JP4863080B2 - Radio buoy call answering system and method - Google Patents

Description

  The present invention relates to a radio buoy that is attached to a fishing net, a longline, or the like that is flowed by a fishing boat and manages the net, and more particularly, to a radio buoy call response system and method related to a receiver selection call function.

  A radio buoy is configured as a system that places a buoy with built-in radio equipment on a target, receives radio waves emitted from it in a ship, etc., and measures its direction. Is received by the ship direction detector, thereby making it easy to find the network and prevent loss or theft.

  There are mainly four types of radio buoys, which always repeat the emission and pause of radio waves (general radio buoys), and have a built-in timer that repeats the emission and pause of radio waves for a certain time from a specific time ( Some radio buoys have timers, others emit radio waves only when a selective call is received (cell call buoys), and others emit radio waves only when radar radio waves are received (radar buoys).

  Among the radio buoys, those equipped with a selective call device are generally called cell call buoys. This radio buoy has a receiving device, and has a mechanism that responds only when calling from the ship and performs a four-signal serial tone type calling response.

  Normally, in maritime communications, a specific selection number (ID) that is determined in advance is selected by a selective call signal generator and a selective call dedicated transmitter installed on the ship side, and when this signal radio wave is transmitted to the radio buoy, the radio buoy is transmitted. If the radio wave selection number is correct, the radio wave is transmitted and received by the direction detector on the ship side, so that the direction in which the buoy is located can be determined.

  This type of radio buoy cell call can be used to select specific ship stations, coast stations, etc. according to specific signals due to the recent increase in ships, increase in traffic, efficient use of frequency, decrease in communication personnel, etc. The selective call that can be used was adopted, and from the latter half of the 1960s, it was considered that this cell call was adopted internationally for ships, and the system was deliberated by CCIR (ITU-R). It was revised by WARC, and its call frequency, signal configuration, etc. were defined in the wireless communication rules.

  This method defines a signal configuration such as a four-digit number corresponding to numbers from 0 to 9 with a tone frequency of about 0.5 to 2 kHz and its transmission time.

  Therefore, the radio buoy selects a selection number specific to the buoy from a ship or the like (hereinafter referred to as a base station), and transmits a radio wave to the cell call buoy by a selective call dedicated transmitter. The buoy that has received the radio wave responds and transmits the radio wave if the selection number is the selection number determined for the buoy. The base station receives the radio wave oscillated from the radio buoy with a direction detector and knows the direction in which the buoy is present.

  FIG. 8 is a block diagram showing a schematic configuration of a radio buoy in the conventional cell call system. An antenna 1 that receives a selective call (cell call) signal from a base station, a switch 2 that inputs to the reception unit 3 that amplifies the selective call signal received by the antenna 1, and a radio buoy that is specific to the selective call signal from the reception unit 3 A signal selection unit 5 for selecting the selection number of the signal, an auto keyer unit 6 for converting the detection result of the signal selection unit 5 into a predetermined signal, and a transmission unit for transmitting the signal of the auto keyer unit 6 from the antenna 1 via the switch 2 It is composed of four.

  The signal selection unit 5 is provided with a plurality of filter circuits 5a, 5b, 5c, and 5d and a signal detection control unit 7. The plurality of filter circuits 5a, 5b, 5c, and 5d are filter circuits that output a signal when a selection number unique to the radio buoy is included in the selection call signal (tone signal). A filter used in each of the plurality of filter circuits outputs a signal in response to a different frequency, for example, a mechanical filter or an active filter having a characteristic of responding to a frequency increased from 502.5 Hz to 30 Hz. One of the is used.

  When the radio buoy includes a specific selection number, the signal detection control unit 7 outputs a switching signal from the terminal TX, and transmits the switching device 2 by a relay circuit (not shown) via the signal line 7a. Switch to part 4 side (B side). The auto keyer unit 6 transmits a response signal to the base station twice in a predetermined format using a known Morse signal.

  FIG. 9 shows a more detailed configuration of a conventional radio buoy, which schematically includes an antenna 10, a receiving unit 11, a transmitting unit 12, and a signal selecting unit 13. The receiver 11 is a superheterodyne receiver, and the signal input to the antenna 10 is output as a tone signal by low-frequency amplification at the final stage. When the frequency of the tone signal is the same as that of the mechanical filter, in the signal selection unit 13, the tone signal sequentially passes through the mechanical filter, passes through the logic circuit of the rectifier and inverter, opens the gate, and passes through each mechanical filter. Then, since it is the same as the order of the fixed selective call numbers given to the radio buoys, the gate array 15 is activated. As a result, the relay circuit 16 is switched to the transmission side, a signal for turning off the power supply of the reception unit 11 is output, and the transmission unit 12 is keyed along the code data stored in the memory. The auto keyer unit 18 outputs an on / off signal synchronized with the keying signal of the gate array 15, and the carrier wave formed by the local oscillation frequency via the transmission amplification stage, the buffer amplification stage, and the power amplification stage constituting the transmission unit 12. Is synchronized with the on / off operation of the keying signal, and the Morse signal intermittent at the transmission frequency is transmitted from the antenna 10.

  However, such a radio buoy uses four mechanical filters, which are constituent elements, and sets a unique selection number for each buoy. Therefore, it is necessary to have a large number of filters corresponding to the selection number in stock. Since much assembly time is required, there are problems such as high manufacturing costs.

  In addition, for the specific selective call signal, the tone duration time is confirmed by using a radio wave synthesized with a total of 11 waves such as No. 1 to No. 0 and No. R currently used. As a result of the selection number being identified, problems such as prevention of operation due to stolen radio waves and interference such as nighttime broadcasting have occurred.

  In order to solve the above problems, the present invention eliminates the configuration of a mechanical filter or the like used in the signal selection unit, makes it possible to freely change the number of identification tones with a simple structure, and also provides a countermeasure against theft signals. It is an object of the present invention to provide a call answering system and method thereof in consideration.

  In order to achieve the above object, a radio buoy call answering system according to the present invention receives a specific selective call signal given to a radio buoy and outputs a detected tone signal; A low-frequency amplification stage that converts the tone signal into a square wave signal, and a CPU that digitally converts each tone frequency of the square wave signal that is continuously input and counts the time of one cycle. When the order of the tone frequencies input in this order matches the unique selection number, the CPU selects a signal selection unit that outputs a transmission control signal as a trigger signal; and a keying signal output corresponding to the trigger signal. It is characterized by comprising a transmitter that generates a carrier wave synchronized with on / off and transmits a Morse signal that is intermittent at a transmission frequency.

  Further, according to another configuration of the present invention, the selection call signal can change the order of the selection numbers according to the setting of the CPU. Further, this selective call signal can arbitrarily set one or both of the number of tones and the length of the tone. In addition, the selective call signal adds one tone in addition to the four-tone call signal, allowing the radio buoy to recognize individual commands.

  In the radio buoy call response method according to the present invention, the reception unit receives the selective call signal based on the unique selection number assigned to the radio buoy, and the tone signal detected by the reception unit is received by the signal selection unit. The square wave signal is converted into a square wave signal by a low frequency amplification stage, the time of one period of each square wave signal corresponding to each tone frequency of the unique selection number is counted by the CPU, and the tones of the square wave signal sequentially input When the order of the tone frequencies that are consecutively input and the frequency is identified matches the unique selection number, the CPU outputs a transmission control signal as a trigger signal to the transmission unit, and the keying signal to the transmission unit In synchronism with on / off, Morse signals that are intermittent at the transmission frequency are output as transmission radio waves.

  According to the present invention, the signal selection unit can be configured with a simple low-frequency amplification stage and CPU without using a mechanical filter or the like, simplifying the configuration of the apparatus, facilitating inventory management, and reducing manufacturing costs. Can do.

  In addition, according to the present invention, since the tone frequency can be set and the tone duration can be easily recognized by changing the software, the number of identification tones can be freely changed and the length of one tone can be recognized. As a result, the operation due to the theft signal can be prevented. The function can be expanded by adding other commands to the 4-tone call signal and adding signals such as a battery voltage transmission command, emergency operation stop command, and call number change command to the radio buoy. it can.

FIG. 1 is a block diagram of a radio buoy according to an embodiment of the present invention.
The present invention is roughly composed of a receiver 30, a transmitter 40, and a signal selector 50 having a control function.

The receiving unit 30 receives a selective call (cell call) signal from the base station and constitutes a superheterodyne type radio receiving unit. The signal input from the antenna 1 is amplified by the high frequency amplification stage 31 to form a mixer. In the mixing amplification stage 32, the reception amplification signal is mixed with the signal of the local oscillation frequency from the VCO 34 adjusted by the PLL control 33, and the intermediate frequency of both frequency differences is set to the intermediate frequency via the filter 35. Send to amplification stage 36. The intermediate frequency amplification stage 36 is composed of two stages in order to obtain a high gain, amplifies a signal of a constant intermediate frequency lower than the reception frequency, and sends it to the detector 37. The detector 37 powers up the signal by a low frequency amplification stage 38 to form a tone signal.
Further, a circuit is added to keep the input level of the detector constant by feeding back the signal output from the detector 37 to the high frequency amplification stage by the AGC amplifier 39.

  The transmission unit 40 receives a signal from a signal selection unit 50 (to be described later), and generates a carrier wave to be transmitted from an input signal having an oscillation frequency from the VCO 34 that is PLL-controlled by the transmission amplification stage 51. The carrier wave is output in synchronization with on / off of a keying signal based on CPU control. The power amplifying stage 53 amplifies the power necessary for transmitting radio waves from the antenna, and transmits a Morse signal intermittent at the transmission frequency from the antenna tuned by the internal loading coil.

  As shown in FIG. 1, the signal selection unit 50, which is a feature of the present invention, includes a low frequency amplification stage 38 including a part of the reception unit 30 instead of the conventional mechanical filters 1 to 4 (see FIG. 8). And a CPU that recognizes the tone frequency by measuring the tone waveform.

  FIG. 2 shows the principle configuration of the signal selection unit. The low frequency amplification stage 38 has a filter function that allows the frequency band of 500 to 800 Hz to pass, and amplifies and saturates the AF output of the reception unit 30. As shown in FIG. 3, the tone waveform is converted into a square wave. The CPU forms a soft filter for recognizing the tone frequency of Hz by measuring the time t of one period of the square wave.

  As shown in FIG. 4A, this soft filter has, for example, a call number 1-2-3-4 (4 tones) and a tone length of 0.2 seconds. 502.5 Hz, the second tone frequency is set to 532.5 Hz, the third tone frequency is set to 562.5 Hz, and the fourth tone frequency is set to 592.5 Hz. Here, the number of tones and the length of the tone can be easily changed by software.

  As shown in the flowchart of FIG. 5, the tone frequency is measured by the CPU by digitally converting each tone frequency of the square wave signal and counting one period of time by the CPU to identify the tone of what frequency. Thus, it is confirmed whether or not it is the first tone frequency (502.5 Hz) (first tone confirmation step A). Further, it is confirmed whether the tone length continues for 0.2 seconds, and as a result, it is determined whether or not the tone is a regular call signal.

  If the condition is satisfied, the second, third, and fourth tone frequencies are sequentially confirmed (tone confirmation steps B, C, and D). Then, a call signal indicating that the designated call number of the designated radio buoy has been called is output when the fourth tone is confirmed. As a result, the CPU outputs a signal for turning off the power supply of the receiving unit 30 and also outputs a trigger signal for issuing a transmission command to the transmission amplification stage of the transmitting unit. Then, a keying signal based on the calling signal is output to the transmission unit 40.

  In this manner, the CPU outputs a selective calling signal from the signal selection unit 50 after measuring the tone frequency, and returns to frequency measurement again after code transmission to the transmission unit synchronized with the on / off of the keying signal.

Next, a radio buoy call response method according to the present invention for executing the above operation will be described with reference to an operation time chart of FIG.
In FIG. 6, when an antenna reception radio wave is transmitted to a designated radio buoy, the radio buoy receiving unit receives a selective call signal based on the assigned unique selection number. Here, an intermediate frequency is given based on the reception time frequency by local oscillation from the VCO adjusted by the PLL control, and the tone frequency is output by the detector through the intermediate amplification stage.

The tone frequency signals T1, T2, T3, and T4 are converted into square wave signals T1, T2, T3, and T4 by the square wave conversion of the low frequency amplification stage in the signal selection unit. This square wave signal corresponds to each tone frequency of a unique selection number of the radio buoy, and the CPU counts the time of one cycle of each square wave signal T1, T2, T3, T4 and sequentially inputs the squares. It is confirmed how many Hz each tone frequency of the wave signal is .

  Then, when the order of the tone frequencies continuously input from the receiver power supply coincides with the unique selection number, a command to turn off the receiver power supply is issued from the CPU, and a transmission control signal from the VCO by PLL control Is output to the transmitter as a trigger signal. Further, a keying signal is output from the CPU to the transmission unit. A carrier wave synchronized with the on / off of the keying signal is formed in the transmission amplification stage of the transmission unit, and further in the buffer amplification stage. In the power amplification stage, the carrier wave is amplified to the power required to transmit the radio wave from the antenna, and is intermittently transmitted at the transmission frequency. The morse code is output as a transmission radio wave.

  The features and advantages of the above-described call answering system of the present invention will be described as follows.

(1) The combination of selection signals can be changed by increasing the number of digits of the tone.
This is because the number of tone frequency confirmation programs can be increased by the CPU software, and as a result, the number of digits for identifying the tone can be increased as long as there is a memory. For example, as 1-2-3-4-5 (5-digit tone recognition), the confirmation step of the fifth tone is increased to check whether the tone frequency is 592.5 Hz. Determine whether the tone lasts 0.2 seconds . By simply increasing the number of steps, the selection signal can be five digits.

(2) Enables prevention of operation due to stolen radio waves.
In the case of the current mechanical filter system, selection specific to the radio buoy by checking the duration of the tone using the stolen radio wave that combines 11 waves currently used such as No. 1 to No. R A call number may be identified. On the other hand, in the present invention, since the CPU counts the frequency, the tone frequency is digitally determined, and in the case of a stolen radio wave of a tone frequency that is not stable with an analog numerical value, the tone length is set. I can't recognize it.

(3) In addition to the conventional 4-tone call signal, the buoy can recognize other commands.
The conventional call number is 1-2-3-4. The tone identification number is changed from 4 to 5 tones, and the 5th tone is used as a command to the radio buoy. That is, when one tone is added to a total of five, the fifth tone frequency can be confirmed as shown in FIG. 7, and the operation of the radio buoy is urgently performed on the fifth tone. In order to judge the battery life of the buoy, a command for transmitting the battery voltage by Morse, a call number change command, or the like can be sent.

(4) The length of one tone can be recognized (becomes a factor that can prevent operation due to a theft signal).
If the tone length does not match the setting, the radio buoy cannot be called. However, in the present invention, since the tone length is also added to the condition, the secrecy can be improved.
Conventionally, since the tone length cannot be detected, the operation is performed regardless of the tone length. However, in the present invention, the CPU can detect the tone length.

  For example, in the call answering system of the present invention, as shown in FIG. 4B, the length of each tone of selection number 1-2-3-4 is set to 0.2 seconds, 0.4 seconds, 0.6 seconds, and 0.8 seconds, respectively. If it is set to, a call signal whose tone length does not match the setting cannot be answered. As a result, the theft signal can be identified.

Therefore, in the call answering system of the present invention, the operation of the theft signal can be prevented by changing the tone length, the mechanical filter and the active filter are not required, and it is not necessary to have a stock of these elements. Furthermore, the confidentiality of the selective call number of the radio buoy can be maintained by increasing the number of tones and detecting the tone length.
Moreover, since the mechanical filter soldering operation or the like is unnecessary, the efficiency of the assembly operation is improved.

It is a schematic block diagram of a radio buoy provided with the call response system which concerns on this invention. It is a principle block diagram of the signal selection part which concerns on this invention. It is a figure which shows conversion from the tone waveform used in the ringing response of this invention to a square wave. It is a pattern figure of the selection call number of a radio buoy. It is a flowchart figure which shows the confirmation procedure of the tone frequency of CPU in the call response of this invention. It is a figure which shows the operation | movement time chart in each step in the call response of this invention. It is a figure which shows the confirmation step of the 5th tone in the call response of this invention. It is a figure which shows schematic structure of the conventional cell call buoy. It is a more detailed block diagram of the conventional cell call buoy.

Explanation of symbols

30 receiver 38 low frequency amplification stage 40 transmitter 50 signal selector

Claims (5)

A receiver that receives a specific selective call signal assigned to the radio buoy and outputs a detected tone signal;
A low-frequency amplification stage that converts the tone signal detected by the receiving unit into a square-wave signal, a CPU that digitally converts each tone frequency of the square-wave signal that is continuously input, and counts one cycle time; And when the order of the tone frequencies that are successively input matches the unique selection number, the CPU outputs a transmission control signal as a trigger signal, and outputs in response to the trigger signal. A radio buoy call answering system comprising a transmitter that generates a carrier wave synchronized with on / off of a keying signal to be transmitted and transmits a Morse signal that is intermittent at a transmission frequency.   2. The call answering system according to claim 1, wherein the selection call signal is changeable in order of selection numbers according to CPU settings.   3. The call answering system according to claim 1, wherein one or both of the number of tones and the length of the tone can be arbitrarily set as the selective call signal.   2. The call answering system according to claim 1, wherein said selective call signal adds one tone in addition to a four-tone call signal to cause a radio buoy to recognize individual commands. The receiving unit receives a selective calling signal based on a unique selection number assigned to the radio buoy, and the tone signal detected by the receiving unit is converted into a square wave signal by a low frequency amplification stage in the signal selecting unit, The CPU counts the time of one cycle of each square wave signal corresponding to each tone frequency of a unique selection number, identifies the tone frequencies of the square wave signals that are sequentially input, and the tone frequencies that are successively input When the order matches the unique selection number, the CPU outputs a transmission control signal as a trigger signal to the transmission unit, and the Morse code is intermittent at the transmission frequency in synchronization with the on / off of the keying signal to the transmission unit. Is output as a transmission radio wave, and a radio buoy ringing response method.

Images