RU2528113C1 - Active sonar - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: invention enables to determine the class of a detected object based on a set of transmissions with identification of echo signals in the series of transmissions.

EFFECT: high probability of correct classification of a detected object.

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Description

The invention relates to sonar technology, and more particularly to the field of active sonar, including active sonar, designed to detect objects, measure coordinates and motion parameters of detected objects, classify detected objects.

Known active sonar (RF patent No. 2346295) containing acoustic emitting and receiving antennas, a device for generating a sounding signal, a generating device, a control device, a device for generating directivity characteristics, a unit for measuring the delay time of an echo signal relative to the moment of emission of a sounding signal, a unit for measuring the angle of arrival echo in the vertical plane, block measuring the depth of the target. However, this sonar does not have a classification system for detected objects.

Known active sonar with object classification (US patent No. 3716823, NKI 340-3R), containing a serially connected control device, a device for generating a sounding signal, a generating device and a radiating acoustic antenna, a serially connected receiving acoustic antenna, a device for processing echo signals from the object and device for measuring the classification parameter (echo spectrum analyzer), a memory cell with reference spectra of echo signals from known objects, a computing device ystvo with which comparison is made of the spectral components of the echo signals with reference spectra and light.

The disadvantage of this device is that the development of a decision on the class of the detected object is made only on one premise, which reduces the reliability of solving the classification problem of the object.

By the number of common features, the closest analogue of the invention is an active sonar containing a serially connected control device, a device for generating a sounding signal, a generating device and a radiating acoustic antenna, a serially connected receiving acoustic antenna, a device for generating directivity characteristics, and an device for processing echo signals from an object, device for measuring the radial velocity of the VIR object, device for measuring the distance to about object D, a device for measuring the heading angle to the object KU, a block of motion parameters of the sonar carrier, an indicator, while the first output of the device for processing the echo signals from the object is connected to the input of the device for measuring the radial velocity of the object VIR, the input of the device for measuring the distance to the object D and the device input measuring the course angle to the KU object (Handbook of hydroacoustics. A. Evtyutov, A. Kolesnikov, E. A. Korepin and others, 2nd ed., L .: Sudostroenie, 1988. P.18-26 , Mittko V.B., Evtyutov A.P., Gushchin S.E. Hydroacoustic communications and surveillance. L .: Shipbuilding, 1982. P.125).

The disadvantage of the prototype device is the lack of a classification system for detected objects, as well as an identification system in the presence of echo signals from several objects when a series of packages is emitted.

The technical result of the invention is to provide a high probability of correct classification of the detected object by realizing the possibility of developing a class of the detected object from the totality of the premises. In addition, for the effective operation of the sonar with the classification and development of a decision on the class of an object from the set of packages, the identification of echo signals in a series of packages is provided.

To achieve the technical result, an active sonar containing a serially connected control device, a device for generating a sounding signal, a generator device and a radiating acoustic antenna, also containing serially connected a receiving acoustic antenna, a device for generating directivity characteristics and a device for processing echo signals from an object, also containing device for measuring the radial velocity of an object (VIR), a device for measuring the distance to objects that (D), a device for measuring the heading angle to the object (KU), a block of motion parameters of the sonar carrier and an indicator, while the first output of the device for processing the echo signals from the object is connected to the input of the VIR measuring device, the input of the measuring device D and the input of the KU measuring device , new features have been introduced, namely, the VIR, D, KU memory block, the D comparison block, the KU comparison block, the object coordinate identification block by a number of parcels, the classification parameter measuring device connected in series, the Pos detection unit t _N , where Papost _N is the posterior probability density of the object class according to the current premise N, the determination block Ppost _F , where Poppost _F is the posterior probability density of the object class according to the set of premises F and the block for making a decision about the class of the object from the set of premises, a memory block is also introduced _April P where P _April - priori distribution density classification parameter values, a memory unit Papost _F, wherein the second output device processing the echo signals from the object is coupled to the input of the classification device measurement pairs the outputs of the VIR measuring device, the measuring device D, the measuring device KU are connected to the first input of the VIR, D, KU memory block, the second output of the control device is connected to the second input of the VIR, D, KU memory block, and the first and second outputs of the latter are connected to the first inputs of the comparison block D and the comparison block KU, respectively, the first and second outputs of the block of motion parameters of the sonar carrier are connected to the second inputs of the comparison block D and the comparison block KU, respectively, the outputs of the comparison block D and the comparison block KU with connected to the first and second input of the unit for identifying the coordinates of the object for a number of parcels, and its output is connected to the second input of the determination unit Papost _F , the output of the memory unit P _{apr is} connected to the second input of the determination unit Papost _N , the second output of the determination unit Papost _{F is} connected to the input of the unit memory Papost _F , and its output is connected to the third input of the determination unit P _apost F, the output of the decision block on the class of the object from the set of premises is connected to the indicator input.

The specified technical result is achieved due to the fact that the class of the detected object is determined by the set of packages, and echo signals are identified when a series of packages is emitted, taking into account the possibility of detecting different objects in different packages, for example, in the overview mode of sonar operation. At the same time, statistical classification methods are used to develop a decision on the class for individual premises (see Gorelik A.L., Skripkin V.A. Recognition Methods. Moscow: Vyssh. Shkola, 1984. P.26-32). a priori probability densities of the values of the classification parameter for objects of different classes Papp (known in advance the probability distributions of the values of the classification parameter for objects of different classes) and after determining an a posteriori probability of the presence of objects of these classes after echo detection in Papost (probability assignment of the detected object to the class based on the measured values of sending a separate classification parameter). The technical result is obtained in the joint work of the newly introduced blocks, the connections between them and the connections of these blocks with other sonar blocks.

The invention is illustrated in figure 1, which shows a block diagram of the proposed active sonar.

The active sonar contains a series-connected control device 5, a device 4 for generating a sounding signal, a generator 3 and a radiating acoustic antenna 1, a series-connected receiving acoustic antenna 2, a device 6 for forming directivity characteristics and a device 7 for processing echoes from an object, a device 8 for measuring VIR , device 9 for measuring D, device 10 for measuring KU, unit 13 for the parameters of motion of the sonar carrier, indicator 22, while the first output of the device 7 is it is single with the input of device 8, the input of device 9, and the input of device 10. Also, the active sonar contains a block 12 of memory VIR, D, KU, block 14 for comparing D, block 15 for comparing KU, block 16 for identifying the coordinates of an object from a number of premises, connected in series to device 11 measuring the classification parameter, block 18 for determining the Post _N , block 19 for determining the Post _F and block 21 for deciding on the class of the object from the totality of the packages, block 17 for the memory block, block 20 for the memory for the post _F , while the second output of the device 7 is connected to the input of the device 11, out The odes of device 8, 9, 10 are connected to the first input of block 12, the second output of device 5 is connected to the second input of block 12, and its first and second outputs are connected to the first inputs of blocks 14 and 15, respectively, the first and second outputs of block 13 are connected to the second the inputs of blocks 14 and 15, respectively, the outputs of block 14 and block 15 are connected to the first and second input of block 16, and its output is connected to the second input of block 19, the output of block 17 is connected to the second input of block 18, the second output of block 19 is connected to the input of the block 20, and its output is connected to the third input of block 19, the output d block 21 is connected to the input 22 of the indicator.

The practical implementation of the blocks included in the invention is known from the practice of hydroacoustics.

The memory blocks 12, 17 and 20 can be implemented on the basis of technical solutions given in the book Design of pulse and digital devices of radio systems. / Digital radio navigation devices. / V.V. Barashenkov, A.E. Lutchenko, E.M. Skorokhodov et al. Ed. V.B. Smolova. M .: Sov. Radio, 1980. S.196-200.

Blocks 11 14, 15. 18, 19 can be implemented using microprogram discrete devices, see, for example, the book Design of pulsed and digital devices of radio systems. / Grishin Yu.P., Kazarinov Yu.M., Katikov V.M. et al. Ed. Yu.M. Kazarinova. M .: Higher. school., 1985. S.164-177.

Blocks 16, 21 are performed using a comparison scheme, see, for example, the book Design of pulse and digital devices of radio systems. / Grishin Yu.P., Kazarinov Yu.M., Katikov V.M. et al. Ed. Yu.M. Kazarinova. - M .: Higher. Shk., 1985. P. 15.

The operation of the device is as follows. The device 4 forming a sounding signal generates sounding signals. The sonar emits a probe signal using a generator device 3 and a radiating acoustic antenna 1. The echo signal reflected from the object from the output of the receiving acoustic antenna 2 is fed to the directivity characteristics forming device 6. From the output of device 6, the signal array arrives at device 7, which processes the received signals, and when echo signals are detected from the object, VIR is measured in device 8, D is measured in device 9, KU is measured in device 10, and KU is measured in device 10 measurement of a classification parameter.

The measured parameters VIR, D and KU on each package are received and stored in block 12.

The device 5 controls in time the formation of the probe signal (block 4) and, accordingly, the operation of the generator device 3, as well as block 12, which allows the identification system to work.

When controlling the device 5 from block 12 to the blocks 14, 15, the measured values of D, VIR, KU are received in two consecutive premises, as well as the magnitude of the speed of the sonar carrier from block 13.

In block 14, two distances to the object are compared on the current (j + 1) and previous (j) premises, for example, by the ratio

Δ Д = | (Д _{j + 1} -Д _j ) -ΔT · (VIR _j -V _n · cos (КУ _j )) |,

where D _j is the measured distance to the object on the j-th premise;

D _{j + 1} - the measured distance to the object on j + 1 package;

VIR _j - the measured radial velocity of the object on the j-th premise;

ΔT is the time interval between j and j + 1 parcel;

V _n - the speed of the sonar carrier,

KU _j - measured heading angle to the object on the j-th premise.

In block 15, two KU values are compared taking into account the speed of the medium, for example, by the ratio

$$\Delta \mathrm{TO}\mathrm{At}=\mathrm{TO}{\mathrm{At}}_{j+\mathrm{one}}-\mathrm{TO}{\mathrm{At}}_j-\arcsin \left(\frac{V_n\Delta T}{D_{j+\mathrm{one}}}\cdot \sin \mathrm{TO}{\mathrm{At}}_j\right)$$

where KU _{j + 1} is the measured heading angle per object on j + 1 parcel.

In block 16 from block 14 and block 15, the calculated ΔД and ΔКУ values are transmitted, where these values are compared with threshold values and a decision is made to identify the object in two consecutive premises.

In block 18, based on the a priori probabilities of the values of the classification parameter Papp coming from block 17, and the measured value of the classification parameter Uiz coming from block 11, Papost _{N is} determined, for example, for objects of two classes A ₁ and A ₂ according to the formula:

where Papp, I (Umean) is the value of the a priori probability distribution density of the i-th class (i = 1, 2) developed in block 18 with the measured value of the classification parameter;

The post _N , i is the calculated value of the posterior probability for the current premise for the object of the i-th class.

The calculated value of Papost _N goes to block 19, where on the first parcel n = 1 (n is the number of the parcel), the value Papost _N is transmitted to block 21 and stored in block 20 as the value of Papost _F. On the second premise, when developing an identification sign in block 16, the Papost _{F is} calculated based on the ratio, for example, for two alternative classes:

where Papost _N , i is the calculated value of the posterior probability for the current package;

- вычисленная величина апостериорной вероятности по совокупности предыдущих посылок;

- the calculated value of the posterior probability for the totality of previous premises;

n is the number of the current package.

запоминается в блоке 20 и выдается в блок 21.The calculated value

stored in block 20 and issued in block 21.

, по совокупности предыдущих посылок (первая и вторая посылка) и величине Pапост_N по третьей посылке. На четвертой посылке вычисляется Pапост_F по величине

, по совокупности предыдущих посылок (1, 2 и 3 посылки) и величине Pапост_N по четвертой посылке и т.д.On the third premise, Papost _{F is} calculated in terms of

, according to the totality of the previous packages (first and second package) and the value of Papost _N for the third package. On the fourth premise, the Papost _{F is} calculated in terms of

, by the totality of the previous packages (1, 2 and 3 packages) and the value of Papost _N for the fourth package, etc.

и

, и решение о классе обнаруженного объекта выдается оператору на индикатор 22.In block 21, a decision is made on the class of the object based on Papost _F , for example, to the maximum of the calculated posterior probabilities

and

, and the decision on the class of the detected object is issued to the operator on indicator 22.

Using the VIR, D, KU memory block, D comparison block, KU comparison block, object coordinate identification block for a number of parcels, classification parameter measuring device, Papost _N determination block, Papost _F determination block, decision block making about the object class from the set of parcels, Papr storage unit, the storage unit Papost _F with corresponding connections between these units and the connections of these units with other units active sonar provides a high probability of correct classification of the object detected way realization of the possibility of developing a class of the object detected by the identification chip aggregate echo signals parcels series.

Thus, the task is successfully solved.

Claims (1)

An active sonar containing a serially connected control device, a probing signal generating device, a generating device and a radiating acoustic antenna, also containing a serially connected acoustic receiving antenna, a device for generating directivity characteristics and an device for processing echo signals from an object, also containing a device for measuring the radial velocity of an object ( VIR), a device for measuring the distance to the object (D), a device for measuring the heading angle to the object ( KU), a block of motion parameters of the sonar carrier and an indicator, while the first output of the device for processing the echo signals from the object is connected to the input of the VIR measurement device, the input of the measurement device D and the input of the KU measurement device, characterized in that the VIR memory block is inserted into it, D CG comparing unit D, a comparison unit CU, the block identification object coordinates on a number of parcels, serially connected measurement device classification parameter determination unit Papost _N, where Papost _N - posteriori probability density STI class object for the current sending N, determining unit Papost _F where Papost _F - posteriori probability density of aggregate F parcels object class and the block making decisions about the class object for the aggregate parcels also introduced memory unit Papr where Papr - priori distribution density values classification parameter storage unit Papost _F, wherein the second output device processing the echo signals from the object is coupled to the input of a classification parameter measurement device, the measurement device outputs VIR device and D measurements, KU measuring devices are connected to the first input of the VIR, D, KU memory block, the second output of the control device is connected to the second input of the VIR, D, KU memory block, and the first and second outputs of the latter are connected to the first inputs of the comparison block D and the comparison block KU, respectively, the first and second outputs of the block of motion parameters of the sonar carrier are connected to the second inputs of the comparison block D and the comparison block KU, respectively, the outputs of the comparison block D and the comparison block KU are connected to the first and second input of the identification block uu object coordinates on a number of parcels, and its output is connected to the second input determination unit Papost _F, the storage unit output Papr connected to the second input of the determining Papost _N, the second output detection unit Papost _F connected to the input of the storage unit Papost _F, and its output is connected with the third input of the determination unit Papost _F , the output of the decision-making unit on the class of the object on the basis of the set of premises is connected to the indicator input.