JPH06118169A - Acoustic position measuring device - Google Patents

Abstract

PURPOSE:To obtain an acoustic position measuring device which can measure the accurate arrival direction of a sound source by obtaining an acoustic receiver spacing accurately and can perform an accurate acoustic position measurement. CONSTITUTION:An SSBL acoustic position measuring device consists of a receiver 3 and a receiver array 4 which are placed in a cruising body 16 and a transponder 2 and is provided with sound speed measuring means 10-15 for measuring the sound speed close to the receiver array 4 and a means 7 for measuring the azimuth angle of a sound source by compensating receiver spacing according to the sound speed. The sound speed measuring means 10-15 send waves from one element of the receiver array 4 and obtain the sound speed around the receiver by the propagation time among other elements of the receiver array 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to phase difference correction of an acoustic positioning device.

[0002]

2. Description of the Related Art Conventional acoustic positioning will be described with reference to the configuration diagram of the conventional acoustic positioning apparatus shown in FIG. In the figure, 1
Is underwater, 2 is a transponder installed on the seabed, 3 is a wave transmitter, 4 is a wave receiver array, and 5 is a Super Short.
t Base Line (hereinafter referred to as "SSBL") receiver, 6 is a transmitter, 7 is an arithmetic control unit, 8 is an indicator, 9 is a reference clock, 16 is a running body, 20 is a temperature sensor,
21 is an analog / digital converter.

The operation of the conventional acoustic positioning device having the above configuration will be described. The transmitter 6 receives a transmission command from the arithmetic and control unit 7 repeatedly at regular intervals from a certain reference time in accordance with an input signal from the reference clock 9 inside the running body 16,
The transmission command is transmitted to the wave transmitter 3. The wave transmitter 3 transmits an ultrasonic pulse to the underwater 1 in response to a transmission command from the transmitter 6. This ultrasonic pulse serves as an acoustic interrogation signal to the transponder 2.

When receiving the acoustic interrogation signal, the transponder 2 transmits an acoustic response signal having a frequency f ₁ (for example, f ₁ = 15 kHz). The acoustic response signal transmitted from the transponder 2 is received by the wave receiver array 4 of the running body 16, converted into an electric signal, and then received by the running body SSBL receiver 5. SSBL receiver 5 for aircraft
Is the time from when the arithmetic control unit 7 outputs the transmission command until the response signal of the transponder 2 is detected (that is,
The direct distance (generally called the slant range) between the running body 16 and the transponder 2 is measured by measuring the propagation time of the ultrasonic pulse reciprocating.

That is, the SSBL receiver 5 for a vehicle receives the response signal of the frequency f ₁ transmitted from the transponder 2 and measures its direct distance. On the other hand, the wave receiver array 4 is basically composed of two wave receiving elements, and the direction of the sound source is detected by the wave reception signals of the two wave receiving elements.
In other words, the wave-receiving element is separated and installed, and the arrival direction of the sound wave is measured by measuring the phase difference between the signals received by the wave-receiving element. It is performed in the SSBL receiver 5 for a vehicle.

Usually, the wave receiver array 4 can measure the azimuth in the right-angle direction by arranging two wave-receiving element groups at right angles, and in that case, it is constructed by using four wave-receiving elements. . Further, in the four wave-receiving elements, the middle wave-receiving element can be shared, so that the wave-receiving element can be configured by three wave-receiving elements. When measuring the phase difference between the signals received by the wave receiving element, the phase difference also changes depending on the acoustic spacing of the wave receiver. Therefore, since the change in the acoustic interval of the wave receiver is an amount that depends on the speed of sound in water 1, the speed of sound in water 1 is required when measuring the phase difference. Also, since the speed of sound changes depending on the water temperature, the temperature around the wave receiver is measured and calculated from the relationship between the temperature and the speed of sound.

Therefore, conventionally, in order to perform compensation by temperature, the temperature around the receiver array 4 is measured by the temperature sensor 10, and the temperature data is converted into a digital signal by an analog / digital converter to perform calculation control. It is input to 7, and is converted into sound velocity by calculation. The true acoustic wave interval is calculated by correcting the distance between the wave receivers by the speed of sound obtained by this, and the true sound wave arrival direction is measured from the phase difference based on the wave receiver interval. There is.

By measuring the direct distance and the azimuth angle,
The position of the transponder 2 can be measured. The obtained direct distance and azimuth angle are input to the calculation control unit 7, and X,
It is converted into Y and Z coordinates and displayed on the display unit 8.

[0009]

However, the acoustic positioning device having the above structure has the following problems. (1) An accurate direction of arrival of a sound source cannot be obtained by correcting the phase difference due to temperature, and accurate positioning cannot be performed.

That is, there is pressure in addition to the water temperature as an element of the speed of sound, and it changes depending on the water temperature and also changes depending on the pressure. Therefore, sufficient correction cannot be performed only by the temperature. For example, if the receiver array is installed at a shallow water depth, the effect of pressure is small and correction of only the water temperature can provide a sufficiently practical sound velocity.
When installed in a deep place, the influence of pressure on the speed of sound becomes large, and an accurate speed of sound cannot be obtained.

Therefore, the acoustic receiver spacing cannot be accurately obtained, and the correct phase difference cannot be corrected.
Therefore, it has a drawback that an accurate arrival direction of a sound source cannot be obtained. The present invention solves the problems of the conventional acoustic positioning device described above, and accurately obtains the arrival direction of a sound source by accurately obtaining the acoustic wave receiving element spacing, thereby performing accurate acoustic positioning. It is an object to provide an acoustic positioning device that can perform.

[0012]

In order to achieve the above-mentioned object, in an acoustic positioning system of the present invention, an SSBL acoustic positioning system comprising a transmitter and a receiver array and a transponder installed on a vehicle. In, the sound velocity measuring means for measuring the speed of sound in the vicinity of the receiver array, and means for measuring the azimuth angle of the sound source by correcting the interval of the receiver array by the speed of sound, the sound speed measuring means, One element of the wave receiver array is used as a wave transmitting means, and the speed of sound around the wave receiver is obtained by the propagation time between the wave transmitting means and another element of the wave receiver array.

[0013]

Therefore, in the acoustic positioning device of the present invention, a pulse is transmitted from one element of the receiver array, and the time during which a sound wave propagates between the other elements of the receiver array is measured, The sound velocity is obtained from the known length between the elements. With this, an accurate receiver interval is obtained and an accurate arrival direction of a sound wave is measured, and accurate positioning can be performed.

[0014]

Embodiments of the present invention will now be described in detail with reference to the drawings. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a structural diagram of a receiver array.
In the figure, 1 is underwater, 2 is a transponder installed on the seabed, 3 is a wave transmitter, 4 is a wave receiver array, and 5 is Supp.
er Short Base Line (hereinafter, "SS
BL ”. ) Receiver, 6 transmitter, 7 arithmetic controller, 8 display, 9 reference clock, 10 transmitter, 11 transmitter / receiver switch, 12 amplifier, 13 detector, 14 level detector , 15 is a counter, and 16 is a running body.

In FIG. 1, positioning by the SSBL system is performed by a transmitter 6, a transmitter 3, a transponder 2, elements 2 and 3 of a receiver array 4, an SSBL receiver 5 for a vehicle.
Also, it is performed by the arithmetic control unit 7. On the other hand, the acoustic distance measurement for correcting the phase difference is performed by the transmitter 10, the transmission / reception switch 11, the amplifier 12, the detector 13, and the level detector 1.
4, the counter 15 and the arithmetic control unit 7.

Further, in FIG. 2, elements 1 to 3 are installed in the wave receiver array 4, element 1 is used as a wave transmitting element, and elements 2 and 3 are used as wave receiving elements. . Among the above-mentioned elements, the element 2 is used as a wave receiving element for both SSBL positioning and acoustic distance measurement for correcting the phase difference, and is installed at a distance L from the element 1. On the other hand, the element 3 is used as a wave receiving element for SSBL positioning.

The acoustic positioning device of the present invention is constructed as described above and operates as follows. First, positioning by the SSBL method will be described. First, the arithmetic control unit 7 repeatedly gives a transmission command to the wave transmitter 3 via the transmitter 6 at regular intervals from a certain reference time in accordance with an input signal from the reference clock 9 inside the running body 16. The wave transmitter 3 transmits an ultrasonic pulse to the underwater 1 in response to a transmission command from the transmitter 6. This ultrasonic pulse becomes an acoustic interrogation signal for the transponder 2. When the transponder 2 receives the acoustic interrogation signal, the transponder 2 transmits an acoustic response signal having a frequency f ₁ (for example, f ₁ = 15 kHz).

The acoustic response signal transmitted from the transponder 2 is received by the wave receiver 4 of the vehicle 16, converted into an electric signal, and then received by the vehicle SSBL receiver 5. The SSBL receiver 5 for a vehicle is a calculation control unit 7
Measures the time until the acoustic response signal of the transponder 2 is detected after the transmission command is output, and the direct distance between the vehicle 16 and the transponder 2 is measured by the time interval.

That is, the SSBL receiver 5 for a vehicle receives the acoustic response signal of the frequency f ₁ transmitted from the transponder 2 and measures its direct distance. In addition, in order to measure the direction of the sound source in SSBL positioning, it is necessary to measure the phase difference between the received signals in the receiver. Therefore,
The wave receiver array 4 is basically composed of two wave receiving elements, and the direction is detected by the wave reception signals of the two wave receiving elements.

That is, the wave receiving element is installed separately from the two,
The arrival direction of the sound wave is measured by measuring the phase difference between the signals received by the wave receiving element, and the signal processing for the azimuth measurement is performed by the SSBL receiver 5 for a vehicle. Usually, the receiver array 4 can measure the azimuth in the right-angle direction by arranging two receiving element groups at right angles. In that case, the receiving array is constructed by using four receiving elements. By making the wave-receiving element of 1 common, it is possible to use three wave-receiving elements.

1 and 2, the element 1 of the wave receiver array 4 receives a transmission command from the transmitter 10 via the transmission / reception switch 1, and the elements 2 and 3 of the wave receiver array 4 are transmitted. Is directly connected to the SSBL receiver 5 for the vehicle.
In the above-mentioned measurement of the phase difference, the phase difference varies depending on the acoustic spacing of the receiver array, and the acoustic spacing is a function of the speed of sound, so that the speed of sound of the water 1 near the receiver array 4 is required. Therefore, a transmission voltage is applied from the transmitter 10 to one of the wave receiver arrays 4 via the transmission / reception switch 11.

In general, the wave receiving element can also be used as a wave transmitting element. Therefore, in the illustrated embodiment, by transmitting a pulse wave to the element 1 of the wave receiver array 4, an ultrasonic pulse is transmitted underwater 1. Send to. The other element 2 or 3 of the receiver array 4 is used for receiving the received signal. In the embodiment shown, the element 2 is used for measuring acoustic spacing,
The element 2 and the element 3 are used for SSBL positioning for a vehicle.

Next, correction of the acoustic distance of the wave receiver will be described with reference to the time chart of the acoustic positioning device of the present invention in FIG. The acoustic distance of the wave receiver of the present invention is corrected by the transmitter 10, the transmission / reception switching device 11, the amplifier 12, the wave detector 13, the level detector 14, and the counter 15. First, the measurement of the acoustic distance between the elements 1 and 2 will be described.

The transmitter 10 sends a transmission command b from the arithmetic control unit 7 to the element 1 of the wave receiver array 4 in response to the control signal, and the element 1 transmits. At this time, the transmission / reception switch 11 is switched to the transmission side by the switching signal f, and the transmission command b inputs the signal g for starting counting to the counter 15 via the amplifier 12, the detector 13, and the level detector 14. . By switching to the transmission side by this switching signal f, the element 2
The signal from the element 1 received by the element 3 is not input to the SSBL receiver 5 for a vehicle.

On the other hand, the transmission signal c emitted from the element 1 propagates in the water near the transmitter array 4 and is received by the element 2, and the reception signal d is input to the amplifier 12. The amplifier 12 amplifies the received signal d to a certain level and detects it by the detector 1.
At 3 the wave is detected and converted to direct current. Level detector 14
Outputs a pulse h when it receives a signal of a certain level or higher from the detected output. The counter 15 starts counting by the signal g and stops counting by the signal h, and counts the time from the time when the transmitter 10 transmits the transmission command b until the element 2 of the wave receiving array 4 receives it. To do.

Since the positional relationship of the elements of the receiving array 4 is known, the known element interval is L (m) and the propagation time is t.
(Sec), the sound velocity C (m / s) can be obtained by C = L / t. The true acoustic receiver interval is obtained from the sound velocity C obtained by this, and the arithmetic control unit 7
Input the data of the acoustic receiver spacing to.

On the other hand, the transmission command a is transmitted from the transmitter 6 at a constant cycle as described above, and the acoustic interrogation signal is transmitted from the wave transmitter 3. The acoustic response signal of the transponder 2 based on this acoustic interrogation signal is received by the element 2 and the element 3 of the wave receiver 4, and the received signal i is detected from the element 2,
The received signal j is detected from the element 3. This received signal i
Upon reception of Ravi j, the transmission / reception switching unit 11 switches the switching signal k.
Has been switched to the receiving side by.

The received signals i and j are input to the SSBL receiver 5 for a vehicle, a signal 1 is obtained, and the arithmetic control unit 7 is input to measure the direct distance and the azimuth. The phase difference, which is the data regarding the azimuth angle from the SSBL receiver 5 for the vehicle, is corrected by the acoustic wave receiver interval data obtained from the counter 15 to obtain an accurate azimuth angle.

The arithmetic control unit 7 measures the position of the transponder 2 based on the direct distance from the SSBL receiver 5 for the vehicle and the corrected azimuth, and further converts it into X, Y, Z coordinates for display. It is displayed on the container 8. Next, a second embodiment of the acoustic distance correction of the receiver array of the present invention will be described. FIG. 5 is a structural diagram of the receiver array of the present invention.

In the second embodiment, the acoustic distance is corrected by sing-around. The element 1 of the wave receiver array 4 also transmits a wave toward the element 2 similarly to the first embodiment. When the element 2 receives the wave, the received signal is fed back to the element 1. The element 1 transmits again to the element 2 based on the feedback signal. The acoustic distance is corrected by repeating the wave transmission between the element 1 and the element 2, and the correction accuracy can be improved.

In the method of correcting the acoustic distance by the sing-around, the sound velocity and the acoustic receiver spacing are measured a plurality of times by repeating the transmission of the wave between the element 1 and the element 2, and The data is averaged, and the phase difference is corrected by the average sound velocity and the acoustic receiver spacing. The present invention is not limited to the above-described embodiments, and various modifications can be made based on the spirit of the present invention, and these modifications are not excluded from the scope of the present invention.

[0032]

As described above in detail, according to the present invention, since the sound velocity around the receiver array can be directly measured, the temperature, water pressure and salt content are not corrected as in the conventional case. It is possible to perform correction due to changes in sound velocity due to various influences such as density, and to perform accurate positioning in SSBL positioning.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a structural diagram of a receiver array of the present invention.

FIG. 3 is a time chart of the acoustic positioning device of the present invention.

FIG. 4 is a configuration diagram of a conventional acoustic positioning device.

FIG. 5 is a structural diagram of a receiver array of the present invention.

[Explanation of symbols]

 1 Underwater 2 Transponder 3 Transmitter 4 Receiver array 5 SSBL receiver for vehicle 6 Transmitter 7 Arithmetic control unit 8 Display 9 Reference clock 10 Transmitter 11 Transmitter / receiver switch 12 Amplifier 13 Detector 14 Level detector 15 Counter 16 Moving body

Front Page Continuation (72) Inventor ▲ Takahashi Hideyuki Hashi 1-1-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd.

Claims (2)

[Claims] 1. (a) A wave transmitter installed in a vehicle,
(B) a receiver array installed on the spacecraft, and (c)
In an SSBL acoustic positioning device including a transponder, (d) sound velocity measuring means for measuring the sound velocity in the vicinity of the receiver array; An acoustic positioning device comprising: 2. The sound velocity measuring means comprises: (a) one element of the receiver array as a transmitting means; and (b) propagation time between the transmitting means and another element of the receiver array. The acoustic positioning device according to claim 1, wherein the sound velocity around the wave receiver is obtained by.