JPH0129273B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an underwater detection device such as a searchlight sonar or a scanning sonar that detects a wide range of directions, and particularly relates to a display device that displays the time course of detection signals returning from a wide range of directions. .

Conventional underwater detection devices of this type, for example, transmit omnidirectional ultrasonic pulses in a wide range of directions;
The reflected waves returning from each direction are received by ultrasonic wave receivers having individual directivity directions for each direction. When the reflected waves returning from each direction are displayed on the cathode ray tube of the display device, each reflected wave is time-seriesized at high speed to sample the reflected waves on the equidistant line, and the sampling signal is used to display the reflected waves on the equidistant line. , the electron beam of a cathode ray tube that performs spiral scanning is intensity-modulated, and the reflected waves from each direction are displayed at each corresponding azimuth position.

However, in such display devices, reflected waves are often displayed in a mosaic pattern on the cathode ray tube due to the directivity of the ultrasonic receiver. In addition, the reflected waves returning from the water are relatively unstable due to the movement of the ship, etc., so it is relatively difficult to distinguish on the display whether noise is being displayed or a detected object is being displayed. . In particular, when the detected object is a small object, the detected object is displayed as a dot on the display, and the display blinks due to the movement of the ship, etc., making it even more difficult to identify the detected object.

Furthermore, since such a display device displays the detected object instantaneously, the operator must rely on the operator's memory of the past movement of the detected object to determine the movement of the detected object over time. Therefore, it is difficult to accurately grasp the continuous movement of the detected object.

Therefore, the present inventors have provided a device that displays detection results in a wide range of directions, selects detection signals returning from a specific direction, and displays the selected detection signals on the same display (particularly Gansho 56
-157196 (Refer to Special Publication No. 62-37348)). According to this device, even if the detected object is a small object, it can be easily identified because it is displayed in chronological order as the fishing boat advances.

However, in the above device, the memory that stores the time course of the detection signal is limited to the depth direction (m
It only has a storage capacity of (bits) x time elapsed (i bits), and can only display the elapsed time of detection signals from a single specified direction out of a wide range of directions. Therefore, the detected object is only displayed two-dimensionally as the fishing boat advances.

On the other hand, since schools of fish and the like are distributed three-dimensionally in the sea, in order to understand the state of their distribution, it is preferable that detection signals be displayed three-dimensionally in a manner that matches the actual distribution of the schools of fish.

In view of the above, an object of the present invention is to display detection results in a wide range of directions on a display, select detection signals from multiple directions close to each other from among detection signals in a wide range of directions, and select the detection signals from multiple directions that are close to each other. The detection signal is displayed on the same display or on a separate display.
By superimposing images at different scales in the depth direction according to each direction, the detected object is displayed three-dimensionally, making it easy to identify the detected object and intuitively understand its distribution state. The purpose is to make it easy to understand.

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

In addition, in the present invention, by superimposing the time course of detection signals from multiple consecutive directions on the display, it is possible to simultaneously display the time course of detection signals from multiple directions. At the same time, relationships with adjacent directions can be displayed in an easy-to-understand manner and three-dimensionally.
Further, in the present invention, by storing the time course of detection signals in all directions in a memory, detection signals in any direction can be displayed at any time.

First, before going into detailed description of the embodiments of the present invention, a method of displaying detection signals in the present invention will be briefly explained with reference to FIG.

FIG. 1 is a diagram showing an example of a display in which detection signals from three consecutive directions received by a scanning sonar are superimposed on a display. In the display drawing of the display device in FIG. 1, the X direction indicates the depth direction, and the Y
The direction indicates the time direction. Three consecutive directions are represented by codes n, n+1, and n+2, respectively. Now, if the display range is 100m deep, the detection signal from the n direction will be 0 from the top to the bottom of the display screen in the X direction.
Displayed as ~100m. The image scale factor in this case is 1. Next, the detection signal from the (n+1) direction is 0 from the top of the display screen in the X direction to _X1 .
Displayed as ~100m. The image scale factor in this case is 1-a. However, 0<a<1.
Similarly, the detection signal from the (n+2) direction is displayed as 0 to 100 m from the upper end of the display screen in the X direction to _X2 . The image scale factor in this case is 1-
It is 2a. In this way, detection signals from three consecutive directions can be displayed continuously and three-dimensionally on the display screen at slightly different scales in the X direction. Here, G ₁ , G ₂ , and G ₃ are schools of fish displayed by detection signals from three directions.
In addition, in the above display example, the detection signals from each direction are displayed with slightly different scales, so
The position of the oscillation line _l1 is the same for all detection signals. In this case, the scale factor is kept constant and the oscillation line
The position of l ₁ may be shifted little by little in response to each detection signal. Furthermore, although the display screens for each detection signal in the above display example vary in size arithmetic in accordance with the respective image scales, the sizes may also vary in a geometric manner. .

In addition, in the above display example, when images G ₁ , G ₂ , G ₃ based on detection signals from three directions overlap, image G ₁ related to the n direction is given top priority as shown in the figure, and then (n+1 ) Image G ₂ regarding the orientation is given priority. Next, the detection signals from the three directions are superimposed on each other at _slightly different scales in the order of priority mentioned above _{. 4} , and as a result, it is very difficult to understand the submarine lines l ₄ and l ₃ in the n direction and (n+1) direction. Therefore,
The periphery of the display signal on the display screen corresponding to the detection signal in each direction is surrounded by a predetermined color corresponding to each direction, and the detection signals including the color are superimposed and displayed in the priority order. In this case,
Instead of surrounding the entire periphery of the display signal with a specific color as described above, an easy-to-understand overlapping display can be obtained by surrounding only the upper end of the ocean floor with a specific color based on seafloor discrimination.

Next, this embodiment based on the above-described display system will be applied to scanning sonar and will be described with reference to FIGS. 2 to 4.

FIG. 2 is a schematic diagram of the display screen in this embodiment. That is, the display screen of this embodiment is L in the Y direction.
It is composed of pixels 0, 1, . . . , L-1 and M pixels 0, 1, ..., M-1 in the X direction. In addition, in this embodiment, the entire 360° circumference of the scanning sonar is
The detection signals from the N directions are written into the memory for L times of transmission, and the detection signals are read out from the memory in principle as shown in the display example above, and will be described in detail later. A display operation is performed by the circuit means to superimpose and display detection signals from each direction on the display screen.

FIG. 3 is a block circuit diagram of this embodiment.
In this example, for convenience of explanation, the following conditions are specified. That is, (1) the number of overlapping directions is up to three, and (2)
Only the upper part of the detection signal shall be surrounded by a specific color,
(3) The detected object shall be displayed on a separate display from the instantaneous display, and (4) The display shall be a color cathode ray tube. Note that the symbols assigned to each component are not necessarily assigned in the order of explanation.

First, in FIG. 3, the ultrasonic transducer 1 transmits ultrasonic pulses in a wide range of directions and receives reflected waves from various directions in the water. here,
As shown in FIG. 4, the ultrasonic transducer 1 is a directional transducer T ₀ , T 1 whose directional directions are slightly different as θ ₀ , θ ₁ , θ ₂ , ..., θ _{N-1 .} , T ₂ , ..., T _N-1 are arranged along the circumferential direction. The ultrasonic transducer 1 having such a configuration has all the directional transducers T ₀ ,
T ₁ , T ₂ , ..., T _N-1 are simultaneously excited to transmit ultrasonic pulses in a wide range of directions. The reflected waves returning from each direction after being transmitted in this manner are received by the directional transducers T ₀ , T ₁ , T ₂ , . . . , T _N-1 .
The received reflected wave is sent to the time series circuit 3. The time-series circuit 3 electronically switches and time-series the detection signals related to the transmitted reflected waves. For example, as shown in FIG.
Soo and directional transducer T ₀ , T ₁ , T ₂ ,…, T _N-1
Fixed terminals S ₀ , S ₁ , S ₂ , ..., corresponding individually to
Consists of S _N-1 . Fixed terminal of time series circuit 3
Each detection signal from the directional transducer _{T 0 ,} T ₁ , T ₂ , ..., T _N-1 guided to each of S 0 , S ₁ , S ₂ , ..., S _N-1 is connected to a movable terminal. Soo connects each fixed terminal S ₀ , S ₁ ,
They are taken out sequentially by contacting S ₂ ,...,S _N-1 .

The switching operation of the movable terminal Soo of the time series circuit 3 is performed by the count output from the azimuth counter 7. The direction counter 7 is an N-ary counter that counts the pulse train sent out from the frequency divider 8, and counts the pulse train of the frequency divider 8 from 0 to N-1, and the time series circuit 3 is connected to the directional transducer T. ₀ , _T1 ,
_{A /}
Sends to D converter 4 and the count value changes from N-1 to 0
When the depth reaches 1, a depth pulse is generated and the depth pulse is sent to the depth counter 6. In addition,
The time series circuit 3 includes directional transducers T ₀ , T ₁ , T ₂ , ..., in the direction indicated by the count value of the direction counter 7 .
The detection signal from T _N-1 is sent to the A/D converter 4.

Next, the depth counter 6 is an M-ary counter and converts the depth pulse from the azimuth counter 7 from 0 to M.
-1, and when the count reaches 0 at the next M-th depth pulse, a time pulse is generated and the time pulse is sent to the time counter 5 and the transmission circuit 2. The transmitting circuit 2 drives the ultrasonic transducer 1 using this time pulse. on the other hand,
The time counter 5 is an L-adic subtraction counter, and the time pulses from the depth counter 6 are L-1, L-
The count is decremented as 2, . . . , 2, 1, 0, and returns to the count value of L-1 at the next time pulse.

Each count value of the azimuth counter 7, depth counter 6, and time counter 5 is used as a detection signal write address signal of a memory circuit 57, which will be described later.

Note that the frequency divider 8 divides the frequency of the output clock pulse (frequency f ₀ ) of the clock pulse circuit 13 according to the setting value of the detection range setting device 9. For example, if the detection distance is 500 m and the underwater sound speed is 1500 m/sec, the output pulse frequency of the frequency divider 8 is given by the following equation.

{1500/2/500}×N×M (Hz) On the other hand, the detection signals from each direction sent from the time series circuit 3 are converted into I-bit digital signals by the A/D converter 4, and then The signal is sent to the memory circuit 57.

Next, the memory circuit 57 will be explained with reference to FIG. This memory circuit 57 has (N-1) corresponding to each direction θ ₀ , θ ₁ , θ ₂ , ..., θ _N-1 .
memories 571, 572,..., 57 (N-
1) exists. Each memory 571, 57
2,...,57(N-1) are respectively Y in FIG.
It has a storage capacity of L number of pixels in the (time) direction x M number of pixels in the X direction (depth) x I bits. In addition, each memory 571, 572, ..., 57
(N-1) is the I-bit input line Di and output line Doi
(i=0, 1, . . . , N-1), an α-bit address line, a 1-bit write/read line, and a 1-bit selection line. Note that the value of α is L−
When 1 and M-1 are expressed in binary numbers,
The number of β bits and the number of ν bits are respectively,
In that case, the formula α=β+ν holds true. Similarly, ψ is the number of bits when N-1 is expressed as a binary number.

Next, each of the memories 571, 572, ..., 57 (N
-1), a 1-bit detection signal is input via the input line Di. Each count output of the depth counter 6 and the time counter 5 is sent to each memory 571, 572, . . . , 57 (N-
1) specifies the address at which the detection signal is written into the memory. Further, the count output of the azimuth counter 7 is decoded by the decoder 45 and inputted to each memory, thereby specifying the memory in which the detection signal is written.

On the other hand, among the detection signals from each direction written in the memory 571 etc. in correspondence with time, depth and direction, only the detection signals from three directions are switched to the changeover switches 17, 18, 19, 42. ，
The data is read out from the memory circuit by being selected at 43 and 44. Here, the changeover switch 19 is n
The direction selector switch 18 selects the (n+1) direction.
The changeover switch 17 selects the memory output data in the (n+2) direction. Further, the changeover switch 42 changes the depth direction address among the read addresses in the n direction, the changeover switch 43 in the (n+1) direction, and the changeover switch 44 in the (n+2) direction. Furthermore, in these memories, the time direction address among the read addresses is read by the adder 10,
Further, the decoder 45 operates to select all memories during reading, and the detection signal of the selected memory location is read out.

Memory 571, 572,..., 57 (n-1)
The writing/reading timing control of the detection signal is performed by the output pulse of the clock pulse generator 13. The frequency f ₀ of the output pulse of the clock pulse generator 13 is the frequency at which the detection signal for display is transferred to the display 50. When the output pulse of clock pulse generator 13 is high, a write is performed to the memory, and when the output pulse is low, a read from the memory is performed. The switches 40, 41 and decoder 45 also operate simultaneously in response to this writing/reading, and when the output pulse is at a high level, the changeover switch switches to the contact on the left side in the figure, and when the output pulse is at a low level. When it is at level, it switches to the right contact. Also decoder 4
5 operates only the memory corresponding to the value obtained by decoding the count value of the azimuth counter 7 when the output pulse is at a high level, while operating all the memories when the output pulse is at a low level.

Since the output frequency of the clock pulse generator 13 is higher than the output frequency of the frequency divider 8, the detection signal will be written to the same memory location many times in succession. The detection signal immediately before the count value changes will be stored. The reason why the switchers 42, 43, and 44 switch the depth direction addresses in three directions is because the scale factors in each direction are different, as described above.

Next, if the count value of the depth direction reading counter 15 indicating the read address in the depth direction is x, the count value for the n direction is x, and the count value for the (n+1) direction is x/( 1-a), and for the (n+2) direction, the count value must be x/(1-2a). The read-only memories 11 and 12 are memories for this purpose; one read-on memory 11 calculates x/(1-2a) for input x, and the other read-on memory 12 calculates x/(1-2a) for input x.
(1-a) are output respectively. Note that a multiplier may be used instead of this lead-on memory.

The depth direction reading counter 15 and the time direction reading counter 14 indicating the time direction read address will be explained. First, the depth direction reading counter 15 is an M-ary counter, and the clock pulse of the clock pulse generator 13 is changed from 0 to (M
-1), and when the next pulse reaches 0, a pulse for reading in the time direction is sent to the counter 14 for reading in the time direction. Time direction reading counter 1
4 is an L-adic counter, which reads pulses for reading in the time direction from the counter 15 for reading in the depth direction from 0 to M.
The count value becomes 0 when the next pulse for reading in the time direction is input. The adder 16 adds 1 to the count value of the depth reading counter 15 by the shift register 2 described later.
This is to advance in advance in order to avoid that the one dot (pixel) display at 3, 24, and 25 lags behind the count value of the depth direction reading counter 15.

When the added value of the adder 16 is M, the adder 16
is designed to output 0.

Next, the I-bit detection signals from the three directions read out from the memory are sent to adders 20, 21, and 22 through switchers 17, 18, and 19. Strictly speaking, the adders 20, 21, and 22 are subtracters, and there are too many weak signals in the n direction in the detection signal.
This is to cancel out weak signals in the detection signals when the detection signals in the (n+1) and (n+2) directions are no longer visible. Adders 20, 21, 22
When subtracted by , it becomes 0 or negative,
0 is output to shift registers 23, 24, and 25, respectively. Here, setting outputs of the same value are sent from the display signal strength setting device 53 to the adders 20, 21, and 22, but a separate display signal strength setting device is provided for each direction, and each direction The subtraction value may be changed accordingly.

The shift registers 23, 24, and 25 are shift registers for two pixels, and the corresponding detectors 26,
27, 28 and switchers 29, 30, 31 to color the upper end of the display signal.
Further, a display detection signal is taken into each shift register 23, 24, 25 in response to a pulse from the clock pulse generator 13 at the same speed as the readout. The two display detection signals captured in this manner are assumed to be Dt and Dt+1. On the display 50,
One display detection signal Dt is displayed on the upper side.
Note that the above coloring is performed when one display detection signal Dt is 0 and the other display detection signal Dt+1 is other than 0. That is, the detectors 26, 27, and 28 detect that one detection signal Dt is 0 and the other detection signal Dt+1 is other than 0. Switch 29, 3
0, 31 is one display detection signal Dt, that is, 0
The data of A, B, and C are output so that specific colors A' (n direction), B' (n+1 direction), and C' (n+2 direction) given in advance are displayed without outputting the data.

The switchers 32 and 33 are configured such that when the three directions are displayed in an overlapping manner, the detection signal in the n direction is (n+
It is opened to erase the display when the detection signals in the 1) and (n+2) directions are difficult to understand. The display direction can be selected using the display direction setting device 5.
4 and adders 55 and 56. When n is set in the display direction setter 54, the adder 5
5 and 56 output setting signals for each direction of n+1 and n+2, respectively. Setting signals for each of the directions n, n+1, and n+2 are output to changeover switches 17, 18, 19 and 42, 43, 44, and the switching positions of these switches are set to positions corresponding to the setting signals.

For example, if it is desired to display only the (n+1) direction instead of each direction n, n+1, and n+2, it is preferable to set the setting signal for the (n+1) direction in the display direction setting device 54 and open the switches 32 and 33. The adders 55 and 56 do not necessarily need to add 1, and may be any positive or negative integer.

The display signals that have passed through the switchers 29, 30, and 31 are input to a lead-on memory 49 for priority and color conversion. This read-on memory 49 assigns display priorities in the order of n, n+1, and n+2 among display signals from three directions. In other words, the signal in the (n+1) direction is displayed only when the signal in the n direction is 0;
2) The direction signal is displayed only when both the n direction and (n+1) direction signals are 0. These signals are thus prioritized for display and
The D/A of each color of red (R), green (G), and blue (B) is further converted into another digital signal to be displayed in a predetermined color corresponding to the signal strength.
Converters 34, 35, 36 and amplifiers 37, 3
8 and 39 to the brightness terminal of the display 50.

The adder 10 is a circuit for displaying the latest detection signal written in the memory circuit 57 on the right end of the display 50, and if the count value of the time counter 5 is 10, for example, the memory circuit 57 5
The 10th memory in the time direction from memory 71 to memory 57 (N-1) is displayed on the right end of the display 50. The adder 10 also determines that the added value is L-1
When the value exceeds this value, the value obtained by subtracting L from the added value is output.

As explained above, according to the present invention, detection results in a wide range of directions are displayed on the display, and
Among the detection signals in a wide range of directions, detection signals from multiple directions that are close to each other are selected, and the selected detection signals from multiple directions are overlaid on the display at different scales in the depth direction depending on each direction. can do.

This is equivalent to observing the same detected object from different viewing angles and simultaneously displaying the results, thereby making it possible to display the detected object three-dimensionally. Therefore, the detected object can be easily identified, and its distribution state can be intuitively grasped.

Furthermore, in the present invention, since the time course of all the detection signals in a wide range of directions is stored in the memory, detection signals in any direction can be selected and displayed as appropriate. Excellent effects such as a greater degree of freedom in selection can be achieved.

[Brief explanation of drawings]

The figures show one embodiment of the present invention. Fig. 1 is a schematic diagram of a display screen for explaining a display example of a detection signal, and Fig. 2 is a diagram showing the depth (X) direction and time (Y) of the display screen. ) A schematic diagram of a display screen for explaining pixels related to directions, FIG. 3 is an overall block circuit diagram, FIG. 4 is a specific configuration diagram of an ultrasonic transducer and a time series circuit, and FIG. 5 is a diagram of the above-mentioned block. FIG. 3 is a detailed diagram of the memory circuit within the circuit. DESCRIPTION OF SYMBOLS 1... Ultrasonic transducer, 2... Transmission circuit, 3... Time series circuit, 5... Time counter, 6... Depth counter,
7... Direction counter, 8... Frequency divider, 9... Detection range setter, 10... Adder, 11, 12... Read only memory, 13... Clock pulse generator, 14... Counter for reading in time direction, 15... Reading in depth direction counter, 16...adder, 17, 18, 19, 2
9, 30, 31, 40, 41...Switcher, 23, 2
4, 25...Shift register, 49...Priority and color conversion read-only memory, 50...Display device, 54...
Display direction setting device, 57...memory circuit.

Claims (1)

[Claims] 1. A method of transmitting omnidirectional ultrasonic pulses in a wide range of directions and individually receiving the reflected waves returning from each direction with a receiver having directivity in each direction. In a display device in an underwater detection device that displays each detection signal obtained by a memory having a storage capacity corresponding to the time lapse (L bits) accompanying the time; a means for selecting detection signals from multiple directions close to each other from among the detection signals stored in this memory; means for reading out detection signals from multiple directions at different scale rates in the depth direction, and displaying the detection signals from the multiple directions read by the readout means on a display with the depth direction as the vertical axis, and 1. A display device for an underwater detection device, comprising: means for simultaneously superimposing and displaying the passage of time along the horizontal axis; and a display device for an underwater detection device.