RU2463624C1 - Hydroacoustic navigation system - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: hydroacoustic navigation system has a navigation base consisting of M hydroacoustic transponders with different response frequencies and a hydroacoustic transceiver. The receiving hydroacoustic antenna consists of four hydrophones mounted on a linear support arm which is perforated. Antennae of the receivers are mounted on a steel plate. At least one of the M hydroacoustic transponders is placed on the water surface. The receiving hydroacoustic antenna also includes nine hydrophones, with formation of receivers of two navigation bases with a common base centre. They lie in a plane which is parallel to the plane of the bottom of the underwater object, wherein the axis of one base X is directed along the axial line of the underwater object, and the axis of another base Y is directed on the beam to the right. Each navigation base is formed from seven hydrophones, one of which is common for both navigation bases, at equal distances from which there are two hydrophones which form a common central part of the navigation bases consisting of nine hydrophones, wherein the outermost hydrophones of each of the navigation bases are displaced from the common central part of the navigation base by a distance greater than the distance between the hydrophones which form the common central part of the navigation bases. The linear support arm is additionally fitted with a sensor for determining sound speed, a hydrodynamic pressure sensor and an inertial sensor. Each of the M hydroacoustic transponders consists of an underwater and a surface module connected by a conducting rope to sensors of the inclination and length of the corroded rope. The surface module is provided with a satellite radio communication channel.

EFFECT: reduced error in measuring coordinates of an underwater object.

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Description

The invention relates to the field of sonar navigation systems and can be used for navigation support of underwater vehicles of increased range, for example, operating in ice conditions, making it difficult for the supply vessel to access them, and can also be used for seismic and geological exploration on the seabed.

The known long-range sonar synchronous navigation system contains a bottom navigation base of M hydroacoustic transponders with different response frequencies, a synchronizer located on the navigation object, an M channel receiver (M + 1) of acoustic signal propagation time meters, M · N blocks for converting time intervals in distance over the number N of possible ray paths, M blocks for selecting the maximum distance value, the coordinates calculator of the navigation object, the acoustic transmitter Igna request frequency receiver synchronous with EDM-direction finder for acoustic acoustic input signal frequency f ₀ request. The navigation object also contains (M + 1) a propagation time meter, (M + 1) a unit for converting time intervals into distances, (M + 1) a unit for selecting the maximum distance value, a bearing and elevation meter. A second synchronizer, synchronized with the first, second M channel receiver with an acoustic input for response signals of hydroacoustic transponders, M modulators, M response frequency generators and a transmitter made by M + 1-channel ([1] patent RU No. 2084923) is placed on the supply vessel; .

The disadvantage of this system is the large error in determining the coordinates associated with the variability of the speed of sound in the marine environment.

The well-known sonar synchronous rangefinder navigation system contains a bottom navigation base of M hydroacoustic receivers with different response frequencies located on the navigation object, a hydroacoustic transmitter with a polling frequency, a clock generator, an M-channel receiver with an acoustic input for response signals, M hydro-acoustic signal propagation time meters to the transponder operating on the frequency of this channel and vice versa, M × N blocks of conversion of time intervals into dist the number of N ray paths and a calculator of coordinates of the navigation object. The navigation object also houses a six-element acoustic receiver with an acoustic input for receiving response signals, the elements of which form three mutually orthogonal pairs of hydrophones spaced shorter than the wavelength, a second M-channel receiver, each channel of which contains three pairs of amplifiers, M difference meters phases, M distance and angle calculators and an invariant speed reference unit. M beam selection blocks ([2] Patent RU No. 2084924).

A disadvantage of such a system is also a large error in determining the coordinates associated with the variability of the speed of sound in the marine environment.

The well-known long-range sonar synchronous long-range navigation system contains a bottom navigation base of M hydroacoustic transponders with different response frequencies f _m (m = 1-M), a clock generator located on the navigation object, an acoustic transmitter with a polling frequency f _o , the input of which is connected to the first the output of the clock generator, an M-channel receiver for receiving response signals with frequencies f _m , M meters of propagation time of acoustic signals to the transponder, operating it at the frequency of this channel, and vice versa, the first inputs of which are connected to the outputs of the M-channel receiver, and the second inputs are connected to the second output of the clock generator, M × N blocks for converting time intervals to distances in the number N of possible ray paths, the inputs of which are connected to the outputs of the respective measuring instruments of propagation time, M blocks for selecting the maximum distance value, the inputs of which are connected to the outputs of N blocks for converting time intervals in the distance of a given channel, and the calculator INAT navigation object, a first input coupled to the outputs of the maximum value selection of the distance M channel blocks. In addition, a second bottom navigation base of M hydro-acoustic pinger beacons with different radiation frequencies F _m (m = 1-M) mechanically connected to the corresponding M responder beacons containing M synchronously operating clock pulses was introduced into the hydroacoustic synchronous rangefinder navigation system , M transmitters with different operating frequencies F _m , the inputs of which are connected to the outputs of the clock generators, M hydroacoustic emitters with operating frequencies F _m , the inputs of which are connected to the output dams of transmitters with corresponding operating frequencies, located on the navigation object, a second clock generator operating synchronously with the clock generators of the pinger beacons, the first output of which is used to synchronize M synchronous clock generators of the sonar pinger beacons before they are installed on the bottom, a towed receiving acoustic antenna, the second M-channel receiver for receiving acoustic signals of pinger beacons, the input of which is connected to the output of the towed receiver an acoustic antenna, M meters of propagation time of acoustic signals from pinger beacons to a navigation object, the first inputs of which are connected to the outputs of the second M-channel receiver, and the second inputs are connected to the second output of the second clock generator, additional M blocks of conversion of time intervals to distances, inputs which are connected to the outputs of the M meters of the propagation time of acoustic signals from pinger beacons to the navigation object, and the outputs are connected to the second inputs of the computer ordinates of the navigation object. M sonar emitters of pinger beacons and a towed receiving acoustic antenna are located near the seabed at a distance of no more than a wavelength at operating frequencies F _m . Additional M blocks for converting time intervals to distances calculate the desired distances r _m through the measured propagation times t _m . Achievable technical result is the provision of determining the coordinates of the navigation object at small and large distances with minimal error ([3] patent RU No. 2289149).

However, as in the known devices, the disadvantage of this system is the relatively large error in determining the coordinates associated with the variability of the speed of sound in the marine environment and the topography of the seabed.

The well-known sonar navigation system (HSS) contains hydroacoustic beacons-transponders located at the bottom of the water area with known coordinates, as well as receiver-emitting and processing equipment used on board the vessel, characterized in that the transmitting unit in the vessel’s receiver-emitting equipment is designed as a command message transmitter (PCS) for transmitting a command message to the responder beacons using time-pulse modulation at the request frequency, and each responder beacon For further comprises auxiliary control device for execution of the command message transmitted from the beam PKC vessel ([4] RU №34020 U patent).

However, as in the known devices, the disadvantage of this system is the relatively large error in determining the coordinates associated with the variability of the speed of sound in the marine environment and the topography of the seabed.

The well-known sonar synchronous rangefinder navigation system contains a bottom navigation base of M sonar transponders with different response frequencies f _m (m = 1-M), a sonar transmitter with a sampling frequency f _o located at the navigation object, the input of which is connected to the first output of the clock generator, M -channel receiver with an acoustic input for response signals, made by M · N-channel in terms of the number M · N of working response frequencies f _mn , M meters of propagation time of hydroacoustic signals about t of the navigation object to the transponder operating on the frequency of this channel and vice versa, made by M · N-channel, M · N blocks for converting time intervals to distances in the number N of radial paths, the inputs of which are connected to the outputs of the corresponding propagation time meters, and the object coordinate calculator navigation, on hydroacoustic transponders placed M identical vertically oriented receiving antennas, each of which consists of M pairs of antiphase excited groups of 2N + 1 hydrophones, the distance is waiting for which is equal to half the wavelength at the polling frequency f _o . Acoustic transmitters located on hydroacoustic transponders are made N-frequency with response frequencies f _mn . A vertically oriented receiving antenna is located at the navigation object, consisting of M pairs of antiphase-excited groups of 2N-1 hydrophones, the distance between which is equal to half the wavelength at the upper frequency f _{mn of the} operating frequency range. The technical result consists in reducing the error of measurement of coordinates ([5] patent RU No. 2158431).

The disadvantage of this system is the large error in determining the coordinates associated with the variability of the speed of sound in sea water. Moreover, the error in determining the distance and coordinates increases significantly when working in the shallow sea, when the time delays between the individual rays are reduced, and the rays themselves cannot be identified and identified separately. In addition, the coordinate determination algorithm, consisting in the fact that the coordinates are determined by the found times, the known profile of the speed of sound in the shallow sea and the radiation-reception horizons corresponding to the navigation object and the hydroacoustic transponder, horizontal distances are determined in the time interval conversion unit, corresponding to the first approximation to the desired distance, and the specified values of the glide angles at the receiving-receiving horizons, according to which the found times are clear VAs are determined in the second approximation, it is not optimal, since the known sound profile for the water area is the average value obtained from long-term observations, and not established for some water areas, which may introduce an additional error in the determination of coordinates.

A hydroacoustic synchronous rangefinder navigation system is also known, which contains a bottom navigation base of M hydroacoustic transponders and a hydroacoustic transmitter, a clock generator, a first M-channel receiver, M meters of the propagation time of acoustic signals to and from the transponder, M × N conversion blocks time intervals in the distance according to the number of N ray paths, a combined acoustic receiver based on a three-component pr a vibrational receiver and a sound pressure receiver with a combined phase center, a second M-channel receiver, each channel of which is made of four subchannels, M distance and glide angle calculators, an invariant speed task unit, M beam selection units, N time-domain distance conversion blocks , a calculator of coordinates of the navigation object according to the criterion of minimum error, a unit for determining mutual bearings, M blocks for correcting distances, connected in a certain way. The technical result is to reduce the error in determining the coordinates of the navigation object ([6] patent RU No. 2308454).

The disadvantage of this navigation system is the relatively large ambiguity in identifying the shortest radial path and, ultimately, a significant error in determining the coordinates.

A long-range hydroacoustic synchronous long-range navigation system is also known, which contains a bottom navigation base of M hydroacoustic transponders with different response frequencies f _m (m = 1-M), a clock generator, an acoustic transmitter with a polling frequency f _o , whose input connected to the first output of the generator clock, the M-channel receiver for receiving response signals with frequencies f _m, M gauges propagation time of the acoustic signals to priemootvet an operating frequency of this channel and vice versa, the first inputs of which are connected to the outputs of the M-channel receiver, and the second inputs are connected to the second output of the clock generator, M × N blocks for converting time intervals to distances in the number N of possible ray paths, the inputs of which are connected with the outputs of the respective meters of propagation time, M blocks for selecting the maximum distance value, the inputs of which are connected to the outputs of N blocks for converting time intervals in the distance of this channel, and subtracting a coordinate remover of the navigation object, the first input of which is connected to the outputs of the blocks for selecting the maximum distance value of all M channels. In addition, a second bottom navigation base of M hydroacoustic pinger beacons with different radiation frequencies F _m (m = 1-M) mechanically connected to the corresponding M beacon transponders containing M synchronously operating clock pulses was introduced into the hydroacoustic synchronous rangefinder navigation system M transmitters with various operating frequencies F _m, whose inputs are connected to outputs of clock generators, M sonar emitters with operating frequencies F _m, which are connected with the inputs O dams of transmitters with corresponding operating frequencies, located on the navigation object, a second clock generator operating synchronously with the clock generators of the pinger beacons, the first output of which is used to synchronize M synchronous clock generators of the sonar pinger beacons before they are installed on the bottom, a towed receiving acoustic antenna, the second M-channel receiver for receiving acoustic signals of pinger beacons, the input of which is connected to the output of the towed receiver acoustic antenna, M meters of propagation time of acoustic signals from pinger beacons to the navigation object, the first inputs of which are connected to the outputs of the second M-channel receiver, and the second inputs are connected to the second output of the second clock generator, additional M blocks of conversion of time intervals to distances, the inputs of which are connected to the outputs of the M meters of the propagation time of acoustic signals from pinger beacons to the navigation object, and the outputs are connected to the second inputs of the calculator to ordinates navigation object. M hydro-acoustic emitters of pinger beacons and a towed receiving acoustic antenna are located near the seabed at a distance of no more than a wavelength at operating frequencies F _m . Additional M blocks for converting time intervals to distances calculate the desired distances r _m through the measured propagation times t _m . Achievable technical result is the provision of determining the coordinates of the navigation object at small and large distances (patent RU No. 2038127 [7]). The disadvantage of this navigation system is the relatively short range when operating the navigation object near the bottom and when using bottom responders, which is associated with the effects of refraction of sound near the bottom, as well as the presence of mechanical connections between pinger beacons and responder beacons, which creates additional acoustic noises.

Also known is the hydroacoustic synchronous rangefinder navigation system ([8] copyright certificate SU No. 713278), which includes a bottom navigation base of M hydroacoustic transponders with different response frequencies and a hydroacoustic transmitter, a clock generator, M-channel receiver, M meters, located on the navigation object the propagation time of hydroacoustic signals to transponders and vice versa, M · N blocks for converting time intervals to a distance of N in each of the channels from M, M block in choosing the maximum distance value from N values and the coordinates calculator of the navigation object, in which each of the M channels is entered according to the number of ray paths N-1 additional measuring instruments for the propagation time of hydroacoustic signals, N-1 multivibrators delay, N-1 multivibrators strobe - pulse, N -1 selectors, the first inputs of N-1 propagation meters connected to the output of the clock generator, the second inputs connected to the first outputs of the respective selectors, and the outputs connected to the M · N inputs of the pre formation of time intervals in the distance, the first input of each of the selectors is connected to the output of the corresponding multivibrator strobe - pulse, the second input is connected to the output of the corresponding channel of the receiver, the input of the first multivibrator of delay is connected to the output of the corresponding channel of the receiver, and the output of each subsequent multivibrator of delay is connected to the second output corresponding selector, N (N-1) additional blocks for converting time intervals into distances are introduced into each of the M channels, N-1 additional блоков blocks for selecting the maximum distance value and a distance averager, the inputs of each of N-1 sets of N blocks for converting time intervals into distances are connected to the corresponding outputs of N-1 additional time interval meters, and the outputs are connected to the inputs of N-1 additional blocks for selecting the maximum the values, outputs of all blocks for selecting the maximum distance value are connected to N inputs of the distance averager, and the output of the distance averager is connected to the input of the coordinate calculator of the navigation object.

The navigation base of such systems, pre-installed at the bottom of the water area, as a rule, consists of 12-16 responder beacons and is pre-calibrated in relative and geographical coordinates (relative and absolute calibrations) using a support vessel equipped with an on-board complex of satellite and sonar navigation systems . After developing their energy resource, the transponder beacons are replaced, and a new calibration of the bottom navigation base is performed. These systems make it possible to ensure the geographic location of the underwater vehicle within an area of up to 100 square kilometers and a length of up to 50 km.

The use of such systems for the navigation of underwater vehicles requires a significant amount of ship time, a large number of bottom lighthouse transponders with a long battery life, and limits the range of the underwater vehicle to the communication range with the bottom navigation base.

A known method of navigating an underwater object by means of a hydroacoustic navigation system containing a navigation base of M hydroacoustic transponders with different response frequencies and a hydroacoustic transceiver located on the navigation object, by which the signal propagation time intervals are measured with their subsequent conversion in the distance between the underwater object and hydroacoustic transponders. According to the method, hydroacoustic transponders are placed at drifting stations on a water surface, the navigation parameters of an underwater object relative to a drifting station or base from drifting stations are determined in a mode with a long and / or ultrashort base, and / or in a combined mode (long + ultrashort base), and / or in a direction finding system, in this case, two navigation bases are formed from receivers with a common center of the base, placing them in a plane parallel to the plane of the deck of the underwater object, while the axis of one base X is directed along the center line of the underwater object, and the axis of the other base Y is directed along the beam to the right ([9] patent RU No. 2365939). When implementing this method, in contrast to the known devices, a drifting station is located on the sea surface, equipped with appropriate equipment, and which, while in a drift, is able to continuously receive signals from medium-orbit satellite navigation systems, process them with the determination of high-precision eigen coordinates at any time . At a certain point in time (according to a request signal from an underwater object or according to the work program of a drifting station) this information is transmitted via a hydroacoustic channel in the form of a noise-like encoded signal of a certain format to an underwater object. Having determined its coordinates relative to the drifting station and having information about the geographical coordinates of the latter, the underwater object performs its own coordination in the geographical coordinate system.

The device by which the known method is implemented [9] is a sonar navigation system that contains a navigation base of M sonar transponders with different response frequencies and a sonar transceiver located on the navigation object, which measures the time intervals of signal propagation with their subsequent conversion in distance between an underwater object and sonar transponders. At the same time, the receiving hydroacoustic antenna consists of four hydrophones, each section of the antenna consists of two single-channel and one multi-channel module mounted on a linear support bracket made perforated, the receiver antennas are made in the form of a spherical surface and placed on at least one of M sonar transponders mounted on the water surface. EFFECT: increased reliability while ensuring navigation of underwater objects ([10] patent RU No. 2371738). The disadvantage of this device is that the achievement of the specified technical result is achieved in favorable weather conditions, which limits the widespread use of this device.

The closest of the analogues is the sonar navigation system, given in the source of information [10] - the prototype. The known navigation system in its technical nature, functionality and technical result achieved is the closest to the claimed invention.

The objective of the proposed technical solution is to reduce the measurement error of the coordinates of the underwater object while reducing labor costs when performing underwater research.

The problem is solved due to the fact that in a hydroacoustic navigation system that contains a navigation base of M hydroacoustic transponders with different response frequencies and a hydroacoustic transceiver located on the navigation object, which measures the time intervals of signal propagation with their subsequent conversion in the distance between the underwater object and hydroacoustic transponders, receiving hydroacoustic antenna consists of four hydrophones installed on a linear support bracket made of perforated, the receiver antennas are placed on a steel plate, but at least one of the M hydroacoustic transponders is installed on the water surface, unlike the prototype, the receiving hydroacoustic antenna includes nine more hydrophones when two navigation bases with a common the center of the base, placing them in a plane parallel to the plane of the deck of the underwater object, while the axis of one base X is directed along the axial line of the underwater object, and the axis of the other base Y is directed along the traverse to the right, unlike the prototype, each navigation base is formed of seven hydrophones, one of which is common for both navigation bases, at equal distances from which two hydrophones are placed, forming a common central part of the navigation bases consisting of nine hydrophones, while the extreme hydrophones of each of the navigation bases are displaced relative to the common central part of the navigation base by a distance exceeding the distance between the hydrophones forming a common the central part of the navigation bases, an additional sound velocity sensor, a hydrodynamic pressure sensor and an inertial sensor are additionally installed on the linear support bracket, each of the M hydroacoustic transponders consists of an underwater and surface module connected by a cable, with sensors for tilting and length of the etched cable, surface the module is equipped with a satellite radio channel.

Distinctive features of the claimed technical lies in the fact that the receiving hydroacoustic antenna includes nine more hydrophones, while two navigation bases with a common center of the base are formed from hydroacoustic receivers, placing them in a plane parallel to the plane of the deck of the underwater object, while the axis of one base X is directed along the center line of the underwater object, and the axis of the other base Y is directed along the beam to the right, each navigation base is formed of seven hydrophones, one of which is common to both on igational bases, at equal distances from which two hydrophones are placed, forming the common central part of the navigation bases, consisting of nine hydrophones, while the extreme hydrophones of each of the navigation bases are displaced relative to the general central part of the navigation base by a distance exceeding the distance between the hydrophones forming the common the central part of the navigation bases, can significantly reduce the error in determining the coordinates due to the fact that the extreme hydrophones in each base are used for accurate Measurements component direction of arrival of the acoustic waves and the central part of the array of hydrophones - to eliminate errors integer wavelengths when measuring the total phase difference between the extreme hydrophones. In addition, the placement on the linear support bracket of a sensor for determining the speed of sound, a hydrodynamic pressure sensor and an inertial sensor when determining the coordinates of an underwater object allows you to quickly take into account changes in such parameters as the speed of sound in water, hydrodynamic pressure, and antenna tilt angles. The implementation of hydroacoustic transponders consisting of underwater and surface modules allows you to implement a satellite radio channel. The presence on each of the M sonar transponders of a satellite radio communication channel allows you to adjust the location (coordinates) of the sonar transponders, which during their operation may differ from the initial installation coordinates when exposed to underwater currents and soil deformations.

The essence of the proposed technical solution is illustrated by drawings.

Figure 1. The layout of the hydrophones of the antenna for receiving hydroacoustic signals.

The scheme includes a steel plate 1 with brackets 2 located in mutually perpendicular planes on which hydrophones 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15. Hydrophones 4, 5, 6, 7, 8, 10, 11, 13, and 14 form the central array of hydrophones, and hydrophones 3, 9, 12, and 15 are extreme hydrophones located at the ends of the respective navigation bases. At the installation site of the hydrophone 6, on a steel plate 1, in a separate housing 16, sensors for determining the speed of sound, hydrodynamic pressure and an inertial sensor are installed. The brackets 2 are mounted on the frame 17. The lateral and rear directions of the hydrophones are drowned out by screens.

Figure 2. The block diagram of the device. The block diagram includes an emitter 18 formed by hydrophones 3, 9, 12 and 15, a receiver 19 formed from hydrophones 4, 5, 6, 7, 8, 10, 11, 13, 14 (Fig. 1), a filter amplifier 20 , ADC 21, controller 2, navigation processor 23, switch 24, reference signal generator 25, power amplifier 26.

Figure 3. Timing diagrams of the signals "REQUEST" (figa) and "RESPONSE" (figb).

The claimed technical solution is intended to determine the coordinates of underwater objects relative to various types of sonar transponders (beacon transponders) in an ultra-short base mode, including autonomous and towed underwater vehicles, various underwater research devices and stations, devices and mechanisms for exploration and production of useful minerals, and can be used in oceanographic and geological studies, mining and other types odvodnyh work in local areas.

The emitter 18 and the receiver 19 form a common sonar transceiver antenna, which is designed to work as part of a sonar navigation system with an ultrashort base (HANS-UKB). The hydro-acoustic transceiver antenna is designed to emit and receive acoustic signals for subsequent determination of the position of the acoustic beacon in a certain range of ranges relative to geographical coordinates and can be performed in three versions, depending on the type of underwater vehicles. For underwater vehicles of the Mir and Sound-6 type with a range of antenna ranges of up to 8000 m, underwater vehicle of the Mezoskan-M type up to 3000 m (vehicles of the Mezoskan-M type) and for underwater vehicles of the Gnome type and "Microsound" up to 500 m, respectively.

The composition of the hydro-acoustic receiving and transmitting antenna includes a multi-channel receiving system, a power amplifier, a microcontroller control and communication module.

The hydro-acoustic transceiver antenna provides radiation and reception of signals, the format of which corresponds to the parameters of one of the beacon-transponders such as “MO-D”, “GMO-6000”, “GMO-2000”, “GMO-200”, and provides equivalent angular accuracy no worse 0.03 ° in the long-range mode and 0.3 ° in the short-range mode.

The inertial sensor is a high-precision inertial sensor of the gyrocompass type for measuring the slopes and course of the sonar transceiver antenna. In a specific technical implementation, a “U-PHINS” sensor from IXSEA is used.

The sound velocity sensor is a cyclic speed meter, which is an acoustic synchronization ring closed through water, formed by two acoustic transducers, an amplifier and a pulse generator, triggered by signals from the amplifier output (1. Gusev MN, Yakovlev GV Hydroacoustic Doppler logs // Shipbuilding abroad, 1976, No. 5, pp. 53-57. 2. Ship speed meters / A.A. Khrebtov, V. N. Koshkarev et al. - Shipbuilding, 1978, p.133).

The hydrodynamic pressure sensor is a sensor, the counterpart of which is the pressure sensor described in the description of patent RU No. 23228757. Each of the M sonar transponders consists of underwater and surface modules connected by a cable. The surface module is equipped with a Sea Tooth satellite radio channel. For raising the satellite radio channel antenna to the surface, for example, a Lerok type marine winch or positive buoyancy like the emergency buoy used on submarines with installed sensors for tilt and length of the etched cable can be used.

The transponder beacon also has a sonar transceiver designed to convert acoustic signals to electrical and convert electrical signals into acoustic ones, and an electronics unit. The electronics unit includes:

- a receiving-amplifying device designed to receive and amplify “REQUEST” signals transmitted from an underwater object through a sonar communication channel;

- decoder signal "REQUEST", which decodes the signal "REQUEST" and determines the moment of arrival of the signal "REQUEST";

- “RESPONSE” signal shaper, which is designed to generate the “RESPONSE” signal after receiving the “REQUEST” signal;

- a power amplifier designed to amplify the “RESPONSE” signal to the required level for the purpose of its transmission through the hydroacoustic communication channel.

- a power supply unit that provides power to all electronic components of the electronics unit.

The electronics unit is housed in a rugged housing that protects it from the effects of hydrostatic pressure.

Bottom beacons-transponders are installed along the route of research work through underwater objects, and their number is determined by the scope of the research. The proposed design of a transceiver sonar antenna allows for underwater navigation in the presence of two beacons transponders. The location coordinates of the underwater object are carried out similarly to the known methods and devices described in the descriptions of patents RU No. 2365939 (Method for navigating an underwater object) and RU No. 2371738 (Hydroacoustic navigation system). Navigation of the underwater object relative to the bottom transponder beacons can be carried out both in the long base (DB) mode, ultrashort base (UHB) and in the combined DB / UHB mode. At the same time, the underwater object is equipped with hydroacoustic transceiver antennas corresponding to the operating mode, a navigation controller and mathematical software.

When providing navigation of an underwater object at depths of more than 1 km, frequencies in the range from 8 to 15 kHz are used, while the energy range of communication with the beacon-transponder will reach 10-14 km, and the error in determining the coordinates of the underwater object will be 7-10 m in DB mode and 0.3% of the range in the UKB mode and 0.5 degrees in the direction finding mode. At a working depth of less than one kilometer, it is advisable to use operating frequencies in the range of 25-35 kHz and work in the UHF mode. In this case, the maximum communication range will reach about 3 km. Each signal of the transponder beacon has a special format and encoding and carries information about the geographical coordinates and its individual number. The most optimal communication range in the UKB mode with an immersion depth of up to 500 m is 1 km. Accuracy of determination of coordinates to 5 m.

The device, in terms of ensuring the positioning of an underwater object, is a sonar navigation system with a combined sonar system with a long and ultra-short base, which allows you to use the direction finding mode and provide a solution to the problem of the underwater object reaching the installation point of the transponder beacon along the line of work being performed. At the same time, the sonar antenna of the beacon transponders, as well as the underwater object, represents two having a common base center and consists of the same number of receivers.

At the same time, when all hydrophones receive at the same working frequency, the mode of determining the delay and direction of arrival of the response from the fixed beacon of the transponder in the ultrashort base mode is implemented, and when each of the hydrophones is tuned to its working frequency, the measurement mode of delays from two or several long base transponder beacons.

The range of working depths of beacons-transponders is from 200 to 6000 m, the inclined range of the HANS-UKB is from 20 to 8000 m, depending on the purpose of the underwater object. The operating frequency range for a communication range of up to 500 m is 30-50 kHz, and for a communication range of up to 8000 m is 7-14 kHz.

Operating modes of beacons of transponders "REQUEST-RESPONSE".

In this mode, a request signal is received and emits a response signal. The request is made via the sonar channel, the request is addressed. The address is determined by its frequency of request.

The frequency range of the “REQUEST” signal is from 7 kHz to 10 kHz. The frequency range of the “ANSWER” signal is from 10 kHz to 14 kHz. The format of the “REQUEST” signal is a packet of two pulses, each of which is filled with its own frequency. The filling frequency of the first pulse is 8192 Hz. The frequency of the second pulse filling is in the range from 9 kHz to 10 kHz. The duration of the first pulse is 50 ms ± 1 ms, of the second 10 ms ± 0.02 ms. The repetition period is 100 ms.

The first pulse takes the beacon out of sleep mode. The second pulse records the time of arrival of the signal and determines the address of the beacon. The “RESPONSE” signal format is a packet of two pulses, each of which is filled with its own frequency. The filling frequency of the first pulse is in the range from 10 kHz to 11.5 kHz. The frequency of the second pulse filling is in the range from 11.5 kHz to 14 kHz. The duration of the first pulse is 50 ms ± 1 ms, of the second 10 ms ± 0.02 ms. The repetition period is 100 ms.

The first pulse is used to measure direction. The second pulse is used to measure range.

The ANSWER signals are the same for each of the beacons. The root-mean-square error of recording the time of arrival of the “REQUEST” signal via the hydroacoustic channel is 2 ms, at a noise pressure level in the zone of the beacon in the 1 Hz band at a frequency of 1 kHz, not more than 0.1 Pa. The probability of skipping the signal "REQUEST" at a noise pressure level of 0.1 Pa in the band of 1 Hz at a frequency of 1 kHz, P _ol - 10 ^-4 , no more.

The sensitivity of the receiver is not worse than 100 dB relative to 1 μPa at a distance of 1 m.The level of acoustic pressure generated by a receiving-emitting antenna in the working frequency band should be at least 190 dB relative to 1 μPa at a distance of 1 m.The radiation pattern of a receiving-emitting antenna is unidirectional. The width of the radiation pattern at the level of 0.707 in the working frequency band is ± 45 ° ± 5 °. Sensitivity at reception at frequencies from 7 kHz to 10 kHz - 300 μV / Pa, not less. Sensitivity to transmission in the frequency range from 10 kHz to 13.5 kHz - 4.5 Pa / V, not less.

The parameters of the signal "REQUEST" transmitted through the hydroacoustic communication channel (figa):

- a pack of two pulses filled with carrier frequencies F _d (standby) and F and 1 or F and 2 (measuring);

- the duration of the first pulse τid - 50 ms ± 1 ms;

- the duration of the second pulse τii - 10 ms ± 0.02 ms;

- the period of the first and second pulses T _s - 0.1 s;

- the frequency of filling the first pulse F _d - 8192 Hz;

- filling frequency of the second pulse F and 1 - 8474 Hz;

- filling frequency of the second pulse F and 2 - 8928 Hz.

The parameters of the signal "ANSWER" (figb):

- a pack of two pulses filled with carrier frequencies Fп (bearing) and Fдал (range);

- the duration of the first pulse τid - 50 ms ± 1 ms;

- the duration of the second pulse τii - 10 ms ± 0.02 ms;

- the period following the first and second pulses Tc - 0.1 s;

- filling frequency of the first pulse Fpel - 10000 Hz;

- filling frequency of the second pulse Fdal - 10416 Hz.

An acoustic request is made through a power amplifier 26 by a radiator 18. The response signals are received by a central array of hydrophones, amplified, filtered, quadrature, digitized and processed by the navigation processor 23. The transceiver hydroacoustic antenna is equipped with hydrodynamic pressure and sound velocity sensors, an inertial sensor to determine its own angular orientation, and the information coming from them during each cycle of receiving responses is attached to the package aka cal information. Subsequently, upon final processing of the data by the navigation processor 23, using the information from the GPS navigation receiver, the exact geographical coordinates of the location of the underwater object are calculated.

In this case, the measured travel time is recalculated taking into account the profile of the speed of sound in an inclined range, and the direction of arrival of the wave on the surface of the antenna, taking into account the slopes and azimuth of the antenna itself, allows you to determine the point from which the sound was generated. The measurement of travel time is carried out by analyzing the shape of the received sound signal, while the accuracy of the time measurement is determined by the bandwidth of the receiving path and the signal-to-noise ratio. The direction of arrival of the sound wave is determined by measuring the phase difference of the signals received by different hydrophones, followed by recalculations of the phase difference into geometric angles, taking into account the characteristic wavelength of the acoustic signal and the spatial diversity of the receivers. The accuracy of the direction measurement is determined by the distance between the receivers and the signal-to-noise ratio. The accuracy of measuring the travel time or, in other words, the accuracy of determining the position of an object along the beam does not depend on distance (at a sufficiently high signal level compared to noise) and for traditional long-range systems is a fraction of a meter. With a fixed angular resolution, the error in measuring the position of the object across the beam increases linearly with distance and, as a rule, is characterized as a percentage of the slant range.

There are two ways to improve the accuracy of HANS-UKB systems. This is an increase in the spatial diversity of the receivers and an increase in the signal-to-noise ratio.

The study of the structural and functional schemes of the well-known GANS-UKB showed that almost all known technical solutions use receiving antennas of relatively small sizes - less than half a meter. An increase in the separation of hydrophones to 1-1.5 m will proportionally increase the angular accuracy of the transceiver sonar antenna with a fixed signal to noise ratio.

An increase in the signal-to-noise ratio is achieved by increasing the signal power and reducing the noise level. As a rule, in the sources of the analyzed sound signals for receiving antennas GANS-UKB piezoelectric radiating elements are used that operate at the limit of radiated power, so the only way to amplify the signal is to increase its energy by increasing the duration. An increase in the duration in the tonal mode leads to a decrease in the accuracy of measuring the travel time of an acoustic wave and, thereby, to a deterioration of the overall navigation performance. The only real way to increase the signal energy without compromising the resolution of the system in range is to use complex signals. However, the use of complex signals requires, on the one hand, a significant increase in processor performance in transponders and an onboard antenna, and on the other hand, it shortens the life of acoustic transponders in standalone mode with a fixed resource of power sources.

There are a number of ways to reduce the level of acoustic noise at the receiver.

The ambient noise at the receiving point has complex frequency and spatial spectra, and its effective level can be reduced by limiting the sensitivity of the receivers in areas that do not contain useful information. The limitation of sensitivity in the frequency domain is achieved by optimal filtering of signals, the limitation of sensitivity in the spatial region by passive or active beamforming. Passive formation is achieved by the use of reflective and damping elements in the antenna structure, which attenuate sound waves from undesirable directions. This method is used in most known UKB systems and is very effective and relatively cheap, but it does not allow to narrow the spatial spectrum of the analyzed signal and to achieve the lowest possible noise level. Active directivity is achieved by using multi-element phased arrays and is used, for example, in Kongsberg's HIPAP-500 system. This method of generating a reception diagram gives the best results, however, implementing antennas of this type is a very difficult and expensive task. In the proposed technical solution, an increase in the navigation accuracy of the underwater object is achieved due to the spatial separation of hydrophones to the maximum technically permissible distance with the formation of a radiation pattern close to uniform in the active half-space, and the lateral and rear directions are drowned out by special screens.

The practical implementation of the proposed technical solution is based on the theoretical principle of constructing the proposed sonar system for underwater navigation with an ultra-short base.

The phase difference α of the signals of two point receivers (first and second) with spacing d when a plane wave with a length of λ is incident on them at an angle

-π / 2≤φ <π <π / 2 to the normal of the pair for d <λ / 2 is equal to:

where -π / 2 <α <π / 2.

The direction of arrival of the wave (bearing) is determined by the formula:

It follows that in the presence of an error δα of measuring the phase difference and error δd in the longitudinal separation of the receivers, the error δφ of the bearing determination is:

where δσ = δd / d is the relative error in the longitudinal separation of the receivers.

и

векторы сигнала и помехи на приемнике, получаем, что вносимая помехой погрешность ε фазы сигнала равна:The error in the measurement of the phase difference δα is due to interference associated with wave reflections from structural elements, ocean noises, ship noises, underwater vehicles and mechanisms, noise from electronic paths, etc. Labeling by

and

vectors of the signal and interference at the receiver, we obtain that the error introduced by the interference ε of the phase of the signal is equal to:

From this we obtain that the rms value of ε is:

where q = s / n is the signal-to-noise ratio. The error in measuring the phase difference of the signals of the two receivers is obviously equal to:

The root mean square error of the determination of the bearing, taking into account the uncorrelatedness of the considered errors, is obviously:

To increase the accuracy of the bearing, you can use a third receiver located on the axis with the existing ones and forming with the first pair with a spacing D> d. If β + 2πn is the phase difference of the first and third receivers (-π / 2 <β <π / 2, n is an integer), then the bearing and its error are determined similarly to the above by the formulas:

,

,

where δs = δD / D is the relative error in the longitudinal separation of the first and third receivers, δD is absolute.

However, when measuring the phase difference, the integer number of periods n is not fixed and a special procedure is used to determine it, which consists in the following. The value of α is multiplied by D / d and the result is equal to β + 2πn: α · (D / d) = β + 2πn, whence the nearest to the integer value of n is determined:

In this case, the standard deviation of the estimate n from the true value for D >> d taking into account the uncorrelatedness of the considered errors is equal to:

It follows that the maximum D / d ratio for a given δn _c is:

Obviously, determining the value of n by this algorithm is possible provided Δn € [-1,2; 1,2], which is performed for | δn | <(1/2) / 3 = 1/6 with a 99.7% probability. Therefore, while providing 99.7% reliability, the maximum possible value of δn _c is 1/6. In particular, for a calibrated system (δσ = 0) for q = 10, we have

(D / d) _max = 7.4. For a non-calibrated system, δσ = 0.1 for q = 10 and α = π, we have (D / d) _max = 3.

To further improve the accuracy of the bearing, you can use the fourth receiver, located on the axis with the existing ones and forming with the first pair with a spacing L> D> d. If γ + 2πm is the phase difference of the first and fourth receivers (-π / 2 <γ <π / 2 m is an integer), then the bearing and its error are determined by the formulas:

,

,

where δl = δL / L is the relative error in the longitudinal separation of the first and fourth receivers, δL is absolute.

As above, when measuring the phase difference, the integer number of periods m is not fixed and a special procedure is used to determine it, which consists in the following. The quantity β + 2πn is multiplied by L / D and the result is equal to γ + 2πm: (β + 2πn) · (L / D) = γ + 2πm, whence the nearest value to the integer m is determined:

Moreover, the standard deviation of the estimate of m from the true value for δn = 0 and L >> D, taking into account the uncorrelatedness of the considered errors, is equal to:

where Δδ = δD / d. It follows that the maximum L / D ratio for a given δm _c is:

Obviously, determining the value of m using this algorithm for δn = 0 is possible provided Δn € [-1,2; 1,2], which is performed at | δ _m | <(1/2) / 3 = 1/6 with a 99.7% probability. Therefore, with 99.7% reliability, the maximum possible value of δm _c is 1/6. The probability of determining m taking into account fluctuations of n is obviously equal to (0.997) ² × l00% = 99.4%. In particular, for a calibrated system (δΔ = 0) with q = 10, we have (L / D) _max = 7.4. For a non-calibrated system with δΔ = 0.1 for q = 10 and α = π, we have (L / D) _max = 3. Thus, for a non-calibrated system (L / d) _max = 9.

The inventive sonar navigation system in a new set of essential features is new, has an inventive step, i.e. it clearly does not follow from the prior art and in its characteristics surpasses known navigation systems. The set of essential features of the claimed invention has a causal relationship with the achieved technical result.

In the inventive sonar navigation system, increasing the accuracy and reliability of determining coordinates is ensured by the spatial separation of hydrophones to the maximum technically permissible distance with the formation of a radiation pattern that is close to uniform in active space. In this case, the extreme hydrophones in each line are used to accurately measure the components of the direction of arrival of the acoustic wave, and the central part of the array of hydrophones is used to eliminate errors on an integer number of wavelengths when measuring the total phase difference between the extreme hydrophones.

Industrial applicability of the proposed technical solution is provided by the use of commercially available basic components and elements.

Information sources

1. Patent RU No. 2084924.

2. Patent RU No. 2084923.

3. Patent RU No. 2289149.

4. Patent RU No. 34020U.

5. Patent RU No. 2158431.

6. Patent RU No. 2308454.

7. Patent RU No. 203 8127.

8. Copyright certificate SU No. 713278.

9. Patent RU No. 2365939.

10. Patent RU No. 2371738.

Claims (1)

A hydro-acoustic navigation system containing a navigation base of M hydro-acoustic transponders with different response frequencies and a hydro-acoustic transceiver located on the navigation object, by which time propagation intervals of signals are measured with their subsequent conversion in the distance between the underwater object and hydro-acoustic transponders, the receiving hydro-acoustic antenna consists of four hydrophones mounted on a linear support bracket made of perforator The receiver antennas are placed on a steel plate, at least one of the M hydroacoustic transponders is installed on the water surface, characterized in that the receiving hydroacoustic antenna includes nine more hydrophones when two navigation bases with a common base center are formed from the receivers, placing them in the plane parallel to the plane of the deck of the underwater object, while the axis of one base X is directed along the axial line of the underwater object, and the axis of the other base Y is directed along the beam to the right, unlike Each navigation base is composed of seven hydrophones, one of which is common for both navigation bases, at equal distances from which two hydrophones are located, forming the common central part of the navigation bases, consisting of nine hydrophones, with the extreme hydrophones of each navigation base shifted relative to the common central part of the navigation base by a distance exceeding the distance between the hydrophones forming the common central part of the navigation base, on a linear support bracket tively installed sensor determining the sound velocity, hydrodynamic pressure sensor and an inertial sensor, each of the M hydroacoustic transponders includes subsea and surface module, a cable-connected cable length and inclination sensors etched rope surface module is provided with a channel of satellite radio.

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