An audio-video fusion explosion equivalent inversion method and system based on a two-wave theory

Abstract

This application discloses a method and system for inverting the explosive yield based on audio-visual fusion using dual-wave theory. The method includes: acquiring audio-visual data from the explosion site, simultaneously acquiring explosion flash and sound wave signals, and recording environmental parameters; using the moment corresponding to the first appearance of the explosion flash in the video frame as the reference moment, identifying the inflection point where the sound wave amplitude rises sharply, determining the arrival time of the sound wave, and calculating the time difference between the two; determining the current explosion condition based on the explosion height and selecting the corresponding overpressure model to calculate the critical proportional distance; calculating the ambient sound velocity based on the environmental parameters; and substituting the time difference, critical proportional distance, ambient sound velocity, and propagation distance into a pre-constructed yield inversion model that integrates the propagation characteristics of the shock wave and sound wave, as well as the ground reflection effect, to solve for the explosive yield. This application requires no specialized monitoring instruments, is adaptable to multiple conditions including airborne and near-ground explosions, and achieves rapid, high-precision, and non-contact inversion of the explosive yield.

Description

Technical Field

[0001] This application belongs to the field of public emergency response technology, specifically involving an audio-visual fusion explosion yield inversion method and system based on dual-wave theory, which is used for rapid assessment of explosion yield at explosion accident sites and can be widely applied to scenarios such as emergency response to sudden explosion accidents, explosion accident investigation, terrorist attack power assessment, and protective engineering design. Background Technology

[0002] In modern public safety defense systems, explosive yield is a core parameter for assessing explosive power, conducting damage assessments, and developing personnel evacuation and emergency rescue plans. Currently, the mainstream explosive yield inversion techniques used in engineering practice are mainly divided into the following two categories:

[0003] (1) Remote inversion technology based on seismic wave monitoring. This technology originates from the empirical relationship between magnitude and yield in the field of nuclear explosion monitoring. It collects seismic wave signals triggered by an explosion through seismic wave monitoring stations and combines the empirical formula for fitting magnitude and explosion yield to achieve remote inversion of large-yield explosions. This technology is only applicable to large-yield explosions of 100 kg or more, and the relevant monitoring data is highly confidential and has a very high acquisition threshold, making it unsuitable for the rapid response to routine sudden explosion accidents in cities.

[0004] (2) Inversion technology based on shock wave overpressure: This technology is currently the mainstream engineering technology for explosive yield assessment. By deploying pressure sensors at the explosion site to collect key parameters such as peak shock wave overpressure and pulse width, and combining them with the classical overpressure empirical model, the explosive TNT equivalent is calculated by inversion. Some derivative technologies also combine the structural damage characteristics, crater morphology, and explosive product ejection range of the post-disaster site to assist in the yield estimation.

[0005] The aforementioned existing technical solutions all have unavoidable technical defects and cannot meet the core requirements of "low cost, rapid response, non-contact, and multi-condition adaptability" in emergency response scenarios for sudden explosion accidents, as detailed below:

[0006] (1) Traditional overpressure inversion technology relies on specialized equipment and has poor engineering applicability: Traditional overpressure inversion technology requires the deployment of high-precision pressure sensors on site in advance. The equipment deployment cost is high and the maintenance is difficult. However, sudden explosion accidents are highly accidental and cannot complete the sensor deployment in advance. After the accident, the on-site survey to obtain overpressure data has a serious time delay, which cannot support the rapid decision-making needs of emergency response. Moreover, the damaged environment at the explosion site will cause sensor data to be damaged or lost, resulting in a very low data acquisition success rate.

[0007] (2) Existing empirical formulas do not cover the complete propagation process of the explosion wave, and the accuracy of far-field inversion is extremely low: Existing classical empirical formulas are only applicable to the mid-to-near field region where the shock wave effect is significant (scale distance less than 10 m / kg). 1 / 3Urban explosions mostly occur in far-field areas (scale distance greater than 20 m / kg). 1 / 3 Within this range, the shock wave will complete the entire evolution process from nonlinear decay to linear sound wave. Existing empirical formulas do not take this physical process into account at all, resulting in the far-field inversion results deviating significantly from the true value. The maximum relative error measured in practice can reach 26.92.

[0008] (3) The ground reflection effect of near-ground explosions is not considered, resulting in extremely narrow adaptability: Most existing technologies only study the free-field air explosion conditions in unlimited airspace, while the vast majority of urban sudden explosion accidents are near-ground / surface explosions. During a near-ground explosion, the shock wave is superimposed on the incident wave after being reflected by the ground, which significantly increases the propagation speed and overpressure peak value of the explosion wave. Existing technologies do not consider this effect at all, which leads to the inversion results under near-ground explosion conditions seriously overestimating the explosive yield and failing to meet the actual engineering needs of multiple scenarios such as air explosions and near-ground explosions. Summary of the Invention

[0009] To overcome the shortcomings of existing explosion yield inversion technology, this application proposes an audio-visual fusion explosion yield inversion method and system based on dual-wave theory. It does not require professional monitoring instruments, can be adapted to multiple working conditions of air explosion and near-ground explosion, and realizes rapid, high-precision, non-contact inversion of explosion yield.

[0010] This application is achieved through the following technical solution:

[0011] An audio-visual fusion explosion equivalent inversion method based on dual-wave theory includes:

[0012] Collect audio and video data from the explosion site, and simultaneously acquire explosion flash and sound signals, while recording environmental parameters;

[0013] The video frame corresponding to the first appearance of the explosion flame is used as the reference time, and the inflection point where the sound wave amplitude rises sharply is identified to determine the arrival time of the sound wave. The time difference between the arrival time of the sound wave and the reference time is calculated.

[0014] Based on the explosion height, determine the current explosion condition and select the corresponding overpressure model to calculate the critical proportional distance.

[0015] The speed of sound in the environment is calculated based on the environmental parameters.

[0016] The time difference, critical proportional distance, ambient sound speed, and propagation distance between the measuring point and the explosion center are substituted into a pre-constructed equivalent inversion model that integrates the propagation characteristics of shock waves and sound waves and the ground reflection effect to obtain the explosion equivalent.

[0017] In some implementations, the process of constructing the equivalent inversion model includes:

[0018] By introducing the explosion similarity rate and the theory of shock wave front propagation, a functional relationship between shock wave overpressure, propagation distance, and explosion equivalent is established.

[0019] Establish the functional relationship between wave velocity and overpressure;

[0020] Establish the integral form of the shock wave propagation time;

[0021] Based on the critical proportional distance, the propagation process of the explosion wave is divided into two stages: the shock wave stage and the sound wave stage. Based on the propagation time of the two stages, the expression for the total propagation time from the explosion center to the measuring point is obtained.

[0022] The total propagation time is approximated by the time difference between the firelight and sound waves measured by audio and video.

[0023] The total propagation time expression is processed to obtain the equivalent inversion model.

[0024] In some implementations, the equivalent inversion model is expressed as:

[0025] ;

[0026] in, The explosive yield; For the distance of propagation; For ambient sound speed; The time difference between the firelight and the sound wave; This represents the propagation time proportion of the shock wave phase. This is the critical proportional distance.

[0027] In some implementations, the acquisition of audio and video data from the explosion site, and the simultaneous acquisition of explosion flash and sound wave signals, includes:

[0028] The explosion flash and sound signals during the explosion process are acquired simultaneously by video acquisition equipment and audio acquisition equipment.

[0029] The video acquisition device continuously captures data until the explosion and flames completely disappear, and the audio acquisition device continuously captures data until the sound wave signal attenuates to the baseline level.

[0030] In some implementations, the step of determining the current explosion condition based on the explosion height and selecting the corresponding overpressure model to calculate the critical proportional distance includes:

[0031] When the current explosion condition is an air explosion, the corresponding critical proportional distance is calculated using the free-field overpressure model;

[0032] When the current explosion condition is a near-ground explosion, the corresponding critical proportional distance is calculated using the near-ground overpressure model.

[0033] In some implementations, the free-field overpressure model includes: the Sadovskyi model, the Baker model, or the Mills model;

[0034] Substituting the critical sound pressure into the free-field overpressure model, the corresponding critical proportional distance is calculated;

[0035] The critical sound pressure is obtained by inversion based on the ambient atmospheric pressure and the Rankine-Hugoniot relationship.

[0036] In some embodiments, the near-ground overpressure model includes: the Ye model, the GB 6722-2014 ground reflected wave overpressure formula, or the Xiao model;

[0037] Substituting the critical sound pressure into the near-ground overpressure model, the corresponding critical proportional distance is calculated;

[0038] The critical sound pressure is obtained by inversion based on the ambient atmospheric pressure and the Rankine-Hugoniot relationship.

[0039] In some embodiments, calculating the ambient sound speed based on the environmental parameters includes:

[0040] The ambient sound speed is obtained by correcting for ambient temperature.

[0041] On the other hand, this application also proposes an audio-visual fusion explosion equivalent inversion system based on dual-wave theory, including:

[0042] The acquisition and processing unit is used to acquire audio and video data at the explosion site, and simultaneously obtain explosion flash and sound wave signals, while recording environmental parameters.

[0043] The first calculation unit is used to take the time corresponding to the video frame where the explosion and fire first appeared as the reference time, identify the inflection point where the sound wave amplitude rises sharply, determine the arrival time of the sound wave, and calculate the time difference between the arrival time of the sound wave and the reference time.

[0044] The second calculation unit is used to determine the current explosion condition based on the explosion height and select the corresponding overpressure model to calculate the critical proportional distance.

[0045] The third calculation unit is used to calculate the ambient sound speed based on the environmental parameters.

[0046] In addition, a solution unit is used to substitute the time difference, critical proportional distance, ambient sound speed, and propagation distance between the measuring point and the explosion center into a pre-constructed equivalent inversion model that integrates sound wave propagation characteristics and ground reflection effects to obtain the explosion equivalent.

[0047] In some implementations, the system further includes:

[0048] The model building unit is used to construct an equivalent inversion model that integrates the propagation characteristics of shock waves and sound waves as well as the ground reflection effect.

[0049] This application proposes a method and system for blast equivalent inversion based on audio-visual fusion using dual-wave theory. For the first time, it explicitly divides the blast wave propagation process into a nonlinear attenuation stage of the shock wave and a linear propagation stage of the sound wave. By introducing a critical proportional distance parameter (corresponding to the inflection point where the shock wave attenuates to the sound wave), the two stages are theoretically unified, constructing a dual-wave theory equivalent inversion model. This model integrates the Hopkinson-Cranz proportionality law, the Rankine-Hugoniot equation, and overpressure attenuation theory, and is more consistent with the physical reality of blast wave propagation than traditional empirical formulas. This application adapts different overpressure models (free-field overpressure model and near-ground overpressure model) for two typical conditions: airborne blasts and near-ground blasts. It can also effectively counteract the enhancement effect of ground reflection on wave velocity in near-ground blasts, achieving equivalent conversion between the two conditions. Furthermore, this application can acquire data using conventional audio-visual equipment, eliminating the need for specialized equipment such as pressure sensors and seismic monitoring stations. This results in low data acquisition costs, fast response speed, and effectively reduces system errors introduced by equipment response delays. Attached Figure Description

[0050] The accompanying drawings, which are included to provide a further understanding of the embodiments of this application and form part of this application, do not constitute a limitation on the embodiments of this application. In the drawings:

[0051] Figure 1 This is a schematic diagram of the audio-visual fusion explosion equivalent inversion method proposed in this application embodiment;

[0052] Figure 2 This is a schematic diagram showing the change in wave velocity from shock wave to sound wave attenuation and the critical proportional distance node.

[0053] Figure 3 Schematic diagram of the setup for air-to-air and near-ground explosion tests;

[0054] Figure 4(a) is a schematic diagram of the audio and video timing of the explosion process under the condition of an air explosion, including the explosion flash frame and the corresponding sound wave waveform;

[0055] Figure 4(b) is a schematic diagram of the audio and video timing of the explosion process under near-ground explosion conditions, including the explosion flash frame and the corresponding sound wave waveform;

[0056] Figure 5 This is a block diagram illustrating the principle of the audio-visual fusion explosion equivalent inversion system proposed in this application embodiment;

[0057] Figure 6 This is a schematic diagram of the electronic device proposed in the embodiments of this application;

[0058] Figure 7 This is a schematic diagram of a computer-readable storage medium proposed in an embodiment of this application.

[0059] Figure reference numerals and corresponding component names:

[0060] 200-Inversion system, 201-Acquisition and processing unit, 202-First calculation unit, 203-Second calculation unit, 204-Third calculation unit, 205-Solving unit, 206-Model building unit, 300-Electronic device, 310-Memory, 320-Processor, 311-Computer program A, 400-Computer-readable storage medium, 411-Computer program B. Detailed Implementation

[0061] In the following, the terms “comprising” or “may include” as used in the various embodiments of this application indicate the presence of a function, operation, or element of the invention and do not limit the addition of one or more functions, operations, or elements. Furthermore, as used in the various embodiments of this application, the terms “comprising,” “having,” and their cognates are intended only to indicate a specific feature, number, step, operation, element, component, or combination of the foregoing and should not be construed as primarily excluding the presence of one or more other features, numbers, steps, operations, elements, components, or combinations of the foregoing, or adding one or more combinations of the foregoing.

[0062] In various embodiments of this application, the expression "or" or "at least one of A and / or B" includes any combination or all combinations of the words listed simultaneously. For example, the expression "A or B" or "at least one of A and / or B" may include A, may include B, or may include both A and B.

[0063] The terms used in the various embodiments of this application (such as "first," "second," etc.) may modify various constituent elements in the various embodiments, but do not limit the corresponding constituent elements. For example, the above terms do not limit the order and / or importance of the elements. The above terms are only used for the purpose of distinguishing one element from other elements. For example, a first user device and a second user device refer to different user devices, although both are user devices. For example, without departing from the scope of the various embodiments of this application, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element.

[0064] It should be noted that if a description is made of "connecting" one component to another, then the first component can be directly connected to the second component, and a third component can be "connected" between the first and second components. Conversely, when a component is "directly connected" to another component, it can be understood that there is no third component between the first and second components.

[0065] The terminology used in the various embodiments of this application is for the purpose of describing particular embodiments only and is not intended to limit the various embodiments of this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which the various embodiments of this application pertain. The terms (such as those defined in a generally used dictionary) are to be interpreted as having the same meaning as in the context of the relevant technical field and are not to be interpreted as having an idealized or overly formal meaning, unless clearly defined in the various embodiments of this application.

[0066] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the embodiments and accompanying drawings. The illustrative embodiments and descriptions of this application are only for explaining this application and are not intended to limit this application.

[0067] Existing explosion yield inversion techniques suffer from the following problems: they rely on specialized equipment, requiring the deployment of dedicated instruments such as pressure sensors, resulting in slow response speeds and high costs; traditional empirical formulas do not fully consider the attenuation process of shock waves to sound waves and the ground reflection effect, leading to low inversion accuracy; and they are difficult to adapt to various typical conditions such as air-to-ground explosions and near-ground explosions simultaneously. To address these issues, this application proposes an audio-visual fusion explosion yield inversion method based on dual-wave theory, such as... Figure 1 As shown, the audio-visual fusion explosion equivalent inversion method includes:

[0068] Step 1: Collect audio and video data from the explosion site, and simultaneously acquire the explosion flash and sound wave signals, while recording environmental parameters;

[0069] Step 2: Take the time corresponding to the first video frame of the explosion and light as the reference time, identify the inflection point where the sound wave amplitude rises sharply, determine the arrival time of the sound wave, and calculate the time difference between the arrival time of the sound wave and the reference time.

[0070] Step 3: Determine the current explosion condition based on the explosion height and select the corresponding overpressure model to calculate the critical proportional distance;

[0071] Step 4: Calculate the ambient sound speed based on environmental parameters;

[0072] Step 5: Substitute the time difference, critical proportional distance, ambient sound speed, and propagation distance between the measuring point and the explosion center into the pre-constructed equivalent inversion model that integrates the propagation characteristics of shock waves and sound waves and the ground reflection effect to obtain the explosion equivalent.

[0073] Optionally, embodiments of this application may record the explosion process using audio and video acquisition devices, simultaneously acquiring explosion flashes and sound signals. These audio and video acquisition devices may include, but are not limited to, public surveillance equipment and personal mobile filming devices. Simultaneously, environmental parameters (temperature, air pressure, wind speed, etc.) are collected and recorded in sequence.

[0074] Optionally, in this embodiment, the video frame in which the explosion light first appears is used as the reference time. A frame-by-frame capture method based on the burst emission is adopted to reduce system errors introduced by device response latency. A gradient threshold algorithm is used to identify the inflection point where the sound wave amplitude rises sharply, thus determining the arrival time of the sound wave. Calculate the time difference for:

[0075] .

[0076] Optionally, in this embodiment of the application, the ambient sound speed can be obtained based on the recorded environmental parameters. The specific calculation method is as follows:

[0077] ;

[0078] in, The speed of sound in undisturbed air under test conditions. The ambient temperature.

[0079] Optionally, this application embodiment, based on the Hopkinson-Cranz proportionality law, the Rankine-Hugoniot equation, and the free field and near-ground overpressure model, introduces a critical proportional distance parameter for the attenuation of shock waves to the sound wave stage, and constructs an equivalent inversion model that integrates the propagation characteristics of shock waves and sound waves as well as the ground reflection effect. The specific construction process includes:

[0080] Introducing the explosion similarity rate and shock wave front propagation theory: According to the Hopkinson-Cranz proportionality law (cubic root law), for explosives of different yields, if the proportional distance... If they are equal, then the shock wave overpressure Due to their similarity, the shock wave overpressure model can be represented as follows:

[0081] ;

[0082] in, For the distance of propagation; It is the explosive yield.

[0083] Establishing the relationship between beam and overpressure: According to the Rankine-Hugoniot equation, the propagation velocity of the shock wave front. Compared with the ambient sound speed in undisturbed air under test conditions and overpressure The relationship is as follows (assuming the specific heat ratio of air γ = 1.4):

[0084] ;

[0085] in, Let γ be the ambient atmospheric pressure. Substituting γ = 1.4, we get:

[0086] ;

[0087] From this, the Mach number of the shock wave can be obtained. The relationship with overpressure, among which, Let be the flow velocity of the wavefront medium, denoted as in the undisturbed state. .

[0088] Establish the integral form of the shock wave propagation time: the shock wave propagates from the explosion center to a distance... The required time can be obtained by integrating the reciprocal of the propagation speed:

[0089] ;

[0090] Introducing proportional distance ,but ,therefore:

[0091] ;

[0092] in, .

[0093] Introducing a critical proportional distance: During the propagation of an explosion wave, the intensity of the shock wave gradually decreases with increasing distance, such as... Figure 2 As shown, it illustrates the change in wave velocity and the critical proportional distance node as the explosion wave attenuates from a shock wave to a sound wave. When the relative deviation between the wave velocity (propagation speed) and the local sound speed is less than 5% (i.e., At this point, the shock wave has attenuated to a weak shock wave, which can be approximated as a sound wave. The overpressure corresponding to this point is called the critical sound pressure. According to the ambient atmospheric pressure The critical sound pressure can be deduced from the Rankine-Hugoniot relationship. For standard atmospheric conditions, by taking... (Corresponding to a sound pressure level of 175dB).

[0094] Substituting the critical sound pressure into the selected overpressure model The corresponding critical proportional distance can be solved. ,Right now:

[0095] ;

[0096] Depending on the different overpressure models, the critical proportional distance The values ​​are different, as shown in Table 1 and Table 2.

[0097] Table 1. Overpressure Model and Critical Scale Distance for Air Explosion

[0098]

[0099] As shown in Table 1, under the condition of an air explosion, a free-field overpressure model was used, including but not limited to the Sadovskyi model, Baker model, and Mills model, and the critical proportional distance corresponding to each model was calculated.

[0100] Table 2 Near-ground explosion overpressure model and critical proportional distance

[0101]

[0102] As shown in Table 2, under near-ground explosion conditions, considering the ground reflection effect, near-ground overpressure models can be used, but are not limited to the Ye model, the GB 6722-2014 ground reflection wave overpressure formula, and the Xiao model, and the critical proportional distance corresponding to each model can be calculated.

[0103] In practical applications, near-ground explosions or air explosions are identified based on the explosion height, and then the critical proportional distance can be calculated by substituting the corresponding parameters into the selected model.

[0104] Calculate the total propagation time of the two waves: Divide the propagation process of the explosion wave into two segments: when Z≤ At that time, the explosion wave propagated in the form of a shock wave with a wave speed of D. a Follow Change; when Z> At that time, the shock wave attenuates into a sound wave, and the wave speed remains constant at the ambient sound speed. .

[0105] The concept of proportional time to shock wave propagation is introduced, and it is defined as the ratio of the shock wave propagation time to the cube root of the equivalent ( ). The calculation formula is:

[0106] ;

[0107] After determining the critical sound pressure and the corresponding critical proportional distance, numerical calculations can be performed on the above integral formula to obtain the shock wave propagation proportional time corresponding to different overpressure models. It should be noted that the time-proportional propagation of the shock wave is calculated by integrating different overpressure models. The actual propagation time, rather than the shock wave phase. For the air-to-ground explosion scenario, the shock wave propagation ratio times corresponding to the Sadovskyi model, Baker model, and Mills model are respectively... =7.394 / c0、 = 7.113 / c0 and = 7.649 / c0; For near-ground explosion conditions, the shock wave propagation ratio times corresponding to the Ye model, the GB 6722-2014 ground reflected wave overpressure formula, and the Xiao model are respectively = 9.875 / c0、 =10.041 / c0 and = 12.455 / c0.

[0108] Therefore, the total propagation time from the explosion center to the measuring point for:

[0109] ;

[0110] The first term is the propagation time of the shock wave stage, and the second term is the propagation time of the sound wave stage.

[0111] but:

[0112] .

[0113] By rearranging the terms, we can derive an equivalent inversion theoretical model based on the theory of two-wave travel time and overpressure attenuation:

[0114] ;

[0115] Right now:

[0116] .

[0117] In the embodiments of this application, the total propagation time of the explosion wave The time difference between firelight and sound waves measured by audio and video. We can approximate the result (ignoring the light propagation time), that is... Therefore, the final equivalent inversion model is:

[0118] .

[0119] Example 1: To verify the feasibility and effectiveness of the audio-visual fusion explosion equivalent inversion method proposed in this application embodiment, this application embodiment uses a 12 kg TNT equivalent explosion source, which is suspended and fixed at a height of 6 m above the ground by a metal bracket and placed horizontally to simulate an airborne free-field explosion. The specific implementation process includes:

[0120] Test points were set at 50 m (A01), 60 m (A02), and 70 m (A03) in an open, unobstructed area around the explosion source (EX01). The horizontal distance between the test points and the explosion center was calibrated using a GPS positioning system, with the error controlled within ±0.5 m.

[0121] The experimental environmental parameters were recorded as follows: temperature 3℃, atmospheric pressure 97 kPa, and environmental sound velocity correction formula. The ambient sound speed was calculated.

[0122] High-definition video acquisition equipment with a frame rate of 240 FPS and audio acquisition equipment with a sampling rate of 48 kHz were used for synchronous data acquisition. The equipment was fixed with a tripod to control the audio and video synchronization error to be less than or equal to 1 ms.

[0123] After the audio and video acquisition equipment is activated, the explosion source is triggered. The video equipment continues to acquire data until the explosion and flames completely disappear, and the audio equipment continues to acquire data until the sound wave signal attenuates to the baseline level.

[0124] The time frame at which the explosion and flames first clearly appeared in the video frame was selected as the reference time. The adaptive gradient thresholding algorithm identifies inflection points where the sound wave amplitude rises sharply in an audio waveform, thus determining the arrival time of the sound wave. The time difference between the firelight and the sound wave at measuring points of 50 m, 60 m, and 70 m was calculated. .

[0125] Substituting propagation distance, time difference, ambient sound speed, critical proportional distance, etc., into the equivalent inversion model The inversion equivalents at the three measuring points were calculated, and the average relative error between them and the actual value of 12 kg was 12.1%.

[0126] Example 2: To verify the feasibility and effectiveness of the audio-visual fusion explosion equivalent inversion method proposed in this application, compared with Example 1, the explosion source (EX02) TNT equivalent of 12 kg, the measuring point layout (B01-50 m, B02-60 m, B03-70 m), audio-visual acquisition equipment, and related parameters are kept unchanged. The explosion source is placed directly on the ground surface, so that the bottom of the explosion source is in close contact with the soil surface, simulating near-ground explosion conditions. The air and near-ground explosion test setups are as follows: Figure 3As shown, EX01 and EX02 represent the blast sources of the air-to-air explosion and the near-ground explosion, respectively; A01, A02, and A03 are three measuring points for the air-to-air explosion; and B01, B02, and B03 are three measuring points for the near-ground explosion.

[0127] The audio and video data acquisition and the extraction of the time difference between the flash and the sound wave were completed following the same procedures and methods as in Example 1. The time differences at the 50 m, 60 m, and 70 m measuring points were calculated. These time differences were all less than the corresponding values ​​for the air-to-ground explosion condition, which is consistent with the law of ground reflection effect increasing the explosion wave velocity. Figures 4(a) and 4(b) show the audio and video timing diagrams of the explosion process at the three measuring points under the air-to-ground and near-ground explosion conditions, respectively, including the explosion flash frame and the corresponding sound wave waveform.

[0128] Substituting the propagation distance, time difference, ambient sound speed, and critical proportional distance into the equivalent inversion model, the inversion equivalents of the three measurement points were calculated, and the average relative error with the actual value of 12 kg was 15.1%.

[0129] As demonstrated by the above simulation experiments, the equivalent inversion model constructed based on the dual-wave theory in this application embodiment covers the complete process from nonlinear attenuation of the shock wave to linear propagation of the sound wave. This has been verified by air-to-ground and near-ground explosion tests with a 12 kg TNT equivalent, at a proportional distance of 21.8 m / kg. 1 / 3 ~ 31.6 m / kg 1 / 3 Within the far-field range, the maximum relative error between the inversion results and the true equivalent in this application embodiment is improved by more than 70% compared with the traditional empirical formula, demonstrating extremely high prediction accuracy. The audio-visual fusion explosion equivalent inversion method proposed in this application embodiment exhibits excellent adaptability to various operating conditions: by introducing a free-field overpressure model and a near-ground overpressure model, it can be adapted to two typical operating conditions: airborne explosion and near-ground explosion. Experimental results show that the deviation between the average predicted equivalent and the true value under both operating conditions is reduced to within 25%. Furthermore, the audio-visual fusion explosion equivalent inversion method proposed in this application embodiment uses non-contact measurement equipment, is low-cost, and has a fast response: it can collect data based on conventional audio-visual equipment (such as public place surveillance cameras, smartphones, etc.), without the need to deploy specialized equipment such as pressure sensors and seismic wave monitoring stations. This results in low data acquisition costs and a fast response speed, enabling rapid extraction of on-site audio and video for inversion after an accident, making it suitable for emergency response scenarios of sudden explosion accidents.

[0130] Based on the same technical concept described above, this application also proposes an audio-visual fusion explosion equivalent inversion system based on dual-wave theory, such as... Figure 5 As shown, the inversion system 200 includes:

[0131] The acquisition and processing unit 201 is used to acquire audio and video data from the explosion site, and simultaneously obtain explosion flash and sound wave signals, while recording environmental parameters. The specific signal acquisition and processing methods are as described in the audio and video fusion explosion equivalent inversion method above, and will not be repeated here.

[0132] The first calculation unit 202 is used to take the time corresponding to the first appearance of the explosion flash in the video frame as the reference time, identify the inflection point where the sound wave amplitude rises sharply, determine the arrival time of the sound wave, and calculate the time difference between the arrival time of the sound wave and the reference time. The specific calculation method is as described in the above-mentioned audio-visual fusion explosion equivalent inversion method, and will not be repeated here.

[0133] The second calculation unit 203 is used to determine the current explosion condition based on the explosion height and select the corresponding overpressure model to calculate the critical proportional distance. The specific calculation method is as described in the audio-visual fusion explosion equivalent inversion method above, and will not be repeated here.

[0134] The third calculation unit 204 is used to calculate the ambient sound speed based on environmental parameters. The specific calculation method is as described in the above-mentioned audio-visual fusion explosion equivalent inversion method, and will not be repeated here.

[0135] Additionally, the solver unit 205 is used to substitute the time difference, critical proportional distance, ambient sound velocity, and propagation distance between the measuring point and the explosion center into a pre-constructed equivalent inversion model that integrates the propagation characteristics of the fused shock wave and sound wave, as well as the ground reflection effect, to obtain the explosion equivalent. The specific solution process is as described in the above-mentioned audio-visual fusion explosion equivalent inversion method, and will not be repeated here.

[0136] Furthermore, the inversion system 200 proposed in this application embodiment also includes:

[0137] Model building unit 206 is used to construct an equivalent inversion model that integrates the propagation characteristics of shock waves and sound waves as well as the ground reflection effect. The specific model construction method is as described in the above-mentioned audio-visual fusion explosion equivalent inversion method, and will not be repeated here.

[0138] Based on the same technical concept described above, this application also proposes an electronic device, such as... Figure 6 As shown, the electronic device 300 includes: a memory 310, a processor 320, and a computer program A311 stored in the memory 310 and executable on the processor 320. When the processor 320 executes the computer program A311, it performs the following steps:

[0139] Collect audio and video data from the explosion site, and simultaneously acquire explosion flash and sound signals, while recording environmental parameters;

[0140] Using the video frame corresponding to the first appearance of the explosion flame as the reference time, and identifying the inflection point where the sound wave amplitude rises sharply, the arrival time of the sound wave is determined, and the time difference between the arrival time of the sound wave and the reference time is calculated.

[0141] Based on the explosion height, determine the current explosion condition and select the corresponding overpressure model to calculate the critical proportional distance.

[0142] The speed of sound in the environment is calculated based on environmental parameters.

[0143] The explosion yields the time difference, critical proportional distance, ambient sound velocity, and propagation distance between the measuring point and the explosion center by substituting them into a pre-constructed equivalent inversion model that integrates the propagation characteristics of shock waves and sound waves as well as the ground reflection effect.

[0144] Optionally, when the processor 320 executes the computer program A311, it can implement any of the corresponding embodiments in the above-described audio-visual fusion explosion equivalent inversion method.

[0145] It should be noted that the electronic device proposed in this application embodiment is a device used to implement the above-mentioned audio and video fusion explosive equivalent inversion method. Therefore, based on the above-mentioned audio and video fusion explosive equivalent inversion method proposed in this application embodiment, those skilled in the art can understand the specific implementation method and various variations of the electronic device in this application embodiment. Therefore, how the electronic device specifically implements the above-mentioned audio and video fusion explosive equivalent inversion method will not be described in detail here. Any electronic device used by those skilled in the art to implement the above-mentioned audio and video fusion explosive equivalent inversion method falls within the scope of protection of this application.

[0146] Based on the same technical concept described above, embodiments of this application also propose a computer-readable storage medium, such as... Figure 7 As shown, the computer-readable storage medium 400 stores a computer program B411, which, when executed by a processor, performs the following steps:

[0147] Collect audio and video data from the explosion site, and simultaneously acquire explosion flash and sound signals, while recording environmental parameters;

[0148] Using the video frame corresponding to the first appearance of the explosion flame as the reference time, and identifying the inflection point where the sound wave amplitude rises sharply, the arrival time of the sound wave is determined, and the time difference between the arrival time of the sound wave and the reference time is calculated.

[0149] Based on the explosion height, determine the current explosion condition and select the corresponding overpressure model to calculate the critical proportional distance.

[0150] The speed of sound in the environment is calculated based on environmental parameters.

[0151] The explosion yields the time difference, critical proportional distance, ambient sound velocity, and propagation distance between the measuring point and the explosion center by substituting them into a pre-constructed equivalent inversion model that integrates the propagation characteristics of shock waves and sound waves as well as the ground reflection effect.

[0152] Optionally, when the computer program B411 is executed by the processor, it can implement any of the embodiments corresponding to the above-described audio-visual fusion explosion equivalent inversion method.

[0153] It should be noted that the descriptions of each embodiment in the above embodiments have different focuses. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0154] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0155] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0156] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0157] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0158] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this application. It should be understood that the above description is only a specific embodiment of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. An audio-video fusion explosion equivalent inversion method based on a two-wave theory, characterized in that, include: Collect audio and video data from the explosion site, and simultaneously acquire explosion flash and sound signals, while recording environmental parameters; The video frame corresponding to the first appearance of the explosion flame is used as the reference time, and the inflection point where the sound wave amplitude rises sharply is identified to determine the arrival time of the sound wave. The time difference between the arrival time of the sound wave and the reference time is calculated. Based on the explosion height, determine the current explosion condition and select the corresponding overpressure model to calculate the critical proportional distance. The speed of sound in the environment is calculated based on the environmental parameters. The time difference, critical proportional distance, ambient sound speed, and propagation distance between the measuring point and the explosion center are substituted into a pre-constructed equivalent inversion model that integrates the propagation characteristics of shock waves and sound waves and the ground reflection effect to obtain the explosion equivalent.

2. The audio-video fusion explosion equivalent inversion method based on the two-wave theory according to claim 1, characterized in that, The construction process of the equivalent inversion model includes: By introducing the explosion similarity rate and the theory of shock wave front propagation, a functional relationship between shock wave overpressure, propagation distance, and explosion equivalent is established. Establish the functional relationship between wave velocity and overpressure; Establish the integral form of the proportional-time propagation of the shock wave; Based on the critical proportional distance, the propagation process of the explosion wave is divided into two stages: the shock wave stage and the sound wave stage. Based on the propagation time of the two stages, the expression for the total propagation time from the explosion center to the measuring point is obtained. The total propagation time is approximated by the time difference between the firelight and sound waves measured by audio and video. The total propagation time expression is processed to obtain the equivalent inversion model.

3. The audio-video fusion explosion equivalent inversion method based on the two-wave theory according to claim 2, characterized in that, The equivalent inversion model is expressed as follows: ； in, The explosive yield; For the distance of propagation; For ambient sound speed; The time difference between the firelight and the sound wave; This represents the propagation time proportion of the shock wave phase. This is the critical proportional distance.

4. The audio-visual fusion explosion equivalent inversion method based on dual-wave theory according to any one of claims 1-3, characterized in that, The aforementioned acquisition of audio and video data from the explosion site, and simultaneous acquisition of explosion flash and sound wave signals, includes: The explosion flash and sound signals during the explosion process were acquired simultaneously by video acquisition equipment and audio acquisition equipment. The video acquisition device continuously captures data until the explosion and flames completely disappear, and the audio acquisition device continuously captures data until the sound wave signal attenuates to the baseline level.

5. The audio-visual fusion explosion equivalent inversion method based on dual-wave theory according to any one of claims 1-3, characterized in that, The process of determining the current explosion condition based on the explosion height, selecting the corresponding overpressure model, and calculating the critical proportional distance includes: When the current explosion condition is an air explosion, the corresponding critical proportional distance is calculated using the free-field overpressure model; When the current explosion condition is a near-ground explosion, the critical proportional distance is calculated using the near-ground overpressure model.

6. The audio-visual fusion explosion equivalent inversion method based on dual-wave theory according to claim 5, characterized in that, The free-field overpressure model includes: the Sadovskyi model, the Baker model, or the Mills model; Substituting the critical sound pressure into the free-field overpressure model, the corresponding critical proportional distance is calculated; The critical sound pressure is obtained by inversion based on the ambient atmospheric pressure and the Rankine-Hugoniot relationship.

7. The audio-visual fusion explosion equivalent inversion method based on dual-wave theory according to claim 5, characterized in that, The near-ground overpressure models include: the Ye model, the GB 6722-2014 ground reflected wave overpressure formula, or the Xiao model; Substituting the critical sound pressure into the near-ground overpressure model, the corresponding critical proportional distance is calculated; The critical sound pressure is obtained by inversion based on the ambient atmospheric pressure and the Rankine-Hugoniot relationship.

8. The audio-visual fusion explosion equivalent inversion method based on dual-wave theory according to any one of claims 1-3, characterized in that, The calculation of the ambient sound speed based on the environmental parameters includes: The ambient sound speed is obtained by correcting for ambient temperature.

9. A system for audio-visual fusion explosion equivalent inversion based on dual-wave theory, characterized in that, include: The acquisition and processing unit is used to acquire audio and video data at the explosion site, and simultaneously obtain explosion flash and sound wave signals, while recording environmental parameters. The first calculation unit is used to take the time corresponding to the video frame where the explosion and fire first appeared as the reference time, identify the inflection point where the sound wave amplitude rises sharply, determine the arrival time of the sound wave, and calculate the time difference between the arrival time of the sound wave and the reference time. The second calculation unit is used to determine the current explosion condition based on the explosion height and select the corresponding overpressure model to calculate the critical proportional distance. The third calculation unit is used to calculate the ambient sound speed based on the environmental parameters. In addition, a solution unit is used to substitute the time difference, critical proportional distance, ambient sound speed, and propagation distance between the measuring point and the explosion center into a pre-constructed equivalent inversion model that integrates sound wave propagation characteristics and ground reflection effects to obtain the explosion equivalent.

10. The audio-visual fusion explosion equivalent inversion system based on dual-wave theory according to claim 9, characterized in that, Also includes: The model building unit is used to construct an equivalent inversion model that integrates the propagation characteristics of shock waves and sound waves as well as the ground reflection effect.

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