RU86321U1 - MULTI-FREQUENCY NAVIGATION SYSTEM - Google Patents

Abstract

A multi-frequency navigation system containing a power source connected to a generator, a chronometer-modulator and a power amplifier, in turn, the generator through a chronizer-modulator and a power amplifier is connected to a radiating electro-acoustic transducer, which together forms a stand-alone pinger emitting in an aqueous medium emitting the electro-acoustic transducer of which is acoustically connected through the location medium with two groups of acoustic transducers, the outputs of which are connected through h compensator with inputs of two parallel processing channels, each of which consists of a series-pass bandpass filter at frequency f1, an amplifier and a detector, the outputs of which are connected to two inputs of a subtractor, the output of which is connected to the second input of the information display device, the first input of which is connected to additional output of the compensator, characterized in that it additionally includes a generator connected both to a power source and through a chronizer-modulator and power amplifier with and a pinger beacon electro-acoustic transducer, as well as four circuits in two parallel-connected channels, each of which contains a series-pass filter at frequencies F = f2-f1, f + = f2 + f1, 2f1,2, an amplifier and a detector, two five-input analog keys, three two-input analog keys, an additional generator, a frequency multiplier, two frequency discriminators, three amplitude meters, a computing unit and a control unit, the outputs of all the detectors of each channel being connected to two five-input

Description

The utility model relates to navigational aids and can be used to determine the spatial and angular coordinates, as well as the motion characteristics of surface (underwater) objects relative to hydroacoustic beacons installed at the bottom with adjustable measurement accuracy, which will ensure their safety in difficult weather conditions (poor visibility, rain, fog, night conditions, submerged conditions, etc.) along the route intended for swimming and maneuvering within the limits of natural narrownesses, arvaterov gidroaerodromov, at the entrances to the harbor, etc. The primary field of use is hydroacoustics, hydroaviation, navigation hydroacoustic equipment of auxiliary vessels for servicing hydrodromes.

Known sonar navigation system with a short base and a pinger beacon (see V.I. Borodin, G.E. Smirnov, N.A. Tolstyakova, G.V. Yakovlev. - Hydroacoustic navigation aids. L .:

Shipbuilding, 1983, p.13), containing a bottom pinger lighthouse (pinger is a hydroacoustic beacon emitting signals according to a given program. - Terminological dictionary-reference book for hydroacoustic. Edited by A.E. Kolesnikov. L .: Shipbuilding, 1989. p. 155), which includes a power source, a generator, a chroniser-modulator, a power amplifier and an emitting electro-acoustic transducer, as well as on-board equipment of the carrier object — three omnidirectional acoustic receivers, a three-channel receiving path including a filter, amplifier, detector, and for irovatel videopulses each connected to the indicator. A pinger lighthouse emits radiation in a pulsed mode according to a program set before setting on sea soil, forming a conical shape of radiation directivity oriented in space vertically upward to the sea surface. The signals received by the acoustic receivers of the onboard equipment carrier object are filtered, amplified, detected, and formed into video pulses with steep leading edges. The direction to the lighthouse is determined by the time delay of the video pulses relative to each other on the screen of the oscilloscope indicator.

Signs that coincide with the claimed object: a lighthouse-pinger, which includes a power source, generator, chronizer-modulator, power amplifier and emitting electro-acoustic transducer, receiving transducers, filters, amplifiers, detectors, indicator.

The reasons that impede the achievement of the technical result are the limited operational capabilities of the short-base sonar navigation system and pinger beacon, which consists in the fact that due to the erosion of the edges of pulsed acoustic signals in real absorbing media (water, gases, etc.), the accuracy of source direction finding is low signal, it is necessary to carry out a mechanical rotation of the base of the receiving transducers in the direction to the direction finding source at large angles (more than 30 °) between the direction eat the lighthouse and the axis of the base, impossible to measure the distance to the beacon and determining motion characteristics of a surface of the object relative to its location is fixed as the operating signal frequency and the area of the irradiation space antenna pinger-beacon is not possible to adjust the direction finding accuracy with this device.

A known navigation system for determining the angular directions to the lighthouse in vertical planes passing through the X and Y axes of the coordinate system of a surface object used to dynamically hold it in a certain direction (see A.L. Prostakov. Electronic key to the ocean. - L .: Shipbuilding , 1978, p.178), containing a power source, a generator, a chronic modulator, a power amplifier and an emitting electro-acoustic transducer, which together form an underwater pinger beacon, as well as on-board equipment of a surface object - riemnuyu antenna consisting of two parts and having thereby two-petalled directional diagram with a partial overlap of the main lobe of the beam that forms a zone. Both parts of the antenna converters are connected through two parallel-connected circuits (filter, amplifier and detector) with two inputs of the subtractor, the output of which is connected to the indicator. The pinger lighthouse emits radiation in a pulsed mode according to a program specified before placing it on the ground, forming a conical shape of the radiation directivity oriented vertically upward in space. The receiving antenna consists of two identical converters deployed one relative to the other at a certain angle φ _cm so that their beams overlap at a predetermined level, which makes it possible to use the equal-signal zone method. Acoustic signals received by the antenna from the pinger beacon are processed in parallel chains, and if the acoustic axis of the receiving antenna coincides with the direction to the beacon, the error signal will be zero, which is read from the indicator screen.

Signs that coincide with the claimed object: a lighthouse-pinger, which includes a power source, generator, chronizer-modulator, power amplifier and emitting electro-acoustic transducer, consisting of two transducers, a receiving antenna having a two-petal radiation pattern with partial overlap of the petals, filters, amplifiers, detectors, indicator.

The reasons hindering the achievement of the technical result are the limited operational capabilities of the navigation system for determining the angular directions to the lighthouse in vertical planes passing through the X and Y axes of the coordinate system of the surface object, consisting in the fact that it is necessary to carry out a mechanical rotation of the electro-acoustic receiving transducers until the signal the mismatch will not be reduced to zero in the future with continuous automatic tracking of the lighthouse in the direction Possible how to measure the distance to the beacon and determine the motion characteristics of the object with respect to a surface of the fixed beacon, operating as a fixed signal frequency, and the irradiation area of the space-pinger beacon antenna, there is no possibility of adjustment of direction finding accuracy with this device.

As a prototype, a navigation direction finding system according to US Pat. Germany No. 2027940, class G01S 3/80, publ. in about. IZR No. 7, 1977, containing a power source connected to a generator, a chronometer-modulator and a power amplifier, in turn, the generator through a chronizer-modulator and a power amplifier is connected to a radiating electro-acoustic transducer, which together forms an autonomous pinger installed in an aqueous environment ; the emitting electro-acoustic transducer of the pinger beacon is acoustically connected through the location medium with two groups of receiving acoustic transducers connected through the compensator to the inputs of two filters, the outputs of each of which are connected through the amplifier and detector to the inputs of the subtractor, the output of which is connected to the second input by an indicator, the first input which is connected to the auxiliary output of the compensator. The operation of the navigation direction finding system is as follows. A pinger lighthouse emits radiation in a pulsed mode according to a program specified before setting on sea soil, forming a conical shape of the radiation directivity oriented in space vertically upward to the sea surface on which the object - the carrier of the navigation direction finding system is located. Each of the groups of acoustic receiving transducers installed on the carrier object has a beamless radiation pattern that is shifted relative to each other by an angle of φ _cm , and there is no mechanical rotation in the space of the groups of transducers. The electrical signals from the groups of converters pass through the compensator, which rotates in the directional pattern of the converters during direction finding of the pinger beacon, from the two outputs of the compensator, the electrical signals, after filtering, amplification, and detection, are fed to two inputs of the subtractor, from the output of which the mismatch signal of both channels goes to the indicator , the second input of which is supplied from the additional output of the compensator with a voltage characterizing the angular position of the diagrams is directed awn converters in space. When receiving acoustic signals from a direction-finding pinger beacon using a compensator, the radiation patterns of the acoustic transducer groups are rotated synchronously so that the equal-signal axis of these groups is aligned with the direction to the direction-finding source. In this case, the electrical signals taken from the outputs of the detectors will be identical, and at the output of the subtracting device, zero voltage is recorded on the indicator screen. In this case, by the magnitude of the voltage removed from the additional output of the compensator, the direction to the direction finding source is fixed.

Signs that coincide with the claimed object: a lighthouse-pinger, which includes a power source, generator, chronizer-modulator, power amplifier and an emitting electro-acoustic transducer, consisting of two groups of transducers, a receiving antenna with a two-petal radiation pattern with partial overlap of the petals, a compensator, filters , amplifiers, detectors, indicator.

The reasons that impede the achievement of the claimed technical result are the limited operational capabilities of the navigation direction-finding system, which is due to its ability to only accurately determine the bearing to the pinger lighthouse using the equal-signal zone method, but it is impossible to measure the distance to the lighthouse and determine the motion characteristics of the surface object relative to the stationary beacon, the working frequency of the signal and the area of the space irradiation by the antenna of the pinger beacon are fixed, is absent in the ability to adjust the direction finding accuracy using this device.

The objective of the utility model is to expand the operational capabilities of the navigation system, which ensures the safety of the movement of an object equipped with this navigation system in difficult weather conditions (poor visibility, rain, fog, night conditions, submerged condition, etc.) along the route intended for sailing and maneuvering within the limits of natural narrownesses, fairways of hydrodromes, at the entrances to the harbor, etc., which is achieved due to the simultaneous accurate measurement of how spatial x and the angular coordinates of the carrier object of the device, and determining the characteristics of its movement relative to those installed at the bottom of the sonar pinger beacons.

The technical result of the utility model consists in the possibility of obtaining by the operator of a multi-frequency navigation system additional updated information about the location of the carrier object (spatial and angular coordinates), as well as the parameters of its motion relative to the pinger beacon, and, unlike the radio navigation and optical means of the carrier object, sonar systems with pinger beacons provides high accuracy of positioning in any meteorological conditions and when sailing on l depths.

The development and design of navigational aids capable of obtaining a more complete and accurate amount of primary data on the location of both underwater and surface carrier objects in the sea relative to the sonar pinger beacons installed at the bottom is an urgent task. In the light of the foregoing, pinger beacons should provide the emission of several working signals with quite different frequencies (low, medium and high - within the range of 20 kHz - 200 kHz) in the presence of one acoustic radiating antenna, which is promising, respectively, for long-range drive with low accuracy the carrier object of the navigation system to the lighthouse, the refined selection of the position of the carrier object for medium distances to the lighthouse and precision maneuvering directly above it at small s. This can be achieved by using a parametric radiating antenna as a beacon antenna, which generates in the aquatic environment both a primary acoustic field - pump signals (average operating frequency), and a secondary acoustic field - a differential frequency signal (low operating frequency) and total frequency signals, second harmonics of the pump signals (high operating frequency).

The technical result is achieved by the fact that in the navigation direction finding system containing a power source connected to a generator, a chronometer-modulator and a power amplifier, in turn, the generator through a chronizer-modulator and a power amplifier is connected to a radiating electro-acoustic transducer, which together forms installed in the water The environment is an autonomous pinger beacon emitting an electro-acoustic transducer of which is acoustically connected through a location medium to two groups of acoustic pre educators whose outputs are connected through the compensator to the inputs of two parallel processing channels, each of which consists of a series-pass bandpass filter at frequency f ₁ , an amplifier and a detector, the outputs of which are connected to two inputs of a subtractor, the output of which is connected to the second input of the information display device , the first input of which is connected to an additional output of the compensator, additionally introduced are a generator connected both to a power source and through a chronizer-modulator and ilitel power to the radiating electro-acoustic transducer pinger-beacon, and four chains in two parallel channels, each of which comprises a serially coupled bandpass filter at the frequency F = f ₁ -f _2, f ₊ = f ₂ + f _1, 2f _{1 2,} amplifier and detector pyativhodovyh two analog switches, three two-input analog switches, an additional generator, a frequency multiplier, frequency discriminator two, three meter amplitude computing unit and a control unit, the outputs of all the detectors of each channel Ser are connected with two five-input analog keys, the outputs of which are connected to two inputs of a subtractor, the output of which is connected to the second input of the information display device, while its first input is connected to the additional output of the compensator, and the control inputs of both analog keys are connected to the corresponding output of the unit management; the outputs of four amplifiers from parallel-connected circuits with frequencies f ₁ , 2f _{1 of the} first and second channels are connected to the inputs of two two-input analog keys, the outputs of which are connected through the first frequency discriminator to the third input of the information display device, and the control inputs of the two-input analog keys are connected to the corresponding control unit output; the output of the two-input analog key from the first channel is additionally connected to the first input of the second frequency discriminator, the second input of which is connected to the output of the third two-input analog key, both inputs of which are connected to an additional generator: one directly and the second through the frequency multiplier, and the output of the second the frequency discriminator is connected to the input of the Doppler information processing unit, and the control inputs of the third two-input analog key and the Doppler information processing unit are unified with the corresponding outputs of the control unit; the outputs of three detectors from parallel-connected chains of the second channel with frequencies 2f ₁ , 2f ₂ , f _{+ are} connected through three amplitude meters with three inputs of the computing unit, the output of which is connected to the fourth input of the information display device, and, in the on-board equipment installed on the object, the carrier includes all the blocks starting with two groups of acoustic transducers that are in acoustic contact with the emitting electro-acoustic transducer of the pinger beacon, and ending with the control unit.

The utility model is illustrated by drawings. Figure 1 shows the structural diagram of the inventive device, figure 2 shows the spatial position of the radiation patterns (NAM) of the device on the used working signals and explains direction finding by the equal-signal zone method using the proposed navigation direction-finding system; figure 3 shows the direction-finding characteristics of the method of the equal-signal zone at the operating frequencies of the proposed device, figure 4 presents the amplitude-frequency characteristic of the frequency discriminator; _figure 5 - graphs of the function y, showing the longitudinal distribution of the secondary signals of high frequency P _2f1 (1), P ₊ (2), P _2f2 (3) on the axis of the parametric antenna of the lighthouse-pinger at ω ₁ / ω ₀ = 0.9 ; ω ₂ / ω ₀ = 1.1.

The multi-frequency navigation system contains a power source 1 connected to two generators 2, 3, a chrono-modulator 4 and a power amplifier 5, in turn, the generators 2, 3 are connected to a radiating electro-acoustic transducer 6 through a chrono-modulator 4 and a power amplifier 5, which together forms an autonomous pinger lighthouse installed in the aquatic environment; the emitting electro-acoustic transducer 6 is acoustically connected through the location medium with two groups of acoustic transducers 7, 8, the outputs of which are connected to the compensator 9, the two outputs of which are connected to the inputs of ten parallel-connected chains of band-pass filters 10, amplifiers 11, detectors 12, forming a two-channel receiving path for processing the signals of the beacon-pinger, moreover, the outputs of all the detectors of each channel are connected to five inputs of two analog keys 13, the outputs of which are connected to two inputs of the calculator melting device 14, whose output is connected to the second input device 15 to display information, while its first input is connected to an additional output of the compensator 9;

the outputs of four amplifiers 11 from parallel-connected circuits with frequencies f ₁ ± f _{D (f1)} , 2f ₁ ± f _{D (2f1) of the} first and second channels are connected to the inputs of two two-input analog switches 16, the outputs of which are connected through the first frequency discriminator 17 to the third the input of the information display device 15;

the output of the two-input analog key 16 from the first channel is additionally connected to the first input of the second frequency discriminator 17, the second input of which is connected to the output of the third two-input analog key 18, both inputs of which are connected to the additional generator 19: one directly and the second through the frequency multiplier 20 and, the output of the second frequency discriminator 17 is connected to the input of the processing unit of the Doppler information 21;

the outputs of three detectors 12 from parallel-connected chains of the second channel with frequencies (2f ₁ ± f _{D (2f1)} ), (2f ₂ ± f _{D (2f2)} ), (f ₊ ± f _{D (f +)} ) are connected through three amplitude meters 22 with three inputs of the computing unit 23, the output of which is connected to the fourth input of the information display device 15;

the control inputs of both analog five-input keys 13, two-input analog keys 16 of the first and second channels, the third two-input analog key 18 and the Doppler information processing unit 21, as well as the computing unit 23 are connected to the corresponding outputs of the control unit 24; moreover, in aggregate, blocks 7-24 are mounted on a surface (underwater) carrier and form its on-board equipment.

The operation of the multi-frequency navigation system is as follows. In the pinger beacon, all electronic units are connected to power source 1 and the generators 2, 3 produce high-frequency harmonic signals with frequencies f ₁ , f ₂ lying in the passband of the electro-acoustic transducer 6, which are fed to two inputs of the chrono-modulator 4, at the output of which A radio pulse with biharmonic RF filling is formed. This radio pulse after the power amplifier 5 is fed to an electro-acoustic transducer 6, which emits a probe pump signal into an aqueous medium that has a non-linearity in its elastic characteristics. In this case, nonlinear interaction of the pump signals with frequencies f ₁ , f ₂ in the propagation channel occurs, the result of which is the parametric generation of secondary acoustic signals of both difference F = f ₂ -f ₁ and total f ₊ = f ₂ + f ₁ frequencies, second harmonics 2f _1.2 pump waves. The pinger beacon emits radiation in a pulsed mode according to a program specified before putting it on the ground, forming cone-shaped radiation directivity characteristics on the initial pump signals oriented vertically upward in space, and the radiation directivity characteristics on secondary acoustic signals have a weakened side field, and the sharpness directional action for the difference frequency signal is commensurate with this parameter for pumping, while the severity of directional action for secondary high frequency signals ~ in times higher. Thus, the pinger beacon ensures the presence of several working signals in the aquatic environment with quite different frequencies and different viewing angles when using a parametric emitting antenna. Due to the quadratic dependence of the viscous sound absorption on the frequency, the initial pump waves and secondary high-frequency acoustic fields decay faster in a fairly extended interaction region in comparison with the secondary waves of the difference frequency, which propagate over considerable distances in the form of a directed beam. Considering that obtaining a more complete volume of primary data on the location of pinger beacons is associated with the movement of the carrier object at a speed υ relative to the stationary source of the above primary and secondary acoustic signals, then when they are received by the groups of converters 7, 8, their Doppler frequencies change. It is known that when the receiver moves relative to a stationary signal source with a frequency f, the changed frequency of the received signal will be equal

where c is the speed of sound in water, θ is the angle between the direction of the speed of the receiver and the direction from the source to the receiver, and if the angle θ is obtuse, then the received frequency increases (+ sign), at θ = 90 ° the emitted and received frequencies will be the same , and if the angle θ is acute, then the received frequency decreases (the sign -) (see Small Encyclopedia. Ultrasound. Edited by I.P. Golyamin. p.133-134).

When propagating in a medium, a polyharmonic acoustic signal with frequencies f ₁ , f ₂ , F = f ₂ -f ₁ , f ₊ = f ₂ + f ₁ , 2f _1,2 reaches two groups of acoustic transducers 7.8 of a moving object with speed carrier, undergoing for each harmonic component the corresponding Doppler frequency shift (± f _{D (f1)} ), (± f _{D (2f1)} ), (± f _{D (f2)} ), (± f _{D (2f2)} ), (± F _D ), (± f _{D (f +)} ), moreover, for each group 7 and 8 the frequency shifts will differ due to the presence of identical radiation patterns that are shifted relative to each other by an angle of 2φ _cm , here (+) and (-) correspond t approaching or removing the carrier object relative to the pinger beacon. The electric signal from two groups of acoustic transducers 7, 8, corresponding to the received acoustic polyharmonic signal through the compensator 9, is fed to the inputs of the first and second processing channels, which contain five circuits in each of the series-connected bandpass filters (10) tuned to the frequencies (f1 ± f _{D (f1)} ), (2f ₁ ± f _{D (2f1)} ), (2f ₂ ± f _{D (2f2)} ), (F ± F _D ), (f ₊ ± f _{D (f +)} ), amplifiers (11 ) and detectors (12), the outputs of which for each frequency in the first and second channels generate video-pulse voltages U _1F , U _{1 (f1)} , U _{1 (f2)} , U _{1 (2f1)} , U _{1 (2f 1)} , U _{1 (f +)} and U _2F , U _{2 (f1)} , U _{2 (f2)} , U _{2 (2f1)} , U _{2 (2f2)} , U _{2 (f +)} , the amplitudes of which are determined by the spatial position of the radiation patterns ( DN) device on the used working signals relative to the direction to the emitting electro-acoustic transducer 6 direction finding beacon-pinger. From the outputs of the detectors of the first and second processing channels, the corresponding pairs of video pulse voltages are (U _1F and U _2F ), (U _{1 (f1)} and U _{2 (f1)} ), (U _{1 (2f1)} and U _{2 (2f1)} ), and t .d. come through five-input analog keys 13 to the inputs of the subtracting device 14, the output of which is connected to the second input of the information display device 15. The selection of the required pair of video pulse voltages supplied to the two inputs of the subtractor 14 is determined by the operator and is carried out by supplying the corresponding signal from the control unit 24.

Before a detailed description of the operation of the on-board equipment of a multi-frequency navigation system, we briefly describe the tasks that are solved by the operator with its help. The receiving airborne equipment of the carrier object of the proposed device functionally includes three receiving paths with which the bearing to the pinger beacon is measured, the distance to it is calculated and the motion parameters of the device carrier object are determined during precision maneuvering at small distances from the pinger beacon. The operation of the receiving path for measuring the bearing on the lighthouse-pinger is based on the operator receiving two signs of accurate direction finding: 1) the minimum amplitude of the resulting electrical signal ΔU = U ₁ -U ₂ mismatch of the first and second channels at the operating frequencies of the device (f ₁ , f ₂ , F = f ₂ -f ₁ , f ₊ = f ₂ + f ₁ , 2f _1,2 ); 2) the minimum Doppler frequency shift [f _{D1K (f1)} - f _{D2K (f1)} ], [ _{fD1K (2f1)} - f _{D2K (2f1)} ] received by the groups of transducers 7 (channel 1) and 8 (channel 2) of acoustic signals of multiple frequencies f ₁ ± f _{D (f1)} , 2f ₁ ± f _{D (2f1).} The functioning of the receiving path for calculating the distance from the carrier to the pinger beacon is based on calculations by the operator in accordance with the calculated ratios obtained as a result of studying the basic physical laws of the generation of secondary high-frequency signals in a nonlinear medium with a parametric antenna, into which the experimental data. The receiving path for determining the motion parameters of the device carrier object relative to the pinger beacon allows the operator to perform this task based on measuring the Doppler shift for acoustic signals of multiple frequencies f ₁ ± f _{D (f1)} , 2f ₁ ± f _{D (2f1)} received by the groups converters 7 (channel 1).

Direction finding by the equal-signal zone method is carried out by determining the difference in the video pulse voltages ΔU = U ₁ -U ₂ (points - • - 1, 2, - ° - 1 ', 2', ^{### U255} - 1 ", 2") in FIG. 2 in a subtractor 14, to the inputs of which from the outputs of the first and second channels of the device’s receiving path at operating frequencies — either differential F = f ₂ -f ₁ , or pump f ₁ , f ₂ , or secondary high-frequency f ₊ = f ₂ + f ₁ , 2f _1,2 , the corresponding pairs of video pulse voltages come through analog switches 13, for example, - (U _1F and U _2F ), (U _{1 (f1)} and U _{2 (f1)} ), (U _{1 (2f1)} and U _{2 (2f1)),} etc., whose amplitudes izmenyayuts when turning groups of acoustic transducers patterns 7, 8, 9 compensator during DF-pinger beacon. Reconfiguration of the compensator 9 can be carried out either by the operator manually or automatically, followed by tracking the pinger beacon. When finding the target on a line passing through the intersection point of the radiation patterns of both groups of acoustic transducers and called the line of equal signal direction, the signals of both channels are equal (U _1F = U _2F or U _{1 (f1)} = U _{2 (f1)} or U _{1 (2f1)} = U _{2 (2f1)} ) and the voltage ΔU will be zero, which will be recorded by the information display device 15. The information display device 15 is a standard block of hydroacoustic means and surveillance systems, with the help of which the received information is presented in a form convenient for the operator to make a decision (see Mitko VB and other Hydroacoustic communication and surveillance means. - L .: Shipbuilding, 1982. p.107-113, Yu. S. Kobyakov et al. Design of hydroacoustic fish-finding equipment. - L .: Sudostroenie, 1986. p. 244-264). A voltage proportional to the angle of rotation Δφ of the equal-signal direction of the antenna system, from the additional output of the compensator 9, is supplied to the first input of the information display device 15, which displays information about the angular coordinate Δφ of the direction-finding pinger beacon. The compensator is a standard block of hydroacoustic monitoring tools designed to detect underwater objects, classify them and determine the bearing (heading angle) on them by receiving the energy of the noise field generated by the object (see the Reference book on hydroacoustic acoustics. Edited by A.E. Kolesnikov. - L .: Shipbuilding, 1982, pp. 14-15, V.N. Krasnov, Location from a submarine.- M., 1968, p.62-72, I.A. Romanian. Fundamentals of hydroacoustics. L: Shipbuilding 1979, p. 176-185). In the proposed device, direction finding is carried out on several acoustic signals of both primary and secondary acoustic fields with frequencies (f _1,2 ± f _{D (f1,2)} ), (2f _1,2 ± f _{D (2f1,2)} ), ( F ± F _D ), (f ₊ ± f _{D (f +)} ), which will allow you to adjust the direction finding accuracy of the pinger beacon.

The direction-finding characteristics of the method of the equal-signal zone at frequencies f ₁ ± f _{D (f1)} (---), 2f ₁ ± f _{D (2f1)} (- · - · -), F ± F _D (-) for the proposed device are presented in FIG. .3. As can be seen from the drawing, the steepness of the direction-finding characteristic S = dU (φ) / dφ, and therefore the direction-finding sensitivity, is maximum when the line of the equal-signal direction is oriented to the target (in this case ΔU = 0), and, for the second harmonic signal 2f _1, direction-finding sensitivity the highest, and for the difference frequency signal - the smallest. This is due to the magnitude of the difference in the video pulse voltages ΔU = U ₁ -U ₂ (points - • - 1,2, ΔU _F , - ° - 1 ', 2', ΔU _f1 , - ^{### U255} - 1 ", 2", ΔU _2f ) for any deviation angle φ from the line of equal signal direction, which is determined by the exacerbation of the main lobe of the groups of acoustic transducers in the receiving mode for higher frequency signals.

We illustrate the above with the following numerical example. The common blocks for all three receiving paths are two groups of acoustic transducers 7, 8 having identical radiation patterns without additional maxima, which are shifted relative to each other by an angle of 2φ _cm (Fig. 2), where φ _cm = (0.5-0, 7) × θ _0.7 , θ _0.7 is the width of the directivity characteristics of the group of acoustic transducers for the pump signal at a level of 0.7. It should be noted that the severity of the directed action of these groups of acoustic transducers substantially depends on the wave dimensions of their aperture, i.e. from the ratio D / λ, where λ is the wavelength of the received signal, D is the diameter of the antenna. So, for example, when using continuous flat multi-element circular antennas with acoustic distribution 7, 8 as acoustic transducers, with an amplitude distribution over the surface described by the relation (1-r ² ) ⁴ , where r is the radial current coordinate measured from the center of the circular surface of the antenna, the width of the characteristic directivity θ _0.7 (in radians) is calculated as the ratio of 1.81 × λ / D at the level of the first lateral maximum of 0.9% of the magnitude of the main one (see the Reference book for hydroacoustics. A. Evtyutov et al. -L .: Shipbuilding, 1982. p.196). Then, for the antenna diameter of 10 cm and wavelengths of the received signals, λ _- = 75 mm (20 kHz), λ _n = 15 mm (100 kHz) and λ ₊ = 7.5 mm (200 kHz) of the main lobe width at level 0 , 7 θ _0.7 will be ~ 78 °, 16 ° and 8 °, which, subject to the condition φ _cm ≈ (0.5-0.7) × θ _0.7n for two groups of acoustic transducers 7, 8, will provide viewing sectors ~ 136 °, 13 ° and 6.4 ° respectively. Thus, direction finding on a difference frequency signal is expedient for long-distance drive with low accuracy of the carrier object to the lighthouse, direction finding on the pump signal is optimal when refining the position of the object for medium distances to the beacon, and direction finding on the signal of the total frequency is relevant for precision maneuvering directly above beacon at small distances. The accuracy of the multi-frequency direction finding can be numerically estimated using the following: the angle Δφ _min at which the operator or the automatic device confidently detects the difference in voltage U ₁ , U ₂ is determined by the expression (see A. Kolchedantsev Hydroacoustic stations. - L .: Shipbuilding , 1982)

moreover, during direction finding by the operator, the value µ = 0.05-0.15 - (visual indicator) and µ≥0.2 (auditory indicator).

Thus, the use in the navigation direction finding system of pump signals with frequencies f ₁ or f ₂ , secondary acoustic signals of both difference F = f ₂ -f ₁ and total f ₊ = f ₂ + f ₁ frequencies, second harmonics 2f _1,2 pump waves processed in five two-channel chains containing sequentially connected band-pass filters (10) tuned to frequencies (f ₁ ± f _{D (f1)} ), (2f ₁ ± f _{D (2f1)} ), (2f ₂ ± f _{D ( 2f2)} ), (F ± F _D ), (f ₊ ± f _{D (f +)} ) „amplifiers (11) and detectors (12) and then fed in pairs through five-input analog keys 13 to the inputs of the subtractor 14, the output to connected to the second input of the information display device 15, it allows direction finding of the pinger beacon by the equal-signal zone method with the required accuracy increasing for higher-frequency signals, which is due to a decrease in the beam width at the level of 0.7 groups of converters 7, 8 of the receiving antenna of the device. The choice of a working signal is carried out by applying from the control unit 23 signals to the control inputs of five-input analog keys 13, which in turn is determined by the necessary accuracy of the task of determining the location of the bottom pinger beacon from the carrier object of the proposed device.

Using the proposed device, it is possible to additionally perform direction finding of the pinger beacon using the Doppler effect, due to the fact that when the carrier object moves at a horizontal speed υ relative to the bottom, the angle 9 changes between the direction of the velocity vector of the carrier object (receiver) and the direction from a pinger beacon (source) to the carrier object (receiver), which causes a Doppler frequency shift of the received both primary and secondary acoustic signals (see relation (1)). Given the design features of the receiving antenna, consisting of two groups of acoustic transducers 7, 8, having identical radiation patterns without additional maxima, which are shifted relative to each other by an angle of 2φ _cm , where φ _cm = (0.5-0.7) × θ _{0 , 7} , θ _0.7 is the width of the directivity characteristics of the group of acoustic transducers for the signals used at a level of 0.7, as well as the conditions for using the pinger beacon used for direction finding in the equal-signal zone method, we can conclude that the main mode the positions of the DNs of the groups of acoustic transducers will always be oriented differently with respect to the direction from the source to the receiver and, accordingly, the angles between the direction of the velocity vector υ of the carrier ship and the directions of the main lobes for accurate direction finding of the pinger beacon will be (θ + 0.6θ _{0, 7} ) and (θ-θ, 6θ _0.7 ). Consider the range of variation of the angle θ: with a significant distance of the carrier object from the location of the pinger beacon, but approaching θ ~ 180 ° and cosθ ~ (-1), while with a significant distance of the carrier object from the location of the pinger beacon, but the distance from it is θ ~ 0 ° and cosθ ~ (+1), which in both cases will determine the maximum change in the frequency of the received signal of the pinger beacon, and only when the carrier object is directly above the pinger beacon θ ~ 90 ° and cosθ ~ 0 , which will determine the absence of a change in the frequency of the received beacon-pinger signal but. Thus, the Doppler frequency shift for each group of acoustic transducers 7, 8 will be different and depend on the location of the carrier object on the water surface, its direction of movement relative to the pinger beacon (angle θ), speed υ, and signal frequency f (see relation (1). Thus, when the carrier object of the proposed device approaches its location above the bottom pinger beacon, the angle θ decreases and tends to 90 °, which will lead to a gradual decrease in the Doppler frequency shift (+ Δf _D ↓) for both groups of acoustic transducers to a minimum value (when the ship is vertically above the lighthouse), and then to a gradual increase in the Doppler shift (-Δf _D ↑) when removed, and, for higher frequency signals, this shift will be large in magnitude, the dynamics of the frequency change is more significant The additional direction-finding path based on the Doppler effect includes two two-input analog switches 16, the inputs of which are connected to the outputs of amplifiers 11 from parallel-connected circuits check for processing electrical signals with frequencies (f _{1 ± f D (f1)),} (2f ₁ ± f _{D (2f1))} in the first channel and the second. The outputs of both analog keys 16 from the first and second channels of the additional direction finding path of the device are connected via a frequency discriminator 17 to the third input of the information display device 15, moreover, the control inputs of the analog keys 16 of both channels are connected to the output of the control unit 24. When the carrier is located directly above with a beacon, the equal-signal direction of the acoustic axis of the antenna will coincide with the vertical, which, due to the design features of the receiving antenna, will result in the following in the space of the principal maxima of groups of acoustic transducers 7, 8 - one angle (90 ° -φ _cm), and the other - (90 ° + φ _cm) with respect to the velocity vector of the carrier vessel that provide different signs ( "+" - channel 1 and “-” - channel 2) of the smallest Doppler shift in both channels at the initial pump frequencies f ₁ in accordance with the relations

On the acoustic signals of the second harmonics 2f ₁ due to the train ~ times of the main lobes of the radiation patterns of transducer groups 7, 8 and the use of a higher frequency, the smallest Doppler shift in adjacent channels (“+” - channel 1 and “-” - channel 2) will have a different value

At the output of the frequency discriminator, a signal voltage U _{B is} generated whose amplitude is proportional to the difference between the Doppler frequencies of the first and second channels on the used working signals f ₁ , 2f _1, which, taking into account the signs (“+” - channel 1 and “-” - channel 2) of the smallest Doppler frequency shifts will lead to their doubling

Then, in accordance with its amplitude-frequency characteristic of the frequency discriminator (Fig. 4) (see Ekimov V.D., Pavlov K.M. Design of radio receivers.- M .: Communication, 1970. p. 282-287) for more high-frequency working signals and, accordingly, large differences of Doppler shifts in the first and second channels, the signal voltage value has a large value (U _{in (2f1)} > U _{in (f1)} ), which increases both the signal-to-noise ratio and noise immunity considered receiving path.

As is known, irradiation of the sea surface with a conical beam of sound waves from a pinger beacon leads to the expansion of the Doppler frequency spectrum, and the width Δf _{D of the} Doppler spectrum in terms of half power can be determined from an approximate ratio (for the case of direct transmission of signals from the source to the receiver) Δf _D ≈υ × f × sinθ _d × θ _{0.7 (m)} / s, where θ _{0.7 (m)} is the beam pattern of the pinger beacon antenna on the working signal with a frequency f at the level of 0.7, θ _d - the angle of the axis of the antenna pattern relative to the mountains zontally surface; c is the speed of sound in water (see Bukaty V.M., Dmitriev V.I. Hydroacoustic logs. M: Pishch. prom., 1980, p. 60, p. 84). The appearance of the Doppler frequency spectrum causes an error in the determination of the Doppler frequency shift for the following reason — the instantaneous frequency of the Doppler spectrum undergoes fluctuations from the average frequency f _{D0 of the} spectrum. The root-mean-square error of measuring the Doppler frequency shift due to fluctuations in the average frequency of the spectrum can be estimated from the approximate ratio δf _D ≈K × (ΔfD / T) ^0.5 , where K is a constant coefficient, T is the averaging time. It can be seen that in order to reduce the measurement error, the main lobe of the antenna pattern should be narrowed to the maximum, which is done for higher-frequency signals. Thus, an additional direction-finding indicator for accurately determining the location of the bottom beacon can be obtained by using a pump signal with a frequency f ₁ emitted by the pinger beacon parametric antenna and a second acoustic signal of the second harmonic 2f ₁ pump wave generated in a nonlinear aquatic environment. To this end, these signals are received by two groups of acoustic transducers 7, 8 installed on the carrier object, and converted into the corresponding electrical signals using two groups of 7, 8 acoustic transducers, the equal-signal direction of which is installed in space on the direction-finding pinger beacon by turning the diagrams directionality by compensator 9. From two outputs of compensator 9, electrical signals corresponding to each of the groups of converters are processed in two channels in parallel chains containing serially connected band-pass filters 10, amplifiers 11 and two-input analog switches 16, the outputs of which are connected to the inputs of the frequency discriminator 17, the output of which is connected to the third input of the information display device 15, which allows direction finding of the pinger beacon based on the use of the Doppler effect with the required accuracy, increasing for higher frequency signals due to a decrease in the width of the beam at the level of 0.7 groups of converters of the receiving antenna of the device. The choice of a working signal is carried out by supplying 24 signals from the control unit to the control inputs of both two-input analog keys 16, which in turn is determined by the necessary accuracy of the task of determining the location of the bottom pinger beacon from the carrier object.

The receiving path for determining the motion parameters of the carrier object of the proposed device relative to the pinger beacon includes two two-input analog keys: - 16 - from the first processing channel and the third additional - 18, the second frequency discriminator 17, additional generator 19, frequency multiplier 20 and block processing Doppler information 21 (in the block diagram of the device in figure 1, these blocks are located in the first channel), moreover, two inputs of the first analog key 16 are connected to the outputs of two amplifiers 11 in the first channel ale, and its output is connected to the first input of the second frequency discriminator 17, the second input of which is connected to the output of the third analog key 18, the two inputs of which are connected to the output of an additional generator 19 - the first is directly, and the second is through a frequency multiplier 20 with a multiplier 2 The Doppler information processing unit 21 is a standard unit used in sonar navigation systems, also in similar radio-Doppler systems (see Borodin V.I. Hydroacoustic navigation aids. L .: Shipbuilding, 1983. p.219-223, Digital navigation devices. Ed. V.B. Smolova. M., Sov. radio, 1980).

To measure the motion characteristics of the carrier object of the proposed device, one of the electrical signals with a frequency of (f ₁ ± f _{D (f1)} ) or (2f ₁ ± f _{D (2f)} ) from the outputs of the respective amplifiers 11 of the first channel through the first analog switch 16 is fed to the first input of the second frequency discriminator 17, the second input of which is from the output of the third analog key 18, respectively, one of the signals with a frequency f ₁ or 2f ₁ without Doppler shift is applied. For this, the inputs of the third analog switch 18 are connected to the output of an additional harmonic signal generator 19 with a frequency f ₁ , as well as to the output of a frequency multiplier 20 with a multiplication factor of “2”. A signal is selected by supplying 24 corresponding signals from the control unit to the control inputs of the first - 16 - and third - 18 - analog keys, as well as the Doppler information processing unit 21. An electric signal with a frequency corresponding to the Doppler shift is allocated at the output of the frequency discriminator ( f _{D (f1)} ) or (f _{D (2f1)} ), which allows calculating the speed values of the carrier object of the proposed device in the Doppler information processing unit 21 based on the Doppler effect in relation

where K _{V (nf)} = 2 × (nf) × cos (θ-φ _cm ) / c is the speed sensitivity of the Doppler meter for an acoustic signal at a frequency nf, which represents the increment of the Doppler frequency when the speed changes by 1 node; υ _(nf) is the speed of relative approach (+) or removal (-) of the pinger beacon and the carrier object, measured on the corresponding acoustic signal; nf is the frequency of the acoustic signal used to measure motion parameters; n = 1,2 - number of the used harmonic; C is the speed of sound in the aquatic environment.

Suppose that the final stage of the exact determination of the location of the pinger beacon is carried out during the precision maneuvering of the carrier object above it, during the execution of which it is advisable, in addition to measuring the bearing of the pinger beacon, to be able to obtain information about the distance to it. In this case, to determine the distance to the direction-finding beacon, you can use some physical features of the nonlinear generation of secondary signals of the total frequency f ₊ = f ₂ + f ₁ , second harmonics 2f _1.2 pump waves propagating in an aqueous medium, the axial distributions of sound pressure levels of which are described the following dependencies (see Voloshchenko V.Yu. Research and development of a parametric antenna in the mode of generating acoustic signals of the total frequency for use in near-acoustic sonar systems Twiya: Thesis for the degree of candidate of technical sciences: 01.04.06, 05.12.01. Taganrog, 1993. p.165) P ₊ = (εω ₊ P ₀₁ P ₀₂ ℓ _g / 2ρ ₀ c ₀ ³ ) × {[0.251n ² (1 + Z _n ² ) + arctan ² Z _n ] / (1 + Z _n ² )} ^0.5 × exp (-β ₊ z), (8)

where ω ₊ = 2π (f ₁ + f ₂ ), ω _1,2 = 2πf _1,2 ; P ₀₁ , P ₀₂ - the amplitude of the sound pressure of the pump signals at the surface of the antenna; ℓ _g = a ² ω ₀ / 2c ₀ , ℓ _g1,2 = a ² ω _1,2 / 2c _{0 are the} lengths of the Fresnel diffraction zones for signals with a central pump frequency f ₀ = (f ₁ + f ₂ ) / 2 and initial frequencies f ₁ , f ₂ ; Z _H = z / ℓ _g and Z _{n 1,2} = z / ℓ _g1,2 - normalized distance; β ₊ , β _{2f 1,2} - attenuation coefficients of the acoustic signals of the total frequency, second harmonics of the initial pump waves. As can be seen from (8) and (9), the factors in curly brackets determine the longitudinal distribution of the sound pressure amplitudes of the secondary high-frequency signals Р _2f1 (1), Р ₊ (2), Р _2f2 (3) on the axis of the parametric antenna of the pinger beacon . The graphs of the functions y _1,2,3 determined by these factors without taking into account the attenuation at ω ₁ / ω ₀ = 0.9; ω ₂ / ω ₀ = 1.1 are presented in figure 5.

An analysis of the nonlinear generation of secondary high-frequency signals by a parametric antenna formed by collinear acoustic beams with a Gaussian transverse distribution of medium intensity pump allows us to draw the following conclusions:

1) on the axis of a parametric antenna (PA) formed by a two-frequency primary pump beam with a Gaussian transverse distribution of sound pressure of medium-intensity signals, with an increase in the longitudinal coordinate z, the amplitudes of the sound pressures of the secondary high-frequency signals (without taking into account attenuation) monotonically increase, reaching maxima of various magnitudes at certain distances z _{m (+)} = 1.425ℓ _g ; z _{m (2f1)} = 1.425ℓ _g (f ₁ / f ₀ ); z _{m (2f2)} = .425ℓ _g (f ₂ / f ₀ ), after which the level drops due to the diffraction divergence of both the initial pump waves and the secondary waves;

2) taking into account the attenuation of secondary high-frequency signals (for f ₁ <f ₂ , P ₀₁ = P ₀₂ = P ₀ ) has a noticeable effect on the levels of amplitudes of sound pressures in the far zone of the PA pump converter, expressed in their equalization and merging of all three axial distributions, due to the following ratio of spatial attenuation coefficients - β _2f2 > β ₊ > P _2f1 ;

3) at any point in the half-space, the Gaussian transverse distribution of the sound pressure of the pump signals in the two-frequency primary beam determines precisely the Gaussian transverse distribution of the sound pressure of the studied signals in the generated secondary beams, moreover, the analytical functions describing the angular distribution of the sound pressure of the acoustic signals of the second harmonics 2f ₁ , 2f ₂ are directly proportional to the functions raised to the second power that describe the angular distribution for each of the primary pump signals f ₁ , f _2, a SSFS to f ₊ - the product of these functions (or second degree function describing the angular distribution of sound pressure of the pump signal with the central frequency f ₀ = (f ₁ + f ₂₎ / 2 = f ₊ / 2).

Based on the presented conclusions and relations (8) - (9), an approximate estimate of the distance of finding the pinger beacon from the carrier object of the proposed device can be carried out, for example, by dividing analytic expressions of the form (9) for sound pressure amplitudes Р _2f1 and Р _{2f2 of the} second harmonics of the initial pump signals, taking into account the fact that the functions have ₁ ≈y ₂ ≈y ₃ provided that the pump frequency is f ₁ ≈f ₂ . In this case we get

Taking the natural logarithm of (10), we can calculate the range of the pinger beacon

Similar relations for the same z-range of the pinger beacon can be obtained for other ratios of amplitudes of sound secondary high-frequency components - P ₊ / P _2f1 , P _2f2 / P ₊ , which will increase the accuracy of the calculation due to averaging. The receiving path for calculating the distance to the pinger beacon is functionally located in the second channel of the device (see Fig. 1) and includes three amplitude meters 22 and a computing unit 22, moreover, the inputs of the amplitude meters 21 are connected to the outputs of the detectors 12 in the second channel, generating video pulse voltages U _{2 (2f1)} , U _{2 (2f2)} , U _{2 (f +)} , the measured values of which are fed to the inputs of the computing unit 23, moreover, at the time of accurate direction finding of the pinger beacon, the necessary calculations are made from the control unit 24, koto results s supplied to the fourth input device 15 display information.

This multi-frequency navigation system can be used to ensure that the carrier object is held at the point of work on the ground associated with the construction of underwater structures, as well as to ensure the safety of the movement of surface objects in difficult meteorological conditions (rain, fog, night conditions, etc. ) along the route intended for navigation and maneuvering within the limits of natural narrownesses, fairways of hydroaerodromes, at the entrances to the harbor, etc.

Claims (1)

A multi-frequency navigation system containing a power source connected to a generator, a chronometer-modulator and a power amplifier, in turn, the generator through a chronizer-modulator and a power amplifier is connected to a radiating electro-acoustic transducer, which together forms a stand-alone pinger emitting in an aqueous medium emitting the electro-acoustic transducer of which is acoustically connected through the location medium with two groups of acoustic transducers, the outputs of which are connected through h compensator with inputs of two parallel processing channels, each of which consists of a series-pass band-pass filter at frequency f ₁ , an amplifier and a detector, the outputs of which are connected to two inputs of a subtractor, the output of which is connected to the second input of the information display device, the first input of which is connected with an additional output of the compensator, characterized in that it additionally includes a generator connected both to a power source and through a chronizer-modulator and power amplifier with zluchayuschim electroacoustic transducer pinger-beacon, and four chains in two parallel channels, each of which comprises a serially coupled bandpass filter at the frequency F = f ₁ -f _2, f ₊ = f ₂ + f _1, 2f _1,2, an amplifier and detector, two five-input analog keys, three two-input analog keys, an additional generator, a frequency multiplier, two frequency discriminators, three amplitude meters, a computing unit and a control unit, the outputs of all the detectors of each channel being connected to two five analogue keys, the outputs of which are connected to two inputs of a subtractor, the output of which is connected to the second input of the information display device, while its first input is connected to the auxiliary output of the compensator, and the control inputs of both analog keys are connected to the corresponding output of the control unit; the outputs of four amplifiers from parallel-connected circuits with frequencies f ₁ , 2f _{1 of the} first and second channels are connected to the inputs of two two-input analog keys, the outputs of which are connected through the first frequency discriminator to the third input of the information display device, and the control inputs of the two-input analog keys are connected to the corresponding control unit output; the output of the two-input analog key from the first channel is additionally connected to the first input of the second frequency discriminator, the second input of which is connected to the output of the third two-input analog key, both inputs of which are connected to an additional generator: one directly and the second through the frequency multiplier, and the output of the second frequency the discriminator is connected to the input of the Doppler information processing unit, and the control inputs of the third two-input analog key and the Doppler information processing unit are dineny to the respective outputs of the control unit; the outputs of three detectors from parallel-connected chains of the second channel with frequencies 2f ₁ , 2f ₂ , f _{+ are} connected through three amplitude meters with three inputs of the computing unit, the output of which is connected to the fourth input of the information display device, and to the on-board equipment installed on the carrier object , includes all blocks, starting with two groups of acoustic transducers that are in acoustic contact with the emitting electro-acoustic transducer of the pinger beacon, and ending with the control unit.