JP3139815B2 - Underwater object display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for transmitting a wide range of sound waves, particularly ultrasonic pulses, into water from a transducer comprising a large number of transducers arranged in a cylindrical or arcuate shape. By forming a receiving beam with directivity by combining the oscillators, and sequentially switching the combination of oscillators, the receiving beam is rotated to receive the reflected wave returning from each direction and display it on the display. A so-called underwater object display device of a scanning sonar.

[0002]

2. Description of the Related Art An example of a conventional scanning sonar display system will be described. FIG. 9 is an example of a transducer of a scanning sonar, in which n transducers are arranged in the circumferential direction, and m transducers are vertically arranged in m stages, and n × m transducers T ₁₁ ,
An assembly of T ₁₂ ,... T _nm is used.

[0003] Then, as shown in FIG. 10, after an ultrasonic pulse is emitted from a transducer T along a horizontal plane or a conical surface B, a reflected wave from an underwater object F is vertically aligned in a row of transducers T. ₁₁ , T ₁₂ , T ₁₃ ... T _1m are grouped to form a sound beam having an appropriate directional angle (width) in the longitudinal direction, and several of these are combined in the circumferential direction to form a direction θ ₁ as shown in FIG. By forming a receiving beam RB having sharp directivity and sequentially changing the receiving beam RB in the circumferential direction, θ ₂ , θ
₃ ... The direction and the conical surface B are sequentially turned at high speed to receive the wave.

The position of the underwater object F on the conical surface B is determined by the azimuth of the reception beam RB and the distance from the time at which the reflected wave from the underwater object F is received after emitting the ultrasonic pulse. We can know by asking.

For example, as shown in FIG. 12, the position of the underwater object F is determined according to the intensity of the reflected wave on a CRT that performs a spiral sweep synchronized with the turning of the received beam, or according to the intensity of the reflected wave. It is displayed as a constant bright spot regardless of the brightness.

Although description of this display is omitted, sweeping in the XY directions according to a television set as shown in FIG. 13 is performed by using a circuit comprising an appropriate storage circuit, a coordinate conversion circuit and a control circuit thereof. It is also well known that it can be displayed on a cathode ray tube.

In the case of displaying a vertical cross section underwater using this scanning sonar, conventionally, as shown in FIG. 14, attention is paid to one direction from the transducer T, or one direction and the opposite direction. A vertical plane is scanned by sequentially changing the depression angle of the transmission / reception beam to detect a sector-shaped cross section S.

The display of this vertical section is shown in FIGS.
As shown in FIG. 1, a vertical section V is displayed on a part of a CRT displaying an image H of an underwater object on a transmission / reception wave beam. In this case, the image H of the underwater object may be displayed by projecting the underwater object on the receiving beam onto a horizontal plane in order to clarify the position of the underwater object.

In this conventional method for displaying a vertical cross section, only a cross section in a certain direction is displayed even though the whole or a part of the periphery of the transducer is detected by a receiving beam which rotates at a high speed. Therefore, there is a drawback that it takes time when searching for a wide range of underwater and when searching by sequentially switching the direction in which the vertical section is displayed.

As one effective means for remedying this drawback, an underwater object display device disclosed in Japanese Patent Publication No. Sho 63-26876 has been proposed. This underwater object display device,
A polar coordinate display that displays the image in polar coordinate format centered on the transducer, and an image that is at an arbitrary distance in the image from the transducer and is in a finite plane or curved surface that does not pass through the transducer Is displayed simultaneously or alternately on the coordinate axes of the angle and depth or the length and depth of the plane or curved surface, thereby shortening the time for detecting an underwater object.

In addition, this underwater object display apparatus displays a cross section of a plane or a curved surface distant from the transmitter / receiver when displaying a cross section underwater, and transmits / receives the wave in a vertical direction with an appropriate directional angle (width). A CRT that scans vertically by changing the depression angle of the beam sequentially, scans horizontally by the receiving beam that rotates at high speed, and displays the image of the underwater object on the transmitting and receiving beam as it is or projected on the horizontal plane By displaying a vertical cross section in the upper part or by switching to this image, it is possible to detect an underwater object in a short time.

[0012]

SUMMARY OF THE INVENTION The above Japanese Patent Publication No. Sho 63-2
According to the underwater object display device disclosed in US Pat.
Although a significant improvement has been made compared to the past, it takes a lot of time to observe a relatively long distance and a wide vertical detection width due to the slow propagation speed of ultrasonic waves in water. It was a practical difficulty.

The present invention has been made in order to solve the above-mentioned disadvantages, and the method of displaying an image is basically the same as that of the underwater object display device disclosed in Japanese Patent Publication No. 63-26876. However, it is an object of the present invention to provide an underwater object display device that can detect an underwater object in a short time even when it is desired to observe a long distance and a wide detection width in the vertical direction.

[0014]

In order to achieve the above object, the present invention provides a transmitter / receiver having a plurality of transducers arranged therein, which emits sound waves into water and receives reflected signals from underwater objects. In the underwater object display device for displaying the underwater object on a display device, a group of cylindrical surface arrayed vibrators for detecting the horizontal position of the underwater object, and left-right symmetric, and with respect to a plane perpendicular to the central axis. A transducer comprising at least two transducer groups for detecting a cross-sectional position having a declination by a predetermined angle, and a return signal from an underwater object received by the cylindrical surface array transducers Is formed by combining a plurality of transducers adjacent to each other on a cylinder to form one receiving beam having directivity and receiving the same, and by sequentially switching the combination of the transducers, the received beam is converted into an electron beam. Rotate underwater And a horizontal plane video circuit for detecting the horizontal orientation of the calculated amplitude sum and difference of the described signals from underwater objects are reception by symmetrical least two transducer groups, further, the denominator the sum By obtaining the quotient, a receiving circuit comprising a cross-sectional image circuit for detecting the cross-sectional direction of the underwater object, and a reflection signal from the underwater object, polar coordinates as an image projected on a horizontal plane including the cylindrical surface array vibrator surface The display device further includes a flat display unit for displaying, and a cross-sectional display unit for displaying a cylindrical surface perpendicular to the horizontal plane including the underwater object displayed on the flat display unit.

[0015]

In the underwater object display device according to the present invention, a single ultrasonic wave (transmitted wave) emitted horizontally with an arbitrary depression angle by the transducer composed of a group of cylindrical vibrators for horizontal position detection. In each case, the horizontal position information of the underwater object is obtained from a plurality of transducer groups that are bilaterally symmetric for cross-sectional position detection and that have a declination by a predetermined angle with respect to a plane perpendicular to the central axis. Ultrasonic waves (transmitted waves) emitted in the vertical direction while sequentially changing the directivity by the configured transducer
As a result, the position information in the vertical direction can be obtained.

Here, the vertical direction of the underwater object can be known from the vertical position information obtained by the transducer for detecting the cross-sectional position, but the horizontal direction can be known. Therefore, it is impossible to obtain an image for displaying a cross section of an underwater object.

Therefore, by controlling the respective phases of the signals received by the respective transducers of the transducer group of the transducer for detecting the position in the sectional direction, the normal direction θ _v0 of the transducer group is controlled. A receiving beam having respective main axes in directions deviated by + θ _v and −θ _v is formed.

[0018] Then, transmission and reception for detecting the position in the sectional direction
Of the return signals (b) and (c) received by the
Calculate the sum and difference of the widths, and use the sum as the denominator
Seeking a quotient. The difference beam (b)-(c) is θ_v0In the direction
0 value and -θ_v, + Θ _vShows the maximum value in the direction of.
The quotient (b−c) / (b + c) of the sum beam and the difference beam is
Direction of arrival of wave signal (reflection signal from position of underwater object)
And -θ_vFrom + θ_vIn the linear relationship
You.

That is, the quotient of the sum beam and the difference beam (b−
c) / (b + c) to obtain + θ _v from + θ _v
arrival direction of the reflected signal in the range of theta _v, i.e., it is possible to detect the cross-sectional direction orientation of underwater objects.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An underwater object display device according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a diagram showing an arrangement structure of a transducer in an underwater object display device according to an embodiment of the present invention.

In the figure, reference numeral 12 denotes a transducer in which transducers are arranged in the same manner as in the conventional scanning sonar shown in FIG. 9, in which n transducers are arranged in a circumferential direction, and these are arranged in a vertical direction. m × n transducers TA (T ₁₁ , T ₁₂ ,... T
_nm ), and the transducer 1
2 and the method of forming an ultrasonic beam are also shown in FIG.
0 to 13 are the same as those shown in FIG.

Reference numerals 14 and 16 are used for displaying a cross section.
And the transducers 14 and 16 are
The same number of transducers TB (T_B11, T_B12, ... T_Bir) And TC
(T _C11, T_C12, ... T_Cir), And i
And r in the horizontal direction are arranged at regular intervals.
I have. Moreover, the vertical oscillator T_B11, T_B21,
... T_Bi1And T_C11, T_C21, ... T_Ci1Has an appropriate radius
Vibrator T arranged in a part on a cylinder having
_B11, T_B12, ... T_B1r, T_C11, T_C12, ... T_C1rIs
They are arranged on a straight line. That is, the transducer 1
Reference numerals 4 and 16 denote one group of transducers arranged in a cylindrical plane of the transducer 12.
Transducer that cuts out part and arranges it by changing direction by 90 degrees
May be considered. And the transducers 14 and 16 are
If the spacing between the transducers 14 and 16 is
Configuration may be used.

The operation of the transducers 14 and 16 is vertically arranged in the transducers 14 and 16 in the same manner as the horizontal ultrasonic beam is formed by the transducer TA of the transducer 12. T transducers T _B11 , T _B21 ,... T
_Bi1, T _C11, T _C21, among ... T _{Ci 1,} phase Tonariru appropriate number of vibrators TB, the combination of TC, as shown in FIG. 2, reception with a sharp directivity in the direction of the theta ₁ ' Beam RB _V
Are formed, and by sequentially shifting the combination of the transducers, the receiving beam is sequentially rotated at high speed in the vertical direction such as θ ₂ ′, θ ₃ ′,.

By such means, the transducer 1 shown in FIG.
Each time the ultrasonic waves (transmitted waves) emitted in the horizontal direction with an arbitrary depression angle by 2 are used, the vertical position information of the underwater object is vertically changed from the transducers 14 and 16 while sequentially changing the directivity. It can be obtained by emitted ultrasonic waves (transmitted waves).

However, the transducers 14 and 16 in FIG.
The vertical orientation of the underwater object can be known only from the vertical position information obtained by, but it is not possible to know the horizontal orientation, and it is not possible to obtain an image for displaying the cross section of the underwater object. Impossible.

Therefore, by controlling the respective phases of the signals received by the transducers T _{B11 to} T _Bir and T _{C11 to} T _Cir of the transducers 14 and 16 in FIG. 1, 14a in FIG. , 16a, the transducer TB,
+ Theta _v with respect to the normal direction theta _v0 of TC, to form a receive beam having a respective major axis in a direction deviated by - [theta] _v.
The formation of the received beam is the same as the formation of the received beam having an arbitrary depression angle as shown in FIG. 2 by the group of cylindrical surface arrayed transducers in FIG. 9, that is, the transducer 12 in FIG. It is a known one.

As another realizing means, + θ _v , −θ in FIG.
A transducer 1 composed of transducers T _{B11 to} T _Bir and T _{C11 to} T _Cir so as to face the direction of _v
Needless to say, 4, and 16 may be arranged so as to have a declination of θ _v in advance.

FIG. 4 is a diagram showing received beams (b) and (c) by the transmitters / receivers 14 and 16, and FIG. 5 is a diagram showing received beams (b) and (b) by the transmitters / receivers 14 and 16 in FIG. The directivity of the receiving beam when the sum beam (b) + (c) and the difference beam (b) − (c) of (c) are calculated is shown. here,
The difference beams (b)-(c) show a value of 0 in the direction of θ _v0 , and show maximum values in the directions of −θ _v and + θ _v .

As is known, the quotient (b−c) / (b + c) of the sum beam and the difference beam is calculated by calculating the arrival direction of the received signal (reflected signal from the position of the underwater object) as shown in FIG. −θ
_v in the range of from + θ _v, there is a linear relationship. That is, by determining the quotient of the sum beam and the difference beam (b-c) / (b + c), can be detected arrival direction of the reflected signal in a range from -θ _v + θ _v. This method is called a monopulse method and is well known.

FIG. 7 is a diagram showing an embodiment of a circuit configuration for performing azimuth detection using the above-described transducers 14 and 16. In FIG. In this circuit, transducers 14 and 16 composed of transducers TB and TC are connected to the same number of amplifiers 18 as the transducers TB and TC, and signals received by the transducers TB and TC are respectively transmitted. Amplified.

These signals are input to horizontal switches 20a, 20b,... Of a horizontal switch group 20 provided for each vertical column, and one of them is converted to a signal B for each vertical column. ₁₁ ... it is output as B _1r and C ₁₁ ... C _1r.
This output signal is input to the delay circuit group 22, 24, relative to the amount - [theta] _v, or + theta _v required in the delay circuit groups 22, 24 an ultrasonic beam to cause deflection angle, vibrators TB, T
Delay amount determined by the interval and the number of C (τ ₁ ... τ _r )
Just delay each.

The signals of the delay circuit groups 22 and 24 are added to the addition circuit 2
After being added in 6, 28, the sum is guided to a sum circuit (SUM) 30 and a difference circuit (DIFF) 32. Sum circuit (SUM) 3
0, the difference circuit (DIFF) 32 calculates the sum and difference of the output signal (b) of the adder circuit 26 and the output signal (c) of the adder circuit 28, and the sum circuit (SUM) 30 outputs (b +
c), the difference circuit (DIFF) 32 outputs (bc).

These signals are input to the divider 34, and a quotient (bc) / (b + c) is obtained. As described above with reference to FIGS. 4 to 6, this value (bc) /
(B + c) indicates the arrival direction of the reflected signal, that is, the horizontal azimuth (θ) of the underwater object.

The signals obtained from the transducers TB and TC in each horizontal row are connected and added from 1 to i for each horizontal row by a buffer circuit 36, and are added electronically by a vertical switch 38.
In addition, each signal is switched at a high speed to obtain a vertical image. This signal and the quotient (bc)
The orientation information signal of / (b + c) is applied to the processor 40, and the orientation of the underwater object in each vertical direction is detected at high speed,
It can be displayed.

Here, as the horizontal switch 20a, for example, an analog switch may be used.
2, 24 can be easily realized by using an LC circuit or the like. The transducers 14 and 16 have main axes of −θ _v and + θ.
_By mechanically turning in any horizontal direction while holding at _v , an underwater cross-sectional image in any direction can be obtained, and the transducers constituting the transducers 12, 14, 16 are the same. Although the above description has been made with reference to the above-mentioned frequency, the present invention can also be realized by using different frequencies.

FIG. 8 is a block diagram showing an embodiment of the underwater object display device according to the present invention, wherein a transmission trigger signal generated by a transmission trigger circuit (not shown) is used as a time reference.
A transmission wave (burst) in which the phase of the transmission wave is shifted is guided to the horizontal plane transmission circuit 44 by the transmission depression angle control circuit 42 so as to tilt the transmission wave to an appropriate depression angle.

The transmission wave (burst) is transmitted to the horizontal transmission circuit 4
The power is amplified to an appropriate level by 4 and guided to a group of horizontal plane vibrators, that is, a transducer 12 (see FIG. 1), and a transmitted ultrasonic pulse is emitted in a wide range direction in the water.

The transmitted transmitted ultrasonic pulse propagates in the water, and if an object is present in the water, it returns to the transducers 12, 14, and 16 when the object is present. As for the reflected signal from the underwater object received by the transducer 12, the horizontal control signal generated by the azimuth control circuit 46 is sent to the horizontal video circuit 48 just like the conventional sonar, Horizontal plane images are amplified and converted from analog to digital quantities.

This signal is supplied to the video memory controlled by the write signal of the horizontal video write / read circuit 50 for each horizontal azimuth every time lapse (corresponding to the horizontal distance from the transducer) with reference to the transmission trigger signal. 52 is written and stored. The stored return signal from the underwater object is C
To display the PPI on the RT display 54, the CRT display 5
In synchronization with the distance and direction of the spiral sweep of No. 4, the readout signal is read out by the horizontal plane video writing / reading circuit 50, and is transferred to the display memory 56, and the content is displayed on the CRT display 54.

On the other hand, a group of cross-sectional vibrators, ie, the transducer 1
The reflected signals from the underwater object received by the underwater objects 4 and 16 (see FIG. 1) are received by the sectional image receiving circuit 58 for each of the cross-sectional directions, as described in detail with reference to FIGS. Is calculated.

That is, the azimuth information (b−c) / (b + c) of the underwater object is calculated for each cross-sectional direction, and FIG.
After the addition of the vertical video information shown in FIG. This signal is written and stored in the video memory 62 controlled by the write signal of the cross-section video write / read circuit 60 as in the case of the horizontal plane video.

The stored signal is read out by the readout signal of the sectional image writing / reading circuit 60 for PPI display on the cathode ray tube display (CRT display) 54, and is transferred to the display memory 64. The content is divided and displayed on a part of the cathode ray tube display (CRT display) 54 together with the horizontal plane image. The method of this division and simultaneous display is the same as that of the underwater object display device described in Japanese Patent Publication No. Sho 63-26876 described above, and the description is omitted. In this manner, the position and density of the underwater object can be divided and displayed on the CRT display 54 as a horizontal plane and a cross-sectional image.

By the way, where in there is a limit to the displayable horizontal angle at one time as a plane image (azimuth), the range is the range of + theta _v from - [theta] _v of FIGS. 4-6.
Therefore, in order to obtain cross-sectional image information over the entire horizontal circumference,
The azimuth control circuit 46 is driven by the azimuth turning drive mechanism 66.
1 to obtain a desired horizontal azimuth signal from the group of section transducers, ie, the transducers 14 and 16 (FIG. 1).
) Can be turned and set in the desired direction, and an arbitrary horizontal cross-sectional image can be obtained.

[0045]

According to the underwater object display device of the present invention, the following effects can be obtained. That is, the present invention provides a group of cylindrical vibrators for detecting the horizontal position of an underwater object and a predetermined angle with respect to a plane which is symmetrical for detecting the cross-sectional position and is perpendicular to the central axis. A transducer is formed from a plurality of transducer groups having angles, and a return signal received by the cylindrical transducer group is combined with a plurality of adjacent transducer rows on the cylinder to form one directivity. The receiving beam is formed and received, and by sequentially switching the combination of the vibrators, the receiving beam is rotated electronically to detect the orientation of the underwater object. By calculating the sum and difference of the amplitudes of the return signals received by the child groups, and further obtaining a quotient using the sum as a denominator, the cross-sectional direction of the underwater object is detected.

Accordingly, when it is desired to observe a relatively long distance and a wide detection width in the vertical direction, it is possible to detect an underwater object in a short time even if the ultrasonic wave propagation speed in the water is low. It is.

[Brief description of the drawings]

FIG. 1 is a diagram showing a structure of a transducer in an underwater object display device according to the present invention.

FIG. 2 is an explanatory diagram of a vertical receiving beam.

FIG. 3 is an explanatory diagram of a circumferential reception beam.

FIG. 4 is an explanatory view of a circumferential direction receiving beam.

FIG. 5 is an explanatory view of a circumferential receiving beam.

FIG. 6 is a diagram showing the quotient obtained from the sum and difference of the reception beams and the orientation of the underwater object.

FIG. 7 is a block diagram of an arithmetic circuit for obtaining the orientation of an underwater object from a receiving beam.

FIG. 8 is a block diagram showing a configuration of an embodiment of an underwater object display device according to the present invention.

FIG. 9 is a diagram showing a structure of a transducer in a conventional underwater object display device.

FIG. 10 is an explanatory diagram of a conventional transmission / reception wave beam.

FIG. 11 is a diagram illustrating turning of a receiving beam.

FIG. 12 is a diagram showing an example of a scanning sonar display method and an example of a display screen thereof.

FIG. 13 is a diagram showing another example of the display method of the scanning sonar and its display screen.

FIG. 14 is an explanatory diagram for obtaining a conventional vertical cross section.

15 is a diagram showing an example of a display screen in the method shown in FIG.

16 is a diagram showing another example of the display screen in the method shown in FIG.

[Explanation of symbols]

 12: Transceiver (for horizontal plane) 14, 16: Transceiver (for cross section) 42 ... Transmission depression angle control circuit 44 ... Horizontal plane transmission circuit 46 ... Orientation control circuit 48 ... Horizontal plane video circuit 50 ... Horizontal plane video writing / reading circuit 52 .. 62 image memory 54 CRT display 56, 64 display memory 58 cross-sectional image receiving circuit 60 cross-sectional image write / read circuit 66

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01S ⁷ /52-7/64 G01S 15/00-15/96

Claims (2)

(57) [Claims] An underwater object display device which emits sound waves into water by a transducer in which a plurality of transducers are arranged, receives a reflected signal from the underwater object, and displays the underwater object on a display, A group of cylindrical surface array transducers for detecting the horizontal position of an object, and at least two for detecting a cross-sectional position having a declination by a predetermined angle with respect to a plane which is symmetrical and perpendicular to the central axis; A transducer composed of two transducer groups, and a return signal from an underwater object received by the cylindrical planar array transducer group is directed by combining a plurality of transducers adjacent to each other on the cylinder. By forming and receiving one receiving beam having the property, by sequentially switching the combination of the vibrators, the receiving beam is rotated electronically,
A horizontal plane video circuit for detecting the horizontal orientation of the underwater object, and calculating the sum and difference of the amplitudes of the written signals from the underwater object received by the at least two symmetrical transducer groups, and further calculating the sum as a denominator A receiving circuit consisting of a cross-sectional video circuit for detecting the cross-sectional direction of the underwater object, and a reflection signal from the underwater object projected on a horizontal plane including the cylindrical surface array vibrator surface An underwater object display device, comprising: a flat display unit that displays a polar coordinate as a cross section; and a cross-section display unit that displays a cylindrical surface perpendicular to the horizontal plane including the underwater object displayed on the flat display unit. 2. The underwater object display device according to claim 1, wherein the transducer includes an azimuth turning drive mechanism, and is configured to be driven to turn in the azimuth direction. .