阅读说明：本技术 转换关系的获取方法、测量方法及测量系统 (Conversion relation obtaining method, measurement method and measurement system ) 是由 陈鲁 吕肃 方一 李青格乐 张嵩 于 2020-09-30 设计创作，主要内容包括：本发明提供一种转换关系的获取方法、测量方法和测量系统,其中,转换关系的获取方法包括：提供检测设备,所述检测设备具有第一坐标系；提供待测物,所述待测物具有第二坐标系,所述待测物表面具有多个特征点,所述特征点在第二坐标系下具有特征坐标；将所述待测物放置于所述检测设备；在将所述待测物放置于所述检测设备之后,通过检测设备对多个所述特征点进行检测,获取特征点在第一坐标系下的测量坐标；根据所述特征坐标与所述测量坐标,获取所述第一坐标系与所述第二坐标系之间的转换关系。所述转换关系的获取方法能够提高获取速度及转换关系的精度。(The invention provides a conversion relation obtaining method, a conversion relation measuring method and a conversion relation measuring system, wherein the conversion relation obtaining method comprises the following steps: providing a detection device having a first coordinate system; providing an object to be tested, wherein the object to be tested is provided with a second coordinate system, the surface of the object to be tested is provided with a plurality of characteristic points, and the characteristic points are provided with characteristic coordinates in the second coordinate system; placing the object to be detected on the detection equipment; after the object to be detected is placed on the detection equipment, detecting the plurality of characteristic points through the detection equipment to obtain measurement coordinates of the characteristic points in a first coordinate system; and acquiring a conversion relation between the first coordinate system and the second coordinate system according to the characteristic coordinates and the measurement coordinates. The method for acquiring the conversion relation can improve the acquisition speed and the precision of the conversion relation.)

1. A conversion relation obtaining method comprises the following steps:

providing a detection device having a first coordinate system;

providing an object to be tested, wherein the object to be tested is provided with a second coordinate system, the surface of the object to be tested is provided with a plurality of characteristic points, and the characteristic points are provided with characteristic coordinates in the second coordinate system;

placing the object to be detected on the detection equipment;

after the object to be detected is placed on the detection equipment, detecting the plurality of characteristic points through the detection equipment to obtain measurement coordinates of the characteristic points in a first coordinate system;

and acquiring a conversion relation between the first coordinate system and the second coordinate system according to the characteristic coordinates and the measurement coordinates.

2. The method according to claim 1, wherein the first coordinate system includes a first coordinate axis, a second coordinate axis, and a third coordinate axis, and a plane formed by the first coordinate axis and the second coordinate axis is a first coordinate plane; the second coordinate system comprises a fourth coordinate axis, a fifth coordinate axis and a sixth coordinate axis, and a plane formed by the fourth coordinate axis and the fifth coordinate axis is a third coordinate plane;

the step of obtaining the conversion relation between the first coordinate system and the second coordinate system according to the feature coordinates and the measurement coordinates comprises: acquiring a first axis position relation between the first coordinate axis and the fourth coordinate axis; acquiring a second axis position relation between the second coordinate axis and the fifth coordinate axis; acquiring an origin position relation between the origin of the first coordinate system and the origin of the second coordinate system; and acquiring the conversion relation according to the first axis position relation, the second axis position relation and the origin position relation.

3. The method according to claim 2, wherein the plurality of feature points include a first feature point and a second feature point, and the first feature point and the second feature point are different feature points;

the step of detecting the feature points through the detection equipment and acquiring the measurement coordinates of the feature points in the first coordinate system comprises the following steps: detecting the first characteristic point through the detection equipment to obtain a first measurement coordinate of the first characteristic point in the first coordinate plane; detecting the second characteristic point through the detection equipment to obtain a second measurement coordinate of the second characteristic point in the first coordinate plane;

the step of obtaining the first axis position relationship between the first coordinate axis and the fourth coordinate axis comprises: acquiring first relative displacement of the first characteristic point and the second characteristic point in the first coordinate plane according to the first measurement coordinate and the second measurement coordinate; and acquiring the first axis position relation according to the first relative displacement.

4. The method for obtaining conversion relation according to claim 3, wherein a connecting line of the first feature point and the second feature point has a first projection line in the third coordinate plane, and the first projection line and the fourth coordinate axis have a first preset included angle;

the step of obtaining the first axis position relationship according to the first relative displacement comprises: rotating the projection of the first relative displacement in the third coordinate plane by the first preset included angle to obtain a first standard displacement; and acquiring the first axis position relation according to the first standard displacement.

5. The method according to claim 3 or 4, wherein the plurality of feature points include a third feature point and a fourth feature point, and the third feature point and the fourth feature point are different feature points;

the step of detecting the feature points through the detection equipment and acquiring the measurement coordinates of the feature points in the first coordinate system comprises the following steps: detecting the third feature point through the detection equipment to obtain a third measurement coordinate of the third feature point in the first coordinate plane; detecting the fourth characteristic point through the detection equipment to obtain a fourth measurement coordinate of the fourth characteristic point in the first coordinate plane;

the step of obtaining a second axis position relationship between the second coordinate axis and the fifth coordinate axis includes: according to the third measurement coordinate and the fourth measurement coordinate, second relative displacement of the third characteristic point and the fourth characteristic point in the first coordinate plane is obtained; and acquiring the second axis position relation according to the second relative displacement.

6. The method for obtaining conversion relation according to claim 5, wherein the first feature point and the third feature point are the same feature point; the second characteristic point and the fourth characteristic point are the same characteristic point.

7. The method for obtaining conversion relation according to claim 3 or 4, wherein a first reference included angle is formed between the first coordinate axis and the second coordinate axis; a second reference included angle is formed between the fourth coordinate axis and the fifth coordinate axis;

the step of obtaining a second axis position relationship between the second coordinate axis and the fifth coordinate axis includes: and acquiring the second axis position relation according to the first axis position relation, the first reference included angle and the second reference included angle.

8. The method according to claim 2, wherein the plurality of feature points include a fifth feature point having a second origin distance vector to the origin of the second coordinate system;

the detection equipment detects the characteristic points, and the step of acquiring the measurement coordinates of the characteristic points in the first coordinate system comprises the following steps: detecting the fifth characteristic point through detection equipment to obtain a fifth measurement coordinate of the fifth characteristic point;

the step of obtaining the origin position relation between the origin of the first coordinate system and the origin of the second coordinate system comprises the following steps: and acquiring the origin position relation according to the fifth measurement coordinate and the second origin distance vector.

9. The method according to claim 8, wherein the fifth feature point coincides with the origin of the second coordinate system;

or, the fifth feature point is not coincident with the origin of the second coordinate system, and obtaining the origin position relationship according to the fifth measurement coordinate and the second origin distance vector includes: acquiring a first origin distance vector of the second origin distance vector in the first coordinate plane according to the first axis position relation and the second axis position relation; acquiring the origin coordinates of the origin of a second coordinate system in the first coordinate system according to the first origin distance vector; and acquiring the origin position relation according to the origin coordinates.

10. The method for obtaining a conversion relation according to claim 1, wherein the step of obtaining the conversion relation further comprises: acquiring a coordinate plane conversion relation between the first coordinate plane and the third coordinate plane;

the step of obtaining the coordinate plane conversion relation between the first coordinate plane and the third coordinate plane comprises the following steps: performing local height measurement on three or more characteristic points on the surface of the object to be measured through the detection equipment under the first coordinate system to obtain height information of the three or more characteristic points along the third coordinate axis, wherein the plane of the three or more characteristic points is parallel to the third coordinate plane; and obtaining the relation representation of the third coordinate plane under the first coordinate system according to the height information of the three or more points to obtain the coordinate plane conversion relation.

11. The method for obtaining a conversion relation according to claim 10, wherein the step of measuring the local height includes: acquiring an object image of the object to be detected in the first coordinate plane; acquiring position information of the three or more characteristic points of the object to be detected according to the object image; and measuring the three or more characteristic points of the object to be measured according to the position information to acquire the height information.

12. The method according to claim 1, wherein the feature point includes a center of a feature structure, the feature structure having an edge line;

the detection equipment detects the coordinates of the characteristic points, and the step of acquiring the measurement coordinates of the characteristic points in the first coordinate system comprises the following steps: detecting a plurality of points of the edge line of the feature structure to obtain the coordinates of the plurality of points of the edge of the feature structure;

fitting the characteristic structure edge line according to the coordinates of the plurality of points of the characteristic structure edge to obtain a fitted edge line;

and obtaining the measurement coordinates of the feature points according to the fitting edge line.

13. The method according to claim 12, wherein the edge line of the feature structure is a circle or a regular polygon; the features are holes or cones.

14. A method of measurement, comprising:

the method according to any one of claims 1 to 13, wherein a conversion relationship between the first coordinate system and a second coordinate system is obtained, the surface of the object to be measured has an area to be measured, and the area to be measured has first coordinate information in the second coordinate system;

acquiring second coordinate information of the area to be detected in a first coordinate system according to the conversion relation and the first coordinate information;

enabling the detection equipment to position the area to be detected according to the second coordinate information;

and after the detection equipment positions the area to be detected according to the second coordinate information, detecting the area to be detected through the detection equipment to acquire the physical information of the area to be detected.

15. The measurement method according to claim 14, wherein the region to be measured has a first measurement point and a second measurement point;

executing the detection step on the first measuring point to obtain first position information of the first measuring point;

executing the detection step on the second measuring point to obtain second position information of the second measuring point;

and acquiring the measuring distance between the first measuring point and the second measuring point according to the first position information and the second position information.

16. A measurement system, comprising:

a detection device having a first coordinate system;

a transformation relation obtaining module, configured to perform the transformation relation obtaining method according to any one of claims 1 to 13, and obtain a transformation relation between the first coordinate system and the second coordinate system.

17. The measurement system of claim 16, further comprising: a detection module for performing the measurement method of claim 14 or 15.

Technical Field

The present invention relates to a measurement method and a measurement system thereof, and more particularly, to a method for acquiring a conversion relationship, a measurement method, and a measurement system thereof.

Background

With the development of modern industry, precision machining is used in more and more fields; meanwhile, the machining precision is also required to be higher and higher. In order to meet the requirement of machining precision and improve the qualification rate of machined samples, the machining process and the machined products need to be frequently tested for shape distortion so as to ensure that the distortion is within a tolerable range.

In distortion detection applications for precision machining, it is often necessary to detect the height, film thickness or line width of a set measurement point (e.g., at a critical location) of an object under test. In the prior art, the detection of a point to be detected is realized by scanning a large area range of the surface of an object to be detected. When the number of the points to be detected is small, the method greatly reduces the detection efficiency. Only the point to be detected is detected, so that the detection efficiency can be effectively improved, however, in the process of detecting the specific point to be detected, the point to be detected needs to be accurately positioned, so that the detection precision is ensured.

The prior art is difficult to ensure the accurate positioning of the point to be measured.

Disclosure of Invention

In order to solve the above problems, the present invention provides a method for obtaining a transformation relation, a method for measuring a transformation relation, and a system for measuring a surface feature point of an object to be measured, so as to obtain a transformation relation between a first coordinate system and a second coordinate system, thereby improving the precision of the transformation relation.

The technical scheme of the invention provides a method for acquiring a conversion relation, which comprises the following steps: providing a detection device having a first coordinate system; providing an object to be tested, wherein the object to be tested is provided with a second coordinate system, the surface of the object to be tested is provided with a plurality of characteristic points, and the characteristic points are provided with characteristic coordinates in the second coordinate system; placing the object to be detected on the detection equipment; after the object to be detected is placed on the detection equipment, detecting the plurality of characteristic points through the detection equipment to obtain measurement coordinates of the characteristic points in a first coordinate system; and acquiring a conversion relation between the first coordinate system and the second coordinate system according to the characteristic coordinates and the measurement coordinates.

Optionally, the first coordinate system includes a first coordinate axis, a second coordinate axis and a third coordinate axis, and a plane formed by the first coordinate axis and the second coordinate axis is a first coordinate plane; the second coordinate system comprises a fourth coordinate axis, a fifth coordinate axis and a sixth coordinate axis, and a plane formed by the fourth coordinate axis and the fifth coordinate axis is a third coordinate plane;

the step of obtaining the conversion relation between the first coordinate system and the second coordinate system according to the feature coordinates and the measurement coordinates comprises: acquiring a first axis position relation between the first coordinate axis and the fourth coordinate axis; acquiring a second axis position relation between the second coordinate axis and the fifth coordinate axis; acquiring an origin position relation between the origin of the first coordinate system and the origin of the second coordinate system; and acquiring the conversion relation according to the first axis position relation, the second axis position relation and the origin position relation.

Optionally, the plurality of feature points include a first feature point and a second feature point, and the first feature point and the second feature point are different feature points;

the step of detecting the feature points through the detection equipment and acquiring the measurement coordinates of the feature points in the first coordinate system comprises the following steps: detecting the first characteristic point through the detection equipment to obtain a first measurement coordinate of the first characteristic point in the first coordinate plane; detecting the second characteristic point through the detection equipment to obtain a second measurement coordinate of the second characteristic point in the first coordinate plane;

the step of obtaining the first axis position relationship between the first coordinate axis and the fourth coordinate axis comprises: acquiring first relative displacement of the first characteristic point and the second characteristic point in the first coordinate plane according to the first measurement coordinate and the second measurement coordinate; and acquiring the first axis position relation according to the first relative displacement.

Optionally, a connecting line between the first feature point and the second feature point has a first projection line in the third coordinate plane, and the first projection line and the fourth coordinate axis have a first preset included angle; the step of obtaining the first axis position relationship according to the first relative displacement comprises: rotating the projection of the first relative displacement in the third coordinate plane by the first preset included angle to obtain a first standard displacement; and acquiring the first axis position relation according to the first standard displacement.

Optionally, the plurality of feature points include a third feature point and a fourth feature point, and the third feature point and the fourth feature point are different feature points;

the step of detecting the feature points through the detection equipment and acquiring the measurement coordinates of the feature points in the first coordinate system comprises the following steps: detecting the third feature point through the detection equipment to obtain a third measurement coordinate of the third feature point in the first coordinate plane; detecting the fourth characteristic point through the detection equipment to obtain a fourth measurement coordinate of the fourth characteristic point in the first coordinate plane;

the step of obtaining a second axis position relationship between the second coordinate axis and the fifth coordinate axis includes: according to the third measurement coordinate and the fourth measurement coordinate, second relative displacement of the third characteristic point and the fourth characteristic point in the first coordinate plane is obtained; and acquiring the second axis position relation according to the second relative displacement.

Optionally, the first feature point and the third feature point are the same feature point; the second characteristic point and the fourth characteristic point are the same characteristic point.

Optionally, a first reference included angle is formed between the first coordinate axis and the second coordinate axis; a second reference included angle is formed between the fourth coordinate axis and the fifth coordinate axis;

the step of obtaining a second axis position relationship between the second coordinate axis and the fifth coordinate axis includes: and acquiring the second axis position relation according to the first axis position relation, the first reference included angle and the second reference included angle.

Optionally, the plurality of feature points includes a fifth feature point having a second origin distance vector to the origin of the second coordinate system;

the detection equipment detects the characteristic points, and the step of acquiring the measurement coordinates of the characteristic points in the first coordinate system comprises the following steps: detecting the fifth characteristic point through detection equipment to obtain a fifth measurement coordinate of the fifth characteristic point;

the step of obtaining the origin position relation between the origin of the first coordinate system and the origin of the second coordinate system comprises the following steps: and acquiring the origin position relation according to the fifth measurement coordinate and the second origin distance vector.

Optionally, the fifth feature point coincides with the origin of the second coordinate system;

or, the fifth feature point is not coincident with the origin of the second coordinate system, and obtaining the origin position relationship according to the fifth measurement coordinate and the second origin distance vector includes: acquiring a first origin distance vector of the second origin distance vector in the first coordinate plane according to the first axis position relation and the second axis position relation; acquiring the origin coordinates of the origin of a second coordinate system in the first coordinate system according to the first origin distance vector; and acquiring the origin position relation according to the origin coordinates.

Optionally, the step of obtaining the conversion relationship further includes: acquiring a coordinate plane conversion relation between the first coordinate plane and the third coordinate plane;

the step of obtaining the coordinate plane conversion relation between the first coordinate plane and the third coordinate plane comprises the following steps: performing local height measurement on three or more characteristic points on the surface of the object to be measured through the detection equipment under the first coordinate system to obtain height information of the three or more characteristic points along the third coordinate axis, wherein the plane of the three or more characteristic points is parallel to the third coordinate plane; and obtaining the relation representation of the third coordinate plane under the first coordinate system according to the height information of the three or more points to obtain the coordinate plane conversion relation.

Optionally, the step of measuring the local height includes: acquiring an object image of the object to be detected in the first coordinate plane; acquiring position information of the three or more characteristic points of the object to be detected according to the object image; and measuring the three or more characteristic points of the object to be measured according to the position information to acquire the height information.

Optionally, the feature point includes a center of a feature, and the feature has an edge line; the detection equipment detects the coordinates of the characteristic points, and the step of acquiring the measurement coordinates of the characteristic points in the first coordinate system comprises the following steps: detecting a plurality of points of the edge line of the feature structure to obtain the coordinates of the plurality of points of the edge of the feature structure; fitting the characteristic structure edge line according to the coordinates of the plurality of points of the characteristic structure edge to obtain a fitted edge line; and obtaining the measurement coordinates of the feature points according to the fitting edge line.

Optionally, the edge line of the feature structure is a circle or a regular polygon; the features are holes or cones.

The technical scheme of the invention also provides a measuring method, which comprises the following steps: acquiring a conversion relation between the first coordinate system and the second coordinate system according to the acquisition method of the conversion relation; the surface of the object to be measured is provided with an area to be measured, and the area to be measured is provided with first coordinate information under the second coordinate system; acquiring second coordinate information of the area to be detected in a first coordinate system according to the conversion relation and the first coordinate information; enabling the detection equipment to position the area to be detected according to the second coordinate information; and after the detection equipment positions the area to be detected according to the second coordinate information, detecting the area to be detected through the detection equipment to acquire the physical information of the area to be detected.

Optionally, the region to be measured has a first measurement point and a second measurement point; executing the detection step on the first measuring point to obtain first position information of the first measuring point; executing the detection step on the second measuring point to obtain second position information of the second measuring point; and acquiring the measuring distance between the first measuring point and the second measuring point according to the first position information and the second position information.

The technical solution of the present invention also provides a measurement system, including: a detection device having a first coordinate system; and the conversion relation acquisition module is used for executing the conversion relation acquisition method and acquiring the conversion relation between the first coordinate system and the second coordinate system.

Optionally, the measurement system further includes: a detection module for the above measurement method.

The technical scheme of the invention has the following beneficial effects:

according to the method for acquiring the conversion relation, provided by the technical scheme of the invention, the conversion relation between the first coordinate system and the second coordinate system is acquired by detecting the characteristic points on the surface of the object to be detected. The detection of a limited number of feature points can improve the measurement speed, so that the speed of acquiring the conversion relation is improved. Meanwhile, the feature points can be selected from the center position of the object to be measured with small distortion, and the accuracy of the acquired conversion relation can be improved.

Further, the feature point comprises a center of a feature; by acquiring the coordinates of a plurality of points at the edge of the feature structure, fitting the edge line of the feature structure and acquiring the fitting edge line, errors of the coordinates of the plurality of points can be offset in the fitting process, so that the detection precision of the feature points can be improved, and the precision of the acquired conversion relation can be improved.

According to the measuring method provided by the technical scheme of the invention, the second coordinate information of the area to be measured in the first coordinate system is obtained by obtaining the conversion relation between the first coordinate system and the second coordinate system according to the conversion relation and the first coordinate information of the area to be measured in the second coordinate system, and the accurate positioning of the measuring point can be realized according to the second coordinate information, so that the quick and high-precision measurement of the area to be measured of the object to be measured can be realized, and whether the object to be measured has errors is judged.

Drawings

Advantages and realisations of the invention will be apparent from the following detailed description, taken in conjunction with the accompanying drawings, which are given by way of illustration only, and not by way of limitation, of the invention, and which are given by way of illustration only, and are not drawn to scale. In the drawings:

FIG. 1 is a flow chart illustrating steps of an embodiment of a translation relation obtaining method according to the present invention;

FIG. 2 is a diagram illustrating an exemplary test object having a second coordinate system (O 'X' Y 'Z') and a test track according to an embodiment of the method for obtaining a transform relationship of the present invention;

FIG. 3 shows a schematic view of the test object of FIG. 2 after being placed in a test device having a first coordinate system (OXYZ) in accordance with the present invention;

FIG. 4 shows a flow chart of steps of an embodiment of a measurement method according to the invention;

FIG. 5 shows a schematic diagram of an exemplary measurement system according to an embodiment of the invention; and

FIG. 6 illustrates a schematic diagram of an exemplary mobile platform, according to an embodiment of the invention.

Detailed Description

One or more specific embodiments of the present invention will be described below. In an effort to provide a concise description of these embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.

As described above, many precision-machined objects have a large size distribution range, and it is necessary to perform three-dimensional measurement to obtain machining error information. The speed of detection is an important parameter in industrial applications. Since the detection time is proportional to the detection area, considering that the surface distortion of the object causes the height change of the surrounding area, the error detection can be realized by performing three-dimensional measurement on the region to be detected at a key position (for example, a key position where the object may generate an error). In the process, how to find a reasonable measurement position and eliminate measurement errors caused by uneven placement of the object to be measured becomes a measurement key point. The traditional detection method can obtain the profile image of the object to be detected only after the measurement of all areas is completed, so that the rapid positioning detection cannot be realized.

According to the technical scheme, the conversion relation between the first coordinate system and the second coordinate system is obtained by detecting the characteristic points of the surface of the object to be detected. The detection of a limited number of feature points can improve the measurement speed, so that the speed of acquiring the conversion relation is improved. And the measuring point of the object to be measured can be positioned according to the conversion relation, so that the rapid distortion measurement is realized. Exemplary embodiments according to the present invention will now be explained with reference to the drawings.

Fig. 1 is a flowchart illustrating steps of an embodiment of a conversion relation obtaining method according to the present invention.

Referring to fig. 1, the present invention provides a method for obtaining a conversion relationship, which includes the following steps: step S1, providing a detection device, wherein the detection device is provided with a first coordinate system; step S2, providing an object to be tested, wherein the object to be tested is provided with a second coordinate system, the surface of the object to be tested is provided with a plurality of characteristic points, and the characteristic points are provided with characteristic coordinates under the second coordinate system; step S3, placing the object to be detected on the detection equipment; step S4, after the object to be detected is placed on the detection equipment, detecting the coordinates of the characteristic points through the detection equipment to obtain the measurement coordinates of the characteristic points in a first coordinate system; step S5, obtaining a transformation relationship between the first coordinate system and the second coordinate system according to the feature coordinates and the measurement coordinates.

In this implementation, the detection device includes an imaging device and a three-dimensional detection device. The imaging device includes a bright field imaging device or a dark field imaging device. Specifically, the three-dimensional inspection apparatus includes a chromatic dispersion confocal apparatus, a laser triangulation measuring apparatus, a three-coordinate inspection apparatus, an interferometry measuring apparatus, or the like. In other embodiments, the detection device may also include other measurement hardware, such as a mobile platform, optical measurement components, and the like. In other embodiments, the detection device may be a two-dimensional detection device, such as a camera.

In one embodiment, the first coordinate system includes a first coordinate axis (X-axis), a second coordinate axis (Y-axis), and a third coordinate axis (Z-axis), and a plane formed by the first coordinate axis and the second coordinate axis is a first coordinate plane (OXY-Y plane). Specifically, for example, the first coordinate system employs a cartesian orthogonal coordinate system (xyz). The second coordinate system includes a fourth coordinate axis (X ' axis), a fifth coordinate axis (Y ' axis), and a sixth coordinate axis (Z ' axis). Specifically, for example, the second coordinate system employs a cartesian rectangular coordinate system (O 'X' Y 'Z'); and a plane formed by the fourth coordinate axis (X 'axis) and the fifth coordinate axis (Y' axis) is a third coordinate plane.

The imaging equipment is used for acquiring an image of the object to be measured in the first coordinate plane, and the image of the object to be measured comprises position information of the object to be measured in the first coordinate plane; the three-dimensional detection equipment is used for acquiring three-dimensional coordinate information of the object to be detected in the first coordinate system.

FIG. 2 shows a schematic diagram of an exemplary test object and test track having a second coordinate system (O 'X' Y 'Z') according to an embodiment of the invention.

Fig. 3 shows a schematic view of the test object of fig. 2 after being placed in a test device having a first coordinate system (xyz) according to the present invention.

In this embodiment, the region to be measured is a track L to be measured, and includes a plurality of points to be measured. In other implementations, the region under test can be a point under test.

In this embodiment, the object has a rectangular surface, and the trace to be measured is a line. Fig. 3 shows a schematic diagram of the dut in fig. 2 after being placed on a detection apparatus (only the moving platform thereof is shown) having a first coordinate system (xyz), according to an embodiment of the present invention. In the embodiment of fig. 3, the object to be measured is placed slightly inclined.

The first coordinate system comprises a first coordinate axis, a second coordinate axis and a third coordinate axis, and a plane formed by the first coordinate axis and the second coordinate axis is a first coordinate plane; the second coordinate system comprises a fourth coordinate axis, a fifth coordinate axis and a sixth coordinate axis, and a plane formed by the fourth coordinate axis and the fifth coordinate axis is a third coordinate plane.

In an embodiment, the measurement plane of the imaging device is set to a first coordinate plane. In addition, the object placing plane of the mobile platform is also coincident with or parallel to the first coordinate plane. Alternatively, in the case where the imaging device is an optical detection device, the third coordinate axis is parallel to the optical axis of the detection device (specifically, the imaging device). In one embodiment, since the position to which the detection apparatus belongs and the measurement angle of view are fixed, the first coordinate system remains unchanged for each measurement, for convenience.

In an exemplary embodiment according to the invention, the imaging device is optionally a telecentric imaging device. In a common imaging device, the distance between an object to be measured and a light collecting lens affects the imaging magnification, so that the imaging size is changed, the phenomenon that the magnification is different due to different heights of the object to be measured at different positions is possible, and the extracted contour precision is low. Compared with the common imaging equipment, the telecentric imaging equipment only collects the light parallel to the optical axis for imaging, so that the magnification is not influenced by the position of the object to be measured, and the profile precision is ensured. Further, according to an embodiment of the present invention, the imaging device may include any suitable imaging device capable of implementing the measurement method of the present invention (e.g., capable of implementing sufficient profile accuracy measurement).

The step of obtaining the conversion relation between the first coordinate system and the second coordinate system according to the first characteristic coordinate and the second characteristic coordinate comprises: acquiring a first axis position relation between the first coordinate axis and the fourth coordinate axis; acquiring a second axis position relation between the second coordinate axis and the fifth coordinate axis; acquiring an origin position relation between the origin of the first coordinate system and the origin of the second coordinate system; and acquiring the conversion relation according to the first axis position relation, the second axis position relation and the origin position relation.

In one embodiment, the step of obtaining the conversion relationship further comprises: and acquiring a coordinate plane conversion relation between the first coordinate plane and the third coordinate plane.

In this embodiment, a second coordinate plane of a plane formed by the fourth coordinate axis and the fifth coordinate axis in the first coordinate system is obtained;

the step of obtaining a translation relationship comprises: acquiring a first axis position relation between a first coordinate axis and a fourth coordinate axis according to the coordinate plane switch; acquiring a second axis position relation between a second coordinate axis and a fifth coordinate axis according to the coordinate plane switch; acquiring an origin position relation between the origin of the first coordinate system and the origin of the second coordinate system according to the coordinate plane switch; and acquiring a conversion relation according to the first axis position relation, the second axis position relation and the origin position relation. For example, the second coordinate plane is based on the actual bottom surface of the object to be measured placed behind the detection device.

In an exemplary embodiment according to the present invention, the step of acquiring the coordinate plane transform relation includes: performing local height measurement on three or more characteristic points on the surface of the object to be measured through the detection equipment under the first coordinate system to obtain height information of the three or more characteristic points along the third coordinate axis, wherein the plane of the three or more characteristic points is parallel to the third coordinate plane; and obtaining the relation representation of the third coordinate plane under the first coordinate system according to the height information of the three or more points to obtain the coordinate plane conversion relation.

Specifically, the coordinate plane transformation relationship includes: and the included angle between the third coordinate plane and the second coordinate plane.

In one embodiment, the step of local height measurement comprises: acquiring an object image of the object to be detected in the first coordinate plane; acquiring position information of the three or more characteristic points of the object to be detected according to the object image; and measuring the three or more characteristic points of the object to be measured according to the position information to acquire the height information.

In this embodiment, an imaging device is used to obtain an object image of the object to be measured in the first coordinate plane; and measuring the local height by using three-dimensional detection equipment.

In other words, when the three-dimensional detection device is used for local height measurement, the three or more feature points can be accurately positioned based on the object image of the object to be measured in the first coordinate plane.

Specifically, in order to enable the obtained coordinate plane conversion relationship to more accurately reflect the accurate positioning relationship between the object to be measured and the detection device, the three or more feature points are located in a flat area with equal distance to the third coordinate plane in the surface of the object to be measured. Optionally, the three or more feature points include two pairs of points that are respectively symmetrical with respect to the centroid of the object to be measured. In one embodiment, the three or more feature points are selected from flat areas of the test object surface that are at the same height, and points that are spaced as far apart as possible are selected. Alternatively, the number of measured feature points can be adjusted according to the surface features of the object to be measured and the required accuracy of the measurement of the topographical distortion. According to embodiments of the present invention, the three-dimensional inspection device may comprise any suitable three-dimensional inspection device capable of implementing the measurement method of the present invention (e.g., capable of achieving sufficient height measurement accuracy), such as a dispersive confocal device, a laser triangulation device, a three-coordinate inspection device, an interferometric measurement device, and the like.

It should be noted that, in another implementation, the third coordinate plane and the first coordinate plane are parallel, and the step of obtaining the conversion relationship may not include: and acquiring a second coordinate plane of a plane formed by the fourth coordinate axis and the fifth coordinate axis under the first coordinate system. Specifically, the object to be measured can be positioned by the positioning piece, so that the third coordinate plane is parallel to the first coordinate plane.

In a further embodiment, the plurality of feature points includes different first and second feature points a and B; the obtaining, by the detection device, the feature point detection includes: detecting the first characteristic point A through the detection equipment to obtain a first measurement coordinate of the first characteristic point A in the first coordinate plane; and detecting the second characteristic point B through the detection equipment to obtain a second measurement coordinate of the second characteristic point B in the first coordinate plane.

The feature points are points that can be identified by the detection device, and include: including the center of a feature having an edge line.

Specifically, the feature points include: the top point of the surface of the object to be measured, the center of the round hole, the center of the square hole or the points with different colors.

The feature point comprises a center of a feature, the feature having an edge line; the detection equipment detects the coordinates of the characteristic points, and the step of acquiring the measurement coordinates of the characteristic points in the first coordinate system comprises the following steps: detecting a plurality of points of the edge line of the feature structure to obtain the coordinates of the plurality of points of the edge of the feature structure; fitting the characteristic structure edge line according to the coordinates of the plurality of points of the characteristic structure edge to obtain a fitted edge line; and obtaining the measurement coordinates of the feature points according to the fitting edge line.

The edge line of the characteristic structure is circular or regular polygon; the features are holes or cones.

The feature point comprises a center of a feature structure; by acquiring the coordinates of a plurality of points at the edge of the feature structure, fitting the edge line of the feature structure and acquiring the fitting edge line, errors of the coordinates of the plurality of points can be offset in the fitting process, so that the detection precision of the feature points can be improved, and the precision of the acquired conversion relation can be improved.

In this embodiment, the feature point is the center of the circular hole.

Specifically, in this embodiment, the edge line of the feature structure is imaged by an imaging device to obtain an edge line image; and acquiring the coordinates of a plurality of points on the edge of the feature structure according to the edge line image.

Specifically, in this embodiment, the first feature point a and the second feature point B may be imaged by an imaging device; acquiring a first measurement coordinate according to the image of the first characteristic point A; and acquiring a second measurement coordinate according to the image of the second characteristic point B. In other embodiments, the first feature point a may be detected by a three-dimensional detection device to obtain the first measurement coordinate; and detecting the second characteristic point B through the three-dimensional detection equipment to obtain the second measurement coordinate.

The step of obtaining the first axis position relationship between the first coordinate axis and the fourth coordinate axis comprises: acquiring first relative displacement of the first characteristic point A and the second characteristic point B in the first coordinate plane according to the first measurement coordinate and the second measurement coordinate; and acquiring the first axis position relation according to the first relative displacement.

For example, if the coordinates of the first feature point a obtained by the inspection apparatus in the first coordinate plane are (X1, Y1) and the coordinates of the second feature point B obtained by the inspection apparatus in the first coordinate plane are (X2, Y2), the first relative displacement is (X1-X2, Y1-Y2).

And a connecting line of the first characteristic point A and the second characteristic point B is provided with a first projection line in a plane where a fourth coordinate and a fifth coordinate are located, and the first projection line and the fourth coordinate have a first preset included angle.

The step of obtaining the first axis position relationship according to the first relative displacement comprises: rotating the projection of the first relative displacement in the third coordinate plane by the first preset included angle to obtain a first standard displacement; and acquiring the first axis position relation according to the first standard displacement.

The step of obtaining the first axis positional relationship further comprises: acquiring a third relative displacement of the first relative displacement on a third coordinate plane according to a coordinate plane conversion relation between the first coordinate plane and the third coordinate plane; rotating the third relative position by the first preset angle to obtain a first standard displacement; and obtaining the first axis position relation according to the first standard displacement, namely obtaining the first axis position relation according to the fact that the first standard displacement is parallel to the fourth coordinate axis.

The first axial positional relationship comprises: and the included angle between the first coordinate axis and the fourth coordinate axis.

In this embodiment, a third relative displacement of the first relative displacement in the third coordinate plane is obtained according to a coordinate plane transformation relationship. In other embodiments, the first coordinate plane is parallel to a third coordinate plane, and the third relative displacement is the same as the first relative displacement.

Specifically, when the third coordinate plane is parallel to the first coordinate plane, the first standard displacement is parallel to the fourth coordinate axis. The projection of the first relative displacement in the third coordinate plane is the same as the first relative displacement. Because the first relative displacement is a displacement vector of the first characteristic point A and the second characteristic point B in the first coordinate system, the position relation between the connecting line of the first characteristic point A and the second characteristic point B and the fourth coordinate axis does not change along with the change of the coordinate system; therefore, the first standard displacement obtained by rotating the first preset included angle by the third relative displacement in the first coordinate system is parallel to the fourth coordinate axis, so that the first axis position relationship between the fourth coordinate axis and the first coordinate axis is established.

Similarly, the plurality of feature points include a third feature point C and a fourth feature point, and the step of detecting the feature points by the detection device includes: detecting the third feature point C through the detection equipment to obtain a third measurement coordinate of the third feature point C in the first coordinate plane; detecting the fourth characteristic point through the detection equipment to obtain a fourth measurement coordinate of the fourth characteristic point in the first coordinate plane;

specifically, in this embodiment, the first feature point a and the second feature point B may be imaged by an imaging device; acquiring a third measurement coordinate according to the image of the first characteristic point A; and acquiring a fourth measurement coordinate according to the image of the second feature point B.

In other embodiments, the third feature point C may be detected by a three-dimensional detection device, so as to obtain the third measurement coordinate; and detecting the fourth feature point through the three-dimensional detection equipment to obtain the fourth measurement coordinate.

The step of obtaining a second axis position relationship between the second coordinate axis and the fifth coordinate axis includes: acquiring a second relative displacement between the third characteristic point C and the fourth characteristic point according to the third measurement coordinate and the fourth measurement coordinate; and acquiring the second axis position relation according to the second relative displacement.

And a connecting line of the third characteristic point C and the fourth characteristic point is provided with a second projection line in the third coordinate plane, and the second projection line and the fifth coordinate axis form a second preset included angle.

The step of obtaining the second axis positional relationship from the second relative displacement includes: rotating the projection of the first relative displacement in the third coordinate plane by the second preset included angle to obtain a second standard displacement; and acquiring the second axis position relation according to the second standard displacement.

In this embodiment, the second feature point B is the same as the fourth feature point. In other embodiments, the second feature point B and the fourth feature point may not be the same.

In this embodiment, the first feature point a and the third feature point C are different feature points; in other embodiments, the second feature point B and the fourth feature point may be the same feature point.

In another embodiment, a first reference included angle is formed between the first coordinate axis and the second coordinate axis; a second reference included angle is formed between the fourth coordinate axis and the fifth coordinate axis;

the step of obtaining a second axis position relationship between the second coordinate axis and the fifth coordinate axis includes: and acquiring the second axis position relation according to the first axis position relation, the first reference included angle and the second reference included angle.

Specifically, the first reference included angle is 90 degrees; the second reference included angle is 90 degrees. And acquiring the second axis position relation according to the first axis position relation, the first reference included angle and the second reference included angle.

The plurality of feature points includes a fifth feature point having an origin distance vector to the origin of the second coordinate system;

the step of obtaining the origin position relation between the origin of the first coordinate system and the origin of the second coordinate system comprises the following steps: detecting the fifth characteristic point through a detection device to obtain a fifth measurement coordinate of the fifth characteristic point in the first coordinate plane; and acquiring the origin position relation according to the fifth measurement coordinate and the origin distance vector.

And if the fifth feature point is coincident with the origin of the second coordinate system, the distance vector of the origin is 0. And the fifth measurement coordinate and the origin coordinate of the second coordinate system are coordinates of the same point in different coordinate systems, and the coordinates of the fifth measurement coordinate and the origin coordinate of the second coordinate system are converted into the same coordinate system according to the conversion relation, so that the origin conversion relation is obtained.

When the fifth feature point is not coincident with the origin of the second coordinate system, obtaining the origin position relationship according to the fifth measurement coordinate and the second origin distance vector includes: acquiring a first origin distance vector of the second origin distance vector in the first coordinate plane according to the first axis position relation and the second axis position relation; acquiring the origin coordinates of the origin of a second coordinate system in the first coordinate system according to the first origin distance vector; and acquiring the origin position relation according to the origin coordinates.

Specifically, obtaining the origin coordinates of the origin of the second coordinate system in the first coordinate system according to the first origin distance vector includes: and translating the fifth measurement coordinate by the first origin distance vector to obtain the origin coordinate of the origin of the second coordinate system in the first coordinate system, thereby establishing the origin position relationship between the origin of the first coordinate system and the origin of the second coordinate system.

The fifth feature point may be the same feature point as one of the first feature point a, the second feature point B, the third feature point C, and the fourth feature point. The fifth feature point may be different from the first feature point a, the second feature point B, the third feature point C, and the fourth feature point.

Referring to fig. 4, the technical solution of the present invention further provides a measurement method, including:

s21, acquiring a conversion relation between the first coordinate system and the second coordinate system according to the acquisition method of the conversion relation; the surface of the object to be measured is provided with an area to be measured, and the area to be measured is provided with first coordinate information under the second coordinate system;

s22, acquiring second coordinate information of the area to be detected in a first coordinate system according to the conversion relation and the first coordinate information;

s23, enabling the detection equipment to position the area to be detected according to the second coordinate information;

and S24, after the detection equipment positions the area to be detected according to the second coordinate information, the detection equipment detects the area to be detected, and physical information of the area to be detected is obtained.

The physical information includes: and one or more combinations of the width, the thickness and the three-dimensional coordinates of the target to be measured in the region to be measured. Correspondingly, when the physical information comprises the thickness of the target to be detected, the detection equipment further comprises a thickness detection module. The thickness detection module comprises an ellipsometer or a spectral reflectometer. The thickness detection module has the first coordinate system.

The second coordinate information of the area to be measured in the first coordinate system is obtained according to the conversion relation and the first coordinate information of the area to be measured in the second coordinate system, and the accurate positioning of the measuring point can be realized according to the second coordinate information, so that the area to be measured of the object to be measured can be measured quickly and accurately, and whether the object to be measured has errors or not can be judged.

It is noted that the above is only one exemplary embodiment of establishing the second coordinate system according to the present invention, and the second coordinate system may be established according to another standard. It will be appreciated that methods of establishing the second coordinate system by other means based on the two-dimensional image obtained by the imaging device and the height information obtained by the three-dimensional inspection device are within the scope of the present invention. The key point of the process of establishing the second coordinate system according to the present invention is to quickly establish accurate positioning of the object to be measured based on the two-dimensional image obtained by the imaging device and the height information of a very small number of points obtained by the three-dimensional detection device. In addition, steps according to embodiments of the present invention may be reordered, combined, and interchanged.

In one embodiment, the transformation relationship between the first coordinate system and the second coordinate system can be represented by a transformation matrix T. According to the transformation matrix T, the coordinate D of the same position in the first coordinate system and the coordinate D' in the second coordinate system satisfy the relationship: d ═ T · D' or D ═ T^-1D', where T^-1Is the inverse matrix of T. In other words, the coordinates D, D' of the same position in the first coordinate system and the second coordinate system can be conveniently transformed by the transformation matrix T, and the design coordinates of any point on the object to be tested can be associated with the first coordinate system of the detection device. It is worth noting that this correlation is established only by the two-dimensional image obtained by the imaging device and the height information of a very small number of points obtained by the three-dimensional detection device, which is much faster and with higher precision than the traditional detection methods which obtain the complete three-dimensional information by the three-dimensional detection device (for the reason detailed in the analysis of the background section). It is noted that although the process of obtaining the conversion relationship between the first coordinate system and the second coordinate system is illustrated only by a cartesian orthogonal coordinate system, it will be understood by those skilled in the art that the process may be performed by using any other suitable coordinate system, for example, a cylindrical coordinate system, a polar coordinate system, etc. Alternatively, an appropriate coordinate system is selected according to the shape characteristics of the object to be measured to improve efficiency and accuracy.

In this embodiment, the physical information includes shape information of the track L to be measured or coordinate information of any point to be measured in the first coordinate system; on the basis, the detection information of the physical information in the second coordinate system is obtained by utilizing the conversion relation. The measuring method further comprises the following steps: and providing design appearance information of the object to be detected, and acquiring the distortion of the object to be detected according to the design appearance information and the detection information of the track to be detected. In other embodiments, the detection method does not include the step of acquiring the distortion of the test object.

In other embodiments, the physical information comprises: one or the combination of the defect information of the track to be detected or the thickness information of the surface film layer of the track to be detected. The detection device further comprises: a defect inspection apparatus or a film thickness inspection apparatus. The defect detection equipment is used for detecting defects in the track to be detected; the thickness detection module is used for measuring the thickness information of the surface film layer of the area to be detected. The defect detection device comprises a differential phase-shifting interferometer or a machine vision device.

The conversion relationship in this embodiment is suitable for the case where the included angle between the first coordinate plane and the second coordinate plane is greater than or equal to zero. The conversion relationship in this embodiment has a wide application range.

In this embodiment, the first coordinate system is a rectangular coordinate system; the second coordinate system is a rectangular coordinate system. In other embodiments, the coordinate axes of the first coordinate system may have acute included angles; the coordinate axes of the second coordinate system may have acute included angles.

In other embodiments, the first coordinate plane is parallel to a second coordinate plane, such as in an inspection apparatus for wafers or glass substrates, where the wafer is held by the chuck, the first coordinate plane is parallel to the surface of the chuck, the surface of the wafer is the second coordinate plane, and the first coordinate plane is parallel to the second coordinate plane.

In an embodiment according to the present invention, it is convenient to designate a region to be measured on the object to be measured to perform measurement on the selected region, particularly three-dimensional measurement. Considering that the distortion generally causes the height of a region to change, the track to be measured optionally passes through a key part of the object to be measured, which may generate the distortion. Optionally, the area to be measured is a line or a plane. Alternatively, for convenience of movement, or to improve measurement efficiency, the trajectory to be measured may be a straight line. It will be appreciated by those skilled in the art that the region under test is a trace under test, and the trace under test may have any suitable shape. Specifically, based on the measurement requirement, a to-be-measured track is selected for the to-be-measured object. Since the track to be measured is set relative to the object to be measured, the coordinates of the track to be measured correspond to the coordinates of the second coordinate system. Then, the second track information of the track to be measured in the first coordinate system is obtained by using the transformation matrix T. For example, the detection device comprises a moving platform, and the moving platform is used for driving the object to be detected to move. The mobile platform can move according to the second track information, and the three-dimensional detection equipment measures the physical information of the object to be detected along the second track information, wherein the physical information is the appearance of the track to be detected and comprises a height data array R along a third coordinate axis. Since the physical information is a measurement result with respect to the first coordinate system, it can be converted into the second coordinate system using the conversion matrix T to obtain the detection information, including the height data sequence R' along the sixth coordinate axis.

And comparing the detection information (comprising the height data series R' along the sixth coordinate axis) with the design topography information (comprising the height data series R along the sixth coordinate axis) to judge the distortion state of the object to be measured, namely the position and the degree of distortion of the object to be measured. And designing morphology information, namely taking the height distribution of the object to be measured along a preset track to be measured when the object to be measured does not have any distortion. Alternatively, the design feature information is the height distribution of the design feature of the object to be measured along the preset track to be measured. In one embodiment, the design topography information is derived from a CAD design model of the test object. In one embodiment, the distortion state of the object is determined according to the absolute value of the difference between the height data series R and the height data series R 'at the same position point (i.e., | R0-R' |). The same position point means that the height data series R and the height data series R 'to be compared have the same coordinates along the fourth coordinate axis, and the height data series R' to be compared have the same coordinates along the fifth coordinate axis.

Specifically, the step of acquiring the distortion of the object to be measured includes: and setting a distortion threshold, and when the absolute value of R0-R' is larger than the distortion threshold at a certain position, considering that the object to be measured has distortion at the position. The specific position of the distortion on the object to be measured can be obtained by using the position of the point larger than the distortion threshold value and the design of the track to be measured. The distortion threshold may be set according to the distortion determination tolerance, and the larger the distortion determination tolerance is, the larger the distortion threshold is. Meanwhile, the three-dimensional measurement precision is superior to the distortion judgment tolerance.

In another embodiment, the physical information is a distance between two measurement points. Specifically, the region to be measured is provided with a first measuring point and a second measuring point; executing the detection step on the first measuring point to obtain first position information of the first measuring point; executing the detection step on the second measuring point to obtain second position information of the second measuring point; and acquiring the measuring distance between the first measuring point and the second measuring point according to the first position information and the second position information. The first position information and the second position information may be acquired by the imaging device or the three-dimensional detection device.

FIG. 5 shows a schematic diagram of an exemplary measurement system according to an embodiment of the invention; and

FIG. 6 illustrates a schematic diagram of an exemplary mobile platform, according to an embodiment of the invention.

Referring to fig. 5 and fig. 6, the present invention further relates to a measurement system for measuring an object to be measured, where the object to be measured has a second coordinate system, the surface of the object to be measured has a plurality of feature points, and the feature points have feature coordinates in the second coordinate system; the measurement system includes:

a detection device having a first coordinate system;

and the conversion relation acquisition module is used for executing the acquisition method of the conversion relation and acquiring the conversion relation between the first coordinate system and the second coordinate system.

The measurement system further comprises: a detection module for performing the measurement method of the measurement method embodiment shown in fig. 4.

In this embodiment, the detection device is the same as the detection device in the embodiment of the method for acquiring the conversion relationship shown in fig. 1 to 3.

The conversion relation obtaining module is specifically configured to execute the method for obtaining the conversion relation shown in fig. 1 to 3.

Specifically, the conversion relation obtaining module is configured to execute: detecting the first characteristic point A through the detection equipment to obtain a first measurement coordinate of the first characteristic point A in the first coordinate plane; detecting the second characteristic point B through the detection equipment to obtain a second measurement coordinate of the second characteristic point B in the first coordinate plane; detecting the third characteristic point C through the detection equipment to obtain a third measurement coordinate of the third characteristic point C in the first coordinate plane; detecting the fourth characteristic point through the detection equipment to obtain a fourth measurement coordinate of the fourth characteristic point in the first coordinate plane; and acquiring the origin position relation according to the fifth measurement coordinate and the second origin distance vector.

Specifically, the conversion relation obtaining module executes the following steps: acquiring a first axis position relation between the first coordinate axis and the fourth coordinate axis; acquiring a second axis position relation between the second coordinate axis and the fifth coordinate axis; acquiring an origin position relation between the origin of the first coordinate system and the origin of the second coordinate system; and acquiring the conversion relation according to the first axis position relation, the second axis position relation and the origin position relation.

The step of obtaining the first axis position relationship between the first coordinate axis and the fourth coordinate axis comprises: acquiring first relative displacement of the first characteristic point A and the second characteristic point B in the first coordinate plane according to the first measurement coordinate and the second measurement coordinate; and acquiring the first axis position relation according to the first relative displacement.

A connecting line of the first characteristic point A and the second characteristic point B is provided with a first projection line in the third coordinate plane, and the first projection line and the fourth coordinate axis form a first preset included angle;

the step of obtaining the first axis position relationship according to the first relative displacement comprises: rotating the projection of the first relative displacement in the third coordinate plane by the first preset included angle to obtain a first standard displacement; and acquiring the first axis position relation according to the first standard displacement.

The step of obtaining a second axis position relationship between the second coordinate axis and the fifth coordinate axis includes: according to the third measurement coordinate and the fourth measurement coordinate, second relative displacement of the third characteristic point C and the fourth characteristic point in the first coordinate plane is obtained; and acquiring the second axis position relation according to the second relative displacement. Or a first reference included angle is formed between the first coordinate axis and the second coordinate axis; a second reference included angle is formed between the fourth coordinate axis and the fifth coordinate axis; the step of obtaining a second axis position relationship between the second coordinate axis and the fifth coordinate axis includes: and acquiring the second axis position relation according to the first axis position relation, the first reference included angle and the second reference included angle.

The step of obtaining the origin position relation between the origin of the first coordinate system and the origin of the second coordinate system comprises the following steps: and acquiring the origin position relation according to the fifth measurement coordinate and the second origin distance vector.

The fifth feature point is coincident with the origin of the second coordinate system; or, the fifth feature point is not coincident with the origin of the second coordinate system, and obtaining the origin position relationship according to the fifth measurement coordinate and the second origin distance vector includes: acquiring a first origin distance vector of the second origin distance vector in the first coordinate plane according to the first axis position relation and the second axis position relation; acquiring the origin coordinates of the origin of a second coordinate system in the first coordinate system according to the first origin distance vector; and acquiring the origin position relation according to the origin coordinates.

The step of obtaining the conversion relationship further comprises: and acquiring a coordinate plane conversion relation between the first coordinate plane and the third coordinate plane.

The step of obtaining the coordinate plane conversion relation between the first coordinate plane and the third coordinate plane comprises the following steps: performing local height measurement on three or more characteristic points on the surface of the object to be measured through the detection equipment under the first coordinate system to obtain height information of the three or more characteristic points along the third coordinate axis, wherein the plane of the three or more characteristic points is parallel to the third coordinate plane; and obtaining the relation representation of the third coordinate plane under the first coordinate system according to the height information of the three or more points to obtain the coordinate plane conversion relation.

The step of local height measurement comprises: acquiring an object image of the object to be detected in the first coordinate plane; acquiring position information of the three or more characteristic points of the object to be detected according to the object image; and measuring the three or more characteristic points of the object to be measured according to the position information to acquire the height information.

The measurement system further comprises: a detection module, the detection module comprising: the coordinate acquisition unit is used for acquiring second coordinate information of the area to be detected in a first coordinate system according to the conversion relation and the first coordinate information; the positioning unit enables the detection equipment to position the area to be detected according to the second coordinate information; and the detection control unit is used for controlling the detection equipment to detect the area to be detected after the detection equipment positions the area to be detected according to the second coordinate information, and acquiring the physical information of the area to be detected.

The detection device includes an imaging device and a three-dimensional detection device. The imaging device comprises a telecentric imaging device. Specifically, the three-dimensional inspection apparatus includes a chromatic dispersion confocal apparatus, a laser triangulation measuring apparatus, a three-coordinate inspection apparatus, an interferometry measuring apparatus, or the like. In other embodiments, the detection device may also include other measurement hardware, such as a mobile platform, optical measurement components, and the like. FIG. 5 shows a schematic diagram of an exemplary measurement system according to an embodiment of the invention. As shown in fig. 5, the measuring system according to the present invention further includes a moving platform having a placing plane to support the object to be measured. The measurement system further includes a gantry that couples the imaging device, the three-dimensional inspection device, and the mobile platform together. The stage, the imaging device, the three-dimensional detection device, and the moving platform may be integrally formed or may be independently formed. The measuring system also comprises a controller which comprises the conversion relation acquisition module, the track information acquisition module, the detection information acquisition module and the like.

FIG. 6 illustrates a schematic diagram of an exemplary mobile platform, according to an embodiment of the invention. In the embodiment shown in fig. 5, the moving platform is a moving platform with multiple degrees of freedom, which can be used to perform precise movement of the object to be measured in three-dimensional topography measurement. The moving platform may also include a device for holding the test object, such as a vacuum chuck as shown in FIG. 6. Alternatively, the mobile platform may be any suitable mobile platform capable of implementing the measurement method according to the invention. In one embodiment, the placement plane of the mobile platform is disposed substantially perpendicular to the optical axis of the imaging device (e.g., a telecentric imaging device) to facilitate establishing a first coordinate system according to embodiments of the invention.

According to the above exemplary embodiments of the present invention, at least the following technical effects and advantages may be achieved:

1) by utilizing the conversion relation between the coordinate system of the object to be measured and the coordinate system of the measuring equipment, the track to be measured of the object to be measured can be directly measured by utilizing the detecting equipment, so that the appearance information of the specified position of the object to be measured can be directly obtained; 2) the method combines a two-dimensional imaging method and a three-dimensional measuring method, quickly establishes accurate positioning of the object to be measured relative to the measuring equipment according to a two-dimensional image obtained by the two-dimensional imaging equipment and the height information of a very small number of points obtained by the three-dimensional detecting equipment, measures (particularly three-dimensional measurement) the track to be measured of the object to be measured according to the positioning relation, obviously reduces the measuring time and improves the measuring precision; 3) the influence of the shape, the placing position and the height noise of the object to be measured on three-dimensional measurement and shape distortion judgment is effectively eliminated, and the method has strong noise resistance and robustness; 4) the processes of measurement and shape distortion judgment at the position of the track to be measured can be completely controlled and executed by a computer program, and are easy to be incorporated into automatic production equipment and an automatic production process, so that the efficiency of the shape distortion measurement of the object to be measured and the whole production process is improved; 5) and detecting the characteristic points of the surface of the object to be detected to obtain the conversion relation between the first coordinate system and the second coordinate system. The detection of a limited number of feature points can improve the measurement speed, so that the speed of acquiring the conversion relation is improved. 6) By acquiring the coordinates of a plurality of points at the edge of the feature structure, fitting the edge line of the feature structure and acquiring the fitting edge line, errors of the coordinates of the plurality of points can be offset in the fitting process, so that the detection precision of the feature points can be improved, and the precision of the acquired conversion relation can be improved.

The foregoing description merely refers to preferred embodiments of the present invention. However, the invention is not limited to the specific embodiments described herein. Those skilled in the art will readily appreciate that various obvious modifications, adaptations, and alternatives may be made to the embodiments to adapt them to particular situations without departing from the spirit of the present invention. Indeed, the scope of the invention is defined by the claims and may include other examples that may occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.

Although the present invention is disclosed above, the present invention is not limited thereto. Various changes and modifications may be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.