CN115682935A - Motion platform error analysis experimental device and measurement method based on machine vision - Google Patents
Motion platform error analysis experimental device and measurement method based on machine vision Download PDFInfo
- Publication number
- CN115682935A CN115682935A CN202211406577.3A CN202211406577A CN115682935A CN 115682935 A CN115682935 A CN 115682935A CN 202211406577 A CN202211406577 A CN 202211406577A CN 115682935 A CN115682935 A CN 115682935A
- Authority
- CN
- China
- Prior art keywords
- platform
- precision
- calibration plate
- axis
- point
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Abstract
The invention discloses a motion platform error analysis experimental device based on machine vision, which comprises a marble platform module, a precise motion platform module and a vision acquisition module; the precision motion platform module and the vision acquisition module are fixedly connected with the marble platform module. Meanwhile, the invention also discloses a measuring method for analyzing the error of the motion platform based on machine vision, which comprises the steps of measuring the position stability of the platform, measuring the repeatability precision of the platform and measuring the positioning precision of the platform. The experimental device has simple structure and small interference from the outside, and can ensure the measurement precision; the measuring method can simultaneously carry out error detection on the precision motion platform from multiple angles and multiple dimensions, and ensures the precision of the precision motion platform leaving the factory, thereby ensuring the processing precision of parts placed on the precision motion platform.
Description
Technical Field
The invention belongs to the field of machine vision detection, and particularly relates to an experimental device and a measuring method for motion platform error analysis.
Background
The precision of the motion platform, particularly the precision motion platform, directly affects the quality of a processed product, so that the precision motion platform needs to be subjected to error measurement and analysis after production and before delivery, so as to ensure the precision of the precision motion platform and the processing precision of parts placed on the precision motion platform.
The traditional measurement method for the precision of a precision motion platform usually adopts a laser interference detection method or an overlay error measurement method and the like, and the measurement methods are all basic rules for measuring the precision of the platform in the past, but have certain limitations.
The laser interferometer with very high precision can generate errors about 1 mu m under the condition that the temperature changes by 1 ℃; in addition, the laser interference measurement system is difficult to build an optical path facing a limited space, so that certain trouble is brought to the measurement of the error of the precise motion platform.
CN101261451A discloses a system and a method for measuring imaging quality of a lithography machine and positioning accuracy of a workpiece stage, wherein the measuring method mainly includes forming an overlay mark by two times of exposure, developing the formed overlay mark, reading overlay errors of all the overlay marks in a whole field by using a special tool, and calculating the positioning accuracy of the workpiece stage by using a special algorithm according to the overlay errors obtained by measurement; the measurement method disclosed in the patent is complicated in steps, and cannot evaluate a precision platform from other dimensions only aiming at positioning precision.
Therefore, the traditional measurement method only performs error analysis on one aspect of the precision motion platform, is complicated in measurement method, and cannot evaluate the precision of the precision motion platform in multiple angles and dimensions.
Disclosure of Invention
The invention aims to provide a motion platform error analysis experimental device and a measurement method based on machine vision. The experimental device has simple structure and small interference from the outside, and can ensure the measurement precision. Meanwhile, the measuring method can simultaneously carry out error detection on the motion platform from multiple angles and multiple dimensions, and ensures the precision of the motion platform leaving factory, thereby ensuring the machining precision of parts placed on the motion platform.
The invention relates to a motion platform error analysis experimental device based on machine vision, which comprises a marble platform module, a precise motion platform module and a vision acquisition module; the precision motion platform module and the vision acquisition module are fixedly connected with the marble platform module.
Further, the marble platform module comprises a marble platform, marble supporting columns, a marble gantry and marble upright columns; the upper end and the lower end of the marble upright post are respectively fixedly connected with the marble platform and the marble gantry, and the marble upright post is fixed above the marble gantry.
Further, the precision motion platform module comprises a precision motion platform, an electric cabinet, a computer and a calibration board; the lower surface of the precision motion platform is fixedly connected with the marble platform, the calibration plate is adsorbed on the upper plane of the precision motion platform, and the electric cabinet is respectively connected with the precision motion platform and the computer.
Furthermore, the visual acquisition module comprises an image acquisition card, a CCD camera, a reflector, an objective lens and two optical lens hoops; the two optical lens hoops are respectively fixed on the marble upright post and the marble gantry, the reflector and the objective lens are respectively arranged in the objective lens hoops, the reflector is positioned right above the objective lens, the CCD camera is fixed on the marble gantry, the reflecting surface of the reflector faces towards the lens and the objective lens of the CCD camera, and two ends of the image acquisition card are respectively connected with the CCD camera and the computer.
The invention relates to a measuring method for motion platform error analysis based on machine vision, which comprises the steps of platform position stability measurement, platform repeatability precision measurement and platform positioning precision measurement; the platform position stability measurement is that a fixed position of the calibration plate is continuously captured by a camera, so that the position stability of the motion platform under a static condition can be measured with high precision; the measurement of the repeatability precision of the platform is that the camera continuously captures the position of the calibration plate after reciprocating along the X direction or after reciprocating along the Y direction, so that the repeatability precision of the movement of the precision motion platform in the X direction or the Y direction can be measured with high precision; positioning error measurement based on machine vision, namely under a single-axis experiment working condition or a double-axis experiment working condition, a camera is used for capturing the position of a moving calibration plate on a platform and processing an image, so that a one-way positioning error or a two-dimensional positioning error of the moving precision motion platform can be measured, and the positioning precision of each point is further determined; the single-axis experiment working condition refers to that the platform moves along the X direction or the Y direction, the double-axis experiment working condition refers to that the platform moves along the XY direction simultaneously, and the stroke control of each movement is the same.
The specific measuring method of the platform position stability comprises the following steps: before the experiment begins, the XY motion platform is electrified, the focal length of the optical lens and the illumination light source are adjusted until the mark point on the calibration plate can be clearly seen, one mark point on the calibration plate is adjusted to the center of the camera view field, and the coordinate value (X) of the center of the mark point at the moment is recorded 0 ，Y 0 ) Then, the camera captures the coordinate value (X) of the center of the mark point every minute by the image processing software in the computer n ，Y n ) (n =1,2,3, \ 8230;), setting the acquisition time n to an appropriate value; the average displacement value in the X direction is obtained by the X-direction drift amount delta X and the Y-direction drift amount delta Y of the center of each marking point
The average displacement value in the Y direction is
Further obtaining the standard deviation delta of the average displacement in the X direction X Y-direction average displacementStandard deviation delta Y Thus, 3sigma of X-direction deviation and 3sigma of Y-direction deviation are obtained.
The method for measuring the repeatability precision of the X direction in the measurement of the repeatability precision of the platform comprises the following steps: the center value of a mark point in the calibration plate is marked by the CCD camera when the device is static as an initial mark (X) 0′ ,Y 0′ ) (ii) a Then the precision motion platform reciprocates in the X direction, the stroke control of each reciprocating motion is the same, when each reciprocating motion returns to the initial position, the CCD camera can carry out position data acquisition on the central value of the mark point in the field, and the coordinate value (X) is n′ ，Y n′ ) (n '=1,2,3, \ 8230;), setting the number of acquisitions n' to an appropriate value; by an offset deltax in the X direction of the centre of each mark 1′ Obtaining the average displacement value in the X direction
Obtaining the standard deviation delta of the average displacement in the X direction X′ And obtaining the 3sigma value of the X-direction deviation, wherein the method for measuring the repeatability precision of the Y direction is the same as the above method.
When the positioning precision measurement of the experimental device is a single-axis measurement experimental working condition, a strip-shaped calibration plate is placed on a platform along the X-axis direction, the platform moves back to an original point, the position of the calibration plate is adjusted, the center of a mark point is aligned with the original point of the platform and the center of a CCD camera view field, the position of the center of the mark point is O (0, 0), then the precision motion platform moves in the X direction, the stroke control of each movement is the same, after each movement, the CCD camera can carry out position data acquisition on the center value of the mark point in the view field, and the position data acquisition is recorded as m i (x i 0), setting the collection times i as an appropriate value; searching the axis of the calibration plate in camera software, and measuring the included angle between the axis of the calibration plate and the X axis to be theta 1; the control platform moves 5mm along the positive direction of the X axis, the CCD camera takes a snapshot along with the control platform, and the coordinate of the mark point is recorded as m 1 (x 1 0); connection Om 1 Perpendicular to the cross-m 1 The axis of the calibration plate intersects at the point a 1 (ii) a The scale of the calibration plate is known, so that the point a can be directly obtained 1 And m 1 S is 1 ；Om 1 Distance x of 1 Is the labelThe actual moving distance in the X-axis direction in this movement of the stationary plate, wherein:
namely, it is
The positioning error on the X-axis is therefore:
by analogy, the platform moves 5mm along the X axis every 5 seconds, the camera takes a snapshot every 5 seconds, and the actual moving distance l is calculated i And obtaining the positioning error of each time:
drawing a point line graph according to the positioning error delta and analyzing the variation trend of the point line graph; the positioning error of the Y axis is analogized.
When the positioning precision measurement of the experimental device is a biaxial measurement experimental working condition, a square calibration plate is placed on a platform, the platform moves back to an original point, the position of the calibration plate is adjusted, the center of one mark point is aligned with the original point of the platform and the center of a CCD camera visual field, the position of the center of the mark point is O (0, 0), then the precision motion platform moves in the X direction and the Y direction, the stroke control of each motion is the same, after each motion, the CCD camera can carry out position data acquisition on the center value of the mark point in the visual field and record the position data acquisition as m 1 (x 1 ，y 1 )，m 2 (x 2 ，y 2 )，……m i (x i ，y i ) Setting the collection times i as an appropriate value; because the two axes of the calibration plate can not be parallel to the X axis and the Y axis when the calibration plate is placed, the axes of the calibration plate are searched in the camera software, and the included angles between the axes of the calibration plate and the X axis and the included angles between the axes of the calibration plate and the Y axis are measured to be theta 1 、θ 2 (ii) a The control platform moves 5mm along the X-axis direction and then moves 5mm along the positive direction of the Y-axis, the CCD camera takes a snapshot with the control platform, and the mark coordinate is marked as m 1 (x 1 ，y 1 ) Another point n is drawn 1 (x 1 0); connect On 1 Perpendicular to the line passing through the O pointn 1 The axis of the calibration plate intersects at the point a 1 (ii) a The calibration plate has a known scale, so that the points O and a can be directly obtained 1 S is 1 ；Om 1 Distance x of 1 I.e. the actual movement distance of the calibration plate in the X-axis direction during this movement, wherein:
connecting m 1 n 1 Over m 1 Perpendicular to the cross-n 1 The axis of the calibration plate intersects at the point b 1 (ii) a The scale of the calibration plate is known, so that the point n can be directly obtained 1 And b 1 Distance f of 1 ；m 1 n 1 Distance y of 1′ I.e. the actual movement distance of the calibration plate in the Y-axis direction during this movement, wherein:
namely, it is
Therefore, the positioning error in the XY biaxial directions is Δ 1 And by analogy, the platform moves 5mm along the X-axis direction and the Y-axis direction every 5 seconds, the camera takes a snapshot once every 5 seconds, the actual moving distance is calculated, and the positioning error of the platform at each snapshot point is obtained: delta i And drawing a point diagram to obtain the positioning precision fluctuation of the platform in the XY biaxial directions.
The experimental device and the measuring method for the error analysis of the motion platform have the advantages that: 1. compared with the traditional measurement by using a laser interference system, the experimental device provided by the invention has the advantages that the machine vision is used for detecting the precise motion platform, so that the measurement error caused by the fluctuation of laser wavelength due to the change of the environment is effectively avoided, and the operation is simpler and more convenient; 2. based on an experimental device, the method can perform repeatability precision measurement, platform position stability measurement and positioning precision measurement through a visual detection method, evaluate the precision motion platform from multiple angles and dimensions, ensure the precision of the precision motion platform and further ensure the machining precision of parts placed on the precision motion platform.
In a word, the experimental device and the measuring method have the advantages of higher stability, lower cost and simpler and more convenient operation, and can measure the precision of the precision motion platform in multiple angles and multiple dimensions.
Drawings
FIG. 1 is a three-dimensional model of an experimental apparatus according to the present invention;
FIG. 2 is a schematic diagram of calibration of platform position stability and repeatability accuracy;
FIG. 3 is a schematic diagram of a bar calibration plate in positioning error measurement;
FIG. 4 is a schematic diagram of a square calibration plate in positioning error measurement;
FIG. 5 is a schematic view of a single axis measurement of positioning error;
FIG. 6 is a schematic diagram of a two-axis measurement of positioning error.
Detailed Description
In order to make the experimental device and the measuring method of the present invention better understood, the present invention is further described in detail with reference to the accompanying drawings and the detailed description.
Example 1
As shown in fig. 1, the invention relates to a motion platform error analysis experimental device based on machine vision, which comprises a marble platform module, a precision motion platform module and a vision acquisition module; the precision motion platform module and the vision acquisition module are fixedly connected with the marble platform module.
The marble platform module comprises a marble platform 1, marble supporting columns 2, a marble gantry 3 and marble upright columns 4; the upper end and the lower end of the marble upright post 2 are respectively fixedly connected with the marble platform 1 and the marble gantry 3, and the marble upright post 4 is fixed above the marble gantry 3.
The precise motion platform module comprises a precise motion platform 5, an electric cabinet 6, a computer 7 and a calibration board 15; the lower surface of the precision motion platform 5 is fixedly connected with the marble platform 1, the calibration plate 15 is adsorbed on the upper plane of the precision motion platform 5, and the electric cabinet 6 is respectively connected with the precision motion platform 5 and the computer 7.
The vision acquisition module comprises an image acquisition card 8, a CCD camera 9, a reflector 10, an objective lens 13 and two optical lens hoops 14; the two optical lens hoops 14 are respectively fixed on the marble upright post 4 and the marble gantry 3, the reflector 10 and the objective lens 13 are respectively arranged in the objective lens hoops 14, the reflector 10 is positioned right above the objective lens 13, the CCD camera 9 is fixed on the marble gantry 3, the reflecting surface of the reflector 10 faces towards the lens and the objective lens 13 of the CCD camera 9, and two ends of the image acquisition card 8 are respectively connected with the CCD camera 9 and the computer 7.
The computer 7 controls the movement of the precision motion platform 5 through the communication with the electric cabinet 6; the reflector 10 feeds back the image on the calibration plate 15 to the CCD camera 9, and the image acquisition card 8 transmits the acquired image to the computer 7. Wherein, the precision motion platform 5 can move along the X direction and the Y direction; the precise motion platform 5 is internally provided with a grating, an origin and XY coordinates are arranged on the grating, and XY numerical values of any point on the calibration plate 15 to the origin of the platform can be read from the computer.
The vision acquisition module also comprises an illumination light source 11 and an illumination hoop 12; the lighting hoop 12 is fixed on the marble gantry 3, and the lighting source 11 is arranged in the lighting hoop 12.
Example 2
A measuring method for motion platform error analysis based on machine vision comprises platform position stability measurement, platform repeatability precision measurement and platform positioning precision measurement.
Platform position stability measurement
The platform position stability measurement based on machine vision is that a fixed position of a calibration plate is continuously captured by a camera, so that the position stability of a motion platform under a static condition can be measured with high precision.
The specific measurement method for researching the position stability of the precision motion platform under the static condition based on the experimental device of the invention comprises the following steps: before the experiment, the XY moving platform is electrified, the focal length of the optical lens and the illumination light source are adjusted until the mark point on the calibration plate can be clearly seen, a mark point on the calibration plate is adjusted to the center of the camera visual field, and the coordinate value (X) of the center of the mark point at the moment is recorded 0 ，Y 0 ) Thereafter through the computerThe image processing software in the camera makes the camera capture the coordinate value (X) of the center of the mark point every minute n ，Y n ) (n =1,2,3, \ 8230;), the acquisition time n is set to an appropriate value.
Marking the center of the point at each time corresponding to the center: as shown in fig. 2
The X-direction drift amounts are respectively:
ΔX 1 ＝X 1 -X 0 ，ΔX 2 ＝X 2 -X 0 ，…，ΔX n ＝X n -X 0 ；
the Y-direction drift amounts are respectively:
ΔY 1 ＝Y 1 -Y 0 ，ΔY 2 ＝Y 2 -Y 0 ，…，ΔY n ＝Y n -Y 0 ；
from this, the average displacement value in the X direction is:
the standard deviation of the mean X-direction displacement is:
the average displacement value in the Y direction is:
the standard deviation of the Y-direction mean displacement is:
therefore, the following formula is given by the 3sigma calculation:
the 3sigma of the X-direction deviation is:
X 3sigma ＝3·δ X
the 3sigma of the Y-direction deviation is:
Y 3sigma ＝3·δ Y
comparing the 3sigma values of the X direction and the Y direction with the standard set by a precision motion platform manufacturing enterprise, the position stability of the precision motion platform in the transverse direction (X direction) and the longitudinal direction (Y direction) in the test time can be evaluated.
(II) measurement of platform repeatability precision
The platform repeatability precision measurement based on machine vision is that a camera is used for continuously capturing the position of a calibration plate after reciprocating along the X direction or after reciprocating along the Y direction, so that the repeatability precision of the precision motion platform moving along the X direction or the Y direction can be measured with high precision.
The specific measurement method for researching the repeatability precision of the precision motion platform under the motion condition based on the experimental device of the invention is as follows:
repeatability precision in X direction: the center value of a mark point in the calibration plate is marked by the CCD camera when the device is static as an initial mark (X) 0′ ，Y 0 B) of the group A and B); then the precision motion platform reciprocates in the X direction, the CCD camera collects position data of the center value of the mark point in the field when the stroke control of each reciprocating motion is the same and each reciprocating motion returns to the initial position, and the coordinate value (X) is obtained n′ ，Y n′ ) (n '=1,2,3, \ 8230;), the number of acquisitions n' is set to an appropriate value.
Each mark center corresponding thereto: as shown in fig. 2
The X-direction offset is respectively
ΔX 1′ ＝X 1′ -X 0′ ，ΔX 2′ ＝X 2′ -X 1′ ，…，ΔX n′ ＝X n′ -X n′-1 ；
From this, the average displacement value in the X direction is:
the standard deviation of the mean X-direction displacement is:
therefore, the following formula is given by the 3sigma calculation:
the 3sigma of the X-direction deviation is:
X′ 3sigma ＝3·δ X′
although the X and Y coordinate values of the center value of the marker point may change when the X direction is repeatedly moved, only the X direction displacement and deviation are considered in the above calculation.
The method for measuring the repeatability precision in the Y direction is the same as the method for measuring the repeatability precision in the Y direction, and finally the method is obtained
The 3sigma of the Y-direction deviation is:
Y 3sigma ＝3·δ Y′
although the center value X and the Y coordinate value of the marking point may change when the Y direction is repeatedly moved, only the displacement and deviation in the Y direction are considered in the above calculation.
Comparing the 3sigma values in the X direction and the Y direction with the standards set by precision motion platform manufacturing enterprises, the repeatability precision of the motion platform in the X direction and the repeatability precision of the motion platform in the Y direction can be evaluated.
(III) measurement of positioning error
The positioning error measurement based on machine vision is that the platform moves along the X direction or the Y direction or the platform moves along the XY direction simultaneously (the stroke control of each movement is the same), the position of the platform after the movement of the calibration plate is captured and the image is processed by the camera, the one-way positioning error or the two-dimensional positioning error of the precision motion platform after the movement can be measured, and the positioning precision of each point is further determined.
According to the experimental requirements, the positioning precision measurement of the experimental device is divided into two experimental working conditions of single-axis measurement and double-axis measurement, and the specific measurement method comprises the following steps:
the working condition I is as follows: when the positioning accuracy measurement of the experimental device is a single-axis measurement experimental working condition, a strip-shaped calibration plate (as shown in figure 3) is placed on the platform along the X-axis direction and is flatMoving the platform back to the original point, adjusting the position of the calibration plate, aligning the center of a mark point with the original point of the platform and the center of the view field of the CCD camera, wherein the position of the center of the mark point is O (0, 0), then moving the precise motion platform in the X direction, controlling the same stroke of each movement, and after each movement, the CCD camera can carry out position data acquisition on the center value of the mark point in the field, and the center value is marked as m 1 (x 1 ，0)、m 2 (x 2 ，0)、……m i (x i 0), setting the collection times i as an appropriate value; because the axis direction of the calibration plate cannot be parallel to the X axis when the calibration plate is placed, the axis of the calibration plate is searched in camera software, and the included angle theta between the axis of the calibration plate and the X axis is measured 1 ；
As shown in figure 5, the control platform moves 5mm along the positive direction of the X axis, the CCD camera takes a snapshot with the control platform, and the coordinate of the mark point is marked as m 1 (x 1 0); connection Om 1 Perpendicular to the cross-m 1 The axis of the calibration plate intersects at the point a 1 (ii) a The scale of the calibration plate is known, so that the point a can be directly obtained 1 And m 1 S is 1 ；Om 1 Distance x of 1 I.e. the actual movement distance of the calibration plate in the X-axis direction during this movement, wherein:
namely, it is
The positioning error on the X-axis is therefore:
by parity of reasoning, the platform moves 5mm along the X axis every 5 seconds, the camera takes a snapshot every 5 seconds, and the actual moving distance l is calculated i And obtaining the positioning error of each time:
and drawing a point line graph according to the positioning error delta and analyzing the variation trend of the point line graph, so that whether the positioning precision fluctuation of the platform in the X-axis direction reaches the relevant standard of a precision platform production enterprise can be known. And the positioning error of the Y axis can be analogized.
Working conditions are as follows: when the positioning precision measurement of the experimental device is a biaxial measurement experimental working condition, a square calibration plate (shown in figure 4) is placed on the platform, the platform moves back to the original point, the position of the calibration plate is adjusted, the center of one mark point is aligned with the original point of the platform and the center of the field of view of the CCD camera, the position of the center of the mark point is O (0, 0), then the precision motion platform moves in the X direction and the Y direction, the stroke control of each movement is the same, after each movement, the CCD camera can carry out position data acquisition on the center value of the mark point in the field of view, and the position data acquisition is recorded as m 1 (x 1 ，y 1 )，m 2 (x 2 ，y 2 )，……m i (x i ，y i ) Setting the collection times i as an appropriate value; because the two axes of the calibration plate can not be parallel to the X axis and the Y axis when the calibration plate is placed, the axes of the calibration plate are searched in the camera software, and the included angles between the axes of the calibration plate and the X axis and the included angles between the axes of the calibration plate and the Y axis are measured to be theta 1 、θ 2 ；
As shown in FIG. 6, the control platform moves 5mm along the X-axis direction, then moves 5mm along the Y-axis positive direction, the CCD camera takes a snapshot with the control platform, and the mark coordinate is marked as m 1 (x 1 ，y 1 ) Another point n is drawn 1 (x 1 0); connect On 1 Perpendicular to the line passing through n 1 The axis of the calibration plate intersects at the point a 1 (ii) a The calibration plate has a known scale, so that the points O and a can be directly obtained 1 S is 1 ；Om 1 Distance x of 1 I.e. the actual movement distance of the calibration plate in the X-axis direction during this movement, wherein:
connection m 1 n 1 Over m 1 Point making vertical line perpendicular to cross n 1 The axis of the calibration plate intersects at the point b 1 (ii) a The scale of the calibration plate is known, so that the point n can be directly obtained 1 And b 1 Distance f of 1 ；m 1 n 1 Distance y of 1 I.e. the actual moving distance in the Y-axis direction in this movement of the calibration plate, wherein:
namely that
Therefore, the positioning error in the XY biaxial is:
by analogy, the platform moves 5mm along the X-axis direction and the Y-axis direction every 5 seconds, the camera takes a snapshot once every 5 seconds, the actual moving distance is calculated, and the positioning error of the platform at each snapshot point is obtained:
and (4) drawing a point line graph to obtain the positioning precision fluctuation of the platform in the XY biaxial directions.
And drawing a point diagram according to the positioning error delta and analyzing the variation trend of the point diagram, so that whether the positioning precision fluctuation of the platform in the XY direction reaches the relevant standard of a precision platform production enterprise can be known. The invention can measure the positioning precision of the XY double axes simultaneously by a 'step' motion mode.
The experimental device is simple in structure, and the measurement based on the experimental device comprises platform position stability measurement, platform repeatability precision measurement, platform positioning precision measurement and the like, so that the precision motion platform can be evaluated in multiple angles and multiple dimensions, the precision of the precision motion platform is ensured, and the machining precision of parts placed on the precision motion platform is further ensured.
Claims (9)
1. The utility model provides a motion platform error analysis experimental apparatus based on machine vision, characterized by: the system comprises a marble platform module, a precision motion platform module and a vision acquisition module; the precision motion platform module and the vision acquisition module are fixedly connected with the marble platform module.
2. The motion platform error analysis experiment apparatus of claim 1, wherein: the marble platform module comprises a marble platform (1), marble supporting columns (2), a marble gantry (3) and marble upright columns (4); the upper end and the lower end of the marble upright post (2) are respectively fixedly connected with the marble platform (1) and the marble gantry (3), and the marble upright post (4) is fixed above the marble gantry (3).
3. The motion platform error analysis experiment apparatus of claim 1, wherein: the precision motion platform module comprises a precision motion platform (5), an electric cabinet (6), a computer (7) and a calibration board (15); the lower surface of the precision motion platform (5) is fixedly connected with the marble platform (1), the calibration plate (15) is adsorbed on the upper plane of the precision motion platform (5), and the electric cabinet (6) is respectively connected with the precision motion platform (5) and the computer (7).
4. The motion platform error analysis experiment apparatus of claim 1, wherein: the vision acquisition module comprises an image acquisition card (8), a CCD camera (9), a reflector (10), an objective lens (13) and two optical lens hoops (14); two optical mirror hoops (14) are respectively fixed on a marble upright post (4) and a marble gantry (3), a reflector (10) and an objective lens (13) are respectively arranged in the objective lens hoops (14), the reflector (10) is positioned right above the objective lens (13), a CCD camera (9) is fixed on the marble gantry (3), the reflecting surface of the reflector (10) faces towards a lens and the objective lens (13) of the CCD camera (9), and two ends of an image acquisition card (8) are respectively connected with the CCD camera (9) and a computer () 7.
5. A measuring method for motion platform error analysis based on machine vision is characterized in that: the method comprises the steps of measuring the position stability of the platform, measuring the repeatability precision of the platform and measuring the positioning precision of the platform; the platform position stability measurement is that a fixed position of the calibration plate is continuously captured by a camera, so that the position stability of the motion platform under a static condition can be measured with high precision; the measurement of the repeatability precision of the platform is to continuously snapshot the position of the calibration plate after reciprocating along the X direction or after reciprocating along the Y direction through a camera, so that the repeatability precision of the movement of the precision motion platform in the X direction or the Y direction can be measured with high precision; positioning error measurement based on machine vision, namely under a single-axis experiment working condition or a double-axis experiment working condition, a camera is used for capturing the position of a moving calibration plate on a platform and processing an image, so that a one-way positioning error or a two-dimensional positioning error of the moving precision motion platform can be measured, and the positioning precision of each point is further determined; the single-axis experiment working condition refers to that the platform moves along the X direction or the Y direction, the double-axis experiment working condition refers to that the platform moves along the XY direction simultaneously, and the stroke control of each movement is the same.
6. The measurement method according to claim 5, wherein: the specific measurement method of the platform position stability is as follows: before the experiment begins, the XY motion platform is electrified, the focal length of the optical lens and the illumination light source are adjusted until the mark point on the calibration plate can be clearly seen, one mark point on the calibration plate is adjusted to the center of the camera view field, and the coordinate value (X) of the center of the mark point at the moment is recorded 0 ，Y 0 ) Then, the camera captures the coordinate value (X) of the center of the mark point every minute by the image processing software in the computer n ，Y n ) (n =1,2,3, \8230;), the acquisition time n is set to an appropriate value; the average displacement value in the X direction is obtained by the X-direction drift amount delta X and the Y-direction drift amount delta Y of the center of each marking point
The average displacement value in the Y direction is
Further obtaining the standard deviation delta of the average displacement in the X direction X Standard deviation delta of Y-direction average displacement Y Thus, 3sigma of the X-direction deviation and 3sigma of the Y-direction deviation are obtained.
7. The measurement method according to claim 5, wherein: the X-direction repeatability precision measurement method comprises the following steps: marking the center value of a marking point in the calibration plate by a CCD camera when the device is static as an initial mark (X) 0′ ,Y 0′ ) (ii) a Then the precision motion platform reciprocates in the X direction, the stroke control of each reciprocating motion is the same, when each reciprocating motion returns to the initial position, the CCD camera can carry out position data acquisition on the central value of the mark point in the field, and the coordinate value (X) is n′ ,Y n′ ) (n '=1,2,3, \ 8230;), setting the number of acquisitions n' to an appropriate value; by X-offset DeltaX of the centre of each mark 1′ Obtaining the average displacement value in the X direction
Obtaining the standard deviation delta of the average displacement in the X direction X′ And obtaining the 3sigma value of the X-direction deviation, wherein the method for measuring the repeatability precision of the Y direction is the same as the above method.
8. The measurement method according to claim 5, wherein: when the positioning precision measurement of the experimental device is a single-axis measurement experimental working condition, a strip-shaped calibration plate is placed on a platform along the X-axis direction, the platform moves back to an original point, the position of the calibration plate is adjusted, the center of a mark point is aligned with the original point of the platform and the center of a CCD camera view field, the position of the center of the mark point is O (0, 0), then the precision motion platform moves in the X direction, the stroke control of each movement is the same, after each movement, the CCD camera can carry out position data acquisition on the center value of the mark point in the view field, and the position data acquisition is recorded as m i (x i 0), setting the collection times i as an appropriate value; searching the axis of the calibration plate in the camera software, and measuring the included angle theta between the axis of the calibration plate and the X axis 1 (ii) a The control platform moves 5mm along the positive direction of the X axis, the CCD camera takes a snapshot along with the control platform, and the coordinate of the mark point is recorded as m 1 (x 1 0); connection Om 1 Perpendicular to the cross-m 1 The axis of the calibration plate intersects at the point a 1 (ii) a The scale of the calibration plate is known, so that the point a can be directly obtained 1 And m 1 S is 1 ；Om 1 Distance x of 1 I.e. the actual movement distance of the calibration plate in the X-axis direction during this movement, wherein:
namely, it is
The positioning error on the X-axis is therefore:
by analogy, the platform moves 5mm along the X axis every 5 seconds, the camera takes a snapshot every 5 seconds, and the actual moving distance l is calculated i And obtaining the positioning error of each time:
drawing a point line graph according to the positioning error delta and analyzing the variation trend of the point line graph; the positioning error of the Y axis is analogized.
9. The measurement method according to claim 5, wherein: when the positioning precision measurement of the experimental device is a biaxial measurement experimental working condition, a square calibration plate is placed on a platform, the platform moves back to an original point, the position of the calibration plate is adjusted, the center of one mark point is aligned with the original point of the platform and the center of a CCD camera visual field, the position of the center of the mark point is O (0, 0), then the precision motion platform moves in the X direction and the Y direction, the stroke control of each motion is the same, after each motion, the CCD camera can carry out position data acquisition on the center value of the mark point in the visual field and record the position data acquisition as m 1 (x 1 ,y 1 )，m 2 (x 2 ,y 2 )，……m i (x i ,y i ) Setting the collection times i as an appropriate value; because the two axes of the calibration plate can not be parallel to the X axis and the Y axis when the calibration plate is placed, the axes of the calibration plate are searched in the camera software, and the included angles between the axes of the calibration plate and the X axis and the included angles between the axes of the calibration plate and the Y axis are measured to be theta 1 、θ 2 (ii) a The control platform moves 5mm along the X-axis direction and then moves 5mm along the positive direction of the Y-axis, the CCD camera takes a snapshot with the control platform, and the mark coordinate is marked as m 1 (x 1 ,y 1 ) Another point n is drawn 1 (x 1 0); connect On 1 Perpendicular to the line passing through n 1 The axis of the calibration plate intersects at the point a 1 (ii) a The calibration plate has a known scale, so that the points O and a can be directly obtained 1 S is 1 ；Om 1 Distance x of 1 I.e. the actual movement distance of the calibration plate in the X-axis direction during this movement, wherein:
connection m 1 n 1 Over m 1 Point making vertical line perpendicular to cross n 1 The axis of the calibration plate intersects at the point b 1 (ii) a The scale of the calibration plate is known, so that the point n can be directly obtained 1 And b 1 Distance f of 1 ；m 1 n 1 Distance y of 1 I.e. the actual moving distance in the Y-axis direction in this movement of the calibration plate, wherein:
namely, it is
So that the positioning error in the XY biaxial directions is Δ 1 And by analogy, the platform moves 5mm along the X and Y axis directions every 5 seconds, and the camera takes a candid photograph once every 5 seconds, and calculates the actual moving distance to obtain the positioning error of the platform at each candid photograph point: delta i And drawing a point diagram to obtain the positioning precision fluctuation of the platform in the XY biaxial directions.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211406577.3A CN115682935A (en) | 2022-11-10 | 2022-11-10 | Motion platform error analysis experimental device and measurement method based on machine vision |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211406577.3A CN115682935A (en) | 2022-11-10 | 2022-11-10 | Motion platform error analysis experimental device and measurement method based on machine vision |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115682935A true CN115682935A (en) | 2023-02-03 |
Family
ID=85052136
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211406577.3A Pending CN115682935A (en) | 2022-11-10 | 2022-11-10 | Motion platform error analysis experimental device and measurement method based on machine vision |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115682935A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116907343A (en) * | 2023-07-25 | 2023-10-20 | 广东凯福电子科技有限公司 | Visual detection instrument and detection method for mechanism movement precision |
-
2022
- 2022-11-10 CN CN202211406577.3A patent/CN115682935A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116907343A (en) * | 2023-07-25 | 2023-10-20 | 广东凯福电子科技有限公司 | Visual detection instrument and detection method for mechanism movement precision |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110006905B (en) | Large-caliber ultra-clean smooth surface defect detection device combined with linear area array camera | |
| KR101318613B1 (en) | Three dimension measuring method | |
| CN101107558B (en) | Tracking auto focus system | |
| TW528881B (en) | Position measuring apparatus | |
| CN104614558B (en) | A kind of, line CCD combine atomic force probe scanning measurement system and measuring method | |
| US20180178339A1 (en) | Measurement, calibration and compensation system and method for machine tool | |
| CN105241399B (en) | A kind of measuring method of precisely locating platform dynamic flatness | |
| US10535157B2 (en) | Positioning and measuring system based on image scale | |
| US10585361B2 (en) | Projection exposure apparatus and method | |
| CN111338290A (en) | Multi-vision-based five-axis numerical control machine tool multifunctional detection method | |
| CN108527007A (en) | Vertical machining centre on-machine measurement system and method based on optical triangulation | |
| TWM530737U (en) | Calibration system of robot | |
| CN203069151U (en) | Three-dimensional hole form detection system based on optical coherence tomography scanning | |
| CN102538707B (en) | Three dimensional localization device and method for workpiece | |
| CN115682935A (en) | Motion platform error analysis experimental device and measurement method based on machine vision | |
| JP2010510519A (en) | Gauge for measuring strain of glass sheet | |
| CN104034259B (en) | A kind of image measurer bearing calibration | |
| CN116000460A (en) | Online vision guiding laser coding method and device | |
| CN209992407U (en) | Large-caliber ultra-clean smooth surface defect detection device combined with linear array camera | |
| JP2007085912A (en) | Position measurement method, position measuring device and position measuring system | |
| CN105046650A (en) | Machine vision-based image mosaic method for small module gear detection process | |
| CN109520443B (en) | Roll angle measuring method based on combined surface type reference part | |
| CN108955530B (en) | Mechanical optical position convenient calibration system and calibration method thereof | |
| CN115289997B (en) | Binocular camera three-dimensional contour scanner and application method thereof | |
| CN115031626B (en) | Substrate coordinate measuring method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |