CN111047552A

CN111047552A - Three-dimensional deflection measuring method and related product

Info

Publication number: CN111047552A
Application number: CN201911075827.8A
Authority: CN
Inventors: 于起峰; 刘肖琳; 张跃强; 朱宪伟; 王三宏
Original assignee: Shenzhen University
Current assignee: Shenzhen University
Priority date: 2019-11-06
Filing date: 2019-11-06
Publication date: 2020-04-21
Anticipated expiration: 2039-11-06
Also published as: CN111047552B

Abstract

The embodiment of the invention provides a three-dimensional deflection measuring method and a related product, wherein the method comprises the following steps: the method comprises the steps of obtaining multiple groups of images shot by multiple groups of measuring cameras at a first preset time aiming at multiple homonymous feature points corresponding to a target object, determining initial positions of the multiple homonymous feature points in a preset space coordinate system according to the multiple groups of images, then controlling the multiple groups of measuring cameras to shoot the multiple homonymous feature points at a second preset time, observing a fixed reference through the multiple groups of self-stabilizing calibrating cameras, performing parameter correction on external parameters of the multiple groups of measuring cameras to obtain multiple second positions of the multiple homonymous feature points in the preset space coordinate system, determining position variation of the multiple homonymous feature points according to the multiple initial positions and the multiple second positions, and determining three-dimensional deflection according to the position variation.

Description

Three-dimensional deflection measuring method and related product

Technical Field

The invention relates to the technical field of three-dimensional deflection measurement, in particular to a three-dimensional deflection measurement method and a related product.

Background

Whether the deformation such as deflection is in the designed safety range or not is an important parameter for evaluating the safety of large-scale structures such as bridges, tunnels, dams and the like, and directly reflects whether the structural deformation is in a dangerous situation or not. With the development of measurement technology, new non-contact measurement methods, such as detection methods of a photoelectric image method, and the like, appear, but in the long-term deflection measurement process, factors such as external vibration and geological settlement of a mounting base can cause instability of a measurement platform, so that a very large measurement error is brought to deflection measurement.

Disclosure of Invention

The embodiment of the invention provides a three-dimensional deflection measuring method and a related product, which are beneficial to accurately measuring three-dimensional deflection.

The first aspect of the embodiments of the present invention provides a three-dimensional deflection measurement method, including:

acquiring a plurality of groups of images shot by the plurality of groups of measuring cameras aiming at a plurality of homonymous feature points corresponding to a target object at a first preset moment, wherein each group of measuring cameras corresponds to one group of images;

determining initial positions of the plurality of homonymous feature points in a preset space coordinate system according to the plurality of groups of images to obtain a plurality of groups of initial positions, wherein each group of images corresponds to one group of initial positions, and each group of initial positions comprises at least one initial position;

acquiring multiple groups of target parameters through the multiple groups of self-stabilizing calibration cameras, wherein each group of target parameters corresponds to one group of deflection measurement platform;

based on the multiple groups of target parameters, performing parameter correction on the internal and external parameters of the multiple groups of measuring cameras to obtain multiple groups of target internal parameters and multiple groups of target external parameters;

based on the multiple groups of target internal parameters and the multiple groups of target external parameters, controlling the multiple groups of measuring cameras to shoot the multiple homonymous feature points at a second preset time to obtain multiple second positions of the multiple homonymous feature points in the preset spatial coordinate system;

and determining the position variation of the plurality of homonymous feature points according to the plurality of initial positions and the plurality of second positions, and determining the three-dimensional deflection corresponding to the target object according to the position variation.

In a second aspect, an embodiment of the present invention provides a three-dimensional deflection measuring apparatus, including: a first acquisition unit, a determination unit, a second acquisition unit, a correction unit and a control unit, wherein,

the first acquisition unit is used for acquiring multiple groups of images shot by the multiple groups of measurement cameras aiming at multiple corresponding characteristic points of the target object at a first preset moment, wherein each group of measurement cameras corresponds to one group of images;

the determining unit is configured to determine initial positions of the plurality of homonymous feature points in a preset spatial coordinate system according to the plurality of groups of images to obtain a plurality of groups of initial positions, each group of images corresponds to one group of initial positions, and each group of initial positions includes at least one initial position;

the second obtaining unit is used for obtaining a plurality of groups of target parameters through the plurality of groups of self-stabilization calibration cameras, wherein each group of target parameters corresponds to one group of deflection measuring platform;

the correcting unit is used for performing parameter correction on the external parameters of the multiple groups of measuring cameras based on the multiple groups of target parameters to obtain multiple groups of target external parameters;

the control unit is used for controlling the multiple groups of measuring cameras to shoot the multiple homonymous feature points at a second preset time based on the multiple groups of target external parameters to obtain multiple second positions of the multiple homonymous feature points in the preset spatial coordinate system;

the determining unit is further configured to determine, according to the plurality of initial positions and the plurality of second positions, position variation amounts of the plurality of homonymous feature points, and determine, according to the position variation amounts, three-dimensional deflection corresponding to the target object.

In a third aspect, the present invention provides a computer-readable storage medium, where the computer-readable storage medium is used for storing a computer program, where the computer program is used to make a computer execute some or all of the steps described in the first aspect of the present invention.

In a fourth aspect, embodiments of the invention provide a computer program product comprising a non-transitory computer readable storage medium storing a computer program operable to cause a computer to perform some or all of the steps as described in the first aspect of embodiments of the invention. The computer program product may be a software installation package.

The embodiment of the invention has the following beneficial effects:

it can be seen that the three-dimensional deflection measuring method and the related product described in the above embodiments of the present invention include: acquiring multiple groups of images shot by multiple groups of measuring cameras at a first preset time aiming at multiple homonymous feature points corresponding to a target object, determining initial positions of the multiple homonymous feature points in a preset space coordinate system according to the multiple groups of images, then controlling the multiple groups of measuring cameras to shoot the multiple homonymous feature points at a second preset time, observing a fixed reference through multiple groups of self-stabilizing calibrating cameras, performing parameter correction on external parameters of the multiple groups of measuring cameras to obtain multiple second positions of the multiple homonymous feature points in the preset space coordinate system, determining position variation of the multiple homonymous feature points according to the multiple initial positions and the multiple second positions, and determining three-dimensional deflection according to the position variation, so that target parameters can be measured by the self-stabilizing calibrating cameras at any two different times, and internal and external parameters of the measuring cameras can be adjusted according to the target parameters, the influence of the shaking of the platform on the measurement of the three-dimensional deflection is reduced, and the three-dimensional deflection is accurately measured.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a schematic structural diagram of a three-dimensional deflection measuring system provided by an embodiment of the invention;

FIG. 2 is a schematic flow chart of a three-dimensional deflection measurement method provided by an embodiment of the invention;

FIG. 3 is a schematic structural diagram of a set of three-dimensional deflection measuring platforms provided by an embodiment of the present invention;

FIG. 4 is a schematic flow chart of an embodiment of a three-dimensional deflection measuring method according to an embodiment of the present invention;

fig. 5 is a schematic structural diagram of an embodiment of a three-dimensional deflection measuring device provided by an embodiment of the invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The terms "first," "second," "third," and "fourth," etc. in the description and claims of the invention and in the accompanying drawings are used for distinguishing between different objects and not for describing a particular order. Furthermore, the terms "include" and "have," as well as any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those steps or elements listed, but may alternatively include other steps or elements not listed, or inherent to such process, method, article, or apparatus.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the invention. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein can be combined with other embodiments.

In an embodiment of the present invention, a three-dimensional deflection measurement system may include multiple deflection measurement platforms, where the multiple deflection measurement platforms include multiple measurement cameras and multiple self-stabilizing calibration cameras, and each deflection measurement platform includes one measurement camera and at least one self-stabilizing calibration camera. Referring to fig. 1, a schematic structural diagram of a three-dimensional deflection measuring system according to an embodiment of the present invention is shown in fig. 1, in which a deflection measuring system 104 includes two sets of deflection measuring platforms 103, which include a target object 101, the target object 101 is a bridge structure to be measured, before three-dimensional deflection measurement is performed, a user can select a plurality of measuring points for the target object 101, the measuring points can be any one spatial point in a space where the target object 101 is located, since the plurality of measuring points in an image can correspond to a plurality of pixel points, an image pixel point obtained by imaging the same measuring point by the same camera or different cameras at the same time can be obtained by shooting the same measuring point by the same camera or different cameras at the same time, each deflection measuring platform corresponds to one measuring camera 102 and one self-stabilized calibrating camera 105, a plurality of stationary reference points can be set within a visible range of the self-stabilized calibrating camera 105, the plurality of fixed reference points may be located in the same fixed platform, and during measurement, at least three of the plurality of fixed reference points may be ensured to be within the field of view of the self-stabilizing calibration camera 105, and the plurality of fixed reference points may be ensured to be always stationary with respect to the ground.

Fig. 2 is a schematic flow chart of a three-dimensional deflection measuring method according to an embodiment of the present invention. The three-dimensional deflection measuring method described in this embodiment is applied to electronic equipment, and the method includes the following steps:

201. and acquiring multiple groups of images shot by the multiple groups of measuring cameras aiming at multiple corresponding characteristic points of the target object at a first preset moment, wherein each group of measuring cameras corresponds to one group of images.

Wherein, above-mentioned first predetermined moment can be for the user sets up by oneself or the system defaults, because at the long-term in-process of measurement of amount of deflection, factors such as external vibration, mounting base geology subside can arouse measuring platform self unstability, thereby bring very big measuring error to the amount of deflection measurement, consequently, it is more convenient to measure to introduce the same name characteristic point, specifically, can mark the characteristic point in the target object in advance, obtain a plurality of characteristic points, based on a plurality of characteristic points, can shoot a plurality of above-mentioned characteristic points through the multiunit measuring camera at first predetermined moment, obtain multiunit image, every group measuring camera corresponds a set of image, above-mentioned target object can include following at least one: bridges, tunnels, dams and the like, wherein the target object is a structural body to be detected without limitation; for example, the characteristic point with the same name is a pixel point corresponding to a screw in the target object, or may be a plurality of pixel points in the beam, and the like.

Optionally, in step 201, acquiring multiple sets of images captured by multiple sets of measurement cameras at a first preset time with respect to multiple feature points with the same name corresponding to the target object may include the following steps:

11. acquiring the plurality of homonymous feature points in the preset space coordinate system;

12. calibrating a plurality of groups of initial internal parameters and a plurality of groups of initial external parameters corresponding to the plurality of groups of measuring cameras, wherein each group of measuring cameras corresponds to one group of initial internal parameters and initial external parameters;

13. based on the multiple groups of initial internal parameters and the multiple groups of initial external parameters, controlling the multiple groups of measuring cameras to perform sub-pixel positioning on the multiple homonymous feature points;

14. and at the first preset moment, controlling the multiple groups of measuring cameras to shoot the multiple characteristic points with the same name to obtain the multiple groups of images.

The initial internal parameters and the initial external parameters may be set by a user or default by a system, and the initial internal parameters may include at least one of the following: focal length, principal point, lens aberration coefficient, etc., and not limited herein, the initial external parameters may include at least one of: translation vectors, rotation matrices, and the like, without limitation; specifically, the initial external parameters and the initial internal parameters may be preset for each of the plurality of sets of measurement cameras, and a plurality of sets of initial internal parameters and a plurality of sets of initial external parameters may be obtained.

Furthermore, when the camera is used for shooting, in order to obtain the real positions of the feature points of the target object, the digital image is discretized and converted into a pixel mode, each pixel can correspond to one image coordinate, but because the real positions of some features are not in the image coordinates corresponding to the pixel lock, in order to realize the accurate positioning of a plurality of homonymous feature points, the plurality of homonymous feature points can be subjected to sub-pixel positioning, and thus, at a first preset time, a plurality of groups of measuring cameras can be controlled to perform sub-pixel positioning tracking shooting on the plurality of homonymous feature points to obtain a plurality of groups of images, so that the positions of the plurality of homonymous feature points can be accurately shot, and the accuracy of three-dimensional deflection measurement is improved.

The sub-pixel positioning technique may include at least one of the following: an adaptive template correlation filtering method, an adaptive threshold centroid method, a gray scale map fitting method, a least square matching technique, and the like, which are not limited herein.

202. According to the multiple groups of images, determining initial positions of the multiple homonymous feature points in a preset space coordinate system to obtain multiple groups of initial positions, wherein each group of images corresponds to one group of initial positions, and each group of initial positions comprises at least one initial position.

The method comprises the steps of establishing a preset space coordinate system for a three-dimensional deflection measurement system, wherein the preset space coordinate system can be used for describing the coordinate position between the target object and a measurement camera in a three-dimensional space, and determining the initial positions of the plurality of homonymous feature points in the preset space coordinate system according to the plurality of groups of images to obtain a plurality of groups of initial positions.

For example, a description may be made for a set of deflection measuring platform, which includes a measuring camera and a self-stabilizing calibrating camera, and a set of images may be captured by the measuring camera based on a plurality of homonymous feature points, specifically, a three-dimensional coordinate system of the measuring camera may be established based on internal parameters of the measuring camera, and an image plane coordinate system may be established with an upper left of the images as an origin, so that a corresponding relationship between three-dimensional coordinates of a preset spatial coordinate system for the homonymous feature points and homonymous feature points in the image plane coordinate system may be established through a conversion relationship between the coordinate systems, and finally, a first spatial coordinate corresponding to a plurality of homonymous feature points in the preset spatial coordinate system may be determined according to the corresponding relationship, that is the initial position, so that a plurality of sets of initial positions may be obtained, where each set of images corresponds to a set of initial positions, each set of initial positions includes at least one initial position.

203. And acquiring multiple groups of target parameters through the multiple groups of self-stabilizing calibration cameras, wherein each group of target parameters corresponds to one group of deflection measurement platform.

The target parameters are offset parameters or shaking parameters corresponding to the deflection measuring platform; in the three-dimensional deflection measurement system, because factors such as external vibration, geological subsidence of a mounting base and the like can cause the shaking of a measurement platform, so that very large measurement errors are brought to deflection measurement.

Optionally, in step 203, acquiring multiple sets of target parameters through the multiple sets of self-stabilization calibration cameras may include the following steps:

acquiring a target parameter i corresponding to each self-stabilizing calibration camera i in each deflection measurement platform i in the multiple deflection measurement platforms to obtain multiple groups of target parameters, wherein the multiple groups of target parameters consist of multiple target parameters i, and i is a positive integer;

the multiple sets of parameters can be obtained by each self-stabilization calibration camera, so that multiple sets of target parameters corresponding to the multiple self-stabilization cameras can be obtained, and each self-stabilization camera corresponds to one set of target parameters.

Optionally, the obtaining of the target parameter i corresponding to each self-stabilizing calibration camera i in each deflection measurement platform i in the multiple sets of deflection measurement platforms may include the following steps:

a1, acquiring a plurality of fixed reference points within a preset range;

a2, establishing a first space coordinate system by taking platforms corresponding to the plurality of motionless reference points as a reference, and determining the space coordinates corresponding to the plurality of motionless reference points in the first space coordinate system to obtain at least one first space coordinate;

a3, controlling the self-stabilizing calibration camera i to shoot the plurality of fixed reference points at the first preset moment to obtain at least one first image, wherein the self-stabilizing calibration camera i is any self-stabilizing calibration camera in any deflection measurement platform i in the multiple deflection measurement platforms;

a4, establishing a second space coordinate system i by taking a calibration platform i corresponding to the self-stabilization calibration camera i as a reference, determining the positions of the multiple fixed reference points in the at least one first image to obtain at least one initial position coordinate, wherein the first space coordinate is in one-to-one correspondence with the initial position coordinate;

a5, obtaining relative position information between a platform corresponding to the plurality of motionless reference points and a calibration platform i corresponding to the self-stabilizing calibration camera i according to the at least one first space coordinate and the at least one initial position coordinate;

a6, acquiring at least one second image shot by the self-stabilization calibration camera i at the second preset moment aiming at the plurality of motionless reference points;

a7, determining at least one second position coordinate corresponding to the plurality of immobile reference points in the at least one second image;

a8, determining the position change information of the calibration platform i according to the at least one second position coordinate and the at least one initial position coordinate;

and A9, obtaining the target parameter i corresponding to the self-stabilization calibration camera i according to the position change information.

The preset range can be set by a user or defaulted by a system, a plurality of fixed reference points can be preset in the preset range and are positioned in the same fixed platform, during measurement, at least three fixed reference points in the plurality of fixed reference points are ensured to be in a view field of the self-stabilizing calibration camera, and the plurality of fixed reference points are ensured to be still relative to the ground all the time, specifically, a cooperation mark can be installed on the fixed reference points, the cooperation mark can be round, opposite vertex angle, cross hair or other shapes easy to recognize, and if the cooperation mark is used for night work, the cooperation mark can be made of a luminous light source.

In addition, a first space coordinate system can be established by taking platforms corresponding to the plurality of motionless reference points as a reference so as to determine space coordinates corresponding to the plurality of motionless reference points in the first space coordinate system to obtain a plurality of space coordinate systems, the three-dimensional deflection measuring system can also comprise a total station measuring instrument, and the total station measuring instrument is used for obtaining a plurality of first space coordinates corresponding to the plurality of motionless reference points.

Further, the relative position information between the self-stabilization calibration camera i and the platforms corresponding to the plurality of motionless reference points can be determined according to the plurality of first spatial coordinates and the plurality of initial position coordinates, the relative position information comprises the position relationship between the position of the calibration platform i and the platforms corresponding to the plurality of motionless reference points, then, the position change information between the initial position coordinates and the second position coordinates corresponding to each motionless reference point can be obtained according to the plurality of initial position coordinates and the plurality of second position coordinates, the position change information of the plurality of motionless reference points can be obtained, the position change information of the calibration platform i relative to the platforms corresponding to the plurality of motionless reference points can be obtained according to the plurality of position change information, and finally, the position change information and the relative position information can be compared, because the self-stabilization calibration camera i and the measurement camera are positioned in one platform, the attitude change of the calibration platform i can be obtained, and the target parameter i corresponding to the self-stabilization calibration camera i can be obtained according to the attitude change, and can comprise the internal and external parameters of the self-stabilization camera.

204. And performing parameter correction on the external parameters of the multiple groups of measuring cameras based on the multiple groups of target parameters to obtain multiple groups of target external parameters.

In general, during shooting, the camera may shoot based on internal and external parameters, where the internal parameters may include at least one of: optical center, equivalent focal length and distortion factor, etc., and not limited herein, the external parameters may include at least one of: translation vectors, rotation matrices, and the like, without limitation; the method includes the steps that a plurality of homonymous feature points are shot by a measuring camera to obtain an image, the three-dimensional homonymous feature points are projected onto a two-dimensional image, deformation of a target object can be obtained through analysis of the two-dimensional image, if a deflection measuring platform shakes, the positions of the homonymous feature points in the image obtained during shooting are inaccurate, and influence is caused on three-dimensional deflection measuring data.

Specifically, specific offset parameters or shaking parameters corresponding to multiple deflection measurement platforms, which can be obtained through multiple sets of self-stabilization calibration cameras, can be corrected based on the multiple sets of target parameters, and external parameters of the measurement cameras corresponding to each self-stabilization calibration camera can be corrected, so that calibration of the multiple sets of measurement cameras is realized, and more accurate measurement data can be obtained through the multiple sets of measurement cameras.

205. And based on the multiple groups of target external parameters, controlling the multiple groups of measuring cameras to shoot the multiple homonymous feature points at a second preset time to obtain multiple second positions of the multiple homonymous feature points in the preset space coordinate system.

The second preset time can be set by a user or defaulted by a system, and the second preset time can be preset to be later than the first preset time, so that the spatial positions corresponding to the plurality of homonymous feature points obtained at different times are different.

Specifically, a plurality of sets of third images corresponding to a plurality of homonymous feature points at a second preset time may be acquired based on the adjusted plurality of sets of measurement cameras, a correspondence relationship between three-dimensional coordinates of a preset spatial coordinate system for the homonymous feature points and homonymous feature points in a third image plane coordinate system may be established through a conversion relationship between the coordinate systems, and finally, a second spatial coordinate corresponding to the plurality of homonymous feature points in the preset spatial coordinate system may be determined according to the correspondence relationship, that is, the second position, so that a plurality of sets of second positions may be obtained.

Optionally, in step 205, the performing, in correspondence to multiple sets of position change information and multiple sets of relative position information, parameter correction on internal and external parameters of the multiple sets of measurement cameras based on the multiple sets of target parameters to obtain multiple sets of target internal parameters and multiple sets of target external parameters may include the following steps:

51. determining a plurality of groups of first conversion relations between the platforms corresponding to the plurality of immobile reference points and the calibration platforms corresponding to the plurality of groups of self-stabilizing calibration cameras according to the plurality of groups of position change information and the plurality of groups of relative position information, wherein the calibration platform corresponding to each self-stabilizing calibration camera corresponds to one group of first conversion relations;

52. acquiring multiple groups of preset conversion relations between calibration platforms corresponding to multiple groups of self-stabilizing calibration cameras and multiple groups of deflection measurement platforms, wherein each deflection measurement platform corresponds to one group of preset conversion relations;

53. determining a plurality of groups of target conversion relations between a plurality of deflection measurement platforms corresponding to the plurality of groups of measurement cameras at the first preset time and the second preset time according to the plurality of groups of first conversion relations and the plurality of groups of preset conversion relations, wherein the deflection measurement platform corresponding to each group of measurement cameras corresponds to one group of target conversion relations;

54. according to the multiple groups of target parameters and the multiple groups of target conversion relations, performing parameter correction on the external parameters of the multiple groups of measuring cameras to obtain multiple groups of target external parameters corresponding to the multiple groups of measuring cameras, wherein each group of measuring cameras corresponds to one group of target external parameters, and the target external parameters comprise at least one of the following parameters: a translation vector and a rotation matrix.

Wherein, the preset space coordinate system can be set by a user or defaulted by a system, a plurality of groups of relative position relations between a plurality of calibration platforms corresponding to a plurality of groups of self-stabilization calibration cameras and platforms corresponding to a plurality of immobile reference points and a plurality of groups of position change information of the plurality of groups of calibration platforms can be obtained, a plurality of groups of first conversion relations between the platforms corresponding to the immobile reference points and the calibration platforms corresponding to the plurality of groups of self-stabilization calibration cameras are determined by the plurality of groups of position change information and the plurality of groups of relative position information, concretely, a calibration platform coordinate system can be established aiming at the plurality of groups of calibration platforms to obtain a plurality of groups of calibration platform coordinate systems, each calibration platform corresponds to one calibration platform coordinate system, an immobile point coordinate system can be established aiming at the platforms corresponding to the immobile reference points, then different immobile reference points can be established in the coordinate systems, according to the plurality of groups of position change information and the plurality of, the method comprises the steps of obtaining relative movement position coordinates of a plurality of groups of calibration platforms corresponding to a first preset time to a second preset time relative to platforms corresponding to a plurality of motionless reference points, obtaining a plurality of relative movement position coordinates, wherein each group of calibration platform corresponds to one relative movement position coordinate, and obtaining a plurality of groups of first conversion relations between the platforms corresponding to the motionless reference points and the calibration platforms corresponding to a plurality of groups of self-stabilization calibration cameras according to the plurality of relative movement position coordinates.

In addition, because the measuring camera and the self-stabilizing calibrating camera are arranged in one platform, a plurality of groups of preset conversion relations between the calibrating platform corresponding to the plurality of groups of self-stabilizing calibrating cameras and a plurality of groups of deflection measuring platforms can be preset, a deflection measuring platform coordinate system can be established for the measuring camera, and the preset conversion relations between the calibrating platform corresponding to the self-stabilizing calibrating cameras and the plurality of groups of deflection measuring platforms can be obtained through the relations between the measuring platform coordinate system and the calibrating platform coordinate system.

Further, a target conversion relation of the multiple deflection measurement platforms between a first preset time and a preset second time can be obtained according to multiple groups of first conversion relations and multiple groups of preset conversion relations, so that multiple groups of target transfer relations can be obtained, the target transfer relation can be understood as a change relation between the first preset time and the second preset time and a coordinate system of the multiple deflection measurement platforms between two different preset times, therefore, multiple groups of target internal parameters and multiple groups of target external parameters corresponding to the multiple groups of measurement cameras can be determined according to the multiple groups of target parameters and the multiple groups of target conversion relations, and finally, corresponding parameter correction can be performed on the external parameters of the multiple groups of measurement cameras based on the multiple groups of target external parameters, so that the measurement cameras after the multiple groups of parameters are modified can be obtained.

For example, as shown in fig. 3, the structure diagram of a set of three-dimensional deflection measurement platforms is shown, the deflection measurement platform includes a measurement camera and a self-stabilizing calibration camera, the three-dimensional deflection measurement system further includes a static reference platform, the static reference platform includes a marker, the marker includes at least 3 motionless reference points, the static reference platform is a platform corresponding to a plurality of motionless reference points, and a deflection measurement platform coordinate system O can be established_uX_uY_uZ_uCalibration platform coordinate system O corresponding to self-stabilizing calibration camera_cX_cY_cZ_cMarker coordinate system O_pX_pY_pZ_pAnd a static reference platform coordinate system O_sX_sY_sZ_sObtaining a coordinate system O of the static reference platform according to the plurality of sets of position change information and the plurality of sets of relative position information_sX_sY_sZ_sTo the calibration platform coordinate system O_cX_cY_cZ_cConversion relation of

Obtaining a preset calibration platform coordinate system O_cX_cY_cZ_cTo the deflection measuring platform coordinate system O_uX_uY_uZ_uHas a conversion relation of

Thus, the target conversion relationship between the deflection measuring platform shown in the figure from the first preset time to the second preset time can be obtained as follows:

206. and determining the position variation of the plurality of homonymous feature points according to the plurality of initial positions and the plurality of second positions, and determining the three-dimensional deflection corresponding to the target object according to the position variation.

The three-dimensional deflection parameter corresponding to the target object can be solved according to the spatial position change information of the plurality of homonymous feature points, specifically, a plurality of initial positions obtained at the first preset time and a plurality of second positions obtained at the second preset time can be obtained, and a plurality of relative position change amounts corresponding to the plurality of homonymous feature points are obtained according to the plurality of initial positions and the plurality of second positions, so that the three-dimensional deflection is obtained.

Optionally, in the step 206, determining the position variation amounts of the plurality of feature points with the same name according to the plurality of initial positions and the plurality of second positions may include the following steps:

61. acquiring corresponding homonymous feature points of any two groups of measurement cameras in the multiple groups of measurement cameras to obtain multiple groups of target homonymous feature points, wherein each two groups of measurement cameras correspond to one group of target homonymous feature points;

62. acquiring a plurality of initial positions m and a plurality of second positions m corresponding to one of the two groups of measuring cameras corresponding to the plurality of target homonymous feature points, wherein the target homonymous feature points are any one of the plurality of groups of target homonymous feature points;

63. acquiring a plurality of initial positions n and a plurality of second positions n corresponding to the other measuring camera in the two groups of measuring cameras corresponding to the plurality of target homonymous feature points;

64. determining a plurality of first three-dimensional coordinates corresponding to the plurality of homonymous feature points at the first preset moment according to the plurality of initial positions m and the plurality of initial positions n;

65. determining a plurality of second three-dimensional coordinates corresponding to the plurality of homonymous feature points at the second preset time according to the plurality of second positions m and the plurality of second positions n;

66. and calculating position variation corresponding to the target homonymous feature points according to the first three-dimensional coordinates and the second three-dimensional coordinates to obtain the position variation corresponding to the homonymous feature points, wherein each homonymous feature point corresponds to at least one position variation.

The deflection is linear displacement of the rod axis in the direction vertical to the axis or linear displacement of the middle surface of the plate shell in the direction vertical to the middle surface when the stress or the non-uniform temperature changes, so that the deflection can be understood as the deformation quantity of a target object, and the three-dimensional deflection corresponding to the target object can be determined according to the variation quantity of the spatial positions of the same-name characteristic points at different moments.

Specifically, homonymous feature points corresponding to any two groups of measurement cameras can be acquired to obtain a plurality of groups of target homonymous feature points, the target homonymous feature points are located in the view angles of the two groups of measurement cameras, and a plurality of initial positions m and a plurality of initial positions n corresponding to the plurality of groups of target homonymous feature points at a first preset time are acquired, wherein the plurality of initial positions m and the plurality of initial positions n respectively correspond to one group and the other group of the two groups of measurement cameras, similarly, a plurality of second positions m and a plurality of second positions n corresponding to the plurality of groups of target homonymous feature points at a second preset time are acquired, wherein the plurality of second positions m and the plurality of second positions n respectively correspond to one group and the other group of the two groups of measurement cameras, three-dimensional coordinates of the plurality of target homonymous feature points can be measured through three-dimensional intersection of the two groups of measurement cameras, that is, three-dimensional coordinates of the plurality of target homonymous feature points corresponding to different times can be obtained according, and obtaining a plurality of first three-dimensional coordinates and a plurality of second three-dimensional coordinates in a preset space coordinate system, and thus, calculating the position variation corresponding to each target homonymous feature point through the plurality of first three-dimensional coordinates and the plurality of second three-dimensional coordinates obtained at different moments, and thus, obtaining a plurality of position variations corresponding to the plurality of homonymous feature points, wherein the plurality of position variations are the three-dimensional deflection of the homonymous feature points corresponding to the target object.

It can be seen that, with the three-dimensional deflection measuring method described in the embodiments of the present invention, multiple sets of images captured by multiple sets of measuring cameras at a first preset time with respect to multiple corresponding characteristic points of a target object are obtained, initial positions of the multiple corresponding characteristic points in a preset spatial coordinate system are determined according to the multiple sets of images, then, the multiple sets of measuring cameras are controlled to capture the multiple corresponding characteristic points at a second preset time, a fixed reference is observed by the multiple sets of self-stabilizing calibrating cameras, parameters of external parameters of the multiple sets of measuring cameras are corrected to obtain multiple second positions of the multiple corresponding characteristic points in the preset spatial coordinate system, position variations of the multiple corresponding characteristic points are determined according to the multiple initial positions and the multiple second positions, three-dimensional deflection is determined according to the position variations, and thus, a target parameter can be measured by self-stabilizing cameras at any two different times, and the internal and external parameters of the measuring camera are adjusted according to the target parameters, so that the influence of the shaking of the platform on the measurement of the three-dimensional deflection is reduced, and the accurate measurement of the three-dimensional deflection is facilitated.

In accordance with the above, please refer to fig. 4, which is a flowchart illustrating an embodiment of a method for measuring three-dimensional deflection according to an embodiment of the present invention. The three-dimensional deflection measurement method described in this embodiment includes the steps of:

401. and acquiring a plurality of homonymous feature points in a preset space coordinate system.

402. Calibrating multiple groups of initial internal parameters and multiple groups of initial external parameters corresponding to multiple groups of measuring cameras, wherein each group of measuring cameras corresponds to one group of initial internal parameters and initial external parameters.

403. And controlling a plurality of groups of measuring cameras to perform sub-pixel positioning on a plurality of characteristic points with the same name based on a plurality of groups of initial internal parameters and a plurality of groups of initial external parameters.

404. And at a first preset moment, controlling a plurality of groups of measuring cameras to shoot a plurality of characteristic points with the same name to obtain a plurality of groups of images.

405. According to the multiple groups of images, determining initial positions of the multiple homonymous feature points in a preset space coordinate system to obtain multiple groups of initial positions, wherein each group of images corresponds to one group of initial positions, and each group of initial positions comprises at least one initial position.

406. And acquiring multiple groups of target parameters through multiple groups of self-stabilizing calibration cameras, wherein each group of target parameters corresponds to one group of deflection measurement platform.

407. And performing parameter correction on the external parameters of the multiple groups of measuring cameras based on the multiple groups of target parameters to obtain multiple groups of target external parameters.

408. And based on the multiple groups of target external parameters, controlling multiple groups of measuring cameras to shoot the multiple homonymous feature points at a second preset time to obtain multiple second positions of the multiple homonymous feature points in a preset space coordinate system.

409. And determining the position variation of the plurality of homonymous feature points according to the plurality of initial positions and the plurality of second positions, and determining the three-dimensional deflection corresponding to the target object according to the position variation.

The detailed description of the step 401-409 can refer to the corresponding description of the three-dimensional deflection measuring method described in fig. 2, and is not repeated herein.

It can be seen that, by the three-dimensional deflection measurement method described in the embodiments of the present invention, a plurality of homonymous feature points in a preset spatial coordinate system are obtained, a plurality of sets of initial internal parameters and a plurality of sets of initial external parameters corresponding to a plurality of sets of measurement cameras are calibrated, each set of measurement camera corresponds to one set of initial internal parameters and initial external parameters, based on the plurality of sets of initial internal parameters and initial external parameters, the plurality of sets of measurement cameras are controlled to perform sub-pixel positioning on the plurality of homonymous feature points, at a first preset time, the plurality of sets of measurement cameras are controlled to perform shooting on the plurality of homonymous feature points to obtain a plurality of sets of images, according to the plurality of sets of images, initial positions of the plurality of homonymous feature points in the preset spatial coordinate system are determined to obtain a plurality of sets of initial positions, each set of images corresponds to one set of initial positions, each set of initial positions includes at, acquiring multiple groups of target parameters, wherein each group of target parameters corresponds to one group of deflection measuring platform, performing parameter correction on internal and external parameters of multiple groups of measuring cameras based on the multiple groups of target parameters to obtain multiple groups of target external parameters, controlling the multiple groups of measuring cameras to shoot multiple homonymous feature points at a second preset time based on the multiple groups of target external parameters to obtain multiple second positions of the multiple homonymous feature points in a preset space coordinate system, determining position variation of the multiple homonymous feature points according to the multiple initial positions and the multiple second positions, and determining three-dimensional deflection according to the position variation, so that the positions of the homonymous feature points, namely the accurate positions of measured objects, can be accurately positioned by a sub-pixel positioning technology, and meanwhile, corresponding shaking parameters, namely the target parameters, of the deflection measuring platform can be measured by a self-stabilized calibrating camera at any two different times, and the internal and external parameters of the measuring camera are adjusted according to the target parameters, so that the measurement of the three-dimensional deflection is realized, the measurement error caused by the shaking of the deflection measuring platform is reduced, and the accuracy of the three-dimensional deflection measurement is improved.

Fig. 5 is a schematic structural diagram of an embodiment of a three-dimensional deflection measuring apparatus according to an embodiment of the present invention. The three-dimensional deflection measuring apparatus described in this embodiment includes: the first acquiring unit 501, the determining unit 502, the second acquiring unit 503, the correcting unit 504 and the control unit 505 are specifically as follows:

the first obtaining unit 501 is configured to obtain multiple sets of images, which are shot by the multiple sets of measurement cameras at a first preset time for multiple corresponding feature points of a target object, where each set of measurement cameras corresponds to one set of images;

the determining unit 502 is configured to determine initial positions of the plurality of homonymous feature points in a preset spatial coordinate system according to the plurality of groups of images to obtain a plurality of groups of initial positions, where each group of images corresponds to one group of initial positions, and each group of initial positions includes at least one initial position;

the second obtaining unit 503 is configured to obtain multiple sets of target parameters through the multiple sets of self-stabilization calibration cameras, where each set of target parameters corresponds to one set of deflection measurement platform;

the correcting unit 504 is configured to perform parameter correction on the external parameters of the multiple groups of measurement cameras based on the multiple groups of target parameters, so as to obtain multiple groups of target external parameters;

the control unit 505 is configured to control, based on the multiple sets of target external parameters, the multiple sets of measurement cameras to shoot the multiple homonymous feature points at a second preset time, so as to obtain multiple second positions of the multiple homonymous feature points in the preset spatial coordinate system;

the determining unit 502 is further configured to determine, according to the plurality of initial positions and the plurality of second positions, position variation amounts of the plurality of homonymous feature points, and determine, according to the position variation amounts, three-dimensional deflection corresponding to the target object.

It can be seen that, with the three-dimensional deflection measuring apparatus described in the above embodiments of the present invention, the apparatus can obtain multiple sets of images captured by multiple sets of measuring cameras at a first preset time with respect to multiple corresponding characteristic points of a target object, determine initial positions of the multiple corresponding characteristic points in a preset spatial coordinate system according to the multiple sets of images, then control the multiple sets of measuring cameras to capture the multiple corresponding characteristic points at a second preset time, observe a fixed reference through multiple sets of self-stabilizing calibrating cameras, perform parameter correction on external parameters of the multiple sets of measuring cameras to obtain multiple second positions of the multiple corresponding characteristic points in the preset spatial coordinate system, determine position variations of the multiple corresponding characteristic points according to the multiple initial positions and the multiple second positions, determine three-dimensional deflection according to the position variations, and thus can measure target parameters through any two self-calibrating cameras at different times, and the internal and external parameters of the measuring camera are adjusted according to the target parameters, so that the influence of the shaking of the platform on the measurement of the three-dimensional deflection is reduced, and the accurate measurement of the three-dimensional deflection is facilitated.

In a possible example, in terms of performing parameter correction on the internal and external parameters of the multiple measurement cameras based on the multiple sets of target parameters to obtain multiple sets of target internal parameters and multiple sets of target external parameters, the correction unit 504 is specifically configured to:

determining a plurality of groups of first conversion relations between the platforms corresponding to the plurality of immobile reference points and the calibration platforms corresponding to the plurality of groups of self-stabilizing calibration cameras according to the plurality of groups of position change information and the plurality of groups of relative position information, wherein the calibration platform corresponding to each self-stabilizing calibration camera corresponds to one group of first conversion relations;

acquiring multiple groups of preset conversion relations between calibration platforms corresponding to multiple groups of self-stabilizing calibration cameras and multiple groups of deflection measurement platforms, wherein each deflection measurement platform corresponds to one group of preset conversion relations;

determining a plurality of groups of target conversion relations between a plurality of deflection measurement platforms corresponding to the plurality of groups of measurement cameras at the first preset time and the second preset time according to the plurality of groups of first conversion relations and the plurality of groups of preset conversion relations, wherein the deflection measurement platform corresponding to each group of measurement cameras corresponds to one group of target conversion relations;

according to the multiple groups of target parameters and the multiple groups of target conversion relations, performing parameter correction on the external parameters of the multiple groups of measuring cameras to obtain multiple groups of target external parameters corresponding to the multiple groups of measuring cameras, wherein each group of measuring cameras corresponds to one group of target external parameters, and the target external parameters comprise at least one of the following parameters: a translation vector and a rotation matrix.

In a possible example, in acquiring multiple sets of images captured by multiple sets of measurement cameras for the multiple feature points with the same name at a first preset time, the first acquiring unit 501 is specifically configured to:

acquiring the plurality of homonymous feature points in the preset space coordinate system;

calibrating a plurality of groups of initial internal parameters and a plurality of groups of initial external parameters corresponding to the plurality of groups of measuring cameras, wherein each group of measuring cameras corresponds to one group of initial internal parameters and initial external parameters;

based on the multiple groups of initial internal parameters and the multiple groups of initial external parameters, controlling the multiple groups of measuring cameras to perform sub-pixel positioning on the multiple homonymous feature points;

and at the first preset moment, controlling the multiple groups of measuring cameras to shoot the multiple characteristic points with the same name to obtain the multiple groups of images.

In one possible example, in terms of determining the amount of position change of the plurality of homonymous feature points according to the plurality of initial positions and the plurality of second positions, the determining unit 502 is specifically further configured to:

acquiring corresponding homonymous feature points of any two groups of measurement cameras in the multiple groups of measurement cameras to obtain multiple groups of target homonymous feature points, wherein each two groups of measurement cameras correspond to one group of target homonymous feature points;

acquiring a plurality of initial positions m and a plurality of second positions m corresponding to one of the two groups of measuring cameras corresponding to the plurality of target homonymous feature points, wherein the target homonymous feature points are any one of the plurality of groups of target homonymous feature points;

acquiring a plurality of initial positions n and a plurality of second positions n corresponding to the other measuring camera in the two groups of measuring cameras corresponding to the plurality of target homonymous feature points;

determining a plurality of first three-dimensional coordinates corresponding to the plurality of homonymous feature points at the first preset moment according to the plurality of initial positions m and the plurality of initial positions n;

determining a plurality of second three-dimensional coordinates corresponding to the plurality of homonymous feature points at the second preset time according to the plurality of second positions m and the plurality of second positions n;

and calculating position variation corresponding to the target homonymous feature points according to the first three-dimensional coordinates and the second three-dimensional coordinates to obtain the position variation corresponding to the homonymous feature points, wherein each homonymous feature point corresponds to at least one position variation.

In a possible example, in the aspect of acquiring multiple sets of target parameters by the multiple sets of self-stabilization calibration cameras, the first acquiring unit 501 is specifically configured to:

and acquiring a target parameter i corresponding to each self-stabilizing calibration camera i in each deflection measurement platform i in the multiple deflection measurement platforms to obtain multiple groups of target parameters, wherein the multiple groups of target parameters consist of multiple target parameters i, and i is a positive integer.

In a possible example, in the acquiring the target parameter i corresponding to each self-stabilized calibration camera i in each deflection measurement platform i of the multiple deflection measurement platforms, the first acquiring unit 501 is specifically configured to:

acquiring a plurality of fixed reference points within a preset range;

establishing a first space coordinate system by taking platforms corresponding to the plurality of motionless reference points as a reference, and determining corresponding space coordinates of the plurality of motionless reference points in the first space coordinate system to obtain a plurality of first space coordinates;

controlling the self-stabilizing calibration camera i to shoot the plurality of fixed reference points at the first preset moment to obtain a plurality of first images, wherein the self-stabilizing calibration camera i is any one self-stabilizing calibration camera in any one deflection measurement platform i in the plurality of deflection measurement platforms;

establishing a second space coordinate system i by taking a calibration platform i corresponding to the self-stabilization calibration camera i as a reference, determining the positions of the plurality of fixed reference points in the plurality of first images to obtain a plurality of initial position coordinates, wherein the first space coordinates correspond to the initial position coordinates one by one;

obtaining relative position information between the platform corresponding to the plurality of fixed reference points and a calibration platform i corresponding to the self-stabilizing calibration camera i according to the plurality of first space coordinates and the plurality of initial position coordinates;

acquiring a plurality of second images shot by the self-stabilization calibration camera i at the second preset moment aiming at the plurality of fixed reference points;

determining a plurality of second position coordinates corresponding to the plurality of stationary reference points in the plurality of second images;

determining position change information of the calibration platform i according to the second position coordinates and the initial position coordinates;

and obtaining the target parameter i corresponding to the self-stabilization calibration camera i according to the position change information and the relative position information.

Embodiments of the present invention further provide a computer storage medium, where the computer storage medium may store a program, and when the program is executed, the program includes some or all of the steps of any one of the three-dimensional deflection measurement methods described in the above method embodiments.

Embodiments of the present invention also provide a computer program product comprising a non-transitory computer readable storage medium storing a computer program operable to cause a computer to perform some or all of the steps of any one of the three-dimensional deflection measurement methods as set out in the above method embodiments.

While the invention has been described in connection with various embodiments, other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a review of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the word "a" or "an" does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, apparatus (device), or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein. A computer program stored/distributed on a suitable medium supplied together with or as part of other hardware, may also take other distributed forms, such as via the Internet or other wired or wireless telecommunication systems.

The present invention has been described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (devices) and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable license plate location device to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable license plate location device, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable computer to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable computer-readable memory to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

While the invention has been described in conjunction with specific features and embodiments thereof, it will be evident that various modifications and combinations can be made thereto without departing from the spirit and scope of the invention. Accordingly, the specification and figures are merely exemplary of the invention as defined in the appended claims and are intended to cover any and all modifications, variations, combinations, or equivalents within the scope of the invention. It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims

1. A method of three-dimensional deflection metrology applied to a three-dimensional deflection metrology system, the system comprising a plurality of deflection metrology platforms comprising a plurality of sets of metrology cameras and a plurality of sets of self-stabilizing calibration cameras, wherein each set of deflection metrology platform comprises a metrology camera and at least one self-stabilizing calibration camera, the method comprising:

determining initial positions of the plurality of homonymous feature points in a preset space coordinate system according to the plurality of groups of images to obtain a plurality of groups of initial positions, wherein each group of initial positions comprises at least one initial position;

based on the multiple groups of target parameters, performing parameter correction on the external parameters of the multiple groups of measuring cameras to obtain multiple groups of target external parameters;

based on the multiple groups of target external parameters, the multiple groups of measuring cameras are controlled to shoot the multiple homonymous feature points at a second preset time, and multiple second positions of the multiple homonymous feature points in the preset space coordinate system are obtained;

2. The method of claim 1, wherein said obtaining a plurality of sets of target parameters from said plurality of sets of self-stabilized cameras comprises:

the acquiring of the target parameter i corresponding to each self-stabilizing calibration camera i in each deflection measurement platform i in the multiple deflection measurement platforms comprises:

acquiring a plurality of fixed reference points within a preset range;

3. The method according to claim 2, wherein the multiple sets of self-stabilization calibration cameras correspond to multiple sets of position change information and multiple sets of relative position information, and the performing parameter correction on the internal and external parameters of the multiple sets of measurement cameras based on the multiple sets of target parameters to obtain multiple sets of target internal parameters and multiple sets of target external parameters includes:

4. The method according to claim 1, wherein the acquiring of the plurality of sets of images shot by the plurality of sets of measurement cameras at the first preset time for the plurality of feature points with the same name comprises:

5. The method according to claim 1, wherein the determining the position variation amounts of the plurality of feature points with the same name according to the plurality of initial positions and the plurality of second positions comprises:

6. A three-dimensional deflection measuring device, characterized in that the device comprises: a first acquisition unit, a determination unit, a second acquisition unit, a correction unit and a control unit, wherein,

7. The apparatus according to claim 6, wherein in terms of performing parameter correction on the internal and external parameters of the multiple measurement cameras based on the multiple sets of target parameters to obtain multiple sets of target internal parameters and multiple sets of target external parameters, the correction unit is specifically configured to:

according to the multiple groups of target parameters and the multiple groups of target conversion relations, performing parameter correction on the internal and external parameters of the multiple groups of measuring cameras to obtain multiple groups of target internal parameters and multiple groups of target external parameters corresponding to the multiple groups of measuring cameras, wherein each group of measuring cameras corresponds to one group of target internal parameters and one group of target external parameters, and the target internal parameters include at least one of the following parameters: an optical center, an equivalent focal length, and a distortion coefficient, the off-target parameters including at least one of: a translation vector and a rotation matrix.

8. The apparatus according to claim 6, wherein in the acquiring of the plurality of sets of images captured by the plurality of sets of measurement cameras for the plurality of feature points with the same name at the first preset time, the first acquiring unit is specifically configured to:

9. The apparatus according to claim 6, wherein in determining the amount of change in the positions of the plurality of homonymous feature points according to the plurality of initial positions and the plurality of second positions, the determining unit is further configured to:

10. A computer-readable storage medium, characterized in that a computer program for electronic data exchange is stored, wherein the computer program causes a computer to perform the method according to any one of claims 1-5.