An autonomous underwater vehicle detection system and method based on seafloor seismic signals

Abstract

The application relates to the technical field of underwater detection, in particular to an underwater vehicle autonomous detection system and method based on seabed seismic wave signals. The system comprises a three-axis seismic wave signal acquisition module, a signal superposition amplification module, a signal filtering module, a signal envelope extraction module, an environmental noise integration module and a threshold comparison determination module. The acquisition module is orthogonally arranged to receive three-axis seismic wave signals and convert the signals into charge signals, the superposition amplification module completes signal conversion and superposition, the filtering module suppresses noise, the envelope extraction module extracts a detection value, the noise integration module obtains a noise integral value, the comparison module compares the two values, and when the detection value is greater than the integral value, an underwater vehicle existing signal is output. The application uses seabed seismic waves as a detection source, has strong anti-interference performance, works in a passive mode, is concealed and has low power consumption, can accurately capture weak seismic wave signals of the underwater vehicle, realizes autonomous detection of the underwater vehicle, and is suitable for long-term unattended deployment on the seabed.

Description

Technical Field

[0001] This application relates to the field of underwater detection technology, and in particular to an autonomous underwater vehicle detection system and method based on seafloor seismic wave signals. Background Technology

[0002] Underwater vehicles have wide applications in marine exploration, marine resource development, and marine engineering support. To achieve effective monitoring and early warning of underwater vehicles, it is usually necessary to deploy detection devices on the seabed or in nearshore areas to detect and identify the signals generated by the underwater vehicles during their movement.

[0003] In existing technologies, the detection of underwater vehicles mainly relies on acoustic detection equipment, such as hydrophone arrays or active sonar systems, to detect targets by receiving sound wave signals or echo signals generated by the underwater vehicle. However, this type of detection method is easily affected by marine environmental noise, ocean current disturbances, and complex seabed topography, resulting in poor detection stability in shallow waters or complex environments. Furthermore, active sonar systems need to emit sound signals during operation, which can easily reveal their own position, and their high power consumption makes them unsuitable for long-term covert deployment. Summary of the Invention

[0004] The purpose of this application is to overcome the above-mentioned deficiencies of the prior art, thereby providing an autonomous detection system and method for underwater vehicles based on seabed seismic wave signals.

[0005] To solve the above-mentioned technical problems, the technical solution of this application provides an autonomous underwater vehicle detection system based on submarine seismic wave signals, comprising: The three-axis seismic wave signal acquisition module is set in the seabed medium and orthogonally arranged along the X-axis, Y-axis and Z-axis directions. It is used to receive seismic wave signals in the X-axis, Y-axis and Z-axis directions propagating from underwater vehicles in the seabed medium, and convert the seismic wave signals in the three directions into seismic wave charge signals respectively. A signal superposition and amplification module, which is connected to the triaxial seismic wave signal acquisition module, is used to convert the seismic wave charge signals in the three-axis directions into seismic wave voltage signals and superimpose them; A signal filtering module, which is connected to the signal superposition and amplification module, is used to perform low-frequency filtering on the superimposed seismic wave voltage signal to suppress environmental noise interference. A signal envelope extraction module, which is connected to the signal filtering module, is used to perform detection processing on the filtered seismic wave signal to extract the detection value of the signal envelope generated when the underwater vehicle passes through the observation area; An environmental noise integration module, connected to the signal superposition and amplification module, is used to integrate the environmental background noise in the superimposed seismic wave voltage signal to obtain an integrated environmental background noise value; and A threshold comparison and determination module is connected to the signal envelope extraction module and the environmental noise integration module, respectively. It is used to compare the detected value of the signal envelope with the integrated value of the environmental background noise. When the detected value is greater than the integrated value, it outputs the presence signal of the underwater vehicle, thereby realizing more autonomous detection of the underwater vehicle.

[0006] As an improvement to the above technical solution, the triaxial seismic wave signal acquisition module includes a triaxial piezoelectric accelerometer, and the seismic wave signal includes: compression wave signal and shear wave signal.

[0007] As an improvement to the above technical solution, the X-axis output terminal, Y-axis output terminal, and Z-axis output terminal of the triaxial piezoelectric accelerometer are connected in parallel.

[0008] As an improvement to the above technical solution, the signal superposition and amplification module includes a charge amplifier, which is used to convert the seismic wave charge signals in the three axes output by the three-axis seismic wave signal acquisition module into seismic wave voltage signals and amplify them respectively.

[0009] As an improvement to the above technical solution, the signal filtering module includes a low-pass filter, which is used to perform low-frequency filtering on the seismic wave voltage signal to suppress environmental noise interference higher than the cutoff frequency of the low-pass filter.

[0010] As an improvement to the above technical solution, the signal envelope extraction module includes: an absolute value detector; the absolute value detector is used to perform absolute value detection processing on the filtered seismic wave signal to extract the signal amplitude change envelope and obtain the detection value of the signal envelope.

[0011] As an improvement to the above technical solution, the environmental noise integration module includes an integrator; the integrator is used to integrate the environmental background noise signal in the superimposed seismic wave voltage signal.

[0012] As an improvement to the above technical solution, the threshold comparison and determination module includes a comparator. The comparator uses the integrated value of the ambient background noise output by the ambient noise integration module as a reference value. When the detected value of the signal envelope output by the signal envelope extraction module is greater than the reference value, the comparator flips from low level to high level, thereby indicating that an underwater vehicle target has been detected.

[0013] To achieve another objective of the present invention, the present invention also provides an autonomous detection method for underwater vehicles based on seafloor seismic wave signals, comprising: Step 1: Deploy a triaxial seismic wave signal acquisition module in the seabed medium to receive seismic wave signals generated by underwater vehicles along the X-axis, Y-axis and Z-axis directions, and convert the seismic wave signals in the three axes into seismic wave charge signals respectively; Step 2: Connect the output terminals of the three-axis seismic wave signal acquisition module in parallel along the X-axis, Y-axis and Z-axis directions to superimpose the seismic wave charge signals in the three directions. Then, use the signal superposition and amplification module to convert the seismic wave charge signals in the three directions into seismic wave voltage signals and superimpose them. Step 3: Input the superimposed seismic wave voltage signal into the signal filtering module for low-frequency filtering to obtain the filtered seismic wave signal. Then, use the envelope extraction module to perform detection processing on the filtered seismic wave signal to obtain the detection value of the signal envelope. Input the superimposed seismic wave voltage signal into the environmental noise integration module to perform integration processing on the environmental background noise in the superimposed seismic wave voltage signal to obtain the environmental background noise integration value. Step 4: Input the detected value of the signal envelope and the integral value of the ambient background noise into the threshold comparison and judgment module for comparison. When the detected value of the signal envelope is greater than the integral value of the ambient background noise, output the presence of the underwater vehicle signal, thereby completing the autonomous detection value update of the underwater vehicle.

[0014] The advantage of this application lies in its use of seafloor seismic waves to replace traditional underwater acoustic signals for detection, significantly improving its anti-interference capability and stealth in complex marine environments. Its core lies in the spatial superposition of three-axis seismic wave signals, enabling the capture of weak compression and shear waves generated by the vehicle's motion without blind spots. Furthermore, by dynamically generating a judgment threshold through real-time environmental noise integration technology, it effectively filters out background noise interference from waves, ocean currents, and other sources, greatly improving the system's detection sensitivity and reliability.

[0015] Furthermore, the system operates in a fully passive mode, requiring no external signal transmission, and boasts advantages such as low power consumption and strong stealth, making it suitable for long-term, unattended seabed deployment. By comparing the signal envelope with an adaptive background noise threshold, the system effectively reduces the false alarm rate, achieving stable and accurate autonomous detection of underwater vehicles, demonstrating significant application value in fields such as military defense and marine monitoring. Attached Figure Description

[0016] Figure 1 A graph showing the changes in seismic wave signals as an underwater vehicle passes an observation point; Figure 2This is an installation diagram of the autonomous underwater vehicle detection system based on submarine seismic wave signals provided in Embodiment 1 of the present invention. Figure 3 This is a structural block diagram of the autonomous underwater vehicle detection system based on submarine seismic wave signals provided in Embodiment 1 of the present invention; Figure 4 The circuit diagram of the autonomous underwater vehicle detection system based on seabed seismic wave signals provided in Embodiment 1 of the present invention is shown. Detailed Implementation

[0017] The technical solutions provided in this application are further illustrated below with reference to the embodiments.

[0018] Example 1 Some low-frequency signal energy from the radiated noise of underwater vehicles propagates on the seabed as seismic waves (primarily concentrated below 40Hz). These seismic waves contain compression and shear waves. Placing a three-component (triaxial) seismic wave sensor on the seabed allows the reception of these signals. Furthermore, as the underwater vehicle moves closer to the receiving seismic wave sensor, the seismic wave signal attenuates due to propagation in the seabed medium. Figure 1 As shown, in the time domain, the amplitude of the signal received by the seismic wave sensor changes from small to large; when the underwater vehicle moves from near to far from the receiving point of the seismic wave sensor, in the time domain, the amplitude of the signal received by the seismic wave sensor changes from large to small. That is, the change in the amplitude of the signal received by the seismic wave sensor reflects the passing characteristics of the underwater vehicle. Therefore, the signal envelope formed by this passing characteristic can be used to further detect the autonomous value of the underwater vehicle.

[0019] The autonomous underwater vehicle detection system based on seabed seismic wave signals provided in this embodiment uses a triaxial piezoelectric accelerometer as a three-component seismic wave sensor. The triaxial piezoelectric accelerometer receives seismic wave signals from the underwater vehicle in the orthogonal X, Y, and Z axes. The output terminals of the triaxial piezoelectric accelerometer are connected in parallel, and the parallel output charge signal enters a charge amplifier, where the signals are superimposed. The superimposed seismic wave signal: on the one hand, enters a low-pass filter to suppress environmental noise interference, and then enters a detector to obtain the underwater vehicle's passage characteristic envelope; on the other hand, the superimposed seismic wave signal enters an integrator. In the integrator, because the underwater vehicle signal changes from far to near, while the environmental noise is stable and slowly changing, the integrated environmental noise value is accumulated, while the changing underwater vehicle signal is suppressed, thus extracting the environmental noise value. The filtered and detected signal is compared with the integrated signal, that is, the underwater vehicle's passage characteristic envelope is compared with the integrated value of the environmental noise using a comparator. When the detected value is greater than the integrated value, it is automatically determined that an underwater vehicle target exists. Since the piezoelectric accelerometers, charge amplifiers, filters, detectors, integrators, comparators and other devices used are all analog devices with low power consumption, they can be used for long-term underwater monitoring when powered by batteries, and therefore can be used as autonomous detection and monitoring devices.

[0020] The purpose of this invention is to autonomously detect underwater vehicles. An autonomous detection and monitoring device is constructed using a triaxial piezoelectric accelerometer, a charge amplifier, a low-pass filter, a detector, an integrator, and a comparator. The triaxial piezoelectric accelerometer is placed on the seabed to receive seismic wave signals from the vehicle. The accelerometer is connected in parallel to the charge amplifier. Since the piezoelectric accelerometer outputs a charge signal, the compression and shear wave signals in the seismic wave signal are superimposed after being connected in parallel to the charge amplifier. The superimposed seismic wave signal is split into two paths: one path enters the filter and detector, and the other path enters the integrator. The filtered and detected signal is compared with the integrated signal in the comparator. When the detected value is greater than the integrated value, it is determined that an underwater vehicle target has arrived, thus completing the autonomous detection and monitoring function.

[0021] The triaxial piezoelectric accelerometers are distributed along the orthogonal X, Y, and Z axes to receive seismic wave signals propagating from the seabed. As charge-type sensors, the seismic wave vibration signals are converted into charge signals. By connecting the outputs of the piezoelectric accelerometers along the three axes in parallel, the charge signals are superimposed. The triaxial piezoelectric accelerometers are low-frequency piezoelectric accelerometers with an operating frequency band of approximately 0.5Hz to 40Hz.

[0022] The piezoelectric accelerometers connected in parallel across three axes are connected to a charge amplifier. The charge amplifier converts the charge signal output by the piezoelectric accelerometers into a voltage signal and then superimposes the signals. The charge amplifier can be a commonly used typical charge amplifier circuit composed of operational amplifiers, resistors, and capacitors.

[0023] The charge amplifier output signal is split into two paths. One path enters a low-pass filter and a detector. The low-pass filter is a common negative feedback filter composed of an operational amplifier, resistors, and capacitors, with a cutoff frequency of 40Hz. The detector is a common absolute detector composed of an operational amplifier, detector diodes, resistors, and capacitors. After passing through the low-pass filter and detector, the passing characteristic envelope caused by the distance change of the underwater vehicle is extracted, since the seismic wave signal of the underwater vehicle is mainly concentrated below 40Hz. The other path enters an integrator, which is a first-order integrator circuit composed of an operational amplifier, resistors, and capacitors. Since the amplitude of the time-domain signal of the underwater vehicle changes with distance, while the environmental background noise is stable and slowly changing, with a rate of change much lower than the amplitude change of the vehicle signal, the integrator, according to electrical principles, accumulates the signal energy for slowly changing, stable signals, but has no effect on rapidly changing signals. This allows the environmental background noise to be extracted.

[0024] The detected signal and the integrated ambient background noise are fed into the positive and negative input terminals of the comparator, respectively. The comparator is an open-loop comparator circuit composed of operational amplifiers. When the underwater vehicle detection signal input to the positive terminal is greater than the ambient background signal input to the negative terminal, the comparator flips and outputs a high level, indicating that a target has been detected, thus enabling autonomous detection.

[0025] The triaxial piezoelectric accelerometer used in this invention is a passive device. The circuits such as charge amplifier, low-pass filter, detector, integrator, and comparator are composed of operational amplifiers and low-power devices such as diodes, resistors, and capacitors. The overall power consumption is low, and it can be operated for a long time in a battery-powered environment.

[0026] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0027] like Figure 2 As shown in the diagram, a triaxial piezoelectric accelerometer is placed on the seabed to sense and receive seismic wave signals from underwater vehicles. Seismic wave signals consist of compression waves and shear waves. The vibration direction of compression waves is the same as the propagation direction, while the vibration direction of shear waves is perpendicular to the propagation direction. A triaxial piezoelectric accelerometer is used, with piezoelectric accelerometers arranged orthogonally along the X, Y, and Z axes to receive both compression and shear waves. Since the seismic wave signals from underwater vehicles are concentrated in the low-frequency band below 40Hz, a low-frequency piezoelectric accelerometer with an operating frequency band close to 0.5Hz to 40Hz is selected.

[0028] like Figure 3As shown in the schematic diagram: piezoelectric accelerometers are connected in parallel along the three axes and input to a charge amplifier. Since the piezoelectric accelerometers output charge signals, after entering the charge amplifier, the signals are superimposed and converted from charge signals to voltage signals. The amplified signal is split into two paths, one of which serves as the envelope detection circuit for the underwater vehicle signal passing characteristics: it enters a low-pass filter with a cutoff frequency of 40Hz to filter out some of the broadband environmental noise signals; the filtered signal enters a detector, which performs peak detection to detect the change in signal amplitude from small to large as the underwater vehicle signal approaches, reflecting the envelope characteristics of the underwater vehicle's passing characteristics.

[0029] The other path enters the integrator. Since the output signal of the preceding charge amplifier contains seismic wave signals from underwater vehicles and marine environmental noise signals, and the amplitude of underwater vehicle signals changes rapidly with distance, while marine environmental noise is relatively stable and changes slowly, with a rate of change much lower than that of underwater vehicle signals, and as can be seen from the basic characteristics of the integrator, the integrator can accumulate slowly changing signals and is not sensitive to rapidly changing signals. This allows the slowly changing marine environmental background noise to be extracted.

[0030] The detector output signal and the integrator signal are respectively input to the positive and negative signal input terminals of the comparator. The comparator compares the two, and the integrator output signal is used as a reference value. When the detector signal is greater than this reference value, the comparator flips, changing from a low level to a high level, indicating that the target underwater vehicle has been detected.

[0031] like Figure 4 As shown in the diagram: a) A triaxial piezoelectric accelerometer (X, Y, Z) connected in parallel is a common low-frequency piezoelectric accelerometer in the seismic measurement industry. The X, Y, and Z axes are installed orthogonally in space to sense and receive compression and shear waves from seismic signals from underwater vehicles. The piezoelectric accelerometer converts the seismic wave signals into charge signals, which enter a charge amplifier U1A. The three superimposed charge signals are converted into voltage signals. When the static capacitances of the three piezoelectric accelerometers X, Y, and Z are Cx, Cy, and Cz respectively, the total capacitance after parallel connection is Cx + Cy + Cz. The charge signal is input to the charge amplifier, which consists of an operational amplifier U1A, a current-limiting resistor R2, a feedback capacitor C1, and a feedback resistor R1. After the triaxial accelerometers are connected in parallel and combined with the charge amplifier, their operating frequency band is: Lower cutoff frequency for: ; Upper limit cutoff frequency for: ; It is evident that parallel connection of three-axis piezoelectric accelerometers, coupled with a matched charge amplifier, not only achieves the superposition of the three-axis signals but also increases the static capacitance, expanding the operating bandwidth in the low-frequency range. When the static capacitance of a certain type of piezoelectric accelerometer in a single axis direction is 10000pC, the total static capacitance after parallel connection of the three axes is 30000pC. With the current-limiting resistor R2 set to 11MΩ, the lower limit operating frequency... for: ; When the feedback capacitor C1 is 2000 pC and the feedback resistor R1 is 2 MΩ, the upper limit of the operating frequency is... for: ; It is close to the operating frequency band of 0.5Hz to 40Hz required by the system.

[0032] b) The voltage signal output from the charge amplifier is divided into two paths: one path enters a low-pass filter and a detector. The low-pass filter includes operational amplifier U1B and resistors R3 and R4, capacitors C2 and C4. Capacitors C2 and C4 form a typical circuit of a general-purpose second-order filter. R4 = R3; Cutoff frequency of low-pass filter : ; The low-pass filtered signal enters the detector, which is a conventional absolute detector consisting of operational amplifier U2A, detector diodes D1 and D2, and resistors and capacitors. Resistors R5 and R7 are gain compensation resistors used to adjust the amplitude of the output signal; resistor R6 is a DC bias adjustment resistor. Diodes D1 and D2, and capacitors C4, C5, and C6 form a rectifier-detector circuit to perform peak signal detection. When the underwater vehicle signal changes amplitude with distance, forming an envelope, the detector extracts this amplitude change characteristic.

[0033] c) The voltage signal output by the charge amplifier enters the integrator through another path. The integrator consists of an operational amplifier U2B, an integrating resistor R9, an integrating capacitor C3, and a balancing resistor R10. The integrating circuit accumulates the relatively stable and slowly changing background noise signal as an environmental detection threshold.

[0034] Integral time constant: ; If R9 is set to 4.3 MΩ and C3 to 4.7 uF, then .

[0035] d) The detector output signal and the integrator signal are respectively input to the positive and negative input terminals of the comparator. The comparator is a comparator circuit composed of an open-loop operational amplifier U3. When the detector output signal is greater than the integrator signal, that is, when the target signal is greater than the background noise signal, the comparator flips and outputs a high level, indicating that a target underwater vehicle exists.

[0036] In summary, the triaxial piezoelectric accelerometer is a passive device. Its circuits, such as charge amplifier, filter, detector, integrator, and comparator, are composed of diodes, resistors, capacitors, and operational amplifiers. It operates in the low-frequency range and is a low-power device. Therefore, it can operate autonomously for a long time even when powered by a battery.

[0037] Example 2 The autonomous underwater vehicle detection method based on submarine seismic wave signals disclosed in this embodiment includes: Step 1: Deploy a triaxial seismic wave signal acquisition module in the seabed medium to receive seismic wave signals generated by underwater vehicles along the X-axis, Y-axis and Z-axis directions, and convert the seismic wave signals in the three axes into seismic wave charge signals respectively; Step 2: Connect the output terminals of the three-axis seismic wave signal acquisition module in parallel along the X-axis, Y-axis and Z-axis directions to superimpose the seismic wave charge signals in the three directions. Then, use the signal superposition and amplification module to convert the seismic wave charge signals in the three directions into seismic wave voltage signals and superimpose them. Step 3: Input the superimposed seismic wave voltage signal into the signal filtering module for low-frequency filtering to obtain the filtered seismic wave signal. Then, use the envelope extraction module to perform detection processing on the filtered seismic wave signal to obtain the detection value of the signal envelope. Input the superimposed seismic wave voltage signal into the environmental noise integration module to perform integration processing on the environmental background noise in the superimposed seismic wave voltage signal to obtain the environmental background noise integration value. Step 4: Input the detected value of the signal envelope and the integral value of the ambient background noise into the threshold comparison and judgment module for comparison. When the detected value of the signal envelope is greater than the integral value of the ambient background noise, output the presence of the underwater vehicle signal, thereby completing the autonomous detection value update of the underwater vehicle.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. An autonomous underwater vehicle detection system based on submarine seismic wave signals, comprising: The three-axis seismic wave signal acquisition module is set in the seabed medium and orthogonally arranged along the X-axis, Y-axis and Z-axis directions. It is used to receive seismic wave signals in the X-axis, Y-axis and Z-axis directions propagating from underwater vehicles in the seabed medium, and convert the seismic wave signals in the three directions into seismic wave charge signals respectively. A signal superposition and amplification module, which is connected to the triaxial seismic wave signal acquisition module, is used to convert the seismic wave charge signals in the three-axis directions into seismic wave voltage signals and superimpose them; A signal filtering module, which is connected to the signal superposition and amplification module, is used to perform low-frequency filtering on the superimposed seismic wave voltage signal to suppress environmental noise interference. A signal envelope extraction module, which is connected to the signal filtering module, is used to perform detection processing on the filtered seismic wave signal to extract the detection value of the signal envelope generated when the underwater vehicle passes through the observation area; An environmental noise integration module, which is connected to the signal superposition and amplification module, is used to integrate the environmental background noise in the superimposed seismic wave voltage signal to obtain the environmental background noise integration value. and A threshold comparison and determination module is connected to the signal envelope extraction module and the environmental noise integration module, respectively. It is used to compare the detected value of the signal envelope with the integrated value of the environmental background noise. When the detected value is greater than the integrated value, it outputs the presence signal of the underwater vehicle, thereby realizing more autonomous detection of the underwater vehicle.

2. The autonomous underwater vehicle detection system based on submarine seismic wave signals according to claim 1, characterized in that, The triaxial seismic wave signal acquisition module includes a triaxial piezoelectric accelerometer, and the seismic wave signal includes compression wave signal and shear wave signal.

3. The autonomous underwater vehicle detection system based on submarine seismic wave signals according to claim 2, characterized in that, The X-axis, Y-axis, and Z-axis output terminals of the triaxial piezoelectric accelerometer are connected in parallel.

4. The autonomous underwater vehicle detection system based on submarine seismic wave signals according to claim 1, characterized in that, The signal superposition and amplification module includes a charge amplifier, which is used to convert the seismic wave charge signals in the three axes output by the triaxial seismic wave signal acquisition module into seismic wave voltage signals and amplify them.

5. The autonomous underwater vehicle detection system based on submarine seismic wave signals according to claim 1, characterized in that, The signal filtering module includes a low-pass filter, which is used to perform low-frequency filtering on the seismic wave voltage signal to suppress environmental noise interference higher than the cutoff frequency of the low-pass filter.

6. The autonomous underwater vehicle detection system based on submarine seismic wave signals according to claim 1, characterized in that, The signal envelope extraction module includes an absolute value detector; the absolute value detector is used to perform absolute value detection processing on the filtered seismic wave signal to extract the signal amplitude change envelope and obtain the detection value of the signal envelope.

7. The autonomous underwater vehicle detection system based on submarine seismic wave signals according to claim 1, characterized in that, The environmental noise integration module includes an integrator; the integrator is used to integrate the environmental background noise signal in the superimposed seismic wave voltage signal.

8. The autonomous underwater vehicle detection system based on submarine seismic wave signals according to claim 1, characterized in that, The threshold comparison and determination module includes a comparator. The comparator uses the integrated value of the ambient background noise output by the ambient noise integration module as a reference value. When the detected value of the signal envelope output by the signal envelope extraction module is greater than the reference value, the comparator flips from low level to high level, thereby indicating that an underwater vehicle target has been detected.

9. A method for autonomous underwater vehicle detection based on submarine seismic wave signals, characterized in that, include: Step 1: Deploy a triaxial seismic wave signal acquisition module in the seabed medium to receive seismic wave signals generated by underwater vehicles along the X-axis, Y-axis and Z-axis directions, and convert the seismic wave signals in the three axes into seismic wave charge signals respectively; Step 2: Connect the output terminals of the three-axis seismic wave signal acquisition module in parallel along the X-axis, Y-axis and Z-axis directions to superimpose the seismic wave charge signals in the three directions. Then, use the signal superposition and amplification module to convert the seismic wave charge signals in the three directions into seismic wave voltage signals and superimpose them. Step 3: Input the superimposed seismic wave voltage signal into the signal filtering module for low-frequency filtering to obtain the filtered seismic wave signal. Then, use the envelope extraction module to perform detection processing on the filtered seismic wave signal to obtain the detection value of the signal envelope. Input the superimposed seismic wave voltage signal into the environmental noise integration module to perform integration processing on the environmental background noise in the superimposed seismic wave voltage signal to obtain the environmental background noise integration value. Step 4: Input the detected value of the signal envelope and the integral value of the ambient background noise into the threshold comparison and judgment module for comparison. When the detected value of the signal envelope is greater than the integral value of the ambient background noise, output the presence of the underwater vehicle signal, thereby completing the autonomous detection value update of the underwater vehicle.

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