CN104330041A - Measuring method for track switch steel rail member drill hole dimension - Google Patents

Abstract

The invention provides a measuring method for track switch steel rail member drill hole dimension, and provides a measuring method for a track switch steel rail member drill hole and hole pitch based on binocular stereo vision. With application of the method, the size of the aperture of the drill hole and drill hole location can be directly measured in a steel rail member production workshop so that work efficiency can be greatly enhanced, measuring work can be completed onsite, the method is flexible and convenient and accurate in measuring results, measuring precision and speed are substantially enhanced, and thus production efficiency is greatly enhanced.

Description

A kind of measuring method of railroad turnout steel rail part bore size

Technical field

The invention belongs to measuring method technical field, relate to a kind of measuring method that can realize the railroad turnout steel rail part bore size of non-contact measurement.

Background technology

Track switch is the crucial track equipment that railway realizes that train turns line operation, its technical merit has embodied a concentrated reflection of the manufacture level of a state-owned railroads track, the high precision of switch manufacture and assembling and high ride are one of important technical indicators, and the relative dimensions manufacturing accuracy of railroad turnout steel rail part is one of key factor affecting track switch high precision and high ride.The measurement of current railroad turnout steel rail part bore size and position is all adopt human contact's formula metering system usually, and human contact's formula metering system measuring process is loaded down with trivial details, length consuming time, and precision is low, measures efficiency low.

Summary of the invention

The present invention is in order to overcome the defect of prior art, devise a kind of measuring method of railroad turnout steel rail part bore size, the non-cpntact measurement of rail part boring aperture size and bore position can be realized, overcome manual measurement length consuming time, problem that precision is not high, can greatly improve measurement efficiency.

The concrete technical scheme that the present invention takes is: a kind of measuring method of railroad turnout steel rail part bore size, and key is: described method comprises the following steps:

A, carry out industrial camera demarcation: first adopt Zhang Zhengyou plane reference method to demarcate, contained the image of plane reference plate at seven width of Different Plane by shooting, obtain the Intrinsic Matrix of industrial camera, then obtain the outer parameter matrix under this plane reference plate place coordinate system by just right plane reference plate in the measurements, also can obtain the fundamental matrix between two industrial cameras simultaneously;

B, preparation rail part, rail part draws the first detect aperture position, the height of adjustment two industrial cameras and angle, make two industrial cameras just to the side of rail part, then tested rail part is taken, obtains two images of same section rail part, and by take a picture and be transferred to control device;

C, control device carry out gaussian filtering process and the rim detection based on Canny respectively to two of gained images, obtain the image of two width respectively containing drilled edge;

D, detected the equation obtaining all ellipses in the picture by the ellipse in the image to step c gained, get the coordinate of oval upper 250 points, the match point in two images on ellipse is obtained by Epipolar geometric constraint relation, then the three-dimensional coordinate of these match points is recovered according to the fundamental matrix between match point and two industrial cameras, these spatial point are carried out to the matching of space circle, so just can obtain the equation of holing in space, also just obtain the pore size of boring and the position in aperture;

The data of steps d gained and the normal data preserved in a database are compared by e, control device, provide the prompting that whether qualified testing result is, if qualified, in the first detect aperture position punching, if defective, carry out step f;

F, repeat step b to step e, until testing result is qualified.

Testing result described in step e is qualified refers to that the product that scale error is less than or equal to 0.5mm is specification product, and testing result is defective refers to that the product that scale error is greater than 0.5mm is substandard product.

The invention has the beneficial effects as follows: provide a kind of based on the railroad turnout steel rail part drilling of the rail of binocular stereo vision and the measuring method of pitch of holes, profit directly can realize the measurement of boring aperture size and bore position in this way at rail part workshop, to greatly increase work efficiency, surveying work just can be completed at the scene, flexibly and easily, measurement result is accurate, significantly improves precision and the speed of measurement, thus substantially increases production efficiency.

Accompanying drawing explanation

Fig. 1 is the structural representation of measurement mechanism in the present invention.

Fig. 2 is the position relationship schematic diagram of the present invention's plane reference plate, industrial camera and rail part when measuring.

Fig. 3 is two Epipolar geometric constraints of binocular stereo vision.

In accompanying drawing, 1 represents base, and 2 represent industrial camera, 3 represent bracing frame, and 4 represent leading screw, and 5 represent motor, 6 represent reductor, and 7 represent slide block, 8 representative location cross bars, 9 representative location vertical poles, 10 represent all-directional tripod head, and 11 represent shaft coupling, 12 represent pulley, and 13 represent control desk, and 14 represent support bar, 15 represent Turning-over plate chair, and 16 represent rail part, and 17 represent plane reference plate.

Embodiment

Below in conjunction with accompanying drawing, the present invention will be further described:

As shown in Figure 1, a kind of railroad turnout steel rail part bore size measurement mechanism, comprise base 1, two industrial cameras 2, control device, arrangement for adjusting height, two industrial cameras 2 are all connected with control device with arrangement for adjusting height, arrangement for adjusting height is vertically arranged on base 1, two industrial cameras 2 are symmetricly set on the both sides of arrangement for adjusting height in the horizontal direction and are formed to be elevated with arrangement for adjusting height and coordinate, and two industrial cameras 2 are formed to be elevated with base 1 by arrangement for adjusting height and coordinate.

Arrangement for adjusting height comprises the bracing frame 3 of door type structure, leading screw 4, motor 5, reductor 6, fixed support, the output shaft of motor 5 is connected with reductor 6 by shaft coupling 11, the bottom of bracing frame 3 is fixedly connected with base 1, leading screw 4 is vertically arranged on the inside of bracing frame 3 door type structure, motor 5 is arranged on the top of bracing frame 3 and is connected with control device, the top perforating branch support 3 of leading screw 4 is fixedly connected with the output shaft of reductor 6, the bottom of leading screw 4 and base 1 are formed and are rotatably assorted, leading screw 4 is set with slide block 7, fixed support comprises location cross bar 8, the two ends of location cross bar 8 are respectively arranged with a location vertical pole 9, two location vertical poles 9 are symmetrical arranged and all cross bar 8 is vertical arranges with location, the end of two location vertical poles 9 is all fixed with all-directional tripod head 10, industrial camera 2 is hinged with all-directional tripod head 10, location cross bar 8 is fixedly connected with slide block 7, industrial camera 2 is formed to be elevated with base 1 by the cooperation of slide block 7 and leading screw 4 and coordinates.During measurement, motor 5 drives reductor 6 to rotate by shaft coupling 11, reductor 6 drives leading screw 4 to rotate, slide block 7 is made to rise on leading screw 4 or decline, slide block 7 drives two industrial cameras 2 to rise or decline by fixed support, and when two industrial cameras 2 arrive required height, motor 5 stops operating, and then utilizes all-directional tripod head 10 to adjust the angle of industrial camera 2, structure is simple, easy to operate.

As to further improvement of the present invention, multiple pulley 12 being set in the bottom of base 1, making this device convenient laborsaving when moving horizontally.

As to further improvement of the present invention, set up the control desk 13 for placing control device, the back side of control desk 13 is fixedly connected with bracing frame 3, the bottom of control desk 13 is fixed with support bar 14, the bottom of support bar 14 is fixedly connected with the upper end of base 1, be arranged on by control device on control desk 13, integrally, during measurement, handled easily personal observations controls.

As to further improvement of the present invention, set up the Turning-over plate chair 15 matched with control desk 13, the bottom of Turning-over plate chair 15 is fixedly connected with base 1, and operating personnel can be sitting in the enterprising line operate of Turning-over plate chair 15, convenient comfortable.

A measuring method for railroad turnout steel rail part bore size, key is: described method comprises the following steps:

A, carry out industrial camera demarcation: first adopt Zhang Zhengyou plane reference method to demarcate, contained the image of plane reference plate 17 at seven width of Different Plane by shooting, obtain the Intrinsic Matrix of industrial camera, then the outer parameter matrix under this plane reference plate 17 place coordinate system is obtained by just right plane reference plate 17 in the measurements, also can obtain the fundamental matrix between two industrial cameras 2, concrete steps are as follows simultaneously:

Respectively Zhang Zhengyou standardization is used to two industrial cameras 2, obtains the Intrinsic Matrix P of two industrial cameras 2 ₁and P ₂(Zhengyou zhang.A Flexible New Technique for Camera Calibration.IEEE Transactions on Pattern Analysis and Machine Intelligence, VOL.22, NO.11.),

Two Epipolar geometric constraints of binocular stereo vision, as shown in Figure 3, in figure 3, X is a bit in space, π ₁, π ₂be the imaging plane of two industrial cameras 2, m ₁, m ₂for X is in the picture point of two industrial cameras 2, C ₁, C ₂be the optical centre of two industrial cameras 2, e ₁, e ₂be two Multi-extended, l ₁, l ₂be respectively m ₂, m ₁eP point;

The pole geometric relationship of two industrial cameras 2 imaging can be portrayed with fundamental matrix F, expresses the outer pole constraint of two width images with fundamental matrix:

$m_2^{T}F{m}_1=0$ ①

l ₁＝Fm ₁

If given fully many corresponding point, can by 1. formula linear calculate fundamental matrix F, make F=(f _ij), m ₁=(u, v, 1) ^t, m ₂=(u', v', 1) ^tthen 1. the equation of constraint of fundamental matrix can be write as following form:

u'uf ₁₁+u'vf ₁₂+u'f ₁₃+v'uf ₂₁+v'vf ₂₂+v'f ₂₃+uf ₃₁+vf ₃₂+f ₃₃＝0 ②

Note

f＝(f ₁₁,f ₁₂,f ₁₃,f ₂₁,f ₂₂,f ₂₃,f ₃₁,f ₃₂,f ₃₃) ^T③

It is 9 dimensional vectors be made up of 3 of F row vectors, then 2. can be write as the form of inner product of vectors:

(u'u,u'v,u',v'u,v'v,v',u,v,1)f＝0

Like this, given N number of corresponding point can obtain system of linear equations:

$\mathrm{Af}=\left[\begin{array}{ccccccccc}{u}_1^{\′}{u}_1& u_1^{\′}{v}_1& u_1^{\′}& v_1^{\′}{u}_1& v_1^{\′}{v}_1& v_1^{\′}& u_1& v_1& 1\\ & & & & .& & & & \\ & & & & .& & & & \\ & & & & .& & & & \\ u_N^{\′}{u}_N& u_N^{\′}{v}_N& u_N^{\′}& v_N^{\′}{u}_N& v_N^{\′}{v}_N& v_N^{\′}& u_N& v_N& 1\end{array}\right]f=0$ ④

Wherein A is the matrix of N × 9.In a practical situation, directly can not determine fundamental matrix by solving system of linear equations, but ask constraint condition || f||=1 system of equations least square solution 4., namely ask following problems:

$\left\{\begin{array}{c}\min \left|\right|\mathrm{Af}\left|\right|\\ \mathrm{subject}\left|\right|f\left|\right|=1\end{array}\right.$ ⑤

The svd of A is made to be A=UDV ^t, then last column vector of explanation V 5., i.e. f=v ₉so fundamental matrix F can be obtained;

B, preparation rail part 16, rail part 16 draws the first detect aperture position, the height of adjustment two industrial cameras 2 and angle, make two industrial cameras 2 just to the side of rail part 16, as shown in Figure 2, then tested rail part 16 is taken, obtains two images of same section rail part 16, and by take a picture and be transferred to control device;

C, control device carry out gaussian filtering process and the rim detection based on Canny respectively to two of gained images, obtain the image of two width respectively containing drilled edge;

D, detected the equation obtaining all ellipses in the picture by the ellipse in the image to step c gained, get the coordinate of oval upper 250 points, the match point in two images on ellipse is obtained by Epipolar geometric constraint relation, then the three-dimensional coordinate of these match points is recovered according to the fundamental matrix between match point and two industrial cameras, these spatial point are carried out to the matching of space circle, so just can obtain the equation of holing in space, also just obtain the pore size of boring and the position in aperture, concrete steps are as follows:

D1, ellipses detection:

Due to two industrial cameras 2 take time, can not keep facing boring shooting simultaneously, therefore when boring projects to industrial camera 2 as plane, not necessarily circle, also be likely oval, so will the ellipse as plane be detected, the oval algorithm used in the present invention can detect ellipses all in image or circle (HO Chun-ta, CHEN Ling-hwei.A fast ellipse/circle detector using geometric symmetry [J] .Pattern Recognition, 1995, 28 (1): 117-124.), if the elliptic equation detected is:

C ₁(x,y)＝a ₁x ²+h ₁xy+b ₁y ²+g ₁x+f ₁y+c ₁

C ₂(x,y)＝ax ²+h ₂xy+b ₂y ²+g ₂x+f ₂y+c ₂

D2, ask the match point on ellipse in two width images:

If m ₁be a bit on ellipse, the point mated with it in the image of another industrial camera 2 is m ₂, retrained by two poles of two pole geometry and can try to achieve fundamental matrix F, so m ₁eP point l ₁=Fm ₁(establish the l tried to achieve ₁equation be: Ax+By+C=0), m ₂must at l ₁on, and m ₂simultaneously also at quafric curve C ₂on (x, y), m ₂can be tried to achieve by system of equations below:

$\left\{\begin{array}{c}\mathrm{Ax}+\mathrm{By}+C=0\\ C_2(x,y)=0\end{array}\right.$ ⑥

If 10. have a solution, so m ₂be exactly solution 6., if 6. there are two solutions, so these two gray-scale values separated and m ₁the most close point of gray-scale value be and m ₁the point matched, can in the hope of points matched all on ellipse by above method;

The three-dimensional coordinate of d3, recovery drilled edge point:

By trying to achieve match point above, the coordinate of these somes point in three dimensions can be tried to achieve, with m ₁and m ₂this to match point be example to ask their three-dimensional coordinate, in step a, we have obtained the projection matrix P of two industrial cameras 2 ₁, P ₂, so respectively projection equation is listed to two industrial cameras 2:

$\left\{\begin{array}{c}{\mathrm{zm}}_1=P_{1}X\\ z{m}_2=P_{2}X\end{array}\right.\⇔\left\{\begin{array}{c}{m}_1\×P_{1}X=0\\ m_2\×P_{2}X=0\end{array}\right.\⇒\left(\begin{array}{c}{\left[m_1\right]}_{\×}{P}_1\\ {\left[m_2\right]}_{\×}{P}_2\end{array}\right)X=0$

⑦

Wherein z is a constant, X is spatial point coordinate, 7. be the equation of a Planar Mechanisms, there are 4 independently linear equalities coming from the coordinate of X, solution 7. can be tried to achieve by least square method, so this has just tried to achieve the three-dimensional coordinate X of match point, can in the hope of the three-dimensional coordinate of all match points by said method;

The matching of d4, space circle:

The three-dimensional point of trying to achieve above, in fact in three dimensions, drop in a common space circle in theory simultaneously, but due to the error of industrial camera 2 demarcation etc., they can not drop in a space circle utterly, but we can utilize these spatial point to carry out the equation of this space circle of matching

Concrete approximating method is as follows:

D4-1, set the equation of plane at space circle place as Ax+By+Cz+D=0, because all points in space circle are all inevitable in this plane, if i-th point is di (i=1,2,3...N) to the distance of this plane, so

$d_i=\frac{|{\mathrm{Ax}}_i+{\mathrm{By}}_i+{\mathrm{Cz}}_i+D|}{\sqrt{A^2+B^2}}$ ⑧

By solve unconstrained optimization below for topic just can in the hope of this plane equation:

$\min \underset{i=1}{\overset{N}{\mathrm{\Σ}}}{d}_i^2=\min \underset{i=1}{\overset{N}{\mathrm{\Σ}}}\frac{{({\mathrm{Ax}}_i+{\mathrm{By}}_i+{\mathrm{Cz}}_i+D)}^2}{A^2+B^2}$

D4-2, the central coordinate of circle utilizing the geometric properties estimation space of circle round, the intersection point of the perpendicular bisector of the string of circle necessarily passes through the center of circle, so utilize this character can estimate the coordinate in the center of circle very simply, then the center of gravity of these central coordinate of circle is asked, the center of gravity that we may be just the centre points of circle these sees the round center of circle approx as, if the central coordinate of circle of circle is (x _o, y _o, z _o);

D4-3, in d4-2, tried to achieve the central coordinate of circle of space circle, so the radius r of space circle is:

$r^2=\frac{1}{N}\underset{i=1}{\overset{N}{\mathrm{\Σ}}}[{(x_i-x_o)}^2+{(y_i-y_o)}^2+{(z_i-z_o)}^2]$

By above process, just by the photo that two industrial cameras 2 are taken, try to achieve the equation of each boring, so just obtain the effective aperture size of boring, and the position in the boring center of circle, pitch of holes is exactly the distance of the hole circle heart;

The data of steps d gained and the normal data preserved in a database are compared by e, control device, if scale error is less than or equal to 0.5mm, are specification product, in the first detect aperture position punching of specification product, otherwise are substandard product, carry out step f;

F, repeat step b to step e, until testing result is qualified.

Measuring method in the present invention directly can realize the measurement of boring aperture size and bore position at rail part 16 workshop, to greatly increase work efficiency, surveying work just can be completed at the scene, flexibly and easily, measurement result is accurate, significantly improve precision and the speed of measurement, thus substantially increase production efficiency.

Claims (2)

1. a measuring method for railroad turnout steel rail part bore size, is characterized in that: described method comprises the following steps:

A, carry out industrial camera demarcation: first adopt Zhang Zhengyou plane reference method to demarcate, contained the image of plane reference plate (17) at seven width of Different Plane by shooting, obtain the Intrinsic Matrix of industrial camera, then obtain the outer parameter matrix under this plane reference plate (17) place coordinate system by just right plane reference plate (17) in the measurements, also can obtain the fundamental matrix between two industrial cameras (2) simultaneously;

B, preparation rail part (16), rail part (16) draws the first detect aperture position, adjust height and the angle of two industrial cameras (2), make two industrial cameras (2) just to the side of rail part (16), then tested rail part (16) is taken, obtain two images of same section rail part (16), and by take a picture and be transferred to control device;

C, control device carry out gaussian filtering process and the rim detection based on Canny respectively to two of gained images, obtain the image of two width respectively containing drilled edge;

D, detected the equation obtaining all ellipses in the picture by the ellipse in the image to step c gained, get the coordinate of oval upper 250 points, the match point in two images on ellipse is obtained by Epipolar geometric constraint relation, then the three-dimensional coordinate of these match points is recovered according to the fundamental matrix between match point and two industrial cameras, these spatial point are carried out to the matching of space circle, so just can obtain the equation of holing in space, also just obtain the pore size of boring and the position in aperture;

The data of steps d gained and the normal data preserved in a database are compared by e, control device, provide the prompting that whether qualified testing result is, if qualified, in the first detect aperture position punching, if defective, carry out step f;

F, repeat step b to step e, until testing result is qualified.

2. the measuring method of a kind of railroad turnout steel rail part bore size according to claim 1, it is characterized in that: the testing result described in step e is qualified refers to that the product that scale error is less than or equal to 0.5mm is specification product, testing result is defective refers to that the product that scale error is greater than 0.5mm is substandard product.