CN116952135A

CN116952135A - Optical measuring device and measuring method

Info

Publication number: CN116952135A
Application number: CN202210392879.3A
Authority: CN
Inventors: 黄建德; 黄敬恒; 粘弘昇; 张信泽; 陈旅涵
Original assignee: Jinxi Huiya Technology Co ltd
Current assignee: Jinxi Huiya Technology Co ltd
Priority date: 2022-04-14
Filing date: 2022-04-14
Publication date: 2023-10-27

Abstract

The invention discloses an optical measuring device and a measuring method, wherein three laser measuring instruments are mainly used for carrying out laser measurement, a sample plate is firstly measured to define the relation among the laser measuring instruments, and then a plate to be measured is measured, so that the aim of conveniently measuring the plate to be measured can be fulfilled; in addition, the image measurement can be used for assisting, the image measurement can calculate the four sides of the board to be measured in a mode of calculating the distance between the horizontal pixels and the vertical pixels, and the error can be reduced.

Description

Optical measuring device and measuring method

Technical Field

The invention relates to an optical measurement device and a measurement method; and more particularly, to an optical measurement device and method using laser measurement and image measurement for assistance.

Background

The floor unit of the raised floor is a cuboid, the top surface is square, and the machining precision requirement is very high, for example, the tolerance range in certain occasions is within plus or minus 0.01 mm. However, the existing measurement methods mostly adopt manual measurement, which is easy to generate errors and causes a lot of troubles.

The inventor has studied for years through the Sophora, has conducted experiments for related product research, and has developed the present invention to solve the shortcomings of the existing measurement methods.

Disclosure of Invention

The invention aims to provide an optical measuring device capable of conveniently measuring a board to be measured.

To achieve the above object, the present invention is structured to include: a platform; the first laser measuring instrument is arranged on one side of the platform; the second laser measuring instrument is arranged on the other side of the platform opposite to the first laser measuring instrument, horizontally aligned with the first laser measuring instrument and spaced by a first interval distance; the third laser measuring instrument is arranged on the other side of the platform opposite to the first laser measuring instrument and is separated from the second laser measuring instrument by a second interval distance.

Preferably, a camera is mounted above the platform to assist in image measurement.

Preferably, the platform is of a structure with adjustable height, can be lifted or lowered, and can conveniently measure the plates to be measured with different heights.

Another object of the present invention is to provide an optical measuring method that can conveniently measure a board to be measured.

To achieve the above object, the present invention includes the steps of: s101: a first laser measuring instrument is arranged on one side of a platform, a second laser measuring instrument and a third laser measuring instrument are arranged on the other side of the platform opposite to the first laser measuring instrument, the first laser measuring instrument and the second laser measuring instrument are separated by a first interval distance (D1), and the second laser measuring instrument and the third laser measuring instrument are separated by a preset second interval distance (D2); s102: placing a sample plate on the platform; the sample plate is cuboid, the top surface is square, and the left side length (L11) of the top surface of the sample plate, the upper side length (L12) of the top surface of the sample plate, the right side length (L13) of the top surface of the sample plate and the lower side length (L14) of the top surface of the sample plate are preset; s103: measuring a first laser pitch (X1), a second laser pitch (X2) and a third laser pitch (X3) between the first, second and third laser gauges and the sample plate, respectively; s104: calculating to obtain the value of the first interval distance (D1); s105: taking the sample plate and placing a plate to be tested on the platform; the board to be tested is cuboid, and the top surface is square, and is provided with a left side length (L15) of the top surface of the board to be tested, a top side length (L16) of the top surface of the board to be tested, a right side length (L17) of the top surface of the board to be tested and a bottom side length (L18) of the top surface of the board to be tested; s106: measuring a fourth laser distance (X4), a fifth laser distance (X5) and a sixth laser distance (X6) between the first, second and third laser measuring instruments and the board to be measured respectively; s107: calculating to obtain the value of the lower side length (L18) of the top surface of the board to be tested.

Preferably, in the step S104, the value of the first distance (D1) is calculated and obtained by a first formula; the first formula is:

the relationship between the first and second laser measuring instruments can be conveniently confirmed.

Preferably, in the step S107, a value of the bottom edge (L18) of the top surface of the board to be tested is calculated and obtained by a second formula; the second formula is:

the purpose of conveniently measuring the board to be measured can be achieved.

Preferably, after the step S102, steps S201 to S206 are performed; s201: erecting a camera above the platform, and taking pictures by using the camera to obtain a sample plate original picture; the camera has a predetermined horizontal resolution and a vertical resolution; s202: performing lens fish eye correction on the original sample plate image to generate a sample plate correction image; s203: converting the sample plate calibration map into a first gray map, and converting the first gray map into a first contour map; s204: searching four corner points of the first profile graph to obtain a first four corner point coordinate; the first four-corner point coordinates are four-corner point coordinates of the sample plate in the sample plate calibration chart; s205: calculating a first horizontal pixel range and a first vertical pixel range of a sample plate obtained in the sample plate correction chart; s206: the first horizontal pixel distance and the first vertical pixel distance in the sample plate correction chart are calculated and obtained, and image measurement can be carried out on the plate to be measured.

Preferably, after the step S105, steps S207 to S212 are performed; s207: taking pictures by using the camera to obtain an original drawing of a board to be tested; s208: performing lens fisheye correction on the original image of the board to be tested to generate a board to be tested correction chart; s209: converting the calibration image of the board to be tested into a second gray image, and converting the second gray image into a second contour image; s210: searching four corner points of the second contour map to obtain a second four corner point coordinate; the second four-corner point coordinates are the four-corner point coordinates of the sample plate in the calibration chart of the plate to be tested; s211: calculating to obtain the left pixel range of the top surface of the board to be tested, the upper pixel range of the top surface of the board to be tested, the right pixel range of the top surface of the board to be tested and the lower pixel range of the top surface of the board to be tested in the calibration chart of the board to be tested; s212: and calculating to obtain the left side length of the top surface of the board to be tested, the upper side length of the top surface of the board to be tested, the right side length of the top surface of the board to be tested and the lower side length of the top surface of the board to be tested in the calibration chart of the board to be tested, and performing image measurement on the board to be tested.

Preferably, after the step S102, steps S301 to S311 are performed; s301: erecting a camera above the platform, and taking pictures by using the camera to obtain a sample plate original picture; the camera has a predetermined horizontal resolution and a vertical resolution; s302: performing lens fish eye correction on the original sample plate image to generate a sample plate correction image; s303: converting the sample plate calibration map into a first gray map, and converting the first gray map into a first contour map; s304: searching four corner points of the first profile graph to obtain a first four corner point coordinate; the first four-corner point coordinates are four-corner point coordinates of the sample plate in the sample plate calibration chart; s305: setting a third four-corner point coordinate, and substituting the first four-corner point coordinate and the third four-corner point coordinate into a first perspective transformation formula to calculate a perspective transformation matrix; s306: substituting the perspective transformation matrix into the first perspective transformation formula to generate a second perspective transformation formula; s307: performing perspective transformation on the sample plate correction chart by using the second perspective transformation formula to generate a sample plate top plane image chart; s308: converting the top plane image of the sample plate into a third gray scale image, and converting the third gray scale image into a third contour image; s309: searching four corner points of the third profile diagram to obtain a fourth four corner point coordinate; the fourth four-corner point coordinates are the four-corner point coordinates of the sample plate in the sample plate top plane image; s310: calculating a second horizontal pixel range and a second vertical pixel range of the sample plate in the top plane image of the sample plate; s311: and calculating and obtaining a second horizontal pixel distance and a second vertical pixel distance in the top plane image graph of the sample plate, and performing image measurement on the plate to be measured.

Preferably, the first perspective transformation formula is:

in the first perspective transformation formula, xi and yi are coordinates of each point in the first four-corner point coordinate, xj and yj are coordinates of each point in the third four-corner point coordinate, and perspective transformation can be conveniently performed.

Preferably, the coordinates of each point in the coordinates of the first and third four corners are brought into the first perspective transformation formula to obtain the perspective transformation matrix

Substituting the perspective transformation matrix into the first perspective transformation formula to generate a second perspective transformation formula, wherein the second perspective transformation formula is as follows:

in the second perspective transformation formula, xk and yk are coordinates of each pixel point in the sample plate correction chart, and the calculated xl and yl are coordinates of each pixel point in the sample plate overlook plane image chart, so that measurement accuracy can be improved.

Preferably, after the step S105, steps S312 to S318 are first performed; s312: taking pictures by using the camera to obtain an original drawing of a board to be tested; s313: performing lens fisheye correction on the original image of the board to be tested to generate a board to be tested correction chart; s314: performing perspective transformation on the board correction diagram to be tested by using the second perspective transformation formula to generate a top plane image diagram of the board to be tested; s315: converting the top plane image of the board to be tested into a fourth gray scale image, and converting the fourth gray scale image into a fourth outline image; s316: searching four corner points of the fourth profile diagram to obtain a fifth four corner point coordinate; the fifth four-corner point coordinates are the four-corner point coordinates of the board to be measured in the top plane image of the board to be measured; s317: calculating to obtain the left pixel range of the top surface of the board to be tested, the upper pixel range of the top surface of the board to be tested, the right pixel range of the top surface of the board to be tested and the lower pixel range of the top surface of the board to be tested in the overlook plane image diagram of the board to be tested; s318: and calculating to obtain the left side length of the top surface of the board to be measured, the upper side length of the top surface of the board to be measured, the right side length of the top surface of the board to be measured and the lower side length of the top surface of the board to be measured in the overlook plane image graph of the board to be measured, and performing image measurement on the board to be measured.

To achieve the foregoing and other objects, and in accordance with the purpose of the invention, as embodied and broadly described, a preferred embodiment of the present invention is illustrated and described below.

Drawings

Fig. 1 is a flowchart of a first embodiment of the present invention.

Fig. 2 is a schematic view of an optical measuring device according to the present invention.

FIG. 3 is a schematic diagram showing the relationship between the first, second and third laser measuring instruments and the sample plate according to the present invention.

FIG. 4 is a schematic diagram showing the relationship between the first, second and third laser measuring instruments and the board to be measured according to the present invention.

Fig. 5 is a flow chart of a second embodiment of the present invention.

Fig. 6 is a flow chart of a third embodiment of the present invention.

Fig. 7 is a schematic illustration of a sample plate artwork according to the present invention.

FIG. 8 is a schematic diagram of a sample plate calibration chart of the present invention.

Fig. 9 is a schematic diagram of a first gray scale and a first contour of the present invention.

Fig. 10 is a schematic diagram of a top plan image of a sample plate of the present invention.

Fig. 11 is a schematic diagram of a third gray scale image and a third contour image according to the present invention.

Fig. 12 is a schematic diagram of a board to be tested according to the present invention.

FIG. 13 is a schematic diagram of a calibration chart of a board under test according to the present invention.

Fig. 14 is a schematic diagram of a top plan image of a board under test according to the present invention.

Fig. 15 is a schematic diagram of a fourth gray scale and a fourth profile of the present invention.

Reference numerals illustrate: 100-an optical measurement device; 1-a platform; 11-a first laser measuring instrument; 12-a second laser measuring instrument; 13-a third laser gauge; 21-a camera; 3-a bracket; 101-sample plate; 102-a board to be tested; d1-a first separation distance; d2—a second separation distance; l11-left side length of top surface of sample plate; l12-the upper edge length of the top surface of the sample plate; l13-the right side of the top surface of the sample plate; l14-the lower edge of the top surface of the sample plate; l15-the left side length of the top surface of the board to be tested; l16-the upper edge length of the top surface of the board to be tested; l17-the right side length of the top surface of the board to be tested; l18-the lower side length of the top surface of the board to be tested; PA 1-sample plate artwork; PA 2-original drawing of the board to be tested; PB 1-sample plate calibration; PB 2-board under test calibration; PC 1-a first gray scale map; PD 1-a first profile; PE 1-a top plan view of a sample plate; PE 2-a top plan image of the board to be tested; PF 1-third gray scale map; PF 2-fourth gray scale map; PG 1-a third profile; PG 2-fourth profile; S101-S107, S201-S212, S301-S318; x1-a first laser pitch; x2-second laser pitch; x3-third laser interval; x4-fourth laser interval; x5-fifth laser interval; x6-sixth laser pitch.

Detailed Description

Fig. 1 to 4 show a first embodiment of the present invention. As shown in fig. 1 to 4, the optical measurement device and the measurement method of the present invention include the following steps: s101: a first laser measuring instrument 11 is arranged on one side of a platform 1, a second laser measuring instrument 12 and a third laser measuring instrument 13 are arranged on the other side of the platform 1 opposite to the first laser measuring instrument 11, the first laser measuring instrument 11 and the second laser measuring instrument 12 are separated by a first interval distance D1, and the second laser measuring instrument 12 and the third laser measuring instrument 13 are separated by a second interval distance D2; s102: placing a sample plate 101 on the platform 1; the sample plate 101 is a cuboid, and the top surface is square, and has a preset left side length L11 of the top surface of the sample plate, a preset upper side length L12 of the top surface of the sample plate, a preset right side length L13 of the top surface of the sample plate and a preset lower side length L14 of the top surface of the sample plate; s103: measuring a first laser distance X1, a second laser distance X2 and a third laser distance X3 between the sample plate and the sample plate by using a first, a second and a third laser measuring instrument respectively; s104: calculating to obtain a value of the first interval distance D1; s105: taking out the sample plate 101, and placing a plate to be tested 102 on the platform 1; the board to be measured 102 is a cuboid, and the top surface is square, and has a left side length L15 of the top surface of the board to be measured, a top side length L16 of the top surface of the board to be measured, a right side length L17 of the top surface of the board to be measured and a bottom side length L18 of the top surface of the board to be measured; s106: measuring a fourth laser distance X4, a fifth laser distance X5 and a sixth laser distance X6 between the first, second and third laser measuring instruments 11, 12 and 13 and the board 102 to be measured respectively; s107: calculating to obtain the value of the lower side length L18 of the top surface of the board to be tested; the method can achieve the purpose of conveniently measuring the board to be measured. As will be described in detail below.

The platform for combining the optical measuring device and the measuring method can be a conveyor belt (not shown) for conveying the board to be measured, and the optical measuring device 100 can be constructed for measuring. The optical measurement device 100 includes: a platform 1; a first laser measuring instrument 11 is arranged on one side of the platform 1; a second laser measuring instrument 12 mounted on the other side of the platform 1 opposite to the first laser measuring instrument 11, aligned horizontally with the first laser measuring instrument 11, and spaced apart by a first spacing distance D1; a third laser measuring instrument 13 mounted on the other side of the platform 1 opposite to the first laser measuring instrument 11 and spaced apart from the second laser measuring instrument 12 by a second spacing distance D2; with the structure, the optical measuring device and the measuring method can be conveniently carried out, and then the side length value of the board to be measured is measured. In addition, a camera 21 may be added above the platform for convenience of image measurement. The frame 3 for mounting the first, second and third laser measuring devices 11, 12, 13 and the camera 21 is a common frame structure, and will not be described in detail.

In step S101, a first laser measuring instrument 11 is installed on one side of a platform 1, a second laser measuring instrument 12 and a third laser measuring instrument 13 are installed on the other side of the platform 1 opposite to the first laser measuring instrument 11, the first laser measuring instrument 11 and the second laser measuring instrument 12 are separated by a first separation distance D1, and the second laser measuring instrument 12 and the third laser measuring instrument 13 are separated by a second separation distance D2.

The first laser measuring instrument 11 and the second laser measuring instrument 12 should be aligned horizontally, for example, the laser beam of the first laser measuring instrument 11 and the laser beam of the second laser measuring instrument 12 are overlapped, or the lasers of the first laser measuring instrument 11 and the second laser measuring instrument 12 are made to strike each other on the mirror surfaces of the other. The lasers of the second laser measuring instrument 12 and the third laser measuring instrument 13 are parallel to each other.

Step S102, a sample plate 101 is placed on the platform 1; the sample plate 101 is rectangular, and has a square top surface, and has a predetermined left side length L11 of the top surface of the sample plate, a predetermined upper side length L12 of the top surface of the sample plate, a predetermined right side length L13 of the top surface of the sample plate, and a predetermined lower side length L14 of the top surface of the sample plate.

In general, the sample plate 101 is specifically customized, so that the sample plate 101 has four sides L11-L14 of predetermined and known values, which can be used as a reference for measurement. In addition, the top surface of the sample plate 101 may be square so that the four sides thereof are equal in length L11 to L14 for convenience of operation.

Step S103 is to measure the first laser distance X1, the second laser distance X2 and the third laser distance X3 between the sample plate 101 and the first, second and third laser measuring instruments 11, 12, 13, respectively.

Step S104 is to calculate and obtain the value of the first distance D1.

The first distance D1 may be calculated by more than one method, for example, the following first formula may be used to obtain the value of the first distance D1. The first formula is:

the first distance D1 is calculated by the first, second and third laser measuring instruments 11, 12, 13 in combination with the first formula, so that the relationship between the first and second laser measuring instruments can be conveniently confirmed, and the accurate measurement can be ensured even if the sample board or the board to be measured is slightly inclined. In addition, for example, the change, movement, resetting, etc. of the laser measuring instrument may cause the value of the first distance D1 to change, and at this time, only the sample plate needs to be replaced and steps S101 to S104 are performed to obtain a new first distance D1. Further, since it is difficult to measure the distance (for example, the first laser distance X1) between the mirror surface of the laser measuring instrument and the sensing object at first when the laser measuring instrument is mounted, the error can be reduced by measuring the sample plate 101 to calculate the first distance D1.

Step S105 is to take out the sample plate 101 and place a plate 102 to be tested on the platform 1; the board to be tested 102 may be a floor unit of an elevated floor, which is a cuboid, with a square top surface, having a left side length L15 of the top surface of the board to be tested, a top side length L16 of the top surface of the board to be tested, a right side length L17 of the top surface of the board to be tested, and a bottom side length L18 of the top surface of the board to be tested.

The values of the four sides L15-L18 of the board to be measured 102 are unknown, and the method aims to conveniently measure the values of the four sides L15-L18 of the board to be measured 102 so as to facilitate the user to evaluate the processing condition of the board to be measured.

In step S106, the first, second and third laser measuring devices 11, 12 and 13 are used to measure the fourth laser distance X4, the fifth laser distance X5 and the sixth laser distance X6 between the board 102.

Step S107 is to calculate and obtain the value of the bottom length L18 of the top surface of the board.

The bottom length L18 of the top surface of the board to be measured can be calculated by the following second formula. The second formula is:

generally, the method can be applied to measuring a board to be measured after edge milling processing to measure whether the four sides of the board to be measured after edge milling are within a tolerance range. Of course, in order to further ensure the measurement accuracy, the three-side lengths L15 to 17 except the lower side length L18 of the top surface of the board to be measured can be calculated through other formulas, or the board to be measured is rotated for about ninety degrees and then one side length is measured, and the total time is carried out for one to three times, so that the numerical values of the four-side lengths L15 to L18 of the board to be measured can be obtained.

The side length value of the plate to be measured can be conveniently measured through the laser measurement in the steps S101-S107. In addition, since only three laser measuring instruments are needed, the structure is simple, the device can be matched with the processing flow setting of the board to be measured, for example, a conveyer belt for conveying the board to be measured is used as a platform, more than one group of three laser measuring instruments are arranged at the front side and/or the rear side of the board to be measured processing equipment, and the board to be measured (not shown in the figure) can be measured together when the board to be measured is conveyed.

Fig. 5 is a second embodiment of the present invention. As shown in fig. 5, the foregoing steps S101 to S107 have already measured the values of the four-side lengths L15 to L18 of the board to be measured. However, in order to reduce the error, the image measurement of steps S201 to S212 may be interposed to assist in performing steps S101 to S107.

Step S201, a camera is arranged above the platform, and a sample plate original picture PA1 is obtained by taking pictures by the camera; the camera has a predetermined horizontal resolution and a vertical resolution.

Step S202 is to perform lens fisheye correction on the original image PA1 of the sample plate to generate a sample plate correction image PB1.

The lens fisheye correction can reduce distortion generated by the fisheye lens.

Step S203 is to convert the sample plate calibration chart PB1 into a first gray chart PC1, and then convert the first gray chart PC1 into a first contour chart PD1.

The sample plate correction chart PB1 is converted into the first gray chart PC1 and then into the first contour chart PD1, so that the influence caused by problems such as reflection, chromatic aberration and the like can be reduced, and four corner coordinates of the sample plate in the sample plate correction chart PB1 can be conveniently found out.

Step S204 is to search four corners of the first contour diagram PD1 to obtain a first four corner coordinate; the first four-corner coordinates are those of the sample plate in the sample plate correction chart PB1, and also those of the sample plate in the first gray-scale chart PC1 and the first contour chart PD1.

Step S205 is to calculate and obtain a first horizontal pixel range R21 and a first vertical pixel range R22 of the sample plate in the sample plate correction chart PB1.

Step S206 is to calculate and obtain a first horizontal inter-pixel distance PP21 and a first vertical inter-pixel distance PP22 in the sample plate correction chart PB1.

By using the inter-pixel distances PP21, PP22 of the sample plate correction chart PB1 as a reference for measuring the board to be measured, the measurement accuracy can be improved, and errors caused by, for example, positional deviation or rotation caused by replacement of the board to be measured can be reduced.

In step S207, a camera is used to take a photograph to obtain a board to be tested original PA2.

Step S208 is to perform lens fisheye correction on the original drawing PA2 of the board to be tested, and generate a board to be tested correction drawing PB2.

In step S209, the board calibration chart PB2 is converted into a second gray chart PC2, and the second gray chart PC2 is converted into a second contour chart PD2.

Step S210 is to search four corners of the second contour plot PD2 to obtain a second four corners coordinates; the second four-corner point coordinates are those of the sample board in the board under test calibration chart PB2.

Step S211 is to calculate and obtain the left pixel range R23, the upper pixel range R24, the right pixel range R25, and the lower pixel range R26 of the top surface of the board under test in the board under test calibration chart PB2.

Step S212 is to calculate and obtain the left side length L21 of the top surface of the board to be tested, the top side length L22 of the top surface of the board to be tested, the right side length L23 of the top surface of the board to be tested, and the bottom side length L24 of the top surface of the board to be tested in the board to be tested calibration chart PB2.

The values of the four sides L21 to L24 of the board to be measured can be conveniently obtained through the image measurement in the steps S201 to S212. In addition, the method can also be analyzed together with laser measurement, for example, when the precision requirement is high, the values of the four sides L15 to L18 of the board to be measured obtained by laser measurement and the values of the four sides L21 to L24 of the board to be measured obtained by image measurement can be required to meet the preset tolerance range, so that the qualified board to be measured can be calculated.

Fig. 6 is a third embodiment of the present invention. As shown in fig. 6, in the case of performing steps S101 to S107, the assistance may be performed by performing the image measurement of steps S301 to S318. The third embodiment adds perspective transformation based on the second embodiment to reduce possible errors caused by tilting of the top surface of the board to be measured, thereby improving the measurement accuracy. The image measurement support in steps S201 to S212 and S301 to S318 may be performed by taking an image mainly by a camera, and may be performed together with steps S101 to S107. For example, steps S201 to S206 and S301 to S311 are performed after step S102, and steps S207 to S212 and S312 to S318 are performed after step S105.

Steps S301 to S304 are the same as steps S201 to S204. The first four-corner coordinates are searched in steps S201 to S204 to calculate the inter-pixel distances PP21 to PP22 in the acquired sample plate correction map PB1, and the first four-corner coordinates are searched in steps S301 to S304 to perform subsequent perspective transformation.

In step S305, a third four-corner coordinate is set, and the first four-corner coordinate and the third four-corner coordinate are substituted into a first perspective transformation formula to calculate a perspective transformation matrix.

The setting value of the third four-corner point coordinate can be based on the first four-corner point coordinate, and a value with a range smaller than that of the first four-corner point coordinate is set so as to improve the precision. The perspective transformation formula is a general formula. In a third embodiment, the first perspective transformation formula is:

in the first perspective transformation formula, xi and yi are coordinates of each point in the first four-corner point coordinates, and xj and yj are coordinates of each point in the third four-corner point coordinates. Bringing the coordinates of each point in the coordinates of the first four corners and the third four corners into a first perspective transformation formula to obtain a perspective transformation matrix, wherein the perspective transformation matrix is as follows:

step S306 is to substitute the perspective transformation matrix into the first perspective transformation formula to generate a second perspective transformation formula.

in the second perspective transformation formula, xk and yk are coordinates of each pixel point in the sample plate correction chart PB1, and the calculated xm and ym are coordinates of each pixel point in the sample plate top plane image chart PE1.

Step S307: and performing perspective transformation on the sample plate correction chart PB1 by using a second perspective transformation formula to generate a sample plate top plane image chart PE1.

In step S308, the sample plate top plane image PE1 is converted into a third gray scale image PF1, and the third gray scale image PF1 is converted into a third contour image PG1.

Step S309 is to search the four corners of the third contour map PG1 to obtain a fourth four corner coordinate; the fourth four-corner coordinates are those of the sample plate in the sample plate top plan image PE1.

Step S310 is to calculate and obtain a second horizontal pixel range R31 and a second vertical pixel range R32 of the sample plate in the sample plate top plane image PE1.

Step S311 is to calculate and obtain the second horizontal inter-pixel distance PP31 and the second vertical inter-pixel distance PP32 in the sample plate top plane image PE1.

Steps S308 to S311 are similar to steps S203 to S206 in principle, except that the object of the operation is different. Steps S203 to S206 act on the lens fisheye corrected sample plate correction chart PB1. Steps S308 to S311 act on the lens fisheye corrected and perspective transformed sample plate top plane image map PE1, thereby further improving the measurement accuracy.

Step S312 is to take a photograph with a camera to obtain a board to be tested original PA2.

Step S313 is to perform lens fisheye correction on the original drawing PA2 of the board to be tested, and generate a board to be tested correction drawing PB2.

Step S314 is to perform perspective transformation on the board to be tested calibration chart PB2 according to the second perspective transformation formula, so as to generate a board to be tested top plane image chart PE2.

In step S314, xk and yk of the second perspective transformation formula are coordinates of each pixel point in the board to be tested correction chart PB2, and the calculated xm and ym are coordinates of each pixel point in the board to be tested top plane image chart PE2. The perspective transformation performed in steps S307, S314 can convert the sample plate, which may be tilted, the board to be tested into a planar image to reduce errors.

In step S315, the top plane image PE2 of the board to be tested is converted into a fourth gray scale image PF2, and the fourth gray scale image PF2 is converted into a fourth contour image PG2.

Step S316 is to search the four corners of the fourth contour PG2 to obtain a fifth four corners coordinates; the fifth four-corner coordinates are those of the board to be measured in the board to be measured top plan image PE2.

Step S317: and calculating to obtain a left pixel range R33, an upper pixel range R34, a right pixel range R35 and a lower pixel range R36 of the top surface of the board to be tested in the top plane image PE2 of the board to be tested.

Step S318: and calculating and obtaining the left side length L31, the upper side length L32, the right side length L33 and the lower side length L34 of the top surface of the board to be tested in the top plane image diagram PE2 of the board to be tested.

In the foregoing embodiments, for example, the first to sixth laser pitches X1 to X6 and the like belong to the measured values, and the average value may be taken as the final value after being performed a plurality of times (for example, 60 times) to reduce the error.

The first interval distance D1 can be conveniently calculated through the optical measuring device and the measuring method, so that the measuring device can be used for measuring plates to be measured with different sizes. In addition, the platform 1 may be a structure with adjustable height to control the board to be measured to rise or fall, so that the boards to be measured with different heights can be measured without adjusting the first, second and third laser measuring instruments.

In order to facilitate understanding of the spirit of the present invention, the following examples are presented.

In example 1, the values of the four sides L15 to L18 of the board to be measured are measured in steps S101 to S107.

Step S101 is performed, where the first distance D1 is unknown and the second distance D2 is 240mm.

Step S102 is performed, wherein the left side length L11 of the top surface of the sample plate, the upper side length L12 of the top surface of the sample plate, the right side length L13 of the top surface of the sample plate and the lower side length L14 of the top surface of the sample plate are 600.017mm.

Step S103 was performed to measure a first laser pitch X1 of 153.623mm, a second laser pitch X2 of 216.377mm, and a third laser pitch X3 of 214.311mm.

Step S104 is performed to calculate and obtain a first distance D1 of 970.039mm.

Step S105 is performed, wherein the left side length L15 of the top surface of the board to be tested, the upper side length L16 of the top surface of the board to be tested, the right side length L17 of the top surface of the board to be tested, and the lower side length L18 of the top surface of the board to be tested are unknown.

Step S106 was performed, and the fourth laser pitch X4 was 154.589mm, the fifth laser pitch X5 was 215.636mm, and the sixth laser pitch X6 was 214.641mm.

Step S107 is performed, wherein the length L18 of the lower edge of the top surface of the board to be tested is 599.809mm. And (3) rotating the board to be tested by ninety degrees, and then performing S101-S107 for three times to obtain the left side length L15 of the top surface of the board to be tested, the upper side length L16 of the top surface of the board to be tested and the right side length L17 of the top surface of the board to be tested which are 599.809mm.

In example 2, steps S101 to S107 are used to insert steps S301 to S318, and the values of the four sides L15 to L18 and L31 to L34 of the two groups of plates to be measured are measured, and the two groups of values can be analyzed in a mutual comparison manner. In example 2, steps S101 to S107 are not repeated.

As shown in fig. 7, step S301 is performed to obtain a sample plate artwork PA1. In example 2, the camera has a horizontal resolution of 3200 pixels and a vertical resolution of 1800 pixels, for example using Logitech 4k Brio.

As shown in fig. 8, step S302 is performed to generate a sample plate calibration map PB1.

As shown in fig. 9, step S303 is performed to generate a first gray scale map PC1 and a first contour map PD1.

Step S304 is performed, where the coordinates of the first four corners are: upper left xi1:92, yi1:609, lower left xi2:107, yi2:2147, upper right xi3:1623, yi3:596, lower right xi4:1648, yi4:2124.

step S305 is performed, and the coordinates of the third four corners are: upper left xj1:107, yj1:609, lower left xj2:107, yj2:2147, upper right xj3:1623, yj3:609, lower right xj4:1623, yj4:2124. bringing the coordinates of each point in the coordinates of the first four corners and the third four corners into a first perspective transformation formula to obtain a perspective transformation matrix, wherein the perspective transformation matrix is as follows:

proceeding to step S306, the second perspective transformation formula is:

as shown in fig. 10, step S307 is performed to generate a sample plate top plan image PE1.

As shown in fig. 11, step S308 is performed to generate a third gray scale map PF1 and a third contour map PG1.

Step S309 is performed, and the fourth four-corner coordinates are: upper left xm1:108, ym1:610, lower left xm2:108, ym2:2125, upper right xm3:1623, ym3:610, lower right xm4:1623, ym4:2125.

proceeding to step S310, the second horizontal pixel range R31 is |xm3-xm1|=1515 mm/pixel, and the second vertical pixel range R32 is |ym2-ym1|=1515 mm/pixel.

Step S311 is performed, wherein the second horizontal inter-pixel distance PP31 is L14/r31= 0.396051, and the second vertical inter-pixel distance PP32 is L13/r32= 0.396051.

As shown in fig. 12, step S312 is performed to obtain a board original PA2 to be tested.

As shown in fig. 13, step S313 is performed to generate a board calibration chart PB2 to be tested.

As shown in fig. 14, step S314 is performed to generate a top plan image PE2 of the board to be tested.

As shown in fig. 15, step S315 is performed to generate a fourth gray scale image PF2 and a fourth profile image PG2.

Step S316 is performed, and the coordinates of the fifth four corners are: upper left xn1:109, yn1:617, lower left xn2:109, yn2:2130, upper right xn3:1622, yn3:617, lower right xn4:1622, yn4:2130.

step S317 is performed, where the left pixel range R33 of the top surface of the board to be tested is |yn2-yn1|=1513 mm/pixel, the upper pixel range R34 of the top surface of the board to be tested is |xn3-xn1|=1513 mm/pixel, the right pixel range R35 of the top surface of the board to be tested is |yn4-yn3|=1513 mm/pixel, and the lower pixel range R36 of the top surface of the board to be tested is |xn4-xn2|=1513 mm/pixel.

Step S318 is performed, where the left side length L31 of the top surface of the board to be tested is PP31×r33= 599.225mm, the top side length L32 of the top surface of the board to be tested is PP32×r34= 599.225mm, the right side length L33 of the top surface of the board to be tested is PP31×r35= 599.225mm, and the bottom side length L34 of the top surface of the board to be tested is PP32×r36= 599.225mm.

The first, second and third laser measuring instruments 11, 12, 13 and the camera 21 can be connected to a computer (not shown) in a wired or wireless manner, and the calculation and image conversion in the above steps can be processed by the computer to save cost.

The foregoing embodiments of the present invention are provided for illustration only, and are not intended to limit the scope of the present invention, i.e., the various modifications made by the claims set forth below should be construed as being included in the scope of the present invention.

Claims

1. An optical measurement device, comprising:

a platform;

the first laser measuring instrument is arranged on one side of the platform;

the second laser measuring instrument is arranged on the other side of the platform opposite to the first laser measuring instrument, horizontally aligned with the first laser measuring instrument and spaced by a first interval distance;

the third laser measuring instrument is arranged on the other side of the platform opposite to the first laser measuring instrument and is separated from the second laser measuring instrument by a second interval distance.

2. The optical measurement device of claim 1 wherein a camera is mounted above the platform.

3. The optical measurement device of claim 1 wherein the platform is height adjustable and capable of being raised and lowered.

4. An optical measurement method, comprising the steps of:

s101: a first laser measuring instrument is arranged on one side of a platform, a second laser measuring instrument and a third laser measuring instrument are arranged on the other side of the platform opposite to the first laser measuring instrument, the first laser measuring instrument and the second laser measuring instrument are separated by a first interval distance (D1), and the second laser measuring instrument and the third laser measuring instrument are separated by a preset second interval distance (D2);

s102: placing a sample plate on the platform; the sample plate is cuboid, the top surface is square, and the left side length (L11) of the top surface of the sample plate, the upper side length (L12) of the top surface of the sample plate, the right side length (L13) of the top surface of the sample plate and/or the lower side length (L14) of the top surface of the sample plate are/is preset;

s103: measuring a first laser distance (X1), a second laser distance (X2) and a third laser distance (X3) between the first laser measuring instrument, the second laser measuring instrument and the third laser measuring instrument and the sample plate respectively;

s104: calculating to obtain the value of the first interval distance (D1);

s105: taking the sample plate and placing a plate to be tested on the platform; the board to be tested is cuboid, and the top surface is square, and is provided with a left side length (L15) of the top surface of the board to be tested, a top side length (L16) of the top surface of the board to be tested, a right side length (L17) of the top surface of the board to be tested and/or a bottom side length (L18) of the top surface of the board to be tested;

s106: measuring a fourth laser interval (X4), a fifth laser interval (X5) and a sixth laser interval (X6) between the first laser measuring instrument, the second laser measuring instrument and the third laser measuring instrument and the board to be measured respectively;

s107: calculating to obtain the value of the lower side length (L18) of the top surface of the board to be tested.

5. The optical measurement method according to claim 4, wherein in the step S104, the value of the first distance (D1) is calculated and obtained by a first formula; the first formula is:

6. the optical measurement method according to claim 4, wherein in the step S107, the value of the bottom edge (L18) of the top surface of the board to be measured is calculated and obtained by a second formula; the second formula is:

7. the optical measurement method according to claim 4, wherein after the step S102, steps S201 to S206 are performed, wherein:

s201: erecting a camera above the platform, and taking pictures by using the camera to obtain a sample plate original picture; the camera has a predetermined horizontal resolution and a vertical resolution;

s202: performing lens fish eye correction on the original sample plate image to generate a sample plate correction image;

s203: converting the sample plate calibration map into a first gray map, and converting the first gray map into a first contour map;

s204: searching four corner points of the first profile graph to obtain a first four corner point coordinate; the first four-corner point coordinates are four-corner point coordinates of the sample plate in the sample plate calibration chart;

s205: calculating a first horizontal pixel range and a first vertical pixel range of a sample plate obtained in the sample plate correction chart;

s206: a first horizontal inter-pixel distance and a first vertical inter-pixel distance in the sample plate calibration map are calculated.

8. The optical measurement method according to claim 7, wherein after the step S105, steps S207 to S212 are performed, wherein:

s207: taking pictures by using the camera to obtain an original drawing of a board to be tested;

s208: performing lens fisheye correction on the original image of the board to be tested to generate a board to be tested correction chart;

s209: converting the calibration image of the board to be tested into a second gray image, and converting the second gray image into a second contour image;

s210: searching four corner points of the second contour map to obtain a second four corner point coordinate; the second four-corner point coordinates are the four-corner point coordinates of the sample plate in the calibration chart of the plate to be tested;

s211: calculating to obtain the left pixel range of the top surface of the board to be tested, the upper pixel range of the top surface of the board to be tested, the right pixel range of the top surface of the board to be tested and/or the lower pixel range of the top surface of the board to be tested in the calibration chart of the board to be tested;

s212: and calculating to obtain the left side length of the top surface of the board to be tested, the upper side length of the top surface of the board to be tested, the right side length of the top surface of the board to be tested and/or the lower side length of the top surface of the board to be tested in the calibration chart of the board to be tested.

9. The optical measurement method according to claim 4, wherein after the step S102, steps S301 to S311 are performed, wherein:

s301: erecting a camera above the platform, and taking pictures by using the camera to obtain a sample plate original picture; the camera has a predetermined horizontal resolution and a vertical resolution;

s302: performing lens fish eye correction on the original sample plate image to generate a sample plate correction image;

s303: converting the sample plate calibration map into a first gray map, and converting the first gray map into a first contour map;

s304: searching four corner points of the first profile graph to obtain a first four corner point coordinate; the first four-corner point coordinates are four-corner point coordinates of the sample plate in the sample plate calibration chart;

s305: setting a third four-corner point coordinate, and substituting the first four-corner point coordinate and the third four-corner point coordinate into a first perspective transformation formula to calculate a perspective transformation matrix;

s306: substituting the perspective transformation matrix into the first perspective transformation formula to generate a second perspective transformation formula;

s307: performing perspective transformation on the sample plate correction chart by using the second perspective transformation formula to generate a sample plate top plane image chart;

s308: converting the top plane image of the sample plate into a third gray scale image, and converting the third gray scale image into a third contour image;

s309: searching four corner points of the third profile diagram to obtain a fourth four corner point coordinate; the fourth four-corner point coordinates are the four-corner point coordinates of the sample plate in the sample plate top plane image;

s310: calculating a second horizontal pixel range and a second vertical pixel range of the sample plate in the top plane image of the sample plate;

s311: and calculating and obtaining a second horizontal pixel distance and a second vertical pixel distance in the top plane image of the sample plate.

10. The optical measurement method of claim 9 wherein the first perspective transformation formula is:

in the first perspective transformation formula, xi and yi are coordinates of each point in the first four-corner point coordinate, and xj and yj are coordinates of each point in the third four-corner point coordinate.

11. The optical measurement method according to claim 10, wherein the coordinates of each point in the first four-corner coordinates and the third four-corner coordinates are brought into the first perspective transformation formula to obtain the perspective transformation matrix as

in the second perspective transformation formula, xk and yk are coordinates of each pixel point in the sample plate correction chart, and the calculated xl and yl are coordinates of each pixel point in the sample plate top plane image chart.

12. The optical measurement method according to claim 9, wherein after the step S105, steps S312 to S318 are performed first;

s312: taking pictures by using the camera to obtain an original drawing of a board to be tested;

s313: performing lens fisheye correction on the original image of the board to be tested to generate a board to be tested correction chart;

s314: performing perspective transformation on the board correction diagram to be tested by using the second perspective transformation formula to generate a top plane image diagram of the board to be tested;

s315: converting the top plane image of the board to be tested into a fourth gray scale image, and converting the fourth gray scale image into a fourth outline image;

s316: searching four corner points of the fourth profile diagram to obtain a fifth four corner point coordinate; the fifth four-corner point coordinates are the four-corner point coordinates of the board to be measured in the top plane image of the board to be measured;

s317: calculating to obtain the left pixel range of the top surface of the board to be tested, the upper pixel range of the top surface of the board to be tested, the right pixel range of the top surface of the board to be tested and/or the lower pixel range of the top surface of the board to be tested in the top plan image of the board to be tested;

s318: and calculating to obtain the left side length of the top surface of the board to be tested, the upper side length of the top surface of the board to be tested, the right side length of the top surface of the board to be tested and/or the lower side length of the top surface of the board to be tested in the overlook plane image diagram of the board to be tested.