JP6821510B2 - Underwater Acoustic Positioning System and Method - Google Patents

Description

The present invention relates to an underwater acoustic positioning system and method for positioning an underwater position of a target using a GNSS signal.

Conventionally, the underwater position of an underwater work machine that works underwater or at the bottom of the water has been determined.

For example, in Patent Document 1, synchronous pinger is provided for each of three automatic position-holding floats such as a buoy or a mini boat, and an acoustic signal is transmitted from each synchronous pinger toward water, and a receiving means attached to a diving machine. Disclosed is an underwater positioning system that receives an acoustic signal in and estimates the latitude and longitude of the diving machine by the bicurve positioning method based on the time difference data of the acoustic signal between each synchronous pinger and the receiving means and the depth data of the diving machine. There is.

In such an automatic position holding floating body, the automatic position holding system unit maintains the set position of the water surface stored in advance based on the GPS signal. The three automatic position-holding floats are arranged so as to form a triangle when the water surface is viewed upward.

JP-A-2017-40500

However, in the invention described in Patent Document 1, since the three automatic position-holding floats move up and down due to the shaking of the waves, the automatic position-holding floats are required to accurately position the underwater position (three-dimensional position) of the diving machine. There is a problem that the position of the synchronous pinger needs to be corrected in consideration of the vertical movement of the system, which complicates the system configuration.

Therefore, a technical problem to be solved in order to accurately and smoothly position the underwater position of the target object arises, and an object of the present invention is to solve this problem.

The present invention has been proposed to achieve the above object, and the invention according to claim 1 is an underwater acoustic positioning system for positioning an underwater position of a target object, and is a receiver installed on the target object. A plurality of transmitters that are installed at known coordinates in water and at substantially the same depth as the receiver and emit sound waves substantially horizontally toward the receiver, and a receiving side GNSS antenna connected to the receiver. The target object is based on the propagation time of the transmitting side GNSS antenna connected to the transmitter and the sound wave emitted from the plurality of transmitters toward the receiver according to the GNSS signal received by the transmitting side GNSS antenna. Provided is an underwater acoustic positioning system equipped with a control unit for calculating an underwater position.

According to this configuration, a plurality of transmitters installed at known coordinates emit sound waves toward the receiver, so that the sound wave transmission position is fixed, which is a complicated transmitter when positioning the underwater position of the target. The underwater position of the target can be smoothly positioned without the need for position correction. Further, since the sound waves emitted from each of the plurality of transmitters are synchronized based on the time information included in the GNSS signal, the underwater position of the target can be accurately positioned. Further, since the sound wave propagates from the transmitter to the receiver under a substantially constant water temperature, the propagation speed of the sound wave is stabilized, so that the underwater position of the target can be accurately and smoothly positioned.

According to a second aspect of the invention, in the configuration of claim 1 Symbol placement, the originating GNSS antenna provides an underwater acoustic positioning system connected by wire to the transmitter.

According to this configuration, the transmitting side GNSS antenna that has received the GNSS signal promptly transmits the pulse signal to the transmitter, so that the sound waves emitted from each of the plurality of transmitters are synchronized, so that the underwater position of the target is accurate. Good positioning is possible.

The invention according to claim 3 provides an underwater acoustic positioning system in which the receiver and the transmitter are time-corrected based on the time information included in the GNSS signal in the configuration according to claim 1 or 2 .

According to this configuration, the transmitter and the receiver are corrected to a common time based on the time information included in the GNSS signal received by the transmitting GNSS antenna and the receiving GNSS antenna, so that the receiver and the transmitter Since the propagation time of the sound wave between the two can be accurately measured, the underwater position of the target can be accurately positioned.

The invention according to claim 4 is provided with a known distance away from the receiver in the configuration according to any one of claims 1 to 3 , and transmits a dummy sound wave toward the receiver. Further including a device, the control unit calculates the propagation speed of a sound wave propagating a known distance between the dummy sound wave transmitter and the receiver, and calculates the propagation speed of the sound wave and the transmitter and the receiver. Provided is an underwater acoustic positioning system that calculates the underwater position of the target based on the propagation time of the sound wave propagating between the two.

According to this configuration, the propagation velocity of the sound wave at the water temperature near the receiver is calculated, and the underwater position of the target is determined based on the propagation velocity of the sound wave and the propagation time of the sound wave propagated between the transmitter and the receiver. By correcting, the underwater position of the target can be accurately positioned.

The invention according to claim 5 provides an underwater acoustic positioning system installed on a breakwater in the configuration according to any one of claims 1 to 4 , wherein the transmitting side GNSS antenna is installed on a breakwater.

According to this configuration, by installing the transmitting GNSS antenna on the breakwater, false detection of the GNSS signal due to the reflection of the GNSS signal on the water surface is suppressed, so that the sound waves emitted from a plurality of transmitters can be accurately detected. Can be synchronized with.

The invention according to claim 6 provides an underwater acoustic positioning system in which the target is an underwater backhoe in the configuration according to any one of claims 1 to 5 .

According to this configuration, the underwater position of the underwater backhoe traveling on the seabed can be accurately and smoothly positioned.

The invention according to claim 7 is an underwater acoustic positioning method for positioning an underwater position of a target object, which comprises a step of providing a receiver on the target object and a plurality of methods for transmitting sound waves substantially horizontally toward the receiver. A step of installing the transmitter in water at known coordinates and at substantially the same depth as the receiver, a step of connecting the receiving side GNSS antenna to the receiver, a step of connecting the transmitting side GNSS antenna to the transmitter, and the above. Underwater including a step in which the control unit calculates the underwater position of the target based on the propagation time of sound waves emitted from the plurality of transmitters toward the receiver according to the GNSS signal received by the transmitting side GNSS antenna. Provide an acoustic positioning method.

According to this configuration, a plurality of transmitters installed at known coordinates emit sound waves toward the receiver, so that the sound wave transmission position is fixed, which is a complicated transmitter when positioning the underwater position of the target. The underwater position of the target can be smoothly positioned without the need for position correction. Further, since the sound waves emitted from each of the plurality of transmitters are synchronized based on the time information included in the GNSS signal, the underwater position of the target can be accurately positioned.

According to the present invention, a plurality of transmitters installed at known coordinates autonomously emit sound waves at substantially the same timing based on the time information included in the GNSS signal, thereby fixing the sound wave transmission position and at the same time. Since the sound waves emitted from each of the plurality of transmitters are synchronized, the underwater position of the target can be accurately and smoothly positioned.

It is a schematic diagram which shows the structure of the underwater acoustic positioning system which concerns on one Example of this invention. It is a schematic diagram which shows the structure of the underwater acoustic positioning system which concerns on the modification of this invention.

The present invention is an underwater acoustic positioning system for positioning the underwater position of a target in order to achieve the object of accurately positioning the underwater position of the target, and the receiver installed on the target and underwater. A plurality of transmitters installed at known coordinates and transmitting sound waves toward the receiver, a receiving side GNSS antenna connected to the receiver, a transmitting side GNSS antenna connected to the transmitter, and a transmitting side GNSS antenna. This was realized by providing a control unit that calculates the underwater position of the target based on the propagation time of sound waves emitted from a plurality of transmitters toward the receiver according to the received GNSS signal.

Further, the present invention is an underwater acoustic positioning method for positioning the underwater position of a target in order to achieve the object of accurately positioning the underwater position of the target, and includes a step of providing a receiver on the target. The process of installing multiple transmitters that emit sound waves toward the receiver at known coordinates in the water, the process of connecting the receiving side GNSS antenna to the receiver, and the process of connecting the transmitting side GNSS antenna to the transmitter. The configuration includes a step in which the control unit calculates the underwater position of the target based on the propagation time of sound waves emitted from a plurality of transmitters toward the receiver according to the GNSS signal received by the transmitting GNSS antenna. It was realized by.

The SBL (Short Base Line) method and the LBL (Long Base Line) method are known as methods for positioning the underwater position of a target object using underwater ultrasonic waves. Further, a transponder or a responder is known as a sound source of underwater ultrasonic waves used for positioning the underwater position of a target object.

In the SBL method, for example, ultrasonic waves are reciprocated between a receiver installed on the bottom of a ship and a transponder installed on a target, and the transponder's measured values of ultrasonic wave propagation time and propagation speed are used. It measures the underwater position.

However, in the SBL method, since the shaking of the ship adversely affects the measured value, it is necessary to correct the measured value in consideration of the inclination of the ship, but an inclinometer is installed on the ship that constantly shakes at sea. It was practically difficult to calibrate and was not suitable for high-precision positioning. In addition, since the water depth at which the receiver and transponder are installed is different, the error in the propagation speed of sound waves is large due to changes in the water temperature and salinity in the water depth direction, and there is a limit to the correction.

On the other hand, in the LBL method, the position of the master station is obtained by measuring each distance between the master station and the plurality of slave stations. The master station is attached to a ship on the sea, a vehicle swimming in the water, a robot walking on the seabed, or the like.

When a transponder is applied to a slave station to perform positioning using the LBL method, the slave station emits ultrasonic waves toward the master station in response to the ringing signal transmitted from the master station, and the ultrasonic waves are the parent of the slave station. The position of the master station is determined from the propagation time and propagation speed when reciprocating with the station. However, time tags are likely to occur, and it is difficult to set the measurement interval to a short value such as 1 second.

In addition, when a responder is applied to a slave station and positioning is performed by the LBL method, ultrasonic waves are transmitted from the slave station to the master station, and the propagation time when the ultrasonic waves propagate from the slave station to the master station. And since the underwater position of the master station is determined from the propagation speed, the time tag can be reduced and a short measurement interval can be set as compared with the case of using a transponder. However, the responder had to be connected by a cable in order to receive the signal from the master station, and the range of movement of the underwater work equipment moving underwater and underwater was limited.

The underwater acoustic positioning system according to the present invention is suitable for solving the above-mentioned various problems and positioning the target underwater position with high accuracy.

Hereinafter, the underwater acoustic positioning system 1 according to an embodiment of the present invention will be described with reference to the drawings. In each of the following examples, when the number, numerical value, quantity, range, etc. of the components are referred to, the specific number is not specified unless it is clearly specified or the number is clearly limited in principle. It is not limited to, and may be more than or less than a specific number.

In addition, when referring to the shape and positional relationship of components, etc., unless otherwise specified or when it is considered that this is not the case in principle, those that are substantially similar to or similar to the shape, etc. shall be used. Including.

In addition, the drawings may be exaggerated by enlarging the characteristic parts in order to make the features easy to understand, and the dimensional ratios and the like of the components are not always the same as the actual ones.

FIG. 1 is a schematic view showing the configuration of the underwater acoustic positioning system 1. The underwater acoustic positioning system 1 uses GNSS (Global Navigation Satellite System) to determine the underwater position (three-dimensional position) of the backhoe 2 lowered to the seabed. The GNSS used for positioning the underwater position of the back hou 2 includes GPS (Global Positioning System), for example, one that dynamically switches between positioning by GLONASS (GLOBAL Navigation Satellite System) and positioning by GPS, and GPS and GLONASS. It is conceivable that the positioning is performed in combination.

The backhoe 2 is operated by the operator on board to perform work such as excavation while moving on the seabed. The power of the backhoe 2 is supplied from the support vessel 3 by a power line (not shown).

The underwater acoustic positioning system 1 includes two transmitters 10 and a receiver 20.

The transmitter 10 is a pinger that autonomously emits ultrasonic waves toward the receiver 20 at regular intervals. The transmitter 10 is attached to a chopstick 11 fixed to the seabed. The position of the transmitter 10 is pre-positioned and does not move and is constant even during the work of the backhoe 2. Hereinafter, when distinguishing between the two transmitters 10, A or B is added to the end of the code.

The receiver 20 is mounted on the backhoe 2. The receiver 20 is connected to the control device 30 via a first repeater 21 mounted on the backhoe 2 and a second repeater 22 mounted on the support vessel 3. Specifically, the receiver 20, the first repeater 21, the second repeater 22, and the control device 30 are connected by wire by a power supply / signal line 31.

A transmitting side GNSS antenna 40 is connected to the transmitter 10. The transmitting side GNSS antenna 40 is installed on the breakwater 4, but may be installed on the sea surface. The transmitter 10 and the transmitting side GNSS antenna 40 are connected by wire by a signal line 41. Hereinafter, when distinguishing between the two transmitting side GNSS antennas, the transmitting side GNSS antenna connected to the transmitter 10A is designated by the reference numeral 40A, and the transmitting side GNSS antenna connected to the transmitter 10B is designated by the reference numeral 40B. And.

The transmitting GNSS antenna 40 receives the GNSS signal from the GNSS satellite 50 at predetermined intervals (for example, every 1 second), and when the GNSS signal is received from the GNSS satellite 50, the pulse signal is transmitted to the transmitter 10 via the signal line 42. Send. The GNSS signal includes time information of a highly accurate atomic clock mounted on the GNSS satellite 50. Therefore, the transmission of the pulse signal from the transmitting side GNSS antenna 40A to the transmitter 10A and the transmission of the pulse signal from the transmitting side GNSS antenna 40B to the transmitter 10B are performed substantially at the same time.

A receiving side GNSS antenna 60 is connected to the receiver 20. The receiving side GNSS antenna 60 is installed on the support vessel 3. The receiver 20 and the receiving side GNSS antenna 60 are connected by wire via a power supply / signal line 61. The receiving side GNSS antenna 60 receives time information from the GNSS satellite 50 at predetermined intervals.

It is preferable that the first water pressure gauge 12 is provided in the vicinity of the transmitter 10. The first water pressure gauge 12 transmits the measured value to the control device 30 via a radio device (not shown). As a result, the water depth in the vicinity of the transmitter 10 can be measured.

A second water pressure gauge 23 is preferably provided in the vicinity of the receiver 20. The second water pressure gauge 23 transmits the measured value to the control device 30 via the first repeater 21 and the second repeater 22. As a result, the water depth in the vicinity of the receiver 20 can be measured. Reference numeral 24 in FIG. 1 is an azimuth meter that detects the direction of the backhoe 2 and transmits the detection result to the control device 30 via the first repeater 21 and the second repeater 22.

The backhoe 2 is provided with a dummy sound wave transmitter 70. The dummy sound wave transmitter 70 transmits a sound wave toward the receiver 20. The dummy sound wave transmitter 70 is arranged at a distance from the receiver 20 by a known distance.

The operation of the underwater acoustic measurement system 1 is controlled by the control device 30. The control device 30 is, for example, a personal computer mounted on the support vessel 3. The control device 30 includes an input unit and an output unit (not shown), and an operator on board the support vessel 30 can operate the control device 30 and confirm the underwater position of the backhoe 2.

Next, a procedure for positioning the underwater position of the backhoe 2 with the underwater acoustic positioning system 1 will be described with reference to FIG. The order of the steps described later is only an example, and the order of each step can be changed as appropriate.

[Caller installation]
The transmitter 10 is installed at a predetermined position. The transmitter 10 is attached to the chopstick 11 fixed to the seabed, the installation position of the transmitter 10 is positioned, and the transmitter 10 is stored in the control device 30.

Further, the transmitter 10 is installed in the chopstick 11 in a state of being connected in advance to the transmitting side GNSS antenna 30 via the signal line 31. The transmitting side GNSS antenna 30 is installed on the breakwater 4 in order to reduce diffused reflection of the GNSS signal on the water surface, but may be provided, for example, at the tip of a buoy floating on the water surface. The transmitter 10 may be connected to the transmitting side GNSS antenna 30 after being provided at a predetermined position in the water.

[Receiver installation]
Next, the receiver 20 is installed at a predetermined position. The receiver 20 is arranged at a position where sound waves can be easily received, such as a position where there is no shield between the receiver 20 and the transmitter 10. Further, the receiver 20 is connected to the receiving side GNSS antenna 40 mounted on the support vessel 3 via the power supply / signal line 41.

It is preferable that the transmitter 10 and the receiver 20 are installed so that the backhoe 2 is located at substantially the same water depth in a state where the backhoe 2 is lowered to the seabed. As a result, the sound wave emitted from the transmitter 10 propagates in the water at a substantially constant water temperature, so that the propagation speed of the sound wave is stable.

[Time adjustment]
The time information of the transmitter 10 is appropriately corrected based on the time information included in the GNSS signal received from the GNSS satellite 50 by the transmitting GNSS antenna 40. This is because the transmitter 10 and the transmitting side GNSS antenna 40 are wiredly connected by the signal line 41, so that the time of the transmitter 10 can be adjusted without delay in communication. As a result, the time of the transmitter 10 can be adjusted as appropriate without the diver diving to the transmitter 10 installed in the sea.

Further, the time information of the receiver 20 is appropriately corrected based on the time information included in the GNSS signal received from the GNSS satellite 50 by the receiving side GNSS antenna 60. This is because the receiver 20 and the receiving side GNSS antenna 60 are wiredly connected by the power supply / signal line 61, so that the time of the receiver 20 can be adjusted without delay in communication. In this way, the times of the transmitter 10 and the receiver 20 are matched in advance prior to the positioning of the backhoe 2.

[Sound wave transmission]
Next, the transmitters 10A and 10B transmit sound waves, respectively. Sound wave transmission by the transmitter 10 is performed based on a pulse signal from the transmitting side GNSS antenna 40.

Specifically, the transmitting side GNSS antenna 40 receives a GNSS signal including time information from the GNSS satellite 50, and transmits a pulse signal to the transmitter 10 at predetermined time intervals (for example, every 1 second). Then, when the transmitter 10 receives the pulse signal of the transmitting side GNSS antenna 40, it transmits a sound wave. The transmitter 10 and the transmitting side GNSS antenna 40 are wiredly connected via a signal line 41, the pulse signal is transmitted without delay, and the transmitter 10 transmits sound waves. That is, the timing at which the transmitters 10A and 10B emit sound waves is linked to the timing at which the transmitting side GNSS antenna 40 emits a pulse signal. As a result, the sound waves emitted from the two transmitters 10A and 10B are synchronized.

Here, "synchronization" means a state in which the timings at which sound waves are emitted from the transmitters 10A and 10B are substantially the same, and is associated with signal processing between the transmitter 10 and the transmitting side GNSS antenna 40, for example. Including delays, etc.

[Positioning underwater position]
The receiver 20 receives the sound wave transmitted from the transmitter 10 and sends the propagation time of the sound wave propagated from the transmitter 10A and the propagation time of the sound wave propagated from the transmitter 10B to the control device 30. The receiver 20 and the control device 30 are wiredly connected via the power supply / signal line 61, and the received data of the receiver 20 can be transmitted to the control device 30 without delay in communication.

The control device 30 can determine the underwater position of the receiver 20 in real time based on the installation position of the transmitters 10A and 10B, the propagation time of the sound wave, and the propagation speed of the sound wave stored in advance.

The propagation speed of the sound wave propagating between the transmitter 10 and the receiver 20 fluctuates as the water temperature changes. Therefore, it is preferable to actually measure the propagation velocity of the sound wave propagating between the transmitter 10 and the receiver 20.

Specifically, the dummy sound wave transmitter 70 transmits a dummy sound wave toward the receiver 20, and the time at which the dummy sound wave propagates over a known distance between the receiver 20 and the dummy sound wave transmitter 60 is set in the control device 30. send. Then, the control device 30 divides the known distance between the receiver 20 and the dummy sound wave transmitter 70 by the propagation time of the sound wave propagating between the receiver 20 and the dummy sound wave transmitter 70, thereby causing the vicinity of the receiver 20. The propagation velocity of sound waves at the water temperature of is obtained. As a result, the underwater position of the receiver 20 can be accurately positioned.

In this way, in the underwater acoustic positioning system 1 according to the present embodiment, the transmitters 10A and 10B installed at the known coordinates emit sound waves toward the receiver 20, so that the sound wave transmission position is fixed. When positioning the underwater position of the backhoe 2, complicated position correction of the transmitters 10A and 10B is not required, and the underwater position of the backhoe 2 can be smoothly positioned. Further, since the sound waves emitted from the transmitters 10A and 10B are synchronized based on the time information included in the GNSS signal, the underwater position of the backhoe 2 can be accurately positioned.

Next, a modified example of the underwater acoustic positioning system 1 will be described with reference to FIG. In this modified example, the target (target object) for positioning the underwater position is different from the above-described embodiment, and although some configurations are omitted, the basic configuration of the underwater acoustic positioning system 1 is common. The configuration to be used is designated by a common reference numeral and the description thereof will be omitted.

The underwater acoustic positioning system 1 according to this modification is applied to a hoisting vessel 6 provided with a crane 5. The hoisting vessel 6 suspends a tamper 7 for compacting the seabed with a crane 5.

The receiver 20 is installed at the upper end of the tamper 7. The receiver 20 is connected to the control device 30 and the second receiving side GNSS antenna 60 via the omitted power supply / signal line.

In this way, in the underwater acoustic positioning system 1 according to the present modification, the transmitters 10A and 10B installed at the known coordinates emit sound waves toward the receiver 20, so that the sound wave transmission position is fixed. When positioning the underwater position of the tamper 7, the underwater position of the tamper 7 can be smoothly positioned without the need for complicated position correction of the transmitters 10A and 10B.

In addition to the structure of the above-mentioned modified example, the present invention can be modified in various ways as long as it does not deviate from the spirit of the present invention, and it is natural that the present invention extends to the modified one.

1 ・ ・ ・ Underwater acoustic positioning system 2 ・ ・ ・ Backhoe 3 ・ ・ ・ Support pontoon 4 ・ ・ ・ Breakwater 5 ・ ・ ・ Crane 6 ・ ・ ・ Moisturizing vessel 7 ・ ・ ・ Tamper 10, 10A, 10B ・ ・ ・ Transmission Instrument 11 ... Crane 12 ... 1st water pressure gauge 20 ... Receiver 21 ... 1st repeater 22 ... 2nd repeater 23 ... 2nd water pressure gauge 24・ ・ ・ Direction meter 30 ・ ・ ・ Control device (control unit)
40, 40A, 40B ... Transmitting side GNSS antenna 41 ... Signal line 50 ... GNSS satellite 60 ... Receiving side GNSS antenna 61 ... Power supply / signal line 70 ... Dummy sound transmitter

Claims (7)

An underwater acoustic positioning system that positions the underwater position of a target.
The receiver installed on the target and
A plurality of transmitters that are installed at known coordinates in water and at substantially the same depth as the receiver and emit sound waves substantially horizontally toward the receiver.
The receiving side GNSS antenna connected to the receiver and
The transmitting side GNSS antenna connected to the transmitter and
A control unit that calculates the underwater position of the target based on the propagation time of sound waves emitted from the plurality of transmitters toward the receiver according to the GNSS signal received by the transmitting side GNSS antenna.
An underwater acoustic positioning system characterized by being equipped with. The originating GNSS antenna, underwater acoustic positioning system of claim 1 Symbol mounting, characterized in that it is connected by wire to the transmitter. The underwater acoustic positioning system according to claim 1 or 2, wherein the receiver and the transmitter are time-corrected based on the time information included in the GNSS signal. A dummy sound wave transmitter, which is provided at a distance from the receiver by a known distance and emits a dummy sound wave toward the receiver, is further provided.
The control unit calculates the propagation speed of the sound wave propagating a known distance between the dummy sound wave transmitter and the receiver, and propagates the sound wave propagation speed and between the transmitter and the receiver. The underwater acoustic positioning system according to any one of claims 1 to 3 , wherein the underwater position of the target object is calculated based on the propagation time of sound waves. The underwater acoustic positioning system according to any one of claims 1 to 4 , wherein the transmitting side GNSS antenna is installed on a breakwater. The underwater acoustic positioning system according to any one of claims 1 to 5 , wherein the target is an underwater backhoe. An underwater acoustic positioning method for positioning the underwater position of a target.
The process of providing a receiver on the target and
A process of installing a plurality of transmitters that emit sound waves substantially horizontally toward the receiver at known coordinates in water and at substantially the same water depth as the receiver.
The process of connecting the receiving side GNSS antenna to the receiver and
The process of connecting the transmitter GNSS antenna to the transmitter and
A step in which the control unit calculates the underwater position of the target based on the propagation time of sound waves emitted from the plurality of transmitters toward the receiver according to the GNSS signal received by the transmitting side GNSS antenna.
An underwater acoustic positioning method comprising.