CN111210479A - Laser auxiliary calibration device and method for measuring sizes of parts with different heights - Google Patents

Laser auxiliary calibration device and method for measuring sizes of parts with different heights Download PDF

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Publication number
CN111210479A
CN111210479A CN202010003187.6A CN202010003187A CN111210479A CN 111210479 A CN111210479 A CN 111210479A CN 202010003187 A CN202010003187 A CN 202010003187A CN 111210479 A CN111210479 A CN 111210479A
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coordinate system
camera
calibration
image
laser
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CN111210479B (en
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陈浙泊
陈镇元
黄丹丹
刘锡安
潘凌锋
林建宇
林晨宽
陈一信
余建安
叶雪旺
吴荻苇
颜文俊
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Research Institute of Zhejiang University Taizhou
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Research Institute of Zhejiang University Taizhou
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    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T7/00—Image analysis
    • G06T7/80—Analysis of captured images to determine intrinsic or extrinsic camera parameters, i.e. camera calibration
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T5/00—Image enhancement or restoration
    • G06T5/80—Geometric correction
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T7/00—Image analysis
    • G06T7/60—Analysis of geometric attributes
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T7/00—Image analysis
    • G06T7/70—Determining position or orientation of objects or cameras
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T2207/00—Indexing scheme for image analysis or image enhancement
    • G06T2207/10—Image acquisition modality
    • G06T2207/10004—Still image; Photographic image
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
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    • Y02E30/30—Nuclear fission reactors

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Abstract

The invention provides a laser auxiliary calibration method for measuring sizes of parts with different heights, which comprises the following steps: the method comprises the steps of enabling three lasers to irradiate a measuring surface by laser by adjusting laser angles, collecting a reference image and storing the reference image as a gray image, removing a calibration object and placing the calibration object on a multi-dimensional translation table, reading the reference image to set the reference image as a dark channel, collecting the current gray image in real time and setting the current gray image as a bright channel, synthesizing the dark channel image and the bright channel image into an image in real time, placing a calibration plate on the translation table to collect the image, extracting angular point information of the calibration plate, calculating internal and external parameters of a camera under an ideal condition, and obtaining a distortion coefficient of radial distortion by using a least square method; the invention can accurately calibrate the detection surfaces of parts with different heights and appearances, can accurately position the detection surface of a measured object, and improves the calibration precision.

Description

Laser auxiliary calibration device and method for measuring sizes of parts with different heights
Technical Field
The invention relates to the field of machine vision image detection, in particular to a laser auxiliary calibration device and method for measuring sizes of parts with different heights.
Background
In image measurement, positioning and machine vision applications, in order to determine the correlation between the geometric position of a certain point on the surface of a space object in a three-dimensional space and the corresponding point in a two-dimensional image, a geometric model of camera imaging needs to be established, wherein the geometric model parameters are the parameters of a camera, and the parameter solving process is called camera calibration. The existing calibration mode is to place a calibration plate on the surface to be measured and calculate by extracting grid angular point coordinates and camera internal parameters, but the process needs to ensure that the calibration plate is placed right above the surface to be measured and is parallel to or coincided with the measurement surface.
However, in actual measurement, due to the uncertainty of the surface shape of the calibration object, problems that the measurement surface is too small, the measurement surface is shielded by other parts of the object, and the calibration plate cannot be placed often occur, so that the detection process cannot be performed normally. As shown in fig. 1 to 4, the measurement surface is located in the middle area inside the cylinder, the calibration plate needs to be placed on the detection surface inside for normal calibration, calibration cannot be performed if no calibration plate with a proper specification can be placed on the measurement surface inside at this time, even if the calibration plate is placed right above the cylinder, it cannot be determined whether calibration is effective or not if the calibration plate is parallel to the detection surface, and the calibration plate needs to have a size larger than 1/3 of the camera view field during calibration, and calibration can be performed only if these two conditions are satisfied. Due to the problems, the calibration cannot be smoothly performed, and the measurement precision is affected.
Disclosure of Invention
The invention aims to overcome the defects of the prior art, and provides a laser auxiliary calibration device and method for measuring the sizes of parts with different heights, which are simple in structure and convenient to use.
A laser auxiliary calibration device used for measuring sizes of parts with different heights comprises a box body, a camera, an adjusting frame, a point light source, an adjusting platform and a calibration plate; the camera, the adjusting frame and the adjusting platform are arranged in the box body; the point light source is arranged on the adjusting frame; the calibration plate is arranged on the adjusting table; the box body is a hexahedron with one open side, the open side is the side of the box body, and the other three sides of the box body are provided with adjusting frames; the top surface of box is provided with the camera, and the bottom surface is provided with the regulation platform.
Further, the adjusting frame is arranged around the camera.
A laser auxiliary calibration method based on the device is characterized by comprising the following steps:
s1: marking the surface of the part to be detected by the point light source;
s2: recording the marked position by the camera, taking away the part to be measured, placing the adjusting table at the position to be measured, and marking the surface of the adjusting table by the point light source;
s3: changing the position and the posture of the adjusting table to enable the camera to record that the point light source mark position on the surface of the current adjusting table is superposed with the point light source mark position in S1;
s4: setting a calibration plate for calibration; and measuring the size of the original part by using the calibration data.
Further, the marking using the point light source in S1 and S2 includes:
s11: adjusting the adjusting frame to enable the point light source to emit light to the detection surface;
s12: the light emitted by the point light source is reflected by the detection surface and transmitted to the camera;
s13: the camera captures real-time images.
Further, the S4 includes the following steps:
s41: transforming from the world coordinate system to the camera coordinate system;
s42: transforming the camera coordinate system to an imaging plane coordinate system, wherein the process of transforming the camera coordinate system to the imaging plane coordinate system comprises a calibration process;
s43: correcting a coordinate system of an imaging plane;
s44: transforming the imaging plane coordinate system after correction into an image coordinate system;
s45: and determining the total parameters inside and outside the camera to finish calibration.
Further, in S41, converting the world coordinate system to the camera coordinate system includes converting the point PwConversion to point PcSpecifically, the following formula is used:
Pc＝R·Pw+T
wherein R represents a rotation matrix, T represents a translation vector, R comprises α and gamma are three rotation angles, and the rotation matrix R (α and gamma) is represented as:
Figure BDA0002354237140000021
wherein α represents the angle between the camera coordinate system and the X-axis of the world coordinate system, β represents the angle between the camera coordinate system and the Y-axis of the world coordinate system, gamma represents the angle between the camera coordinate system and the Z-axis of the world coordinate system, and P represents the angle between the camera coordinate system and the Z-axis of the world coordinate systemcThe coordinate value in the camera coordinate system is represented as (x)c，yc，zc)；T＝(tx,ty,tz)。
Further, in S42, in the process of converting the camera coordinate system to the imaging plane coordinate system, P needs to be convertedcConverting to an imaging plane coordinate system, wherein the conversion process depends on the following conversion relation:
Figure BDA0002354237140000031
wherein f represents the focal length of the camera; u, v represent coordinate values of the point P in the imaging plane coordinate system.
Further, in S43, the rectification imaging plane coordinate system includes:
Figure BDA0002354237140000032
wherein the parameter k represents the distortion magnitude of the radial distortion;
Figure BDA0002354237140000033
the real imaging plane coordinate value of the corrected point P is represented.
Further, in S44, coordinates of the point P in the ideal imaging plane coordinate system are determined
Figure BDA0002354237140000034
Conversion to an image coordinate system, comprising:
Figure BDA0002354237140000035
wherein C isx，CyIs a coordinate value of the perpendicular projection of the projection center on the imaging plane coordinate system, Sx，SyIs the distance between adjacent pixels of the image sensor in the horizontal and vertical directions.
Further, in S45, the process of determining the total camera inside and outside parameters includes: placing the chessboard grid calibration board above the adjusting table, shooting the current calibration board image by using a camera, and firstly obtaining the angular point coordinate m of the chessboard grid from the calibration board imagei,jM is saidi,jIn the image coordinate system; the distance d (c) between the projected coordinates Ti (Mi, c) is calculated by the following formula:
Figure BDA0002354237140000036
determining the total internal and external parameters c ═ f, k, S of the camera by jointly solving two or more images with calibration plates and calculating the minimum value of d (c)x，Sy，Cx，Cy，tx，ty，tzα, γ), the calibration process of the camera is completed.
The invention has the beneficial effects that:
by arranging the point light source auxiliary and adjusting table, the detection surfaces of parts with different heights and appearances can be accurately calibrated;
a plane positioning method is introduced, so that the detection surface of a measured object can be accurately positioned, and the calibration precision is improved;
the distortion value generated in the imaging process is corrected by correcting the imaging plane coordinate system, so that the calibration is more accurate.
Drawings
FIG. 1 is a checkerboard calibration plate;
FIG. 2 is a view of a conventional calibration time measuring surface located in the middle area of the interior of a cylinder;
FIG. 3 is a conventional calibration time calibration plate placed on the inspection surface inside the cylinder;
FIG. 4 is a conventional calibration time calibration plate placed directly above a cylinder;
FIG. 5 is a simplified schematic diagram of the calibration apparatus of the present invention;
FIG. 6 is a simplified top view of the calibration device of the present invention;
FIG. 7 is a diagram illustrating a calibration apparatus according to an embodiment of the present invention;
FIG. 8 is a front view of a calibration device according to an embodiment of the present invention;
FIG. 9 is a schematic view of the reflection of a planar light path of different inclination according to the present invention;
FIG. 10 is a schematic view of a conditioning station of the present invention;
FIG. 11 is a bottom view of the upper base of the present invention;
FIG. 12 is a perspective view of the upper base of the present invention;
FIG. 13 is a perspective view of an adjustable mount of the present invention;
FIG. 14 is a simplified block diagram of the positioning of the detection surface of the measurement object according to the present invention;
FIG. 15 is a schematic view of the detection surface of the measuring object according to the present invention;
FIG. 16 is a schematic view of a camera imaging of a detection surface according to the present invention;
FIG. 17 is a schematic view of the inspection of the conditioner of the present invention;
FIG. 18 is a schematic view of the reduction measurement surface of the conditioning stage according to the present invention;
FIG. 19 is a schematic plan imaging view of the present invention;
FIG. 20 is a flow chart of the present invention.
The attached drawings indicate the following: the device comprises a box body 1, a camera 2, an adjusting frame 3, a fixed seat 31, a crank arm 32, a point light source 4, an adjusting platform 5, an upright rod 51, a reflecting surface 52, a knob 53, a height knob 531, a positioning knob 532, a supporting rod 54, a connecting rod 541, a base 55, an upper base 551, a lower base 552, a sliding rod 56, a sliding block 57, a fixed block 58, a height adjusting rod 59, a calibration plate 6 and a part to be measured 7.
Detailed Description
The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention. It is to be noted that the features in the following embodiments and examples may be combined with each other without conflict.
It should be noted that the drawings provided in the following embodiments are only for illustrating the basic idea of the present invention, and the components related to the present invention are only shown in the drawings rather than drawn according to the number, shape and size of the components in actual implementation, and the type, quantity and proportion of the components in actual implementation may be changed freely, and the layout of the components may be more complicated.
The first embodiment is as follows:
as shown in fig. 5-8, a laser auxiliary calibration device for measuring sizes of parts with different heights comprises a box body 1, a camera 2, an adjusting frame 3, a point light source 4, an adjusting table 5 and a calibration plate 6.
The box 1 is a hexahedron with one open side, wherein one open side is the side of the box 1, the other three sides of the box 1 are provided with adjusting frames 3, the top surface of the box 1 is provided with a camera 2, the bottom surface is provided with an adjusting table 5, the adjusting table 5 is only placed on the bottom surface of the box, and the adjusting table 5 can move on the bottom surface of the box. The point light source 4 is arranged on the adjusting frame 3. The calibration plate 6 is arranged on the adjusting table 5. The box 1 may be made of a metal material, in this embodiment, an iron material is selected, and meanwhile, in order to facilitate the operation of an operator, a base is disposed below the bottom surface of the box, so that the horizontal height of the adjusting table is raised. In order to facilitate the movement of the calibration device, the universal wheels are arranged at the bottom of the box body, so that the calibration device can move randomly.
As shown in fig. 13, the adjustment bracket 3 is provided around the camera 2, and the adjustment bracket 3 is a universal adjustment bracket 3 and can adjust the horizontal height, the inclination angle, and the horizontal position. The alignment jig 3 includes fixing base 31, crank arm 32, the fixing base 31 of alignment jig 3 is provided with magnet, and the purpose makes alignment jig 3 can adsorb on box 1, can adjust the height and the angle of alignment jig 3 simultaneously. The crank arm 32 is hinged with the fixed seat 31. The one end that magnet was kept away from to fixing base 31 sets up the articulated joint, the one end of articulated joint sets up and is connected between screw thread and the fixing base 31, and the other end of articulated joint sets up spherical articulated piece. One end of the crank arm 32 is hinged with the hinge joint of the fixing seat 31, and the other end of the crank arm 32 is provided with a similar hinge joint which is connected with the point light source. Crank arm 32 wholly comprises two parallel elliptical plates, sets up threaded connection between two parallel elliptical plates, and the both ends of elliptical plate set up circular fretwork, and this fretwork cooperates with spherical articulated piece.
As shown in fig. 7 and 13, the number of the point light sources 4 is at least three, one point light source 4 is arranged on one adjusting frame 3, and a thread is arranged between the point light source 4 and the adjusting frame 3. In the present embodiment, the point light sources 4 are semiconductor lasers, and the number of the point light sources 4 is three.
As shown in fig. 10 to 12, the adjusting table 5 includes a vertical rod 51, a reflecting surface 52, a knob 53, a supporting rod 54, a base 55, and a sliding rod 56. The base includes two parts, an upper base 551 and a lower base 552. The reflecting surface 52 is disposed on the upper surface of the upper base 551, and the vertical rod 51 is disposed between the reflecting surface 52 and the upper base 551. The number of the upright posts 51 is four, and the four upright posts 51 are disposed at four corners of the reflecting surface 52. The number of the sliding rods 56 is four, two sliding rods 56 are taken as one group, the four sliding rods 56 are divided into two groups, and the sliding rods 56 in the same group are parallel and are positioned on the same horizontal plane. Two sets of sliding rods 56 are respectively disposed on the lower surface of the upper base 551 and the upper surface of the lower base 552. The knob 53 comprises a height knob 531 and a positioning knob 532, and the knobs are arranged on the upper base 551 and located at one end of the sliding rod 56. The positioning knob 532 can lock the height knob 531, so that the height of the adjusting table is prevented from being changed in the calibration process. And a support rod 54 is further arranged between the upper base 551 and the lower base 552, the support rods 54 are arranged in a crossed manner, the support rods are arranged on two sides of the sliding rod 56, and a connecting rod 541 is arranged between the support rods on the two sides so as to stabilize the support of the support rods. A sliding block 57 and a fixed block 58 are arranged between the support rod 54 and the sliding rod 56, and a sliding block 57 and a fixed block 58 are arranged on one sliding rod 56. The sliding block 57 is sleeved with the sliding rod 56, and the sliding block 57 can slide along the sliding rod 56; the fixed block 58 is arranged at one end of the sliding rod 56, and the fixed block 58 is fixedly connected with the base. The slide block 57 and the fixed block 58 are hinged at both sides to a support rod 54 which can rotate around the hinge point. Wherein, a height adjusting rod 59 is arranged on the slide block 57 of the slide bar 56 of the upper base 551, and the height adjusting rod 59 is connected with the slide block 57 of the upper base 551. The height adjusting rod 59 can extend or contract along with the rotation of the height knob 531, and the sliding block 57 located on the upper base 551 is pushed to slide along the sliding rod 56, so as to adjust the height of the adjusting platform.
A laser-assisted calibration method for measuring dimensions of parts with different heights comprises the following steps:
s1: the semiconductor laser marks the surface of the part 7 to be detected; the semiconductor laser is arranged on the adjusting frames 3 at two sides of the lens; the adjusting frame 3 is a universal adjusting frame 3, and the horizontal height, the inclination angle and the horizontal position of the semiconductor laser can be adjusted through the adjusting frame 3;
s2: the camera 2 records the marked position at this time, takes away the part 7 to be measured, places the adjusting platform 5 at the position to be measured, and marks the surface of the adjusting platform 5 by the point light source 4;
s3: changing the position posture of the adjusting table 5 to make the camera 2 record that the point light source 4 mark position on the surface of the current adjusting table 5 is coincident with the point light source 4 mark position in S1;
s4: setting a calibration plate 6 for calibration;
s5: and measuring the size of the original part by using the calibration data.
As shown in fig. 9 and 14-20, in the marking processes of S1 and S2, the adjusting frame 3 is first adjusted so that the point light source 4 emits light to the detection surface of the part 7 to be detected, and in the present embodiment, the point light source 4 is a semiconductor laser. The light emitted by the point light source 4 from the side of the camera 2 is reflected by the detection surfaces with different inclinations and then transmitted to the camera 2, and the reflection is diffuse reflection. Since the point light source 4 is irradiated on the detection surface at different positions, the imaging position of the point light source 4 on the camera 2 is also different. Therefore, three points which are not on the same straight line in the image obtained by the camera 2 can determine the position of a plane in a space, and the position of the plane can be recorded by the imaging position of the bright point on the image. The invention needs at least three semiconductor lasers to realize positioning, and in the embodiment, three semiconductor lasers are arranged to realize positioning.
In the embodiment, three semiconductor lasers emit laser to irradiate on the detection surface of the part to be detected 7, and images of three dark spots can be shot by the camera 2; the image of the dark spot is saved and the adjustment stage 5 is replaced without changing the posture of the semiconductor laser. Since the height and the inclination angle of the adjusting table 5 may be different from the detection surface of the part to be detected 7, the positions of the three laser points may be deviated. The camera 2 collects images of the adjusting table 5 in real time, and the images of the detection surface of the part 7 to be detected and the images of the adjusting table 5 are synthesized in real time through an image processing algorithm to observe the position of the bright point. The heights of the four vertical rods 51 of the adjusting platform 5 are adjusted, so that the height and the inclination angle of the reflecting surface 52 of the adjusting platform 5 are controlled. When the height and the level of the adjusting table 5 are changed, the position of the bright spot is changed in real time. And observing the imaging of the camera 2, and when the bright spot moves to coincide with the dark spot, indicating that the plane where the detection surface of the part 7 to be detected is located is coincident with the plane where the reflection surface 52 of the adjusting table 5 is located, and then placing the calibration plate 6 above the adjusting table 5 for calibration.
As shown in fig. 15, step S4 includes the steps of:
s41: firstly, transforming the world coordinate system to a camera 2 coordinate system;
s42: then the coordinate system of the camera 2 is transformed to the coordinate system of the imaging plane;
s43: correcting a coordinate system of an imaging plane;
s44, transforming the corrected imaging plane coordinate system into an image coordinate system;
s45: and determining the total internal and external parameters of the camera 2 to finish calibration.
In S41, converting from the world coordinate system to the camera 2 coordinate system includes converting the point PwConversion to point PcSpecifically, the following formula is used:
Pc＝R·Pw+T
wherein R represents a rotation matrix, T represents a translation vector, R comprises α, and gamma are three rotation angles, the rotation matrix R (α, gamma) is represented as:
Figure BDA0002354237140000081
wherein T ═ Tx,ty,tz) Is a translation vector, α denotes the angle between the camera 2 coordinate system and the X-axis of the world coordinate system, β denotes the angle between the camera 2 coordinate system and the Y-axis of the world coordinate system, gamma denotes the angle between the camera 2 coordinate system and the Z-axis of the world coordinate system, T and R are extrinsic parameters of the camera 2 for describing the position of the camera 2 in the world coordinate system, which can be transformed to the camera 2 coordinate system by extrinsic parameters, PcThe coordinate values in the camera 2 coordinate system are represented as (x)c，yc，zc)。
In S42, the method comprisesIn the process of converting the coordinate system of the camera 2 into the coordinate system of the imaging plane, P needs to be convertedcConverting to an imaging plane coordinate system, wherein the conversion process depends on the following conversion relation:
Figure BDA0002354237140000082
where f denotes the focal length of the camera 2; u, v represent coordinate values of the point P in the imaging plane coordinate system.
Since the lens is distorted, the imaging plane coordinate values u, v obtained here have an error from the real imaging plane coordinate values. To convert the imaging plane obtained in S42 into a real imaging plane also needs to pass through S43: distortion correction is performed on the radial direction of the lens.
The formula of the lens radial distortion correction is as follows:
Figure BDA0002354237140000083
wherein the parameter k represents the distortion magnitude of the radial distortion;
Figure BDA0002354237140000084
the real imaging plane coordinate value of the corrected point P is represented.
In S44, coordinates of point P in the ideal imaging plane coordinate system are set
Figure BDA0002354237140000085
Conversion to an image coordinate system, comprising:
Figure BDA0002354237140000086
wherein C isx，CyIs a coordinate value of the perpendicular projection of the projection center on the imaging plane coordinate system, Sx，SyIs the distance between adjacent pixels of the image sensor in the horizontal and vertical directions; (f, k, S)x，Sy，Cx，Cy) Are camera 2 intrinsic parameters.
In S45, the process of determining the total parameters inside and outside the camera 2 is: the chessboard grid calibration board 6 is placed above the adjusting table 5, the camera 2 is used for shooting the current image of the calibration board 6, firstly, the image of the calibration board 6 obtained by the camera 2 is processed by an algorithm, and the angular point coordinate m of the chessboard grid is obtained from the image of the calibration board 6i,jM is saidi,jIn the image coordinate system. The distance d (c) between the projected coordinates Ti (Mi, c) is calculated by the following formula:
Figure BDA0002354237140000091
the parameters of the camera 2 are determined by jointly solving two or more images with the calibration plate 6 to find the minimum value of d (c). The total internal and external parameters c of the camera 2 are obtained as (f, k, S)x，Sy，Cx，Cy，tx，ty，tzα, γ), the calibration process of the camera 2 is completed.
The above description is only one specific example of the present invention and should not be construed as limiting the invention in any way. It will be apparent to persons skilled in the relevant art(s) that, having the benefit of this disclosure and its principles, various modifications and changes in form and detail can be made without departing from the principles and structures of the invention, which are, however, encompassed by the appended claims.

Claims (10)

1. A laser auxiliary calibration device used for measuring sizes of parts with different heights is characterized by comprising a box body, a camera, an adjusting frame, a point light source, an adjusting platform and a calibration plate; the camera, the adjusting frame and the adjusting platform are arranged in the box body; the point light source is arranged on the adjusting frame; the calibration plate is arranged on the adjusting table; the box body is a hexahedron with one open side, the open side is the side of the box body, and the other three sides of the box body are provided with adjusting frames; the top surface of box is provided with the camera, and the bottom surface is provided with the regulation platform.
2. The laser-assisted calibration device for the measurement of the dimensions of parts with different heights as claimed in claim 1, wherein the adjusting frame is arranged around the camera.
3. A laser-assisted calibration method based on the device of claim 1, characterized by comprising the following steps:
s1: marking the surface of the part to be detected by the point light source;
s2: recording the marked position by the camera, taking away the part to be measured, placing the adjusting table at the position to be measured, and marking the surface of the adjusting table by the point light source;
s3: changing the position and the posture of the adjusting table to enable the camera to record that the point light source mark position on the surface of the current adjusting table is superposed with the point light source mark position in S1;
s4: setting a calibration plate for calibration; and measuring the size of the original part by using the calibration data.
4. The laser-assisted marking method for the measurement of the dimensions of parts with different heights as claimed in claim 3, wherein the marking steps of S1 and S2 by using a point light source comprise:
s11: adjusting the adjusting frame to enable the point light source to emit light to the detection surface;
s12: the light emitted by the point light source is reflected by the detection surface and transmitted to the camera;
s13: the camera captures real-time images.
5. The laser-assisted calibration method for the measurement of the dimensions of parts with different heights as claimed in claim 4, wherein the step S4 comprises the following steps:
s41: transforming from the world coordinate system to the camera coordinate system;
s42: transforming the camera coordinate system to an imaging plane coordinate system, wherein the process of transforming the camera coordinate system to the imaging plane coordinate system comprises a calibration process;
s43: correcting a coordinate system of an imaging plane;
s44: transforming the imaging plane coordinate system after correction into an image coordinate system;
s45: and determining the total parameters inside and outside the camera to finish calibration.
6. The laser-assisted calibration method for measurement of dimensions of parts with different heights as claimed in claim 5, wherein in S41, the transformation from the world coordinate system to the camera coordinate system comprises the step of converting the point PwConversion to point PcSpecifically, the following formula is used:
Pc＝R·Pw+T
wherein R represents a rotation matrix, T represents a translation vector, R comprises α and gamma are three rotation angles, and the rotation matrix R (α and gamma) is represented as:
Figure FDA0002354237130000021
wherein α represents the angle between the camera coordinate system and the X-axis of the world coordinate system, β represents the angle between the camera coordinate system and the Y-axis of the world coordinate system, gamma represents the angle between the camera coordinate system and the Z-axis of the world coordinate system, and P represents the angle between the camera coordinate system and the Z-axis of the world coordinate systemcThe coordinate value in the camera coordinate system is represented as (x)c，yc，zc)；T＝(tx,ty,tz)。
7. The laser-assisted calibration method for the measurement of the dimensions of parts with different heights as claimed in claim 6, wherein in the step S42, P is required to be converted from the camera coordinate system to the imaging plane coordinate systemcConverting to an imaging plane coordinate system, wherein the conversion process depends on the following conversion relation:
Figure FDA0002354237130000022
wherein f represents the focal length of the camera; u, v represent coordinate values of the point P in the imaging plane coordinate system.
8. The laser-assisted calibration method for measurement of dimensions of parts with different heights according to claim 7, wherein in the step S43, the correcting the imaging plane coordinate system comprises:
Figure FDA0002354237130000023
wherein the parameter k represents the distortion magnitude of the radial distortion;
Figure FDA0002354237130000024
the real imaging plane coordinate value of the corrected point P is represented.
9. The laser-assisted calibration method for the measurement of the dimensions of parts with different heights as claimed in claim 8, wherein the coordinates of the point P in the ideal imaging plane coordinate system are obtained in S44
Figure FDA0002354237130000025
Conversion to an image coordinate system, comprising:
Figure FDA0002354237130000031
wherein C isx，CyIs a coordinate value of the perpendicular projection of the projection center on the imaging plane coordinate system, Sx，SyIs the distance between adjacent pixels of the image sensor in the horizontal and vertical directions.
10. The laser-assisted calibration method for the measurement of the dimensions of parts with different heights as claimed in claim 9, wherein in the step S45, the process of determining the total parameters inside and outside the camera is as follows: placing the chessboard grid calibration board above the adjusting table, shooting the current calibration board image by using a camera, and firstly obtaining the angular point coordinate m of the chessboard grid from the calibration board imagei,jM is saidi,jIn the image coordinate system;calculating the projection to obtain the coordinate T by the following formulai(MiDistance d (c) between:
Figure FDA0002354237130000032
determining the total internal and external parameters c ═ f, k, S of the camera by jointly solving two or more images with calibration plates and calculating the minimum value of d (c)x，Sy，Cx，Cy，tx，ty，tzα, γ), the calibration process of the camera is completed.
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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112330599A (en) * 2020-10-15 2021-02-05 浙江大学台州研究院 Size measurement scoring device, adjusting method and scoring method
CN114705120A (en) * 2020-10-15 2022-07-05 浙江大学台州研究院 Mask information-based size measurement method and scoring system
CN115170675A (en) * 2022-07-22 2022-10-11 信利光电股份有限公司 Method for expanding camera view

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110109906A1 (en) * 2000-03-21 2011-05-12 Liphardt Martin M Fast sample height, AOI and POI alignment in mapping ellipsometer or the like
JP2012255756A (en) * 2011-06-10 2012-12-27 Panasonic Corp Three-dimensional measuring method
CN104331896A (en) * 2014-11-21 2015-02-04 天津工业大学 System calibration method based on depth information
CN104913737A (en) * 2015-06-30 2015-09-16 长安大学 Component quality checking device based on line laser three-dimensional measurement and detection method of device
CN106885532A (en) * 2016-09-09 2017-06-23 武汉滨湖电子有限责任公司 A kind of detection method of high-precision rail geometric profile
CN108120719A (en) * 2017-12-11 2018-06-05 苏州大学 A kind of cone surface finish detection method and device

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110109906A1 (en) * 2000-03-21 2011-05-12 Liphardt Martin M Fast sample height, AOI and POI alignment in mapping ellipsometer or the like
JP2012255756A (en) * 2011-06-10 2012-12-27 Panasonic Corp Three-dimensional measuring method
CN104331896A (en) * 2014-11-21 2015-02-04 天津工业大学 System calibration method based on depth information
CN104913737A (en) * 2015-06-30 2015-09-16 长安大学 Component quality checking device based on line laser three-dimensional measurement and detection method of device
CN106885532A (en) * 2016-09-09 2017-06-23 武汉滨湖电子有限责任公司 A kind of detection method of high-precision rail geometric profile
CN108120719A (en) * 2017-12-11 2018-06-05 苏州大学 A kind of cone surface finish detection method and device

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
宋文爱;马彦珍;: "基于虚拟棋盘的校准精度分析", 科学技术与工程 *
燕必希;董明利;宗敏;: "多高度小零件视觉测量方法设计", 机械设计与制造 *

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112330599A (en) * 2020-10-15 2021-02-05 浙江大学台州研究院 Size measurement scoring device, adjusting method and scoring method
CN114705120A (en) * 2020-10-15 2022-07-05 浙江大学台州研究院 Mask information-based size measurement method and scoring system
CN114705120B (en) * 2020-10-15 2023-06-23 浙江大学台州研究院 Dimension measurement method and scoring system based on mask information
CN112330599B (en) * 2020-10-15 2024-02-20 浙江大学台州研究院 Dimension measurement scoring device, adjustment method and scoring method
CN115170675A (en) * 2022-07-22 2022-10-11 信利光电股份有限公司 Method for expanding camera view
CN115170675B (en) * 2022-07-22 2023-10-03 信利光电股份有限公司 Method for expanding camera vision

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