JPH045152B2 - - Google Patents

Description

[Detailed description of the invention]

a. Technical Field of the Invention The present invention relates to a device for displaying underwater received signals obtained by transmitting and receiving ultrasonic pulses underwater on a pen recorder, a cathode ray tube display, or the like. B. Conventional Field In general underwater detection devices, particularly in devices that transmit and receive ultrasonic signals in one direction from the bottom of a ship, a recording pen is moved from one end of a recording sheet to the other end at the same time as the ultrasonic pulse is transmitted. Then, by guiding the reflected waves returning from the water to a recording pen, the reflected waves are recorded on recording paper. Therefore, on the recording paper,
A record is obtained in which the distance from the recording start position to the recording position corresponds to the distance to the underwater detection object. Further, the recording paper is sent out in a direction perpendicular to the traveling direction of the recording pen, thereby recording the passage of time of the underwater detection signal. In this case, if the feeding speed of the recording paper is set in relation to the moving speed of the own ship, the record in the time elapsed direction can be made to correspond to the length of the detected object in the horizontal direction. As described above, a device has been proposed that records the passage of time of an underwater detection signal in relation to the feeding speed of recording paper. c. Disadvantages of Conventional Devices In the above, when controlling the recording paper feeding speed in relation to the moving speed of the own ship, it is necessary to increase the recording paper feeding speed as the moving speed of the own ship increases. For example, 25 on the recording paper
When recording a detection range of 750 m in a recording width of cm,
A length of 1 mm on the recording paper corresponds to a detection distance of 3 m. Therefore, if the own ship moves at a speed of 3 m/sec, the recording paper feeding speed must be set to 1 mm/sec. Therefore, when detecting a distance of 750 m, the cycle of the detection pulse must be at least 1 second, so display lines are displayed at 1 mm intervals on the recording paper. Also, if the own ship moves at a speed of 6m/sec, the recording paper feeding speed is 2mm/sec.
Since it must be set to sec, display lines are displayed at 2 mm intervals on the recording paper. As a result, as the speed increases, the display linear density becomes coarser, making it difficult to distinguish between displayed images. The above-mentioned problem of display linear density occurs not only in pen recorder displays but also in cathode ray tube displays. Therefore, in the following example of the present invention, a cathode ray tube display will be explained. d. Purpose of the Invention As described above, the object of the present invention is to interpolate between display lines when the intervals between the display lines become coarse. In other words, the purpose is to average the display images of the current display line and the previous display line, and display the averaged display image as a display line between the current display line and the previous display line. do. Furthermore, when averaging,
The purpose is to weight and average the image of the current display line and the image of the previous display line, respectively. In other words, for example, if two display lines are interpolated and displayed between the current display line and the previous display line, the display line that is closer to the previous display line will have a larger weight on the image of the previous display line. However, the purpose of displaying the display line closer to the current display line is to increase the weighting of the image of the current display line. e. Summary of the Invention As shown in FIG. 1, consider the case where the above underwater detection signal is displayed on a cathode ray tube display screen measuring Hcm vertically and Wcm horizontally. Assuming that the cathode ray tube display screen is composed of N vertical scanning lines, and each scanning line corresponds to the display line of the underwater detection signal, when the detection distance displayed on one display line is Rm, the display The scale ratio on the screen is determined by R/H. Therefore, the horizontal display distance on the display screen is calculated as R/H×W (m), so if the display screen is composed of N scanning lines, the display distance per scanning line is is given by RW/H×1/N=RW/HN (m). Now, when the own ship performs underwater detection while moving at a speed of Vm/sec, the time required for the own ship to move the display distance RW/HN (m) per one scanning line is: RW/HN It is obtained as ×1/V=RW/HNV (sec). Therefore, when the period of the detection pulse for underwater detection matches RW/HNV, a display line is displayed for each scanning line, and when the period of the detection pulse is RW/HNV×2 (sec), the scanning line It is displayed every two lines. That is, when the period of the detection pulse is T (sec), display lines are displayed at a scanning line interval of T/RW/HNV=HNVT/RW. Therefore, when a display line is displayed every two scanning lines as described above, a pixel dropout occurs between the previous display line and the current display line, so the difference between the previous display line and the current display line Interpolation display is performed using the display line that has been subjected to the above-mentioned averaging process. f Embodiment of the Invention In FIG. 2, the display 1 is, for example, a cathode ray tube display, and the display screen is constructed in the same manner as in FIG. Reference numeral 2 indicates a display memory, which is composed of (m×n) memory addresses, and each memory address corresponds to each pixel of the display device 1. In the display device 1, pixel scanning is repeatedly performed by the scanning circuit 3, and in conjunction with the pixel scanning, the stored data at the storage address of the display memory 2 corresponding to the pixel at the scanning position is read out. Reading of stored data is performed by a read control circuit 4 in conjunction with pixel scanning by a scanning circuit 3. The stored data read from the storage circuit 2 is converted into an analog signal or a color signal in the D/A conversion circuit 5, and then guided to the display pixels of the display 1 and displayed. In the display memory 2, stored data is read out as described above, and an underwater detection signal detected by the ultrasonic transducer 6 is written. The ultrasonic transducer 6 is excited by a transmitter 7 to transmit ultrasonic pulses into the water, and the transmitter 7 is driven every time a keying pulse is sent out from the keying pulse generating circuit 8. The ultrasonic pulses transmitted into the water from the ultrasonic transducer 6 are reflected by the object to be detected, return to the ultrasonic transducer 6, and then guided to the receiver 9 where they are amplified and detected. The received output of the receiver 9 is sent to an A/D converter 10, converted into a digital signal, and then sent to buffer memories 11A and 11B. The buffer memories 11A and 11B are the display line 1 of the display 1.
It has a storage capacity corresponding to a book, and the reception signal sent from the receiver 9 every time an ultrasonic pulse is sent is alternately stored in either buffer memory 11A or 11B. For example, when the previous received signal is stored in the buffer memory 11A, the current received signal is written into the buffer memory 11B. This writing is performed by the write/read control circuit 12. The write/read control circuit 12 also sends a write pulse to the buffer memories 11A and 1 every time a keying pulse is sent from the keying pulse generation circuit 8.
Send alternately to 1B. This write pulse is as shown in FIG. 3c. It is set so that a fixed number of pulse trains are sent out during the reception time T _r set by the range setter 13 for each transmission of the transmission pulses T ₁ , T ₂ , and T ₃ . The write/read control circuit 12 sends the received signal of the receiver 9 to buffer memories 11A and 11 at every detection period.
After alternately writing data into buffer memories 11A and 11B, the data stored in buffer memories 11A and 11B are read out simultaneously. That is, the current received signal and the previous received signal are read out at the same time. Incidentally, as shown in FIG. 3d, this reading is performed for a short time Δt ₁ immediately after the writing to the buffer memory 11A or 11B is completed. The received signal data read from buffer memories 11A and 11B is sent to interpolation calculation circuit 14. The interpolation calculation circuit 14 uses the received signal data stored in the buffer memories 11A and 11B to generate an interpolated signal between the current received signal and the previous received signal. The generated interpolation signals are then led to and stored in the interpolation data storage circuits 15 ₁ to 15 ₅ . Each of the interpolation data storage circuits 15 ₁ to 15 ₅ stores five types of interpolation data in which the weighting of the current reception signal and the previous reception signal is changed. For example, if the current received signal data is _D0 and the previous received signal data is _D1 , then the stored data _M1 to _M5 of the interpolation data storage circuits ₁₅₁ to ₁₅₅ are expressed as shown in Table 1. That is, the number of interpolation signals to fill in the gap between the current received signal and the previous received signal varies depending on the boat speed, etc., and the weighting also varies depending on the number of interpolated signals. However, as the ship speed increases, the number of interpolation signals increases, so interpolation signals with standard weighting are generated and stored in advance, and those with similar weighting are selected as shown in Table 2 below. I try to do that. For example, for the stored data _M3 in Table 1, the number of required interpolation signals is 1.
, and is interpolated with a weight of 1/2. Furthermore, the stored data M ₁ , M ₂ , M ₄ , and M ₅ are weighted in units of 1/5 (1/5, 2/5, 3/5, 4/5). If the number of interpolation signals is 2, the weighting will be in units of 1/3 (1/3, 2/3), but 2/2 of the weighting in units of 1/5 will be applied.
5. 3/5 can be substituted. In addition, when the number of interpolated signals is 3, weighting is performed in units of 1/4 (1/4).
4, 2/4, 3/4), 1/5 and 4/5 of the weighting unit of 1/5 can be substituted for 1/4 and 3/4. Furthermore, the number of interpolated signals is 5.
In the case of , weighting is done in units of 1/6 (1/6...5/6)
So, for 1/6, 2/6, 4/6 and 5/6, 1/
Weighting in units of 5: 1/5, 2/5, 3/5, 4/
5 can be substituted. In this way, the number of stored data that is generated and stored in advance is five.

[Table] Note that the weighted interpolated data in Table 1 is calculated in the interpolation calculation circuit 14.
Further, writing to the interpolation data storage circuits 15 ₁ to 15 ₅ is performed based on a clock sent from the write/read control circuit 16 in synchronization with the interpolation calculation period Δt ₁ . After writing the interpolation data to the interpolation data storage circuits 15 ₁ to 15 ₅ , the write/read control circuit 16
The stored data is read out as appropriate and transferred to the display memory 2. This transfer, as shown in Figure 3e,
This is done △t ₂ hours after the interpolation calculation is completed. moreover,
The write/read control circuit 16 reads out the interpolated data storage circuits 15 ₁ to 15 ₅ that correspond to the count value of the counter 18 sent from the decoder 17 . That is, as shown in Table 2, the data stored in the interpolation data storage circuit marked with a circle for the count value of the counter 18 is read out.

[Table] Counter 18 is keying pulse generation circuit 8
The count value is reset every time a keying pulse is sent out from the decoder 17, and at the same time, the count value immediately before the reset is sent to the decoder 17. The counter 18 counts the range pulses sent out from the range pulse generation circuit 19. The range pulse generation circuit 19 sends out a movement pulse indicating the movement status of the ship based on ship speed data sent from the ship speedometer 20. This moving pulse is
As explained above, the repetition period is set to match the time required for the own ship to move the display distance per one scanning line on the display 1. Therefore, when the period of the movement pulse is larger than the period of the keying pulse, that is, when the keying pulse is sent out repeatedly while the own ship moves the display distance per scanning line, the counter 18 Always held at "0". Therefore, in this case, the interpolated data storage circuit 1
No stored data is read from 5 ₁ to 15 ₅ . and buffer memory 11A or 11B
The current received signal data written in any of the fields is displayed on the display line next to the display line displaying the previous received signal data. This display is performed by writing the received signal data in the column position corresponding to the display line in the display memory 2. or,
Writing to the display memory 2 is performed by the write/read control circuit 12 to the buffer memories 11A and 1.
When 1B of stored data is read out, the selection gate 21 selects the data stored in the buffer memory 11A and 11B that stores the current received signal data, and the OR gate 22
This is done by being guided to the display memory 2 through the. When specifying the write address in the display memory 2, the column position is specified by the output value of the decoder 17, and the row position is specified by the lock sent from the write/read control circuit 12 when reading the buffer memories 11A and 11B. It is specified. Next, when the period of the movement pulse of the range pulse generation circuit 19 is smaller than the period of the keying pulse,
The counter 18 sends out a count value according to the own ship's movement speed. Then, as shown in Table 2, the data stored in the interpolation data storage circuits 15 ₁ to 15 ₅ corresponding to the counted value is read out. This readout is performed by the readout clock of the write/read control circuit 16, and is led to the display memory 2 via the OR gate 22. This read clock is also sent to the write control circuit 23, and the row position of the write address is specified. Furthermore, the output numerical value of the decoder 17 is also led to the write control circuit 23, and the column position of the write address is specified by the output numerical value of the decoder 17. For example, when the output value of the decoder 17 is "2",
The write/read control circuit 16 reads the data stored in the interpolation data storage circuits 15 ₂ and 15 ₄ . The write control circuit 23 includes the interpolation data storage circuit 15 ₂
The data stored in the interpolation data storage circuit 154 is written to the column position adjacent to the column position where the previous received signal data is stored, and the data stored in the interpolation data storage circuit ₁₅₄ is written to the column position adjacent to the column position where the previous received signal data is stored. Furthermore, the current received signal data is written in the adjacent column position. g. Effects of the Invention The horizontal and vertical lengths of the detected object displayed on the display correspond to the actual object, and even when the ship speed increases, the distance between the display lines can be maintained close.

[Brief explanation of drawings]

FIG. 1 shows an example of a display screen for explaining this invention, FIG. 2 shows an embodiment of this invention, and FIG. 3 shows a time chart for explaining its operation. DESCRIPTION OF SYMBOLS 1... Display device, 2... Display memory, 3... Scanning circuit, 4... Readout control circuit, 5... D/A converter, 6... Ultrasonic transducer, 7... Transmitter, 8
...Keying pulse generation circuit, 9...Receiver,
10...A/D converter, 11A, 11B...Buffer memory, 12...Writing/reading control circuit, 1
3... Range setting device, 14... Interpolation calculation circuit, 1
51, 152, 153, 154... interpolation data storage circuit, 16... write/read control circuit, 17...
...Decoder, 18...Counter, 19...Run pulse generation circuit, 20...Speedometer, 21...Selection gate, 22...OR gate, 23...Write control circuit.

Claims (1)

[Claims] 1. Ultrasonic pulses are repeatedly transmitted and received into the water, and the reflected waves from the water obtained each time the ultrasound pulses are transmitted are made to correspond to the distance to the reflector on one display line of the display. In an underwater detection device that displays the indicated line position and connects the position of the display line to the transmission of the ultrasonic pulse, the ultrasonic wave transmitting/receiving device repeatedly transmits and receives the ultrasonic pulse into the water and receives the reflected wave underwater. a device, first and second buffer memories for storing received signals obtained by the ultrasonic wave transmitting/receiving device and having a storage capacity equivalent to one of the display lines; the received signals are stored alternately in the first and second buffer memories, and the data stored in the first and second buffer memories are read after the storage and before the next ultrasonic pulse is transmitted. A buffer memory storage/readout control circuit that controls storage and readout as the data is output, and a buffer memory storage/readout control circuit that controls storage and readout from the first and second buffer memories to the received signal obtained by the current detection pulse and the previous detection pulse. an interpolation calculation circuit that generates a plurality of interpolation data with varying weighting between the received signals thus obtained; an interpolation data storage circuit that stores the interpolation data on which the interpolation calculation has been performed; ship speed data; and 1. a range pulse generation circuit that sends out a pulse wave every time the own ship moves a specific distance on the display based on range data that sets a detection distance to be displayed on the display line; a counting circuit that counts pulse waves sent out from the travel pulse generation circuit in between; and interpolation that determines the number of interpolated data to be read from the interpolated data storage circuit based on the counted value of the counting circuit and that has substantially equal weighting. Select the data and display the selected interpolated data between the display line that displays the received signal from the current detection pulse and the display line that displays the received signal from the previous detection pulse on the display above. An underwater detection device comprising an interpolated data display device that displays the data as a line.