An explosion origin positioning method based on shock wave overpressure time sequence signal

Abstract

The application belongs to the technical field of explosion origin positioning, and discloses an explosion origin positioning method based on a shock wave overpressure time sequence signal. n According to an explosion test scheme or a region where an explosion accident may occur and needs to be monitored, not less than four shock wave overpressure monitoring points S1, S2, … S n are set, shock wave overpressure sensors are arranged at the S1, S2, … S i points, shock wave overpressure signals P i received by the shock wave overpressure sensors at the S points are monitored and stored in cycles, a theoretical expression of different distance arrival times is obtained according to time sequence signals of shock wave overpressure peak values at different points and air pressure, temperature and humidity conditions of an explosion region A, and the most possible explosion origin coordinates and errors are calculated in three-dimensional space by using a constraint optimization interior point algorithm and a nonlinear least square method. The explosion origin is positioned by using a shock wave overpressure signal propagation speed law, the anti-interference capability is high, the explosion origin is not easily affected by external factors, and the positioning result is high in accuracy.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of explosion origin positioning, and particularly relates to an explosion origin positioning method based on a shock wave overpressure time sequence signal. BACKGROUND

[0002] Explosion origin positioning is an important link in carrying out explosion tests, is an important basis for evaluating the precision of weapons and equipment, and is also a key to accident analysis and investigation after an unexpected explosion accident. Accurate analysis of the characteristic field signals such as shock wave overpressure, seismic vibration, sound, light and the like in the space around the explosion is a prerequisite for explosion origin positioning. However, explosion is a very rapid physical or chemical energy release process, in which the matter in the space releases the energy contained therein at a very fast speed, and various energy fields develop at a very fast speed and have strong mutual coupling. Therefore, it is extremely difficult to accurately measure and analyze the signals such as shock wave overpressure, seismic vibration, sound, light and the like at the explosion site when the explosion occurs, which also leads to difficulty in accurately positioning the explosion origin after the explosion test and explosion accident.

[0003] The known explosion origin positioning methods in China at present include a seismic source positioning method based on seismic wave signals, a five-element cross array sound positioning algorithm, a dynamic explosion center positioning method based on air explosion shock waves and the like. The seismic source positioning method based on seismic wave signals needs to arrange at least four seismic vibration sensors in the explosion site before the explosion, and place them in a unified time system, and based on the assumption that the seismic vibration signals propagate at a uniform speed in different directions after the explosion, the positioning is realized by measuring the time difference of the explosion seismic signals received by the test nodes at different positions, and the positioning error depends on the number of measurement points and the time synchronization error therebetween. Since this method is based on the assumption that the seismic wave propagates at a uniform speed after the explosion, but in fact the huge energy generated at the moment of explosion will cause the ground soil to liquefy and change the seismic wave propagation speed, so that the seismic wave does not propagate at a uniform speed, thereby causing the model approximation of this positioning method to be too large and the positioning precision to be low. Furthermore, the seismic wave signal is easily affected by many factors such as environmental temperature, humidity, geological structure and the like, resulting in poor environmental interference resistance.

[0004] Five cross array acoustic positioning algorithm needs to arrange more than 5 sound sensors in the vicinity of the explosion point before the explosion occurs. After collecting and recording the sound signals of different nodes, the time difference of the sound signals generated by the explosion to different sound sensor nodes is calculated by using the delay estimation algorithm, and the most possible explosion origin is calculated combined with the geometric relationship between the array elements. This method is based on the uniform speed of sound wave propagation in the calculation, but in fact the huge energy generated by the explosion will cause the temperature and air pressure around the explosion to rise instantaneously, and the speed of sound wave propagation in the air will change greatly due to the influence of temperature and air pressure. Therefore, after the explosion, the sound wave does not propagate at a constant speed, which will cause the model approximation of the positioning method to be too large, and the positioning accuracy is low.

[0005] The dynamic explosion center positioning method based on air explosion shock wave needs to arrange digital pressure recorders in the explosion area to form a test square array before the explosion. A plurality of groups of measuring points are obtained by selecting one measuring point in each area. The relative coordinates and shock wave overpressure values of each group of measuring points are used as original data. A function equation set is established based on the propagation law of the peak value of the shock wave overpressure in the free field of static explosion in the air, the engineering calculation formula of the dynamic explosion shock wave overpressure, and the wall reflection law to calculate the explosion origin. This method is based on the propagation law of the peak value of the shock wave overpressure in the free field to position. This method is only applicable to the positioning of the explosion origin in the air, and when the explosion origin is on the open ground or in a limited space with protective structure, the positioning accuracy cannot be guaranteed. In addition, when the shock wave is reflected and diffracted, the propagation speed does not change significantly, but the peak value is significantly reduced. The propagation process of the shock wave is affected by temperature, humidity, air pressure and other conditions, which also affects the propagation law of the peak value. Therefore, this method may be affected by the structure reflection and environment in the explosion range, and has poor anti-interference ability.

[0006] Therefore, there is a need for an explosion origin positioning method with high positioning accuracy and strong anti-interference ability. SUMMARY

[0007] In order to solve the above problems, the present application provides an explosion origin positioning method based on shock wave overpressure time sequence signal.

[0008] The above technical purpose of the present application is realized by the following technical scheme: an explosion origin positioning method based on shock wave overpressure time sequence signal, comprising the following steps:

[0009] S1: according to the explosion test scheme or the area where the explosion accident may occur and needs to be monitored, determining the explosion area A that needs to be monitored, and establishing a space rectangular coordinate system;

[0010] S2: more than 4 shock wave overpressure monitoring points S1, S2,... S n , measuring the three-dimensional coordinates of the S i points and recording them as (xi , y i , z i );

[0011] S3: In S1, S2,... S n point arrangement shock wave overpressure sensor, monitoring S i point shock wave overpressure sensor received shock wave overpressure signal P i , and cycle storage;

[0012] S4: When any point shock wave overpressure signal jumps more than the set threshold within 1ms, it is considered to have occurred explosion, record the time point as trigger time t0, trigger each monitoring point to save the shock wave overpressure signal between 2s before the trigger time and 5s after the trigger time, form the shock wave overpressure overpressure signal-time curve;

[0013] S5: Read the point where the shock wave overpressure signal jumps more than 0.5MPa within 1ms in the shock wave overpressure overpressure signal-time curve of each monitoring point, record the difference t i between its corresponding time and trigger time t0;

[0014] S6: According to the air pressure, temperature and humidity of the explosion area A, determine the sound speed c0, air density p0 and isentropic index K;

[0015] S7: According to the shock wave overpressure propagation law of hard ground, the theoretical expression of different distance arrival time is obtained:

[0016]

[0017] In the formula: τ is the arrival time; r is the distance between the measuring point and the explosion center; r0 is the integral starting point, taking 0.01m; m is the explosion equivalent; c0 is the sound speed; p0 is the air density; K is the isentropic index;

[0018] S8: Based on the constrained optimization interior point algorithm and the nonlinear least square method, a set of coordinates (x, y, z) and explosion equivalent m in the region A are solved,

[0019]

[0020] The minimum value of x, y, z and m is solved, and the coordinates (x, y, z) are the coordinates of the explosion origin, and the explosion equivalent m is the actual explosion equivalent;

[0021] S9: Calculate the positioning error of the explosion origin coordinates.

[0022] By adopting the technical scheme, at least four shock wave overpressure monitoring points are arranged in the area where explosion accidents are likely to occur, according to the time sequence signals of the peak values of the shock wave overpressure of different points, based on the propagation speed model of the peak values of the shock wave overpressure in the explosion process, the most likely explosion origin coordinates in the three-dimensional space are calculated by using the constrained optimization interior point algorithm and the nonlinear least square method. Since the shock wave can continue to diffract and propagate after encountering an obstacle, although the peak value of the shock wave overpressure is reduced, the propagation speed is almost not affected, the propagation speed is fast, and the method is not easily affected by other signals, so that the positioning accuracy of the method is high, and the anti-interference ability is strong.

[0023] Further, the explosion area A is a cuboid area, a space rectangular coordinate system is established with a vertex of the bottom surface of the cuboid area as an origin and three edge lengths intersecting the vertex as an x-axis, a y-axis and a z-axis.

[0024] By adopting the technical scheme, the explosion area A is set as a cuboid area, which is beneficial to the establishment of the space rectangular coordinate system.

[0025] Further, the shock wave overpressure monitoring points at least include four vertex positions of the top surface of the explosion area A.

[0026] By adopting the technical scheme, the shock wave overpressure monitoring points at least include four vertex positions of the top surface of the explosion area A, so that the point arrangement is more reasonable.

[0027] Further, the step S9 includes:

[0028] S9.1: the minimum value in the step S8 is taken into the formula (2) to calculate the value of the function F, and the value is recorded as an optimized residual error F0;

[0029] S9.2: the average time measurement error σ is calculated t =F0 / n; wherein n is the number of monitoring points;

[0030] S9.3: the derivatives of the function F with respect to the values of x, y and z are calculated,

[0031]

[0032] wherein δ is a positive small quantity, and δ is taken as 10 -12 ;

[0033] S9.4: the positioning error is calculated according to the derivatives and the average time measurement error,

[0034] δx=σ t ×x′, δy=σ t ×y′, and δz=σ t ×z′.

[0035] By adopting the technical scheme, the average time measurement error is calculated according to the optimization residual F0 of the minimum value of the function F, and the partial derivative of the arrival time signal of each point is calculated according to the positioning coordinate calculation result x, y, z, and then the error of the positioning result is calculated, so as to further verify the accuracy of the positioning result.

[0036] In summary, the present application has the following advantages: in the present application, not less than four shock wave overpressure monitoring points are arranged in the area where an explosion accident may occur, the time sequence signal of the peak value arrival time of the shock wave overpressure of different points is obtained, the most possible explosion origin coordinates and error are calculated in three-dimensional space based on the propagation speed model of the peak value of the shock wave overpressure in the explosion process, the constrained optimization interior point algorithm and the nonlinear least square method. The shock wave overpressure signal propagation speed law is used for explosion origin positioning. Firstly, the shock wave can continue to diffract and propagate after encountering an obstacle, although the peak value of the shock wave overpressure is reduced, the propagation speed is almost not affected, so the accuracy of the positioning is not affected. Secondly, after the explosion, the shock wave overpressure signal propagates the fastest except the light signal, and the propagation speed in the air is higher than that in other media, so each monitoring point can receive the shock wave overpressure signal generated from the explosion origin and propagating in the air in the first time, and is not disturbed by the shock wave signal propagating along the ground, wall and other structures, and has strong anti-interference ability. Thirdly, the physical model of the shock wave propagation law is used, the influence of the shock wave front overpressure on the propagation speed in the propagation process is considered, and the influence of different TNT equivalent on the shock wave propagation speed is considered, so as to ensure the accuracy of the explosion origin positioning result. DETAILED DESCRIPTION

[0037] The technical scheme in the embodiments of the present application is described clearly and completely below; obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the present application.

[0038] The present application discloses an explosion origin positioning method based on shock wave overpressure time sequence signal, comprising the following steps:

[0039] S1: According to the explosion test scheme or the area where the explosion accident may occur, the explosion area A to be monitored is determined, and a space rectangular coordinate system is established. Specifically, the explosion area A is selected as a cuboid region in three-dimensional space, and if the area where the explosion accident may occur is not a cuboid, the smallest circumscribed cuboid thereof is taken as the possible explosion area A. When selecting the explosion area A, it is ensured that there are no obvious structures that hinder or reflect the shock wave in the area. If such structures exist, the area should be divided into each region without such structures. Then, a space rectangular coordinate system is established with the bottom vertex of the cuboid region as the origin and the three edges intersecting the vertex as the x-axis, y-axis and z-axis, respectively, and it is ensured that the explosion center will not be on the x-axis.

[0040] S2: At least four shock wave overpressure monitoring points S1, S2,... S n are set in the explosion area A, and the three-dimensional coordinates of the points S i are measured and recorded as (x i , y i , z i ). Specifically, the shock wave overpressure monitoring points at least include the four vertex positions of the top surface of the explosion area A, and can also include the midpoint positions of the four edge lengths of the top surface, etc.

[0041] S3: Shock wave overpressure sensors are arranged at the points S1, S2,... S n , and the shock wave overpressure sensors are wired to ensure that the signal lines do not pass through the explosion area A, and the lines are as far away from the explosion center as possible; the signal lines within 5m from the explosion center are protected by pipe penetration or buried to avoid damage to the lines by explosion; the signal lines of the shock wave overpressure sensors at each point are connected to a data acquisition instrument with a sampling frequency of more than 100MHz, the gain coefficient of the data acquisition instrument is set according to the sensitivity of the shock wave overpressure sensor, the trigger mode of the data acquisition instrument is set to rising edge self-trigger, the data acquisition instrument is turned on, the shock wave overpressure signal P i received by the shock wave overpressure sensor at the point S i is monitored, and the circular storage is turned on and waits for triggering.

[0042] S4: When the shock wave overpressure signal at any point jumps more than the set threshold value within 1ms, it is considered that an explosion has occurred, the time point is recorded as the trigger time t0, the data acquisition instrument saves the shock wave overpressure signal between 2s before the trigger time and 5s after the trigger time at each monitoring point, and a shock wave overpressure signal-time curve is formed.

[0043] S5: The points where the shock wave overpressure signal jumps more than 0.5MPa within 1ms in the shock wave overpressure signal-time curve at each monitoring point are read, and the difference t i between the corresponding time and the trigger time t0 is recorded.

[0044] S6: Monitor the air pressure, temperature, humidity of the explosion area A, and determine the sound speed c0, air density p0, and isentropic index K according to the change relationship of sound speed, air density, and air pressure, environmental temperature and humidity.

[0045] S7: According to the propagation law of hard ground shock wave overpressure, the theoretical expression of arrival time at different distances is obtained:

[0046]

[0047] In the formula: τ is the arrival time, unit s; r is the distance from the measuring point to the explosion center, unit m; r0 is the integral starting point, 0.01 m, unit m; m is the explosion equivalent, unit kg; c0 is the sound speed, generally 340 m / s; p0 is the air density, generally 1.29 kg / m 3 ; K is the isentropic index, generally 1.4.

[0048] S8: Set the coordinates of the explosion origin as (x, y, z), and obtain m>0 from the non-negative constraint condition of the explosion equivalent; based on the nonlinear least squares method, solve a set of coordinates (x, y, z) and explosion equivalent m in the [0, +∞] interval in area A, and obtain

[0049]

[0050] Use the constrained optimization interior point algorithm, such as the fmincon optimization function of matlab software, to solve the minimum value of formula (2) x, y, z, m, that is

[0051]

[0052] Solve the minimum value of x, y, z, m, and the coordinates (x, y, z) are the coordinates of the explosion origin.

[0053] S9: Calculate the positioning error of the explosion origin coordinates.

[0054] S9.1: Take the minimum value of x, y, z in step S8 and bring it into formula (2) to calculate the value of the function F, which is denoted as the optimization residual F0;

[0055] S9.2: Divide the optimization residual by the number of arranged measuring points n to calculate the average time measurement error t = F0 / n; Wherein, n is the number of monitoring points;

[0056] S9.3: Calculate the derivative of the function F with respect to the numerical solution of x, y, z,

[0057]

[0058] Wherein, δ is a positive small quantity, which is 10-12 ;

[0059] S9.4: Calculate the positioning error according to the derivative and average time measurement error,

[0060] δx = σ t x', δy = σ t y', δz = σ t z'.

[0061] In this embodiment, the shock wave overpressure signal propagation speed law is used to locate the explosion origin. Firstly, the shock wave can continue to diffract and propagate after encountering an obstacle, although the overpressure peak value will be reduced, the propagation speed is almost not affected, so the accuracy of the positioning will not be affected. Secondly, after the explosion, the shock wave overpressure signal propagates the fastest, and its propagation speed in air is higher than in other media, so each monitoring point can receive the shock wave overpressure signal generated by the explosion origin and propagating in the air at the first time, and will not be disturbed by the shock wave signal propagating along the ground, wall and other structures, and has strong anti-interference ability. Thirdly, the shock wave propagation law physical model is used, the influence of the shock wave front overpressure on the propagation speed in the propagation process is considered, and the influence of different TNT equivalent on the shock wave propagation speed is considered, so as to ensure the accuracy of the explosion origin positioning result.

[0062] The above only describes the preferred embodiments of the present application, and the protection scope of the present application is not limited to the above-mentioned embodiments. Any technical scheme falling within the concept of the present application shall fall within the protection scope of the present application. It should be noted that for ordinary skilled persons in the art, some improvements and decorations without departing from the principles of the present application shall also be considered as the protection scope of the present application.

Claims

1. A method for locating the explosion origin based on shock wave overpressure timing signals, characterized in that: Includes the following steps: S1: Based on the explosion test plan or the area where an explosion accident may occur, determine the explosion area A that needs to be monitored and establish a spatial rectangular coordinate system; S2: Set up no fewer than 4 shock wave overpressure monitoring points S1, S2, ... S in explosion zone A. n Measure S i The three-dimensional coordinates of the point are denoted as (x i ,y i ,z i ); S3: In S1, S2, ... S n Shock wave overpressure sensors are installed at the points to monitor S i The shock wave overpressure signal P received by the point shock wave overpressure sensor i And store it cyclically; S4: When the shock wave overpressure signal at any point jumps beyond the set threshold within 1ms, it is considered that an explosion has occurred. This time point is recorded as the trigger time t0. Each monitoring point is triggered to save the shock wave overpressure signal from 2s before the trigger time to 5s after the trigger time, forming a shock wave overpressure signal-time curve. S5: Read the shock wave overpressure signal-time curves at each monitoring point where the shock wave overpressure signal experiences a jump of more than 0.5 MPa within 1 ms, and record the difference t between the corresponding time and the trigger time t0. i ; S6: Determine the speed of sound c0, air density ρ0, and isentropic index κ based on the air pressure, temperature, and humidity conditions in explosion area A; S7: Theoretical expressions for arrival times at different distances are derived based on the overpressure propagation law of shock waves over hard ground: Where: τ is the arrival time; r is the distance from the measuring point to the explosion center; r0 is the integration starting point, taken as 0.01m; m is the explosive equivalent; c0 is the speed of sound; ρ0 is the air density; κ is the isentropic exponent; S8: Solve for a set of coordinates (x, y, z) and the explosive yield m in the interval [0, +∞] in the explosion region A based on the constrained optimization interior point algorithm and nonlinear least squares method. Solve for the minimum values ​​of x, y, z, and m. The coordinates (x, y, z) are the coordinates of the origin of the explosion, and the explosion yield m is the actual explosion yield. S9: Calculate the positioning error of the explosion origin coordinates.

2. The explosion origin localization method based on shock wave overpressure timing signal according to claim 1, characterized in that: The explosion area A is a cuboid region. A spatial rectangular coordinate system is established with one vertex of the bottom surface of the cuboid region as the origin and the lengths of the three edges intersecting with the vertex as the x-axis, y-axis, and z-axis, respectively.

3. The explosion origin localization method based on shock wave overpressure timing signal according to claim 2, characterized in that: The shock wave overpressure monitoring points include at least the four vertices of the top surface of the explosion area A.

4. The explosion origin location method based on shock wave overpressure timing signal according to claim 1, characterized in that: Step S9 includes: S9.1: Take the minimum value in step S8 and substitute it into formula (2) to calculate the value of the function F, which is denoted as the optimization residual F0; S9.2: Calculate the average time measurement error σ t =F0 / n; where n is the number of monitoring points; S9.3: Calculate the numerical derivatives of the function F at x, y, and z. Where δ is a small positive quantity, taken as 10. -12 ; S9.4: Calculate the positioning error based on the derivative and average time measurement error, δx=σ t ×x′,δy=σ t ×y′,δz=σ t ×z′.

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