JPS644639B2 - - Google Patents

Description

[Detailed Description of the Invention] This invention performs underwater detection using an ultrasonic transducer that transmits and receives ultrasonic pulses in a single direction.
The present invention relates to an underwater detection device that performs underwater detection in a wide range of directions by rotating its ultrasonic transducer.

This type of underwater detection device transmits and receives ultrasonic signals in one direction and sequentially changes the direction of transmission and reception to perform underwater detection over a wide angle range, so it has the disadvantage that it takes a long time to detect a wide angle range. There is. For example, if you are trying to detect a distance of 750m, it will take about 1 second, so if you are trying to detect a 360° circumference at 5° intervals, it will take about 72 seconds for one detection.

Further, this type of underwater detection device often uses a cathode ray tube display as a display. Therefore, when performing underwater detection over a long period of time as described above,
Even if the afterglow characteristic of a cathode ray tube is used, it is impossible to simultaneously observe all circumferential directions, and the cathode ray tube only displays detection signals near the current detection direction.

This invention solves the above-mentioned drawbacks, and by arranging several sets of ultrasonic transducers at regular angular intervals, it is possible to detect the entire circumference in a relatively short time, and also to detect The object of the present invention is to store a detection signal in a storage circuit and then read out and display the stored contents, thereby making it possible to simultaneously display all circumferential directions.

Examples of the present invention will be described below.

In Fig. 1, T _D1 , T _D2 , and T _D3 are ultrasonic transducers, and as shown in Fig. 2, they are
They are placed at 120° intervals. The ultrasonic transducers T _D1 , T _D2 , and T _D3 are operated based on the rotation device each time a pulse wave is sent out from the control pulse generation circuit 2.
It can be rotated by 120°/n. Each of the ultrasonic transducers T _D1 , T _D2 , and T _D3 is excited by the transmitters 3, 4, and 5, and the ultrasonic transducer T _D1 transmits an ultrasonic pulse of frequency f ₁ . . Further, the ultrasonic transducer T _D2 transmits an ultrasonic pulse with a frequency of f ₂ , and the ultrasonic wave transducer T _D3 transmits an ultrasonic pulse with a frequency of f ₃ .

The transmitters 3, 4 and 5 are driven each time a control pulse is sent out from the control pulse generation circuit 2, and each sends out a pulse wave of a natural frequency.

The ultrasonic transducers T _D1 , T _D2 , and T _D3 transmit ultrasonic pulses in different directions by 120 degrees using their respective transmitters 3, 4, and 5, and receive reflected waves from the detected object. . The received detection signal is transmitted to amplifiers 6, 7, 8.
gate circuit 9 after being amplified respectively in
10 and 11, respectively. Gate circuit 9, 1
Either 0 or 11 becomes conductive in accordance with the count value of the ternary counter 12 and allows the received signal to pass through. The received signal that has passed through the gate circuit is guided to the A/D conversion circuit 13 and converted into a digital value.

In the above, the ternary counter 12 counts the clock pulses passing through the gate circuit 14 and sends out the counted value, and also sends out the counted value to the X-axis counter 15 every time it counts three clock pulses. X
The axis counter 15 is composed of an m-ary counter,
Every time m output pulses of the ternary counter 12 are counted, the output pulses are transferred to the Y-axis counters 161 and 162.
and 163, respectively. Y-axis counter 1
Each of 61, 162, and 163 is composed of a 3n-adic counting circuit, and when a pulse wave is sent out from the bow pulse generation circuit 17, the respective count value is preset to a specific value. That is, the Y-axis counter 161 is set to the number "1", the Y-axis counter 162 is set to the number "n+1", and the Y-axis counter 16 is set to the number "n+1".
3 is preset to the numerical value "2n+1". The bow pulse generation circuit 17 generates a pulse representing the bow direction, and when the ultrasonic transducers T _D1 , T _D2 , T _D3 in FIG. 2 turn, for example, the ultrasonic transducer T _D1 An output pulse is sent every time the direction matches. In addition, ultrasonic transducers T _D1 , T _D2 ,
T _D3 is the output pulse 3n from the control pulse generation circuit 2.
Since it makes one turn when the number is counted, the detection direction of the ultrasonic transducer T _D1 with respect to the bow direction can be determined from the count value of the Y-axis counter 161.

The output pulses of the X-axis counter 15 are sent to the Y-axis counters 161, 162, 163 and counted as described above, and are also sent to the gate circuit 14 to cut off its input/output. Therefore, the gate circuit 14 becomes conductive every time the output pulse of the control pulse generating circuit 2 is sent out, and remains conductive only while the X-axis counter 15 counts m clock pulses. During this time, the ultrasonic transducers T _D1 , T _D2 , T _D3
The received signal arriving at the gate circuits 9, 10, 11
are sent alternately. Also, X-axis counter 15
is reset each time a control pulse is sent out, and its count value changes in accordance with the distance to the detected object.

Therefore, the direction and distance of the reflected waves returning to the ultrasonic transducers T _D1 , T _D2 , T _D3 can be determined by the count value of the X-axis counter 15 and the count value of each Y-axis counter 161 , 162 , 163 . You can know.

The count value of the X-axis counter 15 is determined by the changeover switch 1.
The counted values of Y-axis counters 161, 162, and 163 are led to the storage circuit 19 via changeover switches 20 and 18, respectively. Then, the output data of the A/D conversion circuit 13 is stored in the storage address of the storage circuit 18 indicated by each count value.

As shown in FIG. 3, the memory circuit 18 has memory addresses m in the X-axis direction and 3n in the Y-axis direction. , 162, 163 specify the address in the Y-axis direction.

In the above, Y-axis counters 161, 16
One of the 2,163 count values is led to the storage circuit 19 via the changeover switch 20. The changeover switch 20 is connected to the ternary counter 12.
The switching operation is performed in conjunction with the gate circuits 9, 10, and 11 according to the count value. Further, the switching operation of the changeover switch 20 is performed in sequence while the count value of the X-axis counter 15 changes by a unit value.

As a result, while the memory address of the memory circuit 19 changes by one address in the X-axis direction, every n memory address in the Y-axis direction is sequentially designated. Then, according to this address designation, the received signals of the ultrasonic transducers T _D1 , T _D2 , and T _D3 are stored in order. In addition, in the above, the switching operation of the gate circuits 9, 10, 11 and the changeover switch 20 takes into account the distance resolution of the ultrasonic pulse that performs underwater detection, and ignores the distance displacement of the detection signal that occurs during the switching operation. It will be done within the time possible.

Next, reading and displaying the storage data written in the storage circuit 19 as described above will be explained.

A display 21 is a cathode ray tube display, for example, and displays the data stored in the storage circuit 19 converted into analog by the D/A conversion circuit 22.

Reading of the memory circuit 19 is performed by a Y-axis read counter 23 and an X-axis read counter 24. The Y-axis readout counter 23 is composed of a 3n-base counter, and sends an output pulse to the X-axis readout counter 24 every time 3n clocks from the clock pulse source 25 are counted. The X-axis read counter 24 is composed of an m-ary counter.

The count value of the Y-axis read counter 23 is led to the storage circuit 19 via the changeover switch 18, and specifies the storage address in the Y-axis direction. Further, the count value of the X-axis read counter 24 is led to the storage circuit 19 via the changeover switch 18, and specifies the storage address in the X-axis direction. Then, the stored data at the designated storage address is read out.

In the above, the count value of the X-axis readout counter 24 changes by a unit count value each time the count value of the Y-axis readout counter 23 is sequentially increased. Therefore, the stored data in the storage circuit 19 is sequentially read out in the Y-axis direction, and each time the stored data in the Y-axis direction is read out in sequence, the read address in the X-axis direction changes by one address. do.

The count value of the Y-axis read counter 23 specifies the storage address as described above, and is also sent to the sine wave generation circuit 27 and the cosine wave generation circuit 28.
The sine wave generation circuit 27 is connected to the Y-axis read counter 2
A sine wave whose phase is fixed at a count value of 3 and whose phase changes by one cycle while the count value changes from "1" to "3n" is generated. Similarly, cosine wave generation circuit 2
8 generates a cosine wave for the above sine wave.

The sine wave and cosine wave from the sine wave generation circuit 27 and the cosine wave generation circuit 28 are guided to the scanning circuit 30 of the display 21 via the modulation circuit 29 to perform pixel scanning. Therefore, the pixels of the display 21 are scanned in a circular manner, and while the circular scan is being performed, the data stored in the storage address in the Y-axis direction of the storage circuit 19 is read out and displayed. As described above, the Y-axis direction memory address of the memory circuit 19 corresponds to the detection direction of underwater detection, so while the circular scanning of the display 21 is performed, the detection signal in each direction is sent to the pixel corresponding to that direction. Is displayed.

Moreover, a sine wave generation circuit 27 and a cosine wave generation circuit 2
When the sine wave and cosine wave of No. 8 pass through the modulation circuit 29, their amplitudes are controlled by the sawtooth wave of the sawtooth wave generation circuit 31. Sawtooth wave generation circuit 31
The output voltage changes according to the count value of the X-axis read counter 24, and sends out a sawtooth wave with a period matching the count repetition of the X-axis read counter 24.
As a result, the pixels of the display device 21 are scanned in a spiral manner, and the storage addresses in the X-axis direction of the storage circuit 19 are sequentially read out as the radius of the spiral increases. When one spiral scan is completed, all memory addresses in the memory circuit 19 are read out, and the stored data at each memory address is displayed at the corresponding direction and distance position on the display screen of the display 21.

In the above, when the address is specified by the Y-axis read counter 23, the memory circuit 19
The memory contents are read and the X-axis counter 1
5. When an address is designated by the Y-axis counters 161, 162, 163, storage data is written. This switching between writing and reading is performed by introducing a clock pulse from the clock pulse source 25 to the writing/reading switching terminal. The clock pulse of the clock pulse source 25 is Y
The data is sent to the axis read counter 23, and the storage addresses in the Y-axis direction of the storage circuit 19 are sequentially read out every time the clock is sent. Then, while the read address changes by one address in the Y-axis direction, the memory circuit 19 is switched to a write operation, and the X-axis counter 15 and Y
The designated addresses of the axis counters 161, 162, 163 are led to the storage circuit 19 via the changeover switch 18. For switching between writing and reading of the memory circuit 19, for example, reading is performed during the high level period of the clock pulse of the clock pulse source 25, and writing is performed during the low level period. The changeover switch 18 also changes the designated address in conjunction with this changeover.
Further, this clock pulse is frequency-divided by a frequency dividing circuit 26 and then guided to the X-axis counter 15. Therefore, address specification during reading is performed much faster than during writing, and even when the read address changes many times, the same write address is specified. Thereby, storage can be performed without causing any write failure of the received signal.

As described above, according to the present invention, since a plurality of vibrators are arranged at constant angular intervals to perform detection in the entire circumference direction, underwater detection can be performed in the entire circumference within a relatively short period of time. Furthermore, since each of the plurality of transducers is configured to transmit and receive ultrasonic waves of different frequencies, underwater detection can be performed without interference between the transmitted and received signals of each transducer. In the above embodiment, three sets of transducers are arranged at 120° intervals, but the number of transducers arranged can be arbitrarily determined, such as two or four sets.

[Brief explanation of drawings]

FIG. 1 shows an embodiment of the present invention, FIG. 2 is a diagram for explaining the configuration of the ultrasonic transducer, and FIG. 3 is a diagram for explaining the memory circuit.

Claims (1)

[Claims] 1. An ultrasonic transducer comprising first to k-th ultrasonic transducers having unidirectional characteristics and each transmitting and receiving ultrasonic pulses of different frequencies, arranged at equal angular intervals. a rotating device that rotates the ultrasonic transducer by 1/n of the equal angle within the arrangement plane of the ultrasonic transducer; a transmitting device that simultaneously transmits ultrasonic pulses of respective natural frequencies in directions directed by each of the ultrasonic transducers while rotating at an angle corresponding to the interval; and after transmitting the ultrasonic pulse, transmits the next ultrasonic wave. Until the pulse is transmitted, each of the received signals of the first to k-th ultrasonic transducers is switched and taken out in a very short period of time, and each of the received signals is switched and taken out. A received signal switching circuit that performs up to m cycles; a memory circuit that is composed of memory addresses in m rows and (k×n) columns; each time the received signals of the first to k-th ultrasonic transducers are sequentially switched and extracted, the column direction designated address changes by n addresses, and the ultrasonic transducer is The address of the storage circuit is designated so that the column direction designation address is shifted by one address each time it turns by 1/n of the angle, and the first to kth ultrasonic transducers receive waves at the designated address. A write address designation circuit for writing a signal, a display device that performs spiral pixel scanning and displays the received signal of the ultrasonic transducer, and a memory circuit that stores data in synchronization with the pixel scanning of the display. A readout circuit for reading out a signal and displaying it on the display device, which designates the column-direction address of the storage address once during one round of the spiral pixel scanning,
a read address designation circuit that sequentially designates addresses in the row direction in synchronization with the change in the radial direction of the spiral scan; and after the read address designation circuit reads out the stored data in the storage circuit, it reads the stored data at the next storage address. a write/read switching circuit that controls switching between writing and reading of the storage circuit so as to write the received signal sent from the received signal switching circuit to a designated address of the write address designation circuit; Underwater detection equipment equipped with.