Method and system for rapidly predicting detonation velocity of energetic material under laser loading

Abstract

The application discloses a laser loading energetic material detonation velocity rapid prediction method and system, and belongs to the field of energetic material detonation performance detection. The application uses a pulse laser to interact with an energetic material to generate a shock wave, uses a single-point APD detector to record and store voltage changes of the APD, obtains an attenuation signal of the shock wave when the shock wave passes through a detection light beam, extracts interval time between a pulse signal and different height attenuation peaks from the energetic material surface, fits a time-position relationship through a corrected point explosion model, obtains corresponding shock wave characteristic velocity, establishes a linear regression relationship with a macroscopic detonation velocity, and realizes rapid prediction of the energetic material detonation velocity. The application only needs 5-10 mg of a sample, realizes extraction of the shock wave velocity of the energetic material through a single-point detector, obtains the shock wave characteristic velocity, linearly fits the shock wave velocity and a known detonation velocity, and predicts the energetic material detonation velocity. The application can improve the research and development efficiency of the energetic material and reduce the research and development cost.

Description

Technical Field

[0001] This invention relates to a method and system for extracting shock wave velocity and predicting detonation velocity of energetic materials, belonging to the field of detonation performance testing of energetic materials. Background Technology

[0002] Energetic materials, as the most important power and destructive energy source in weapon systems, release a large amount of energy through their own redox reactions and are widely used in blasting industries, pyrotechnics, weaponry, and rocket propulsion. Detonation performance and safety performance are the two most important properties of energetic materials, directly determining their destructive capability and reliability.

[0003] Detonation performance is typically measured by five parameters: detonation velocity, detonation pressure, detonation heat, detonation volume, and detonation temperature, as well as thermodynamic parameters such as the enthalpy of formation. Detonation velocity is of paramount importance for energetic materials; therefore, predicting the detonation velocity of energetic materials, especially novel energetic materials, is crucial for optimizing explosive formulations and ensuring safe and rational production. Current methods often involve measuring the detonation velocity using approximately 100 grams or 1 kilogram of explosive based on national military standards. However, due to issues such as charge density, this method suffers from poor repeatability and high risk.

[0004] In recent years, a method has emerged that uses schlieren to extract images of laser-induced shock waves, and then uses these images to extract the characteristic wave velocities of the shock waves, thereby accurately and efficiently predicting the detonation velocity of energetic materials. This method is safe, reliable, fast, and accurate. However, to improve the temporal resolution of schlieren, it is necessary to rely on high-speed cameras to capture the schlieren images. High-speed cameras are expensive; a high-speed camera with a resolution of 200,000 frames per second costs as much as 800,000 yuan. Furthermore, the core technology is dependent on foreign countries and cannot be domestically produced. This greatly limits the application of schlieren. Summary of the Invention

[0005] To address the challenges of determining the detonation velocity of energetic materials, the inherent risks involved, and the high cost of high-speed cameras for extracting laser-induced shock wave images using schlieren imaging, as well as the lack of domestically developed high-temporal-resolution high-speed cameras, this invention aims to provide a rapid prediction method and system for the detonation velocity of laser-loaded energetic materials. This method utilizes a single-point stepping detector to extract the shock wave velocity generated by the laser-loaded energetic material and predicts the detonation velocity of the energetic material based on the characteristic velocity of the shock wave.

[0006] The objective of this invention is achieved through the following technical solution.

[0007] The laser-loaded energetic material detonation velocity prediction method disclosed in this invention includes the following steps:

[0008] Step 1: Generate a shock wave.

[0009] Using a nanosecond pulsed laser, the excitation energy is adjusted to above 110 mJ and focused onto a preset position below the sample surface through a lens. The laser loads the energetic material sample to generate a shock wave, thus avoiding the uncertainty caused by the high-energy pulsed laser breaking down the air.

[0010] Preferably, a nanosecond pulsed laser with a wavelength of 1064 nm and a pulse width of 9 ns is used. The excitation energy is adjusted to 110 mJ and focused 3 mm below the surface of the energetic material sample through a lens with a focal length of f = 150 mm. The laser loads the energetic material sample to generate a shock wave, so as to avoid the uncertainty caused by the high-energy pulsed laser breaking down the air.

[0011] Step 2: Detect the shock wave.

[0012] A laser is used as the detection light source. A silicon-based avalanche photodiode is used as the detector. Straight enameled copper wires are connected to the anode and cathode pads of the detector, respectively. The soldered module is then placed on a PCB board and fixed with UV-curing adhesive. After fixing, the detector position is finely adjusted using enameled copper wires to ensure that the detection beam accurately hits the photosensitive surface of the detector, ensuring the best initial signal response.

[0013] When the probe laser passes through the shock wave region, the shock wave density distribution is not uniform. When the probe light passes through the disturbed area of ​​the shock wave, due to the higher density at the leading edge of the shock wave, the law of refraction, n1sin(θ1)=n2sin(θ2), determines that the exit position of the light after passing through the disturbed area will be deflected downwards relative to the initial propagation direction. The deflected light spot gradually deviates from the center position of the detector's detection surface. Due to the photocurrent generated by the photodetector... The incident light power P, which in turn depends on the irradiated area A, is determined by the incident light power P = A·I. Therefore, when the probe beam is deflected by the leading edge of the shock wave, the area of ​​the light spot on the detector's photosensitive surface decreases, resulting in an attenuation peak on top of the original signal.

[0014] Simultaneously, due to the bremsstrahlung emission of the high-brightness plasma plume in the early stages of plasma generation, this emission exhibits a broad spectrum characteristic, with an emission range of 400-1100 nm. Since this light falls within the corresponding range of the detector, it significantly affects the detection signal, often resulting in strong noise signals observed on the detector. To reduce the influence of this plasma radiation, a bandpass filter with a center wavelength of 635±20 nm was selected. Its high transmittance range precisely covers the 632.8 nm detection light used in the experiment. This filter was placed parallel to the detector at a distance of 2.5 cm to 3 cm, eliminating the influence caused by the bremsstrahlung emission of the plasma plume and the scattering of the excitation light, significantly improving the signal-to-noise ratio.

[0015] As a preferred option, a He-Ne laser, used as the light source for detection, has an output power of 1mW and a wavelength of 632.8nm.

[0016] The silicon-based avalanche photodiode used as a detector has a photosensitive surface of 200 μm, a cutoff frequency of 2 GHz, a detection wavelength of 400-1100 nm, and a gain of 100.

[0017] Enameled copper wires with a diameter of 0.4 mm were used to connect to the anode and cathode pads of the detector, respectively.

[0018] Place the bandpass filter parallel to the detector at a distance of 2.5cm to 3cm.

[0019] Step 3: Current-to-voltage conversion.

[0020] The analog module includes an APD power supply module and an APD current-to-voltage conversion module. One end of the copper wire leading from the detector is connected to the power supply module, and the other end is connected to the current-to-voltage conversion module. The output voltage of the main chip of the APD power supply module is determined by the voltage on the feedback pin FB, calculated using the following formula: Connect resistors R1 and R 22 And substituting potentiometer R4 into the above equation, we get: The desired voltage can be adjusted by adjusting potentiometer R4.

[0021] Since the APD is a high-speed semiconductor photodetector with internal gain, it can only convert photons into electrons and generate an amplified photocurrent signal. Therefore, a current-to-voltage conversion module is added after the power supply module, and it passes through a filter circuit to filter the multiplied photocurrent signal from the APD while converting it into a voltage signal. The electrical signal is output from the P2 pin (anode) of the APD, enters the inverting input of the operational amplifier, forming a negative feedback amplification circuit, and the voltage output is then passed through a capacitor before being sent to the subsequent data acquisition module for acquisition and recording.

[0022] As a preferred option, the main chip used in the APD power module is the TPS5534 (TSSOP package).

[0023] The operational amplifier used is the OPA657U.

[0024] The negative feedback amplifier circuit outputs the voltage through a 0.1μF capacitor and then outputs it to the subsequent data acquisition module.

[0025] Step 4: Data collection.

[0026] From the moment the probe beam is 2 mm from the sample surface until the measurement is complete, the height of both the laser focusing lens and the sample stage are adjusted simultaneously to lower them in sync. Each measurement uses a preset step size to vary the probe distance between 2 and 10 mm. Simultaneously, each time the height is lowered, the X and Y axes of the sample stage need to be adjusted to ensure that the excitation laser hits a new sample surface each time, avoiding the influence of newly generated chemical substances due to repeated ablation of the sample surface.

[0027] Preferably, the measurement step is 0.5 mm each time.

[0028] Step 5: Data processing.

[0029] First, the signal is denoised and smoothed using SVD filtering. SVD denoising algorithm implementation: (1) The collected signal data is represented by A(k), where A(k) represents the signal data detected when the height of the probe light relative to the sample surface is k; the signal A(k) is decomposed into an m×n matrix, i.e., A(k)→A m×n (k). Where m and n are the number of rows and columns, respectively, and the product of m and n is equal to the total number of data. (2) Signal A m×n (k) can be decomposed into the product of three matrices, i.e., A m×n (k)=U m×n ·∑ m×n ·V m×n Where U is an m×m unitary matrix, V is an n×n unitary matrix, and ∑ is an m×n matrix whose elements outside the main diagonal are all 0, and the values ​​are arranged in descending order, i.e. σ1>σ2>σ3>... (3) Set all values ​​in ∑ except the maximum value σ1 to 0 to obtain ∑1; multiply the obtained ∑1 with U and V to obtain the denoised signal A1. m×n (k). (4) Calculate the percentage of σ1 to all σ, i.e. Determine if the condition is met: f > preset threshold. If met, the denoising process ends; otherwise, use the denoised signal A1. m×n (k) is used as the new initial signal. Repeat steps (1), (2), and (3) until the preset noise reduction conditions are met.

[0030] Next, the attenuation signal range is selected. The location of the minimum value is found within the entire signal range. After obtaining the location of the minimum attenuation signal, X is used as the reference point. min Pixels are extracted before and after the center.

[0031] After extracting the corresponding portion of the attenuation signal, the attenuation signal curve for each measurement is fitted. X min The default value is 0. Gaussian linear regression is used for fitting, and the fitting formula is as follows: The fitting parameters are a1 and b1. After the first fitting is completed, the regression coefficient R is calculated. 2 And determine R 2 >Is the preset value valid? If it is, the fitting ends here; if not, a second fitting is performed, i.e. Then the previous judgment conditions are repeated until the i-th time, R 2 The preset value is met, and the final fitting result is as follows:

[0032] After obtaining the fitted attenuation signal, the arrival time of the shock wave is determined. The zero point of the signal's time is defined as the arrival time of the pump laser pulse. The moment when the signal attenuation reaches its minimum is the arrival time of the shock wave. Therefore, the fitting results... Perform differentiation and search The position is denoted as x. min The location was then reconstructed, yielding the arrival time of the shock wave in the original signal as t = (X... min +x min -1500)*0.001us. Repeat the above steps to process all signal data at different heights from the sample surface, ultimately obtaining multiple sets of time and distance data.

[0033] After obtaining the time and distance data, the relationship between the two is fitted using a formula. In the early stages of plasma evolution, the pressure at the shock wave front is much greater than the pressure of the surrounding gas, meaning the surrounding gas pressure is negligible. The early propagation phase of the laser-induced shock wave is described using the Sedov-Taylor principle. The relationship between the distance R from the shock wave front to the explosion center and the propagation time t is expressed as: Where A and q are the parameters to be fitted. In the later stages of plasma evolution, the high-temperature and high-pressure plasma nucleus gradually collapses, at which point the ambient gas pressure cannot be ignored. During the outward propagation of the shock wave, it encounters resistance from the ambient gas, causing the shock wave to rapidly attenuate to the speed of sound. The later stages of laser-induced shock wave propagation are described using the drag model principle. The relationship between the distance R from the shock wave front to the explosion center and the propagation time t can be expressed as: r = r0(1-e -βt R0 and β are the parameters to be fitted. Since the measured range (on both time and distance scales) spans the periods before and after the shock wave propagation, the point explosion model is improved: R = At q +vt. Where v=R0·β. This improved point explosion model simultaneously considers the periods before and after shock wave propagation, improving the fitting accuracy of shock wave propagation. After obtaining the corresponding Rt fitting curve, its derivative yields the vt curve. That is, the relationship between shock wave velocity and time evolution is obtained.

[0034] As a preferred option, X minTake 1500 pixels before and after the center point, that is, X min ±1500.

[0035] Step 6: Predict the detonation velocity of energetic materials using the established model.

[0036] After obtaining the vt curve, the characteristic velocity of the shock wave is extracted, and a linear regression relationship between the characteristic velocity of different energetic materials and the macroscopic detonation velocity is established by using the PLS method, thus realizing the prediction of the detonation velocity of energetic materials.

[0037] This invention also discloses a rapid prediction system for the detonation velocity of laser-loaded energetic materials, used to implement the aforementioned rapid prediction method for the detonation velocity of laser-loaded energetic materials. The rapid prediction device for the detonation velocity of laser-loaded energetic materials includes a nanosecond pulsed laser, a mirror, a 150mm focusing lens, a one-dimensional displacement stage, a three-dimensional automatically adjustable sample stage, a He-Ne laser, a filter, an avalanche photodiode (APD), an analog circuit module, and a data acquisition module.

[0038] The nanosecond pulsed laser is used to induce energetic materials to generate laser shock waves.

[0039] The three-dimensional displacement stage is used to adjust the height and position of the sample.

[0040] The one-dimensional displacement stage is used to adjust the height of the focusing lens above the sample, ensuring that the laser focal point is 3mm inside the sample. Simultaneously, after focusing inside the sample, it moves synchronously with the three-dimensional displacement stage to change the distance between the probe light and the sample surface.

[0041] The He-Ne laser is used to generate a probe laser source.

[0042] The avalanche photodiode is used to receive the signal of the probe light.

[0043] The filter is placed in front of the avalanche photodiode to filter out stray light and improve the smoothness of the received signal of the detector.

[0044] The analog circuit module is connected to the APD and is used to provide bias voltage to the APD and convert current signals into voltage signals.

[0045] The data acquisition module is connected after the analog circuit module and is used to acquire and record the output voltage of the analog circuit.

[0046] Beneficial effects:

[0047] 1. This invention discloses a method and system for rapid prediction of detonation velocity of laser-loaded energetic materials. By advancing the sample stage by 0.5 mm in a single step, it achieves sampling of 4 points within 10 μs, equivalent to completing the task of a 400,000-frame high-speed camera. A 200,000-frame high-speed camera costs as much as 800,000 yuan, while this device costs approximately 80,000 yuan. Compared to the high-speed camera required for schlieren imaging, this method saves 90% of the cost.

[0048] 2. This invention discloses a method and system for rapid prediction of detonation velocity of laser-loaded energetic materials. By setting the initial distance between the probe beam and the sample stage surface to 2 mm, the minimum detection time is 1.8 μs, while the shortest shooting time of a 200,000-frame high-speed camera is 5 μs. Compared to the high-speed camera required for schlieren imaging, its performance is improved by approximately 60%.

[0049] 3. The present invention discloses a method and system for rapid prediction of the detonation velocity of laser-loaded energetic materials. It utilizes laser-induced shock waves generated by energetic materials and can measure the shock wave velocity of laser-induced energetic materials with a single consumption of only 5-10 mg. By modeling the shock wave velocity and the known detonation velocity, a simple, safe and reliable new method is provided for predicting the detonation velocity of energetic materials. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of a laser-induced shock wave detonation velocity extraction system for energetic materials.

[0051] Figure 2 It is the collected shock wave attenuation peak curve.

[0052] Figure 3 Figure showing the results of extracting the characteristic velocities of shock waves from four energetic materials.

[0053] 1—Nanosecond pulsed laser, 2—Reflector, 3—150mm focusing lens, 4—He-Ne laser, 5—One-dimensional displacement stage, 6—Three-dimensional automatic adjustment sample stage, 7—Filter, 8—Avalanche photodiode (APD), 9—Analog circuit module, 10—Data acquisition module. Detailed Implementation

[0054] The present invention will now be described in further detail with reference to the embodiments and accompanying drawings.

[0055] like Figure 1 As shown, this embodiment discloses a laser-loaded energetic material detonation velocity rapid prediction system, including a nanosecond pulse laser 1, a reflector 2, a 150mm focusing lens 3, a He-Ne laser 4, a one-dimensional displacement stage 5, a three-dimensional automatically adjustable sample stage 6, a filter 7, an avalanche photodiode 8, a data simulation module 9, and a data acquisition module 10.

[0056] A nanosecond pulse laser beam emitted by nanosecond pulse laser 1 is reflected by mirror 2 and then incident parallel to a 150mm focusing lens 3 before converging onto a three-dimensional automatically adjustable sample stage 6. The 150mm focusing lens 3 is fixed on a one-dimensional adjustable one-dimensional displacement stage 5. A probe beam emitted by He-Ne laser 4 passes through a filter 7 and then illuminates an avalanche photodiode 8. The filter 7 is placed parallel to the avalanche photodiode 8 3cm in front of it. The avalanche photodiode 8 is connected to an analog module 9, and then to a data acquisition module 10.

[0057] The nanosecond pulsed laser has a laser wavelength of 1064nm, a pulse width of 9ns, and a single-pulse laser energy that is adjustable from 10-120mJ at 1064nm.

[0058] The reflective lens is used to change the path of the pulsed laser, so that the laser acts perpendicularly on the sample.

[0059] The focusing lens is used to focus the laser emitted by the pulsed laser onto the sample, thereby inducing the sample to generate a shock wave.

[0060] The detection laser is a 632.8nm continuous laser, used as a laser source to generate the detection light.

[0061] The filter is a 635nm narrow bandpass filter, used to filter stray light and improve signal quality, while shielding most of the plasma light.

[0062] The avalanche photodiode is a silicon-based APD diode, and the detector is fixed to the support rod by a combination of welding and UV adhesive curing.

[0063] The simulation module shown is an integrated circuit board, which mainly provides reverse bias for the APD and converts the current signal of the APD into a voltage signal.

[0064] The data acquisition equipment is a four-channel oscilloscope with a bandwidth of 350MHz, used to record and store the voltage values ​​returned by the analog module.

[0065] The three-dimensional displacement stage is used to place the sample and realize the horizontal displacement of the sample as well as adjust the height of the sample.

[0066] The one-dimensional displacement stage is used to adjust the height of the focusing lens above the sample, ensuring that the laser focal point is 3mm inside the sample. Simultaneously, after focusing inside the sample, it moves synchronously with the three-dimensional displacement stage to change the distance between the probe light and the sample surface.

[0067] This embodiment discloses a method for rapid prediction of the detonation velocity of laser-loaded energetic materials, and the specific implementation steps are as follows:

[0068] Step 1: Turn on the He-Ne laser and place the probe beam 2mm away from the sample surface. After passing through the filter, the beam illuminates the detector surface.

[0069] Step 2: Using a nanosecond pulsed laser with a wavelength of 1064 nm and a pulse width of 9 ns, the excitation energy is adjusted to above 110 mJ, and focused onto the sample surface 3 mm below the surface through a lens with a focal length of f = 150 mm. A single attenuation signal is acquired.

[0070] Step 3: Simultaneously lower the height of the one-dimensional and three-dimensional displacement stages by 0.5mm.

[0071] Step 4: Adjust the X and Y axes of the three-dimensional displacement stage to ensure that each laser ablation is performed on a new sample.

[0072] Step 4: After obtaining the signal within the range of 2 to 10 mm, use the SVD method to perform noise reduction and smoothing on the signal.

[0073] Step 5: Extract the attenuation signal range from the denoised data. After extracting the corresponding portion of the attenuation signal, fit the attenuation signal curve for each measurement. Then, determine the arrival time of the shock wave and extract its arrival time.

[0074] Step 6: After obtaining the time and distance data, fit the relationship between the two. Then, obtain the relationship between time and velocity by differentiation, and extract the velocity at 0.8 μs as the characteristic velocity of the shock wave.

[0075] Step 7: Establish a linear regression relationship between the characteristic velocities of different energetic materials and the macroscopic detonation velocity using the PLS method to predict the macroscopic detonation velocity.

[0076] This achievement enables the extraction of laser-induced shock waves from energetic materials and the prediction of detonation velocities. Compared to the national military standard method, which consumes approximately 100 grams or kilograms of explosive charge per measurement, this method requires only milligrams of charge. Detonation parameters for four energetic materials were predicted. Compared to the schlieren method, which consumes the same amount of charge, the velocity prediction error of this method is approximately 15 m / s to 85 m / s. In contrast, the schlieren method using a high-speed camera has an error of approximately 80 m / s to 120 m / s, meaning this method reduces the error by 30% to 60%.

[0077] Comparison of predicted detonation parameters of four energetic materials with reported results.

[0078]

[0079] In this embodiment, a shock wave is first generated by the interaction of a pulsed laser with an energetic material. Then, a single-point APD detector is used to record and store the voltage changes of the APD, obtaining the attenuation signal of the shock wave as it passes through the detector beam. An algorithm is then used to extract the time interval between the pulse signal and the attenuation peaks at different heights from the energetic material surface. A modified point explosion model is then used to fit the time-position relationship to obtain the corresponding shock wave characteristic velocity, establishing a linear regression relationship with the macroscopic detonation velocity to achieve rapid prediction of the energetic material's detonation velocity. This shock wave extraction method requires only a small amount of energetic material, extracting the shock wave velocity using a single-point detector to obtain the shock wave characteristic velocity. Finally, a linear fit is performed between the shock wave velocity and the known detonation velocity to predict the detonation velocity of the energetic material. This embodiment requires only 5-10 mg of sample, significantly reducing the research and development cycle of energetic materials, improving research efficiency, and lowering research and development costs.

[0080] The above detailed description further illustrates the purpose, technical solution, and beneficial effects of the invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for rapid prediction of detonation velocity of laser-loaded energetic materials, characterized in that: Includes the following steps, Step 1: Generate a shock wave; Using a nanosecond pulsed laser, the excitation energy is adjusted to above 110mJ and focused onto a preset position below the sample surface through a lens. The laser loads the energetic material sample to generate a shock wave, thus avoiding the uncertainty caused by the high-energy pulsed laser breaking down the air. Step 2: Detect the shock wave; A He-Ne laser is used as the detection light source; a silicon-based avalanche photodiode is used as the detector; straight enameled copper wires are used to connect to the anode and cathode pads of the detector respectively. The soldered module is then placed on the PCB board and fixed with UV curing adhesive. After fixing, the position of the detector is finely adjusted using enameled copper wires so that the detection beam hits the photosensitive surface of the detector precisely, ensuring the best initial signal response. When the probe laser passes through the shock wave region, the shock wave density distribution is not uniform. When the probe light passes through the shock wave disturbance region, due to the higher density at the shock wave leading edge, the law of refraction n1sin(θ1)=n2sin(θ2) determines that after the light passes through the shock wave disturbance region, its exit position will be deflected downwards relative to the initial propagation direction. The deflected light spot gradually deviates from the center position of the detector's detection surface. Due to the photocurrent generated by the photodetector... It depends on the incident light power P, and the incident light power P = A·I depends on the irradiation area A; therefore, when the probe beam is deflected by the leading edge of the shock wave, the area of ​​the light spot on the photosensitive surface of the detector becomes smaller, which will produce an attenuation peak on the basis of the original signal. To reduce the influence of plasma radiation light, a bandpass filter with a center wavelength of 635±20nm was selected and placed parallel to the detector at a distance of 2.5cm to 3cm in front of it. Step 3: Current-to-voltage conversion; The analog module includes an APD power supply module and an APD current-to-voltage conversion module; one end of the copper wire leading out from the detector is connected to the power supply module, and the other end is connected to the current-to-voltage conversion module; the output voltage of the main chip of the APD power supply module is determined by the voltage on the feedback pin FB; Since the APD is a high-speed semiconductor photodetector with internal gain, it can only convert photons into electrons and generate an amplified photocurrent signal. Therefore, a current-to-voltage conversion module is added after the power supply module and passed through a filter circuit to filter the multiplied photocurrent signal of the APD while converting it into a voltage signal. The electrical signal is output from the P2 pin of the APD and enters the inverting input of the operational amplifier to form a negative feedback amplifier circuit. The voltage output is then passed through a capacitor and output to the subsequent data acquisition module for acquisition and recording. Step 4: Data Collection; From the moment the probe beam is 2 mm from the sample surface until the measurement is completed, the height of the laser focusing lens and the sample stage are adjusted simultaneously to lower them in sync. Each measurement is performed by setting a step size to make the probe distance vary from 2 to 10 mm. At the same time, each time the height is lowered, the X and Y axes of the sample stage need to be adjusted so that the excitation laser hits a new sample surface each time, avoiding the influence of new chemical substances generated by repeated ablation of the sample surface. Step 5: Data Processing; The signal is denoised and smoothed using SVD filtering; the SVD denoising algorithm is implemented as follows: (1) The collected signal data is represented by A(k), where A(k) represents the signal data detected when the height between the probe light and the sample surface is k; the signal A(k) is decomposed into an m×n matrix, i.e., A(k)→A m×n (k); where m and n are the number of rows and columns, respectively, and the product of m and n is equal to the total number of data; (2) Signal A m×n (k) can be decomposed into the product of three matrices, i.e., A m×n (k)=U m×n ·∑ m×n ·V m×n ; where U is an m×m unitary matrix, V is an n×n unitary matrix, and ∑ is an m×n matrix whose elements outside the main diagonal are all 0, and the values ​​of the main diagonal elements are arranged in descending order, i.e. σ1>σ2>σ3>...; (3) Set all values ​​in ∑ except the maximum value σ1 to 0 to obtain ∑1; multiply the obtained ∑1 with U and V to obtain the denoised signal A1. m×n (k); (4) Calculate the percentage of σ1 to all σ, i.e. Determine if the condition is met: F > preset threshold. If met, the denoising process ends; otherwise, use the denoised signal A1. m×n (k) is used as a new initial signal. Steps (1), (2), and (3) are repeated until the preset noise reduction conditions are met. Next, the attenuation signal range is truncated; the location of the minimum value is found within the entire signal range. After obtaining the location of the minimum attenuation signal, X is used as the starting point. min Extract pixels before and after the center point; After extracting the corresponding portion of the attenuation signal, the attenuation signal curve for each measurement is fitted; X min The default value is 0. Gaussian linear regression is used for fitting, and the fitting formula is as follows: The fitting parameters are a1 and b1; after the first fitting, the regression coefficient R is calculated. 2 And determine R 2 > Check if the preset value is valid; if valid, the fitting ends here; if not, perform a second fitting, that is... Then the previous judgment conditions are repeated until the i-th time, R 2 The preset value is met, and the final fitting result is as follows: After obtaining the fitted attenuation signal, the arrival time of the shock wave is determined; the zero point of the signal is defined when the pump laser pulse arrives; the moment when the signal attenuation reaches its minimum is the arrival time of the shock wave; therefore, the fitting results are... Perform differentiation and search The position is denoted as x. min The location was then reconstructed, yielding the arrival time of the shock wave in the original signal as t = (X... min +x min -1500)*0.001us; Repeat the above steps to process all signal data at different heights from the sample surface, and finally obtain multiple sets of time and distance data; After obtaining the time and distance data, the relationship between the two is fitted using a formula; in the early stage of plasma evolution, the pressure at the shock wave front is much greater than the pressure of the ambient gas, i.e., the ambient gas pressure is negligible; the early stage of laser-induced shock wave propagation is described by the Sedov-Taylor principle; the relationship between the distance R from the shock wave front to the explosion center and the propagation time t is expressed as: Where A and q are the parameters to be fitted; in the later stage of plasma evolution, the high-temperature and high-pressure plasma nucleus gradually collapses, and the ambient gas pressure cannot be ignored at this time; during the outward propagation of the shock wave, it is resisted by the ambient gas, causing the shock wave to rapidly attenuate to the speed of sound; the later stage of laser-induced shock wave propagation is described by the Drag model principle; the relationship between the distance R from the shock wave front to the explosion center and the propagation time t can be expressed as: R = R0(1-e -βt ), where R0 and β are the parameters to be fitted; since the measured range (on both time and distance scales) spans the period before and after the shock wave propagation, the point explosion model is improved: R = At q +vt; where v=R0·β; This improved point explosion model takes into account both the period before and after the shock wave propagation, thus improving the fitting accuracy of the shock wave propagation; After obtaining the corresponding Rt fitting curve, its derivative is used to obtain the vt curve; that is, the relationship between the shock wave velocity and time evolution is obtained. Step Six: Predict the detonation velocity of energetic materials using the established model; After obtaining the vt curve, the characteristic velocity of the shock wave is extracted, and a linear regression relationship between the characteristic velocity of different energetic materials and the macroscopic detonation velocity is established by using the PLS method, thus realizing the prediction of the detonation velocity of energetic materials.

2. The method for rapid prediction of detonation velocity of laser-loaded energetic materials as described in claim 1, characterized in that: A nanosecond pulsed laser with a wavelength of 1064 nm and a pulse width of 9 ns was used. The excitation energy was adjusted to 110 mJ and focused onto the energetic material sample 3 mm below the surface through a lens with a focal length of f = 150 mm. The laser applied to the energetic material sample to generate a shock wave, in order to avoid the uncertainty caused by the high-energy pulsed laser breaking down the air.

3. The method for rapid prediction of detonation velocity of laser-loaded energetic materials as described in claim 1, characterized in that: The He-Ne laser used as the light source for detection has an output power of 1mW and a wavelength of 632.8nm. The silicon-based avalanche photodiode used as a detector has a photosensitive surface of 200μm, a cutoff frequency of 2GHz, a detection wavelength of 400-1100nm, and a gain of 100. Enameled copper wires with a diameter of 0.4 mm were used to connect to the anode and cathode pads of the detector, respectively. Place the bandpass filter parallel to the detector at a distance of 2cm to 3cm.

4. The method for rapid prediction of detonation velocity of laser-loaded energetic materials as described in claim 1, characterized in that: The main chip used in the APD power module is TPS5534; The operational amplifier used is the OPA657U operational amplifier; The negative feedback amplifier circuit outputs the voltage through a 0.1μF capacitor before sending it to the subsequent data acquisition module.

5. The method for rapid prediction of detonation velocity of laser-loaded energetic materials as described in claim 1, characterized in that: Each measurement step is 0.5mm.

6. The method for rapid prediction of detonation velocity of laser-loaded energetic materials as described in claim 1 or 2, characterized in that: With X min Take 1500 pixels before and after the center point, that is, X min ±1500.

7. A laser-loaded energetic material detonation velocity rapid prediction system, used to implement the laser-loaded energetic material detonation velocity rapid prediction method as described in claims 1, 2, 3, 4, 5 or 6, characterized in that: Includes a nanosecond pulsed laser, a mirror, a 150mm focusing lens, a one-dimensional displacement stage, a three-dimensional automatically adjustable sample stage, a He-Ne laser, filters, an avalanche photodiode (APD), an analog circuit module, and a data acquisition module; The nanosecond pulsed laser is used to induce energetic materials to generate laser shock waves; The three-dimensional displacement stage is used to adjust the height and position of the sample; The one-dimensional displacement stage is used to adjust the height of the focusing lens above the sample to ensure that the laser focus is 3mm inside the sample; at the same time, after focusing inside the sample, it is used to move synchronously with the three-dimensional displacement stage to change the distance between the probe light and the sample surface. The He-Ne laser is used to generate a detection laser source; The avalanche photodiode is used to receive the signal of the probe light; The filter is placed in front of the avalanche photodiode to filter out stray light and improve the smoothness of the received signal of the detector. The analog circuit module is connected to the APD and is used to provide bias voltage to the APD and convert current signals into voltage signals. The data acquisition module is connected after the analog circuit module and is used to acquire and record the output voltage of the analog circuit.

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