JPS591014B2 - Koukoutainiokerujido Sentakujiyushinboushiki - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a system in which a navigation object such as a ship selects and receives image signals transmitted toward itself.

The inventor previously filed a patent application for a control system for watercraft.

This method installs a high-performance radar transmitter/receiver and a signal processing device assisted by a computer at a land-based facility, and images displayed on the radar receiver are divided into different types of watercraft, e.g., by type of ship or by each individual ship. The images will be transmitted using various still image transmission methods. On the other hand, the ship side selects and receives only those necessary for its own ship from among the image signals transmitted as described above.
Immediately after receiving the radar signal, the ship heads for land, first returns its own identification signal, and then communicates with land as necessary. In this system, there are many types of images transmitted from land, and if a ship mistakenly receives a signal intended for another ship and misidentifies it as being for its own ship, a collision or other scandal is likely to occur.

Therefore, on the ship side, it is desirable to automate the channel selection of a predetermined image to prevent misidentification. The present invention has been made in view of the above-mentioned points, and when an ultra-high frequency signal transmitted from a fixed station is detected in a navigation vehicle, a self-identification signal is generated within a receiving device installed in the navigation vehicle, and based on the self-identification signal, The present invention aims to provide a new automatic selection reception method that automatically selects and receives image broadcasts directed to the user. An embodiment of the reception method according to the present invention will be described in detail below based on the drawings.

Figure 1 shows a simplified system diagram of land facilities and shipboard equipment when the method of the present invention is applied to ship control in ports. This applies to each internal device.

First, in Figure 1A, 1 is the central control device that is the core of the land facility, and is a part that can be compared to the human brain.

2 is a high-performance radar device; if the central control device 1 is the brain, the radar device 2 corresponds to the eyes.

The radar device 2 monitors the number of ships in the port, their positions, speeds, etc. every moment, and the resulting data is transmitted to the central control device 1 along with video signals that form the basis of radar images.
sent to. In this figure, 3 is a receiving device for radio waves transmitted from ships, and 4 is a transmitting device for image signals to each ship, the roles of which will be described later. Note that 5 is a radar antenna, and 6 is a transmitting antenna. Next, the first
In FIG. B, when a radar radio wave from land is input to the microwave antenna 8, the radio wave is amplified and detected in the receiving section 9 and becomes a radar video signal.

However, since this signal is not used to directly display an image on the ship side, the output signal of the receiving section 9 will be hereinafter referred to as a video pulse in order to distinguish it from a signal for image transmission. After the video pulse once passes through the level detection circuit 10, if the amplitude exceeds a predetermined level, the self-identification signal generator 11 is triggered to generate a code signal unique to the own ship. This signal enters the mixing amplification circuit 12 together with an image reception ready signal, which will be described later, and is modulated into a carrier wave in the VHF band by the amplification and modulation circuit 13.
The modulated VHF waves are radiated from the antenna 14 toward land. This VHF wave is transmitted to antenna 7 on land.
The signal is then demodulated by the receiving device 3 of FIG. 1A and sent to the central control device 1. This allows the shore side to identify the responding ship. Therefore, the image signal transmitting device 4 transmits still images to each ship as a television signal through the antenna 6. This signal is time-division multiplexed, and in the case of this embodiment, after one frame of the coded image, one frame of an analog format image, that is, an image including halftones, is sent to the same ship. Next, both types of signals described above are similarly transmitted one frame at a time to another ship.Let the analog image signal for one ship be A, the code image signal A', and each other Both types of signals to ships are designated as B, B', C, respectively.
When expressed as C/, etc., the signal sent from the image transmitting device 4 is A-A'-B-B'-C-C'D-D'
-... The images will be emitted to the sea from the image transmitting antenna 6 in a time series as follows. This time-series signal enters the image receiving antenna 15 in FIG. 1B,
It is demodulated by the image signal receiving section 16 and becomes a signal corresponding to a television video signal. This signal includes a code signal for image selection (hereinafter referred to as a selection signal) in advance on the transmitting side, that is, within the transmitter 4 on land. Is this possible by making the selection signal droop during the blanking period of the vertical synchronization signal? All you have to do is go.

This selection signal is determined by the central monitoring device 1 on land based on the ship identification signal transmitted from the ship.For example, the ship identification signal may be a binary code representing the unique number assigned to each ship. For example, a code pulse in which the binary code corresponds to the presence or absence of a pulse may be used as the selection signal. The image signal including the above-mentioned selection signal enters the image signal receiving section 16 through the image signal receiving antenna 15 in FIG. 1B, and thereafter becomes a video signal through the same process as in ordinary television.

The automatic selection operation, which is the main focus of the present invention, is performed using the selection signal extracted from the video signal.

17 and 18 are image signal selection sections, and 17 is for analog images.

The detailed structure of these will be described later, but when the selection signal enters both the selection sections 17 and 18, the mixing amplifier 12 to which the selection section 17 outputs a signal indicating completion of image reception preparation.
The signal is transmitted, modulated by the modulation circuit 13, and transmitted or returned from the antenna 14 toward shore, notifying the ship that the image receiving section is ready to receive the image. Next, the operation of the image signal selection section will be explained with reference to FIG. The video signal output from the image signal receiving section 16 is synchronously separated by a synchronous separation circuit 20, and a selection signal is extracted from the synchronous signal by a selection signal extraction section 21a.

The extracted selection signal is stored in the first register 22. In reality, a signal shaping circuit is often required before the register 22, but it is omitted in the figure for simplicity. On the other hand, the self-identification signal generated by the self-identification signal generating section 11 is stored in the second register 24 via the analog bit adding circuit 23.

The analog bit addition circuit is for adding one bit of information to the self-identification signal in order to distinguish between an analog image and a code image. Also for selection signals from land,
Analog images and self-identification signals sent from the ship,
1-bit information that distinguishes it from the code image, i.e. 1 or O
By adding "," it is possible for the ship to distinguish between the two types of images without error. Incidentally, in the example shown in the figure, for convenience, the synchronous separation circuit 20 is placed in front of the image signal selection section 17 as a separate block from the image signal receiving section 17, but the circuit configuration is such that one synchronous separation circuit is shared by both sections. You can also do that. Now, the first register 22 and the second register 2
4 results in an output from match circuit 25.

When this output is received, notification of completion of preparation for image reception and display of the image (that is, image reception) are performed. These operations can be carried out by, for example, using the output of the matching circuit 25 to trigger the circuit systems that play the respective roles described above to activate them. Since a wide variety of trigger methods are already well known, detailed explanations will be omitted. Reference numeral 26 denotes a circuit that generates a signal indicating the completion of image reception preparation (hereinafter referred to as a preparation completion signal), and the output of this circuit is inputted to the mixing amplifier 12 of FIG. 1B as described above and transmitted.

Note that unlike entertainment television, the image signals necessary for own ship exist only for a short period of time (for example, 1/30 seconds), so the brightness modulation signals are temporarily stored in the memory 27.
The still image is sent to the image display unit 28 a required number of times to reproduce the still image. Next, the code image signal is processed by the dedicated signal selection section 18 shown in FIG. 2B, but since the selection signal is 1 bit different from that of the analog image signal,
After the code image signal bit applying circuit 29, a dedicated selection signal extraction circuit 21b and two registers 30 and 3 are provided.
1, the contents of both registers are compared by a match circuit 32, and when they match, a match signal is outputted, and the match signal activates the decoder 33 and causes the image display device 34 to display an image.

In this embodiment, for the sake of simplicity, the ready signal generation circuit is of a single system, and the signal is generated by either output of the two matching circuits 25 and 32. However, of course, the code image signal selection section A separate ready signal generation circuit may also be provided. According to the method of the present invention described above, different images can be transmitted from a land-based control station to each navigation object such as a ship.

On the other hand, the navigation vehicle side has the excellent advantage of being able to automatically select and receive image information intended for itself, and no errors occur. Therefore, the method of the present invention is extremely advantageous when applied to control of various ships in ports, transmission of necessary information, etc., and can also be applied not only to ships but also to control of aircraft at airports. It is.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing an example of the configuration of a transmitting/receiving device according to the method of the present invention. FIG. 1A shows a transmitting/receiving device installed in a land facility, and FIG. 1B shows a transmitting/receiving device mounted on a ship. FIG. 2 is a system diagram showing an example of the circuit configuration of an image signal selection section in a ship-mounted transmitting/receiving device according to the present invention.
1: central control device, 2: radar device, 3: land receiving device, 4: image signal transmitting device, 9: radar radio wave receiving section,
10: Level detection circuit, 11: Self-identification signal generation section, 1
3: VHF modulation circuit, 16: image signal receiving section, 17 and 18: image signal selection section, 20: synchronization separation circuit, 21a:
Analog selection signal extraction section, 21b: Code selection signal extraction section, 22: First register, 23: Analog bit addition circuit, 24: Second register, 25: Matching circuit, 26:
Ready completion signal generation circuit, 27: memory, 28: analog image display section, 33: decoder, 34: code image display section.

Claims (1)

[Claims] 1. A fixed station transmits an ultra-high frequency signal for detection and a multiplexed image signal including a code signal for specifying the receiving side toward a navigation object, and the navigation object is equipped with an ultra-high frequency receiver that receives and demodulates the ultra-high frequency signal. , a self-identification signal generating section that is activated by the output of the ultra-high frequency receiving section; an identification signal transmitting section that modulates a carrier wave with the self-identifying signal and transmits the modulated wave toward the fixed station; and an image signal receiving section. A transmitting/receiving device having an image signal selecting section and an image displaying section is installed, and the transmitting/receiving device detects only when the code signal included in the image signal transmitted from the fixed station and the self-identification signal are encoded. An automatic selection reception system in a navigation vehicle, characterized in that the image display section is activated.