Blasting monitoring system and method based on PVDF

Abstract

The invention provides a PVDF (polyvinylidene fluoride)-based blasting monitoring system and a PVDF-based blasting monitoring method, which can realize accurate capture and time sequence analysis of each blasting event so as to accurately evaluate the blasting quality and provide a reliable basis for safe danger elimination, and comprises a vibration sensing module, a signal acquisition terminal and a control module, the signal acquisition terminal processes the electric signal, converts the electric signal into a digital vibration signal and transmits the digital vibration signal; the data monitoring terminal processes the received digital vibration signal by using an HHT algorithm to generate a Hilbert spectrum representing the time-frequency characteristic of the vibration signal; based on the Hilbert spectrum, identifying an effective blasting signal corresponding to the single blasting event; according to the time sequence of the effective blasting signals, an actual blasting time sequence is reconstructed; and the actual blasting time sequence is compared with a preset blasting scheme time sequence, and the blasting operation effect is judged.

Description

Technical Field

[0001] This invention relates to the field of blasting monitoring technology, specifically to a blasting monitoring system and method based on PVDF. Background Technology

[0002] In modern blasting projects such as mining and tunneling, digital electronic detonators have gradually replaced traditional industrial detonators due to their delay time being accurate to the millisecond level.

[0003] Although electronic detonators can solve the problem of accurate blasting delay time, in complex engineering environments, blasting accidents such as misfires or premature detonations may still occur due to various reasons such as geological conditions, detonator malfunctions, wiring problems, or on-site operational errors. These accidents are difficult to monitor, which not only seriously affect the blasting effect, but also leave unexploded misfires, posing a great safety hazard to subsequent work.

[0004] Traditional post-blasting site investigation methods are almost impossible to accurately determine which blast hole misfired due to the drastic changes in the terrain. Bomb disposal personnel are forced to conduct blind searches without knowing the specific location of the misfire, posing a significant threat to their personal safety. Some existing vibration monitoring technologies use traditional piezoelectric ceramic sensors with high inherent resonant frequencies, resulting in insufficient sensitivity and an inability to distinguish millisecond-level time differences. Other signal processing methods are relatively simple and struggle to accurately extract each individual blasting event from background noise and signal aliasing. Some detection equipment is also bulky and has complex wiring, making it unsuitable for harsh blasting environments in the field. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a PVDF-based blasting monitoring system and method, which can accurately capture and analyze the timing of each blasting event to accurately assess blasting quality and provide a reliable basis for safety hazard mitigation.

[0006] The technical solution is as follows: a PVDF-based blasting monitoring system, comprising: A vibration sensing module, comprising a PVDF sensor, wherein the PVDF sensor is used to monitor vibrations generated by blasting during blasting operations and convert the vibrations into electrical signals; A signal acquisition terminal is electrically connected to the vibration sensing module. The signal acquisition terminal receives the electrical signal from the vibration sensing module, processes the electrical signal, and converts it into a digital vibration signal for transmission. The data monitoring terminal receives digital vibration signals transmitted by the signal acquisition terminal via wireless communication; the data monitoring terminal is configured as follows: The received digital vibration signals are processed to identify the valid blasting signals corresponding to a single blasting event; based on the time information of the valid blasting signals, the actual blasting sequence is reconstructed.

[0007] Furthermore, the data monitoring terminal applies the HHT algorithm to process the received digital vibration signal to generate a Hilbert spectrum characterizing the time-frequency characteristics of the vibration signal; based on the Hilbert spectrum, it identifies the effective blasting signal corresponding to a single blasting event; according to the time sequence of the effective blasting signal, it reconstructs the actual blasting sequence; and compares the actual blasting sequence with the preset blasting scheme sequence to determine the effectiveness of the blasting operation.

[0008] Furthermore, the vibration sensing module includes a conical metal housing, and the PVDF sensor is disposed inside the conical metal housing; the conical metal housing can be inserted into the ground to transmit the blasting vibration to the PVDF sensor through the earth.

[0009] Furthermore, the signal acquisition terminal includes: A connecting cable is used to connect the vibration sensing module; The signal conditioning circuit is used to condition the electrical signal received from the vibration sensing module. An analog-to-digital converter circuit is used to convert the received electrical signal into a digital vibration signal. The wireless communication module is used to transmit the converted digital vibration signal; The power supply battery is used for power generation. The signal conditioning circuit, analog-to-digital conversion circuit, wireless communication module, and power supply battery are encapsulated in a metal casing.

[0010] Furthermore, the vibration sensing module is provided with a metal housing, and magnets are respectively provided on the metal housing of the vibration sensing module and the metal housing of the signal acquisition terminal.

[0011] A PVDF-based blasting monitoring method, characterized by being implemented based on the aforementioned PVDF-based blasting monitoring system, the method comprising the following steps: Vibration sensing modules containing PVDF sensors are installed at blasting monitoring points; During blasting operations, the vibration sensing module is used to collect vibration signals generated by blasting. The vibration signals are then processed by the signal acquisition terminal and wirelessly transmitted to the data monitoring terminal. On the data monitoring terminal, the received digital vibration signals are processed to identify the valid blasting signals representing a single blasting event; Based on the occurrence time of the effective blasting signal, the actual blasting sequence of the blasting operation is reconstructed; The actual blasting sequence is compared with the preset blasting plan sequence to determine the effectiveness of the blasting operation.

[0012] Furthermore, on the data monitoring terminal, the HHT algorithm is applied to the received digital vibration signal to generate the Hilbert spectrum of the vibration signal; Based on the Hilbert spectrum analysis of the vibration signal's time-frequency energy distribution, the effective blasting signal representing a single blasting event is identified. Based on the occurrence time of the effective blasting signal, the actual blasting sequence of the blasting operation is reconstructed; The actual blasting sequence is compared with the preset blasting plan sequence to determine the effectiveness of the blasting operation.

[0013] Furthermore, the Hilbert spectrum of the vibration signal is generated using the HHT algorithm, specifically as follows: Empirical mode decomposition is performed on the digital vibration signal to decompose it into several IMF components; Perform a Hilbert transform on each IMF component to calculate the instantaneous amplitude and instantaneous frequency of the signal; By combining time and frequency information, the Hilbert spectrum of the vibration signal is constructed.

[0014] Furthermore, empirical mode decomposition is performed on the digital vibration signal to decompose the signal into several IMF components, as follows: Using the original signal r(t) as the initial input, extract the signal envelope; Draw the mean envelope q(t) from the extracted envelope; Calculate the intermediate signal pt(t): pt(t) = r(t) - q(t); Determine whether the IMF's criteria are met; If satisfied, then further determine whether the standard deviation SD is within the required range; If the conditions are met, proceed to the Hilbert transform stage; otherwise, take r(t)-IMF(i) as the new original signal and IMF(i) as the intermediate signal that satisfies the IMF condition, return to the signal envelope extraction step, and continue to decompose the new IMF components.

[0015] Furthermore, the valid blasting signal is identified, specifically as follows: Set the energy threshold and time-frequency window; In the Hilbert spectrum, regions where the energy concentration exceeds the energy threshold within the time-frequency window are searched, and the signals corresponding to the found regions are identified as valid blasting signals, thus distinguishing blasting events from environmental noise and interference.

[0016] Furthermore, the actual blasting sequence is reconstructed as follows: noise and interference signals that are determined to be invalid blasting signals are filtered out from the digital vibration signal, and all valid blasting signals are retained according to the original timestamp to form the reconstructed actual blasting sequence.

[0017] Furthermore, the actual blasting sequence is compared with the preset blasting plan sequence to determine the effectiveness of the blasting operation, specifically including: By comparing the number of valid blasting signals in the actual blasting sequence with the number of preset blasting events in the blasting plan sequence, it can be determined whether there is a misfire. By comparing the time interval between adjacent effective blasting signals in the actual blasting sequence with the preset delay time in the blasting plan sequence, it can be determined whether there is premature blasting or delay anomaly.

[0018] The PVDF-based blasting monitoring system of the present invention uses a PVDF sensor. The PVDF sensor has extremely high sensitivity and response speed, and can accurately capture and distinguish blasting time differences at the microsecond level and above, providing a high-quality original signal basis for reconstructing the blasting sequence. The present invention processes the blasting-generated signal through the HHT algorithm, which is very suitable for extracting the characteristics of such sudden blasting signals from a background of strong interference, and can significantly improve the accuracy of blasting event identification. The vibration sensing module of the blasting monitoring system based on PVDF of the present invention provides two deployment schemes: ground insertion and magnetic attachment. The device is lightweight, compact, and flexible in installation, and can adapt to the monitoring needs of different terrains and working conditions. The system uses wireless data transmission, allowing operators to monitor in real time from a safe area away from the blasting site using handheld devices, ensuring personal safety. It enables real-time monitoring of the entire blasting network, can determine whether there is a misfire or premature detonation, and can obtain complete actual blasting time sequence data, which can be used for playback analysis. It can provide strong data support for optimizing blasting design, investigating the causes of blasting failures, and evaluating blasting quality. Attached Figure Description

[0019] Figure 1 This is a block diagram of the PVDF-based blasting monitoring system in the embodiment; Figure 2 This is a schematic diagram of the signal acquisition terminal in the embodiment; Figure 3 This is a schematic diagram of a PVDF-based blasting monitoring system in one embodiment; Figure 4 This is a schematic diagram of a PVDF-based blasting monitoring system in another embodiment; Figure 5 This is a schematic diagram of the PVDF-based blasting monitoring method in the embodiments; Figure 6This is a flowchart of step S3 of the method in the embodiment. Detailed Implementation

[0020] See Figure 1 In an embodiment of the present invention, a PVDF-based blasting monitoring system is provided, comprising: The vibration sensing module 100 includes a PVDF sensor. The PVDF sensor is used to monitor the vibration generated by blasting during blasting operations and convert the vibration into an electrical signal. The PVDF sensor can accurately capture and distinguish blasting time differences at the microsecond level and above. The improved accuracy of time difference measurement can directly improve the accuracy of borehole blasting timing analysis and provide a reliable data basis for accurately identifying misfires and premature blasts. The signal acquisition terminal 200 is electrically connected to the vibration sensing module 100. The signal acquisition terminal 200 receives the electrical signals from the vibration sensing module 100, processes the electrical signals, and converts them into digital vibration signals for transmission. The data monitoring terminal 300 receives digital vibration signals transmitted by the signal acquisition terminal 200 via wireless communication. The data monitoring terminal 300 processes the received digital vibration signals and identifies the valid blasting signals corresponding to a single blasting event; based on the time information of the valid blasting signals, it reconstructs the actual blasting sequence.

[0021] See Figure 3 In one embodiment of the present invention, the vibration sensing module 100 includes a conical metal housing 101, and a PVDF sensor is disposed inside the conical metal housing 101; the conical metal housing 101 can be inserted into the ground to transmit the blasting vibration to the PVDF sensor through the ground.

[0022] In use, the tip of the conical metal shell of the vibration sensing module 100 is inserted into the ground outside the blasting safety zone. When the blast occurs, the generated seismic waves propagate through the earth medium to the vibration sensing module 100. After the PVDF sensor senses the vibration, it generates an electrical signal proportional to the vibration intensity based on the piezoelectric effect. The electrical signal is output through the sensor pin.

[0023] See Figure 2 In this embodiment, the signal acquisition terminal 200 includes: Connecting cable 201 is used to connect vibration sensing module 100; The signal conditioning circuit 202 is used to condition the electrical signal received from the vibration sensing module; The analog-to-digital converter circuit 203 is used to convert the received electrical signal into a digital signal to obtain a digital vibration signal. Wireless communication module 204 is used to transmit the converted digital vibration signal; Battery 205 is used for power supply; The signal conditioning circuit 202, analog-to-digital conversion circuit 203, wireless communication module 204, and power supply battery 205 are encapsulated in a sealed metal casing 206. The metal casing 206 has a waterproof and dustproof rating of IP67 or IP68 and can effectively shield external electromagnetic interference.

[0024] The signal conditioning circuit 202 includes a multi-stage bandpass filter and a low-noise amplifier. The filter is used to filter out power supply noise and environmental interference that exceeds the target frequency band. The amplifier amplifies the microvolt or millivolt level signal output by the PVDF sensor to a level suitable for acquisition by the analog-to-digital converter circuit 203. The analog-to-digital converter circuit 203 uses an ADC chip to convert the conditioned analog signal into a digital signal stream at a high sampling rate. The wireless communication module 204 transmits the real-time digital signal stream output by the ADC in real time through a specific wireless protocol, such as a point-to-point proprietary protocol, Wi-Fi, or Bluetooth. Point-to-point transmission can avoid public network congestion and ensure low latency and high reliability of data transmission. The power supply battery 205 uses a rechargeable high-capacity lithium battery to support long-term field work.

[0025] See Figure 4 In another embodiment, a magnet 207 is provided on the metal casing 206 of the signal acquisition terminal; the vibration sensing module 100 has a metal box, and a powerful magnet 102 is embedded on the outer wall of the box. The PVDF sensor is installed inside the metal box in the form of a cantilever beam. When the vibration sensing module is attracted to the machine, support or other magnetic rigid structure by the magnet, the structural vibration caused by the explosion will cause the cantilever beam structure to bend and deform, causing the PVDF film to generate an electrical signal.

[0026] The signal acquisition terminal 200 adopts a fully sealed metal casing with a protection level of IP67 or IP68. The metal casing provides excellent electromagnetic shielding, effectively resisting strong electromagnetic interference at the blasting site and ensuring the accuracy of signal acquisition and the stability of system operation. Both signal acquisition terminals in the two embodiments are lightweight and compact, requiring no complex installation tools or procedures; deployment can be completed by one person, adapting to monitoring needs in different terrains and working conditions.

[0027] In this embodiment, the data monitoring terminal 300 can be an industrial-grade tablet computer, laptop computer, or dedicated handheld device that receives and displays the collected vibration data in the form of waveform curves on the interface in real time. All raw data and analysis results are recorded and timestamped, and stored locally for easy retrieval at any time.

[0028] The system in this embodiment uses wireless data transmission, and there is no need for a cable connection between the signal acquisition terminal 200 and the data monitoring terminal 300. Operators can view the vibration waveform and analysis results in real time through a tablet computer or handheld terminal in a safe area away from the blasting site, avoiding personnel approaching dangerous areas and improving personal safety.

[0029] In one embodiment, the data monitoring terminal 300 applies the HHT algorithm to process the received digital vibration signal and generate a Hilbert spectrum characterizing the time-frequency characteristics of the vibration signal; based on the Hilbert spectrum, it identifies the effective blasting signal corresponding to a single blasting event; according to the time sequence of the effective blasting signal, it reconstructs the actual blasting sequence; and compares the actual blasting sequence with the preset blasting scheme sequence to determine the effectiveness of the blasting operation.

[0030] The data monitoring terminal 300 allows users to set parameters for HHT analysis according to the site conditions, such as energy threshold and time-frequency window. The data monitoring terminal 300 processes the received data, captures valid blasting signals, reconstructs the blasting sequence, and compares it with the imported blasting design scheme. Finally, it displays the blasting results in an intuitive way, including the number of successful blasts, the number of misfired holes, and the number of early detonated holes.

[0031] With just one system as described in this embodiment, real-time monitoring of the entire blasting network can be achieved. It can not only monitor the blasting rate of the blast holes, but also monitor the blasting sequence of the blast holes in the entire blasting plan. It can also collect blasting vibration data in real time and store it locally, which is beneficial for data analysis and troubleshooting.

[0032] In this embodiment, a PVDF-based blasting monitoring method is also provided, the method comprising the following steps: Step 1: Install vibration sensing modules containing PVDF sensors at the blasting monitoring points; Step 2: During the blasting operation, the vibration signal generated by the blasting is collected using a vibration sensing module, and the vibration signal is processed by the signal acquisition terminal and then wirelessly transmitted to the data monitoring terminal. Step 3: On the data monitoring terminal, the received digital vibration signals are processed to identify the valid blasting signals representing a single blasting event; Step 4: Based on the processing results, analyze the time-frequency energy distribution of the vibration signal and identify the effective blasting signal representing a single blasting event; Step 5: Based on the occurrence time of the effective blasting signal, reconstruct the actual blasting sequence of the blasting operation; Step 6: Compare the actual blasting sequence with the preset blasting plan sequence to determine the effectiveness of the blasting operation. See Figure 5Specifically, in one embodiment, the PVDF-based blasting monitoring system described in the above embodiments includes the following steps: Step 1: Install vibration sensing modules containing PVDF sensors at the blasting monitoring points; Step 2: During the blasting operation, the vibration signal generated by the blasting is collected using a vibration sensing module, and the vibration signal is processed by the signal acquisition terminal and then wirelessly transmitted to the data monitoring terminal. Step 3: On the data monitoring terminal, apply the HHT algorithm to the received digitized vibration signal to generate the Hilbert spectrum of the vibration signal; Step 4: Based on Hilbert spectrum analysis, analyze the time-frequency energy distribution of the vibration signal to identify the effective blasting signal representing a single blasting event; Step 5: Based on the occurrence time of the effective blasting signal, reconstruct the actual blasting sequence of the blasting operation; Step 6: Compare the actual blasting sequence with the preset blasting plan sequence to determine the effectiveness of the blasting operation.

[0033] In one embodiment, in step 1, before the blasting operation, the vibration sensing module is deployed at a selected monitoring point. The monitoring point has a good vibration propagation path from the blasting area and is at a safe distance. The signal acquisition terminal and data monitoring terminal are then activated and a connection is established. In this embodiment, the detonation system can send a synchronization signal to the data monitoring terminal simultaneously with issuing the detonation command, serving as the zero point for analysis.

[0034] In step 2 of the embodiment, the PVDF sensor captures the ground vibration waves generated by the sequential detonation of each borehole in real time, converts them into continuous analog voltage signals, and the signal acquisition terminal filters, amplifies, and samples the analog voltage signals at high speed to obtain digital signals, which are then transmitted to the data monitoring terminal in real time via a wireless module.

[0035] In step 3 of the embodiment, the Hilbert spectrum of the received digitized vibration signal is generated using the HHT (Hilber-Huang Transform) algorithm, specifically as follows: Empirical mode decomposition (EMD) is performed on the digital vibration signal to decompose it into several IMF components, including: Using the original signal r(t) as the initial input, extract the signal envelope; Draw the mean envelope q(t) from the extracted envelope; Calculate the intermediate signal pt(t): pt(t) = r(t) - q(t); Determine whether the IMF's criteria are met; If satisfied, then further determine whether the standard deviation SD is within the required range; If the conditions are met, proceed to the Hilbert transform stage; otherwise, take r(t)-IMF(i) as the new original signal and IMF(i) as the intermediate signal that satisfies the IMF condition, return to the signal envelope extraction step, and continue to decompose the new IMF components. Perform a Hilbert transform on each IMF component to construct an analytic signal, and calculate the instantaneous amplitude and instantaneous frequency of the signal; The instantaneous amplitude and instantaneous frequency information of all IMF components are integrated onto a time-frequency plane to construct the Hilbert spectrum of the vibration signal; The Hilbert spectrum obtained during the implementation intuitively shows the distribution of signal energy in both time and frequency dimensions, which is suitable for analyzing the time-frequency characteristics of transient non-stationary signals such as blasting vibration.

[0036] In this embodiment, the complex non-stationary signal is adaptively decomposed into several IMF components through empirical mode decomposition. Each IMF component represents a quasi-steady vibration mode. Then, Hilbert transform is performed on each IMF component to calculate the instantaneous amplitude and instantaneous frequency, and a Hilbert spectrum is constructed. The Hilbert spectrum clearly shows the distribution of signal energy in both time and frequency dimensions, which is suitable for processing signals such as blasting vibration.

[0037] In the Hilbert spectrum, a single explosion event exhibits a significant characteristic: within a very short time interval, energy rapidly accumulates within a specific frequency range, forming energy peaks or bright spots. In contrast, background noise or structural resonances typically have lower energy, are distributed across different frequency bands, or have a longer duration. In step 4 of the embodiment, the valid explosion signal is identified, specifically as follows: Set the energy threshold and time-frequency window; In the Hilbert spectrum, regions where the energy concentration exceeds the energy threshold within the time-frequency window are searched. The signal corresponding to the found region is identified as a valid blasting signal, and the time corresponding to its energy peak is recorded as the actual occurrence time of the blast. Step 4 effectively distinguishes blasting signals from interference, identifying each blast. Background noise has low energy and is persistent, not meeting the peak condition; mechanical vibration or equipment operation has a relatively uniform energy distribution and a long duration, not meeting the instantaneous concentration condition; electromagnetic interference has a different frequency component than the blasting signal and can be excluded by limiting the frequency range.

[0038] In step 5 of the embodiment, the actual blasting timing sequence is reconstructed as follows: noise and interference signals that are determined to be invalid blasting signals are filtered out from the digital vibration signal, and all valid blasting signals are retained according to the original timestamp to obtain the actual blasting timing sequence.

[0039] In step 6 of the embodiment, the actual blasting sequence is compared with the preset blasting plan sequence to determine the effectiveness of the blasting operation, specifically including: By comparing the number of valid blasting signals in the actual blasting sequence with the number of preset blasting events in the blasting plan sequence, it can be determined whether there is a misfire. If the total number of valid blasting events k identified is less than the preset number of blast holes N, then it is determined that an blasting event has occurred. By comparing the position of the missing event in the sequence, the sequence number of the misfired blast hole can be roughly inferred.

[0040] By comparing the time interval between adjacent effective blasting signals in the actual blasting sequence with the preset delay time in the blasting plan sequence, it can be determined whether there is premature blasting or delay anomaly.

[0041] Calculate the time interval between actual adjacent blasting events , t i Indicates the time of the i-th explosion event, and is relative to the design delay. Compare, if If the error exceeds the allowable range, it can be determined that a premature detonation or delayed detonation has occurred, and the specific blast hole can be located.

[0042] Ultimately, the data monitoring terminal will present the analysis results, such as blasting success rate, list of misfired holes, and list of prematurely detonated holes, to the on-site engineers in a clear and intuitive manner, providing real-time and accurate data support for blasting quality assessment and safety hazard mitigation.

[0043] Those skilled in the art should understand that the specific algorithm used to analyze digital vibration signals to identify valid blasting signals is not limited to the specific method described in the preferred embodiments of the present invention. The HHT algorithm is used in the preferred embodiments of the present invention because blasting signals are essentially typical transient non-stationary signals. The HHT algorithm, through its core empirical mode decomposition, can adaptively decompose complex signals into a series of intrinsic mode functions. This gives the HHT algorithm an advantage over traditional Fourier transforms or short-time Fourier transforms when processing such sudden signals, providing higher time-frequency resolution and more clearly presenting the energy accumulation characteristics of each independent blasting event in the time-frequency spectrum.

[0044] However, other advanced signal processing techniques can also be applied to the framework of this invention. For example, wavelet transform can be used to perform multi-scale analysis of the signal, which can also effectively capture the instantaneous characteristics of the signal. This invention aims to protect the overall system and method for acquiring and reconstructing the blasting timing using a PVDF sensor.

[0045] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0046] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A blasting monitoring system based on PVDF, characterized in that, include: A vibration sensing module, comprising a PVDF sensor, wherein the PVDF sensor is used to monitor vibrations generated by blasting during blasting operations and convert the vibrations into electrical signals; A signal acquisition terminal is electrically connected to the vibration sensing module. The signal acquisition terminal receives the electrical signal from the vibration sensing module, processes the electrical signal, and converts it into a digital vibration signal for transmission. The data monitoring terminal receives digital vibration signals transmitted by the signal acquisition terminal via wireless communication; the data monitoring terminal is configured as follows: The received digital vibration signals are processed to identify the valid blasting signals corresponding to a single blasting event; based on the time information of the valid blasting signals, the actual blasting sequence is reconstructed.

2. The blasting monitoring system based on PVDF according to claim 1, characterized in that: The data monitoring terminal uses the HHT algorithm to process the received digital vibration signal and generate a Hilbert spectrum characterizing the time-frequency characteristics of the vibration signal; based on the Hilbert spectrum, it identifies the effective blasting signal corresponding to a single blasting event; and reconstructs the actual blasting sequence according to the time sequence of the effective blasting signal. The actual blasting sequence is compared with the preset blasting plan sequence to determine the effectiveness of the blasting operation.

3. The blasting monitoring system based on PVDF according to claim 1, characterized in that: The vibration sensing module includes a conical metal housing, and the PVDF sensor is disposed inside the conical metal housing; the conical metal housing can be inserted into the ground to transmit the blasting vibration to the PVDF sensor through the earth.

4. The blasting monitoring system based on PVDF according to claim 1, characterized in that: The signal acquisition terminal includes: A connecting cable is used to connect the vibration sensing module; The signal conditioning circuit is used to condition the electrical signal received from the vibration sensing module. An analog-to-digital converter circuit is used to convert the received electrical signal into a digital vibration signal. The wireless communication module is used to transmit the converted digital vibration signal; The power supply battery is used for power generation. The signal conditioning circuit, analog-to-digital conversion circuit, wireless communication module, and power supply battery are encapsulated in a metal casing.

5. The blasting monitoring system based on PVDF according to claim 3, characterized in that: The vibration sensing module is equipped with a metal housing, and magnets are respectively installed on the metal housing of the vibration sensing module and the metal housing of the signal acquisition terminal.

6. A blasting monitoring method based on PVDF, characterized in that, The method, based on the PVDF-based blasting monitoring system according to any one of claims 1 to 5, includes the following steps: Vibration sensing modules containing PVDF sensors are installed at blasting monitoring points; During blasting operations, the vibration sensing module is used to collect vibration signals generated by blasting. The vibration signals are then processed by the signal acquisition terminal and wirelessly transmitted to the data monitoring terminal. On the data monitoring terminal, the received digital vibration signals are processed to identify the valid blasting signals representing a single blasting event; Based on the occurrence time of the effective blasting signal, the actual blasting sequence of the blasting operation is reconstructed; The actual blasting sequence is compared with the preset blasting plan sequence to determine the effectiveness of the blasting operation.

7. The PVDF-based blasting monitoring method according to claim 6, characterized in that, On the data monitoring terminal, the HHT algorithm is applied to the received digital vibration signal to generate the Hilbert spectrum of the vibration signal; Based on the Hilbert spectrum analysis of the vibration signal's time-frequency energy distribution, the effective blasting signal representing a single blasting event is identified. Based on the occurrence time of the effective blasting signal, the actual blasting sequence of the blasting operation is reconstructed; The actual blasting sequence is compared with the preset blasting plan sequence to determine the effectiveness of the blasting operation.

8. The PVDF-based blasting monitoring method according to claim 7, characterized in that, The Hilbert spectrum of the vibration signal is generated using the HHT algorithm, as follows: Empirical mode decomposition is performed on the digital vibration signal to decompose it into several IMF components; Perform a Hilbert transform on each IMF component to calculate the instantaneous amplitude and instantaneous frequency of the signal; By combining time and frequency information, the Hilbert spectrum of the vibration signal is constructed.

9. The PVDF-based blasting monitoring method according to claim 8, characterized in that, Empirical Mode Decomposition (EMD) is performed on the digital vibration signal, decomposing the signal into several IMF components, as follows: Using the original signal r(t) as the initial input, extract the signal envelope; Draw the mean envelope q(t) from the extracted envelope; Calculate the intermediate signal pt(t): pt(t) = r(t) - q(t); Determine whether the IMF's criteria are met; If satisfied, then further determine whether the standard deviation SD is within the required range; If the conditions are met, proceed to the Hilbert transform stage; otherwise, take r(t)-IMF(i) as the new original signal and IMF(i) as the intermediate signal that satisfies the IMF condition, return to the signal envelope extraction step, and continue to decompose the new IMF components.

10. The blasting monitoring method based on PVDF according to claim 6, characterized in that, To identify a valid blasting signal, the following steps are required: Set the energy threshold and time-frequency window; In the Hilbert spectrum, regions where the energy concentration exceeds the energy threshold within the time-frequency window are searched, and the signals corresponding to the found regions are identified as valid blasting signals, thus distinguishing blasting events from environmental noise and interference.

11. The blasting monitoring method based on PVDF according to claim 6, characterized in that, The actual blasting sequence is reconstructed as follows: noise and interference signals that are determined to be invalid blasting signals are filtered out from the digital vibration signal, and all valid blasting signals are retained according to the original timestamp to form the reconstructed actual blasting sequence.

12. The blasting monitoring method based on PVDF according to claim 6, characterized in that, The actual blasting sequence is compared with the preset blasting plan sequence to determine the effectiveness of the blasting operation, specifically including: By comparing the number of valid blasting signals in the actual blasting sequence with the number of preset blasting events in the blasting plan sequence, it can be determined whether there is a misfire. By comparing the time interval between adjacent effective blasting signals in the actual blasting sequence with the preset delay time in the blasting plan sequence, it can be determined whether there is premature blasting or delay anomaly.

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