CN115666125A - Method for detecting and compensating positioning error of XY platform of chip mounter based on machine vision - Google Patents
Method for detecting and compensating positioning error of XY platform of chip mounter based on machine vision Download PDFInfo
- Publication number
- CN115666125A CN115666125A CN202211681882.3A CN202211681882A CN115666125A CN 115666125 A CN115666125 A CN 115666125A CN 202211681882 A CN202211681882 A CN 202211681882A CN 115666125 A CN115666125 A CN 115666125A
- Authority
- CN
- China
- Prior art keywords
- point
- coordinate system
- calculating
- error
- positioning error
- 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.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims abstract description 47
- 238000001514 detection method Methods 0.000 claims abstract description 45
- 238000004364 calculation method Methods 0.000 claims description 8
- 238000012545 processing Methods 0.000 claims description 6
- 239000003550 marker Substances 0.000 claims description 4
- 239000011521 glass Substances 0.000 description 25
- 230000033001 locomotion Effects 0.000 description 13
- 238000012937 correction Methods 0.000 description 9
- 238000010586 diagram Methods 0.000 description 9
- 238000013178 mathematical model Methods 0.000 description 8
- 238000012360 testing method Methods 0.000 description 5
- 238000004458 analytical method Methods 0.000 description 4
- 238000005259 measurement Methods 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012546 transfer Methods 0.000 description 2
- 230000000007 visual effect Effects 0.000 description 2
- NAWXUBYGYWOOIX-SFHVURJKSA-N (2s)-2-[[4-[2-(2,4-diaminoquinazolin-6-yl)ethyl]benzoyl]amino]-4-methylidenepentanedioic acid Chemical compound C1=CC2=NC(N)=NC(N)=C2C=C1CCC1=CC=C(C(=O)N[C@@H](CC(=C)C(O)=O)C(O)=O)C=C1 NAWXUBYGYWOOIX-SFHVURJKSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000026058 directional locomotion Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 238000010295 mobile communication Methods 0.000 description 1
- 238000003672 processing method Methods 0.000 description 1
- 230000011218 segmentation Effects 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
Images
Classifications
-
- 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
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P90/00—Enabling technologies with a potential contribution to greenhouse gas [GHG] emissions mitigation
- Y02P90/30—Computing systems specially adapted for manufacturing
Landscapes
- Supply And Installment Of Electrical Components (AREA)
Abstract
The invention relates to the technical field of chip mounter control, and particularly discloses a chip mounter XY platform positioning error detection and compensation method based on machine vision, wherein the detection method comprises the following steps: calculating theoretical position coordinates of each marking point in the XY platform based on a mechanical coordinate system; respectively moving a reference mark camera to each mark point, and obtaining the corresponding actual position coordinates of each mark point based on a mechanical coordinate system through the reference mark camera; and calculating the positioning error of each marking point according to the theoretical position coordinates and the actual position coordinates. According to the scheme, the error detection model is established by analyzing the error source, the size and the distribution rule of the positioning error are effectively summarized and accurately calculated, on the basis, the error detection flow is designed, the efficient error detection scheme is realized, the positioning accuracy is greatly improved, and the time and the cost of error detection are greatly reduced.
Description
Technical Field
The invention relates to the technical field of chip mounter control, in particular to a method for detecting and compensating an XY platform positioning error of a chip mounter based on machine vision.
Background
The conventional chip mounter includes a mounting head module, an XY axis motion module, a transfer rail module, and the like, as shown in fig. 1, in the component mounting process, the mounting head is moved to a target position by an X axis 1 and a Y axis 2, a reference point motion of a PCB circuit board on a transfer rail 5 is recognized by a reference mark camera 3 component, and component suction, component mounting, and the like are performed by a plurality of suction nozzle rods 4 on the mounting head. Therefore, the X, Y axis moving and positioning accuracy is an important component of the component mounting accuracy, and directly influences the production quality.
X, Y shaft positioning error is mainly due to control error, which is usually caused by the inaccuracy of the control system, and geometric error, which is mainly caused by the manufacturing and assembling accuracy of the parts, and due to the shape and position error of the machine parts themselves and their assembling process, these shape and position errors are reflected on the moving parts when X, Y shaft moving parts move or rotate, thereby generating geometric error. The control error can be achieved by adopting an advanced control system to achieve the micron-scale precision, so that the geometric error is a main error factor influencing the X, Y axis positioning precision.
The commonly used XY moving platform geometric error correction method measures X, Y axis errors one by means of a precision testing instrument, such as a laser interferometer, a laser range finder or an electronic level meter, and has the following defects for actual field error correction: firstly, a high-precision instrument needs to be operated skillfully, and the requirement of a correction process on the knowledge plane of an engineer is high; secondly, considering a production line consisting of a plurality of chip mounters, the correction environment space is compact, a platform based on a high-precision test instrument is difficult to effectively build, and the correction method is complex to realize; thirdly, the high-precision test instrument usually has the characteristic of long detection time, and the randomness of the axis error of the chip mounter X, Y may be increased due to the overlong correction data acquisition time interval, and even the consistency and the correlation between data are affected, so that the effective degree of the data is reduced.
In addition, the conventional method for compensating the shaft positioning error of the chip mounter X, Y only comprises two parts of detection and compensation, the error compensation is realized only by modifying a program or a code, and error modeling is omitted or lacked. The effective error compensation needs to establish an error model, and on the basis, error detection and compensation can be effectively carried out, and error modeling and detection are closely related and interdependent, so that error modeling in the X, Y axis positioning error correction of the chip mounter is an indispensable component.
Disclosure of Invention
The invention aims to solve the problems, the method provides a method for detecting and compensating the positioning error of the XY platform of the chip mounter based on machine vision, and aims at the error source of the XY motion platform of the chip mounter, an error model is established, the method for detecting the positioning error is designed, and the error compensation model is established, so that the positioning accuracy of the XY axis of the chip mounter is greatly improved.
In order to achieve the above object, a first aspect of the present invention provides a method for detecting a positioning error of an XY stage of a chip mounter based on machine vision, including the following steps:
calculating theoretical position coordinates of each marking point in XY platform based on mechanical coordinate systemPt(xt mn , yt mn ) The formula is as follows:
，
wherein each marking point is calibrated by a jig and distributed on the jig in a rectangular array, and deltaθRepresents the inclination angle of the jig relative to the XY stage,
、
respectively representmGo to the firstnThe horizontal and vertical coordinates of the row of mark points under the jig coordinate system,
、
respectively represent the horizontal and vertical coordinates of the reference point under the coordinate system based on the jig,xr 11 、yr 11 respectively representing the horizontal and vertical coordinates of the actual position of the reference point I in the mechanical coordinate system;
respectively moving a reference mark camera to each mark point, and obtaining the corresponding actual position coordinate Pr (based on a mechanical coordinate system) of each mark point by the reference mark cameraxr mn , yr mn )；
Calculating the positioning error (delta) of each marking pointx mn ，Δy mn ) The formula is as followsx mn =xt mn - xr mn ，Δy mn =yt mn - yr mn 。
Preferably, the inclination angle delta of the jig relative to the XY platformθThe calculation formula is as follows:
wherein,θ T as a theoretical angle of the jig,θ R in order to obtain the actual angle of the jig,x MN 、y MN respectively represents the horizontal and vertical coordinates, delta, of the reference point II based on the mechanical coordinate systemx MN 、Δy MN Respectively, the positional deviations, delta, of the reference points twox 11 、Δy 11 Respectively, the positional deviations of the reference points one,x 11 、y 11 respectively represent the horizontal and vertical coordinates of the reference point I under the mechanical coordinate system.
Preferably, the positional deviation is obtained by the fiducial mark camera using a recognition mark circle method.
Preferably, the jig is of a plate-shaped structure and is arranged on the XY platform; the reference mark camera is fixedly arranged on the mounting head.
Preferably, the method further comprises storing the position information of each of the marker points and the positioning error thereofxr mn, yr mn , Δx mn , Δy mn ]。
The invention provides a chip mounter XY platform positioning error detection system based on machine vision, which comprises
The image acquisition module is used for shooting a mark point image when the mounting head moves to the position of each mark point, and comprises a reference mark camera and a jig, wherein the reference mark camera is arranged on the mounting head, the jig is arranged on the XY platform, and each mark point is distributed on the jig in a rectangular array;
the image processing module is used for identifying the center position of the mark points on the image and calculating the position deviation of each mark point through the deviation between the center of the mark point and the center position of the image;
the operation control module is used for driving the XY axes to move the reference mark camera to the position of each mark point;
and the calculation module is used for executing the steps of the detection method according to the position information of each mark point.
The invention provides a chip mounter XY platform positioning error compensation method based on machine vision, which comprises the following steps:
calculating the inclination angle delta of the circuit board positioned in the XY platform relative to the XY platformθ R ；
Calculating the positioning error according to the detection method, and calculating the power by using an interpolation algorithmDatum point on circuit boardJ 0 Positioning error of (1), is
,
) Then, there are:
in the formulaf x 、f y X, Y axis positioning error compensation values obtained by interpolation algorithm, respectively (xr J0 ，yr J0 ) As a reference pointJ 0 Based on the actual position coordinates in the mechanical coordinate system;
according to the theoretical position coordinates of the mounting point P based on the mechanical coordinate system (xt P , yt P ) Calculating the corresponding actual position coordinates (xr P , yr P ) Then, there are:
in the formulaxt J0 、yt J0 Are respectively reference pointsJ 0 The horizontal and vertical coordinates of the theoretical position under a mechanical coordinate system;
calculating the compensation value of the positioning error of the mounting point P, and (C)
,
) Then, there are:
to the mountingThe point P is compensated, and the compensated mounting position coordinate is recorded as (
,
) Then, there are:
。
preferably, the inclination angle Δ of the circuit board with respect to the XY-stageθ R The calculation process of (2) is as follows:
determining two reference points on a circuit board located within an XY stageJ 0 AndJ 1 two reference pointsJ 0 AndJ 1 respectively recording the theoretical position coordinates based on a mechanical coordinate systemJ t0 (xt J0 , yt J0 ) AndJ t1 (xt J1 , yt J1 )；
identifying two reference points using a fiducial mark cameraJ 0 AndJ 1 respectively, are denoted as ΔJ 0 (Δx J0 ，Δy J0 ) And ΔJ 1 (Δx J1 ，Δy J1 ) (ii) a Calculating the inclination angle delta of the circuit board relative to the XY platformθ R The formula is as follows:
xr J 0 =xt J0 + Δx J0 ，yr J0 =yt J0 + Δy J0 ，xr J1 =xt J1 + Δx J1 ，yr J1 =yt J1 + Δy J1 ，
wherein,xr J1 ，yr J1 are respectively reference pointsJ 1 Based on the horizontal and vertical coordinates of the actual position in the mechanical coordinate system.
Preferably, the interpolation algorithm is implemented according to nearest neighbor interpolation, linear interpolation or bilinear interpolation.
The fourth aspect of the invention provides a chip mounter XY platform positioning error compensation system based on machine vision, comprising: a circuit board inclination angle module for calculating the inclination angle delta of the circuit board positioned in the XY platform relative to the XY platformθ R ；
A datum point positioning error module for calculating datum points on the circuit board by using an interpolation algorithmJ 0 Positioning error of (1), is
,
) Then, there are:
in the formulaf x 、f y X, Y axis positioning error compensation values obtained by interpolation algorithm, respectively (xr J0 ，yr J0 ) As a reference pointJ 0 Based on the actual position coordinates in the mechanical coordinate system;
an actual position coordinate module used for obtaining theoretical position coordinates (based on the mechanical coordinate system) of the mounting point Pxt P , yt P ) Calculating the corresponding actual position coordinates (xr P , yr P ) Then, there are:
in the formula (A), (B)xt J0 ，yt J0 ) As a reference pointJ 0 Theoretical position coordinates under a mechanical coordinate system;
a mounting point positioning error module for calculating the positioning error compensation value of the mounting point P, and (b)
,
) Then, there are:
a compensation module for compensating the mounting point P, wherein the compensated mounting position coordinate is (
,
) Then, there are:
。
through the technical scheme, error sources are analyzed, the error detection model is established, the size and the distribution rule of the positioning errors are effectively summarized and accurately calculated, on the basis, an error detection flow is designed, an efficient error detection scheme is realized, the positioning accuracy is greatly improved, and the time and the cost of error detection are greatly reduced.
Drawings
Fig. 1 is a schematic structural diagram of a conventional chip mounter;
FIG. 2 is a schematic view of an XY stage positioning error compensation glass plate jig;
FIG. 3 is a schematic view of the calibration positions of glass plate jigs under two coordinate systems;
FIG. 4 is a schematic diagram of a machine vision-based integrated error for identifying marking points on a jig;
FIG. 5 is a schematic view of the error correction of the inclination angle of the glass plate jig;
FIG. 6 is a diagram illustrating an example of an XY motion trajectory for error detection;
FIG. 7 is a schematic diagram showing the error comparison before and after the XY stage compensation, wherein FIG. 7 (a) shows the result before the compensation and FIG. 7 (b) shows the result after the compensation;
in the figure: 1. an X axis; 2. a Y axis; 3. a fiducial mark camera; 4. a nozzle rod; 5. and (4) conveying the track.
Detailed Description
The following detailed description of embodiments of the invention refers to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating embodiments of the invention, are given by way of illustration and explanation only, not limitation.
In order to meet the requirement of high-precision positioning precision of an XY platform of a chip mounter, firstly, analyzing a positioning error source of an XY axis, wherein the positioning error mainly comes from an XY axis geometric error, and the analysis process of the XY axis geometric error source is as follows:
when the mounting heads move respectively alongX、YWhen the shaft is fed, neglectZGeometric error of direction, axialx、yActual position point after directional movement: (x real , y real ) And ideal position points (x theory , y theory ) In thatXYError delta of platform in two directionsx geo 、Δy geo Namely:
in the formula,E x (x, y)、E y (x, y) For attaching the head respectively alongX、YAfter the shaft movesx、yAn error value generated in the direction;E x (x, y) Error value is edgeXThe shaft moves atxThe synthesis of errors generated in the direction comprises positioning errors and straightness errorsDifference, corner error and perpendicularity error. In the same way, the method for preparing the composite material,E y (x, y) Is a rimYThe shaft moves atyIntegration of the errors generated in the direction. The detection and compensation method of the invention is aimed atX、YGeometric errors due to shaft motion.
X、YThe measurement of the geometric error of the axis motion adopts a jig to calibrate the XY platform, the jig is preferably a precise glass plate, the precise glass plate is marked by adopting a circle of a rectangular array as a marking point, and the plane comprehensive positioning correction is carried out, as shown in FIG. 2, FIG. 2 is a schematic diagram of the XY platform positioning error compensation glass plate jig. Suppose thatX g -Y g Is used as a coordinate system of the jig,X-Ythe glass plate can be regarded as an ideal rectangular plane array in a mechanical coordinate system (namely a coordinate system constructed based on an XY platform), and the row spacing of the marking points isD x At a row pitch ofD y In aX g -Y g Under the coordinate system of the tool, the firstmGo to,nThe coordinate positions of the measurement point units are (
，
）：
As shown in FIG. 3, FIG. 3 is a diagram of two coordinate systems (i.e., two coordinate systems)X g -Y g Coordinate system of the tool andX-Ymechanical coordinate system) glass plate jig correcting position schematic diagram, and the glass plate is placed onXOYIn plane, the glass sheets have an inclination on the conveying track, i.e.X g -Y g Coordinate system of the tool andX-Ythere is a slight angle error in the mechanical coordinate system.
Suppose thatF 11 For reference points (see the notation in figure 2),by passingX、YIncrement of shaft movementD x Multiple and incrementD y When the multiple reaches a certain mark point position, the position image position deviation is obtained and recorded according to an image circle identification method, and as shown in fig. 4, the deviation delta exists between the actual measurement position and the theoretical positionxAnd ΔyOffset ΔxAnd ΔyCan be described as the following relation:
in the formula,. DELTA.x jig Caused by inclination of glass plate jigXError in direction, Δx geo Is composed ofXGeometric error of the axis, Δx rec Generated for machine vision recognition of circlesXA directional error. In the same way, Δ y jig Caused by inclination of glass sheetsYError in direction, Δy geo Is composed ofYGeometric error of axis, Δ y rec Generated for recognition of circlesYA directional error.
Further, the image circle identification method is to calculate the pixel position of the center of the marked circle by using an image processing method, and adopt a routine least square fitting circle process of threshold segmentation, binarization processing and edge extraction points, so that the calculated center of the circle can obtain sub-pixel precision which is about 0.1 pixel (pixel represents pixel). Preferably, the fiducial mark camera used in the image circle recognition method of the present invention employs a magnification lens, and the pixel resolution in the image is about 5 μm/pixel, so that the machine vision can achieve the following accuracy: 0.1 pixel 5 μm/pixel = 0.5 μm, the accuracy requirement of the detection is well met.
Considering that the error generated by the identification of the marker circle image is small and not more than 1 μm, Δ may be ignored for the convenience of analysisx rec And Δ y rec Error, i.e. Δx rec = 0 and Δ y rec And = 0. Therefore, equation (3) can be simplified as:
as can be seen from the equation (4), in order to obtain the measurement pointXYGeometric error Δ of axisx geo 、Δy geo The tilt error delta caused by the placement of the glass plate needs to be eliminatedx jig 、Δy jig 。
Secondly, constructing an XY axis geometric error detection mathematical model based on XY axis geometric error source analysis, wherein the basic principle is as follows: the reference mark camera on the mounting head can be seen as precision equipment, a machine vision based on the reference mark camera is adopted to provide a precise reference datum, the reference mark camera is further used as a measuring tool of a mechanical motion positioning error, the positioning accuracy is determined by the machine vision positioning accuracy and the mechanical motion accuracy together, and on the basis, an XY axis geometric error detection mathematical model is constructed.
The specific process of modeling the mathematical model for detecting the geometric errors of the XY axes comprises the following steps:
in thatX g -Y g Marking the reference point by exemplarily taking the marking point of the 1 st column and the 1 st line as the reference point under the jig coordinate systemF 11 (see FIG. 2 notation) has a coordinate position of (
,
) Datum point ofF MN (see FIG. 2 notation) has a coordinate position of (
, 
) = (
+m*D x ,
+n*D y ) (ii) a In thatX-YRecording reference points under a mechanical coordinate systemF 11 The corresponding theoretical position coordinate is
(x 11 , y 11 ) Then reference pointF MN The corresponding theoretical position coordinate is
(x MN , y MN )= (x 11 +m*D x , y 11 +n* D y )。
In thatX-YMoving the reference mark camera on the mounting head to a position under a mechanical coordinate system
(x 11 , y 11 ) Position and image taking, and circle identification to obtain reference point
Deviation, let us note deviation as (Δ)x 11 , Δy 11 ) Datum point of
The actual position coordinates of (A) arexr 11 , yr 11 ) = (x 11 +Δx 11 , y 11 +Δy 11 ). Then theXMovement of the shaftm*D x Distance andYmovement of the shaftn*D y Distance to the reference point
Similarly, the recognition deviation is (Δ)x MN , Δy MN ) Then reference point
The actual position coordinates of (A) arexr MN , yr MN ) = (x MN +Δx MN , y MN +Δy MN ) As shown in fig. 5. The inclined angle delta of the glass plateθThe calculation formula is as follows:
Δθ =θ R - θ T （5）
in the formula (5)θ T Is a theoretical angle of the glass plate,θ R the relation is shown as the actual angle of the glass plate:
the elongation of the default jig is 1, and when the glass plate is adopted as the jig, the inclination of the glass plate is consideredX-YMechanical coordinate system, firstmLine ofnThe theoretical coordinate of the column mark point after eliminating the inclination error is recorded asPt(xt mn , yt mn ) Then, there are:
（8）
wherein,
、
respectively representmGo to the firstnAnd the horizontal and vertical coordinates of the row of mark points under the jig coordinate system.
Further eliminating the tilt error of the glass sheet, i.e. applying a reference according to equation (8)The marking camera moves to the marking point positionPt(xt mn , yt mn ) Similarly, the circle center recognition offset is obtained according to the circle image recognition processing and is marked as (delta)x mn , Δy mn ) Of 1 atmLine for mobile communication terminalnThe actual position coordinates of the column mark points arePr(xr mn , yr mn ) Then, there are:
according to the formulae (4) and (9), the first one can be obtainedmLine ofnThe geometric error value of the column mark points is as follows:
thus, according to the formula (10), aX-YAnd obtaining the positioning error of each marking point by the geometric error data of each marking point under the two-dimensional plane.
Based on the positioning error source analysis and the constructed mathematical model, the invention provides a chip mounter XY platform positioning error detection method based on machine vision, which comprises the following steps:
s1, calculating theoretical position coordinates of each marking point in the XY platform based on a mechanical coordinate systemPt(xt mn , yt mn ) The formula is as follows:
wherein each marking point is calibrated by a jig and distributed on the jig in a rectangular array, and deltaθRepresents the inclination angle of the jig relative to the XY stage,
、
respectively representmGo to the firstnThe horizontal and vertical coordinates of the row of mark points under the jig coordinate system,
、
respectively represent reference pointsF 11 In the horizontal and vertical coordinates of the jig coordinate system,xr 11 、yr 11 respectively represent reference pointsF 11 And the horizontal and vertical coordinates of the theoretical position under a mechanical coordinate system.
Before the step S1 is executed, a process of calculating the tilt angle of the glass plate needs to be executed, which specifically includes the following steps:
s11, firstly adjusting the width of the conveying track, placing the glass plate on the conveying track, and then clamping and fixing the glass plate by using a substrate clamp;
s12, manually moving the reference mark camera toF 11 Within the visual field range of the mark point, ensure as much as possibleF 11 The marked circle is obtained at the visual center of the camera by identifying the marked circleF 11 Deviation of marked point (delta)x11, Δy11)；
S13, moving X, Y shaft, and moving the reference mark toF MN The position of the mark point is obtained by using a method of identifying a mark circleF MN Mark point offset, noted as (Δ)x MN, ΔyMN)；
S14, calculating according to a formula (7) to obtain a jig inclination angle deltaθ。
S2, moving the reference mark camera to each mark point respectively, and obtaining the corresponding actual position coordinates of each mark point based on a mechanical coordinate system through the reference mark cameraPr(xr mn , yr mn )；
After the process of calculating the inclination angle of the glass plate is completed, the fiducial mark camera is sequentially moved to each mark point, for example, the position and the motion track of each mark point are as shown in fig. 6, and the mark points are sequentially photographed from m =1 m, n =1As indicated by the arrow: 1->2->3->4, acquiring the corresponding actual position coordinates of each marking point based on the mechanical coordinate system asPr(xr mn , yr mn )。
S3, calculating the positioning error (delta) of each mark pointx mn , Δy mn ) The formula is as follows:
Δx mn =xt mn - xr mn ，
Δy mn =yt mn - yr mn 。
s4, storing the position information of each marking point and the positioning error thereofxr mn , yr mn , Δx mn , Δy mn ]And storing the data into a data file in a table form to provide a data set for subsequent compensation implementation.
Based on the same inventive concept, a second aspect of the present invention provides a system for detecting a positioning error of an XY stage of a chip mounter based on machine vision, comprising:
the image acquisition module is used for shooting the mark point images when the mounting head moves to the position of each mark point, and comprises a reference mark camera, a jig and an image acquisition card, wherein the reference mark camera is arranged on the mounting head, the jig is arranged on the XY platform, and each mark point is distributed on the jig in a rectangular array; the image acquisition card transmits the image information to an upper computer for image identification processing;
the image processing module is used for identifying the center position of the mark points on the image and calculating the position deviation of each mark point through the deviation between the center of the mark point and the center position of the image;
the operation control module is used for driving the XY axes to move the reference mark camera to the position of each mark point; an upper computer sends an XY axis motion control instruction to an XY axis operation control system, and a servo motor in the operation control system drives a ball screw to realize XY axis positioning; the motion control error in the operation control system is the steady-state error of the control system, and the motion control error in the scheme of the invention is less than 4 mu m, so the system error generated by motion control is ignored;
and the computing module is used for executing the steps of the chip mounter XY platform positioning error detection method based on the machine vision according to the position information of each mark point. According to the scheme, the error detection model is established by analyzing the error source, the size and the distribution rule of the positioning error are effectively summarized and accurately calculated, on the basis, the error detection flow is designed, the efficient error detection scheme is realized, the positioning accuracy is greatly improved, and the time and the cost of error detection are greatly reduced.
The third aspect of the invention provides a chip mounter XY platform positioning error compensation method based on machine vision, which comprises the following steps:
(1) Calculating the inclination angle delta of the circuit board positioned in the XY platform relative to the XY platformθ R ；
Illustratively, taking a PCB as an example, a mathematical model for error compensation of the PCB is established to realize error compensation. First calculate the tilt angle Δθ R : suppose that a PCB has 2 reference points respectively marked asJ 0 AndJ 1 in aX-YThe theoretical position coordinate data of the mechanical coordinate system are recorded asJ t0 (xt J0 , yt J0 ) AndJ t1 (xt J1 , yt J1 ) Recognizing the deviation of the reference mark as Δ using the reference mark camera imageJ 0 (Δx J0 ，Δy J0 ) And ΔJ 1 (Δx J1 ，Δy J1 ) Therefore, it isJ 0 AndJ 1 in thatX-YThe actual position coordinate of the mechanical coordinate system isJ 0r (xr J0 , yr J0 ) = (xt J0 +Δx J0 , yt J0 + Δy J0 ) AndJ 1r (xr J1 , yr J1 ) = (xt J1 + Δx J1 , yt J1 + Δy J1 )。
according to the formula (5), the inclination angle of the PCB is as follows:
(2) Calculating the positioning error according to the detection method, and calculating the reference point on the circuit board by using an interpolation algorithmJ 0 The positioning error of (2);
calculating a reference point based on an interpolation algorithm and stored positioning error compensation dataJ 0 The geometric errors of (1), (b), (c)
,
) As a reference pointJ 0 Identifying the geometric error values of the XY axes includes:
in the formulaf x 、f y And X, Y axis geometric error compensation values obtained by the interpolation algorithm respectively.
(3) According to the theoretical position coordinate of the mounting point P based on the mechanical coordinate system, the method is described as (xt P , yt P ) Calculating the corresponding actual position coordinates (xr P , yr P ) (ii) a Calculating the actual mounting position of the mounting point P according to the inclination angle of the PCB, and then:
(4) Calculating the compensation value of the positioning error of the mounting point P, and (C)
,
)；
Further calculating a mounting point calculation geometric error compensation value according to the equation (13) ((
,
) Compensating error values for the geometric errors of the XY stage, then:
(5) Further to the mounting pointsPCompensating, and recording the compensated mounting coordinate position as (A)
,
) Then, there are:
thus, inX-YUnder the mechanical coordinate system, after error compensation, the points are pastedPThe final mounting position of (A) is
,
)。
Further, the interpolation algorithm can obtain XY axis geometric error compensation data of the target position according to conventional algorithms such as nearest neighbor interpolation, linear interpolation or bilinear interpolation.
Based on the same inventive concept, a fourth aspect of the present invention provides a system for compensating a positioning error of an XY stage of a chip mounter based on machine vision, comprising:
a PCB inclination angle module for calculating the inclination angle delta of the circuit board in the XY platform relative to the XY platformθ R ；
A datum point positioning error module for calculating datum points on the circuit board by using an interpolation algorithmJ 0 Positioning error of (1), is
,
) Then, there are:
in the formulaf x 、f y Positioning error compensation values obtained for the interpolation algorithm, respectively (a)xr J0 ，yr J0 ) Is a reference point J 0 Based on the actual position coordinates in the mechanical coordinate system;
an actual position coordinate module for mounting points according to the mounting pointsPBased on the theoretical position coordinates in the mechanical coordinate system (xt P , yt P ) Calculating the corresponding actual position coordinates (xr P , yr P ) Then, there are:
a mounting point positioning error module for calculating the mounting pointPThe positioning error compensation value of (1), (b)
,
) Then, there are:
a compensation module for aligning the mounting pointsPCompensating, and recording the compensated mounting position coordinates as (A), (B)
,
) Then, there are:
according to the technical scheme, a mathematical model for XY-axis geometric error detection based on machine vision is constructed according to XY-axis geometric error sources, then an automatic error detection process is designed through the error detection model, finally, a PCB error compensation mathematical model is established according to error data, and a new error which is equal to the original error in magnitude and opposite in direction is utilized to offset the XY-axis positioning error, so that the XY-axis positioning accuracy of the chip mounter is greatly improved, and the purpose of improving the equipment accuracy is achieved.
Therefore, the scheme provides a compensation method for the positioning error of the axis X, Y of the chip mounter based on machine vision, an error detection model is established by analyzing error sources, the size and the distribution rule of geometric errors are effectively summarized and accurately calculated, on the basis, an error detection flow is designed, an efficient error detection scheme is realized, and the time and the cost of error detection are greatly reduced. Furthermore, a compensation means of software technology is provided, a new error is artificially generated to offset the original error which is a problem at present, the effectiveness of the method is verified, the error compensation effect of the X, Y shaft of the chip mounter is obvious, the positioning precision is greatly improved, and the method for effectively and accurately improving the positioning precision of the X, Y of the chip mounter is realizedThe method achieves the purpose of improving the precision of the equipment. In order to verify the effectiveness of the technical scheme of the invention, an error compensation comparison test is performed, the detection conditions before and after compensation and the installation modes of the external members such as the glass plate jig and the like are unchanged, and corresponding error compensation data are obtained, as shown in fig. 7, fig. 7 is an error comparison schematic diagram before and after XY platform compensation, wherein Δ isxWith the abscissa representing actual and theoretical positionsXDeviation in direction, analogously, Δy Of actual and theoretical positions of ordinateYThe direction deviation is marked as the schematic diagram of FIG. 4.
As can be seen from the figure 7 of the drawings,Xthe directional position error is reduced from 30 μm before compensation as shown in fig. 7 (a) to 5 μm after compensation as shown in fig. 7 (b),Ythe directional error decreases from 20 um before compensation to 5 um after compensation,X、Ythe positioning precision is improved well, the reduction amplitude of partial errors exceeds 20 mu m, the partial precision is improved by over 50 percent, and the comparison tests show that the error compensation effect is obvious after the technical scheme provided by the invention is used for compensation,X、Ythe positioning precision is greatly improved.
In conclusion, the technology establishes an error detection model by analyzing error sources, and effectively induces and accurately calculates the size and the distribution rule of the geometric errors. By means of the high-precision glass plate jig, an efficient error detection scheme is achieved, error detection is an automatic process, time and cost of error detection are greatly reduced, a PCB error compensation mathematical model is built by adopting a compensation means of a software technology, a new error is generated to offset an original error which is a problem at present, validity of the method is verified, positioning precision after compensation is obviously improved, the method is suitable for a X, Y shaft high-precision positioning system of a chip mounter, and the purpose of improving equipment precision is achieved.
The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, numerous simple modifications can be made to the technical solution of the invention, including combinations of the individual specific technical features in any suitable way. The invention is not described in detail in order to avoid unnecessary repetition. Such simple modifications and combinations should be considered within the scope of the present disclosure as well.
Claims (10)
1. A chip mounter XY platform positioning error detection method based on machine vision is characterized by comprising the following steps:
calculating theoretical position coordinates of each marking point in XY platform based on mechanical coordinate systemPt(xt mn , yt mn ) The formula is as follows:
，
wherein each marking point is calibrated by a jig and distributed on the jig in a rectangular array, and deltaθRepresents the inclination angle of the jig relative to the XY stage,
、
respectively representmGo to the firstnThe horizontal and vertical coordinates of the row of mark points under the jig coordinate system,
、
respectively represent the horizontal and vertical coordinates of the reference point under the coordinate system based on the jig,xr 11 、yr 11 respectively representing the horizontal and vertical coordinates of the actual position of the reference point I under the mechanical coordinate system;
respectively moving a reference mark camera to each mark point, and obtaining the corresponding actual position coordinate Pr (based on a mechanical coordinate system) of each mark point by the reference mark cameraxr mn , yr mn )；
Calculating each markError (delta) in positioning of pointsx mn ，Δy mn ) The formula is as followsx mn =xt mn - xr mn ，Δy mn =yt mn - yr mn 。
2. The method of claim 1, wherein the jig has an inclination angle Δ with respect to the XY stageθThe calculation formula is as follows:
wherein,θ T as a theoretical angle of the jig,θ R in order to obtain the actual angle of the jig,x MN 、y MN respectively represents the horizontal and vertical coordinates, delta, of the reference point II based on the mechanical coordinate systemx MN 、Δy MN Respectively, the positional deviations, delta, of the reference points twox 11 、Δy 11 Respectively, the positional deviations of the reference points one,x 11 、y 11 respectively represent the horizontal and vertical coordinates of the reference point I under the mechanical coordinate system.
3. The detection method according to claim 2, wherein the positional deviation is obtained by the fiducial mark camera using an identification mark circle method.
4. The detecting method according to any one of claims 1 to 3, wherein the jig has a plate-like structure and is provided on the XY stage; the reference mark camera is fixedly arranged on the mounting head.
5. The detection method according to claim 4, further comprising storing position information of each marker point and a positioning error thereofxr mn , yr mn , Δx mn , Δy mn ]。
6. A chip mounter XY platform positioning error detection system based on machine vision is characterized by comprising
The image acquisition module is used for shooting a mark point image when the mounting head moves to the position of each mark point, and comprises a reference mark camera and a jig, wherein the reference mark camera is arranged on the mounting head, the jig is arranged on the XY platform, and each mark point is distributed on the jig in a rectangular array;
the image processing module is used for identifying the center position of the mark points on the image and calculating the position deviation of each mark point through the deviation between the center of the mark point and the center position of the image;
the operation control module is used for driving the XY axes to move the reference mark camera to the position of each mark point;
a calculation module for performing the steps of the method according to any of claims 1-3 based on the position information of each marker point.
7. A chip mounter XY platform positioning error compensation method based on machine vision is characterized by comprising the following steps:
calculating the inclination angle delta of the circuit board positioned in the XY platform relative to the XY platformθ R ；
Calculating the positioning error according to the method of any of claims 1-5, calculating the reference point on the circuit board using an interpolation algorithmJ 0 Positioning error of (a), (b)
,
) Then, there are:
in the formulaf x 、f y X, Y axis positioning error compensation values obtained by interpolation algorithm, respectively (xr J0 ，yr J0 ) As a reference pointJ 0 Based on the actual position coordinates in the mechanical coordinate system;
according to the theoretical position coordinates of the mounting point P based on the mechanical coordinate system (xt P , yt P ) Calculating the corresponding actual position coordinates (xr P , yr P ) Then, there are:
in the formulaxt J0 、yt J0 Are respectively reference pointsJ 0 The horizontal and vertical coordinates of the theoretical position under a mechanical coordinate system;
calculating a positioning error compensation value of the mounting point P, and (c)
,
) Then, there are:
compensating the mounting point P, after compensationThe mounting position coordinates of (a) are
,
) Then, there are:
。
8. compensation method according to claim 7, wherein the inclination angle Δ of the circuit board with respect to the XY-stageθ R The calculation process of (2) is as follows:
determining two reference points on a circuit board located within an XY stageJ 0 AndJ 1 two reference pointsJ 0 AndJ 1 the theoretical position coordinates based on the mechanical coordinate system are respectively marked as: (xt J0 , yt J0 ) And (a)xt J1 , yt J1 )；
Identifying two reference points using a fiducial mark cameraJ 0 AndJ 1 respectively, are expressed as (Δ)x J0 ，Δy J0 ) And (Δ)x J1 ，Δy J1 ) (ii) a Calculating the inclination angle delta of the circuit board relative to the XY platformθ R The formula is as follows:
xr J 0 =xt J0 + Δx J0 ，yr J0 =yt J0 + Δy J0 ，xr J1 =xt J1 + Δx J1 ，yr J1 =yt J1 + Δy J1 ，
wherein,xr J1 ，yr J1 are respectively reference pointsJ 1 Based on the horizontal and vertical coordinates of the actual position in the mechanical coordinate system.
9. Compensation method according to claim 7 or 8, characterized in that the interpolation algorithm is implemented according to nearest neighbor interpolation, linear interpolation or bilinear interpolation.
10. The utility model provides a chip mounter XY platform positioning error compensation system based on machine vision which characterized in that includes: a circuit board inclination angle module for calculating the inclination angle delta of the circuit board positioned in the XY platform relative to the XY platformθ R ；
A datum point positioning error module for calculating datum point on the circuit board by interpolation algorithmJ 0 Positioning error of (1), is
,
) Then, there are:
in the formulaf x 、f y X, Y axis positioning error compensation values obtained by interpolation algorithm, respectively (xr J0 ，yr J0 ) As a reference pointJ 0 Based on the actual position coordinates in the mechanical coordinate system;
an actual position coordinate module used for obtaining theoretical position coordinates (based on the mechanical coordinate system) of the mounting point Pxt P , yt P ) Calculating the corresponding actual position coordinates (xr P , yr P ) Then, there are:
in the formulaxt J0 、yt J0 Are respectively a reference pointJ 0 The horizontal and vertical coordinates of the theoretical position under a mechanical coordinate system;
a mounting point positioning error module for calculating the positioning error compensation value of the mounting point P, and (b)
,
) Then, there are:
a compensation module for compensating the mounting point P, wherein the compensated mounting position coordinate is (
,
) Then, there are:
。
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211681882.3A CN115666125B (en) | 2022-12-27 | 2022-12-27 | Machine vision-based method for detecting and compensating positioning error of XY platform of chip mounter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211681882.3A CN115666125B (en) | 2022-12-27 | 2022-12-27 | Machine vision-based method for detecting and compensating positioning error of XY platform of chip mounter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115666125A true CN115666125A (en) | 2023-01-31 |
| CN115666125B CN115666125B (en) | 2023-08-18 |
Family
ID=85023482
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211681882.3A Active CN115666125B (en) | 2022-12-27 | 2022-12-27 | Machine vision-based method for detecting and compensating positioning error of XY platform of chip mounter |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115666125B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116709764A (en) * | 2023-08-02 | 2023-09-05 | 深圳市诺泰芯装备有限公司 | Position deviation compensation method for turret type MiniLED patch equipment |
| CN117835690A (en) * | 2024-03-04 | 2024-04-05 | 合肥安迅精密技术有限公司 | Machine vision-based mounting plane coordinate thermal compensation method and system and storage medium |
Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0449700A (en) * | 1990-06-19 | 1992-02-19 | Oki Electric Ind Co Ltd | Apparatus and method for indication of pin on support plate |
| KR19980020835A (en) * | 1996-09-12 | 1998-06-25 | 이종수 | How to calibrate the mounting position of chip mounters |
| JP2003069293A (en) * | 2001-08-29 | 2003-03-07 | Fuji Mach Mfg Co Ltd | Detector for misregistration of printed board and correcting method for coordinates of part mount point |
| WO2014103027A1 (en) * | 2012-12-28 | 2014-07-03 | 富士機械製造株式会社 | Working machine and positional deviation data acquisition method |
| CN111992911A (en) * | 2020-09-04 | 2020-11-27 | 武汉华工激光工程有限责任公司 | Visual positioning method based on paraxial visual structure galvanometer jigsaw processing |
| CN112261864A (en) * | 2020-10-12 | 2021-01-22 | 合肥安迅精密技术有限公司 | Population initialization method and system for solving mounting optimization problem of chip mounter |
| KR20210022195A (en) * | 2019-08-19 | 2021-03-03 | 하이윈 테크놀로지스 코포레이션 | Calibration method for robot using vision technology |
| CN113037970A (en) * | 2021-03-02 | 2021-06-25 | 合肥安迅精密技术有限公司 | Image data acquisition and transmission device and method for chip mounter equipment |
| CN113423191A (en) * | 2021-07-26 | 2021-09-21 | 合肥安迅精密技术有限公司 | Correction method and system for MARK point camera of chip mounter |
| CN113658884A (en) * | 2016-07-08 | 2021-11-16 | 科迪华公司 | Transmission path correction techniques and related systems, methods, and apparatus |
| CN114488944A (en) * | 2020-10-26 | 2022-05-13 | 上海霍塔浩福自动化测试技术有限公司 | Interpolation-based servo displacement error compensation method |
| CN114841925A (en) * | 2022-04-12 | 2022-08-02 | 深圳市凯码时代科技有限公司 | Test equipment alignment calculation method, terminal and storage medium |
| CN115119497A (en) * | 2022-08-31 | 2022-09-27 | 合肥安迅精密技术有限公司 | Tape-type flight-reach correction method and system for chip mounter and storage medium |
-
2022
- 2022-12-27 CN CN202211681882.3A patent/CN115666125B/en active Active
Patent Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0449700A (en) * | 1990-06-19 | 1992-02-19 | Oki Electric Ind Co Ltd | Apparatus and method for indication of pin on support plate |
| KR19980020835A (en) * | 1996-09-12 | 1998-06-25 | 이종수 | How to calibrate the mounting position of chip mounters |
| JP2003069293A (en) * | 2001-08-29 | 2003-03-07 | Fuji Mach Mfg Co Ltd | Detector for misregistration of printed board and correcting method for coordinates of part mount point |
| WO2014103027A1 (en) * | 2012-12-28 | 2014-07-03 | 富士機械製造株式会社 | Working machine and positional deviation data acquisition method |
| CN113658884A (en) * | 2016-07-08 | 2021-11-16 | 科迪华公司 | Transmission path correction techniques and related systems, methods, and apparatus |
| KR20210022195A (en) * | 2019-08-19 | 2021-03-03 | 하이윈 테크놀로지스 코포레이션 | Calibration method for robot using vision technology |
| CN111992911A (en) * | 2020-09-04 | 2020-11-27 | 武汉华工激光工程有限责任公司 | Visual positioning method based on paraxial visual structure galvanometer jigsaw processing |
| CN112261864A (en) * | 2020-10-12 | 2021-01-22 | 合肥安迅精密技术有限公司 | Population initialization method and system for solving mounting optimization problem of chip mounter |
| CN114488944A (en) * | 2020-10-26 | 2022-05-13 | 上海霍塔浩福自动化测试技术有限公司 | Interpolation-based servo displacement error compensation method |
| CN113037970A (en) * | 2021-03-02 | 2021-06-25 | 合肥安迅精密技术有限公司 | Image data acquisition and transmission device and method for chip mounter equipment |
| CN113423191A (en) * | 2021-07-26 | 2021-09-21 | 合肥安迅精密技术有限公司 | Correction method and system for MARK point camera of chip mounter |
| CN114841925A (en) * | 2022-04-12 | 2022-08-02 | 深圳市凯码时代科技有限公司 | Test equipment alignment calculation method, terminal and storage medium |
| CN115119497A (en) * | 2022-08-31 | 2022-09-27 | 合肥安迅精密技术有限公司 | Tape-type flight-reach correction method and system for chip mounter and storage medium |
Non-Patent Citations (1)
| Title |
|---|
| 尚亚光;徐维荣;王石刚;: "高精度贴片机多吸嘴位姿误差分析与标定算法", 机电一体化, no. 12 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116709764A (en) * | 2023-08-02 | 2023-09-05 | 深圳市诺泰芯装备有限公司 | Position deviation compensation method for turret type MiniLED patch equipment |
| CN116709764B (en) * | 2023-08-02 | 2023-12-08 | 深圳市诺泰芯装备有限公司 | Position deviation compensation method for turret type MiniLED patch equipment |
| CN117835690A (en) * | 2024-03-04 | 2024-04-05 | 合肥安迅精密技术有限公司 | Machine vision-based mounting plane coordinate thermal compensation method and system and storage medium |
| CN117835690B (en) * | 2024-03-04 | 2024-05-03 | 合肥安迅精密技术有限公司 | Machine vision-based mounting plane coordinate thermal compensation method and system and storage medium |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115666125B (en) | 2023-08-18 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN115666125A (en) | Method for detecting and compensating positioning error of XY platform of chip mounter based on machine vision | |
| CN113240674B (en) | Coplanarity detection method based on three-dimensional point cloud and two-dimensional image fusion | |
| CN111992911B (en) | Visual positioning method based on paraxial visual structure galvanometer jigsaw processing | |
| CN103945653B (en) | Automatic correction method of multi-degree-of-freedom platform for flexible printed circuit printing | |
| CN109283804B (en) | Method for improving exposure precision and expansion and contraction measurement precision of direct-writing exposure machine | |
| CN109556515B (en) | A kind of systematic error calibration method, system and equipment based on machine vision | |
| US6268920B1 (en) | Registration of sheet materials using statistical targets and method | |
| JPWO2014037993A1 (en) | Work equipment | |
| CN104251695B (en) | System and centering measurement method thereof are measured in a kind of laser alignment | |
| CN109870883A (en) | A kind of position compensation method of the scaling board for write-through exposure machine | |
| US10535157B2 (en) | Positioning and measuring system based on image scale | |
| CN116615020B (en) | Suction nozzle pose error calibration and compensation method and system based on machine vision | |
| US6819789B1 (en) | Scaling and registration calibration especially in printed circuit board fabrication | |
| US6563530B1 (en) | Camera position-correcting method and system and dummy component for use in camera position correction | |
| JP2012033829A (en) | Component mounting machine and image processing method | |
| JP2010147401A (en) | Electronic component mounting apparatus and image distortion correcting method | |
| JP4515814B2 (en) | Mounting accuracy measurement method | |
| CN107024185B (en) | Method and device for measuring basal surface | |
| CN117012688A (en) | Wafer detection positioning correction method and system | |
| CN114283207B (en) | Calibration method for alignment crimping of FPC (flexible printed circuit) and screen body cell | |
| CN114964056B (en) | Self-calibration method for micro-assembly equipment | |
| CN114295056B (en) | Rapid correction method and application of visual positioning system of laser processing equipment | |
| JP3286105B2 (en) | Mounting position correction method for mounting machine | |
| CN110706292B (en) | Two-dimensional workbench error self-calibration method based on machine vision | |
| CN111308868B (en) | Alignment compensation method of direct-writing exposure machine |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |