JP2563790Y2 - Underwater position measurement system using pinger - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underwater position measuring system, and more particularly to detecting a position of a pinger by receiving a signal from a pinger installed in water using an underwater position measuring device mounted on a ship or the like. The present invention relates to an underwater position measuring system for determining the position of a ship or the like.

[0002]

2. Description of the Related Art Conventionally, in this type of underwater position measuring system, the direction in which the pingers are present has been detected by an underwater position measuring device, but the distance to the pingers is almost always detected. I didn't. As a method attempted in the past, there is a method of receiving a sound of a certain frequency transmitted by Pinger, measuring the attenuation of the sound, and calculating the distance. However, this method is far from practical use due to large errors and variations in the measurement distance due to the influence of the sound propagation path in water and fluctuations in the sound pressure transmitted by Pinger itself.

[0003]

The above-described conventional underwater position measuring system detects the direction in which the pingers are present, but it is difficult to detect the distance to the pingers.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide an underwater position measuring system capable of easily detecting a direction in which a pinger exists and a distance to the pinger.

[0005]

Means for Solving the Problems There are two types of underwater sound attenuation: diffusion attenuation and absorption attenuation. In diffusion attenuation, there is no difference depending on the frequency of the underwater sound. The higher the value, the more the sound will attenuate in proportion to the distance the underwater sound travels. Both are generally expressed by the following equation (1),
It is expressed by (2), and the sum of the two is the total attenuation.

Diffusion attenuation = 20 log R (1) where R is the distance from the pinger (m) Absorption attenuation (α) = ｛40f ² / (4100 + f ² ) ＋ + 0.1f ² / (1 + f ² ) + 0.000275f ² +0.003 (2) On the basis of this principle, the first and second ultrasonic waves having different frequencies are transmitted from the pinger and their attenuations are obtained. If the difference is detected, the distance to the pinger can be detected. In addition, the direction in which the pingers exist is based on the conventionally known SSB.
L can be easily detected from either one of the first and second ultrasonic waves, and if used together with the distance calculated from the first and second ultrasonic waves transmitted from the pinger at a fixed period, the position of the pinger can be detected. Or, the position of own ship can be accurately detected.

Therefore, the underwater position measuring system of the present invention comprises a pinger and an underwater position measuring device, wherein the pingers have first and second ultrasonic waves having first and second frequencies, respectively. From the transmitter, the underwater position measuring device receives the first and second ultrasonic waves from the pinger via a receiver, and outputs the first and second reception outputs. And a first receiving output for S
An SSBL processing unit that performs an SBL process to detect a direction in which the pinger exists, and a first and a second reception outputs from the first and second reception outputs.
A level detector for detecting a reception level of the second ultrasonic wave;
A distance calculation unit that calculates a distance to the pingers from a difference in reception levels of the first and second ultrasonic waves detected by the level detection unit, and a direction and a distance calculation unit where the pingers are detected by the SSBL processing unit are calculated. And a display unit for displaying the position of the pinger from the set distance. Preferably, the pinger transmits the first and second ultrasonic waves from the transmitter at the same level, and the distance calculation unit changes in accordance with a traveling distance of the first and second ultrasonic waves. From the level difference between the first and second ultrasonic waves, which is the same as the difference between the reception levels of the first and second ultrasonic waves, from the level difference between the first and second ultrasonic waves to the pinger. Is calculated. Alternatively, the distance to the pinger is calculated by a level ratio instead of the level difference.

[0008]

The higher the frequency of the first and second ultrasonic waves transmitted from the pinger, the faster the attenuation. The distance calculation unit calculates the distance to the pinger from the difference or ratio between the reception levels of the first and second ultrasonic waves detected by the level detection unit. The display unit displays the position of the pinger from the direction in which the pinger is detected by the SSBL processing unit and the distance to the pinger calculated by the distance calculation unit.

[0009]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the underwater position measuring system of the present invention, and FIG. 2 is a characteristic diagram for explaining the operation of the embodiment of FIG. The underwater distance measuring system according to the present embodiment includes a pinger 10 and an underwater distance measuring device 20.

The pinger 10 is connected to the transmitter 11 by the time T
Timers 12 and 13 for setting T1 and T2, and after transmitting a signal of the first frequency for a time T1, transmit a signal of a second frequency for a time T2. And a transmitting unit 14 for transmitting the message.

The underwater position measuring device 20 includes a receiving section 22 for outputting a reception output for receiving an ultrasonic wave from the pinger 10 via a receiver 21 and an SSBL based on the reception output of the first frequency among the reception outputs. An SSBL processing unit 23 that detects the direction in which the pinger 10 is present, a reception level detection units 24 and 25 that detect the reception levels of the ultrasonic waves of the first and second frequencies, and a reception level detection unit 24, 25
And a comparing unit 26 for detecting a ratio between the detected reception levels. Further, the underwater distance measuring device 20 includes a comparing unit 26
The CPU 27 calculates the distance to the pinger 10 from the detected level ratio and refers to the direction in which the pinger 10 is detected by the SSBL processing unit 23 to determine the position of the pinger 10 and display it on the display unit 28. .

In the present embodiment, the ratio between the reception levels of the ultrasonic waves of the first and second frequencies received by the receiver 21 is determined by the output of the reception level detectors 24 and 25.
The frequency characteristics and the gain are adjusted so as to be kept as they are. Further, the CPU 27 stores a relationship (see FIG. 2) between the above-described ratio between the reception levels (a difference in the case of logarithmic display) and the distance to the pinger 10 in a memory (not shown). The stored data is discrete, but the value between each data is calculated by a complementary operation.

In the case of the example shown in FIG. 2, the first frequency is 30 kHz.
z, the second frequency, the ultrasonic wave A and the ultrasonic wave B of 80 kHz are transmitted from the pinger at the level of 140 dB.
Since the level difference between the detected ultrasonic waves A and B is 62 dB, it is detected that the distance to the pinger is 3000 m.

In the present embodiment, the first and second ultrasonic waves are transmitted from the same oscillator of the transmitter 11, but separate oscillators may be provided and transmitted from each. . Also, the first and second ultrasonic waves are transmitted at the same level by the transmitter 1.
Although the transmission is started from 1, the ultrasonic wave having a larger attenuation may be transmitted at a higher level.

[0015]

As described above, according to the present invention, the first and second ultrasonic waves transmitted from the pinger are attenuated faster at higher frequencies, and the level detector is provided to the distance calculator. The distance to the pinger is calculated from the ratio of the reception levels of the detected first and second ultrasonic waves, and the direction in which the pinger is detected by the SSBL processing unit and the distance to the pinger calculated by the distance calculation unit are displayed on the display unit. By displaying the position of the pinger, the position of the pinger can be accurately determined.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an underwater position measuring system of the present invention.

FIG. 2 shows a first and a second used in the embodiment of FIG.
FIG. 4 is a characteristic diagram showing a relationship between a reception level of an ultrasonic wave and a distance to a pinger.

[Explanation of symbols]

 Reference Signs List 10 Pinger 11 Transmitter 12, 13 Timer 14 Transmitter 20 Underwater distance measuring device 21 Receiver 22 Receiver 23 SSBL processing unit 24, 25 Received level detector 26 Comparison unit 27 CPU 28 Display unit

Claims (4)

(57) [Scope of request for utility model registration] 1. An underwater position measuring system comprising a pinger and an underwater position measuring device, wherein the pinger transmits first and second ultrasonic waves having first and second frequencies, respectively, from a transmitter. A receiving unit that receives the first and second ultrasonic waves from the pinger via a receiver and outputs first and second reception outputs, SSB detecting the direction in which the pinger exists by adding SSBL processing to the reception output of No. 1
An L processing unit, a level detection unit that detects reception levels of the first and second ultrasonic waves from the first and second reception outputs, and a reception level of the first and second ultrasonic waves detected by the level detection unit A distance calculation unit that calculates the distance to the pinger from the difference between
A display unit for displaying the position of the pingers based on the direction in which the pingers are detected by the SSBL processing unit and the distance calculated by the distance calculation unit. 2. The underwater position measuring system according to claim 1, wherein the pingers transmit the first and second ultrasonic waves from the transmitter at the same level. 3. The distance calculator stores a level difference between the first and second ultrasonic waves that changes in accordance with the traveling distance of the first and second ultrasonic waves. The underwater position measuring system according to claim 1, wherein a distance to the pinger is calculated from a level difference between the first and second ultrasonic waves that is the same as a difference between reception levels of the ultrasonic waves. 4. The distance calculator stores a level ratio of the first and second ultrasonic waves that changes in accordance with a traveling distance of the first and second ultrasonic waves. The underwater position measurement system according to claim 1, wherein a distance to the pinger is calculated from a level ratio of the first and second ultrasonic waves that is the same as a ratio of reception levels of the ultrasonic waves.