JPS6140072B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a device for converting coordinates from a polar coordinate display screen to an XY coordinate display screen in an underwater detection device that detects in a wide range of directions. When performing underwater detection over a wide area, transducers with different pointing directions are arranged along the circumference, and the reflected waves returning from each direction are received by the transducers pointing in each direction. By displaying the signals received by the device in time series at high speed, underwater detection over a wide area can be performed instantaneously. In this case, the position of the displayed detection signal is represented by a polar coordinate position. When displayed in polar coordinate positions, the pixel size differs between the center and the periphery of the polar coordinates. Therefore,
When performing various image processing on display signals, for example, when displaying characters or numbers indicating the depth, distance, etc. of a detection signal on an image, the displayed characters may vary because the pixel size differs depending on the display position. , there is a drawback that numbers etc. are distorted depending on the display position. In addition, in the case of polar coordinate display, the displayed characters, numbers, etc. are displayed in the direction seen from the center of the polar coordinates, so the characters, numbers, etc.
It is very difficult to read the numbers. Therefore, when performing such image processing, it is desired to convert the coordinates of the display screen from polar coordinates to XY coordinates.
When performing coordinate transformation, it corresponds to the polar coordinate position.
A storage circuit for position conversion that stores the XY coordinate position for each pixel is required. In this case, if an attempt is made to store the pixel positions for all pixels, a storage circuit with a very large capacity will be required and the cost will be high. The present invention provides an apparatus that uses a memory circuit with as little memory capacity as possible and is capable of high-speed coordinate transformation. First, an overview of an underwater detection device that performs coordinate transformation will be explained. In FIG. 1, a wave transmitting/receiving device 1 is composed of a large number of wave transmitters/receivers with different pointing directions arranged in the circumferential direction, and each of the wave transmitters/receivers is simultaneously excited by a transmitter 2 to generate ultrasonic waves in a wide range of directions. Send pulses. The reflected waves returning from each direction are sent to the time series circuit 3 after being received by transducers oriented in the respective directions. The time series circuit 3 converts the received signals in each direction into a time series at high speed and sends it to the AD converter 4. The AD converter 4 converts the analog level of the time-series received signal into a digital value and sends it to the storage circuit 5. Based on the direction counter 6, the time series circuit 3
Performs time series operation. That is, the direction counter 6
counts the pulse train of the clock pulse source 7, and the time series circuit 3 extracts and transmits the received signal in the direction corresponding to the counted value. When the direction counter 6 has counted up to a count value corresponding to the arrangement direction of the transducers, it sends an output pulse to the distance counter 8,
Thereafter, repeat the same counting. The distance counter 8 counts the output pulses of the azimuth counter 6, and sends out an output pulse when the counted value reaches a certain value corresponding to the detection distance. Then, the operation of the clock pulse source 7 is stopped by the output pulse. Note that the clock pulse source 7 starts sending out clock pulses in response to the transmission pulses from the transmitter 2. The count value of the azimuth counter 6 indicates the azimuth θ of the time-series signal, and the count value of the distance counter 8 corresponds to the distance γ of the received signal. The azimuth count value θ and the distance count value γ are guided to the storage circuit 5 via the switch 9. In the storage circuit 5, the conversion output of the AD converter 4 is stored in the storage element corresponding to the azimuth count value θ and the distance count value γ. 10 is a polar coordinate address circuit, which sends out the direction designation value θ and the distance designation value γ;
When γ is led to the memory circuit 5 via the switch 9,
The stored contents of the storage element corresponding to the specified numerical values θ and γ are read out and sent out. The read storage contents are sent to the storage circuit 11. And the memory circuit 11
The XY coordinate address circuit 12 specifies the location of the storage circuit. That is, the XY coordinate address circuit 12 sends out a specified value xy on the XY coordinate, and when the specified values x, y are led to the storage circuit 11 via the switch 13, the The memory contents read from the memory circuit 5 are stored in the memory element. Therefore, the XY coordinate address circuit 12 specifies the position of the memory element in the memory circuit 11 for storing data, and the polar coordinate address circuit 10 specifies the position of the memory element in the memory circuit 5 for reading data. Here, the polar coordinate address circuit 10 is the XY coordinate address circuit 1
The position is specified based on 2. That is, XY
When the coordinate address circuit 12 specifies a position,
The polar coordinate address circuit 12 specifies a position on polar coordinates corresponding to a designated position on the XY coordinates. Note that this operation will be described later. The stored contents transferred to the storage circuit 11 as described above are read by the X-axis read counter 14 and the Y-axis read counter 15. The X-axis read counter 14 counts the clock pulse train sent out by the clock pulse source 16 and specifies the position in the X-axis direction on the XY coordinates.
Then, the X-axis read counter 14 outputs an output pulse to Y every time the position in the X-axis direction is specified.
Sends an output pulse to the axis read counter 15. The Y-axis read counter 15 counts the output pulses of the X-axis read counter 14 and specifies the position in the Y-axis direction. Then, when the Y-axis read counter 15 completes the position designation in the Y-axis direction, the Y-axis read counter 14 sends out an output pulse to stop the operation of the clock pulse source 16. The specified values x, y on the XY coordinates of the Y-axis read counter 14 and the Y-axis read counter 15 are led to the storage circuit 11 via the switch 13. Then, in the storage circuit 11, the storage element corresponding to the specified value is read out and sent to the DA converter 17. The DA converter 17 reads out the stored contents of the storage circuit 11 as a digital value, and converts this into an analog signal and sends it out. The signal converted into an analog signal is sent to the brightness terminal of the cathode ray tube display 18. In the cathode ray tube display 18, the electron beam is
It is pulled back in the axial direction. The X-axis deflection circuit 19 receives the count value of the X-axis readout counter 14 and deflects the electron beam to a position on the X-axis corresponding to the count value. Similarly, the Y-axis deflection circuit 20 receives the count value of the Y-axis readout counter 15 and deflects the electron beam to a position on the Y-axis corresponding to the count value. As a result of the above, the storage contents stored in the storage circuit 11 in the XY coordinates are stored on the cathode ray tube display 18 at the corresponding positions on the XY coordinates. Since the storage circuit 11 stores the stored contents stored in polar coordinate positions after being converted into XY coordinates, the underwater detection signal detected by the wave transmitting/receiving device 1 is displayed on the cathode ray tube display 18 after all. is displayed at each corresponding azimuth position. In the above, storage and read operations of the storage circuits 5 and 11 are performed based on the controller 21. That is, the controller 21 first activates the transmitter 2 and causes the wave transmitting/receiving device 1 to perform underwater detection. Then, the detection result is stored in the storage circuit 5. Thereafter, the controller 21 switches the switch 9 to guide the position designation value of the polar coordinate address circuit 10 to the storage circuit 5. At this time, the position designation value of the XY coordinate address circuit 12 is led to the memory circuit 11, and the memory circuit 5
The stored contents of are transferred to the storage circuit 11. Here, the transfer from the storage circuit 5 to the storage circuit 11 is performed during the idle time of the detection operation of the wave transmitting/receiving device 1 and during the retrace time of the electron beam of the cathode ray tube display 8. Next, specific examples of the polar coordinate address circuit 10 and the XY coordinate address circuit 12 will be explained, but first, the principle thereof will be explained. In Figure 2, a straight line passing through the origin 0 of the XY coordinates
Divide the XY coordinates into eight equal regions using L ₁ and L ₂ . Then, in the area, any point A ₁
, and the position of this point A ₁ on the XY coordinates is (x ₁ ,
y ₁ ), and the position obtained by converting the point A ₁ to a position on polar coordinates is (γ ₁ , θ ₁ ). Next, in the region, a point A ₂ that is symmetrical to point A ₁ with respect to the Y axis is determined.
Furthermore, in the area, a point _A3 that is symmetrical to point _A2 with respect to straight line _L2 is determined. Similarly, in other areas, , , symmetric points A ₄ , A ₅ , A ₆ , respectively with respect to the boundary line of the adjacent area
Define _A7 and _A8 . The position of each point is expressed in XY coordinates and polar coordinates as shown in Table 1.

[Table] As is clear from Table 1, once you know the correspondence between the XY coordinate position and the polar coordinate position of point _A1 , you can
The coordinate transformation of A ₁ to A ₈ can be performed using the transformation value of point A ₁ as a reference. Therefore, the storage circuit that stores the transformed position from XY coordinates to polar coordinates only needs to store the transformed values in the area. In this case, the storage capacity of the storage circuit may be set to store the converted positions of all pixels within the area;
The present invention is characterized in that coordinate transformation is performed using a storage circuit whose storage capacity is much smaller than the number of pixels in the area. In FIG. 3, take an arbitrary point A ₁ within the area, and let A' ₁ be the intersection of the extension of the straight line 0A ₁ connecting this point A ₁ and the origin 0 and the maximum value y max of y on the display screen. The positions of points A ₁ and A′ ₁ on the orthogonal coordinates are (x ₁ ,
y ₁ ), (x′ ₁ , y max), and the position on the coordinate mark is (γ
₁ , θ ₁ ), (γ′ ₁ , θ′ ₁ ). Here, the point
Assuming that the memory circuit stores the polar coordinate position (γ' ₁ , θ' ₁ ) corresponding to the XY coordinate position (x _{' 1} , y' ₁ ) of point A' ₁ , the polar coordinate position (γ ₁ , θ ₁ )
is γ ₁ = γ' ₁ × α ... (1) θ ₁ = θ' ₁ ... (2) However, α = y ₁ /y max ... (3) and points A for point A' ₁ Indicates a reduction ratio of ₁ . Therefore, in order to perform the coordinate transformation of point _A1 , (a) First, since y max is known in advance, the reduction rate α is calculated from α=y/y max. (b) Next, from x ₁ ×1/α=x′ ₁ , point A′ on y max
Find ₁ . (c) Then, read out the polar coordinate position (γ' ₁ , θ' ₁ ) with respect to the XY coordinates (X' ₁ , y max) of point A' ₁ from the conversion storage circuit. (d) From γ ₁ = γ' ₁ ×α, θ ₁ = θ' ₁ , (γ ₁ ,
θ ₁ ). In the above, since the reduction ratio α is known in advance for each point on the Y axis, if the reduction ratio of each point is stored in the storage circuit in advance, coordinate transformation can be performed at a higher speed. FIG. 4 shows a specific example of the polar coordinate address circuit 10 and the XY coordinate address circuit 12 based on the above principle. In the XY coordinate address circuit 12, a clock pulse source 22 sends out a clock pulse train based on the controller 21. This pulse train is sent to an octal counter 23 and counted. Octal counter 2
3 sends the counted value to the decoder 25, and at the same time sends a carry pulse to the X-axis counter 24 every time the pulse train is counted in octal. The decoder 25 includes changeover switches 26 and 27 and changeover switches 28 and 2 of the polar coordinate address circuit 10.
9 is linked and switched, and the octal counter 23
When the count value changes from 1 to 8, the changeover terminal _C0 of each changeover switch is sequentially changed over from the fixed terminals _C1 to _C8 . Then, the changeover switches 26 and 2
7 is switched from fixed terminal C ₁ to C ₈ , each point A ₁ , A ₂ ,
Sends the XY coordinate positions of A ₃ , A ₄ , A ₅ , A ₆ , A ₇ , and A ₈ . This operation is performed by first using the X-axis counter 24 and Y-axis counter 30 to determine the points in the area.
The position of _A1 on the XY coordinates is specified. The designated values x ₁ and y ₁ are inverted in sign to opposite signs by inverting circuits 31 and 32. Then, this inverted value −x ₁ ,
-y ₁ is appropriately distributed to each of the fixed terminals C ₁ to C ₈ of the changeover switches 26 and 27 together with the specified values x ₁ and y ₁ . This distribution is done according to Table 1 above. That is, the fixed terminals C ₁ of the changeover switches 26 and 27 have designated values x ₁ , y ₁ , the fixed terminal C ₂ has -x ₁ , y ₁ , and the fixed terminal C ₃ has -y ₁ , x ₁ It is distributed as follows. After each XY coordinate position in the area is designated by the changeover switches 26 and 27, an output pulse is sent from the octal counter 23 to the X-axis counter 24, and the next XY coordinate in the area is determined based on the counted value. The upper position is specified. Then, other areas and positions symmetrical to that position are sequentially designated. In this way, each time the x-axis counter 24 counts, the position in the X-axis direction within the area is sequentially specified. Then, the count value of the X-axis counter 24 is compared with the count value of the Y-axis counter 30 in a comparison circuit 33, and when the count value matches the count value of the Y-axis counter 30, the comparison circuit 35 sends out an output pulse. This output pulse resets the X-axis counter 24 while simultaneously causing the Y-axis counter 30 to count. Therefore, the X-axis counter 24 performs a new count and specifies the position in the X-axis direction. At this time,
The count value of the Y-axis counter increases by one. Therefore, the X-axis counter 24 and the Y-axis counter 30
The positions within the area on the XY coordinates in FIG. 2 are specified in order in the XY direction. And Y-axis counter 30
When the count reaches the maximum value y max on the display screen, Y-axis counter 30 sends an output pulse to stop clock pulse source 22 from operating. On the other hand, in the polar coordinate address circuit 10, the Y-axis specified value y ₁ of the Y-axis counter 30 is led to the enlargement/reduction ratio storage circuit 34. Enlargement/reduction ratio storage circuit 34
stores and sends out the reduction ratio α or enlargement ratio 1/α of the specified Y-axis value y ₁ with respect to the maximum value y max in the y-axis direction explained in FIG. Then, the magnification rate is 1/
α is sent to the multiplication circuit 35, and the X-axis counter 2
Multiplication is performed with the X-axis specified value _x1 specified by 4.
Therefore, the multiplication circuit 35 outputs the X-axis designated value X _{' 1} which is the X-axis designated value x ₁ expanded by 1/α in FIG. This specified value x' ₁ is sent to the position converter 36, and coordinate conversion from XY coordinates to polar coordinates is performed. In other words, the specified value X′ ₁ and the maximum Y-axis value y
The polar coordinate position γ′ ₁ corresponding to the specified position of max,
θ′ ₁ is stored and sent. Of the coordinate transformation values γ' ₁ and θ' ₁ , the distance component γ' ₁ is sent to the multiplication circuit 37, where it is multiplied by the reduction ratio α sent from the enlargement/reduction ratio storage circuit 34. Therefore, in the multiplication circuit 27, as a result of reducing the distance component γ' ₁ by α, as is clear from FIG. 3, the XY coordinate position (x ₁ , y ₁ ) becomes the distance component of the corresponding polar coordinate position. γ ₁ is sent out. On the other hand, the angular component θ' ₁ sent from the position converter 36 is transferred to the fixed terminal C 1 of the changeover switch ₂₉ together with the angular component -θ' ₁ whose sign is inverted by the inverter 38.
to _C8 . This distribution is done according to (Table 1) above. i.e. fixed terminal
An angular component θ' ₁ is introduced to C ₁ , C ₃ , C ₅ , and C ₇ , and an angular component −θ′ ₁ is introduced to fixed terminals C ₁ , C ₄ , C ₆ , and C ₈ . The switching output of the changeover switch 29 is sent to an adder 40 and added to the changeover output of the changeover switch 28. Each fixed terminal C ₁ of the changeover switch 28
Constants are set in C8 to _C8 by a constant setter 39. The constants to be set are determined according to the above (Table 1). That is, fixed terminal C ₁ has a constant 0, fixed terminals C ₂ and C ₅ have a constant π, fixed terminals C ₃ and C ₈ have a constant π/2, and fixed terminals C ₄ and C ₇ have a constant 3/2π is set respectively. Therefore, from the adder 40, the changeover switches 28, 29
When the terminals sequentially perform switching operations, angular components indicating the polar coordinate positions of the points A ₁ to A ₈ in Table 1 are sent out. This angular component is calculated by the multiplication circuit 37
The distance component _γ1 is sent to the storage circuit 5 as a position designation value for reading. In FIG. 1, the storage contents of each divided area in FIG. 2 are transferred from the storage circuit 5 to the storage circuit 11 in a time-division manner. If this is transferred as shown in FIG. 5, it is possible to transfer the storage contents of each area at the same time. In FIG. 5, components with the same numbers as in FIG. 1 perform the same operations, and the conversion output of AD converter 4 is guided to storage circuits 51 to 58. The memory circuits 51 to 58 are obtained by dividing the memory circuit 5 of FIG. 1 corresponding to the divided regions of FIG. 2, and the memory circuit 51 stores pixels of the divided regions in polar coordinates. Similarly,
The storage circuits 52 to 58 each store pixels from corresponding divided areas in polar coordinates. That is, the storage circuit 51 stores the conversion output of the AD converter 4 while the angle count value within the divided area is being sent from the azimuth counter 6. Then, while the angle count value within the divided area is being sent from the azimuth counter 6, the storage circuit 52 stores the AD conversion output. Similarly, each time the azimuth counter 6 sends out the angle count value of each divided area,
Memory circuits 53 to 58 corresponding to each area perform a memory operation. Note that the position designation values of the azimuth counter 6 and the distance counter 8 are set by the changeover switches 91 to 98.
are led to respective storage circuits 51-58. The memory circuits 51 to 58 read out their respective memory contents when the address designation value is sent from the polar coordinate address circuit 10 after the switching devices 91 to 98 perform switching operations in conjunction with each other based on the controller 21. It can be done. In this readout, the addressing value of the polar coordinate address circuit 10 is
1 to 58 separately. In the address circuit 10 shown in FIG. 4, the changeover switches 28 and 29 perform switching operations in conjunction with each other to send out the specified angle values for each divided area in a time-division manner. When guiding this to the memory circuits 51 to 58 in FIG. 5, the fixed terminals C ₁ of changeover switches 28 and 29
Each output of C8 to _C8 is separately stored in the memory circuit 51.
58. In other words, changeover switch 2
An adder circuit for adding up the corresponding fixed terminals 8 and 29 is provided separately for each fixed terminal, and the respective addition outputs are led to each of the memory circuits 51 to 58. For example, the addition output of each fixed terminal _C1 of the changeover switches 28 and 29 is sent to each fixed terminal C1 to the memory circuit 51.
The addition output of C ₂ is guided to storage circuit 52 . Similarly, the addition outputs of the fixed terminals C ₃ to C ₈ are guided to the respective storage circuits 53 to 58. Note that the distance designation value γ sent from the multiplication circuit 37 is commonly led to the storage circuits 51 to 58. Therefore, the storage contents of the storage circuits 51 to 58 are simultaneously read out in parallel from each divided area to each corresponding position in FIG. The storage contents read from the storage circuits 51 to 58 are transferred to the storage circuits corresponding to the storage circuits 111 to 118, respectively. Memory circuits 111 to 1
18 is provided corresponding to the divided areas in FIG. 2, and the memory circuit 111 stores each pixel in the divided area.
Store in XY coordinate position. The storage circuit 112 stores each pixel in the divided area as an XY coordinate position. Similarly, the storage circuits 113 to 118 store each pixel in each divided area as an XY coordinate position. Addressing values for writing into the memory circuits 111 to 118 are derived from the XY coordinate address circuit 12. In the XY coordinate address circuit 12 in FIG. 4,
The address designation values for each divided area are sent out in a time-division manner by the changeover switches 26 and 27. When guiding this to the memory circuits 111 to 118, the outputs of the fixed terminals C1 to _C8 of the changeover switches ₂₆ and 27 are connected to the respective memory circuits 111 to 118.
Leads directly to 18. For example, the changeover switches 26, 2
Each fixed terminal _C1 of 7 is led to a memory circuit 111,
Each fixed terminal C ₂ is led to a storage circuit 112 . Similarly, each fixed terminal _C3 to _C8 is connected to the memory circuit 1.
13 to 118, respectively. Note that from the XY coordinate address circuit 12 to the memory circuits 111 to 11
The specified values of the XY coordinates sent to each of the memory circuits 8 are guided to the respective storage circuits 111 to 118 via the respective changeover switches 131 to 138. Therefore,
The memory contents read out simultaneously from the memory circuits 51 to 58 are stored in the corresponding memory circuits 111 to 1, respectively.
18 at the same time. In this case, as explained in FIG. 4, the XY coordinate designation values sent to the storage circuits 111 to 118 correspond to the polar coordinate designation values sent to the storage circuits 51 to 58, so they are stored as polar coordinate positions. The storage contents of the storage circuits 51 to 58 are converted into XY orthogonal coordinate positions and transferred to the storage circuits 111 to 118. The stored contents transferred to the memory circuits 111 to 118 are transferred to the changeover switches 131 to 138 from the X-axis readout counter 14 and the Y-axis readout counter 15 after the changeover switches 131 to 138 are switched in conjunction with each other based on the controller 21. When the specified XY coordinate values are then sent to each of the storage circuits 111 to 118, the storage contents corresponding to each specified value are read out. The read memory contents are DA
After being converted into an analog signal by the converter 17, it is displayed on the cathode ray tube display 18. Therefore, as shown in FIG. 5, if memory circuits 51 to 58 and 111 to 118 are provided corresponding to each divided area and the memory contents of each memory circuit are transferred simultaneously, the transfer time is extremely short. Therefore, high-speed coordinate transformation becomes possible. As explained above, according to the present invention, coordinate transformation can be performed at high speed using an extremely small storage capacity of the storage circuit for coordinate transformation.
It is suitable for use when performing image processing.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the present invention, FIGS. 2 and 3 are diagrams for explaining the principle of coordinate transformation, and FIG. 4 shows a polar coordinate address circuit in the embodiment,
A specific example of an XY coordinate address circuit will be shown. Further, FIG. 5 shows another embodiment.

Claims (1)

[Claims] 1. In a wide range underwater detection display device that transmits ultrasonic pulses in a wide range of directions and displays reflected waves returning from each direction on an XY coordinate display screen, the ultrasonic pulses are transmitted in a wide range of directions. a wave transmitting/receiving device that receives reflected waves returning from each direction with a wave transmitter/receiver oriented in each direction; a first storage circuit that stores the received signals in each direction in polar coordinate positions; a second memory circuit that reads the memory content of the first memory circuit and stores it in the XY coordinate position; and a second memory circuit that reads the memory content of the first memory circuit, exchanges the polar coordinate position with the XY coordinate position, 2
a coordinate conversion circuit that transfers the data to the second storage circuit, and an XY display screen that reads and displays the stored content of the second storage circuit, and the coordinate conversion circuit converts the XY display screen into
Divided into 8 equal parts by a straight line passing through the origin of the XY coordinates, and the 8
The coordinates of each pixel position in a specific area divided into equal parts are converted from polar coordinates to It is configured to calculate coordinate transformation, and the coordinate transformation in the specific area is Y when the polar coordinate position is extended in the same direction.
A wide range directional underwater detection display device, characterized in that it is configured to be calculated based on a stored output of a coordinate transformation value at a maximum value position in the axial direction, and a reduction ratio with respect to the maximum value in the Y-axis direction at the polar coordinate position. .