JPS6326876B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention emits sound waves, particularly ultrasonic pulses, into water over a wide range from a transducer consisting of a large number of transducers arranged in a cylindrical or circular arc shape, An underwater detection device that combines the elements to form a directional receiving beam, rotates this receiving beam by sequentially switching the combination of transducers, receives reflected waves returning from each direction, and displays them on a cathode ray tube. This invention relates to a so-called scanning sonar underwater object display device.

An example of a conventional scanning sonar display method will be described. Figure 1 shows an example of a scanning sonar transducer, which consists of n transducers T ₁ , T ₂ ,
T ₃ ...T _o are arranged in the circumferential direction and stacked vertically in m stages to form an assembly of n×m transducers T ₁₁ , T ₁₂ , ...T _on . As shown in FIG. 2, after emitting ultrasonic pulses from the transducer T along the horizontal plane or conical surface B, the reflected waves from the underwater object F are transmitted vertically to a row of transducers T ₁₁ , T ₁₂ , T ₁₃ ...T _1n are grouped together to create a sound wave beam with an appropriate directivity angle (width) in the vertical direction, and several of these are combined in the circumferential direction to create a receiver with sharp directivity in the direction θ ₁ as shown in Figure 3. By forming a wave beam RB and changing this receiving beam RB sequentially in the circumferential direction, the θ ₂ , θ ₃ ... directions and the conical surface B
The waves are received by rotating the top one after another at high speed. The position of the underwater object F on the conical surface B is determined by the direction of the receiving beam RB,
This can be determined by determining the distance from the time it takes for the reflected wave from the underwater object F to be received after the ultrasonic pulse is emitted. For example, as shown in Fig. 4, the position of the underwater object F is determined by a constant brightness that is displayed on a cathode ray tube that sweeps in a spiral manner in synchronization with the rotation of the receiving beam, depending on the intensity of the reflected waves or regardless of the intensity of the reflected waves. It is displayed as a point. The explanation of this display will be omitted, but by using a circuit consisting of an appropriate memory circuit, coordinate conversion circuit, and their control circuit, it can be displayed on a cathode ray tube that performs sweeping in the X and Y directions similar to a television set, as shown in Figure 5. It is also well known that it is possible to

When using this scanning sonar to display a vertical section underwater, conventionally, as shown in Figure 6, the transmitting and receiving beams are focused on one direction or one direction and the opposite direction from the transducer T. A sector-shaped cross section S is detected by scanning a vertical plane while sequentially changing the depression angle. As an example of this vertical section display, as shown in FIGS. 7 and 8, a vertical section V is displayed on a portion of the cathode ray tube that displays the image H of underwater objects on the transmission/reception beam. In this case, in order to clarify the position of the underwater object, the image H of the underwater object may be displayed in a form in which the underwater object located on the receiving beam is projected onto a horizontal plane.

This conventional method of displaying a vertical cross section only displays a cross section in one direction, even though all or part of the surroundings of the transducer are detected by the receiving beam that rotates at high speed. When searching underwater within a range, there is a drawback that it takes time to sequentially change the direction in which vertical sections are displayed.

The present invention therefore aims to remedy this drawback. That is, the present invention provides an underwater object display device that can search and display a wide range of underwater objects in a short time. To achieve this purpose, there is a polar coordinate display that displays the image in polar coordinate format centered on the transducer, and a finite plane or This method simultaneously or alternately displays a cross-sectional display in which an image within a curved surface is displayed using coordinate axes of angle and depth, or length and depth on this plane or curved surface, thereby shortening the detection time for underwater objects. Moreover, when displaying an underwater cross section, the cross section of a flat or curved surface away from the transducer can be scanned in the vertical direction by sequentially changing the depression angle of the transducer beam with an appropriate directivity angle (width) in the vertical direction. , scanned in the horizontal direction by a receiving beam rotating at high speed, and displaying the image of underwater objects on the transmitting and receiving beam as it is or in the form of a projection on a horizontal plane, or by switching with this image. By displaying a vertical section, underwater objects can be detected in a short time.

FIG. 9 shows an example of the positional relationship between the transducer and the displayed underwater cross section when displaying the underwater cross section according to the present invention. The figure shows a cross section S taken along a perpendicular plane at a certain distance A from the transducer T.
FIG. 10 shows an example of the display screen, in which the display area of the rectangular cathode ray tube is divided into two, and all or part of the horizontal plane image H is displayed in one area, for example, on the upper side.
This is an example in which the image is displayed in polar coordinate format with the transducer T at the center, and a vertical cross-sectional image V is displayed below the same cathode ray tube with distance in the horizontal direction and depth in the vertical direction. The distance A can be arbitrarily set from a control panel, etc., and a mark M indicating a position where a vertical section at a distance corresponding to the distance A is displayed is displayed superimposed on the horizontal plane image H as necessary.

Furthermore, if necessary, both images H and V can be switched and displayed alternately on the same image screen. Furthermore, both images can be displayed on separate display screens.

FIG. 11 shows another underwater cross section according to the present invention, in which a curved surface located at a certain distance A from the transducer T, for example, a cylindrical vertical cross section S
Fig. 12 shows an example of the display screen.A horizontal plane image H is displayed on the upper side of the cathode ray tube, and a vertical section V is displayed on the lower side of the same cathode ray tube at an angle or circumferential distance in the horizontal direction, and in the vertical direction. This is an expanded view of a cylindrical cross section with depth determined.

FIG. 13 is a block diagram of one embodiment of the present invention, and is an example of displaying the cross section shown in FIG. 9. In FIG. 13, 1 is a transmission trigger generation circuit,
Trigger signals are generated at longer intervals than the time required for the ultrasonic waves to travel back and forth over the maximum distance to be detected. Reference numeral 2 denotes a depression angle control signal generation circuit, which generates a signal for scanning a vertical plane by sequentially changing the depression angle at a certain rate of change each time it is transmitted. This depression angle control signal is applied to a transmission depression angle control circuit 3 consisting of a phase shifter to generate a signal that transmits a conical ultrasonic pulse having a given depression angle, thereby driving a transmitter 4. When a transmission trigger signal is generated, an ultrasonic pulse is emitted from the transmitter 4 into the water from the transducer 6 via the transmitter/receiver switching circuit 5. The ultrasonic pulse reflected by the underwater object is received by the transducer 6,
Via the transmission/reception switching circuit 5, it is applied to the reception depression angle control circuit 7 consisting of a large number of phase shifters, and by using the same depression angle control signal as in the case of transmission, a reflected signal from the same depression angle as when the ultrasonic pulse was emitted is generated. waves are received. Next, in the azimuth switching circuit 8, a signal of the corresponding azimuth is selected according to the azimuth control signal from the azimuth control circuit 9. The received signal from the selected direction is amplified to the required amplitude by the amplifier 10, and then converted into a digital quantity by the analog-to-digital converter 11 and stored in the vertical plane image memory 12 and the horizontal plane image memory 13. Ru. At this time, the address where the signal is stored is determined by the vertical plane write address creation circuit 14.
and by the horizontal plane write address creation circuit 15,
It is created using the azimuth signal from the azimuth control circuit 9, the depression angle signal from the depression angle control signal generation circuit 2, and the distance signal from the distance counting circuit 16 that is initialized by the transmission trigger. Vertical image memory 1
Writing to 2 is performed only during the time when the write control circuit 17 receives a reflected signal from the cross section to be displayed. In the horizontal plane write address creation circuit 15, if a signal reflected from an underwater object located at an angle of depression φ, an azimuth θ, and a distance r is stored in a horizontal plane image memory having two-dimensional addresses represented by, for example, X and Y, the following ( Calculate the address to which the signal should be written by calculating equations 1) and (2).

_{X=K X ・ cosφ}・_r・_cosθ + _C These are coefficients depending on the scale, and C _X and C _Y are, for example, constants to ensure that X and Y are always positive within a required range, or constants related to correction of the position on the display. In the vertical plane write address creation circuit 14, if a signal reflected from an underwater object located at an angle of depression φ, an azimuth θ, and a distance r is stored in a vertical plane image memory having two-dimensional addresses represented by W and Z, for example, the following Calculate the address to which the signal should be written by calculating equations (3) and (4).

W=K _W・cosφ・r・sinθ+C _W ...(3) Z=K _Z・sinφ・r+C _Z ...(4) In the above equation, K _W , K _Z , C _W and C _Z are respectively
These correspond to K _X , K _Y , C _X and C _Y in formulas (1) and (2). When displaying a vertical section at a distance A from the transducer, φ on this vertical section,
Since the relationship between θ, r, and A is expressed by the following equation (5), the write control circuit 17 performs control so that a signal is written into the vertical image memory only when equation (5) is established.

r・cosθ=A/cosφ... (5) Specifically, the write address creation circuits 14, 15 and the write control circuit 17 further input A in the φ, θ, and r write control circuits, and correspond to each input. This can be realized by a read-only memory that outputs the values of X, Y, W, and Z or a write control signal, or an arithmetic circuit that directly executes the above operations.

As described above, by one transmission, images of a vertical plane and a horizontal plane of a conical surface having a certain depression angle are stored in the image memories 12 and 13, respectively. Next, the contents of the vertical plane image memory 12 and the horizontal plane image memory 13 are stored in the read address generation circuit 1.
Vertical plane display memory 19 sequentially according to addresses from 8
The data is then transferred to the horizontal display memory 20, and the contents of the display memories 19 and 20 are displayed on the cathode ray tube 21.

Next, by repeatedly writing the signals reflected from underwater objects on conical surfaces with different depression angles to the vertical image memory, the vertical image memory stores information about the vertical cross section underwater. Become.

The cross section shown in FIG. 11 can also be displayed using the block diagram shown in FIG. 13. In this case, the vertical plane write address creation circuit 14 performs the following calculation instead of the calculations of equations (3) and (4).

W=K _W・θ+C _W ...(6) Z=K _Z・sinφ・r+C _Z ...(7) The write control circuit 17 sends a signal to the vertical image memory only when the following equation (8) is satisfied. Write it down.

r=A/cosφ...(8) In addition to displaying the horizontal image H on the upper side of the cathode ray tube and the vertical image V on the lower side as shown in Figs. 10 and 12, the display method shown in Fig. 14 or As shown in FIG. 15, the horizontal image H can be displayed on the left or right side of the cathode ray tube, and the vertical image V can be displayed on the opposite side. It can also be displayed.

Further, the signal amplitude of the reflected wave received by the transducer is made to correspond to the color, and the shape, density, etc. of the underwater object can be substantially displayed by the difference in color.

The above explanation deals with the case of a conical transmitting/receiving beam, but as shown in Fig. 16, a fan-shaped beam by a transmitting/receiving device T consisting of transducers arranged in an arc is mechanically given an angle of depression to make it perpendicular. Even when scanning in a direction, a similar display is possible using the configuration shown in the block diagram of FIG.

As explained above, it is possible to display a vertical section underwater on a plane or curved surface that does not pass through the own ship at a location far from the own ship, which has the advantage of being able to detect underwater conditions over a wide area in a short time. .

[Brief explanation of drawings]

Figure 1 is an example of a scanning sonar transmitter/receiver, Figure 2 is a diagram of the radiation state of the transmitting and receiving beam, Figure 3 is an explanatory diagram of the rotation of the receiving beam, and Figures 4 and 5 are of the scanning sonar. display method and its display screen,
Figure 6 is an explanatory diagram of the conventional vertical section display, Figures 7 and 8 are examples of the front screen of Figure 6, Figures 9 and 1.
1 shows a display example of a vertical section according to the present invention, FIGS. 10 and 12 show the display screens of FIGS. 9 and 11, respectively, FIG. 13 is a block diagram of an embodiment of the present invention, and FIG. 15 and 15 are examples of other display screens according to the present invention, and FIG. 16 is a pattern diagram showing the scanning state of another transmission and reception beam of a scanning sonar. DESCRIPTION OF SYMBOLS 1... Transmission trigger generation circuit, 2... Depression angle control signal generation circuit, 3... Transmission depression angle control circuit, 4... Transmitter, 5
... Transmission/reception switching circuit, 6... Transducer/receiver, 7... Receiving depression angle control circuit, 8... Direction switching circuit, 9... Direction control circuit,
10...Amplifier, 11...Analog-digital converter,
12...Vertical plane image memory, 13...Horizontal plane image memory, 14...Vertical plane write address creation circuit, 15...
Horizontal plane write address generation circuit, 16... Distance counting circuit, 17... Write control circuit, 18... Read address generation circuit, 19... Vertical plane display memory, 20... Horizontal plane display memory, 21... Braun tube.

Claims (1)

[Claims] 1. An underwater object display device that uses a transducer in which a plurality of vibrators are arranged to emit sound waves into the water, receive reflected signals from underwater objects, and display the signals on a cathode ray tube display. , a flat display section that displays the reflected signal in polar coordinates as an image projected onto a horizontal plane containing the transducer; and a plane that is perpendicular to the horizontal plane and does not include the transducer and that includes the object displayed on the plane display section; What is claimed is: 1. An underwater object display device comprising: a cross-section display section that displays a cylindrical surface; and a plane display section that displays a cursor that indicates the section to be displayed in cross-section. 2. The underwater object display device according to claim 1, wherein the display surface of the cathode ray tube display is divided into the horizontal display section and the cross-sectional display section. 3. The underwater object display device according to claim 1, wherein the cathode ray tube display is switched between a flat display section and a cross-sectional display section.