Semi-active parametric sound wave guidance method
By adopting the semi-active parametric acoustic wave guidance method in the underwater guidance system, low-frequency narrow beam parametric acoustic waves and guidance control modules can achieve long-distance and high-precision target guidance, solving the problems of limited role distance and low guidance accuracy in the existing technology, improving anti-interference ability and reducing system complexity.
Patent Information
- Application Number
- CN202510312416.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-17
- Publication Date
- 2025-06-13
AI Technical Summary
The existing underwater guidance methods have problems such as limited working distance, low guidance accuracy, weak anti-interference ability, high system complexity and difficulty in flexibly applying it to underwater equipment.
The semi-active parameter acoustic wave guidance method is adopted. By carrying a parameter array of low-frequency narrow beam parametric sound waves at the transmitting end, the target scattered wave is transmitted and received at the receiving end. The guidance control module generates guidance instructions based on the target position information to achieve accurate tracking of the target.
Long-distance and high-precision target guidance is achieved, significantly improving anti-interference capabilities, and reducing system complexity and cost, which is suitable for flexible applications of underwater equipment.
Smart Images
Figure CN120141228A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of acoustic wave guidance methods, and particularly relates to a semi-active parametric acoustic wave guidance method. Background Art
[0002] Current underwater guidance methods mainly include active acoustic guidance, passive acoustic guidance, wake guidance, wired command guidance, etc. Among them, active acoustic guidance can use the scattered waves generated after the acoustic signals of underwater equipment are reflected by the target for guidance, and has good anti-interference performance. However, due to the limitation of the size of underwater equipment, it is difficult to equip a large-scale low-frequency acoustic guidance system, the working frequency band is relatively high, and the action distance is limited; passive acoustic guidance can directly locate and track the target through the noise signals generated by the target itself, but its action distance is affected by the noise control ability of the target ship, and it is easily deceived by false signal sources; wake guidance uses the wake of the ship's navigation to track the target, and has strong anti-interference ability, but it is difficult to apply to underwater navigation targets with relatively weak wakes. At the same time, it is also affected by the target's ability to use high-speed maneuverability to get rid of pursuit. In addition, it also has defects such as high speed, high noise, poor concealment, and relatively fixed course and trajectory that are easy to be discovered; wired command guidance guides the underwater equipment to approach the target by sending commands to the underwater equipment through the wire connecting the launch platform and the underwater equipment. This method has low accuracy, is difficult to perform large-scale maneuvers, and may also fail due to cable entanglement.
[0003] Therefore, there is an urgent need in the prior art for an acoustic wave guidance method with a long action distance, high guidance accuracy, strong anti-interference ability, low system complexity, and can be flexibly and conveniently applied to underwater equipment. Summary of the Invention
[0004] To solve the problems of the prior art, the object of the present invention is to propose an acoustic wave guidance method with a long action distance, high guidance accuracy, strong anti-interference ability, low system complexity, and can be flexibly and conveniently applied to underwater equipment.
[0005] The technical solution of the present invention is as follows:
[0006] A semi-active parametric acoustic wave guidance method, which uses a parametric acoustic wave guidance system containing a separated transmitting end and receiving end. Among them, the transmitting end includes a parametric array that emits low-frequency and narrow-beam parametric acoustic waves into the water; the receiving end can receive the target scattered wave, that is, the echo of the scattering formed by the target on the parametric acoustic wave, and determine the position information of the target according to the target scattered wave.
[0007] According to some specific embodiments of the present invention, the parametric acoustic wave guidance system further includes a guidance control module connected to the receiving end, and the guidance control module can generate a guidance command according to the position information of the target to track the target.
[0008] According to some specific embodiments of the present invention, the transmitting end is carried on a reconnaissance platform, and the receiving end is carried on a guided platform.
[0009] According to some specific embodiments of the present invention, the receiving end is formed by a hydrophone or a hydrophone array.
[0010] According to some specific embodiments of the present invention, the hydrophone array is a four-element orthogonal hydrophone array.
[0011] According to some specific embodiments of the present invention, the low-frequency and narrow-beam parametric acoustic wave is a single-frequency sine pulse acoustic wave modulated by a square root with a width of 1 - 50 ms, a frequency of 5 kHz, and a beam width ≤ 6°.
[0012] According to some specific embodiments of the present invention, the semi-active parametric acoustic wave guidance method includes:
[0013] S1: Transmit parametric acoustic waves through the transmitting end;
[0014] S2: Receive the target scattered wave signal through the receiving end;
[0015] S3: Calculate the target distance and azimuth based on the received target scattered wave signal or the preprocessed target scattered wave signal obtained after preprocessing;
[0016] S4: Generate a guidance command based on the obtained target distance and azimuth, and control the movement trajectory of the guided platform to track the target.
[0017] According to some specific embodiments of the present invention, the preprocessing includes one or more of the following processes: band-pass filtering, adaptive gain control, and noise suppression.
[0018] According to some specific embodiments of the present invention, the target distance calculation is determined by the following calculation model:
[0019] R = cΔt
[0020] where R represents the distance between the target and the receiving end, c represents the sound speed in water, and Δt is the time difference between the transmitted parametric acoustic wave and the received target scattered wave.
[0021] According to some specific embodiments of the present invention, the receiving end is formed by a four-element orthogonal hydrophone array, and the target azimuth calculation is determined by the following calculation model:
[0022] τ = dsinα / c;
[0023] or determined by the following calculation model:
[0024] α = arcsin(λΔφ / 2πd);
[0025] Among them, τ represents the time delay difference of the target scattered wave received between two sets of opposite hydrophones in the hydrophone array, Δφ represents the phase difference therebetween; d represents the element spacing of the hydrophone array; α represents the target azimuth angle, and λ represents the wavelength of the received target scattered wave.
[0026] The guidance method of the present invention uses parametric array sound waves, which have a narrow beam and strong directivity. At the same time, they have a low frequency, small absorption, strong penetration ability, and long propagation distance. They can effectively penetrate the sound-absorbing tiles and air curtain barriers to implement anti-interference and precise target capture; compared with conventional transducers, the parametric array has a longer operating distance and is smaller and lighter, which is very suitable for being carried on small-sized unmanned platforms. In addition, the parametric array can also be combined with any waveform modulation algorithm to disguise the transmitted signal as a bionic signal, thereby improving the concealment of the work.
[0027] Compared with the active acoustic guidance method, the semi-active parametric acoustic wave guidance method of the present invention adopts a separated transmitting and receiving mode, and emits low-frequency parametric acoustic waves, which can increase the operating distance and reduce the complexity of the system.
[0028] Compared with the passive acoustic guidance method, the semi-active parametric acoustic wave guidance method of the present invention uses parametric acoustic waves with a relatively narrow beam as the transmitted signal, which is not easily confused by false signals and has high guidance accuracy. Brief Description of the Drawings
[0029] Figure 1 It is a schematic diagram of the composition structure of the guidance system of the present invention.
[0030] Figure 2 It is a schematic diagram of the composition structure of a four-element hydrophone array.
[0031] Figure 3 It is a schematic diagram of the principle for resolving the target azimuth angle according to the time delay received by the hydrophone.
[0032] Figure 4 It is a waveform diagram of the original frequency wave signal emitted by the parametric array in Example 1.
[0033] Figure 5 It is a waveform diagram of the parametric acoustic wave generated in water by the signal emitted by the parametric array in Example 1. Detailed Embodiments
[0034] The present invention will be described in detail below in combination with embodiments and drawings. However, it should be understood that the embodiments and drawings are only used for an exemplary description of the present invention, and cannot constitute any limitation to the protection scope of the present invention. All reasonable transformations and combinations within the scope of the inventive concept of the present invention fall within the protection scope of the present invention.
[0035] Unless otherwise specified, the methods or operations used in the following embodiments are conventional methods or operations in the art.
[0036] Referring to the attached Figure 1 , the guidance system used in the semi-active parametric acoustic guidance method of the present invention adopts a separated transmitter 1 and receiver 3. Among them, the transmitter 1 is provided with a parametric array capable of transmitting low-frequency and narrow-beam parametric acoustic waves into the water, and can be carried on a reconnaissance platform such as an underwater unmanned vehicle or a surface ship. Through the propagation of the water medium, it reaches the target 2 to be tracked, and then generates a target scattered wave; the receiver 3 has the function of receiving the target scattered wave and calculating parameters such as the azimuth and distance of the target 2 to be tracked according to the target scattered wave, and it can be carried on an underwater unmanned platform. Preferably, the guidance system further includes a guidance control module connected to the receiver 3, and the guidance control module can generate a guidance command according to the target information calculated by the receiver 3, and control the movement trajectory of the guided platform to track the target.
[0037] According to some specific embodiments of the present invention, the receiver 3 includes a hydrophone with direction-finding and ranging capabilities, such as a vector hydrophone or a hydrophone array, and a signal processing module. The signal processing module can calculate the information of the target to be tracked according to adaptive filtering algorithms, beamforming algorithms, etc.
[0038] According to some specific embodiments of the present invention, the receiver 3 is formed by a four-element orthogonal hydrophone array, where the spatial spacing between each hydrophone is ≤ λ / 2, and λ is the acoustic wavelength.
[0039] According to some specific embodiments of the present invention, the frequency of the parametric acoustic wave generated by the transmitter 1 is 5 kHz, the carrier frequency is 150 kHz, and the beam width is ≤ 6°.
[0040] Furthermore, based on the above guidance system, the semi-active parametric acoustic guidance method of the present invention includes:
[0041] S1 Conduct parametric acoustic wave transmission.
[0042] According to some specific embodiments of the present invention, the parametric acoustic wave transmission includes:
[0043] S11 Transmit a high-frequency modulation signal through the parametric array. Preferably, it is a single-frequency signal with a carrier frequency of 150 kHz and a modulation frequency of 5 kHz using the square root algorithm.
[0044] S12 Directly transmit the high-frequency modulation signal into the water, and use the nonlinear effect of the water medium to obtain a low-frequency acoustic wave with a difference frequency f 差 ; Preferably, the high-frequency modulation signal is beam-controlled before being transmitted into the water.
[0045] Among them, the process of the beam control can be as follows:
[0046] Adjust the phase distribution of the array elements of the parametric array to form a narrow beam with a beam width ≤ 6°, and direct the beam to the target area.
[0047] S2 receives the target scattered wave signal.
[0048] According to some specific embodiments of the present invention, the reception is implemented by a four-element orthogonal hydrophone array as shown in the appendix Figure 2 The signals of each element in the hydrophone array are synchronously sampled, and the sampling rate can be set to ≥ 2f 差 .
[0049] According to the above specific embodiments, the present invention can perform positioning through the time delay difference of the sound wave reaching the hydrophone array. As shown in the appendix Figure 3 The time delay difference τ = dsinα / c between the signals received by two sets of relative hydrophones in the hydrophone array, such as hydrophone 1 and 3 or hydrophone 2 and 4, where c represents the sound speed in water, d represents the hydrophone element spacing, and α represents the target azimuth angle.
[0050] S3 preprocesses the received target scattered wave signal.
[0051] According to some specific embodiments of the present invention, the preprocessing includes one or more of the following processes:
[0052] Band-pass filtering: Filter out non-difference frequency signals in the received signal;
[0053] Adaptive gain control: Dynamically adjust the amplification factor according to the received signal strength;
[0054] Noise suppression: Use algorithms such as the LMS algorithm to eliminate environmental noise such as ocean background noise and multipath interference noise.
[0055] S4 calculates the target distance and azimuth according to the preprocessed signal.
[0056] According to some specific embodiments of the present invention, the target distance calculation can be achieved through the echo time delay, that is, determined by the time difference between the transmitted sound wave and the received echo, and obtained through the following calculation formula:
[0057] R = cΔt
[0058] where c represents the sound speed in water, and Δt is the time difference between the transmitted sound wave and the received echo.
[0059] According to some specific embodiments of the present invention, the target distance calculation can be achieved through the direction of arrival (DOA) estimation method of the four-element orthogonal hydrophone array or directly obtained through time delay calculation. More specifically, the target azimuth angle is obtained through the reception time delay of two sets of relatively arranged hydrophones, and the calculation formula is as follows:
[0060] τ = dsinα / c, where c represents the sound speed in water, d represents the hydrophone element spacing, and α represents the target azimuth angle;
[0061] Or obtain the target azimuth angle through the phase difference of the signals received by these two groups of hydrophones. The calculation formula is as follows:
[0062] α = arcsin(λΔφ / 2πd), where α represents the target azimuth angle, λ represents the wavelength of the received signal, Δφ represents the phase difference, and d represents the hydrophone element spacing.
[0063] S5 generates a guidance command based on the obtained target distance and azimuth, and controls the movement trajectory of the guided platform to track the target.
[0064] Embodiment 1
[0065] According to the above specific implementation manners, in a simulation embodiment of the present invention, the receiving end adopts a four-element hydrophone array arranged orthogonally. The distance between the transmitting end and the target to be tracked is 1200 m. The parametric array emits a pulse width of 2 ms, which is a single-frequency sine signal of the square root modulation algorithm, with a frequency of 5 kHz and a carrier frequency of 150 kHz. The original wave signal emitted by the parametric array is as Figure 4 shown, and the simulation result of the parametric acoustic wave of the emitted signal in water is as Figure 5 shown.
[0066] Calculating according to the underwater sound speed of 1500 m / s, the parametric acoustic wave will reach the target to be tracked after 0.8 s and generate a target scattered wave. The receiving end receives the target scattered wave after 1 s, so the distance between the target and the receiving end is 1500 m.
[0067] The element spacing of the four-element hydrophone array is 1.5 m, and the time delay difference of the signals received by two hydrophones is 0.5 ms. Then the azimuth angle α of the target can be calculated as 30°.
[0068] According to the above calculation results, the tracking of the target can be realized.
[0069] Through the above technical solutions, the present invention realizes high-precision and long-distance guidance of underwater equipment, and at the same time significantly reduces the system complexity and cost, having important application value.
[0070] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.
Claims
1. A semi-active parametric acoustic wave guidance method, characterized in that: It adopts a parametric acoustic wave guidance system containing a separate transmitting end and a receiving end, wherein the transmitting end includes a parametric array that emits low-frequency and narrow-beam parametric acoustic waves into the water; the receiving end can receive target scattered waves, that is, the echo scattered by the target to the parametric acoustic waves, and determine the target's position information based on the target scattered waves.
2. The semi-active parametric acoustic wave guidance method according to claim 1, characterized in that: The parametric acoustic wave guidance system also includes a guidance control module connected to the receiving end. The guidance control module can generate guidance instructions according to the position information of the target to track the target.
3. The semi-active parametric acoustic wave guidance method according to claim 1, characterized in that: in, The transmitting end is mounted on a reconnaissance platform, and the receiving end is mounted on a guided platform.
4. The semi-active parametric acoustic wave guidance method according to claim 1, characterized in that: The receiving end is formed by a hydrophone or a hydrophone array.
5. The semi-active parametric acoustic wave guidance method according to claim 4, characterized in that: The hydrophone array is a four-element orthogonal hydrophone array.
6. The semi-active parametric acoustic wave guidance method according to claim 1, characterized in that: The low-frequency and narrow-beam parametric sound wave is a square-root modulated single-frequency sinusoidal pulse sound wave with a width of 1-50 ms, a frequency of 5 kHz, and a beam width of ≤6°.
7. The semi-active parametric acoustic wave guidance method according to claim 1, characterized in that: It includes: S1 transmits a parametric acoustic wave through the transmitting end; S2 receives the target scattered wave signal through the receiving end; S3 calculates the target distance and azimuth according to the received target scattered wave signal or the preprocessed target scattered wave signal obtained through preprocessing; S4 generates guidance instructions based on the target distance and azimuth, and controls the motion trajectory of the guided platform to track the target.
8. The semi-active parametric acoustic wave guidance method according to claim 7, characterized in that: The preprocessing includes one or more of the following processes: bandpass filtering, adaptive gain control, and noise suppression.
9. The semi-active parametric acoustic wave guidance method according to claim 7, characterized in that: The target distance solution is determined by the following calculation model: R=cΔt Where R represents the distance between the target and the receiver, c represents the speed of sound in water, and Δt is the time difference between the emitted parametric sound wave and the received target scattered wave.
10. The semi-active parametric acoustic wave guidance method according to claim 7, characterized in that: The receiving end is formed by a four-element orthogonal hydrophone array, and the target azimuth solution is determined by the following calculation model: τ = dsinα / c; Or the following calculation model determines: α=arcsin(λΔφ / 2πd); Among them, τ represents the time delay difference of receiving the target scattered wave between two groups of opposite hydrophones in the hydrophone array, Δφ represents the phase difference between them; d represents the array element spacing of the hydrophone array; α represents the target azimuth, and λ represents the wavelength of the received target scattered wave.