CN112556614B

CN112556614B - Conversion relation acquisition method, conversion relation measurement method and conversion relation measurement system

Info

Publication number: CN112556614B
Application number: CN202011070282.4A
Authority: CN
Inventors: 陈鲁; 吕肃; 方一; 李青格乐; 张嵩
Original assignee: Shenzhen Zhongke Feice Technology Co Ltd
Current assignee: Shenzhen Zhongke Feice Technology Co Ltd
Priority date: 2020-09-30
Filing date: 2020-09-30
Publication date: 2023-06-27
Anticipated expiration: 2040-09-30
Also published as: CN112556614A

Abstract

The invention provides a conversion relation acquisition method, a measurement method and a measurement system, wherein the conversion relation acquisition method comprises the following steps: providing a detection device having a first coordinate system; providing an object to be detected, wherein the object to be detected is provided with a second coordinate system, the surface of the object to be detected is provided with a plurality of characteristic points, and the characteristic points are provided with characteristic coordinates under the second coordinate system; placing the object to be detected in the detection equipment; after the object to be detected is placed in the detection equipment, detecting a plurality of characteristic points through the detection equipment, and obtaining measurement coordinates of the characteristic points under 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.

Description

Conversion relation acquisition method, conversion relation measurement method and conversion relation measurement system

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 processing precision is also required to be higher and higher. In order to meet the requirement of processing precision and improve the qualification rate of processed samples, the processing process and the processed products need to be tested for morphology distortion frequently so as to ensure that the distortion is within a tolerable range.

In precision-machining distortion detection applications, it is often desirable 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 the to-be-detected point is realized by scanning a large area range of the surface of the to-be-detected object. When the number of points to be detected is small, the method greatly reduces the detection efficiency. Only detecting the to-be-detected point can effectively improve the detection efficiency, however, in the detection process of the specific to-be-detected point, accurate positioning is required to be carried out on the to-be-detected point, so that the detection precision is ensured.

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

Disclosure of Invention

In order to solve the above problems, the invention provides a method for acquiring a conversion relationship, a measurement method and a measurement system, which can improve the accuracy of the conversion relationship by measuring the surface characteristic points of an object to be measured to acquire the conversion relationship between a first coordinate system and a second coordinate system.

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 detected, wherein the object to be detected is provided with a second coordinate system, the surface of the object to be detected is provided with a plurality of characteristic points, and the characteristic points are provided with characteristic coordinates under the second coordinate system; placing the object to be detected in the detection equipment; after the object to be detected is placed in the detection equipment, detecting a plurality of characteristic points through the detection equipment, and obtaining measurement coordinates of the characteristic points under 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 coordinate and the measurement coordinate comprises 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 relationship 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 original point position relation.

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

the step of detecting the feature point through the detection device and obtaining the measurement coordinates of the feature point under 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 includes: 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 first projection line is formed in the third coordinate plane by a connecting line of the first feature point and the second feature point, and a first preset included angle is formed between the first projection line and the fourth coordinate axis; the step of obtaining the first axis positional relationship from the first relative displacement includes: 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 point through the detection device and obtaining the measurement coordinates of the feature point under the first coordinate system comprises the following steps: detecting the third characteristic point through the detection equipment to obtain a third measurement coordinate of the third characteristic 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 the second axis position relationship between the second coordinate axis and the fifth coordinate axis includes: acquiring second relative displacement of the third feature point and the fourth feature point in the first coordinate plane according to the third measurement coordinate and the fourth measurement coordinate; and acquiring the second axial 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 feature point and the fourth feature point are the same feature 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 the 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, the fifth feature point having a second origin distance vector to the second coordinate system origin;

the step of detecting the plurality of feature points through the detection equipment to obtain the measurement coordinates of the feature 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 acquiring the origin position relationship between the first coordinate system origin and the second coordinate system origin includes: and acquiring the origin position relationship 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 relationship and the second axis position relationship; acquiring origin coordinates of a second coordinate system origin 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 relation 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: carrying out local height measurement on three or more characteristic points of the surface of the object to be detected under the first coordinate system by the detection equipment to obtain height information of the three or more characteristic points along the third coordinate axis, wherein the plane where the three or more characteristic points are located is parallel to the third coordinate plane; and acquiring a relation representation of the third coordinate plane under a first coordinate system according to the height information of the three or more points, and obtaining 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, and acquiring the height information.

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

Optionally, the edge line of the feature structure is a circle or a regular polygon; the feature is a hole or cone.

The technical scheme of the invention also provides a measuring method, which comprises the following steps: according to the method for acquiring the conversion relation, acquiring the conversion relation between the first coordinate system and the second coordinate system; the surface of the object to be detected is provided with a region to be detected, and the region to be detected is provided with first coordinate information under the second coordinate system; acquiring second coordinate information of the region to be measured in a first coordinate system according to the conversion relation and the first coordinate information; positioning the region to be detected by the detection equipment according to the second coordinate information; and after the detection equipment positions the region to be detected according to the second coordinate information, detecting the region to be detected through the detection equipment to acquire the physical information of the region 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 acquire first position information of the first measuring point; executing the detection step on the second measuring point to acquire second position information of the second measuring point; and acquiring the measurement distance between the first measurement point and the second measurement point according to the first position information and the second position information.

The technical scheme of the invention also provides a measuring system, which comprises: 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 comprises: the detection module is used for the measuring 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 increase the measurement speed, thereby increasing the speed of acquiring the conversion relationship. Meanwhile, the selection of the characteristic points can be the center position of the object to be detected with small distortion, and the accuracy of the acquired conversion relationship can be improved.

Further, the feature point includes a center of the feature structure; the coordinates of a plurality of points at the edge of the feature structure are obtained, the edge line of the feature structure is fitted, the fitted edge line is obtained, errors of the coordinates of the plurality of points can be counteracted in the fitting process, and therefore the accuracy of feature point detection can be improved, and the accuracy of the obtained conversion relation can be improved.

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

Drawings

The advantages and the manner of carrying out the invention will become more apparent from the detailed description of the invention given hereinafter with reference to the accompanying drawings, which are given by way of illustration only and are not limitative of the present invention in any sense, and which are merely schematic and are not drawn to scale strictly. In the drawings:

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

FIG. 2 is a schematic diagram of an exemplary test object and a test trajectory with a second coordinate system (O 'X' Y 'Z') according to an embodiment of a method for acquiring a conversion relationship of the present invention;

FIG. 3 shows a schematic diagram of the test object of FIG. 2 after placement in a test apparatus having a first coordinate system (OXYZ) in accordance with the present invention;

FIG. 4 shows a flow chart of the 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 shows 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 three-dimensional measurement is required 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 to be detected causes the height change of the surrounding area, the error detection can be achieved by performing three-dimensional measurement on the region to be detected at a critical position (for example, a critical position where the object to be detected may generate an error). In this process, how to find a reasonable measurement position and to exclude measurement errors caused by uneven placement of the object to be measured becomes a measurement key point. The traditional detection method can acquire the contour image of the object to be detected only after the measurement of all areas is completed, so that the quick positioning detection cannot be realized.

According to the technical scheme, the characteristic points on the surface of the object to be detected are detected, so that the conversion relation between the first coordinate system and the second coordinate system is obtained. The detection of a limited number of feature points can increase the measurement speed, thereby increasing the speed of acquiring the conversion relationship. And the measuring point of the object to be measured can be positioned according to the conversion relation, so that quick distortion measurement is realized. Exemplary embodiments according to the present invention will now be described with reference to the accompanying drawings.

Fig. 1 shows a flowchart of the steps of an embodiment of a method for obtaining a conversion relation 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 detected, wherein the object to be detected is provided with a second coordinate system, the surface of the object to be detected is provided with a plurality of characteristic points, and the characteristic points are provided with characteristic coordinates under the second coordinate system; s3, placing the object to be detected in the detection equipment; step S4, after the object to be detected is placed in the detection equipment, detecting coordinates of a plurality of feature points through the detection equipment, and obtaining measurement coordinates of the feature points under a first coordinate system; and S5, acquiring a conversion relation between the first coordinate system and the second coordinate system according to the characteristic 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 detection device includes a chromatic dispersion confocal device, a laser triangulation device, a three-coordinate detection device, an interferometry device, 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 plane). Specifically, for example, the first coordinate system employs a cartesian rectangular coordinate system (ozz). 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 adopts a cartesian rectangular coordinate system (O 'X' Y 'Z'); the plane formed by the fourth coordinate axis (X 'axis) and the fifth coordinate axis (Y' axis) is a third coordinate plane.

The imaging device is used for acquiring an image of the object to be detected in the first coordinate plane, wherein the image of the object to be detected comprises the position information of the object to be detected in the first coordinate plane; the three-dimensional detection device 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 a test trajectory with a second coordinate system (O 'X' Y 'Z') according to an embodiment of the invention.

Fig. 3 shows a schematic view of the object to be measured in fig. 2 after being placed in a detection apparatus having a first coordinate system (ozz) according to the invention.

In this embodiment, the area to be measured is a track L to be measured and includes a plurality of points to be measured. In other implementations, the to-be-measured area may be a point to be measured.

In this embodiment, the object to be measured has a rectangular surface, and the track to be measured is a line. Fig. 3 shows a schematic diagram of the object to be measured in fig. 2 after being placed in a detection device (only the moving platform of which is shown) with a first coordinate system (ozz) according to an embodiment of the invention. In the embodiment of fig. 3, the test object 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 one embodiment, a measurement plane of the imaging device is set to a first coordinate plane. In addition, the object placing plane of the moving 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, the first coordinate system remains unchanged for each measurement, since the location to which the detection device belongs and the measurement viewing angle are fixed.

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

The step of obtaining the conversion relationship between the first coordinate system and the second coordinate system according to the first feature coordinate and the second feature coordinate includes: 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 relationship 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 original point 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 the conversion relation comprises the following steps: acquiring a first axis position relation between the first coordinate axis and the fourth coordinate axis according to the coordinate plane transformation relation; acquiring a second axis position relation between the second coordinate axis and the fifth coordinate axis according to the coordinate plane transformation relation; acquiring an origin position relationship between the origin of the first coordinate system and the origin of the second coordinate system according to the coordinate plane transformation relation; and acquiring a conversion relation according to the first axis position relation, the second axis position relation and the original point 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 transfer relation includes: carrying out local height measurement on three or more characteristic points of the surface of the object to be detected under the first coordinate system by the detection equipment to obtain height information of the three or more characteristic points along the third coordinate axis, wherein the plane where the three or more characteristic points are located is parallel to the third coordinate plane; and acquiring a relation representation of the third coordinate plane under a first coordinate system according to the height information of the three or more points, and obtaining the coordinate plane conversion relation.

Specifically, the coordinate plane conversion relationship includes: and an 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, and acquiring 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; local height measurements are made using a three-dimensional inspection device.

In other words, in the case of local height measurement with the three-dimensional detection apparatus, 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 make the acquired coordinate plane conversion relationship more accurately reflect the accurate positioning relationship of the object to be measured and the detection apparatus, the three or more feature points are located in a flat area in the surface of the object to be measured, which is equidistant from the third coordinate plane. Optionally, the three or more feature points include two pairs of points that are respectively symmetrical about the centroid of the object to be measured. In one embodiment, the three or more feature points are selected from a flat region of the surface of the test object that is the same height, and as far apart as possible. Alternatively, the number of measured feature points may be adjusted according to the surface features of the object to be measured and the desired topography distortion measurement accuracy. According to embodiments of the present invention, the three-dimensional detection device may comprise any suitable three-dimensional detection device capable of implementing the measurement method of the present invention (e.g., capable of achieving a sufficient height measurement accuracy), such as a dispersive confocal device, a laser triangulation device, a three-dimensional detection device, an interferometry measurement device, and the like.

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 detected can be positioned through 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 a first feature point a and a second feature point B that are different; the step of obtaining the feature points through the detection equipment comprises the following steps: 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 which can be identified by the detection equipment, and the feature points comprise: including the center of a feature having an edge line.

Specifically, the feature points include: the convex 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 structure, and the feature structure is provided with an edge line; the detecting device detects coordinates of a plurality of the feature points, and the step of obtaining measurement coordinates of the feature points in a first coordinate system comprises the following steps: detecting a plurality of points of the characteristic structure edge line to obtain coordinates of the plurality of points of the characteristic structure edge; fitting the characteristic structure edge line according to coordinates of a plurality of points of the characteristic structure edge to obtain a fitting edge line; and obtaining the measurement coordinates of the characteristic points according to the fitting edge line.

The edge line of the characteristic structure is round or regular polygon; the feature is a hole or cone.

The feature points comprise centers of feature structures; the coordinates of a plurality of points at the edge of the feature structure are obtained, the edge line of the feature structure is fitted, the fitted edge line is obtained, errors of the coordinates of the plurality of points can be counteracted in the fitting process, and therefore the accuracy of feature point detection can be improved, and the accuracy of the obtained conversion relation can be improved.

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

Specifically, in this embodiment, an image is formed on an edge line of the feature structure by using an imaging device, so as to obtain an edge line image; and acquiring coordinates of a plurality of points at the edge of the characteristic 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 feature point A; and acquiring second measurement coordinates according to the image of the second characteristic point B. In other embodiments, the first measurement coordinate may be obtained by detecting the first feature point a by a three-dimensional detection device; 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 includes: 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, the first relative displacement is (X1-X2, Y1-Y2) when the first feature point a acquired by the detection device has (X1, Y1) in the first coordinate plane and the second feature point B acquired by the detection device has (X2, Y2) in the first coordinate plane.

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

The step of obtaining the first axis positional relationship from the first relative displacement includes: 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 includes: acquiring a third relative displacement of the first relative displacement in 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 acquiring the first axis position relation according to the first standard displacement, namely, acquiring the first axis position relation according to the first standard displacement which is parallel to the fourth coordinate axis.

The first axis positional relationship includes: and an 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 the coordinate plane conversion relationship. In other embodiments, the first coordinate plane is parallel to a third coordinate plane, and then 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. Since the first relative displacement is a displacement vector of the first feature point a and the second feature point B under the first coordinate system, the positional relationship between the connection line of the first feature point a and the second feature point B and the fourth coordinate axis does not change with the change of the coordinate system; therefore, the third relative displacement in the first coordinate system rotates the first standard displacement acquired by the first preset included angle to be parallel to the fourth coordinate axis, so that the first axis position relation 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 that are different, and the step of detecting the feature points by the detection device includes: 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;

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 fourth measurement coordinates according to the image of the second characteristic point B.

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

The step of obtaining the 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 a fourth characteristic point according to the third measurement coordinate and the fourth measurement coordinate; and acquiring the second axial position relation according to the second relative displacement.

And a second projection line is arranged in the third coordinate plane and forms a second preset included angle with the fifth coordinate axis.

The step of obtaining the second axial 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 B may be different.

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;

Specifically, the first reference included angle is 90 degrees; the second reference 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 acquiring the origin position relationship between the first coordinate system origin and the second coordinate system origin includes: detecting the fifth characteristic point through detection equipment to obtain a fifth measurement coordinate of the fifth characteristic point in the first coordinate plane; and acquiring the origin position relationship according to the fifth measurement coordinate and the origin distance vector.

And if the fifth characteristic point coincides with the origin of the second coordinate system, the origin distance vector is 0. And the origin coordinates of the fifth measurement coordinate and the second coordinate system are the coordinates of the same point under different coordinate systems, and the coordinates are the same when the origin coordinates of the fifth measurement coordinate and 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 does not coincide 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 relationship and the second axis position relationship; acquiring origin coordinates of a second coordinate system origin 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 an origin coordinate of the origin of the second coordinate system under the first coordinate system, so that an origin position relationship between the origin of the first coordinate system and the origin of the second coordinate system is established.

The fifth feature point may be the same 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 scheme of the present invention further provides a measurement method, including:

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

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

S23, positioning the region to be detected by the detection equipment according to the second coordinate information;

s24, after the detection equipment locates the region to be detected according to the second coordinate information, the detection equipment detects the region to be detected, and physical information of the region to be detected is obtained.

The physical information includes: one or more of the width, thickness and three-dimensional coordinates of the object to be measured in the measurement area are combined. 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.

By acquiring the conversion relation between the first coordinate system and the second coordinate system and acquiring the second coordinate information of the to-be-measured area in the first coordinate system according to the conversion relation and the first coordinate information of the to-be-measured area in the second coordinate system, accurate positioning of the measuring point can be realized according to the second coordinate information, so that quick and high-precision measurement of the to-be-measured area of the to-be-measured object can be realized, and whether the to-be-measured object 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 that the second coordinate system may be established according to further criteria. It will be appreciated that it is within the scope of the present invention to establish 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 detection device. The process of establishing the second coordinate system according to the present invention is characterized in that accurate positioning of the object to be measured is rapidly established 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 detecting device. Furthermore, 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 may be represented by a transformation matrix T. According to the transformation matrix T, the coordinate D in the first coordinate system and the coordinate D' in the second coordinate system of the same position satisfy the relationship: d=t·d' or d=t ^-1 D', wherein T ^-1 Is the inverse 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 converted by the conversion matrix T, and the design coordinates of any point on the object to be detected can be related to the first coordinate system of the detection device. Notably, thisThe seed correlation is established only by the two-dimensional image obtained by the imaging device and the height information of the very few points obtained by the three-dimensional detection device, which is far faster than the conventional detection method of obtaining complete three-dimensional information by the three-dimensional detection device and with a higher accuracy (for reasons of this detailed description see the background section). Note that although the process of obtaining the conversion relationship between the first coordinate system and the second coordinate system is described only with reference to the cartesian rectangular coordinate system, it will be understood by those skilled in the art that any other suitable coordinate system may be employed to perform the process, for example, a cylindrical coordinate system, a polar coordinate system, and the like. Alternatively, a suitable 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 morphology information of the track L to be measured or coordinate information of any one point to be measured in the first coordinate system; on the basis, detection information of the physical information under the second coordinate system is obtained by utilizing the conversion relation. The measuring method further comprises the following steps: providing design morphology information of the object to be detected, and acquiring distortion of the object to be detected according to the design morphology information and 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 includes: one or both of defect information of the track to be detected and thickness information of a surface film layer of the track to be detected. The detection device further comprises: a defect detecting device or a film thickness detecting device. The defect detection equipment is used for detecting defects in the track to be detected; the thickness detection module is used for measuring thickness information of the surface film layer of the region to be detected. The defect detection device comprises a differential phase shift interferometer or a machine vision device.

The conversion relation in this embodiment is applicable to 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 relation application range in the present embodiment is large.

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 an acute included angle; the coordinate axes of the second coordinate system may have acute included angles.

In other embodiments, the first coordinate plane is parallel to the second coordinate plane, for example, in a wafer or glass substrate inspection apparatus, the wafer is held by the chuck, the first coordinate plane is parallel to the chuck surface, the surface of the wafer is the second coordinate plane, and the first coordinate plane is parallel to the second coordinate plane.

In embodiments according to the present invention, it may be convenient to designate a region to be measured on an object to be measured for measurement of a selected area, in particular three-dimensional measurement. Considering that distortion generally causes a change in the height of an area, the trajectory to be measured may alternatively pass through a critical location where the object to be measured may be distorted. Optionally, the area to be measured is a line or a plane. Alternatively, the trajectory to be measured may be a straight line for convenience of movement, or for improving measurement efficiency. It will be appreciated by those skilled in the art that the region to be measured is a trace to be measured, and the trace to be measured may have any suitable shape. Specifically, a trajectory to be measured is selected for the object to be measured based on the measurement needs. Since the track to be measured is set with respect to the object to be measured itself, 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 tested in the first coordinate system is obtained by using the transformation matrix T. For example, the detection device includes a moving platform, where the moving platform is used to drive the object to be detected to move. The moving platform can be made to move according to the second track information, and the three-dimensional detection equipment measures 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 by using the conversion matrix T to obtain detection information including the height data array R' along the sixth coordinate axis.

The detection information (including the height data array R' along the sixth coordinate axis) is compared with the design topography information (including the height data array R along the sixth coordinate axis) to determine the distortion state of the object to be measured, i.e., the position and degree of the distortion of the object to be measured. The design of the morphology information refers to taking the height distribution along a preset track to be measured when the object to be measured does not have any distortion. Alternatively, the design morphology information is a height distribution of the design morphology of the object to be measured along a 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 to be measured is determined from the absolute value of the difference between the height data sequence R and the height data sequence R 'at the same position point (i.e., |r0-R' |). The same position point means that the height data sequence R and the height data sequence R 'to be compared are identical in coordinates along the fourth coordinate axis, and the height data sequence R' to be compared are identical in 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 I R0-R' | is larger than the distortion threshold at a certain position, considering that the object to be detected has distortion at the position. And obtaining the specific position of the distortion on the object to be detected by utilizing the position of the point larger than the distortion threshold value and the design of the track to be detected. The distortion threshold value may be set according to the distortion judgment tolerance, and the larger the distortion judgment tolerance is, the larger the distortion threshold value is. Meanwhile, the three-dimensional measurement precision is better than 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 acquire first position information of the first measuring point; executing the detection step on the second measuring point to acquire second position information of the second measuring point; and acquiring the measurement distance between the first measurement point and the second measurement point according to the first position information and the second position information. The first and second position information may be acquired by the imaging device or a three-dimensional detection device.

Referring to fig. 5 and 6, the technical scheme of the invention also relates to a measurement system, which is used for measuring an object to be measured, wherein the object to be measured is provided with a second coordinate system, the surface of the object to be measured is provided with a plurality of characteristic points, and the characteristic points are provided with characteristic coordinates under 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 converted relation and acquiring the conversion relation between the first coordinate system and the second coordinate system.

The measurement system further includes: the detection module is used for executing the measuring method of the measuring method embodiment shown in fig. 4.

In this embodiment, the detection apparatus is the same as that in the embodiment of the acquisition method of the conversion relationship shown in fig. 1 to 3.

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

Specifically, the conversion relation obtaining module is configured to perform: 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 by 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 relationship according to the fifth measurement coordinate and the second origin distance vector.

Specifically, the conversion relation acquisition module performs 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 relationship 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 original point position relation.

The 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 are provided with a first preset included angle;

The step of obtaining the second axis position relationship between the second coordinate axis and the fifth coordinate axis includes: acquiring second relative displacement of the third characteristic point C and the fourth characteristic point in the first coordinate plane according to the third measurement coordinate and the fourth measurement coordinate; and acquiring the second axial 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 the 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 fifth characteristic 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 relationship and the second axis position relationship; acquiring origin coordinates of a second coordinate system origin 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 relation further includes: and acquiring a coordinate plane conversion relation between the first coordinate plane and the third coordinate plane.

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, and acquiring the height information.

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

The detection device comprises an imaging device and a three-dimensional detection device. The imaging device comprises a telecentric imaging device. Specifically, the three-dimensional detection device includes a chromatic dispersion confocal device, a laser triangulation device, a three-coordinate detection device, an interferometry device, 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 placement plane to support the object to be measured. The measurement system further includes a gantry coupling the imaging device, the three-dimensional inspection device, and the mobile platform together. The stage, imaging device, three-dimensional inspection device, and 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, a track information acquisition module, a detection information acquisition module and the like.

Fig. 6 shows a schematic diagram of an exemplary mobile platform according to an embodiment of the invention. In the embodiment shown in fig. 5, the mobile platform is a mobile platform with multiple degrees of freedom that can be used to perform precise movements of the object under test in three-dimensional topography measurements. The mobile platform may also include means for holding an object to be measured, such as a vacuum chuck as shown in fig. 6. Alternatively, the mobile platform may be any suitable mobile platform capable of implementing the measuring 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., telecentric imaging device) in order to facilitate establishing a first coordinate system in accordance with embodiments of the present invention.

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

1) The method comprises the steps that by means of the conversion relation between the coordinate system of the object to be detected and the coordinate system of the measuring equipment, the track to be detected of the object to be detected can be directly measured by the detecting equipment, and therefore the shape information of the appointed position of the object to be detected can be directly obtained; 2) Combining a two-dimensional imaging method with a three-dimensional measuring method, rapidly establishing accurate positioning of an object to be measured relative to 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, measuring the track to be measured of the object to be measured (particularly three-dimensional measurement) according to the positioning relation, obviously reducing the measuring time and improving the measuring precision; 3) The influence of the shape, the placement position and the height noise of the object to be measured on the three-dimensional measurement and the morphological distortion judgment is effectively eliminated, and the noise-proof performance and the robustness are very strong; 4) The process of measuring and judging the shape distortion at the track to be measured can be completely controlled by a computer program, so that the process is easy to be integrated into automatic production equipment and an automatic production process, and the shape distortion measurement of the object to be measured and the efficiency of the whole production flow are improved; 5) And detecting the characteristic points on 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 increase the measurement speed, thereby increasing the speed of acquiring the conversion relationship. 6) The coordinates of a plurality of points at the edge of the feature structure are obtained, the edge line of the feature structure is fitted, the fitted edge line is obtained, errors of the coordinates of the plurality of points can be counteracted in the fitting process, and therefore the accuracy of feature point detection can be improved, and the accuracy of the obtained conversion relation can be improved.

The foregoing description refers only to the 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 substitutions may be made to these embodiments without departing from the spirit of the invention, as appropriate for the particular situation. Indeed, the scope of the invention is defined by the claims and may include other examples that may be envisioned by one of ordinary skill 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 made by one skilled in the art without departing from the spirit and scope of the invention, and the scope of the invention should be assessed accordingly to that of the appended claims.

Claims

1. A method for acquiring a conversion relation capable of positioning a measurement point of an object to be measured includes:

Providing a detection device, wherein the detection device is provided with a first coordinate system, 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;

providing an object to be detected, wherein the object to be detected is provided with a second coordinate system, the second coordinate system comprises a fourth coordinate axis, a fifth coordinate axis and a sixth coordinate axis, a plane formed by the fourth coordinate axis and the fifth coordinate axis is a third coordinate plane, the surface of the object to be detected is provided with a plurality of characteristic points, and the characteristic points are provided with characteristic coordinates under the second coordinate system;

placing the object to be detected in the detection equipment;

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

according to the feature coordinates and the measurement coordinates, obtaining the conversion relation between the first coordinate system and the second coordinate system comprises the following steps: acquiring a first axis position relation between the first coordinate axis and the fourth coordinate axis;

the step of obtaining the conversion relation further includes: acquiring a coordinate plane conversion relation between the first coordinate plane and the third coordinate plane; the step of the coordinate plane conversion relation comprises the following steps: the included angle between the third coordinate plane and the second coordinate plane is a plane under the first coordinate system and is based on the actual bottom surface of the object to be detected placed on the detection equipment;

The plurality of feature points comprise 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 obtaining the first axis position relationship between the first coordinate axis and the fourth coordinate axis includes: 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; acquiring the first axis position relation according to the first relative displacement;

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

The step of obtaining the first axis positional relationship from the first relative displacement includes: 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; acquiring the first axis position relation according to the first standard displacement;

the step of obtaining the first axis positional relationship further includes: acquiring a third relative displacement of the first relative displacement in a third coordinate plane according to a coordinate plane conversion relation between the first coordinate plane and the third coordinate plane; and rotating the third relative displacement by the first preset included angle to obtain a first standard displacement.

2. The method of claim 1, wherein the step of acquiring the conversion relationship between the first coordinate system and the second coordinate system based on the feature coordinates and the measurement coordinates further comprises: acquiring a second axis position relation between the second coordinate axis and the fifth coordinate axis; acquiring an origin position relationship 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 original point position relation.

3. The method of obtaining a conversion relation according to claim 2, wherein the plurality of feature points includes a third feature point and a fourth feature point, the third feature point and the fourth feature point being different feature points;

4. The method for obtaining a conversion relation according to claim 3, wherein the first feature point and the third feature point are the same feature point; the second feature point and the fourth feature point are the same feature point.

5. The method for acquiring the conversion relation according to claim 2, 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;

6. The method of obtaining a conversion relation according to claim 2, wherein the plurality of feature points includes a fifth feature point having a second origin distance vector to the origin of the second coordinate system;

7. The method according to claim 6, wherein the fifth feature point coincides with the origin of the second coordinate system;

8. The method of acquiring a conversion relation according to claim 1, wherein the step of acquiring a coordinate plane conversion relation between the first coordinate plane and the third coordinate plane includes: carrying out local height measurement on three or more characteristic points of the surface of the object to be detected under the first coordinate system by the detection equipment to obtain height information of the three or more characteristic points along the third coordinate axis, wherein the plane where the three or more characteristic points are located is parallel to the third coordinate plane; and acquiring a relation representation of the third coordinate plane under a first coordinate system according to the height information of the three or more points, and obtaining the coordinate plane conversion relation.

9. The method of claim 8, wherein the step of measuring the local height 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, and acquiring the height information.

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

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

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

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

11. The method for obtaining a conversion relation according to claim 10, wherein an edge line of the feature structure is a circle or a regular polygon; the feature is a hole or cone.

12. A method of measurement, comprising:

the method for obtaining a conversion relationship according to any one of claims 1 to 11, wherein the conversion relationship between the first coordinate system and the second coordinate system is obtained, the surface of the object to be measured has a region to be measured, and the region to be measured has first coordinate information under the second coordinate system;

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

positioning the region to be detected by the detection equipment according to the second coordinate information;

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

13. The measurement method of claim 12, wherein the region under test has a first measurement point and a second measurement point;

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

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

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

14. A measurement system, comprising:

a detection device having a first coordinate system;

a conversion relation acquisition module, configured to execute the conversion relation acquisition method according to any one of claims 1 to 11, and acquire a conversion relation between the first coordinate system and the second coordinate system.

15. The measurement system of claim 14, wherein the measurement system further comprises: a detection module for performing the measurement method of claim 12 or 13.