KR102267862B1 - Examining apparatus and examinig method thereof - Google Patents

Abstract

The inspection device includes a laser irradiation unit that irradiates a laser to a target point of the subject or a measurement point separated by a preset distance from the target point, and when the laser is irradiated to the target point, generates forward measurement data at the measurement point, and and a measurement unit that generates backward measurement data at a target point when the laser is irradiated, and a signal processing unit that determines a defect in the subject based on autocorrelation and cross-correlation between the forward measurement data and the backward measurement data.

Description

Inspection device and its control method {EXAMINING APPARATUS AND EXAMINIG METHOD THEREOF}

The present invention relates to an inspection apparatus for inspecting a defect in a subject, and an inspection method of the inspection apparatus.

Inspection devices that detect defects in an object such as parts generally use a two-dimensional image of the object acquired by a vision camera to detect surface damage of the object, or heat generated in the object using a thermal imaging system. Or infrared was detected.

In addition, the inspection apparatus may use a radiation system to detect X-rays transmitted by a subject or use an ultrasound system to detect the amount of energy or duration of ultrasonic waves reflected from the subject using various methods, such as the surface or Internal faults could also be detected.

In addition, the inspection device irradiates a laser to the subject, and when the irradiated laser is reflected from the subject or an ultrasonic wave is generated on the subject by the irradiated laser, the reflected laser or ultrasonic wave is received or measured to detect defects in the subject. can also be detected.

An object of the present invention is to provide an inspection apparatus for detecting a surface or internal defect of an object using a laser, and an inspection method of the inspection apparatus.

Inspection apparatus according to one aspect is a laser irradiator that irradiates a laser to a target point of an object or a measurement point separated by a preset distance from the target point, when the laser is irradiated to the target point, generating forward measurement data at the measurement point, , a measurement unit that generates reverse measurement data at the target point when a laser is irradiated to the measurement point, and a signal processing unit that determines a defect in the subject based on the autocorrelation and cross-correlation of the forward measurement data and the reverse measurement data includes

The signal processing unit may determine the defect of the subject based on a difference between any two correlation degrees of the autocorrelation degree of the forward measurement data, the autocorrelation degree of the backward measurement data, and the cross-correlation degree of the forward measurement data and the backward measurement data. .

The signal processing unit, a correlation calculation unit for determining the auto-correlation and cross-correlation of the forward measurement data and the backward measurement data, a damage index calculation unit for determining the damage index based on the auto-correlation and cross-correlation, and the damage index It may include a damage determination unit for determining the defect of the subject based on the.

The damage determination unit may determine the defect of the subject by comparing the damage index with a preset reference value.

The damage index calculator may determine the damage index based on the degree to which any two of the autocorrelation of the forward measurement data, the autocorrelation of the backward measurement data, and the cross correlation between the forward measurement data and the backward measurement data are different. .

When the laser is irradiated to the target point, the measuring unit detects the ultrasonic wave at the measuring point to generate forward measurement data, and when the laser is irradiated to the measuring point, the measuring unit detects the ultrasonic wave at the target point to generate reverse measurement data.

The inspection apparatus may further include an output unit for outputting the determination result of the signal processing unit as an image or sound to the user.

The inspection apparatus further includes a storage unit storing reverse measurement data for a normal subject, wherein the measurement unit generates forward measurement data of the inspected object to be inspected, and the signal processing unit performs forward measurement data and normal direction measurement data of the inspected object to be inspected Defects in the inspected object may be determined based on the degree of autocorrelation and cross-correlation of the backward measurement data with respect to the object.

The laser irradiation unit irradiates a laser to a target point of the inspected object to be inspected, and irradiates a laser to a measurement point of the normal inspected object, and the measurement unit generates forward measurement data of the inspected object to be inspected, and Reverse measurement data can be generated.

The laser irradiation unit may irradiate a laser to the subject in a non-contact manner, and the measurement unit may detect the ultrasonic wave of the subject in a non-contact manner.

An inspection method of an inspection apparatus according to another aspect includes irradiating a laser to a target point of an object, generating forward measurement data at a measurement point separated by a preset distance from the target point, irradiating the laser to the measurement point, and the target generating backward measurement data at the point, and determining a defect in the subject based on autocorrelation and cross-correlation between the forward measurement data and the backward measurement data.

Determining the defect may include determining the defect of the subject based on a difference between any two correlations among the autocorrelation of the forward measurement data, the autocorrelation of the backward measurement data, and the cross-correlation of the forward measurement data and the backward measurement data. can do.

Determining the defect may include determining the autocorrelation and cross-correlation of the forward measurement data and the backward measurement data, determining a damage index based on the autocorrelation and cross-correlation, and based on the damage index It may include determining a defect in the subject.

The step of determining the defect of the subject based on the damage index may determine the defect of the subject by comparing the damage index with a preset reference value.

The step of determining the damage index may include determining the damage index based on the degree to which any two of the autocorrelation degree of the forward measurement data, the autocorrelation degree of the reverse measurement data, and the cross-correlation degree of the forward measurement data and the reverse measurement data are different. can do.

The generating of the forward measurement data may generate forward measurement data by detecting ultrasonic waves at a measurement point, and the generating of the reverse measurement data may include detecting ultrasonic waves at a target point to generate reverse measurement data.

The inspection method of the inspection apparatus may further include outputting the determination result of the step of determining the defect of the subject as an image or sound to the user.

In the determining of the defect, the defect of the subject may be determined based on the autocorrelation and cross-correlation of the forward measurement data generated in the generating of the forward measurement data and the reverse measurement data previously stored in the inspection apparatus.

The step of generating forward measurement data includes irradiating a laser to a target point of an object to be inspected, generating forward data at a measurement point separated by a preset distance from the target point, and generating reverse measurement data is normal. The step of irradiating a laser to the measurement point of the subject, generating reverse data at the target point, and judging the defect includes the autocorrelation between the forward measurement data of the inspected object and the reverse measurement data of the normal inspected object and The defect of the subject may be determined based on the degree of cross-correlation.

The inspection method of the inspection apparatus may further include, before the step of determining the defect of the inspected object, the step of storing reverse measurement data of the normal inspected object.

According to the inspection apparatus and the inspection method according to an embodiment, by using a laser, it is possible to precisely detect a surface or internal defect of a subject without contacting the subject, and by using the autocorrelation and cross-correlation of the detection data, Defect detection is possible even for small defects.

According to the inspection apparatus and the inspection method according to an exemplary embodiment, not only a linear defect but also a non-linear defect of an object may be detected by using the auto-correlation and cross-correlation of detected data.

1 is a control block diagram of an inspection apparatus according to an exemplary embodiment.
2 is an external view of an inspection apparatus according to an exemplary embodiment.
3 and 4 are diagrams for explaining a movement path of an ultrasonic wave at a target point irradiated with a laser in a forward direction.
5 is a view for explaining a movement path of an ultrasonic wave at a target point irradiated with a laser in a reverse direction.
6 is a flowchart of an inspection method of an inspection apparatus according to an exemplary embodiment.
7 is a detailed control block diagram of an inspection apparatus according to an exemplary embodiment.
8 is a flowchart of an inspection method of an inspection apparatus according to another exemplary embodiment.
9 is a detailed control block diagram of an inspection apparatus according to another exemplary embodiment.

The objects, specific advantages and novel features of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings and preferred embodiments. In the present specification, in adding reference numbers to the components of each drawing, it should be noted that only the same components are given the same number as possible even though they are indicated on different drawings. In addition, in describing the present invention, if it is determined that a detailed description of a related known technology may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

Terms such as first, second, etc. are used to distinguish one component from another, and the component is not limited by the terms.

Hereinafter, an embodiment of the inspection apparatus will be described with reference to FIG. 1 . 1 is a control block diagram of an inspection apparatus according to an exemplary embodiment.

The inspection apparatus 100 includes a laser irradiator 110 that irradiates a pulse laser to the surface or inside of the subject 10 , a measurement unit 130 that measures ultrasonic waves generated in the subject 10 by the irradiated laser, and a measurement unit 130 . ) includes a signal processing unit 140 that analyzes the ultrasound data generated to determine a defect in the subject, and an output unit 150 that outputs the result determined by the signal processing unit 140 .

The subject 10 may be, for example, a component of an electronic device. Also, the subject 10 may be made of a material such as plastic that can transmit [absorb and reflect] a laser. In addition, various materials capable of transmitting [absorption and reflection] of the laser may be an example of the subject 10 .

The laser irradiation unit 110 includes a light source 111 for generating and irradiating a laser and a laser direction adjusting unit 112 for changing the irradiation direction of the laser irradiated by the light source 111 so that the laser is irradiated to the target point.

The laser irradiated from the light source 111 may be a visible light laser, an infrared laser, for example, an Nd:YAG laser, or an ultraviolet laser.

The light source 111 may adjust the output level of the laser irradiated per unit area of the subject.

According to an exemplary embodiment, when a pulse laser is irradiated to a target point of the object 10 by the laser irradiation unit 110, thermal expansion occurs at the target point and a thermoelastic wave is generated. These thermoelastic waves generate ultrasonic waves having a pulse waveform.

The measurement unit 130 may measure the ultrasound generated by laser irradiation at another point separated by a preset distance from the target point, generate ultrasound data as a result of the measurement, and store or output the generated ultrasound data. In this case, the measurement unit 130 may measure ultrasonic waves in a non-contact manner.

The signal processing unit 140 determines whether a defect exists in the subject 10 based on the ultrasound data generated by the measurement unit 130 .

According to an embodiment, the signal processing unit 140 may be implemented by a processor and a memory embedded in the test apparatus 100 . The processor and the memory may be implemented using various semiconductor chips and the like. According to another embodiment, the signal processing unit 140 may be implemented by a separate workstation 160 (refer to FIG. 2 ) capable of transmitting and receiving data between the test apparatus 100 and a wired communication network or a wireless communication network. .

A detailed method of determining the defect of the signal processing unit 140 will be described later.

The output unit 150 outputs the determination result of the signal processing unit 140 through various images or sounds. For example, the output unit 150 outputs the presence or absence of a defect or the degree of damage of the subject 10 to the user.

The output unit 150 may be an image display device, such as a television or monitor, or a sound output device, such as a speaker, according to an embodiment. Also, the output unit 150 may be an image forming apparatus such as a printer capable of printing characters or pictures.

According to another embodiment, the output unit 150 may be implemented by a separate workstation 160 (refer to FIG. 2 ) capable of transmitting and receiving data to and from the test apparatus 100 through a wired communication network or a wireless communication network.

Hereinafter, an inspection apparatus 100 for detecting a surface or internal defect of the subject 10 as an embodiment of the inspection apparatus 100 will be described with reference to FIG. 2 . 2 is an external view of an inspection apparatus according to an exemplary embodiment.

Referring to FIG. 2 , the inspection apparatus 100 is disposed on the subject, for example, the part 10, and a laser irradiation unit 110 that irradiates a pulse laser to a target point on the surface or inside of the part 10, the target The measurement unit 130 may include a measurement unit 130 that measures ultrasonic waves at a measurement point separated by a preset distance from the point.

The laser irradiation unit 110 may irradiate a pulse laser so that the pulse laser is absorbed to a target point on the surface or inside of the component 10 .

The laser irradiator 110 may be disposed on the upper part of the part 10 to irradiate the laser in a direction perpendicular to the surface of the part 10 as shown in FIG. 2 .

The laser irradiation unit 110 may have a small width as shown in FIG. 2 , but may have a wide width to irradiate light to the entire upper portion of the component 10 according to the needs of a system designer or user.

The measuring unit 130 , for example, a laser vibrometer measures the displacement of a target point on the surface or inside of the part 10 by using the Doppler effect. The Doppler effect is an effect that occurs when one or more of the wave source and the observer observing the wave are in motion. As the distance between the wave source and the observer decreases, the frequency of the wave becomes higher, and as the distance increases, the frequency of the wave becomes higher. The lower frequency of the wave is observed.

Therefore, when the pulse laser is irradiated to the target point on the surface or inside of the part 10, ultrasonic waves are generated by the vibration of the target point on the surface or inside of the part 10, and displacement measurement is performed at the measurement point separated by a preset distance. ultrasound can be measured.

Two galvano mirrors are installed in the laser vibrating system, enabling two-dimensional scanning.

In addition to the laser vibrometer, a laser interferometer capable of measuring ultrasonic waves in a non-contact manner may be used for the measurement unit 20 .

The inspection apparatus 100 may further include predetermined frames 5 to 7 . Predetermined frames 5 to 7 are arranged opposite to the first frame 5 , the second frame 6 connected to the first frame 5 , and the second frame 6 connected to the first frame 5 . and a third frame 7 which is

The component 10 can move between the first frame 5 and the third frame 7 . A laser irradiation unit 110 and a measurement unit 130 may be installed in the frames 5 to 7 . The laser irradiation unit 110 may be installed in the second frame 6 provided on the upper part of the part 10 in order to irradiate a pulse laser from the upper part of the part 10 to the target point on the surface or inside the part 10 . .

Similarly, the measurement unit 130 may be installed in the second frame 6 vertically connected to the first frame 5 so as to face the downward direction of the component 10 .

The laser irradiation unit 110 and the measurement unit 130 may move along the second frame 6 , respectively. In this case, the laser irradiation unit 110 and the measuring unit 130 may be further provided with wheels, such as a circular wheel or a cog wheel, which are rotated along the second frame 2 to move the measuring unit 130 , respectively. The laser irradiation unit 110 and the measurement unit 130 may be moved by actuators provided in the second frame 6 , respectively.

The inspection apparatus 100 may further include a transfer unit 4 for automatically transferring the component 10 in a predetermined direction d. Any device capable of moving a specific object, such as a conveyor belt, may be employed as the transfer unit 4 .

When the component 10 is conveyed according to the conveying unit 4 , it is possible to continuously and automatically inspect whether defects exist in the plurality of components 10 .

The inspection apparatus 100 may further include a workstation 160 capable of controlling each component of the inspection apparatus 100 and determining a defect or a degree of a defect of the part 10 or displaying the determination result. can

The workstation 160 determines a defect of the component 10 based on the ultrasound data generated by the measurement unit 130 , and includes a main body 163 including various components for controlling the operation of the workstation 160 , the component (10) including a display unit 161 capable of displaying the determination result for the defect, and an input unit 162 for the user to input various commands for controlling the operation of the inspection apparatus 100 or the workstation 160 can do.

The display unit 162 may be a display device such as a monitor employing a liquid crystal display (LCD), or a light emitting diode (LED) or an organic light emitting diode (OLED). It may be a single display device. Also, it may be a display device employing a plasma display panel (PDP). According to an embodiment, the display unit 161 may be a touch screen, and in this case, the display unit 161 may also perform the function of the input unit 162 .

The input unit 162 may include various devices such as a keyboard, a keypad, a touch pad, a touch screen, a trackball, or a mouse. The main body 163 may have a built-in semiconductor chip or circuit for performing a function of a processor or a function of a storage medium.

Various parts of the main body 163 may be used to control not only the operation of the workstation 160 but also the operation of the inspection apparatus 100 . According to an exemplary embodiment, operations such as image processing and image comparison for performing defect inspection of the component 10 in the semiconductor chip embedded in the main body 163 may be performed.

According to an embodiment, the signal processing unit 140 and the output unit 150 of the test apparatus 100 may be provided in the workstation 160 , and the output unit 150 may be implemented as the above-described display unit 161 . have.

Hereinafter, a principle of determining a defect by irradiating a laser to a target point on the surface or inside of the component 10 by using the inspection apparatus 100 with reference to FIGS. 3 to 5 and detecting an ultrasonic wave generated at a measurement point will be described. 3 and 4 are diagrams for explaining a movement path of an ultrasonic wave from a target point irradiated with a laser in the forward direction, and FIG. 5 is a diagram for explaining a movement path of an ultrasonic wave from a target point irradiated with a laser in a reverse direction.

Referring to FIG. 3 , the laser irradiation unit 110 according to an embodiment may include a light source 111 irradiating a pulse laser and a laser direction adjusting unit 112 having a galvano mirror.

When the light source 111 irradiates the pulse laser, the laser direction control unit 112 provided with the galvano mirror changes the angle according to the control signal of the body unit 163 or the manual operation of the user, and in the light source 111 The irradiation angle of the irradiated pulse laser is changed. The laser irradiated from the light source 111 is irradiated to the target point a1 by changing the irradiation angle of the laser direction control unit 112 .

In this case, the laser direction control unit 112 is provided with two galvano mirrors, the pulse laser may be irradiated in two dimensions.

When the laser is irradiated to the target point a1, a thermoelastic wave is generated at the target point a1, and the thermoelastic wave generates an ultrasonic wave having a pulse waveform.

The measuring unit 130 is implemented as, for example, a laser vibrometer, and detects an ultrasonic wave through displacement measurement at a measuring point a2 separated by a preset distance from the target point a1, and based on the detected ultrasonic wave, the measuring point ( Ultrasound data in a2) can be generated.

Meanwhile, referring to FIG. 4 , the laser irradiation unit 110 according to another embodiment may include a light source 111 irradiating a pulse laser and a laser direction adjusting unit 112 provided with a manipulator. Here, the manipulator refers to a device that changes the irradiation angle of a pulse laser in the shape of a human arm.

A light source 111 may be provided at one end of the laser direction control unit 112 provided with the manipulator, and the laser direction control unit 112 bends the manipulator according to a control signal of the body unit 163 or a user's manual operation. By changing the angle, the irradiation angle of the pulse laser irradiated from the light source 111 is changed. The laser irradiated from the light source 111 is irradiated to the target point a1 by changing the irradiation angle of the laser direction control unit 112 .

When the laser is irradiated to the target point a1, a thermoelastic wave is generated at the target point a1, and the thermoelastic wave generates an ultrasonic wave having a pulse waveform.

The measuring unit 130 is implemented as, for example, a laser vibrometer, and detects an ultrasonic wave through displacement measurement at a measuring point a2 separated by a preset distance from the target point a1, and based on the detected ultrasonic wave, the measuring point ( Ultrasound data in a2) can be generated.

In addition to the embodiments shown in FIGS. 3 and 4 , the laser direction control unit 112 may be implemented as various mechanical devices such as a robot that automatically changes the irradiation angle of a pulse laser.

So far, a method for measuring ultrasonic waves in the forward direction has been described. Hereinafter, a method of measuring ultrasonic waves in the reverse direction will be described with reference to FIG. 5 .

Referring to FIG. 5 , in order to measure the ultrasonic waves in the reverse direction, the laser direction control unit 112 is a pulse laser irradiated from the light source 111 according to a control signal of the main body 163 or a user's manual operation at the measurement point a2 . ) to change the irradiation angle. The laser irradiated from the light source 111 by changing the irradiation angle of the laser direction control unit 112 is irradiated to the measurement point (a2).

When a laser is irradiated to the measurement point a2, a thermoelastic wave is generated at the measurement point a2, and this thermoelastic wave generates an ultrasonic wave having a pulse waveform.

The measurement unit 130 may detect an ultrasound at the target point a1 and generate ultrasound data at the target point a1 based on the detected ultrasound.

Hereinafter, with reference to FIGS. 6 to 9 , ultrasonic data generated by the forward ultrasonic measurement method (hereinafter referred to as forward measurement data) and ultrasonic data generated by the reverse ultrasonic measurement method (hereinafter referred to as reverse measurement data) A method for the signal processing unit 140 to determine the defect of the component 10 will be described using .

6 is a flowchart of an inspection method of an inspection apparatus according to an embodiment, and FIG. 7 is a detailed control block diagram of the inspection apparatus according to an embodiment. 8 is a flowchart of an inspection method of an inspection apparatus according to another embodiment, and FIG. 9 is a detailed control block diagram of the inspection apparatus according to another embodiment.

Referring to FIG. 6 , the inspection apparatus 100 according to an embodiment acquires forward measurement data by the aforementioned forward ultrasonic measurement method (S1100), and acquires reverse measurement data by the reverse ultrasonic measurement method (S1200) . In this case, both the forward measurement data and the backward measurement data may be for an object to be inspected, for example, the component 10 .

Subsequently, the signal processing unit 140 uses the forward measurement data for the component 10 to be inspected and the reverse measurement data for the component 10 to be inspected to determine a defect or damage to the component 10 to be inspected. It is determined whether or not (S1300).

Specifically, referring to FIG. 7 , the signal processing unit 140 determines the correlation between the forward measurement data and the backward measurement data, based on the correlation calculated by the correlation calculation unit 141 and the correlation calculation unit 141 . and a damage index calculation unit 142 to determine the damage index, and a damage determination unit 143 to determine whether the component 10 to be inspected is damaged according to the determination result of the damage index calculation unit 142 can do.

The correlation calculation unit 141 includes an autocorrelation of the forward measurement data generated by the measurement unit 130 , an autocorrelation of the backward measurement data generated by the measurement unit 130 , and a forward direction generated by the measurement unit 130 . A cross correlation between the measurement data and the backward measurement data is determined (refer to Equations 1 to 3).

[Equation 1]

[Equation 2]

[Equation 3]

Here, x and y represent forward measurement data and reverse measurement data of _{the component 10 to be inspected, respectively, and R xx} , R _yy , and R _xy are the magnetism of the forward measurement data of the component 10 to be inspected, respectively. The correlation degree, the autocorrelation degree of reverse measurement data of the component 10 to be inspected, and the cross-correlation degree between the forward measurement data of the component 10 to be inspected and the reverse measurement data of the component 10 to be inspected indicates.

When there is no defect in the component 10 to be inspected, the forward measurement data and the reverse measurement data of the component 10 to be inspected must be the same, so R _xx , R _yy , and R _xy represent similar values .

However, if a linear defect or a non-linear defect exists in the component 10 to be inspected, it affects the progress of ultrasonic waves such as additional reflection and diffraction, and non-linear forward measurement data or reverse measurement data is generated. Accordingly, the forward measurement data and the backward measurement data show a difference, and R _xx , R _yy , and R _xy indicate different values.

Damage index calculation unit 142 based on the degree of autocorrelation and cross-correlation determined by the correlation calculation unit 141 as a statistical value (ie, damage index) the degree of the defect of the component 10 to be inspected. Calculate (refer to Equation 4).

[Equation 4]

Here, DI is the damage index, R _xx , R _yy , and R _xy are the autocorrelation of the forward measurement data of the component 10 to be inspected, and the autocorrelation of the reverse measurement data of the component 10 to be inspected, respectively , a cross-correlation degree between the forward measurement data of the component 10 to be inspected and the reverse measurement data of the component 10 to be inspected, D(a, b) means a numerical value indicating the degree to which a and b are different .

The damage determination unit 143 determines whether the component 10 to be inspected is defective based on the damage index calculated by the damage index calculation unit 142 .

For example, if the damage index of the component 10 to be inspected is less than a preset reference value, the damage determination unit 143 may determine that it is a normal part, and if it is greater than or equal to the reference value, it may determine that it is a defective part.

Conversely, if the damage index of the component 10 to be inspected is greater than or equal to a preset reference value, the damage determination unit 143 may determine that it is a normal part, and if it is less than the reference value, it may be determined as a defective part. It may vary according to the setting stored in the determination unit 143 .

The output unit 150 outputs the determination result of the damage determination unit 143 to the user through various images or sounds.

For example, the output unit 150 may be implemented as the display unit 161 of the workstation 160 to output the presence or absence of a defect or a damage index of the component 10 to the user.

The correlation calculation unit 141, the damage index calculation unit 142, and the damage determination unit 143 calculate the degree of correlation and the damage index, respectively, and a memory for storing programs and data for determining whether or not damage is stored in the memory; The processor may include a processor that calculates a correlation and a damage index according to the program and data, and determines whether or not there is damage. The correlation calculation unit 141 , the damage index calculation unit 142 , and the damage determination unit 143 may be implemented using various semiconductor chips and the like.

Meanwhile, the damage determination unit 143 may be omitted, and the output unit 150 may output the damage index calculated by the damage index calculation unit 142 to the user. In this case, the user may directly determine whether the component 10 is defective through the output damage index.

In addition, the damage index calculation unit 142 may also be omitted, and the output unit 150 is an autocorrelation diagram of the forward measurement data calculated by the correlation calculation unit 141, an autocorrelation diagram of the backward measurement data, and a forward measurement A cross-correlation between the data and the backward measurement data may be output to the user. In this case, the user may directly determine the presence or absence of a defect in the component 10 through the output autocorrelation and cross-correlation.

According to another embodiment, when the inspection apparatus 100 performs the reverse ultrasonic measurement method, the measurement unit 130 does not acquire reverse measurement data of the component 10 to be inspected, but reverse measurement data of the normal part. can be obtained.

That is, in order to perform the forward ultrasonic measurement, the laser irradiation unit 110 irradiates a laser to the target point a1 of the component 10 to be inspected, and the measurement unit 130 is the component 10 to be inspected. The ultrasonic wave is measured at the measuring point a2, but in order to measure the reverse ultrasonic wave, the laser irradiator 110 irradiates a laser to the measuring point a2 of the normal part, and the measuring part 130 is the target of the normal part. Ultrasound can be measured at the point a1.

In this case, the correlation calculation unit 141 calculates the autocorrelation of the forward measurement data of the component 10 to be inspected, calculates the autocorrelation of the reverse measurement data of the normal component, and the component to be inspected The cross-correlation between the forward measurement data of (10) and the reverse measurement data of a normal part can be calculated.

The damage index determination unit 142 calculates the damage index based on the autocorrelation and cross-correlation calculated by the correlation calculation unit 141, and the damage determination unit 143 is the component 10 to be inspected. determine whether there is a defect in The descriptions of the correlation calculation unit 141, the damage index determination unit 142, and the damage determination unit 143 are redundant and will be omitted below.

Referring to FIG. 8 , according to another embodiment, reverse measurement data for a normal part generated by the measurement unit 130 may be stored in the storage unit. In this case, the inspection apparatus 100 may obtain forward measurement data for the component 10 to be inspected by the aforementioned forward ultrasonic measurement method (S2100), and call the previously stored reverse measurement data from the storage unit ( S2200).

In addition, the signal processing unit 140 may determine whether the component 10 to be inspected is defective or damaged by using the forward measurement data and the reverse measurement data stored in advance for the component 10 to be inspected (S2300). ).

Specifically, referring to FIG. 9 , the correlation calculation unit 141 performs auto-correlation of the forward measurement data generated by the measurement unit 130 , and the reverse measurement data fetched from the storage unit, for example, the memory 160 . The auto-correlation of , and the cross-correlation between the forward measurement data generated by the measurement unit 130 and the backward measurement data stored in advance are determined (refer to Equations 5 to 7 described above).

[Equation 5]

[Equation 6]

[Equation 7]

Here, x and z represent forward measurement data and reverse measurement data previously stored in the memory 160 _{of the component 10 to be inspected, respectively, and R xx} , R _zz , and R _xz are the components 10 to be inspected, respectively. ), the autocorrelation of the forward measurement data, the autocorrelation of the previously stored reverse measurement data, and the cross-correlation of the forward measurement data of the component 10 to be inspected and the previously stored reverse measurement data.

If there is no defect in the component 10 to be inspected, the forward measurement data of the component 10 to be inspected and the reverse measurement data serving as the reference value must be the same, so R _xx , R _zz , R _xz are similar represents a value.

However, if a linear defect or a non-linear defect exists in the component 10 to be inspected, it affects the progress of ultrasonic waves such as additional reflection and diffraction, and non-linear forward measurement data or reverse measurement data is generated. Accordingly, the forward measurement data and the backward measurement data show a difference, and R _xx , R _zz , and R _xz indicate different values.

Damage index calculation unit 142 based on the degree of autocorrelation and cross-correlation determined by the correlation calculation unit 141 as a statistical value (ie, damage index) the degree of the defect of the component 10 to be inspected. Calculate (refer to Equation 8).

[Equation 8]

Here, DI is the damage index, R _xx , R _zz , and R _xz are the autocorrelation of the forward measurement data of the component 10 to be inspected, the autocorrelation of the reverse measurement data stored in advance, the component to be inspected ( 10), the cross-correlation between the forward measurement data and the previously stored backward measurement data, D(a, b) means a numerical value indicating the degree of difference between a and b.

The damage determination unit 143 determines whether the component 10 to be inspected is defective based on the damage index calculated by the damage index calculation unit 142 , and the output unit 150 determines whether the damage is determined by the damage index 143 . ) is output to the user through various images or sounds. The description of the damage determination unit 143 and the output unit 150 has been described above, and thus will be omitted below.

According to the inspection apparatus and the inspection method according to an embodiment as described above, by using a laser, it is possible to precisely detect a surface or an internal defect of an inspected object without contacting the inspected object, and to determine the autocorrelation and cross-correlation of the detection data. By using it, defect detection is possible even for small defects.

According to the inspection apparatus and the inspection method according to an exemplary embodiment, not only a linear defect but also a non-linear defect of an object may be detected by using the auto-correlation and cross-correlation of detected data.

In the above-described embodiment, some of the components constituting the inspection apparatus 100 may be implemented as a kind of 'module'. Here, 'module' means software or hardware components such as Field Programmable Gate Array (FPGA) or Application Specific Integrated Circuit (ASIC), and the module performs certain roles. However, a module is not meant to be limited to software or hardware. A module may be configured to reside on an addressable storage medium and may be configured to execute one or more processors.

Thus, by way of example, a module includes components such as software components, object-oriented software components, class components and task components, and processes, functions, properties, procedures, subroutines. data, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. The functionality provided by the components and modules may be combined into a smaller number of components and modules or further divided into additional components and modules. In addition, the components and modules may execute one or more CPUs within the device.

Meanwhile, the above-described inspection method of the inspection apparatus may be implemented as computer-readable codes on a computer-readable recording medium. The computer-readable recording medium includes any type of recording medium in which data that can be read by a computer system is stored. For example, there may be a read only memory (ROM), a random access memory (RAM), a magnetic tape, a magnetic disk, a flash memory, an optical data storage device, and the like. In addition, the computer-readable recording medium may be distributed in computer systems connected through a computer communication network, and stored and executed as readable codes in a distributed manner.

10: subject
100; Inspection device 110: laser irradiation unit
111: light source 112: laser direction control unit
130: measurement unit 140: signal processing unit
150: output unit

Claims (20)

a laser irradiator for irradiating a laser to a target point of the subject or a measurement point separated by a preset distance from the target point;
a measurement unit that generates forward measurement data at the measurement point when the laser is irradiated to the target point, and generates reverse measurement data at the target point when the laser is irradiated to the measurement point; and
and a signal processing unit configured to determine a defect of the subject based on autocorrelation and cross-correlation between the forward measurement data and the backward measurement data. The method of claim 1,
The signal processing unit determines the defect of the subject based on a difference between any two correlation degrees among the autocorrelation degree of the forward measurement data, the autocorrelation degree of the backward measurement data, and the cross-correlation degree of the forward measurement data and the backward measurement data Inspection device for judging. The method of claim 1,
The signal processing unit,
a correlation calculator for determining autocorrelation and cross-correlation between the forward measurement data and the backward measurement data;
a damage index calculation unit for determining a damage index based on the autocorrelation and cross-correlation; and
and a damage determination unit configured to determine a defect of the subject based on the damage index. 4. The method of claim 3,
The damage determination unit compares the damage index with a preset reference value to determine the defect of the subject. 4. The method of claim 3,
The damage index calculation unit is a damage index based on a different degree of correlation between any two of the autocorrelation of the forward measurement data, the autocorrelation of the backward measurement data, and the cross correlation between the forward measurement data and the reverse measurement data. Inspection device for judging. The method of claim 1,
When the laser is irradiated to the target point, the measuring unit detects ultrasonic waves at the measuring point to generate forward measurement data, and when the laser is irradiated to the measuring point, the measuring unit detects ultrasonic waves at the target point to generate reverse measurement data generating inspection device. The method of claim 1,
The test apparatus further comprising an output unit for outputting the determination result of the signal processing unit as an image or sound to the user. The method of claim 1,
Further comprising a storage unit in which reverse measurement data for a normal subject is stored,
The measurement unit generates forward measurement data of the subject to be inspected,
The signal processing unit is an inspection device for determining a defect of the inspected object to be inspected based on the autocorrelation and cross-correlation of the forward measurement data of the inspected object and the reverse measurement data of the normal inspected object . The method of claim 1,
The laser irradiator irradiates a laser to a target point of an inspection target, and irradiates a laser to a measurement point of a normal inspected object
The measurement unit generates forward measurement data of the inspected object to be inspected, and generates reverse measurement data of the normal inspected object. The method of claim 1,
The laser irradiation unit irradiates a laser to the subject in a non-contact manner,
The measurement unit is an inspection apparatus for detecting the ultrasonic wave of the subject in a non-contact manner. irradiating a laser to a target point of the subject, and generating forward measurement data at a measurement point separated by a preset distance from the target point;
irradiating a laser to the measurement point and generating reverse measurement data at the target point; and
and determining the defect of the subject based on autocorrelation and cross-correlation between the forward measurement data and the backward measurement data. 12. The method of claim 11,
The determining of the defect may include: based on a difference between any two correlations among the auto-correlation of the forward measurement data, the auto-correlation of the backward measurement data, and the cross-correlation between the forward measurement data and the backward measurement data. An inspection method of an inspection device that determines a defect in a specimen. 12. The method of claim 11,
The step of determining the defect is,
determining autocorrelation and cross-correlation between the forward measurement data and the backward measurement data;
determining a damage index based on the autocorrelation and cross-correlation; and
and determining the defect of the subject based on the damage index. 14. The method of claim 13,
The determining of the defect of the subject based on the damage index may include comparing the damage index with a preset reference value to determine the defect of the subject. 14. The method of claim 13,
The step of determining the damage index is based on a different degree of correlation between any two of the auto-correlation of the forward measurement data, the auto-correlation of the backward measurement data, and the cross-correlation between the forward measurement data and the backward measurement data. Inspection method of the inspection device to determine the damage index. 12. The method of claim 11,
The generating of the forward measurement data includes generating forward measurement data by detecting ultrasonic waves at the measurement point,
The generating of the reverse measurement data may include detecting an ultrasonic wave at the target point to generate reverse measurement data. 12. The method of claim 11,
and outputting a determination result of the step of determining the defect of the subject as an image or sound to a user. 12. The method of claim 11,
In the determining of the defect, the defect of the subject is determined based on the autocorrelation and cross-correlation of the forward measurement data generated in the step of generating the forward measurement data and the reverse measurement data previously stored in the inspection apparatus. Inspection method of inspection device. 12. The method of claim 11,
In the generating of the forward measurement data, a laser is irradiated to a target point of an object to be inspected, and forward data is generated at a measurement point separated by a preset distance from the target point,
The generating of the reverse measurement data includes irradiating a laser to a measurement point of a normal subject, generating reverse data at a target point,
In the determining of the defect, the inspection apparatus for determining the defect of the inspected object is based on the autocorrelation and cross-correlation of the forward measurement data of the inspected object and the reverse measurement data of the normal inspected object. Way. 20. The method of claim 19,
Prior to the step of determining the defect of the subject,
The inspection method of the inspection apparatus further comprising the step of storing the reverse measurement data of the normal subject.

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