Method and device for detecting weak seismic wave signals of a target based on fourth-order stochastic resonance

Abstract

The present invention discloses a method and device for detecting weak seismic wave signals of a target based on fourth-order stochastic resonance. The method includes: detecting the original seismic wave feature signals of an underwater vehicle target in a marine environment based on a sensor; intercepting the target seismic wave signals with a frequency band of 0-20 Hz from the original seismic wave feature signals based on a first-order filtering algorithm; normalizing the target seismic wave signals to obtain normalized target seismic wave signals; establishing a detection model for the target seismic wave signals based on fourth-order stochastic resonance, inputting the normalized target seismic wave signals into the detection model for the target seismic wave signals to obtain target signals, and outputting the detection results for the target signals. The method of the present invention can extract the waveforms of weak target seismic wave signals under strong noise interference.

Description

Technical Field

[0001] The present invention relates to the field of signal detection and recognition, and particularly to a method and device for detecting weak seismic wave signals of a target based on fourth-order stochastic resonance. Background Art

[0002] A sailing body sailing in water will generate low-frequency vibration signals due to the rotation of the power device. The frequency range of this vibration signal is distributed within 0 - 20 Hz. The vibration signal is quickly transmitted to the seabed through seawater, causing the soft sediment on the seabed to vibrate. This vibration signal is called a seismic wave signal. Under the background of strong ocean vibration noise interference, the seismic wave signals of weak underwater vehicle targets are submerged by colored noise, Gaussian white noise, and noise generated by marine organisms, and there is no effective means to successfully detect them. The existing main solution is to use a filtering method, which is suitable for situations where the noise interference is small and the target signal is not completely submerged by the noise, that is, the outline of the target signal can be recognized from the mixed signal. For the original seismic wave signal with a high signal-to-noise ratio, the target detection algorithm based on the filtering principle has a low false alarm rate for the target detection result, but in the case of a low signal-to-noise ratio, this algorithm cannot detect the weak seismic wave signals of the target. Due to the complexity of the ocean environment, in the actual detection process of weak seismic wave signals, the measured data contains strong noise interference, and the target signal is usually completely submerged by the noise.

[0003] Therefore, there is an urgent need for a method that can detect the characteristic signals of weak seismic waves of a target in the presence of strong non-Gaussian noise in the ocean, and overcome the problem of being unable to detect the seismic wave signals of weak underwater vehicle targets in a strong noise background. Summary of the Invention

[0004] In view of this, the present invention provides a method and device for detecting weak seismic wave signals of a target based on fourth-order stochastic resonance, which can solve the technical problem that traditional detection methods cannot detect weak seismic wave signals with low frequencies in a strong noise background.

[0005] To solve the above technical problems, the present invention is implemented as follows.

[0006] A method for detecting weak seismic wave signals of a target based on fourth-order stochastic resonance includes:

[0007] Step S1: Detect the original characteristic signals of the seismic waves of the underwater vehicle target in the ocean environment based on a sensor;

[0008] Step S2: Intercept the target seismic wave signals with a frequency band of 0 - 20 Hz from the original characteristic signals of the seismic waves based on a first-order filtering algorithm;

[0009] Step S3: Normalize the target seismic wave signal to obtain a normalized target seismic wave signal;

[0010] Step S4: Establish a target seismic wave signal detection model based on fourth-order stochastic resonance. Input the normalized target seismic wave signal into the target seismic wave signal detection model to obtain a target signal and output the detection result of the target signal.

[0011] The target seismic wave signal detection model with four layers is as follows:

[0012]

[0013] where a1 = a2 = a3 = a, b1 = b2 = b3 = b, both are model parameters and are obtained by fitting based on historical data; S(t) is the input normalized target seismic wave signal, x1 is the output of the first layer and the input of the second layer of the target seismic wave signal detection model, x2 is the output of the second layer and the input of the third layer of the target seismic wave signal detection model, x3 is the output of the third layer and the input of the fourth layer of the target seismic wave signal detection model, and x is the output of the target seismic wave signal detection model; the formulas corresponding to each layer of the target seismic wave signal detection model; each layer of the target seismic wave signal detection model uses the fourth-order Runge-Kutta algorithm for solution.

[0014] Preferably, the sensor is a triaxial orthogonal acceleration sensor.

[0015] Preferably, the first-order filtering algorithm is an LC first-order low-pass filter.

[0016] Preferably, a1 = a2 = a3 = a = 20, b1 = b2 = b3 = b = 13.

[0017] A target weak seismic wave signal detection device based on fourth-order stochastic resonance provided by the present invention, the device includes:

[0018] Signal acquisition module: configured to detect the original seismic wave feature signal of the underwater vehicle target in the marine environment based on a sensor;

[0019] Interception module: configured to intercept the target seismic wave signal with a frequency band of 0 - 20 Hz from the original seismic wave feature signal based on a first-order filtering algorithm;

[0020] Normalization module: configured to normalize the target seismic wave signal to obtain a normalized target seismic wave signal;

[0021] Calculation module: Configured to establish a target seismic wave signal detection model for fourth-order stochastic resonance, input the normalized target seismic wave signal into the target seismic wave signal detection model, obtain a target signal, and output the detection result of the target signal.

[0022] The target seismic wave signal detection model with four layers is as follows:

[0023]

[0024] Among them, a1 = a2 = a3 = a, b1 = b2 = b3 = b, which are all model parameters and are obtained by fitting based on historical data; S(t) is the input normalized target seismic wave signal, x1 is the output of the first layer and the input of the second layer of the target seismic wave signal detection model, x2 is the output of the second layer and the input of the third layer of the target seismic wave signal detection model, x3 is the output of the third layer and the input of the fourth layer of the target seismic wave signal detection model, and x is the output of the target seismic wave signal detection model; the formulas corresponding to the layers of each target seismic wave signal detection model; each layer of the target seismic wave signal detection model uses the fourth-order Runge-Kutta algorithm for solution.

[0025] A computer-readable storage medium provided by the present invention stores multiple instructions; the multiple instructions are used to be loaded and executed by a processor to perform the method as described above.

[0026] An electronic device provided by the present invention is characterized in that the electronic device includes:

[0027] A processor for executing multiple instructions;

[0028] A memory for storing multiple instructions;

[0029] Among them, the multiple instructions are used to be stored by the memory and loaded and executed by the processor to perform the method as described above.

[0030] Beneficial effects:

[0031] (1) Under the background of complex non-Gaussian and strong noise in the ocean, an LC first-order low-pass filter is selected to intercept the original signal mixed with the target seismic wave and ocean vibration noise within 0 - 20 Hz detected by a triaxial acceleration sensor. The original signal within 0 - 20 Hz is normalized to the range of (0, 1) using a normalization algorithm, that is, the original signal is standardized. In the normalized signal, the target signal is a weak signal with low frequency and small amplitude. After processing by the above algorithm, relevant information such as the amplitude and frequency of the target signal still cannot be determined. The present invention overcomes this shortcoming. The normalized original signal is input into a detection model for target seismic wave signals based on fourth-order stochastic resonance, which can accurately detect the distribution trend of the target signal under strong noise interference, that is, it can output the waveform of the target signal. Therefore, the present invention can extract the waveform of the weak target seismic wave signal under strong noise interference.

[0032] (2) Under the background of complex strong ocean vibration noise, the present invention can detect the target seismic wave signal with micro-amplitude within the frequency range of 0 - 20 Hz, and fully extract the target seismic wave signal of the underwater vehicle.

[0033] (3) The present invention has a high recognition accuracy.

[0034] (4) The present invention is easy to implement. Description of the Drawings

[0035] Figure 1 Schematic diagram of the flow of the method for detecting weak target seismic wave signals based on fourth-order stochastic resonance provided by the present invention;

[0036] Figure 2 Schematic diagram of the detection of target seismic wave signals based on the fourth-order stochastic resonance algorithm provided by the present invention;

[0037] Figure 3 Schematic diagram of the original signal of the x-axis component of the target seismic wave signal provided by the present invention;

[0038] Figure 4 Schematic diagram of the original signal of the x-axis component of the filtered target seismic wave signal provided by the present invention;

[0039] Figure 5 Schematic diagram of the mixed signal of the x-axis component of the normalized target seismic wave signal and noise provided by the present invention;

[0040] Figure 6 Schematic diagram of the waveform output of the detected signal provided by the present invention;

[0041] Figure 7 Schematic diagram of the structure of the device for detecting weak target seismic wave signals based on fourth-order stochastic resonance provided by the present invention. Detailed Embodiments

[0042] The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0043] As Figure 1 - Figure 2 shown, the present invention provides a method for detecting weak seismic wave signals of a target based on fourth-order stochastic resonance, including the following steps:

[0044] Step S1: Detect the original seismic wave feature signals of an underwater vehicle target based on a sensor in a marine environment;

[0045] Step S2: Intercept the target seismic wave signals with a frequency band of 0 - 20 Hz from the original seismic wave feature signals based on a first-order filtering algorithm;

[0046] Step S3: Normalize the target seismic wave signals to obtain normalized target seismic wave signals;

[0047] Step S4: Establish a detection model for target seismic wave signals based on fourth-order stochastic resonance, input the normalized target seismic wave signals into the detection model for target seismic wave signals to obtain target signals, and output the detection results of the target signals.

[0048] The detection model for target seismic wave signals having four layers is:

[0049]

[0050] where a1 = a2 = a3 = a, b1 = b2 = b3 = b, are all model parameters and are obtained by fitting based on historical data; S(t) is the input normalized target seismic wave signal, x1 is the output of the first layer and the input of the second layer of the detection model for target seismic wave signals, x2 is the output of the second layer and the input of the third layer of the detection model for target seismic wave signals, x3 is the output of the third layer and the input of the fourth layer of the detection model for target seismic wave signals, x is the output of the detection model for target seismic wave signals; the formulas corresponding to each layer of the detection model for target seismic wave signals; each layer of the detection model for target seismic wave signals uses the fourth-order Runge - Kutta algorithm for solution.

[0051] Furthermore, the sensor is a three-axis orthogonal acceleration sensor.

[0052] Furthermore, the first-order filtering algorithm is an LC first-order low-pass filter.

[0053] Furthermore, a1 = a2 = a3 = a = 20, b1 = b2 = b3 = b = 13.

[0054] An embodiment of a method for detecting a target weak seismic wave signal based on fourth-order stochastic resonance is provided. The method for detecting a target weak seismic wave signal based on fourth-order stochastic resonance includes:

[0055] Step 1: Use a sensor to detect a target seismic wave signal in a marine environment to form an original target seismic wave signal sample set, as Figure 3 shown. In an embodiment of the present invention, three single-axis acceleration sensors are combined into a three-axis orthogonal acceleration sensor.

[0056] Step 2: Use an LC first-order low-pass filter to select a target seismic wave signal within a frequency range of (0 - 20) Hz, as Figure 4 shown. In an embodiment of the present invention, the expression of the LC first-order low-pass filter is

[0057] Y(n) = αX(n) + (1 - α)Y(n - 1), where the parameter α = 5.

[0058] Step 3: Use a normalization algorithm to normalize the target seismic wave signal with a truncated frequency band of 0 - 20 Hz, as Figure 5 shown. In an embodiment of the present invention, the expression of the normalization algorithm is

[0059] Step 4: Initialize the parameters of the fourth-order stochastic resonance algorithm. In an embodiment of the present invention, the initialized parameter values of the fourth-order stochastic resonance algorithm in Step 4 are a1 = a2 = a3 = a = 20, b1 = b2 = b3 = b = 13.

[0060] Step 5: Use the fourth-order stochastic resonance algorithm to detect the seismic wave signal of an underwater vehicle target after normalization, and the system outputs a smooth target signal, as Figure 6 shown.

[0061] In another embodiment of the present invention, the target original signal is the component data of the x-axis of a three-axis orthogonal acceleration sensor, the data sample size is 20,000 sampling points, the signal sampling frequency is 500 Hz, and the target is a large merchant ship traveling in a marine background.

[0062] First step: The original data is Figure 3 shown. After filtering the signal in this figure using the LC first-order low-pass filtering algorithm, high-frequency noise interference is removed, and a target signal to be measured in the low-frequency band is obtained, as Figure 4 shown. The frequency band range of the target signal to be measured is (0, 20) Hz.

[0063] Second step: Use a normalization algorithm to normalize the target seismic wave signal with a truncated frequency band of 0 - 20 Hz, as Figure 5 shown.

[0064] Step 3: Take the initial values a1 = a2 = a3 = a = 20 and b1 = b2 = b3 = b = 13.

[0065] Step 4: Substitute the target seismic wave signal to be measured into the following formula and use the fourth-order Runge-Kutta algorithm to solve for the system output x(t). The waveform of x(t) is the waveform of the target seismic wave signal.

[0066]

[0067] The present invention also provides a target weak seismic wave signal detection device based on fourth-order stochastic resonance, as Figure 7 shown. The device includes:

[0068] Signal acquisition module: configured to detect the original seismic wave feature signal of the underwater vehicle target in the ocean environment based on a sensor;

[0069] Interception module: configured to intercept the target seismic wave signal with a frequency band of 0 - 20 Hz from the original seismic wave feature signal based on a first-order filtering algorithm;

[0070] Normalization module: configured to normalize the target seismic wave signal to obtain a normalized target seismic wave signal;

[0071] Calculation module: configured to establish a target seismic wave signal detection model based on fourth-order stochastic resonance, input the normalized target seismic wave signal into the target seismic wave signal detection model to obtain a target signal, and output the detection result of the target signal.

[0072] The target seismic wave signal detection model with four layers is:

[0073]

[0074] where a1 = a2 = a3 = a and b1 = b2 = b3 = b are both model parameters and are obtained by fitting based on historical data; S(t) is the input normalized target seismic wave signal, x1 is the output of the first layer and the input of the second layer of the target seismic wave signal detection model, x2 is the output of the second layer and the input of the third layer of the target seismic wave signal detection model, x3 is the output of the third layer and the input of the fourth layer of the target seismic wave signal detection model, and x is the output of the target seismic wave signal detection model; the formulas corresponding to each layer of the target seismic wave signal detection model; each layer of the target seismic wave signal detection model uses the fourth-order Runge-Kutta algorithm for solution.

[0075] The above specific embodiments only describe the design principle of the present invention. The shapes and names of the components in this description can be different and are not restricted. Therefore, those skilled in the art of the present invention can modify or make equivalent replacements to the technical solutions described in the foregoing embodiments; and these modifications and replacements do not depart from the gist and technical solutions of the present invention, and shall all fall within the protection scope of the present invention.

Claims

1. A method for detecting weak seismic wave signals of a target based on fourth-order stochastic resonance, characterized in that It includes the following steps: Step S1: Detect the original seismic wave characteristic signal of the underwater vehicle target in the marine environment based on the sensor; Step S2: Intercept the target seismic wave signal with a frequency band of 0 - 20 Hz from the original seismic wave characteristic signal based on the first-order filtering algorithm; Step S3: Normalize the target seismic wave signal to obtain the normalized target seismic wave signal; Step S4: Establish a target seismic wave signal detection model of fourth-order stochastic resonance, input the normalized target seismic wave signal into the target seismic wave signal detection model to obtain the target signal, and output the detection result of the target signal. The target seismic wave signal detection model with four layers is: Wherein, a1 = a2 = a3 = a, b1 = b2 = b3 = b, are all model parameters and are obtained by fitting based on historical data; S(t) is the input normalized target seismic wave signal, x1 is the output of the first layer of the target seismic wave signal detection model and the input of the second layer, x2 is the output of the second layer of the target seismic wave signal detection model and the input of the third layer, x3 is the output of the third layer of the target seismic wave signal detection model and the input of the fourth layer, x is the output of the target seismic wave signal detection system; the formulas corresponding to each layer of the target seismic wave signal detection model; each layer of the target seismic wave signal detection model uses the fourth-order Runge-Kutta algorithm for solution.

2. The method according to claim 1, characterized in that The sensor is a three-axis orthogonal acceleration sensor.

3. The method according to claim 1, characterized in that The first-order filtering algorithm is an LC first-order low-pass filter.

4. The method according to claim 1, characterized in that a1 = a2 = a3 = a = 20, b1 = b2 = b3 = b = 13.

5. A device for detecting weak seismic wave signals of a target based on fourth-order stochastic resonance, characterized in that The device includes: Signal acquisition module: configured to detect the original seismic wave characteristic signal of the underwater vehicle target in the marine environment based on the sensor; Interception module: configured to intercept the target seismic wave signal with a frequency band of 0 - 20 Hz from the original seismic wave characteristic signal based on the first-order filtering algorithm; Normalization module: configured to normalize the target seismic wave signal to obtain the normalized target seismic wave signal; Calculation module: configured to establish a target seismic wave signal detection model of fourth-order stochastic resonance, input the normalized target seismic wave signal into the target seismic wave signal detection model to obtain the target signal, and output the detection result of the target signal. The target seismic wave signal detection model with four layers is: Wherein, a1 = a2 = a3 = a, b1 = b2 = b3 = b, are all model parameters and are obtained by fitting based on historical data; S(t) is the input normalized target seismic wave signal, x1 is the output of the first layer of the target seismic wave signal detection model and the input of the second layer, x2 is the output of the second layer of the target seismic wave signal detection model and the input of the third layer, x3 is the output of the third layer of the target seismic wave signal detection model and the input of the fourth layer, x is the output of the target seismic wave signal detection system; the formulas corresponding to each layer of the target seismic wave signal detection model; each layer of the target seismic wave signal detection model uses the fourth-order Runge-Kutta algorithm for solution.

6. A computer-readable storage medium, in which multiple instructions are stored; the multiple instructions are used to be loaded and executed by a processor to perform the method according to any one of claims 1-4.

7. An electronic device, characterized in that The electronic device includes: A processor for executing a plurality of instructions; A memory for storing a plurality of instructions; Wherein the plurality of instructions are for being stored by the memory and loaded and executed by the processor to perform the method according to any one of claims 1-4.

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