JPS6249591B2 - - Google Patents

Description

[Detailed Description of the Invention] As is well known, in the bottom trawl fishing method or mid-water trawl fishing method, in order to know the condition of the trawl net, that is, the fishing net, a detection and transmitter is attached to the trawl net, and information from the fish school, the seabed, the sea surface, etc. is attached. This is a so-called school of fish for seine fishing, which is transmitted using ultrasonic waves for transmission, receives the transmitted ultrasonic information by a receiving and recording device on the ship side, and detects, reproduces, and records and displays this information based on the synchronization of transmission and reception. Fishing net information detection devices such as detectors are used.

The method of searching for information such as schools of fish in the detection and transmitter section of these devices is exactly the same as that of general fish finders, and uses a method of periodically transmitting ultrasonic pulses and receiving and detecting reflected waves from schools of fish, the seabed, etc. ing.

Therefore, in some types of bottom trawling fishing, it is necessary to have a detection and transmitter that transmits relatively high-frequency ultrasonic pulses at a relatively short repetition rate to obtain detailed information. Mid-water towing fishing methods that operate in ocean waters require a detection and transmitter that transmits ultrasonic pulses at a relatively low frequency over a relatively long period to obtain information over a wider range.

Conventionally, when it is necessary to use detecting and transmitting units with different repetition periods like this, two reception and recording devices adapted to each repetition period are installed, or two types of synchronous repetition period generation circuits are installed in the reception and recording device in advance. The synchronization repetition period was manually changed each time. The former method is expensive, and the latter method may cause operational problems due to forgetting to switch the switch.

The present invention eliminates such drawbacks, and when two types of detection and transmission sections with different repetition periods are used, the synchronization repetition period of the ship's side reception and recording device is automatically switched to the repetition period of the detection and transmission section being used. The present invention provides a fish finder for seine fishing that can be constructed relatively easily. This will be explained in detail below with reference to the drawings.

FIG. 1 is a system diagram showing one embodiment of the present invention, and FIG. 2 is a waveform diagram of each part for explanation.

In FIG. 1, 1 is a receiver, 2 is a receiving amplifier, 3 is a signal processing device, and 4 is a recording device.
These have the same configuration and operation as conventional fish finders for seine fishing. 5 is a synchronization signal detection circuit which selects a synchronization signal from the output signal of the receiving amplifier 2 using conventional means. Reference numeral 6 denotes a synchronous repetition cycle generation circuit which divides the frequency of a stable frequency signal such as crystal oscillation to create a frequency that is the same as the short cycle of the repetition cycle of the detection and transmitter. Reference numeral 7 denotes a frequency dividing circuit which divides the output of the synchronous repetition period generating circuit 6 by an integer to produce a signal with the same frequency as the repetition period of the long period detection transmitter. In the present invention, since the individual repetition periods of the detection and transmitting units used are selected in a multiple relation, it is easy to generate a frequency synchronized with the above-mentioned repetition period within the reception and recording apparatus. Reference numeral 8 denotes a signal switching circuit which switches between the output signal of the synchronous repetition period generating circuit 6 and the output signal of the frequency dividing circuit 7 by means to be described later. Reference numeral 9 denotes a timing pulse generation circuit, which generates various trigger pulses necessary for signal processing in the signal processing device 3 using the output signal of the signal switching circuit 8 and the output signals of the frequency-divided stages of the synchronous repetition period generation circuit. Add. Reference numeral 10 denotes a short-cycle synchronization signal scheduled position gate pulse generation circuit which generates short-cycle synchronization signal scheduled position gate pulses based on the output signals of the frequency division stages of the synchronization repetition cycle generation circuit 6 and the output signal of the frequency division circuit 7. Reference numeral 11 denotes a coincidence circuit which obtains an output signal when the output of the synchronization signal detection circuit 5, that is, the detected synchronization signal, and the output signal of the short-period synchronization signal scheduled position gate pulse generation circuit 10 coincide in time. A counting circuit 12 counts the output signals of the coincidence circuit 11, and when a predetermined number is counted, the output is applied to the signal switching circuit 8 to switch from a long period signal to a short period signal. Reference numeral 13 denotes a required time interval pulse generation circuit, and this output pulse causes a counting circuit 12 to be generated.
Reset. Therefore, the counting circuit 12 operates only when there is a required number of matching signals within the required time.

In order to further clarify the operation of the configuration described above, the explanation will be given with reference to the waveform diagram of each part in FIG. 2. A in FIG. 2 (hereinafter, FIG. 2 is omitted) is a synchronization signal of the detection transmitter with a long period (period T), and a waveform diagram showing the transmission timing of each information, 21 and 24 are synchronization signals, and 22 is, for example, an upper Information 23 indicates, for example, the time relationship of downward information. B is a waveform diagram showing the short-cycle detection transmitter transmission timing, 31, 34, 37 are synchronization signals, 32, 35 are upper information, and 33, 36 are the time relationships of lower information. In the present invention, the repetition period of the detection and transmission section is selected to have a multiple relation (1/2 for simplicity in the figure), so the period is T/2.
becomes. C shows the output signal of the synchronization signal detection circuit 5 of the ship's reception and recording device. When the detection and transmission section has a long period, only the waveforms 41 and 43 appear as synchronization signals, and when the period is short, the waveforms 41, 42, and 43 appear. A waveform appears. Waveform A or B under synchronized transmission and reception
and waveform C coincide in time. Waveforms D, F, and G represent waveforms at each stage of the synchronous repetition period generating circuit 6.
H indicates the output waveform of the frequency dividing circuit 7. These waveforms D, E, F, G and waveform H are synthesized by a short-period synchronization signal expected position gate pulse generation circuit 10, and the output is a short-period synchronization signal expected position gate pulse waveform I, that is, as shown in the figure. In addition, the synchronization signals 21 and 2 are much shorter than the period of the short-period synchronization signals.
4, 31, 34, and 37 are generated with such a narrow width that they can be detected. In this explanation, five waveforms D, E, F, G, and H are used for waveform synthesis for simplicity, but in reality, more waveforms are used to narrow the pulse width of the synchronization signal scheduled position gate pulse. A waveform is used. Furthermore, various methods other than those described herein are conceivable as means for creating the waveform I. If the pulse width of waveform I is narrowed enough and waveform J is generated as a matching signal with waveform C by matching circuit 11, it is easy to see that almost no pulse of waveform J will be generated except when the repetition period of the detection and transmitter is short. can be understood. Therefore, if this coincidence signal, waveform J, is counted by the counting circuit 12, and the switching signal is output from the counting circuit only when a predetermined number is counted in a predetermined time, there will be no malfunction at all, and long and short period Switching becomes possible.

In the present invention, the relationship between long and short periods is explained as 2:1, but it can be easily implemented if there is a multiple relationship, and it is also easy to automatically switch the period of the detection and transmitter for more types than just two types. It is also self-explanatory that it can be implemented.

As explained above, in the present invention, when detecting and transmitting sections with different repetition periods are required to satisfy the performance required in various fishing grounds, the repeating periods of the detecting and transmitting sections are selected in a multiple relationship, and the ship's reception record is recorded. The synchronization repetition period of the device is normally set to the repetition period of the long-period detection and transmission section, and when the synchronization signal from the short-period detection and transmission section arrives, the detection synchronization signal and the short-period synchronization signal scheduled position gate pulse are When a match is detected and a predetermined number of match signals are counted in a predetermined time, the synchronization repetition cycle of the receiving and recording device is switched to a short cycle, so it can be configured relatively easily and operates reliably. This type of device is extremely effective.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing one embodiment of the present invention, and FIG. 2 is a waveform diagram of each part for explanation. DESCRIPTION OF SYMBOLS 1... Receiver, 2... Receiving amplifier, 3... Signal processing device, 4... Recording device, 5... Synchronous signal detection circuit, 6... Synchronous repetition cycle generation circuit, 7... Frequency division Circuit, 8... Signal switching circuit, 9... Timing pulse generation circuit, 10... Short period synchronization signal scheduled position gate pulse generation circuit, 11... Coincidence circuit, 1
2...Counting circuit, 13...Required time interval pulse generation circuit, A...Long period detection transmitter transmission timing waveform, B...Short period detection transmitter transmission timing waveform, C...Output of synchronization signal detection circuit 5 Waveform, D,
E, F, G...Waveform of each stage of the synchronous repetition cycle generation circuit 6, H...Output waveform of the frequency dividing circuit 7, I...Short period synchronization signal scheduled position gate pulse generator 10
Output waveform of J... Output waveform of matching circuit 11, 2
1, 24, 31, 34, 37...Transmission synchronization signal timing of the detection and transmission section, 22, 23, 32, 3
3, 35, 36...Transmission information timing of the detection transmitter, 41, 42, 43...Detection synchronization signal.

Claims (1)

[Scope of Claims] 1. Information obtained by detecting schools of fish, the seabed, the sea surface, etc. on the fishing net side is transmitted by the detection transmitting section as a detection information signal having a repetition period with a synchronization signal, and the receiving device transmits the information obtained by detecting the school of fish, the seabed, the sea surface, etc. A fishing net information detection device that processes the information by operating a signal obtained by receiving an information signal in synchronization with the synchronization signal, wherein the repetition period is set to a plurality of periods having a multiple relationship, and the plurality of The synchronous operation is performed in one of the periods, comprising: a first synchronization means for performing the synchronous operation using a longer period among the plurality of periods; b the synchronous operation. a second synchronizing means that performs the synchronizing operation using a short period among the plurality of periods, c. a constant synchronizing means that always performs the synchronizing operation by the first synchronizing means, and d. a repeating period of the short period. a scheduled position signal generating means for generating a pulse with a width narrow enough to detect the synchronizing signal at the scheduled position of the synchronizing signal; and e synchronizing detecting means for detecting the synchronizing signal and outputting it as a detected synchronizing signal. , f detecting coincidence between the detected synchronization signal obtained by the synchronization detection means and the gate pulse obtained by the expected position signal generation means,
a coincidence detection means for outputting a coincidence signal; g. a switching signal output means for outputting a switching signal when a predetermined number of coincidence signals obtained by the coincidence detection means are obtained within a predetermined time; and h. a switching signal output means for outputting a switching signal. and synchronization switching means for switching the synchronization operation by the first synchronization means to the second synchronization means in response to a switching signal obtained by the signal output means, so that the repetition period of the detection and transmission section is adjusted to the multiple relationship. 1. A fishing net information detecting device characterized in that the receiving device can automatically operate in synchronization with a set repetition period, regardless of which one of a plurality of repetition periods is set.