabling bidirectional data transmission. Operators can send control commands to the PLC via input devices such as buttons, touchscreen, or knobs on the OP270 panel, such as starting / stopping the rotation of the ladle turntable, setting the target rotation angle, and selecting manual / automatic control modes. Simultaneously, the PLC also sends real-time system operating status information, such as the current actual rotation angle of the ladle turntable, real-time speed, motor operating current, whether fault alarms have occurred (such as overspeed, overcurrent, limit switch triggering, etc.), and the target angle setpoint, to the OP270 panel. This information is presented intuitively on the OP270 panel's display screen, such as with digital displays, graphical indicators, and dynamic curves, allowing operators to monitor the system's operating status in real time and make corresponding operations and adjustments as needed. For example, when the trolley table rotates to near the target angle, the OP270 panel will display the difference between the current angle and the target angle, and may remind the operator to slow down or stop through color changes or flashing.

[0036] The PLC sends request messages to the frequency converter at fixed intervals (e.g., 100ms) via its integrated DP interface. Upon receiving the request, the frequency converter packages its internally stored real-time speed data into a response message and returns it to the PLC via the bus. After parsing the speed value from the received message, the PLC stores the data in a specially created data block (DB block) according to pre-programmed instructions. This DB block can be an array or a series of variables, continuously storing each acquired speed value for subsequent distance calculation modules to access. By reading real-time speed data from the frequency converter via the PROFIBUS-DP fieldbus and storing the real-time speed data in the programmable logic controller's data block, the reliability of instantaneous speed value acquisition for the rotary table and the convenience of data management are improved.

[0037] S300: Calculate the instantaneous rotation distance of the large package rotary table within the current cycle based on the collected instantaneous rotation speed value and fixed cycle.

[0038] For example, if the fixed period T = 100ms and the collected instantaneous rotational speed value is V (unit: meters per minute), then unit conversion is required. First, based on the motor speed N, the gear ratio S of the reducer, and the equivalent diameter d of the transmission mechanism (such as the slewing support of the large-scale rotary table), the linear velocity of the large-scale rotary table can be calculated, i.e., V' = N × S × π × d. However, in this embodiment, a more direct method is to use the frequency or speed output by the frequency converter, combined with the known reduction ratio and mechanical parameters, to directly calculate the rotational linear velocity of the rotary table. To simplify the calculation and improve real-time performance, the instantaneous rotational speed value V of the frequency converter is directly collected. The instantaneous rotational distance Sn in the current period is Sn = (T / 60000) × Vn, where T is in milliseconds and 60000 is used to convert minutes to milliseconds.

[0039] S400: Accumulate the instantaneous rotation distance from the start of rotation to the current moment to obtain the actual rotation distance of the large bag turntable.

[0040] Specifically, the actual rotation distance L = S1 + S2 + S3 + ... + Sn is updated in real time in the PLC's data block (DB block), continuously performing the steps of calculating the walking distance and accumulating the distance.

[0041] S500: Compares the actual rotation distance with the preset deceleration position distance value.

[0042] S600: Based on the comparison result of the actual rotation distance reaching the deceleration position distance value, the programmable logic controller sends a deceleration command to the frequency converter to switch the large package rotary table from high-speed rotation to low-speed rotation.

[0043] S700: Compare the actual rotation distance with the preset casting position distance value.

[0044] S800: Based on the comparison result of the actual rotation distance reaching the casting position distance value, the programmable logic controller sends a stop command to the frequency converter to stop the ladle rotary table at the casting position.

[0045] Specifically, after obtaining the precise actual rotation distance L, it is compared with two key position values ​​pre-stored in the PLC: the "preset deceleration position distance value" and the "preset casting position distance value." When L first reaches the deceleration position value, the PLC's logic control module sends a deceleration command to the frequency converter via the PROFIBUS-DP bus. The frequency converter then reduces its output frequency, switching the rotary table from high-speed rotation to low-speed rotation, preparing for a precise stop. When L continues to increase and reaches the casting position value, the PLC immediately sends a stop command. The frequency converter cuts off the motor power and may apply brakes, causing the ladle rotary table to stop precisely at the casting position, at which point the ladle nozzle and the tundish receiving position are accurately aligned. This method, through pure software calculation, completely avoids the problem of detection signal distortion caused by mechanical vibration.

[0046] The rotation of the ladle turret's rotary motor is controlled by a frequency converter. A programmable logic controller (PLC) collects the instantaneous speed value of the frequency converter via a fieldbus at fixed intervals. Based on the collected instantaneous speed value and the fixed interval, the instantaneous rotation distance of the ladle turret within the current cycle is calculated. The actual rotation distance of the ladle turret is obtained by accumulating the instantaneous rotation distances from the start of rotation to the current moment. This actual rotation distance is compared with preset deceleration position distances and casting position distances. Based on the comparison result of the actual rotation distance reaching the deceleration position distance, the PLC sends a deceleration command to the frequency converter to switch the ladle turret from high-speed rotation to low-speed rotation. Finally, based on the comparison result of the actual rotation distance reaching the casting position distance, the PLC sends a stop command to the frequency converter to stop the ladle turret at the casting position. This improves the accuracy of the rotation positioning of the ladle turret in the continuous casting machine.

[0047] In some embodiments, the system further includes: displaying the operating status, rotation speed, and actual rotation distance of the ladle rotary table in real time through a host computer monitoring system, and receiving modification instructions for the deceleration position distance value or the casting position distance value through the human-machine interface of the host computer monitoring system.

[0048] For example, an industrial control computer with Siemens WINCC 6.0 software installed communicates with a Siemens S7-300 PLC in the field via Ethernet, forming a configuration such as... Figure 2The control system shown displays the current operating status of the ladle rotary table (e.g., "Rotating," "Decelerating," "Stopped"), real-time rotation speed, and actual rotation distance L on the WINCC screen in real time and dynamically. Operators can intuitively monitor the entire rotation process. Simultaneously, the system provides a user-friendly human-machine interface (HMI). When production processes need adjustment, such as changing the tundish to a different steel grade resulting in a change in the centering position, operators can directly open the parameter modification panel on the screen and input new deceleration or casting position distance values. The modified parameters are sent to the PLC via Ethernet, and the PLC will then use the new preset values ​​for comparison in subsequent rotation control. Figure 2 The "host computer" part of the document.

[0049] The operating status, rotation speed, and actual rotation distance of the ladle turret are displayed in real time through the host computer monitoring system. Modification commands for the deceleration position distance or casting position distance value are received through the human-machine interface of the host computer monitoring system, thereby improving the visualization of the rotation and positioning process of the ladle turret of the continuous casting machine and the convenience of parameter adjustment.

[0050] In some embodiments, the method further includes: calculating the deviation between the actual position of the ladle rotary table after it stops and the casting position, comparing the deviation with a preset allowable error range, and issuing an alarm through a host computer monitoring system based on the comparison result that the deviation exceeds the allowable error range.

[0051] It should be understood that after the PLC executes the stop command, the ladle rotary table finally stops at a position. At this time, the distance calculation module inside the PLC records the final actual rotation distance Lstop, which is theoretically the distance between the ladle rotary table's stopping position and the starting point. The PLC's logic control module calculates the deviation value Δ = |Lstop - Ltarget|, where Ltarget is the preset casting position distance value. Then, this deviation value Δ is compared with a pre-set, allowable error range ε ​​(e.g., ±5 mm). If Δ ≤ ε, it means the positioning accuracy is within the allowable range, and the system does not operate or displays normally. If Δ > ε, that is, the deviation value exceeds the allowable error range, the PLC will immediately send an alarm trigger signal to the host computer monitoring system. After receiving the signal, the alarm module in the host computer monitoring system will pop up an alarm window on the WINCC screen, change the indicator light color, or issue an audible alarm to remind the operator that the current positioning is abnormal and needs to be checked and handled in time.

[0052] By calculating the deviation between the actual position of the ladle turret after it stops and the casting position, and comparing the deviation with the preset allowable error range, an alarm is issued through the host computer monitoring system based on the comparison result that the deviation exceeds the allowable error range, thereby improving the monitoring capability of the ladle turret positioning accuracy.

[0053] This application also provides a positioning device for the position of the ladle turret of a continuous casting machine, used to implement the positioning method for the position of the ladle turret of the continuous casting machine described in the above embodiments. The device includes: A programmable logic controller (PLC) includes a data acquisition module, a distance calculation module, and a logic control module. The frequency converter communicates with the programmable logic controller via a fieldbus. A rotary motor is electrically connected to a frequency converter and is connected to the mechanical transmission mechanism of the large-scale rotary table through a reduction gearbox. The data acquisition module is used to acquire instantaneous speed values ​​from the frequency converter at fixed intervals via fieldbus; The distance calculation module is used to calculate the instantaneous rotation distance based on the instantaneous rotation speed value and a fixed period, and to accumulate the instantaneous rotation distances to obtain the actual rotation distance; The logic control module compares the actual rotation distance with the preset deceleration position distance value and casting position distance value, and sends a deceleration command or stop command to the frequency converter via the fieldbus according to the comparison result.

[0054] It should be understood that, such as Figure 2As shown, the core of this device is a programmable logic controller (PLC), preferably a Siemens S7-300 series CPU with a DP interface (such as CPU315-2 DP). At the software level, it is logically divided into three functional modules: a data acquisition module, responsible for data acquisition tasks, communicating with the frequency converter via the PROFIBUS-DP bus; a distance calculation module, responsible for executing algorithms, converting the acquired speed values ​​into distance and accumulating them; and a logic control module, responsible for logical judgments and issuing control commands. The frequency converter, as the actuator, is connected to the PLC via the PROFIBUS-DP bus, receiving start / stop and speed adjustment commands from the PLC, and changing the frequency and voltage of the output power supply according to the commands. The rotary motor, typically an AC asynchronous motor with brake, is electrically connected to the output of the frequency converter and rotates under its drive. The rotary motor is connected to the mechanical transmission mechanism (such as a slewing bearing) of the large rotary table through transmission components such as a reduction gearbox, thereby transmitting the motor's rotational power to the huge rotary table, causing it to rotate slowly but powerfully. In actual operation, after the system starts rotating, the PLC's data acquisition module works first, periodically retrieving instantaneous speed data from the frequency converter and storing it in the DB block. The distance calculation module then reads this data in real time, calculates the minute rotational distance within each cycle according to the formula, and accumulates the total distance L from the start of rotation to the current position, also storing it in the DB block. The logic control module continuously compares this total distance L with the preset deceleration and casting positions stored in the PLC. When L reaches the preset deceleration position, the logic control module sends a "deceleration" control word to the frequency converter via the bus, and the frequency converter immediately reduces the output frequency, the motor speed decreases, and the turntable slows down. When L reaches the preset casting position, the logic control module sends a "stop" control word, the frequency converter stops outputting, the motor brakes, and the turntable stops precisely.

[0055] By setting up an electrical connection between the frequency converter and the rotating motor, and the rotating motor connected to the mechanical transmission mechanism of the ladle turret via a reduction gearbox, and by setting up a programmable logic controller (PLC) including a data acquisition module, a distance calculation module, and a logic control module, the accuracy of the rotational positioning of the ladle turret in the continuous casting machine is improved. The data acquisition module collects instantaneous speed values ​​from the frequency converter at fixed intervals via a fieldbus. The distance calculation module calculates the instantaneous rotational distance based on the instantaneous speed values ​​and the fixed intervals, and accumulates them to obtain the actual rotational distance. The logic control module compares the actual rotational distance with preset deceleration position distance values ​​and casting position distance values, and sends deceleration or stop commands to the frequency converter via the fieldbus based on the comparison results.

[0056] In some embodiments, a host computer monitoring system is also included. The host computer monitoring system is communicatively connected to the programmable logic controller. The host computer monitoring system is used to provide a human-machine interface to display the rotation status, rotation speed and actual rotation distance of the large package rotary table.

[0057] It should be understood that a host computer monitoring system is typically an industrial PC with industrial configuration software (such as Siemens WinCC) installed. It communicates with the field PLC via Ethernet, establishing an information exchange channel. The host computer monitoring system provides a graphical human-machine interface (HMI) on which engineers or operators can intuitively see an animation based on a large ladle turntable, alongside real-time displays of various data read from the PLC, such as whether it is currently in a "stop," "high-speed rotation," or "low-speed rotation" state, the current rotation speed (meters / minute or rpm), and the "actual rotation distance" (meters) calculated by the PLC representing the actual position of the large ladle turntable. This presents the program data and calculation results, originally hidden deep within the PLC, to the operator in an easily understandable and monitorable manner.

[0058] By setting up a host computer monitoring system that communicates with the programmable logic controller, the rotation status, rotation speed, and actual rotation distance of the large package rotary table can be displayed using the human-machine interface provided by the host computer monitoring system, thereby improving the visualization of the rotation and positioning process of the large package rotary table.

[0059] In some embodiments, the host computer monitoring system is also used to receive input parameter modification instructions through a human-machine interface and send the modified deceleration position distance value or casting position distance value to the programmable logic controller.

[0060] It should be understood that when production processes change, such as requiring the casting of billets of different sizes, or when the ladle nozzle position needs fine-tuning due to wear, the stop position of the ladle rotary table needs to be modified. Without this function, modifying position parameters might require engineers to connect to PLC programming software and modify preset values ​​in the program online, which is cumbersome and risky. This device, however, allows operators to directly find the corresponding parameter setting window on the WINCC monitoring screen and input new deceleration or casting position distance values. The host computer software packages this modification instruction and data and sends it to the PLC via Ethernet. After receiving the data, the PLC automatically updates the preset values ​​used by its internal logic control module for comparison, thereby achieving online and seamless adjustment of process parameters.

[0061] The system receives parameter modification commands through the human-machine interface of the host computer monitoring system and sends the modified deceleration position distance value or casting position distance value to the programmable logic controller, thereby improving the convenience of adjusting the deceleration position and casting position parameters during the rotation positioning of the ladle rotary table.

[0062] In some embodiments, the host computer monitoring system further includes an alarm module, which is used to issue an alarm signal when the deviation between the actual stop position of the ladle rotary table and the casting position exceeds a preset threshold.

[0063] It should be understood that the alarm module is an independent software component in the host computer monitoring system. It receives status information from the PLC logic control module in real time, the most crucial of which is the calculation result of the positioning deviation value Δ. Internally, after each rotation stops, the logic control module calculates the deviation Δ between the actual stopping position and the target casting position and compares it with a preset threshold ε. If Δ > ε, the PLC sends a specific trigger signal to the alarm module. Upon receiving this signal, the alarm module immediately executes preset actions on the HMI interface, such as: popping up a red alarm window displaying the text "Positioning deviation too large"; changing an indicator light icon on the screen from green to red and flashing; playing an alarm voice message through the industrial computer's sound card; or even writing the alarm record to a historical database. These are all specific forms of issuing an "alarm signal."

[0064] By setting up an alarm module in the host computer monitoring system, an alarm signal is issued when the deviation between the actual stop position of the ladle rotary table and the casting position exceeds a preset threshold, thereby improving the monitoring capability of the positioning accuracy of the ladle rotary table.

[0065] In some embodiments, the programmable logic controller program is implemented using a modular programming approach, including a main program module, a data acquisition module, a distance calculation module, and a logic control module. The main program module is used to sequentially call the data acquisition module, the distance calculation module, and the logic control module.

[0066] It should be understood that this is a detailed description of the PLC's internal software architecture. In Siemens STEP7 programming software, the control program of this invention does not employ chaotic linear programming, but rather an advanced modular / structured programming method. The program is clearly decomposed into several independent, single-function logic blocks: the main program module [OB1] is the entry point and organizer of the entire program; it does not execute specific control logic itself. The data acquisition module (possibly a function block FB or function FC) encapsulates all instructions for communicating with the inverter, reading speed, and storing data. The distance calculation module (another FB / FC) encapsulates all algorithms for unit conversion, distance accumulation, and data updates. The logic control module (yet another FB / FC) encapsulates all logic for comparison and judgment, and issuing deceleration / stop commands. In each program scan cycle, the main program module OB1 calls the data acquisition module, distance calculation module, and logic control module in a fixed order, forming an ordered, highly cohesive, and loosely coupled program structure.

[0067] By adopting a modular programming approach to implement the programmable logic controller (PLC) program, the main program module is configured to call the data acquisition module, distance calculation module, and logic control module in sequence, thereby improving the development efficiency and maintainability of the PLC program.

[0068] In some embodiments, the fieldbus is a PROFIBUS-DP bus.

[0069] It should be understood that PROFIBUS-DP (Decentralized Periphery) is a fieldbus standard widely used in factory automation, renowned for its high speed, real-time performance, reliability, and openness. In this device, both the PLC and the frequency converter are equipped with communication interfaces compliant with the PROFIBUS-DP standard. They are connected via shielded twisted-pair cables, forming a master-slave communication network. The PLC acts as the DP master, controlling communication on the network; the frequency converter acts as the DP slave, sending data only when requested by the master. All data related to frequency converter control, such as control words, status words, set speeds, and actual speeds, are exchanged periodically or aperiodically through this DP network.

[0070] By specifically configuring the fieldbus as a PROFIBUS-DP bus, the reliability of data transmission during the rotation and positioning of the large package rotary table is improved.

[0071] As can be seen from the above technical solutions, the embodiments of this application provide a method and device for positioning the ladle turret of a continuous casting machine. The method involves controlling the rotation of the ladle turret's rotary motor via a frequency converter; collecting the instantaneous speed value of the frequency converter via a fieldbus at fixed intervals using a programmable logic controller (PLC); calculating the instantaneous rotation distance of the ladle turret within the current cycle based on the collected instantaneous speed value and the fixed cycle; accumulating the instantaneous rotation distances from the start of rotation to the current moment to obtain the actual rotation distance of the ladle turret; comparing the actual rotation distance with a preset deceleration position distance value; sending a deceleration command to the frequency converter via the PLC based on the comparison result of the actual rotation distance reaching the deceleration position distance value, thereby switching the ladle turret from high-speed rotation to low-speed rotation; comparing the actual rotation distance with a preset casting position distance value; and sending a stop command to the frequency converter via the PLC based on the comparison result of the actual rotation distance reaching the casting position distance value, thereby stopping the ladle turret at the casting position. This method effectively solves the problem of inaccurate positioning of the ladle turret's rotation.

Claims

1. A method for positioning the ladle turret of a continuous casting machine, characterized in that, include: The rotary motor of the large bag turntable is controlled by a frequency converter. The instantaneous speed value of the frequency converter is acquired at fixed intervals via a fieldbus through a programmable logic controller; Based on the collected instantaneous rotational speed value and the fixed period, the instantaneous rotational distance of the large bag rotary table within the current period is calculated; The actual rotation distance of the large bag turntable is obtained by summing the instantaneous rotation distance from the start of rotation to the current moment; The actual rotation distance is compared with the preset deceleration position distance value; Based on the comparison result of the actual rotation distance reaching the deceleration position distance value, the programmable logic controller sends a deceleration command to the frequency converter to switch the large package rotary table from high-speed rotation to low-speed rotation. The actual rotation distance is compared with the preset casting position distance value; Based on the comparison result of the actual rotation distance reaching the distance value of the casting position, the programmable logic controller sends a stop command to the frequency converter to stop the ladle rotary table at the casting position.

2. The positioning method for the ladle turret of a continuous casting machine according to claim 1, characterized in that, Also includes: The host computer monitoring system displays the real-time operating status, rotation speed, and actual rotation distance of the ladle rotary table, and receives modification commands for the deceleration position distance value or the casting position distance value through the human-machine interface of the host computer monitoring system.

3. The method for positioning the ladle turret of a continuous casting machine according to claim 1, characterized in that, Also includes: The deviation between the actual position of the ladle rotary table after it stops and the casting position is calculated, and the deviation is compared with a preset allowable error range. If the deviation exceeds the allowable error range, an alarm is issued through the host computer monitoring system.

4. The method for positioning the ladle turret of a continuous casting machine according to claim 1, characterized in that, The step of acquiring the instantaneous speed value of the frequency converter via the programmable logic controller and fieldbus at fixed intervals includes: reading real-time speed data from the frequency converter via the PROFIBUS-DP fieldbus and storing the real-time speed data in the data block of the programmable logic controller.

5. A positioning device for the position of the ladle turret of a continuous casting machine, characterized in that, The device for positioning the ladle turret of a continuous casting machine as described in any one of claims 1 to 4 includes: A programmable logic controller, comprising a data acquisition module, a distance calculation module, and a logic control module; A frequency converter, wherein the frequency converter is communicatively connected to the programmable logic controller via a fieldbus; A rotary motor, which is electrically connected to the frequency converter and connected to the mechanical transmission mechanism of the large-bag rotary table through a reduction gearbox; The data acquisition module is used to acquire instantaneous speed values ​​from the frequency converter at fixed intervals via the fieldbus; The distance calculation module is used to calculate the instantaneous rotation distance based on the instantaneous rotation speed value and the fixed period, and to accumulate the instantaneous rotation distance to obtain the actual rotation distance; The logic control module is used to compare the actual rotation distance with the preset deceleration position distance value and the casting position distance value, and send a deceleration command or a stop command to the frequency converter through the fieldbus according to the comparison result.

6. The positioning device for the position of the ladle turret of a continuous casting machine according to claim 5, characterized in that, It also includes a host computer monitoring system, which is communicatively connected to the programmable logic controller. The host computer monitoring system is used to provide a human-machine interface to display the rotation status, rotation speed and actual rotation distance of the large package rotary table.

7. The positioning device for the position of the ladle turret of a continuous casting machine according to claim 6, characterized in that, The host computer monitoring system is also used to receive input parameter modification instructions through the human-machine interface, and send the modified deceleration position distance value or casting position distance value to the programmable logic controller.

8. The positioning device for the position of the ladle turret of a continuous casting machine according to claim 6, characterized in that, The host computer monitoring system also includes an alarm module, which is used to issue an alarm signal when the deviation between the actual stop position of the ladle rotary table and the casting position exceeds a preset threshold.

9. The positioning device for the position of the ladle turret of a continuous casting machine according to claim 5, characterized in that, The programmable logic controller (PLC) is implemented using a modular programming approach, including a main program module, a data acquisition module, a distance calculation module, and a logic control module. The main program module is used to sequentially call the data acquisition module, the distance calculation module, and the logic control module.

10. The positioning device for the position of the ladle turret of a continuous casting machine according to claim 5, characterized in that, The fieldbus is the PROFIBUS-DP bus.

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