CN103290535B - Integrated piercing template equidistant solid matter micro hole positioner and method - Google Patents

Abstract

The invention discloses a kind of integrated piercing template equidistant solid matter micro hole localization method, comprising: miniature CCD camera is demarcated, distort with removal of images; Determine the draw point array of integrated piercing; Carry out binaryzation to image and mark, after pointwise traversal, the central point controlling tracking cross is equal to the distance of four end points, realizes locating hole coaxial with cloth pin datum hole; According to the relative position relation between needle falling hole and locating hole, calculate the relative position relation between needle falling hole and cloth pin datum hole; According to the draw point array of integrated piercing, control base plate and do transverse direction, vertically move, thus realize the location of the equidistant solid matter micro hole of integrated piercing template.The present invention is used in carbon fiber tri-dimensional fabric integrated piercing technique, and upper left corner micro hole cloth pin datum hole is defined in puncture template, what be draw point array based on image and cross laser device lays the home position information that mechanism provides necessary cloth pin datum hole, is convenient to laying of puncture needle.

Description

Integrated piercing template equidistant solid matter micro hole positioner and method

Technical field

The present invention relates to the auxiliary equipment in a kind of carbon fiber tri-dimensional fabric puncture moulding process, particularly relate to a kind of calibration system for the template micro hole that punctures in puncture needle array arranging device in carbon fiber tri-dimensional fabric integrated piercing technique.

Background technology

Three dimensional fabric is the fiber reinforcing texture of the best performance grown up over nearly 40 years, is mainly used in Aeronautics and Astronautics, automobile, medical treatment and new technical field.Integrated piercing technology is a kind of forming technique of three dimensional fabric, and the draw point array of integrated piercing refers to puts into the thousands of puncture array formed to tens thousand of equidistant solid matter micro hole of puncture template by draw point.

Along with the progress of science and technology, people progressively will the technology such as manual flow process, technique and information, microelectronics, automation, precision manufactureing combine, to enhance productivity, to reduce labour intensity in the past.

Compared with traditional manual operations, automated production equipment has operation accurately, and production efficiency is high, reduces labour intensity, saves the advantage of production cost.For this reason, various automation equipments weaving for carbon fiber tri-dimensional fabric is developed.

The patent No. be 200810064847.0 patent of invention disclose a kind of robot puncturing hole in endoscope operation localization method based on image and geometrical model, the position of endoscopic surgery puncturing hole is demarcated for scope (endoscope) operation robot, for robot provides necessary scope attitude information, be convenient to the operation to scope.The red spot shaped laser spot laser instrument of two different angle is installed below robot end's mechanical arm, simultaneously, at the extension type connecting rod of end mechanical arm tip, a miniature CCD camera is installed, the intersection point of two light is made to drop on below and the picture centre of miniature CCD camera camera lens, by the intersection point indirect inspection puncturing hole of two light position coordinates relative to robot base's coordinate system.This invention improves the positioning precision of puncturing hole, save ccd video camera etc. and demarcate device, avoid only utilizing video camera to carry out binocular and multiple target timing takies a large amount of resource for computer system in three-dimensional reconstruction process, cause system works slow, make puncturing hole calibration process rapidly, accurately, be conducive to reducing costs, be convenient to product development and production.Its weak point is: the restriction of Stimulated Light device facula area, only can be used for carrying out accurate quick position to diameter in patient's abdomen wall puncture hole of about 10mm, be not suitable for and have diameter and be less than or equal to 2mm, the equidistant solid matter that pitch of holes is less than 2.3mm is the location of aperture plate.

Technical paper " part vision based on preprocessing ccd image is located " (building-block machine and automation process technology 2010,9:79-82) for the purpose of stamping-out array micropore on sheet brass, to improve preprocessing hole estimating precision for approach, describe a kind of method coming positioning workpieces position based on preprocessing hole ccd image.This localization method adopts the thought of will locate after first for workpiece clamping: one is workpiece clamping on a mobile station, and adopt one side three block modes to locate, spring leaf steps up; Two is location (mould is fixed on lathe) of the relative lathe positioning datum of travelling carriage.Finally complete workpiece first to the location with mould." vision location " is exactly using preprocessing hole as location feature, and after travelling carriage is just located, passing hole ccd image determines that the error between this hole and positioning datum also feeds back the process that travelling carriage is relocated.Following process for benchmark, has strict size and positional precision relation with this hole circle heart with it.The method can effectively reduce position error, improves location efficiency.Positioning precision by the accuracy guarantee of error measure, and then depends on the accuracy of detection of center, hole.Its weak point is, for microwell array stamping-out location, can not be used for the microwell array location machined, and especially can not be used for the location of the equidistant solid matter micro hole of puncture template that orifice plate has frock that one side three block modes cannot be adopted to locate.

Summary of the invention

For above-mentioned prior art, the invention provides a kind of integrated piercing template equidistant solid matter micro hole positioner and method, for the precise positioning of template micro hole position of puncturing in puncture needle array arranging device in carbon fiber tri-dimensional fabric integrated piercing technique, based on image and cross laser device for draw point array arranging device provides the home position information of necessary puncture template upper left corner micro hole, so that the laying of puncture needle.

In order to solve the problems of the technologies described above, a kind of integrated piercing template of the present invention equidistant solid matter micro hole positioner, comprise Industrial PC Computer, Bu Zhen mechanism, ruddiness cross laser device and miniature CCD camera, be fitted with video frequency collection card in the slot of described Industrial PC Computer, described Bu Zhen mechanism comprises base plate, and described base plate can move by X-Y, described base plate is provided with locating hole, needle falling hole and a telescopic connecting rod, and the distance of described locating hole and needle falling hole is the integral multiple of pattern hole spacing of puncturing; Described miniature CCD camera is arranged on the end of telescopic connecting rod, and the tracking cross that described ruddiness cross laser device sends is positioned at the below of described miniature CCD camera, and the central point of this tracking cross is coaxial with described locating hole; The micro hole belonged in puncture template is cloth pin datum hole, described miniature CCD camera is connected to described Industrial PC Computer by data wire, what ruddiness cross laser device sent by described miniature CCD camera passes to video frequency collection card through the vision signal of the tracking cross of cloth pin datum hole on described locating hole and puncture template, described Industrial PC Computer changes laggard row relax to this vision signal A/D, thus obtains the relative position relation between needle falling hole and cloth pin datum hole according to the relative position relation between needle falling hole and locating hole.

Realize a kind of integrated piercing template of the present invention equidistant solid matter micro hole localization method, adopt above-mentioned integrated piercing template equidistant solid matter micro hole positioner, and comprise the following steps:

Step one, miniature CCD camera to be demarcated, distort with removal of images;

Step 2, determine the draw point array of integrated piercing;

Step 3, binaryzation carried out to image and marks, and respectively from the traversal of four direction pointwise up and down, finding out four end points of tracking cross and the Position Approximate of central point, controlling base plate and do transverse direction, vertically move, until capture a cross connected domain;

Step 4, pointwise traversal, find out the position of the central point of tracking cross, horizontal and vertical four end points, calculate the distance of central point to horizontal and vertical four end points of tracking cross respectively;

Step 5, judge that whether the central point of tracking cross is equal to the distance of horizontal two end points, and control described base plate and laterally move, until the central point of tracking cross is equal to the distance of transverse direction two end points;

Judge that whether the central point of tracking cross is equal to the distance of longitudinal two end points, and control described base plate and vertically move, until central point is equal to the distance of longitudinal direction two end points;

Judge that whether the central point of tracking cross is equal to the distance of four end points, if the central point of tracking cross is equal to the distance of four end points, realize locating hole coaxial with cloth pin datum hole; According to the relative position relation between needle falling hole and locating hole, calculate the relative position relation between needle falling hole and cloth pin datum hole;

Step 6, the draw point array of integrated piercing determined according to step 2, control base plate and do transverse direction, vertically move, thus realize the location of the equidistant solid matter micro hole of integrated piercing template.

Further, in above-mentioned steps one, comprising:

Step 1-1, definition world coordinate system (X _w, Y _w, Z _w), camera coordinate system (X _c, Y _c, Z _c), image pixel coordinates system (u, v) with image physical coordinates system (X, Y), wherein:

World coordinate system (X _w, Y _w, Z _w) being used for the position of any object in describe environment, in world coordinate system, 1 M in space is expressed as (X _w, Y _w, Z _w);

Camera coordinate system (X _c, Y _c, Z _c) initial point be defined in the photocentre of camera lens, Z _caxle is optical axis, Z _caxle and Y _caxle is parallel to trunnion axis and the vertical axis of the plane of delineation respectively;

Image pixel coordinates system (u, v) in units of pixel, u, v represent columns in digital picture and line number respectively;

Image physical coordinates system (X, Y) is with the intersection point of the optical axis of camera and the plane of delineation for initial point, and X-axis and Y-axis are parallel with v axle with the u axle of image pixel coordinates system respectively;

Step 1-2, set up mathematical relationship between dimensional target point and corresponding picture point, comprising:

The conversion of world coordinate system and camera coordinate system;

The conversion of image coordinate system and camera coordinate system;

The conversion of world coordinate system and image coordinate system;

Obtain the image pixel coordinates of distortion error and undistorted error according to the relation of image physical coordinates system and image coordinate system respectively, utilize the distortion error model of nonlinear imaging model to carry out distortion correction.

Further, in above-mentioned steps two, when the needle falling hole on base plate and the transverse direction relative motion of puncture template, needle falling hole center of circle movement locus is parallel with the often row aperture circle center line connecting of draw point array or overlap; During needle falling hole relative motion longitudinal with puncture template, the circle center line connecting of the every row aperture of needle falling hole deferent and draw point array is parallel or overlap.

Further, in step 6, if cloth pin datum hole is the aperture being positioned at the puncture template upper left corner, the centre-to-centre spacing of the equidistant solid matter micro hole of puncture template is r, and the distance of locating hole and needle falling hole is l _x=a × r, a is integer, if locating hole is coaxial with cloth pin datum hole, then and the line of locating hole and needle falling hole and the line coincident in the first row aperture center of circle of draw point array in puncture template, thus show that needle falling hole (x, y) with the relative position relation of cloth pin datum hole is:

$\left\{\begin{array}{c}x=a\×r\\ y=0\end{array}\right.$

In the present invention, because in puncture template, upper left corner micro hole is identical with the micro hole diameter dimension of other positions, in puncture template, upper left corner micro hole is coaxial with the position of the locating hole on cloth pin organization soleplate, and it is all fixing with the pitch of holes of adjacent micro hole, be first aperture starting to process in puncture template micro hole machining process, this aperture be defined as the datum hole in process.After coaxial by locating hole and upper left corner micro hole in puncture template, the needle falling hole determined is the simplest with the position relationship of upper left corner micro hole in puncture template.Certainly, in the template that punctures, the micro hole of other specific positions is also passable as the datum hole in process, such as be positioned at the aperture at other 3 angles, but be first first overlength puncture needle is put into upper left corner aperture in puncture template during cloth pin, like this for cloth pin work most convenient, not so carry out draw point lay upper left corner aperture also will be got back to behind other specific position apertures location, therefore, upper left corner aperture in puncture template being defined as cloth pin datum hole is position the most easily in cloth pin process.

Compared with prior art, the invention has the beneficial effects as follows:

The present invention adopts miniature CCD camera and cross laser device to coordinate, by judging the distance whether equal position coordinates of determining needle falling hole and puncture template in associated aperture of the center of tracking cross to four end points, not only increase the positioning precision of puncture plate aperture, and avoid in prior art only utilize video camera carry out binocular and multiple target timing in three-dimensional reconstruction process, take a large amount of resource for computer system, cause system works problem slowly, make puncture plate aperture calibration process rapid, accurately, be conducive to reducing costs, be convenient to product development and production.The present invention can ensure the positional precision of the array of orifices of puncture template, to meet requirement when draw point lays, and the application scenario of locating after being applicable to first clamping.In addition, the present invention saves video acquisition element, and its structure and job control principle are simple, compared with the location of the equidistant solid matter micro hole of traditional puncture template under the prerequisite that can effectively use advantage of lower cost.

Accompanying drawing explanation

Fig. 1 is the formation simplified schematic diagram of integrated piercing template of the present invention equidistant solid matter micro hole positioner;

Fig. 2 is the structural representation of the pin of cloth shown in Fig. 1 organization soleplate;

Fig. 3 is neutral line model of the present invention and each coordinate system graph of a relation;

Fig. 4 is the plane target drone image of vision measurement system;

Fig. 5 is control block diagram in the present invention;

Fig. 6 is the standard grid image field figure in shooting process;

Fig. 7 is image tagged flow chart in the present invention;

Fig. 8 is integrated piercing template of the present invention equidistant solid matter micro hole localization method flow chart.

Detailed description of the invention

Below in conjunction with detailed description of the invention, the present invention is described in further detail.

As shown in Figure 1, a kind of integrated piercing template of the present invention equidistant solid matter micro hole positioner, comprise Industrial PC Computer 0, Bu Zhen mechanism, ruddiness cross laser device 1 and miniature CCD camera 2, as shown in Figure 5, video frequency collection card 01 is fitted with in the slot of described Industrial PC Computer 0, described Bu Zhen mechanism comprises base plate 3, described base plate 3 can move by X-Y, as shown in Figure 2, described base plate 3 is provided with locating hole, needle falling hole and a telescopic connecting rod, described locating hole is for determining the position of described ruddiness cross laser device 1, the distance of described locating hole and needle falling hole is the integral multiple of pattern hole spacing of puncturing, described miniature CCD camera 2 is arranged on the end of telescopic connecting rod 4, described ruddiness cross laser device 1 is arranged on the top of base plate 3 and coaxial with locating hole, described miniature CCD camera 2 is arranged on the below of base plate 3, the tracking cross that described ruddiness cross laser device 1 sends is positioned at the below of described miniature CCD camera 2, and the central point of this tracking cross is coaxial with described locating hole, the micro hole belonged in puncture template is cloth pin datum hole, as shown in Figure 5, described miniature CCD camera 2 is connected to described Industrial PC Computer 0 by data wire, what ruddiness cross laser device 1 sent by described miniature CCD camera 2 passes to video frequency collection card 01 through the vision signal of the tracking cross of cloth pin datum hole on described locating hole and puncture template, described Industrial PC Computer 0 changes laggard row relax to this vision signal A/D, thus obtains the relative position relation between needle falling hole and cloth pin datum hole according to the relative position relation between needle falling hole and locating hole.

The model of the ruddiness cross laser device 1 in the present invention is the LD-G650A23 of Kunshan Bo Ye Electronic Science and Technology Co., Ltd., is of a size of Ф 12 × 35mm, or adopts the cross red laser of other producer's same sizes; The model of CCD camera 2 is SONY PH-TV1301, and video frequency collection card model is the quick VC4000 in sky, or adopts USB minisize pick-up head.

In the embodiment of the present invention, in puncture template, upper left corner micro hole is identical with the micro hole diameter dimension of other positions, in puncture template, upper left corner micro hole is coaxial with the position of the locating hole on cloth pin organization soleplate, and it is all fixing with the pitch of holes of adjacent micro hole, be first aperture starting to process in puncture template micro hole machining process, therefore this aperture be defined as the datum hole in process.After coaxial by locating hole and upper left corner micro hole in puncture template, the needle falling hole determined is the simplest with the position relationship of upper left corner micro hole in puncture template.

Certainly, in the template that punctures, the micro hole of other specific positions is also passable as the datum hole in process, such as be positioned at the aperture at other 3 angles, but be first first overlength puncture needle is put into upper left corner aperture in puncture template during cloth pin, like this for cloth pin work most convenient, not so carry out draw point lay upper left corner aperture also will be got back to behind other specific position apertures location, therefore, upper left corner aperture in puncture template being defined as cloth pin datum hole is position the most easily in cloth pin process.

When the equidistant solid matter micro hole of puncture template is located, puncture template is packed in draw point array to be laid in frock, ensure that puncture template the first row equidistant solid matter small hole center line is parallel with the direction of motion of cloth pin organization soleplate simultaneously, then draw point array is laid tool locating, and then carry out the location of puncture template upper left corner micro hole.

Utilize above-mentioned integrated piercing template equidistant solid matter micro hole positioner to realize the method for the equidistant solid matter micro hole location of integrated piercing template, as shown in Figure 8, comprise the following steps:

Determine the position of ruddiness cross laser device 1 locating hole and needle falling hole:

As shown in Figure 2, the locating hole of ruddiness cross laser device 1 correspondence and the distance of needle falling hole are the integral multiple of plate aperture pitch of holes of puncturing.If the centre-to-centre spacing of the equidistant solid matter micro hole of puncture template is r, the distance of locating hole and needle falling hole is l _x, then:

l _x=a×r （1）

If locating hole is coaxial with puncture template upper left corner aperture, locating hole overlaps with puncture template the first row aperture circle center line connecting with needle falling hole line, then needle falling hole (x, y) with the relative position relation of puncture template upper left corner aperture is:

$\left\{\begin{array}{c}x=a\×r\\ y=0\end{array}\right.$

Miniature CCD camera is demarcated, with removal of images distortion, guarantees miniature CCD camera accurate positioning and there is higher positioning accuracy.

Commonly use the following coordinate system in vision measurement, its definition is as follows respectively, see Fig. 3:

(1) world coordinate system (X _w, Y _w, Z _w): also referred to as absolute coordinate system, be used for the position of any object in describe environment, in world coordinate system, 1 M in space is expressed as (X _w, Y _w, Z _w).

(2) camera coordinate system (X _c, Y _c, Z _c): the initial point of this coordinate system is defined in the photocentre of camera lens.Z _caxle is optical axis, Z _caxle and Y _caxle is parallel to trunnion axis and the vertical axis of the plane of delineation respectively.

(3) image pixel coordinates system (u, v): deposit coordinate also referred to as frame, it is in units of pixel, generally with the image upper left corner for initial point, uv represents columns in digital picture and line number respectively.

(4) image physical coordinates system (X, Y): its center is the intersection point of optical axis and the plane of delineation is initial point, and X-axis and Y-axis are parallel with the uv axle of image pixel coordinates system respectively.

After defining above-mentioned various rectangular coordinate system in space, just can obtain the imaging of camera under linear model and describe, namely set up the mathematical relationship between dimensional target point and corresponding picture point.

1, the transformation relation of world coordinate system and camera coordinate system

Point in world coordinate system can be described by an a rotational transformation matrix R and translation transformation vector t to the conversion process of camera coordinates system.If the homogeneous coordinates of certain M point under world coordinate system and camera coordinates system are [X respectively in space _w, Y _w, Z _w] ^t[X _c, Y _c, Z _c] ^tso, there is following relation:

$\left[\begin{array}{c}{x}_c\\ y_c\\ z_c\\ 1\end{array}\right]=\left[\begin{array}{cc}R& t\\ 0^r& 1\end{array}\right]\left[\begin{array}{c}{x}_w\\ y_w\\ z_w\\ 1\end{array}\right]---\left(2\right)$

Wherein, R is 3 × 3 orthogonal matrices, and t is D translation vector, t=[t _x, t _y, t _z] ^t,

$R=\left[\begin{array}{ccc}{r}_1& r_2& r_3\\ r_4& r_5& r_6\\ r_7& r_8& r_9\end{array}\right].$

2, the transformation relation of image coordinate system and camera coordinate system

The picture point m coordinate of some M in image physical coordinates system in camera coordinate system is:

$\left\{\begin{array}{c}x={\mathrm{fx}}_c/Z_c\\ y={\mathrm{fy}}_c/Z_c\end{array}\right.---\left(3\right)$

The image physical coordinates system of above formula is changed into image pixel coordinates is further:

$\left\{\begin{array}{c}u=x/d_x+u_0\\ v=y/d_y+v_0\end{array}\right.---\left(4\right)$

Wherein, u ₀, v ₀the coordinate of picture centre (intersection point of optical axis and the plane of delineation), d _xand d _ybe respectively the physical size of a pixel in X and Y-direction.The transformation relation between spatial point M and the pixel coordinate of picture point m can be obtained by formula (3) and formula (4), represent with homogeneous coordinates:

$z_c\left[\begin{array}{c}u\\ v\\ 1\end{array}\right]=\left[\begin{array}{ccc}1/d_x& 0& u_0\\ 0& 1/d_y& v_0\\ 0& 0& 1\end{array}\right]\left[\begin{array}{cccc}f& 0& 0& 0\\ 0& f& 0& 0\\ 0& 0& 1& 0\end{array}\right]\left[\begin{array}{c}{x}_c\\ y_c\\ z_c\\ 1\end{array}\right]=\left[\begin{array}{cccc}f/d_x& 0& u_0& 0\\ 0& f/d_y& v_0& 0\\ 0& 0& 1& 0\end{array}\right]\left[\begin{array}{c}{x}_c\\ y_c\\ z_c\\ 1\end{array}\right]---\left(5\right)$

Make α=f/d _y, β=f/d _ythen formula (5) is rewritten as:

$z_c\left[\begin{array}{c}u\\ v\\ 1\end{array}\right]=\left[\begin{array}{cccc}\mathrm{\α}& 0& u_0& 0\\ 0& \mathrm{\β}& v_0& 0\\ 0& 0& 1& 0\end{array}\right]\left[\begin{array}{c}{x}_c\\ y_c\\ z_c\\ 1\end{array}\right]---\left(6\right)$

3. the transformation relation of world coordinate system and image coordinate system

Formula (2) being brought into formula (6) just can obtain with regard to the transformation relation between the coordinate of spatial point M in world coordinate system and the coordinate of its picture point m in image pixel coordinates system:

$z_c\left[\begin{array}{c}u\\ v\\ 1\end{array}\right]=\left[\begin{array}{cccc}\mathrm{\α}& \mathrm{\γ}& u_0& 0\\ 0& \mathrm{\β}& v_0& 0\\ 0& 0& 1& 0\end{array}\right]\left[\begin{array}{cc}R& t\\ 0^r& 1\end{array}\right]\left[\begin{array}{c}{x}_w\\ y_w\\ z_w\\ 1\end{array}\right]=\begin{array}{}\end{array}\left[\begin{array}{ccc}\mathrm{\α}& \mathrm{\γ}& u_0\\ 0& \mathrm{\β}& v_0\\ 0& 0& 1\end{array}\right]\left[\begin{array}{cc}R& t\end{array}\right]\left[\begin{array}{c}{x}_w\\ y_w\\ z_w\\ 1\end{array}\right]---\left(7\right)$

Above formula can be write a Chinese character in simplified form into: z _cu _uv=AX _w(8)

Wherein, U _uv=[u, v, 1] ^tand X _w=[x _w, y _w, z _w, 1] ^tspatial point M=[x respectively _w, y _w, z _w] ^rwith its picture point m=[u, v] ^thomogeneous coordinates, matrix A is 3 × 4 singular matrixs, also referred to as projection matrix.

$A=\left[\begin{array}{cccc}{\mathrm{\αr}}_1+u_0{r}_7& {\mathrm{\αr}}_2+u_0{r}_8& {\mathrm{\αr}}_3+u_0{r}_9& {\mathrm{\αt}}_x+u_0{t}_z\\ {\mathrm{\βr}}_4+v_0{r}_7& {\mathrm{\βr}}_5+v_0{r}_8& {\mathrm{\βr}}_6+v_0{r}_9& {\mathrm{\βt}}_y+v_0{t}_z\\ r_7& r_8& r_9& t_z\end{array}\right]---\left(9\right)$

Owing to there is various error component in actual imaging system, actual imaging model does not meet linear relationship, but a kind of non-linear relation.For the camera lens of mid-focal length normal quality, probably there is the distortion error of 1-3 pixel sizes on the border of image.In order to obtain higher certainty of measurement, nonlinear model must be adopted to demarcate camera system.The nonlinear distortion of Description Image point can use formula below:

$\left\{\begin{array}{c}x=x_d+{\mathrm{\δ}}_x\\ y=y_d+{\mathrm{\δ}}_y\end{array}\right.---\left(10\right)$

Wherein, (x, y) is the ideal coordinates of the picture point under pin-hole model image-forming condition, (x _d, y _d) be the coordinate of picture point reality, δ _xwith δ _ybe respectively the distortion value in X profit Y-direction, it is relevant with the position of picture point.

Camera calibration adopts distortion error model---Weng ' the s peg model of nonlinear imaging model, and total distortion is expressed as:

$\left\{\begin{array}{c}{\mathrm{\δ}}_x=k_1{x}_d(x_d^2+y_d^2)+{\mathrm{\ρ}}_1({3x}_d^3+y_d^2)+{2\mathrm{\ρ}}_2{x}_d{y}_d+s_1(x_d^2+y_d^2)\\ {\mathrm{\δ}}_y=k_1{x}_d(x_d^2+y_d^2)+{\mathrm{\ρ}}_2(x_d^3+{3y}_d^2)+{2\mathrm{\ρ}}_1{x}_d{y}_d+s_2(x_d^2+y_d^2)\end{array}\right.---\left(11\right)$

Make g ₁=s ₁+ ρ ₁, g ₂=s ₂+ ρ ₂, g ₃=2 ρ ₁, g ₄=2 ρ ₂, g ₅=k ₁then have:

$\left\{\begin{array}{c}{\mathrm{\δ}}_x=(g_1+g_2)x_d^2+g_4{x}_d{y}_d+g_1{y}_d^2+g_5{x}_d(x_d^2+y_d^2)\\ {\mathrm{\δ}}_y=g_2{x}_d^2+g_3{x}_d{y}_d+(g_2+g_4)y_d^2+g_5{y}_d(x_d^2+y_d^2)\end{array}\right.---\left(12\right)$

(12) are brought into (10) to obtain:

$\left\{\begin{array}{c}x=x_d+(g_1+g_3)x_d^2+g_4{x}_d{y}_d+g_1{y}_d^2+g_5{x}_d(x_d^2+y_d^2)\\ y=y_d+g_2{x}_d^2+g_3{x}_d{y}_d+(g_2+g_4)y_d^2+g_5{y}_d(x_d^2+y_d^2)\end{array}---\left(13\right)\right.$

Above formula is the distortion error model of nonlinear imaging model, and camera calibration utilizes above-mentioned model to carry out distortion correction.

Video camera process is: the space lattice image of shooting the known world coordinate, obtains the image coordinate of corresponding picture point, then calculate inside and outside parameter.The method of fractional steps is used to solve.First with the approximate free from error grid image field of the mesh node matching one of extracting; Then according to the relation of the grid image field that simulates and space actual grid, solve by (8) formula, the projection matrix of video camera can be solved thus.Finally lens error correction coefficient is solved with the nodal value extracted according to matching grid field out.

In vision measurement system, adopt plane target drone as demarcation thing (see Fig. 4), this target has a series of being uniformly distributed, the straight line of square crossing, and the relative position of the intersection point between line is known.And the X-axis of world coordinate system is the horizontal direction of this target, Y-axis is the vertical direction of this target, and its initial point is positioned at plane target drone.Obviously Z is had for any point on plane target drone _w=0.

Following adjustment to be done to system before demarcation:

A. adjust plane target drone, make the line of the mutual disposal on target be parallel to X respectively _waxle and Y _waxle.

B. adjust camera, make its primary optical axis direction as far as possible perpendicular to demarcation plane.

C. adjust miniature CCD camera and become level.

Fit standard grid (see Fig. 6) can be expressed as follows respectively to the straight line of horizontal direction and vertical direction in the grid image field shown in Fig. 6:

y=ia+b ₀（14）

x=ia+b ₁（15）

Wherein a is interval between the lines, b ₀, b ₁for side-play amount, i is the label of grid lines.

Least square method is adopted to calculate a, b ₀, b ₁etc. parameter, specific practice is as follows:

Get k horizontal line and the l bar vertical line of image central region, note:

$f(a,b_0,b_1)=\underset{i=1}{\overset{k}{\mathrm{\Σ}}}\underset{j=1}{\overset{l}{\mathrm{\Σ}}}{(\mathrm{ia}+b_0-y_{\mathrm{ij}})}^2+\underset{i=1}{\overset{l}{\mathrm{\Σ}}}\underset{j=1}{\overset{k}{\mathrm{\Σ}}}{(\mathrm{ia}+b_1-x_{\mathrm{ij}})}^2=\underset{i=1}{\overset{k}{\mathrm{\Σ}}}\underset{j=1}{\overset{l}{\mathrm{\Σ}}}[{(\mathrm{ia}+b_0-y_{\mathrm{ij}})}^2+{(\mathrm{ja}+b_1-x_{\mathrm{ij}})}^2]$

（16）

Ask partial derivative respectively, obtain 3 equations:

$\frac{\mathrm{df}}{\mathrm{da}}=2\underset{i=1}{\overset{k}{\mathrm{\Σ}}}\underset{j=1}{\overset{l}{\mathrm{\Σ}}}[(\mathrm{ia}+b_0-y_{\mathrm{ij}})+(\mathrm{ja}+b_1-x_{\mathrm{ij}})j]$

$=\frac{1}{3}\mathrm{kl}[(k+1)(2k+1)+(l+1)(2l+1)]a+\mathrm{kl}(k+1)b_0+\mathrm{kl}(l+1)b_1-2\underset{i=1}{\overset{k}{\mathrm{\Σ}}}\underset{j=1}{\overset{l}{\mathrm{\Σ}}}({\mathrm{iy}}_{\mathrm{ij}}+{\mathrm{jx}}_{\mathrm{ij}})=0$

$\frac{\mathrm{df}}{{\mathrm{db}}_0}=2\underset{i=1}{\overset{k}{\mathrm{\Σ}}}\underset{j=1}{\overset{l}{\mathrm{\Σ}}}(\mathrm{ia}+b_0-y_{\mathrm{ij}})=\mathrm{kl}(k+l)-2\underset{i=1}{\overset{k}{\mathrm{\Σ}}}\underset{j=1}{\overset{l}{\mathrm{\Σ}}}{y}_{\mathrm{ij}}=0$

$\frac{\mathrm{df}}{{\mathrm{db}}_1}=2\underset{i=1}{\overset{k}{\mathrm{\Σ}}}\underset{j=1}{\overset{l}{\mathrm{\Σ}}}(\mathrm{ja}+b_1-y_{\mathrm{ij}})=\mathrm{kl}(k+l)-2\underset{i=1}{\overset{k}{\mathrm{\Σ}}}\underset{j=1}{\overset{l}{\mathrm{\Σ}}}{y}_{\mathrm{ij}}=0$

Solve an equation

WF=B （17）

Wherein:

$W=\left[\begin{array}{ccc}\frac{1}{3}[(k+1)(2k+1)+(l+1)(2l+1)]& k+1& l+1\\ k+1& 2& 0\\ l+1& 0& 2\end{array}\right],$ $F=\left[\begin{array}{c}a\\ b_0\\ b_1\end{array}\right],$ $B=\frac{2}{\mathrm{kl}}\left[\begin{array}{c}\underset{i=1}{\overset{k}{\mathrm{\Σ}}}\underset{j=1}{\overset{l}{\mathrm{\Σ}}}({\mathrm{iy}}_{\mathrm{ij}}+{\mathrm{jx}}_{\mathrm{ij}})\\ \underset{i=1}{\overset{k}{\mathrm{\Σ}}}\underset{j=1}{\overset{l}{\mathrm{\Σ}}}{y}_{\mathrm{ij}}\\ \underset{i=1}{\overset{k}{\mathrm{\Σ}}}\underset{j=1}{\overset{l}{\mathrm{\Σ}}}{x}_{\mathrm{ij}}\end{array}\right]$

The intersection point of whole grid can be obtained thus.

Solve camera position parameter.

(8) formula is launched, cancellation Z _chave:

$\left\{\begin{array}{c}(u-u_0)x_w{r}_7+(u-u_0)y_w{r}_8+(u-u_0)z_w{r}_9+(u-u_0)t_z-x_w{\mathrm{\αr}}_1-y_w{\mathrm{\αr}}_2-z_w{\mathrm{\αr}}_3-{\mathrm{\αt}}_x=0\\ (v-v_0)x_w{r}_7+(v-v_0)y_w{r}_8+(v-v_0)z_w{r}_9+(v-v_0)t_z-x_w{\mathrm{\βr}}_4-y_w{\mathrm{\βr}}_5-z_w{\mathrm{\βr}}_6-{\mathrm{\βt}}_y=0\end{array}\right.---\left(18\right)$

Suppose as next group intermediate variable:

$\left\{\begin{array}{c}{q}_1={\mathrm{\αr}}_1+u_0{r}_7\\ q_2={\mathrm{\αr}}_2+u_0{r}_8\\ q_3={\mathrm{\αr}}_3+u_{0_{}}r9\\ q_4={\mathrm{\βr}}_4+v_0{r}_7\\ q_5={\mathrm{\βr}}_5+v_0{r}_8\\ q_6={\mathrm{\βr}}_6+v_0{r}_9\\ q_7=r_7\\ q_8=r_8\\ q_9=r_9\\ q_{10}={\mathrm{\αt}}_x+u_0{t}_z\\ q_{11}={\mathrm{\βt}}_y+v_0{t}_z\\ q_{12}=t_z\end{array}\right.---\left(19\right)$

(19) formula can be expressed as: HQ=0 (20)

Wherein:

$H=\left[\begin{array}{cccccccccccc}-x_w& {-y}_w& -z_w& 0& 0& 0& {\mathrm{ux}}_w& {\mathrm{uy}}_w& {\mathrm{uz}}_w& -1& 0& u\\ 0& 0& 0& -x_w& -y_w& -z_w& {\mathrm{vx}}_w& {\mathrm{vy}}_w& {\mathrm{vz}}_w& 0& -1& v\end{array}\right],$

$Q={\left[\begin{array}{cccccccccccc}{q}_1& q_2& q_3& q_4& q_5& q_6& q_7& q_8& q_9& q_{10}& q_{11}& q_{12}\end{array}\right]}^r$

Because (20) formula is a homogeneous equation, it has infinitely organizes solution more, and required camera parameters meets following two conditions:

(1) because r ₇, r ₈, r ₉be the row vector of last column of orthogonal matrix, it should be a unit vector, so $q_7^2+q_8^2+q_9^2=1.$

(2) q ₁₂symbol should adapt with the position of video camera in world coordinates, if it is at Z _wthe forward of axle is just then, otherwise is negative, is just being taken as in such a system.Answer this, after Q determines, actual camera parameters should be:

$N=\frac{Q}{\sqrt{q_7^2+q_8^2+q_9^2}}$

One particular solution just known solution all is only needed for solving of (20) formula, first can suppose the value of a known unknown number, ask all the other unknown numbers, obtain a particular solution, because world coordinate system initial point is generally defined on measuring object, t _xvalue be non-vanishing, so can q be supposed ₁₂=1, solve Q, then press the value on the realistic border of (20) formula, under the assumptions, (20) formula can turn to:

H′Q′+q=0 （21）

Wherein H ' is 11 row before H, and q is last 1 row of H, and Q ' is 11 variablees before Q.Can Q ' be solved according to least square method, then can try to achieve Q value, then try to achieve camera parameters according to (19) formula.

Had by the relation of image physical coordinates and image coordinate:

x _d=(u _d-u ₀)dx=(u-u ₀)f/α

y _d=(v _d-v ₀)dy=(v-v ₀)f/β

x=(u-u ₀)dx=(u-u ₀)f/α

y=(v-v ₀)dy=(v-v ₀)f/β

Wherein x _d, y _dwith x, y indicate the image pixel coordinates of distortion error and undistorted error respectively, substitute into formula (13), obtain error coefficient g _ilinear equation, can solve and obtain, can demarcate camera according to above parameter.

Perform puncture template micro hole finder, determine the draw point array of integrated piercing.When the needle falling hole on base plate and the transverse direction relative motion of puncture template, needle falling hole center of circle movement locus is parallel with the often row aperture circle center line connecting of draw point array or overlap; During needle falling hole relative motion longitudinal with puncture template, the circle center line connecting of the every row aperture of needle falling hole deferent and draw point array is parallel or overlap.

Calculate the relative position relation between needle falling hole and cloth pin datum hole.

Binaryzation is carried out to image, and mark (see Fig. 7), then respectively from the traversal of four direction pointwise up and down, find out four end points of tracking cross and the Position Approximate of central point, namely do transverse direction, vertically move by controlling base plate, till capturing a cross connected domain; Subsequently, pointwise travels through, and finds out the position of the central point of tracking cross, horizontal and vertical four end points, calculates the distance of central point to horizontal and vertical four end points of tracking cross respectively; Judge that whether the central point of tracking cross is equal to the distance of horizontal two end points, and control described base plate and laterally move, until the central point of tracking cross is equal to the distance of transverse direction two end points; Judge that whether the central point of tracking cross is equal to the distance of longitudinal two end points, and control described base plate and vertically move, until central point is equal to the distance of longitudinal two end points, central point is coaxial with puncture template upper left corner aperture to the distance equal then proof base plate locating hole of four end points, realizes locating hole coaxial with cloth pin datum hole; According to the relative position relation between needle falling hole and locating hole, calculate the relative position relation between needle falling hole and cloth pin datum hole; Carry out the distortion of demarcation removal of images to CCD camera only to carry out once after whole system is set up, each location does not need to demarcate again later.

According to the draw point array of integrated piercing, control base plate and do transverse direction, vertically move, thus realize the location of the equidistant solid matter micro hole of integrated piercing template.

Although invention has been described for composition graphs above; but the present invention is not limited to above-mentioned detailed description of the invention; above-mentioned detailed description of the invention is only schematic; instead of it is restrictive; those of ordinary skill in the art is under enlightenment of the present invention; when not departing from present inventive concept, can also make a lot of distortion, these all belong within protection of the present invention.

Claims (5)

1. an integrated piercing template equidistant solid matter micro hole positioner, comprise Industrial PC Computer, Bu Zhen mechanism, ruddiness cross laser device and miniature CCD camera, is characterized in that,

Video frequency collection card is fitted with in the slot of described Industrial PC Computer, described Bu Zhen mechanism comprises base plate, described base plate can move by X-Y, and described base plate is provided with locating hole, needle falling hole and a telescopic connecting rod, and the distance of described locating hole and needle falling hole is the integral multiple of pattern hole spacing of puncturing; Described miniature CCD camera is arranged on the end of telescopic connecting rod, and the tracking cross that described ruddiness cross laser device sends is positioned at the below of described miniature CCD camera, and the central point of this tracking cross is coaxial with described locating hole; The micro hole belonged in puncture template is cloth pin datum hole, described miniature CCD camera is connected to described Industrial PC Computer by data wire, what ruddiness cross laser device sent by described miniature CCD camera passes to video frequency collection card through the vision signal of the tracking cross of cloth pin datum hole on described locating hole and puncture template, described Industrial PC Computer changes laggard row relax to this vision signal A/D, thus obtains the relative position relation between needle falling hole and cloth pin datum hole according to the relative position relation between needle falling hole and locating hole.

2. an integrated piercing template equidistant solid matter micro hole localization method, is characterized in that, adopts integrated piercing template equidistant solid matter micro hole positioner as claimed in claim 1, and comprises the following steps:

Step one, miniature CCD camera to be demarcated, distort with removal of images;

Step 2, determine the draw point array of integrated piercing;

Step 3, binaryzation carried out to image and marks, and respectively from the traversal of four direction pointwise up and down, finding out four end points of tracking cross and the Position Approximate of central point, controlling base plate and do transverse direction, vertically move, until capture a cross connected domain;

Step 4, pointwise traversal, find out the position of the central point of tracking cross, horizontal and vertical four end points, calculate the distance of central point to horizontal and vertical four end points of tracking cross respectively;

Step 5, judge that whether the central point of tracking cross is equal to the distance of horizontal two end points, and control described base plate and laterally move, until the central point of tracking cross is equal to the distance of transverse direction two end points;

Judge that whether the central point of tracking cross is equal to the distance of longitudinal two end points, and control described base plate and vertically move, until central point is equal to the distance of longitudinal direction two end points;

Judge that whether the central point of tracking cross is equal to the distance of four end points, if the central point of tracking cross is equal to the distance of four end points, realize locating hole coaxial with cloth pin datum hole; According to the relative position relation between needle falling hole and locating hole, calculate the relative position relation between needle falling hole and cloth pin datum hole;

Step 6, the draw point array of integrated piercing determined according to step 2, control base plate and do transverse direction, vertically move, thus realize the location of the equidistant solid matter micro hole of integrated piercing template.

3. integrated piercing template according to claim 2 equidistant solid matter micro hole localization method, in step one, comprising:

Step 1-1, definition world coordinate system (X _w, Y _w, Z _w), camera coordinate system (X _c, Y _c, Z _c), image pixel coordinates system (u, v) with image physical coordinates system (X, Y), wherein:

World coordinate system (X _w, Y _w, Z _w) being used for the position of any object in describe environment, in world coordinate system, 1 M in space is expressed as (X _w, Y _w, Z _w);

Camera coordinate system (X _c, Y _c, Z _c) initial point be defined in the photocentre of camera lens, Z _caxle is optical axis, Z _caxle and Y _caxle is parallel to trunnion axis and the vertical axis of the plane of delineation respectively;

Image pixel coordinates system (u, v) in units of pixel, u, v represent columns in digital picture and line number respectively;

Image physical coordinates system (X, Y) is with the intersection point of the optical axis of camera and the plane of delineation for initial point, and X-axis and Y-axis are parallel with v axle with the u axle of image pixel coordinates system respectively;

Step 1-2, set up mathematical relationship between dimensional target point and corresponding picture point, comprising:

The conversion of world coordinate system and camera coordinate system;

The conversion of image coordinate system and camera coordinate system;

The conversion of world coordinate system and image coordinate system;

Obtain the image pixel coordinates of distortion error and undistorted error according to the relation of image physical coordinates system and image coordinate system respectively, utilize the distortion error model of nonlinear imaging model to carry out distortion correction.

4. integrated piercing template according to claim 2 equidistant solid matter micro hole localization method, in step 2, when the needle falling hole on base plate and the transverse direction relative motion of puncture template, needle falling hole center of circle movement locus is parallel with the often row aperture circle center line connecting of draw point array or overlap; During needle falling hole relative motion longitudinal with puncture template, the circle center line connecting of the every row aperture of needle falling hole deferent and draw point array is parallel or overlap.

5. integrated piercing template according to claim 2 equidistant solid matter micro hole localization method, wherein, if cloth pin datum hole is the aperture being positioned at the puncture template upper left corner, the centre-to-centre spacing of the equidistant solid matter micro hole of puncture template is r, and the distance of locating hole and needle falling hole is l _x=a × r, a is integer, if locating hole is coaxial with cloth pin datum hole, then and the line of locating hole and needle falling hole and the line coincident in the first row aperture center of circle of draw point array in puncture template, thus show that needle falling hole (x, y) with the relative position relation of cloth pin datum hole is:

$\left\{\begin{array}{c}x=a\×r\\ y=0\end{array}\right..$