JP2022152255A - Object measurement method - Google Patents

Abstract

To easily measure an underwater object with high accuracy.SOLUTION: When an acoustic transceiver 30 simultaneously transmits an acoustic signal to a plurality of acoustic transponders 101, the acoustic transponders 101 respectively reply response signals responding to the acoustic signal transmitted from the acoustic transceiver 30. An information processing device 20 calculates a position of each of the acoustic transponders 101 on the basis of a position measured by a GNSS sensor 40 when the acoustic signal is transmitted, a transmission time when the acoustic transceiver 30 transmits the acoustic signal, a receiving time of a response signal received from each of the acoustic transponders 101 by the acoustic transceiver 30, and a transponder ID included in each of the response signals. The information processing device 20 calculates the position and shape of a water bottom by performing interpolation processing or the like about a space between the acoustic transponders 101.SELECTED DRAWING: Figure 1

Description

The present invention relates to techniques for measuring objects in water.

When small-scale dredging work is carried out in shallow waters, a sand pump is suspended underwater from a ship to dredge the bottom of the water. At this time, in order to turn the surface of the submerged ground into muddy water, a water jet or the like is also used to disturb the soil and sand on the ground, which is then sucked up by a sand pump. During dredging work, in order to grasp the shape and progress after dredging, equipment that operates underwater such as sand pumps is stopped, and divers check the dredging shape each time. However, visibility is poor due to the high turbidity of the dredged area due to the influence of the jet stream, etc., and the confirmation results of the dredged shape vary depending on the diver.

As a technology to measure the topography of the seabed, a survey ship is equipped with a narrow multi-beam sounding device, GNSS (Global Navigation Satellite System), and motion sensors, etc., and a large number of acoustic beams are directed from the narrow multi-beam sounding device to the seabed. It is known to acquire the topography of the water bottom as three-dimensional data by receiving and transmitting in a fan shape. At this time, there is a problem that the positioning error by GNSS and the error of motion correction by the motion sensor are included in the three-dimensional data. Moreover, in order to carry out the above-mentioned survey using a survey ship, it is necessary to retract the dredging equipment such as the sand pump, which may reduce work efficiency.

As a positioning technique using sound, for example, in Patent Document 1, for an underwater wave receiver group having wave receivers a1 to an floating on a float from the bottom of the water 3, an acoustic An acoustic signal is transmitted from the signal generator, and each wave receiver that receives the acoustic signal converts the acoustic signal into an electric signal and sends it to the shape measuring device 10 via the transmission cable 5, so that the arrival time difference of the electric signal is discloses determining the shape of an underwater receiver group.

JP-A-2001-330666

SUMMARY OF THE INVENTION It is an object of the present invention to measure an underwater object simply and accurately by a method different from the conventional method.

In order to solve the above problems, the present invention provides a first step of transmitting an acoustic signal from an acoustic transducer to a plurality of acoustic transponders laid on an underwater object; a second step in which a plurality of acoustic transponders respectively return response signals in response to the transmitted acoustic signals; and the acoustic transducer receives the response signals respectively returned from the plurality of acoustic transponders. a third step of calculating at least one of the position, shape, and orientation of the object based on the time difference between each of the response signals received by the acoustic transducer and the acoustic signal; and 4 steps.

A step performed before the first step may include a step of submerging a flexible member having a plurality of acoustic transponders provided at predetermined intervals in water.

If the absolute position of at least one acoustic transponder among the plurality of acoustic transponders is known, in the fourth step other acoustic responses based on the known absolute position of the at least one acoustic transponder A position of the vessel may be specified, and the calculation may be performed based on the specified position.

The plurality of acoustic transponders may be attached to a diver's hookah hose as the object.

The plurality of acoustic transponders may be attached to a connection member that connects the sinker and the buoy as the objects.

The plurality of acoustic transponders may be attached to the underwater working machine as the object.

One or more acoustic transponders may be attached to each of the diver and the underwater working machine as the objects.

The distance or number of the acoustic transponders attached to the object may vary depending on the required measurement accuracy for the object.

The acoustic signal or response signal in the first step and/or the second step may be wired or wireless.

ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to measure an underwater object simply and accurately by a method different from the conventional method.

1 is a block diagram showing an example of the overall system configuration according to an embodiment of the present invention; FIG. The top view which shows an example of the structure of the acoustic transponder group which concerns on the same embodiment. FIG. 2 is a block diagram showing an example of the hardware configuration of the information processing apparatus according to the embodiment; The block diagram which shows an example of the hardware constitutions of the acoustic transponder which concerns on the same embodiment. 4 is a flowchart showing an example of an object measuring method according to the same embodiment; The table|surface which shows an example of the measurement result in the same embodiment. The block diagram which shows an example of a structure of the whole system based on the modification of this invention.

An example of a mode for carrying out the present invention will be described.
[Constitution]
FIG. 1 is a block diagram showing an example of the overall system configuration according to an embodiment of the present invention. This system includes an information processing device 20 equipped on a ship 10, an acoustic transceiver 30, a GNSS (Global Navigation Satellite System) 40, and an acoustic transponder group 100 arranged on the bottom of the water. This system measures the shape of the bottom of the water as an underwater object. In FIG. 1, G is the bottom of the water (bottom of the sea) and W is the surface of the water (sea surface).

The information processing device 20 is a computer device and performs various calculations for measuring the shape of the bottom of the water. The acoustic transmitter/receiver 30 is installed underwater below the ship 10 and transmits a predetermined acoustic signal underwater. The GNSS 40 performs positioning by receiving satellite signals transmitted from a plurality of satellites orbiting the earth. The information processing device 20, the acoustic transducer 30, and the GNSS 40 are communicably connected via a wire or radio.

The acoustic responder group 100 includes a plurality of acoustic responders 101, connecting members 102 for interconnecting these acoustic responders, and one or more anchors 103 for fixing the acoustic responder group 100 to the bottom of the water. I have. Each of the acoustic transponders 101, upon receiving the acoustic signal transmitted from the acoustic transducer 30, returns a response signal in response thereto. The connecting member 102 is made of a heavy and flexible flexible member so that when the acoustic transponder group 100 is submerged in water, it is laid along the shape of the bottom of the water. The connecting member 102 is, for example, wire-shaped or sheet-shaped, and a plurality of acoustic transponders 101 are arranged on the connecting member 102 at predetermined intervals.

Here, FIG. 2 is a plan view showing an example of the structure of the acoustic transponder group 100. As shown in FIG. In the example of FIG. 2, the connecting member 102 has a structure in which a plurality of wires are arranged in a grid pattern, and the acoustic transponders 101 are arranged at positions corresponding to the intersections of the wires. An anchor 103 fixed to the bottom of the water is attached to at least one or more connecting members 102 among the plurality of connecting members 102 . Although the anchors 103 are attached to the three connecting members 102 in the example of FIG. 2, the number and attachment positions of the anchors 103 can be arbitrarily determined. It is desirable that the intervals between the acoustic transponders 101 are different according to the required measurement accuracy for the object to be measured. That is, when the required measurement accuracy for the object is high, the intervals between the acoustic transponders 101 can be made smaller, and when the required measurement accuracy for the object is low, the intervals between the acoustic transponders 101 can be made larger. . Note that the intervals between the acoustic transponders 101 do not necessarily have to be equal, and their arrangement may be sparse or dense. In other words, the intervals between the acoustic transponders 101 are made small in portions where high measurement accuracy is required in the measurement object, and the intervals between the acoustic transponders 101 are made large in portions where low measurement accuracy is acceptable even in the same measurement object. You may make it Similarly, it is desirable that the number of acoustic transponders be different according to the measurement accuracy required for the object to be measured. In other words, if the measurement accuracy required for the object is high, the number of acoustic transponders 101 is increased, and if the measurement accuracy required for the object is low, the number of acoustic transponders 101 is increased. less.

FIG. 3 is a diagram showing the hardware configuration of the information processing device 20. As shown in FIG. The information processing device 20 is physically configured as a computer device including a processor 2001, a memory 2002, a storage 2003, a communication device 2004, an input device 2005, an output device 2006, and a bus connecting them. Each of these devices operates with power supplied from a power source (not shown). Note that in the following description, the term "apparatus" can be read as a circuit, device, unit, or the like. The hardware configuration of the information processing device 20 may be configured to include one or more of the devices shown in FIG. 3, or may be configured without some of the devices.

Each function of the information processing apparatus 20 is performed by causing the processor 2001 to perform calculations, controlling communication by the communication apparatus 2004, and performing other functions by loading predetermined software (programs) onto hardware such as the processor 2001 and the memory 2002. or by controlling at least one of reading and writing of data in the memory 2002 and the storage 2003 .

The processor 2001, for example, operates an operating system and controls the entire computer. The processor 2001 may be configured by a central processing unit (CPU) including an interface with peripheral devices, a control device, an arithmetic device, registers, and the like. Also, for example, a baseband signal processing unit, a call processing unit, and the like may be implemented by the processor 2001 .

The processor 2001 reads programs (program codes), software modules, data, etc. from at least one of the storage 2003 and the communication device 2004 to the memory 2002, and executes various processes according to them. As the program, a program that causes a computer to execute at least part of the operations described below is used. The functional blocks of information processing device 20 may be implemented by a control program stored in memory 2002 and running on processor 2001 . Various processes may be executed by one processor 2001, but may also be executed by two or more processors 2001 simultaneously or sequentially. Processor 2001 may be implemented by one or more chips. Note that the program may be transmitted to the information processing apparatus 20 via an electric communication line or installed in the memory 2002 or the storage 2003 .

The memory 2002 is a computer-readable recording medium, and is composed of at least one of, for example, ROM (Read Only Memory), EPROM (Erasable Programmable ROM), EEPROM (Electrically Erasable Programmable ROM), and RAM (Random Access Memory). may be The memory 2002 may also be called a register, cache, main memory (main storage device), or the like. The memory 2002 can store executable programs (program code), software modules, etc. to perform the methods of the present invention.

The storage 2003 is a computer-readable recording medium, for example, an optical disc such as a CD-ROM (Compact Disc ROM), a hard disk drive, a solid state drive, a flexible disc, a magneto-optical disc (e.g., a compact disc, a digital versatile disc , Blu-ray disc), smart card, flash memory (eg, card, stick, key drive), floppy disc, magnetic strip, and/or the like. Storage 2003 may also be called an auxiliary storage device.

The communication device 2004 is hardware (transmitting/receiving device) for communicating between computers via at least one of wired or wireless, and communicates with the acoustic transducer 30 and the GNSS 40 .

The input device 2005 is an input device (for example, keyboard, mouse, microphone, switch, button, etc.) that receives input from the outside. The output device 2006 is an output device (for example, display, speaker, LED lamp, printer, etc.) that outputs to the outside. Note that the input device 2005 and the output device 2006 may be integrated (for example, a touch panel).

The information processing device 20 includes hardware such as a microprocessor, a digital signal processor (DSP), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), and an FPGA (Field Programmable Gate Array). A part or all of each functional block may be implemented by the hardware. For example, processor 2001 may be implemented using at least one of these pieces of hardware.

FIG. 4 is a diagram showing the hardware configuration of the acoustic transponder 101. As shown in FIG. The acoustic transponder 101 receives acoustic signals from the arithmetic device 1010, the battery 1014, and the acoustic transducer 30 installed on the bottom of the ship 10, and responds to the acoustic signals for returning response signals. It is composed of a wave transmitting/receiving device 1015 and a depth gauge (water pressure gauge) 1016 for measuring the water depth of the acoustic transponder 101 .

Arithmetic device 1010 comprises processor 1011 , memory 1012 and communication device 1013 . The processor 1011 and memory 1012 are common to the processor 2001 and memory 2002 of the information processing apparatus 20 as hardware. The communication device 1013 shares hardware with the communication device 200 of the information processing device 20, and is connected to the acoustic wave transmitting/receiving device 1015 and the depth gauge 1016 by wire. The communication device 1013 communicates with the acoustic wave transmitting/receiving device 1015 and depth gauge 1016 . A battery 1014 powers each part of the acoustic transponder 101 .

[motion]
Next, the operation of this embodiment will be described. FIG. 5 is a flow chart showing an example of the object measuring method according to this embodiment. In FIG. 5, first, an operator of a dredging device such as a sand pump dredges a target area using the dredging device (step S11).

Next, a plurality of divers submerge the group of acoustic transponders 100 from the ship in the dredged target area and lay each acoustic transponder 101 on the bottom of the water (step S12). At this time, each diver arranges the group of acoustic transponders 100 so as to cover the bottom of the dredged target area, and fixes them to the bottom of the water with anchors 103 . As described above, since the connecting member 102 connecting each acoustic responder 101 is flexible, each acoustic responder 101 is arranged according to the shape of the dredged water bottom as illustrated in FIG. It will be.

Next, the operator of the information processing device 20 operates the information processing device 20 to perform positioning by the GNSS 40 and to transmit an acoustic signal from the acoustic transducer 30 (step S13). As a result, as the first step of the present invention, acoustic signals are simultaneously transmitted from the acoustic transducer 30 to the plurality of acoustic transponders 101 laid on the bottom of the water.

Each acoustic transponder 101, upon receiving the acoustic signal transmitted from the acoustic transducer 30, returns a response signal in response thereto (step S14). This response signal includes information (referred to as responder ID) for identifying the acoustic transponder 101 of the reply source and depth data measured by the depth gauge 1016 of the acoustic transponder 101 of the reply source. As a result, as the second step of the present invention, the plurality of acoustic transponders 101 respectively return response signals responding to the acoustic signals.

The response signals respectively returned from the plurality of acoustic transponders 101 reach the acoustic transducer 30 (step S15). Accordingly, as the third step of the present invention, the acoustic transducer 30 receives the response signals respectively returned from the plurality of acoustic transponders 101 . The reception time of the response signal and the responder ID and depth data included in the response signal are transmitted from the acoustic transducer 30 to the information processing device 20 .

Next, the information processing device 20 acquires the position measured by the GNSS 40 when the acoustic signal was transmitted, the transmission time when the acoustic transducer 30 transmitted the acoustic signal, and the acoustic transducer 30 received from each acoustic transponder 101. The position of each acoustic transponder 101 is calculated based on the reception time of the received response signal and the transponder ID and depth data included in each response signal (step S16).

FIG. 6 is a table showing an example of measurement results. In FIG. 6, the "vessel position (absolute position)" is the absolute position measured by the GNSS 40, and the absolute Although the position is also known, the absolute position measured by the GNSS 40 is considered as the position of the acoustic transducer 30 in the following description. Since the distance between the acoustic transducer 30 and each acoustic transponder 101 is different, the transmission time when the acoustic signal is transmitted from the acoustic transducer 30 and the acoustic transmitter/receiver 30 is transmitted to each acoustic transponder 101. The difference (time difference) from the reception time when the response signal is received from is different. For this reason, from the relationship between the time difference corresponding to each acoustic transponder 101, the sound wave velocity in water, and the interval between each acoustic transponder 101, relative A position can be calculated. As a result, the "responder position (relative position)" corresponding to each "responder ID" is calculated. Further, since the absolute position of the acoustic transducer 30 corresponds to the "vessel position (absolute position)", the absolute position of each acoustic transponder 101, ie, the "responder position (absolute position)", is determined based on this. It is possible to calculate At this time, since the positions of the plurality of acoustic transponders 101 are calculated based on the acoustic signals transmitted at the same time, the fluctuation correction that has been required conventionally is not required. Therefore, it is possible to calculate the position of the acoustic transponder 101 by simple processing in a short time. Of the xyz coordinates indicating the position of each acoustic transponder 101 in the three-dimensional space, the information processing apparatus 20 calculates the z coordinate using the depth data included in each response signal. Even if the depth gauge 1016 is removed from the configuration of the acoustic transponder 101, the difference between the transmission time when the acoustic signal is transmitted and the reception time of the response signal received by the acoustic transducer 30 from each acoustic transponder 101 is used to determine each acoustic signal. Since the xyz coordinates of the responder 101 can be calculated, the depth gauge 1016 is not necessarily required, but the depth measured by the depth gauge 1016 can be used to calculate the coordinates with higher accuracy.

Returning to the description of FIG. 5, the information processing device 20 calculates the position and shape of the bottom of the water that is the object (step S17). Specifically, since the absolute positions of the acoustic transponders 101 are calculated in step S15, the information processing apparatus 20 uses these positions as respective positions on the bottom of the water, and interpolates between adjacent acoustic transponders 101. The position and shape of the bottom of the water are calculated by performing processing. As a result, as the fourth step of the present invention, the position and shape of the bottom of the water, which is the object, are calculated based on the time difference between each response signal received by the acoustic transducer 30 and the transmitted acoustic signal. Become.

According to the above-described embodiment, the acoustic responders 101 connected by the flexible connecting members 102 are submerged in the dredged water bed so that each acoustic responder 101 can be laid according to the shape of the water bed. can be done. In addition, since the positions of the plurality of acoustic transponders 101 are calculated based on the acoustic signals transmitted at the same time, the vibration correction that has been required conventionally is no longer required, which makes it simpler and more accurate than conventional systems. measurement becomes possible. Furthermore, since the positions of the plurality of acoustic transponders 101 are calculated almost simultaneously, it is possible to grasp the position and shape of the target water bottom in a short period of time.

[Modification]
The embodiment described above may be modified as follows. Also, two or more of the following modified examples may be combined for implementation.

[Modification 1]
When the position (absolute position) of at least one acoustic transponder among the plurality of acoustic transponders 101 is known (such an acoustic transponder is called a known transponder), GNSS positioning in step S13 of FIG. In steps S16 and S17, based on the position (absolute position) of this known transponder, the positions (absolute positions) of other acoustic transponders 101 (acoustic transponders 101 other than the known transponders) are identified and identified as targets. You may make it measure an object. The position of the known transponder is calculated, for example, based on the absolute position of the acoustic transducer 30 as described with reference to FIG. 5, and the information processing device 20 stores the absolute position. The known transponder is also left on the bottom as an acoustic marker. Then, for example, after dredging another nearby target area, the information processing device 20 determines the relative position of each acoustic transponder 101 (that is, the acoustic transducer 30 relative position based on), the relative position of the known transponder (that is, the relative position based on the acoustic transducer 30), and the absolute position of the known transponder that has already been positioned, the target area Calculate the absolute position of each acoustic transponder 101 installed in the . In this way, positioning errors by GNSS can be excluded.

[Modification 2]
Any object in water can be applied. For example, the object may be a hookah hose for supplying air to a diver working underwater. In this case, a plurality of acoustic transponders 101 are attached to the hookah hose at predetermined intervals. The information processing device 20 grasps the position and shape (state) of the hookah hose by calculating the position of each acoustic transponder 101 . This makes it possible, for example, to monitor or prevent contact or entanglement between hookah hoses or between hookah hoses and nearby structures.

[Modification 3]
Sinkers and buoys for surveying ocean currents and the like may also be used as objects. In this case, a plurality of acoustic transponders 101 are laid at predetermined intervals on a connection member that connects the sinker and the buoy as objects. The information processing device 20 calculates the positions and shapes of these sinkers, connecting members and buoys from the positions of the acoustic transponders 101 . This makes it possible to measure ocean currents and the like.

[Modification 4]
The object may be an underwater working machine such as an underwater backhoe that performs some kind of work underwater. In this case, a plurality of acoustic transponders 101 are installed at predetermined positions of the underwater working machine. The information processing device 20 grasps the position and attitude of the underwater working machine by calculating the position of each acoustic transponder 101 . This makes it possible to monitor underwater work and give work instructions.

[Modification 5]
When a diver works underwater using some type of underwater work machine, the diver and the underwater work machine may be targets. In this case, one or more acoustic transponders 101 are installed in each of the diver and the underwater work machine. When at least one acoustic transponder 101 is laid on each of the objects such as the diver and the underwater work machine, the information processing device 20 calculates the position of each of these acoustic transponders 101 to determine the position of the diver and the underwater work machine. It is possible to grasp the position of the machine. Furthermore, when two or more acoustic transponders 101 are installed in at least one of the diver and the underwater work machine, the information processing device 20 calculates the position of each of these acoustic transponders 101 to Alternatively, it is possible to grasp the position of the underwater work machine and grasp the attitude of the object on which two or more acoustic transponders 101 are laid. This makes it possible to confirm safety and give work instructions during underwater work.

[Modification 6]
The acoustic transducer 30 may be installed on the bottom of the water or an existing underwater structure. In this case, if the absolute position of the installed acoustic transducer 30 (hereinafter referred to as an acoustic marker) is measured in advance, the transmission time of the acoustic signal transmitted from this acoustic marker and the acoustic marker can be obtained from each acoustic marker without GNSS. The absolute position of the acoustic transponder 101 can be calculated based on the reception time difference of each response signal received from the transponder 101 and the absolute position of the acoustic marker.

[Modification 7]
FIG. 7 is a block diagram showing an example of the configuration of the entire system according to this modification. An acoustic marker 31 is installed on the bottom of the water or an existing structure in the water. That is, the acoustic marker 31 is a known point in water whose absolute position is known (a variant of the acoustic transponder whose absolute position is known). In this system, the relative positions of the ship 10 and the acoustic marker 31 are measured according to the procedure of steps S13 to S16 in FIG. 5 except for GNSS positioning. Since the absolute position of the acoustic marker 31 is known, the absolute position of the ship 10 can also be derived from the relative position to the known point. The absolute positions of the plurality of acoustic transponders 101 laid on the bottom of the water can also be calculated from the absolute positions of the ship 10 . The acoustic marker 31 is battery or powered and asynchronously emits an acoustic signal into the water.
Using the absolute positions of these acoustic transponders 101, measurements of the object are made. If such an acoustic marker 31 is always installed in a large harbor, for example, and is used continuously, the position, shape, etc. of the bottom of the water can be obtained with the same accuracy even in successive construction works in the harbor by different contractors. can be calculated, the construction standard can be kept constant.

[Modification 8]
In the above embodiment, the acoustic signals and/or response signals between the acoustic transducer 30 and the acoustic transponders 101 are wireless (that is, sound waves), but may be wired.
An information processing device 20 installed on a ship and an acoustic transponder 101 laid on the seabed are connected by a wire, and a calling signal is transmitted to each acoustic transponder 101 by using a wire. The acoustic transmitter/receiver 30 only needs to have the acoustic wave receiving function of receiving the response signal from each acoustic transponder 101 . As a result, the configuration of the acoustic transponder 101 can also be made up of only the acoustic transmitter and the depth gauge, so that improvement in economy and handling can be achieved. In particular, the downsizing of the acoustic transponder 101 enables it to be installed not only by a diver but also by an ROV (Remotely Operated Vehicle) or an underwater drone.

10: Ship, 20: Information processing device, 30: Acoustic transducer, 40: GNSS, 100: Acoustic responder group, 101: Acoustic responder, 102: Connecting member, 103: Anchor, 1010: Arithmetic device, 1011: Processor, 1012: Memory, 1013: Communication device, 1014: Battery, 1015: Acoustic transceiver, 1016: Depth gauge, 2001: Processor, 2002: Memory, 2003: Storage, 2004: Communication device, 2005: Input device, 2006 : output device, G: bottom of water, W: surface of water.

In order to solve the above problems, the present invention provides a first step of transmitting an acoustic signal from an acoustic transducer to a plurality of acoustic transponders laid on an underwater object; a second step in which a plurality of acoustic transponders respectively return response signals in response to the transmitted acoustic signals; and the acoustic transducer receives the response signals respectively returned from the plurality of acoustic transponders. a third step of calculating at least one of the position, shape, and orientation of the object based on the time difference between each of the response signals received by the acoustic transducer and the acoustic signal; 4 , in an area of interest, in the fourth step, based on the absolute position of the acoustic transducer in the first step, at least one acoustic transponder of the plurality of acoustic transponders. Absolutely positioning, leaving the at least one absolutely positioned acoustic transponder installed, in another area of interest, without using the absolute positioning of the acoustic transducer, in the fourth step and determining the positions of the other acoustic transponders based on the known absolute positions of the at least one acoustic transponder, and performing the calculation based on the determined positions .

In the first step, calling signals are transmitted by wire from the acoustic transducer to the plurality of acoustic transponders in place of the acoustic signals, and in the second step, the plurality of acoustic transponders transmit The identification signals of the plurality of acoustic transponders and the depth data measured by the plurality of acoustic transponders may be added to a response signal in response to the received call signal, and returned wirelessly. Further, in the first step, the acoustic signal is wirelessly transmitted from the acoustic transducer to the plurality of acoustic transponders, and in the second step, the plurality of acoustic transponders transmit the transmitted acoustic signal. The identification signals of the plurality of acoustic transponders and the depth data measured by the plurality of acoustic transponders may be added to a response signal in response to the signal and returned wirelessly. Further, in the fourth step, each position of the plurality of acoustic transponders is set as each position of the object, and interpolation processing is performed between the adjacent acoustic transponders to determine the position of the object or The shape may be calculated.

Claims (9)

a first step of transmitting acoustic signals from an acoustic transducer to a plurality of acoustic transponders laid on an underwater object;
a second step in which the plurality of acoustic transponders installed on the underwater object respectively return response signals in response to the transmitted acoustic signals;
a third step in which the acoustic transducer receives the response signals respectively returned from the plurality of acoustic transponders;
and a fourth step of calculating at least one of the position, shape, and orientation of the object based on the time difference between each of the response signals received by the acoustic transducer and the acoustic signal. Object measurement method. A step performed before the first step, comprising submerging in water a flexible member having a plurality of acoustic transponders provided at predetermined intervals.
The object measuring method according to claim 1. when the absolute position of at least one acoustic transponder of the plurality of acoustic transponders is known,
3. The method according to claim 1, wherein in the fourth step, the positions of the other acoustic transponders are identified based on the known absolute positions of the at least one acoustic transponder, and the calculation is performed based on the identified positions. object measurement method. The plurality of acoustic transponders are attached to a diver's hookah hose as the object.
The object measuring method according to claim 1. The plurality of acoustic responders are attached to a connection member that connects the sinker and the buoy as the objects.
The object measuring method according to claim 1. The object measuring method according to claim 1, wherein the plurality of acoustic transponders are attached to an underwater working machine as the object. One or more acoustic transponders are attached to each of the diver and the underwater working machine as the objects.
The object measuring method according to claim 1. The object measuring method according to any one of claims 1 to 7, wherein the distance or number of said acoustic transponders attached to said object differs depending on the required measurement accuracy for said object. the acoustic signal or response signal in the first step and/or the second step is wired or wireless;
The object measuring method according to any one of claims 1 to 8.

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