Wing defect detection device and method

Abstract

The invention relates to the technical field of part defect detection, and discloses a wing defect detection device and method.The wing defect detection device comprises a lifting table and a guide rail platform, and the lifting table and the guide rail platform are fixed to the ground and arranged in parallel; the rotating assembly comprises a connecting disc and a spindle, the connecting disc is rotationally connected to the top end of the lifting table through the spindle, two rotating disc connectors are fixedly connected to the side, away from the lifting table, of the connecting disc, and the wings are connected with the rotating disc connectors; the detection assembly comprises a three-axis moving table and a laser ultrasonic probe, the three-axis moving table is arranged on the guide rail platform, and the laser ultrasonic probe is fixedly connected to the three-axis moving table and used for detecting the wing. The single-excitation-point double-detection-point laser ultrasonic probe is adopted, ultrasonic signals in the wingspan direction and the wing circumference direction can be measured at the same time, the sensitivity and the resolution ratio are high, subsurface defect and surface defect detection and three-dimensional imaging of internal defects can be completed in the wingspan direction and the wing circumference direction, and the detection effect is comprehensive and accurate.

Description

Technical Field

[0001] The present invention relates to the technical field of parts defect detection, and in particular to a wing defect detection device and method. Background Art

[0002] With the rapid development of modern industry, the requirements for the accuracy and reliability of parts are getting higher and higher, especially for curved structural parts, which play a vital role in the fields of aviation, aerospace, automobiles, precision machinery, etc. Due to their complex geometric shapes, traditional non-destructive testing technologies face many challenges in detecting defects in curved structural parts. As a typical curved structural part, the wing is also an important part of the aircraft, and its structural integrity directly affects the safety and performance of the aircraft. Defects may lead to weakening of the wing structure, the formation of fatigue cracks, and reduced airtightness and stability, which in turn poses a potential threat to the flight safety and flight performance of the aircraft. Therefore, it is extremely necessary to accurately and timely detect wing defects, which can help discover and repair potential defects, ensure the structural integrity and safe operation of the wing, and thus ensure the safety of the aircraft and its passengers.

[0003] With the development of the aerospace industry and the advancement of technology, the selection and design of wing materials have received increasing attention. Traditional aluminum alloys have been replaced by metal materials such as titanium alloys and magnesium alloys, as well as advanced materials such as carbon fiber composites and glass fiber composites to meet the needs of lightweight, high strength and design flexibility. Taking carbon fiber composites as an example, since the structure of carbon fiber composites is usually composed of multiple layers of fiber and resin, this multi-layer structure makes it difficult to accurately grasp the location and morphology of defects. Secondly, due to the defects such as bubbles, interlayers and fiber breakage that may exist in the manufacturing process of carbon fiber composites, these defects are often not easy to be detected by naked eye observation or traditional detection methods. Therefore, for the defect detection of curved surface structural parts such as composite wings, a wing defect detection device and method with high sensitivity and high resolution is required, which can penetrate into the multi-layer structure of the composite material for comprehensive and accurate detection. Summary of the invention

[0004] The purpose of the present invention is to provide a wing defect detection device and method to solve the problems existing in the above-mentioned prior art.

[0005] To achieve the above object, the present invention provides the following solution: The present invention provides a wing defect detection device, comprising:

[0006] A lifting platform and a guide rail platform, wherein the lifting platform and the guide rail platform are respectively fixed on the ground and arranged in parallel;

[0007] The rotating assembly comprises a connecting disc and a main shaft, wherein the connecting disc is rotatably connected to the top of the lifting platform through the main shaft, and two turntable joints are fixedly connected to one side of the connecting disc away from the lifting platform, and the wings are connected to the turntable joints;

[0008] A detection component, comprising a three-axis moving platform and a laser ultrasonic probe, wherein the three-axis moving platform is arranged on the guide rail platform, and the laser ultrasonic probe is fixedly connected to the three-axis moving platform for detecting the wing;

[0009] The laser ultrasonic probe is a laser ultrasonic probe with a single excitation point and two detection points.

[0010] Preferably, the two turntable joints are respectively located on both sides of the connecting disc and on the same diameter line.

[0011] Preferably, a transmission box is fixedly connected to the lifting platform, a servo motor is fixedly connected inside the transmission box, the output shaft of the servo motor is connected to the main shaft through a reducer, a coupling and an absolute photoelectric encoder, and a gap is set between the main shaft and the lifting platform.

[0012] A wing defect detection method comprises the following steps:

[0013] S1, mounting the wing on the connecting disc and performing laser ultrasonic scanning;

[0014] S2. performing sub-surface crack defect detection on the wing;

[0015] S3, performing surface crack defect detection on the wing;

[0016] S4, performing three-dimensional imaging on the wing to obtain a three-dimensional image of the internal defects of the wing.

[0017] Preferably, in S1, the wing is kept parallel to the horizontal plane at the initial position, and the height of the lifting platform is H J , the distance between the main shaft and the top surface of the lifting platform is h z , the maximum wing width of the wing is W max , satisfying: H J +h z ≥1.5W max ;

[0018] The height of the guide rail platform is H, and the initial height of the Z axis of the three-axis moving platform is Z pt0 , satisfying: H J +h z =H+Z pt0 .

[0019] Preferably, during laser ultrasonic scanning, a global rectangular coordinate system XYZ is first established, wherein the X direction points to the span direction of the wing at the initial position, the Y direction points to the wing width direction perpendicular to the X direction, the XOY plane is parallel to the horizontal plane, and the direction perpendicular to the XOY plane is the Z direction. Then, the surface of the wing is discretized into points, and laser ultrasonic scanning is performed along the discretized curve by connecting a number of discrete points into lines. A local coordinate system Lm-Ln-Lz is established according to the scanning curve to obtain a span direction data set p(I 1i ,Lm,t),p(I 1i ,Lm,t) and wing circumference direction data set p(J j ,Ln,t) is used to image the defect.

[0020] Preferably, the subsurface crack defect is a plane defect, and the subsurface crack defect has a subsurface defect located on the wing periphery curve J s In the corresponding span section LnOLz, using the wing circumference data set p(J j ,Ln,t) to detect sub-surface defects. The specific steps of the sub-surface crack defect detection process are as follows:

[0021] Subsurface defect vertex coordinates Ln 0 Determination: During the scanning process, only the curve J in the wing circumferential direction s Scanning data p(J s ,Ln,t), a defect echo signal RL will appear. Observe the defect echo signal RL of the scanned data set to determine the wing circumferential section where the sub-surface defect is located;

[0022] Subsurface defect vertex coordinates Ln 0 Determination: Observe the scan data p(J s ,Ln,t), when the arrival time of the reflected wave RL is t RL When the minimum value is obtained, the defect vertex is located at the midpoint between the excitation point and the second detection point in the Ln direction, thus obtaining the sub-surface defect vertex coordinate Ln 0 ;

[0023] Subsurface defect vertex coordinates Lz 0 Determination: The coordinates of the defect vertex are (Ln 0 ,Lz 0 ), the coordinates of the excitation point are (Ln 1 ,0), the coordinates of the second detection point are (Ln 1 +l,0), l is the distance between the excitation point and the detection point 2, c is the wave velocity, then the subsurface crack burial depth Lz 0 It can be calculated by the following formula:

[0024]

[0025] By scanning the data set p(I 1i ,Lm,t) and p(I 2i ,Lm,t) to perform sub-surface defect detection on the span section.

[0026] Preferably, the surface crack defect is a plane defect, and a surface defect is located on the wingspan curve I 1s The specific steps for surface defect detection within the corresponding span section LmOLz are as follows:

[0027] According to the scan data set p(I 1i ,Lm,t) draw all the span section B scans in sequence;

[0028] During the scanning process, the excitation point and the detection point are fixed. When there is no defect between the excitation point and the detection point, the propagation time of the surface acoustic wave from the excitation point to the detection point is the same, and the B-scan image is a continuous straight line.

[0029] When there is a defect between the excitation point and the detection point, most of the surface waves will be reflected when they are transmitted from the excitation point to the side of the defect. The signal intensity detected at the detection point is very low, and the scanning image is a straight line with a gap, thereby determining the span section I where the surface defect is located. 1s ;

[0030] The position of the notch in the B-scan is the position of the surface defect, and the spanwise coordinates Lms1 and Lms2 can be obtained based on the B-scan.

[0031] By p(J s ,Ln,t) to carry out surface defect detection on the wing circumference section.

[0032] Preferably, according to the scan data set p(I 1i ,Lm,t),p(I 2i ,Lm,t) and p(J j ,Ln,t) can achieve three-dimensional imaging in two ways to present the location and shape of internal defects;

[0033] Extract span curve I 1i The corresponding two-dimensional data set p 1i (Lm,t) for span curve I 1i The focused imaging corresponding to the two-dimensional span section includes the following specific steps: calculating the equivalent velocity in the frequency-wave number domain by numerical calculation, calculating the phase shift factor according to the equivalent velocity, two-dimensional spectrum extrapolation and imaging matrix calculation. The equivalent velocity can be calculated by the following formula:

[0034]

[0035] Change the imaging depth Lz, repeat the above steps until the amplitude calculation of all imaging points is completed, and the wingspan curve I is obtained. 1i The imaging matrix I(Lm,Lz) corresponding to the two-dimensional wingspan section;

[0036] Collect all wingspan cross-sectional imaging matrices to obtain L 1 The three-dimensional imaging matrix I(I 1i ,Lm,Lz);

[0037] Perform coordinate transformation to obtain the three-dimensional imaging matrix I (x, y, z) in the rectangular coordinate system and perform imaging.

[0038] Preferably, based on the wing circumferential scanning data set p(J j The specific steps of the three-dimensional imaging of the wing of FIG. , Ln, t) are as follows:

[0039] The wing circumference section is divided into several contour segments, the outer contour is unfolded into a straight line, the wing circumference section in the imaging segment is unfolded into a plane, and the imaging segment is imaged in the frequency domain to obtain the plane frequency domain imaging matrix in the contour segment;

[0040] The surface images in all contour segments are stitched together to form the wing circumference curve J j The frequency domain imaging matrix I(Ln,Lz) corresponding to the 2D cross section of the wing;

[0041] The wing circumference curve is sequentially imaged in two-dimensional wingspan sections, and all wing circumference section imaging matrices are combined to obtain the three-dimensional imaging matrix I(J) of the wing. j ,Ln,Lz).

[0042] Compared with the prior art, the present invention has the following advantages and technical effects:

[0043] 1. The present invention provides a wing defect detection device for non-destructive detection of carbon fiber composite material wing skin defects. The wing is mounted on a connecting disk, the wing is rotated by a main shaft, and a three-axis moving platform adjusts the position of a laser ultrasonic probe to achieve all-round non-contact detection of the wing. The tangent at the excitation point at any time is kept vertical to facilitate detection by the laser ultrasonic probe, thereby achieving all-round detection of the wing.

[0044] 2. The present invention provides a wing defect detection method, which is difficult to detect through traditional scanning methods for irregular surface defects of wings. The wing is discretized into spatial curves in a discrete manner to improve the resolution, and can penetrate into the multi-layer structure of the composite material for comprehensive and accurate detection.

[0045] 3. The present invention adopts a laser ultrasonic probe with a single excitation point and dual detection points, which can simultaneously measure ultrasonic signals in the span direction and the circumference direction. Combined with the laser ultrasonic scanning method proposed in the present invention, the circumference curve scanning data set and the span curve scanning data set can be obtained in a simple way, thereby performing three-dimensional imaging of defects.

[0046] 4. The detection method provided by the present invention can detect surface defects and sub-surface defects in both the span direction and the circumferential direction, thus avoiding missed detection due to crack orientation. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative labor:

[0048] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0049] Figure 2 It is a schematic diagram of the structure of the rotating assembly of the present invention;

[0050] Figure 3 It is a schematic diagram of discrete points on the wing surface of the present invention;

[0051] Figure 4 This is a working diagram of the patented laser ultrasonic detection probe of the present invention;

[0052] Figure 5 This is a schematic diagram of the sub-surface defect detection principle of the present invention;

[0053] Figure 6 This is a schematic diagram of the surface defect detection principle of the present invention;

[0054] Figure 7 This is a scanning example diagram of the surface crack defect B of the present invention;

[0055] Figure 8 This is a schematic diagram of the equivalent speed calculation principle of the present invention;

[0056] Fig. 9 This is an example diagram of focused imaging of a two-dimensional cross section of a wingspan curve of the present invention;

[0057] Fig.10 This is an example diagram of three-dimensional imaging of defects of the present invention;

[0058] Fig.11 This is an example diagram of the focused imaging of the two-dimensional cross section of the wing circumference curve of the present invention;

[0059] Fig.12This is a schematic diagram of the overall structure of Embodiment 2 of the present invention;

[0060] Fig.13 This is a schematic diagram of the structure of a rotating support member according to a second embodiment of the present invention;

[0061] Among them, 1. lifting platform; 2. guide rail platform; 3. connecting disc; 4. main shaft; 5. turntable joint; 6. wing; 7. three-axis moving platform; 8. laser ultrasonic probe; 9. transmission box; 10. servo motor; 11. reducer; 12. coupling; 13. absolute photoelectric encoder; 14. turntable; 15. mobile clamping slide; 16. mobile slide; 17. drive motor. DETAILED DESCRIPTION

[0062] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0063] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0064] Embodiment 1:

[0065] Reference Figure 1-Figure 11 The present invention provides a wing defect detection device, comprising:

[0066] The lifting platform 1 and the guide rail platform 2 are respectively fixed on the ground and arranged in parallel;

[0067] The rotating assembly includes a connecting disc 3 and a main shaft 4. The connecting disc 3 is rotatably connected to the top of the lifting platform 1 through the main shaft 4. Two turntable joints 5 are fixedly connected to the side of the connecting disc 3 away from the lifting platform 1. The wing 6 is connected to the turntable joint 5.

[0068] The detection component includes a three-axis moving platform 7 and a laser ultrasonic probe 8. The three-axis moving platform 7 is arranged on the guide rail platform 2. The laser ultrasonic probe 8 is fixedly connected to the three-axis moving platform 7 for detecting the wing 6.

[0069] The laser ultrasonic probe 8 is a laser ultrasonic probe with a single excitation point and two detection points.

[0070] According to a further optimized solution, the two turntable joints 5 are respectively located on two sides of the connecting disc 3 and on the same diameter line.

[0071] According to a further optimization scheme, a transmission box 9 is fixedly connected to the lifting platform 1, a servo motor 10 is fixedly connected inside the transmission box 9, an output shaft of the servo motor 10 is connected to the main shaft 4 through a reducer 11, a coupling 12 and an absolute photoelectric encoder 13, and a gap is set between the main shaft 4 and the lifting platform 1.

[0072] A wing defect detection method comprises the following steps:

[0073] S1, mounting the wing 6 on the connecting disc 3 and performing laser ultrasonic scanning;

[0074] S2, performing sub-surface crack defect detection on wing 6;

[0075] S3, performing surface crack defect detection on the wing 6;

[0076] S4. Perform three-dimensional imaging on the wing 6 to obtain a three-dimensional image of the internal defects of the wing 6.

[0077] In one embodiment of the present invention, defect detection is the detection of surface, sub-surface and internal defects of the wing 6 .

[0078] Further optimization scheme, in S1, the wing 6 is kept parallel to the horizontal plane at the initial position, and the height of the lifting platform 1 is H J , the distance between the spindle 4 and the top surface of the lifting platform 1 is h z , the maximum wing width of wing 6 is W max , satisfying: H J +h z ≥1.5W max ;

[0079] The height of the guide rail platform 2 is H, and the initial height of the Z axis of the three-axis moving platform 7 is Z pt0 , satisfying: H J +h z =H+Z pt0 .

[0080] To further optimize the scheme, during the laser ultrasonic scanning, the global rectangular coordinate system XYZ is first established, the X direction points to the wingspan direction of the wing 6 at the initial position, the Y direction points to the wing width direction perpendicular to the X direction, the XOY plane is parallel to the horizontal plane, and the direction perpendicular to the XOY plane is the Z direction. Then, the surface of the wing 6 is discretized into points, and laser ultrasonic scanning is performed along the discretized curve by connecting several discrete points into lines. The local coordinate system Lm-Ln-Lz is established according to the scanning curve, and the wingspan direction data set p(I 1i ,Lm,t),p(I 1i ,Lm,t) and wing circumference direction data set p(J j ,Ln,t) is used to image the defect.

[0081] In one embodiment of the present invention, when imaging defects, the surface of the wing 6 is first discretized into points, and then a number of discrete points are connected into lines, such as Figure 3 As shown, it is convenient for the laser ultrasonic scanning in S1. The span direction along the surface of the wing 6 is M, the circumference direction is N, and the distance λ between every two discrete points on the left side of the wing 6 contour in the N direction is used to discretize the contour line in this direction into n points. The circumference of the leftmost contour line is c 0 =n×λ, measure the perimeter c of the contour line in the N direction every λ along the M direction n , the circumference of the contour line of wing 6 at the position mλ from the leftmost side of wing 6 is c m , discretize each contour line into n points, and the distance between each two points of the contour line of wing 6 in the N direction is c m λ / c 0 , divide the wing 6 into m contour lines along the M direction, each contour line is discretized into n points, the total length of the wing 6 along the M direction is L = m × λ, divide the wing 6 into left and right parts, and divide the wing 6 along the M direction into L 1 =m 1 ×λ,L 2 =m 2 ×λ, thus dividing the wing 6 surface into (m 1 +m 2 )×n discrete points;

[0082] Establish the coordinate system: Establish the global space rectangular coordinate system XYZ at the end of the wing 6 with the center point of the joint of the two wings 6 as the origin O. The X direction points to the wingspan direction of the wing 6 at the initial position, and the Y direction points to the wing width direction perpendicular to the X direction. The XOY plane is parallel to the horizontal plane, and the direction perpendicular to the XOY plane is the Z direction. The coordinates (d, e, f) of each discrete point are determined by the secondary coordinate system. At the initial position, the maximum transverse plane of the wing 6 is parallel to the XOY plane, and the position of the bottom plate of the three-axis mobile platform 7 on the XYZ coordinate is (0, e 0 ,f pt0 )-(L,e 0 ,f pt0 ), where L is the wingspan length of wing 6, e 0 is the distance between the three-axis mobile platform 7 and the wing 6, e 0 ≥0.5W max +0.5W pt , W pt is the width of the guide rail platform 2;

[0083] Connect discrete points into lines: 1 and L 2In the two contour segments, each discrete point is connected into a curve along the N direction to form a wing circumferential section contour curve of the wing 6. Each discrete point in the N direction is connected to a discrete point on the next section contour curve closest to each point along the M direction to form a spanwise curve. The two curves together form a mesh space curve. The curve in the M direction closest to the laser ultrasonic probe 8 in the initial state is defined as I 10 , in L 1 The curve segment with a distance of i×λ along the N direction is I 1i ; in L 2 The curve along the N direction is I 2i , define the curve in the N direction of the leftmost end of wing 6 in the initial state as J 0 , the curve with a distance of j×λ along the M direction is J j ;

[0084] L 1 Segment scan; first find out J 0 In J 0 with I 10 Intersection point (d 0 ,e 0 ,f 0 ) at the tangent line ff 0 =k 0 (ee 0 ), by k 0 The inclination angle of the tangent at this point is calculated, and the wing 6 is rotated by connecting the disk 3 to keep the tangent vertical, and then the position of the laser ultrasonic probe 8 is adjusted through the Z axis to make the laser light path perpendicular to the curve I at the intersection. 10 , and along I 10 Scan from the leftmost end of wing 6 to the right at a speed of v, with a scanning time of t. When the X-axis scanning position is at d = vt = L 1 When the movement stops, the connecting disc 3 drives the wing 6 to rotate, so that J 1 In J 1 with I 11 Intersection point (d 1 ,e 1 ,f 1 ) at the tangent line ff 1 =k 1 (ee 1 ) is kept vertical, and the Z axis is adjusted so that the optical path of the ultrasonic laser probe is perpendicular to I at the intersection. 11 , and along the curve I 11 Scan from right to left, and the scanning time is reset, thus completing a round of scanning. The excitation point of the i-th scan is (d i ,e i ,f i ), repeat the above steps until all L 1iThe curve scanning is completed. During the scanning process, the laser ultrasonic probe 8 works as follows: Figure 4 When the laser ultrasonic probe 8 is working, there is one excitation point and two detection points on the surface of the wing 6 at the same time. The coordinates of the excitation point are (d i ,e i ,f i ), the signal in the wingspan direction is measured by detection point 1, and the signal in the wing circumference direction is measured by detection point 2. The local coordinate system Lm-Ln-Lz is established based on the scanning curve, and the Lz direction is the surface of the wing 6 at the excitation point (d i ,e i ,f i ) points to the inside of the wing 6, and the Lm direction points to the current wingspan curve I 1i The scanning direction of Ln is the wing circumference direction at this point. 1i Curve, the span direction I can be obtained at the same time 1i The scanned data set p(I 1i ,Lm,t) and L 1 Segment wing circumferential direction curve J j The upper scan data set p(J j ,Ln,t);

[0085] L 2 Segment scan: L 1 When the segment scan is completed, the wing 6 returns to the initial position, and J is calculated at this time. 0 In J 0 With L 20 The tangent line at the intersection of L and L is kept vertical by adjusting the optical path of the laser ultrasonic probe 8 to be perpendicular to L at the intersection. 20 , and along the curve L 20 Scan in the span direction and repeat L 1 Segment scan until all L 2i Scan to obtain the span direction I 2i The scanned data set p(I 2i ,Lm,t) and L 2 Segment wing circumferential direction curve J j The upper scan data set p(J j ,Ln,t).

[0086] Further optimization scheme, the sub-surface crack defect is a plane defect, and the sub-surface crack defect has a sub-surface defect located on the wing periphery curve J s In the corresponding span section LnOLz, using the wing circumference data set p(J j ,Ln,t) to detect sub-surface defects. The specific steps of the sub-surface crack defect detection process are as follows:

[0087] Subsurface defect vertex coordinates Ln0 Determination: During the scanning process, only the curve J in the wing circumferential direction s Scanning data p(J s ,Ln,t), a defect echo signal RL will appear. Observe the defect echo signal RL of the scanned data set to determine the wing circumferential section where the sub-surface defect is located;

[0088] Subsurface defect vertex coordinates Ln 0 Determination: Observe the scan data p(J s ,Ln,t), when the arrival time of the reflected wave RL is t RL When the minimum value is obtained, the defect vertex is located at the midpoint between the excitation point and the second detection point in the Ln direction, thus obtaining the sub-surface defect vertex coordinate Ln 0 ;

[0089] Subsurface defect vertex coordinates Lz 0 Determination: The coordinates of the defect vertex are (Ln 0 ,Lz 0 ), the coordinates of the excitation point are (Ln 1 ,0), the coordinates of the second detection point are (Ln 1 +l,0), l is the distance between the excitation point and the detection point 2, c is the wave velocity, then the subsurface crack burial depth Lz 0 It can be calculated by the following formula:

[0090]

[0091] By scanning the data set p(I 1i ,Lm,t) and p(I 2i ,Lm,t) to perform sub-surface defect detection on the span section.

[0092] In one embodiment of the present invention, S2 sub-surface defect detection: Sub-surface defects are plane defects. The above scanning process can realize sub-surface defect detection on the wing circumference section LnOLz and the wing span section LmOLz. Assume that there is a sub-surface defect located on the wing circumference curve J s Within the corresponding span section LnOLz, the specific steps of sub-surface defect detection are as follows:

[0093] Determination of wing circumferential section: 1 Duan He L 2 During the scanning process, only the curve J in the wing circumference direction s The upper scan data p(J s ,Ln,t), the defect echo signal RL will appear, and the scan data set p(J j ,Ln,t) can determine the wing section where the sub-surface defect is located;

[0094] Subsurface defect vertex coordinates Ln0 Determination: Observe the scan data p(J s ,Ln,t), when the arrival time of the reflected wave RL is t RL When the minimum value is obtained, the defect vertex is located at the midpoint between the excitation point and the second detection point in the Ln direction, thus obtaining the sub-surface defect vertex coordinate Ln 0 ;

[0095] Subsurface defect vertex coordinates Lz 0 Determination: Figure 5 The coordinates of the defect vertex are shown as (Ln 0 ,Lz 0 ), the coordinates of the excitation point are (Ln 1 ,0), the coordinates of the second detection point are (Ln 1 +l,0), l is the distance between the excitation point and the detection point 2, c is the wave velocity, then the subsurface crack burial depth Lz 0 It can be calculated by the following formula:

[0096]

[0097] After the above steps, we can obtain s The subsurface defect vertex position of the wing circumferential section (J s ,Ln 0 ,Lz 0 ), the coordinate transformation can be further performed to obtain the defect vertex position in the rectangular coordinate system (x 0 ,y 0 ,z 0 ). Similarly, by scanning the data set p(I 1i ,Lm,t) and p(I 2i ,Lm,t) to perform sub-surface defect detection on the span section.

[0098] Further optimization scheme, the surface crack defect is a plane defect, and there is a surface defect located on the wingspan curve I 1s The specific steps for surface defect detection within the corresponding span section LmOLz are as follows:

[0099] According to the scan data set p(I 1i ,Lm,t) draw all the span section B scans in sequence;

[0100] During the scanning process, the excitation point and the detection point are fixed. When there is no defect between the excitation point and the detection point, the propagation time of the surface acoustic wave from the excitation point to the detection point is the same, and the B-scan image is a continuous straight line.

[0101] When there is a defect between the excitation point and the detection point, most of the surface waves will be reflected when they are transmitted from the excitation point to the side of the defect. The signal intensity detected at the detection point is very low, and the scanning image is a straight line with a gap, thereby determining the span section I where the surface defect is located. 1s ;

[0102] The position of the notch in the B-scan is the position of the surface defect, and the spanwise coordinates Lms1 and Lms2 can be obtained based on the B-scan.

[0103] By p(J s ,Ln,t) to carry out surface defect detection on the wing circumference section.

[0104] In one embodiment of the present invention, S3 surface defect detection: The surface defect is a plane defect. The location of the defect can be determined by presenting the scan data set in the form of a B-scan image. Assume that there is a surface defect located on the wing span curve I 1s Within the corresponding span section LmOLz, the specific steps of surface defect detection are as follows:

[0105] According to the scan data set p(I 1i ,Lm,t) draw all the span section B scans in sequence;

[0106] During the scanning process, the excitation point and the detection point are fixed. When there is no defect between the excitation point and the detection point, the propagation time of the surface acoustic wave from the excitation point to the detection point is the same, and the B-scan image is a continuous straight line.

[0107] like Figure 6 As shown in the figure, when there is a defect between the excitation point and the detection point, most of the surface waves will be reflected when they are transmitted from the excitation point to the side of the defect. The signal intensity detected at the detection point is very low, and the scanning image is a straight line with a gap, thereby determining the span section I where the surface defect is located. 1s ;

[0108] The position of the notch in the B-scan image is the position of the surface defect. Figure 7 As shown in Figure 2, the spanwise coordinates Lms1 and Lms2 can be obtained from the B-scan diagram. Similarly, p(J s ,Ln,t) to carry out surface defect detection on the wing circumference section.

[0109] Further optimization scheme, according to the scan data set p(I 1i ,Lm,t),p(I 2i ,Lm,t) and p(J j ,Ln,t) can achieve three-dimensional imaging in two ways to present the location and shape of internal defects;

[0110] Extract span curve I1i The corresponding two-dimensional data set p 1i (Lm,t) for span curve I 1i The specific steps of focusing imaging corresponding to the two-dimensional span section include calculating the equivalent velocity in the frequency-wavenumber domain by numerical calculation, calculating the phase shift factor according to the equivalent velocity, two-dimensional spectrum extrapolation and imaging matrix calculation. The equivalent velocity can be calculated by the following formula:

[0111]

[0112] Change the imaging depth Lz, repeat the above steps until the amplitude calculation of all imaging points is completed, and the wingspan curve I is obtained. 1i The imaging matrix I(Lm,Lz) corresponding to the two-dimensional wingspan section;

[0113] Collect all wingspan cross-sectional imaging matrices to obtain L 1 The three-dimensional imaging matrix I(I 1i ,Lm,Lz);

[0114] Perform coordinate transformation to obtain the three-dimensional imaging matrix I (x, y, z) in the rectangular coordinate system and perform imaging.

[0115] Further optimization scheme, based on the wing circumferential scanning data set p(J j The specific steps of three-dimensional imaging of the wing 6 of ,Ln,t) are as follows:

[0116] The wing circumference section is divided into several contour segments, the outer contour is unfolded into a straight line, the wing circumference section in the imaging segment is unfolded into a plane, and the imaging segment is imaged in the frequency domain to obtain the plane frequency domain imaging matrix in the contour segment;

[0117] The surface images in all contour segments are stitched together to form the wing circumference curve J j The frequency domain imaging matrix I(Ln,Lz) corresponding to the 2D cross section of the wing;

[0118] The 2D wing span section imaging corresponding to the wing circumference curve is performed in sequence, and all wing circumference section imaging matrices are combined to obtain the 3D imaging matrix I(J) of the wing 6. j ,Ln,Lz)

[0119] In one embodiment of the present invention, three-dimensional imaging of internal defects of S4 wings: by scanning the data set p(I 1i ,Lm,t),p(I 2i ,Lm,t) and p(J j ,Ln,t) can realize three-dimensional imaging and present defects more intuitively. 1i ,Lm,t) 1 An example of three-dimensional imaging of section wing 6 is shown below:

[0120] Step S4.1.1, extracting wingspan curve I 1i The corresponding two-dimensional data set p 1i (Lm,t) for span curve I 1i Corresponding to the focused imaging of the two-dimensional wingspan section. The specific implementation steps of the two-dimensional focused imaging algorithm are as follows:

[0121] Step S4.1.2, calculate the equivalent speed c eq . Equivalent speed c eq The calculation principle is as follows Figure 8 The coordinates of the target point G are (Lm0, Lz0), the coordinates of the excitation point are (LmE, 0), and the coordinates of the corresponding detection point 1 are (LmR, 0). The distance between the two points is such that the equivalent detection point M (LmR-l / 2, 0) is located at the midpoint between the two points. T is the excitation angle, γ R is the detection angle, γ M is the equivalent detection angle, c is the actual wave speed. eq The calculation process is as follows:

[0122] Calculate the excitation angle γ of different target points when the detection position changes T , detection angle γ R and the equivalent detection angle γ M , we get γ T , γ R and γ M The functional relationship f(γ T ,γ R ,γ M );

[0123] Calculate the wavenumber domain excitation angle γ′ in the wavenumber domain T , wave number domain detection angle γ′ R , the calculation process can be expressed by the following formula:

[0124] k Lm = k(sinγ′ T +sinγ′ R )

[0125] In the formula, k Lm is the wave number in the Lm direction, which is determined by the scanning step length in the span direction, k is the wave number, k = ω / c, ω is the frequency;

[0126] Calculated wave number domain excitation angle γ′ T and wavenumber domain detection angle γ′ R According to the functional relationship f(γ T ,γ R ,γ M ) Calculate the equivalent detection angle γ′ in the wavenumber domainM ;

[0127] From the wave number domain excitation angle γ′ T , wave number domain detection angle γ′ R , wave number domain equivalent detection angle γ′ M and the actual wave speed c to calculate the equivalent wave speed c eq , the calculation process is shown as follows:

[0128]

[0129] The wingspan curve I 1i The corresponding two-dimensional data set p 1i (Lm, t) is transformed into a two-dimensional Fourier transform to obtain the two-dimensional spectrum P(k Lm ,0,ω);

[0130] The two-dimensional spectrum at depth Lz = 0 is extrapolated to the plane of depth Lz to obtain the two-dimensional spectrum P(k Lm ,0,ω), the calculation process is as follows:

[0131] P(k Lm ,Lz,ω)=P(k Lm ,0,ω)α(k Lm ,Lz,ω)

[0132] In the formula, α(k Lm ,Lz,ω) is the phase shift factor, which can be calculated using the following formula, where jj represents the imaginary unit:

[0133]

[0134] The two-dimensional spectrum P(k Lm ,Lz,ω) performs a two-dimensional Fourier inverse transform on Lm and Lz to obtain the imaging matrix of depth Lz. During the inverse transform process, t = 0, and the amplitude I(Lm,Lz) of the imaging point (Lm,Lz) can be calculated by the following formula:

[0135]

[0136] Change the imaging depth Lz, repeat the above steps until the amplitude calculation of all imaging points is completed, and the wingspan curve I is obtained. 1i Corresponding to the imaging matrix I(Lm,Lz) of the two-dimensional wingspan section, the two-dimensional wingspan section focusing imaging is drawn as follows Fig. 9 As shown;

[0137] Step S4.1.3, repeat steps S4.1.1-S4.1.2, and perform two-dimensional span section imaging corresponding to the span curve in sequence. Collect all span section imaging matrices to obtain L 1The three-dimensional imaging matrix I(I 1i ,Lm,Lz);

[0138] Step S4.1.4, perform coordinate transformation to obtain the three-dimensional imaging matrix I (x, y, z) in the rectangular coordinate system, and draw L 1 The three-dimensional focused image of section wing 6 is shown in FIG. Fig.10 shown.

[0139] The present invention is based on a wing circumferential scanning data set p(J j An example of three-dimensional imaging of the wing 6 of FIG. , Ln, t) is shown below:

[0140] Step S4.2.1, the shape of the circumferential section of the wing 6 is irregular, and the section is divided into several contour segments. The outer contour of the wing 6 is unfolded into a straight line, and the normal direction is set as the depth direction. The circumferential section of the wing 6 in the imaging segment is unfolded into a plane, and the imaging segment is imaged in the frequency domain according to the method in step S4.1.2 to obtain the plane frequency domain imaging in the contour segment;

[0141] Step S4.2.2, repeat step S4.2.1 until the surface images of all contour segments are obtained, and the surface images in all contour segments are spliced ​​into the wing circumference curve J j The corresponding 2D cross-sectional frequency domain imaging matrix I(Ln,Lz) is as follows: Fig.11 As shown;

[0142] Step S4.2.3, repeat steps S4.2.1-S4.2.2, and perform two-dimensional wing span section imaging corresponding to the wing circumference curve in sequence. Collect all wing circumference section imaging matrices to obtain L 1 The three-dimensional imaging matrix I(J j ,Ln,Lz);

[0143] Step S4.2.4, perform coordinate transformation to obtain the three-dimensional imaging matrix I (x, y, z) in the rectangular coordinate system, and draw a three-dimensional focused image of the wing 6.

[0144] Embodiment 2:

[0145] Reference Figure 12-13 The difference between this embodiment and the first embodiment is that a rotating clamping mechanism is further provided, and the rotating clamping mechanism includes a turntable 14, on which a movable clamping slide rail 15 is provided. The turntable 14 is installed on the movable slide rail 16 through a support frame, and a driving motor 17 is provided on the support frame to drive the turntable 14 to rotate.

[0146] In one embodiment of the present invention, when in use, the left end of the wing 6 is installed on the connecting disc 3, and the wing 6 is rotated to a position where the maximum cross-section is parallel to the ground, i.e., the initial position, and the bottom movable slide rail 16 is moved to align the rotating clamping mechanism with the right end of the wing 6 in the length direction, and the turntable 14 is rotated, and the movable clamping slide rail 15 is slid to clamp the right end of the wing 6 on the movable clamping slide rail 15. Due to the influence of gravity, the right end of the wing 6 has a certain flexural deformation when it is installed, so the turntable 14 is adjusted again to rotate the wing 6 to a position where the maximum cross-section is parallel to the ground, i.e., the initial position.

[0147] The provided rotating clamping mechanism can assist in clamping the wing 6, reducing the disadvantage of curvature, thereby making the detection more accurate.

[0148] Embodiment 3. The difference between this embodiment and embodiment 2 is that a long hole is provided at the movable clamping slide rail 15 and the corresponding turntable 14 for extending the right end of the wing 6. The turntable 14 and the laser ultrasonic probe 8 are arranged to move synchronously along the axial direction, thereby further reducing the bending deformation of the detection point due to gravity, thereby further improving the detection accuracy.

[0149] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0150] The above embodiments are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A wing defect detection device, characterized in that: include: A lifting platform (1) and a guide rail platform (2), wherein the lifting platform (1) and the guide rail platform (2) are respectively fixed on the ground and arranged in parallel; A rotating assembly comprises a connecting disc (3) and a main shaft (4), wherein the connecting disc (3) is rotatably connected to the top of the lifting platform (1) via the main shaft (4), two rotating disc joints (5) are fixedly connected to a side of the connecting disc (3) away from the lifting platform (1), and the wing (6) is connected to the rotating disc joints (5); A detection component, comprising a three-axis moving platform (7) and a laser ultrasonic probe (8), wherein the three-axis moving platform (7) is arranged on the guide rail platform (2), and the laser ultrasonic probe (8) is fixedly connected to the three-axis moving platform (7) for detecting the wing (6); The laser ultrasonic probe (8) is a laser ultrasonic probe with a single excitation point and two detection points.

2. A wing defect detection device according to claim 1, characterized in that: The two rotating disk joints (5) are respectively located on two sides of the connecting disk (3) and on the same diameter line.

3. A wing defect detection device according to claim 1, characterized in that: A transmission box (9) is fixedly connected to the lifting platform (1), a servo motor (10) is fixedly connected inside the transmission box (9), an output shaft of the servo motor (10) is connected to the main shaft (4) via a reducer (11), a coupling (12) and an absolute photoelectric encoder (13), and a gap is provided between the main shaft (4) and the lifting platform (1).

4. A wing defect detection method, applicable to a wing defect detection device according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1, mounting the wing (6) on the connecting disc (3) and performing laser ultrasonic scanning; S2, performing sub-surface crack defect detection on the wing (6); S3, performing surface crack defect detection on the wing (6); S4. Perform three-dimensional imaging on the wing (6) to obtain a three-dimensional image of internal defects of the wing (6).

5. A wing defect detection method according to claim 4, characterized in that: In S1, at the initial position, the wing (6) is kept parallel to the horizontal plane, and the height of the lifting platform (1) is H J The distance between the main shaft (4) and the top surface of the lifting platform (1) is h z The maximum wing width of the wing (6) is W max , satisfying: H J +h z ≥1.5W max ; The height of the guide rail platform (2) is H, and the initial height of the Z axis of the three-axis moving platform (7) is Z pt0 , satisfying: H J +h z =H+Z pt0 .

6. A wing defect detection method according to claim 5, characterized in that: During laser ultrasonic scanning, a global rectangular coordinate system XYZ is first established, wherein the X direction points to the wingspan direction of the wing (6) at the initial position, the Y direction points to the wing width direction perpendicular to the X direction, the XOY plane is parallel to the horizontal plane, and the direction perpendicular to the XOY plane is the Z direction. Then, the surface of the wing (6) is discretized into points, and laser ultrasonic scanning is performed along the discretized curve by connecting a number of discrete points into lines. A local coordinate system Lm-Ln-Lz is established according to the scanning curve, and a wingspan direction data set p(I 1i ,Lm,t),p(I 1i ,Lm,t) and wing circumference direction data set p(J j ,Ln,t) is used to image the defect.

7. A wing defect detection method according to claim 6, characterized in that: Subsurface crack defect is a plane defect. Subsurface crack defect has a subsurface defect located on the wing periphery curve J. s In the corresponding span section LnOLz, using the wing circumference data set p(J j ,Ln,t) to detect sub-surface defects. The specific steps of the sub-surface crack defect detection process are as follows: Determination of the sub-surface defect vertex coordinates Ln0: During the scanning process, only the wing circumferential direction curve J s Scanning data p(J s ,Ln,t), a defect echo signal RL will appear. Observe the defect echo signal RL of the scanned data set to determine the wing circumferential section where the sub-surface defect is located; Determination of the sub-surface defect vertex coordinates Ln0: Observe the scanning data p(J s ,Ln,t), when the arrival time of the reflected wave RL is t RL When the minimum value is obtained, the defect vertex is located at the midpoint between the excitation point and the second detection point in the Ln direction, thus obtaining the sub-surface defect vertex coordinate Ln0; Determination of the coordinates of the sub-surface defect vertex Lz0: The coordinates of the defect vertex are (Ln0, Lz0), the coordinates of the excitation point are (Ln1, 0), the coordinates of the second detection point are (Ln1 + l, 0), l is the distance between the excitation point and the second detection point, c is the wave velocity, and the sub-surface crack burial depth Lz0 can be calculated by the following formula: By scanning the data set p(I 1i ,Lm,t) and p(I 2i ,Lm,t) to perform sub-surface defect detection on the span section.

8. A wing defect detection method according to claim 7, characterized in that: The surface crack defect is a plane defect. There is a surface defect located on the wingspan curve I 1s The specific steps for surface defect detection within the corresponding span section LmOLz are as follows: According to the scan data set p(I 1i ,Lm,t) draw all the span section B scans in sequence; During the scanning process, the excitation point and the detection point are fixed. When there is no defect between the excitation point and the detection point, the propagation time of the surface acoustic wave from the excitation point to the detection point is the same, and the B-scan image is a continuous straight line. When there is a defect between the excitation point and the detection point, most of the surface waves will be reflected when they are transmitted from the excitation point to the side of the defect. The signal intensity detected at the detection point is very low, and the scanning image is a straight line with a gap, thereby determining the span section I where the surface defect is located. 1s ; The position of the notch in the B-scan is the position of the surface defect, and the spanwise coordinates Lms1 and Lms2 can be obtained based on the B-scan. By p(J s ,Ln,t) to carry out surface defect detection on the wing circumference section.

9. A wing defect detection method according to claim 8, characterized in that: According to the scan data set p(I 1i ,Lm,t),p(I 2i ,Lm,t) and p(J j ,Ln,t) can achieve three-dimensional imaging in two ways to present the location and shape of internal defects; Extracting the wingspan curve I 1i The corresponding two-dimensional data set p 1i (Lm,t) for span curve I 1i The focused imaging corresponding to the two-dimensional span section includes the following specific steps: calculating the equivalent velocity in the frequency-wave number domain by numerical calculation, calculating the phase shift factor according to the equivalent velocity, two-dimensional spectrum extrapolation and imaging matrix calculation. The equivalent velocity can be calculated by the following formula: Change the imaging depth Lz, repeat the above steps until the amplitude calculation of all imaging points is completed, and the wingspan curve I is obtained. 1i The imaging matrix I(Lm,Lz) corresponding to the two-dimensional wingspan section; Collect all wingspan cross-sectional imaging matrices to obtain the three-dimensional imaging matrix I (I 1i ,Lm,Lz); Perform coordinate transformation to obtain the three-dimensional imaging matrix I (x, y, z) in the rectangular coordinate system and perform imaging.

10. A wing defect detection method according to claim 9, characterized in that: Based on the wing circumferential scanning data set p(J j The specific steps of three-dimensional imaging of the wing (6) of FIG. , Ln, t) are as follows: The wing circumference section is divided into several contour segments, the outer contour is unfolded into a straight line, the wing circumference section in the imaging segment is unfolded into a plane, and the imaging segment is imaged in the frequency domain to obtain the plane frequency domain imaging matrix in the contour segment; The surface images in all contour segments are stitched together to form the wing circumference curve J j The frequency domain imaging matrix I(Ln,Lz) corresponding to the 2D cross section of the wing; The two-dimensional wingspan section imaging corresponding to the wing circumference curve is performed in sequence, and all wing circumference section imaging matrices are combined to obtain the three-dimensional imaging matrix I(J) of the wing (6). j ,Ln,Lz).

Images