Automatic calibration device and method for laser slab sizing

Abstract

The invention discloses an automatic calibration device and method for laser slab sizing, and the device consists of a laser range finder, an encoder, a steel wire rope, a hook, a hook positioning cone, a spring winding drum and the like, and is integrally installed on a cutting gun. Full-automatic calibration of the plate blank sizing process is achieved through the PLC program control module and the HMI, and repeated measurement conducted in the high-temperature, dust and noise environment by workers is not needed. The hook is fixed in a magnetic attraction mode, stable attachment can be kept in the slab moving process or the equipment vibration process, position deviation is prevented, and it is ensured that the measuring benchmark is consistent. The steel wire rope protection tube and the fixing hoop structure effectively reduce swing and abrasion, improve the measurement stability of the encoder and prolong the service life of the encoder. The system has a one-key calibration function and can automatically complete slab movement, positioning, data acquisition and angle calculation, manual intervention is not needed in the whole process, and the calibration precision and the production efficiency are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of calibration technology, specifically to an automatic calibration device and method for laser slab length measurement. Background Technology

[0002] In continuous casting of steel, before the long slabs (master slabs) cast and straightened at high temperature are cut into short billets (sub-bills), the master slabs must be precisely measured and positioned using a laser rangefinder and laser length-finding software. The laser rangefinder can be installed at the head or tail end of the master slab, and its laser beam is directed at a certain angle. When the master slab is conveyed to the cutting area along the continuous casting direction and is ready for positioning and cutting, it is necessary to ensure that the laser spot continuously illuminates the cross-section of the master slab. The laser length-finding software automatically calculates and determines the precise position of the master slab in the cutting system based on the length value D obtained in real time by the rangefinder and the pre-calibrated data in the system.

[0003] However, due to harsh on-site conditions, such as long-term equipment vibration or mechanical collisions, the installation angle or position of the laser rangefinder is prone to shift, severely affecting measurement accuracy. To ensure the reliability of laser positioning, the laser rangefinder needs to be recalibrated after displacement or operation for a period of time; otherwise, the cutting error will increase, affecting the quality of the blank.

[0004] Existing calibration methods primarily rely on manual operation, typically requiring the use of a measuring tape or handheld laser rangefinder to manually measure the distance from the laser point to the center of the cutting nozzle of the flame cutter within the cutting area. This distance is then matched and recorded with the rangefinder readings. The entire process demands the coordinated efforts of multiple personnel, including roller conveyor operators, power supply and shutdown personnel, measurement personnel, and safety supervisors. Furthermore, to ensure data accuracy, several sets of measurement data are usually required, necessitating multiple power outages, power restorations, and billet movements. Measurement personnel also repeatedly need to enter high-risk work areas. Due to the presence of roller conveyors, grooves, and harmful gases within the cutting area, the calibration process presents significant personal safety hazards and exhibits low overall efficiency. Summary of the Invention

[0005] This invention provides an automatic laser slab length calibration device and method. Existing laser slab length calibration methods largely rely on manual operation, requiring machine shutdown for measurement and adjustment. This is not only inefficient and labor-intensive but also susceptible to errors due to human factors. Furthermore, in harsh environments such as high temperature, dust, and equipment vibration, the hook positioning is prone to loosening, leading to instability and decreased accuracy in the calibration process. This invention aims to provide an automatic laser slab length calibration device and method that achieves automated calibration and maintains reliable connection and measurement accuracy under high temperature, dust, and vibration conditions.

[0006] This invention provides an automatic calibration device for laser slab length measurement, including a laser rangefinder and an automatic calibration mechanism mounted on a cutting gun; The automatic calibration mechanism includes an encoder, a control mechanism, a hook positioning cone, a hook, a wire rope, and a spring drum; The hook is magnetic and is used to adhere and position itself to the end face of the slab. The hook positioning cone is installed between the upper part of the hook and the wire rope; The other end of the wire rope is connected to the spring drum, which is used to wind up and unwind the wire rope and drive the encoder to operate through traction, outputting a signal to calculate the displacement.

[0007] Preferably, the automatic calibration device further includes an encoder digital display and an encoder bracket.

[0008] Preferably, a wire rope protective tube is provided on the outside of the wire rope, the center line of the wire rope protective tube is parallel to the center line of the cutting gun nozzle, and the wire rope protective tube is fixed to the east or west side of the cutting gun by a protective tube fixing clamp.

[0009] Preferably, the control mechanism includes a PLC program control module and an HMI human-machine interface. The control module has one-click calibration control logic and supports automatic execution of slab movement, positioning, data recording and angle calculation processes.

[0010] On the other hand, the present invention provides an automatic calibration method for laser slab length measurement, which uses the aforementioned automatic calibration device for calibration. The specific steps are as follows: S100 Adjust the position of the hook so that the hook hooks onto the end face of the slab and is stably positioned; S200 starts the roller conveyor to drive the slab into the cutting area and makes the laser rangefinder spot continuously irradiate the end face of the slab. After the S300 slab stops moving, the control mechanism records the laser ranging value D1 and the encoder displacement value L1. S400 Repeat steps S100 to S300 to collect multiple sets of Di and Li data at different locations; The control mechanism in S500 automatically calculates the laser irradiation angle and completes the calibration based on the data.

[0011] Preferably, the adjustment of the hook position in step S100 includes the adjustment of the hook angle.

[0012] Preferably, step S400 involves collecting at least 6 sets of valid data.

[0013] Preferably, the method further includes an automatic calibration mode, in which the system automatically controls the movement, stopping and data acquisition of the slab after the operator triggers a one-click calibration command through the HMI, until the data acquisition is completed and the angle result is automatically calculated.

[0014] Beneficial effects: This invention provides an automatic calibration device and method for laser slab length measurement. By integrating a laser rangefinder, encoder, magnetic hook, hook positioning cone, and spring drum onto a cutting gun, and combining a PLC program control module and HMI human-machine interface, the invention achieves fully automated calibration of the slab length measurement process. This eliminates the need for repeated manual entry into high-temperature, dusty, and noisy environments for measurement, avoiding safety hazards and production downtime caused by manual operation. The hook uses a magnetic fixing method, maintaining a stable connection even during high-speed slab movement, production line vibration, or impact, significantly reducing the risk of loosening, misalignment, or data interruption. The hook positioning cone, through its own weight, ensures stable contact between the hook and the slab end face throughout the calibration process, preventing hook position displacement due to wire rope tension or equipment vibration, thus guaranteeing accurate and consistent measurement reference. The wire rope protective tube and its fixing clamp effectively reduce wire rope sway and wear during operation, improving the stability and long-term service life of the encoder data acquisition. The one-click calibration function can automatically drive the slab movement, automatically position, automatically record multiple sets of distance and displacement data, and automatically calculate the laser irradiation angle without stopping the machine. The entire process requires no manual intervention, significantly shortening calibration time, reducing worker labor intensity, minimizing human error, and improving calibration accuracy and overall production line operating efficiency. The system has a compact structure, strong adaptability, and can be directly deployed in existing production lines, possessing high industrial application value and promising prospects for widespread adoption. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 Example 1: Automatic calibration device for laser slab length setting.

[0017] 1-Encoder digital display, 2-Encoder, 3-Spring drum, 4-Protective tube fixing clamp, 5-Encoder bracket, 6-Wire rope protective tube, 7-Wire rope, 8-Hook positioning cone, 9-Hook. Detailed Implementation

[0018] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments, but the scope of protection of the present invention is not limited to the content.

[0020] On the one hand, the present invention provides an automatic calibration device for laser slab length setting, such as... Figure 1 As shown, it includes a laser rangefinder and an automatic calibration mechanism mounted on the cutting gun.

[0021] The automatic calibration mechanism includes an encoder 2, a PLC control module, an HMI human-machine interface, a hook 9, a hook positioning cone 8, a wire rope 7, a spring drum 3, and a wire rope protection tube 6.

[0022] The automatic calibration device also includes an encoder digital display 1 and an encoder bracket 5.

[0023] The hook 9 is made of high-strength magnetic material, and the front end of the hook 9 is machined into an arc shape so as to hook onto the end face of the slab. The hook 9 is connected to the encoder 2 by a steel wire rope 7. When the slab moves on the roller conveyor, the steel wire rope 7 drives the central shaft of the encoder 2 to rotate and output a displacement signal.

[0024] In detail, the hook 9 can be made of high-strength magnetic material, including neodymium iron boron permanent magnet alloy, rare earth permanent magnet steel, etc. In the continuous casting site, the slab temperature is high, and the surface has oxide scale or minor impacts. The material must have high tensile strength, impact toughness, and high-temperature demagnetization resistance. The high-strength magnetic material used in this invention can ensure sufficient mechanical strength to withstand the tensile and impact loads when the slab moves. On the other hand, the strong magnetic force can enable the hook 9 to quickly and stably attach and position itself when it contacts the end face of the slab.

[0025] In detail, hook 9 is connected to the central shaft of encoder 2 via wire rope 7, and the central shaft of encoder 2 is coaxially fixed with spring drum 3. When the slab moves along the conveying direction under the drive of the roller conveyor, hook 9 generates linear displacement, which is transmitted to encoder 2 via wire rope 7. Encoder 2 outputs pulse signals, and PLC calculates the actual distance L moved by the slab by counting the number of pulses and the linear displacement corresponding to each revolution.

[0026] The angle of hook 9 is adjustable.

[0027] In detail, hook 9 is designed with an adjustable angle to adapt to different shapes and cutting angles of slab end faces. The angle of hook 9 is adjusted via a hinge or rotating connector, allowing operators to adjust the angle between hook 9 and the slab end face according to actual needs, ensuring that hook 9 fits tightly against the slab end face.

[0028] The hook positioning cone 8 is installed between the upper part of the hook 9 and the wire rope 7.

[0029] In detail, the hook positioning cone 8 is a key positioning component in the overall calibration device. It is mainly used to achieve a precise and stable mechanical connection between the hook 9 and the end face of the slab. The hook positioning cone 8 keeps the wire rope 7 taut, preventing uneven winding during the winding process. Uneven winding of the wire rope 7 will directly lead to inaccurate displacement data measured by the encoder 2, thus affecting the calibration accuracy. The hook positioning cone 8 in this invention ensures that the wire rope 7 is always under uniform force and tension, ensuring stable and reliable displacement signals acquired by the encoder 2. Therefore, the hook positioning cone 8 is a core component ensuring a stable connection between the hook 9 and the slab, and is also an important guarantee for improving the measurement accuracy of the laser ranging system and the smooth implementation of the automatic calibration process.

[0030] The spring drum 3 is installed above the steel rope protection tube and is used to wind and retrieve the steel wire rope 7, ensuring that the steel wire rope 7 maintains a constant tension throughout the calibration process. This effectively prevents the steel wire rope 7 from becoming slack or excessively tight during the movement of the slab, thereby avoiding measurement errors caused by slack in the steel wire rope 7 and ensuring the accuracy and reliability of the displacement signal transmitted by the encoder 2. The drum has a built-in spring, which automatically adjusts the tension of the steel wire rope 7 through the spring force, allowing the steel wire rope 7 to be smoothly wound and unwound as the length of the slab changes.

[0031] A wire rope protective tube 6 is fitted over the wire rope 7, with its centerline parallel to the centerline of the cutting gun nozzle. It is fixed to the east or west side of the cutting gun using a wire rope protective tube fixing clamp 4. Specifically, the wire rope protective tube 6 is fitted over the wire rope 7, with its centerline parallel to the centerline of the cutting gun nozzle. This ensures that the wire rope 7 moves smoothly along a straight line throughout the entire movement, avoiding measurement errors caused by deviations in the wire rope 7's trajectory. The parallel arrangement reduces bending and friction of the wire rope 7, improving the accuracy and stability of the displacement signal acquired by the encoder 2. Regarding the installation position of the protective tube, the conveying direction of the roller conveyor at the cutting site is generally east-west, while the cutting gun moves north-south. To avoid interference with the normal operation of the cutting gun, the protective tube is fixed to the east or west side of the cutting gun. This installation method ensures the stability and protective effect of the protective tube without hindering the free movement and operation of the cutting gun.

[0032] The control mechanism includes a PLC program control module and an HMI human-machine interface. The control module has one-click calibration control logic and supports automatic execution of slab movement, positioning, data recording and angle calculation processes.

[0033] In detail, the control mechanism includes a PLC program control module and an HMI (Human Machine Interface), with the PLC program control module having built-in one-key calibration control logic. This logic can automatically coordinate the movement and positioning of the slab, achieving precise displacement and laser ranging data acquisition. Encoder 2 automatically acquires displacement signals, eliminating the need for manual measurement of the distance from the laser point to the center point of the cutting torch nozzle using a tape measure or handheld laser, greatly simplifying the measurement process. Through the HMI, only one person is needed to complete the entire calibration process on the computer in the control room, eliminating the need for multiple people on-site and avoiding the tediousness and danger of repeatedly stopping and starting power and personnel repeatedly entering the cutting area to measure data. The system can automatically measure the distance from the laser point to the center point of the cutting torch nozzle, effectively eliminating the threat to the personal safety of calibration personnel posed by hazardous environments such as roller conveyors, ditches, and harmful gases. The automatic data recording function avoids the negligence and errors that may occur with manual input, ensuring the accuracy and stability of the system measurement and improving the efficiency and reliability of calibration.

[0034] In summary, this technical solution achieves high-precision automatic calibration of laser slab dimensions by integrating a laser rangefinder, encoder 2, and automatic calibration device. The encoder 2 automatically acquires displacement signals through the linkage of hook 9 and wire rope 7, eliminating the tediousness and errors of traditional manual measurement and greatly improving measurement accuracy and repeatability. The hook positioning cone 8 ensures a stable and reliable connection between hook 9 and the slab end face, effectively absorbing impact forces and keeping the wire rope 7 taut, avoiding signal deviation. The wire rope protection tube 6 enhances the durability and stability of the device in high-temperature spark and dust environments. The control mechanism incorporates a PLC program and human-machine interface, enabling one-click automatic calibration, reducing manual operation steps, lowering safety risks for on-site personnel, and improving operational convenience and system automation. The overall solution not only improves calibration efficiency and accuracy but also ensures operational safety and long-term stable operation of the equipment, demonstrating significant application value and promising prospects for widespread adoption.

[0035] On the other hand, the present invention provides an automatic calibration method for laser slab length measurement, which uses an automatic calibration device for calibration. The specific steps are as follows: S100 Adjust the angle of hook 9 so that hook 9 hooks onto the end face of the slab and is stably positioned; S200 starts the roller conveyor to drive the slab into the cutting area and makes the laser rangefinder spot continuously irradiate the end face of the slab. After the S300 slab stops moving, the control mechanism records the laser ranging value D1 and the encoder 2 displacement value L1; S400 Repeat steps S100 to S300 to collect at least 6 sets of valid data Di and Li data at different locations; The control mechanism in S500 automatically calculates the laser irradiation angle and completes the calibration based on the data.

[0036] The automatic laser slab length calibration method proposed in this invention is based on the collaborative working principle of an automatic calibration device, a laser rangefinder, an encoder 2, and a control mechanism. Its basic principle is to use a hook 9 linked to a wire rope 7 and an encoder 2 to acquire displacement signals in real time during slab movement, while the laser rangefinder collects the laser distance value from the slab end face. Through the corresponding acquisition and calculation of multiple sets of data, the laser illumination angle can be accurately determined, achieving the calibration of the laser rangefinder system. The advantage of this method is that the hook 9 ensures the laser spot remains stably applied to the slab end face, avoiding the uncertainties of manual measurement, and the automated control system enables full-process control of slab movement, positioning, data recording, and calculation. Compared to traditional manual calibration methods, this method eliminates the need for personnel to carry measuring tapes or handheld lasers to the site, avoids the need for multiple personnel collaboration and repeated power outages and re-energizations, and allows calibration personnel to complete the operation simply by triggering a one-click calibration command through an HMI interface in the control room. It can automatically, quickly, and accurately calibrate the distance from the laser point to the center point of the cutting gun nozzle, greatly improving measurement efficiency and accuracy, avoiding human input errors, and ensuring consistent results. At the same time, it effectively eliminates safety hazards of personnel entering roller conveyors, ditches, and high-temperature and harmful gas environments, significantly improving the system's automation level and operational safety.

[0037] Example 1 This invention provides an automatic calibration device for laser slab length measurement, including a laser rangefinder and an automatic calibration mechanism mounted on a cutting gun; the automatic calibration mechanism includes an encoder 2, a PLC control module, an HMI human-machine interface, a hook 9, a hook positioning cone 8, a wire rope 7, a spring drum 3, a wire rope protection tube 6, an encoder digital display 1, and an encoder bracket 5.

[0038] The hook 9 is made of neodymium iron boron permanent magnet alloy. The front end of the hook 9 is machined into an arc shape so as to hook onto the end face of the slab. The hook 9 is connected to the encoder 2 by a steel wire rope 7. The hook positioning cone 8 keeps the steel wire rope 7 taut at all times to avoid displacement signal errors caused by uneven winding.

[0039] Hook 9 adopts an angle-adjustable structure, and the included angle can be adjusted from 0 to 60° through a hinge connection.

[0040] The other end of the wire rope 7 is wound in the spring drum 3, which maintains a constant tension in the wire rope 7 and prevents slack from occurring during the movement of the slab. A wire rope protective tube 6 is installed on the outside of the wire rope 7. The center line of the wire rope protective tube 6 is parallel to the center line of the cutting gun nozzle. The wire rope protective tube 6 is installed on the east side of the cutting gun through a protective tube fixing clamp 4, thereby reducing wear on the wire rope 7 caused by sparks, high temperature and dust.

[0041] When the wire rope 7 is pulled, it works in conjunction with the spring drum 3 to drive the central shaft of the encoder 2 to rotate and output a displacement signal.

[0042] The control mechanism consists of a PLC program control module and an HMI (Human-Machine Interface). The PLC has one-button calibration logic, which can automatically control the roller conveyor to drive the slab movement, positioning, and data acquisition. The HMI interface allows operators to start the calibration process with one click. The entire process eliminates the need for manual measurement with a measuring tape or handheld laser; calibration personnel only need to complete the operation on the computer in the control room, avoiding repeated entry into the cutting area and improving safety.

[0043] The calibration was performed using a laser slab length-fixing automatic calibration device. The specific calibration method is as follows: S100: Adjust the angle of hook 9 so that hook 9 hooks onto the end face of the slab and is stably positioned; S200: Start the roller conveyor to drive the slab into the cutting area and make the laser rangefinder spot continuously irradiate the end face of the slab.

[0044] S300: When the slab stops moving, the system automatically records the laser ranging value D1 and the encoder 2 displacement value L1.

[0045] S400: Repeat S100 to S300 to collect 6 sets of Di and Li data at different locations. S500: The control mechanism automatically calculates the laser irradiation angle and completes the calibration based on the data.

[0046]

[0047] This embodiment enables automatic calibration of the distance from the laser point to the center point of the cutting gun nozzle without anyone entering the cutting site, ensuring the accuracy of the measurement results. The difference between the six angle coefficients measured and calculated by the improved encoder 2 is smaller than that of the six angle coefficients measured and calculated manually with a tape measure, and the average value is more stable. The coefficients measured and calculated by the encoder 2 are more accurate, improving calibration efficiency and eliminating the safety hazards to personnel posed by dangerous environments such as roller conveyors, ditches, and harmful gases.

[0048] Example 2 This embodiment is basically the same as the automatic calibration device and method for laser slab length measurement in Embodiment 1. The difference is that the data measured in Embodiment 1 is the selective calibration during the slab retraction process, while in Embodiment 2 it is the selective calibration during the forward movement process.

[0049] This demonstrates that, regardless of whether the slab is moving forward or backward, the device and method of this invention can obtain stable and accurate displacement values, thereby enabling the calculation of more accurate angle coefficients.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An automatic laser slab length calibration device, characterized in that, Includes a laser rangefinder and an automatic calibration mechanism mounted on the cutting gun; The automatic calibration mechanism includes an encoder, a control mechanism, a hook positioning cone, a hook, a wire rope, and a spring drum; The hook is magnetic and is used to adhere and position itself to the end face of the slab. The hook positioning cone is installed between the upper part of the hook and the wire rope; The other end of the wire rope is connected to the spring drum, which is used to wind up and unwind the wire rope and drive the encoder to operate through traction, outputting a signal to calculate the displacement.

2. The automatic calibration device according to claim 1, characterized in that, The automatic calibration device also includes an encoder digital display and an encoder bracket.

3. The automatic calibration device according to claim 1, characterized in that, The wire rope is provided with a wire rope protection tube on the outside.

4. The automatic calibration device according to claim 1, characterized in that, The centerline of the wire rope protection tube is parallel to the centerline of the cutting gun nozzle.

5. The automatic calibration device according to claim 1, characterized in that, The wire rope protection tube is fixed to the east or west side of the cutting gun by a protection tube fixing clamp.

6. The calibration device according to claim 1, characterized in that, The control mechanism includes a PLC program control module and an HMI human-machine interface. The control module has one-click calibration control logic and supports automatic execution of slab movement, positioning, data recording and angle calculation processes.

7. A method for automatic calibration of laser slab dimensions, comprising using the automatic calibration device described in any one of claims 1-6, characterized in that, The specific steps are as follows: S100 Adjust the position of the hook so that the hook hooks onto the end face of the slab and is stably positioned; S200 starts the roller conveyor to drive the slab into the cutting area and makes the laser rangefinder spot continuously irradiate the end face of the slab. After the S300 slab stops moving, the control mechanism records the laser ranging value D1 and the encoder displacement value L1. S400 Repeat steps S100 to S300 to collect multiple sets of Di and Li data at different locations; The control mechanism in S500 automatically calculates the laser irradiation angle and completes the calibration based on the data.

8. The automatic calibration method according to claim 7, characterized in that, The adjustment of the hook position in step S100 includes the adjustment of the hook angle.

9. The automatic calibration method according to claim 7, characterized in that, In step S400, at least 6 sets of valid data are collected.

10. The automatic calibration method according to claim 7, characterized in that, The method further includes an automatic calibration mode. After the operator triggers a one-click calibration command through the HMI, the system automatically controls the movement, stopping, and data acquisition of the slab until the acquisition is completed and the angle result is automatically calculated.

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