Multichannel underwater acoustic planar array receiving system of sonar

Abstract

The utility model relates to a multichannel underwater acoustic planar array receiving system of sonar, which comprises an underwater acoustic planar array unit and a shore-based equipment unit, the underwater acoustic planar array unit comprises a plurality of groups of planar receiving arrays, a lead plate, a back plate and an analog front amplification plate which are connected in sequence, and the output end of the back plate is connected with the transmitting end of an optical transceiver. The optical transmitter and receiver transmitting end is connected with an optical transmitter and receiver receiving end in the shore-based equipment unit through a submarine cable, and then the optical transmitter and receiver receiving end is connected with an upper computer to realize communication; the plane receiving array is used for receiving underwater acoustic signals and converting the acoustic signals into acoustic analog electric signals, the acoustic analog electric signals are input to the analog front amplification plate through the lead plate and the back plate, and the analog front amplification plate processes the acoustic analog electric signals and converts the acoustic analog electric signals into acoustic digital signals to be transmitted to the shore-based equipment unit. The frogman detection sonar device has the characteristics of simple structure, small size, low maintenance cost and strong stability, and can effectively improve frogman detection sonar accuracy and working efficiency.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of multichannel underwater acoustic plane array receiving system of sonar, belong to the technical field of sonar receiving system. BACKGROUND

[0002] Underwater acoustic plane array receiving system is a kind of passive sonar technology, passive sonar technology refers to sonar passively receiving the radiated noise of underwater target such as ship and the signal emitted by underwater acoustic equipment, to determine the bearing and distance of target.It evolves from simple hydrophone, listens to the noise emitted by target, judges the position and certain characteristics of target, especially suitable for submarine that cannot emit sound to expose itself and want to detect enemy ship activity.Passive sonar is used to detect target by receiving the noise or signal emitted by target itself using receiving transducer array.

[0003] Since passive sonar does not emit signal, target will not be aware of the existence of sonar and its intention.The sound emitted by target and its characteristics are not controlled by designer when designing sonar, and the understanding of them is often not comprehensive.Sonar designer can only design the sound of certain predetermined target, such as target is frogman, then the noise emitted by target itself includes oxygen bottle noise, hydrodynamic noise generated by friction between human body and water flow, etc.Therefore, the most fundamental difference between passive sonar (noise station) and active sonar is that it receives the noise emitted by far-field target under the background of body noise.If target noise is used as signal, it will become very weak after long-distance propagation.

[0004] Moreover, passive sonar often works under low signal-to-noise ratio condition, so it needs to adopt more signal processing measures than active sonar.But passive sonar has no transmitter part, echo station, depth finder, communication instrument, mine detector, etc.can be classified into active sonar class, noise station, reconnaissance instrument, etc.are classified into passive sonar class.As frogman detection sonar has not been fully realized productization, there is still room for improvement in working accuracy.At the same time, traditional frogman detection sonar has single function, short detection distance, and cannot realize accurate detection of frogman.Therefore, a kind of underwater acoustic plane array receiving system device capable of improving the accuracy of frogman detection sonar is urgently needed. SUMMARY

[0005] The summary portion of the application is used to introduce the concept in a brief form, which will be described in detail in the specific embodiment part.The summary part of the application is not intended to identify the key features or essential features of the claimed technical solution, nor is it intended to limit the scope of the claimed technical solution.

[0006] The utility model discloses a multichannel underwater acoustic plane array receiving system of sonar which is provided to solve the problems in the prior art.

[0007] To achieve the above object, the utility model provides the following technical scheme: including underwater acoustic plane array unit and shore base equipment unit, the underwater acoustic plane array unit includes multiple groups of plane receiving array, lead plate, backboard and analog preamplifier that connect in turn, the output of backboard is connected optical transmitter end, and the optical transmitter end is connected optical receiver end in the shore base equipment unit through the sea cable, and then realizes communication by the optical receiver end and the host computer connection, the plane receiving array is used for receiving underwater acoustic signal, and the acoustic signal is converted into acoustic analog electric signal, the acoustic analog electric signal is input to the analog preamplifier through the lead plate and backboard, and the analog preamplifier processes the acoustic analog electric signal and converts into acoustic digital signal and is delivered to the shore base equipment unit.

[0008] Further, the analog preamplifier includes multiple preamplifier circuits, filter circuits, secondary amplification circuits and AD conversion circuits connected in turn, the output of the AD conversion circuit is connected to the FPGA control module, and the output of the FPGA control module is connected to the signal processing system and the storage control system. The signal received by the plane receiving array is preamplified, high-pass and low-pass filtered, second amplified and analog-digital converted in turn, and then the acoustic digital signal is output to the shore base equipment unit.

[0009] Further, the plane receiving array and the lead plate are connected through a water-tight connector. The water-tight connector is a special connector applied to underwater robots, sensors, sonars and ships, which is used to connect various underwater devices to ensure the stability of data transmission and energy transmission.

[0010] Further, the signal output of the lead plate adopts twisted pair differential output, and the input end of the analog preamplifier is connected to a differential amplifier. To improve the noise resistance of the plane receiving array output signal, the signal output of the lead plate adopts twisted pair differential output, and the input end of the analog preamplifier is connected to a differential amplifier.

[0011] Further, the horizontal direction of the plane receiving array includes 128 column transducer arrays, and the vertical direction of each column of the transducer arrays includes 30 transducer elements.

[0012] Further, the plane receiving array, the lead plate, the back plate and the analog preamplifier plate are sequentially connected to form three groups.

[0013] Further, the preamplifier circuit includes a low-noise high-impedance operational amplifier chip.

[0014] Further, the secondary amplification circuit includes a variable gain amplifier, which is composed of a fixed gain amplifier and a variable attenuator.

[0015] Further, the filter circuit includes a four-order Butterworth active band-pass filter composed of operational amplifiers.

[0016] Compared with the prior art, the present application has the following advantages:

[0017] The utility model discloses simple structure, low maintenance cost and strong stability can effectively improve frog person detection sonar accuracy and work efficiency. Including the plane receiving array of multiple groups of connection, the lead plate, the backboard and the analog preamplifier board, and the plane receiving array is detected to the sound signal by sound signal conversion into electric signal, is transmitted to the lead plate through the watertight connector, and then the signal channel of backboard is input to the analog preamplifier board. The received sound wave analog electric signal is amplified, filtered, AD converted, demodulated by the analog preamplifier board, and is converted into the baseband digital signal suitable for beam forming algorithm, and the data is packed and is output through the high speed serial interface on the backboard and is sent to the optical transmitter end, is realized communication by the host computer of optical receiving end connection. Through three different directions' plane receiving array, the detection angle and range of frog person detection sonar can be effectively increased, and the reliability and accuracy of detection data are improved. Meanwhile, because three plane receiving arrays are relatively independent, the relevance of crosstalk noise can be effectively reduced, the precision of detection data is improved, and the detection distance is increased. In addition, the utility model also has small size, low power consumption, low maintenance cost and the like. BRIEF DESCRIPTION OF DRAWINGS

[0018] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application and are incorporated herein in their entirety. The drawings illustrate preferred embodiments of the present application and, together with their description, serve to explain the application.

[0019] In the drawings:

[0020] Figure 1 It is the connection structure schematic drawing of the whole utility model;

[0021] Figure 2 It is the transmission principle block diagram of the whole utility model;

[0022] Figure 3 It is the structure schematic drawing of the back side and right side of plane receiving array in the utility model;

[0023] Figure 4 It is the connection structure schematic drawing of plane receiving array and watertight connector in the utility model;

[0024] Figure 5 It is the connection system block diagram of analog preamplifier board in the utility model;

[0025] Figure 6 It is the transmission principle block diagram of analog preamplifier board in the utility model;

[0026] Figure 7 It is the circuit board schematic drawing of plane receiving array in the utility model;

[0027] Figure 8The transducer array element of the plane receiving array in the utility model receives corresponding curves.

[0028] Figure 9 The transducer array element of the plane receiving array in the utility model is horizontally arranged.

[0029] Figure 10 The transducer array element of the plane receiving array in the utility model is vertically arranged. DETAILED DESCRIPTION

[0030] Embodiments of the present disclosure will be described in more detail with reference to the drawings. Although certain embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms, and should not be interpreted as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present disclosure can be more thoroughly and completely understood. It should be understood that the drawings and embodiments of the present disclosure are for exemplary purposes only, and are not intended to limit the scope of protection of the present disclosure.

[0031] In addition, it should be further noted that, for the convenience of description, only parts related to the utility model are shown in the drawings. The embodiments in the present disclosure and the features in the embodiments can be combined with each other without conflict.

[0032] The present disclosure will be described in detail below with reference to the drawings and in conjunction with embodiments.

[0033] The multi-channel underwater acoustic plane array receiving system of the sonar provided in the embodiment comprises three plane receiving arrays arranged around the CDSD-85 sonar, so as to provide relatively independent signal acquisition and transmission channels. Figure 1 and Figure 2 As shown in the drawings, the multi-channel underwater acoustic plane array receiving system of the sonar comprises a underwater acoustic plane array unit and a shore-based device unit. The underwater acoustic plane array unit comprises multiple groups of plane receiving arrays, lead plates, back plates and analog preamplifier plates connected in sequence. The output end of the back plate is connected to the transmitting end of an optical transceiver, and the transmitting end of the optical transceiver is connected to the receiving end of the optical transceiver in the shore-based device unit through a submarine cable, and then the receiving end of the optical transceiver is connected to a host computer to realize communication. The plane receiving array is used for receiving underwater acoustic signals and converting the acoustic signals into acoustic analog electric signals. The acoustic analog electric signals are input to the analog preamplifier plate through the lead plate and the back plate, and the analog preamplifier plate processes and converts the acoustic analog electric signals into acoustic digital signals for transmission to the shore-based device unit. The transmitting end of the optical transceiver is responsible for converting electric signals into optical signals and transmitting the optical signals through the submarine cable. The receiving end of the optical transceiver is responsible for receiving the optical signals transmitted through the submarine cable and converting the optical signals into electric signals for use by the subsequent host computer device.

[0034] Specifically, the plane receiving array is installed in a receiving electronic cabin, and the plane receiving array is composed of multiple linear hydrophone arrays. Figure 7The horizontal direction has 128 transducer arrays, and the vertical direction has 15*2 transducer elements in each transducer array. The 128 transducer arrays in the horizontal direction are numbered from left to right as 1-128, each of which has positive and negative lead wires, and the shell is made of aluminum alloy material and filled with polyurethane glue. The decoupling material is high-density foam with a water pressure resistance of more than 4 MPa, so that the plane receiving array can withstand a working water depth of 300 meters.

[0035] The back side of the receiving electronic cabin of the plane receiving array adopts an end flange sealing method, and the overall schematic diagram is shown in Figure 3 The array spacing of the transducer array in the plane receiving array is 9.375 mm, so the transducer array can be designed with a smaller transverse size, usually using piezoelectric ceramic particles. Each transducer array in the horizontal direction includes 15*2, a total of 30 transducer elements in the vertical direction, and the total number of transducer elements in the entire plane receiving array is 128*15*2, a total of 3840 transducer elements. Through calculation, the size of each transducer element is a P5 piezoelectric ceramic particle with a size of 4*4*24 mm, and the spacing between the transducer arrays in the horizontal direction is 9.375 mm. Therefore, in the directivity design of the plane receiving array, the full array length of the transducer array is 128*9.375=1200 mm, and the length of the transducer element in the vertical direction is 30*5.2=156 mm. The spacing between the transducer elements is designed according to the half wavelength of less than 80 kHz, and the calculated directivity beam is as follows: the horizontal direction 80 kHz beam width is 0.99°, and the vertical direction single beam width is about 6°. According to theoretical calculation, the impedance and sensitivity curve of the transducer element is shown in Figure 8 、 Figure 9 and Figure 10 The receiving sensitivity is near 80 kHz, and the fluctuation is within 3 dB.

[0036] The plane receiving array is connected to the lead plate through a water-tight connector, and the lead plate also includes a connector connected to the sonar tank body external sensor, the transmitting tank, the towed body sea cable and other equipment. The water-tight connector is located in the middle position of the upper part of the plane receiving array, as shown in Figure 4 The model of the water-tight connector is selected as Season 16 core, the connection line contains gigabit Ethernet line and power supply and synchronization line, the data transmission is in the form of gigabit Ethernet, and the control command and array element original data are transmitted, and the data transmission rate reaches 46 Mbps.

[0037] The backboard is used to provide power supply and signal connection for all circuit boards and modules connected to the respective signal acquisition board, analog preamplifier board and lead board. The backboard connects the analog preamplifier board to transmit acoustic analog signals. The entire multi-channel underwater acoustic plane array receiving system has a high-frequency sub-array input of 1x128 channels. The analog preamplifier board includes four printed boards, each of which contains up to 32 channels for analog signal preprocessing. To improve the noise immunity of the output signal of the plane receiving array, the signal output end of the lead board uses double twisted differential output, and a differential amplifier is added at the input end of the analog preamplifier board. In order to cooperate with the lead wire mode of the sonar tank, independent lead wire inserts are designed around the backboard, which are connected to the connectors of the sonar tank and some internal modules through cables, such as power supply, switch, water leakage detection sensor, etc.

[0038] As shown in Figure 5 and Figure 6 , the analog preamplifier board includes multiple preamplifier circuits, filter circuits, second amplifier circuits, AD conversion circuits and FPGA control modules, and is provided with an input communication interface connected to a signal processing system and a storage control system. The input end of the analog preamplifier board is connected to the plane receiving array. The main function of the analog preamplifier board is to input the weak analog signal output by the plane receiving array, amplify, filter, analog-digital convert and demodulate it, and then convert it into a baseband digital signal suitable for beam forming algorithm, and pack the data and output it to the signal processing machine. In order to reduce the interference of the signal, the analog preamplifier board is designed as a separate module. The analog preamplifier board uses four printed boards with 32 channels (i.e. four 8 channels) on both sides, i.e. a total of 32x4 channels, which are used for acquisition and processing. Each printed board is provided with 32 analog input interfaces, and each channel is provided with input protection, preamplifier, filter, gain amplifier and analog-digital converter, which amplify, filter and condition the weak signal from the plane receiving array, and then convert it into a digital signal and send it to the sampling signal processor. The sampling signal processor performs data acquisition, processing and packaging functions, pre-processes the 32-channel digital signal after analog-digital conversion, and then sends it to the signal processing system and the storage control system through a high-speed serial interface.

[0039] The analog preamplifier board has the advantages of small volume, low power consumption and high integration, and has a system power supply independently powered and controlled by an FPGA control module, and can realize opening, closing and resetting operations. Each channel of the analog preamplifier board is composed of a preamplifier circuit, a two-stage amplifier circuit, a filter circuit and an A / D conversion circuit. The preamplifier circuit adopts a high-impedance preamplifier composed of a low-noise operational amplifier chip AD8656 with a gain of 28dB produced by ADI company. The two-stage amplifier circuit adopts two-stage variable gain amplifiers composed of a fixed gain amplifier and a variable attenuator, and the gain is continuously adjustable in a range of 32dB. The fixed gain amplifier is composed of a low-power operational amplifier chip MAX4257 produced by MAXIM company, and the variable attenuator is composed of a digital-to-analog converter AD5450 produced by ADI company. The filter circuit adopts a four-order Butterworth active band-pass filter composed of a multi-path negative feedback of an operational amplifier chip TLV2782 produced by TI company. The A / D conversion circuit adopts an ADC module with a conversion precision of 16Bit, and the FPGA control module adopts a control module produced by LATTICE company. The FPGA control module code is stored in SPI-FLASH, because reading out 32 channels of quantized digital signals in a single analog preamplifier board simultaneously needs to occupy more I / O ports of the FPGA control module in the acquisition control board.

[0040] The use method of the utility model

[0041] Three plane receiving arrays are arranged in different directions around the frogman detection CDSD-85 sonar. Each plane receiving array includes 3840 transducer array elements and is provided with a water-tight connector connected with a lead plate. When the underwater acoustic signals are detected by the transducer array elements of the plane receiving array, the acoustic signals can be converted into electric signals. The electric signals are transmitted to the lead plate through the water-tight connector, and then input to the analog preamplifier board through the signal channels on the back plate. The analog preamplifier board amplifies, high-pass and low-pass filters, A / D converts and demodulates the received analog electric signals in sequence, so as to convert them into baseband digital signals suitable for beam forming algorithm, and sends the digital signals out to the signal processing system and storage control system of the transmitting end of the optical transceiver through the high-speed serial interface arranged on the back plate.

[0042] In the description of the utility model, it is understood that the indicated orientation or position relationship is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the indicated device or element must have a specific orientation, a specific orientation and operation, so it cannot be understood as a limitation of the utility model.

[0043] In addition to the above embodiments, the utility model can have other implementation manners. For those skilled in the art, the technical scheme recorded in the above embodiments can still be modified, or part of the technical features can be replaced equivalently, and any modification, equivalent replacement, improvement, etc. within the spirit and principle of the utility model should be included in the protection scope of the utility model.

Claims

1. A multichannel underwater acoustic plane array receiving system for sonar, characterized by: The application relates to an underwater acoustic communication system, which comprises a water acoustic plane array unit and a shore-based equipment unit, the water acoustic plane array unit comprises multiple groups of sequentially connected plane receiving arrays, lead plates, back plates and analog preamplifier plates, the output end of the back plate is connected with a transmitting end of an optical terminal, the transmitting end of the optical terminal is connected with a receiving end of an optical terminal in the shore-based equipment unit through a submarine cable, and the receiving end of the optical terminal is connected with an upper computer to realize communication; the plane receiving array is used for receiving underwater acoustic signals and converting the acoustic signals into acoustic analog electric signals, the acoustic analog electric signals are input into the analog preamplifier plate through the lead plate and the back plate, the analog preamplifier plate processes the acoustic analog electric signals and converts the acoustic analog electric signals into acoustic digital signals to be delivered to the shore-based equipment unit.

2. A multichannel underwater acoustic plane array receiving system for sonar according to claim 1, characterized in that: The analog preamplifier plate comprises multiple groups of sequentially connected preamplification circuits, filter circuits, secondary amplification circuits and AD conversion circuits, the output end of the AD conversion circuit is connected with an FPGA control module, and the output end of the FPGA control module is connected with a signal processing system and a storage control system.

3. The multi-channel underwater acoustic plane array receiving system of claim 1, wherein: The plane receiving array and the lead plate are connected through a water-tight connector.

4. The multi-channel underwater acoustic plane array receiving system of claim 1, wherein: The signal output of the lead plate adopts double-twisted differential output, and the input end of the analog preamplifier plate is connected with a differential amplifier.

5. The multichannel underwater acoustic plane array receiving system of claim 1, wherein: The horizontal direction of the plane receiving array comprises 128 transducer base arrays, and the vertical direction of each column of the transducer base array comprises 30 transducer elements.

6. A multichannel underwater acoustic plane array receiving system for sonar according to claim 1, characterized in that: The sequentially connected plane receiving array, lead plate, back plate and analog preamplifier plate are provided as three groups.

7. A multichannel underwater acoustic plane array receiving system for sonar according to claim 2, characterized in that: The preamplification circuit comprises a low-noise high-impedance operational amplifier chip.

8. A multichannel underwater acoustic plane array receiving system for sonar according to claim 7, characterized in that: The secondary amplification circuit comprises a variable gain amplifier which is composed of a fixed gain amplifier and a variable attenuator.

9. A multichannel underwater acoustic plane array receiving system for sonar according to claim 8, characterized in that: The filter circuit comprises a four-order Butterworth active band-pass filter which is composed of an operational amplifier.

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