KR101878435B1 - A System and a Method for Monitoring a Fish Farm under Water Using Scanning Sonar with Variable Frequency - Google Patents

Abstract

The present invention is to provide an underwater monitoring system for a fish farm using a variable frequency type scanning sonar, and a method thereof. The scanning sonar comprises a single transducer which transmits transmission ultrasonic waves; a transmission signal amplification unit which generates a transmission signal provided to the single transducer based on a complex modulation signal; a modulation unit which generates the complex modulation signal based on a resonance frequency and an upper limit frequency, and provides the complex modulation signal to the transmission signal amplification unit; a comparison reference signal generation unit which adaptively generates an ultrasonic echo signal obtained from the transmission ultrasonic waves received after being reflected from an outside object, and a comparison reference signal calculated by a reference signal based on the transmission signal; a comparison unit which generates an ultrasonic output signal by comparing the comparison reference signal with the received ultrasonic echo signal; and a signal processing control unit which calculates a distance from the outside object based on the ultrasonic output signal, and controls a long distance mode or a short distance mode based on the calculated distance. In the long distance mode, the transmission ultrasonic waves are transmitted through the resonance frequency. In the short distance mode, the transmission ultrasonic waves are transmitted through the upper limit frequency. Therefore, the underwater monitoring system and method for a fish farm can monitor a long distance and a short distance at the same time by using the scanning sonar including a single transducer in a variable frequency type.

Description

Field of the Invention The present invention relates to a monitoring system for aquaculture underwater using a variable frequency scanning sonar,

The present invention relates to a monitoring system for aquaculture underwater using a variable frequency scanning sonar and a method thereof and more particularly to a monitoring system for aquaculture underwater having a scanning sonar capable of simultaneously monitoring far and near by a variable frequency system ≪ / RTI >

As a conventional underwater surveillance method, a method using a movable side scan sonar and a method of installing a plurality of fixed hydrophone arrays on the seabed have been mainly used.

However, in the case of the method using the side scan sonar, it is necessary to acquire the image while moving the ship after mounting the side scan sonar on a separate vessel every time, so that the application to the floating structure requiring a wide range of real- There is a limit. In addition, the method of installing the fixed hydrophone array has a limitation in the installation in a wide area. Since the once installed hydrophone array can not change the detection cycle and the detection resolution, various types of underwater intruders having different speeds and sizes can be flexibly monitored There is a limit to building a general-purpose sensing system as much as possible.

In order to overcome these drawbacks, a system has been proposed for detecting a penetrating person or an infiltrating object at a distance or a near vicinity of a marine floating structure such as a farm site by using a plurality of scanning sonar arranged in a band shape in the sea surface or underwater there was.

(Patent Document 1) KR10-1268402B

However, in the conventional system, since a rotary scanning sonar having two transducers opposed to each other having different scanning frequencies is mounted in one housing, the system construction cost is high and it is difficult to adopt it for underwater surveillance in a small scale farm etc. .

Therefore, it is urgently required to develop a mid-low-cost high resolution monitoring system for surveillance alarms that can detect infiltration objects at a distance or a close distance while replacing expensive high-resolution transducers.

SUMMARY OF THE INVENTION The present invention has been made in order to meet the above-mentioned needs, and it is an object of the present invention to provide a monitoring system for aquaculture underwater which can simultaneously monitor a long distance and a short distance using a scanning sonar having a single frequency transducer / RTI >

A monitoring system for aquaculture underwater according to an embodiment of the present invention includes: a single transducer for transmitting a transmission ultrasonic wave; A transmission signal amplifying unit for generating a transmission signal provided to the single transducer based on the composite modulation signal; A modulator for generating the complex modulation signal based on the resonance frequency and the upper frequency limit and providing the composite modulation signal to the transmission signal amplifier; A comparison reference signal generator for adaptively generating the comparison reference signal calculated by the ultrasonic echo signal reflected from the external object and the reference signal based on the transmission signal; A comparison unit for comparing the comparison reference signal with the received ultrasonic echo signal to generate an ultrasonic output signal; And a signal processing controller for calculating a distance to the external object based on the ultrasonic output signal and controlling the remote mode and the near mode on the basis of the calculated distance. In the remote mode, When the transmitting ultrasonic wave is transmitted at the resonant frequency and in the short-range mode, the transmitting ultrasonic wave can be transmitted at the upper limit frequency.

In this case, the modulator may generate the first frequency modulated wave based on the first carrier and the first frequency control signal, and generate the second frequency modulated wave based on the second carrier and the second frequency control signal.

The modulator may generate the first complex modulated wave and the second composite modulated wave having the controlled amplitude by controlling the duty ratio of the first frequency modulated wave and the second frequency modulated wave, respectively.

The composite modulation signal may further include: a synchronization signal indicating the start of the composite modulation signal; A header including far or near mode information; An ID signal which is a unique number of a scanning sonar; A scan signal used for detecting the external object, and a parity signal for determining whether the composite modulation signal is erroneous.

The reference signal generator may include an exclusive-OR circuit that receives the received ultrasonic echo signal and the reference signal and generates an exclusive-OR (XOR) signal. And integrating the exclusive-OR signal to generate a comparison reference signal adaptively.

The monitoring system and method for monitoring aquaculture underwater according to the present invention as described above can change the frequency according to characteristics of environment / distance by utilizing a scanning sonar equipped with a low-cost single transducer. Therefore, significant cost reduction is possible compared to farm monitoring system using existing high-priced dual transducers.

In addition, the monitoring system for aquaculture underwater according to the present invention is advantageous for commercialization since the system configuration is simple and applicable to various environmental conditions so that it can be applied to small scale farms.

In addition, the monitoring system for aquaculture underwater according to the present invention can monitor a near / far approaching object using a scanning sonar having a single transducer, and can realize a high-resolution surveillance system with only a mid-sized scanning scanner. In addition, it is possible to monitor underwater environmental condition and structure health, underwater theft in the farm, and to monitor the detection of the dangerous object. Of course, the scope of the present invention is not limited by these effects.

1 is a diagram illustrating a farm monitoring system according to an embodiment of the present invention.
2 is a diagram illustrating a scanning sonar according to an embodiment of the present invention.
3 is a view illustrating a sonar processing unit and a motor driving unit according to an embodiment of the present invention.
4 is a view showing equivalent circuits and transmission curves of the transducer resonator of the scanning sonar according to the embodiment of the present invention.
5 is a diagram illustrating a frequency modulated wave according to an embodiment of the present invention.
6 is a diagram illustrating amplitude modulation according to an embodiment of the present invention.
7 is a diagram illustrating a transmission protocol of a composite modulation signal according to an embodiment of the present invention.
8 is a diagram illustrating a transmission signal amplifier according to an embodiment of the present invention.
9 is a diagram illustrating a transmission signal according to an embodiment of the present invention.
10 is a diagram illustrating operations of a comparison reference signal generator and a comparison reference signal generator according to an embodiment of the present invention.
11 is a diagram for selecting a short-distance remote operation mode through an operation of a comparison unit according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be understood, however, that the invention is not limited to the disclosed embodiments, but may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, Is provided to fully inform the user. In addition, for convenience of explanation, components may be exaggerated or reduced in size.

However, it should be understood that the following embodiments are provided so that those skilled in the art will be able to fully understand the present invention, and that various modifications may be made without departing from the scope of the present invention. It is not.

The variable frequency scanning sonar or underwater monitoring system detects the farm environment in the detection area as a sonar image by setting optimal frequency and sonar characteristics according to the farm environment conditions. Since the optimal detection conditions are different between near and far, it is configured to be able to monitor both near and far distance at the same time by varying frequency and characteristic setting periodically. In addition, an intruder for underwater robbery, a dangerous object, an abnormal state, and an image can be used to display the position (distance, direction) of the detection target and alert the operator with the alarm.

1 is a diagram illustrating a system for monitoring aquaculture underwater according to an embodiment of the present invention.

1, a system 100 for monitoring aquaculture underwater according to an embodiment of the present invention includes an information processing unit 120 and a rotary scanning sonar 10. In accordance with the present invention, the aquaculture underwater monitoring system 100 is capable of monitoring the status of the aquaculture network 170, detecting underwater penetrants 130, monitoring and alerting the aquaculture surface contaminants 160.

The information processing unit 120 of the farm underwater monitoring system 100 according to the present invention is interlocked with the control board 110 of the rotary scanning sonar 10 so that various user settings of the rotary scanning sonar 10, Or the like, or may store information generated from the sonar.

2, the rotary scanning sonar 10 includes an acoustic lid 11, a transducer 12, a slip ring 14, a control board 110, a stepping motor 20, a housing 18, (19).

The transducer 12 converts a voltage signal supplied from the control board 110 into a pressure signal (sonar signal) and outputs the signal to the outside. The transducer 12 converts the externally reflected signal or received signal into a voltage signal To the control board 110 mounted at the lower end.

However, according to the embodiment of the present invention, the transducer 12 is a single transducer, and the rotary scanning sonar 10 of the present invention transmits a sonar having a plurality of frequencies and a plurality of amplitudes in a single transducer. Therefore, it is distinguished from a scanning sonar having a scanning sonar transmitting a single frequency and amplitude and a plurality of transducers having each single frequency in a conventional single transducer.

On the other hand, the rotation of the transducer 12 is performed by a fixed stepping motor 20 fastened to the transducer. At this time, the faster the rotational speed of the stepping motor 20, the lower the resolution of the image, while the speed of the image increases. At this time, the control of the stepping motor 20 is performed by the motor control unit of the acoustic signal processing board 17 mounted at the lower end. Since the transducer 12 is rotated by the stepping motor 20, electrical connection with the control board 110 at the lower end is made through the slip ring 14. [ Further, since it is difficult to fasten the transducer directly to the stepping motor, the housing 18 in which the transducer 12 is installed can be provided and the housing can be fastened to the stepping motor 20. [

The control board 110 is formed of a printed circuit board (PCB) and is shielded by an aluminum bulkhead from the upper slip ring 14 for minimizing external noise. The transducer 12 and the control board 110 are connected to the panel-rate connector 15 for connection of the signal transmitted from the slip ring 14.

The control board 110 may include a sonar processing unit 300 and a motor driving unit 400 as shown in FIG. 3. Detailed operations of the sonar processing unit 300 will be described later in detail with reference to FIG. 3 to FIG.

The motor driving unit 400 is controlled by the user interface or setting of the information processing unit 120 and controls the stepping motor 20 through a stepping driver (motor driver) 420. Also, the current position of the motor is sensed through the position sensing sensor 440. The orientation of the transducer 12 can thus be determined.

The outside of the scanning sonar 10 is structured such that the control board 110, the transducer 12, and the like are placed in a waterproof housing 18 for operation in water. The upper part of the transducer 12 through which acoustic signals pass is composed of an acoustic lid 11 which is separately manufactured to increase the transmittance of the acoustic signal. The acoustic transducer 12 includes a housing 18 for signal transmission with the information processing unit 120 The watertight connector 19 can be mounted. In this case, the outer portion, which is in contact with the sea of the scanning sonar 10, may be formed of aluminum material except for the acoustic cover.

As described above, by installing the scanning sonar (including the rotary scanning sonar) around the floating structure of the ocean, it becomes possible to detect / monitor the penetration water, the underwater sediment and the fishery condition of the farm.

Hereinafter, the sonar transmission / reception of the rotary scanning sonar 10 according to the embodiment of the present invention will be described in detail with reference to FIG. 3 to FIG.

First, the frequency range of ultrasonic waves used by the rotary scanning sonar 10 of the present invention will be described with reference to Figs. 4 (a) to 4 (c). Fig. 4 (a) shows an equivalent circuit of the transducer resonator of the rotary scanning sonar according to the embodiment of the present invention, and Fig. 4 (b) shows the transfer curve of the equivalent circuit. 4 (c) is a diagram for a resonance bandwidth according to the fidelity (Q) such as a general resonance frequency and a half power point. On the other hand, the capacitance, inductance, resistance, and frequency values shown in the equivalent circuit and transfer curve shown in Figs. 4 (a) and 4 (b) are all examples, and the present invention is not limited thereto.

Basically, the scanning sonar 10 according to the embodiment of the present invention uses the resonant frequency Fr and the upper frequency Fh. In this case, the scanning sonar performs monitoring in aquaculture water at a resonant frequency (for example, 675 kHz), and when the object is detected at a long distance, it is variable to a low frequency, and when an object is detected at a short distance, it is variably detected at a high frequency.

A conventional scanning sonar or ultrasonic transceiver mainly utilizes the resonance frequency (Fr) or its surrounding frequency in order to maximize the transmission / reception efficiency. That is, in a typical scanning sonar, it is configured to transmit and receive an ultrasonic wave using a fixed single frequency in consideration of the efficiency of the frequency of the resonant frequency (Fr) or its surroundings as much as possible. In this case, the conventional rotary scanning sonar 10 utilizes a sonar having a narrow bandwidth (or a high Q value) to improve the resolution of the ultrasonic image and remove the noise. Particularly, in order to utilize the high-band sonar, a high Q value is preferred in order to increase the amplification degree, and the construction cost of the scanning sonar is remarkably increased.

However, in order to reduce the cost, the rotary scanning sonar 10 according to the embodiment of the present invention utilizes both frequencies of the resonant frequency Fr and the upper limit frequency Fh in a single transducer. The upper limit frequency means a higher frequency of the frequency when the value is 1 / √2 times the maximum value in the transfer curve. In particular, the rotary scanning sonar 10 applies a resonant frequency Fr of, for example, 675 kHz in a remote area (for example, an area between 5 m and 50 m) in consideration of the size of fishing nets, The upper limit frequency Fh, for example, 900 kHz can be applied.

Therefore, it is possible to roughly confirm whether there is an intruding object in the remote area, and in the case where the intruding object approaches closely, it is possible to acquire a high-resolution image using the upper frequency.

The rotary scanning sonar 10 according to the embodiment of the present invention has a structure as shown in FIGS. 3 to 11 for using the resonant frequency Fr and the upper frequency Fh as carriers, Detection can be switched automatically.

3, the sonar processing unit 300 of the rotary scanning sonar 10 according to the embodiment of the present invention includes a signal processing control unit 310, a carrier and signal generating unit 320, a modulating unit 330, The amplification unit 340, the reception signal amplification unit 380, the filter unit 370, the comparison reference signal generation unit 360, and the comparison unit 350.

The signal processing control unit 310 controls the entire process related to the driving of the transducer 12 and the ultrasonic reception, and can determine the mode switching between the near mode and the far mode.

The carrier and signal generator 320 generates a carrier wave and a modulated signal for frequency modulation and amplitude modulation and provides the carrier wave and the modulated signal to the modulator 330.

The modulator 330 generates a signal suitable for the near mode or the remote mode by using the carrier wave and the modulated signal of the carrier and the signal generator 320 and provides the signal to the transmission signal amplifier 340.

Referring to FIG. 5, the carrier and signal generator 320 generates a carrier wave and a control signal required to generate a desired plurality of frequency transducer drive signals. In this case, FIG. 5A shows a first carrier and a first frequency control signal for generating a resonance frequency Fr for driving in a long distance mode, FIG. 5B shows an upper frequency And a second frequency control signal for generating the second frequency control signal Fh. In this case, preferably, the first carrier for generating the resonant frequency Fr utilizes a frequency lower than the second carrier for generating the upper limit frequency Fh.

The modulator 330 generates a first frequency modulated wave by combining the first carrier wave and the first frequency control signal in the long distance mode, and generates a second frequency modulated wave by combining the second carrier wave and the second frequency control signal . At this time, the frequencies of the synthesized first frequency modulated wave and the second frequency modulated wave correspond to the resonant frequency Fr and the upper limit frequency Fh, respectively.

Also, the modulator 330 determines the duty ratio of the first frequency-modulated wave and the second frequency-modulated wave, which determines the amplitude of the ultrasound ultimately transmitted. The duty ratio is determined by the ratio of the ON time of the pulse to the OFF time.

In this case, the duty ratio is determined according to the amplitude control signal (see FIG. 6 (c)), and the first and second frequency modulated waves are combined with the first amplitude control signal and the second amplitude control signal, 1 complex modulated wave and the second composite modulated wave are generated, respectively. For example, the duty ratio of the first composite modulated wave is a value between 0.7 and 0.9 (for example, 0.8, see Fig. 6 (a)) and the duty ratio of the second composite modulated wave is a value between 0.2 and 0.4 An example can be determined by referring to FIG.

When the duty ratio is 30% (0.3), the underwater ultrasonic signal is output at 30% of the maximum value, and when the duty ratio is 80%, the underwater ultrasonic signal is output at 80% of the maximum value. That is, it is possible to adjust the intensity of the output signal through the duty ratio.

The duty ratio of the first composite modulated wave in the long distance mode corresponding to the resonant frequency Fr may be made larger than the duty ratio of the second composite modulated wave in the short range mode corresponding to the high frequency Fh. This is because it is advantageous to shorten the reception time by utilizing ultrasonic waves of small amplitude when generating a high-resolution ultrasonic image through the second complex modulated wave of high frequency.

In other words, while using a single transducer, it is possible to control the size of underwater ultrasonic signal through amplitude modulation, and it is possible to perform near-distance / remote monitoring in aquaculture site. In addition, by adjusting the duty ratio, that is, by controlling the output to a magnitude of 30% for detecting a near object and 80% for detecting a remote object with a duty ratio, an object in the detection area to be detected can be detected with an optimal resolution do.

Therefore, if the frequency and amplitude are varied according to the characteristics of the farm detection environment, it is possible to detect both the near and far detection areas with the optimal resolution. In addition, sonar detection images can be acquired with higher resolution through sonar characteristics setting (Pulse Length, Threshold, TVG Slope, Duty Cycle, Gain, Contrast, Sensitivity). The technology of the farm monitoring system according to the present invention is advantageous for detection of an intruder or a dangerous object for underwater theft approaching from a remote place of the farm than a conventional scanning sonar or a technology for detecting an abnormal condition in a farm or near the farm.

Finally, the first composite modulated wave and the second composite modulated wave are provided to the transmission signal amplification section 340 as a composite modulated signal according to a transmission protocol (shown in FIG. 7) under the control of the transmission control section 315.

Through the above-described frequency modulation and amplitude modulation, it is possible to monitor the pollution state of the marine aquaculture farm, the contamination of the farm net and the damaged state in high resolution in the near mode, and the infiltration personnel and the object detection / alarm of the marine farm in the remote mode.

According to the transmission protocol shown in FIG. 7, the transmission signal according to the embodiment of the present invention can be transmitted at any scanning position in a situation where information capable of automatically determining a near / far distance and a plurality of ultrasonic waves transmitted by other scanning sonar are applied. It is possible to clearly distinguish the transmitted ultrasonic waves.

A transmission signal according to an embodiment of the present invention may include a synchronization signal 710, a header 720, an ID signal 730, a scan signal 740, and a parity signal 750 have.

The synchronization signal 710 is a signal for notifying the start of communication that the received signal is decoded based on the synchronization signal 710 upon reception. The header 720 includes information for identifying the near mode and the far mode. The ID signal is a unique number of the receiving apparatus. In a situation where a plurality of ultrasonic waves transmitted by a plurality of scanning sonars are applied, the ID signal can clearly distinguish the ultrasonic waves transmitted in which scanning sonar according to the ID signal. For example, the ID signal may be a unique number of a scanning sonar including 000 to 777.

Meanwhile, the scan signal 740 is a signal that substantially performs scanning, and the rotary scanning sonar 10 according to the embodiment of the present invention can calculate the distance to an external object based on the scan signal.

The parity signal includes information for checking the error of the transmission signal.

Meanwhile, the composite modulation signal according to the transmission protocol generated by the modulation unit 330 is amplified by the transmission signal amplification unit 340 and transmitted to the transducer 12.

8, the transmission signal amplification unit 340 may include first and second input units 342 and 343, a switching unit 345, and a transforming unit 347. At this time, the transmission signal amplification unit 340 generates a driving signal so as to transmit the composite modulation signal provided from the modulation unit 330 to a target distance, and provides the driving signal to the transducer 12.

The first and second input units 342 and 343 receive the composite modulation signal from the modulation unit 330.

The switching unit 345 is switched based on the complex modulation signal applied through the first and second input units 342 and 343. The switching unit 345 may include a first transistor 345-1 and a second transistor 345-2 as switching elements and may include a first transistor 345-1 and a second transistor 345-2, A grounding portion 346 may be included.

A current flows to the primary side of the transforming unit 347 while the switching unit 345 is switched to induce a voltage to the secondary side. The voltage induced in the secondary side is transmitted to the transducer 12 as a drive signal.

On the other hand, the transducer 12 transmits the ultrasonic signal based on the transmission signal of the transmission signal amplification section 340. The transducer 12 is generally a piezo element, and can transmit ultrasonic waves by repeating shrinkage as the voltage is applied and cut off.

Ultrasonic waves transmitted through the transducer 12 are again received through the transducer 12, and ultimately signals as shown in Figs. 9 (b) and 9 (c) are received.

More specifically, the composite modulated signal according to the present invention is ultimately transmitted as an ultrasonic signal through a transducer. In this case, since the equivalent circuit of the transducer resonance portion of the scanning sonar is as shown in Fig. 4 (a), finally, the output signal through the band-pass filter as shown in Fig. 9 (a) is received.

Therefore, in the long distance mode, a signal of low amplitude (resonance frequency Fr) with large amplitude without attenuation is received as shown in FIG. 9 (b) The upper limit frequency Fr) is received. However, in the near-field mode, some signals may be reduced depending on the use of the upper limit frequency (Fr). However, since the reflected ultrasonic waves are received in a close vicinity, high-resolution image quality can be obtained in spite of some attenuation.

Hereinafter, the ultrasonic reception operation of the scanning sonar 10 according to the embodiment of the present invention will be described with reference to FIGS. 3, 10 and 11. FIG.

3, a scanning sonar 10 according to an embodiment of the present invention is configured to transmit ultrasound echoes reflected from an external object such as an external infringing person 150 by a transducer 12 to a transducer 12 ).

The transducer 12 converts the received ultrasonic echoes into electrical signals and provides them to the received signal amplifying unit 380.

The received ultrasonic echoes then receive the ultrasonic waves reflected from the external object and convert them into electric signals, and then transmit them to the received signal amplification unit 380.

The received signal amplifying unit 380 amplifies the ultrasonic echo signal received by the transducer 12 and provides the amplified ultrasonic echo signal to the filter unit 370. The filter unit 370 passes the generated frequency through the band pass filter, Of frequencies.

The reception transfer curve of the filter unit 370 is as shown in FIG. 4 (b), and a signal of a certain frequency band is passed around the resonance frequency Fr.

The comparison reference signal generator 360 may include an exclusive-OR comparator including an exclusive-OR (XOR) circuit 365 and an integrating circuit 367. In this case, the exclusive-OR circuit 365 receives the received ultrasonic echo signal that has passed through the filter unit 370 and the reference signal, performs an exclusive-OR operation, for example, outputs 0 when it is the same signal, An exclusive OR signal 361 for outputting the exclusive OR signal 361 can be generated. In this case, the reference signal can be generated based on the transmitted ultrasonic signal.

The exclusive OR signal 361 is applied to an integrating circuit 367 to generate an integrated comparison reference signal 363.

In summary, when the difference between the transmitted signal and the received signal is large (e.g., when the distance is long), the comparison reference signal also becomes large. When the difference between the transmitted ultrasonic signal and the received ultrasonic signal is small The comparison reference signal also becomes smaller.

In a complicated environment such as underwater, there is a high possibility that various noises are generated, so that a signal having a size smaller than the comparison reference signal can be removed as noise. However, in the embodiment of the present invention, since the near mode and the remote mode having different amplitudes and frequencies are used, the comparison reference signal is adaptively changed according to the distance of the external object 150. [

Referring to FIG. 11, after the comparison reference signal 363 is generated, the input ultrasonic signal (the received ultrasonic echo signal) is applied to the comparator 350 to be compared with the comparison reference signal 363 described above, The ultrasonic output signal 375 is generated only when the input ultrasonic signal is applied.

The reception control unit 317 can measure the distance to the external object 150 based on the ultrasonic output signal 375. [ Further, the near mode and the remote mode can be determined based on the distance to the measured external object.

The determined mode is transmitted again to the transmission control unit 315 and the transmission control unit 315 can automatically set the transmission frequency and the amplitude according to the long / short mode determined by the reception control unit 317. [

Therefore, according to the present invention, the system and method for monitoring aquaculture underwater according to the embodiment of the present invention can change the frequency according to characteristics of environment / distance by utilizing a scanning sonar equipped with a low-cost single transducer. Therefore, significant cost reduction is possible compared to farm monitoring system using existing high-priced dual transducers.

In addition, since the system configuration is simple and applicable to various environmental conditions, it can be applied to a small scale farm, which is advantageous for commercialization.

In addition, it is possible to monitor near / far approaching objects using a scanning sonar equipped with a single transducer, and it is possible to implement a high-resolution surveillance system with only a mid-low-priced scanning sonar. In addition, the monitoring system and method for aquaculture underwater in accordance with the present invention can monitor the health of the underwater environment and structure, monitor underwater theft of the aquaculture site, and monitor the detection of a dangerous object by utilizing a low-cost single transducer.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, Various substitutions, modifications, and variations are possible without departing from the scope of the invention. Accordingly, the scope of the present invention should be construed as being limited to the embodiments described, and it is intended that the scope of the present invention encompasses not only the following claims, but also equivalents thereto.

10: Scanning Sonar
12: Transducer
100: Farm monitoring system
110: control board
120: Information processor
150: External object (invaders, etc.)
300: Sonar processor
400:

Claims (5)

A single transducer for transmitting a transmitted ultrasonic wave;
A transmission signal amplifying unit for generating a transmission signal provided to the single transducer based on the composite modulation signal;
A modulator for generating the complex modulation signal and providing the complex modulation signal to the transmission signal amplification unit;
A comparison reference signal generator for adaptively generating the comparison reference signal calculated by the ultrasonic echo signal reflected from the external object and the reference signal based on the transmission signal;
A comparison unit for comparing the comparison reference signal with the received ultrasonic echo signal to generate an ultrasonic output signal; And
And a signal processing control section that calculates a distance to the external object based on the ultrasonic output signal and controls the remote mode and the near mode based on the calculated distance,
Wherein the modulator is adapted to generate the composite modulated signal based on the resonant frequency when in the remote mode and to generate the composite modulated signal based on the upper frequency when in the short mode,
Wherein the single transducer transmits the transmission ultrasonic wave in accordance with the transmission signal,
Aquaculture underwater monitoring system. The method according to claim 1,
Wherein the modulator generates a first frequency-modulated wave having a frequency corresponding to the resonance frequency based on the first carrier and the first frequency control signal,
And generating a second frequency modulated wave having a frequency corresponding to the upper frequency based on the second carrier and the second frequency control signal,
Aquaculture underwater monitoring system. 3. The method of claim 2,
Wherein the modulator generates a first complex modulated wave having a controlled amplitude by controlling a duty ratio of the first frequency modulated wave to provide the first modulated wave as the composite modulated signal when in the long distance mode, Modulated wave to generate a second composite modulated wave having a controlled amplitude and providing the second modulated wave as the composite modulated signal,
Aquaculture underwater monitoring system. The method of claim 3,
The complex modulation signal
A synchronization signal for indicating the start of the composite modulation signal;
A header including far or near mode information;
An ID signal that is a unique number of the scanning sonar;
A scan signal used for detecting the external object,
And a transmission protocol including a parity signal for determining whether the composite modulation signal is erroneous,
Aquaculture underwater monitoring system. The method according to claim 1,
Wherein the comparison reference signal generator comprises: an exclusive OR circuit for generating an exclusive OR (XOR) signal by receiving the received ultrasonic echo signal and the reference signal; and an exclusive OR circuit for integrating the exclusive OR signal to generate an adaptive reference signal And an exclusive OR circuit that includes an integrating circuit for generating an exclusive OR
Aquaculture underwater monitoring system.

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