Electronic detonator delay precision test method based on underwater shock wave measured waveform

Abstract

A kind of electronic detonator delay precision test method based on underwater shock wave measured waveform, a group of electronic detonators to be measured are arranged at different heights in the vertical projection direction of Archimedes spiral in open water, and a plurality of underwater shock wave sensors are arranged at different heights of vertical axis in the center of spiral plane, all electronic detonators are sequentially initiated by initiator control, and the water shock wave pressure curve generated by the explosion of each electronic detonator is obtained by water shock wave sensor after initiation;Then, the water shock wave pressure curve generated by each electronic detonator obtained by the water shock wave sensor is analyzed by using wavelet analysis method suitable for non-stationary signal analysis, and the time-energy density curve of the waveform is obtained to obtain the accurate time of each water shock wave arrival, and the accurate delay time of each electronic detonator is obtained by subtracting the time required for water shock wave propagation in water;The actual obtained electronic detonator delay time is compared with the designed delay time of electronic detonator to determine the delay precision of electronic detonator.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of blasting, and particularly relates to an electronic detonator delay precision testing method based on underwater shock wave measured waveforms, which can batch-determine the delay time of electronic detonators and is suitable for precision determination of electronic detonators in the field of water and electricity, transportation and other fields of engineering blasting excavation. BACKGROUND

[0002] With the continuous development of China's economic construction, the requirements for engineering blasting control are getting higher and higher in the field of engineering blasting projects such as mining, water conservancy and hydropower, civil engineering, railways, and transportation. With the rapid development of blasting equipment and construction technology, blasting technology and blasting vibration control measures have made great progress, and differential blasting technology and fine blasting technology have become mainstream technologies. In differential blasting and fine blasting, the accuracy of delay time directly determines whether the blasting purpose can be achieved and whether the blasting effect is ideal. Therefore, using high-precision delay detonators and reasonably determining the delay interval time of differential blasting can achieve the purposes of improving the blasting effect, reducing the unit consumption of explosives, and controlling the blasting pile.

[0003] Electronic detonators, as a kind of safe and reliable, high-precision, intelligent, and environmentally friendly initiation equipment with excellent performance, can meet the requirements of differential shock absorption in complex blasting engineering, and are increasingly used in engineering. In blasting engineering, the delay precision of detonators is the key to the implementation of differential blasting technology, and the delay precision of detonators directly affects the blasting effect and safety, so it is necessary to test the delay precision of electronic detonators to provide high-precision digital electronic detonator products with excellent performance.

[0004] The professional detonator precision testing method is the on-off method and the professional instrument explosion-proof box testing method, which is usually high-precision measurement by detonator manufacturers, requires high equipment, and has complicated procedures, and is not suitable for on-site testing. The conventional detonator precision testing method is to determine the detonation time of the detonator by monitoring various effects such as blasting vibration, blasting sound pressure, and shock wave caused by detonation of the detonator, and then to determine the precision of the detonator, i.e. the seismometry method and the sound pressure measurement method. The seismometry method determines the detonation time by receiving the blasting vibration caused by the detonation of the detonator through a blasting vibration tester. Due to the uncertainty of the propagation of blasting vibration in the stratum, the propagation time of vibration caused by different sources will also be different, and the measurement error is large. The sound wave measurement method determines the detonation time by receiving the air shock wave caused by the detonation of the detonator through a sound pressure testing device. Since the sound propagation in the air is greatly affected by wind speed, air temperature and other external factors, the test may also have large errors. In view of the above problems, it is necessary to propose an electronic detonator delay precision testing method which is convenient for on-site testing, efficient and practical, and has small detection error. SUMMARY

[0005] In order to solve the problems of large error and great interference in the existing detonator delay precision measurement, the present application provides an electronic detonator delay precision testing method based on underwater shock wave measured waveform, which can measure the precision of detonator at any time in blasting engineering.

[0006] An electronic detonator delay precision testing method based on underwater shock wave measured waveform, comprising the following steps:

[0007] (1) Select a safe open water area, set a horizontal plane under the water surface as the position of the plane Archimedes spiral, arrange a group of electronic detonators under the plane Archimedes spiral in the water area, the group of electronic detonators contains three or more electronic detonators, each electronic detonator in the group has a unique number MSn, n = 1, 2, 3…, and the group of electronic detonators to be tested are arranged at different heights along the vertical projection direction of the Archimedes spiral under the plane Archimedes spiral in the water area according to the number;

[0008] (2) Arrange three or more water shock wave sensors at different heights along the vertical direction axis of the center of the plane Archimedes spiral in the water, sequentially numbered i from top to bottom, i = 1, 2, 3…, the water shock wave sensor is used to receive the shock wave signal transmitted by the explosion of the electronic detonator; the signal output end of the water shock wave sensor is connected to the signal input end of the shock wave tester, the shock wave tester is arranged in a safe area on the shore away from the explosion position; the signal output end of the shock wave tester is connected to the data input end of the computer; the shock wave tester is used to record the waveform data transmitted by the water shock wave sensor and transmit it to the computer for processing;

[0009] (3) Measure the straight-line position distance S of each electronic detonator and the water shock wave sensor by using a measuring scale or a range finder ni ;

[0010] (4) Set the detonation time of each electronic detonator, so that the detonation time interval between two adjacent electronic detonators is 30 ms; each electronic detonator is connected to a detonator, wherein the electronic detonator set as the first detonator is a nominal delay detonator;

[0011] The detonator controls the detonation of each electronic detonator in turn, and the shock wave tester records the underwater shock wave waveform of each detonated electronic detonator; the shock wave tester transmits the measured waveform data to the computer, and the computer reads the waveform data and performs calculation and processing:

[0012] The wave peak starting time in each wave band is determined by using wavelet analysis and time-energy density method, the arrival time of the water shock wave generated by each differential section explosion is obtained according to the position of the prominent peak value, so as to obtain the actual detonation delay time of each section of electronic detonator, and the specific steps are as follows:

[0013] (4.1) Determine and record the initiation start time at the moment of initiation, denoted as T n ;

[0014] (4.2) According to the waveform data obtained by the shock wave tester, use wavelet analysis method to find out the start time T ni ;

[0015] (4.3) According to the distance S ni obtained in step (3), the initiation start time T n recorded in step (4.1), and the start time T ni of each wave peak obtained in step (4.2), calculate the delay time of each electronic detonator:

[0016]

[0017] In the formula:

[0018] v i - the underwater propagation speed of explosion shock wave in the current test environment calculated by the i th sensor, m / s;

[0019] S li - the distance between the 1 st electronic detonator and the i th sensor;

[0020] T li - the start time of the shock wave peak generated by the 1 st electronic detonator measured by the i th sensor;

[0021] T1- the initiation start time of the 1 st nominal electronic detonator, ms;

[0022] - the nominal delay time of the 1 st electronic detonator, ms;

[0023] - the average underwater propagation speed of explosion shock wave in the current test environment, m / s;

[0024] t ni - the delay time of the n th electronic detonator calculated by the i th sensor, ms;

[0025] T ni - the start time of the shock wave peak generated by the n th electronic detonator measured by the i th sensor, ms;

[0026] T n - the initiation start time of the n th electronic detonator, ms;

[0027] S ni - the distance between the n th electronic detonator and the i th sensor, m;

[0028] the average delay time of the nth electronic detonator, ms;

[0029] (5) calculating the measured delay time precision of the nth electronic detonator:

[0030]

[0031] ε n the measured delay time precision of the nth electronic detonator, %;

[0032] the actual average delay time of the nth electronic detonator, ms;

[0033] t n0 the factory design delay time of the nth electronic detonator, ms.

[0034] Further, the electronic detonator delay precision test method based on the measured waveform of underwater shock wave is characterized in that: the distance between each electronic detonator and the water level is h1≥1m, the distance between each electronic detonator and the water bottom is h3≥1.5m, and the depth H of the selected water area is≥2.5m+h2, wherein h2 is the distance between the lowest electronic detonator and the plane of the Archimedes spiral line; and h3 is the distance between the lowest electronic detonator and the water bottom.

[0035] Further, the electronic detonator delay precision test method based on the measured waveform of underwater shock wave is characterized in that: the distance between each electronic detonator and the water level is h1≥1m, the distance between each electronic detonator and the water bottom is h3≥1.5m, and the depth H of the selected water area is≥2.5m+h2, wherein h2 is the distance between the lowest electronic detonator and the plane of the Archimedes spiral line; and h3 is the distance between the lowest electronic detonator and the water bottom. wherein is the charge amount of the electronic detonator;

[0036] Further, the electronic detonator delay precision test method based on the measured waveform of underwater shock wave is characterized in that: the maximum circumferential diameter D of the selected spiral line should satisfy: 30d≤D≤300d, and D≤2h3, wherein d is the diameter of the electronic detonator, and h3 is the distance between the lowest electronic detonator and the water bottom.

[0037] The electronic detonator delay precision test method based on the measured waveform of underwater shock wave provided by the application has the advantages that the test is simple, multiple electronic detonators of different sections can be arranged in a detonation network at the same time, the delay time of each electronic detonator can be measured at the same time, the test efficiency is high, the analysis result is reliable, the cost is low, the interference of the outside world on the shock wave is small due to the constant density of water, the test is not affected by external factors such as temperature, wind speed, and water flow speed, the application is simple in a blasting construction site, the delay precision of the electronic detonator can be tested in real time, the detonation network can be arranged flexibly, and the method has great popularization value. The delay time of the electronic detonator can be batch determined, and the method is suitable for precision determination of electronic detonators in engineering blasting excavation in the fields of water and electricity and transportation. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 is the electronic detonator and sensor arrangement azimuth plane schematic diagram;

[0039] Figure 2 is the electronic detonator and sensor arrangement azimuth side view schematic diagram;

[0040] Figure 3 is the wave shape graph recorded by the water shock wave tester;

[0041] Figure 4 is the control flow chart of the test method of the present application. DETAILED DESCRIPTION

[0042] A test method for the delay precision of electronic detonator based on the measured wave shape of underwater shock wave, which comprises the following steps:

[0043] (1) Select a safe open water area, set a horizontal plane under the water surface as the position of the plane Archimedes spiral, arrange a group of electronic detonators under the plane Archimedes spiral in the water area, the group of electronic detonators contains three or more electronic detonators, each electronic detonator in the group has a unique number MSn, n = 1, 2, 3…, and arrange the group of electronic detonators to be tested in the water area under the plane Archimedes spiral at different heights along the vertical projection direction of the Archimedes spiral according to the number;

[0044] (2) Arrange three or more water shock wave sensors at different heights along the vertical central axis of the plane Archimedes spiral in the water, number them from top to bottom as i, i = 1, 2, 3…, the water shock wave sensors are used to receive the shock wave signals from the explosion of electronic detonators; the signal output end of the water shock wave sensor is connected to the signal input end of the shock wave tester, the shock wave tester is set in a safe area on the shore far away from the explosion position; the signal output end of the shock wave tester is connected to the data input end of the computer; the shock wave tester is used to record the wave shape data from the water shock wave sensor and transmit it to the computer for processing;

[0045] (3) Measure the straight line distance S between each electronic detonator and the water shock wave sensor with a measuring scale or a range finder ni ;

[0046] (4) Set the detonation time of each electronic detonator, so that the detonation time interval between two adjacent electronic detonators is 30 ms; connect each electronic detonator to a detonator, wherein the electronic detonator set as the first detonator is a nominal delay detonator;

[0047] The initiator controls the sequential initiation of each electronic detonator, and the shock wave tester records the underwater shock wave waveform of each initiated electronic detonator; the shock wave tester transmits the measured waveform data to the computer, and the computer reads the waveform data and performs calculation and processing:

[0048] The wave peak starting time in each wave band is determined by wavelet analysis and time-energy density method, the arrival time of the water shock wave generated by each differential section explosion is obtained according to the position of the prominent peak value, so as to obtain the actual initiation delay time of each section of electronic detonator, and the specific steps are as follows:

[0049] (4.1) The initiation starting time is determined and recorded at the initiation moment, denoted as T n ;

[0050] (4.2) According to the waveform data obtained by the shock wave tester, the wavelet analysis method is used to find out the starting time T ni of each wave peak of the explosion shock wave measured by the shock wave tester;

[0051] (4.3) According to the distance S ni obtained in step (3), the initiation starting time T n recorded in step (4.1), and the starting time T ni of each wave peak obtained in step (4.2), the delay time of each electronic detonator is calculated:

[0052]

[0053] In the formula:

[0054] v i is the underwater propagation speed of explosion shock wave in the current test environment calculated by the i-th sensor, m / s;

[0055] S li is the distance between the first electronic detonator and the i-th sensor;

[0056] T li is the starting time of the wave peak of the shock wave generated by the first detonator measured by the i-th sensor;

[0057] T1 is the initiation starting time of the first nominal electronic detonator, ms;

[0058] is the nominal delay time of the first electronic detonator, ms;

[0059] is the average underwater propagation speed of explosion shock wave in the current test environment, m / s;

[0060] t ni— The delay time of the nth electronic detonator calculated by the ith sensor, ms;

[0061] T ni — The time of the nth electronic detonator calculated by the ith sensor, ms;

[0062] T n — The time of the nth electronic detonator calculated by the ith sensor, ms;

[0063] S ni — The distance between the nth electronic detonator and the ith sensor, m;

[0064] — The delay time of the nth electronic detonator calculated by the ith sensor, ms;

[0065] (5), Calculate the accuracy of the measured delay time of the nth electronic detonator:

[0066]

[0067] ε n — The accuracy of the measured delay time of the nth electronic detonator, %;

[0068] — The actual average delay time of the nth electronic detonator, ms;

[0069] t n0 — The factory design delay time of the nth electronic detonator, ms.

[0070] The distance between each electronic detonator and the water surface is h1≥1m, and the distance between each electronic detonator and the water bottom is h3≥1.5m, then the depth of the selected water area H≥2.5m+h2, wherein h2 is the distance between the lowest electronic detonator and the plane of the Archimedes spiral; h3 is the distance between the lowest electronic detonator and the water bottom;

[0071] The distance L between the arranged electronic detonators and the surrounding water area should meet: wherein is the charge of the electronic detonator;

[0072] The maximum circumferential diameter D of the selected spiral should meet: 30d≤D≤300d, and D≤2h3, wherein d is the diameter of the electronic detonator, and h3 is the distance between the lowest electronic detonator and the water bottom.

[0073] Wavelet transform is a time-scale(time-frequency) analysis method of signal, which has the characteristics of multi-resolution and can represent the local characteristics of signal in both time and frequency domains. It has high frequency resolution and low time resolution in low frequency domain, and high time resolution and low frequency resolution in high frequency domain, which is very suitable for detecting the transient abnormal phenomena in normal signal and displaying its components.

[0074] The continuous wavelet transform of any energy-limited function f(t) with respect to ψ(t) is defined as follows:

[0075]

[0076] In the above equation, a and b are the scale factor and the translation factor respectively. According to Moyal inner product theorem, the following equation is true:

[0077]

[0078] The above equation shows that the integral sum of the square of wavelet transform amplitude is proportional to the energy of the analyzed signal. According to the concept of energy density, equation (4) can be written as:

[0079] ∫ R |f(t)| 2 dt=∫ R E(b)db (5)

[0080] In the above equation:

[0081]

[0082] In wavelet transform, the scale a corresponds to the frequency ω in a certain sense, so equation (6) gives the distribution of the energy of all frequency bands of the signal with respect to time b, which is called time-energy density function. In practical application, the integral upper and lower limits of the above equation can be changed so that the integral interval falls within a certain frequency range of the signal to be analyzed, thereby obtaining the distribution characteristics of the energy density of the signal in the frequency band with respect to time.

[0083] If a certain blasting is considered as a system, the initiation of each detonator is the process of inputting energy to the system, and the initiation of each detonator will inevitably cause the change of energy density in the system. Therefore, the integral upper and lower limits can be appropriately selected to calculate the energy density in the main frequency band of single blasting vibration signal according to equation (6), and the time-energy density graph is drawn. According to the position of the peak appearing in the graph, the arrival time of the vibration induced by each millisecond blasting can be obtained, and the actual delay time of each detonator can be obtained.

[0084] The principle of the electronic detonator delay precision test method based on underwater shock wave measured waveform of the present application lies in: according to the principle of the shock wave produced by the explosion of the electronic detonator propagating in water, a suitable water area is selected, a nominal delay detonator calibrated and a group of electronic detonators are fixed in order according to the number at different heights in the vertical projection direction of an Archimedes spiral trajectory, and a plurality of water shock wave sensors are arranged at different heights of the central axis of the spiral line, all the electronic detonators are sequentially initiated by the initiator, the underwater shock wave pressure curves excited by the explosion of each electronic detonator are obtained, the wavelet analysis method suitable for non-stationary signal analysis is used to analyze the measured waveform, and the time-energy density curve of the waveform is obtained to obtain the accurate time of each water shock wave to arrive, and the accurate delay time of the detonator is obtained by subtracting the time required for the water shock wave to propagate in water. In an initiation network, a plurality of electronic detonators with different segment numbers are arranged at the same time, and the delay time of each electronic detonator can be measured.

[0085] The electronic detonator delay precision test method based on underwater shock wave measured waveform of the present application has the advantages that:

[0086] 1. The present application does not require professional electronic detonator precision test instruments, and can meet the requirements of electronic detonator precision test in engineering field;

[0087] 2. In an initiation network, a plurality of electronic detonators with different segment numbers are arranged at the same time, and the delay time of each electronic detonator can be measured;

[0088] 3. Compared with air, water has large density and small compressibility, and the energy dissipation of the shock wave propagating in water is less, and the test in water is less affected by external interference such as wind, vehicle or explosion induced vibration;

[0089] 4. The shock wave propagation speed in the current test environment is calculated by the nominal detonator, which can eliminate the influence of environmental factors such as temperature, wind speed, water flow speed, water impurities and other environmental factors on the result, and has high reliability;

[0090] 5. The test efficiency is high, the analysis result is reliable, the cost is low, the application in blasting construction site is simple, the delay precision of the electronic detonator can be tested in real time, the initiation network can be arranged flexibly, and the present application has great popularization value.

[0091] The present application will be further described below with reference to the accompanying drawings. The arrangement of electronic detonators and sensors is shown in Figure 1 and Figure 2 . An open and safe water area is selected, and the electronic detonators are arranged in order according to the segment number size on the Archimedes spiral trajectory with a radius r=3.0m, wherein the first electronic detonator is a nominal detonator calibrated with a nominal delay time of 0.5ms, and the delay time of each subsequent electronic detonator is 0.5ms longer than that of the previous one. The included angle between adjacent electronic detonators is 45°, three water shock wave sensors are arranged at different heights in the center of the spiral line, the underwater explosion shock wave is recorded by a water shock wave tester, the height difference between the sensors is 20 cm, and a detonator is connected.

[0092] The detonation is carried out according to the above detonation network, the underwater explosion shock wave generated by the explosion is transmitted to the monitoring point and received by the water shock wave sensor, the water shock wave waveform is read by the shock wave tester, the measured data is processed, and finally the waveform image is obtained as shown in Figure 3 The image contains multiple wave bands, and the number of wave bands is consistent with the number of electronic detonators in theory.

[0093] The wave peak starting time in each wave band is determined by wavelet analysis and time-energy density method, and the arrival time of the shock wave generated by each differential segment explosion can be obtained according to the peak position, so that the actual detonation delay time of each segment electronic detonator is obtained. The specific implementation process is as follows:

[0094] (1) Determine the explosion starting time, denoted as T n ;

[0095] (2) Find the starting time of each wave peak, denoted as T ni ;

[0096] (3) Measure the distance S ni between each electronic detonator and the sensor;

[0097] (4) Calculate the average delay time of each electronic detonator according to formula (1) using the measured data;

[0098] (5) Calculate the measured delay time precision difference of each electronic detonator according to formula (2).

[0099] The above is the best embodiment of the present application, which does not limit the present application in any form, and any simple modification, equivalent change and modification of the above examples according to the technical essence of the present application still falls within the protection scope of the present application.

[0100] The above is only a specific implementation method of the present application, but the protection scope of the present application is not limited thereto, any skilled person in the technical field can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be limited by the protection scope of the claims.

Claims

1. A method for testing the delay precision of an electronic detonator based on the measured waveform of an underwater shock wave, characterized in that It comprises the following steps: (1) Select a safe open water area, set a horizontal plane under the water surface as the position of the plane Archimedes spiral, arrange a group of electronic detonators under the plane Archimedes spiral in the water area, each electronic detonator in the group has a unique number MSn, n = 1, 2, 3…, and arrange the group of electronic detonators to be tested at different heights along the vertical projection direction of the Archimedes spiral under the plane Archimedes spiral in the water area according to the number; (2) Arrange three or more water shock wave sensors at different heights along the vertical direction axis of the center of the plane Archimedes spiral in the water, and number them from top to bottom as i, i = 1, 2, 3…, the water shock wave sensor is used to receive the shock wave signal transmitted by the electronic detonator explosion; the signal output end of the water shock wave sensor is connected to the signal input end of the shock wave tester, and the shock wave tester is set in a safe area on the shore away from the explosion position; the signal output end of the shock wave tester is connected to the data input end of the computer; the shock wave tester is used to record the waveform data transmitted by the water shock wave sensor and transmit it to the computer for processing; (3) Measure the linear position distance S of each electronic detonator from the water hammer sensor with a ruler or range finder ni ; (4) Set the detonation time of each electronic detonator, and set the detonation time interval between two adjacent electronic detonators as 30 ms; Each electronic detonator is connected to a detonator, and the electronic detonator set as the first detonator is a nominal delay detonator; The detonator controls the detonation of each electronic detonator in turn, and the shock wave tester records the underwater shock wave waveform of each detonated electronic detonator; the shock wave tester transmits the measured waveform data to the computer, and the computer reads the waveform data and performs calculation and processing: Determine the peak starting time in each wave band by wavelet analysis and time-energy density method, obtain the arrival time of the water shock wave generated by each differential segment explosion according to the prominent peak position, and obtain the actual detonation delay time of each segment electronic detonator, the specific steps are as follows: (4.1) At the moment of detonation, determine and record the detonation start time, denoted as T n ; (4.2) According to the waveform data obtained by the shock wave tester, the wavelet analysis method is used to find out the starting time T of each wave peak of the explosion shock wave measured by the shock wave tester ni ; (4.3) the distance S obtained according to step (3) ni the start time T of the initiation recorded in step (4.1) n the start time T of each wave peak obtained in step (4.2) ni the delay time of each electronic detonator is calculated In the formula: v i - the underwater propagation speed of the explosion shock wave in the current test environment, m / s, calculated by the i-th sensor S li — is the distance between the 1st electronic detonator and the i-th sensor; T li — is the time when the shock wave peak generated by the first detonator is detected by the i-th sensor; T1 is the detonation start time of the first nominal electronic detonator, ms; - nominal delay time of the 1st electronic detonator, ms; - average underwater propagation speed of the blast shock wave in the current test environment, m / s; t ni — the delay time calculated by the i-th sensor for the n-th electronic detonator, ms T ni - the time of the beginning of the shock wave peak produced by the n-th detonator, measured by the i-th sensor, ms; T n - the start time of the initiation of the nth electronic detonator, ms; S ni - distance between the nth electronic detonator and the ith sensor, m; - average delay time of the n-th electronic initiating detonator, ms; (5) Calculate the measured delay time precision of the nth electronic detonator: ε n - measured delay time accuracy of the nth electronic initiating detonator, %; - actual average delay time of the nth electronic initiating detonator, ms; t n0 - factory design delay time of the nth electronic detonator, ms; The distance between each arranged electronic detonator and the water surface height h1≥1m, the distance between each electronic detonator and the water bottom height h3≥1.5m, and the selected water area depth H≥2.5m+h2, wherein h2 is the distance between the lowest position of the detonator and the plane of the Archimedes spiral; h3 is the distance between the lowest arranged electronic detonator and the water bottom; The distance L from the electronic detonator to the water area should satisfy: wherein W is the charge weight of the electronic detonator; The maximum circumferential diameter D of the selected spiral line should meet: 30d≤D≤300d, and D≤2h3, wherein d is the diameter of the electronic detonator, and h3 is the distance between the lowest arranged electronic detonator and the water bottom.

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