KR101048563B1 - Harmonic Detection System of Tone Burst Ultrasound - Google Patents

Abstract

Disclosed is a harmonic detection system of tone burst ultrasonic waves in which one signal is divided into two signals to remove fundamental waves and detect only harmonic components. Since the harmonic detection system as described above can measure harmonics in real time using a single signal, time for measuring harmonics can be saved, and harmonics can be measured without using a separate post-processing method.

Tone Burst Ultrasound, Harmonics, Distribution, Time Delay

Description

Harmonic detection system of tone burst ultrasonic wave {EXTRACTING SYSTEM FOR HARMONIC WAVE OF TONE BURST WAVE}

The present invention relates to a harmonic detection system, and more particularly, to divide one signal into two signals, delay the time of one of the distributed signals, and add the other signals that do not delay the time to remove fundamental waves and detect only harmonics. It relates to a harmonic detection system of tone burst ultrasound.

Mechanical structures need to be inspected during use because, as time passes, they can be damaged by physical and chemical damage, deterioration and corrosion. In order to minimize the damage of the mechanical structure, the inspection is generally performed by ultrasonic, X-ray, eddy current, or the like.

Among these, defects such as internal cracks are detected using ultrasonic waves to detect signals reflected from the defects, and measure the position and size of the defects.In the case of material degradation and fatigue, the propagation velocity, which is a linear characteristic of ultrasonic waves, The damping degree has been evaluated by measuring the change in the scattering coefficient.

Recently, the nonlinear acoustic effect of ultrasonic waves is used as a technique that uses harmonics other than the fundamental frequency components generated when sound waves propagate along a medium. It is sensitive and sensitive to microcracks, material degradation and fatigue, and is used as a method of diagnosing the integrity of structures.

In order to output the harmonics, the fundamental frequency and the harmonic components must be measured, and each component is measured using a signal processing technique or a frequency analysis device that stores the received signal and compares the frequency spectrum to measure each component. Use processing techniques.

Alternatively, a method of extracting harmonics by transmitting ultrasonic waves having 180 degrees out of phase with each other and adding each received signal may be used. In this regard, referring to Japanese Laid-Open Patent Publication No. 2005-031462, there is disclosed an apparatus for extracting harmonics by transmitting ultrasonic waves having a phase difference of 180 degrees at regular time intervals and adding them with time differences.

As described above, the method of measuring harmonics using a post-processing technique increases processing time, which makes it difficult to measure the characteristics of an object in real time.

In addition, a method of measuring harmonics with a time difference requires generation of ultrasonic waves inverted from each other, and inconveniences in that a certain time is required because ultrasonic waves having different phases are transmitted with a time difference.

An embodiment of the present invention provides a harmonic detection system of tone burst ultrasonic waves capable of measuring harmonics in real time.

In addition, an embodiment of the present invention provides a harmonic detection system of tone burst ultrasonic waves capable of removing only the fundamental waves included in a signal using one signal and measuring harmonics.

In addition, an embodiment of the present invention provides a harmonic detection system of tone burst ultrasonic waves capable of measuring harmonics using less time.

In addition, an embodiment of the present invention provides a harmonic detection system of tone burst ultrasonic waves capable of measuring harmonics without performing separate post-processing.

According to an embodiment of the present invention, a harmonic detection system of tone burst ultrasonic waves includes an ultrasonic generator; An ultrasonic transmitter for transmitting ultrasonic waves received from the ultrasonic generator to an object to be inspected; An ultrasonic receiver for receiving ultrasonic waves transmitted from the ultrasonic transmitter; An ultrasonic distributor distributing the ultrasonic waves received by the ultrasonic receiver into a first signal and a second signal; A time delay unit configured to receive one of the first signal and the second signal and delay the signal; An adder configured to add a signal passing through the time delay unit and a signal not passing through the time delay unit; And a measuring unit measuring the signal summed by the adding unit.

Since the harmonic detection system of the tone burst ultrasonic waves can measure harmonics in real time using a single signal, it can reduce the time for measuring harmonics and measure harmonics without using a separate post-processing method. can do.

The ultrasonic distribution unit may include a first transmission circuit which transmits one of a first signal and a second signal to the time delay unit; And a second transmitting circuit for transmitting a signal not transmitted to the time delay unit to the adding unit.

The time delay unit may include a time controller for controlling a delay time of the received signal. The first transmitting circuit or the second transmitting circuit controls one signal of the first signal or the second signal to pass through the time controller.

The time delay unit may remove the fundamental wave of any one of the first signal and the second signal transmitted to the time delay unit. The signal from which the fundamental wave is removed remains only harmonics, and the harmonics can measure the subject.

일 때

, 또는

시간으로 지연할 수 있다. 상기와 같이 주파수를 지연시키게 되면 고조파가 증폭되어 출력될 수 있다. On the other hand, the time controller has a frequency of the fundamental wave

when

, or

You can delay with time. When the frequency is delayed as described above, harmonics can be amplified and output.

The adder may add a delayed signal from a first signal or a second signal and a non-time delayed signal to remove the fundamental wave from the components of the ultrasonic wave and output a harmonic.

On the other hand, the harmonic detection system may further include a filter unit for removing the fundamental wave remaining in the ultrasonic wave summated the first signal and the second signal. The filter unit removes the fundamental wave remaining in the first signal or the second signal passing through the adder so as to output only a signal having only harmonic components.

The measurement unit may compare the amplitude of the original signal that does not pass through the ultrasonic distributor and the signal from which the fundamental wave is removed through the adder, and may measure the nonlinear parameter in real time through the amplitude. That is, the measurement unit may measure only the harmonics by comparing the amplitudes of the original signal that transmits both the fundamental wave and the harmonics that do not pass through the ultrasonic distributor and the signal from which the fundamental wave is removed.

The harmonic detection system of the tone burst ultrasonic wave according to an embodiment of the present invention can measure the harmonics by distributing one signal into two signals and removing the fundamental waves included in the original signal by adding the divided two signals. Harmonics can be detected without additional post-processing.

In addition, the harmonic detection system of the tone burst ultrasonic wave according to an embodiment of the present invention can detect the harmonics in real time, thereby reducing the time and manpower for detecting harmonics.

In addition, since the harmonic detection system of the tone burst ultrasonic wave according to an embodiment of the present invention can detect harmonics using one frequency, harmonics can be easily detected.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited or limited by the embodiments. Like reference numerals in the drawings denote like elements.

1 is a block diagram schematically showing the configuration of a harmonic detection system of tone burst ultrasonic waves according to an embodiment of the present invention, Figures 2 and 3 are graphs showing the results measured in the measuring unit of FIG. 4 is a graph illustrating fundamental and harmonics, and FIG. 5 is a graph illustrating amplification of harmonics of FIG. 4.

First, referring to FIG. 1, the harmonic detection system 100 of the tone burst ultrasonic wave according to an embodiment of the present invention includes an ultrasonic wave received from the ultrasonic wave generator 110 and the ultrasonic wave generator 110 capable of generating ultrasonic waves. Ultrasonic transmitter 130 for transmitting to the object to be inspected 10, the ultrasonic receiver 140 for receiving the ultrasonic wave transmitted from the ultrasonic transmitter 130, the ultrasonic wave received from the ultrasonic receiver 140, the first signal 162 and The ultrasonic distribution unit 160, which distributes the second signal 164, the time delay unit 170 and the time delay unit 170 for delaying the time by receiving any one of the first signal or the second signal It may include an adder 180 that adds a signal that has passed and a signal that does not pass through the time delay unit 170, and a measurement unit 190 that measures the signal 165 that is added by the adder 180.

The ultrasonic wave generated by the ultrasonic wave generator 110 may generate general ultrasonic waves including fundamental waves and harmonics. In particular, in the ultrasonic wave generator 110 according to an embodiment of the present invention, tone-burst ultrasonic waves may be generated. May occur. Tone-burst ultrasound may have a single frequency and may have several signal waveforms for narrowband (narrow band) ultrasound signals. In addition, the ultrasonic transmitter 130 may be generated to a size of several hundred volts so that the ultrasonic waves of high sound pressure can be generated. In order to generate the tone-burst ultrasound as described above, the ultrasound generator 110 may be connected to the main computer 20 so as to control the frequency, the magnitude of the signal, and the number of signals.

The generated ultrasonic waves may be transmitted to the ultrasonic transmitter 130 and transmitted to the inspected object 10, and the ultrasonic waves may penetrate the inspected object 10 by the ultrasonic transmitter 130. The ultrasonic transmitter 130 may receive a high voltage signal and vibrate the vibrator by the reverse piezoelectric phenomenon, and thus ultrasonic waves may be transmitted to the object 10 to be measured.

That is, the ultrasonic transmitter 130 may inject the ultrasonic wave transmitted from the ultrasonic generator 110 into the inspected object 10, and for example, a piezoelectric transducer, an EMAT, a laser ultrasonic wave, or the like may be provided. .

The ultrasonic wave transmitted through the inspected object 10 may be received by the ultrasonic receiver 140. The ultrasonic transmitter 130 and the ultrasonic receiver 140 may be provided at a position adjacent to the inspected object 10. For example, the ultrasonic transmitter 130 and the ultrasonic receiver 140 may be provided based on the inspected object 10. Is provided at a corresponding position can easily transmit and receive the ultrasonic wave passing through the inspected object (10).

The ultrasonic waves received by the ultrasonic receiver 140 may pass through the ultrasonic expansion unit 150 capable of receiving and amplifying a signal. The ultrasonic wave amplifies the ultrasonic wave received in the process of passing through the ultrasonic expansion unit 150 to easily measure the ultrasonic wave required for the operation.

A portion of the ultrasonic waves amplified by the ultrasonic expansion unit 150 may be received by the ultrasonic distributor 160, and the ultrasonic distributor 160 may distribute ultrasonic waves to the first signal 162 and the second signal 164. It may include a first transmitting circuit and a second transmitting circuit so as to.

The first transmitting circuit may transmit the first signal 162 to the time delay unit 170, and the second transmitting circuit may transmit the second signal 164 to the adder 180, which will be described later. Hereinafter, the ultrasonic distribution unit 160 according to an embodiment of the present invention receives the first signal 162 as the time delay unit 170, and the second signal 164 does not pass through the time delay unit 170. Although described with an example, the signal received by the time delay unit 170 may be changed according to a condition.

The time delay unit 170 may be connected to the main computer 20 that determines the delay time of the signal, and receives the information of the main computer 20 to control the delay time of the first signal 162. ) May be included.

일 때, 기본파에 의해 발생되는 고조파의 주파수

는 기본 주파의 2배에 해당한다. 시간 지연부(170)는 기본 주파수에 대하여 그 두 배에 해당하는 시간

또는

으로 지연 시킬 수 있으며, 지연되는 시간에 따라 제1신호(162)의 기본파가 제거될 수 있다. 이 때, 시간 제어부(175)는 제1신호(162)를 다음과 같은 식(1) 및 식(2)에 의해 지연시킬 수 있다. The time delay unit 170 has a fundamental frequency of the first signal 162.

When is the frequency of harmonics generated by fundamental waves

Is twice the fundamental frequency. The time delay unit 170 is a time corresponding to twice that of the fundamental frequency

or

It can be delayed, and the fundamental wave of the first signal 162 can be removed according to the delay time. At this time, the time controller 175 may delay the first signal 162 by the following equations (1) and (2).

(식 1)

(Equation 1)

(식 2)

(Equation 2)

For example, referring to FIGS. 2 and 3, the solid line of FIG. 2 represents a fundamental wave, and the dotted line represents a delayed wave having twice the fundamental wave frequency. Since the delayed wave delayed by the fundamental wave can be canceled by the inverse phase difference, the fundamental wave can be eliminated, and the remaining frequency from which the fundamental wave is removed remains at the beginning and end of the signal, and its magnitude can be about one. have.

As described above, the first signal 162 whose time is delayed by the time controller 175 through the time delay unit 170 and the second signal 164 that does not pass through the time delay unit 170 in the adder 180 are different from each other. Can be summed.

The adder 180 may detect a signal 165 obtained by summing the first signal 162 and the second signal 164 by the following equation (3).

(식 3)

(Equation 3)

As shown in Equation (3), the output signal output through the adder 180 may remove fundamental wave components, and may output about 2 times harmonics.

As shown in FIG. 4 and FIG. 5, when the frequency of 5 MHz corresponding to the fundamental wave and the frequency of 10 MHz corresponding to the harmonic are received by the ultrasonic distributor 160, the fundamental wave is removed and only the harmonic component remains. At this time, although the magnitude of the remaining harmonics is very small, about 0.007, when the pass through the adder 180, the harmonics increased by about 2 times may be output. That is, as shown in FIG. 5, the magnitude of the harmonics is about 0.013, which is about 2 times greater than the magnitude of the harmonics before passing through the adder 180.

As such, the fundamental wave of the circuit received by the adder 180 is removed and only the harmonic component remains, so that harmonic component detection can be facilitated.

Meanwhile, the harmonic output system 100 may include a filter unit 30 passing only harmonic components in order to output a clear signal. In this case, since the fundamental wave component is removed or reduced, only the harmonic component may be extracted by the filter unit 30. The filter unit 30 is a filter capable of passing only harmonic components, and may remove fundamental wave components remaining in the signal weakly, and may remove other noise components. The filter unit 30 may be, for example, a filter capable of passing only a specific frequency such as a high pass filter (HPF), a band pass filter (BPF), and the like, and the filter unit 30. The present invention is not limited or limited by the type of).

Harmonic components remain in the signal passing through the filter unit 30, but in some cases, the signal may be very weak and difficult to measure. In this case, the signal passing through the filter unit 30 passes through the amplifier 40 to amplify harmonic components.

The amplifier 40 may amplify the harmonics so that the operator can easily observe the signal, and the signal passed through the amplifier 40 may be measured in real time by the measuring unit 190.

Meanwhile, in the harmonic detection system 100, an original signal 155, which is a signal not received by the ultrasonic distribution unit 160, may remain, and the original signal 155 may be received by the measurement unit 190 in real time. . The measuring unit 190 may measure the nonlinear parameter in real time by comparing the amplification of the signal in which the fundamental wave is removed and only the harmonics are left through the original signal 155 and the ultrasonic distributor 160.

The harmonic detection system 100 can detect harmonics using a single signal, and by measuring the detected harmonics in real time, a time for detecting harmonics can be shortened. In addition, since harmonics can be measured in real time without additional post-processing, harmonics detection can be facilitated. Furthermore, a detection system using a single signal can detect harmonics even with a small amount of memory. Harmonic components can be measured.

6 is a block diagram showing the configuration of a harmonic detection system of tone burst ultrasonic waves according to a modification of the present invention.

Prior to describing the modifications according to the present invention, the same or equivalent components as those described above are denoted by the same or equivalent components, and detailed description thereof will be omitted.

Referring to FIG. 6, the harmonic detection system 200 of the tone burst ultrasound may generate ultrasonic waves from the ultrasonic generator 110. The generated ultrasound may be transmitted to the ultrasound transmitter 230, and the transmitted ultrasound may be received by the ultrasound receiver 240.

In this case, the ultrasound receiver 240 may receive the reflector reflecting the object 10 without receiving the ultrasound transmitted through the object 10. Therefore, the ultrasonic transmitter 230 and the ultrasonic receiver 240 may be provided at the same surface or in close proximity to the object 10.

The received ultrasound may be received by the ultrasound receiver 150, and the ultrasound receiver may receive and amplify the minute voltage generated by the ultrasound receiver.

The amplified ultrasound wave may be distributed as the first signal 162 and the second signal 164 by the ultrasonic distributor 160, and the first signal 162 may be received by the time delay unit 170 and the second signal ( 164 may be received by the adder 160.

의 시간이 지연될 수 있지만 경우에 따라서는

의 시간이 지연될 수도 있다. The first signal 162 received by the time delay unit 170 may be delayed by about two times the fundamental wave, thereby eliminating the fundamental wave due to an inverse phase difference, and generally corresponding to twice the fundamental wave.

May be delayed, but in some cases

May be delayed.

The first signal 162 delayed by the time delay unit 170 may be added to the second signal 164 by the adder 160, and the adder 160 removes the fundamental wave from the summed signal 165. And harmonic content can remain.

Harmonics may be measured by the measuring unit 190 based on the filter unit 30 and the amplifying unit 40 in some cases. In the measuring unit 190, the original signal 155 not received by the ultrasonic distributor 160 may be used. By amplifying the signal and amplifying only the harmonics remaining signal 165 can be measured in real time non-linear parameters.

The harmonic detection system 200 divides one signal into two signals so that one signal may be delayed by a specific time and combined with another signal that is not delayed to detect harmonics in real time.

Although the preferred embodiments of the present invention have been described above by way of example, the scope of the present invention is not limited to these specific embodiments, and may be appropriately changed within the scope described in the claims.

1 is a block diagram schematically showing the configuration of a harmonic detection system of tone burst ultrasonic waves according to an embodiment of the present invention.

2 and 3 are graphs showing the results measured by the measuring unit of FIG. 1.

4 is a graph illustrating fundamental and harmonics, and FIG. 5 is a graph illustrating amplification of harmonics of FIG. 4.

6 is a block diagram showing the configuration of a harmonic detection system of tone burst ultrasonic waves according to a modification of the present invention.

<Explanation of symbols for the main parts of the drawings>

100: harmonic detection system of the tone burst ultrasonic 130: ultrasonic transmitter

140: ultrasonic receiver 160: ultrasonic distributor

162: second signal 164: second signal

170: time delay unit 180: adder unit

Claims (8)

An ultrasonic generator; An ultrasonic transmitter for transmitting ultrasonic waves received from the ultrasonic generator to an object to be inspected; An ultrasonic receiver for receiving ultrasonic waves transmitted from the ultrasonic transmitter; An ultrasonic distributor distributing the ultrasonic waves received by the ultrasonic receiver into a first signal and a second signal; A time delay unit configured to receive one of the first signal and the second signal and delay the signal; An adder configured to add a signal passing through the time delay unit and a signal not passing through the time delay unit; And A measuring unit measuring a signal summed by the adding unit; Including; And the measuring unit measures a non-linear parameter in real time based on an amplitude of an original signal not passing through the ultrasonic distribution unit and a signal from which the fundamental wave is removed through the adding unit, in real time. The method of claim 1, The ultrasonic distribution unit, A first transmitting circuit which sends one of the first and second signals to the time delay unit; And a second transmission circuit for sending a signal not transmitted to the time delay unit to the adder. The method of claim 2, The time delay unit includes a time control unit for controlling the delay time of the received signal, harmonic detection system of the tone burst ultrasound. The method of claim 2, And the time delay unit removes a fundamental wave of any one of the first signal and the second signal transmitted to the time delay unit. The method of claim 4, wherein The time control unit has a frequency of the fundamental wave

when

, or

Harmonic detection system of tone burst ultrasonic waves, delayed by time. 6. The method according to any one of claims 1 to 5, And the adder adds the delayed signal among the first signal or the second signal and the non-time delayed signal to remove the fundamental wave from the components of the ultrasonic wave and output harmonics. The method of claim 6, The harmonic detection system according to claim 1, wherein the harmonic detection system includes a filter unit for removing fundamental waves remaining in the ultrasonic wave obtained by adding the first signal and the second signal. delete

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