A method for detecting the position of a reinforcing sheet of a flexible circuit board and an image acquisition system

Abstract

The present invention discloses a method for detecting the position of a reinforcing sheet of a flexible circuit board, including collecting a template image of a reinforcing sheet of a flexible circuit board; performing preprocessing, detecting the center of the template circle of the reinforcing sheet of the flexible circuit board, and obtaining the angle between the center of the template circle of the reinforcing sheet of the flexible circuit board and the horizontal; performing binary processing and screening the target area; obtaining the position information and the perimeter of the circumscribed rectangle, and saving them in a template matrix; collecting an image of a reinforcing sheet of a flexible circuit board to be tested; obtaining the position of the center of the circle after preprocessing, and rotating the reinforcing sheet of the flexible circuit board to be tested to an angle parallel to the template; obtaining the position information and the perimeter of the circumscribed rectangle of each reinforcing sheet of a flexible circuit board to be tested, and saving them in a matrix to be tested; comparing the data of the matrix to be tested with the template matrix, and outputting whether the position is abnormal. The present invention also discloses an image acquisition system based on the method for detecting the position of a reinforcing sheet of a flexible circuit board. The present invention is simple to operate, highly efficient, and has high recognition accuracy.

Description

Technical Field

[0001] The invention belongs to the field of image position processing, and in particular relates to a method for detecting the position of a reinforcing sheet of a flexible circuit board and an image acquisition system. Background Art

[0002] Flexible printed circuit board (FPC) is made of polyimide or polyester film. It is widely used in aerospace, military, mobile phones, digital cameras and other fields because of its small size, light weight, strong flexibility, high-density wiring and low cost. FPC is soft, so it needs to be mounted with reinforcement sheets at the plug-in position to enhance its hardness and facilitate the overall assembly of the product. The mounting error is one of the important reasons for product defects. At present, the commonly used reinforcement sheet mounting methods are divided into two types: manual mounting and mounting using a mounting machine. Due to the high position accuracy requirements of the reinforcement sheet, the position of the reinforcement sheet needs to be detected before and after mounting. At present, this detection process is mostly manual visual inspection, which is inefficient and the detection quality is seriously affected by accidental factors. Another detection method is to use AOI optical detection equipment for detection. This method has very high measurement accuracy, but it leads to the problem of extremely low detection pass rate. When the product has met the enterprise's accuracy requirements but has not reached the AOI detection accuracy, false detection will occur.

[0003] The use of machine vision technology to detect the quality of product workpieces has the advantages of non-contact, no damage to workpieces and fast detection speed. At the same time, the detection accuracy and reliability have also been correspondingly improved, and it has broad application prospects in manufacturing and modern industrial detection. Patent CN201510771942.4 discloses a visual detection method and detection method for the quality of FPC reinforcement patch patches. The working principle is: based on the laser triangulation method, the Gaussian Laplace operator is used to separate the optical center area of ​​the laser spot using morphological closing operations, and the invariance of the moment is used to perform ellipse fitting to obtain the thickness of the reinforcement patch. The disadvantage of this method is that it can only identify the thickness of the chip, but cannot identify the position and angle of the chip. Patent CN201510771942.4 discloses a PFC reinforcement sheet positioning auxiliary device, which mainly uses reinforcement plate fixing grooves, support legs and other devices to fix the reinforcement sheet, and cannot detect whether the reinforcement sheet is attached to the specified position; Patent CN 201210405133 discloses a chip position and inclination detection device and method, the working principle of which is to obtain the chip position information by using an autocollimator and two sets of cameras with different field of view. The detection device has low detection accuracy, is difficult to disassemble, and cannot achieve one-time detection and obtain the position information of dozens of reinforcement sheets on the flexible printed circuit board at the same time. Summary of the invention

[0004] One of the purposes of the present invention is to provide a method for detecting the position of a reinforcing sheet of a flexible circuit board, which has high detection accuracy and accurate identification. Another purpose of the present invention is to provide an image acquisition system based on the method for detecting the position of a reinforcing sheet of a flexible circuit board, which is easy to disassemble and can accurately acquire the image of a template of a reinforcing sheet of a flexible circuit board and the image of a reinforcing sheet of a flexible circuit board to be tested.

[0005] The method for detecting the position of the reinforcing sheet of the flexible circuit board provided by the present invention comprises the following steps:

[0006] S1. Collecting the image of the flexible circuit board reinforcement sheet template;

[0007] S2. Preprocessing the image of the flexible circuit board reinforcement sheet template, detecting the center of the flexible circuit board reinforcement sheet template, and obtaining the angle between the center of the flexible circuit board reinforcement sheet template and the horizontal;

[0008] S3. perform binary processing and screen the target area;

[0009] S4. Obtain the position information and circumscribed rectangle perimeter of each flexible circuit board reinforcement sheet template in the target area and save it in the template matrix;

[0010] S5. Collecting an image of the reinforcement sheet of the flexible circuit board to be tested;

[0011] S6. After preprocessing, the center position of the circle is obtained, and the reinforcing sheet of the flexible circuit board to be tested is rotated to an angle parallel to the template;

[0012] S7. Obtain the position information and the perimeter of the circumscribed rectangle of each flexible circuit board reinforcement sheet to be tested, and save them in the matrix to be tested;

[0013] S8. Compare the data of the matrix to be tested with the template matrix, and output whether the position of the reinforcing sheet of the flexible circuit board is abnormal.

[0014] The step S2 includes calibrating the camera using a chessboard method, then graying and Gaussian filtering the flexible circuit board reinforcement sheet template image, detecting the coordinates of the center of the flexible circuit board reinforcement sheet template using a hough algorithm, and then comparing the ordinates of the centers of the flexible circuit board reinforcement sheet templates, and saving the coordinates of the centers of the flexible circuit board reinforcement sheet templates in ascending order in the template center array A (a1, a2, a3, a4), where a1 represents the center of the first template; a2 represents the center of the second template; a3 represents the center of the third template; and a4 represents the center of the fourth template; the coordinates of the center of the first template a1 are set to (x1, y1), and the coordinates of the center of the second template a2 are set to (x2, y2), and the inverse tangent function is used. Calculate the angle β between the center of the template and the horizontal.

[0015] The step S3 includes performing adaptive binary processing on the flexible circuit board reinforcement sheet template image, calculating the area of ​​each region of the flexible circuit board reinforcement sheet template image using the image moment, and setting the region with a preset area to black.

[0016] The preset area includes an area smaller than 2400 square millimeters and an area larger than 2600 square millimeters.

[0017] The step S4 comprises the following steps:

[0018] A1. Use image moments to calculate the centroid coordinates M of the i-th flexible circuit board reinforcement template i (m ix ,m iy ) and the perimeter H of the circumscribed rectangle of the i-th flexible circuit board reinforcement template i ;

[0019] A2. Set the centroid coordinates M of the i-th flexible circuit board reinforcement template i (m ix ,m iy ) minus the coordinates of the center of the first template a1 (x1, y1), and then save the minus coordinates together with the perimeter of the circumscribed rectangle to the vector B corresponding to the i-th flexible circuit board reinforcement sheet template i =(b ix ,b iy ,H i ), b ix b represents the abscissa of the center of mass of the flexible circuit board reinforcement sheet template; iy The ordinate representing the center of mass of the flexible circuit board reinforcement sheet template;

[0020] A3. Compare the ordinate b of the center of mass of each flexible circuit board reinforcement template iy Value, the vertical coordinate b of the center of mass of the flexible circuit board reinforcement template iy The reinforcement pieces with values ​​within the predetermined value are taken as a row; the vector B corresponding to the i-th flexible circuit board reinforcement piece template in the j-th row is taken as the vector B corresponding to the i-th flexible circuit board reinforcement piece template in the j-th row i Vector array K stored in row j j In, j = 1, 2, ..., k, k represents the total number of rows of the flexible circuit board reinforcement sheet template;

[0021] A4. Compare the vector array K of row j j The horizontal coordinate b of the center of mass of the flexible circuit board reinforcement template ix Value, with the horizontal coordinate b of the center of mass of the flexible circuit board reinforcement template ix In ascending order, the vector array K of row j is j The vector B corresponding to the i-th flexible circuit board reinforcement template i Sort by

[0022] A5. Calculate the vector array K of the jth row j The vertical coordinate b of the center of mass of the flexible circuit board reinforcement template iy The average Compare the average values ​​of each array The average value Save each array into the template matrix C in ascending order.

[0023]

[0024] Where n represents the number of flexible circuit board reinforcement sheet templates; b iy The vertical coordinate representing the center of mass of the flexible circuit board reinforcement sheet template.

[0025] The step S6 comprises the following steps:

[0026] B1. Use the Hough algorithm to detect the center coordinates of the reinforcing sheet of the flexible circuit board to be tested, and then compare the ordinates of each center, and save the center coordinates of each reinforcing sheet of the flexible circuit board to be tested to the array of centers to be tested B (b1, b2, b3, b4) in ascending order, where b1 represents the first center to be tested; b2 represents the second center to be tested; b3 represents the third center to be tested; and b4 represents the fourth center to be tested;

[0027] B2. Set the coordinates of the first circle center b1 to be measured to (x3, y3), set the coordinates of the second circle center b2 to be measured to (x4, y4), and use the inverse tangent function to calculate the angle α between the circle center and the horizontal.

[0028] B3. With point b1 as the center, rotate the reinforcement sheet of the flexible circuit board to be tested by α-β degrees.

[0029] The step S8 includes subtracting the element value corresponding to the template matrix from each element value in the matrix to be tested. When the difference of the elements is greater than a preset length, it is prompted that the position of the reinforcing sheet of the flexible circuit board to be tested is incorrect.

[0030] The image acquisition system based on the flexible circuit board reinforcement sheet position detection method comprises a T-frame, a camera bracket, a camera, a light frame, a plurality of LED strip lights, and a moving board; the camera is mounted on the camera bracket, the camera bracket is mounted on the T-frame, the plurality of LED strip lights are respectively mounted on four sides of the light frame, the light frame is located directly below the camera, the light frame is mounted on the T-frame, and the flexible circuit board reinforcement sheet template image or the flexible circuit board reinforcement sheet image to be tested is placed on the moving board; the camera is used for shooting; the plurality of LED strip lights are used for providing light sources; the color of the moving board is light color, which is used to increase the contrast of the flexible circuit board reinforcement sheet template; the acquisition method of the flexible circuit board reinforcement sheet position detection method comprises placing the flexible circuit board reinforcement sheet template image or the flexible circuit board reinforcement sheet image to be tested on the moving board, then starting the power supply, the moving board transports the flexible circuit board reinforcement sheet template image or the flexible circuit board reinforcement sheet image to be tested to directly below the camera, then the camera acquires the image, and finally the moving board returns to the origin.

[0031] The flexible circuit board reinforcing sheet position detection method and image acquisition system provided by the present invention are simple to operate and highly efficient, and can detect more than 50 flexible circuit board reinforcing sheets in one minute. At the same time, the detection method has high recognition accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the process of the present invention.

[0033] Figure 2 This is a schematic diagram of a flexible circuit board reinforcement sheet template according to the method of the present invention.

[0034] Figure 3 The figure is a schematic diagram of the horizontal angle of the center of the flexible circuit board reinforcement sheet template of the method of the present invention.

[0035] Figure 4 This is an adaptive binary processing image of the flexible circuit board reinforcement sheet template of the method of the present invention.

[0036] Figure 5 It is the target area image after the flexible circuit board reinforcement sheet template is screened in the method of the present invention.

[0037] Figure 6 The figure is a schematic diagram of the centroid coordinates and circumscribed perimeter of the flexible circuit board reinforcement sheet template of the method of the present invention.

[0038] Figure 7 It is a schematic diagram of the horizontal angle of the reinforcing sheet of the flexible circuit board to be tested in the method of the present invention.

[0039] Figure 8 It is a schematic diagram of the structure of the system of the present invention. DETAILED DESCRIPTION

[0040] like Figure 1The flowchart of the method of the present invention is as follows: The method for detecting the position of the reinforcing sheet of the flexible circuit board provided by the present invention comprises the following steps:

[0041] S1. Collecting the image of the flexible circuit board reinforcement sheet template;

[0042] S2. Preprocessing the image of the flexible circuit board reinforcement sheet template, detecting the center of the flexible circuit board reinforcement sheet template, and obtaining the angle between the center of the flexible circuit board reinforcement sheet template and the horizontal;

[0043] S3. perform binary processing and screen the target area;

[0044] S4. Obtain the position information and circumscribed rectangle perimeter of each flexible circuit board reinforcement sheet template in the target area and save it in the template matrix;

[0045] S5. Collecting an image of the reinforcement sheet of the flexible circuit board to be tested;

[0046] S6. After preprocessing, the center position of the circle is obtained, and the reinforcing sheet of the flexible circuit board to be tested is rotated to an angle parallel to the template;

[0047] S7. Obtain the position information and the perimeter of the circumscribed rectangle of each flexible circuit board reinforcement sheet to be tested, and save them in the matrix to be tested;

[0048] S8. Compare the data of the matrix to be tested with the template matrix, and output whether the position of the reinforcing sheet of the flexible circuit board is abnormal.

[0049] like Figure 2 FIG. 1 is a schematic diagram of a flexible circuit board reinforcement sheet template of the method of the present invention. Figure 3 The figure is a schematic diagram of the horizontal angle of the center of the flexible circuit board reinforcement sheet template of the method of the present invention. The step S2 includes calibrating the camera using the chessboard method, then graying and Gaussian filtering the flexible circuit board reinforcement sheet template image, detecting the coordinates of the center of the flexible circuit board reinforcement sheet template using the hough algorithm, and then comparing the ordinates of the centers of the flexible circuit board reinforcement sheet templates, and saving the coordinates of the centers of the flexible circuit board reinforcement sheet templates in ascending order to the template center array A (a1, a2, a3, a4), where a1 represents the center of the first template; a2 represents the center of the second template; a3 represents the center of the third template; a4 represents the center of the fourth template; the coordinates of the center of the first template a1 are set to (x1, y1), the coordinates of the center of the second template a2 are set to (x2, y2), and the inverse tangent function is used. Calculate the angle β between the template center and the horizontal. The horizontal angle is as follows: Figure 3 shown.

[0050] like Figure 4 This is an adaptive binary processing image of the flexible circuit board reinforcement sheet template of the method of the present invention. Figure 5The target area image after the flexible circuit board reinforcement sheet template screening of the method of the present invention. The step S3 includes performing adaptive binary processing on the flexible circuit board reinforcement sheet template image, such as Figure 4 As shown in the figure, the image moment is used to find the area of ​​each region of the flexible circuit board reinforcement sheet template image, and the area with an area less than 2400 and the area greater than 2600 is turned black, with the unit being square millimeters. The target area after screening is as follows Figure 5 shown.

[0051] The step S4 comprises the following steps:

[0052] like Figure 6 A1. Calculate the centroid coordinates M of the i-th flexible circuit board reinforcement sheet template using the image moment i (m ix ,m iy ) and the perimeter H of the circumscribed rectangle of the i-th flexible circuit board reinforcement template i .like Figure 6 The purpose of calculating the circumscribed rectangle of the flexible circuit board reinforcement sheet template is to indirectly obtain the angle information of the reinforcement sheet, because the perimeter of the circumscribed rectangle is different for different angles of the reinforcement sheet.

[0053] A2. Set the centroid coordinates M of the i-th flexible circuit board reinforcement template i (m ix ,m iy ) minus the coordinates of the center of the first template a1 (x1, y1), and then save the minus coordinates together with the perimeter of the circumscribed rectangle to the vector B corresponding to the i-th flexible circuit board reinforcement sheet template i (b ix ,b iy ,H i ), b ix b represents the abscissa of the center of mass of the flexible circuit board reinforcement sheet template; iy The ordinate representing the center of mass of the flexible circuit board reinforcement sheet template;

[0054] A3. Compare the ordinate b of the center of mass of each flexible circuit board reinforcement template iy Value, the vertical coordinate b of the center of mass of the flexible circuit board reinforcement template iy The reinforcement pieces with values ​​less than 50 are taken as a row, and the vector B corresponding to the i-th flexible circuit board reinforcement piece template in the j-th row is taken as the vector B corresponding to the i-th flexible circuit board reinforcement piece template in the j-th row. i Vector array K stored in row j j In the example, j = 1, 2, ..., k, where k represents the total number of rows of the flexible circuit board reinforcement sheet template; the array K j Used to store the vector B corresponding to the i-th flexible circuit board reinforcement template in each row i; Figure 3 It can be seen that the entire circuit board has 3 rows of reinforcement sheets, and the first row has 5 reinforcement sheets. i Save to array K1. There are 6 reinforcement pieces in the second row. The B corresponding to the 6 reinforcement pieces in the second row will be saved. i Save to array K2. There are 5 reinforcement pieces in the 3rd row. i Save to array K3.

[0055] A4. Compare the vector array K of row j j The horizontal coordinate b of the center of mass of the flexible circuit board reinforcement template ix Value, with the horizontal coordinate b of the center of mass of the flexible circuit board reinforcement template ix In ascending order, the vector array K of row j is j The vector B corresponding to the i-th flexible circuit board reinforcement template i Sort by

[0056] A5. Calculate the vector array K of the jth row j The vertical coordinate b of the center of mass of the flexible circuit board reinforcement template iy The average Compare the average values ​​of each array The average value Save each array into the template matrix C in ascending order.

[0057]

[0058] Where n represents the number of flexible circuit board reinforcement sheet templates; b iy The vertical coordinate representing the center of mass of the flexible circuit board reinforcement sheet template.

[0059] like Figure 7 The horizontal angle diagram of the reinforcing sheet of the flexible circuit board to be tested in the method of the present invention is shown in FIG. The step S6 includes the following steps:

[0060] B1. Use the Hough algorithm to detect the center coordinates of the reinforcing sheet of the flexible circuit board to be tested, and then compare the ordinates of each center, and save the center coordinates of each reinforcing sheet of the flexible circuit board to be tested to the array of centers to be tested B (b1, b2, b3, b4) in ascending order, where b1 represents the first center to be tested; b2 represents the second center to be tested; b3 represents the third center to be tested; and b4 represents the fourth center to be tested;

[0061] B2. Set the coordinates of the first circle center b1 to be measured to (x3, y3), set the coordinates of the second circle center b2 to be measured to (x4, y4), and use the inverse tangent function to calculate the angle α between the circle center and the horizontal.

[0062] B3. With point b1 as the center, rotate the reinforcing sheet of the flexible circuit board to be tested by α-β degrees. The horizontal angle diagram of the reinforcing sheet of the flexible circuit board to be tested is as follows: Figure 7 shown.

[0063] The step S8 includes subtracting the element value corresponding to the template matrix from each element value in the matrix to be tested. When the difference of the elements is greater than 0.05 mm, it is prompted that the position of the reinforcing sheet of the flexible circuit board to be tested is incorrect and needs to be re-pasted.

[0064] like Figure 8 The present invention also provides an image acquisition system for detecting the position of a reinforcing sheet of a flexible circuit board, comprising a T-shaped frame 1, a camera support 2, a camera 3, a light stand 4, a plurality of LED strip lights 5, and a movable plate 7, wherein 6 is a template image of a reinforcing sheet of a flexible circuit board or an image of a reinforcing sheet of a flexible circuit board to be tested; the camera 3 is mounted on the camera support 2, the camera support 2 is mounted on the T-shaped frame 1, a plurality of LED strip lights 5 are respectively mounted on the four sides of the light stand 4, the light stand 4 is located directly below the camera 3, the light stand 4 is mounted on the T-shaped frame 1, and the template image of the reinforcing sheet of a flexible circuit board or the image of the reinforcing sheet of a flexible circuit board to be tested 6 is placed on the movable plate 7; the camera 3 is used for shooting; a plurality of LED strip lights 5 are used for providing a light source, and 4 are used in this embodiment; the color of the movable plate 7 is light, which is used to increase the contrast of the template image of the reinforcing sheet of a flexible circuit board or the image of the reinforcing sheet of a flexible circuit board to be tested 6. The acquisition method of the present system includes placing a flexible circuit board reinforcement sheet template image or a flexible circuit board reinforcement sheet image to be tested 6 on a movable plate 7, and then starting the power supply. The movable plate 7 transports the flexible circuit board reinforcement sheet template image or the flexible circuit board reinforcement sheet image to be tested 6 to the bottom of the camera 3, and then the camera 3 acquires the image, and finally the movable plate 7 returns to the origin.

[0065] In this embodiment, the steps for detecting the patch position information are as follows:

[0066] Step 1: With the assistance of several LED strip lights, an image acquisition system is used to acquire an image of a flexible circuit board reinforcement sheet template;

[0067] Step 2: Use the chessboard method to calibrate the camera, then grayscale and Gaussian filter the image, use the Hough algorithm to detect the coordinates of the center of the circle, and then compare the vertical coordinates of each center of the circle, and save the coordinates of each center of the circle in array A (a1, a2, a3, a4) in ascending order. Set the coordinates of a1 to (x1, y1), set the coordinates of a2 to (x2, y2), and use the inverse tangent function to calculate the angle β between the center of the circle and the horizontal.

[0068] Step 3: Perform adaptive threshold processing on the template image and filter the target area;

[0069] Step 4: Obtain the position information and circumscribed rectangle perimeter of each flexible circuit board reinforcement sheet template in the target area, and save them in the template matrix;

[0070] Step 5: Use an image acquisition device to acquire an image of the reinforcing sheet of the flexible circuit board to be tested, use an inverse tangent function to calculate the angle α between the center of the circle and the horizontal, and rotate the reinforcing sheet to be tested by α-β degrees with point b1 as the center of the circle.

[0071] Step 6: Obtain the position information of each reinforcement piece to be tested and the perimeter of the circumscribed rectangle, and save them in the matrix to be tested.

[0072] Step 7: Compare the data of the matrix to be tested with the template matrix and output the result.

Claims

1. A method for detecting the position of a reinforcing sheet of a flexible circuit board, characterized in that The steps include: S1. Collecting the image of the flexible circuit board reinforcement sheet template; S2. Preprocess the flexible circuit board reinforcement sheet template image, detect the center of the flexible circuit board reinforcement sheet template, and calculate the angle between the center of the flexible circuit board reinforcement sheet template and the horizontal; including using the chessboard method to calibrate the camera, then grayscale the flexible circuit board reinforcement sheet template image and perform Gaussian filtering, use the hough algorithm to detect the coordinates of the center of the flexible circuit board reinforcement sheet template, and then compare the vertical coordinates of the centers of the flexible circuit board reinforcement sheet templates, and save the coordinates of the centers of the flexible circuit board reinforcement sheet templates in ascending order to the template center array A (a1, a2, a3, a4), where a1 represents the center of the first template; a2 represents the center of the second template; a3 represents the center of the third template; a4 represents the center of the fourth template; the coordinates of the first template center a1 are set to (x1, y1), the coordinates of the second template center a2 are set to (x2, y2), and the inverse tangent function is used. Calculate the angle β between the template center and the horizontal; S3. perform binary processing and screen the target area; S4. Obtain the position information and circumscribed rectangle perimeter of each flexible circuit board reinforcement sheet template in the target area and save it in the template matrix; S5. Collecting an image of the reinforcement sheet of the flexible circuit board to be tested; S6. After preprocessing, the center position of the circle is obtained, and the reinforcing sheet of the flexible circuit board to be tested is rotated to an angle parallel to the template; S7. Obtain the position information and the perimeter of the circumscribed rectangle of each flexible circuit board reinforcement sheet to be tested, and save them in the matrix to be tested; S8. Compare the data of the matrix to be tested with the template matrix, and output whether the position of the reinforcing sheet of the flexible circuit board is abnormal.

2. The method for detecting the position of the reinforcing sheet of a flexible circuit board according to claim 1, characterized in that The step S3 includes performing adaptive binary processing on the flexible circuit board reinforcement sheet template image, calculating the area of ​​each region of the flexible circuit board reinforcement sheet template image using the image moment, and setting the region with a preset area to black.

3. The method for detecting the position of the reinforcing sheet of a flexible circuit board according to claim 2, characterized in that The preset area includes an area smaller than 2400 square millimeters and an area larger than 2600 square millimeters.

4. The method for detecting the position of the reinforcing sheet of a flexible circuit board according to claim 3, characterized in that The step S4 comprises the following steps: A1. Use image moments to calculate the centroid coordinates M of the i-th flexible circuit board reinforcement template i (m ix ,m iy ) and the perimeter H of the circumscribed rectangle of the i-th flexible circuit board reinforcement template i ; A2. Set the centroid coordinates M of the i-th flexible circuit board reinforcement template i (m ix ,m iy ) minus the coordinates of the center of the first template a1 (x1, y1), and then save the minus coordinates together with the perimeter of the circumscribed rectangle to the vector B corresponding to the i-th flexible circuit board reinforcement sheet template i =(b ix ,b iy ,H i ), b ix b represents the abscissa of the center of mass of the flexible circuit board reinforcement sheet template; iy The ordinate representing the center of mass of the flexible circuit board reinforcement sheet template; A3. Compare the ordinate b of the center of mass of each flexible circuit board reinforcement template iy Value, the vertical coordinate b of the center of mass of the flexible circuit board reinforcement template iy The reinforcement pieces with values ​​within the predetermined value are taken as a row; the vector B corresponding to the i-th flexible circuit board reinforcement piece template in the j-th row is taken as the vector B corresponding to the i-th flexible circuit board reinforcement piece template in the j-th row i Vector array K stored in row j j In, j = 1, 2, ..., k, k represents the total number of rows of the flexible circuit board reinforcement sheet template; A4. Compare the vector array K of row j j The horizontal coordinate b of the center of mass of the flexible circuit board reinforcement template ix Value, with the horizontal coordinate b of the center of mass of the flexible circuit board reinforcement template ix In ascending order, the vector array K of row j is j The vector B corresponding to the i-th flexible circuit board reinforcement template i Sort by A5. Calculate the vector array K of the jth row j The vertical coordinate b of the center of mass of the flexible circuit board reinforcement template iy The average Compare the average values ​​of each array The average value Save each array into the template matrix C in ascending order; Where n represents the number of flexible circuit board reinforcement sheet templates; b iy The vertical coordinate representing the center of mass of the flexible circuit board reinforcement sheet template.

5. The method for detecting the position of the reinforcing sheet of a flexible circuit board according to claim 4, characterized in that The step S6 comprises the following steps: B1. Use the Hough algorithm to detect the center coordinates of the reinforcing sheet of the flexible circuit board to be tested, and then compare the ordinates of each center, and save the center coordinates of each reinforcing sheet of the flexible circuit board to be tested to the array of centers to be tested B (b1, b2, b3, b4) in ascending order, where b1 represents the first center to be tested; b2 represents the second center to be tested; b3 represents the third center to be tested; and b4 represents the fourth center to be tested; B2. Set the coordinates of the first circle center b1 to be measured to (x3, y3), set the coordinates of the second circle center b2 to be measured to (x4, y4), and use the inverse tangent function to calculate the angle α between the circle center and the horizontal. B3. With point b1 as the center, rotate the reinforcement sheet of the flexible circuit board to be tested by α-β degrees.

6. The method for detecting the position of the reinforcing sheet of a flexible circuit board according to claim 5, characterized in that The step S8 includes subtracting the element value corresponding to the template matrix from each element value in the matrix to be tested. When the difference of the elements is greater than a preset length, it is indicated that the position of the reinforcing sheet of the flexible circuit board to be tested is abnormal.

7. An image acquisition system based on the method for detecting the position of a reinforcing sheet of a flexible circuit board according to any one of claims 1 to 6, characterized in that The invention comprises a T-shaped frame, a camera bracket, a camera, a light bracket, a plurality of LED strip lights and a moving board; the camera is mounted on the camera bracket, the camera bracket is mounted on the T-shaped frame, a plurality of LED strip lights are respectively mounted on four sides of the light bracket, the light bracket is located directly below the camera, the light bracket is mounted on the T-shaped frame, and a flexible circuit board reinforcement sheet template image or a flexible circuit board reinforcement sheet image to be tested is placed on the moving board; the camera is used for shooting; a plurality of LED strip lights are used for providing light sources; the color of the moving board is light color, which is used to increase the contrast of the flexible circuit board reinforcement sheet template; collecting the flexible circuit board reinforcement sheet template image or collecting the flexible circuit board reinforcement sheet image to be tested comprises placing the flexible circuit board reinforcement sheet template image or the flexible circuit board reinforcement sheet image to be tested on the moving board, then starting the power supply, the moving board transports the flexible circuit board reinforcement sheet template image or the flexible circuit board reinforcement sheet image to be tested to directly below the camera, the camera collects the image, and finally the moving board returns to the origin.

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