CN115615350A

CN115615350A - Detection method and system thereof

Info

Publication number: CN115615350A
Application number: CN202110807884.1A
Authority: CN
Inventors: 陈鲁; 刘欢敏; 吕肃; 张嵩
Original assignee: Shenzhen Zhongke Feice Technology Co Ltd
Current assignee: Shenzhen Zhongke Feice Technology Co Ltd
Priority date: 2021-07-16
Filing date: 2021-07-16
Publication date: 2023-01-17

Abstract

A detection method and a system thereof are used for detecting the line profile of a workpiece to be detected, and the method comprises the following steps: selecting an actual point on a workpiece to be detected, acquiring a measurement point of the actual point and an ideal contour in the same coordinate system, acquiring a first reference point and a second reference point which are adjacent on the ideal contour, wherein at least one of the first reference point and the second reference point is a reference point with the minimum distance from the measurement point, the direction of the first reference point pointing to the second reference point is clockwise around a point in the ideal contour, and acquiring a first vector formed by the first reference point or any point between the first reference point and the second reference point; and acquiring a second vector formed by the second reference point and the measuring point, judging that the measuring point is positioned inside or outside the ideal profile of the workpiece to be detected or on the ideal profile based on the cross product value of the first vector and the second vector, and correspondingly judging that the actual point in the workpiece to be detected is positioned inside or outside the ideal profile or on the ideal profile.

Description

Detection method and system thereof

Technical Field

The invention relates to the field of profile tolerance detection, in particular to a detection method and a detection system.

Background

With the progress of the automatic processing technology in the modern manufacturing industry, workpieces with linear profile can be processed to meet diversified functional requirements. Specifically, the line profile is a requirement for a curve shape, and the definition of line profile tolerance is an index for limiting the variation of an actual curve to an ideal curve, which is a requirement for the shape accuracy of a non-circular curve. Line profile tolerance is the allowable variation of the actual measured element (contour element) to the ideal contour.

In order to keep the forming quality of the workpiece in mind, a strict detection program needs to be executed on the workpiece, and the line profile is an important index for measuring the distortion of the workpiece.

In the prior art, the steps of detecting the line profile degree of a workpiece and determining whether an actual point to be detected on the workpiece to be detected is positioned inside or outside an ideal profile of the workpiece to be detected are complex.

Disclosure of Invention

The embodiment of the invention solves the problem of providing a detection method and a detection system thereof to determine that a measurement point is positioned inside, outside or on an ideal contour of a workpiece to be detected, and further determine that an actual point on the workpiece to be detected is positioned inside, outside or on the ideal contour.

In order to solve the above problem, an embodiment of the present invention provides a detection method for detecting a line profile of a workpiece to be detected, where the detection method includes: providing an ideal profile of a workpiece to be detected, wherein the ideal profile comprises a plurality of datum points; selecting an actual point on the workpiece to be detected; obtaining a measuring point of the actual point and the ideal contour in the same coordinate system; acquiring a first reference point and a second reference point which are adjacent on the ideal contour, wherein at least one of the first reference point and the second reference point is a reference point with the minimum distance from the measuring point; the direction in which the first datum points to the second datum is clockwise about a point inside the ideal contour; acquiring a first vector formed by the first datum point or any one point between the first datum point and the second datum point; acquiring a second vector formed by the second reference point and the measuring point; and judging that the measuring point is positioned inside or outside the ideal profile of the workpiece to be measured or on the ideal profile based on the cross product value of the first vector and the second vector.

The embodiment of the invention also provides a detection system, which is used for detecting the line profile of a workpiece to be detected, and the detection system comprises: the workpiece ideal contour module is used for providing an ideal contour of a workpiece to be detected, and the ideal contour comprises a plurality of datum points; the measuring point acquisition module is used for selecting an actual point on the workpiece to be detected and acquiring a measuring point of the actual point and the ideal contour in the same coordinate system; a feature reference point acquisition module, configured to acquire a first reference point and a second reference point that are adjacent to each other on the ideal contour, where at least one of the first reference point and the second reference point is a reference point that is the smallest distance from the measurement point; the direction in which the first reference point points to the second reference point is clockwise around a point inside the ideal profile; the measuring point position judging module is used for acquiring a first vector formed by the first reference point or any one point between the first reference point and the second reference point; acquiring a second vector formed by the second reference point and the measuring point; and the cross product value of the first vector and the second vector is used for judging that the measuring point is positioned inside, outside or on the ideal contour of the workpiece to be measured.

Compared with the prior art, the technical scheme of the embodiment of the invention has the following advantages:

in the detection method provided by the embodiment of the invention, an actual point is selected on the workpiece to be detected, a measurement point of the actual point and the ideal contour in the same coordinate system is obtained, a first reference point and a second reference point which are adjacent to each other are obtained on the ideal contour, at least one of the first reference point and the second reference point is a reference point with the minimum distance from the measurement point, the direction of the first reference point pointing to the second reference point is a clockwise direction around one point in the ideal contour, and a first vector formed by the first reference point or any point between the first reference point and the second reference point is obtained; and acquiring a second vector formed by a second reference point and the measuring point, and judging that the measuring point is positioned inside or outside the ideal contour of the workpiece to be detected or on the ideal contour based on the cross product value of the first vector and the second vector, wherein the actual point in the workpiece to be detected is correspondingly judged to be positioned inside or outside the ideal contour or on the ideal contour.

Drawings

FIG. 1 is a schematic flow diagram of a detection method;

FIG. 2 is a schematic view of the structure of the present invention showing the desired contour of the workpiece to be inspected;

FIG. 3 is a diagram illustrating measurement points obtained from an ideal contour of a workpiece to be inspected according to the present invention;

FIG. 4 is a functional image of the quadrant arctangent values of the datum points in the ideal contour of the workpiece to be inspected according to the present invention;

FIG. 5 is a schematic diagram of the ideal contour of the workpiece to be inspected showing the selection of corresponding measurement points according to the present invention;

FIG. 6 is a schematic view of a workpiece to be inspected showing a first datum point and a second datum point;

FIG. 7 is a schematic diagram of the measurement point of the workpiece to be inspected in the ideal contour, the vector of the first reference point pointing to the second reference point and the vector of the second reference point pointing to the measurement point according to the present invention;

FIG. 8 is a schematic diagram of the measurement point of the workpiece to be inspected being outside the ideal contour, the vector of the first reference point pointing to the second reference point and the vector of the second reference point pointing to the measurement point according to the present invention;

FIG. 9 is a schematic view of a workpiece being inspected according to the present invention with the measurement point located on an ideal contour between a first datum point and a second datum point;

FIG. 10 is a schematic view of the workpiece to be inspected according to the present invention, wherein the measuring point is located on the line segment extension of the first reference point and the second reference point, and the measuring point is located on the side of the first reference point away from the second reference point;

FIG. 11 is a schematic view of the workpiece to be inspected according to the present invention, wherein the measuring point is located on the line segment extension line of the first reference point and the second reference point, and the measuring point is located on the side of the second reference point far from the first reference point;

FIG. 12 is a functional block diagram of the detection system of the present invention.

Detailed Description

As can be seen from the background art, in the prior art, the steps of detecting the line profile of the workpiece and determining whether the actual point to be detected on the workpiece to be detected is located inside or outside the ideal profile of the workpiece to be detected are complicated.

In order to solve the technical problem, an embodiment of the present invention provides a detection method for detecting a line profile of a workpiece to be detected, where the detection method includes: providing an ideal profile of a workpiece to be detected, wherein the ideal profile comprises a plurality of datum points; selecting an actual point on the workpiece to be detected; obtaining a measuring point of the actual point and the ideal contour in the same coordinate system; acquiring a first reference point and a second reference point which are adjacent on the ideal contour, wherein at least one of the first reference point and the second reference point is a reference point with the minimum distance from the measuring point; the direction in which the first datum points to the second datum is clockwise about a point inside the ideal contour; acquiring a first vector formed by the first datum point or any one point between the first datum point and the second datum point; acquiring a second vector formed by the second reference point and the measuring point; and judging that the measuring point is positioned inside, outside or on the ideal profile of the workpiece to be measured based on the cross product value of the first vector and the second vector.

In the detection method provided by the embodiment of the invention, an actual point is selected on a workpiece to be detected, a measurement point of the actual point and the ideal contour in the same coordinate system is obtained, a first reference point and a second reference point which are adjacent to each other are obtained on the ideal contour, at least one of the first reference point and the second reference point is a reference point with the minimum distance from the measurement point, the direction of the first reference point pointing to the second reference point is a clockwise direction around one point in the ideal contour, and a first vector formed by the first reference point or any point between the first reference point and the second reference point is obtained; and acquiring a second vector formed by a second reference point and the measuring point, judging that the measuring point is positioned inside or outside the ideal profile of the workpiece to be detected or on the ideal profile based on the cross product value of the first vector and the second vector, and correspondingly judging that the actual point in the workpiece to be detected is positioned inside or outside the ideal profile or on the ideal profile.

In order to make the aforementioned objects, features and advantages of the embodiments of the present invention more comprehensible, embodiments of the present invention are described in detail below with reference to the accompanying drawings.

Referring to fig. 1 and 2, step S1, an ideal profile 100 of a workpiece to be detected is provided, the ideal profile 100 including a plurality of fiducials (only the fiducials on a portion of the ideal profile 100 are illustrated in fig. 2).

In this embodiment, the ideal contour 100 is a two-dimensional model provided by engineering drawing software, and the engineering drawing software includes: solidWorks, creo (PRO/E) or AutoCAD.

In this embodiment, the ideal profile 100 is composed of straight or curved line segments connecting adjacent reference points. Specifically, the ideal contour 100 is formed by connecting straight line segments of adjacent reference points, and the subsequent determination accuracy can be increased by the ideal contour of the straight line segments of the adjacent reference points.

As an example, the ideal profile 100 model of the workpiece to be inspected is a two-dimensional graph of the flange. In other embodiments, the ideal contour model of the workpiece to be detected can also be a three-dimensional model.

It should be noted that, in the step of acquiring the ideal profile 100 of the workpiece to be detected, the smaller the interval between adjacent reference points is, the finer the reference line segment obtained by connecting subsequent reference points is, in this case, even if the actual point is very close to the edge of the workpiece to be detected, it can be accurately determined whether the measurement point is inside or outside the ideal profile 100 according to the measurement point corresponding to the actual point.

With reference to fig. 1 and step S2, an actual point is selected on the workpiece to be detected.

In this embodiment, in the step of selecting the actual point on the workpiece to be detected, the actual point is a distortion point to be measured in advance.

Referring to fig. 3 in conjunction with fig. 1, in step S3, a measurement point P of the ideal contour 100 and the actual point are obtained in the same coordinate system.

And obtaining a measuring point P of the actual point and the ideal profile 100 in the same coordinate system, comparing the measuring point P with the ideal profile 100 to obtain that the measuring point P is positioned inside, outside or on the ideal profile 100 of the workpiece to be measured, and further judging that the actual point is positioned inside, outside or on the ideal profile 100 of the workpiece to be measured.

The fact that the actual point and the ideal contour 100 are in the same coordinate system means that the measured point is the corresponding point of the actual point on the ideal contour 100, that is: the ideal contour is completely overlapped with the contour of the workpiece without distortion, the actual workpiece can generate distortion to cause the point on the workpiece to deviate from the ideal contour, and the position relation between the measuring point and the ideal contour is the same as the position relation between the actual point on the workpiece without distortion by the acquired measuring point.

Specifically, when the coordinate system of the ideal contour is a two-dimensional coordinate system, the measuring point is a two-dimensional point and has two coordinate components; when the coordinate system of the ideal contour is a three-dimensional coordinate system (the coordinate system of the 3D model), the measurement points are three-dimensional points having three coordinate components.

The step of obtaining the measurement point of the ideal contour 100 under the same coordinate system as the actual point includes: detecting the workpiece to be detected to obtain a measurement coordinate of the actual point in a first coordinate system; acquiring a conversion relation between a first coordinate system and a second coordinate system in which the ideal contour 100 is located; unifying the measurement coordinate and the ideal profile 100 to the same coordinate system according to the conversion relationship to obtain the measurement point.

The step of detecting the workpiece to be detected comprises the following steps: the image acquisition unit acquires a picture of the workpiece to be detected; and acquiring the actual profile of the workpiece to be detected according to the area of the workpiece to be detected in the picture.

In this embodiment, the image acquiring unit includes: an imaging device or a three-dimensional detection device. Specifically, the imaging device comprises an area array image sensor and a linear array image sensor. In other embodiments, the imaging device further comprises a lens; the unit detection equipment is chromatic dispersion confocal equipment, a white light interferometer or a three-coordinate measuring instrument.

The step of establishing the first coordinate system comprises: and selecting a first reference point in the workpiece to be detected, and establishing a first coordinate system by taking the first reference point as an origin. Each point on the actual contour of the workpiece to be detected has a determined unique position coordinate relative to the origin.

As an example, the first reference point of the workpiece to be detected is a center or a gravity center of the workpiece to be detected.

The step of establishing a second coordinate system in the ideal contour 100 comprises: and selecting a second reference point O in the ideal contour 100 of the workpiece to be detected, and establishing a second coordinate system by taking the second reference point O as an origin.

And establishing a second coordinate system by taking the second reference point O as an origin, wherein the second coordinate system is used for enabling each point on the ideal contour 100 of the workpiece to be detected to have a determined position relative to the origin, and preparing for acquiring the coordinate position of the point on the ideal contour 100 subsequently.

In this embodiment, the origin of the second coordinate system is an origin O, and an abscissa x and an ordinate y are perpendicular to each other. Each point on the ideal contour 100 of the workpiece to be inspected has a certain unique position coordinate with respect to the origin.

As an example, the second reference point is the center or center of gravity of the ideal contour 100. In other embodiments, the second reference point may not be the center or center of gravity of the ideal contour 100.

In this embodiment, the step of obtaining a conversion relationship between the first coordinate system and the second coordinate system where the ideal contour 100 is located includes: detecting the workpiece to be detected, and acquiring first characteristic coordinates of at least three characteristic points in a first coordinate system; acquiring a second characteristic coordinate of the characteristic point of the workpiece in the second coordinate system; and acquiring the conversion relation according to the first characteristic coordinate and the second characteristic coordinate of at least three characteristic points, wherein the conversion relation is used for enabling the first characteristic coordinate and the second characteristic coordinate of the same characteristic point to coincide under the same coordinate system.

The step of acquiring the first feature coordinates of the at least three feature points in the first coordinate system comprises the following steps: detecting the workpiece to be detected to obtain a measurement profile of the workpiece to be detected; fitting the measured profile according to the shape of the ideal profile 100 to obtain a fitted profile of the measured profile; and acquiring the center of the fitted contour and a first characteristic direction, wherein the first characteristic direction is the extension direction of the characteristic size of the fitted contour.

In this embodiment, one of the three feature points is a center of the fitted contour, and the other two feature points constitute the first feature direction. The obtaining of the first characteristic coordinates of the at least three characteristic points in the first coordinate system includes obtaining a center of the fitted contour and a first characteristic direction of the workpiece to be measured.

The ideal contour 100 has a second characteristic direction, which is the extension of the characteristic dimension of the fitted contour. And acquiring second characteristic coordinates of the at least three characteristic points in a second coordinate system comprises acquiring the center of the fitted contour and a second characteristic direction of the workpiece to be detected.

The step of obtaining the conversion relationship according to the first feature coordinates and the second feature coordinates of at least three feature points includes: making the fitting center coincide with the center of the ideal contour 100 and making the first feature direction and the second feature direction the same by performing a rotation and/or translation transformation on the first coordinate system and the second coordinate system; and acquiring the conversion relation according to the rotation and/or translation change.

In other embodiments, the workpiece to be measured includes a feature including the feature point, the feature having rotational asymmetry about an axis other than the feature point. Acquiring first feature coordinates of at least three feature points in a first coordinate system comprises: and acquiring first characteristic coordinates of the characteristic points of the at least three characteristic structures in a first coordinate system. The feature may be a hole, a sphere, the feature point is a center of the feature, or the feature has an apex angle, the feature point is an apex angle of the feature.

The step of detecting the workpiece to be detected and acquiring the first characteristic coordinates of at least three characteristic points in the first coordinate system comprises the following steps: and detecting the workpiece to be detected to obtain first characteristic coordinates of at least three characteristic points in a first coordinate system.

The step of obtaining the conversion relationship according to the first feature coordinates and the second feature coordinates of at least three feature points includes: rotating and/or translating the first coordinate system and the second coordinate system to enable the first coordinate and the second coordinate of the same characteristic point to coincide; and acquiring the conversion relation according to the rotation and/or translation change.

In other embodiments, the workpiece to be tested includes a feature including the feature point, the feature having rotational symmetry about an axis other than the feature point.

The shape of the ideal contour of the workpiece to be detected is circular, the first characteristic direction and the second characteristic direction are both radius directions, or the shape of the ideal contour of the workpiece to be detected is rectangular, and the first characteristic direction and the second characteristic direction are extension directions of corresponding sides of the ideal contour.

Referring to fig. 4 to 6 in conjunction with fig. 1, in step S4, a first reference point and a second reference point which are adjacent to each other are obtained on the ideal profile 100, at least one of the first reference point and the second reference point is a reference point which is the smallest distance from the measuring point, and the direction in which the first reference point points to the second reference point is a clockwise direction around a point inside the ideal profile 100.

And acquiring the ideal reference line segment, and acquiring a first reference point and a second reference point at two ends of the ideal reference line segment to prepare for subsequently judging whether the measuring point P is positioned inside or outside the ideal outline 100 of the workpiece to be detected.

Acquiring adjacent first and second reference points on the ideal profile 100, at least one of which is a reference point having a minimum distance from the measuring point, comprising: as shown in fig. 5, a connecting line between two adjacent reference points forms a reference line segment; as shown in fig. 6, the measurement distances L from the measurement point P to the plurality of reference line segments are respectively obtained; comparing the plurality of measured distances L to obtain a reference line segment corresponding to the shortest measured distance L as the ideal reference line segment, wherein two ends of the ideal reference line segment are respectively the first reference point and the second reference point.

And the measuring distance from the measuring point P to the reference line segment is the shortest distance from the measuring point P to the reference line segment.

Subsequently, the reference line segment is taken as a reference boundary, and whether the measuring point is inside or outside the ideal outline 100 is judged according to the fact that the measuring point is on one side of the reference line segment, so that whether the actual point is inside or outside the workpiece to be detected is judged.

In this embodiment, the reference line segment shown in fig. 5 includes P1P2, P2P3, P3P4, P4P5, P5P6, P6P7, P7P8, P8P9, P9P10, P10P11, P11P12, and P12P13.

In this embodiment, the ideal reference line segment is obtained by repeatedly obtaining the measurement distances from the measurement point P to the plurality of reference line segments, and obtaining the shortest measurement distance by comparing the plurality of measurement distances, where two ends of the ideal reference line segment are the first reference point and the second reference point, respectively, and at least one of the first reference point and the second reference point is a reference point at which the distance between the measurement point P and the reference line segment is the smallest.

As an example, the measurement distances from the measurement point P to the plurality of reference line segments, respectively, are repeatedly obtained using a For loop statement.

In the step of acquiring an ideal reference line segment having the smallest distance from the measurement point P among the plurality of reference line segments, a projection of the measurement point P in a direction perpendicular to the ideal reference line segment is located in the ideal reference line segment.

When the partial contour region of the ideal contour 100 of the workpiece to be detected is a straight line, the situation that the measuring point has a plurality of corresponding ideal reference line segments can be avoided through the provision that the projection of the measuring point P in the shortest distance direction is located in the ideal reference line segment.

In other embodiments, acquiring adjacent first and second fiducial points on the ideal contour, at least one of the first and second fiducial points being a reference fiducial point having a minimum distance from the measurement point, comprises: respectively acquiring the distances from the measuring points to the plurality of reference points; comparing the distances from the measuring points to the plurality of datum points, obtaining the datum point with the shortest distance from the measuring points as a reference datum point, and respectively setting the reference datum point and the datum point adjacent to the reference datum point as a first datum point and a second datum point. In particular, the fiducial adjacent to the reference fiducial may be a fiducial that is aligned clockwise or counterclockwise from the reference fiducial about a point within the ideal profile.

In this embodiment, the direction in which the first reference point points to the second reference point is clockwise around a point inside the ideal contour 100 includes: the four-quadrant inverse trigonometric function of the first reference point is greater than the four-quadrant inverse trigonometric function of the second reference point.

Specifically, the four-quadrant inverse trigonometric function includes: four-quadrant arc tangent, four-quadrant arc sine four-quadrant arc cotangent or four-phenomenon arc cosine.

As an example, the detection method includes: before acquiring a first reference point and a second reference point which are adjacent on the ideal contour 100, acquiring a four-quadrant arc tangent value corresponding to each reference point according to the coordinates of each reference point; sorting the four-quadrant arc tangent values corresponding to the reference points according to the function image of the four-quadrant arc tangent values, and sorting the reference points corresponding to the four-quadrant arc tangent values; sorting according to the reference points corresponding to the four-quadrant arc tangent values; and connecting the reference points corresponding to the quadrant arc tangent values from large to small in sequence. In this embodiment, after the reference points corresponding to the quadrant arc tangent values are sequentially connected from large to small, the direction of the first vector is made to be the same as the arrangement direction of the reference points when the first vector is obtained.

Specifically, the function of the quadrant arc tangent value is D1= atan2D (Y, X), where X and Y are the abscissa and ordinate values of the reference point in the coordinate system, and as shown in fig. 4, D1 is an angle value range of [ -180,180].

The reference points are sorted according to the four-quadrant arc tangent values of the coordinates of the reference points, so that the obtained reference line segments are connected in sequence, and the reference line segments are not crossed.

Taking the four-quadrant anti-sine value as an example, the manner of determining the angle of each reference point in the coordinate system according to the coordinate of each reference point is as follows:

the abscissa x and the ordinate y of the reference point in the first quadrant are both greater than 0,D = arcsin (y) ² /exp(x ² +y ² ))；

The abscissa x of the reference point in the second quadrant is less than 0 and the ordinate y is greater than 0, the second quadrant being D =180 ° -arcsin (y) ² /exp(x ² +y ² ))；

The abscissa x of the reference point in the third quadrant is less than 0, the ordinate y is less than 0, D =180 ° -arcsin (y) ² /exp(x ² +y ² ))；

The abscissa x of the reference point in the fourth quadrant is greater than 0, the ordinate y is less than 0, D =360 ° + arcsin (y) ² /exp(x ² +y ² ))。

In this embodiment, the four-quadrant arc tangent value is obtained according to the abscissa and the ordinate of the position of each reference point.

Taking the four-quadrant inverse cosine value as an example, the manner of determining the angle of each reference point in the coordinate system according to the coordinates of each reference point is as follows:

the abscissa x and the ordinate of the reference point in the first quadrant are both greater than 0,D = arccos (y) ² /exp(x ² +y ² ))；

The abscissa x of the reference point in the second quadrant is less than 0, the ordinate y is greater than 0, and the second quadrant is D =180+ arccos (y) ² /exp(x ² +y ² ))；

The abscissa x of the reference point in the third quadrant is less than 0, the ordinate y is less than 0, D =180 ° -arccos (y) ² /exp(x ² +y ² ))；

The abscissa x of the reference point in the fourth quadrant is greater than 0, the ordinate y is less than 0, D =360 ° -arccos (y) ² /exp(x ² +y ² ))。

Taking the four-quadrant inverse cotangent value as an example, the manner of determining the angle of each reference point in the coordinate system according to the coordinate of each reference point is as follows:

the abscissa x and the ordinate of the reference point in the first quadrant are both greater than 0,D = arccot (x/y);

the abscissa x of the reference point in the second quadrant is less than 0, the ordinate y is greater than 0, D =180+ arccot (x/y);

the abscissa x of the reference point in the third quadrant is less than 0, the ordinate y is less than 0, d =180 ° + arccot (x/y);

the abscissa x of the reference point in the fourth quadrant is greater than 0 and the ordinate y is less than 0, d =360 ° + arccot (x/y).

S5, acquiring a first vector formed by the first reference point or any one point between the first reference point and the second reference point; and acquiring a second vector formed by the second reference point and the measuring point.

The first vector and the second vector cross product value are used for subsequently judging whether the measuring point is positioned inside or outside the ideal profile 100 of the workpiece to be measured or on the ideal profile 100.

In this embodiment, the direction in which the first reference point points to the second reference point or the direction in which any point between the first reference point and the second reference point points to the second reference point is the first direction is the clockwise direction, and the direction in which the second reference point points to the measurement point is the second direction.

Referring to fig. 7 to 11 in conjunction with fig. 1, in step S6, it is determined that the measuring point is located inside, outside, or on the ideal contour 100 of the workpiece to be measured based on the cross product value of the first vector and the second vector.

In the embodiment of the invention, an actual point is selected on the workpiece to be detected, a measurement point of the actual point and the ideal contour 100 in the same coordinate system is obtained, a first reference point and a second reference point which are adjacent to each other are obtained on the ideal contour 100, at least one of the first reference point and the second reference point is a reference point which has the minimum distance from the measurement point, the direction of the first reference point pointing to the second reference point is clockwise around one point in the ideal contour 100, and a first vector formed by the first reference point or any point between the first reference point and the second reference point is obtained; and acquiring a second vector formed by a second reference point and the measuring point, judging that the measuring point is positioned inside or outside the ideal profile 100 of the workpiece to be measured or on the ideal profile 100 based on a cross product value of the first vector and the second vector, and correspondingly judging that an actual point in the workpiece to be measured is positioned inside or outside the ideal profile 100 or on the ideal profile 100.

The determining that the measuring point is located inside, outside or on the ideal profile 100 of the workpiece to be measured based on the cross product value of the first vector and the second vector comprises: judging whether the measuring point is positioned on the ideal profile 100 or not according to the fact that the cross product is zero; and judging that the measuring point is positioned in the ideal contour 100 or outside the ideal contour 100 according to the positive and negative of the cross product.

Specifically, judging whether the measurement point is located inside the ideal contour 100 or outside the ideal contour 100 according to the positive or negative of the cross product includes:

as a first example, the direction of the first vector is the same as the first direction, the direction of the second vector is the same as the second direction, as shown in fig. 7, the cross product of the first vector and the second vector is greater than zero, and the measurement point is located inside the ideal profile 100 of the workpiece to be measured; as shown in fig. 8, the cross product of the first vector and the second vector is less than zero, and the measurement point is located outside the ideal profile 100 of the workpiece to be measured.

Accordingly, the method can be used for solving the problems that,

in the above-mentioned

The measurement point P is inside the ideal profile 100; in the above-mentioned

At this time, the measurement point P is outside the ideal profile 100.

As a second example, the direction of the first vector is the same as the first direction, the direction of the second vector is opposite to the second direction, the cross product of the first vector and the second vector is greater than zero, and the measurement point is outside the ideal profile 100 of the workpiece to be measured; the cross product of the first vector and the second vector is less than zero, and the measurement point is located inside the ideal profile 100 of the workpiece to be measured.

Accordingly, the method has the advantages that,

in the above-mentioned

At times, measurement point P is outside of the ideal profile 100; in the above-mentioned

The measurement point P is inside the ideal profile 100.

As a third example, the direction of the first vector is opposite to the first direction, the direction of the second vector is the same as the second direction, the cross product of the first vector and the second vector is greater than zero, and the measurement point is located outside the ideal profile 100 of the workpiece to be measured; the cross product of the first vector and the second vector is less than zero, and the measurement point is located inside the ideal profile 100 of the workpiece to be measured.

Accordingly, the method can be used for solving the problems that,

the measurement point P is outside the ideal profile 100,

the measurement point P is inside the ideal profile 100.

As a fourth example, the direction of the first vector is opposite to the first direction, the direction of the second vector is opposite to the second direction, the cross product of the first vector and the second vector is greater than zero, and the measurement point is located inside the ideal profile 100 of the workpiece to be measured; the cross product of the first vector and the second vector is less than zero and the measurement point is outside the ideal profile 100 of the workpiece to be measured.

The measurement point P is inside the ideal profile 100,

measurement point P is outside of the ideal profile 100.

In particular, according to the cross product being zero, i.e.

Determining whether the measurement point is located on the ideal profile 100 comprises:

as a fifth example, as shown in fig. 9, when the cross product value of the first vector and the second vector is zero, and the measurement point is located on the line segment where the first reference point and the second reference point are located, the measurement point is located on the ideal profile 100.

As a sixth example, as shown in fig. 10 and 11, a cross product value of the first vector and the second vector is zero, and the measurement point is located on an extension of a line segment where the first reference point and the second reference point are located, and a neighboring reference point P3 adjacent to the reference point except for the first reference point and the second reference point among the reference points is obtained; and taking the reference datum point and the adjacent datum point P3 as the new first datum point and the second datum point, and repeating the step of judging that the measuring point is positioned inside or outside the ideal profile 100 of the workpiece to be measured or on the ideal profile 100 based on the cross product value of the first vector and the second vector.

In one example, after the cross product is obtained, it is determined whether the cross product is zero: if the cross product is zero, judging whether the measuring point is positioned on the ideal profile; otherwise, judging that the measuring point is positioned in the ideal profile or outside the ideal profile according to the positive and negative of the cross product.

In another embodiment, before the cross product is obtained, it is determined whether the measurement point is on a line segment where the first reference point and the second reference point are located and a line segment between the reference point and an adjacent reference point: if the measuring point is on the line segment where the first reference point and the second reference point are located, the measuring point is located on the ideal contour; otherwise, judging that the measuring point is positioned in the ideal profile or outside the ideal profile according to the positive and negative of the cross product.

Fig. 10 includes fig. 10a and 10b, and fig. 10b shows the first reference point and the second reference point newly determined after the reference point is determined. When the first reference point is a reference point, that is, the obtained adjacent reference point P3 is located at an end of the first reference point P1 away from the second reference point P2, therefore, a direction in which the new first reference point points to the second reference point or a direction in which any point between the first reference point and the second reference point points to the second reference point is clockwise with respect to a point inside the ideal contour.

Specifically, as shown in fig. 10a, when the cross product is zero, the reference datum point is a first datum point P1, and P is located outside the line segment between P1 and P2, and the adjacent datum point is P3, the method for determining that the measurement point is located inside, outside or on the ideal contour of the workpiece to be measured based on the cross product value of the first vector and the second vector according to the new first datum point and the new second datum point includes: and judging that the measuring point is positioned on the ideal profile according to the fact that the cross product is zero.

As a first example, when

In the above-mentioned

The measurement point P is inside the ideal profile 100; in the above-mentioned

While the measurement point P is outside the ideal profile 100, the remaining three examples refer to the aforementioned transformations and are not described in detail herein.

Fig. 11 includes fig. 11a and 11b, and fig. 11b shows the first reference point and the second reference point newly determined after the reference point is determined. When the first reference point is a reference point, that is, the obtained adjacent reference point P3 is located on the side of the second reference point P2 away from the first reference point P1, therefore, the direction in which the new first reference point points to the second reference point or the direction in which any point between the first reference point and the second reference point points to the second reference point is clockwise with respect to a point inside the ideal contour.

As shown in fig. 11a, when the cross product is zero, the reference datum point is a second datum point P2, P is located outside the line segment between P1 and P2, and the adjacent datum point is P3, the determining that the measurement point is located inside, outside or on the ideal contour of the workpiece to be measured according to the new first datum point and the second datum point and based on the cross product value of the first vector and the second vector, includes: and judging that the measuring point is positioned on the ideal profile according to the fact that the cross product is zero.

As a first example, when

In the above-mentioned

The measurement point P is inside the ideal contour 100, and the remaining three examples refer to the aforementioned transformation, which is not described herein again.

Correspondingly, the invention also provides a detection system. Referring to FIG. 12, a functional block diagram of the detection system of the present invention is shown.

With combined reference to fig. 12, the detection system comprises: the line profile tolerance detection device is used for detecting the line profile tolerance of a workpiece to be detected, and is characterized by comprising: a workpiece ideal profile 100 module 10 for providing an ideal profile 100 of a workpiece to be inspected, said ideal profile 100 comprising a plurality of fiducials; a measurement point obtaining module 20, configured to select an actual point on the workpiece to be detected, and obtain a measurement point where the actual point and the ideal contour 100 are located in the same coordinate system; a feature reference point obtaining module 30, configured to obtain a first reference point and a second reference point that are adjacent to each other on the ideal contour 100, where at least one of the first reference point and the second reference point is a reference point with a minimum distance from the measurement point; the direction in which the first reference point points to the second reference point is clockwise about a point inside the ideal profile 100; a measuring point position determining module 40, configured to obtain a first vector formed by the first reference point or any point between the first reference point and the second reference point; acquiring a second vector formed by the second reference point and the measuring point; and the cross product value of the first vector and the second vector is used for judging that the measuring point is positioned inside or outside the ideal outline 100 of the workpiece to be measured or on the ideal outline 100.

The embodiment of the present invention provides a feature datum point obtaining module 30, configured to obtain a first datum point and a second datum point adjacent to each other on the ideal contour 100, where at least one of the first datum point and the second datum point is a reference datum point with a minimum distance from the measurement point; the direction in which the first reference point points to the second reference point is clockwise about a point inside the ideal profile 100; the measuring point position judging module 40 is configured to obtain a first vector formed by the first reference point or any one point between the first reference point and the second reference point; acquiring a second vector formed by the second reference point and the measuring point; the method is used for judging whether the measuring point is positioned inside or outside the ideal profile 100 of the workpiece to be detected or on the ideal profile 100 based on the cross product value of the first vector and the second vector, and correspondingly judging whether the actual point in the workpiece to be detected is positioned inside the ideal profile 100 or outside the ideal profile 100.

The workpiece ideal profile 100 module 10 is used to provide an ideal profile 100 of a workpiece to be inspected.

In this embodiment, the ideal contour 100 is composed of straight or curved line segments connecting adjacent reference points. When the ideal contour 100 consists of curved segments connecting adjacent reference points, the reference points can be connected by a smooth curve.

As an example, the ideal profile 100 model of the workpiece to be inspected is a two-dimensional pattern of convex edges. In other embodiments, the ideal contour model of the workpiece to be detected may also be a three-dimensional model.

It should be noted that the smaller the interval between adjacent reference points, the finer the reference line segment obtained by connecting the subsequent reference points, in this case, even if the actual point is very close to the edge of the workpiece to be detected, the subsequent determination of whether the measurement point is inside or outside the ideal profile 100 can be accurately made according to the measurement point corresponding to the actual point.

The measurement point obtaining module 20 is configured to use distortion points prepared for measurement in advance as the actual points.

And obtaining a measuring point P of the actual point and the ideal contour 100 in the same coordinate system, comparing the measuring point P with the ideal contour 100 to obtain that the measuring point P is positioned inside or outside the ideal contour 100 of the workpiece to be measured or on the ideal contour 100, and further judging that the actual point is positioned inside or outside the ideal contour 100 of the workpiece to be measured or on the ideal contour 100.

The measurement point acquisition module 20 includes: an actual point position unit 21, configured to detect the workpiece to be detected, and obtain a measurement coordinate of the actual point in a first coordinate system; a conversion unit 22, configured to obtain a conversion relationship between a first coordinate system and a second coordinate system in which the ideal contour 100 is located; and a measuring point position unit 23, configured to unify the measuring coordinate and the ideal profile 100 to the same coordinate system according to the conversion relationship, so as to obtain the measuring point.

The actual point position unit 21 is configured to obtain a picture of the workpiece to be detected through the image obtaining unit; and the method is used for obtaining the actual profile of the workpiece to be detected according to the area of the workpiece to be detected in the picture.

The image acquisition unit includes: an imaging device or a three-dimensional detection device. Specifically, the imaging device includes an area array image sensor and a linear array image sensor. In other embodiments, the imaging device further comprises a lens; the unit detection equipment is chromatic dispersion confocal equipment, a white light interferometer or a three-coordinate measuring instrument.

And a first reference point is arranged in the workpiece to be detected, and a first coordinate system is established by taking the first reference point as an origin. The workpiece to be detected obtains each point on the actual contour, and a determined unique position coordinate is arranged relative to the origin.

Inside the ideal contour 100, there is a second reference point O, and the second coordinate system is established with the second reference point O as a center. And establishing a second coordinate system by taking the second reference point O as an origin, wherein the second coordinate system is used for enabling each point on the ideal contour 100 of the workpiece to be detected to have a determined position relative to the origin, and preparing for acquiring the coordinate position of the point on the ideal contour 100 subsequently.

In this embodiment, the origin of the second coordinate system is an origin O, and an abscissa x and an ordinate y are perpendicular to each other. Each point on the ideal contour 100 of the workpiece to be inspected has a defined unique position coordinate with respect to the origin.

It should be noted that the first reference point of the workpiece to be detected is a center or a center of gravity of the workpiece to be detected, and correspondingly, the selected second reference point O is a center or a center of gravity of the ideal contour 100. In other embodiments, the second reference point may not be the center or center of gravity of the ideal contour 100.

The conversion unit 22 is configured to detect the workpiece to be detected, and obtain first feature coordinates of at least three feature points in a first coordinate system; acquiring a second characteristic coordinate of the characteristic point of the workpiece in the second coordinate system; and acquiring the conversion relation according to the first characteristic coordinate and the second characteristic coordinate of at least three characteristic points, wherein the conversion relation is used for enabling the first characteristic coordinate and the second characteristic coordinate of the same characteristic point to be overlapped under the same coordinate system.

The conversion unit 22 is configured to detect the workpiece to be measured to obtain a measurement profile of the workpiece to be measured; fitting the measured profile according to the shape of the ideal profile 100 to obtain a fitted profile of the measured profile; acquiring the center of the fitted contour and a first characteristic direction, wherein the first characteristic direction is the extension direction of the characteristic size of the fitted contour;

in this embodiment, one of the three feature points is a center of the fitted contour, and the other two feature points constitute the first feature direction. The obtaining of the first feature coordinates of the at least three feature points in the first coordinate system includes obtaining a center of the fitted contour and a first feature direction of the workpiece to be measured.

The conversion unit 22 is configured to perform rotation and/or translation transformation on the first coordinate system and the second coordinate system, so that the fitting center coincides with the center of the ideal contour 100, and the first feature direction is the same as the second feature direction; and acquiring the conversion relation according to the rotation and/or translation change.

In other embodiments, the workpiece to be measured includes a feature, the feature includes the feature point, and the feature has rotational asymmetry about an axis other than the feature point. Acquiring first feature coordinates of at least three feature points in a first coordinate system comprises: and acquiring first characteristic coordinates of the characteristic points of the at least three characteristic structures in a first coordinate system. The feature may be a hole or a sphere, and the feature point is a center of the feature, or the feature has a vertex angle, and the feature point is a vertex angle of the feature.

The conversion unit 22 is configured to detect the workpiece to be detected to obtain first feature coordinates of at least three feature points in a first coordinate system; the first coordinate system and the second coordinate system are subjected to rotation and/or translation transformation, so that the first coordinate and the second coordinate of the same characteristic point are superposed; and acquiring the conversion relation according to the rotation and/or translation change.

The shape of the ideal contour of the workpiece to be detected is circular, the first characteristic direction and the second characteristic direction are both in the radius direction, or the shape of the ideal contour of the workpiece to be detected is rectangular, and the first characteristic direction and the second characteristic direction are the extending directions of the corresponding sides of the ideal contour.

And the characteristic reference point acquiring module 30 is configured to acquire a first reference point and a second reference point at two ends of the ideal reference line segment, so as to prepare for subsequently judging whether the measurement point P is located inside or outside the ideal contour 100 of the workpiece to be detected.

The characteristic reference point obtaining module 30, as shown in fig. 5, is configured to form a reference line segment by connecting lines of two adjacent reference points; as shown in fig. 6, the measurement distances L from the measurement point P to the plurality of reference line segments are respectively obtained; comparing the plurality of measured distances L to obtain a reference line segment corresponding to the shortest measured distance L as the ideal reference line segment, wherein two ends of the ideal reference line segment are respectively the first reference point and the second reference point.

And the measurement distance from the measurement point P to the reference line segment is the shortest distance from the measurement point P to the reference line segment.

The reference line segment provides a reference boundary for the measuring point position determining module 40, and determines whether the measuring point is inside or outside the ideal contour 100 according to whether the measuring point is on one side of the reference line segment, thereby determining whether the actual point is inside or outside the workpiece to be detected.

In the step of acquiring an ideal reference line segment having the smallest distance from the measurement point P among the plurality of reference line segments, a projection of the measurement point P along a direction perpendicular to the ideal reference line segment is located in the ideal reference line segment.

In other embodiments, the characteristic reference point obtaining module 30 is configured to obtain distances from the measuring point to the plurality of reference points respectively; and the distance measuring device is used for comparing the distances from the measuring point to the plurality of datum points, obtaining the datum point with the shortest distance from the measuring point as a reference datum point, and respectively setting the reference datum point and the datum point adjacent to the reference datum point as a first datum point and a second datum point. In particular, the fiducial adjacent to the reference fiducial may be a fiducial that is aligned clockwise or counterclockwise from the reference fiducial about a point within the ideal profile.

In this embodiment, the characteristic reference point obtaining module 30 is configured to make a four-quadrant inverse trigonometric function of the first reference point larger than a four-quadrant inverse trigonometric function of the second reference point.

Specifically, the four-quadrant inverse trigonometric function includes: four-quadrant arc tangent, four-quadrant arcsine four-quadrant inverse cotangent or four-phenomenon arccosine.

As an example, the characteristic reference point obtaining module 30 is configured to obtain a four-quadrant arc tangent value corresponding to each reference point according to the coordinate of each reference point; the four-quadrant arc tangent value sorting device is used for sorting the four-quadrant arc tangent values corresponding to the reference points according to the function images of the four-quadrant arc tangent values, so that the reference points corresponding to the four-quadrant arc tangent values are sorted; and the reference points are used for sequentially connecting the reference points corresponding to the four-quadrant arc tangent values from large to small according to the sequence of the reference points corresponding to the four-quadrant arc tangent values to form the reference line segment. In this embodiment, after the reference points corresponding to the quadrant arc tangent values from large to small are sequentially connected, the direction of the first vector is made to be the same as the arrangement direction of the reference points when the first vector is obtained.

Specifically, the function of the quadrant arc tangent value is D = atan2D (Y, X), where X and Y are abscissa and ordinate values of the reference point in the coordinate system, and D is an angle value range of [ -180,180], as shown in fig. 4.

Taking a four-quadrant inverse cosine value as an example, according to the coordinates of each reference point, the manner of determining the angle of each reference point in the coordinate system is as follows:

the abscissa x of the reference point in the third quadrant is less than 0, the ordinate y is less than 0, d =180 ° + arc (x/y);

The first vector and the second vector cross product value are used for judging whether the measuring point is positioned inside or outside the ideal profile 100 of the workpiece to be measured or on the ideal profile 100.

The measuring point position determining module 40 is configured to determine whether the measuring point is located on the ideal profile 100 according to that the cross product is zero; for judging whether the measurement point is located inside the ideal contour 100 or outside the ideal contour 100 according to the positive or negative of the cross product.

Specifically, the determining, according to the positive or negative of the cross product, whether the measurement point is located inside the ideal contour 100 or outside the ideal contour 100 includes:

as a first example, the measuring point position determining module 40 is configured to make a direction of a first vector be the same as a first direction, and a direction of a second vector be the same as a second direction, as shown in fig. 7, a cross product of the first vector and the second vector is greater than zero, and the measuring point is located inside the ideal profile 100 of the workpiece to be measured; as shown in fig. 8, the cross product of the first vector and the second vector is less than zero, and the measurement point is located outside the ideal profile 100 of the workpiece to be measured.

Accordingly, the method can be used for solving the problems that,

in the above-mentioned

The measurement point P is inside the ideal profile 100; in the above-mentioned

The measurement point P is outside the ideal profile 100.

As a second example, the measuring point position determining module 40 is configured to make a direction of a first vector be the same as a first direction, a direction of a second vector be opposite to a second direction, a cross product of the first vector and the second vector is greater than zero, and the measuring point is located outside the ideal profile 100 of the workpiece to be measured; the cross product of the first vector and the second vector is less than zero, and the measurement point is located inside the ideal profile 100 of the workpiece to be measured.

Accordingly, the method has the advantages that,

in the above-mentioned

Measurement point P is outside of the ideal profile 100; in the above-mentioned

The measurement point P is inside the ideal profile 100.

As a third example, the measuring point position determining module 40 is configured to make a direction of a first vector opposite to the first direction, a direction of a second vector same as the second direction, a cross product of the first vector and the second vector is greater than zero, and the measuring point is located outside the ideal profile 100 of the workpiece to be measured; the cross product of the first vector and the second vector is less than zero, and the measurement point is located inside the ideal profile 100 of the workpiece to be measured.

Accordingly, the method can be used for solving the problems that,

the measurement point P is outside the ideal profile 100,

the measurement point P is inside the ideal profile 100.

As a fourth example, the measuring point position determining module 40 is configured to enable a direction of a first vector to be opposite to the first direction, a direction of a second vector to be opposite to the second direction, a cross product of the first vector and the second vector is greater than zero, and the measuring point is located inside the ideal profile 100 of the workpiece to be measured; the cross product of the first vector and the second vector is less than zero and the measurement point is outside the ideal profile 100 of the workpiece to be measured.

The measurement point P is inside the ideal profile 100,

measurement point P is outside of the ideal profile 100.

Specifically, the determining that the measurement point is located on the ideal profile 100 according to that the cross product is zero includes:

As a sixth example, as shown in fig. 10 and 11, the cross product value of the first vector and the second vector is zero, and the measurement point is located on the extension line of the line segment where the first reference point and the second reference point are located, and a neighboring reference point P3 adjacent to the reference point except the first reference point and the second reference point is obtained; and taking the reference datum point and the adjacent datum point P3 as the new first datum point and second datum point, and repeating the step of judging that the measuring point is positioned inside or outside the ideal profile 100 of the workpiece to be measured or on the ideal profile 100 based on the cross product value of the first vector and the second vector.

Specifically, as shown in fig. 10a, when the cross product is zero, the reference datum point is a first datum point P1, and P is located outside the line segment between P1 and P2, and the adjacent datum point is P3, the adjacent datum point is taken as a new first datum point, the first datum point P2 is taken as a new second datum point, and the determining that the measurement point is located inside, outside, or on the ideal contour of the workpiece to be measured according to the new first datum point and the new second datum point and based on the cross product value of the first vector and the second vector includes: and judging that the measuring point is positioned on the ideal profile according to the fact that the cross product is zero.

As a first example, when

In the above-mentioned

The measurement point P is inside the ideal profile 100; in the above-mentioned

Fig. 11 includes fig. 11a and 11b, and fig. 11b shows the first reference point and the second reference point newly determined after the reference point is determined. When the first reference point is the reference point, that is, the obtained adjacent reference point P3 is located on the side of the second reference point P2 away from the first reference point P1, therefore, the direction in which the new first reference point points to the second reference point or the direction in which any point between the first reference point and the second reference point points to the second reference point is clockwise with respect to a point inside the ideal contour.

As a first example, when

In the above-mentioned

The measurement point P is inside the ideal profile 100, and the remaining three examples refer to the aforementioned transformation, which is not described herein again.

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.

Claims

1. A detection method is used for detecting the line profile of a workpiece to be detected, and is characterized by comprising the following steps:

providing an ideal profile of a workpiece to be detected, wherein the ideal profile comprises a plurality of datum points;

selecting an actual point on the workpiece to be detected;

obtaining a measuring point of the actual point and the ideal contour in the same coordinate system;

acquiring adjacent first and second reference points on the ideal contour, wherein at least one of the first and second reference points is a reference point with the smallest distance from the measuring point; the direction in which the first datum points to the second datum is clockwise about a point inside the ideal contour;

acquiring a first vector formed by the first datum point or any one point between the first datum point and the second datum point; acquiring a second vector formed by the second reference point and the measuring point;

and judging that the measuring point is positioned inside or outside the ideal profile of the workpiece to be measured or on the ideal profile based on the cross product value of the first vector and the second vector.

2. The inspection method of claim 1, wherein determining that the measurement point is located inside, outside, or on the ideal profile of the workpiece to be inspected based on the cross product value of the first vector and the second vector comprises:

judging whether the measuring point is positioned on the ideal profile or not according to the fact that the cross product is zero;

and judging whether the measuring point is positioned in the ideal profile or outside the ideal profile according to the positive and negative of the cross product.

3. The detection method according to claim 2, wherein a direction in which the first reference point points to the second reference point or a direction in which any point between the first reference point and the second reference point points to the second reference point is a first direction, and a direction in which the second reference point points to the measurement point is a second direction;

judging whether the measuring point is positioned in the ideal profile or outside the ideal profile according to the positive and negative of the cross product comprises the following steps:

the direction of the first vector is the same as the first direction, the direction of the second vector is the same as the second direction, the cross product of the first vector and the second vector is larger than zero, and the measuring point is positioned inside the ideal contour of the workpiece to be measured; the cross product of the first vector and the second vector is less than zero, and the measuring point is positioned outside the ideal outline of the workpiece to be measured;

or the direction of the first vector is the same as the first direction, the direction of the second vector is opposite to the second direction, the cross product of the first vector and the second vector is greater than zero, and the measuring point is positioned outside the ideal contour of the workpiece to be measured; the cross product of the first vector and the second vector is less than zero, and the measuring point is positioned inside the ideal contour of the workpiece to be measured;

or the direction of the first vector is opposite to the first direction, the direction of the second vector is the same as the second direction, the cross product of the first vector and the second vector is greater than zero, and the measuring point is positioned outside the ideal contour of the workpiece to be measured; the cross product of the first vector and the second vector is less than zero, and the measuring point is positioned in the ideal outline of the workpiece to be measured;

or the direction of the first vector is opposite to the first direction, the direction of the second vector is opposite to the second direction, the cross product of the first vector and the second vector is greater than zero, and the measuring point is positioned inside the ideal contour of the workpiece to be measured; and the cross product of the first vector and the second vector is less than zero, and the measuring point is positioned outside the ideal outline of the workpiece to be measured.

4. The method of claim 2, wherein determining whether the measurement point lies on the ideal profile based on the cross product being zero comprises: the cross product value of the first vector and the second vector is zero, and the measuring point is located on the line segment where the first reference point and the second reference point are located, so that the measuring point is located on the ideal contour;

the cross product value of the first vector and the second vector is zero, the measuring point is positioned on the extension line of the line segment where the first datum point and the second datum point are positioned, and adjacent datum points adjacent to the reference datum point except the first datum point and the second datum point are obtained; and taking the reference datum point and the adjacent datum point as a new first datum point and a new second datum point, and repeating the step of judging that the measuring point is positioned inside or outside the ideal contour of the workpiece to be measured or on the ideal contour based on the cross product value of the first vector and the second vector.

5. The detection method according to any one of claims 1 to 4, wherein the ideal profile is composed of straight or curved line segments connecting adjacent reference points.

6. The method of detecting as in claim 1, wherein acquiring adjacent first and second fiducial points on the ideal contour, at least one of the first and second fiducial points being a reference fiducial point having a minimum distance from the measurement point comprises:

forming a reference line segment by connecting lines of two adjacent reference points;

respectively acquiring the measuring distances from the measuring points to the plurality of reference line segments;

comparing the plurality of measured distances to obtain a reference line segment corresponding to the shortest measured distance as an ideal reference line segment, wherein two ends of the ideal reference line segment are respectively the first reference point and the second reference point;

or, acquiring adjacent first and second reference points on the ideal contour, at least one of which is a reference point having a minimum distance from the measuring point, comprises:

respectively acquiring the distances from the measuring points to the plurality of reference points;

comparing the distances from the measuring points to the plurality of datum points, obtaining the datum point with the shortest distance from the measuring points as a reference datum point, and respectively setting the reference datum point and the datum point adjacent to the reference datum point as a first datum point and a second datum point.

7. The detection method according to claim 1,

the direction in which the first datum points toward the second datum is clockwise about a point inside the ideal contour includes: the four-quadrant inverse trigonometric function of the first reference point is greater than the four-quadrant inverse trigonometric function of the second reference point, the four-quadrant inverse trigonometric function comprising: four-quadrant arc tangent, four-quadrant arcsine, four-quadrant inverse cotangent or four-phenomenon arccosine;

the detection method further comprises the following steps: before acquiring adjacent first and second fiducial points on the ideal contour,

obtaining a four-quadrant arc tangent value corresponding to each reference point according to the coordinate of each reference point; sorting the four-quadrant arc tangent values corresponding to the reference points according to the function image of the four-quadrant arc tangent values, and sorting the reference points corresponding to the four-quadrant arc tangent values; sorting the reference points corresponding to the four-quadrant arc tangent values; and sequentially connecting the reference points corresponding to the quadrant arc tangent values from large to small.

8. The detection method according to claim 1,

the step of obtaining the measuring point of the actual point and the ideal contour in the same coordinate system comprises the following steps:

detecting the workpiece to be detected to obtain a measurement coordinate of the actual point in a first coordinate system;

acquiring a conversion relation between a first coordinate system and a second coordinate system in which the ideal contour is located;

unifying the measuring coordinate and the ideal contour to the same coordinate system according to the conversion relation to obtain the measuring point.

9. The inspection method of claim 8, wherein the step of obtaining a transformation relationship between the first coordinate system and a second coordinate system in which the ideal contour is located comprises:

detecting the workpiece to be detected, and acquiring first characteristic coordinates of at least three characteristic points in a first coordinate system;

acquiring a second characteristic coordinate of the characteristic point of the workpiece in the second coordinate system;

and acquiring the conversion relation according to the first characteristic coordinate and the second characteristic coordinate of at least three characteristic points, wherein the conversion relation is used for enabling the first characteristic coordinate and the second characteristic coordinate of the same characteristic point to be overlapped under the same coordinate system.

10. The inspection method according to claim 9, wherein the step of acquiring first feature coordinates of at least three feature points in a first coordinate system for inspecting the workpiece to be inspected comprises: detecting the workpiece to be detected to obtain a measurement profile of the workpiece to be detected; fitting the measurement profile according to the shape of the ideal profile to obtain a fitted profile of the measurement profile; acquiring the center of the fitted contour and a first characteristic direction, wherein the first characteristic direction is the extension direction of the characteristic size of the fitted contour;

the ideal contour has a second characteristic direction, and the second characteristic direction is an extension direction of a characteristic size of the ideal contour; the step of obtaining the conversion relationship according to the first feature coordinates and the second feature coordinates of at least three feature points includes: enabling the fitting center to coincide with the center of the ideal contour by performing rotation and/or translation transformation on the first coordinate system and the second coordinate system, and enabling the first characteristic direction to be the same as the second characteristic direction; acquiring the conversion relation according to the rotation and/or translation change;

or,

the workpiece to be measured comprises a feature structure, the feature structure comprises the feature points, and the feature structure has rotational asymmetry around an axis other than the feature points; the step of detecting the workpiece to be detected and acquiring the first characteristic coordinates of at least three characteristic points in the first coordinate system comprises the following steps:

detecting the workpiece to be detected to obtain first characteristic coordinates of at least three characteristic points in a first coordinate system;

the step of obtaining the conversion relation according to the first feature coordinates and the second feature coordinates of at least three feature points includes: rotating and/or translating the first coordinate system and the second coordinate system to enable the first coordinate and the second coordinate of the same characteristic point to coincide; and acquiring the conversion relation according to the rotation and/or translation change.

11. The inspection method according to claim 9, wherein the workpiece to be inspected includes a feature including the feature point, the feature having rotational symmetry about an axis other than the feature point;

the shape of the ideal outline of the workpiece to be measured is circular, and the first characteristic direction and the second characteristic direction are both radius directions; or the shape of the ideal contour of the workpiece to be measured is a rectangle, and the first characteristic direction and the second characteristic direction are extension directions of corresponding sides of the ideal contour.

12. A detection system for detecting line profile of a workpiece to be detected is characterized by comprising:

the workpiece ideal contour module is used for providing an ideal contour of a workpiece to be detected, and the ideal contour comprises a plurality of datum points;

the measuring point acquisition module is used for selecting an actual point on the workpiece to be detected and acquiring a measuring point of the actual point and the ideal contour in the same coordinate system;

a feature reference point acquisition module, configured to acquire a first reference point and a second reference point that are adjacent to each other on the ideal contour, where at least one of the first reference point and the second reference point is a reference point that is the smallest distance from the measurement point; the direction in which the first datum points to the second datum is clockwise about a point inside the ideal contour;

the measuring point position judging module is used for acquiring a first vector formed by the first reference point or any one point between the first reference point and the second reference point; acquiring a second vector formed by the second reference point and the measuring point; and the cross product value of the first vector and the second vector is used for judging that the measuring point is positioned inside, outside or on the ideal contour of the workpiece to be measured.

13. The detection system according to claim 12, wherein the measuring point position determining module is configured to determine whether the measuring point is located on the ideal profile according to the cross product being zero;

and the measuring point is used for judging whether the measuring point is positioned in the ideal profile or outside the ideal profile according to the positive and negative of the cross product.

14. The detection system of claim 13, wherein the first datum point points to a second datum point

The direction of the reference point or the direction from any point between the first reference point and the second reference point to the second reference point is a first direction, and the direction from the second reference point to the measuring point is a second direction;

the measuring point position judging module is used for enabling the direction of a first vector to be the same as the first direction, the direction of a second vector to be the same as the second direction, the cross product of the first vector and the second vector is larger than zero, and the measuring point is positioned inside an ideal contour of a workpiece to be measured; the cross product of the first vector and the second vector is less than zero, and the measuring point is positioned outside the ideal outline of the workpiece to be measured;

or, the direction of the first vector is the same as the first direction, the direction of the second vector is opposite to the second direction, the cross product of the first vector and the second vector is greater than zero, and the measuring point is located outside the ideal contour of the workpiece to be measured; the cross product of the first vector and the second vector is less than zero, and the measuring point is positioned inside the ideal contour of the workpiece to be measured;

15. The detecting system according to claim 13, wherein the measuring point position determining module is configured to determine that the measuring point is located on the ideal contour when a cross product value of the first vector and the second vector is zero and the measuring point is located on an extension of a line segment where the first reference point and the second reference point are located;

when the cross product value of the first vector and the second vector is zero and the measuring point is positioned outside a line segment where the first datum point and the second datum point are positioned, acquiring an adjacent datum point which is adjacent to the reference datum point except the first datum point and the second datum point in the datum points; and taking the reference datum point and the adjacent datum point as a new first datum point and a new second datum point, and repeating the step of judging that the measuring point is positioned inside or outside the ideal contour of the workpiece to be measured or on the ideal contour based on the cross product value of the first vector and the second vector.

16. The detection system of claim 12, wherein the characteristic reference point acquisition module is configured to form a reference line segment by connecting lines of two adjacent reference points; the measuring distance between the measuring point and the plurality of reference line segments is respectively obtained;

the reference line segment is used for comparing the plurality of measured distances to obtain the shortest reference line segment corresponding to the measured distances, and the two ends of the ideal reference line segment are the first reference point and the second reference point respectively; or, the characteristic reference point obtaining module is configured to obtain distances from the measurement point to the plurality of reference points respectively;

and the distance measuring device is used for comparing the distances from the measuring point to the plurality of datum points, obtaining the datum point with the shortest distance from the measuring point as a reference datum point, and respectively setting the reference datum point and the datum point adjacent to the reference datum point as a first datum point and a second datum point.

17. The detection system of claim 12, wherein the feature reference point acquisition module is configured to make a quadrant inverse trigonometric function of the first reference point larger than a quadrant inverse trigonometric function of the second reference point, the quadrant inverse trigonometric function comprising: a four-quadrant arc tangent, a four-quadrant arc sine, a four-quadrant arc cotangent or a four-phenomenon arc cosine;

the characteristic reference point acquisition module is used for acquiring a four-quadrant arc tangent value corresponding to each reference point according to the coordinate of each reference point; the system comprises a base station, a data processing unit and a processing unit, wherein the base station is used for sequencing the four-quadrant arc tangent values corresponding to the reference points according to function images of the four-quadrant arc tangent values so as to sequence the reference points corresponding to the four-quadrant arc tangent values; and the reference points are used for sequentially connecting the reference points corresponding to the four-quadrant arc tangent values from large to small according to the sequence of the reference points corresponding to the four-quadrant arc tangent values to form the reference line segment.

18. The detection system of claim 12, wherein the measurement point acquisition module comprises:

the actual point position unit is used for detecting the workpiece to be detected and acquiring a measurement coordinate of the actual point under a first coordinate system;

the conversion unit is used for acquiring a conversion relation between a first coordinate system and a second coordinate system where the ideal contour is located;

and the measuring point position unit is used for unifying the measuring coordinate and the ideal profile to the same coordinate system according to the conversion relation to obtain the measuring point.

19. The inspection system of claim 18, wherein the conversion unit is configured to inspect the workpiece to be inspected to obtain first feature coordinates of at least three feature points in a first coordinate system; acquiring a second characteristic coordinate of the characteristic point of the workpiece in the second coordinate system; and acquiring the conversion relation according to the first characteristic coordinate and the second characteristic coordinate of at least three characteristic points, wherein the conversion relation is used for enabling the first characteristic coordinate and the second characteristic coordinate of the same characteristic point to coincide under the same coordinate system.

20. The inspection system of claim 19, wherein the converting unit is configured to inspect the workpiece to obtain a measurement profile of the workpiece; fitting the measurement profile according to the shape of the ideal profile to obtain a fitted profile of the measurement profile; acquiring the center of the fitted contour and a first characteristic direction, wherein the first characteristic direction represents the shape of the fitted contour;

the ideal contour has a second characteristic direction, and the second characteristic direction represents the shape of the ideal contour;

the conversion unit is used for enabling the fitting center to coincide with the center of the ideal contour by rotating and/or translating the first coordinate system and the second coordinate system, and enabling the first characteristic direction to be the same as the second characteristic direction; acquiring the conversion relation according to the rotation and/or translation change;

or the workpiece to be detected comprises a feature structure, the feature structure comprises the feature points, and the feature structure has rotational asymmetry around an axis except the feature points;

the conversion unit is used for detecting the workpiece to be detected to obtain first characteristic coordinates of at least three characteristic points in a first coordinate system; the first coordinate system and the second coordinate system are subjected to rotation and/or translation transformation, so that the first coordinate and the second coordinate of the same characteristic point are superposed; and acquiring the conversion relation according to the rotation and/or translation change.