Method for measuring size of hot-rolled bar

Abstract

The invention discloses a method for measuring the size of a hot-rolled bar, and relates to the technical field of optical precision measurement, and the method comprises the steps: mixing high-cadmium core-shell quantum dots with a high-temperature-resistant ceramic adhesive, and spraying the mixture to the surface of the hot-rolled bar to form a hot-rolled bar with a fluorescent mark; the method comprises the following steps of: exciting fluorescence by irradiating a hot-rolled bar with a fluorescence mark through laser, and penetrating an oxide layer by utilizing vortex laser to generate a double-spectrum signal; capturing the terahertz phase distortion in the dual-spectrum signal, and separating the fluorescence peak wavelength of the quantum dots through a narrow-band filter; inversely solving the surface temperature of the hot-rolled bar according to the fluorescence peak wavelength of the quantum dots, and calculating the thickness of an oxide layer; according to the method, the terahertz phase distortion amount and the vibration characteristics are analyzed, the piezoelectric ceramic fast reflecting mirror is driven to implement millisecond-level light path dynamic compensation, and active image stabilization of the measured light spots is achieved; the composite interference of high temperature, oxidation, vibration and the like is effectively overcome.

Description

Technical Field

[0001] This invention relates to the field of optical precision measurement technology, and in particular to a method for measuring the dimensions of hot-rolled bars. Background Technology

[0002] In modern metallurgical industry, hot-rolled bars are widely used as important basic materials in fields such as construction, machinery manufacturing, and transportation. Dimensional accuracy directly affects the quality of subsequent processing and product performance. With the development of intelligent manufacturing and online inspection technologies, non-contact dimensional measurement technology has gradually become a key link in the automated control of hot-rolling production lines. Online diameter measurement systems based on the combination of laser triangulation and infrared thermometry have been applied in some steel plants. By acquiring the profile information of the bar through multi-angle laser scanning and combining it with infrared radiation thermometry to calculate the thermal expansion coefficient of the material, dynamic diameter measurement can be achieved. This method improves the measurement response speed and environmental adaptability to a certain extent, especially under complex working conditions such as high temperature and high dust, showing better stability than traditional contact measurement. In recent years, terahertz time-domain spectroscopy (THz-TDS) technology has also been explored for non-destructive testing of metal surface conditions due to its good penetration ability of non-polar materials and oxide layers, providing a new technical path for multi-physics field fusion measurement.

[0003] In actual high-temperature rolling environments, existing measurement technologies still face the problem of combined interference caused by the dynamic formation of oxide layers on material surfaces and the coupling of mechanical vibrations in the production line. The continuously forming iron oxide scale on the surface of hot-rolled bars not only produces strong scattering and absorption effects on visible and near-infrared wavelengths, affecting the signal-to-noise ratio of optical signals, but its time-varying thickness also alters the thermal radiation characteristics of the material, thus introducing temperature inversion errors. The unavoidable mechanical vibrations during the operation of production line equipment can cause optical axis offset in optical measurement systems, resulting in drift in spatial sampling coordinates. If data calculation is performed solely based on static calibration parameters, the long-term stability and repeatability of dimensional measurements will be significantly reduced. Although some systems attempt to introduce inertial navigation units or active alignment mechanisms to suppress the effects of vibration, their compensation strategies often fail to fully consider the impact of oxide layers on photothermal transmission characteristics, leading to systematic deviations between the compensation model and the actual physical field. Summary of the Invention

[0004] In view of the aforementioned existing problems, the present invention is proposed.

[0005] Therefore, this invention provides a method for measuring the dimensions of hot-rolled bars to solve the problem of achieving high-precision and interference-resistant online dimension measurement under high-temperature dynamic conditions.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0007] In a first aspect, the present invention provides a method for measuring the dimensions of hot-rolled bars, comprising: mixing high-cadmium core-shell quantum dots with a high-temperature resistant ceramic binder and spraying the mixture onto the surface of a hot-rolled bar to form a hot-rolled bar with a fluorescent mark; irradiating the hot-rolled bar with the fluorescent mark with a laser to excite fluorescence, while simultaneously using a vortex laser to penetrate the oxide layer to generate a dual-spectral signal; capturing the terahertz phase distortion variable in the dual-spectral signal and separating the peak wavelength of the quantum dot fluorescence using a narrow-band filter; reversing the surface temperature of the hot-rolled bar based on the peak wavelength of the quantum dot fluorescence and calculating the oxide layer thickness; inputting the terahertz phase distortion variable and the oxide layer thickness into a piezoelectric ceramic fast-reflection mirror controller to generate a driving voltage; driving the mirror deflection angle to compensate for vibration errors using the driving voltage and outputting the corrected spot coordinates; and calculating the diameter of the hot-rolled bar based on the corrected spot coordinates.

[0008] In a preferred embodiment of the hot-rolled bar dimensional measurement method of the present invention, the steps of mixing high-cadmium core-shell quantum dots with a high-temperature resistant ceramic binder and spraying the mixture onto the surface of the hot-rolled bar to form a hot-rolled bar with fluorescent markings are as follows.

[0009] High-cadmium core-shell quantum dots are mixed with a high-temperature resistant ceramic binder to form a quantum dot composite slurry;

[0010] The surface of the hot-rolled bar is sandblasted and activated to generate a roughened and clean surface. Quantum dot composite slurry is then uniformly sprayed onto the roughened and clean surface to form a wet coating.

[0011] The wet coating is heated and cured, and its temperature-sensitive fluorescence properties are activated to form hot-rolled bars with fluorescent markings.

[0012] In a preferred embodiment of the hot-rolled bar dimensional measurement method of the present invention, the steps of exciting fluorescence by irradiating the hot-rolled bar with fluorescent markings using laser, and simultaneously using a vortex laser to penetrate the oxide layer to generate a dual-spectral signal, are as follows:

[0013] The surface of a hot-rolled bar with fluorescent markings is vertically irradiated with a semiconductor laser beam to excite cadmium selenide zinc sulfide zinc core-shell quantum dots, generating characteristic fluorescent bands;

[0014] A vortex laser beam is emitted synchronously, penetrating the oxide layer on the surface of hot-rolled bar to generate a terahertz carrier wave;

[0015] Based on the characteristic fluorescence band and terahertz carrier, a dual-spectral signal is output through spatial matching spectral fusion of dual-ring focal spots.

[0016] In a preferred embodiment of the hot-rolled bar dimension measurement method of the present invention, the steps for capturing the terahertz phase distortion in the dual-spectral signal and separating the quantum dot fluorescence peak wavelength using a narrow-band filter are as follows:

[0017] The terahertz carrier signal and quantum dot fluorescence optical signal are separated based on the dual-spectral signal. The vortex laser component in the terahertz carrier signal is analyzed by the orbital angular momentum sensor to obtain the terahertz phase distortion.

[0018] In a narrowband tunable filter, the visible light frequency band quantum dot fluorescence component in the quantum dot fluorescence optical signal is filtered out to obtain the peak wavelength of quantum dot fluorescence.

[0019] As a preferred embodiment of the hot-rolled bar dimension measurement method of the present invention, the specific steps for calculating the surface temperature of the hot-rolled bar based on the quantum dot fluorescence peak wavelength and calculating the oxide layer thickness are as follows:

[0020] Based on quantum dot composite slurry, within a set range covering the typical temperature range of hot rolling, the quantum dot composite slurry is subjected to isothermal residence in a gradient manner.

[0021] The measured temperature values ​​were collected, and the linear correlation between the quantum dot fluorescence peak wavelength and the measured temperature values ​​was fitted by statistical analysis to obtain the temperature-sensitive characteristic equation.

[0022] Substitute the peak wavelength of quantum dot fluorescence into the temperature-sensitive characteristic equation to calculate the surface temperature of hot-rolled bars;

[0023] Record the cumulative hot rolling time on the production line, input the surface temperature of the hot-rolled bar and the cumulative hot rolling time on the production line into the oxide layer thickness growth model, and generate the oxide layer thickness through the oxidation growth kinetic equation.

[0024] In a preferred embodiment of the hot-rolled bar dimension measurement method of the present invention, the steps of inputting the terahertz phase distortion and oxide layer thickness into the piezoelectric ceramic fast-reflection mirror controller to generate a driving voltage are as follows:

[0025] Based on the terahertz phase distortion and oxide layer thickness, the comprehensive error is obtained through the comprehensive error calculation formula.

[0026] Two consecutive cycles of terahertz phase distortion were collected. The terahertz phase distortion of the first cycle and the terahertz phase distortion of the second cycle were combined into a calculation pair. The instantaneous change rate of the oxide layer was calculated using the phase change rate formula, and then a fourth-order moving average filter was applied to obtain the filtered phase change rate.

[0027] Mechanical vibration signals are collected and subjected to fast Fourier transform spectrum analysis to extract the characteristic values ​​of the main vibration frequency;

[0028] Based on the frequency range of the principal vibration frequency characteristic value, select the corresponding combination of proportional coefficient and derivative coefficient to obtain the proportional-derivative control parameter set;

[0029] The integrated error, the filtered phase change rate, and the proportional-derivative control parameter set are input into the control algorithm to generate the drive voltage.

[0030] In a preferred embodiment of the hot-rolled bar dimension measurement method of the present invention, the step of compensating for vibration errors by driving the lens deflection angle with a driving voltage and outputting the corrected light spot coordinates includes the following specific steps.

[0031] The driving voltage is amplified by high voltage to output a high voltage driving signal, which drives the piezoelectric ceramic actuator to produce axial mechanical displacement.

[0032] The axial mechanical displacement is converted into the physical deflection angle of the reflector using a conversion formula.

[0033] The position of the reflector edge is measured in real time, the deflection angle deviation value is calibrated, the calibrated deflection angle is obtained, and the theoretical offset coordinates of the beam on the focal plane are calculated.

[0034] The actual spot position coordinates are measured and compared with the theoretical offset coordinates to verify the correction accuracy, and the corrected spot coordinates are obtained.

[0035] In a preferred embodiment of the hot-rolled bar size measurement method of the present invention, the specific steps for calculating the diameter of the hot-rolled bar based on the coordinates of the corrected light spot are as follows:

[0036] The coordinates of the correction spot are transformed into the measurement coordinate system, and the measurement plane coordinates are output. The hot-rolled bar is rotated and scanned around the circumference to collect multiple sets of measurement plane coordinates and reconstruct the edge point cloud.

[0037] Perform ellipse fitting calculation on the edge point cloud and output the original diameter parameters;

[0038] Thermal expansion compensation is performed on the original diameter parameter based on the surface temperature of the hot-rolled bar to output a temperature-compensated diameter.

[0039] The rolling speed parameters of the rolling mill are acquired in real time, and motion hysteresis compensation is performed on the temperature compensation diameter based on the rolling speed parameters to output the diameter of the hot-rolled bar.

[0040] In a preferred embodiment of the hot-rolled bar dimension measurement method of the present invention, the step of selecting a corresponding combination of proportional and derivative coefficients based on the frequency range of the principal vibration frequency characteristic value to obtain a proportional-derivative control parameter set is as follows:

[0041] Vibration spectrum data and stability control parameters are collected, and a proportional-derivative parameter relationship library is established through big data regression analysis.

[0042] The main vibration frequency is collected and Fourier transform is used to generate the main vibration frequency feature value. Based on the frequency range of the main vibration frequency feature value, it is classified into low frequency band, mid frequency band and high frequency band to obtain the frequency band classification result.

[0043] Based on the frequency band classification results, the corresponding proportional coefficient and derivative coefficient combination is called from the proportional-derivative parameter relationship library to obtain the proportional-derivative control parameter group.

[0044] In a preferred embodiment of the hot-rolled bar dimension measurement method of the present invention, the specific steps for amplifying the driving voltage and outputting a high-voltage driving signal are as follows:

[0045] The driving voltage signal is filtered and denoised, and the gain is pre-adjusted to generate a pre-processed voltage signal;

[0046] The pre-processed voltage signal is input into a four-stage high-voltage drive architecture, where it undergoes high-frequency switching modulation, transformer boosting, opto-isolation conversion, and wide-bandgap semiconductor power output to generate a high-voltage drive signal.

[0047] In a second aspect, the present invention provides a computer device including a memory and a processor, wherein the memory stores a computer program, wherein when the computer program is executed by the processor, it implements any step of the hot-rolled bar dimension measurement method as described in the first aspect of the present invention.

[0048] Thirdly, the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein, when the computer program is executed by a processor, it implements any step of the hot-rolled bar dimension measurement method as described in the first aspect of the present invention.

[0049] The beneficial effects of this invention are as follows: By combining high-cadmium core-shell quantum dots with high-temperature resistant ceramic binders to form a temperature-sensitive fluorescent labeling layer, and using vortex laser to excite dual-spectral signals, synchronous and highly sensitive detection of the surface temperature and oxide layer thickness of hot-rolled bars is achieved, converting environmental interference into quantifiable information; furthermore, by analyzing terahertz phase distortion and vibration characteristics, a piezoelectric ceramic fast-reflecting mirror is driven to perform millisecond-level dynamic optical path compensation, achieving active image stabilization of the measurement spot; effectively overcoming the combined interference of high temperature, oxidation, and vibration, significantly improving the accuracy, stability, and robustness of dimensional measurement under the dynamic environment of hot rolling, and providing reliable technical support for online quality control. Attached Figure Description

[0050] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0051] Figure 1 This is a flowchart of a method for measuring the dimensions of hot-rolled bars.

[0052] Figure 2 A flowchart for forming hot-rolled bars with fluorescent markings.

[0053] Figure 3 This is a flowchart for generating a bispectral signal.

[0054] Figure 4 A flowchart for capturing phase distortion and separating peak wavelengths. Detailed Implementation

[0055] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0056] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0057] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0058] Reference Figures 1-4 As one embodiment of the present invention, this embodiment provides a method for measuring the dimensions of hot-rolled bars, including the following steps:

[0059] S1. High cadmium core-shell quantum dots are mixed with high-temperature resistant ceramic adhesive and sprayed onto the surface of hot-rolled bars to form hot-rolled bars with fluorescent markings.

[0060] High-cadmium core-shell quantum dots are mixed with high-temperature resistant ceramic binders to form quantum dot composite slurry.

[0061] Specifically, high-cadmium core-shell quantum dots and high-temperature resistant ceramic adhesive are placed in a mixing container at a mass ratio of 1:9 (example value). The mixture is stirred continuously for 10 minutes at a speed of 2000 rpm (example value) using a mechanical stirrer to form a preliminary mixture. The preliminary mixture is then transferred to an ultrasonic processor and ultrasonically treated for 5 minutes at a frequency of 40 kHz and a power of 300 watts (example value) to uniformly disperse the quantum dots in the ceramic adhesive matrix. The viscosity of the slurry is measured using a rotational viscometer and adjusted to a range of 35 ± 2 centipoise to obtain the quantum dot composite slurry.

[0062] The surface of the hot-rolled bar is sandblasted and activated to generate a roughened and clean surface. Quantum dot composite slurry is then uniformly sprayed onto the roughened and clean surface using a high-pressure airless spray gun to form a wet coating.

[0063] Specifically, the surface of the hot-rolled bar is sandblasted using 80-mesh alumina sand (example value). The sandblasting pressure is controlled at 0.6 MPa (example value), the distance between the spray gun and the surface is maintained at 200 mm (example value), and the spray gun moving speed is 0.5 m / s (example value). The treatment is carried out until the surface roughness reaches 3.2 ± 0.5 micrometers (example value). After sandblasting, the bar is preheated to 300 ± 10 degrees Celsius (example value) and kept at that temperature for 5 minutes (example value). A 2% (w / w) silane coupling agent ethanol solution is uniformly sprayed onto the surface. The quantum dot composite slurry prepared in the previous step is injected into the storage tank of the high-pressure airless spray gun. The nozzle diameter is adjusted to 0.3 mm (example value), the spraying pressure is 0.8 MPa (example value), the spray gun moving speed is 0.3 m / s (example value), and the spraying distance is 150 mm (example value). The spraying is carried out in four passes, with an interval of 1 minute between each pass using infrared drying at 120 degrees Celsius to form a wet coating.

[0064] The wet coating is heated and cured, and its temperature-sensitive fluorescence properties are activated to form hot-rolled bars with fluorescent markings.

[0065] Specifically, the previously formed wet coating is placed in a gradient temperature control furnace, and the temperature is increased from room temperature to 200 degrees Celsius at a rate of 5 degrees Celsius per minute (example value) and held for 10 minutes (example value). Then, the temperature is increased to 500 degrees Celsius at a rate of 3 degrees Celsius per minute (example value) and held for 15 minutes (example value). Finally, the temperature is increased to 800 degrees Celsius at a rate of 2 degrees Celsius per minute (example value) and held for 30 minutes (example value). After the holding period, the temperature is cooled to 300 degrees Celsius (example value) in the furnace to obtain hot-rolled bars with fluorescent markings.

[0066] S2. Fluorescence is excited by irradiating the hot-rolled bar with fluorescent markings with a laser, while a vortex laser is used to penetrate the oxide layer to generate a dual-spectral signal.

[0067] A semiconductor laser beam is used to vertically irradiate the surface of a hot-rolled bar with fluorescent markings, exciting cadmium selenide, zinc sulfide, and core-shell quantum dots to generate characteristic fluorescent bands.

[0068] Specifically, a semiconductor-pumped solid-state laser with a wavelength of 532±1 nm (example value) is vertically aligned with the surface of a hot-rolled bar with fluorescent markings. The laser output power is adjusted to 50±5 mW (example value), and the spot diameter is set to 1.5 times the diameter of the bar (example: 75 mm spot for a 50 mm bar). The laser lens is kept at a vertical distance of 100 mm (example value) from the surface of the bar. The laser beam excites energy level transitions in high-cadmium-content cadmium zinc selenide / zinc sulfide core-shell quantum dots, generating a characteristic fluorescent band with a wavelength of 635-655 nm (example value).

[0069] A synchronously emitted vortex laser beam penetrates the oxide layer on the surface of hot-rolled bar stock to generate a terahertz carrier wave.

[0070] Specifically, a 0.3 terahertz gyroscope with a topological charge of l=1 is used, and the laser is aimed at the oxide layer region on the surface of the hot-rolled bar at an incident angle of 30±1 degrees (example value). The laser output power is adjusted to 100±5 milliwatts (example value), and the beam diameter is controlled to be 1.2 times the diameter of the oxide layer region (example: 50 mm diameter of oxide layer region corresponds to 60 mm beam diameter). During the process of the vortex laser penetrating the oxide layer, wavefront phase modulation occurs, which is received by a low-temperature cooled indium gallium arsenide focal plane array detector at a position of 200 mm (example value) in the vertical direction of the transmission optical path, and the optical signal is converted into a terahertz carrier in the voltage range of 0-5 volts.

[0071] Based on the characteristic fluorescence band and terahertz carrier, a dual-spectral signal is output through spatial matching spectral fusion of dual-ring focal spots.

[0072] Specifically, the characteristic fluorescent band is incident perpendicularly onto the transmission surface of a 5 mm thick cadmium telluride dichroic mirror, while a terahertz carrier signal is projected onto the reflection surface of the cadmium telluride dichroic mirror at a 45-degree incident angle. The spatial orientation of the cadmium telluride dichroic mirror is adjusted so that the two beams coincide on the beam-splitting surface. A fused silica optical path compensator is installed along the signal path of the characteristic fluorescent band, and the optical path is adjusted according to the time difference between the two signals detected by a high-speed oscilloscope (example: a time difference of 0.1 milliseconds corresponds to a 15 mm movement of the compensator). An infrared thermal imager is used to verify that the coaxiality deviation of the output beam is less than 0.1 milliradians, thus forming a dual-spectral signal.

[0073] S3. Capture the terahertz phase distortion in the dual-spectral signal and separate the quantum dot fluorescence peak wavelength using a narrowband filter.

[0074] The terahertz carrier signal and quantum dot fluorescence optical signal are separated based on the dual-spectral signal. The vortex laser component in the terahertz carrier signal is analyzed by the orbital angular momentum sensor to obtain the terahertz phase distortion.

[0075] Specifically, the dual-spectral signal is input into the cadmium telluride beam splitter, the transmission channel outputs the terahertz carrier signal to the orbital angular momentum sensor, and the reflection channel outputs the quantum dot fluorescence optical signal to the narrowband filter. The orbital angular momentum sensor causes the terahertz carrier signal to pass through a fused silica spiral phase plate with a topological charge of l=1 to generate interference fringes. The four-quadrant terahertz detector captures the light intensity distribution in the bright and dark regions of the interference pattern. The terahertz phase distortion is obtained by the ratio of the maximum light intensity in the bright region to the minimum light intensity in the dark region.

[0076] In a narrowband tunable filter, the visible light frequency band quantum dot fluorescence component in the quantum dot fluorescence optical signal is filtered out to obtain the peak wavelength of quantum dot fluorescence.

[0077] Specifically, the quantum dot fluorescence optical signal is input into an acousto-optic tunable filter, and the spectral range from 630 nm to 660 nm is scanned with an example wavelength step precision of 0.1 nm. The acousto-optic tunable filter drives the radio frequency signal frequency to increase linearly from the example value of 80 MHz to the example value of 120 MHz, with each frequency point corresponding to the output of monochromatic light of a different wavelength. The photomultiplier tube detects the intensity of transmitted light in real time and records the light intensity value of the corresponding wavelength. The wavelength corresponding to the maximum light intensity is located as the peak wavelength of quantum dot fluorescence.

[0078] S4. Determine the surface temperature of the hot-rolled bar based on the peak wavelength of quantum dot fluorescence, and calculate the oxide layer thickness.

[0079] Based on quantum dot composite slurry, within a set range covering the typical temperature range of hot rolling, the quantum dot composite slurry is subjected to constant temperature residence in a gradient manner.

[0080] Specifically, the quantum dot composite slurry was placed in a high-temperature sintering furnace and subjected to a segmented isothermal residence program: the temperature was increased from room temperature to 200 degrees Celsius at a rate of 5 degrees Celsius per minute (example value) and held for 10 minutes to evaporate the solvent; the temperature was increased to 500 degrees Celsius at a rate of 3 degrees Celsius per minute (example value) and held for 15 minutes to form a ceramic glass phase; the temperature was increased to 800 degrees Celsius at a rate of 2 degrees Celsius per minute (example value) and held for 30 minutes to activate fluorescence stability; after the holding period, the temperature was cooled to 300 degrees Celsius at a rate not exceeding 10 degrees Celsius per minute (example value) and then air-cooled to below 50 degrees Celsius (example value); the treated slurry was verified using a 532 nm laser (example value) to have a stable fluorescence peak in the wavelength range of 635-655 nm (example value) and a half-maximum width of less than 25 nm (example value), thus completing the isothermal residence of the quantum dot composite slurry.

[0081] The measured temperature values ​​were collected, and the linear correlation between the peak wavelength of quantum dot fluorescence and the measured temperature values ​​was fitted by statistical analysis to obtain the temperature-sensitive characteristic equation, and the surface temperature of the hot-rolled bar was calculated.

[0082] Specifically, within a temperature range of 200°C to 1200°C, constant temperature points are set at 50°C intervals. At each temperature point, the measured surface temperature of the hot-rolled bar is measured using a thermocouple, while the fluorescence peak wavelength of high-cadmium core-shell quantum dots is collected. The dataset of characteristic parameters of the measured temperature and the characteristic parameters of the fluorescence peak wavelength are fitted using the least squares method to establish a linear relationship to calculate the characteristic parameters of the surface temperature of the hot-rolled bar. The real-time fluorescence peak wavelength characteristic parameters are then substituted into the temperature-sensitive characteristic equation to calculate and output the surface temperature of the hot-rolled bar.

[0083] It should be noted that the expression for calculating the surface temperature of hot-rolled bars is as follows:

[0084]

[0085] Where G represents the surface temperature of the hot-rolled bar, λ represents the peak wavelength of quantum dot fluorescence, E represents the reference wavelength, and F represents the temperature drift coefficient.

[0086] Record the cumulative hot rolling time on the production line, input the surface temperature of the hot-rolled bar and the cumulative hot rolling time on the production line into the oxide layer thickness growth model, and generate the oxide layer thickness through the oxidation growth kinetic equation.

[0087] Specifically, the cumulative hot rolling time provided by the rolling mill is recorded; the cumulative hot rolling time and the surface temperature of the hot-rolled bar are input into the oxide layer thickness growth model; the oxide layer thickness growth model performs the oxidation growth kinetics calculation process: the square root of the cumulative hot rolling time characteristic parameter is calculated, and the temperature influence factor is calculated by combining the surface temperature characteristic parameter of the hot-rolled bar through the Arrhenius equation; the product of the square root result, the temperature influence factor, and the oxidation rate constant is then used to generate the oxide layer thickness characteristic parameter.

[0088] It should be noted that, to train the oxide layer thickness growth model, standard Q235 steel samples were prepared on a Gleeble 3800 thermal simulation testing machine, and combined working conditions were set with temperature gradients (800℃, 900℃, 1000℃, 1100℃, 1200℃) and holding time gradients (0.5 hours, 1 hour, 2 hours, 4 hours). Under each working condition, the measured oxide layer thickness was accurately measured using a micrometer, and the temperature control curve was recorded simultaneously. After collecting temperature-time-thickness data pairs for all working conditions, the oxidation rate constant and oxidation activation energy parameter values ​​in the oxidation growth kinetic equation were optimized using a nonlinear least squares regression algorithm to minimize the root mean square error between the oxide layer thickness value calculated by the oxidation growth kinetic equation and the measured oxide layer thickness value. The calibration parameters were then incorporated into the oxide layer thickness growth model to obtain the trained oxide layer thickness growth model.

[0089] S5. Input the terahertz phase distortion and oxide layer thickness into the piezoelectric ceramic fast reflector controller to generate the driving voltage.

[0090] The comprehensive error is obtained based on the terahertz phase distortion and oxide layer thickness using a comprehensive error calculation formula.

[0091] It should be noted that the expression for calculating the comprehensive error is as follows:

[0092] ε=Δφ-a·δ;

[0093] Where ε represents the overall error, Δφ represents the terahertz phase distortion, δ represents the oxide layer thickness, and a represents the oxide layer thickness compensation factor.

[0094] Two consecutive cycles of terahertz phase distortion were collected. The terahertz phase distortion of the first cycle and the terahertz phase distortion of the second cycle were combined into a calculation pair. The instantaneous change rate of the oxide layer was calculated using the phase change rate formula, and then a fourth-order moving average filter was applied to obtain the filtered phase change rate.

[0095] Specifically, terahertz phase distortion is recorded at fixed intervals using a high-speed data acquisition card. The characteristic parameters of the terahertz phase distortion are acquired for two consecutive sampling periods. The terahertz phase distortion of the first period and the terahertz phase distortion of the second period are combined to form a calculation pair. The instantaneous rate of change of the oxide layer is calculated using a difference formula. A fourth-order moving average filter is applied to the instantaneous rate of change of the oxide layer calculated four times consecutively. The calculation results of the instantaneous rate of change of the oxide layer for the four consecutive periods are stored. The four values ​​are arranged in chronological order as a sequence. The arithmetic mean is obtained. The arithmetic mean is output as the filtered characteristic parameter of the phase change rate. The filtered characteristic parameter of the phase change rate is then obtained.

[0096] It should be noted that the expression for calculating the instantaneous rate of change of the oxide layer is:

[0097]

[0098] Where B represents the instantaneous rate of change of the oxide layer, t represents the time variable, Δt represents the fixed sampling time period, and Δφ t-1 This represents the terahertz phase distortion of the previous fixed sampling time period.

[0099] Mechanical vibration signals are collected and subjected to fast Fourier transform spectrum analysis to extract the characteristic values ​​of the main vibration frequency.

[0100] Specifically, a triaxial accelerometer is installed in the bearing housing of the hot-rolled bar production line mill. Mechanical vibration signals are continuously collected using a sampling frequency of 10 kHz as an example. The collected mechanical vibration signals are input into a fast Fourier transform processor. A Hanning window function is applied to the 512-point data frame to suppress spectral leakage, and a fast Fourier transform is performed to calculate the power spectral density. The power spectral density amplitude distribution is scanned, and the frequency corresponding to the point with the maximum amplitude is located as the characteristic value of the principal vibration frequency.

[0101] Based on the frequency range of the principal vibration frequency characteristic value, select the corresponding combination of proportional and derivative coefficients to obtain the proportional-derivative control parameter set.

[0102] Specifically, the principal vibration frequency characteristic value is input into the frequency band classifier. When the principal vibration frequency characteristic value is less than the example value of 20 Hz, the example value of the proportional coefficient (0.8) and the example value of the derivative coefficient (0.02) are selected to form the first parameter group. When the principal vibration frequency characteristic value is in the range of 20 Hz to 50 Hz, the example value of the proportional coefficient (0.5) and the derivative coefficient (0.05) are selected to form the second parameter group. When the principal vibration frequency characteristic value is greater than the example value of 50 Hz, the proportional coefficient (0.3) and the derivative coefficient (0.08) are selected to form the third parameter group, thus obtaining the proportional-derivative control parameter group.

[0103] The integrated error, the filtered phase change rate, and the proportional-derivative control parameter set are input into the control algorithm to generate the drive voltage.

[0104] Specifically, the comprehensive error, the filtered phase change rate, and the proportional-derivative control parameter set are input into the proportional-derivative control algorithm; the driving voltage is obtained by multiplying the comprehensive error and the proportional gain coefficient, and then superimposing the product of the filtered phase change rate and the derivative gain coefficient; and the driving voltage is limited to the range of -10V to +10V in the example; the driving voltage is output through a 16-bit digital-to-analog converter.

[0105] S6. The lens deflection angle is driven by the driving voltage to compensate for vibration error and output the corrected spot coordinates.

[0106] The driving voltage is amplified by high voltage to output a high-voltage driving signal, which drives the piezoelectric ceramic actuator to produce axial mechanical displacement.

[0107] Specifically, the driving voltage is input to the high-voltage amplifier gain circuit, and the driving voltage is amplified by a fixed gain factor of 50 times; the output of the high-voltage amplifier is connected to the piezoelectric ceramic actuator electrode, and the piezoelectric ceramic actuator generates the inverse piezoelectric effect under the action of the electric field; the axial displacement of the piezoelectric ceramic actuator is measured in real time by a laser displacement sensor, and after verifying that the displacement deviation is less than ±0.1 micrometers, the axial mechanical displacement is output.

[0108] The axial mechanical displacement is converted into the physical deflection angle of the reflector using a conversion formula.

[0109] It should be noted that the expression for calculating the physical deflection angle of the reflector is:

[0110]

[0111] Where θ represents the physical deflection angle of the reflector, ΔL represents the axial mechanical displacement, and r represents the radius of the lever arm from the rotation center of the flexible hinge to the fulcrum of the reflector.

[0112] The position of the reflector edge is measured in real time, the deflection angle deviation value is calibrated, the calibrated deflection angle is obtained, and the theoretical offset coordinates of the beam on the focal plane are calculated.

[0113] Specifically, the physical deflection angle of the reflector and the measured edge displacement of the reflector by the laser displacement sensor are input into the calibration formula to calculate the calibrated deflection angle; when the calibration angle deviation value is >0.1 milliradians, the calibration coefficient is updated; based on the calibrated deflection angle, the theoretical offset coordinates of the beam on the focal plane are calculated.

[0114] It should be noted that the expression for the calculated and calibrated deflection angle is as follows:

[0115]

[0116] Where, θ 校准 The calibrated deflection angle, Δd 理论 The theoretical displacement, Δd 实测 This represents the measured displacement.

[0117] The actual spot position coordinates are measured and compared with the theoretical offset coordinates to verify the correction accuracy, and the corrected spot coordinates are obtained.

[0118] Specifically, the four-quadrant detector is placed at the focal plane position, and after receiving the correction beam, it outputs photocurrent signals in the first, second, third, and fourth quadrants; the X-direction coordinates and Y-direction coordinates are obtained respectively and combined to form the actual spot position coordinates; the Euclidean distance between the actual spot position coordinates and the theoretical offset coordinates is calculated, for example, when the Euclidean distance is less than 0.1 mm, the correction accuracy is deemed qualified; and the correction spot coordinates are output.

[0119] It should be noted that the expression for calculating Euclidean distance is:

[0120]

[0121] Where A represents the Euclidean distance, X 实际 This represents the actual coordinates of the four-quadrant detector in the X direction, Y direction. 理论 This shows the theoretical coordinates of the X-direction and Y-direction of the four-quadrant detector. 实际 This represents the actual Y-axis coordinates of the four-quadrant detector. 理论 This represents the theoretical Y-axis coordinates of the four-quadrant detector.

[0122] S7. Calculate the diameter of the hot-rolled bar based on the coordinates of the corrected spot.

[0123] The coordinates of the calibrated spot are transformed into the measurement coordinate system, and the measurement plane coordinates are output. The measurement plane coordinates are then scanned around the circumference of the hot-rolled bar to collect multiple sets of measurement plane coordinates and reconstruct the edge point cloud.

[0124] Specifically, the measurement plane coordinate feature parameters are obtained based on the calibration spot coordinates; the scanning galvanometer is controlled to rotate around the central axis of the hot-rolled bar with a step angle of 5°, and the measurement plane coordinates are collected at each angle position; the 72 sets of coordinate points are converted into polar coordinate points according to the radial distance, and the edge point cloud is output.

[0125] Perform ellipse fitting calculations on the edge point cloud and output the original diameter parameters.

[0126] Specifically, 72 sets of coordinates are received from the point cloud of the edge of the hot-rolled bar section. Each set of coordinates represents the position of the bar section contour point obtained by laser scanning. A 6-dimensional vector is generated for each set of coordinates. The 72 sets of vectors are combined into a 72-row × 6-column design matrix. The covariance of the design matrix is ​​obtained. The eigenvector corresponding to the smallest eigenvalue is selected to obtain the elliptic coefficients. Based on the elliptic coefficients, the coordinates of the ellipse center, the length of the major semi-axis, the length of the minor semi-axis, and the rotation angle are solved. The numerical values ​​of the length of the major semi-axis and the length of the minor semi-axis are compared, and twice the maximum value is taken as the original diameter.

[0127] Thermal expansion compensation is performed on the original diameter parameter based on the surface temperature of the hot-rolled bar to output a temperature-compensated diameter.

[0128] It should be noted that the expression for calculating the temperature-compensated diameter is:

[0129]

[0130] Where D represents the temperature compensation diameter, D 原 The original diameter is represented by α, the coefficient of thermal expansion of the material is represented by T, the surface temperature of the hot-rolled bar is represented by e, and the reference temperature is represented by e.

[0131] The rolling speed parameters of the rolling mill are acquired in real time, and motion hysteresis compensation is performed on the temperature compensation diameter based on the rolling speed parameters to output the diameter of the hot-rolled bar.

[0132] Specifically, the rolling speed parameters of the rolling mill are acquired in real time via PROFINET industrial Ethernet; the rolling speed parameters and temperature-compensated diameter characteristic parameters are subjected to motion hysteresis compensation, and the compensation amount generated by the product of the compensation coefficient of 0.005 mm·s / m, the rolling speed and the rolling mill response time of 50 ms is superimposed; the diameter of the hot-rolled bar is output.

[0133] S8. Based on the frequency range of the main vibration frequency characteristic value, select the corresponding combination of proportional coefficient and derivative coefficient to obtain the proportional-derivative control parameter set.

[0134] Vibration spectrum data and stability control parameters are collected, and a proportional-derivative parameter relationship library is established through big data regression analysis.

[0135] Specifically, vibration acceleration time-series signals during the rolling process are acquired using a vibration acceleration sensor array (e.g., IEPE acceleration sensors positioned in the rolling mill bearing housing); the vibration acceleration time-series signals are processed using Fast Fourier Transform (sampled at a frequency of 51.2 kHz with a Hanning window function) to extract vibration spectrum data in characteristic frequency bands; the stability control parameters of the piezoelectric ceramic fast-reflection mirror are recorded simultaneously; the vibration spectrum data and stability control parameters are combined to form a dataset; multiple linear regression analysis is performed on the dataset (with vibration spectrum characteristic parameters as independent variables) to establish a proportional-differential parameter relationship library with vibration spectrum characteristics as input.

[0136] The main vibration frequency is collected and Fourier transform is used to generate the main vibration frequency feature value. Based on the frequency range of the main vibration frequency feature value, it is classified into low frequency band, mid frequency band and high frequency band, and the frequency band classification result is obtained.

[0137] Specifically, the original vibration acceleration time-series signal is acquired using an IEPE piezoelectric accelerometer; a Hanning window-windowed discrete Fourier transform is performed on the original vibration acceleration time-series signal (sample sampling frequency 51.2 kHz, frequency resolution 1 Hz in the example), and the frequency point corresponding to the vibration component with the largest fundamental amplitude is extracted as the main vibration frequency feature value; the frequency band is divided into low-frequency band, mid-frequency band, and high-frequency band according to the frequency band size, and the main vibration frequency feature value is assigned to the corresponding frequency band: when the main vibration frequency feature value is less than the example value of 30 Hz, the low-frequency band classification result is output; when the main vibration frequency feature value is between the example value of 30 Hz and 200 Hz (inclusive of the endpoint value), the mid-frequency band classification result is output; and when the main vibration frequency feature value is greater than the example value of 200 Hz, the high-frequency band classification result is output.

[0138] Based on the frequency band classification results, the corresponding proportional coefficient and derivative coefficient combination is called from the proportional-derivative parameter relationship library to obtain the proportional-derivative control parameter group.

[0139] Specifically, based on the frequency band classification results (including low-frequency, mid-frequency, and high-frequency band classification results), the currently obtained frequency band classification results are used as index keys and input into the storage structure of the proportional-derivative parameter relation library. The mapping records corresponding to the index keys are matched in the proportional-derivative parameter relation library. The proportional gain coefficient and derivative gain coefficient values ​​associated within the mapping records are extracted (example: low-frequency band classification results are associated with a proportional gain coefficient of 1.15 V / radian and a derivative gain coefficient of 0.032 V / ms / radian; mid-frequency band classification results are associated with a proportional gain coefficient of 1.20 V / radian and a derivative gain coefficient of 0.050 V / ms / radian; high-frequency band classification results are associated with a proportional gain coefficient of 0.98 V / radian and a derivative gain coefficient of 0.065 V / ms / radian). The combined parameters of the proportional gain coefficient and derivative gain coefficient values ​​are output as the proportional-derivative control parameter set.

[0140] S9. The driving voltage is amplified by high voltage to output a high voltage driving signal.

[0141] The driving voltage signal is filtered and denoised, and the gain is pre-adjusted to generate a pre-processed voltage signal.

[0142] Specifically, a third-order Butterworth low-pass filter is performed based on the driving voltage signal (the example cutoff frequency is set to 1.5 times the characteristic value of the current main vibration frequency and not less than 200 Hz) to filter out high-frequency switching noise; the product of the filtered signal and the temperature compensation coefficient is subjected to voltage limiting processing to generate a preprocessed voltage signal.

[0143] The pre-processed voltage signal is input into a four-stage high-voltage drive architecture, where it undergoes high-frequency switching modulation, transformer boosting, opto-isolation conversion, and wide-bandgap semiconductor power output to generate a high-voltage drive signal.

[0144] Specifically, the pre-processed voltage signal is input to a high-frequency full-bridge inverter switching circuit (the example uses a typical pulse width modulation frequency of 300 kHz) to generate a square wave signal with an adjustable duty cycle through high-frequency switching modulation. The square wave signal is then loaded onto a ferrite core step-up transformer (the example uses a step-up ratio of 12:1) for electromagnetic induction boosting to obtain an amplitude-enhanced AC signal. The AC signal is then sent to an optically coupled isolation converter to complete the electro-optical-electrical conversion and achieve electrical isolation. After isolation, the signal is input to an H-bridge power amplifier circuit based on silicon carbide MOSFETs for wide-bandgap semiconductor power amplification and shaping to output a high-voltage drive signal.

[0145] This embodiment also provides a computer device applicable to the hot-rolled bar size measurement method, including: a memory and a processor; the memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions to implement the hot-rolled bar size measurement method proposed in the above embodiment.

[0146] The computer device can be a terminal, comprising a processor, memory, communication interface, display screen, and input devices connected via a system bus. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, carrier networks, NFC (Near Field Communication), or other technologies. The display screen can be an LCD screen or an e-ink screen. The input devices can be a touch layer covering the display screen, buttons, a trackball, or a touchpad on the computer device's casing, or an external keyboard, touchpad, or mouse.

[0147] This embodiment also provides a storage medium storing a computer program that, when executed by a processor, implements the hot-rolled bar dimension measurement method as proposed in the above embodiments. The storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as Static Random Access Memory (SRAM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Erasable Programmable Read Only Memory (EPROM), Programmable Red-Only Memory (PROM), Read-Only Memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk.

[0148] In summary, this invention achieves simultaneous and highly sensitive detection of the surface temperature and oxide layer thickness of hot-rolled bars by combining high-cadmium core-shell quantum dots with a high-temperature resistant ceramic binder to form a temperature-sensitive fluorescent labeling layer and using vortex laser excitation of dual-spectral signals, thus converting environmental interference into quantifiable information. Furthermore, by analyzing terahertz phase distortion and vibration characteristics, it drives a piezoelectric ceramic fast-reflecting mirror to perform millisecond-level dynamic optical path compensation, achieving active image stabilization of the measurement spot. This effectively overcomes the combined interference of high temperature, oxidation, and vibration, significantly improving the accuracy, stability, and robustness of dimensional measurements under dynamic hot-rolling conditions, and providing reliable technical support for online quality control.

[0149] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for measuring the dimensions of hot-rolled bars, characterized in that: include, High-cadmium core-shell quantum dots are mixed with high-temperature resistant ceramic adhesive and sprayed onto the surface of hot-rolled bars to form hot-rolled bars with fluorescent markings. Fluorescence is excited by irradiating hot-rolled bars with fluorescent markings with a laser, while a vortex laser is used to penetrate the oxide layer to generate a dual-spectral signal. The terahertz phase distortion in the dual-spectral signal was captured, and the peak wavelength of quantum dot fluorescence was separated by a narrow-band filter; The surface temperature of the hot-rolled bar is determined by inverse analysis of the quantum dot fluorescence peak wavelength, and the oxide layer thickness is calculated. The terahertz phase distortion and oxide layer thickness are input into the piezoelectric ceramic fast-reflection mirror controller to generate a driving voltage. The driving voltage drives the mirror deflection angle to compensate for vibration errors and outputs the corrected spot coordinates. The diameter of the hot-rolled bar is calculated based on the coordinates of the corrected light spot.

2. The method for measuring the dimensions of hot-rolled bars as described in claim 1, characterized in that: The process involves mixing high-cadmium core-shell quantum dots with a high-temperature resistant ceramic binder and spraying the mixture onto the surface of hot-rolled bars to form hot-rolled bars with fluorescent markings. The specific steps are as follows: High-cadmium core-shell quantum dots are mixed with a high-temperature resistant ceramic binder to form a quantum dot composite slurry; The surface of the hot-rolled bar is sandblasted and activated to generate a roughened and clean surface. Quantum dot composite slurry is then uniformly sprayed onto the roughened and clean surface to form a wet coating. The wet coating is heated and cured, and its temperature-sensitive fluorescence properties are activated to form hot-rolled bars with fluorescent markings.

3. The method for measuring the dimensions of hot-rolled bars as described in claim 2, characterized in that: The process involves irradiating the hot-rolled bar with a fluorescent label using a laser to excite fluorescence, while simultaneously using a vortex laser to penetrate the oxide layer to generate a dual-spectral signal. The specific steps are as follows: The surface of a hot-rolled bar with fluorescent markings is vertically irradiated with a semiconductor laser beam to excite cadmium selenide zinc sulfide zinc core-shell quantum dots, generating characteristic fluorescent bands; A vortex laser beam is emitted synchronously, penetrating the oxide layer on the surface of hot-rolled bar to generate a terahertz carrier wave; Based on the characteristic fluorescence band and terahertz carrier, a dual-spectral signal is output through spatial matching spectral fusion of dual-ring focal spots.

4. The method for measuring the dimensions of hot-rolled bars as described in claim 3, characterized in that: The specific steps for capturing the terahertz phase distortion in the dual-spectral signal and separating the quantum dot fluorescence peak wavelength using a narrowband filter are as follows. The terahertz carrier signal and quantum dot fluorescence optical signal are separated based on the dual-spectral signal. The vortex laser component in the terahertz carrier signal is analyzed by the orbital angular momentum sensor to obtain the terahertz phase distortion. In a narrowband tunable filter, the visible light frequency band quantum dot fluorescence component in the quantum dot fluorescence optical signal is filtered out to obtain the peak wavelength of quantum dot fluorescence.

5. The method for measuring the dimensions of hot-rolled bars as described in claim 4, characterized in that: The specific steps for calculating the surface temperature of the hot-rolled bar based on the quantum dot fluorescence peak wavelength and then calculating the oxide layer thickness are as follows: Based on quantum dot composite slurry, within a set range covering the typical temperature range of hot rolling, the quantum dot composite slurry is subjected to isothermal residence in a gradient manner. The measured temperature values ​​were collected, and the linear correlation between the quantum dot fluorescence peak wavelength and the measured temperature values ​​was fitted by statistical analysis to obtain the temperature-sensitive characteristic equation. Substitute the peak wavelength of quantum dot fluorescence into the temperature-sensitive characteristic equation to calculate the surface temperature of hot-rolled bars; Record the cumulative hot rolling time on the production line, input the surface temperature of the hot-rolled bar and the cumulative hot rolling time on the production line into the oxide layer thickness growth model, and generate the oxide layer thickness through the oxidation growth kinetic equation.

6. The method for measuring the dimensions of hot-rolled bars as described in claim 5, characterized in that: The steps for inputting the terahertz phase distortion and oxide layer thickness into the piezoelectric ceramic fast-reflection mirror controller to generate the driving voltage are as follows: Based on the terahertz phase distortion and oxide layer thickness, the comprehensive error is obtained through the comprehensive error calculation formula. Two consecutive cycles of terahertz phase distortion were collected. The terahertz phase distortion of the first cycle and the terahertz phase distortion of the second cycle were combined into a calculation pair. The instantaneous change rate of the oxide layer was calculated using the phase change rate formula, and then a fourth-order moving average filter was applied to obtain the filtered phase change rate. Mechanical vibration signals are collected and subjected to fast Fourier transform spectrum analysis to extract the characteristic values ​​of the main vibration frequency; Based on the frequency range of the principal vibration frequency characteristic value, select the corresponding combination of proportional coefficient and derivative coefficient to obtain the proportional-derivative control parameter set; The integrated error, the filtered phase change rate, and the proportional-derivative control parameter set are input into the control algorithm to generate the drive voltage.

7. The method for measuring the dimensions of hot-rolled bars as described in claim 6, characterized in that: The process of compensating for vibration errors by driving the lens deflection angle with a driving voltage and outputting corrected light spot coordinates involves the following specific steps. The driving voltage is amplified by high voltage to output a high voltage driving signal, which drives the piezoelectric ceramic actuator to produce axial mechanical displacement. The axial mechanical displacement is converted into the physical deflection angle of the reflector using a conversion formula. The position of the reflector edge is measured in real time, the deflection angle deviation value is calibrated, the calibrated deflection angle is obtained, and the theoretical offset coordinates of the beam on the focal plane are calculated. The actual spot position coordinates are measured and compared with the theoretical offset coordinates to verify the correction accuracy, and the corrected spot coordinates are obtained.

8. The method for measuring the dimensions of hot-rolled bars as described in claim 7, characterized in that: The specific steps for calculating the diameter of the hot-rolled bar based on the corrected spot coordinates are as follows. The coordinates of the correction spot are transformed into the measurement coordinate system, and the measurement plane coordinates are output. The hot-rolled bar is rotated and scanned around the circumference to collect multiple sets of measurement plane coordinates and reconstruct the edge point cloud. Ellipse fitting calculation is performed on the edge point cloud to output the original diameter parameter. Thermal expansion compensation is performed on the original diameter parameter based on the surface temperature of the hot-rolled bar to output the temperature-compensated diameter. The rolling speed parameters of the rolling mill are acquired in real time, and motion hysteresis compensation is performed on the temperature compensation diameter based on the rolling speed parameters to output the diameter of the hot-rolled bar.

9. The method for measuring the dimensions of hot-rolled bars as described in claim 6, characterized in that: The step of selecting the corresponding proportional and derivative coefficient combinations based on the frequency range of the principal vibration frequency characteristic value to obtain the proportional-derivative control parameter set is as follows: Vibration spectrum data and stability control parameters are collected, and a proportional-derivative parameter relationship library is established through big data regression analysis. The main vibration frequency is collected and Fourier transform is used to generate the main vibration frequency feature value. Based on the frequency range of the main vibration frequency feature value, it is classified into low frequency band, mid frequency band and high frequency band to obtain the frequency band classification result. Based on the frequency band classification results, the corresponding proportional coefficient and derivative coefficient combination is called from the proportional-derivative parameter relationship library to obtain the proportional-derivative control parameter group.

10. The method for measuring the dimensions of hot-rolled bars as described in claim 7, characterized in that: The specific steps for amplifying the driving voltage to output a high-voltage driving signal are as follows. The driving voltage signal is filtered and denoised, and the gain is pre-adjusted to generate a pre-processed voltage signal; The pre-processed voltage signal is input into a four-stage high-voltage drive architecture, where it undergoes high-frequency switching modulation, transformer boosting, opto-isolation conversion, and wide-bandgap semiconductor power output to generate a high-voltage drive signal.

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