阅读说明：本技术 一种基于合成孔径聚焦成像的激光超声检测装置及方法 (Laser ultrasonic detection device and method based on synthetic aperture focusing imaging ) 是由 袁金晶 何文 何浩辉 黎灼佳 罗鑫洪 陈小琼 严俊韬 杨巧源 于 2021-07-30 设计创作，主要内容包括：本发明涉及激光超声检测技术领域,公开了一种基于合成孔径聚焦成像的激光超声检测装置及方法,包括脉冲激光发生器、复眼透镜、干涉仪、示波器、三维平移台和工控机；三维平移台用于承载待检测工件,脉冲激光发生器、复眼透镜和三维平移台从上到下依次设置,复眼透镜包括若干个用于将激光汇聚至待检测工件上的透镜,脉冲激光发生器发出的激光经透镜聚焦至待检测工件的表面上,以在待检测工件的表面激发激光超声；干涉仪和示波器连接,且干涉仪和示波器均设置于三维平移台的上方；工控机分别与脉冲激光发生器、干涉仪、示波器电连接。本发明能有效提升激光超声的检测效率。(The invention relates to the technical field of laser ultrasonic detection, and discloses a laser ultrasonic detection device and a method based on synthetic aperture focusing imaging, wherein the device comprises a pulse laser generator, a fly-eye lens, an interferometer, an oscilloscope, a three-dimensional translation stage and an industrial personal computer; the three-dimensional translation table is used for bearing a workpiece to be detected, the pulse laser generator, the fly-eye lens and the three-dimensional translation table are sequentially arranged from top to bottom, the fly-eye lens comprises a plurality of lenses used for converging laser onto the workpiece to be detected, and the laser emitted by the pulse laser generator is focused onto the surface of the workpiece to be detected through the lenses so as to excite laser ultrasound on the surface of the workpiece to be detected; the interferometer and the oscilloscope are connected and are arranged above the three-dimensional translation stage; the industrial personal computer is respectively and electrically connected with the pulse laser generator, the interferometer and the oscilloscope. The invention can effectively improve the detection efficiency of laser ultrasound.)

1. A laser ultrasonic detection device based on synthetic aperture focusing imaging is characterized by comprising a pulse laser generator, a fly-eye lens, an interferometer, an oscilloscope, a three-dimensional translation stage and an industrial personal computer;

the three-dimensional translation table is used for bearing a workpiece to be detected, the pulse laser generator, the fly-eye lens and the three-dimensional translation table are sequentially arranged from top to bottom, the fly-eye lens comprises a plurality of lenses used for converging laser onto the workpiece to be detected, and the laser emitted by the pulse laser generator is focused onto the surface of the workpiece to be detected through the lenses so as to excite laser ultrasound on the surface of the workpiece to be detected; the interferometer is connected with the oscilloscope, and the interferometer and the oscilloscope are both arranged above the three-dimensional translation stage;

the industrial personal computer is respectively and electrically connected with the pulse laser generator, the interferometer and the oscilloscope.

2. The laser ultrasonic inspection device based on synthetic aperture focused imaging of claim 1, wherein the lens is a biconvex lens.

3. The laser ultrasonic detection device based on the synthetic aperture focused imaging according to claim 1, wherein the interferometer comprises a detection probe and a first controller connected with the detection probe, and the first controller is electrically connected with the industrial personal computer.

4. The laser ultrasonic detection device based on the synthetic aperture focusing imaging of claim 1, wherein the pulse laser generator comprises a laser generating head and a second controller connected with the laser generating head; and the light emitting end of the laser generating head is provided with a beam expanding lens.

5. A laser ultrasonic detection method based on synthetic aperture focusing imaging is characterized by comprising the following steps:

s01, adjusting the positions of the three-dimensional translation stage, the fly-eye lens and the interferometer to enable the fly-eye lens and the interferometer to be focused on the surface of the workpiece to be detected on the three-dimensional translation stage;

s02, emitting laser by a pulse laser generator, wherein the laser is converged by a lens of the fly-eye lens to irradiate a plurality of detection points on the surface of a workpiece to be detected simultaneously so as to excite laser ultrasound, and the number of the lenses is consistent with that of the irradiated detection points;

s03, acquiring an ultrasonic echo signal of the surface of the workpiece to be detected by the interferometer, processing the acquired ultrasonic echo signal by the oscilloscope, and sending the processed ultrasonic echo signal to the industrial personal computer;

s04, changing the position of the workpiece to be detected by using the three-dimensional translation table, and repeating the steps S02 and S03 until all detection points on the surface of the product are detected;

and S05, carrying out SAFT reconstruction by the industrial personal computer according to the received processed ultrasonic echo signal, and displaying the internal defect image of the workpiece to be detected.

6. The laser ultrasonic detection method based on the synthetic aperture focused imaging according to claim 5, characterized in that the lens is a biconvex lens.

7. The laser ultrasonic detection method based on the synthetic aperture focused imaging according to claim 5, wherein the pulse laser generator emits laser, specifically:

the pulse laser generator excites the laser for a plurality of times;

the interferometer acquires an ultrasonic echo signal of the surface of a workpiece to be detected, and the oscilloscope processes the acquired ultrasonic echo signal, specifically comprising the following steps:

the interferometer obtains a plurality of times of ultrasonic echo signals of the surface of a workpiece to be detected, and the oscilloscope carries out averaging processing on the plurality of times of ultrasonic echo signals to form processed ultrasonic echo signals.

8. The laser ultrasonic detection method based on the synthetic aperture focusing imaging according to claim 5, wherein the pulse laser generator comprises a laser generating head and a second controller connected with the laser generating head; a beam expanding lens is arranged at the light emitting end of the laser generating head;

and the second controller controls the laser light emitting frequency of the laser generating head.

9. The laser ultrasonic detection method based on the synthetic aperture focusing imaging of claim 5, wherein the distance from each detection point to the interferometer is different, and the interferometer distinguishes ultrasonic echo signals of different detection points based on time.

Technical Field

The invention relates to the technical field of laser ultrasonic detection, in particular to a laser ultrasonic detection device and method based on synthetic aperture focusing imaging.

Background

Laser ultrasound is a non-contact, high-precision, non-destructive novel ultrasonic detection technology, which combines the advantages of high precision of ultrasonic detection and non-contact of optical detection. The laser pulse is used for exciting ultrasonic waves in a detected workpiece and detecting ultrasonic echo signals, so that defects and the like of the workpiece are obtained. The technology combines the advantages of high precision of ultrasonic detection and non-contact optical detection, and has the advantages of high sensitivity and high detection bandwidth.

In the existing laser ultrasonic detection device, only one detection point of a workpiece can be irradiated by laser at a time and laser ultrasonic is triggered, an interferometer collects ultrasonic echo signals of the detection point, and an industrial personal computer collects the ultrasonic echo signals to analyze the defects of the workpiece. However, a workpiece to be detected usually has hundreds of detection points, even more detection points, which results in long detection time and low detection efficiency.

In view of this, a laser ultrasonic detection apparatus and method based on synthetic aperture focused imaging need to be designed to improve the detection efficiency.

Disclosure of Invention

The invention aims to provide a laser ultrasonic detection device and method based on synthetic aperture focusing imaging so as to improve the detection efficiency.

In order to achieve the purpose, the invention adopts the following technical scheme:

a laser ultrasonic detection device based on synthetic aperture focusing imaging comprises a pulse laser generator, a fly-eye lens, an interferometer, an oscilloscope, a three-dimensional translation stage and an industrial personal computer;

the three-dimensional translation table is used for bearing a workpiece to be detected, the pulse laser generator, the fly-eye lens and the three-dimensional translation table are sequentially arranged from top to bottom, the fly-eye lens comprises a plurality of lenses used for converging laser onto the workpiece to be detected, and the laser emitted by the pulse laser generator is focused onto the surface of the workpiece to be detected through the lenses so as to excite laser ultrasound on the surface of the workpiece to be detected; the interferometer is connected with the oscilloscope, and the interferometer and the oscilloscope are both arranged above the three-dimensional translation stage;

the industrial personal computer is respectively and electrically connected with the pulse laser generator, the interferometer and the oscilloscope.

Optionally, the lens is a lenticular lens.

Optionally, the interferometer comprises a detection probe and a first controller connected with the detection probe, and the first controller is electrically connected with the industrial personal computer.

Optionally, the pulse laser generator comprises a laser generating head and a second controller connected with the laser generating head; and the light emitting end of the laser generating head is provided with a beam expanding lens.

A laser ultrasonic detection method based on synthetic aperture focusing imaging comprises the following steps:

s01, adjusting the positions of the three-dimensional translation stage, the fly-eye lens and the interferometer to enable the fly-eye lens and the interferometer to be focused on the surface of the workpiece to be detected on the three-dimensional translation stage;

s02, emitting laser by a pulse laser generator, wherein the laser is converged by a lens of the fly-eye lens to irradiate a plurality of detection points on the surface of a workpiece to be detected simultaneously so as to excite laser ultrasound, and the number of the lenses is consistent with that of the irradiated detection points;

s03, acquiring an ultrasonic echo signal of the surface of the workpiece to be detected by the interferometer, processing the acquired ultrasonic echo signal by the oscilloscope, and sending the processed ultrasonic echo signal to the industrial personal computer;

s04, changing the position of the workpiece to be detected by using the three-dimensional translation table, and repeating the step S and the step S until all detection points on the surface of the product are detected;

and S05, carrying out SAFT reconstruction by the industrial personal computer according to the received processed ultrasonic echo signal, and displaying the internal defect image of the workpiece to be detected.

Optionally, the lens is a lenticular lens.

Optionally, the pulse laser generator emits laser, specifically:

the pulse laser generator excites the laser for a plurality of times;

the interferometer acquires an ultrasonic echo signal of the surface of a workpiece to be detected, and the oscilloscope processes the acquired ultrasonic echo signal, specifically comprising the following steps:

the interferometer obtains a plurality of times of ultrasonic echo signals of the surface of a workpiece to be detected, and the oscilloscope carries out averaging processing on the plurality of times of ultrasonic echo signals to form processed ultrasonic echo signals.

Optionally, the pulse laser generator comprises a laser generating head and a second controller connected with the laser generating head; a beam expanding lens is arranged at the light emitting end of the laser generating head;

and the second controller controls the laser light emitting frequency of the laser generating head.

Optionally, the distance from each detection point to the interferometer is different, and the interferometer distinguishes the ultrasonic echo signals of different detection points based on time.

Compared with the prior art, the invention has the following beneficial effects:

in the ultrasonic detection device in this embodiment, the fly-eye lens includes a plurality of lenses for converging laser onto a workpiece to be detected, and laser emitted from the pulse laser generator is focused onto the surface of the workpiece to be detected through the lenses so as to excite laser ultrasound on the surface of the workpiece to be detected; the interferometer is used for receiving ultrasonic echo signals so as to enable the industrial personal computer to analyze the defects of the workpieces. The ultrasonic detection device of this embodiment can once only detect a plurality of check points, has greatly promoted laser ultrasonic detection's efficiency, has reduced laser ultrasonic detection's time.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive exercise.

The structure, proportion, size and the like shown in the drawings are only used for matching with the content disclosed in the specification, so that the person skilled in the art can understand and read the description, and the description is not used for limiting the limit condition of the implementation of the invention, so the method has no technical essence, and any structural modification, proportion relation change or size adjustment still falls within the scope of the technical content disclosed by the invention without affecting the effect and the achievable purpose of the invention.

Fig. 1 is a schematic structural diagram of an ultrasonic detection apparatus according to an embodiment of the present invention.

Illustration of the drawings: 1. a pulse laser generator; 11. a laser generating head; 12. a second controller; 13. a beam expanding lens; 2. a fly-eye lens; 3. an interferometer; 31. detecting a probe; 32. a first controller; 4. an oscilloscope; 5. a three-dimensional translation stage; 6. and an industrial personal computer.

Detailed Description

In order to make the objects, features and advantages of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the embodiments described below are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention. It should be noted that when one component is referred to as being "connected" to another component, it can be directly connected to the other component or intervening components may also be present.

The technical scheme of the invention is further explained by the specific implementation mode in combination with the attached drawings.

The embodiment of the invention provides a laser ultrasonic detection device based on synthetic aperture focusing imaging, which is used for improving the detection efficiency of laser ultrasonic detection.

Example one

The laser ultrasonic detection device comprises a pulse laser generator 1, a fly-eye lens 2, an interferometer 3, an oscilloscope 4, a three-dimensional translation stage 5 and an industrial personal computer 6;

the three-dimensional translation table 5 is used for bearing a workpiece to be detected, and the three-dimensional translation table 5 can drive the workpiece to move in a three-dimensional space so as to adjust the position of the workpiece.

The pulse laser generator 1, the fly-eye lens 2 and the three-dimensional translation stage 5 are sequentially arranged from top to bottom, the fly-eye lens 2 comprises a plurality of lenses used for converging laser onto a workpiece to be detected, and the laser emitted by the pulse laser generator 1 is focused onto the surface of the workpiece to be detected through the lenses so as to excite laser ultrasound on the surface of the workpiece to be detected. And the laser light converged by each lens is focused on the surface of the workpiece.

The interferometer 3 is connected with the oscilloscope 4, and the interferometer 3 and the oscilloscope 4 are both arranged above the three-dimensional translation stage 5; the workpiece to be detected is excited to generate an ultrasonic echo signal under the action of the focused laser, the interferometer 3 detects the ultrasonic echo signal, and the oscilloscope 4 averages the ultrasonic echo signal. It should be clear that multiple laser shots, e.g., 128 shots; the interferometer 3 sends the ultrasonic echo signals detected each time to the oscilloscope 4, the oscilloscope 4 averages the ultrasonic echo signals, the ultrasonic echo signals obtained after averaging processing are sent to the industrial personal computer 6, the industrial personal computer 6 carries out SAFT reconstruction according to a preset algorithm and the received ultrasonic echo signals, and internal defect images of the workpiece to be detected are displayed on the display screen.

It should be noted that the industrial personal computer 6 is electrically connected with the pulse laser generator 1, the interferometer 3 and the oscilloscope 4 respectively.

The laser ultrasonic detection device in the embodiment can detect a plurality of points of a workpiece at a time, greatly improves the detection efficiency of laser ultrasonic detection, and effectively reduces the detection time.

Optionally, the lens is a biconvex lens, and the biconvex lens has a good light-gathering effect. It should be noted that the focal length of the lenticular lens needs to be set according to actual conditions, and the radius of the lenticular lens needs to be specifically set according to the irradiation intensity of the laser light.

Optionally, the interferometer 3 includes a detection probe 31 and a first controller 32 connected to the detection probe 31, and the first controller 32 is electrically connected to the industrial personal computer 6. Specifically, the industrial personal computer 6 can control the opening and closing of the detection probe 31 through the first controller 32 to adapt to the detection rhythm.

Optionally, the pulse laser generator 1 comprises a laser generating head 11 and a second controller 12 connected to the laser generating head 11; the light-emitting end of the laser generating head 11 is provided with an expander lens 13. It should be clear that the beam expander lens 13 is a lens assembly that changes the diameter and divergence angle of the laser beam, so that the laser is irradiated onto the lenses in parallel, so that each lens can converge the laser onto the surface of the workpiece to be detected.

Example two

A laser ultrasonic detection method based on synthetic aperture focusing imaging comprises the following steps:

s01, adjusting the positions of the three-dimensional translation stage 5, the fly-eye lens 2 and the interferometer 3 so that the fly-eye lens 2 and the interferometer 3 can be focused on the surface of the workpiece to be detected on the three-dimensional translation stage 5;

s02, emitting laser by a pulse laser generator 1, converging the laser by a plurality of lenses of a fly-eye lens 2 to irradiate a plurality of detection points on the surface of a workpiece to be detected simultaneously to excite laser ultrasound, wherein the number of the lenses is consistent with the number of the irradiated detection points;

s03, the interferometer 3 acquires an ultrasonic echo signal of the surface of the workpiece to be detected, the oscilloscope 4 processes the acquired ultrasonic echo signal and sends the processed ultrasonic echo signal to the industrial personal computer 6;

s04, changing the position of the workpiece to be detected by using the three-dimensional translation table 5, and repeating the steps S02 and S03 until all detection points on the surface of the product are detected;

s05, the industrial personal computer 6 carries out SAFT reconstruction according to the received processed ultrasonic echo signals, and the internal defects of the workpiece to be detected are imaged and displayed.

Through fly-eye lens 2, can form the laser beam that the product that can make to detect arouses the ultrasonic wave, every laser beam shines on the surface of product to once only detect a plurality of points, effectively promoted the efficiency that laser ultrasonic detected.

Optionally, the lens is a biconvex lens, and the biconvex lens has a good light-gathering effect. It should be noted that the focal length of the lenticular lens needs to be set according to actual conditions, and the radius of the lenticular lens needs to be specifically set according to the irradiation intensity of the laser light.

Optionally, the pulse laser generator 1 emits laser, specifically:

the pulse laser generator 1 excites the laser for a plurality of times;

the interferometer 3 acquires an ultrasonic echo signal of the surface of a workpiece to be detected, and the oscilloscope 4 processes the acquired ultrasonic echo signal, specifically:

the interferometer 3 acquires a plurality of times of ultrasonic echo signals of the surface of the workpiece to be detected, and the oscilloscope 4 averages the plurality of times of ultrasonic echo signals to form processed ultrasonic echo signals.

It should be clear that, in order to make the detection error as small as possible, by carrying out averaging processing on the ultrasonic echo signals for several times, the problem that the detection result error is large due to the large detection error of a single time is avoided.

Optionally, the pulse laser generator 1 comprises a laser generating head 11 and a second controller 12 connected to the laser generating head 11; the light-emitting end of the laser generating head 11 is provided with a beam expanding lens 13; the beam expanding lens 13 is a lens assembly that changes the diameter and the divergence angle of the laser beam, and makes the laser irradiate the lenses in parallel, so that each lens can converge the laser to the surface of the workpiece to be detected. The second controller 12 is used for controlling the laser emitting frequency of the laser generating head 11.

Alternatively, the distance from each detection point to the interferometer 3 is different, and the interferometer 3 distinguishes the ultrasonic echo signals of different detection points based on time. It should be clear that, because the distances from each detection point to the interferometer 3 are different, the times for transmitting the laser-excited ultrasonic waves to the interferometer 3 are different, so that the interferometer 3 can effectively distinguish the ultrasonic echo signals triggered by different detection points.

The above-mentioned embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.