JP2020003431A - Method of detecting attached matter using ultrasonic waves, and system for detecting attached matters using ultrasonic waves - Google Patents

Abstract

To provide a method of detecting attached matter using ultrasonic waves capable of detecting the state of attached matters on one surface of a structure by applying ultrasonic waves from one surface in order to detect the state of deposits on the outer surface of the hull even from inside the hull for example, and to provide a detection system of attached matter by ultrasonic waves.SOLUTION: The method of detecting attached matter for detecting the state of matters attached to a structure 1, includes the steps of: measuring first reflected echo of ultrasonic waves while radiating of the ultrasonic waves to incident on the structure 1 at a first point of time; measuring second reflected echo of ultrasonic waves while radiating of the ultrasonic waves to incident on the structure 1 at a second point of time; and comparing the integrated value or power spectrum of the first reflected echo and the second reflected echo; to thereby detecting.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for detecting an attached matter using an ultrasonic wave and a system for detecting an attached matter using an ultrasonic wave, which detects an attached state of an attached matter to a structure using an ultrasonic wave.

Attachment of marine organisms such as barnacles to the hull surface significantly increases hull resistance during propulsion. In addition, there is also a problem of "crossing borders" in which marine organisms adhere to the hull of ships and move, and fall off and proliferate away from their natural habitats.
At present, the observation of marine organisms attached to the hull is almost always performed visually after drying up (draining) when docking at the repair dock. Observation is possible by divers or ROVs (remote-operated unmanned underwater vehicles), for example, by taking images of the bottom of the ship. However, observation during ship navigation is difficult, and the timing of observation is limited.

Here, in Patent Document 1, a pair of probes for transmission and reception of an ultrasonic flaw detector are symmetrically applied to the outside of a tube to be inspected, an ultrasonic pulse is transmitted, and the received pulse is transmitted. A method of measuring the state of adhesion of marine organisms inside the pipe by comparing the waveform of the pipe with the waveform of a healthy pipe is disclosed. In Patent Document 1, a probe of an ultrasonic flaw detector is applied to a point outside the tube to be inspected, and an echo from the tube body and an echo from a marine life surface are measured, and an echo from a marine life surface is measured. There is also disclosed a method of measuring the attached thickness of marine organisms inside the piping by reading the propagation distance of the seawater.
Also, in Patent Document 2, an ultrasonic transmitter and a receiver are arranged to face each other with a predetermined gap from the outer wall of the tube, and the ultrasonic transducer is filled with the same kind of acoustic bonding liquid as the fluid in the tube. The ultrasonic wave propagates through the fluid toward the receiver, detects the ultrasonic attenuation ratio, and calculates the ultrasonic attenuation ratio from the detected value and the calibration value of the ultrasonic attenuation ratio obtained for a known scale thickness into the pipe by calculation. A method for determining the thickness of an attached scale is disclosed.
Further, in Patent Document 3, a scanning body having an ultrasonic transducer mounted on a guide bar fixed to a frame having a supporting leg is slidably supported, and ultrasonic waves are transmitted from the ultrasonic transducer at regular intervals. The scanning body is moved while emitting a pulse signal, and the emitted pulse signal is received by an ultrasonic transducer to receive a signal reflected from a marine organism, and a time difference between the emitted signal and the received signal is detected. Calculate the distance between the ultrasonic transducer and the marine organism from the sound velocity and time difference of the ultrasonic wave, calculate the layer thickness of the marine organism from the distance between the known ultrasonic transducer and the base, and calculate the signal An apparatus for measuring and scanning the layer thickness of marine organisms is disclosed.

JP-A-3-188390 JP-A-62-54113 Japanese Utility Model Publication No. 3-8967

However, in the methods or apparatuses described in Patent Literatures 1 to 3, it is difficult to detect, for example, the state of attachment of the extraneous matter to the outer surface of the hull from the inside of the hull for the following reasons.
The first of the methods described in Patent Literature 1 and the method described in Patent Literature 2 use two ultrasonic sensors, one for transmission and the other for reception, which are arranged opposite to each other with a tube therebetween. The attached state of the attached matter in the pipe is detected by the attenuation of the transmitted wave. However, it is difficult to install an ultrasonic sensor for reception outside the hull when trying to detect the extraneous matter on the outer surface of the hull from inside the hull.
The second method described in Patent Literature 1 and the device described in Patent Literature 3 use the ultrasonic Time of Flight method (TOF method) to measure the thickness of the deposit attached to the inside of the pipe. It measures the height. However, when trying to detect the extraneous matter on the outer surface of the hull from the inside of the hull, the adhering surface of the extraneous material (the outer surface of the hull) is the surface immediately opposite to the surface where the ultrasonic sensor comes into contact (the inner surface of the hull). As a result, since the reflected echo from the attached surface and the reflected echo from the attached matter are measured and superimposed, the starting point of the echo due to the attached matter becomes unclear, and it is difficult to apply the TOF method.

  Therefore, the present invention relates the adhesion state of the adhering matter on one surface of the structure to the one-sided relationship with the one surface so that the adhering state of the adhering matter on the outer surface of the hull can be detected, for example, even from the inside of the hull. It is an object of the present invention to provide a method for detecting an attached matter by an ultrasonic wave and a system for detecting an attached matter by an ultrasonic wave, which can be detected by entering an ultrasonic wave from a certain other surface.

A method for detecting an attached matter by using an ultrasonic wave according to claim 1 is a method for detecting an attached matter on an object using an ultrasonic wave, the method comprising detecting an attached matter at a first time. A sound wave is made incident on a structure to measure a first reflected echo, and at a second time, an ultrasonic wave is made incident on at least the structure to measure a second reflected echo, and a first reflected echo and a second reflected echo are measured. The integrated state or the power spectrum of is compared to detect the state of attachment of the attached matter to the structure.
The attached matter includes an extraneous attached matter, an attached matter that has grown, a substance that has precipitated out from the surroundings, and a structure in which the structure has undergone a chemical change and the surface of the structure has become an attached matter.
According to the first aspect of the present invention, the adhesion state is detected by comparing the integrated value or the power spectrum of the first reflection echo and the second reflection echo, and thereby the adhesion of the adhesion substance on one surface of the structure is detected. The adhesion state can be detected from, for example, the other surface which is in a front-to-back relationship with the one surface. Thus, for example, the presence or absence of extraneous matter on the outer surface of the hull can be detected even from the inside of the hull, so that it is possible to timely monitor the state of adhesion of extraneous matter to the outer surface of the hull, whether at anchor or while navigating. It becomes possible.

According to a second aspect of the present invention, the first reflected echo at the first time is measured and recorded in advance, and the recorded first reflected echo is used for comparison.
According to the second aspect of the present invention, it is not necessary to measure the first reflection echo, which is a reference for comparison, every time measurement is performed, so that the time can be reduced. For example, if the first time is a start time with no attached matter and the second time is an elapsed time with the attached matter, at the elapsed time, the attached matter is peeled off and the first reflected echo is measured. You don't have to. In addition, since the comparison standard is constant, the detection accuracy of the adhesion state is improved.

According to the third aspect of the present invention, the first reflected echo intensity is measured as the first reflected echo, the second reflected echo intensity is measured as the second reflected echo, and the first reflected echo intensity and the integrated value are measured as integrated values. A temporal integration value of the second reflected echo intensity is used.
According to the third aspect of the present invention, since the difference between the first reflected echo and the second reflected echo is clarified by using the reflected echo intensity that is easy to measure, it is possible to detect the attached state of the attached matter. It will be easier.

According to a fourth aspect of the present invention, the first power spectrum is measured as the first reflected echo and the second power spectrum is measured as the second reflected echo, and the first power spectrum and the second power spectrum are measured. It is characterized in that a change in a dominant frequency band is used for comparison.
According to the present invention, the difference between the first reflected echo and the second reflected echo is clarified by using a change in the frequency band of the power spectrum in which the attached state is reflected. It becomes easy to detect the state of adhesion of the particles.

According to a fifth aspect of the present invention, the structure is a hull, and the attached matter is a marine organism attached to the hull.
According to the fifth aspect of the present invention, it is possible to detect the state of attachment of marine organisms and the like that adhere to the hull.

The present invention according to claim 6 is characterized in that ultrasonic waves are incident from the inside of the hull, and the first reflected echo or the second reflected echo is measured inside.
According to the sixth aspect of the present invention, the state of adhesion of marine organisms and the like can be detected from the inside of the hull even during navigation and during berthing.

The present invention according to claim 7 is characterized in that the incidence of ultrasonic waves and the measurement of the first reflected echo and the second reflected echo are performed at the same place on the structure.
According to the present invention, even if the time is changed, it is possible to accurately detect the attached state of the attached matter at the same location.

The present invention according to claim 8 is characterized in that the incidence of the ultrasonic wave and the measurement of the first reflected echo and the second reflected echo are performed at different places of the structure.
According to the eighth aspect of the present invention, it is possible to detect the attached state of the attached matter over a wide range.

According to a ninth aspect of the present invention, the ultrasonic wave is incident at a plurality of locations on the structure, and the first reflected echo and the second reflected echo are measured at one location on the structure.
According to the ninth aspect of the present invention, it is possible to detect the attached state of the attached matter over a wider range.

According to a tenth aspect of the present invention, the state of attachment of the attached matter to the detected structure is notified.
According to the tenth aspect of the present invention, it is possible to notify a person who is away from the detection site of the adhesion status.

An attached matter detection system using ultrasonic waves according to claim 11, wherein the attached matter detection system detects an attached state of an attached matter to a structure using ultrasonic waves, and the ultrasonic wave is applied to at least the structure. An ultrasonic wave incident means for making the reflected light reflected from the structure, a reflected echo measuring means for measuring at least a reflected echo from the structure, and an integrated value of a first reflected echo at a first time and a second reflected echo at a second time or And an adhesion detecting means for comparing the power spectra and detecting the state of adhesion of the extraneous matter to the structure.
According to the eleventh aspect of the present invention, the adhesion state is detected by comparing the integrated value or the power spectrum of the first reflection echo and the second reflection echo, so that the adhesion substance on one surface of the structure is detected. The adhesion state can be detected from, for example, the other surface which is in a front-to-back relationship with the one surface. Thus, for example, the presence or absence of extraneous matter on the outer surface of the hull can be detected even from the inside of the hull, so that it is possible to timely monitor the state of adhesion of extraneous matter to the outer surface of the hull, whether at anchor or while navigating. It becomes possible.

According to a twelfth aspect of the present invention, there is provided a recording means for recording a result of previously measuring the first reflected echo at the first time and using the result for comparison with the second reflected echo. .
According to the twelfth aspect of the present invention, it is not necessary to measure the first reflection echo, which is a reference for comparison, every time measurement is performed, so that the time required for measurement can be reduced. In addition, since the comparison standard is constant, the detection accuracy of the adhesion state is improved.

According to a thirteenth aspect of the present invention, the reflected echo measuring means measures the first reflected echo intensity as the first reflected echo and the second reflected echo intensity as the second reflected echo, and the adhesion detecting means measures the reflected echo intensity. , Wherein a temporal integrated value of the first reflected echo intensity and the second reflected echo intensity is used for comparison as an integrated value.
According to the thirteenth aspect of the present invention, since the difference between the first reflected echo and the second reflected echo is clarified by using the reflected echo intensity that is easy to measure, it is possible to detect the attached state of the attached matter. It will be easier.

According to a fourteenth aspect of the present invention, the reflection echo measuring means measures the first power spectrum as the first reflected echo and the second power spectrum as the second reflected echo, and the adhesion detecting means measures the first power spectrum as the second reflected echo. It is characterized in that a change in a dominant frequency band between the first power spectrum and the second power spectrum is used for comparison.
According to the present invention, the difference between the first reflected echo and the second reflected echo is clarified by using the change in the frequency band of the power spectrum in which the attached state is reflected. It becomes easy to detect the state of adhesion of the particles.

According to a fifteenth aspect of the present invention, the structure is a hull, and the attached matter is a marine organism attached to the hull.
According to the fifteenth aspect of the present invention, it is possible to detect the state of adhesion of marine organisms and the like that adhere to the hull.

The invention according to claim 16 is characterized in that the ultrasonic wave incident means makes the ultrasonic wave incident on the hull from inside the hull, and the reflected echo measuring means measures the reflected echo inside.
According to the sixteenth aspect of the present invention, the state of attachment of marine organisms and the like can be detected from the inside of the hull even during navigation and during berthing.

According to a seventeenth aspect of the present invention, the incidence of ultrasonic waves and the measurement of the first reflected echo and the second reflected echo are performed at the same location on the structure.
According to the seventeenth aspect of the present invention, it is possible to detect the attached state of the attached matter at the same location even when the time changes.

The present invention according to claim 18 is characterized in that the ultrasonic wave incident means and the reflected echo measuring means are provided at different places of the structure, and the incidence of the ultrasonic wave and the measurement of the reflected echo are performed at different places.
According to the eighteenth aspect of the present invention, it is possible to detect the attached state of the attached matter over a wide range.

According to the present invention, the ultrasonic wave incident means is provided at a plurality of positions of the structure, the ultrasonic wave is incident at a plurality of positions, the reflected echo measuring means is provided at one position of the structure, and the reflected echo is measured. Is performed in one place.
According to the nineteenth aspect of the present invention, it is possible to detect the attached state of the attached matter over a wider range.

According to a twentieth aspect of the present invention, there is provided a notifying means for notifying the adhesion state of the adhering matter to the structure detected by the adhering detecting means.
According to the twentieth aspect of the present invention, it is possible to notify a person who is away from the detection site of the adhesion status.

  According to the method for detecting an attached matter by ultrasonic waves of the present invention, the attached state is detected by comparing the integrated value or the power spectrum of the first reflected echo and the second reflected echo, so that one surface of the structure can be detected. The attached state of the attached matter can be detected from, for example, the other surface which is in a front-to-back relationship with the one surface. Thus, for example, the presence or absence of extraneous matter on the outer surface of the hull can be detected even from the inside of the hull, so that it is possible to timely monitor the state of adhesion of extraneous matter to the outer surface of the hull, whether at anchor or while navigating. It becomes possible.

  When the first reflected echo at the first time is measured and recorded in advance, and the recorded first reflected echo is used for comparison, the first reflected echo serving as a reference for comparison is measured each time. Since there is no need to measure, the time can be reduced. For example, if the first time is a start time with no attached matter and the second time is an elapsed time with the attached matter, at the elapsed time, the attached matter is peeled off and the first reflected echo is measured. You don't have to. In addition, since the comparison standard is constant, the detection accuracy of the adhesion state is improved.

  In addition, the first reflected echo intensity is measured as the first reflected echo, and the second reflected echo intensity is measured as the second reflected echo, and the integrated values of the first reflected echo intensity and the second reflected echo intensity are measured. When a temporal integration value is used, the difference between the first reflected echo and the second reflected echo is clarified using the reflected echo intensity that is easy to measure, so that it is easy to detect the attached state of the attached matter. It becomes.

  Also, the first power spectrum is measured as the first reflected echo, and the second power spectrum is measured as the second reflected echo, and the change of the dominant frequency band between the first power spectrum and the second power spectrum is measured. Is used for comparison, the difference between the first reflected echo and the second reflected echo is clarified using the change in the frequency band of the power spectrum in which the attached state is reflected. Detection becomes easy.

  Further, when the structure is a hull and the attached matter is marine organisms attached to the hull, the attached state of marine organisms attached to the hull can be detected.

  Further, when ultrasonic waves are incident from the inside of the hull and the first reflected echo or the second reflected echo is measured inside the hull, the state of attachment of marine organisms and the like to the hull during navigation and during mooring is determined. It can be detected from inside.

  Further, when the incidence of the ultrasonic wave and the measurement of the first reflected echo and the second reflected echo are performed at the same location of the structure, the attached state of the attached substance at the same location can be detected even if the time changes.

  Further, when the incidence of the ultrasonic wave and the measurement of the first reflected echo and the second reflected echo are performed at different portions of the structure, the attached state of the attached matter can be detected over a wide range.

  Further, when ultrasonic waves are incident at a plurality of locations on a structure and the first reflected echo and the second reflected echo are measured at one location on the structure, the state of adhesion of the attached matter over a wider range can be measured. Can be detected.

  In addition, in the case of notifying the attached state of the attached matter to the detected structure, the attached state can be notified to a person who is away from the detection site.

  According to the attached matter detection system using ultrasonic waves of the present invention, the attached state is detected by comparing the integrated value or the power spectrum of the first reflected echo and the second reflected echo, so that one of the structures can be detected. The attached state of the attached matter on the surface can be detected, for example, from the other surface side which is in a front-to-back relationship with the one surface. Thus, for example, the presence or absence of extraneous matter on the outer surface of the hull can be detected even from the inside of the hull, so that it is possible to timely monitor the state of adhesion of extraneous matter to the outer surface of the hull, whether at anchor or while navigating. It becomes possible.

  In the case where recording means for recording the result of measuring the first reflected echo at the first time in advance and using the result for comparison with the second reflected echo is provided, the first reference serving as a reference for comparison is provided. Since it is not necessary to measure the reflected echo every time the measurement is performed, the time required for the measurement can be reduced. In addition, since the comparison standard is constant, the detection accuracy of the adhesion state is improved.

  The reflected echo measuring means measures the first reflected echo intensity as the first reflected echo and the second reflected echo intensity as the second reflected echo, and the adhesion detecting means measures the first reflected echo as an integrated value. When the temporal integration value of the reflected echo intensity and the second reflected echo intensity is used for comparison, the difference between the first reflected echo and the second reflected echo is clarified using the easily reflected reflected echo intensity. Therefore, it is easy to detect the attached state of the attached matter.

  The reflection echo measuring means measures the first power spectrum as the first reflection echo and the second power spectrum as the second reflection echo, and the adhesion detecting means measures the first power spectrum and the second power spectrum. When the change in the dominant frequency band of the power spectrum is used for comparison, the difference between the first reflected echo and the second reflected echo is determined using the change in the frequency band of the power spectrum reflecting the adhesion state. Because it is clear, it is easy to detect the attached state of the attached matter.

  Further, when the structure is a hull and the attached matter is marine organisms attached to the hull, the attached state of marine organisms attached to the hull can be detected.

  Also, when the ultrasonic wave incident means makes the ultrasonic wave incident on the hull from the inside of the hull and the reflected echo measuring means measures the reflected echo inside the hull, even when navigating, berthing, etc. The state of adhesion can be detected from inside the hull.

  Further, when the incidence of the ultrasonic wave and the measurement of the first reflected echo and the second reflected echo are performed at the same location of the structure, the attached state of the attached substance at the same location can be detected even if the time changes.

  Well, when ultrasonic incidence means and reflection echo measurement means are provided at different places in the structure, and when ultrasonic incidence and reflection echo measurement are performed at different places, the adhesion state of the deposits over a wide range Can be detected.

  Also, when ultrasonic incident means are provided at a plurality of locations of a structure, ultrasonic waves are incident at a plurality of locations, and a reflected echo measuring means is provided at one location of the structure, and measurement of a reflected echo is performed at one location. Can detect the attached state of the attached matter over a wider range.

  In addition, when a notification unit is provided for notifying the attachment state of the attachment to the structure detected by the attachment detection unit, the attachment state can be notified to a person who is away from the detection site.

FIG. 2 is a diagram illustrating an example of an arrangement of a system for detecting an attached substance using ultrasonic waves in the present embodiment. Schematic diagram of the equipment used for the experiment Diagram showing an example of reflected echo Conceptual diagram showing an example of ultrasound reflection Diagram showing an example of the integrated value (cumulative value) of the reflected echo intensity The figure which shows the example of the integrated value of the reflected echo intensity | strength at the time when the gap | interval of a 1st reflected echo and the 2nd reflected echo became substantially constant. Diagram showing an example of the power spectrum of a reflected echo Diagram showing another arrangement example of the ultrasonic wave incident means and the reflected echo measuring means

A method for detecting an attached matter using ultrasonic waves and a system for detecting an attached matter using ultrasonic waves according to an embodiment of the present invention will be described.
The method and system for detecting an attached matter by ultrasonic waves according to the present embodiment transmits an ultrasonic wave and detects the attached state of the attached matter to the structure using reflected echoes reflected from the structure and the attached matter. .
The attached matter includes an extraneous attached matter, an attached matter that has grown, a substance that has precipitated out from the surroundings, and a structure in which the structure has undergone a chemical change and the surface of the structure has become an attached matter.

FIG. 1 is a diagram illustrating an example of an arrangement of a system for detecting an attached substance using ultrasonic waves according to the present embodiment.
In the structure 1, one surface 1A is in contact with the liquid, and the other surface 1B is not in contact with the liquid. The space between the ultrasonic probe 10 and the other surface 1B is preferably filled with a couplant (such as glycerin) that promotes transmission of ultrasonic waves. The structure 1 is, for example, a hull. When the liquid in contact with one surface (such as the outer surface of the hull) 1A is seawater, marine organisms such as barnacles may adhere to the one surface 1A. The “hull” includes, in addition to the hull skin, parts that are submerged in seawater, such as sea chests, propellers, components of seawater cooling systems (piping, heat exchangers, gratings, etc.), steering devices such as rudders, and stabilizers. And so on.
The system for detecting an attached matter using ultrasonic waves includes an ultrasonic wave incident means 11 for transmitting ultrasonic waves, a reflected echo measuring means 12 for receiving ultrasonic waves (reflected echoes) reflected by a reflecting surface to become echoes, and a reflected echo. Detecting means 21 for detecting the state of attachment of the attached matter to the structure 1 based on the information, recording means 22 for recording the data of the reflected echo, and notification for notifying the attached state of the attached matter by sound or characters. Means 23 are provided.
In the present embodiment, one ultrasonic probe 10 that transmits and receives ultrasonic waves serves as both the ultrasonic wave incident means 11 and the reflected echo measuring means 12.
Further, the attachment detecting means 21, the recording means 22, and the notifying means 23 are provided in one notebook personal computer 20.
A pulsar receiver 30 for transmitting and receiving an ultrasonic signal and an oscilloscope 40 are disposed between the ultrasonic probe 10 and the notebook computer 20. And the oscilloscope 40 and the notebook computer 20 are connected by wire. Note that a part or all of the wired connection may be wireless.
The signal of the reflected echo measured by the ultrasonic probe 10 is taken into the notebook computer 20 via the oscilloscope 40. The incident unit 11 and the reflected echo measuring unit 12 of the ultrasonic probe 10, the adhesion detecting unit 21 as a function of the notebook computer 20, the recording unit 22 and the notifying unit 23, the pulsar receiver 30, and the oscilloscope 40 are appropriately individually It can be configured in combination.

As shown in FIG. 1, the system for detecting an attached matter using ultrasonic waves is disposed on only one side of the structure 1 including the ultrasonic wave incident means 11 and the reflected echo measuring means 12.
In FIG. 1, the tip of an ultrasonic probe 10 (ultrasonic incident means 11 and reflected echo measuring means 12) is brought into contact with the other surface 1 </ b> B of the wall of the structure 1, and a notebook computer 20, a pulsar receiver 30, and an oscilloscope 40 On the floor.

The detection of the attached matter attached to the structure 1 is performed in the following procedure.
First, with respect to the structure 1, a measurement point which is a position for checking the state of attachment of attached matter such as marine organisms is determined. It is preferable to select a position where there is no attached matter on the one surface 1A at that time.
Next, the tip of the ultrasonic probe 10 is brought into close contact with the other surface 1B of the structure 1 at the determined measurement point via glycerin or the like. Next, the ultrasonic wave is transmitted from the ultrasonic wave incident means 11 to the measurement location, the ultrasonic wave is made incident on the structure 1, and the reflected echo is measured by the reflected echo measuring means 12. The reflected echo measured at this time is recorded in the recording unit 22 as the first reflected echo at the first time.
After a lapse of a predetermined time from the measurement of the first reflected echo at the first time, the reflected echo is measured at the same position as that of the first reflected echo at the first time. First, the tip of the ultrasonic probe 10 is brought into close contact with the other surface 1B of the hull 1 at the measurement location. Next, the ultrasonic wave is transmitted from the ultrasonic wave incident means 11 to the measurement location, the ultrasonic wave is made incident on the structure 1, and the reflected echo is measured by the reflected echo measuring means 12. The reflected echo measured at this time is recorded in the recording unit 22 as a second reflected echo at the second time.

After measuring the second reflected echo at the second time, the adhesion detecting means 21 calculates the integrated value or power spectrum of the first reflected echo recorded in the recording means 22 and the integrated value of the second reflected echo. Alternatively, the power spectrum is read, and the two are compared.
As a result of the comparison, when a predetermined difference does not occur between the integrated value or the power spectrum of the first reflected echo and the integrated value or the power spectrum of the second reflected echo, between the first time and the second time It is determined that the state of attachment of the attached matter to one surface 1A at the measurement location has not changed. When a predetermined difference occurs between the integrated value or the power spectrum of the first reflected echo and the integrated value or the power spectrum of the second reflected echo, the measurement is performed between the first time and the second time. It is determined that the state of attachment of the attachment to one surface 1A at the location has changed.
The system for detecting an attached matter by ultrasonic waves notifies the measurement result by the attached detection means 21 to a measurer, a manager, or the like through the notifying means 23 connected to a wired or wireless communication network. By providing the notification means 23, it is possible to notify a person who is away from the detection site of the adhesion state. Note that the notification means 23 includes all means capable of providing general information such as images, sounds, and tactile sensations.

Here, an experiment using the present invention will be described. FIG. 2 is a schematic diagram of the apparatus used for the experiment.
In this experiment, the structure was simulated with the test piece 2. The test piece 2 is made of general structural steel (SS400), and has dimensions of 200 mm in height, 190 mm in width, and 9 mm in thickness. The surface of the test piece 2 is coated with an anticorrosive paint having a coating film pressure of 250 μm. By immersing the test piece 2 in the seawater in the actual sea area for a long time, barnacles were attached only to one surface 2A. The size of the attached barnacle is about 10 mm in diameter at the portion in contact with the test piece 2.
Assuming a measurement from the inside of the hull during navigation, one surface 2A of the test piece 2 on which the barnacles are attached is brought into contact with the water surface, and the surface of the test piece 2 is superposed from the other surface 2B on which the barnacles are not attached. The measurement was performed by injecting a sound wave. Two measurement points were selected for the test piece 2, and the first measurement point was a position where no barnacle was attached to one surface 2A, and the second measurement point was a barnacle attached to one surface 2A. Position.
First, at the first measurement point (without barnacle adhesion), an ultrasonic wave is transmitted from the ultrasonic wave incident means 11 while the tip of the ultrasonic probe 10 is in close contact with the other surface 2B, and the ultrasonic wave is transmitted to the test piece 2. The reflected echo was measured by the reflected echo measuring means 12. The reflection echo measured at this time was recorded in the recording unit 22 as a first reflection echo at a first time.
Next, at the second measurement point (with barnacles adhered), ultrasonic waves are transmitted from the ultrasonic wave incident means 11 while the tip of the ultrasonic probe 10 is in close contact with the other surface 2B, and the ultrasonic waves are applied to the test piece. 2 and the reflected echo was measured by the reflected echo measuring means 12. The reflected echo measured at this time was recorded in the recording unit 22 as a second reflected echo at a second time.

FIG. 3 is a diagram showing the reflection echo in this experiment, in which the vertical axis represents the voltage [mV] and the horizontal axis represents the time [nsec]. In FIG. 3A, the voltage is represented by positive and negative values, and in FIG. 3B, the voltage is represented by an absolute value. In FIG. 3, the broken line indicates the measurement result at the first measurement point (without barnacle adhesion), and the solid line indicates the measurement result at the second measurement point (with barnacle adhesion).
FIG. 4 is a conceptual diagram showing reflection of ultrasonic waves in this experiment. FIG. 4A shows the reflection at the second measurement point (with barnacles attached), and FIG. 4B shows the reflection at the first measurement point (without barnacles adhesion).
From FIG. 3, it can be seen that after a lapse of a predetermined time from the start of the measurement (at a position distant from the ultrasonic probe 10 by a certain distance), a shift occurs between the two waveforms. This shift is due to the difference in the number of reflecting surfaces between the two. As shown in FIG. 4A, in the case of the second measurement point (with barnacles attached), the reflection surface of the ultrasonic wave incident on the test piece 2 has a boundary surface between the test piece 2 and the anticorrosion paint 3, The boundary surface between the anticorrosion paint 3 and the barnacle 4 and the boundary surface between the barnacle 4 and the seawater 5 are three in total. On the other hand, as shown in FIG. 4B, in the case of the first measurement point (no barnacle adhesion), the reflection surface of the ultrasonic wave incident on the test piece 2 is a boundary between the test piece 2 and the anticorrosion paint 3. Surface and the boundary surface between the anticorrosive paint 3 and the seawater 5 in total. In other words, the second measurement location (with barnacles attached) has more reflective echoes than the first measurement location (without barnacles attached), resulting in more reflected echoes, resulting in a shift in both waveforms.

In the case where there is an adhering substance, the number of interfaces (reflection surfaces) that reflect ultrasonic waves increases, so that more reflected echoes are returned. Therefore, the temporal integration value of the first reflected echo intensity as the first reflected echo at the first measurement point (with no barnacle adhesion) and the second reflection at the second measurement point (with barnacle adhesion) By comparing the temporally integrated value of the intensity of the second reflected echo as an echo, the difference between the first reflected echo and the second reflected echo is clarified by using the easily measured reflected echo intensity, It is easy to detect the presence or absence of the attached matter.
FIG. 5 is a diagram showing the integrated value (cumulative value) of the reflected echo, where the vertical axis represents voltage [mV] and the horizontal axis represents time [nsec]. In FIG. 5, the broken line indicates the measurement result at the first measurement point (without barnacle adhesion), and the solid line indicates the measurement result at the second measurement point (with barnacle adhesion).
FIG. 6 is a diagram showing the integral value [μV · s] of the reflected echo at the time when the deviation between the first reflected echo and the second reflected echo becomes substantially constant. In FIG. 6, the data on the left side shows the measurement results at the first measurement point (without barnacle adhesion), and the data on the right side shows the measurement results at the second measurement point (with barnacle adhesion).
5 and 6 that the integrated value of the reflected echo intensity is larger at the second measurement point (with barnacles attached) than at the first measurement point (without barnacles adhesion).
FIG. 5 shows a temporal transition of the integrated value (cumulative value) of the reflected echo, and FIG. 6 shows the difference of the cumulative value at a certain time in FIG. 5 as an integral value. By seeing the difference, the presence or absence of the adhesion can be determined. The determination of the adhesion based on the integral value is made not only based on the difference between the integral values, but also before the accumulated value (integral value) or the difference becomes substantially constant, for example, the two curves of FIG. Judgment can also be made from the transition of the difference (slope, differentiation, etc.). At this time, the comparison can be made using visual observation, pattern recognition, image processing, artificial intelligence (AI), and the like.

FIG. 7 is a diagram showing the power spectrum of the reflected echo. The vertical axis represents the power spectrum, and the horizontal axis represents the frequency [MHz].
The data in FIG. 7 is obtained by frequency-converting the data in FIG. 3 by Fourier transform. In FIG. 7, the measurement result at the first measurement point (without barnacle adhesion) is indicated by a broken line, and the measurement result at the second measurement point (with barnacle adhesion) is indicated by a solid line.
From FIG. 7, it can be seen that there is a significant difference in the degree of change between the frequency bands of both power spectra.
As described above, the degree of change in the frequency band of the power spectrum is different between the case where the attached matter is attached and the case where the attached matter is not attached, so that the first power spectrum is measured as the first reflected echo, By measuring the second power spectrum as the second reflection echo and using the change in the dominant frequency band of both power spectra for comparison, the change in the frequency band of the power spectrum reflecting the adhesion state is used. The difference between the first reflected echo and the second reflected echo becomes clear, and it becomes easy to detect the presence or absence of the attached matter.
The comparison of changes in the dominant frequency band can be made by using visual observation, pattern recognition, image processing, artificial intelligence (AI), and the like.
The first power spectrum and the second power spectrum can be integrated and compared.

According to the above experiment, a difference occurs in the integrated value or the power spectrum of the reflected echo between the case where the barnacle is attached and the case where the barnacle is not attached. Therefore, the integrated value or the power spectrum of the first reflected echo and the second reflected echo are different. By comparing at least one of them, it can be understood that the attached state of the attached matter such as the presence or absence of the attached matter can be detected.
Therefore, as described with reference to FIG. 1, the ultrasonic wave is made incident on the structure 1 at the first time, the first reflected echo is measured, and the ultrasonic wave is made incident on at least the structure 1 at the second time. By measuring the second reflected echo and comparing the integrated value or power spectrum of the first reflected echo and the second reflected echo to detect the state of attachment of the attached matter to the structure 1, the structure of the structure 1 is detected. The attached state of the attached matter on one surface 1A can be detected, for example, from the other surface 1B side, which is in an integrated relationship with one surface 1A. Thus, for example, the presence or absence of extraneous matter on the outer surface of the hull can be detected even from the inside of the hull, so that it is possible to timely monitor the state of adhesion of extraneous matter to the outer surface of the hull, whether at anchor or while navigating. This makes it possible to perform efficient maintenance management of the hull. In addition, in a ship having a long berthing interval, the detection result of the adhesion state can be used for determining whether or not it is necessary to advance the docking time. In the future, it is expected that the status of biofouling on the hull when entering a port of an ocean going vessel will be stricter from the viewpoint of biological transboundary issues, and it is expected to be used as a countermeasure. Note that the integrated value of the reflected echo and the power spectrum can be combined to detect the attached state of the attached matter.

In addition, in a state where no deposit is attached to the structure 1 such as at the time of new shipbuilding or maintenance, the first reflected echo at the first time is measured in advance for each structure 1 and recorded in the recording means 22. It is preferable to keep it.
By recording the first reflected echo as a reference for comparison in advance, it is not necessary to measure the first reflected echo every time measurement is performed, so that the time required for measurement can be reduced. For example, if the first time is a start time with no attached matter and the second time is an elapsed time with the attached matter, at the elapsed time, the attached matter is peeled off and the first reflected echo is measured. You don't have to. In addition, by making the comparison standard constant, the detection accuracy of the adhesion state by the adhesion detection unit 21 is improved. Furthermore, by recording the reflected echo in the state where no attached matter is attached to the structure 1 as the first reflected echo, the data of the reflected echo in the state where there is no attached matter becomes clear, and the presence or absence of the attached matter is determined. Detection accuracy can be further improved.

Further, the relative positions and numbers of the ultrasonic wave incident means 11 and the reflected echo measuring means 12 may be changed according to the type of the structure 1 and the measurement range. Also in this case, the ultrasonic wave incident means 11 and the reflected echo measuring means 12 are arranged on only one side of the structure 1.
FIG. 8 is a diagram illustrating another arrangement example of the ultrasonic wave incidence unit and the reflection echo measurement unit. In FIG. 8, the left side is a bottom view in which the structure is omitted, and the right side is a side cross-sectional view.
FIG. 8A shows a case where the ultrasonic wave incident means 11 and the reflected echo measuring means 12 are accommodated in one housing, and the ultrasonic wave incident, the first reflected echo and the second reflected echo are carried out similarly to FIG. Is performed at the same location of the structure 1. With this arrangement, even if the time changes, it is possible to accurately detect the attached state of the attached matter at the same location. In FIG. 1, the ultrasonic wave incident means 11 also serves as the reflected echo measuring means 12, but in FIG. 8A, the ultrasonic wave incident means 11 and the reflected echo measuring means 12 are independent. .
In FIG. 8B, the ultrasonic wave incident means 11 and the reflected echo measuring means 12 are provided separately, and the ultrasonic wave incident and the reflected echo are measured at different places. With this arrangement, it is possible to detect the attached state of the attached matter over a wider range.
FIG. 8C shows that the ultrasonic wave incident means 11 is provided at a plurality of locations on the structure 1, the reflected echo measuring means 12 is provided at one location on the structure 1, and the ultrasonic wave is incident at a plurality of places, Is measured at one place. With this arrangement, it is possible to detect the attached state of the attached matter over a wider range.
The ultrasonic wave transmitted from the ultrasonic wave incident means 11 selects a longitudinal wave, a transverse wave, or a surface wave according to the arrangement of the ultrasonic wave incident means 11 and the reflected echo measuring means 12 and the measurement range.

The structure 1 is not limited to the hull described above.
The structure 1 can also be a grating installed on the shore of a power plant or a factory, or a piping facility, a piping facility, or a seawater intake for cooling.
Further, the structure 1 may be a facility or facility such as wind power generation, wave power generation, ocean current power generation, tidal current power generation, water current power generation, or drilling equipment for petroleum and minerals on or off the sea.
Further, the structure 1 may be a navigation sign, a buoy, an air / port facility, a barnacle culture facility, or the like.

  In addition, the incidence of the ultrasonic wave and the measurement of the reflected echo can be performed from the outside of the structure 1 to detect the attached state of the attached matter. For example, when the structure 1 is a hull, an ultrasonic wave is applied from the outside (attachment side) to the hull outer plate or the like using seawater, Alternatively, it is made incident through water, and its reflected echo is measured outside.

  According to the present invention, it is possible to detect the presence or absence of extraneous matter on the outer surface of the hull even from the inside of the hull, and therefore, it is possible to monitor the state of adhesion of extraneous matter to the outer surface of the hull irrespective of whether the ship is anchored or traveling It becomes possible in a timely manner, and efficient maintenance management of the outer surface of the hull can be performed. In addition, it can help to solve the problem of trans-border crossing by oceangoing vessels. Further, it is possible to detect the state of adhesion of various kinds of deposits to various structures.

DESCRIPTION OF SYMBOLS 1 Structure 11 Ultrasonic wave incidence means 12 Reflection echo measurement means 21 Adhesion detection means 22 Recording means 23 Notification means

Claims (20)

  A method for detecting a substance attached to a structure using ultrasonic waves, wherein the ultrasonic wave is incident on the structure at a first time to measure a first reflected echo, At a second time, the ultrasonic wave is made incident on at least the structure, a second reflected echo is measured, and an integrated value or a power spectrum of the first reflected echo and the second reflected echo is compared with each other. A method for detecting an attached matter by ultrasonic waves, comprising detecting an attached state of the attached matter to an object.   2. The method according to claim 1, wherein the first reflected echo at the first time is measured and recorded in advance, and the recorded first reflected echo is used for the comparison. Detection method.   A first reflected echo intensity is measured as the first reflected echo, and a second reflected echo intensity is measured as the second reflected echo. The first reflected echo intensity and the second reflected intensity are measured as the integrated value. 3. The method for detecting a deposit using ultrasonic waves according to claim 1, wherein a temporal integration value of the echo intensity is used.   A first power spectrum is measured as the first reflected echo, and a second power spectrum is measured as the second reflected echo, and the dominant frequency bands of the first power spectrum and the second power spectrum are measured. The method according to claim 1, wherein a change in the attached matter is used for the comparison.   The method according to any one of claims 1 to 4, wherein the structure is a hull, and the attached matter is a marine organism attached to the hull.   The method according to claim 5, wherein the ultrasonic wave is incident from the inside of the hull, and the first reflected echo or the second reflected echo is measured inside the hull. .   The incident of the ultrasonic wave and the measurement of the first reflected echo and the second reflected echo are performed at the same location on the structure. For detecting deposits by ultrasonic waves.   The method according to any one of claims 1 to 6, wherein the incidence of the ultrasonic wave and the measurement of the first reflected echo and the second reflected echo are performed at different locations on the structure. A method for detecting an attached matter by using the ultrasonic waves described in the above.   2. The apparatus according to claim 1, wherein the ultrasonic wave is incident at a plurality of locations on the structure, and the first reflected echo and the second reflected echo are measured on one location on the structure. 3. 7. The method for detecting an adhering matter by ultrasonic waves according to any one of items 6 to 6.   The method for detecting an attached matter by using an ultrasonic wave according to any one of claims 1 to 9, wherein the detected attachment state of the attached matter to the structure is notified.   An attachment detection system for detecting an attachment state of an attachment to a structure by using an ultrasonic wave, wherein an ultrasonic wave incidence unit that causes the ultrasonic wave to enter at least the structure, and at least a reflection from the structure. Reflection echo measuring means for measuring an echo, comparing the integrated value or power spectrum of the first reflection echo at the first time and the second reflection echo at the second time, and adhering the deposit to the structure An adhesion detection system using ultrasonic waves, comprising: an adhesion detection unit that detects a situation.   12. The apparatus according to claim 11, further comprising a recording unit for recording a result of previously measuring the first reflected echo at the first time and using the result for the comparison with the second reflected echo. Detection system by ultrasonic waves.   The reflected echo measuring means measures a first reflected echo intensity as a first reflected echo, and a second reflected echo intensity as the second reflected echo, and the adhesion detecting means measures the reflected echo as the integrated value. 13. The ultrasonic detecting system according to claim 11, wherein a temporal integration value of the first reflected echo intensity and the second reflected echo intensity is used for the comparison.   The reflection echo measurement means measures a first power spectrum as the first reflection echo, and a second power spectrum as the second reflection echo, and the adhesion detection means measures the first power spectrum. 13. The system for detecting an attached matter by ultrasonic waves according to claim 11, wherein a change in a dominant frequency band of the second power spectrum and a change of the second power spectrum are used for the comparison.   The said attached matter is a marine life which attaches to the said hull, and the said attached matter is a marine life, The detection system of the attached matter by the ultrasonic wave of any one of Claims 11 to 14 characterized by the above-mentioned.   The supersonic wave according to claim 15, wherein the ultrasonic wave incident means makes the ultrasonic waves enter the hull from inside the hull, and the reflected echo measuring means measures the reflected echo inside the hull. A system for detecting deposits using sound waves.   17. The apparatus according to claim 11, wherein the incidence of the ultrasonic wave and the measurement of the first reflected echo and the second reflected echo are performed at the same location of the structure. Detection system by ultrasonic waves.   12. The apparatus according to claim 11, wherein the ultrasonic wave incident means and the reflected echo measuring means are provided at different places of the structure, and the incidence of the ultrasonic wave and the measurement of the reflected echo are performed at different places. Item 17. A system for detecting an attached matter using ultrasonic waves according to any one of Items 16.   The ultrasonic wave incident means is provided at a plurality of places on the structure, the ultrasonic waves are made incident at a plurality of places, the reflected echo measuring means is provided at one place of the structure, and the measurement of the reflected echo is performed at one place. 17. The ultrasonic detection system according to any one of claims 11 to 16, wherein:   20. An attachment according to any one of claims 11 to 19, further comprising a notifying means for notifying the adhesion state of the attached matter to the structure detected by the attachment detecting means. Kimono detection system.