JP3188055B2 - Fish school monitoring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fish school monitoring apparatus for monitoring a school of fish entering and leaving a fixed net using ultrasonic waves.

[0002]

2. Description of the Related Art In a fixed net installed in the sea, it is necessary to constantly monitor a school of fish entering and leaving the fixed net and to raise the fish when there are many schools of fish in the fixed net for effective catching. There is. However, since it is not possible to see the school of fish entering and leaving the fixed net from the sea or from a remote place, a school of fish using ultrasonic waves is used.

FIG. 6 is a block diagram showing the configuration of a conventional device of this type. In the figure, reference numeral 1 denotes a transmission circuit, 2 denotes a transmitter / receiver, 3 denotes a preamplifier circuit, 4 denotes a TVG circuit, and 5 denotes a detection circuit. A circuit, 6 is a Doppler detection circuit, 7 is a signal processing circuit, and 8 is a display circuit.

Next, the operation will be described. The burst signal power-amplified by the transmission circuit 1 is radiated into the water as an ultrasonic pulse signal by the transmitter / receiver 2, reflected by the underwater fish school and the like, received again by the transmitter / receiver 2, and converted into an electric signal. It is sent to the preamplifier circuit 3. The preamplifier circuit 3 amplifies the received signal to a predetermined level and sends it to the next TVG circuit 4, where the propagation attenuation due to the difference in distance is corrected, and the corrected signal is detected by the detection circuit 5 and the Doppler detection circuit 6. Send to The detection circuit 5 performs envelope detection on the signal after the propagation attenuation correction, and outputs an envelope signal proportional to the reflected signal to the signal processing circuit 7. The Doppler detection circuit 6 detects the Doppler frequency based on the transmission signal from the transmission circuit 1 and the signal after the propagation correction, and outputs the detected Doppler frequency to the signal processing circuit 7.

[0005] The signal processing circuit 7 detects an abnormal value occurring at the rising and falling portions of the input Doppler frequency from the envelope signal, removes this portion, performs averaging processing, and outputs the result to the display circuit 8.

FIG. 7 shows an example of display contents of the display circuit 8. In other words, the display indicates whether a school of fish is entering or leaving a net depending on whether the rectangular signal indicating the average value of the Doppler frequency is (+) or (−), and the height (h) of the signal indicates the school of fish. The size of the school is displayed.

[0007]

Since the above-mentioned conventional fish school monitoring apparatus is configured and operates as described above, it is possible to determine whether a school of fish entering or leaving the net is entering or leaving the net. In addition, the fish school scale and the water depth position can be determined, but the access network speed (moving speed) cannot be determined. However, if the scale, water depth position, moving state, and moving speed of the fish school entering and leaving the net can be determined, the size and species of the fish in the fish school entering and leaving the net can be estimated, and more effective catching can be performed.

The present invention has been made in order to solve such a problem, and an object of the present invention is to provide a fish school monitoring apparatus capable of displaying information effective for estimating a fish species of a school of fish entering and leaving the net.

[0009]

A fish school monitoring apparatus according to the present invention detects a Doppler frequency accurately to obtain a moving state and a moving speed of a school of fish, and performs color-coded display according to a difference in the moving speed.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing one embodiment of the present invention.
In the figure, 1 is a transmission circuit, 2 is a transducer, 3 is a preamplifier circuit, 4 is a TVG circuit, 5 is a detection circuit, 6 is a Doppler detection circuit, 7 is a signal processing circuit, 10 is a moving speed detection circuit, Reference numeral 11 denotes a display circuit.

Next, the operation of the present invention will be described. The burst signal power-amplified by the transmission circuit 1 is radiated into the water as an ultrasonic pulse signal by the transmitter / receiver 2, reflected by the underwater fish school and the like, received again by the transmitter / receiver 2, and converted into an electric signal. It is sent to the preamplifier circuit 3. The preamplifier circuit 3 amplifies the received signal to a predetermined level and sends it to the next TVG circuit 4, where the propagation attenuation due to the difference in distance is corrected, and the corrected signal is detected by the detection circuit 5 and the Doppler detection circuit 6. Send to The detection circuit 5 performs envelope detection on the signal after the propagation attenuation correction, and outputs an envelope signal proportional to the reflected signal to the signal processing circuit 7 as shown in FIG. Further, the Doppler detection circuit 6 detects the Doppler frequency based on the transmission signal from the transmission circuit 1 and the signal after the propagation correction, and outputs the voltage in the form of a voltage signal as shown in FIG.

The signal processing circuit 7 removes abnormal values occurring at the rising and falling portions of the envelope from the input Doppler frequency signal, sends the output to the moving speed detecting circuit 10 and performs an averaging process. Output (this is
Is sent to the display device 11. By the processing up to this point, the size and depth position of the fish school entering and leaving the fixed net, and whether the fish school is entering or leaving the net are known.

The moving speed detecting circuit 10 detects the moving speed of each fish school from the input Doppler frequency and sends this information to the display circuit 11. As shown in FIG. 5, the display circuit 11 first determines whether a school of fish entering the net or a school of fish leaving the net is C.
The information is displayed so as to be distinguished on the RT, the vertical axis is the water depth, the horizontal axis is the time, the fish school scale is the size of the fish shadow, and the speed is displayed by color coding. With this display, the school of fish entering and leaving the fixed net can be separately grasped, and the water depth and the moving speed of the school of fish can be easily grasped. , It is possible to provide effective information for estimating the fish species.

In the above embodiment, the moving speed of the school of fish is indicated by color-coded display using color samples. However, other identification marks, for example, a mark of a large or small fish body itself or a mark of a fish species itself are displayed. May be displayed.

Further, the detection circuit 5 and the Doppler detection circuit 6 are installed in the vicinity of a fixed network, from which data is transmitted via a radio line and displayed on the display circuit 11 via a processing circuit 7 installed on land or the like. It may be a device. Further, although the present invention has been described as a device for monitoring a fixed net, its implementation is not limited to a fixed net, and it goes without saying that the present invention can be widely applied, for example, to monitor a school of fish in an estuary.

[0016]

As described above, the fish school monitoring apparatus of the present invention can easily display the moving speed of the school of fish entering and leaving the net, so that it is possible to provide effective information for estimating the fish species. .

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2 is a diagram illustrating an envelope signal from a detection circuit.

FIG. 3 is a diagram illustrating a Doppler frequency signal.

FIG. 4 is a diagram showing a signal obtained by removing an abnormal value and performing an averaging process.

FIG. 5 is a diagram for explaining an example of a display mode of the device of the present invention.

FIG. 6 is a block diagram showing a configuration of a conventional device.

FIG. 7 is a diagram showing an example of a display mode of a conventional device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transmission circuit 2 Transceiver 3 Preamplifier circuit 4 TVG circuit 5 Detection circuit 6 Doppler detection circuit 7 Signal processing circuit 10 Moving speed detection circuit 11 Display circuit

 ────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-27033 (JP, A) JP-A-53-125059 (JP, A) JP-A-4-339288 (JP, A) 281737 (JP, A) JP-A-59-220688 (JP, A) JP-A-5-288856 (JP, A) JP-A-5-288848 (JP, A) JP-B-48-14266 (JP, B1)

Claims (2)

(57) [Claims] 1. means for transmitting and receiving ultrasonic pulses in water;
Means for detecting an envelope of a received signal reflected by a school of fish to obtain an envelope signal proportional to the intensity of the reflected signal; means for obtaining a Doppler frequency signal from the received signal; comparing the Doppler frequency signal with the above-mentioned envelope signal; Signal processing means for obtaining information on the size, depth position, perspective movement direction, and movement speed of the school of fish, eliminating abnormal values at the time of falling, and separate screens for the perspective movement direction on the display screen of the display device Means for displaying the depth of water on the vertical axis of each screen, the time on the horizontal axis, the size of the fish school, the size of the fish shadow, and the moving speed by color coding. 2. The fish school monitoring apparatus according to claim 1, wherein the moving speed is displayed as a difference in a shape mark such as a shape of a fish shadow.