A simulation system for detecting underwater target acoustic scattering characteristics by a multi-static sonar

Abstract

The application discloses a kind of simulation systems for detecting underwater target acoustic scattering characteristics of multi-base sonar, including simulator group, including multiple simulators, for the simulation of underwater target acoustic scattering characteristics;Multiple transducers are used to emit sound source and receive sound source to simulator group;System control module is used to control the operation of the simulator group and transducer and state data analysis.The model of the underwater target is divided into multiple sub-regions, and the system control module uses the plate element method suitable for multi-base to construct the impulse response function of the sub-region, generates echo simulation signals, and transmits to the simulation transmitting transducer of the simulator group.

Description

Technical Field

[0001] This invention belongs to the field of underwater acoustic simulation technology, and specifically relates to a simulation system for the acoustic scattering characteristics of multi-site sonar detection of underwater targets. Background Technology

[0002] With the development of underwater acoustic countermeasures technology, traditional monostatic sonar faces increasingly severe challenges, with its effective range significantly shortened, its concealment performance greatly reduced, and its application effectiveness severely affected. Compared to monostatic sonar, multistatic active sonar, due to its unique design of separating the transmitting source and receiver, forms a geometrical triangular layout with the target, thus possessing advantages such as good concealment, long effective range, and strong anti-interference capability. These characteristics make multistatic sonar an important trend in the development of active sonar technology. Summary of the Invention

[0003] One embodiment of this disclosure provides a simulation system for the acoustic scattering characteristics of underwater targets for multistatic sonar detection, comprising:

[0004] The simulator group, consisting of multiple simulators, is used to simulate the acoustic scattering characteristics of underwater targets;

[0005] Multiple transducers are used to transmit and receive sound sources for the simulator group;

[0006] The system control module is used for the operation control and status data analysis of the simulator group and transducer.

[0007] The underwater target model is divided into multiple sub-regions. The system control module uses a multi-base applicable plate element method to construct the impulse response function of each sub-region, generate an echo simulation signal, and transmit it to the simulation transmitter transducer of the simulator group. Attached Figure Description

[0008] The above and other objects, features, and advantages of exemplary embodiments of the present invention will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings. Several embodiments of the invention are illustrated in the drawings by way of example, not limitation, in which:

[0009] Figure 1 A block diagram of a target acoustic scattering waveform simulation system for multi-base sonar detection according to one embodiment of the present invention.

[0010] Figure 2 A schematic diagram of the composition of a simulation system according to one embodiment of the present invention.

[0011] Figure 3 A schematic diagram of a simulator group structure according to one embodiment of the present invention, wherein,

[0012] Figure 3-a indicates a single emulator. Figure 3 -b indicates a multi-emulator group.

[0013] Figure 4 A schematic diagram of the relative positions of an underwater target and a multi-base sonar according to one embodiment of the present invention.

[0014] Figure 5 A schematic diagram of the distribution of bright spots in an underwater target sub-region (2kHz) according to one embodiment of the present invention.

[0015] in, Figure 5 -a represents an incident angle of 45°. Figure 5 -b indicates a 90° incident angle.

[0016] Figure 6 A schematic diagram of a simulated underwater target signal received by a multi-base sonar according to one embodiment of the present invention.

[0017] Figure 7 A schematic diagram of the original underwater target signal received by a multi-base sonar according to one embodiment of the present invention. Detailed Implementation

[0018] Underwater target acoustic scattering simulators, as key equipment for evaluating the detection performance of multistatic active sonar systems, offer advantages such as small size, low cost, and ease of deployment and retrieval. Currently, various types of underwater target simulators have been developed, including buoy-type, towed, and self-propelled models, capable of simulating the acoustic scattering characteristics of underwater moving targets. However, these simulators are primarily designed for monostatic sonar systems and cannot accurately simulate the contribution of the acoustic shadow zone to the multistatic scattering sound field of the target. Consequently, the distortion increases with the setting angle of the multistatic sonar system.

[0019] Furthermore, a single simulator cannot accurately simulate the scale characteristics of a target; only a combination of multiple simulators can achieve this simulation. The number of simulators and the amplitude of the simulated signal depend on the target's acoustic scattering characteristics. It is worth noting that current underwater target acoustic scattering simulators have not fully considered the contribution of the shadow zone to the scattered sound field under multi-base detection mode, nor the impact of changes in the target's spatial position on the amplitude fluctuations of the scattered sound field. Therefore, their simulation performance still has room for improvement.

[0020] To overcome the limitations of existing underwater target acoustic scattering characteristic simulators, this disclosure provides an underwater target acoustic scattering characteristic simulation system and method for multistatic sonar detection. This simulation system and method not only designs an expandable multi-simulator group that can accurately simulate the scale characteristics of the target, but also can simulate the target's multistatic acoustic scattering waveforms that vary with the azimuth angle and time in real time. It has advantages such as high fidelity, high mobility, and expandability, providing support for key tasks such as underwater combat training, underwater weapon testing and performance evaluation in the Navy.

[0021] According to one or more embodiments, such as Figure 1 As shown, an underwater target acoustic scattering waveform simulation system for multi-site active sonar detection comprises two parts: a target sub-region acoustic scattering waveform simulator group and system control software. The simulator group includes a transmitting transducer, buoyancy material, a fairing, a controller module, a wireless communication module, a signal acquisition module, and a power supply module. The system control software includes remote control software (host computer) and embedded control software (slave computer).

[0022] Figure 1 The architecture of a target acoustic scattering waveform simulation system for multi-base sonar detection is presented. The system includes a target sub-region acoustic scattering waveform simulator group and control software.

[0023] The target sub-region acoustic scattering waveform simulator group includes:

[0024] 1. Buoyancy material, used to provide buoyancy for the system, ensuring that the entire simulation system can be stably suspended in the water.

[0025] 2. A flow deflector is used to reduce the interference of water flow on the propagation of sound waves, ensuring that sound waves can more accurately simulate the propagation of sound waves in the actual environment.

[0026] 3. The transmitting transducer converts electrical signals into sound waves and transmits the sound waves into the water.

[0027] 4. Signal acquisition module, used to acquire sound wave signals reflected back from the target object.

[0028] 5. Controller module, responsible for system control and coordination.

[0029] 6. Wireless communication module, used for wireless data transmission between the system and external devices.

[0030] 7. Power supply module, which supplies power to the system.

[0031] The system control software includes:

[0032] 8. Remote control software (host computer).

[0033] 9. Embedded control software (lower-level machine).

[0034] According to one or more embodiments Figure 2 The architecture of a sonar detection system is demonstrated, which is used to simulate and process acoustic signals from underwater targets. The system consists of multiple modules, including:

[0035] 1. Backend database module: This module divides the target mesh file into multiple target sub-regions and calculates the excitation response function of different sub-regions at different orientations using the multi-base applicable plate element method.

[0036] 2. Human-computer interaction module, including:

[0037] Simulate target parameters, including type (including size), depth, heading, etc., to define the characteristics of the target.

[0038] The detection signal parameters, including the azimuth of arrival, the distance of arrival, the signal waveform, and the transmission interval, are used to define the characteristics of the detection signal.

[0039] Output waveform display is used to visualize the processed acoustic signal.

[0040] The backend database module and the human-computer interaction module are loaded into the host computer.

[0041] 3. An embedded control software module, loaded into the lower-level machine, including...

[0042] A receiving hydrophone is used to receive underwater acoustic signals. After detecting the signal, the trigger unit initiates subsequent data processing.

[0043] Data processing includes convolution operations. The excitation response functions of different orientations in each sub-region are processed by this convolution operation to obtain the echo signals of each sub-region that are forwarded in real time.

[0044] The echo signal is sent to each transmitting transducer after passing through a delay unit.

[0045] Transmitting transducers are used to transmit sound wave signals.

[0046] Therefore, the lower-level computer is not only responsible for processing the echo signals of each sub-region, but also sends the processed signals to the upper-level computer.

[0047] The remote control software (host computer) and embedded control software (slave computer) include:

[0048] (1) System host computer.

[0049] The host computer includes remote control software based on a client / server architecture. It can be located on land or remotely from a land base. Control communication with the slave computer is achieved via Transmission Control Protocol / Internet Protocol (TCP / IP). High-speed, stable data transmission is maintained between the slave computer and the controller module (slave computer) located in the simulator via Gigabit Ethernet, enabling human-machine interaction. The host computer portion of the system includes a backend database module and a human-machine interaction module.

[0050] a. The backend database module contains impulse response functions for different regions and orientations of the target. Its construction method involves: obtaining the target mesh file; dividing the target into sub-regions based on the contribution of bright spots on the target surface; and calculating the impulse response functions for different regions and orientations using a plate element method applicable to multiple sites.

[0051] b. In the human-computer interaction module, the simulation target parameters (type, depth, and heading) and the detection signal parameters (arrival azimuth, arrival distance, signal waveform, transmission period, etc.) are set to calculate and generate corresponding control commands, and call the impulse response functions of different areas and azimuths of the target stored in the background database.

[0052] (2) System lower-level machine.

[0053] The lower-level software, run by the controller module in the simulator, is used to generate simulated echo signals from different areas and directions of the target, establish a gigabit Ethernet transmission communication mode, and customize the network interconnection protocol to achieve high-speed, stable, and reliable data transmission. The specific workflow is as follows:

[0054] The receiver continuously collects data from the sonar (hydrophone). When a detection signal is detected, the trigger unit activates, calculating the azimuth and distance of the incoming wave. Combined with parameters set by the host computer and the impulse response function in the background database, convolution operations are performed to generate a simulated echo signal in real time. A delay unit waits for the transmitting transducer to reach the same position as the incoming wave before synchronously outputting the signal through the transmitting transducer, achieving coordinated triggering of the real-time echo.

[0055] A single simulator consists of a transmitting transducer, buoyancy material, a fairing, a controller module, a wireless communication module, a signal acquisition module, and a power supply module. It operates with zero buoyancy underwater, with its center of buoyancy higher than its center of gravity. The transmitting transducer is fixed to a tow cable, the end of which is equipped with a depth stabilizer. Then, by setting the number of acoustic simulators and their relative spatial positions, a scale target is simulated. During the winch-towed simulator's movement, the hydrophone continuously receives signals. When a detection signal is detected, the trigger unit activates and calculates the azimuth of the incoming wave, uploading it to the host computer. Combining the set target parameters and transmitted signal parameters, a simulated echo signal is generated in real time and transmitted to the simulator's transmitting transducer. The multistatic sonar receives this relay signal, realizing the simulation of underwater target scattering waveforms for multistatic sonar detection.

[0056] like Figure 3 As shown, Figure 3 -a is a single simulator, which includes a controller module, a signal acquisition module, buoyancy material, and a transmission transducer. Figure 3 -b represents a multi-simulator group. One end of this group is connected to the first depth finder, and the other end is connected to the winch via a receiving hydrophone and a second depth finder. The hydrophone here refers to the receiving sonar in the multi-base sonar system of this disclosure. The communication cable or fiber optic cable between the depth finder, hydrophone, and simulator can also be fixed to the tow cable. Figure 3 This is just one example. In order to deploy a multi-base sonar system in a comprehensive manner from multiple angles and directions, multiple tow cables can be set up and towed by a winch. The host computer controls the winch to tow the multiple tow cables. On each tow cable, the same or different numbers of depth stabilizers, simulator groups, and hydrophones can be set up as needed. The acoustic scattering characteristics of underwater targets can be simulated according to different combinations to meet different research needs.

[0057] According to one or more embodiments, such as Figure 4 The example shown illustrates a simulation study of multistatic sonar detection using an underwater benchmark model. The model includes a transmitting transducer and receiving transducers 1, 2, and 3. The geometric acoustic center of the model is taken as the origin, and the transmitting and receiving transducers are located in the xy plane, θ... i θ s and θ b These are the incident angle, receiving angle, and separation angle of the sound wave, respectively. The azimuth of the incoming wave is set as θ. i =45° and θ i =90°, azimuth of sound wave emission θ s =0°~360°. The model is divided into two sub-regions, bow and stern. The impulse response functions of the two regions are constructed using the plate element method applicable to multiple sites, and simulated echo signals are generated and transmitted to... Figure 3 The simulator group shown contains different transmitting transducers. The distribution of bright spots in the underwater target sub-regions under these two incoming wave azimuths is as follows. Figure 5 As shown, the simulated underwater target signal received by the multi-base sonar is as follows: Figure 6 As shown. The Benchmark model is a model used in this disclosure embodiment to test and evaluate the performance of the acoustic model or algorithm. This model typically has known acoustic properties and can be used to simulate the sound scattering characteristics of underwater targets. It is used to verify the accuracy and effectiveness of the acoustic model or algorithm during acoustic simulation and algorithm development.

[0058] Here, the multi-base applicability plate element method is suitable for multi-base sonar detection, i.e., emitting sound waves from different locations and receiving the target's scattered signal. This plate element method divides the target into multiple small plate elements, each of which can be considered an acoustic source. These acoustic sources collectively contribute to the total acoustic scattering signal. This simulates the complex geometry and material properties of the target, thereby generating relatively accurate acoustic scattering signal simulation results. For example, the target is divided into two sub-regions, bow and stern, and then the plate element technique is applied to each region to construct an impulse response function. These impulse response functions reflect the response of each plate element to the incident sound wave, and their superposition generates the target's total acoustic scattering signal. In this embodiment, a simulator from a simulator group is used to simulate the acoustic scattering waveform of a target sub-region. This allows for the simulation of changes in the sound wave incident angle, reception angle, and offset angle, as well as the time-varying multi-base acoustic scattering waveform of the target, thereby providing highly realistic, highly maneuverable, and scalable simulation results.

[0059] Figure 7 The original underwater target signal received by multistatic sonar is presented. A comparison between the simulated underwater target signal and the original signal shows a high degree of agreement, demonstrating that the simulation system and method proposed in this disclosure can generate a simulated signal that closely matches the original underwater target signal. This high degree of agreement indicates that the simulation system has high accuracy and reliability, providing strong support for the testing, verification, and optimization of multistatic sonar systems.

[0060] In summary, the beneficial effects of this disclosure include:

[0061] An innovative plate-based method applicable to multi-base systems was adopted, which can accurately simulate the contribution of the acoustic shadow region to the multi-base scattered sound field of the target, significantly improving the accuracy of acoustic scattering waveform simulation. In addition, a towed multi-simulator group was designed to accurately simulate the scale characteristics of underwater targets.

[0062] Through the aforementioned technical means, this disclosure successfully achieves a high-fidelity simulation of the acoustic scattering waveform of underwater targets for multistatic sonar detection. This not only improves the accuracy of the simulation but also provides a solid foundation for performance testing, target identification, and optimization of detection strategies for multistatic sonar systems.

[0063] It should be understood that in the embodiments of the present invention, the term "and / or" is merely a description of the relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Furthermore, the character " / " in this document generally indicates that the preceding and following associated objects have an "or" relationship.

[0064] It is worth noting that although the spirit and principles of this invention have been described with reference to several specific embodiments, it should be understood that this invention is not limited to the disclosed specific embodiments, and the division of aspects does not imply that the features in these aspects cannot be combined; such division is merely for the convenience of description. This invention is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. A simulation system for the acoustic scattering characteristics of underwater targets for multi-static sonar detection, characterized in that, The system includes: The simulator group, consisting of multiple simulators, is used to simulate the acoustic scattering characteristics of underwater targets; Multiple transducers are used to transmit and receive sound sources for the simulator group; The system control module is used for the operation control and status data analysis of the simulator group and transducer. The system control module includes an upper computer module and a lower computer module. The upper computer module is based on a client / server architecture and has a background database module and a human-computer interaction module. The lower computer module is used to generate echo simulation signals of different areas and directions of the underwater target. The underwater target model is divided into multiple sub-regions. The system control module uses a multi-base applicable plate element method to construct the impulse response function of the sub-region, generate an echo simulation signal, and transmit it to the simulation transmitter transducer of the simulator group. The simulator is fixed to the tow cable connected to the winch. A depth stabilizer is also fixedly installed on the tow cable. A hydrophone is installed on the tow cable. When the hydrophone receives a detection signal, it calculates the azimuth of the incoming wave and uploads it to the host computer module. Combined with the preset underwater target parameters and transmission signal parameters, it generates an echo simulation signal in real time and transmits it to the simulator's simulation transmission transducer.

2. The system according to claim 1, characterized in that, The system control module synchronously sends the echo analog signal to each simulator, thereby achieving synchronous output of the echo analog signal.

3. The system according to claim 1, characterized in that, The simulator includes a simulated transmission transducer, buoyancy material, fairing, controller module, wireless communication module, signal acquisition module, and power supply module.

4. The system according to claim 3, characterized in that, The simulator has the characteristics of zero buoyancy underwater and a center of buoyancy higher than the center of gravity.

5. The system according to claim 1, characterized in that, The multiple transducers include multiple transmitting transducers and multiple receiving transducers located at different positions. By setting the number of acoustic simulators and their relative spatial positions, the scale target is simulated.

6. The system according to claim 1, characterized in that, The lower-level module achieves high-speed and stable transmission with the controller module located in the simulator via gigabit Ethernet.

7. The system according to claim 1, characterized in that, The background database module contains impulse response functions for different regions and orientations of the target. Its construction method is as follows: obtain the target mesh file, divide the target into sub-regions based on the contribution of bright spots on the target surface, and calculate the impulse response functions for different regions and orientations using the plate element method applicable to multiple bases.

8. The system according to claim 1, characterized in that, The host computer module calculates and generates corresponding control commands based on the set simulated target parameters and detection signal parameters, and calls the impulse response functions of different areas and directions of the target stored in the background database. The simulated target parameters include type, depth and heading, and the detection signal parameters include azimuth of arrival, distance of arrival, signal waveform and transmission period.

9. The system according to claim 1, characterized in that, The lower-level module includes a receiving hydrophone, a triggering unit, a data processing unit, a delay unit, and a transmitting transducer. The receiving hydrophone is used to receive underwater acoustic signals. After detecting the signal, the triggering unit initiates data processing. The data processing includes convolution operations. The impulse response functions of different orientations of each sub-region are processed by the convolution operation to obtain the echo signals of each sub-region that are forwarded in real time. The echo signals are then sent to each transmitting transducer through the delay unit.

10. The system according to claim 1, characterized in that, The system uses a winch to tow multiple tow cables, and each tow cable is equipped with the same or different number of depth stabilizers, simulator groups and hydrophones, so as to simulate the acoustic scattering characteristics of underwater targets according to different combinations.

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