Underwater detection device

An underwater detection system is provided that can effectively use a discrimination result. A fish detector of the system is configured to implement a discrimination function including a fish species discrimination function; however, a fish detector and a sonar of the system do not comprise such a discriminator including a fish species discriminator. The fish detector transmits various discrimination results such as fish species discrimination, etc., through an onboard LAN to the fish detector or the sonar. The fish detector and the sonar superimpose various received discrimination results on the detection result of the device itself and display them on a display.

FIELD OF THE INVENTION

The present invention relates to an underwater detection device that detects a school of fish by transmitting an acoustic wave underwater and receiving an echo.

BACKGROUND ART

A conventional underwater detection device as shown in the Patent Document 1 discriminates fish species based on an envelope of the echo.

RELATED ART

Patent Document

Patent Document 1: Japanese Unexamined Patent Application Publication No. 2008-267834

SUMMARY OF THE INVENTION

Problems to be Solved by the Invention

However, with the conventional device, a discrimination result is displayed only on a display of an underwater detection device and is not used effectively.

Accordingly, it is a primary object of the present invention that provides an underwater detection device, an underwater display system, a program and an underwater display method that can use a discrimination result effectively.

BRIEF SUMMARY OF THE INVENTION

An underwater detection device according to the present invention, which detects a school of fish based on an echo obtained from underwater detection by transmitting and receiving an underwater ultrasonic signal and displays an echo image of the school of fish on a screen, comprises an acquisition module that acquires fish species information in connection with position information indicating a position where an external device distinguished the fish species information, a determiner that decides based on the position information whether the school of fish displayed as the echo image on the screen and the school of fish for which fish species information has been acquired by the acquisition module are the same school of fish or not, and a display combiner that displays the acquired fish species information on the screen by superimposing on the echo image of the school of fish when the determiner determines they are the same school of fish.

In this manner, the underwater detection device receives the fish species information including the information such as a fish species discrimination result or a fish body length, etc. from the external device (for example, a fish detector) having a fish species discrimination function and displays the various received discrimination results on the display by superimposing on the detection result of the device itself and therefore the discrimination result can be used effectively. For example, even if there are a plurality of underwater detection devices, various kinds of information can be collected or gathered to one device. In particular, in many cases users determine a school of fish to catch by comparing the echo images of a plurality of fish detectors or the echo image of a sonar when they fish; however, the underwater detection device according to the present invention enables determination of the school of fish to catch by collecting or gathering the discrimination result for each school of fish at one fish detector or the sonar.

In addition, the position information includes longitude, latitude, and information such as a depth of the school of fish.

The external device is not limited merely to other underwater detection devices provided on the subject ship but also to underwater detection devices provided on other ships.

Effects of the Invention

According to the present invention, the underwater detection fish species discrimination result can be used effectively.

DETAILED DESCRIPTION OF THE EMBODIMENTS

A first embodiment.FIG. 1(A) is a block diagram of an underwater detection system according to a first embodiment of the present invention. The underwater detection system comprises a plurality of underwater detection devices connected through an onboard LAN5. In an example ofFIG. 1(A), the underwater detection device comprises a fish detector1, a fish detector2, a sonar3, and a sensor4. In the first embodiment, the fish detector1is the equivalent of an external device of the present invention, and the fish detector2and the sonar3are the equivalent of the underwater detection device of the present invention. The sensor4includes an azimuth sensor or a location sensor (GPS or LORAN, etc.) and acquires a position (longitude and latitude) of the ship itself (i.e., the subject ship). Although the present embodiment shows an example in which the sensor4is connected to each device such as the fish detector1, the fish detector2, and the sonar through onboard LAN5, an embodiment in which the sensor4is built in each device might be also possible.

Although the fish detector1has various discrimination functions including a fish species discrimination, the fish detector2and sonar3do not have various discrimination functions including fish species discrimination. Therefore, with the underwater detection system according to this embodiment, by transmitting various discrimination results such as the fish species discrimination of the fish detector1by onboard LAN5and displaying them including the detection result of the fish detector2or the sonar3, the underwater detection device lacking functions such as the fish species discrimination can also display the discrimination results.

Hereinafter, the components and the functions of each device are explained.FIG. 1(B) is a block diagram showing a component of the fish detector1. The fish detector1comprises an user input device10, an echo sounder transducer11, a duplexer12, a transmission circuit13, a controller14, a receiver circuit15, an A/D converter16, a signal processor17, a display18, and a transmitter19.

The controller14is for centralized controlling of the fish detector. The controller14sets up a transmission period and a detection range, etc., of the transmission circuit13according to each operation (instruction input, etc. for setting up the detection range, etc.) from the user input device10and executes a sampling period setting of the corresponding A/D converter16and provides the command instructions for various processes to the signal processor17. The display18displays echo data on the screen with the longitudinal axis as the depth direction and the horizontal axis as the time direction.

The transmission circuit13inputs a pulsating signal to the echo sounder transducer11, which is a transmitter and receiver, through the duplexer12embedded in a trap circuit. An input timing, a level, and a pulse duration, etc., of the signal are controlled by the controller14. The echo sounder transducer11is a vibrator installed on a ship bottom, etc., and outputs an ultrasonic wave underwater according to the pulsating signal inputted from the transmission circuit13.

The ultrasonic wave outputted from the echo sounder transducer11is reflected by targets such as a single fish, a school of fish, and the bottom of the sea, etc., and is received as the echo signal. The echo sounder transducer11outputs the received signal according to an intensity of the received echo signal to the receiver circuit15through the duplexer12. The receiver circuit15amplifies the inputted received signal and outputs it to the A/D converter16. The A/D converter16converts the received signal to a digital signal with a predetermined sampling period and outputs it to the signal processor17. The signal processor17records the digitalized received signal in memory (not shown) in sequence.

In addition, the controller14receives position information from the sensor4for each transmission and reception of the ultrasonic wave and records the position information in memory (not shown) for each transmission and reception timing (every ping) of the ultrasonic wave.

The signal processor17executes various processes such as an ocean bottom detection process and a fish species discrimination process based on the received signal recorded in memory. The information showing the results of the ocean bottom detection process and the fish species discrimination process is displayed on the screen of the display18, and they are output to other devices through the transmitter19and the onboard LAN5.

Referring toFIG. 2, a process of the signal processor17is explained in detail.FIG. 2is a block diagram showing components of the signal processor17. The signal processor17comprises a discriminator170and a display data generator171.

The display data generator171performs processing to generate display data in order to output each received signal as the detection result to the display18, as echo data corresponding to a depth according to an elapsed time from outputting the ultrasonic wave. Thus, the display data generator171processes each inputted received signal to perform averaging, etc., according to the resolution (longitudinal screen resolution) of the display18, and compiles them. However, when the longitudinal screen resolution of display18is close to or the same as a resolving power of the received signal, the received signal without being processed may become the echo data corresponding to each pixel. As a result, the echo data of the ping of multiple time points is displayed on the display18.

The discriminator170comprises functionally an ocean bottom detector175and a fish species discriminator177and each of them analyzes the received signal and executes various processes such as an ocean bottom detection process and a fish species discrimination process.

The ocean bottom detector175detects an ocean bottom depth from the received signal. The information showing the detected ocean bottom depth is outputted to the display data generator171and the controller14. Regarding a detection technique for the ocean bottom depth, a variety of techniques can be used; for example, a technique on the basis of a timing at which a received signal having more than a threshold value is received, another technique on the basis of a timing at which a derivative value becomes the highest, or another technique on the basis of a timing at which a correlation value becomes the highest wherein the correlation is measured with the received signal by making a waveform equal (or near) to a pulse width of the outputted ultrasonic wave into a reference signal.

The fish species discriminator177discriminates the fish species from the received signal. The fish species are discriminated by an echo area (sample number) of a single fish or a school of fish, an average strength, an average time length (average length of a depth direction), or a reverberation part (tailing). Moreover, it may be discriminated by the matching degree (similarity) of the echo of the single fish or the school of fish to reference data.

FIG. 3(A) is an illustration showing a display example of the display18.FIG. 4is an illustration showing information that the discriminator170outputs (the fish species information in this example). The display data generator171is equivalent of the display combiner of the present invention and generates a display data in which the information that the discriminator170outputs is superimposed and displayed on the echo data showing the detection result.

As shown inFIG. 3(A), the echo data which assigned the ping at a longitudinal axis and the depth at a vertical axis is displayed in display18. In the example ofFIG. 3(A), an echo data201of the school of fish is displayed on the right hand side of the middle of the screen as the detection result. Moreover, the ocean bottom depth (showing302min the figure) as a result of the ocean bottom detection processing, and a result of the fish species discrimination (the histogram indicates Mackerel 99% and Herring 16% in the figure) are displayed.

The ocean bottom depth detected by the newest ping is displayed. As the result of the fish species discrimination, the discrimination result is displayed about the echo data (echo data201in this example) of any one of or all of the schools of fish displayed on the screen.

In addition, although the ocean bottom depth is shown on the left hand side screen and the fish species discrimination result is shown in vicinity of the echo data of the school of fish in this example, the display positions of a variety of information are not restricted to this example.

As shown inFIG. 4, a variety of information (the result of the fish species discrimination, here) with corresponding position information is transmitted to other devices. For example, regarding the fish species information corresponding to the echo data201of the school of fish shown inFIG. 3(A), the position information received from the sensor4at the time when the ultrasonic wave in the most past ping (point A) was transmitted among the echo data201and the position information received from sensor4at the time when the ultrasonic wave in the newest ping (point B) was transmitted from the corresponding echo data201. In the position information, the depth information of the school of fish is included. The depth of the school of fish is equivalent to the shallowest depth among the detected school of fish at point A and is equivalent to the deepest depth among the detected school of fish at point B. The fish species information includes similarity in each fish species name and the fish body length.

In addition, the position information may be position information received from the sensor4at the timing of the transmitted ultrasonic wave in the oldest ping (point A) and the newest ping (point B) within a range selected on the screen of the detection result, upon a user operating the input device10.

The fish species information such as mentioned above is transmitted to the fish detector2and the sonar3through the controller14, the transmitter19, and the onboard LAN5.

FIG. 5(A) is a block diagram showing the components of the fish detector2. Regarding the fish detector2, the similar reference numbers are given to similar components of the fish detector1shown inFIG. 1(B) and a detailed explanation of such similar components is omitted for the sake of brevity. Although the signal processor27of the fish detector2has the same function as the signal processor17of the fish detector1, it does not have various discrimination functions including the fish species discrimination.

The controller24receives the fish species information from the fish detector1. Moreover, the controller24receives the position information from the sensor4for every ping and stores it in memory (not shown). The acquisition module of the present invention is embodied by the transmitter19and the controller24. The controller24outputs the fish species information received from the fish detector1to the signal processor27.

The signal processor27executes the school of fish detection from the detection results of the device itself. For example, the signal processor27determines the school of fish exists when the echo more than a predetermined level exists between the sea surface and the sea bottom. When the school of fish is detected, the signal processor27inputs the position information for every ping from the controller24and compares the position of the detected school of fish with the fish species information received from the controller24. That is, when the position (the longitude, the latitude, and the depth) of the detected school of fish and the position information included in the fish species information inputted from the controller24are the same or close, the fish species information inputted from the controller24is considered to be corresponding to the school of fish detected by the device and the display data in which the fish species information inputted from the controller24is superimposed and displayed on the echo data showing the detection result is generated. Moreover, when there is a plurality of detected schools of fish, the school of fish with the nearest position is determined to be corresponding. In addition, regarding the longitude, the latitude, and the depth, when at least one of them is matched the school of fish might be determined to be corresponding, or alternatively, only when all of them are matched the school of fish might be determined to be corresponding. In this manner, the controller24embodies the determiner of the present invention.

FIG. 3(B) is an illustration showing display examples of the display18in fish detector2. As shown inFIG. 3(B), the echo data which assigned the depth at the longitudinal axis and the ping at the horizontal axis are displayed in the display18, and the echo data301of the school of fish is displayed on the right hand side of the middle of the screen as the detection result of the fish detector2. Then the fish species information (Mackerel 99% and Herring 16% shown in the figure) inputted from controller24is displayed in vicinity of the echo data301.

In addition, when the fish species information inputted from the controller24is determined to be corresponding to the school of fish detected by the device itself, only a mark302as shown inFIG. 3(B) might be displayed at the position of the school of fish. In this case, when the user operates the user input device10and selects the mark302, the fish species information will be displayed.

Moreover, fish species information including not only the similarity but also histogram data can be transmitted and received so that the histogram can be also displayed in the fish detector2.

FIG. 5(B) is a block diagram showing the components of the sonar3. Although the sonar3has the same fundamental components as the fish detector2and has the same functions, an ultrasonic wave is transmitted and received except for in a direction directly below the sonar. In this example, the sonar3comprises an echo sounder transducer31which consists of a plurality of vibrators attached to the ship bottom. The echo sounder transducer31outputs the ultrasonic wave around the ship itself and receives the echo signal reflected in targets, such as a single fish, a school of fish, and the sea bottom.

The controller34receives the fish species information from the fish detector1. Moreover, it receives the position information from the sensor4and stores it in the memory (not shown). The controller34outputs the fish species information received from the fish detector1to the signal processor37.

The signal processor37executes the school of fish detection from the detection result of the device itself. For example, the signal processor37determines the school of fish exists when an echo of more than a predetermined level exists between the sea surface and the sea bottom. When the school of fish is detected, the signal processor37inputs the position information and calculates the position (latitude and longitude) of the school of fish from the received signal, the output angle of the ultrasonic wave, and the position information of the ship itself received from sensor4, etc. The signal processor37compares the calculated position of the school of fish with the fish species information received from the controller34. That is, when the calculated position of the school of fish and the position information included in the fish species information inputted from the controller34are the same or close, the fish species information inputted from the controller34is considered to be corresponding to the school of fish detected by the device itself and the display data in which the fish species information inputted from the controller34is superimposed and displayed on the echo data showing the detection result is generated. In the same manner as discussed above, when there are a plurality of detected schools of fish, the school of fish having the nearest position is determined to be corresponding.

FIG. 3(C) is an illustration showing a display example of the display18in the sonar3. As shown inFIG. 3(C), the ship itself is displayed on the middle of the screen and the echo data is displayed by the rectangular coordinate system corresponding to the direction and the distance. In this example, the echo data401from the school of fish is displayed on the upper right of the display as the result of the sonar3. Then, the fish species information (Mackerel 99% and Herring 16% shown in the figure) inputted from controller34is displayed in vicinity of the echo data401.

Additionally in this example, when the fish species information inputted from the controller34is determined to be corresponding to the school of fish detected by the device itself, at the position of the school of fish as shown inFIG. 3(C) only a mark402may be displayed. In this case, when the user operates the user input device10and selects the mark402, the fish species information will be displayed.

Moreover, fish species information including not only similarity but also histogram data can be transmitted and received so that a histogram can be also displayed via the sonar3.

Additionally, since the time t1when the fish species is determined by the fish detector1and the time t2when the determination is processed on the sonar3(or the fish detector2) are not necessarily the same time, a determination with consideration of the position change of a school of fish that move during a time difference (Δt=t2−t1) is desirable. For example, as shown inFIGS. 8(A) and 8(B), when the school of fish exists within the range of a distance d (Δt×swimming velocity) calculated from the swimming velocity of the school of fish, the school of fish is determined to be corresponding. In the example ofFIG. 8(A), although the school of fish501and the school of fish502exist, only the school of fish502that exists within the range of the distance d from the received position information is determined to be the corresponding school of fish, and the mark402is superimposed on the school of fish502. In addition, although the swimming velocity may be a fixed value corresponding to the average swimming velocity of the school of fish, the swimming velocity can be calculated from an elapsed time between scanning and by detecting the position changes of the school of fish between scanning by the sonar3. Moreover, from the position changes of the school of fish between scanning, the movement direction of the school of fish can be taken into consideration. For example, as shown inFIG. 8(B), when a school of fish502and a school of fish503exist at approximately the same distance as determined from the received position information, sonar3may judge from the received position information whether a school of fish exists or not in an area5021and an area5031that correspond to the direction of movement of each school of fish. The school of fish (school of fish502in the example ofFIG. 8(B)) that is determined to exist within the area after taking into account the movement direction of the school of fish, is determined to be corresponding.

In addition, after determining the corresponding school of fish, the superimposed mark or the fish species information can be moved along with the movement of the school of fish so that an appropriate display can be kept on the screen of the sonar3even if the school of fish moves.

Moreover, although the present embodiment shows an example of transmitting and receiving the result of the fish species discrimination, it is also possible to transmit and receive other information such as a measurement result of the fish body length, etc. Furthermore, it is also possible to display the echo image itself on other devices by transmitting and receiving the echo image itself. For example, in case of detecting the school of fish by the fish detector1, even if the position of the school of fish exists outside of the detection area of the sonar3, by transmitting and receiving the echo image and the position information of the school of fish, the echo image can be superimposed and displayed at the appropriate position on the display screen of the sonar3.

Moreover, the received discrimination result can be displayed not only on an underwater detection device such as a fish detector or sonar, etc., but also on the display of other devices such as a radar or a plotter, etc.

Next,FIG. 6(A) is a flow chart showing an operation of the fish detector1.FIG. 6(B) is a flow chart showing an operation of the fish detector2(or the sonar3).

First of all, the fish detector1transmits and receives an ultrasonic wave (s11). Second, the fish detector1processes the received signal (s12). That is, the signal processor17generates an echo data corresponding to the depth according to the elapsed time after outputting the ultrasonic wave and executes various discrimination processes such as fish species discrimination, etc.

After that, the controller14of the fish detector1determines whether the fish species was able to be discriminated or not from the received signal at the signal processor17(s13). When the fish species was not discriminated, the operation will be terminated. When the fish species was discriminated, the controller14transmits the result of the fish species discrimination to the other devices (s14). Then, the signal processor17displays the result of the fish species discrimination on the display18(s15).

Meanwhile, the fish detector2, which is on the receiving side, transmits and receives the ultrasonic wave first (s21). Then, the fish detector2processes the received signal (s22). That is, the signal processor27generates echo data corresponding to the depth according to the elapsed time after outputting the ultrasonic wave. Furthermore, the signal processor27detects the school of fish at this time.

The controller24judges whether the school of fish was detected or not at the signal processor27(s23) and judges whether the result of the school of fish discrimination was received from the fish detector1(s24). When the school of fish was not detected or the result of the school of fish discrimination was not received, the operation will be terminated.

When the school of fish was detected and the result of the fish species discrimination was received, the signal processor27inputs the position information for each ping and compares the position of the detected school of fish with the received result of the fish species discrimination (s25).

When the position of the detected school of fish and the position information included in the inputted result of the fish species discrimination are the same or close, the signal processor27determines that the inputted result of fish species discrimination and the detected fish species by the device itself are corresponding (s26). When it determines that they are not corresponding, the operation will be terminated.

When the signal processor27determines that the inputted result of fish species discrimination and the detected fish species by the device itself are corresponding, the inputted result of fish species discrimination is displayed on the display18(s27).

In this manner, at the fish detector2(or the sonar3), the result of fish species discrimination of the fish detector1is superimposed and displayed on the detection result of the device itself.

Moreover, although the flow chart shown inFIG. 6(B) shows an example that detects a target such as the school of fish in the detection result of the device itself and displays the discrimination result after corresponding the detection target to the received discrimination result, even though the device itself does not detect a target, the received discrimination result may be displayed. For example, as discussed above, when the echo image itself is transmitted and received, regardless of the result of the target detection of the device itself, it is desirable to superimpose and display the received echo image on the detection result of the device.

In this manner, the various discrimination results, such as the fish species discrimination, etc., are transmitted to the fish detector2or the sonar3through onboard LAN5from the fish detector1with the fish species discrimination function, and the various discrimination results received are superimposed and displayed on the display, so that a variety of information can be collected or gathered at one device even when a plurality of underwater detection devices exists. Although the user, especially in the case of fishing, determines the school of fish to catch by comparing the echo images of a plurality of fish detectors with the echo image of the sonar in many cases, the underwater detection system according to the first embodiment enables the user to determine the school of fish to catch by collecting or gathering the discrimination results for each school of fish at one fish detector or sonar.

A second embodiment.FIG. 7(A) is a schematic diagram showing components of an underwater detection system according to a second embodiment. The underwater detection system according to the second embodiment comprises a plurality of marine vessels (a marine vessel51, a marine vessel52, and a marine vessel53).FIG. 7(B) is a block diagram showing the components of each device on board of the marine vessel51, a marine vessel52, and a marine vessel53. In addition, similar reference characters are used to indicate components similar to those in the first embodiment, and the explanation thereof is omitted for the sake of brevity.

The marine vessel51comprises a fish detector1that is connected through onboard LAN5, a sensor4, and a radio communicator71. The composition and function of the fish detector1, the sensor4, and the onboard LAN5are in common with the first embodiment.

The marine vessel52comprises a fish detector2that is connected through onboard LAN5, a sensor4, and a radio communicator71. The composition and function of the fish detector2, the sensor4, and the onboard LAN5are in common with the first embodiment.

The marine vessel53comprises a sonar3that is connected through onboard LAN5, a sensor4, and a radio communicator71. The composition and function of the fish detector1, the sensor4, and the onboard LAN5are in common with the first embodiment.

Although an example that transmits the discrimination result of the fish detector1to other devices within the ship connected through onboard LAN5was shown in the first embodiment, the discrimination result of the fish detector1is transmitted to other devices in other ships.

In the second embodiment, when performing fleet operation, it is possible for the other ships to refer to the information of the school of fish that is discovered by a marine vessel, so that the smooth operation can be achieved.

Moreover, since the received discrimination result can be displayed not only on an underwater detection device such as the fish detector or the sonar, etc., but also on the display of other devices such as a radar or a plotter, etc., it becomes possible to refer to the information on the school of fish in the marine vessel without the fish detector and the sonar.