Novel cast-rolling titanium wire speed monitoring visualization system

Abstract

The invention provides a novel cast-rolling titanium wire speed monitoring visualization system, which comprises a laser engraving device used for periodically engraving a microgroove structure on the surface of a titanium wire, the depth of the microgroove being 20 [mu] m and the width being 50 [mu] m; the SAW resonator array emits surface acoustic waves to penetrate through the titanium steam layer; when the titanium wire moves, the surface microgrooves pass through a detection area of the SAW resonator array, the acoustic impedance characteristic is changed, and resonant frequency drift delta f is caused; establishing a mathematical model of frequency drift and speed: deltaf / f0 = k.v.cos theta, k being a material constant, v being a titanium wire speed, and theta being an included angle between the microgroove and a sound wave propagation direction; a time-frequency domain hybrid decoupling algorithm is adopted to eliminate roller vibration noise, the titanium wire movement speed is obtained through calculation, and high-precision, high-reliability and real-time measurement of the titanium wire speed is achieved.

Description

TECHNICAL FIELD

[0001] The application relates to a novel cast titanium wire speed monitoring visualization system. BACKGROUND

[0002] In the continuous casting process of titanium alloy, the stable control of titanium wire speed directly affects the product size accuracy and organizational uniformity. At present, laser Doppler velocimeter (LDV) is generally used for speed monitoring in industrial field, and the principle is based on the Doppler frequency shift of the reflected light of the moving object. However, when the environmental temperature exceeds 800 DEG C, the concentration of titanium vapor increases sharply, strong light scattering and refraction are generated, and the signal attenuation of LDV is up to 15 dB / cm, and the measurement error is > 15%. At the same time, the mechanical vibration of the roller (typical amplitude 1mm, frequency 100Hz) further reduces the signal-to-noise ratio.

[0003] The prior art attempts to suppress interference by increasing laser power, adding narrow-band optical filter or using adaptive filtering algorithm, but high-power laser will accelerate the aging of the optical window, and the filtering algorithm cannot distinguish the random scattering of titanium vapor from the effective signal, and neither of them can fundamentally solve the principle measurement obstacle caused by high-temperature titanium vapor.

[0004] Therefore, a new speed measurement method which is independent of the optical properties of titanium vapor, can work stably for a long time in a 1200 DEG C environment, and has high anti-vibration performance is urgently needed. SUMMARY

[0005] The application provides a novel cast titanium wire speed monitoring visualization system, overcomes the defects of large error, poor anti-vibration ability and short service life of the existing laser Doppler velocimeter in the high-temperature titanium vapor environment, provides a hybrid speed measurement method and system based on physical markers and surface acoustic wave detection, and realizes high-precision, high-reliability and real-time measurement of titanium wire speed. The purpose of the application is achieved in the following way:

[0006] The application provides a novel cast titanium wire speed monitoring visualization system, which comprises a laser engraving device for periodically engraving a micro-groove structure on the surface of the titanium wire, the micro-groove has a depth of 20 microns and a width of 50 microns; a SAW resonator array for transmitting surface acoustic waves to penetrate the titanium vapor layer; when the titanium wire moves, the surface micro-groove passes through the detection area of the SAW resonator array, changes the acoustic impedance characteristic, and causes the resonant frequency to drift Δf; a mathematical model of frequency drift and speed is established: Δf / f0=k*v*cos theta, wherein k is a material constant, v is the speed of the titanium wire, and theta is the included angle between the micro-groove and the direction of propagation of the acoustic wave; a time-frequency domain hybrid decoupling algorithm is used to eliminate the roller vibration noise, and the speed of the titanium wire is calculated.

[0007] Further, the laser engraving device is a pulsed fiber laser, the wavelength is 1064 nm, the pulse width is 100 ns, and the repetition frequency is 50 kHz.

[0008] Further, the SAW resonator array comprises 6 resonators, and the resonators are arranged at intervals along the rolling direction, and the interval is 200mm.

[0009] Further, the SAW resonator is installed obliquely, and the angle between the titanium wire movement direction and the titanium wire movement direction is 45°.

[0010] Further, the time-frequency domain hybrid decoupling algorithm comprises the following steps: identifying a pulse signal caused by the micro groove passing; determining a time interval Δt; extracting a frequency shift amount Δf through FFT; combining time domain and frequency domain information to eliminate random vibration noise; and synthesizing the measurement results of multiple resonators.

[0011] Further, the titanium wire movement speed is calculated according to the following formula: v = d / (n·Δt)·(1+α·ΔT), wherein d is the nominal interval of the micro groove; n is the number of micro grooves passing; Δt is the passing time; α is a temperature compensation coefficient; and ΔT is a temperature change amount.

[0012] Compared with the prior art, the beneficial effects of the present application are: a periodic and high-precision micro groove structure is formed on the surface of the titanium wire through laser engraving, and a non-contact detection is performed in combination with a SAW resonator array, thereby avoiding the wear and pollution problems caused by traditional contact measurement, and providing stable physical characteristics for speed measurement; the specifications of the micro groove depth of 20μm and the micro groove width of 50μm ensure the sensitivity and reliability of SAW detection, and have little influence on the performance of the titanium wire body.

[0013] The SAW technology can penetrate the titanium vapor layer and a certain degree of dust, and has stronger environmental adaptability than optical measurement, and significantly improves the measurement stability in the harsh environment of casting and rolling. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of a new type of casting and rolling titanium wire speed monitoring visualization system. DETAILED DESCRIPTION

[0015] In order to deepen the understanding of the present application, the present application will be further described in combination with the embodiments and the drawings, and the embodiments are only used to explain the present application, and do not constitute a limitation on the protection scope of the present application.

[0016] Please refer to Figure 1The application provides a novel cast-rolling titanium wire speed monitoring visual system, which comprises a laser engraving device for periodically engraving a microgroove structure on the surface of the titanium wire, the microgroove has a depth of 20 μm and a width of 50 μm; and a SAW resonator array for transmitting a surface acoustic wave to penetrate a titanium vapor layer; when the titanium wire moves, the surface microgroove passes through the detection area of the SAW resonator array, changes the acoustic impedance characteristic, and causes a resonant frequency drift Δf; a mathematical model of the frequency drift and the speed is established: Δf / f0=k·v·cosθ, wherein k is a material constant, v is the speed of the titanium wire, and θ is the included angle between the microgroove and the direction of propagation of the acoustic wave; a time-frequency domain hybrid decoupling algorithm is used to eliminate the rolling vibration noise, and the speed of the titanium wire is calculated.

[0017] The laser engraving device is a pulse fiber laser, has a wavelength of 1064 nm, a pulse width of 100 ns and a repetition frequency of 50 kHz; the SAW resonator array comprises six resonators, the resonators are arranged at intervals along the rolling direction and have an interval of 200 mm; the SAW resonators are installed obliquely and form an included angle of 45° with the direction of movement of the titanium wire; the time-frequency domain hybrid decoupling algorithm comprises the following steps: identifying the pulse signal caused by the passing microgroove, determining the time interval Δt; extracting the frequency drift Δf through FFT; eliminating the random vibration noise by combining the time domain and frequency domain information; synthesizing the measurement results of the plurality of resonators; and calculating the speed of the titanium wire, including: the speed calculation formula is v=d / (n·Δt)·(1+α·ΔT), wherein d is the nominal interval of the microgroove, n is the number of passing microgrooves, Δt is the passing time, α is a temperature compensation coefficient, and ΔT is the temperature change amount.

[0018] It should be noted that the laser engraving device is used to periodically engrave a microgroove structure on the surface of the titanium wire, specifically, the depth of the microgroove structure is 20 μm and the width is 50 μm, and such a microgroove design aims to provide periodically changing surface features that can be effectively identified by the SAW resonator array, while minimizing the impact on the performance of the titanium wire; when there is no microgroove passing through the SAW resonator or when the titanium wire is stationary, there is an inherent and stable resonant frequency, which is f0; when the titanium wire with the microgroove moves, the microgroove passes through the detection area of the SAW resonator, causing the acoustic impedance characteristic to change, thereby causing the actual working frequency of the resonator to produce a drift Δf relative to the reference frequency f0, and Δf / f0 is the relative change of the frequency, which is proportional to the speed v of the titanium wire.

[0019] The laser engraving device is a pulse fiber laser, the wavelength of the pulse fiber laser is 1064 nm, the pulse width is 100 ns, and the repetition frequency is 50 kHz. The pulse fiber laser can realize high-precision, high-efficiency and non-contact micro-groove engraving on the surface of the titanium wire, ensure the size consistency and periodicity of the micro-groove, and the wavelength of 1064 nm has good material absorption characteristics. The pulse width of 100 ns helps to realize effective material removal without excessive heat effect area, and the repetition frequency of 50 kHz ensures that continuous and uniform periodic micro-grooves can be formed when the titanium wire moves at high speed. The SAW resonator penetrates the titanium vapor layer in the casting and rolling environment by emitting a surface acoustic wave to scan the surface of the titanium wire with micro-grooves. When the titanium wire moves, the periodic micro-grooves on the surface of the titanium wire pass through the detection area of the SAW resonator array, which changes the propagation path and boundary conditions of the surface acoustic wave, causing the acoustic impedance characteristics of the SAW resonator to change, and further causing the drift of the resonant frequency Δf. The SAW resonator array includes six SAW resonators, which are arranged at intervals along the rolling direction of the titanium wire with a spacing of 200 mm. This multi-resonator array layout can perform multi-point and redundant measurement, improving the reliability and accuracy of the measurement. On the other hand, the measurement results of multiple resonators can be combined to eliminate the influence of local disturbances. In order to optimize the sensitivity of the acoustic wave detection micro-groove, the SAW resonator is installed at an angle of 45° to the direction of titanium wire movement. This inclined installation can make the interaction between the acoustic wave and the micro-groove more significant during propagation, causing more obvious frequency drift signals, which is beneficial to improve the signal-to-noise ratio. By establishing a mathematical model of frequency drift and titanium wire speed: Δf / f0=k·v·cosθ, where Δf represents the drift of the resonant frequency, f0 represents the reference resonant frequency, k is a material constant related to the materials of the SAW resonator and the titanium wire, v is the speed of the titanium wire, and θ is the angle between the micro-groove and the direction of acoustic wave propagation. This model establishes a direct mathematical relationship between the change of physical quantity and the measured physical quantity, providing a theoretical basis for accurate speed calculation.

[0020] Further, during the casting and rolling process, the vibration of the roller produces irregular noise, which seriously affects the speed measurement accuracy. The system uses a time-frequency domain hybrid decoupling algorithm to effectively eliminate the roller vibration noise. The time-frequency domain hybrid decoupling algorithm includes the following steps:

[0021] a) Identify the micro-groove passing caused pulse signal and determine the time interval Δt: When the micro-groove passes through the SAW resonator, it will produce a transient frequency drift signal in the form of a pulse. Through signal processing techniques such as threshold detection and peak identification, these pulse signals can be accurately identified, and the time interval Δt of the continuous two micro-grooves passing through the sensor can be determined.

[0022] b) Extract the frequency shift amount Δf by FFT, and perform fast Fourier transform on the real-time frequency signal output by the SAW resonator to analyze its frequency spectrum characteristics. The frequency shift caused by the micro groove is periodic and will show specific frequency components in the frequency domain. By comparing with the background noise spectrum characteristics, the frequency shift amount Δf caused by the micro groove is extracted.

[0023] c) Combine time domain and frequency domain information to eliminate random vibration noise. The roll vibration noise is usually wideband random noise, which may be mixed with the micro groove signal in the time domain, but its energy distribution is different from the periodic signal caused by the micro groove in the frequency domain. By combining time series such as pulse interval with frequency spectrum analysis, digital filtering, wavelet transform and other methods are used to filter and denoise the signal. For example, time interval is used to assist gating, and only the frequency data in the time window where the micro groove signal is expected to appear is analyzed by FFT; or by establishing a noise model, adaptive filtering and other techniques are used for noise suppression.

[0024] d) Synthesize the measurement results of multiple resonators: considering that a single resonator may be disturbed by local environment, the measurement results of the six SAW resonators 31 are processed comprehensively, and methods such as average, weighted average, Kalman filtering, etc. can be used to fuse the data of all resonators, further improve the stability and accuracy of speed measurement, and reduce random error.

[0025] After processing the signal by the above method, the titanium wire movement speed is finally calculated. Specifically, the titanium wire movement speed is calculated, and the speed calculation formula is: v=d / (n·Δt)·(1+α·ΔT), wherein d is the nominal pitch of the micro groove set by laser engraving; n is the number of micro grooves passing through the detection area; Δt is the total time interval passing through these micro grooves; α is the temperature compensation coefficient, which is used to correct the slight influence of material thermal expansion and contraction on the micro groove pitch; ΔT is the temperature change amount (the difference between the actual measurement temperature and the calibration temperature), which formula considers the influence of micro groove pitch, passing time and temperature on measurement, and ensures the accuracy of speed measurement under different working conditions.

[0026] In a possible application scenario, at the initial stage of the casting and rolling production, first, the surface of the casting and rolling titanium wire is periodically engraved with a micro groove with a depth of 20 microns and a width of 50 microns by a laser engraving device, and a laser is used for engraving. When the titanium wire starts to move at a high speed, the SAW resonator array arranged beside the rolling line starts to emit surface acoustic waves and receive reflected signals. The signal processing unit receives the original frequency signals output by the SAW resonator. The signal processing unit performs preliminary amplification and digitization on these signals. Subsequently, the time-frequency domain hybrid decoupling algorithm in the data analysis and control unit is started. It first identifies the pulse signals caused by the micro groove passing through the SAW resonator, accurately measures the time interval Δt, and at the same time, performs FFT analysis on the original frequency signals to extract the frequency drift Δf caused by the micro groove. By combining the time domain Δt and frequency domain Δf information, the system effectively eliminates random noise caused by roll vibration and other factors using digital filtering and other methods. For the measurement results of multiple resonators, comprehensive average or weighted processing is performed. Finally, the data analysis and control unit calculates the real-time movement speed of the titanium wire according to the preset speed calculation formula v = d / (n·Δt)·(1+α·ΔT), wherein d and n are known parameters, Δt is a measured value, and α and ΔT are environmental compensation parameters. The calculated speed data is displayed in real time through the visualization display module and can be linked with the production control system to realize precise monitoring and adjustment of the casting and rolling titanium wire production speed. Through the system, the operator can intuitively understand the running status of the titanium wire, timely discover and correct abnormalities, and ensure product quality and production efficiency.

[0027] In summary, the introduction of the time-frequency domain hybrid decoupling algorithm can also effectively identify and eliminate noise caused by roll vibration during the casting and rolling process, improve the anti-interference ability and precision of the speed measurement, and ensure the purity of the data source. The entire system can output the movement speed data of the titanium wire in real time and continuously, and can realize the visualization of the speed flow in combination with the monitoring system, providing a reliable basis for the immediate adjustment of the production process, greatly improving the automation level and product quality control ability.

[0028] Finally, it should be pointed out that the above embodiments are only used to illustrate the technical solutions of the present application and not to limit it. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced equivalently without departing from the purpose and scope of the present application, and they should be covered in the scope of the claims of the present application.

Claims

1. A novel speed monitoring and visualization system for cast and rolled titanium wire, characterized in that, include: A laser engraving device is used to periodically engrave microgroove structures on the surface of titanium wire, wherein the microgroove depth is 20μm and the width is 50μm; A SAW resonator array emits surface acoustic waves that penetrate the titanium vapor layer. When the titanium wire moves, the surface microgrooves pass through the detection area of ​​the SAW resonator array, changing the acoustic impedance characteristics and causing a resonant frequency drift Δf. A mathematical model of frequency drift and velocity is established: Δf / f0=k·v·cosθ, where k is a material constant, v is the velocity of the titanium wire, and θ is the angle between the microgroove and the direction of sound wave propagation. A time-frequency domain hybrid decoupling algorithm is used to eliminate the roller vibration noise and calculate the velocity of the titanium wire.

2. The novel casting and rolling titanium wire speed monitoring and visualization system according to claim 1, characterized in that, The laser engraving device is a pulsed fiber laser with a wavelength of 1064nm, a pulse width of 100ns, and a repetition frequency of 50kHz.

3. The novel casting and rolling titanium wire speed monitoring and visualization system according to claim 1, characterized in that, The SAW resonator array includes 6 resonators, which are arranged at intervals of 200mm along the rolling line direction.

4. The novel casting and rolling titanium wire speed monitoring and visualization system according to claim 3, characterized in that, The SAW resonator is mounted at an angle, with the titanium wire moving at a 45° angle.

5. The novel casting and rolling titanium wire speed monitoring and visualization system according to claim 1, characterized in that, The time-frequency domain hybrid decoupling algorithm includes the following steps: The pulse signal caused by the passage of the microslot is identified to determine the time interval Δt; the frequency drift Δf is extracted by FFT; random vibration noise is eliminated by combining time-domain and frequency-domain information; and the measurement results of multiple resonators are integrated.

6. The novel casting and rolling titanium wire speed monitoring and visualization system according to claim 1, characterized in that, The calculation of the titanium wire's movement speed includes: the speed calculation formula is: v=d / (n·Δt)·(1+α·ΔT), where d is the nominal spacing of the microgrooves; n is the number of microgrooves passed through; Δt is the passage time; α is the temperature compensation coefficient; and ΔT is the temperature change.

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