JP2987252B2 - Acoustic positioning device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an acoustic positioning device for measuring the position of a ship or a moving object in water using underwater ultrasonic waves.

[0002]

2. Description of the Related Art Conventionally, an acoustic positioning device that measures the position of a ship or a moving object in the water using underwater ultrasonic waves has been used to determine the distance between elements of a ship-mounted transducer or a beacon on which a coordinate system is determined. There are three types, LBL, SBL and SSBL (USBL), depending on the length.

FIG. 3 shows a conventional LBL acoustic positioning device.
It is a functional block diagram. LBL acoustic positioning device
Installs three or more transponders on the sea floor and
The direct distance between the transducer and each transponder
Runt range, slant range_i(I = 1,2,3
・ ・) (Hereinafter referred to as slant range)
Therefore, transmission from the coordinate system created by the transponder
Receiver position (x_v, Y _v, Z_v)
You. The baseline length of this method is the transponder spacing
It is thought to be long and spans several kilometers.

In FIG. 3, 1A is an arithmetic control unit, 2 is a transmission controller, 3 is a power amplifier, 4 is a transmission / reception switch, 5 is connected to the present apparatus on board by a cable, and transmits and receives ultrasonic waves provided under the sea. 6-1 to 6-3 are first to third transponders respectively installed on the sea floor, 7 is a preamplifier, 8
-1 to 8-3 are first to third mixers (also referred to as frequency mixers), 9-1 to 9-3 are first to third local oscillators, 10-
1 to 10-3 are first to third bandpass filters (BP
F), 11-1 to 11-3 are first to third amplifiers, 12-
1 to 12-3 are first to third detectors, 13-1 to 13-3
Denotes first to third counters, and 14 denotes a display.

Hereinafter, the operation of the conventional acoustic positioning device will be described with reference to FIG. First, the arithmetic control unit 1A sends a timing signal for starting measurement to the transmission control unit 2. Transmission control unit 2
Receives a timing signal, determines a transmission frequency, and generates a transmission pulse. This transmission pulse is output to the power amplifier 3 and the first to third counters 13-1 to 13-3
Is started. The first to third counters 13
The stop of the counting operation of -1 to 13-3 is performed based on a reception signal from a transponder described later. The power amplifier 3 power-amplifies the transmission pulse from the transmission control unit 2, and amplifies the amplified transmission pulse via the transmission / reception switch 4.
Is applied. The transducer 5 transmits an ultrasonic pulse into the sea. This ultrasonic pulse becomes an interrogation signal to the transponder. First to third transponders 6 installed on the sea floor
When receiving the ultrasonic pulse, which is the interrogation signal transmitted from the transducer 5, 1 to 6-3 receive frequencies f ₁ , f ₂ , f ₃ (for example, f ₁ = 1) which are respectively designated in advance.
(5 kHz, f ₂ = 16 kHz, f ₃ = 17 kHz). These response signals propagate through the sea again, are received by the transducer 5 and converted into electric signals. The electric signal from the transmitter / receiver 5 is transmitted to the preamplifier 7 via the transmission / reception switch 4 and amplified, and then supplied to the first to third mixers 8-1 to 8-3, respectively. In the first to third mixer 8-1 to 8-3 to convert the frequency of the signal received by the transducer 5 converts the frequency to an intermediate frequency f _1F to be used in the apparatus of the present invention.

The frequency conversion will be described with reference to FIGS.
U. FIG. 5 is a configuration diagram of the frequency conversion, and FIG.
It is a frequency relation diagram by a change operation. In FIG.
The input signal g (t) and the frequency from the local oscillator
f _i+ F_1FSignal or frequency f_i−f_1FSignal
And s (t) is output. Output signal s (t) is band
S after passing through the pass filter 10 (BPF)_o(T)
You. Input signal g (t) and output signal s_o(T)
Wave number conversion is performed.

[0007] (a) in FIG. 6 is a frequency spectrum G of the input signal g (t) (f), it has a frequency component of ± f _i. A shown in FIG. 6 (b) the frequency spectrum S (f) of the output signal s of the mixer 8 when performed Saha multiplication (t), the frequency separated by f _i at the center frequency of f _1F -f _i Has frequency components at the frequency f _1F -2f _i and the frequency f _1F which are the positions of. The frequency f _1F -2f _i and the frequency f _1F
The output signal s of frequency f _1F except frequency f _1F -2f _i with the frequency components input to the bandpass filter 10 with
_o (t) is obtained. The frequency spectrum S of the output signal s _o (t) (f) is shown in (c) of FIG. 6, only the output signal of the frequency f _1F is obtained. FIG. 6D shows the frequency spectrum S _o (f) of the output signal s (t) of the mixer 8 when the sum wave multiplication is performed, and the frequency spectrum S _o (f) is separated from the frequency of f _1F + f _i by f _i. Frequency f _1F + 2f which is the position of the frequency
_i and frequency f _1F have frequency components. This frequency f _1F
+ 2f _i and frequency frequency of the frequency component is input to the band-pass filter 10 with f _1F f _1F + 2f _i except frequency f
Obtaining a _1F output signal s _o (t). The frequency spectrum S of the output signal s _o (t) (f) is shown in (e) of FIG. 6, only the output signal of the frequency f _1F is obtained. Thus, the frequency conversion to the frequency f _1F is performed from the frequency f _i.

The first to third local oscillators 9-1 to 9-3 are:
Respectively the response frequency f of the transponder₁, F_Two,
f_ThreeIntermediate frequency f used in this device_1FOnly high or
Is the lower frequency f₁± f_1F, F_Two± f_1F, F_Three± f_1FOf +
Oscillates on either side of the
It is supplied to the corresponding first to third mixers 8-1 to 8-3.
Therefore, the first local oscillator 9-
1 to frequency f₁+ F _1FOr f₁−f_1FIs the signal
And the frequency f from the transducer 5 ₁,
f_Two, F_ThreeIs input. First mixer 8-1
At the frequency f from the transducer 5₁Input signal
On the other hand, after the frequency conversion, the intermediate frequency f_1FOutput signal
But the frequency f_TwoAnd f_ThreeFor the input signal of
Wave number f_1FIs not output. Similarly, the second mixer 8-
2 is the frequency f_Two, The third mixer 8-3
Frequency f_ThreeAfter frequency conversion for each input signal
To the intermediate frequency f_1FThe signal of is output.

First to third bandpass filters 10-1 to 10-1
0-3 are the intermediate frequencies f_1FThe center frequency
Band pass filter that passes the required band. I
Therefore, each of these three bandpass filters is different.
Frequency f₁, F _Two, F_ThreeResponse signal selection by
Is done. The first to third amplifiers 11-1 to 11-3 are
The first to third bandpass filters 10-1 to 10-3 respectively
These output signals are amplified to a certain level. And
These amplified received signals are respectively subjected to first to third detections.
Preset by the wavers 12-1 to 12-3.
Compared to the reference level, the received signal exceeds this reference level
When it receives the pulse, it outputs the received pulse.

First to third counters 13-1 to 13-3
Start counting at the time of transmission, respectively,
The counting is stopped when the received pulses from the detectors 12-1 to 12-3 are input. This means that the first to third counters 13-1 to 13-3 have measured the direct distances from the transducer 5 to the first to third transponders 6-1 to 6-3, respectively. This is generally called a slant range, which is exactly the propagation time for the ultrasonic pulse to reciprocate, but the direct distance is calculated from the underwater sound velocity of the ultrasonic wave. Now
A straight distance to the first transponder 6-1 measured by the first counter 13-1 and r _1, a second counter 6
It is assumed that the direct distance to the second transponder 6-2 measured by the second counter ₂ is r ₂ , and the direct distance to the third transponder 6-3 measured by the third counter 6-3 is r ₃ . These direct distance data r ₁ , r ₂ , r ₃ are supplied to the arithmetic and control unit 1A. Now, the first to third transponders 6-1 to 6
-3 is set at a position forming a triangle, and the relative positional relationship between the transponders is determined by an operation called calibration. Further, when the transducer 5 is referred to as being in the area of the triangle, the calculation control unit 1A from the straight distance data r _1, r _2, r ₃ can be calculated by calculating the position of the transducer 5. Therefore, it is possible to measure the position of the ship on which the present device is mounted. The measured position of the ship and the display 14 are displayed.

The operation of the conventional sound measuring device will be described with reference to the time chart of FIG. The timing pulse from the arithmetic and control unit 1A is transmitted to the transmission control unit 2, which determines the transmission frequency according to the timing pulse and generates the transmission pulse P. The transmission pulse P is output to the power amplifier 3 and starts the counting operation of the first to third counters 13-1 to 13-3. Further, the transmission pulse P power-amplified by the power amplifier 3 is transmitted to the transmitter / receiver 5 via the transmission / reception switch 4 to drive the transmitter 5-1. The transmitter 5-1 transmits the ultrasonic pulse Q of the transmission frequency into water. The ultrasonic pulse Q transmitted into the water has a distance r ₁ ,
The light propagates through the distances r ₂ and r ₃ and reaches the first to third transponders 6-1 to 6-3 installed on the sea floor. The first transponder 6-1 in response as a question signal the ultrasound pulse Q, the response signal of a frequency f ₁ that is designated in advance T-
Send 1 Time interval between the transmission time of the transmission time and the response signal of the interrogation signal from the wave transmitter 5-1, which corresponds to the distance r ₁ between the transducer 5 and the first transponder 6-1 . The response signal T-1 propagates underwater again and is received by the receiver 5-2 of the transmitter / receiver 5 to generate a received signal R-1. The frequency of the received signal R-1 is a frequency f _1, the time interval between the transmission time and the reception signal R-1 of the reception time of the interrogation signal from the wave transmitter 5-1 wave transceiver vessel 5 and which corresponds to twice the 2r ₁ of the distance between the first transponder 6-1. Similarly, the first transponder 6-2 and 6-3 responds as a question signal the ultrasound pulse Q, the frequency f ₂ and f ₃ that is designated in advance
Are transmitted as response signals T-2 and T-3. This transmitter 5
The time interval between the transmission time of the interrogation signal from -1 and the transmission time of the response signal is determined by the transducer 5 and the first transponder 6.
Which corresponds to the distance r ₂ and r ₃ with 2 and 6-3. The response signals T-2 and T-3 propagate through the water again and are received by the receiver 5-2 of the transmitter / receiver 5 to generate received signals R-2 and R-3. This received signal R-2,
Frequency of R-3 is a frequency f ₂ and f _3, the time interval between the transmission time and the reception signal R-2 and R-3 of the reception time of the interrogation signal from the wave transmitter 5-1 , The distances r ₂ and r ₃ between the transducer 5 and the first transponders 6-2, 6-3
This corresponds to 2r ₂ and 2r _{3 which} are twice as large as

The received signals R-1, R-2 and R-3 are transmitted and received.
The signal is sent to the preamplifier 7 via the switch 4, and the signal is amplified.
It is transmitted to the first to third mixers 8-1 to 8-3. 1st to 1st
The first to third local oscillations are applied to the three mixers 8-1 to 8-3, respectively.
From the units 9-1 to 9-3, the frequency f₁± f_1F, F_Two±
f_1F, F_Three± f_1FOf either + side or-side of
Supplied. Output of first to third mixers 8-1 to 8-3
Are the first to third bandpass filters 10-1 to 10-10, respectively.
-3, the frequency is converted, and the frequency f_1FNo faith
Output a signal. First to third bandpass filters 10-1 to 10-1
The output of 0-3 is increased by the first to third amplifiers 11-1 to 11-3.
After being spread, the first to third detectors 12-1 to 12-1 are smelled.
Output signal when the signal exceeds the set value. First
From the detector 12-1, the signal was received by the receiver 5-2.
Frequency f₁U-1 signal corresponding to the ultrasonic pulse of
Power in the first band pass filter 10-1.
If the cut-off characteristic is not sufficient,
In addition, U-2 and U-3 signals are output. This U-2,
The signal of U-3 is the frequency received by the receiver 5-2.
f _Two, F_ThreeCorresponding to the ultrasonic pulse of
In the band-pass filter 10-1, the frequency f_Two, F_Threeof
Output due to insufficient frequency separation
You. If the first bandpass filter 10-1 is ideal,
Wave number f₁Is output only for the U-1 signal corresponding to. First
The detector 12-1 is set in the output of the first amplifier 11-1.
Only those signals that are equal to or greater than the specified value are output.
In this case, among the signals of U-1, U-2 and U-3, U-
Select 1 signal. The selected U-1 signal is
It is input to one counter 13-1. First counter 13-
For 1, the count value C-1 is obtained by the signal of U-1. this
The count value C-1 is calculated by using the transducer 5 and the first transponder 6-6.
Distance r from 1₁And the arithmetic control unit 1A
At distance r₁Is calculated. Similarly, the second and third
The transmitter / receiver 5 and the second and third receivers are connected to the counters 13-2 and 13-3.
Distance r to ransponder 6-2, 6-3_Two, R_ThreeCompatible with
The counted values C-2 and C-3 are obtained. Operation control unit 1A
Then, from the count values C-1, C-2 and C-3, the position of the transducer
The position is calculated and displayed on the display 14.

[0013]

However, in the above-mentioned conventional acoustic positioning apparatus, when a large number of transponders are installed, if the frequency intervals allocated to the transponders are reduced, the band-pass filter of the receiving unit on the ship may have a large number of transponders. However, there is a disadvantage in that the transponder cannot be identified because the skirt characteristic cannot be sufficiently separated. Further, it is difficult to manufacture a filter having a sharp skirt characteristic, and even if it can be manufactured, it becomes extremely large. When a frequency around 15 kHz is used, the frequency interval is generally set to 500 Hz. However, when the frequency interval is 100 to 200 Hz, it is difficult to manufacture a filter that sufficiently separates signals.

This is shown in FIGS. 6B and 6C and FIG.
This will be described with reference to FIGS. The frequency f in the mixer 8_i
Is the frequency f of the local oscillator_1F−f_iWhen mixed with
For example, frequency f_1FBesides f_1F-2f_i(I = 1, 2,
A signal having the frequency of 3) is obtained. 1st bandpass filter
As shown in FIG. 7, the frequency characteristic of 10-1
If the filter characteristics are not sufficient, unnecessary
A signal will also be output. That is, the first mixer 8-
The frequency f by 1₁Input signal has a frequency f_1FAnd frequency
f_1F-2f₁Of the frequency f_TwoThe input signal of
Frequency f_1F−f₁−f_TwoOf the frequency f_Threeof
The input signal has a frequency f_1F−f₁−f_ThreeGenerates a signal.
In the figure, the relationship between the frequencies is merely an example,
Number f_iIt changes according to. 1st band pass filter
If the frequency characteristics of the filter 10-1 are sufficiently designed
In this case, the first band-pass filter 10-1 has the frequency f_1Fof
Passes only the signal and cuts other frequency signals.
If the frequency characteristics of the filter are insufficient, the frequency
Wave number f_1FAnd frequency f_1F-2f₁Signal and frequency f_1F−f
₁−f_TwoSignal and frequency f_1F−f₁−f_ThreePass through the signal
And the output depends on the output characteristics of the filter.
V₁, V_Four, V_Two, V_ThreeBecomes This output signal is a detector
At the reference level V₀Is compared with the reference level V
₀Only the above signals are output. Therefore, in the case of FIG.
Has a frequency f on the first channel.₁f_Twof_ThreeSignal is input
Then, the frequency f_1FAnd frequency f_1F−f₁−
f_TwoAnd frequency f_1F−f₁−f_ThreeSignal is output and the frequency
Number cannot be sufficiently separated and accurate positioning cannot be performed.
No. In FIG. 7, the frequency characteristics of the filter and the input
Number f _iFrequency and output value output from detector according to
Is different.

FIG. 8 shows that the frequency f₁
Output characteristics of each band-pass filter when
FIG. 8A shows the first bandpass filter.
8 (b) is a second bandpass filter.
FIG. 8C shows the output characteristic of the third band-pass filter.
It is a force characteristic. Frequency f on the first channel₁Signal is input
Then, in the first mixer 8-1, the first local oscillator 9-
1 frequency f_1F−f₁Is input and the frequency is mixed.
Wave number f_1FAnd frequency f_1F-2f₁Occurs, and the first detector 12
-1 by the reference level V ₀V of above signal₁Is output
Is done. In addition, the frequency f₁Signal is input
Then, in the second mixer 8-2, the second local oscillator 9-
Frequency f of 2_1F−f_TwoIs input and the frequency is mixed.
Wave number f_1F−f₁−f_TwoAnd the output value V_TwoIs the reference
Bell V₀In the above case, the second detector 12-2
V_TwoIs output (FIG. 8 (b)). Also, the third
Frequency f₁Is input, the third mixer
8-3, the frequency f of the third local oscillator 9-3_1F−f
_ThreeIs input and frequency-mixed, the frequency f_1F−f₁−f
_ThreeAnd the output value V_ThreeIs the reference level V₀More places
In this case, V is detected by the third detector 12-3._ThreeSignal is output
It is.

Accordingly, when the filter characteristics can be sufficiently designed, the output signals are output only from the first detector 12-1 while the output signals are simultaneously output from the first to third detectors 12-1 to 12-3. Output to the first to third counters 13-1 to 13-1
3-3 performs counting, and accurate positioning becomes difficult. SUMMARY OF THE INVENTION It is an object of the present invention to solve the problems of the conventional acoustic positioning device and to provide an acoustic positioning device that separates adjacent frequencies without using a special filter.

[0017]

In order to achieve the above object, an acoustic positioning device according to the present invention transmits and receives an acoustic interrogation signal and receives an acoustic response signal, and receives the acoustic interrogation signal and receives the acoustic interrogation signal. A plurality of transponders each transmitting the acoustic response signal having a different frequency, a filter performing frequency separation of the acoustic response signal, and transmission of the interrogation signal and reception of the response signal provided on channels corresponding to the different frequencies And a counter for controlling the counting by comparing the reception level of the frequency-separated acoustic response signal with a set level, and outputting a detection signal when the frequency exceeds the set level. Means for monitoring an output level and selecting a channel having a maximum reception level as a reception channel and selecting a counter value of the channel. Measuring the position from the-option value of the counter.

[0018]

According to the present invention, the acoustic positioning apparatus is constructed as described above, an interrogation signal is transmitted from the transducer, and a plurality of different frequencies are transmitted from the plurality of transponders installed on the seabed in response to the interrogation signal. The acoustic response signal is transmitted, the frequency of the acoustic response signal is separated by a filter, and the time interval between the transmission of the interrogation signal and the reception of the response signal is counted by a counter provided in a channel corresponding to the different frequency. Measure the distance between the transducer and the transponder to perform a comparison between the reception level and the set level of the frequency-separated acoustic response signal in the detector,
A detection signal is output when the set level is exceeded, and
Means for monitoring the output level of the detector and selecting a channel value having the maximum reception level as a reception channel and selecting a counter value of the channel, and measuring a position from the selected counter value.

[0019]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a functional block diagram of an acoustic positioning device according to a first embodiment of the present invention. This embodiment will be described by taking the LBL system as an example, similarly to the conventional acoustic positioning device of FIG. In the acoustic positioning device according to the first embodiment of the present invention,
Three or more transponders are installed on the sea floor, and the direct distance (slant rang) r _i (i = 1, 2, 3,...) Between the transducer on the ship and each transponder
By measuring (hereinafter referred to slant range), the position of the transducer as viewed from the coordinate system made by the transponder _{(x v, y v, z} v) Request. This baseline length is considered transponder spacing and can be as long as several kilometers.

In FIG. 1, 1A is an arithmetic control unit, 2 is a transmission controller, 3 is a power amplifier, 4 is a transmission / reception switch, 5 is connected to this device on board by a cable, and transmits and receives ultrasonic waves provided in the sea. 6-1 to 6-3 are first to third transponders respectively installed on the sea floor, 7 is a preamplifier, 8
-1 to 8-3 are first to third mixers (also referred to as frequency mixers), 9-1 to 9- are first to third local oscillators, 10-1
10 to 10-3 are first to third bandpass filters (BP
F), 11-1 to 11-3 are first to third amplifiers, 12-
1 to 12-3 are first to third detectors, 13-1 to 13-3
Denotes first to third counters, 14 denotes a display, 15-1 to 15
-3 is the first to third analog-digital conversion (hereinafter A / D
Reference numeral 16 denotes a magnitude comparison circuit.

Next, the operation of the acoustic positioning apparatus according to the first embodiment of the present invention will be described with reference to FIG. First, the arithmetic control unit 1A
Sends a measurement start timing signal to the transmission control unit 2. The transmission control unit 2 receives the timing signal, determines a transmission frequency, and generates a transmission pulse. This transmission pulse is output to the power amplifier 3 and the first to third counters 1
The counting operation of 3-1 to 13-3 is started. This first one
The stop of the counting operation of the third counters 13-1 to 13-3 is as follows.
This is performed based on a received signal from a transponder described later. The power amplifier 3 power-amplifies the transmission pulse from the transmission control unit 2 and applies the amplified signal to the transmitter / receiver 5 disposed under the sea via the transmission / reception switch 4. The transducer 5 transmits an ultrasonic pulse into the sea. This ultrasonic pulse becomes an interrogation signal to the transponder. When the first to third transponders 6-1 to 6-3 installed on the sea floor receive the ultrasonic pulse, which is the interrogation signal transmitted from the transmitter / receiver 5, the frequencies f ₁ and f designated in advance, respectively. ₂ , f
₃ (for example, f ₁ = 15 kHz, f ₂ = 16 kHz, f
₃ = 17 kHz). These response signals propagate through the sea again, are received by the transducer 5 and converted into electric signals. The electric signal from the transmitter / receiver 5 is transmitted to the preamplifier 7 via the transmission / reception switch 4 and amplified, and then supplied to the first to third mixers 8-1 to 8-3, respectively. In the first to third mixer 8-1 to 8-3 to convert the frequency of the signal received by the transducer 5 converts the frequency to an intermediate frequency f _1F to be used in the apparatus of the present invention.

The first to third local oscillators 9-1 to 9-3 are:
Respectively the response frequency f of the transponder₁, F_Two,
f_ThreeIntermediate frequency f used in this device_1FOnly high or
Is the lower frequency f₁± f_1F, F_Two± f_1F, F_Three± f_1FOf +
Oscillates on either side of the
It is supplied to the corresponding first to third mixers 8-1 to 8-3.
Therefore, the first local oscillator 9-
1 to frequency f₁+ F _1FOr f₁−f_1FIs the signal
And the frequency f from the transducer 5 ₁,
f_Two, F_ThreeIs input. First mixer 8-1
At the frequency f from the transducer 5₁Input signal
On the other hand, after the frequency conversion, the intermediate frequency f_1FOutput signal
But the frequency f_TwoAnd f_ThreeFor the input signal of
Wave number f_1FIs not output. Similarly, the second mixer 8-
2 is the frequency f_Two, The third mixer 8-3
Frequency f_ThreeAfter frequency conversion for each input signal
To the intermediate frequency f_1FThe signal of is output.

First to third band-pass filters 10-1 to 10-1
Reference numerals 10-3 denote band-pass filters that pass the required band with the center frequency of the intermediate frequency _f1F .
Therefore, response signals are selected by these three band-pass filters at different frequencies f ₁ , f ₂ and f ₃ . The first to third amplifiers 11-1 to 11-3 are:
First to third bandpass filters 10-1 to 10 respectively
-3 is amplified to a certain level. Then, these amplified reception signals are first to first, respectively.
The third detectors 12-1 to 12-3 compare the signal with a preset reference level, and output a reception pulse when the reception signal exceeds the reference level.

First to third A / D converters 15-1 to 15-
3 converts the analog output of each detector into a digital value. The received signal converted into a digital value is input to the magnitude comparison circuit 16. With this circuit, the channel indicating the first to third maximum values is notified to the arithmetic and control unit 1A.
With this circuit, the data of the counter indicating the first to third maximum values is read. This value becomes the slant range. As described in the conventional example, if the frequency characteristic of the first band-pass filter 10-1 is not sufficient as shown in FIG. 7, an unnecessary signal is output to the filter output. Become. Here, the channels of the first mixer, the first band-pass filter, the first amplifier, the first detector, and the first counter are defined as the first channel, and the second and third mixers, the second and the third band-pass filters, Second,
The channels of the three amplifiers, the second and third detectors, and the second and third counters are assumed to be the second and third channels.

FIG. 8 shows the output signals of the first to third band-pass filters when the signal f1 is input to the first, second, and third channels, and the output level of each channel is the band-pass filter. 5 shows a signal level corresponding to the skirt characteristic of FIG. As described in the related art, in the acoustic positioning device of the related art, if there is a signal of a certain level, it is detected as a received signal. Therefore, when the receiving frequencies are made closer, the three receiving units are in a state of receiving simultaneously.

To avoid this, the outputs of the three band-pass filters are monitored, and it is determined which band-pass filter has passed the signal based on the level difference between them. Signals below a certain level are not detected as received signals. If the same signal is received on all three channels at a signal above a certain level, the three signals are processed as if they were received simultaneously.

Assuming that the detection outputs are V1, V2, and V3 as the outputs of the first to third band-pass filters, the magnitude comparison circuit 16 performs the following processing according to the level. However, signals below a certain level are not detected as received signals. In the case of V1ＶV2, V1 受 信 V3: receiving the first channel In the case of V2≫V1, V2 第 V3: receiving the second channel In the case of V3 受 信 V1, V3≫V2: receiving the third channel V1 = In the case of V2, V1 ： V3: receiving the first and second channels V2 = V3, in the case of V2≫V1: receiving the second and third channels V1 = V3, V1≫V2: receiving the first and third channels Receiving When V1 = V2 = V3: Receiving the first, second, and third channels The first to third counters 13-1 to 13-3 start counting at the time of transmission by the transmission control unit 2, respectively. The first to third
The counting at the time when the reception pulses from the detectors 12-1 to 12-3 are input is counted.

The end of counting by the first to third counters 13-1 to 13-3 is performed as follows. The magnitude comparison circuit 16 selects a channel to be received from among the signals input to the first, second, third, and third channels, inputs the selected signal to the arithmetic control unit 1A, and outputs the selected signal to the first to third counters 13-1 to 13-1. 13
The counter of the corresponding channel is selected from -3, and the count value is obtained.

Thus, the first to third counters 13-1
13 to 13-3 indicate the direct distances from the transducer 5 to the first to third transponders 6-1 to 6-3, respectively. This is generally called a slant range, which is exactly the propagation time for the ultrasonic pulse to reciprocate, but the direct distance is calculated from the underwater sound velocity of the ultrasonic wave. Now, the straight distance to the first transponder 6-1 measured by the first counter 13-1 and r _1, a straight distance to the second transponder 6-2 measured by the second counter 6-2 r ₂ ,
A straight distance to the third transponder 6-3 is measured by the third counter 6-3 and r _3. These direct distance data r ₁ , r ₂ , r ₃ are supplied to the arithmetic and control unit 1A. Now, it is assumed that the first to third transponders 6-1 to 6-3 are installed at positions so as to form a triangle, and the relative positional relationship between the transponders is determined by an operation called calibration. If the transducer 5 is within the area of the triangle, the direct distance data r
_1, r _2, from r ₃ arithmetic control unit 1A can be calculated by calculating the position of the transducer 5. Therefore, it is possible to measure the position of the ship on which the present device is mounted. The measured position of the ship and the display 14 are displayed.

The operation of the sound measuring apparatus according to the first embodiment of the present invention will be described with reference to the time chart of FIG. The timing pulse from the arithmetic and control unit 1A is transmitted to the transmission control unit 2, which determines the transmission frequency according to the timing pulse and generates the transmission pulse P. The transmission pulse P is output to the power amplifier 3 and the first to third counters 13
The counting operation of -1 to 13-3 is started. Further, the transmission pulse P power-amplified by the power amplifier 3 is transmitted to the transmitter / receiver 5 via the transmission / reception switch 4 to drive the transmitter 5-1. The transmitter 5-1 transmits the ultrasonic pulse Q of the transmission frequency into water. Ultrasonic pulses Q which is transmitting in the water reaches the distance r _1, r _2, first to third transponder 6-1 to 6-3 which propagates a distance r ₃ installed in seabed. The first transponder 6-1 responds with the ultrasonic pulse Q as an interrogation signal, and outputs a predetermined frequency f
It sends a response signal T-1 _1. Time interval between the transmission time of the transmission time and the response signal of the interrogation signal from the wave transmitter 5-1, which corresponds to the distance r ₁ between the transducer 5 and the first transponder 6-1 . The response signal T-1 propagates underwater again and is received by the receiver 5-2 of the transmitter / receiver 5 to generate a received signal R-1. This received signal R-
1 is the frequency f ₁ , and the time interval between the transmission time of the interrogation signal from the transmitter 5-1 and the generation time of the received signal R-1 is the time interval between the transmitter / receiver 5 and the first transponder. 6-1
2r ₁ which is twice the distance to Similarly, the first transponder 6-2 and 6-3 responds as a question signal the ultrasound pulses Q, and sends a response signal T-2 and T-3 frequencies f ₂ and f ₃ that is specified in advance. The time interval between the transmission time of the interrogation signal from the transmitter 5-1 and the transmission time of the response signal is the same as the time interval between the transmitter / receiver 5 and the first.
Distances r ₂ and r _{3 to} transponders 6-2 and 6-3
It corresponds to. The response signals T-2 and T-3
Propagates through the water again and is received by the receiver 5-2 of the transmitter / receiver 5 to generate received signals R-2 and R-3. The frequency of the received signal R-2, R-3, the frequency f ₂ and f
₃ , the time interval between the transmission time of the interrogation signal from the transmitter 5-1 and the generation time of the received signals R-2 and R-3 is determined by the transmitter / receiver 5 and the first transponder 6-2. , which corresponds to 2r ₂ and 2r ₃ 2 times the distance r ₂ and r ₃ with 6-3.

The received signals R-1, R-2, R-3 are sent to the preamplifier 7 via the transmission / reception switch 4 and amplified to be transmitted to the first to third mixers 8-1 to 8-3. Is done. The first to third mixers 8-1 to 8-3 output the frequencies f ₁ ± f _1F and f ₂ ± from the first to third local oscillators 9-1 to 9-3, respectively.
Either the _positive side or the negative side of f _1F , f ₃ ± f _1F is supplied. Outputs of the first to third mixers 8-1 to 8-3 are first to third band pass filters 10-1 to 10-10, respectively.
-3, is subjected to frequency conversion, and outputs a signal of frequency _f1F . First to third bandpass filters 10-1 to 10-1
After the output of 10-3 is amplified by the first to third amplifiers 11-1 to 11-3, the first to third detectors 12-1 to 12-1 output an output signal when the signal exceeds a set value. I do. From the first detector 12-1, but U-1 of the signal corresponding to the ultrasonic pulse frequency f ₁ that reception at receivers 5-2 are output, in the first band-pass filter 10-1 If the cutoff characteristic is not sufficient, U-2 and U-3 signals are output in addition to the U-1 signal. This U-
2, the signal of U-3 are those corresponding to the ultrasonic pulse frequency f _2, f ₃ is reception at receivers 5-2,
In the first band-pass filter 10-1, the frequencies f ₂ , f
_This is output because the frequency separation of ₃ is not sufficient. The first band-pass filter 10-1 is output only U-1 of the signal corresponding to the frequency f ₁ if ideal. The first detector 12-1 selects and outputs only those having a set value or more from the outputs of the first amplifier 11-1, and in this case, U-1, U-2, U-3 Out of the signals of U-1. This selected signal U-1
Is input to the first counter 13-1. 1st counter 1
At 3-1 a count value C-1 is obtained from the signal of U-1.
However, if the separation of the filter is insufficient, the first
-3 detectors 12-1 to 12-3, the response signal R1
Are output not only for the frequency f ₁ but also for the frequency f ₂ and f ₃ parts, so that not only the U-1 signal but also V-2 and W-
A signal of 3 is also selected, and an erroneous count is performed. Therefore, the first to third A / D converters 15-1 to 15-1
15-3 converts the analog output of each detector into a digital value. For example, in the first A / D converter 15-1, the signal U-
The data of Vl, Vs, and Vs are output to 1, U-2, and U-3. Also, the second and third A / D converters 15-2 and 15-2
In 5-3, the signals V-1, V-2, V-3 and W-1, W
, Vs, Vs data and V for V-2, W-3
The data of s, Vs, and Vl are output. The received signal data converted into the digital value is input to the magnitude comparison circuit 16. With this circuit, the channel indicating the first to third maximum values is notified to the arithmetic and control unit 1A. For the response signal R1, the first A / D converter 15-1 has Vl data, the second A / D converter 15-2 has Vs data,
Since the data is Vs data in the third A / D converter 15-3, the data Vl is determined to be large in the first A / D converter 15-1, and the magnitude comparison circuit 16 outputs the first A / D converter 15-1.
Is output. Based on the signal of the magnitude comparison circuit 16, the arithmetic control unit 1A reads the data of the counter indicating the first to third maximum values. This value becomes the slant range. Signal 15-1
, The count value C-1 of the counter of the first counter 13-1 is read into the arithmetic and control unit 1A. The count value C-1, which corresponds to the distance r ₁ between the transducer 5 and the first transponder 6-1 computes the distance r ₁ in the arithmetic control unit 1A. Similarly, the second and third counters 13-2 and 13-3 have count values C− corresponding to the distances r ₂ and r ₃ between the transducer 5 and the second and third transponders 6-2 and 6-3. 2, C-3 is obtained. The arithmetic control unit 1A calculates the position of the transducer from the count values C-1, C-2, C-3 and displays the position on the display 14.

Next, a second embodiment of the present invention will be described with reference to FIG. The second embodiment of the present invention differs from the first embodiment of the present invention shown in FIG.
1 to 13-3 to disconnect the connection between the detector 12 and the counter 13. First to third in this case
The counting of the counters 13-1 to 13-3 is completed as follows. The magnitude comparison circuit 16 selects a channel to be received from the signals input to the first, second, third, and third channels, and outputs the selected signal to the first to third counters 13-1 to 13-1.
13-3, the counting of the counter of the selected channel is stopped. According to this count value, the first to third counters 1
3-1 to 13-3 indicate that the direct distances from the transducer 5 to the first to third transponders 6-1 to 6-3 are measured. First to third counters 13-1 to 13-3
Are input to the arithmetic and control unit 1A to calculate the position of the transducer and display it on the display 14.

Next, a third embodiment of the present invention will be described. The third embodiment of the present invention differs from the first embodiment of the present invention in that the center frequency of the local oscillator and the band frequency of the band-pass filter are different for each channel in correspondence with the center frequency. For example, the center frequencies of the first, second and third local oscillators 9-1, 9-2 and 9-3 are represented by f _1F ,
f _2F , f _3F , the first, second and third bandpass filters 10 −
The band frequencies of ₁ , 10-2, and 10-3 are represented by f _1F , f _2F , f
_3F . By setting the value of the center frequency according to the frequency of the response signal, the filter characteristics can be improved.

Next, a fourth embodiment of the present invention will be described with reference to FIG.
Performed by 0. The fourth embodiment is similar to the third embodiment.
The band frequency of the band-pass filter for each channel.
In the first embodiment.
Mixers 8-1 to 8-3 provided in the channel and the first
To 3 local oscillators 9-1 to 8-1
It is. That is, after the preamplifier 7, the mixer 8 and the local
Only one oscillator 9 is connected, and the output of the mixer 8 is
Channel first to third band pass filters 10-1 to 10-3
To enter. In the local oscillator 9, for each channel
And the center frequency is f_1F, F_2F, F_3FAnd the frequency f₁± f
_1F, F_Two± f_2F, F _Three± f_2FEither + side or-side of
At the same time. In the mixer 8,
Wave number f₁± f_1F, F_Two± f_2F, F_Three± f_2F+ Or-side of
And the response frequency f from the transducer 5
₁, F_Two, F_ThreeAre mixed and connected to the mixer 8
1, 2, 3 bandpass filters 10-1, 10-2, 10
At -3, frequency conversion is performed. In the response frequency
f₁If there is, f of the local oscillator 9₁± f_1F+ Side of
Center frequency by mixing with either
Number f_1FOccur in the first band-pass filter 10-1.
Therefore, the center frequency is f_1FAre separated and the response frequency
F inside₁Can be detected. this
Center frequency is f_1FIs amplified by the amplifier 11-1 and detected.
A signal exceeding the reference value is output by the wave device 12-1,
It is input to the first counter 13-1. In addition, the present invention
Channel selection is performed in the same manner as in the first embodiment. First
In addition to the band-pass filter 10-1, the second and third band-pass filters
In filters 10-2 and 10-3, f of local oscillator 9 is also used.
₁± f_1FFor mixing with either + side or-side frequency
Is input. Second and third bandpass filters
The center frequencies of passing through the filters 10-2 and 10-3 are f
_2F, F_3FAnd if the filter characteristics are sufficient, the center frequency
To f_1FIs not output depending on the mixing frequency
If the filter characteristics are sufficient, the second and third bandpass filters 1
Also output from 0-2 and 10-3, may cause erroneous signal
There is. Therefore, the output of the magnitude comparison circuit 16
Select the channel to be output, and
The characteristics of the data. The output of the detector 12-1 is the first A / D conversion
Is converted to a digital value by the converter 15-1 and
Input to the comparison circuit 16. The magnitude comparison circuit 16 is
Comparison with the values of the second and 31 A / D converters 15-2 and 15-3
To select the channel with the largest value and enter it into the arithmetic control unit 1A.
Power. In other words, from the frequency characteristics of the filter, three
Output in the output signal of the band-pass filter
Because the output value from the power filter has the maximum value.
You. This selection signal is input to the arithmetic and control unit 1A, and
The calculation is performed in the same manner as in.

According to this embodiment, the number of mixers and local oscillators can be reduced. Next, a fifth embodiment of the present invention will be described with reference to FIG. The fifth embodiment of the present invention is different from the first embodiment of the present invention in that the mixer 8 and the local oscillator 9 are omitted and the frequency is separated by the band-pass filter 10, and other configurations are the same. is there. That is, the output signal of the transmitter / receiver 5 is
The signal is directly input to the bandpass filter 10 via the preamplifier 7 and then input to the amplifier 11 and the detector 12.

The output signal of the preamplifier 7 contains the frequencies f ₁ , f ₂ and f ₃ of the response signal. The response signal is converted by the band-pass filter 10 into frequencies f ₁ , f ₂ , f ₃
Separate according to. That is, the first band-pass filter 10
-1 passes the frequency of the signal of the frequency f _1, the second band-pass filter 10-2 and the third band-pass filter 10
3 passes frequencies f ₂ and f ₃ . The response signal that has passed through the band-pass filter 10 is input to the counter 13 via the amplifier 11 and the detector 12. On the other hand, the output of the detector 12 is converted into a digital signal by the A / D converter 15, the magnitude of the signal value is compared in the magnitude comparison circuit 16, and the comparison result is input to the arithmetic control unit 1 A. The calculation is performed in the same manner as in Example 1.

When the frequencies of the response frequencies f ₁ , f ₂ and f ₃ are in a frequency band in which signal processing is possible, the mixer 8 and the local oscillator 9 can be omitted according to the fifth embodiment. In the present invention, the case where the reception frequency is three channels has been described. However, even if the frequency increases, the same effect can be obtained only by increasing the number of processing channels.

It should be noted that the present invention is not limited to the above-described embodiment, but can be variously modified based on the gist of the present invention, and they are not excluded from the scope of the present invention.

[0039]

As described in detail above, according to the present invention, signals of adjacent frequencies can be separated without using a sharp filter, and many channels can be separated in a limited frequency band. Can have.

[Brief description of the drawings]

FIG. 1 is a functional block diagram of an acoustic positioning device according to a first embodiment of the present invention.

FIG. 2 is a time chart for explaining the operation of the acoustic measuring device according to the first embodiment of the present invention.

FIG. 3 is a functional block diagram of a conventional acoustic positioning device.

FIG. 4 is a time chart for explaining the operation of a conventional acoustic measurement device.

FIG. 5 is a configuration diagram of frequency conversion.

FIG. 6 is a diagram showing a frequency relationship by a frequency conversion operation.

FIG. 7 is a frequency characteristic diagram of the band-pass filter.

FIG. 8 is an output characteristic diagram of the band-pass filter.

FIG. 9 is a functional block diagram of an acoustic positioning device according to a second embodiment of the present invention.

FIG. 10 is a functional block diagram of an acoustic positioning device according to a fourth embodiment of the present invention.

FIG. 11 is a functional block diagram of an acoustic positioning device according to a fifth embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1A Operation control unit 2 Transmission controller 3 Power amplifier 4 Transmission / reception switch 5 Transceiver 6-1 to 6-3 Transponder 7 Preamplifier 8-1 to 8-3 Mixer 9-1 to 9-3 Local oscillator 10- 1-10-3 Band Pass Filter 11-1 to 11-3 Amplifier 12-1 to 12-3 Detector 13-1 to 13-3 Counter 14 Display 15-13 to 15-3 A / D Converter 16 Size comparison circuit

Continuation of the front page (72) Inventor Shigeo Nakagawa 1-7-12 Toranomon, Minato-ku, Tokyo Examiner, Oki Electric Industry Co., Ltd. Tetsunobu Miyagawa (56) References JP-A-4-40391 (JP, A) JP-A-63-256881 (JP, A) JP-A-61-104272 (JP, A) JP-A-63-163476 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) G01S 3/80-3/86 G01S 5/00-5/30 G01S 7/52-7/64 G01S 15/00-15/96

Claims (2)

(57) [Claims] 1. A transmitter / receiver that transmits an acoustic interrogation signal and receives an acoustic response signal, and (b) a plurality of transducers that receive the acoustic interrogation signal and transmit the acoustic response signals having different frequencies, respectively. A transponder, (c) a counter provided in a channel corresponding to the different frequency, wherein counting is controlled by transmission of the interrogation signal and reception of the response signal, and (d) frequency separation of the acoustic response signal. A filter to be performed; (e) a detector that compares a reception level of the acoustic response signal with a set level and outputs a detection signal when the level exceeds the set level; and (f) monitors an output level of the detector. Means for selecting a channel having the highest reception level as a reception channel and selecting a counter value of the channel, and (g) measuring a position from the value of the selected counter. An acoustic positioning device, comprising: 2. The means for selecting the value of the channel counter comprises an analog-to-digital converter for converting a detection signal of the detector into a digital signal, and a magnitude comparison circuit for comparing the magnitude of the digital signal. Item 3. The acoustic positioning device according to Item 1.