RU2348054C1 - Echo sounder for water anomaly identification - Google Patents

Abstract

FIELD: physics, acoustics.

SUBSTANCE: invention concerns acoustic location systems and is intended for continuous identification of water anomalies from running vessel or manned submarine apparatus. Echo sounder includes display 1, controller 2, temporary automatic adjustment unit (TAAU) 3, averaging unit 4, square-law generator 5, multiplier 6, digital filtration unit 7, analog-to-digital converter (ADC) 8, electroacoustic receiver 9, memory unit 10, transmitter 11, reception/transmission switchboard 12, two-dimension; averaging unit 13, mode and parameter assignment console 14, threshold comparison unit 15, anomaly classification unit 16.

EFFECT: extended functional capacities of echo sounder due to identification and classification of water anomalies.

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Description

The invention relates to acoustic location systems and is intended for continuous recognition of anomalies in the aquatic environment from a moving vessel or inhabited underwater vehicle.

An anomaly of the aquatic environment is a region of the water body where the statistical characteristics of the ocean fields significantly differ from the background values. Methods for recognizing anomalies of the aquatic environment are widely used in ocean research in the interests of shipping, the ecology of the aquatic environment, including the extraction of mineral resources on the shelf, to determine the technogenic impact of economic activity and the navy on pollution of the hydrosphere, and in solving other applied problems.

Recognition of anomalies in the aquatic environment consists in determining the presence of an anomaly and the reason for its formation: the anomaly is caused by natural processes in the ocean or anthropogenic impact on the aquatic environment.

Various acoustic systems are known that are used to determine the state of the aquatic environment and to recognize objects (see, for example, [1] - [5]).

In particular, in an echo sounder [4], which contains a synchronizer, a pulse generator, a piezoelectric vibrator, an amplifier, a detector, a threshold device, an indication unit, a time interval measuring device, an automatic gain control unit (VARU), and a VARU unit, it is possible to stationaryize the amplitude of the echo signals, which varies with depth. In this echo sounder, the use of a non-adaptive threshold device under conditions of a changing noise level makes it difficult to correctly detect echo signals from the bottom.

The acoustic distance measuring system described in the source [5] contains a microprocessor, memory, a number of interfaces, a digital-to-analog converter, a display, a transmitter, a receiver, an analog-to-digital converter, and an electro-acoustic converter. In this system, constant power is periodically emitted by the transmitter, the receiver is made logarithmic, that is, its gain according to the logarithmic law depends on the amplitude of the input signal. The output signal from the receiver is digitized by an analog-to-digital converter, and fed to the microprocessor for the purpose of detecting the echo signal from the bottom and measuring the distance to it, using an adaptive detection threshold, the level of which depends on both the signal amplitude and the noise level, which allows you to confidently detect echo signals from the bottom against the background of interference of false signals.

Also known is the echo sounder [6], which, by its technical nature, is closest to the proposed one. This echo sounder contains a microcontroller, a transmitter, a receiver, and an analog-to-digital converter in series, the output of which is connected to a microcontroller, as well as an electro-acoustic transducer (electro-acoustic antenna) connected to the transmitter and a receiver, and a display, the input of which is connected to the microcontroller, contains new signs, namely: a temporary automatic gain control unit, the input of which is connected to the microcontroller, and the transmitter is made with step-wise power adjustment, input The adjustment signal of which is connected to the microcontroller, the receiver is made with two gain control inputs, the first adjustment input, which provides step-by-step gain control, is connected to the microcontroller, and the second adjustment input is connected to the output of the temporary automatic gain control unit.

The disadvantage of the echo sounder adopted as a prototype is the inability to detect and recognize anomalies in the aquatic environment with high reliability. For known echo sounders, anomalies in the aquatic environment are interferences in their work and measures have been taken to reduce their impact.

The problem solved by the invention is to expand the functionality of the echo sounder by ensuring the detection and classification of anomalies in the aquatic (marine) environment.

The essence of the invention lies in the fact that in the echo sounder for recognizing anomalies in the aquatic environment, containing a controller and a transmitter connected in series, the input of which parameters of the emitted signal is connected to the controller, a display and a temporary automatic gain control unit connected by inputs to the controller, an analog-to-digital converter, as well as an electro-acoustic antenna, a receive-transmit switch connected to the output of the transmitter is introduced, the output of which is connected to the input of the analog-to-digital conversion call, and the input-output is connected by a bi-directional bus to the electro-acoustic antenna, a digital filtering unit is connected in series, connected by an information input to an analog-to-digital converter, and a control input is connected to a controller, a multiplier connected by a second input to a temporary automatic gain control unit, a quadrator and a unit averaging, connected by the control input to the controller output, and by the output - to the controller input, a memory block connected in series, connected to the information and control the inputs to the controller, a two-dimensional averaging unit connected by a control input to the controller output, a threshold comparison unit and an anomaly classification unit, the information input of which is connected to the output of the memory unit, the control input - with the controller output, and the output - with the second controller input.

In addition, the echo sounder may contain an anomaly classification unit, the first input of which is a threshold value input, the second, third and fourth inputs are connected respectively to the output of the detection unit, the output of the memory unit and to the controller output to which the output of the anomaly classification unit is connected, while The classification of anomalies contains four threshold elements, two two-input elements And, two counters, two decoders and a three-input element And, while the outputs of the first and second threshold elements are connected to the inputs of the first two-input element And, the outputs of the third and fourth threshold elements are connected to the corresponding inputs of the second two-input element And, the outputs of the first and second two-input elements And are connected to the clock inputs of the first and second counters connected by the outputs to the inputs of the first and second decoders, the outputs of which are connected with the first and second inputs of the three-input element AND, the first inputs of all threshold elements and the second inputs of the decoders are connected to the first input of the ano classification block malium, the third input and output of the three-input element And are connected respectively to the second input and output of the anomaly classification block, paired the second inputs of the first and second, third and fourth threshold elements are connected to the third input of the anomaly classification block, and the third inputs of the threshold comparison blocks and inputs the zero settings of the first and second counters are connected to the fourth input of the anomaly classification block.

The invention is illustrated by drawings, which depict:

figure 1 is a functional diagram of an echo sounder;

figure 2 is a functional block diagram of the classification of anomalies;

figure 3 is a functional diagram of an echo sounder with remote control modes and parameters.

Figure 1-3 marked:

1 - display;

2 - controller;

3 - block automatic temporary adjustment (VARU);

4 - averaging unit;

5 - a quadrator;

6 - multiplier;

7 - digital filtering unit;

8 - analog-to-digital Converter (ADC);

9 - electro-acoustic antenna;

10 - memory block;

11 - transmitter;

12 - receive-transmit switch;

13 - block two-dimensional averaging;

14 - remote control settings modes and parameters;

15 is a comparison block with a threshold;

16 - block classification of anomalies;

17, ..., 20 - threshold elements;

21, 22 - two-input elements And;

23, 25 - counters;

24, 26 - decoders;

27 - three-input element I.

The proposed echo sounder for recognizing anomalies in the aquatic environment, contains a series-connected controller 2 and a transmitter 11, the input of the parameters of the emitted signal of which is connected to the controller 2, a display 1 and a block 3 of temporary automatic gain control connected to the inputs to the controller 2, an analog-to-digital converter 8, as well as an electro-acoustic antenna 9. The receive-transmit switch 12 is connected to the output of the transmitter 11, the output of which is connected to the input of the analog-to-digital converter 8, and the input-output is connected a bi-directional bus to the electro-acoustic antenna 9. The echo sounder also contains a series-connected digital filtering unit 7 connected by an information input to an analog-to-digital converter 8, and a control input to a controller 2, a multiplier 6 connected to the second input to a block 3 of temporary automatic gain control, a quadrator 5 and averaging unit 4, connected by a control input to the output of controller 2, and by an output - to the input of controller 2, sequentially connected memory block 10, connected by information and control vlyayuschim inputs to the controller 2, the two-dimensional averaging unit 13, a control input connected to the output of controller 2 and the block 15 with the comparison threshold (a detection unit), whose output is the output of detection (Figure 1).

In addition, the echo sounder may include an anomaly classification unit 16, the first input of which is a threshold value input, the second, third and fourth inputs are connected respectively to the output of the detection unit 15, the output of the memory unit 10 and to the output of the controller 2, to which the output of the classification unit 16 anomalies, while the block 16 classification of anomalies contains four threshold elements 17, ..., 20, two two-input elements And 21 and 22, two counters 23 and 25, two decoders 24 and 26 and three-input element And 27. The outputs of the first and second threshold element 17 and 18 are connected to the corresponding inputs of the first two-input element And 21, the outputs of the third and fourth threshold elements 19 and 20 are connected to the corresponding inputs of the second two-input element And 22, the outputs of the first and second two-input elements And 21 and 22 are connected to the clock inputs of the first and second counters 23 and 25 connected by outputs to the inputs of the first and second decoders 24 and 26, the outputs of which are connected to the first and second inputs of the three-input element And 27, the first inputs of all threshold elements 17, ..., 20 and the second inputs of the decoder tori 24 and 26 are connected to the first input of the anomaly classification block 16, the third input and output of the three-input element And 27 are connected respectively to the second input and output of the anomaly classification block 16, the second inputs of the first and second, third and fourth threshold elements 17, ..., 20 are connected to the third input of the anomaly classification block 16, and the third inputs of the threshold elements 17, ..., 20 and the zeroing inputs of the first and second counters 23 and 25 are connected to the fourth input of the anomaly classification block (Fig. 2).

The sounder may also contain a remote control 14 for setting modes and parameters, the outputs of which are connected respectively to the inputs of the settings of the controller 2, block 13 two-dimensional averaging, block 15 comparing with the threshold and the first input of block 16 for classifying anomalies.

For practical implementation of the echo sounder, AXIOM SBC 8360 microcontroller can be used as microcontroller 2 - a single-board industrial-format 3.5-inch computer with Intel's Celeron-1.1 GHz processor with a set of interfaces and an integrated electronic Flash-disk for storing the echo sounder software .

As the transmitter 11, a pulse amplifier assembled according to a bridge circuit can be used, and by changing the supply voltage of the bridge output stage, the radiated power of the transmitter can be changed. An LCD monitor with a VGA interface can be used as a display.

Block 3 VARU can be implemented on the basis of a counter, the synchronization of which should be carried out by the controller 2, sorting through the addresses of the permanent storage device in which the law VARU is recorded.

Blocks 3 through 8 form the receiving path.

Blocks 11, 12 form a transmission path.

The device blocks provide the following functions:

Electro-acoustic antenna 9 - reception and transmission of acoustic signals.

Display 1 - displays the background signal level and anomalies.

Controller 2 - control: the operation of the reception paths, the transmission of information processing and the distribution of information flows.

Blocks 10, 13, 15, 16 - information processing, while:

- block 10 - storage of data about the received signal horizontally and vertically;

- blocks 13, 15 - selection (detection) of anomalies in relation to the background signal level;

- block 16 - assignment of the anomaly to one of two classes:

a) an anomaly of natural origin;

b) the anomaly is caused by anthropogenic impact on the aquatic environment.

Remote control 14 settings and parameters - enables and disables the fish finder and sets parameter values:

a) the radiation power, period and duration of the sending signal of the transmitter 11;

b) the bandwidth of the digital filtering unit 7;

c) the law of the Varu block 3;

d) the averaging time constant of averaging blocks 4 and 13;

d) the threshold value of the block 15 comparison with the threshold;

e) the values of the parameters of block 16 classification of anomalies.

In block 16 classification of anomalies (see figure 2):

The threshold elements 17 and 18 and the element And 21 determine the fact that the horizontal size of the anomaly in a particular period of radiation falls into the range of values corresponding to the anomaly of technogenic origin.

The threshold elements 19 and 20 of the comparison with the threshold and the element And 22 determine the fact that the vertical size of the anomaly in a particular range element falls into the range of values corresponding to the anomaly of technogenic origin.

Counters 23 and 25 calculate the general quality of hits, which respectively determine the horizontal and vertical sizes of anomalies of technogenic origin.

The decoders 24 and 26 are triggered when the counters reach certain values that ensure high reliability of the classification of anomalies.

Element And 27 opens when the decoders are triggered and the logical unit signal arrives from the comparison unit 15 with a threshold, indicating the detection of an anomaly.

The work of the echo sounder is as follows.

The probe signal of ultrasonic frequency (with the set parameter values) from the transmitter 11 through the switch 12, the reception-transmission enters the antenna 9 and is radiated into the aquatic environment. At the time of signal emission, the transmit-receive switch 12 is open in the transmission direction and closed in the reception direction, protecting the receiving path from entering its own sounding signal. The signal reflected from the anomaly of the aquatic environment, which enters the zone of the radiation pattern of the antenna 9, enters through the receive-transmit switch 12 to the receive path. Anomalies of the aquatic environment are characterized by a low effective reflectivity compared with the bottom and the water surface. Signals reflected from anomalies have low contrast with respect to the background and a wide frequency spectrum, and the background signal level can vary over a wide dynamic range. Therefore, the receiving path of the echo sounder should be broadband, have high sensitivity and a wide dynamic range. To ensure the specified technical characteristics, the receiving path is made digital. The reflected signal passing through the receive-transmit switch 12 is immediately digitized by a multi-bit (16 ÷ 24 bit) analog-to-digital converter 8 (without preliminary analog amplification) and goes to the digital filtering unit 7. In block 7 of digital filtering, band-pass filtering of the reflected signal is performed. The passband of the filter is consistent with the duration of the probe signal. When changing the duration of the probe signal from the remote control 14 changes and the passband of the filter. The digital filter has a high bit depth and a negligible level of intrinsic noise.

The filtered signal enters the multiplier 6, where it is multiplied by the VARU coefficient, which varies in distance to equalize the signal level reflected from anomalies located at different distances from the equipment carrier. The law of variation of the VARU coefficient is generated by block 3 and can be the same for all conditions or set from the panel 14. The output signal of the multiplier 6 is squared by block 5 and averaged in averaging block 4. At the output of block 4, a signal is generated proportional to the square of the envelope of the signal. To efficiently isolate a low-contrast useful signal with respect to the interfering background, the principle of energy storage for a number of radiations of the probe signal is used. The number of accumulated reflected signals depends on the time during which the anomaly falls into the antenna pattern. This time depends on the width of the radiation pattern, the velocity of the carrier of the equipment, the period of radiation of the probe signal and the size of the anomaly horizontally. In addition to the energy storage along the horizontal size of the anomaly, the signal energy is stored along the vertical size of the anomaly. The vertical size of the anomaly takes a number of range elements. The magnitude of the range element is determined by the duration of the probe signal.

The accumulated values of the envelope squared are stored in the memory unit 10, where they come from the averaging unit 4 through the controller 2.

, и в блок 16 классификации аномалий.If the number of effectively accumulated radiation periods is N, and the number of effectively accumulated range elements is M, then the total number of used cells of the memory unit 10 is N · M words (N words horizontally and M words vertically). The accumulated values of the envelope square vertically and horizontally enter block two-dimensional averaging, performing a typical operation of two-dimensional averaging

, and in block 16 classification of anomalies.

The average value is compared in block 15 of the comparison with the threshold set, for example, from the remote 14. When the threshold is exceeded, indicating the allocation of anomalies, an anomaly detection signal is generated.

Classification of anomalies is carried out by block 16 classification of anomalies by the detection signal generated by block 15.

The main classification features that make it possible to divide anomalies into two classes — a natural anomaly or an anomaly of technogenic origin — are the horizontal and vertical dimensions of the anomaly. Anomalies of technogenic origin have a certain range of horizontal and vertical sizes, and the vertical size of the anomalies is always smaller than the horizontal size.

In block 16, it is checked that the horizontal and vertical sizes of the anomalies fall within the specified allowable limits, and the tolerance on the vertical size is always narrower than on the horizontal.

If the conditions for falling within the specified limits are met, then at the output of the anomaly classification block 16 a logical unit signal is generated (high level), indicating that the detected anomaly is of technogenic origin. Otherwise, a logical zero signal (low level) is formed indicating that the detected anomaly is of natural origin. The signal from the output of the block 16 classification of anomalies enters the controller 2, which gives a display 1 signal to visualize on the screen a sign of anomaly class. The display also shows the envelope signal coming from the output of the averaging unit 4, i.e. all anomalies (if any) and the average background level of the aquatic environment.

Block 16 classification of anomalies can be implemented in various ways.

In the embodiment shown in figure 2, the operation of block 16 classification of anomalies is as follows.

The values of the envelope squares corresponding to the samples of the horizontal and vertical size of the anomalies are sequentially supplied from the memory unit 10 to the information input 3 of the anomaly classification block 16. Each incoming value of the horizontal size of the anomaly is compared in the threshold elements 17 and 18 with a threshold, respectively, with the lower and upper boundary value of the horizontal size of the anomaly established from the panel 14 from the input 1 of block 16. At the time of the next count of the horizontal size of the anomaly, the threshold elements 17 and 18 open a control signal from the controller to the input 4 of the block 16 for classifying anomalies and to the third inputs of the threshold elements 17 and 18. When the next horizontal p For example, within the specified tolerance (between the lower and upper values) at the outputs of the threshold elements 17 and 18, logical unit signals are generated that are fed to the inputs of the And 21 element, the output of which appears a logical unit signal counted by the counter 23. When the number accumulated in the counter reaches threshold value, on which the decoder 24 from the console 14 is pre-installed, the recorded signal of a logical unit at the decoder output.

The operation of the block 16 classification of anomalies upon receipt of samples of the vertical size of the anomaly occurs similarly.

In this case, the blocks 19, 20, 22, 25 and 26 are triggered in a similar way. When the vertical size falls within the specified tolerance, the decoder 26 is triggered and a logical unit signal is generated at its output. If an anomaly is detected, a logical unit signal acts at the input 2 of block 16, while the signals of a logical unit act on all inputs of the And 27 element. At the output of element And 27, a signal of a logical unit appears, which means that the detected anomaly is of technogenic origin.

All modes and parameters of the echo sounder can be fixed or set by the operator using the remote control 14 (see figure 3). In this case, the necessary power of radiation, the period and duration of sending the signal of the transmitter 11 are set on the control panel 14 for setting the modes and parameters. In addition, the passband of the digital filtering unit 7, the VARU law of the unit 3, and the averaging time constants of the averaging units 4 and 13 are set on the remote control 14. , the threshold value of the comparison block 15 with the threshold, the parameter values of the block 16 classification of anomalies. Parameters are set from the keyboard included in the remote control 14. The values of these parameters installed on the remote control 14 depend on the coordinates of the location, depth of the sea, time of year, the speed of movement of the equipment carrier and the typical hydrological characteristics of the aquatic environment for a given navigation area obtained from marine atlases (sound velocity in water, salinity, temperature depending on the depth). The basic values of the parameters for a particular navigation area are usually set before starting work in this area and can be refined during the work in the area. The parameters are transmitted to the transceiver path from the console 14 through the controller 2 to blocks 3, 4, 7, 11, and to blocks 13, 15, 16 - directly from the console 14.

The high efficiency of recognition of anomalies in the aquatic environment is provided by the following new technical solutions incorporated into the invention:

1. The receiving path of the echo sounder is digital, which can significantly reduce the level of intrinsic noise, provide a wide dynamic range of the receive path, provide signal reception in the entire necessary frequency range, significantly increase the sensitivity of the receive path, resulting in high-quality reception of low contrast (relative to the background level) of the signal reflected from anomalies in the aquatic environment.

раз. При средних значениях размеров аномалий, типовых значениях параметров зондирующего сигнала, ширины диаграммы направленности антенны и скорости движения носителя величина

составляет от 400 до 800, что обеспечивает увеличение отношения сигнал/шум от 20 до 28 раз. Это обеспечивает надежное обнаружение аномалий водной среды.2. The energy accumulation of the reflected signals is applied both over the entire horizontal size of the anomaly for N periods of radiation of the probe signal, and over the total vertical size of the anomaly, determined by the number of elementary discrete ranges M, as a result, the total number of accumulated reflected signals is N · M, which is equivalent to an increase signal to noise ratios at approximately

time. With average values of the size of the anomalies, typical values of the parameters of the probing signal, the antenna radiation pattern width and the carrier velocity

ranges from 400 to 800, which provides an increase in signal-to-noise ratio from 20 to 28 times. This provides reliable detection of anomalies in the aquatic environment.

3. High classification efficiency is ensured by the selection of classification features based on a wide experimental material obtained during many years of oceanological research and the corresponding construction of block 16 for classification of anomalies.

Thus, the technical result is to ensure the detection and classification of anomalies in the aquatic, mainly marine, environment.

The high technical efficiency of the invention is confirmed by sea trials of the model of the echo sounder.

Industrial applicability of the invention is determined by the fact that the proposed echo sounder can be manufactured according to the above description and drawings using known means for recognizing (detecting) anomalies in the aquatic (marine) environment.

Information sources

1. RF patent No. 1669288, IPC G01S 15/08, publ. 09/27/1999.

2. RF patent No. 2045081, IPC G01V 1/38, publ. 09/27/1995.

3. Application for invention No. 94025298 (G01S 15/00)

4. RF patent No. 2123191, IPC G01S 15/00, publ. 12/10/1998.

5. European patent A2 0340953, IPC G01S 7/52, G01S 15/88, publ. 11/08/1989.

6. RF patent №2241242, IPC G01S 15/08, publ. 11/27/2004 (prototype).

Claims (2)

1. An echo sounder for recognizing anomalies in the aquatic environment, comprising a controller and a transmitter connected in series, the input of which parameters of the emitted signal is connected to the controller, a display and a temporary automatic gain control unit connected by inputs to the controller, an analog-to-digital converter, and an electro-acoustic antenna, characterized in the fact that it includes a receive-transmit switch connected to the output of the transmitter, the output of which is connected to the input of the analog-to-digital converter, and the input - the output is connected by a bi-directional bus to the electro-acoustic antenna, a digital filtering unit connected in series, connected by an information input to an analog-to-digital converter, and a control input to a controller, a multiplier connected by a second input to a temporary automatic gain control unit, a quadrator and an averaging unit connected by a control an input to the controller’s output, and an output to the controller’s input, the memory block connected in series to the information and control inputs to to the controller, a two-dimensional averaging unit connected by the control input to the controller output, and a comparison unit with a threshold. 2. The echo sounder according to claim 1, characterized in that it further comprises an anomaly classification unit, the first input of which is a threshold value input, the second, third and fourth inputs are connected respectively to the output of the comparison unit with a threshold, the output of the memory unit and the controller output, to to which the output of the anomaly classification block is connected, while the anomaly classification block contains four threshold elements, two two-input elements And, two counters, two decoders and a three-input element And, while the outputs of the first and second thresholds x elements are connected to the corresponding inputs of the first two-input element And, the outputs of the third and fourth threshold elements are connected to the corresponding inputs of the second two-input element And, the outputs of the first and second two-input elements And are connected to the clock inputs of the first and second counters connected by the outputs to the inputs of the first and second decoders the outputs of which are connected to the first and second inputs of the three-input element And, the first inputs of all threshold elements and the second inputs of the decoders are connected to the first at the input of the anomaly classification block, the third input and output of the three-input element And are connected respectively to the second input and output of the anomaly classification block, the second inputs of the first and second, third and fourth threshold elements combined in pairs are connected to the third input of the anomaly classification block, and the third inputs of the comparison blocks with a threshold and the zero inputs of the first and second counters are connected to the fourth input of the anomaly classification block.

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