JP6943792B2 - Ultrasonic exploration device - Google Patents

Description

The present invention relates to an ultrasonic exploration device that performs underwater detection.

Patent Documents 1 to 5 and the like are known as prior art. Patent Document 1 discloses a technique of a multi-frequency fish finder that transmits waves into water in a predetermined order and records only the signals reflected in the predetermined order in order to prevent interference. Patent Document 2 states that "an ultrasonic pulse transmitting means for transmitting two types of ultrasonic pulses having similar frequencies at a timing shifted by a certain period of time, and a reflection of the two types of ultrasonic pulses are received and received from the received signal. An underwater detection device including a detection signal generation means for extracting signal components having the same level at the same distance to generate a detection signal. " Patent Document 3 includes, in order to eliminate interference with fish finder of another ship, "a pulse transmitter capable of switching to a plurality of frequencies and transmitting a wave, and a receiver receiving the same frequency as the transmission frequency. Then, the frequency is sequentially changed and transmitted, the reflected wave is received and stored, and one detection and reception signal is used as one display line, and many detection and storage data are arranged in chronological order. A technique of having a means of displaying and displaying only when there is a correlation between the detected signal data between adjacent display lines detected at different frequencies is shown. Patent Document 4 states that "the frequency of ultrasonic waves transmitted from a transducer is within a range of ± 10% or less, or within a range from a frequency at which reactance or susceptance is maximized to a frequency at which it is minimized, etc. by manual or automatic operation. By making it changeable, mutual interference with other aircraft is avoided. "

Patent Document 5 states, "When forming a transmission beam, ultrasonic transmission beams having different frequencies in the horizontal or vertical direction are formed. When forming a reception beam, frequency components corresponding to the transmission frequencies of each transmission beam are extracted. This allows the detection image in the horizontal or vertical direction to be obtained at the same time. "

Japanese Unexamined Patent Publication No. 59-125085 Japanese Unexamined Patent Publication No. 1-2213381 Japanese Unexamined Patent Publication No. 7-198829 Japanese Unexamined Patent Publication No. 2001-147265 Japanese Unexamined Patent Publication No. 2003-202370

The technique of Patent Document 1 is a technique of preventing interference by using multiple frequencies, but a circuit for receiving frequencies is required. Patent Document 2 indicates that it is possible to remove interference with a fish finder of another ship, but the fish finder of another ship cannot remove the interference in the case of the same fish finder. In Patent Documents 3 and 4, since the detection is performed at a different frequency each time, two or more detections are required to eliminate the interference with the fish finder of another ship. Therefore, it takes time to eliminate the interference. Further, Patent Document 5 continuously transmits beams having different frequencies, but is not a technique for eliminating interference with other devices.

The present invention has been made in view of such a problem, and an object of the present invention is to perform exploration in a short time and to eliminate interference with other ultrasonic exploration devices.

The ultrasonic exploration device of the present invention includes a transmitting unit, a receiving unit, a first processing unit, and a second processing unit. The transmission unit transmits the first sound wave, which is the sound wave of the first frequency, and then transmits the second sound wave, which is the sound wave of the second frequency. The receiving unit has a plurality of receivers that receive sound waves, and an A / D converter that converts the sound wave signal received by each of the receivers into a digital sound wave signal. The first processing unit performs signal processing on the digital sound wave signal and outputs the first search information based on the sound wave of the first frequency band including the first frequency. The second processing unit performs signal processing on the digital sound wave signal and outputs the second search information based on the sound wave of the second frequency band including the second frequency. Then, the transmitting unit determines in advance the interval between the transmission of the first sound wave and the transmission of the second sound wave within a range in which the receiving unit has a period in which the reflected wave of the first sound wave and the reflected wave of the second sound wave are simultaneously received. Change as often as possible.

According to the ultrasonic exploration device of the present invention, sound waves having two frequencies are used during one exploration, so that the exploration can be performed in a short time. In addition, since the interval between the transmission of sound waves of two frequencies is changed, the timing of transmitting the two sound waves can be made different even when other ultrasonic exploration devices also use the sound waves of the same two frequencies. , The position of the interference wave included in the exploration information can be set to a different position. Therefore, the interference wave can be identified and removed.

The figure which shows the functional configuration example of the ultrasonic exploration apparatus of this invention. The figure which shows the example of the processing flow of the ultrasonic exploration apparatus of the invention. The figure which showed from the timing when a transmitting part transmits a sound wave to the timing when a receiving part receives a sound wave in the process of one exploration. The figure which shows the relationship between the 1st exploration information, the 2nd exploration information and exploration information. Other ship using the first frequency f ₁ and a second frequency f ₂ to the ultrasonic inspection, first search information when the distance between the transmission of the first wave and the second wave coincides exploration information and second search information The figure which shows the relationship of. Other ship using the first frequency f ₁ and a second frequency f ₂ to the ultrasonic inspection, first search information when the distance between the transmission of the first wave and the second acoustic wave are different, exploration information and second search information The figure which shows the relationship.

Hereinafter, embodiments of the present invention will be described in detail. The components having the same function are given the same number, and duplicate explanations will be omitted. Further, N is an integer of 2 or more, and n is an integer of 1 or more and N or less.

FIG. 1 shows an example of the functional configuration of the ultrasonic exploration device of the present invention. FIG. 2 shows an example of the processing flow of the ultrasonic exploration apparatus of the present invention. The ultrasonic exploration device 100 includes a transmission unit 110, a reception unit 120, a first processing unit 130, a second processing unit 140, and an exploration information unit 150. FIG. 3 is a diagram showing from the timing at which the transmitting unit transmits sound waves to the timing at which the receiving unit receives sound waves in one exploration process. The horizontal axis is time.

Transmission unit 110, after transmitting a first sound wave which is a first wave of frequency _{f 1,} transmitting a second acoustic wave is a wave of the second frequency _{f 2} (S110). Transmitting section 110, to the extent that the interval T _s of the transmission of the transmission and the second wave of the first wave, the period during which the receiving unit 120 receives a reflected wave of the reflected wave and the second wave of the first wave simultaneously present, Change at a predetermined frequency. The frequency of the sound wave may be appropriately selected from about 50 kHz to 250 kHz according to the object to be explored. Further, it is preferable that the interval between the frequencies of the first frequency and the second frequency is narrow because the characteristics of the reflected wave are similar. However, when the object is moving or when the ship equipped with the ultrasonic exploration device is moving, the frequency of the reflected wave changes due to the influence of the Doppler effect, so it can be distinguished even after being affected by the Doppler effect. Need to be separated. In the case of the present invention, the frequency interval between the first frequency and the second frequency may be 8 kHz or more and 20 kHz or less. Specifically, for example, the first frequency may be set to 200 kHz and the second frequency may be set to 210 kHz.

_{The transmission time T P} of the first sound wave and the second sound wave greatly affects the distance resolution of the exploration information. The transmission time T _P may be appropriately determined from the range of the distance to be ultrasonically explored and the distance resolution, and may be selected from, for example, 10 μs to 10 msec. In particular, in the case of short-range ultrasonic exploration, it is desirable to use a short-time pulse with _{a transmission time T P of 10 μsec to 100 μsec.} In the present invention, it is possible to shorten the _{transmission time T P} by devising the first processing unit 130 and the second processing unit 140. Details will be described later.

Interval T _s of the transmission of the transmission and the second wave of the first wave may be determined in a range that allows the observation of the two sound waves in the processing of a single search. That is, "transmission unit 110 described above, the interval T _s of the transmission of the transmission and the second wave of the first wave, the receiving unit 120 is a period during which simultaneously receiving reflected waves reflected wave and the second wave of the first wave "Existing range" means observing the reflected waves of two sound waves in a single exploration process. However, the narrower the interval, the shorter the processing of one exploration. The above-mentioned "predetermined frequency" may be performed every time or once every few times. The effect of changing the interval T _s will be described in detail later.

The receiving unit 120 includes a plurality of receivers 121-1, ..., N that receive sound waves, and an A / D converter 122-1, ..., N that converts the sound wave signal received by each of the receivers into a digital sound wave signal. Has N. The plurality of receivers 121-1, ..., N may be arranged in an array, for example. The reflected wave f ₁ of the first sound wave is received by the receiver 121-n _{from the time T w} after the start of transmission of the first sound wave to the time T _m. The reflected wave f ₂ of the second sound wave is received by the receiver 121-n _{from after the time T w of the} start of transmission of the second sound wave to the time T _m. Therefore, the receiver 121 receives both sound waves for at least time _Tr (= T _s + T _m ) (S121-n). The sound wave signal received by the receiver 121-n is converted into a digital sound wave signal by the A / D converter 122-n (S122-n). Step S120 is a process in which steps S121-1, ..., N and steps S122-1, ..., N are combined. By converting the sound wave signal received by the receiver 121-n into a digital signal, deterioration due to signal division is eliminated, so that it is easy to perform the processing of the first processing unit 130 and the second processing unit 140 described later in parallel. , It is easy to avoid increasing the size of the device.

The first processing unit 130 performs signal processing on the digital sound wave signal and outputs the first search information based on the sound wave of the first frequency band including the first frequency (S130). More specifically, the first processing unit 130 has first delayers 131-1, ..., N and a first synthesizer 132. The first delay device 131-n performs a process of giving a corresponding delay for each digital sound wave signal output by the A / D converter 122-n and a process of extracting the first frequency band according to the direction to be searched. , The first frequency band delay addition digital sound wave signal is output (S131-n). Either the process of giving a delay according to the direction to be searched or the process of extracting the first frequency band may be processed first. The first synthesizer 132 synthesizes the first frequency band delay-added digital sound wave signal and outputs the first exploration information (S132).

The “first frequency band including the first frequency” means that the frequency changed by the Doppler effect is also included, and the frequency band may be appropriately selected from about ± 3 kHz to ± 8 kHz. If the frequency band is widened, it is necessary to widen the interval between the frequencies of the first frequency and the second frequency, so the determination may be made in consideration of the characteristics of the object to be explored. When extracting sound waves in the direction to be searched from a plurality of receivers, it is common to adjust the phase, but the first delayer 131-n of the present invention gives a delay. Assuming that the frequency of the sound wave is 100 kHz and the propagation speed of the sound wave in water is 1500 m, the wavelength λ of the sound wave is 15 mm (= 1500 m / 100 kHz). Since the width of the receivers 121-1, ..., N is several tens of centimeters, when the direction of exploration is determined by adjusting the phase, the number of sounds transmitted from the transmitter 110 at the same timing is not superposed. Overlapping will be performed for each cycle. Since there are no sound waves for several cycles required for superposition near the start and end of transmission, superimposition is performed only for the time when sound waves for several cycles exist (time avoiding near the start and end of transmission). Will be. _{This is not a problem when the transmission time T P of the} sound wave to be transmitted is sufficiently long, but it becomes an obstacle for shortening the _{transmission time T P.} Therefore, in order to superimpose the sounds (sounds having the same period) transmitted from the transmission unit 110 at the same timing, it is necessary to adjust by delay instead of adjusting the phase. In the present invention, since the first delay device 131-n adjusts the direction to be searched by the delay, the transmission time T _{P of the} sound wave transmitted by the transmission unit 110 can be shortened.

The second processing unit 140 performs signal processing on the digital sound wave signal and outputs the second search information based on the sound wave of the second frequency band including the second frequency (S140). More specifically, the second processing unit 140 has second delayers 141-1, ..., N and a second synthesizer 142. The second delay device 141-n performs a process of giving a corresponding delay for each digital sound wave signal output by the A / D converter 122-n and a process of extracting the second frequency band according to the direction to be searched. , The second frequency band delay addition digital sound wave signal is output (S141-1). Either the process of giving a delay according to the direction to be searched or the process of extracting the second frequency band may be processed first. The second synthesizer 142 synthesizes the second frequency band delay-added digital sound wave signal and outputs the second exploration information (S142). The contents related to the frequency band and the effect of extracting the sound wave in the direction to be searched by the delay are the same as those of the first processing unit 130.

The exploration information unit 150 uses information in which the first exploration information and the second exploration information are different as interference information with other devices, and obtains exploration information from the first exploration information or the second exploration information based on the interference information. (S150). Alternatively, the exploration information unit 150 obtains exploration information from the information common to the first exploration information and the second exploration information (S150). FIG. 4 shows the relationship between the first exploration information and the second exploration information and the exploration information. Since the first frequency f ₁ and the second frequency f ₂ are close to the extent that the characteristics of the reflected waves are similar, the information regarding the reflected waves in the first exploration information and the second exploration information is similar. When the nearby vessels were using the same frequency as the first frequency f ₁ to the ultrasonic inspection, the first search information includes the effects of interference waves, the second search information includes the effects of interference waves I can't. Therefore, the exploration information may be obtained by using the information in which the first exploration information and the second exploration information are different as the interference information with other devices and deleting the interference information from the first exploration information or the second exploration information. Then, the exploration information may be obtained from the information common to the first exploration information and the second exploration information. It should be noted that different information and common information may be obtained from cross-correlation and the like.

In FIG. 5, other ships also use the first frequency f ₁ and the second frequency f ₂ for ultrasonic exploration, and the first exploration information and the second exploration when the transmission intervals of the first sound wave and the second sound wave match. It is a figure which shows the relationship between information and exploration information. In FIG. 6, other ships also use the first frequency f ₁ and the second frequency f ₂ for ultrasonic exploration, and the first exploration information and the second exploration information when the transmission intervals of the first sound wave and the second sound wave are different. It is a figure which shows the relationship between and exploration information. Other boat using a first frequency f ₁ and the second frequency f ₂ to the ultrasonic inspection, if the distance between the transmission of the first wave and the second acoustic wave is matched to both the first search information and second search information Similarly, since the influence of the interference wave is included, the influence of the interference wave cannot be eliminated even in the exploration information. On the other hand, even if other ships also use the first frequency f ₁ and the second frequency f ₂ for ultrasonic exploration, if the transmission intervals of the first sound wave and the second sound wave are different, the first exploration information and the second exploration Since the influence of the interference wave on the information is different, the influence of the interference wave can be eliminated in the exploration information. Other boat using a first frequency f ₁ and the second frequency f ₂ to the ultrasonic inspection, the interval of transmission of the first wave and the second acoustic waves are coincident, but the probability is considered low, might No. However, the transmission unit 110, an interval T _s of the transmission of the transmission and the second wave of the first wave, the range of the period in which the second sound wave also received while receiving unit 120 is receiving the waves of the first frequency , Change at a predetermined frequency. The other ship even lower possibility to modify the same manner interval T _s at the same frequency, can remove the effect of substantially interfering wave.

As described above, according to the ultrasonic exploration device 100, sound waves having two frequencies are used during one exploration, so that the exploration can be performed in a short time. In addition, since the interval between the transmission of sound waves of two frequencies is changed, the timing of transmitting the two sound waves can be made different even when other ultrasonic exploration devices also use the sound waves of the same two frequencies. , The position of the interference wave included in the exploration information can be set to a different position. Therefore, the interference wave can be identified and removed.

100 Ultrasonic probe 110 Transmitter 120 Receiver 121 Receiver 122 A / D converter 130 First processing unit 131 First delayer 132 First synthesizer 140 Second processing unit 141 Second delayer 142 Second synthesizer 150 Exploration Information Department

Claims (4)

A transmitter that transmits a first sound wave, which is a first frequency sound wave, and then a second sound wave, which is a second frequency sound wave,
A plurality of receivers that receive sound waves, a receiver having an A / D converter that converts the sound wave signal received by each of the receivers into a digital sound wave signal, and a receiver.
A first processing unit that performs signal processing on the digital sound wave signal and outputs first search information based on sound waves in the first frequency band including the first frequency.
A second processing unit that performs signal processing on the digital sound wave signal and outputs second exploration information based on sound waves in the second frequency band including the second frequency.
Information that differs between the first exploration information and the second exploration information is used as interference information with another device, and based on the interference information, exploration for obtaining exploration information from the first exploration information or the second exploration information. Equipped with an information department
The transmitting unit has a range in which the interval between the transmission of the first sound wave and the transmission of the second sound wave has a period in which the receiving unit simultaneously receives the reflected wave of the first sound wave and the reflected wave of the second sound wave. An ultrasonic exploration device that is characterized by changing at a predetermined frequency. A transmitter that transmits a first sound wave, which is a first frequency sound wave, and then a second sound wave, which is a second frequency sound wave,
A plurality of receivers that receive sound waves, a receiver having an A / D converter that converts the sound wave signal received by each of the receivers into a digital sound wave signal, and a receiver.
A first processing unit that performs signal processing on the digital sound wave signal and outputs first search information based on sound waves in the first frequency band including the first frequency.
A second processing unit that performs signal processing on the digital sound wave signal and outputs second exploration information based on sound waves in the second frequency band including the second frequency.
Exploration information unit that obtains exploration information from the information common to the first exploration information and the second exploration information
With
The transmitting unit has a range in which the interval between the transmission of the first sound wave and the transmission of the second sound wave includes a period during which the receiving unit simultaneously receives the reflected wave of the first sound wave and the reflected wave of the second sound wave. And change it at a predetermined frequency
An ultrasonic exploration device characterized by this. The ultrasonic exploration device according to claim 1 or 2.
An ultrasonic exploration device characterized in that the plurality of receivers are arranged in an array. The ultrasonic exploration device according to any one of claims 1 to 3.
The first processing unit
A first delayer that outputs a first frequency band delay-added digital sound wave signal by performing a process of giving a corresponding delay for each digital sound wave signal and a process of extracting the first frequency band according to the direction to be searched. ,
It has a first synthesizer that synthesizes the first frequency band delay-added digital sound wave signal and outputs the first exploration information.
The second processing unit
A second delayer that outputs a second frequency band delay-added digital sound wave signal by performing a process of giving a corresponding delay for each digital sound wave signal and a process of extracting the second frequency band according to the direction to be searched. ,
An ultrasonic exploration apparatus comprising a second synthesizer that synthesizes the second frequency band delay-added digital sound wave signal and outputs the second exploration information.

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