CN103954221B

CN103954221B - The binocular photogrammetric survey method of large-size pliable structure vibration displacement

Info

Publication number: CN103954221B
Application number: CN201410191705.6A
Authority: CN
Inventors: 王聪; 许畅; 高晶波; 张春芳
Original assignee: Harbin Institute of Technology
Current assignee: Harbin Institute of Technology
Priority date: 2014-05-08
Filing date: 2014-05-08
Publication date: 2016-08-17
Anticipated expiration: 2034-05-08
Also published as: CN103954221A

Abstract

The binocular photogrammetric survey method of large-size pliable structure vibration displacement, belongs to flexible structure dynamic analysis and field of measuring technique.The present invention be in order to solve existing contact type measurement can the problem that impacts of performance to flexible structure own.First it demarcate industrial camera；Then the tested flexible structure of exciting, synchronizes to trigger by all industrial cameras of Single-chip Controlling simultaneously, carries out the shooting of tested flexible structure measured point vibration displacement；The image obtained the shooting of all industrial cameras again processes, and utilizes Corner Detection Algorithm to obtain the pixel coordinate of measuring point, and recycling binocular three-dimensional reconfiguration technique obtains the object coordinates of each moment measuring point, thus obtains the vibration displacement curve of tested flexible structure.The present invention is for the measurement of flexible structure vibration displacement.

Description

The binocular photogrammetric survey method of large-size pliable structure vibration displacement

Technical field

The present invention relates to the binocular photogrammetric survey method of large-size pliable structure vibration displacement, belong to flexible structure dynamic analysis and Field of measuring technique.

Background technology

The application that binocular camera shooting is measured mainly has car three-dimensional profile is carried out high precision test, the change of structure in wind tunnel experiment Shape, large-scale antenna profile measure of precision, the field such as ground type mapping.These measure the shooting Three Dimensional Reconfiguration major part used Three-dimensional feature for stationary body is measured, and cannot measure the vibration of object.For the vibration of flexible structure, adopt By the contact type measurement mode of traditional acceleration transducer, not only the dynamic performance of flexible structure can be brought impact, also Complicated owing to measuring equipment, cause error to be difficult to control to and influence of noise is bigger.

Summary of the invention

The invention aims to solve existing contact type measurement can the problem that impacts of performance to flexible structure own, it is provided that A kind of binocular photogrammetric survey method of large-size pliable structure vibration displacement.

The binocular photogrammetric survey method of large-size pliable structure vibration displacement of the present invention, it comprises the following steps:

Step one: demarcate industrial camera, the quantity of described industrial camera is 2-5；

Step 2: the tested flexible structure of exciting, synchronizes to trigger by all industrial cameras of Single-chip Controlling simultaneously, carries out tested The shooting of flexible structure measured point vibration displacement；

Step 3: the image obtaining the shooting of all industrial cameras processes, utilizes Corner Detection Algorithm to obtain the picture of measuring point Element coordinate, recycling binocular three-dimensional reconfiguration technique obtains the object coordinates of each moment measuring point, thus obtains tested flexible structure Vibration displacement curve.

Demarcate industrial camera method particularly includes:

Using scaling board to demarcate industrial camera, described scaling board is 7 × 9 be made up of chequered with black and white square Gridiron pattern, the square length of side is 5mm；The position of scaling board is set, makes the field range of each industrial camera cover Whole scaling board, and use the rest image of industrial camera shooting scaling board, complete to demarcate.

The quantity of industrial camera is 2, obtains the vibration displacement curve of tested flexible structure in step 3 method particularly includes:

Shot the measured point of tested flexible structure by 2 industrial cameras simultaneously, after the image obtaining shooting processes, build Vertical equation group is as follows:

\{\begin{matrix} Z_{c 1} [\begin{matrix} u_{1} \\ v_{1} \\ 1 \end{matrix}] = N_{1} M_{1} [\begin{matrix} X_{w} \\ Y_{w} \\ Z_{w} \\ 1 \end{matrix}] = Q_{1} [\begin{matrix} X_{w} \\ Y_{w} \\ Z_{w} \\ 1 \end{matrix}] \\ Z_{c 2} [\begin{matrix} u_{2} \\ v_{2} \\ 1 \end{matrix}] = N_{2} M_{2} [\begin{matrix} X_{w} \\ Y_{w} \\ Z_{w} \\ 1 \end{matrix}] = Q_{2} [\begin{matrix} X_{w} \\ Y_{w} \\ Z_{w} \\ 1 \end{matrix}] \end{matrix},

In formula, Z_c1Be the first industrial camera under its photocentre coordinate system, the Z axis coordinate figure of measuring point P, (u₁,v₁) it is measuring point The pixel coordinate value of P, (X_w,Y_w,Z_w) it is the object coordinates value of measuring point P, N₁It is the Intrinsic Matrix of the first industrial camera, M₁It is the outer parameter matrix of the first industrial camera, Q₁It is the projection matrix of the first industrial camera, Q₁=N₁M₁；

Z_c2Be the second industrial camera under its photocentre coordinate system, the Z axis coordinate figure of measuring point P, (u₂,v₂) it is the picture of measuring point P Element coordinate figure, (X_w,Y_w,Z_w) it is the object coordinates value of measuring point P, N₂It is the Intrinsic Matrix of the second industrial camera, M₂For The outer parameter matrix of the second industrial camera, Q₂It is the projection matrix of the second industrial camera, Q₂=N₂M₂；

Above-mentioned photocentre coordinate system represents that optical axis is the coordinate system of Z axis with the photocentre of industrial camera as initial point；

Above-mentioned equation group is processed, it is thus achieved that overdetermined equation:

\{\begin{matrix} {Q^{1}}_{11} X_{w} + {Q^{1}}_{12} Y_{w} + {Q^{1}}_{13} Z_{w} + {Q^{1}}_{14} - u_{1} {Q^{1}}_{31} X_{w} - u_{1} {Q^{1}}_{32} Y_{w} - u_{1} {Q^{1}}_{33} Z_{w} = u_{1} {Q^{1}}_{34} \\ {Q^{1}}_{21} X_{w} + {Q^{1}}_{22} Y_{w} + {Q^{1}}_{23} Z_{w} + {Q^{1}}_{24} - v_{1} {Q^{1}}_{31} X_{w} - v_{1} {Q^{1}}_{32} Y_{w} - v_{1} {Q^{1}}_{33} Z_{w} = v_{1} {Q^{1}}_{34} \\ {Q^{2}}_{11} X_{w} + {Q^{2}}_{12} Y_{w} + {Q^{2}}_{13} Z_{w} + {Q^{2}}_{14} - u_{2} {Q^{2}}_{31} X_{w} - u_{2} {Q^{2}}_{32} Y_{w} - u_{2} {Q^{2}}_{33} Z_{w} = u_{2} {Q^{2}}_{34} \\ {Q^{2}}_{21} X_{w} + {Q^{2}}_{22} Y_{w} + {Q^{2}}_{23} Z_{w} + {Q^{2}}_{24} - v_{2} {Q^{2}}_{31} X_{w} - v_{2} {Q^{2}}_{32} Y_{w} - v_{2} {Q^{2}}_{33} Z_{w} = v_{2} {Q^{2}}_{34} \end{matrix},

Q in formula¹ _ijRepresent Q₁I-th row jth row, i=1,2,3, j=1,2,3,4；

Q² _ijRepresent Q₂I-th row jth row, i=1,2,3, j=1,2,3,4；

Arrange overdetermined equation, obtain:

[\begin{matrix} {Q^{1}}_{11} - u_{1} {Q^{1}}_{31} & {Q^{1}}_{12} - u_{1} {Q^{1}}_{32} & {Q^{1}}_{13} - u_{1} {Q^{1}}_{33} \\ {Q^{1}}_{21} - v_{1} {Q^{1}}_{31} & {Q^{1}}_{22} - v_{1} {Q^{1}}_{32} & {Q^{1}}_{23} - v_{1} {Q^{1}}_{33} \\ {Q^{2}}_{11} - u_{2} {Q^{2}}_{31} & {Q^{2}}_{12} - u_{2} {Q^{2}}_{32} & {Q^{2}}_{13} - u_{2} {Q^{2}}_{33} \\ {Q^{2}}_{21} - v_{2} {Q^{2}}_{31} & {Q^{2}}_{22} - v_{2} {Q^{2}}_{32} & {Q^{2}}_{23} - v_{2} {Q^{2}}_{33} \end{matrix}] [\begin{matrix} X_{w} \\ Y_{w} \\ Z_{w} \end{matrix}] = [\begin{matrix} u_{1} {Q^{1}}_{34} - {Q^{1}}_{14} \\ v_{1} {Q^{1}}_{34} - {Q^{1}}_{24} \\ u_{2} {Q^{2}}_{34} - {Q^{2}}_{14} \\ v_{2} {Q^{2}}_{34} - {Q^{2}}_{24} \end{matrix}],

Set

K = [\begin{matrix} {Q^{1}}_{11} - u_{1} {Q^{1}}_{31} & {Q^{1}}_{12} - u_{1} {Q^{1}}_{32} & {Q^{1}}_{13} - u_{1} {Q^{1}}_{33} \\ {Q^{1}}_{21} - v_{1} {Q^{1}}_{31} & {Q^{1}}_{22} - v_{1} {Q^{1}}_{32} & {Q^{1}}_{23} - v_{1} {Q^{1}}_{33} \\ {Q^{2}}_{11} - u_{2} {Q^{2}}_{31} & {Q^{2}}_{12} - u_{2} {Q^{2}}_{32} & {Q^{2}}_{13} - u_{2} {Q^{2}}_{33} \\ {Q^{2}}_{21} - v_{2} {Q^{2}}_{31} & {Q^{2}}_{22} - v_{2} {Q^{2}}_{32} & {Q^{2}}_{23} - v_{2} {Q^{2}}_{33} \end{matrix}],

h = [\begin{matrix} X_{w} \\ Y_{w} \\ Z_{w} \end{matrix}], U = [\begin{matrix} u_{1} {Q^{1}}_{34} - {Q^{1}}_{14} \\ v_{1} {Q^{1}}_{34} - {Q^{1}}_{24} \\ u_{2} {Q^{2}}_{34} - {Q^{2}}_{14} \\ v_{2} {Q^{2}}_{34} - {Q^{2}}_{24} \end{matrix}],

Then above formula is deformed into Kh=U,

Solve obtain h least square solution:

H=(K^TK)^-1K^TU,

Thus solve the object coordinates value obtaining time dependent measuring point P, and then obtain the vibration position of tested flexible structure Move curve.

The Intrinsic Matrix N of the first industrial camera₁Intrinsic Matrix N with the second industrial camera₂Preparation method identical, The outer parameter matrix M of one industrial camera₁Outer parameter matrix M with the second industrial camera₂Preparation method identical, the first work The Intrinsic Matrix N of industry camera₁With outer parameter matrix M₁Preparation method be:

In the calibration process of the first industrial camera, the rest image of scaling board shooting obtained utilizes Corner Detection Algorithm to extract The angle point of adjacent square grid, it is thus achieved that the corner pixels coordinate in scaling board, further according to the corner pixels coordinate obtained, asks Solve following equation:

Z_{c} [\begin{matrix} u \\ v \\ 1 \end{matrix}] = [\begin{matrix} f / dx & 0 & u_{0} \\ 0 & f / dy & v_{0} \\ 0 & 0 & 1 \end{matrix}] [\begin{matrix} R & t \end{matrix}] [\begin{matrix} X_{w} \\ Y_{w} \\ Z_{w} \\ 1 \end{matrix}] = N_{1} M_{1} [\begin{matrix} X_{w} \\ Y_{w} \\ Z_{w} \\ 1 \end{matrix}],

In formula, Z_cBeing the first industrial camera Z axis coordinate figure of angle point under its photocentre coordinate system, (u v) is the pixel of angle point Coordinate figure, f is the focal length of the first industrial camera, and (dx, dy) is the physical width of the first industrial camera image-forming component, (u₀,v₀) Being the imaging center coordinate figure of the first industrial camera, R is the spin matrix in the outer parameter matrix of the first industrial camera, and t is the Translation matrix in the outer parameter matrix of one industrial camera；

Solve above formula, it is thus achieved that the Intrinsic Matrix N of the first industrial camera₁With outer parameter matrix M₁。

Advantages of the present invention: the binocular photogrammetric survey method of large-size pliable structure vibration displacement of the present invention, by two or Two or more high-speed industrial camera, shoots the vibration processes of flexible structure from different angles, and utilizes Corner Detection Algorithm to obtain The pixel coordinate of measuring point, obtain the three-dimensional coordinate in measuring point each moment further according to three-dimensionalreconstruction principle, this three-dimensional coordinate time Between sequence be exactly displacement vibration information.

The present invention solves the vibration displacement of large-size pliable structure and measures problem, it is to avoid contact type measurement performance to structure own Impact, reduce test equipment complexity, Three Dimensional Reconfiguration based on image is applied to kinetic measurement by it simultaneously, carries Go out a kind of method utilizing digital camera measurement technology that flexible structure is carried out vibration-testing.The method utilizes more than two works Industry photographic camera shoots testee with same frame per second, utilizes MCS51 Single-chip Controlling sequential to reach stringent synchronization.It is kept away Exempt from the impact of performance on flexible structure own, there is test process simple, measurement result precision high, can be extensive It is applied to the vibration measurement of space flight large-size pliable structure.

It is quick that the inventive method has measurement process simultaneously, it is not necessary to extra amplifying circuit；Strong adaptability, can be according to survey Amount requires to change camera frame per second and resolution, to obtain the feature of more accurate result；It is little by Environmental Noise Influence；At mark On the premise of fixing really, certainty of measurement is higher.

Accompanying drawing explanation

Fig. 1 is the structural representation of scaling board；

Fig. 2 is the schematic diagram of binocular three-dimensional reconstruct；First industrial camera image space coordinate system O₁-x_ly_lz_lWith object coordinates system O-xyz overlaps, and image coordinate system is O_l-X_lY_l, effective focal length is f_l；Second industrial camera image space coordinate system O₂-x_ry_rz_r, image coordinate system is O_r-X_rY_r, effective focal length is f_r；Point P coordinate in O-xyz in thing side is (X, Y, Z), its picture point p corresponding in the first industrial camera photo is at O₁-x_ly_lz_lIn coordinate be (x, y, f_l), P exists Picture point p corresponding in second industrial camera photo_rAt O₂-x_ry_rz_rIn coordinate be (x_r,y_r,f_r)；

Fig. 3 is the measuring state schematic diagram of the binocular photogrammetric survey method of large-size pliable structure vibration displacement of the present invention；Figure In 1 be tested flexible structure, 2 is the first industrial camera, and 3 is the second industrial camera, the round dot in tested flexible structure 1 Represent measuring point.

Detailed description of the invention

Detailed description of the invention one: present embodiment is described below in conjunction with Fig. 1 to Fig. 3, large-scale flexible knot described in present embodiment The binocular photogrammetric survey method of structure vibration displacement, it comprises the following steps:

In present embodiment, the displacement range of tested flexible structure is in the visual field of arbitrary industrial camera, to tested flexible structure Energisation mode can be according to test request unrestricted choice.Synchronization to multiple industrial cameras triggers, and uses MCS51 monolithic Machine controls sequential, it is ensured that multiple industrial cameras trigger simultaneously and stop；Industrial camera frame per second is according to the vibration of tested flexible structure Frequency selects, it is desirable to meet nyquist sampling theorem, it is desirable to there is not frame losing phenomenon.

Detailed description of the invention two: present embodiment is described below in conjunction with Fig. 1, embodiment one is made further by present embodiment Illustrating, present embodiment demarcates industrial camera method particularly includes:

Scaling board in present embodiment uses high-precision printer to print, to ensure that the precision that industrial camera is demarcated meets measurement Requirement.Demarcate installation site and the angle of postindustrial camera, and lens focus etc. all must not change.Shoot vibrated The field range without departing from arbitrary camera of the measuring point target on measured object is ensured during journey.Being chosen as more than being closed of camera frame per second 3 times of the frequency of vibration of the heart, minimum resolution is for being not less than 30w pixel, and the distance between camera and measured object is less than 3m.The shooting of all industrial cameras must be carried out by stringent synchronization, it is desirable to there is not frame losing phenomenon.Use MCS51 single-chip microcomputer Carry out shooting sequencing contro, utilize switching signal to realize the triggering of each camera.Triggering time sequence precision is 1 μ s.

The a series of pictures that industrial camera shoots finally imports in computer and processes, and utilizes Corner Detection in processing procedure Algorithm obtains each measuring point pixel coordinate in different industrial camera images, carries out coordinate change further according to known camera parameter Change, obtain the object coordinates of each frame moment measuring point.The time series of object coordinates is exactly the displacement vibration curve of measuring point.

Detailed description of the invention three: present embodiment is described below in conjunction with Fig. 2 and Fig. 3, embodiment two is made by present embodiment Further illustrating, the quantity of industrial camera described in present embodiment is 2, obtains the vibration of tested flexible structure in step 3 Displacement curve method particularly includes:

\{\begin{matrix} Z_{c 1} [\begin{matrix} u_{1} \\ v_{1} \\ 1 \end{matrix}] = N_{1} M_{1} [\begin{matrix} X_{w} \\ Y_{w} \\ Z_{w} \\ 1 \end{matrix}] = Q_{1} [\begin{matrix} X_{w} \\ Y_{w} \\ Z_{w} \\ 1 \end{matrix}] \\ Z_{c 2} [\begin{matrix} u_{2} \\ v_{2} \\ 1 \end{matrix}] = N_{2} M_{2} [\begin{matrix} X_{w} \\ Y_{w} \\ Z_{w} \\ 1 \end{matrix}] = Q_{2} [\begin{matrix} X_{w} \\ Y_{w} \\ Z_{w} \\ 1 \end{matrix}] \end{matrix},

\{\begin{matrix} {Q^{1}}_{11} X_{w} + {Q^{1}}_{12} Y_{w} + {Q^{1}}_{13} Z_{w} + {Q^{1}}_{14} - u_{1} {Q^{1}}_{31} X_{w} - u_{1} {Q^{1}}_{32} Y_{w} - u_{1} {Q^{1}}_{33} Z_{w} = u_{1} {Q^{1}}_{34} \\ {Q^{1}}_{21} X_{w} + {Q^{1}}_{22} Y_{w} + {Q^{1}}_{23} Z_{w} + {Q^{1}}_{24} - v_{1} {Q^{1}}_{31} X_{w} - v_{1} {Q^{1}}_{32} Y_{w} - v_{1} {Q^{1}}_{33} Z_{w} = v_{1} {Q^{1}}_{34} \\ {Q^{2}}_{11} X_{w} + {Q^{2}}_{12} Y_{w} + {Q^{2}}_{13} Z_{w} + {Q^{2}}_{14} - u_{2} {Q^{2}}_{31} X_{w} - u_{2} {Q^{2}}_{32} Y_{w} - u_{2} {Q^{2}}_{33} Z_{w} = u_{2} {Q^{2}}_{34} \\ {Q^{2}}_{21} X_{w} + {Q^{2}}_{22} Y_{w} + {Q^{2}}_{23} Z_{w} + {Q^{2}}_{24} - v_{2} {Q^{2}}_{31} X_{w} - v_{2} {Q^{2}}_{32} Y_{w} - v_{2} {Q^{2}}_{33} Z_{w} = v_{2} {Q^{2}}_{34} \end{matrix},

Q in formula¹ _ijRepresent Q₁I-th row jth row, i=1,2,3, j=1,2,3,4；

Q² _ijRepresent Q₂I-th row jth row, i=1,2,3, j=1,2,3,4；

Arrange overdetermined equation, obtain:

[\begin{matrix} {Q^{1}}_{11} - u_{1} {Q^{1}}_{31} & {Q^{1}}_{12} - u_{1} {Q^{1}}_{32} & {Q^{1}}_{13} - u_{1} {Q^{1}}_{33} \\ {Q^{1}}_{21} - v_{1} {Q^{1}}_{31} & {Q^{1}}_{22} - v_{1} {Q^{1}}_{32} & {Q^{1}}_{23} - v_{1} {Q^{1}}_{33} \\ {Q^{2}}_{11} - u_{2} {Q^{2}}_{31} & {Q^{2}}_{12} - u_{2} {Q^{2}}_{32} & {Q^{2}}_{13} - u_{2} {Q^{2}}_{33} \\ {Q^{2}}_{21} - v_{2} {Q^{2}}_{31} & {Q^{2}}_{22} - v_{2} {Q^{2}}_{32} & {Q^{2}}_{23} - v_{2} {Q^{2}}_{33} \end{matrix}] [\begin{matrix} X_{w} \\ Y_{w} \\ Z_{w} \end{matrix}] = [\begin{matrix} u_{1} {Q^{1}}_{34} - {Q^{1}}_{14} \\ v_{1} {Q^{1}}_{34} - {Q^{1}}_{24} \\ u_{2} {Q^{2}}_{34} - {Q^{2}}_{14} \\ v_{2} {Q^{2}}_{34} - {Q^{2}}_{24} \end{matrix}],

Set

K = [\begin{matrix} {Q^{1}}_{11} - u_{1} {Q^{1}}_{31} & {Q^{1}}_{12} - u_{1} {Q^{1}}_{32} & {Q^{1}}_{13} - u_{1} {Q^{1}}_{33} \\ {Q^{1}}_{21} - v_{1} {Q^{1}}_{31} & {Q^{1}}_{22} - v_{1} {Q^{1}}_{32} & {Q^{1}}_{23} - v_{1} {Q^{1}}_{33} \\ {Q^{2}}_{11} - u_{2} {Q^{2}}_{31} & {Q^{2}}_{12} - u_{2} {Q^{2}}_{32} & {Q^{2}}_{13} - u_{2} {Q^{2}}_{33} \\ {Q^{2}}_{21} - v_{2} {Q^{2}}_{31} & {Q^{2}}_{22} - v_{2} {Q^{2}}_{32} & {Q^{2}}_{23} - v_{2} {Q^{2}}_{33} \end{matrix}],

h = [\begin{matrix} X_{w} \\ Y_{w} \\ Z_{w} \end{matrix}], U = [\begin{matrix} u_{1} {Q^{1}}_{34} - {Q^{1}}_{14} \\ v_{1} {Q^{1}}_{34} - {Q^{1}}_{24} \\ u_{2} {Q^{2}}_{34} - {Q^{2}}_{14} \\ v_{2} {Q^{2}}_{34} - {Q^{2}}_{24} \end{matrix}],

Then above formula is deformed into Kh=U,

Solve obtain h least square solution:

H=(K^TK)^-1K^TU,

In present embodiment, measuring point can use reflecting piece to identify to extract.The extracting method of pixel coordinate is corner detection approach, Preset calculation procedure can be used to realize, it is not necessary to each frame pixel extracts respectively, and efficiency is higher.Pixel coordinate and thing side sit Target conversion needs the calibration result utilized in step one.

Detailed description of the invention four: embodiment three is described further by present embodiment, the first industry described in present embodiment The Intrinsic Matrix N of camera₁Intrinsic Matrix N with the second industrial camera₂Preparation method identical, the first industrial camera Outer parameter matrix M₁Outer parameter matrix M with the second industrial camera₂Preparation method identical, the internal reference of the first industrial camera Matrix number N₁With outer parameter matrix M₁Preparation method be:

Z_{c} [\begin{matrix} u \\ v \\ 1 \end{matrix}] = [\begin{matrix} f / dx & 0 & u_{0} \\ 0 & f / dy & v_{0} \\ 0 & 0 & 1 \end{matrix}] [\begin{matrix} R & t \end{matrix}] [\begin{matrix} X_{w} \\ Y_{w} \\ Z_{w} \\ 1 \end{matrix}] = N_{1} M_{1} [\begin{matrix} X_{w} \\ Y_{w} \\ Z_{w} \\ 1 \end{matrix}],

Detailed description of the invention five: embodiment one, two, three or four is described further by present embodiment, present embodiment Described single-chip microcomputer is MCS51 single-chip microcomputer.

The inventive method in calibration process, first by industrial camera install put in place, regulate proper focal length, after scaling board is put Enter viewing field of camera to take pictures.Corner Detection Algorithm is utilized to obtain corner pixels coordinate in scaling board the most in a computer. Try to achieve camera parameter matrix again.Then all industrial cameras are connected to single chip machine controlling circuit, and test triggers and picture stores. In the inventive method, the video camera number used in theory is the most, and the measurement result obtained is the most accurate.Utilize the most in the same time The image sequence that shooting obtains, it is possible to obtain the displacement vibration curve of measuring point, completes the reconstruct of the Three-Dimensional Dynamic to measuring point.Point Take the three-dimensional coordinate in each moment indescribably, just obtain the three-shaft displacement oscillating curve of measuring point.

The present invention can effectively utilize industrial camera and carry out flexible structure vibration-testing, through overtesting, sufficient in illumination, mark In the case of fixing really, using 30w pixel camera, shooting distance is the flexible structure of 2m, and certainty of measurement is up to 0.1mm. Flexible structure vibration non-contact measurement requirement in most cases can be met.

Claims

1. a binocular photogrammetric survey method for large-size pliable structure vibration displacement, it comprises the following steps:

Step 3: the image obtaining the shooting of all industrial cameras processes, utilizes Corner Detection Algorithm to obtain the picture of measuring point Element coordinate, recycling binocular three-dimensional reconfiguration technique obtains the object coordinates of each moment measuring point, thus obtains tested flexible structure Vibration displacement curve；

Demarcate industrial camera method particularly includes:

Using scaling board to demarcate industrial camera, described scaling board is the chess of be made up of chequered with black and white square 7 × 9 Dish lattice, the square length of side is 5mm；The position of scaling board is set, makes the field range of each industrial camera cover complete Scaling board, and use the rest image of industrial camera shooting scaling board, complete to demarcate；

It is characterized in that, the quantity of industrial camera is 2, obtains the vibration displacement curve of tested flexible structure in step 3 Method particularly includes:

\{\begin{matrix} Z_{c 1} [\begin{matrix} u_{1} \\ v_{1} \\ 1 \end{matrix}] = N_{1} M_{1} [\begin{matrix} X_{w} \\ Y_{w} \\ Z_{w} \\ 1 \end{matrix}] = Q_{1} [\begin{matrix} X_{w} \\ Y_{w} \\ Z_{w} \\ 1 \end{matrix}] \\ Z_{c 2} [\begin{matrix} u_{2} \\ v_{2} \\ 1 \end{matrix}] = N_{2} M_{2} [\begin{matrix} X_{w} \\ Y_{w} \\ Z_{w} \\ 1 \end{matrix}] = Q_{2} [\begin{matrix} X_{w} \\ Y_{w} \\ Z_{w} \\ 1 \end{matrix}] \end{matrix},

In formula, Z_c1Be the first industrial camera under its photocentre coordinate system, the Z axis coordinate figure of measuring point P, (u₁,v₁) it is measuring point P Pixel coordinate value, (X_w,Y_w,Z_w) it is the object coordinates value of measuring point P, N₁It is the Intrinsic Matrix of the first industrial camera, M₁ It is the outer parameter matrix of the first industrial camera, Q₁It is the projection matrix of the first industrial camera, Q₁=N₁M₁；

\{\begin{matrix} {Q^{1}}_{11} X_{w} + {Q^{1}}_{12} Y_{w} + {Q^{1}}_{13} Z_{w} + {Q^{1}}_{14} - u_{1} {Q^{1}}_{31} X_{w} - u_{1} {Q^{1}}_{32} Y_{w} - u_{1} {Q^{1}}_{33} Z_{w} = u_{1} {Q^{1}}_{34} \\ {Q^{1}}_{21} X_{w} + {Q^{1}}_{22} Y_{w} + {Q^{1}}_{23} Z_{w} + {Q^{1}}_{24} - v_{1} {Q^{1}}_{31} X_{w} - v_{1} {Q^{1}}_{32} Y_{w} - v_{1} {Q^{1}}_{33} Z_{w} = v_{1} {Q^{1}}_{34} \\ {Q^{2}}_{11} X_{w} + {Q^{2}}_{12} Y_{w} + {Q^{2}}_{13} Z_{w} + {Q^{2}}_{14} - u_{2} {Q^{2}}_{31} X_{w} - u_{2} {Q^{2}}_{32} Y_{w} - u_{2} {Q^{2}}_{33} Z_{w} = u_{2} {Q^{2}}_{34} \\ {Q^{2}}_{21} X_{w} + {Q^{2}}_{22} Y_{w} + {Q^{2}}_{23} Z_{w} + {Q^{2}}_{24} - v_{2} {Q^{2}}_{32} X_{w} - v_{2} {Q^{2}}_{32} Y_{w} - u_{2} {Q^{2}}_{33} Z_{w} = v_{2} {Q^{2}}_{34} \end{matrix},

Q in formula¹ _ijRepresent Q₁I-th row jth row, i=1,2,3, j=1,2,3,4；

Q² _ijRepresent Q₂I-th row jth row, i=1,2,3, j=1,2,3,4；

Arrange overdetermined equation, obtain:

[\begin{matrix} {Q^{1}}_{11} - u_{1} {Q^{1}}_{31} & {Q^{1}}_{12} - u_{1} {Q^{1}}_{32} & {Q^{1}}_{13} - u_{1} {Q^{1}}_{33} \\ {Q^{1}}_{21} - v_{1} {Q^{1}}_{31} & {Q^{1}}_{22} - v_{1} {Q^{1}}_{32} & {Q^{1}}_{23} - v_{1} {Q^{1}}_{33} \\ {Q^{2}}_{11} - u_{2} {Q^{2}}_{31} & {Q^{2}}_{12} - u_{2} {Q^{2}}_{32} & {Q^{2}}_{13} - u_{2} {Q^{2}}_{33} \\ {Q^{2}}_{21} - v_{2} {Q^{2}}_{31} & {Q^{2}}_{22} - v_{2} {Q^{2}}_{32} & {Q^{2}}_{23} - v_{2} {Q^{2}}_{33} \end{matrix}] [\begin{matrix} X_{w} \\ Y_{w} \\ Z_{w} \end{matrix}] = [\begin{matrix} u_{1} {Q^{1}}_{34} - {Q^{1}}_{14} \\ v_{1} {Q^{1}}_{34} - {Q^{1}}_{24} \\ u_{2} {Q^{2}}_{34} - {Q^{2}}_{14} \\ v_{2} {Q^{2}}_{34} - {Q^{2}}_{24} \end{matrix}],

Set

K = [\begin{matrix} {Q^{1}}_{11} - u_{1} {Q^{1}}_{31} & {Q^{1}}_{12} - u_{1} {Q^{1}}_{32} & {Q^{1}}_{13} - u_{1} {Q^{1}}_{33} \\ {Q^{1}}_{21} - v_{1} {Q^{1}}_{31} & {Q^{1}}_{22} - v_{1} {Q^{1}}_{32} & {Q^{1}}_{23} - v_{1} {Q^{1}}_{33} \\ {Q^{2}}_{11} - u_{2} {Q^{2}}_{31} & {Q^{2}}_{12} - u_{2} {Q^{2}}_{32} & {Q^{2}}_{13} - u_{2} {Q^{2}}_{33} \\ {Q^{2}}_{21} - v_{2} {Q^{2}}_{31} & {Q^{2}}_{22} - v_{2} {Q^{2}}_{32} & {Q^{2}}_{23} - v_{2} {Q^{2}}_{33} \end{matrix}],

h = [\begin{matrix} X_{w} \\ Y_{w} \\ Z_{w} \end{matrix}],

U = [\begin{matrix} u_{1} {Q^{1}}_{34} - {Q^{1}}_{14} \\ v_{1} {Q^{1}}_{34} - {Q^{1}}_{24} \\ u_{2} {Q^{2}}_{34} - {Q^{2}}_{14} \\ v_{2} {Q^{2}}_{34} - {Q^{2}}_{24} \end{matrix}],

Then above formula is deformed into Kh=U,

Solve obtain h least square solution:

H=(K^TK)^-1K^TU,

Thus solve the object coordinates value obtaining time dependent measuring point P, and then obtain the vibration displacement of tested flexible structure Curve.

The binocular photogrammetric survey method of large-size pliable structure vibration displacement the most according to claim 1, it is characterised in that The Intrinsic Matrix N of the first industrial camera₁Intrinsic Matrix N with the second industrial camera₂Preparation method identical, the first work The outer parameter matrix M of industry camera₁Outer parameter matrix M with the second industrial camera₂Preparation method identical, the first industrial camera Intrinsic Matrix N₁With outer parameter matrix M₁Preparation method be:

Z_{c} [\begin{matrix} u \\ v \\ 1 \end{matrix}] = [\begin{matrix} f / d x & 0 & u_{0} \\ 0 & f / d y & v_{0} \\ 0 & 0 & 1 \end{matrix}] [\begin{matrix} R & t \end{matrix}] [\begin{matrix} X_{w} \\ Y_{w} \\ Z_{w} \\ 1 \end{matrix}] = N_{1} M_{1} [\begin{matrix} X_{w} \\ Y_{w} \\ Z_{w} \\ 1 \end{matrix}],

In formula, Z_cBe the first industrial camera Z axis coordinate figure of angle point under its photocentre coordinate system, (u, v) be angle point pixel sit Scale value, f is the focal length of the first industrial camera, and (dx, dy) is the physical width of the first industrial camera image-forming component, (u₀,v₀) Being the imaging center coordinate figure of the first industrial camera, R is the spin matrix in the outer parameter matrix of the first industrial camera, and t is the Translation matrix in the outer parameter matrix of one industrial camera；

The binocular photogrammetric survey method of large-size pliable structure vibration displacement the most according to claim 1 and 2, its feature exists In, described single-chip microcomputer is MCS51 single-chip microcomputer.