Transparent part optical array type angular deviation high-precision optical measurement method

Abstract

The invention provides a transparent part optical array type angular deviation high-precision optical measurement method, and relates to the technical field of automatic detection. The method comprises the following steps: firstly, acquiring four-point array light spot images before and after a transparent part is placed, and obtaining a light spot reference image and an array light spot image after light spot offset; secondly, detecting the light spot brightness centers of the light spot reference image and the array light spot image after light spot offset to obtain coordinates of four light spot brightness center points in the light spot reference image and the array light spot image; the optical angle deviation of four light spot brightness center points in the array light spot image is calculated; and finally, estimating an optical angle deviation area according to the optical angle deviation of the brightness center points of the four light spots in the array light spot image, and determining an angle deviation value of any point in the area. Compared with a traditional optical angle deviation measurement method, the method has the advantages of being large in detection range, high in detection precision, high in calculation efficiency, high in automation degree and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of automated detection, and particularly to a high-precision optical measurement method for the angular deviation of an optical array of transparent parts. Background Art

[0002] The arc-shaped curved windshield is an important transparent part for drivers to observe the external environment and determine distances. For the arc-shaped windshield, the influencing factors of its optical performance include: optical angular deviation, optical distortion, light transmittance, refractive index, parallax, clarity, etc. Among them, the determination of optical angular deviation is of great significance for the optical quality detection of transparent parts. Essentially, optical angular deviation is the amount of angular change in the propagation direction of light after passing through a transparent part, which macroscopically manifests as slight changes in the imaging position and shape.

[0003] To accurately measure optical angular deviation, corresponding standards have been formulated at home and abroad (GB / T5137.2-2002, GJB50388, ASTM F801), including: the collimator telescope measurement method, the projection line measurement method, and the automated measurement method based on the "L"-shaped mark. The collimator telescope measurement method emits a parallel light beam through a collimator mirror, and this beam of light enters the telescope system after passing through the transparent part. By reading the scale value of the telescope reticle, the deflection angle of the light beam can be accurately obtained, achieving a measurement accuracy of seconds. However, this method is complex to operate and has high technical requirements; the projection line measurement method projects a line scale onto a screen using a projector, and calculates the angular deviation by comparing the scale position changes before and after the transparent part is placed. Although this method is simple to operate, its accuracy can only reach the level of minutes. The automated measurement method based on the "L"-shaped mark uses two CCD cameras to capture the position changes of the "L"-shaped mark in the X and Y directions, thereby calculating the optical angular deviation. This method has improved in terms of accuracy and efficiency, but there are problems such as unclear physical meaning and unclear measurement position. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a high-precision optical measurement method for the angular deviation of an optical array of transparent parts in view of the deficiencies of the above-mentioned prior art, realizing automated, high-precision, high-efficiency, and full-field angular deviation detection of transparent parts.

[0005] To solve the above technical problem, the technical solution adopted by the present invention is: a high-precision optical measurement method for the angular deviation of an optical array of transparent parts, which is realized based on an optical system for multi-point angular deviation measurement of an optical array of transparent parts, and includes the following steps:

[0006] Step 1: Obtain the four-point array spot images before and after the transparent part is placed, and obtain the spot reference image and the array spot image after the spot is offset.

[0007] Step 1.1: Obtain the reference spot image I(x,y) when the transparent optical array multi-point angular deviation measurement optical system does not contain a transparent component.

[0008] When no transparent component is present, use the array laser emission device to emit 4 collimated lasers. Four Gaussian spots with equal intervals are formed on the CCD area array through the collimated laser receiving device. At the same time, capture the current reference spot image I(x,y), where x and y are the horizontal and vertical pixel coordinates on the camera's CCD area array respectively; the two-dimensional coordinates (x,y) represent any pixel unit on the CCD area array.

[0009] The Gaussian spot consists of a spot brightness center and a divergence region.

[0010] Step 1.2: Place the transparent component in the transparent optical array multi-point angular deviation measurement optical system and capture the array spot image J(x,y) after the spot offset.

[0011] Place the transparent component in the optical path between the laser emission end and the receiving end, and capture the array spot image J(x,y) after the spot offset. I(x,y) and J(x,y) are represented as a two-dimensional grayscale matrix, and the value of each point represents the grayscale of the image. The sizes of these two matrices are the same as the resolution of the camera.

[0012] Step 2: Detect the spot brightness centers of the reference spot image and the array spot image after the spot offset, and obtain the coordinates of the four spot brightness centers in the reference spot image and the array spot image.

[0013] Step 2.1: Divide the images I(x,y) and J(x,y) into four regions according to the array spot positions respectively, extract the Gaussian spots from the backgrounds of the four regions to obtain the spot region images; select a grayscale value that can filter out the ambient light and retain the divergent part of the spot edge as the threshold ε 1 , and filter out the ambient light with a grayscale value less than the threshold ε in the spot region image 1 .

[0014] Step 2.2: Statistically analyze the grayscale value distributions of the spot region images respectively, select the mutated grayscale value as the threshold ε 2 , and perform secondary segmentation to obtain the spot brightness center region.

[0015] Step 2.3: Use the Sobel operator to calculate the gradient value of each pixel point in the four spot brightness center regions to identify the edges of the pixels and obtain the spot brightness center contour.

[0016] Step 2.4: Adopt the cubic spline interpolation algorithm to improve the accuracy of the spot brightness center contour to the sub-pixel level. Based on the sub-pixel level contour, perform least squares ellipse fitting to obtain the high-precision coordinates of the four spot brightness center points in the images I(x, y) and J(x, y) before and after the spot offset respectively;

[0017] The mathematical form of performing least squares ellipse fitting based on the sub-pixel level contour is as follows:

[0018]

[0019] where, (x i , y i ) are the sub-pixel coordinates obtained by edge detection combined with cubic spline interpolation calculation, n is the number of pixels for which least squares ellipse fitting needs to be performed, and k 1 ~k 6 represent the parameters of the ellipse equation;

[0020] The calculated ellipse center after fitting is This ellipse center is the high-precision coordinate of the spot brightness center point;

[0021] Step 3: Calculate the optical angle deviation of the four spot brightness center points in the array spot image;

[0022] The comprehensive deviation angle is calculated from the spot brightness center coordinates on the CCD area array. The comprehensive deviation angle is the superposition of the angular deviation θ generated by the deflection of the array laser emitted by the array laser emitting device when passing through the transparent part and the fixed polarization angle generated by passing through the polarizer; Furthermore, the optical angle deviation of the four spot brightness center points in the array spot image J(x, y) is obtained, as shown in the following formula:

[0023]

[0024] where, represents the comprehensive angular deviation, θ represents the optical angle deviation of the spot brightness center point in the array spot image J(x, y), f represents the focal length of the focusing lens at the array laser receiving end; x, y represent the coordinates of the spot brightness center point in the spot reference image I(x, y), and x′, y′ represent the coordinates of the spot brightness center point in the array spot image J(x, y);

[0025] Step 4: Estimate the optical angle deviation area based on the optical angle deviation of the four spot brightness center points in the array spot image, and determine the angular deviation value of any point within this area;

[0026] Set the optical angular deviations of the four spot brightness centers in the array spot image obtained in step 3 as the four corners of a rectangular bounding box. By performing bilinear interpolation on the rectangular region, calculate the angular deviation value of any point in this rectangular region, as shown in the following formula:

[0027] θ P =(1 - μ)(1 - v)·θ A + μ(1 - v)·θ B +(1 - μ)v·θ C + μv·θ D

[0028] Where, θ A 、θ B 、θ C 、θ D are respectively the optical angular deviations of the four spot brightness centers in the array spot image, and θ P represents the angular deviation value of any point P within the rectangular region, and its relative position within the rectangle is represented by the parameters μ and ν, where 0 ≤ μ, ν ≤ 1.

[0029] The present invention proposes a new measurement method based on an array laser system and digital image processing technology. This method can identify and calculate the position offset of the array spots before and after the transparent part is placed, and then accurately calculate the angular deviation. In addition, combined with the bilinear interpolation method, it can also estimate the angular deviation value of any point within the array region, achieving high-precision measurement of the angular deviation of the transparent part. This method has the advantages of full-field measurement, high automation degree, high measurement efficiency, and detection accuracy, significantly improving the measurement technology level of the optical angular deviation.

[0030] The beneficial effects of adopting the above technical solution are as follows: The high-precision optical measurement method for the optical array angular deviation of a transparent part provided by the present invention, based on digital image processing, combines ellipse least squares fitting and linear interpolation calculation, and can obtain the optical angular deviation values and distribution within the full field of view of the transparent part; compared with the traditional optical angular deviation measurement method, it has the advantages of a large detection range, high detection accuracy, high calculation efficiency, and high automation degree. Brief Description of the Drawings

[0031] Figure 1 is a flowchart of a high-precision optical measurement method for the optical array angular deviation of a transparent part provided by an embodiment of the present invention;

[0032] Figure 2 is an optical path system diagram provided by an embodiment of the present invention;

[0033] Figure 3 is a schematic diagram of the angular deviation calculation principle provided by an embodiment of the present invention.

[0034] In the figure: 1. Array laser emission device; 2. Transparent part installation area; 3. Array laser reception device; 4. CCD area array; 5. Transparent part; 6. Polarizing lens; 7. Focusing lens. Detailed implementation mode

[0035] The following combines the accompanying drawings and embodiments to further describe in detail the specific implementation mode of the present invention. The following embodiments are used to illustrate the present invention, but are not used to limit the scope of the present invention.

[0036] In this embodiment, the transparent part optical array type angular deviation high-precision optical measurement method of the present invention is used to detect the angular deviation values of 4 standard optical wedges to verify the accuracy of the method of the present invention. A standard optical wedge means that the angular deviation generated by incident light from any angle is a fixed value and can be used as a standard value. The standard deviation of the angular deviation values calculated by the method of the present invention is statistically calculated. The larger the standard deviation, the lower the accuracy, and vice versa. The four selected standard optical wedges are 1°, 2°, 3°, and 4° respectively, that is, the standard value of the angular deviation is the same as the angle of the optical wedge.

[0037] The detection process includes four parts: obtaining the four-point array light spot images before and after the transparent part is placed, detecting the light spot brightness center of the reference image and the image after the light spot is offset, calculating the optical angular deviation of the four light spot brightness center points, and estimating the optical angular deviation area.

[0038] In this embodiment, a transparent part optical array type angular deviation high-precision optical measurement method is based on a transparent part optical array type multi-point angular deviation measurement optical system. Among them, the transparent part optical array type multi-point angular deviation measurement optical system includes an array laser emission device 1, a transparent part installation area 2, an array laser reception device 3, a CCD area array 4, and a transparent part 5; the array laser reception device includes a polarizing lens 6 and a focusing lens 7.

[0039] This measurement method is as Figure 1 shown and includes the following steps:

[0040] Step 1: Obtain the four-point array light spot images before and after the transparent part is placed to obtain the light spot reference image and the array light spot image after the light spot is offset;

[0041] Step 1.1: In the case where the transparent part is not placed in the transparent part optical array type multi-point angular deviation measurement optical system, obtain the light spot reference image I(x, y), where x and y are the horizontal and vertical pixel coordinates on the camera CCD area array 4 respectively; use the two-dimensional coordinates (x, y) to represent any pixel unit on the CCD area array 4.

[0042] When the transparent part is not placed, the array laser emitting device 1 is used to emit a 2×2 array laser of 4 beams. Four Gaussian spots with a diameter of 2 mm and equal intervals are formed on the CCD area array 4 through the array laser receiving device 3, and the current reference spot image I(x, y) is captured at the same time. The Gaussian spot consists of a spot brightness center and a divergence region.

[0043] Step 1.2: Place the transparent part in the optical array multi-point angular deviation measurement optical system of the transparent part, and capture the array spot image J(x, y) after the spot offset.

[0044] Place the transparent part 5 in the optical path of the laser emitting end and the receiving end, and capture the array spot image J(x, y) after the spot offset. I(x, y) and J(x, y) are represented as a two-dimensional gray matrix, and the value of each point represents the gray level of the image. The size of this matrix is the same as the resolution of the camera.

[0045] The implementation conditions of Step 1 are: 1) The array laser emitting device 1, the array laser receiving device 3, and the CCD area array 4 are kept on the same horizontal straight line, and the placed transparent part 5 must be within the optical path of the emitting end and the receiving end; 2) Before and after the transparent part 5 is placed, the spatial position relationship of the optical path system does not change; 3) Select a CCD area array 4 with high resolution; 4) Ensure that the environmental illumination conditions do not change and the light is sufficient during the two shootings; 5) Ensure that the array laser receiving device 3 can accurately focus the spot on the CCD area array 4. In this embodiment, first, the optical wedge to be measured is installed on the transparent part bracket at an actual installation angle of 15 degrees with respect to the horizontal line. Adjust the heights of the transparent part bracket, the array laser emitting device 1, and the array laser receiving device 3 to ensure that the center of the rectangular area formed by the four-point array laser is on the same horizontal line as the geometric center of the optical wedge transparent part. Then adjust the distance in the horizontal direction so that the distance between the laser emitting end and the transparent part is L 1 = 1.5 m, and the distance between the receiving end and the transparent part is L 2 = 1.2 m, as Figure 2As shown in the figure. In the array laser receiving device, a polarizing mirror 6 with a polarization angle of 1.15° and a focusing lens 7 with a focal length of 1.5 mm are selected. A linear array CCD of Work Power WP-UT880 / M is selected for spot acquisition. A tripod of Benro CB258CKB is selected. The exposure time of the camera is adjusted to 30 s, and the laser intensity is set to 5 mw. Then, without inserting the optical wedge transparent part, the array laser transmitting and receiving device is turned on, and a four-point array spot with regular shape, uniform distribution, obvious and stable brightness is observed on the PC side. Save this frame of image and name it (Pic0). Secondly, insert a 1° optical wedge. After observing a stable four-point spot on the PC side, save this frame of image and name it (Pic1). Finally, insert 2°, 3°, and 4° optical wedges in sequence, and save the images as (Pic2, Pic3, Pic4) respectively to obtain the spot offset images (Pic1, Pic2, Pic3, Pic4). During the whole shooting process, ensure that the array laser transmitting end, receiving end, and transparent part bracket do not move.

[0046] Step 2: Detect the brightness centers of the spots in the spot reference image and the array spot image after spot offset, and obtain the coordinates of the four spot brightness center points in the spot reference image and the array spot image;

[0047] Step 2.1: Divide the images I(x, y) and J(x, y) into four regions equally according to the positions of the array spots, extract the Gaussian spots from the backgrounds of the four regions to obtain the spot region images; Select a gray value that can filter out the ambient light and retain the divergent part of the spot edge as the threshold ε 1 , filter out the ambient light with a gray value less than the threshold ε in the spot region image 1 .

[0048] Step 2.2: Statistically analyze the gray value distributions of the spot region images respectively, select the mutated gray value as the threshold ε 2 , and perform secondary segmentation to obtain the spot brightness center region;

[0049] Step 2.3: Use the Sobel operator to calculate the gradient value of each pixel point in the four spot brightness center regions to identify the edges of the pixels and obtain the spot brightness center contour;

[0050] Step 2.4: Use the cubic spline interpolation algorithm to improve the accuracy of the spot brightness center contour to the sub-pixel level, and perform least squares ellipse fitting based on the sub-pixel level contour to obtain the high-precision coordinates of the four spot brightness center points in the images I(x, y) and J(x, y) before and after spot offset respectively;

[0051] The mathematical form of least squares ellipse fitting based on the sub-pixel level contour is as follows:

[0052]

[0053] Among them, (x i , y i ) are sub-pixel coordinates obtained by edge detection combined with cubic spline interpolation. n is the number of pixels for which least squares ellipse fitting needs to be performed, and k 1 ~k 6 represent the parameters of the ellipse equation;

[0054] The center of the ellipse calculated after fitting is This ellipse center is the high-precision coordinate of the center point of the spot brightness;

[0055] From this, the high-precision coordinates of the four center points of the spot brightness in the images I(x, y) and J(x, y) before and after the spot offset are respectively obtained;

[0056] In this embodiment, the four center points of the spots in the image I(x, y) are respectively A, B, C, and D; the four corresponding center points of the spots in the image J(x, y) are respectively A′, B′, C′, and D′.

[0057] The implementation condition of step 2 is to ensure that the implementation condition of step 1 remains unchanged and at the same time ensure that the spot distribution is uniform.

[0058] In this embodiment, first, background threshold ε 1 = 210 and secondary segmentation ε 2 = 235 threshold segmentation are respectively performed on the reference image Pic0 and the spot offset images (Pic1, Pic2, Pic3, Pic4) to segment out the accurate high-brightness spot regions. Then, least squares ellipse fitting and center positioning are performed on the high-brightness spot regions to respectively obtain the four points (A, B, C, D) detected in the image Pic0; the four points (A′ 1 , B′ 1 , C 1 ′, D′ 1 ) detected in Pic1; the four points (A′ 2 , B′ 2 , C 2 ′, D′ 2 ) detected in Pic2; the four points (A′ 3 , B′ 3 , C 3 ′, D′ 3 ) detected in Pic3; the four points (A′ 4 , B 4 ′, C 4 ′, D′ 4 ) detected in Pic4.

[0059] In this embodiment, A(x A , yA ) is the center coordinate of the upper left light spot in the reference image 1; B(x B , y B ) is the center coordinate of the upper right light spot in the reference image 1; C(x C , y C ) is the center coordinate of the lower left light spot in the reference image 1; D(x D , y D ) is the center coordinate of the lower right light spot in the reference image 1; a′(x A′ , y A′ ) is the center coordinate of the upper left light spot in the image 2 after the light spot offset; B′(x B′ , y B′ ) is the center coordinate of the upper right light spot in the image 2 after the light spot offset; C′(x C′ , y C′ ) is the center coordinate of the lower left light spot in the image 2 after the light spot offset; D′(x D′ , y D′ ) is the center coordinate of the lower right light spot in the image 2 after the light spot offset;

[0060] Step 3: Calculate the optical angular deviation of the four light spot brightness centers in the array light spot image;

[0061] As Figure 3 shown, the array laser emitted by the array laser emitting device is deflected when passing through the transparent member 5, generating an angular deviation θ; subsequently, a fixed polarization angle is generated through the polarizer 6 Finally, four-point offset light spots are formed on the CCD area array 4 through the focusing lens 7; at this time, the angular deviation calculated using this offset light spot is actually the combined angular deviation of the angular deviation θ and superimposed, that is, the optical angular deviation of the light spot brightness center point in the image I(x, y) shifted to the light spot brightness center point in the image J(x, y); and because is the fixed polarization angle determined by the polarizer, the angular deviation θ generated by the deflection of the array laser when passing through the transparent member 5 can be accurately extracted through mathematical derivation, that is, the optical angular deviation of the light spot brightness center point in the array light spot image J(x, y);

[0062] The combined deviation angle is calculated from the light spot brightness center coordinates on the CCD area array. The combined deviation angle is the angular deviation θ generated by the deflection of the array laser emitted by the array laser emitting device when passing through the transparent member 5 and the fixed polarization angle superimposed; thus, the optical angular deviation of the four light spot brightness center points in the array light spot image J(x, y) is obtained, as shown in the following formula:

[0063]

[0064] Among them, represents the comprehensive angular deviation, θ represents the optical angular deviation of the center point of the spot brightness in the array spot image J(x, y), f represents the focal length of the focusing mirror at the receiving end of the array laser, that is Figure 3 the L in; x, y represent the coordinates of the center point of the spot brightness in the spot reference image I(x, y), and x′, y′ represent the coordinates of the center point of the spot brightness in the array spot image J(x, y);

[0065] In this embodiment, θ A is the angular deviation value of the center point A of the spot brightness calculated by combining A(x A , y A ) and A′(x A′ , y A′ ); θ B is the angular deviation value of the center point B of the spot brightness calculated by combining B(x B , y B ) and B′(x B′ , y B′ ); θ C is the angular deviation value of the center point C of the spot brightness calculated by combining C(x C , y C ) and C′(x C′ , y C′ ); θ D is the angular deviation value of the center point D of the spot brightness calculated by combining D(x D , y D ) and D′(x D′ , y D′ );

[0066] The implementation condition of step 3 is to ensure that the implementation conditions of step 1 and step 2 remain unchanged.

[0067] In this embodiment, the optical angular deviations of the four center points of the spot brightness in the array spot image J(x, y) are calculated. Using the image Pic0 to calculate the angular deviations with the corresponding four center points of the spot brightness of the images Pic1, Pic2, Pic3, and Pic4 respectively, the following results are obtained:

[0068] 1° optical wedge: Point A: 1.0117°; Point B: 1.0137°; Point C: 1.0135°; Point D: 1.0118°;

[0069] 2° optical wedge: Point A: 2.0170°; Point B: 2.0161°; Point C: 2.0182°; Point D: 2.0169°;

[0070] 3° optical wedge: Point A: 3.0198°; Point B: 3.0199°; Point C: 3.0193°; Point D: 3.0197°;

[0071] 4° optical wedge: Point A: 4.0206°; Point B: 4.0217°; Point C: 4.0207°; Point D: 4.0211°.

[0072] Step 4: Estimate the optical angle deviation region based on the optical angle deviations of the four light spot brightness centers in the array light spot image, and determine the angle deviation value of any point within this region;

[0073] It is generally considered that for a transparent part without manufacturing defects, the change in its optical performance is uniform. Therefore, set the optical angle deviations of the four light spot brightness centers in the array light spot image calculated in Step 3 as the four corners of a rectangular bounding box. By performing bilinear interpolation on the rectangular region, calculate the angle deviation value of any point within this rectangular region, as shown in the following formula:

[0074] θ P =(1 - μ)(1 - ν)·θ A +μ(1 - v)·θ B +(1 - μ)v·θ C +μv·θ D

[0075] where, θ A 、θ B 、θ C 、θ D are respectively the optical angle deviations of the four light spot brightness centers in the array light spot image, θ P represents the angle deviation value of any point P within the rectangular region, and its relative position within the rectangle is represented by the parameters μ and v, where 0 ≤ μ, ν ≤ 1.

[0076] The implementation condition of Step 4 is to ensure that the implementation conditions of Step 1 and Step 2 remain unchanged, and at the same time limit the estimated angle deviation region not to exceed the rectangular region formed by the four light spot centers.

[0077] Finally, it should be noted that: The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it; Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: They can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; And these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope defined by the claims of the present invention.

Claims

1. A high-precision optical measurement method for transparent optical array angular deviation, based on a transparent optical array multi-point angular deviation measurement optical system, characterized in that: The following steps are involved: Step 1: Obtain the four-point array spot image before and after the transparent part is placed, and obtain the spot reference image and the array spot image after the spot is shifted; Step 2: Detect the brightness center of the light spot of the light spot reference image and the array light spot image after the light spot is shifted, and obtain the coordinates of the four light spot brightness center points in the light spot reference image and the array light spot image; Step 3: Calculate the optical angle deviation of the brightness center points of the four light spots in the array light spot image; Step 4: Estimate the optical angle deviation area according to the optical angle deviation of the brightness center points of the four light spots in the array light spot image, and determine the angle deviation value of any point in the area.

2. A method for high-precision optical measurement of angular deviation of a transparent component optical array according to claim 1, characterized in that: The step 1 comprises: Step 1.1: When the transparent component optical array multi-point angular deviation measurement optical system is not placed in the transparent component, obtain a light spot reference image I (x, y); When no transparent part is placed, an array laser emitting device is used to emit 4 collimated lasers, which are then passed through a collimated laser receiving device to form 4 equally spaced Gaussian spots on the CCD array, and the current spot reference image I (x, y) is captured at the same time, where x and y are the horizontal and vertical pixel coordinates on the camera CCD array, respectively; the two-dimensional coordinates (x, y) represent any pixel unit on the CCD array; The Gaussian spot consists of a spot brightness center and a divergent area; Step 1.2: Place a transparent part in the transparent part optical array multi-point angular deviation measurement optical system to capture the array spot image J(x, y) after the spot is shifted; A transparent component is placed in the optical path of the laser emitting end and the receiving end to capture the array spot image J(x, y) after the spot is shifted; I(x, y) and J(x, y) are expressed as a two-dimensional grayscale matrix, and the value of each point represents the grayscale of the image. The size of these two matrices is the same as the resolution of the camera.

3. A high-precision optical measurement method for angular deviation of a transparent component optical array according to claim 2, characterized in that: The step 2 comprises: Step 2.1: Divide the images I(x, y) and J(x, y) into four regions according to the array spot positions, extract the Gaussian spot from the background of the four regions, and obtain the spot region image; select a gray value that can filter out the ambient light and retain the divergent part of the spot edge as the threshold ε1, and filter out the ambient light with a gray value less than the threshold ε1 in the spot region image; Step 2.2: Count the gray value distribution of the spot area image respectively, select the sudden gray value as the threshold ε2, perform secondary segmentation, and obtain the brightness center area of ​​the spot; Step 2.3: Use the Sobel operator to calculate the gradient value of each pixel in the four light spot brightness center areas to identify the edge of the pixel and obtain the light spot brightness center contour; Step 2.4: Use the cubic spline interpolation algorithm to improve the accuracy of the center contour of the light spot brightness to the sub-pixel level. Perform the least squares ellipse fitting based on the sub-pixel level contour to obtain the high-precision coordinates of the four light spot brightness center points in the images I(x, y) and J(x, y) before and after the light spot offset.

4. A method for high-precision optical measurement of angular deviation of a transparent component optical array according to claim 3, characterized in that: The mathematical form of the least squares ellipse fitting based on the sub-pixel level contour is as follows: Among them, (x i ,y i ) is the sub-pixel coordinate obtained by edge detection combined with cubic spline interpolation, n is the number of pixels that need to be fitted with the least squares ellipse, and k1~k6 represent the parameters of the ellipse equation; The center of the ellipse calculated after fitting is The center of the ellipse is the high-precision coordinate of the brightness center of the light spot.

5. The method for high-precision optical measurement of angular deviation of a transparent component optical array according to claim 4, characterized in that: The step 3 comprises: The comprehensive deviation angle is calculated from the center coordinates of the brightness of the light spot on the CCD array. The comprehensive deviation angle is the angle deviation θ generated by the deflection of the array laser emitted by the array laser emitting device when passing through the transparent part and the fixed polarization angle generated by the polarizer. The optical angle deviation of the brightness center points of the four light spots in the array light spot image J(x,y) is obtained as shown in the following formula: in, represents the comprehensive angular deviation, θ represents the optical angular deviation of the center point of the brightness of the light spot in the array light spot image J(x,y), and f represents the focal length of the focusing mirror at the receiving end of the array laser. x, y represent the coordinates of the center point of the brightness of the light spot in the light spot reference image I(x,y), and x′, y′ represent the coordinates of the center point of the brightness of the light spot in the array light spot image J(x,y).

6. A method for high-precision optical measurement of angular deviation of a transparent component optical array according to claim 5, characterized in that: In step 4, the optical angular deviations of the four spot brightness center points in the array spot image calculated in step 3 are set as the four corners of the rectangular bounding box, and the angular deviation value of any point in the rectangular area is calculated by bilinear interpolation of the rectangular area.

7. A method for high-precision optical measurement of angular deviation of a transparent component optical array according to claim 6, characterized in that: The angular deviation value of any point in the rectangular area is shown in the following formula: i P =(1-μ)(1-v)·θ A +μ(1-v)·θ B +(1-μ)v·θ C +μv·θ D Among them, θ A ,θ B ,θ C ,θ D are the optical angle deviations of the brightness center points of the four light spots in the array light spot image, θ P It represents the angular deviation value of any point P in the rectangular area. Its relative position inside the rectangle is represented by parameters μ and v, 0≤μ,v≤1.

Images