JPS6359470B2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a fish detection buoy.

Conventional fish detection buoys generally include a device called a tele-sounder.
In this device, the buoy is equipped with a fishfinder transducer and the echoes are sent out using a wireless transmitter.
By receiving this information on the fishing boat and displaying it on the display device of the fish finder installed on the fishing boat, the status of the school of fish below the sea surface at the position of the buoy was displayed on the fishing boat. In this case, the display device installed on the fishing boat is a cathode ray tube display device or a recorder for a fish finder. Therefore, the disadvantage of the telesounder mentioned above is that the fishing boat must be equipped with a dedicated display device as described above. First, this display device is large and expensive, and since a synchronization signal for synchronizing the display device must be added to the echo itself and transmitted, the occupied frequency bandwidth of the signal becomes wide and noise interference is caused. At the same time, the number of channels that can be allocated within a certain frequency band also decreases.
Additionally, due to the configuration of the display device onboard the fishing boat, it takes a considerable amount of time for the echoes of the fish school to be visible on the display device, and during this time the transducer and radio receiver installed on the buoy must be kept in working order. Therefore, power consumption increases, and other wireless transmitters using the same wavelength cannot transmit during the transmission time.

This invention was made to eliminate the above-mentioned drawbacks of conventional devices, and it is possible to reliably transmit information on schools of fish by simply transmitting radio waves with a narrow occupied frequency bandwidth for a short period of time, and to transmit this information to fishing boats. To understand the above, the purpose is to provide a fish detection buoy that does not require any special equipment or only requires the addition of extremely simple equipment.

Embodiments of the invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing one embodiment of the present invention, showing a connection system of equipment installed on a fish finding buoy, where 1 is an antenna, 2 is a transmission/reception switch, 3 is a radio receiver, and 4 is a selective call signal. Detection circuit, 5 is a timing control circuit, 6 is an ultrasonic oscillator, 7 is a vibrator used as an ultrasonic transducer, 8 is a gate circuit, 9 is an integrator, 10 is an analog-to-digital converter (hereinafter abbreviated as ADC) ), 11 is a code conversion circuit, 12 is a latch, 13 is an identification code generator, 1
4 is a wireless transmitter, and 20, 21, . . . , 28 are signal lines that transmit timing signals, respectively.
Although not shown in Figure 1, power supplies are provided for each part, and power is always connected to parts 2, 3, 4, and 5, and parts 6, 8, 9, 10, 1
It is assumed that power is connected to portions 1, 12, 13, and 14 only during the period described in a later section.

2 and 3 are operation time charts showing the operation of the circuit of FIG. 1. The operation of the circuit shown in FIG. 1 will be explained below using FIGS. 2 and 3. A fishing boat that wishes to receive information from this fish detection buoy sends a selective call signal to the buoy using a predetermined carrier wave from a fishing boat transmitter. For convenience of explanation, this selective calling signal is assumed to be a four-frequency tone series signal as shown in FIG. 2a. antenna 1
is initially connected to the radio receiver 3, and the transmission from the fishing boat is amplified and detected, and the detection output shown in Figure 2a is input to the selective calling signal detection circuit 4. If the detection output is a selective call signal for the buoy, the detection circuit 4 detects this, and as shown in FIG.
As shown in the figure, at time _t0 , a signal is output to the signal line 20 to activate the timing control circuit 5 and initialize the ADC 10, code conversion circuit 11, and latch 12. When the timing control circuit 5 is activated, the antenna 1 is connected to the radio transmitter 14 side for the period shown in FIG.
Power is supplied to parts 0, 11, 12, 13, and 14. Next, the identification code generator 13 is activated under the control of the signal line 22 to generate an identification code, and this code is transmitted by the radio transmitter 14. For convenience of explanation, this identification code is assumed to be the Morse code shown in FIG. 2d.

Next, the ultrasonic oscillator 6 is activated by the signal on the signal line ₂₃ , and as shown in FIG. In the example, only 5 pulses) are generated. The electric vibrations are converted into ultrasonic waves by the vibrator 7 and emitted into the sea, and the echoes are converted into electric vibrations by the vibrator 7 and input into the gate circuit 8. The gate circuit 8 is as shown in FIG.
Only the echo of time T ₁ during the period T ₀ is sent to the integrator 9.

FIG. 3 shows the relationship between the echo and the gate circuit 8. FIG. 3a shows the echo input of the gate circuit 8, FIG. show. In Fig. 3a, 30 indicates the transmitted wave and the reflected wave from the nearby sea surface, 31 indicates the reflected wave from the school of fish, and 32 indicates the reflected wave from the seabed, and the gate circuit 8 extracts only the reflected wave 31 from the school of fish. Designed to.

The output of the gate circuit 8 is amplified and integrated by an integrator 9. The gate signal shown in Figure 2g is on the signal line 25.
The signal is applied to the integrator 9 via , and integration is performed for that period. During the period when the gate signal shown in FIG. 2g is logic 0, the capacitor of the integrator 9 circuit is discharged, and therefore, before time t ₂ shown in FIGS. 2f and 2g, the output voltage of the integrator 9 is 0. Therefore, the output of the integrator 9 at the end point t ₃ of the integration (see g and f in FIG. 2) represents the integrated value of the strength of the reflected wave from the school of fish shown at 31 in FIG. 3. Corresponding to the output of integrator 9 at time t ₄ (Fig. 2h) immediately after time t ₃
The output of the ADC 10 is input to the code conversion circuit 11. That is, the pulse shown in FIG. As an example, ADC1
The output of 0 is a BCD (binary coded decimal) code and represents a 2-digit decimal number. Code conversion circuit 11
converts this two-digit decimal number into Morse code for each digit, making it an extremely simple conversion circuit.

Due to space constraints in Figure 2, time _t4 is shown in Figure 2 (i) to the left, and j and k in the same figure are shown based on this, but in actual time relationships, Figure 2 h The waveforms shown in Figure 2 j and k follow to the right of _t4 . Since the code conversion in the code conversion circuit 11 is completed in a minute time after time _t4 , a signal is outputted on the signal line 27 at that time and the output of the code conversion circuit 11 is stored in the latch 12. After the Morse code is stored in latch 12, a timing signal is output on signal line 28 to read the latch. An example of the read Morse code is shown in FIG. 2j. The read Morse code is transmitted by the wireless transmitter 14. If the sending of the Morse code ends at time t ₅ in Figure 2 j, then t ₆ after time t ₅
6, 8, 9, 10, 11, 1 at time (Fig. 2 k)
Turn off the power to antennas 2, 13, and 14 and turn antenna 1 off.
is connected to the wireless receiver 3, and the state before time _t0 in FIG. 2 is restored.

Therefore, after transmitting the selective call signal shown in Figure 2a, the fishing boat listens for the identification code shown in Figure 2d, confirms that the desired buoy is operating, and then calls the buoy in Figure 2j. Since it is possible to obtain fish detection information regarding the buoy by listening to the Morse code of do not need.

Furthermore, since the transmission speed of Morse code shown in Figure 2j can be made equal to or lower than that of hand-transmitted Morse code, its occupied frequency bandwidth is extremely narrow, and it is less likely to interfere with other communications. , and is also less susceptible to interference due to noise interference. Furthermore, in the example shown in FIG. 2j, the mall code 2
Since the process only involves transmitting characters, the process can be completed in an extremely short time, and the amount of time the buoy occupies the radio waves is also shortened, making it possible to reduce power consumption at the buoy.

It should be noted that the timing relationship shown in FIG. 2 is merely an example, and it goes without saying that the present invention is not limited to this timing relationship. Furthermore, in the example shown in FIG. 2, the selective calling signal in FIG. 2 a, the identification code in FIG. 2 d, and the Morse code in FIG. It is also easy to design such a code to be sent out repeatedly multiple times.

Also, the code conversion circuit 11 is omitted and the ADC 10
It is also easy to read out the output BCD code at a slow reading speed, send it out, and display it on a numerical display device on the fishing boat that receives this BCD code. In the explanation of FIG. 2, the output of the ADC 10 was explained as two decimal digits, but it may be any number of decimal digits, and it goes without saying that a pure binary code may be used instead of the BCD code.

As described above, according to the present invention, fish detection information can be reliably transmitted using radio waves with a narrow occupied frequency bandwidth for a short period of time.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention, and FIGS. 2 and 3 are operation time charts showing the operation of the circuit shown in FIG. 3... Radio receiver, 4... Selective call signal detection circuit,
5... Timing control circuit, 6... Ultrasonic oscillator, 7
...Resonator, 8...Gate circuit, 9...Integrator, 10...
ADC, 11... code conversion circuit, 12... latch,
13...Identification code generator, 14...Radio transmitter.

Claims (1)

[Claims] 1. A radio receiver that receives a command signal, a radio transmitter that transmits an identification code of its own station in response to the command signal received by the radio receiver, and a radio transmitter that transmits an identification code of its own station in response to the command signal received by the radio receiver. means for activating an ultrasonic oscillator to emit pulse-modulated ultrasonic waves into the sea for a predetermined number of pulses at a predetermined pulse repetition period; and during each period of the pulse repetition period, a transmitted wave and a reflected wave from a nearby sea surface;
and a gate circuit that receives the reflected waves of the ultrasonic wave during a time period excluding the time period in which the reflected waves arrive from the seabed, and a gate circuit that receives the reflected waves of the ultrasonic wave during a time period in which the reflected waves from the seabed arrive, and a reception output of this gate circuit that corresponds to the total number of pulses of the predetermined number of pulses. an analog-to-digital converter that converts the output of this integrator circuit into a digital code, a code converter circuit that converts the output of this analog-to-digital converter into a code suitable for decoding on the receiving side, and this code. It comprises a latch for temporarily storing the output of the conversion circuit, and means for reading the stored contents of the latch at a predetermined speed suitable for transmission over a radio line and transmitting it by the radio transmitter following the identification code of the own station. Fish detection buoy. 2. The fish school detection buoy according to claim 1, wherein the code conversion circuit converts the numerical value represented by the output of the analog-to-digital conversion device into a Morse code representing the numerical value of each digit of a decimal number. Detection buoy. 3. The fish-finding buoy according to claim 1, wherein the code conversion circuit inputs the code representing the output of the analog-to-digital converter to the latch as is. 4. In the fish detection buoy described in claim 1, the code conversion circuit converts the numerical value represented by the output of the analog-to-digital conversion device into BCD (binary coded decimal).
A fish detection buoy characterized by being converted into a code. 5. In the fish detection buoy described in claim 1, the speed at which the contents of the memory of the latch are read out is such that the meaning of the code can be easily identified by the receiver who receives the read code. Characteristic fish detection buoy.