RU2572666C1 - Hydroacoustic system for imaging underwater space - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: hydroacoustic system for imaging underwater space, having antenna units for the portside and the starboard, the outputs of which are connected to corresponding series-connected receiving amplifiers and analogue-to-digital converters, and the inputs are connected to the outputs of the power amplifiers, a roll measuring device, a module for generating, receiving and packing signals, the inputs of which are connected to the analogue-to-digital converters, the power amplifiers and the roll measuring device, an interface unit, a navigation system and an on-board computer, wherein the input of the on-board computer is connected to the output of the navigation system and through the interface unit to the output of the module for generating, receiving and packing signals, a multi-beam echo sounder antenna, series-connected receiving amplifier unit and analogue-to-digital converter unit, connected between the output of the multi-beam echo sounder antenna and the module for generating, receiving and packing signals, a power amplifier unit connected between the input of the multi-beam echo sounder antenna and the output of the module for generating, receiving and packing signals, as well as a depth measuring device connected to the input of said unit; the system is provided with forward-looking sector-scanning sonar, which includes a receiving-transmitting antenna, a power amplifier, the input of which is connected to the unit for generating, receiving and packing signals, and the output is connected to the radiator of the receiving-transmitting antenna, multichannel amplifiers connected in series to the receiving elements of the receiving-transmitting antenna and a multichannel analogue-to-digital converter, the output of which is connected to the unit for generating, receiving and packing signals, and a sound and light signalling device, connected to the output of the computer. The invention provides high reliability of the hydroacoustic system owing to early detection of navigation hazards on the towing course of the underwater module of the hydroacoustic system and preventing collision with said hazards.

EFFECT: providing early detection of navigation hazards and preventing collision with said hazards owing to a larger scanning sector on the heading of the underwater module of the system.

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Description

The invention relates to the field of hydroacoustic technology and can be used as part of equipment for reproducing the bottom topography in real time.

A device for a hydroacoustic system for visualizing the underwater space based on a multichannel technological complex for studying the shelf, comprising a side-scan sonar module, a seismic-acoustic profiler module, an echo sounder module, a navigation system, a processing and recording unit, an operational control information unit, a synchronous display unit and registration, operating mode switch, and HBO contains a gondola towed on a cable-rope, which is equipped with hydroacoustic an tennami, analog-to-digital converter, controlling a computer with a monitor and blocks of graphic and magnetic recording. (Certificate for utility model of the Russian Federation No. 16406, IPC G01V 1/38, G05D 27/00, publ. 12/27/2000).

The disadvantage of this device is the inability to reproduce with its bottom topography and the presence of an invisible zone in the center of the field of view.

A device for a hydroacoustic system for visualizing underwater space based on the “IAC” marine geo-acoustic complex is known, comprising an onboard module of a carrier vessel, connected by a cable with a towed hardware module, including a measurement data collection unit and an information recording and processing unit connected in series, outboard the towed module includes a long-range side-scan sonar (HBO), a high-resolution HBO, an acoustic profilograph, an echo sounder, and sonar navigation igation system, sounding signal synthesizer, control signal interface, towing module spatial position sensors, digital sensors block, pressure sensor and analog sensors block, analog sensors interface, cable interface, digital transceiver, single-board computer and towing module power supply connected via the system bus data and control, and the outputs of the sounding signal synthesizer are connected to the first inputs of the long-range sonar, long-range sonar high-resolution survey, acoustic profilograph, echo sounder and transponder beacon, control signal interface inputs and outputs are connected to the second inputs of long-range side-scan sonar blocks, high-resolution side-scan sonar, acoustic profilograph, echo sounder and transponder beacon, the outputs of which are connected to the inputs cable interface, with the input-output of which is connected a digital transceiver (Certificate for a useful model of the Russian Federation No. 38233, IPC G01V 1/38, G05D 27/00, publ. 05/27/2004).

The disadvantage of this device is the inability to reproduce the topography of the bottom and the presence of an invisible zone.

Known sonar system for visualizing the underwater space, containing blocks of antennas of the left and right sides, the outputs of which are connected to the corresponding series-connected receiving amplifiers and analog-to-digital converters, and the inputs are connected to the outputs of the power amplifiers, roll meter, a module for generating, receiving and packing signals, the inputs of which are connected to analog-to-digital converters, power amplifiers and a roll meter, an interface unit, a navigation system and an on-board computer ter, moreover, the output of the navigation system is connected to the input of the on-board computer and, through the interface block, the output of the module for generating, receiving and packing signals, as well as the blocks of the receiving antenna of the profilograph and the first and second antennas of pumping the profilograph. (Matvienko Yu.V., Voronin V.A., Tarasov S.P., Sknarya A.V., Tutynin E.V. Ways to improve hydroacoustic technologies for the examination of the seabed using autonomous uninhabited underwater vehicles / Underwater research and robotics. 2009 No. 2 (8) p. 4-15).

Thanks to the use of interferometric side-scan sonars (IHBO), the device allows reproducing the bottom topography. However, an invisible zone still remains in his line of sight. In addition, the construction of an accurate relief is possible only in the process of secondary processing using data obtained on different tacks.

The closest in technical essence and the achieved result to the proposed invention (prototype) is the well-known sonar imaging system for the underwater space, containing the left and right side antenna blocks, the outputs of which are connected to the corresponding series-connected receiving amplifiers and analog-to-digital converters, and the inputs are connected to the outputs power amplifiers, roll meter, module for generating, receiving and packing signals, to the inputs of which analog-to-digital are connected transducers, power amplifiers and a roll meter, an interface unit, a navigation system and an on-board computer, the output of the navigation system and the output of a module for generating, receiving and packing signals, an antenna of a multi-beam echo sounder, a series of receiving amplifiers and block of analog-to-digital converters connected between the output of the multi-beam echo sounder antenna and the module for generating, receiving and packing signals, block of power amplifiers, VK located between the antenna input of the multipath echo sounder and the output of the module for generating, receiving and packing signals, as well as the depth gauge connected to the input of this unit (RF Patent No. 2461845 of 04/28/2011, IPC G01S 15/89).

The disadvantage of this device is the inability to proactively detect navigation obstacles and prevent collisions with them due to the small sector of view at the direction of movement of the underwater module of the system.

The technical result of the invention is to provide proactive detection of navigational obstacles and prevent collisions with them by increasing the field of view at the direction of movement of the underwater module of the system.

The technical result is achieved due to the fact that the hydro-acoustic imaging system of the underwater space, containing the left and right side antenna blocks, the outputs of which are connected to the corresponding series-connected receiving amplifiers and analog-to-digital converters, and the inputs are connected to the outputs of the power amplifiers, roll meter, formation module , receiving and packing signals, to the inputs of which are connected analog-to-digital converters, power amplifiers and a roll meter, an interface unit, n the navigation system and the on-board computer, and the output of the navigation system is connected to the input of the on-board computer and, through the interface block, the output of the module for generating, receiving and packing signals, the multipath echo sounder antenna, the receiver amplifiers block and the analog-to-digital transducer block connected between the multipath echo sounder output and a module for generating, receiving and packing signals, a power amplifier unit connected between the input of the multi-beam echo sounder antenna and the output of the module signal receiving, receiving and packing, as well as a depth gauge connected to the input of this unit, is equipped with a forward-looking sector-based sonar, including a transmitting and receiving antenna, a power amplifier, the input of which is connected to a signal generating, receiving and packing unit, and the output to the transmitter transmitting antennas, multichannel amplifiers and a multichannel analog-to-digital converter, the output of which is connected to the forming unit, connected in series to the receiving elements of the transmitting and receiving antenna, receiving and packing signals, and a sound and light alarm device connected to the output of the computer.

The invention is illustrated by drawings. In FIG. 1 shows a block diagram of the proposed device, and in FIG. 2 is a block diagram of computer signal processing.

The underwater imaging system contains blocks of left and right side antennas 1 and 1 ′, the outputs of which are connected to the corresponding series-connected receiving amplifiers 2 and 2 ′ and analog-to-digital converters 3 and 3 ′, and the inputs are connected to the outputs of power amplifiers 4 and 4 ′, An antenna 5 of a multi-beam echo sounder, the receiving elements of which are connected in series with the inputs of the blocks of the receiving amplifiers 6 and the blocks of analog-to-digital converters 7, the block of power amplifiers 8 connected to the radiation the antenna elements of the multi-beam echo sounder 5, roll meter 9, depth meter 10, module for generating, receiving and packing signals 11, an interface unit 12, navigation system 13 and on-board computer 14, while the analogue signal is connected to the inputs of the module for generating, receiving and packing signals 11 digital converters 3, 3 ′ and block 7, power amplifiers 4, 4 ′ and blocks 8, roll meter 9, and depth gauge 10, and the navigation system 13 is connected to the inputs of the on-board computer 14 and the output of the formation, reception module through the interface unit 12 and pack Signals, an up-and-coming sector survey sonar (GSO), including a transmit-receive antenna 15, multi-channel amplifiers 16 and multi-channel analog-to-digital converter 17, the output of which is connected to a signal generation, reception and packaging block 11, an amplifier power 18, the input of which is connected to the block for the formation, reception and packaging of signals 11, and the output to the emitter of the receiving and transmitting antenna 15, and the sound and light signaling device 19, connected to move the computer 14.

The block diagram of a computer signal processing system (Fig. 2) contains a signal reading and unpacking unit 20, a directional characteristic formation unit 21, an evaluation unit of the delay times of the echo signals 22, and also blocks connected in series to the output of the unit 20, respectively, blocks phase and amplitude measurements 23 and 23 ′, initial phase estimation blocks 24 and 24 ′, ray incidence angle estimation blocks 25 and 25 ′, blocks for calculating the coordinates of the points of intersection of the rays with the bottom surface 26, 26 ′ and 26 ″, per Cross sections with a bottom to the geographical map 27, as well as a block for generating directivity characteristics 28, a block for calculating correlation functions 29, and a threshold block 30, which are connected between the output of the signal reading and decompressing unit 20 and the input of the sound and light signaling device 19.

The device operates as follows.

All emitted signals are simultaneously generated by block 11 and connected in series to blocks of power amplifiers 4, 4 ′, 8, and 18 and radiating elements of antennas 1, 1 ′, 5, and 15. Structurally, antennas 1, 1 ′, and 5 are designed so that each of these, it is narrow along the direction of travel and wide in the transverse direction, with the antenna sector of sight 5 being in the middle of the bottom viewing band, and the antenna sectors of the left and right sides 1 and 1 ′ are located to the left and right of the underwater module tow and intersect with the field of view multibeam woofer. The receiving elements of the antenna 5 of the multi-beam echo sounder are located along a line (or arc facing down) lying in a plane perpendicular to the direction of movement. The antenna blocks of each side 1 and 1 ′ consist of two vertically spaced linear antennas with a directivity characteristic narrow in the horizontal plane and wide in the vertical. The transmit-receive antenna 18 is located in the bow of the underwater module. Its elements are located on at least two vertically spaced horizontal lines or arcs facing forward. The signals from the output of the receiving elements of the antennas 1, 1 ′ 5 and 15 are amplified in blocks 2, 2 ′, 6 and 16, digitized in blocks 3, 3 ′, 7 and 17 and fed to block 11, in which the received signals are packaged for subsequent transmitting them through the interface unit 12 to the on-board computer 14. The signals from the output of the roll meter 9 and the depth meter 10 are mixed with the signals from the receiving antennas 1, 1 ′, 5, and 15; the navigation system 13 is additionally connected to the on-board computer 14, which provides necessary source data for referencing reproduced terrain and the bottom to the geographical map of the area.

Signal processing in the on-board computer 14 is as follows. Signals from the receiving elements of all antennas through the interface unit 12 are received by the signal reading and unpacking unit 20 and distributed into four streams corresponding to signals from the receiving antenna blocks of the multi-beam echo sounder 5, antenna blocks 1 and 1 ′ of the left and right sides and from the antenna 15 of the forward looking sector sonar review. Based on the aggregate of signals from the elements of the receiving antenna of the multipath echo sounder, a fan of directional characteristics is formed in block 21, the axes of which are uniformly distributed over the width of the viewing sector of the multipath echo sounder. For each beam formed in block 22, the correlation function of the received signal with the emitted is calculated and the delay time of the echo signal coming from the point of intersection of the beam with the bottom is estimated from the position of the maximum of the correlation function. Thus, at the output of block 22, a combination of delay times τ (α _i ) and maxima of the correlation function A (α _i ) for each ray characterized by the angle α _{1 is formed} .

The signals from the output of the pairs of receiving antennas of the left and right sides in blocks 23 and 23 ′, respectively, make current estimates of the amplitude of the echo signal and the phase shift between the signals at the outputs of the pair of antennas. The signal amplitude is determined by adding the squares of the real and imaginary parts from the output of each antenna:

where Re ₁ , Im _i , Re ₂ and Im ₂ are the real and imaginary components of the signals at the output of the first and second antennas, respectively.

The phase shift is determined in a known manner:

Due to the periodicity of the arc tangent function, this estimation of the phase shift is carried out accurate to a constant multiple of π.

The phase shift corresponds to the angle of incidence α:

where β is the angle of inclination of the line connecting the linear HBO antennas;

d is the distance between the linear HBO antennas;

λ is the wavelength of radiation in water.

The ambiguity of the estimation of the phase shift leads to the ambiguity of determining the angle of incidence of the beam. In the prototype device, to eliminate the ambiguity, the bottom topography is reproduced by secondary processing using data obtained on several tacks. In the proposed device, the ambiguity of determining the phase shift is eliminated in blocks 24 and 24 ′ directly in the process of processing current data. This is achieved by the fact that to identify the correspondence between the phase shift and the angle of incidence of the beam data are used multipath echo sounder. According to the obtained set of delays τ (α _i ), each time t can be associated with the angle of incidence α, for which the signal delay time is t. Having chosen some reference time t ₀ , it is possible to determine the corresponding initial angle α ₀ and, in accordance with formula (3), set the initial phase Δφ _{0 to it} .

where γ ₀ is the roll value of the carrier at time t ₀ .

In blocks 25 and 25 ′, the current angle of incidence of the beam is calculated. The equation for calculating this angle is obtained by subtracting (4) from (3):

Due to the fact that in the recalculation formula the difference of phase shifts at the initial and current time points is used, the ambiguity of the phase calculation at the initial time moment becomes irrelevant. However, when calculating the phase shift at the current time, it is necessary to take into account phase increments that are multiples of 2π. To do this, it is necessary to calculate interference fringes and, with the advent of each new fringe, add 2π to the current phase estimate made by formula (2).

Thus, at the output of blocks 25 and 25 ′, estimates of the angles of incidence of the beam on the bottom surface are formed for each time instant. In blocks 26, 26 ′ and 26 ″ according to the obtained estimates of the dependence of the angle α, the coordinates of the intersection with the bottom are calculated for the current time t _i . Assuming that the speed of sound with depth remains unchanged, the coordinates X _{a, i} and Z _{a, i of the} point of intersection of the beam with the bottom relative to the center of the corresponding antenna are determined analytically:

To determine the coordinates of the point of intersection of the beam with the bottom under the conditions of a known distribution of the speed of sound over depth, a beam program can be used which, for a given angle of incidence of the beam, builds the path of the beam and calculates the propagation time along this path. The beam path is constructed until the propagation time of sound along the beam is equal to half the current time. The set of ends of the constructed trajectories determines the coordinates of the points X _{a, i} , Z _{a, i} on the surface of the relief in the coordinate system of the corresponding antenna. In block 27, these points are recalculated in the geographical map of the area according to the following formula:

X _i = X _H + (X _a + X _{a, i} ) cosK + (Y _a -L _G ) sinK

Y _i = Y _H + (Y _a -L _Г ) cosK + (X _a + X _{a, i} ) sinК

Z _i = H _PM + Z _a + Z _i

where X _N and Y _H are the geographical coordinates of the sonar carrier, determined by the navigation system of the carrier;

L _G - the horizontal distance between the coordinates of the carrier and the underwater module of the sonar.

K - heading angle of carrier movement;

X a , Y a , Z a - coordinates of the phase center of the antenna relative to the center of the underwater sonar module.

N _PM - the immersion depth of the underwater module.

Processing data from the antenna of the forward-looking sector-based sonar includes the formation in block 28 of a two-dimensional directivity pattern, the calculation in block 29 of the correlation function of the signal received in the generated channels with the emitted signal and the allocation of spatial channels in the threshold block 30 in which the threshold has been exceeded. When the threshold is exceeded, computer 14 turns on sound and light alarms, and the coordinates of the spatial channels in which the threshold is exceeded are displayed on its display. The generated acoustic image of the bottom and its relief are also displayed here.

The invention, in contrast to the prototype, provides increased reliability of the sonar system due to proactive detection of navigation hazards at the tow rate of the underwater module of the sonar system and to prevent collision with them.

Claims (1)

A hydro-acoustic system for visualizing the underwater space, containing the left and right side antenna blocks, the outputs of which are connected to the corresponding series-connected receiving amplifiers and analog-to-digital converters, and the inputs are connected to the outputs of the power amplifiers, a roll meter, a module for generating, receiving and packing signals, to the inputs which is connected to analog-to-digital converters, power amplifiers and a roll meter, an interface unit, a navigation system and an on-board computer, and to the output of the navigation system is connected to the input of the on-board computer and, through the interface block, the output of the module for generating, receiving and packing signals, the multipath echo sounder antenna, the block of receiving amplifiers and the analog-to-digital transducer unit connected between the output of the multipath echo sounder antenna and the module for generating, receiving and packing signals , a unit of power amplifiers connected between the input of the multipath echo sounder antenna and the output of the module for generating, receiving and packing signals, as well as connected Depth measuring device that is connected to the input of this unit, characterized in that it is equipped with a forward-looking sector-based sonar, including a transmitting and receiving antenna, a power amplifier, the input of which is connected to a block for generating, receiving and packing signals, and the output to a transmitter-receiver antenna multi-channel amplifiers and a multi-channel analog-to-digital converter connected to the receiving elements of the receiving and transmitting antenna, the output of which is connected to the signal generating, receiving, and packing unit And device audible and visual alarm connected to the output computer.

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