JPH041874B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to an underwater vehicle tracking device that tracks an underwater vehicle performing active homing using an active sonar and displays the direction and distance of the underwater vehicle.

(Prior art) An underwater vehicle (hereinafter referred to as a vehicle) that performs active homing transmits ultrasonic pulses from an active sonar, and when the echoes reflected by the sonar target are received by the active sonar, it points to the sonar target. The steering system is controlled to track the sonar target. Such active homing vehicles are well known. Underwater vehicle tracking equipment is used in practical training and functional verification tests for these vehicles to determine the position and speed of the vehicle during homing in real time.

A conventional underwater vehicle tracking device consists of a small ultrasonic transmitter (hereinafter referred to as a pinger) attached to the vehicle, an underwater measurement section, and a track display section. Generally, there is no space between the underwater measurement section and the track display section. Cables have been laid, and track display sections are installed at fixed facilities on land. FIG. 1 is a general configuration diagram of a conventional underwater vehicle tracking device of this type. Pinga 1 for craft 1
4 and a synchronous clock circuit 13 are attached.
The synchronous clock circuit 10 of the track display 3 is synchronized to the synchronous clock circuit 13 before installation, and both clock circuits produce synchronized clocks. The pinger 14 receives a synchronous clock 301 from the synchronous clock circuit 13 and transmits an ultrasonic pulse 401.
The transmission frequency of this pulse 401 and the transmission frequency of the active sonar 12 of the vehicle are made different from each other so as not to interfere with each other. The receivers 5, 6, and 7 of the underwater measuring section 2 are arranged at a distance of several hundred meters from each other. These receivers 5,
6 and 7, upon receiving the ultrasonic pulse 401, send the received sounds 501 to 701 to the processing unit 8 through the installed cable. The processing unit 8 receives the received sounds 501 and 6.
The position of the vehicle 1 is calculated from the time difference between 01,701 and the synchronous clock 301. The position is displayed on the display 9. Since the display 9 continuously displays the position of the vehicle 1, the track of the vehicle 1 is displayed on the display 9.

However, such a conventional underwater vehicle tracking device requires a tracking pinger to be mounted on the underwater vehicle in addition to the active sonar. Therefore, the structure of the underwater vehicle becomes complicated and the cost becomes high.

(Object of the Invention) An object of the present invention is to provide an underwater vehicle tracking device that can track an underwater vehicle without installing a tracking pin in addition to an active sonar on the underwater vehicle.

(Structure of the Invention) The underwater vehicle tracking device of the present invention is an underwater vehicle that has an active sonar that transmits sound waves at predetermined timing and detects the direction and distance of an underwater vehicle that is homing to a target. a synchronous clock circuit that generates a synchronous clock signal at the predetermined timing by synchronizing the tracking device with the sound waves sent out by the active sonar; a wave receiving unit that receives the sound waves sent out by the active sonar; distance calculation means for calculating the distance of the underwater vehicle by detecting a delay time difference between the output signal of the wave section and the synchronous clock signal generated by the synchronous clock circuit; and display means for displaying the distance. The configuration is as follows.

(Example) Next, the present invention will be explained in detail with reference to Examples.

Fig. 2 is a block diagram of one embodiment of the present invention;
The figure is a timing diagram of signals associated with this embodiment. This embodiment is composed of an underwater measuring section consisting of blocks indicated by numerals 21 to 28 and a track display section consisting of blocks indicated by numerals 31 to 33.
The wave receiving unit 21 is formed by arranging a plurality of directional wave receivers in a cylindrical shape, and is suspended in the sea from a buoy by a cable. The reference direction detection section 24 is also the wave receiving section 21
is fixed to and suspended from a cable. Other underwater measurement units are housed inside the buoy at sea. On the other hand, the track display unit is installed on the ship or on land, receives data from the underwater measurement unit via radio waves 128, and displays and records the track.

Next, the functions of each part will be explained in detail. Before the vehicle travels, an external trigger is simultaneously applied to the synchronous clock circuit built into the vehicle and the synchronous clock circuit 26 of this embodiment to synchronize both clock circuits. Therefore, if the clock output from the synchronous clock circuit of the vehicle is 100, and the clock output from the synchronous clock circuit 26 is 126, then both clocks are generated at the same timing as shown in FIG. The period of these clocks is T _c and the pulse width is T _p . T _c is about 1.5 to 2 seconds,
T _p is about 20 milliseconds. Both synchronous clock circuits use a crystal oscillator as a reference oscillator, and there is no problem in practical use since both clocks are considered to remain in perfect agreement within several hours from when they are synchronized until the end of cruising. When a mobile vehicle uses an active sonar and performs homing travel, the sonar transmission sound coincides with the synchronization clock 100. The sonar transmitted sound propagates underwater, and the sound waves 102 that arrive at the wave receiving unit 21 are converted into electrical signals. The wave receiver 21 consists of a plurality of wave receivers with directivity arranged at equal intervals on a cylindrical surface, and the output 121 of these wave receivers is transmitted to the receiver circuit 22 for each receiver channel.
is input to. The receiving circuit 22 generates a received signal 122 from which reverberation, noise, etc. are removed from the receiver output 121 of each channel using a filter and an amplifier. This received signal 122 is input to the direction detection circuit 23 and the time difference detection circuit 25.

The direction detection circuit 23 detects the incoming sound wave 102 from the received signal 122 of each channel with respect to the reference line of the wave receiving unit 21 (horizontal axis fixed to the wave receiving unit 21).
, that is, the relative orientation of the vehicle,
Next, the relative orientation is added to the reference line orientation 124 from the reference line orientation detector 24 fixed to the wave receiving unit 21 to obtain the absolute orientation. The reference line direction detector 24 is
Consisting of a gyro or magnetic compass, the wave receiving section 21
The direction 124 of the reference line is output. The azimuth detection circuit 23 further converts the received signal 122 into a received sound pressure level and outputs it to the data transmitter 28 as azimuth/sound pressure data 123 along with the above-mentioned absolute azimuth data.

The time difference detection circuit 25 has a synchronous clock circuit 26.
It always receives a synchronization clock 126 from the receiving circuit 22, and also receives a receiving signal 122 from the receiving circuit 22. As shown in FIG. 3, the received signal 122 is delayed from the synchronization clock 126 by the propagation time of the sound wave corresponding to the relative distance (R) between the underwater measurement unit and the vehicle. The time difference detection circuit 25 detects the received signal 122 and the synchronous clock 12.
The time differences t ₁ , t _{2 , .} . . with respect to 6 are sequentially detected.

The distance/speed calculating circuit 16 receives the time differences t ₁ , t _{2 .} . . and calculates the relative distance R to the vehicle and the vehicle speed V. If the time difference is t and the speed of sound is C, then R and V
is calculated using the following formula: R=t×C...(1) V=( _t1 - _t2 )C/Tc...(2). The calculated distance/speed data 127 is input to the data transmitter 28. The data transmitter 28 transmits the azimuth/sound pressure data 123 and the distance/velocity data 127 thus obtained as radio waves 128 to the receiver 31 of the track display section.

Radio waves 128 from the underwater measuring section are received by the receiving section 31, converted into azimuth, sound pressure, distance, and speed data 131, and inputted to the display 32 and recorder 33. The display device 32 has a circular display, the center of which is set at the underwater measurement section, and displays the position of the vehicle at the corresponding position on the display according to the azimuth and distance data, and also displays sound pressure and speed data at the same time. Display with letters or symbols. The recorder 33 records data 1
31 can be saved on a disk or magnetic tape, and can also be printed out, and has the function of printing the display contents of the display 19 directly onto paper.

As described above, this embodiment is portable and enables real-time tracking of a moving object in any sea area. Furthermore, since there is no need to mount a pinga on the vehicle, the device is simple.

(Effects of the Invention) As explained above, according to the present invention, by providing a synchronous clock circuit that generates a synchronous clock signal that is synchronized with the timing of the sound waves sent out by the active sonar, it is possible to There is no need to install a tracking pin in addition to the active sonar. Therefore, the configuration of the underwater vehicle can be simplified and costs can be reduced.

[Brief explanation of drawings]

Figure 1 is a configuration diagram of a conventional underwater vehicle tracking device.
FIG. 2 is a block diagram showing one embodiment of the present invention, and FIG. 3 is a timing diagram of signals related to this embodiment. 1... Underwater vehicle, 2... Underwater measurement section, 3...
Track display section, 5, 6, 7... Receiver installed on the seabed, 12... Active sonar, 13... Synchronous clock circuit, 14... Pinga, 100... Output from the synchronous clock circuit of the vehicle. clock, 1
02... Arriving sound wave, 122... Received signal, 126
. . . A clock that is the output of the synchronous clock circuit 26.

Claims (1)

[Claims] 1. In an underwater vehicle tracking device that has an active sonar that transmits sound waves at predetermined timing and detects the direction and distance of an underwater vehicle homing to a target, the system is synchronized in advance with the sound waves transmitted by the active sonar. a synchronous clock circuit that generates a synchronous clock signal at a predetermined timing; a wave receiving section that receives the sound waves sent out by the active sonar; What is claimed is: 1. An underwater vehicle tracking device comprising: distance calculation means for calculating the distance of the underwater vehicle by detecting a delay time difference with a synchronous clock signal; and display means for displaying the distance.