AUV (Autonomous Underwater Vehicle) detection system based on multiple sensors and detection method thereof

Abstract

The invention relates to the technical field of underwater detection, in particular to an AUV (Autonomous Underwater Vehicle) detection system based on multiple sensors and a detection method thereof, which can realize detection of port underwater acoustic stations, active warning sonar, obstacles, small targets, underwater topography and the like and realize the detection capability of AUV near-shore sea areas. The foresight sonar is carried on the head of the AUV, the AUV platform sails forward at a stable speed, and the sonar transmits pulse signals according to a certain period, so that the detection of a suspended or sinking target in the advancing direction of the AUV is realized, and a detected front obstacle can be sent to an AUV control system, so that the obstacle avoidance of the AUV is realized, and the sailing safety of the AUV is ensured.

Description

Technical Field

[0001] The present invention relates to the field of underwater detection technology, and in particular to an AUV detection system based on multiple sensors and a detection method thereof. Background Art

[0002] In recent years, with the development of information technology and computers, low-power signal processing and transducer technology, acoustic equipment has been rapidly developed and widely used in underwater detection. As an underwater unmanned platform, the Autonomous Under-Water Vehicle (AUV) is equipped with various advanced acoustic detection equipment, and adopts autonomous navigation or receives remote control commands to carry out target detection and intelligence information collection in important and sensitive waters. Since there is no casualties and the economic loss is small, it is suitable for performing various high-risk and covert detection tasks.

[0003] Ports, waterways, docks, near-shore anchorages, etc. are increasingly valued by people due to their huge economic potential and strategic importance. As strategic locations in the defense system, the security defense of these near-shore waters has become the focus of attention and protection of all countries. Targeted research and defense have been carried out on near-shore defenses such as ports. In some ports, near-shore waterways and other key waters, underwater all-weather monitoring or warning systems composed of various acoustic sensors or sensor arrays have been deployed, mainly including active warning sonars, acoustic monitoring systems, etc., to implement real-time and effective automatic monitoring and alarm of invasion threats.

[0004] At present, there are problems such as single detection means and limited detection capabilities in the detection of ports and nearshore waters. Traditional detection technology is difficult to meet the comprehensive detection needs of targets such as port and nearshore underwater terrain, hydroacoustic stations, active warning sonar, obstacles, etc., which limits the detection capabilities of AUVs in the waters near the coast. Therefore, there is an urgent need for a comprehensive detection technology that can achieve effective detection of multiple targets in ports and nearshore areas and improve the working capabilities of AUVs in nearshore waters. Summary of the invention

[0005] In view of this, the present invention provides an AUV detection system based on multiple sensors and a detection method thereof, which can realize the detection of ports and nearshore underwater terrain, hydroacoustic stations, active warning sonars, obstacles, small targets, etc., and enhance the detection capability of AUV in the waters near the coast.

[0006] To achieve the above purpose, the technical solution of the present invention is as follows:

[0007] An AUV detection system based on multiple sensors, including: forward-looking sonar, passive sonar, side-scan sonar and an AUV platform; wherein the forward-looking sonar and the passive sonar are mounted on the head of the AUV platform, and the side-scan sonar is installed downward at a certain angle on the left and right sides of the AUV platform;

[0008] Among them, when the AUV is sailing underwater, the forward-looking sonar emits a periodic pulse signal to the front and receives the echo signal. After conversion, amplification, sampling, filtering and other processing, the target acoustic image is generated to realize target detection in the direction of the AUV's advance. Combined with the inertial navigation on the AUV, the AUV is provided with obstacle information to realize the AUV's obstacle avoidance. The vertical opening angle of the forward-looking sonar signal is smaller than the horizontal opening angle; the passive sonar realizes passive detection of targets within a certain angle range in the direction of the AUV's advance by receiving the target radiation noise; the side-scan sonar realizes the detection of terrain and targets on both sides of the AUV, and completes the detection of suspected targets in combination with the carrier position and heading information provided by other sensors.

[0009] Among them, the forward-looking sonar includes a transducer array, a sonar electronic module, a watertight connecting cable and related software, wherein the transducer array includes a transmitting transducer and a receiving transducer, and the sonar electronic module includes a digital signal processing module, a transmitting module, a receiving module and a power supply module; the digital signal processing module controls the transmitting module to excite the transmitting transducer to generate an acoustic signal; controls the receiving module to receive the signal and sends it to the digital processing module for further processing after filtering and amplification by the preprocessing module in the receiving transducer.

[0010] The passive sonar includes: a receiving transducer, an interface board, a preamplifier, a receiver, a sonar system baseboard, an FPGA core board, a network, a processing module, a display and control software, a display and control computer and a power supply system; wherein the signal is sequentially transmitted through the receiving transducer, the interface board and the preamplifier to the receiver; the receiver outputs the signal to the sonar system baseboard, the FPGA core board controls the sonar system baseboard and the processing module to realize signal processing, and the signal of the sonar system baseboard is transmitted to the processing module through the network; the signal processed by the processing module is processed by the display and control software and displayed by the display and control computer.

[0011] Wherein, the network is realized by accessing a multi-element broadband linear array through a network interface.

[0012] Among them, the operating frequency of the passive sonar covers the typical frequency band of the port active monitoring sonar, and the effective detection distance is not less than 1.5 times the maximum detection distance of the active sonar.

[0013] The side scan sonar adopts a modular design, including: a transducer array, an electronic processing box, a network, a storage module and a control device; wherein the electronic processing box is provided with a transmitter, a receiver and a control and processing module.

[0014] The present invention also provides an AUV detection method based on multiple sensors, which is implemented based on the detection system of the present invention and includes the following steps:

[0015] After receiving the detection mission, the AUV is first powered on to carry out technical preparation and function inspection, and the detection mission file is prepared. The AUV's navigation system inertial navigation is powered on, and the initial alignment is started. The detection mission file can be bound to the AUV simultaneously; after the inertial navigation alignment is completed, it is deployed into the water;

[0016] The AUV autonomously navigates to the operating area, turns on forward-looking sonar and side-scan sonar detection, and stores the detected data. When it reaches the port, it turns on passive sonar, detects the port active warning sonar, etc., and stores the data. At this time, the side-scan sonar can be turned off as needed to reduce the probability of being detected by the port active warning. The AUV status can be monitored in real time through underwater acoustic communication when carrying out the mission;

[0017] When the AUV performs its mission normally, it collects information from each module in real time and makes the AUV move along the planned path according to the position information provided by the navigation and positioning module;

[0018] After completing the detection mission, the AUV returns home autonomously. After arriving at the predetermined recovery point, it floats to the surface for recovery. After recovery, it can download internal data through wireless local area or wired network to analyze the mission execution status.

[0019] Beneficial effects:

[0020] 1. In the present invention, the forward-looking sonar is mounted on the head of the AUV. The AUV platform maintains a stable speed and sails forward. The sonar emits pulse signals at a certain period to detect suspended or sunken targets in the forward direction of the AUV. The detected obstacles in front can also be sent to the AUV control system to achieve obstacle avoidance of the AUV and ensure the navigation safety of the AUV.

[0021] 2. The forward-looking sonar in the present invention adopts an integrated design, using low-power, low-noise, and small-volume devices to fully reduce the heat dissipation requirements of the receiver while ensuring the sonar performance, optimize the interconnection design between the components, greatly compress the internal space, and solve the biggest bottleneck of miniaturization design;

[0022] 3. In the present invention, the detection sensor is integrated into the payload detection compartment, which realizes the modularization and integration of the mission payload, and is convenient for later disassembly, maintenance, repair and guarantee; it integrates multiple acoustic sensors for real-time detection of nearshore targets such as ports, with high detection efficiency, greatly improving the detection capability, and can effectively obtain various target information in nearshore waters.

[0023] 3. The present invention analyzes the characteristics of important waters such as ports and their defense systems. This type of active sonar uses small targets, AUVs, divers, etc. as detection objects, and belongs to high-resolution image sonar. The typical frequency of this type of sonar is generally between 50kHz and 100kHz. The low frequency of some active warning sonars can be around 30kHz, and the high frequency of some active warning sonars can reach 130kHz. The present invention proposes to use broadband passive sonar to detect typical active sonar systems or hydroacoustic stations deployed in ports. It can detect active sonars deployed in ports in real time, and has the characteristics of wide detection bandwidth, long detection distance, strong anti-interference and good real-time performance.

[0024] 4. The present invention solves the acoustic compatibility problem between acoustic devices through acoustic compatibility technology and adopts acoustic equipment frequency domain and timing control technology. At the same time, it has strong small target detection capability, and can realize the reconnaissance of targets, hydroacoustic stations and other obstacles deployed in key waters such as important waterways; it has strong terrain acquisition capabilities for ports, waterways, and scheduled landing sites, and can realize covert detection of acoustic detection equipment deployed in ports, fully considering use, protection and recovery, and closely linking technology, design and use.

[0025] 5. The present invention adopts a combination of active and passive sonars to realize the detection of different target types at different distances; all three types of sonars focus on lightweight and miniaturized design, light weight, low power consumption, suitable for unmanned ships, UUVs and other carriers, and also suitable for divers to detect and use; forward-looking sonar takes into account underwater target detection and obstacle avoidance to improve the sonar performance in shallow water and high reverberation environments; passive sonar has a wide range of applications and can realize the detection and tracking of various periodic or continuous sound source targets.

[0026] 6. All detection data in the present invention have two storage methods. They can be stored in the underwater vehicle at the same time, and can also be uploaded to the shore-based control center through a wired method, which improves the security of the detection data and the effectiveness of the detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The schematic diagram of the AUV detection system based on multiple sensors of the present invention is shown in FIG. 1- forward-looking sonar; 2- passive sonar; 3- side-scan sonar; 4- AUV platform.

[0028] Figure 2 It is a schematic diagram of the forward-looking sonar composition in the system of the present invention.

[0029] Figure 3 It is a schematic diagram of the passive sonar composition in the system of the present invention.

[0030] Figure 4 It is a schematic diagram of the side scan sonar composition in the system of the present invention.

[0031] Figure 5 It is a schematic diagram of the flow of the AUV detection method based on multiple sensors of the present invention. DETAILED DESCRIPTION

[0032] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0033] The present invention provides an AUV detection system based on multiple sensors. According to the characteristics of ports and their acoustic defense systems, waterways, and nearshore areas, a comprehensive detection technology based on forward-looking sonar, side-scan sonar, and passive sonar multi-acoustic payloads is proposed to achieve target detection of ports and nearshore underwater terrain, hydroacoustic stations, active warning sonars, obstacles, etc., and enhance the detection capability of AUVs in the waters near the nearshore. At the same time, according to different task requirements, one or more detection payloads can be selected to carry and meet the corresponding work requirements. The system of the present invention is as follows: Figure 1 As shown, it includes: forward-looking sonar 1, passive sonar 2, side-scan sonar 3 and AUV platform 4. The forward-looking sonar 1 and passive sonar 2 are mounted on the head of the AUV platform 4, and the side-scan sonar 3 is installed downward at a certain angle on the left and right sides of the AUV platform 4.

[0034] The forward-looking sonar is mainly used to detect targets and avoid obstacles in the direction of the AUV's advance. As the carrier navigates, the forward-looking sonar completes periodic pulse emission and collection in front to generate a clear acoustic image; the passive sonar can detect targets within a certain angle range in the direction of the AUV's advance; the side-scan sonar can detect terrain and targets on both sides of the AUV; the AUV platform can combine the carrier's position, heading and other information provided by other sensors to complete the detection of suspected targets and avoidance of obstacles.

[0035] The system is generally deployed around the port according to the active warning sonar. The application scenario of the present invention is mainly shallow water areas such as ports, where the waters are complex, reverberation and multipath are serious. For this reason, the vertical opening angle of the forward-looking sonar signal is small to reduce the multipath effect in the shallow water environment, and the horizontal opening angle is large to ensure a wide field of view ahead.

[0036] Specifically, in the present invention, the forward-looking sonar is mounted on the head of the AUV, and the AUV platform maintains a stable speed while sailing forward. The sonar emits pulse signals at a certain period to detect suspended or sunken targets in the forward direction of the AUV. The detected obstacles ahead can also be sent to the AUV control system to achieve obstacle avoidance for the AUV and ensure the navigation safety of the AUV.

[0037] The forward-looking sonar in this embodiment is Figure 2As shown, it includes: transducer array, sonar electronic module, connecting cable and related software. The transducer array includes transmitting transducer and receiving transducer, and the sonar electronic module includes digital signal processing module, transmitting module, receiving module and power supply module; the digital signal processing module controls the transmitting module to excite the transmitting transducer and generate acoustic signal; controls the receiving module to receive the signal and sends it to the digital processing module for further processing after filtering and amplification by the pre-processing module in the receiving transducer.

[0038] Furthermore, the forward-looking sonar adopts an integrated design, using low-power, low-noise, and small-volume components to fully reduce the receiver's heat dissipation requirements while ensuring sonar performance, optimize the interconnection design between components, greatly compress the internal space, and solve the biggest bottleneck of miniaturized design.

[0039] The passive sonar in this embodiment is as follows Figure 3 As shown, it includes: receiving transducer, interface board, preamplifier, receiver, sonar system baseboard, FPGA core board, network (through network interface to access multi-element broadband linear array), processing module, display and control software, display and control computer and power supply system. Among them, the signal is sequentially transmitted through the receiving transducer, interface board and preamplifier to the receiver; the receiver outputs the signal to the sonar system baseboard, the FPGA core board controls the sonar system baseboard and the processing module to realize signal processing, and the signal of the sonar system baseboard is transmitted to the processing module through the network; the signal processed by the processing module is processed by the display and control software and displayed by the display and control computer.

[0040] The port and nearshore defense system includes the installation of active warning sonar in the warning area such as ports, docks, nearshore anchorages, etc. to detect intruding targets such as underwater unmanned vehicles and divers. By analyzing the characteristics of important waters such as ports and their defense systems, it can be seen that this type of active sonar detects small targets and belongs to high-resolution image sonar. The typical frequency of this type of sonar is generally between 50kHz and 100kHz. The low frequency of some active warning sonars can be around 30kHz, and the high frequency of some active warning sonars can reach 130kHz. The present invention proposes to use broadband passive sonar to realize the detection of typical active sonar systems or hydroacoustic stations deployed in ports. In order to implement effective detection, the working frequency of the passive sonar covers the typical frequency band of the currently common port active monitoring sonar, and the effective detection distance is not less than 1.5 times the maximum detection distance of the active sonar. At the same time, due to the harsh port environment, large environmental noise, severe reverberation, and combined with the detection probability requirements, environmental noise and the influence of platform self-noise, the use environment of passive sonar is worse than that of active sonar. To this end, the present invention provides an active sonar that can detect the port deployment in real time, which has the characteristics of wide detection bandwidth, long detection distance, strong anti-interference and good real-time performance.

[0041] The side scan sonar of this embodiment is as follows Figure 4 As shown in the figure, it adopts modular design, including: transducer array, electronic processing box, network, storage module and control device. It can detect the terrain of waters such as ports and waterways, small underwater targets, submarine obstacles, unburied submarine optical cables and pipelines, etc. Among them, the electronic processing box is equipped with a transmitter, a receiver and a control and processing module.

[0042] The present invention also provides an AUV detection method based on multiple sensors, which is implemented based on the system of the present invention. The process is as follows: Figure 5 As shown, the following steps are included:

[0043] After receiving the detection mission, the AUV is first powered on for technical preparation and functional inspection, and the detection mission file is prepared. The AUV's navigation system inertial navigation is powered on, and the initial alignment is started. The detection mission file can be bound to the AUV at the same time; after the inertial navigation alignment is completed, it is deployed into the water; the AUV autonomously navigates to the operation area, turns on the forward-looking sonar and side-scan sonar detection, and stores the detection data. When it arrives near the port, it turns on the passive sonar, detects the port active warning sonar, etc., and stores the data. At this time, the side-scan sonar can be turned off as needed to reduce the probability of being detected by the port active warning. When carrying out the mission, the AUV status can be monitored in real time through underwater acoustic communication.

[0044] When the AUV is performing its mission normally, it collects information from each module in real time and moves the AUV along the planned path based on the location information provided by the navigation and positioning module. After completing the detection mission, the AUV returns home autonomously, and after arriving at the predetermined recovery point, it floats to the surface for recovery. After recovery, it can download internal data through a wireless local area or wired network to analyze the mission execution status.

[0045] In summary, the above are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A multi-sensor based AUV detection system, characterized in that: include: Forward-looking sonar, passive sonar, side-scan sonar and AUV platform; the forward-looking sonar and passive sonar are mounted on the head of the AUV platform, and the side-scan sonar is installed downward at a certain angle on the left and right sides of the AUV platform; Among them, when the AUV is sailing underwater, the forward-looking sonar emits a periodic pulse signal to the front and receives the echo signal. After conversion, amplification, sampling, filtering and other processing, the target acoustic image is generated to realize target detection in the direction of the AUV's advance. Combined with the inertial navigation on the AUV, the AUV is provided with obstacle information to realize the AUV's obstacle avoidance. The vertical opening angle of the forward-looking sonar signal is smaller than the horizontal opening angle; the passive sonar realizes passive detection of targets within a certain angle range in the direction of the AUV's advance by receiving the target radiation noise; the side-scan sonar realizes the detection of terrain and targets on both sides of the AUV, and completes the detection of suspected targets in combination with the carrier position and heading information provided by other sensors.

2. The system according to claim 1, characterized in that The forward-looking sonar includes a transducer array, a sonar electronic module, a watertight connection cable and related software, wherein the transducer array includes a transmitting transducer and a receiving transducer, and the sonar electronic module includes a digital signal processing module, a transmitting module, a receiving module and a power supply module; The digital signal processing module controls the transmitting module to excite the transmitting transducer to generate an acoustic signal; controls the receiving module to receive the signal and sends it to the digital processing module for further processing after filtering and amplification by the pre-processing module in the receiving transducer.

3. The system according to claim 1 or 2, characterized in that The passive sonar includes: a receiving transducer, an interface board, a preamplifier, a receiver, a sonar system baseboard, an FPGA core board, a network, a processing module, a display and control software, a display and control computer and a power supply system; wherein, the signal is sequentially transmitted through the receiving transducer, the interface board and the preamplifier to the receiver; the receiver outputs the signal to the sonar system baseboard, the FPGA core board controls the sonar system baseboard and the processing module to realize signal processing, and the signal of the sonar system baseboard is transmitted to the processing module through the network; the signal processed by the processing module is processed by the display and control software and displayed by the display and control computer.

4. The system according to claim 3, characterized in that ,The network is realized by accessing a multi-element broadband linear array through a network interface.

5. The system according to claim 4, characterized in that The operating frequency of the passive sonar covers the typical frequency band of the port active monitoring sonar, and the effective detection distance is not less than 1.5 times the maximum detection distance of the active sonar.

6. The system of claim 1, 2, 4 or 5, wherein: The side scan sonar adopts a modular design, including: a transducer array, an electronic processing box, a network, a storage module and a control device; wherein the electronic processing box is provided with a transmitter, a receiver and a control and processing module.

7. A multi-sensor based AUV detection method, characterized in that: The detection system according to any one of claims 1 to 6 is implemented, comprising the following steps: After receiving the detection mission, the AUV is first powered on to carry out technical preparation and function inspection, and the detection mission file is prepared. The AUV's navigation system inertial navigation is powered on, and the initial alignment is started. The detection mission file can be bound to the AUV simultaneously; after the inertial navigation alignment is completed, it is deployed into the water; The AUV autonomously navigates to the operating area, turns on forward-looking sonar and side-scan sonar detection, and stores the detected data. When it reaches the port, it turns on passive sonar, detects the port active warning sonar, etc., and stores the data. At this time, the side-scan sonar can be turned off as needed to reduce the probability of being detected by the port active warning. When carrying out the mission, the AUV status can be monitored in real time through underwater acoustic communication; When the AUV performs its mission normally, it collects information from each module in real time and makes the AUV move along the planned path according to the position information provided by the navigation and positioning module; After completing the detection mission, the AUV returns home autonomously. After arriving at the predetermined recovery point, it floats to the surface for recovery. After recovery, it can download internal data through wireless local area or wired network to analyze the mission execution status.

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