KR20240121540A - Location detecting system and method for underwater vhicle using underwater sound source - Google Patents

Abstract

The present invention relates to a system and method for setting a position of an underwater vehicle such as a submarine or a submersible. An underwater position setting system according to one embodiment of the present invention includes: an underwater sound source device which is separated from the underwater vehicle and fixed to a predetermined seabed location and periodically transmits sound source information including position information, sound source direction information, and sound source transmission time; an acoustic detector which periodically receives sound source information transmitted from the underwater sound source device; and an underwater position calculating device which calculates a direction and distance based on sound source information of the underwater sound source device received through the acoustic detector to calculate an underwater position of the underwater vehicle.

Description

LOCATION DETECTING SYSTEM AND METHOD FOR UNDERWATER VHICLE USING UNDERWATER SOUND SOURCE

The present invention relates to a system and method for determining the position of an underwater vehicle, and more particularly, to a system and method for determining the position using an underwater sound source device.

The material described in this section merely provides background information for the present embodiment and does not constitute prior art.

Underwater vehicles such as submarines and submersibles that navigate underwater inevitably perform surface navigation or periscope depth navigation to receive GPS information in order to calculate their own positions. However, surfacing or performing periscope depth navigation to receive GPS may expose them to detection or safety risks.

Therefore, for safety reasons, if an underwater vehicle does not surface, it cannot receive GPS information, so it must be equipped with an inertial navigation system (INS) or utilize a separate micro navigation function to calculate its location.

However, in the case of submarines that require stealth and must continue to navigate underwater for long periods of time, there is a problem that the inertial navigation system (INS) generates accumulated position errors due to the influence of currents, etc. In addition, in the case of deep seas, it is impossible to utilize ground speed information using Doppler-Log, so the composite navigation function also generates accumulated position errors in proportion to time.

Due to these problems, the current submarine operation system has the problem that, when it is necessary to continue underwater navigation for a long period of time, it must either conduct operations while taking into account a certain level of positional error or surface to periscope depth and receive GPS information while taking risks in terms of exposure and safety.

The purpose of the present invention is to provide a system and method for determining the position of an underwater vehicle, which can improve the accuracy of underwater complex navigation by correcting the exact position information of the underwater vehicle using sound source information received from an underwater sound source device.

However, the purpose of the present invention is not limited to the matters mentioned above, and other purposes not mentioned will be clearly understood by those skilled in the art from the description below.

An underwater position determination system according to one embodiment of the present specification includes: an underwater sound source device that is separated from an underwater vehicle and fixed to a predetermined seabed location and periodically transmits sound source information including position information, sound source direction information, and sound source transmission time; an acoustic detector that periodically receives sound source information transmitted from the underwater sound source device; and an underwater position calculation device that calculates direction and distance based on sound source information of the underwater sound source device received through the acoustic detector to calculate the underwater position of the underwater vehicle.

Preferably, the underwater position determination system further includes an inertial navigation system; a Doppler log that measures the speed of an underwater vehicle in the forward and backward directions and left and right directions using the Doppler effect of sound waves underwater; and a composite navigation device that corrects position information by utilizing signals derived from the inertial navigation system and the Doppler log for the underwater position derived from the underwater position calculating device.

Additionally, it may preferably further include a GPS receiver.

In addition, it is preferable that the underwater sound source device is launched outside the underwater vehicle through the torpedo launcher of the underwater vehicle and fixed at a predetermined seabed location.

In addition, it is preferable that the underwater position calculation device sets (presets) mutual time synchronization, the sound source transmission cycle, and the operating period of the underwater sound source device before launching the underwater sound source device.

In addition, preferably, the underwater sound source device includes a timer; a battery; and a sound wave transmitter that transmits the sound source information.

A method for determining an underwater position of an underwater vehicle according to one embodiment of the present specification includes: a preset step of setting a sound source transmission cycle and an operation period of the underwater sound source device, and synchronizing the time between the underwater sound source device and the underwater vehicle; a step of launching the underwater sound source device outside the underwater vehicle and taking the launching position as a starting point; a step of receiving sound source information including position information, sound source direction information, and sound source transmission time from the underwater sound source device separated from the underwater vehicle and fixed to a predetermined seabed location; a step of calculating a direction and distance based on the received sound source information to calculate the underwater position of the underwater vehicle; and a step of correcting the calculated underwater position using a composite navigation device.

Preferably, the step of calculating the position of the underwater vehicle is characterized by calculating the position through a BO (Bearing Only) algorithm based on sound source information transmitted from one underwater sound source device.

Alternatively, preferably, the step of calculating the position of the underwater vehicle is characterized by calculating the position through a CO (Crossover) algorithm based on sound source information transmitted from two underwater sound source devices.

In addition, preferably, the CO algorithm is characterized in that it calculates a distance R1 between the first underwater sound source device and the underwater vehicle using the position information P1, direction information B1, sound source transmission time TT, sound source reception time RT1, and sonar environment analysis information of the first underwater sound source device, calculates a distance R2 between the second underwater sound source device and the underwater vehicle using the position information P2, direction information B2, sound source transmission time TT, sound source reception time RT2, and sonar environment analysis information of the second underwater sound source device, and calculates position information and intersecting direction information using the direction information B1 and distance R1 of the first underwater sound source device, and the direction information B2 and distance R2 of the second underwater sound source device, calculates weights through the same, and determines the position of the underwater vehicle by reflecting the calculated weights.

In addition, preferably, the underwater position correction step is characterized in that the composite navigation device corrects the position information by utilizing signals generated from an inertial navigation device and a Doppler log.

In addition, it is preferable that the underwater sound source device is launched outside the underwater vehicle through the torpedo launcher of the underwater vehicle and fixed at a predetermined seabed location.

According to one embodiment of the present invention, there is an effect of improving the accuracy of underwater composite navigation by correcting the exact location information of an underwater vehicle by utilizing sound source information received from an underwater sound source device.

In addition, it has the effect of improving the underwater operational sustainability by being able to maintain the accuracy of the ship's location underwater without surfacing to periscope depth, ensuring the stealth and safety of the underwater vehicle.

In addition, it has the effect of maintaining the ship's position accuracy without GPS information even when extensive GPS interference occurs in the operational area.

Furthermore, if the underwater vehicle is an unmanned submersible, it can be effectively utilized as a means to improve the positional accuracy of autonomous underwater navigation.

In addition, according to one embodiment of the present invention, the effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description below.

FIG. 1 is a conceptual diagram illustrating an underwater position determination system of a submarine using an underwater sound source device according to one embodiment of the present invention.
FIG. 2 is a block diagram schematically illustrating a configuration of a submarine positioning system according to one embodiment of the present invention.
FIG. 3 is a reference diagram for explaining the concept and method of determining an underwater position using a seabed-fixed underwater sound source device according to one embodiment of the present invention.
FIG. 4 is a reference diagram for explaining an underwater position determination method using two submarine fixed underwater sound source devices according to one embodiment of the present invention.
Fig. 5 is a reference diagram for explaining a method for determining an underwater position considering weights in the embodiment of Fig. 4.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. First, when adding reference numerals to components of each drawing, it should be noted that the same components are given the same numerals as much as possible even if they are shown in different drawings. In addition, when describing the present invention, if it is determined that a specific description of a related known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted. In addition, although preferred embodiments of the present invention will be described below, it should be understood that the technical idea of the present invention is not limited thereto and can be modified and implemented in various ways by those skilled in the art.

FIG. 1 is a conceptual diagram illustrating an underwater position determination system of a submarine using an underwater sound source device according to one embodiment of the present invention.

Hereinafter, in the embodiments of this specification, a submarine is used as an example as a representative underwater vehicle, but the present invention is not limited to this embodiment, and can be applied to various types of underwater vehicles such as submersibles, ships, and unmanned submarines.

As illustrated, the submarine (100) is equipped with an underwater position determination system for searching and determining the underwater position of the submarine.

The submarine's underwater position determination system includes a seabed-fixed underwater sound source device (200), an underwater position calculation device (10), a composite navigation device (20), an inertial navigation device (30), a Doppler log (40), a passive sonar (50), a GPS system (60), a torpedo launcher (70), etc.

At least one or more underwater sound source devices (200) can be mounted on a submarine (100), and the underwater sound source device (200) can be initially mounted on a submarine (100) to perform preset settings for time synchronization and various sound source transmission operations through an underwater position calculation device (10). In addition, in order to perform an operation, the underwater sound source device can be separated from the submarine (100), dropped and fixed at a predetermined seabed location, and periodically transmit sound source information including its own location information, sound source direction information, and sound source transmission time.

The underwater sound source device (200) can be launched externally through the torpedo launcher (70) of a submarine (100) and fixed at a predetermined seabed location.

A passive sonar (50) may also be referred to as a sound detector, and periodically receives sound source information transmitted from an underwater sound source device (200) fixed at a predetermined location.

For reference, sonar (SOund Navigation And Ranging) is a device that uses sound waves to determine the direction and distance of underwater targets, and is also called a sound detector, acoustic detector, or sound sensor.

In the air, electromagnetic waves travel faster and farther than sound waves, so radar can be used to detect targets in the air, on land, and at sea, and the underwater equipment that corresponds to this is sonar. The sound waves used in sonar are pressure waves that travel at a speed of about 1,500 meters per second, and have the property of traveling quickly underwater. They can be categorized as passive sonar or active sonar.

Passive sonar is a key detection device of submarines that can identify the type of target by receiving noises from engines or propellers while the submarine is sailing from a distance. It is a sonar that listens to all sounds underwater as if listening to the sound inside the stomach with a stethoscope while the submarine is sailing quietly at low speed in key waters or passages. This passive sonar analyzes whether it is a warship, a merchant ship, or a fishing boat, how many propulsion shafts there are, how many screw blades there are, and even the course and speed.

Active sonar is a method of detecting enemy submarines or mines by detecting the direction and distance of targets by receiving signals from sound waves that are reflected from targets by the submarine. It uses the principle of transmitting sound waves from a submarine and then returning after hitting the target. However, since a submarine's location is immediately exposed when it transmits sound waves, it is used for very limited purposes, such as checking for underwater obstacles in safe waters or transmitting them momentarily to determine the exact distance before a torpedo attack.

The underwater position calculation device (10) calculates the direction and distance of the fixed underwater sound source device (200) on the seabed based on the sound source information of the underwater sound source device (200) received through the sonar (50) and calculates the underwater position of the submarine (100).

An inertial navigation system (INS) (30) is a device installed on submarines, aircraft, missiles, etc. to detect its own position and guide it to its destination. The operating principle is to determine the direction reference using a gyroscope, obtain the displacement using an accelerometer, and reflect the displacement from its original position, so that the position and speed of the ship in motion can always be calculated and reflected. It has the advantage of not being affected by bad weather or radio interference, but errors accumulate and increase when moving a long distance, so it is desirable to use it with additional correction using GPS or active radar guidance.

The hybrid navigation device (20) combines a dead reckoning (DR) system composed of a speedometer, a geomagnetic sensor, an inertial sensor, etc., with a GPS receiver to provide positioning information without interruption when a GPS signal is interrupted, and the hybrid navigation positioning technology can be configured in various forms depending on the form of the dead reckoning (DR), the combining technique, and the combining filter. Here, a Kalman filter is typically used as the combining filter, and an extended Kalman filter (EKF: Extended Kalman Filter) is used to apply a Kalman filter used in a linear system to a DR/GPS hybrid navigation system, which is a nonlinear system. The extended Kalman filter (EKF) can accurately estimate errors in good environments, such as small initial estimation errors, small system/measurement noise, and no model uncertainty, and can provide positioning information with good performance in a DR/GPS hybrid navigation system. However, in environments where initial azimuth information cannot be calculated, system/measurement noise is large, or model uncertainty exists, it may exhibit suboptimal or divergent characteristics.

The Doppler Log (40) is a device used in underwater navigation, which measures the speed of an underwater vehicle in the forward and backward directions and left and right directions over land or water by utilizing the Doppler effect of sound waves underwater. For reference, the Doppler effect (Doppler effect or Doppler shift, Doppler phenomenon, Doppler shift phenomenon) refers to a phenomenon in which the frequency and wavelength of a wave change depending on the relative speed of the wave source and the observer. In waves moving through a medium, such as sound waves, the effect changes depending on the relative speed of the observer and the wave source with respect to the medium.

Meanwhile, speed of the ground refers to the speed relative to land, which includes the effects of external forces, and speed through water refers to the speed relative to water, which includes the effects of external forces. For example, if a ship with a speed of 3 m/s in flowing water and a speed of 10 m/s on the ground moves in the direction of flowing water, its speed through water will be 7 m/s.

The GPS system (60) is a means for receiving GPS information and is used when a submarine (100) is navigating on the surface or under periscope depth, enabling the submarine to search for its own location and navigate based on GPS location information.

FIG. 2 is a block diagram schematically illustrating the configuration of a positioning system for a submarine according to one embodiment of the present invention.

As described above, the underwater sound source device (200) performs mutual time synchronization with the underwater position calculation device (10) before being launched outside the submersible (100). In addition, by presetting the sound source transmission cycle and operating period of the underwater sound source device (200), the underwater sound source device (200) is enabled to periodically transmit sound source information according to the set criteria from a fixed location on the seabed.

The underwater sound source device (200) is fixed on the seabed and can be operated in at least one or more units, and it is preferable to have a presetting function (time synchronization, sound source transmission cycle, operation period, etc.). The underwater sound source device (200) can be launched through the torpedo launcher of a submarine (100), and is equipped with a high-precision timer (230) and a periodic (hourly) sound source transmission function. In addition, a battery (220) for long-term operation, at least 2 years, can be built-in, and preferably, it can have a pressure-resistant watertight function that can be operated at a depth of 300 m or more.

The underwater position calculation device (10) has a presetting function for a seabed-fixed underwater sound source device (200) and a launching position starting point function for the seabed-fixed underwater sound source device (200).

In addition, it includes a predetermined algorithm for calculating the self-ship position, and the algorithm may be a self-ship position calculating algorithm using sound source information of one underwater sound source device (200) (hereinafter referred to as a 'BO' (Bearing Only) algorithm), or a self-ship position calculating algorithm using sound source information of two underwater sound source devices (200, 300) (hereinafter referred to as a 'CO' (Crossover) algorithm).

The method for determining the self-position performed in the underwater position calculation device (10) will be described later with reference to the relevant drawings.

The composite navigation device (20) receives information for self-position correction from the inertial navigation system (30) and the Doppler log (40) and corrects the self-position calculated by the underwater position calculation device (10).

That is, by receiving ground or water velocity from the Doppler log (40) and receiving position/velocity and self-attitude information from the inertial navigation device (30), more accurate position determination becomes possible by performing self-position correction.

That is, the present invention improves the accuracy of underwater composite navigation of a submarine currently in operation or scheduled for future operation by correcting accurate location information using sound source information from an underwater sound source device (200). In the case of existing composite navigation, a location error of about 2 km occurs during 24-hour underwater navigation, but in the case of the present invention, the location accuracy can be maintained within about 500 m.

The underwater position determination method in the underwater position determination system illustrated in Fig. 2 is described as follows.

First, the underwater position calculating device (10) sets the sound source transmission cycle and operating period of the underwater sound source device (200), and synchronizes the time between the underwater sound source device (200) and the underwater position calculating device (10).

Afterwards, the underwater sound source device (200) is launched outside the submarine (100) and the launching location is taken as a starting point. The underwater sound source device (200) is separated from the submarine (100) and launched, fixed at a predetermined location on the seabed, and periodically transmits sound source information to the outside according to a preset method.

Thereafter, sound source information periodically transmitted by an underwater sound source device (200) is received through the sonar (50) of the submarine (100), i.e., a passive sonar. The sound source information may include location information, sound source direction information, and sound source transmission time.

The underwater position calculating device (10) calculates the underwater position of a submarine (100) by calculating direction and distance based on sound source information received through a sonar detector (50).

The algorithm for calculating the location of a submarine (100) by utilizing sound source information of an underwater sound source device (200), i.e. the BO function, is explained as follows.

The underwater position calculation device (10) can calculate direction and distance using the position information (P) of the underwater sound source device (200), sound source direction information (B), sound source transmission time (TT, preset information), sound source reception time (RT), and sonar environment analysis information (sound speed, sound wave path, etc.).

If the distance between the underwater sound source device (200) and the submarine (100) is R ₀ , R ₀ can be calculated using the following mathematical expression 1.

In mathematical expression 1, SV represents the speed of sound, RT represents the sound reception time, and TT represents the sound transmission time.

The location of a submarine (100) can be calculated using direction and distance information from a seabed-fixed underwater sound source device (200), and then the calculated underwater location is corrected using a composite navigation device (20).

Meanwhile, the algorithm for calculating the location of a submarine (100) by utilizing sound source information of two underwater sound source devices (200), i.e. the CO (Crossover) function, is described with reference to FIGS. 3 and 4.

FIG. 3 is a reference diagram for explaining the concept and method of determining an underwater position using a seabed-fixed underwater sound source device according to one embodiment of the present invention.

As shown, there are at least two underwater sound source devices (200, 300, 400) that are separated from a submarine (100) and installed at a fixed location on the seabed and are spaced apart from each other by a distance R.

When the first underwater sound source device (200) periodically transmits its position information P1 and direction information B1, the underwater position calculation device (10) of the submarine (100) calculates the distance R1 between the first underwater sound source device (200) and the submarine (100) using the received sound source information, preset sound source transmission time TT, sound source reception time RT1, and sonar environment analysis information as shown in mathematical expression 2. Here, the sonar environment analysis information is information about sound speed and sound wave transmission path.

Likewise, when the second underwater sound source device (300) periodically transmits its location information P2 and direction information B2, the underwater position calculation device (10) of the submarine (100) calculates the distance R2 between the second underwater sound source device (300) and the submarine (100) using the received sound source information, preset sound source transmission time TT, sound source reception time RT2, and sonar environment analysis information as in mathematical expression 3. Here, the sonar environment analysis information is information about sound speed and sound wave transmission path.

Therefore, the location information of the submarine (100) is calculated by utilizing the direction B1 and B2 information and the distance R1 and R2 information from the first underwater sound source device (200) and the second underwater sound source device (300) fixed on the seabed.

At this time, the direction information B1 and distance R1 of the first underwater sound source device (200), and the direction information B2 and distance R2 of the second underwater sound source device (300) are used to derive the location information and the cross-direction information, and the weight is calculated through this.

The method of calculating weights and determining underwater position using the same is explained with reference to FIGS. 4 and 5.

FIG. 4 is a reference diagram for explaining an underwater position determination method using two submarine fixed underwater sound source devices according to one embodiment of the present invention.

As shown, the crossover point coordinates [x, y] are calculated using the direction information B1 of the first underwater sound source device (200) and the direction information B2 of the second underwater sound source device (300).

And, using the direction information B1 and the distance R1 of the first underwater sound source device (200), the first location coordinate [x1, y1] is calculated, and using the direction information B2 and the distance R2 of the second underwater sound source device (300), the second location coordinate [x2, y2] is calculated. Thereafter, weights can be calculated to correct the location information based on the three coordinates. At this time, the weights can be inversely proportional to the distance. That is, the closer the distance, the higher the weight is given, and the farther the distance, the lower the weight is given, thereby increasing the reliability of the location estimation. In the embodiment of Fig. 4, when R2 is smaller than R1, the accuracy of R2 is better than that of R1, and therefore, the accuracy of B2 can be seen to be better than that of B1.

Fig. 5 is a reference diagram for explaining a method for determining an underwater position considering weights in the embodiment of Fig. 4.

As described above with reference to FIG. 4, when the intersection point coordinates (Crossover Point), the first position coordinates (Own Position #1), and the second position coordinates (Own Position #2) are set, the following mathematical expression 4 is obtained.

Then, the center of gravity point (C) coordinates for three coordinates [(x+x1+x2)/3, (y+y1+y2)/3] are calculated and produced.

Afterwards, the weight is calculated using the distance information of the underwater sound source device (200, 300), as shown in the following mathematical expression 5.

If the weights calculated as above are vector-summed, the result is as follows: Mathematical Formula 6.

The weight vector (size and direction) calculated as above is reflected at the center of gravity point C to correct the underwater position.

That is, at the center of gravity C In the direction The corrected position is finally determined by moving by that amount.

As described above, since the present invention determines the ship's location by utilizing sound source information from an underwater sound source device, GPS can be omitted, thereby ensuring the stealth and safety of the submarine. In other words, since the submarine can maintain the accuracy of its ship's location underwater without surfacing to periscope depth, the submarine's underwater operational sustainability can be improved.

In addition, there is an advantage in that the accuracy of underwater composite navigation can be improved by correcting accurate location information as in the embodiment of Fig. 5.

The above description is merely an illustrative description of the technical idea of the present invention, and those skilled in the art will appreciate that various modifications, changes, and substitutions may be made without departing from the essential characteristics of the present invention. Accordingly, the embodiments disclosed in the present invention and the accompanying drawings are not intended to limit the technical idea of the present invention but to explain it, and the scope of the technical idea of the present invention is not limited by these embodiments and the accompanying drawings. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within a scope equivalent thereto should be interpreted as being included in the scope of the rights of the present invention.

100: Underwater motor vehicle 200: Underwater sound source device
10: Underwater positioning device 20: Composite navigation device
30: Inertial Navigation System 40: Doppler Log
50: Sonar 60: GPS
210: Sound transmitter 220: Battery
230: Timer

Claims (13)

In an underwater position determination system using a fixed underwater acoustic source device on the seabed,
An underwater sound source device that is separated from an underwater vehicle, fixed at a predetermined seabed location, and periodically transmits sound source information including location information, sound source direction information, and sound source transmission time:
A sonar detector that periodically receives sound source information transmitted from the above underwater sound source device; and
An underwater position determination system including an underwater position calculation device that calculates the underwater position of an underwater vehicle by calculating direction and distance based on sound source information of the underwater sound source device received through the sonar detector. In the first paragraph,
Inertial Navigation System;
Doppler Log, which measures the speed of an underwater object relative to the ground or water in the forward and backward directions and left and right directions by using the Doppler effect of sound waves in water; and
An underwater position determination system further comprising a composite navigation device that corrects position information by utilizing signals generated from the inertial navigation device and the Doppler log for the underwater position generated from the underwater position calculating device. In the second paragraph,
An underwater positioning system further comprising a GPS receiver. In the first paragraph,
The above underwater sound source device is,
An underwater position determination system characterized in that it is launched outside the underwater vehicle through the torpedo launcher of the underwater vehicle and fixed at a predetermined seabed location. In the first paragraph,
The above underwater position calculating device is,
An underwater position determination system characterized by setting (preset) mutual time synchronization and the sound source transmission cycle and operating period of the underwater sound source device prior to deployment of the underwater sound source device. In the first paragraph,
The above underwater sound source device is,
timer;
Battery; and
An underwater position determination system characterized by including a sound wave transmitter that transmits the above sound source information. In a method for determining the underwater position of an underwater vehicle using a fixed underwater sound source device on the seabed,
A preset step for setting the sound source transmission cycle and operating period of the underwater sound source device and synchronizing the time between the underwater sound source device and the underwater vehicle;
A step of launching the above underwater sound source device outside the underwater vehicle and determining the launching position as a starting point;
A step of receiving sound source information including location information, sound source direction information, and sound source transmission time from the underwater sound source device separated from the underwater vehicle and fixed to a predetermined seabed location;
A step for calculating the underwater position of an underwater vehicle by calculating the direction and distance based on the received sound source information; and
A method for determining an underwater position, comprising: a step of correcting the calculated underwater position using a composite navigation device. In Article 7,
The step of calculating the position of the above underwater vehicle is:
An underwater position determination method characterized by calculating a location using a BO (Bearing Only) algorithm based on sound source information transmitted from an underwater sound source device. In Article 7,
The step of calculating the position of the above underwater vehicle is:
An underwater position determination method characterized by calculating a location using a CO (Crossover) algorithm based on sound source information transmitted from two underwater sound source devices. In Article 9,
The above CO algorithm is,
Using the location information P1 of the first underwater sound source device, direction information B1, sound source transmission time TT, sound source reception time RT1, and sonar environment analysis information, the distance R1 between the first underwater sound source device and the underwater vehicle is calculated.
Using the location information P2 of the second underwater sound source device, direction information B2, sound source transmission time TT, sound source reception time RT2, and sonar environment analysis information, the distance R2 between the second underwater sound source device and the underwater vehicle is calculated.
Using the direction information B1 and distance R1 of the first underwater sound source device and the direction information B2 and distance R2 of the second underwater sound source device, the location information and the cross-direction information are calculated, and the weights are calculated through this.
An underwater position determination method characterized by determining the position of an underwater vehicle by reflecting the calculated weights above. In Article 10,
The above CO algorithm is,
Using the direction information B1 of the first underwater sound source device and the direction information B2 of the second underwater sound source device, the intersection point coordinates [x, y] are calculated,
Using the direction information B1 of the first underwater sound source device and the distance R1, the first position coordinate [x1, y1] is calculated,
Using the direction information B2 of the second underwater sound source device and the distance R2, the second position coordinate [x2, y2] is calculated,
Calculate the center of gravity coordinates [(x+x1+x2)/3, (y+y1+y2)/3] for the above intersection, first location, and second location coordinates,
Calculate the weight (Wc) of the above intersection, the weight (W ₁ ) of the first position, and the weight (W ₂ ) of the second position,
The position of the underwater vehicle is determined by reflecting the calculated weights above.
The above weights are each expressed by the following formula:
Wc=1/3, W ₁ =2×(1-R1/(R1+R2))/3, and W ₂ =2×(1-R2/(R1+R2))/3
is determined by,
An underwater position determination method characterized in that the position of the underwater vehicle is determined by reflecting the weights Wc, W ₁ , and W ₂ as vector values in the center of gravity point coordinates [(x+x1+x2)/3, (y+y1+y2)/3]. In Article 7,
The above underwater position correction step is,
An underwater position determination method, characterized in that the above-mentioned composite navigation device corrects position information by utilizing signals generated from an inertial navigation device and a Doppler log. In Article 7,
An underwater position determination method characterized in that the underwater sound source device is launched outside the underwater vehicle through the torpedo launcher of the underwater vehicle and fixed at a predetermined seabed location.

Images