JPH11211809A - Underwater position measuring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure the positions of multiple acoustic receivers installed underwater with good accuracy. SOLUTION: A test ship 6 is operated on the sea surface afar in horizontal distance from multiple acoustic receivers 21 -2n , acoustic signals are radiated into the sea from a sound generator 26, and the time and absolute position are recorded on a floppy disk(FD) 24. The test ship 6 is operated on the sea surface nearly above the acoustic receivers 21 -2n , and the time and absolute position are recorded on the FD 24. A measuring ship 4 obtains the arrival time difference between the acoustic signals received by multiple acoustic receivers 21 -2n with a correlating unit 11, and the time difference is recorded on a FD 14 together with the time. The data of the FD 14, 24 are compared in time, and the horizontal positions of the acoustic receivers 21 -2n are calculated from the data of the absolute position of the sound generator 26 at the long distance and the arrival time difference of the acoustic signals at that time. The vertical positions of the acoustic receivers 21 -2n are calculated from the data of the absolute position of the sound generator 26 at a short distance and the arrival time difference of the acoustic signals at that time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underwater position measuring method for measuring the position of an acoustic receiver installed in water.

[0002]

2. Description of the Related Art FIG. 2 is a block diagram showing an example of a conventional underwater position measuring system. This underwater position measuring system is a system for measuring the position of an underwater vehicle 1 such as a submarine traveling underwater, and is installed on the sea floor at predetermined intervals to detect noise radiated from the underwater vehicle 1. Acoustic receivers 2a, 2b, 2c. The acoustic receivers 2a to 2c receive sound such as underwater noise and convert the sound into an electric signal. The converted electric signal is mounted on a measuring ship 4 at sea via the cable 3. Is input to the measured measuring device 5. In the measuring device 5, the position of the underwater vehicle 1 is determined based on the data on the installation positions of the acoustic receivers 2a to 2c and the data on the time difference between the electric signals input from the acoustic receivers 2a to 2c. Is calculated.

[0003] Calculation of the position of the underwater vehicle 1 requires accurate data of the installation positions of the acoustic receivers 2a to 2c. Each of these acoustic receivers 2a to 2c is installed in such a way that it is dropped from a ship and submerged on the seabed.
Prior to the position measurement of the underwater vehicle 1, it is necessary to measure the exact positions of the acoustic receivers 2a to 2c in advance. In addition, even after the start of operation, the installation position may move due to the tide of the sea floor or the like, and the positions of the acoustic receivers 2a to 2c need to be measured again.

Conventionally, the position of such acoustic receivers 2a to 2c is measured by the following method. Assuming a straight line connecting the estimated installation positions of the acoustic receivers 2a to 2c, the sound source 7 is suspended from the test ship 6 at a point S on a straight line perpendicular to the assumed straight line, and the sound source 7 is transmitted. Machine 8
And emits an acoustic signal for measurement into the sea.
As the acoustic signal for measurement, for example, an ultrasonic wave having a constant amplitude of 30 kHz is output intermittently for 0.1 second every 3 seconds. Further, based on the arrival time difference of the acoustic signal converted into the electric signal by each of the acoustic receivers 2a to 2c, the latitude and longitude of the known point S, the sound speed in seawater, and the like are set to known numbers, and each acoustic receiver Simultaneous equations are established with the horizontal positions and depths of the vessels 2a to 2c as unknowns. Then, the positions of the acoustic receivers 2a to 2c are obtained by solving the simultaneous equations.

[0005]

However, the conventional method of measuring the position of an acoustic receiver has the following problems. That is, the sound source 7 and the plurality of acoustic receivers 2a to 2c
However, since simultaneous equations were established assuming that all exist on the same plane, they could only correspond to the acoustic receivers 2a to 2c installed on the flat sea floor. When the sound source 7 and the acoustic receivers 2a to 2c are not on the same plane, a measurement error has occurred. The present invention solves the problems of the conventional technology and provides an underwater position measuring method capable of accurately measuring the position of an acoustic receiver installed in water.

[0006]

According to a first aspect of the present invention, there is provided an underwater position measuring method, comprising: a signal generator for generating a test signal for position measurement; A sound radiating unit that emits a sound signal into water, and a sound signal output unit including a position detecting unit that detects an absolute position of the sound radiating unit, and the sound signal outputting unit is installed at different positions in the water and propagates through the water. A plurality of acoustic receivers that receive an acoustic signal and convert it into an electric signal, and the acoustic signals received by the acoustic receivers that determine the correlation between the electric signals output from the plurality of acoustic receivers. The position of the plurality of acoustic receivers installed in the water is measured by the following processing using an acoustic signal detection unit having a correlation detection unit that detects a difference in arrival time.

[0007] The sound output means is moved to a plurality of long-distance positions in the horizontal direction from a position where the plurality of acoustic receivers are installed, and the sound signal is transferred from the long-distance position to the underwater. Radiating long-distance output processing, receiving the acoustic signals radiated from each of the long-distance positions by the plurality of acoustic receivers, and detecting a difference in arrival time of the acoustic signals received by the plurality of acoustic receivers Perform long distance detection processing. Then, based on the data of the absolute position of the acoustic radiating section at each of the long distance positions and the data of the arrival time difference detected in the long distance detection processing for each of the long distance positions, the plurality of acoustic receivers are used. Horizontal position calculation processing for calculating the position in the horizontal plane of the horizontal axis. Further, the acoustic output means is moved to a plurality of short distance positions on a vertical line of the acoustic receiver at a short distance in a horizontal direction from a position where the plurality of acoustic receivers are installed, and the respective A short-range output process of radiating the acoustic signal into the water from a distance position, and receiving the acoustic signals radiated from each of the short-range positions with the plurality of acoustic receivers; And a short distance detection process for detecting a difference in arrival time of the received acoustic signal. Then, based on the data of the absolute position of the acoustic radiating unit at each of the short distance positions and the data of the arrival time difference detected by the short distance detection processing for each of the short distance positions, the plurality of acoustic receivers A vertical position calculation process for calculating the vertical position of is performed.

According to the first aspect of the invention, since the underwater position measuring method is configured as described above, the following operation is performed. The sound output means is moved to a plurality of long distance positions far from the position where the acoustic receiver is installed, and an acoustic signal is emitted into the water from each long distance position. The acoustic signals radiated from each of the long distance positions are received by a plurality of acoustic receivers, and the arrival time differences of the acoustic signals received by the plurality of acoustic receivers are detected. Then, the position of each acoustic receiver in the horizontal plane is calculated based on the data of the absolute position of the acoustic radiation unit at each of the long-distance positions and the data of the arrival time difference detected for each of the long-distance positions. You. Further, the sound output means is moved to a plurality of short distance positions that are short distances from the position where the acoustic receiver is installed, and an acoustic signal is emitted into the water from each short distance position. The acoustic signals radiated from each of the short distance positions are received by a plurality of acoustic receivers, and the arrival time differences of the acoustic signals received by the plurality of acoustic receivers are detected. Then, the vertical position of each acoustic receiver is calculated based on the data of the absolute position of the acoustic radiation unit at each of the short distance positions and the data of the arrival time difference detected for each of the short distance positions. You.

In the second invention, the horizontal position calculation processing and the vertical position calculation processing in the first invention are performed in the following procedures. First, an assumed position setting process for setting assumed position data of the plurality of acoustic receivers is performed. Next, a difference between a value when the assumed position data is substituted into a calculation equation for position calculation and a value when the absolute position data and the arrival time difference data are substituted into the calculation equation is calculated as an error. And a position correction process for correcting the assumed position data based on the error calculated in the error calculation process. Then, a repetition process of repeatedly performing the error calculation process and the position correction process is performed until the error becomes equal to or less than a predetermined value.

In the second invention, the following operation is performed in the position calculating process. Assumed position data of a plurality of acoustic receivers is set, and the value obtained when this assumed position data is substituted into a calculation equation for position calculation, and the absolute position data and arrival time difference data of the acoustic radiation unit are calculated by the calculation equation. Is calculated. Then, the assumed position data is corrected based on the calculated error. Until the error becomes equal to or less than a predetermined value, such error calculation processing and position correction processing are repeatedly performed, and finally the position of each acoustic receiver is measured.

[0011]

FIG. 1 is a configuration diagram of an underwater position measuring system to which a measuring method according to an embodiment of the present invention is applied. This underwater position measuring system includes a plurality of acoustic receivers 2.
_{1, 2} 2, ..., and has a _{2 n.} Acoustic wave receiver ₂ 1 to 2
_n is installed so as to be scattered on the sea floor or the like in order to detect underwater sound waves, receives sound such as underwater noise, and converts it into an electric signal. The electric signal converted by each acoustic receiver 2 _j (where j = 1 to n) is a cable 3
Acoustic signal detection means (for example, a measuring ship) 4 via the sea
Is input to a correlation detection unit (for example, a correlator) 11 mounted on the device. Correlator 11, by determining the correlation between the electrical signals input from the acoustic wave receiver 2 _j, in order to calculate the difference between the detection time of these waves detected by each acoustic wave receiver 2 _j accurately belongs to.

The output side of the correlator 11 is connected to a central processing unit (hereinafter referred to as “CPU”) 12. CPU
A clock 12 for outputting an accurate current time and a recording medium such as a floppy disk (hereinafter, referred to as “FD”) 14 are connected to 12. CPU12 the data of the difference between the acoustic wave detection time in each acoustic receivers 2 _j output from the correlator 11, together with the time data read from the clock 13, and has a function of recording the sequential FD 14. Moreover, the underwater position measuring system includes a sound signal output means (e.g., test vessels) 6 for providing an acoustic signal for testing from a plurality of positions in the acoustic wave receiver 2 ₁ to 2 _n. The test ship 6 has a position detection unit (for example, an absolute position measuring device,
A GPS 21) and a clock 22 that outputs an accurate current time are mounted. The GPS 21 and the clock 22 are connected to the CPU 23. The CPU 23 is further connected to a storage medium such as the FD 24 and a signal generator (for example, a transmitter) 25 for generating a test signal for position measurement.

The CPU 23 has a function of controlling the transmission operation for the transmitter 25, reading the current position of the test boat 6 and its current time from the GPS 21 and the clock 22, and sequentially recording them on the FD 24. . A sound radiating unit (for example, a sound generator) 26 suspended from the test boat 6 in the sea is connected to the transmitter 25. The sound generator 26 is driven by a test signal output from the transmitter 25. For example, an ultrasonic wave having a constant amplitude of 30 kHz emits an acoustic signal output intermittently every 3 seconds for 0.1 second. Things.

[0014] Then, in such underwater position measuring system, a measuring method for measuring the installation position of the acoustic receivers 2 _j, will be described according to the procedure of the following (I) ~ (IV). (I) of a position measuring acoustic receiving transducer 2 ₁ to 2 _n of the long-distance data is assumed to be installed, at a sufficiently large (e.g., 10 times or more) horizontal distance in comparison to the estimated depth The test boat 6 is turned. However, the acoustic signal radiated into the sea from the sound generator 26, there must be securely distance range that can be received by the acoustic wave receiver 2 ₁ to 2 _n. While turning the test ship 6, while emitting an acoustic signal from the sound generator 26 into the sea,
The current position and the current time are sequentially read from the GPS 21 and the clock 22 by the CPU 23 and recorded in the FD 24. On the other hand, in the measurement vessel 4, an acoustic signal emitted from the test vessels 6 side is received by the acoustic wave receiver 2 _j, correlators These electrical signals from each acoustic wave receiver 2 _j via the cable 3 11 is input. By the correlator 11, the correlation between the electrical signals input from the acoustic wave receiver 2 _j is determined, the difference in detection time of the acoustic signals received by each acoustic wave receiver 2 _j is the arrival of an acoustic signal Output as time difference. The data of the arrival time difference output from the correlator 11 and the current time of the clock 13 are sequentially read out by the CPU 12 and recorded in the FD 14 as long-distance data.

[0015] (II) at sea near around the position measuring acoustic receiving transducer 2 ₁ to 2 _n of the short-range data are assumed to be installed to pivot test vessels 6.
Then, while turning the test boat 6, an acoustic signal is emitted from the acoustic generator 26 into the sea, and the current position and the current time are sequentially read from the GPS 21 and the clock 22 by the CPU 23 and recorded on the FD 24. On the other hand, in the measurement vessel 4, similarly, the current time of the acoustic receivers 2 obtains the arrival time difference of the detected acoustic signal by the correlator 11 in _j, the arrival time difference data and clock 13 (I), The data is sequentially read out by the CPU 12 and recorded in the FD 14 as short-distance data.

(III) Calculation of Horizontal Position The data recorded in the FDs 14 and 24 in the measurement of the long distance data in (I) is collated by a data processing computer to obtain a certain time ti (where i = 1 and position data αi of the acoustic generator 26 in ~m), data τij1 arrival time difference between the acoustic receivers 2 _j at the time ti 1
As a set of measurement data, for each time t1 to tm, m
Extract a set of measurement data.

Here, the sound generator 26 at time ti
Is represented by a matrix shown in the following equation (1) using a three-dimensional orthogonal coordinate system. ^{αi = [αxi αyi αzi] T} i = 1~m ··· (1) ( where, T is representative of a transposed matrix.) Time Acoustic receivers _{2 1} measured at ti and the acoustic wave receiver _{2 j} the arrival time difference τij1 is the propagation time between the sound generator 26 and the acoustic wave receiver 2 _j at that time ti tau
If it is defined as ij, it is expressed as the following equation (2). τij1 = τij-τi1 ··· (2 ) Further, the position bj acoustic receivers _{2 j} to be measured, 3
It is represented by a matrix shown in the following equation (3) using a three-dimensional rectangular coordinate system. bj = [bxj byj bzj] ^T j = 1 to n (3) Further, the position bj is an assumed approximate position b ⁰ j (= [b ⁰
xj b ⁰ yj b ⁰ zj] ^T ) and an approximation error Δbj (= [Δ
bxj Δbyj Δbzj] ^T ) and is expressed by the following equation (4). bj = b ⁰ j + Δbj (4) On the other hand, the distance r ij between the sound generator 26 and the sound receiver 2 _j at the time ti is expressed by the following equation (5). rij = {αi−bj} (5) By substituting equation (4) into equation (5) and tailoring it around b ⁰ j, rij is approximated by the following equation (6) You. ^{rij = ‖αi-b 0 j‖ +} {(αi-b 0 j) T / ‖αi-b 0 j‖} Δbj ··· (6) Thus, the acoustic generator at time ti 26 and the acoustic wave receiver 2 the distance rij between _j, sound generator 26 and the acoustic wave receiver _{2 1}
The difference lij between the distances ri1 is expressed by the following equations (7) and (8). lij = rij-ri1 ··· (7 ) = ‖αi-b 0 j‖-‖αi-b 0 1‖ ^{+ {(αi-b 0 1} ) T / ‖αi-b 0 1‖} Δb1 - {( αi−b ⁰ j) ^T / ‖αi−b ⁰ j‖｝ Δbj (8) Further, assuming that the average value of the effective sound velocity in seawater is Ce, the following equation (9) is established. lij = Ce · τij1 (9) Since each τij1 is the measurement data obtained by measuring the long-distance data of (I), ν = [Δτ11 ^T Δτ21 ^T ... Δτm1 ^T ] (10) where, Derutatauai1 = a [τi21 τi31 · · · τin1] T the observation ^{vector, W = [Δb1 T Δb2 T} · · · Δbn T] T ··· (11) When an unknown quantity vector, the position bj A calculation equation (for example, an observation equation) for calculation is as shown in the following equation (12). B · W = Ce · ν−P (12) where P = {αi−b ⁰ j} − {αi−b ^{0 1} } where the matrix B is defined by the following equation (13). You.

[0018]

(Equation 1) When the equation (12) is solved for the unknown quantity vector W, the following equation (14) is obtained. W = Ce (B ^T B) ^-1 B ^T ν (14) Equation (14) is a solution of equation (8) obtained by approximating the nonlinear equation of equation (7). Using a computer for data processing, from each element Δbj of the unknown quantity vector W obtained by the equation (14) and the approximate position b ⁰ j (old) at that time,
A new approximate position b ⁰ j (new) is determined by the following equation (15), and the operation of solving the equation (14) is repeated to obtain the value of the converged approximate position b ⁰ j. b ⁰ j (new) = b ⁰ j (old) + Δbj (15) The horizontal coordinate [b ⁰ of the final approximate position b ⁰ j of each acoustic receiver 2j obtained in this manner. xj b ⁰ yj]
Determine as horizontal position.

(IV) Calculation of vertical position The sound generator at a certain time ti (where i = 1 to m) is obtained by comparing the data recorded in the FDs 14 and 24 in the measurement of the short distance data in (II). Using the 26 position data αi and the data τij1 of the arrival time difference between the respective acoustic receivers 2 _j at the time ti as one set of measurement data, m sets of measurement data are extracted for each of the times t1 to tm. Based on the position data αi of these sound generators 26 and the data τij1 of the arrival time difference corresponding to the position data αi, the (III)
In the same procedure as the calculation of the horizontal position, to calculate the final approximate location b ⁰ j of each acoustic receivers 2j. Then, the obtained vertical coordinates b ⁰ zj at the final approximate position b ⁰ j of each acoustic receiver 2j are determined as the vertical positions. Then, the horizontal position determined by the (III), from a vertical position determined by (IV), the position of each acoustic wave receiver 2 _j is calculated.

[0020] Thus, water position measuring method of this embodiment, the arrival of the acoustic signal between a plurality of the far position by radiating acoustic signals each acoustic receiving transducer 2 ₁ to 2 _n spaced horizontally calculating the horizontal position from the time difference, further, a short distance in the vertical direction of each of the plurality of acoustic receivers 2 ₁ to 2 _n from a short position
The acoustic signal is radiated to calculate the vertical position. Therefore, there is an advantage that the installation position of each of the acoustic receivers 2 _j can be accurately measured.

The present invention is not limited to the above embodiment, but can be variously modified. For example, there are the following modifications (a) and (b). (A) the measurement vessel 4 the data measured by FD 14, the data measured by the test vessels 6 respectively recorded in the FD 24, after the completion of the measurement, an acoustic wave receiver _{2 1} collates the data of these FD14,24 _2n are calculated. For example, the measurement data of the test vessel 6 is
, And the measurement data may be simultaneously recorded on the measurement vessel 4. As a result, the accurate clocks 13, 22
Becomes unnecessary. (B) Although the measurement of the short distance data is performed after the measurement of the long distance data, the order of the measurement may be reversed. Also,
Measurement data may be collected at random, and long-distance data and short-distance data may be sorted according to the position data αi of the sound generator 26.

[0022]

As described above in detail, according to the first aspect, the horizontal positions of a plurality of acoustic receivers are calculated based on the arrival time differences of acoustic signals radiated from a plurality of distant positions. Horizontal position calculation processing, and vertical position calculation processing for calculating vertical positions of the plurality of acoustic receivers based on arrival time differences of acoustic signals radiated from a plurality of short distance positions in a short distance. And go. For this reason, there is an effect that the installation position of each acoustic receiver can be accurately measured in the horizontal direction and the vertical direction. According to the second aspect, in the calculation of the horizontal and vertical positions, the assumed position data is sequentially corrected so as to reduce the error between the assumed position data and the measurement data, and the calculation is repeatedly performed. Are suitable. For this reason, there is an effect that high-precision calculations can be performed quickly by using a computer for data processing.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an underwater position measurement system to which a measurement method according to an embodiment of the present invention is applied.

FIG. 2 is a configuration diagram of a conventional underwater position measurement system.

[Explanation of symbols]

2 _i acoustic receiver 4 measuring vessel 6 test vessel 11 correlator 21 GPS (absolute position measuring device) 25 transmitter 26 sound generator

Claims (2)

[Claims] 1. A signal generator for generating a test signal for position measurement, an acoustic radiator for radiating the test signal as an acoustic signal into water, and a position detector for detecting an absolute position of the acoustic radiator. Acoustic signal output means, a plurality of acoustic receivers installed at different positions in the water and receiving the acoustic signals propagating in the water and converting the acoustic signals into electric signals, and output from the plurality of acoustic receivers Using a sound signal detection means having a correlation detection unit for detecting the correlation of the electric signal and detecting the arrival time difference of the sound signal received by each sound receiver, wherein the plurality of sound receivers Moving the sound output means to a plurality of long-distance positions in the horizontal direction far from the installed position, and irradiating the acoustic signal into the water from each of the long-distance positions; From a distance position A long-distance detection process of receiving the radiated acoustic signal by the plurality of acoustic receivers and detecting an arrival time difference between the acoustic signals received by the plurality of acoustic receivers; A horizontal position for calculating the position of the plurality of acoustic receivers in a horizontal plane based on the data of the absolute position of the radiating section and the data of the arrival time difference detected in the long distance detection processing for each of the long distance positions Calculation processing, at a short distance in the horizontal direction from the position where the plurality of acoustic receivers are installed, to move the acoustic output means to a plurality of short distance positions on a substantially vertical line of the acoustic receiver, respectively A short-range output process of radiating the acoustic signal into the water from a short-range position, and receiving the acoustic signals radiated from the short-range positions with the plurality of acoustic receivers, and Arrival time of the acoustic signal received by the instrument A short-distance detection process for detecting the data of the absolute position of the sound radiating unit at each of the short-distance positions, and data of the arrival time difference detected in the short-distance detection process for each of the short-distance positions, Performing a vertical position calculation process of calculating a vertical position of the plurality of acoustic receivers, thereby measuring a position of the acoustic receiver installed in the water. 2. The horizontal position calculation process and the vertical position calculation process each include a hypothetical position setting process for setting hypothetical position data of the plurality of acoustic receivers, and a calculation equation for calculating the hypothetical position data. And an error calculation process of calculating a difference between a value when the absolute position data and the arrival time difference data are substituted into the calculation equation as an error, and an error calculated by the error calculation process. And a repetition process of repeatedly performing the error calculation process and the position correction process until the error is equal to or less than a predetermined value. The underwater position measuring method according to claim 1, wherein