Six-degree-of-freedom displacement positioning auxiliary correction method for three-dimensional vision measurement system

Abstract

The present invention discloses a six-degree-of-freedom displacement positioning auxiliary correction method for a three-dimensional vision measurement system, which relates to the field of three-dimensional vision measurement technology. The method comprises: calibrating the three-dimensional vision measurement system; fixing the measured object to the six-degree-of-freedom displacement stage, and solving the first pose between the two coordinate systems based on the coordinates of the characteristic points of the measured object in the world coordinate system and the six-degree-of-freedom displacement stage coordinate system; the six-degree-of-freedom displacement stage moves the measured object and outputs six-degree-of-freedom displacement information; solving the second pose between the two coordinate systems after the movement based on the coordinates of the characteristic points of the measured object in the two coordinate systems; determining the pose change information based on the first pose and the second pose, and correcting the rotation matrix and translation vector of the three-dimensional vision measurement system in combination with the six-degree-of-freedom displacement information. The present invention corrects the three-dimensional vision measurement system in real time through the high-precision pose output of the six-degree-of-freedom displacement stage, thereby improving the accuracy and reliability of the three-dimensional vision measurement system.

Description

Technical Field

[0001] The present invention relates to the technical field of three-dimensional vision measurement, and in particular to a six-degree-of-freedom displacement positioning auxiliary correction method for a three-dimensional vision measurement system. Background Art

[0002] 3D vision measurement systems primarily use camera imaging technology to acquire 3D coordinate information on an object's surface, enabling high-precision, non-contact measurement. Existing 3D vision measurement systems typically use markers or tracking multi-stage scanning systems to determine the locations of feature points on the object being measured. The marker method is widely used due to its low cost and high accuracy, but it requires manual application of markers, which is time-consuming and unsuitable for assembly line operations and large-scale measurement. The tracking multi-stage scanning method primarily uses a binocular tracker to track a scanner with known structural information. The coordinate transformation matrix is ​​calculated using information from markers attached to the scanner. This method is relatively flexible, but it places high demands on the scanner's structural design and operational procedures. Furthermore, due to the large size of the attached markers, information on the interior of the object being measured cannot be measured. Furthermore, both the marker method and the tracking multi-stage scanning method require manual intervention during the measurement process, requiring a certain level of operator skill. This prevents the formation of an automated measurement field, hindering the widespread application of 3D vision measurement equipment. Summary of the Invention

[0003] The purpose of the present invention is to provide a six-degree-of-freedom displacement positioning auxiliary correction method for a three-dimensional vision measurement system. On the basis of the existing technical system of three-dimensional vision measurement systems, a high-precision six-degree-of-freedom displacement stage is used as the position reference of the object to be measured. The three-dimensional vision measurement system is corrected in real time through the high-precision position output of the six-degree-of-freedom displacement stage. This can effectively realize the rapid determination or correction of the position of the feature points of the measured object, thereby improving the accuracy and reliability of the three-dimensional vision measurement system.

[0004] In a first aspect of the present invention, a six-degree-of-freedom displacement positioning auxiliary correction method for a three-dimensional vision measurement system is provided, the method comprising:

[0005] Calibrate the 3D vision measurement system;

[0006] The object to be measured is fixedly connected to the six-degree-of-freedom translation stage, and the coordinates of the feature points of the object to be measured in the world coordinate system and the coordinates of the feature points of the object to be measured in the six-degree-of-freedom translation stage coordinate system are obtained based on the three-dimensional vision measurement system. The first pose between the two coordinate systems is solved according to the coordinates of the feature points of the object to be measured in the two coordinate systems, including the first rotation matrix and the first translation vector;

[0007] The six-degree-of-freedom translation stage moves the object under test and outputs six-degree-of-freedom displacement information, including rotation matrix components and displacement matrix components;

[0008] According to the coordinates of the feature points of the measured object in the two coordinate systems after the movement, the second posture between the two coordinate systems after the movement is solved, including the second rotation matrix and the second translation vector;

[0009] The posture change information is determined according to the first posture and the second posture, and the three-dimensional vision measurement system is corrected in combination with the six-degree-of-freedom displacement information, including: determining the rotation matrix change value of the two coordinate systems according to the first rotation matrix and the second rotation matrix, and then correcting the rotation matrix of the three-dimensional vision measurement system in combination with the rotation matrix components; determining the displacement matrix change value of the two coordinate systems according to the first translation vector and the second translation vector, and then correcting the translation vector of the three-dimensional vision measurement system in combination with the displacement matrix components.

[0010] In some embodiments, calibrating a 3D vision measurement system includes:

[0011] Establish the world coordinate system Ow and the camera image coordinate system. According to the camera imaging model, the three-dimensional space point in the world coordinate system and the coordinate in the camera image coordinate system have the following relationship:

[0012]

[0013] Among them, A is the intrinsic parameter matrix of the camera, R and T are the rotation matrix and translation vector from the world coordinate system to the camera image coordinate system, (c x ,c y ) is the principal point of the image, (u,v) is the spatial point P(X w ,Y w ,Z w ) is projected into the camera image coordinate system, f x ,f y are the scale factors of the u-axis and v-axis, respectively, and f s is the non-perpendicular factor of the two coordinate axes, s is the spatial point P(X w ,Y w ,Z w ) is the projection along the optical axis in the camera image coordinate system; r ij is the element of the rotation matrix; t i are the elements of the translation vector.

[0014] In some embodiments, obtaining the coordinates of the feature points of the measured object in the world coordinate system based on the three-dimensional vision measurement system and obtaining the coordinates of the feature points of the measured object in the six-degree-of-freedom translation stage coordinate system, and solving the first position between the two coordinate systems according to the coordinates of the feature points of the measured object in the two coordinate systems, includes:

[0015] Assume that the point set {P1,P2,...,P n} are all feature points on the object being measured, and their coordinates in the world coordinate system Ow are {P 1w ,P 2w ,...,P nw According to the imaging pixel (u, v) information of the feature point P of the object to be measured in the camera image coordinate system, the coordinates P (X w ,Y w ,Z w );

[0016] Assume that the point set {P1,P2,...,P n The coordinates of the six-degree-of-freedom platform coordinate system Os are {P 1s ,P 2s ,...,P ns}, then the following relationship exists:

[0017]

[0018] Where, is the first rotation matrix, is the first translation vector, and the two together constitute the first position of the six-degree-of-freedom translation stage coordinate system in the world coordinate system.

[0019] Solve the above equation by singular value decomposition method to obtain the first rotation matrix and the first translation vector The objective function is solved as follows:

[0020]

[0021] Where i represents the i-th feature point on the object being measured, and n represents the total number of feature points.

[0022] In some embodiments, solving a second pose between the two coordinate systems after the movement based on the coordinates of the feature points of the measured object in the two coordinate systems after the movement includes:

[0023] Assume that the feature point set {P1,P2,...,P n}Move to {P′1,P′2,...,P′ n}, whose coordinates in the world coordinate system Ow are {P′ 1w ,P′ 2w ,...,P′ nw According to the imaging pixel (u′, v′) information of the feature point P′ of the object to be measured in the camera image coordinate system, the coordinates P′ (X′ w,Y′ w ,Z′ w );

[0024] Assume that the point set {P′1,P′2,...,P′ n The coordinates of the six-degree-of-freedom platform coordinate system Os are {P′ 1s ,P′ 2s ,...,P′ ns}, then the following relationship exists:

[0025]

[0026] Where, is the second rotation matrix, is the second translation vector, and the two together constitute the second posture of the six-degree-of-freedom translation stage coordinate system in the world coordinate system after movement

[0027] Solve the above equation by singular value decomposition method to obtain the second rotation matrix and the second translation vector The objective function is solved as follows:

[0028]

[0029] Where i represents the i-th feature point on the object being measured, and n represents the total number of feature points.

[0030] In some embodiments, determining the rotation matrix change values ​​of the two coordinate systems according to the first rotation matrix and the second rotation matrix, and then correcting the rotation matrix of the three-dimensional vision measurement system in combination with the rotation matrix components; determining the displacement matrix change values ​​of the two coordinate systems according to the first translation vector and the second translation vector, and then correcting the translation vector of the three-dimensional vision measurement system in combination with the displacement matrix components, includes:

[0031] For the characteristic point P of the object being measured, when the six-degree-of-freedom translation stage drives it to move to point P', the following relationship should be met:

[0032]

[0033] Similarly, for the feature point set {P1, P2, ..., P n} also satisfies the above relationship, namely:

[0034]

[0035] in, is the rotation matrix change value of the six-degree-of-freedom translation stage coordinate system relative to the world coordinate system, is the second rotation matrix, is the first rotation matrix; is the displacement matrix change value of the six-degree-of-freedom translation platform coordinate system relative to the world coordinate system, is the second translation vector, is the first translation vector; P(X w ,Y w ,Z w ) is the coordinate of point P in the world coordinate system, P′(X′ w ,Y′ w ,Z′ w ) is the coordinate of point P′ in the world coordinate system; the point set {P1,P2,...,P n}Move to {P′1,P′2,...,P′ n}, whose coordinates in the world coordinate system Ow are {P′ 1w ,P′ 2w ,...,P′ nw}, n represents the total number of feature points;

[0036] By minimizing the residual root mean square of the visual pose change value of the feature point set and the measured change value of the six-degree-of-freedom displacement platform, the six-degree-of-freedom displacement information ΔP is used. s Assist in correcting the positioning information of the 3D vision measurement system, namely:

[0037]

[0038] Among them, R is the rotation matrix of the three-dimensional vision measurement system, T is the translation vector of the three-dimensional vision measurement system, ΔP sR ΔP s The rotation matrix component, ΔP sT ΔP s The displacement matrix component of , n' is the total number of feature point sets.

[0039] In some embodiments, the method further comprises:

[0040] The coordinates of the feature points of the measured object in the world coordinate system are updated using the rotation matrix and translation vector of the calibrated 3D vision measurement system.

[0041] In some embodiments, the method further comprises:

[0042] The six-degree-of-freedom translation stage moves the object to be measured multiple times. Every time the object to be measured moves, the rotation matrix and translation vector of the three-dimensional vision measurement system are corrected once.

[0043] According to a second aspect of the present invention, a three-dimensional vision measurement system is provided, which includes the steps of the six-degree-of-freedom displacement positioning auxiliary correction method for a three-dimensional vision measurement system described in any one of the first aspects.

[0044] According to a third aspect of the present invention, an electronic device is provided, comprising: a processor and a memory, the memory storing programs or instructions that can be run on the processor, and when the programs or instructions are executed by the processor, the steps of the six-degree-of-freedom displacement positioning auxiliary correction method for a three-dimensional vision measurement system described in any one of the first aspects are implemented.

[0045] According to a fourth aspect of the present invention, a readable storage medium is provided, on which a program or instruction is stored. When the program or instruction is executed by a processor, the steps of the six-degree-of-freedom displacement positioning auxiliary correction method for a three-dimensional vision measurement system described in any one of the first aspects are implemented.

[0046] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0047] The six-degree-of-freedom displacement positioning auxiliary correction method for a three-dimensional vision measurement system proposed in the present invention is based on the existing technical system of three-dimensional vision measurement systems. It uses a high-precision six-degree-of-freedom displacement stage as the position reference of the object being measured. The three-dimensional vision measurement system is corrected in real time through the high-precision position output of the six-degree-of-freedom displacement stage. This can effectively realize the rapid determination or correction of the position of the feature points of the object being measured, thereby improving the accuracy and reliability of the three-dimensional vision measurement system. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 A schematic flow chart of a six-degree-of-freedom displacement positioning auxiliary correction method for a three-dimensional vision measurement system provided in an embodiment of the present application;

[0049] Figure 2 A schematic diagram of a six-degree-of-freedom translation stage moving an object under test provided in an embodiment of the present application;

[0050] Figure 3 A schematic diagram of the hardware structure of a computer device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0051] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. Based on the embodiments provided in this application, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of the present invention.

[0052] Obviously, the drawings described below are merely examples or embodiments of the present application. Those skilled in the art can, without inventive effort, apply the present application to other similar scenarios based on these drawings. Furthermore, it is also understood that, although the effort involved in such a development process may be complex and lengthy, for those skilled in the art related to the content disclosed in this application, changes in design, manufacturing, or production based on the technical content disclosed in this application are merely conventional technical means and should not be construed as an insufficiency of the content disclosed in this application.

[0053] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it refer to independent or alternative embodiments that are mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described in this application may be combined with other embodiments unless there is a conflict.

[0054] Unless otherwise defined, the technical or scientific terms used in this application should have the ordinary meaning understood by a person of ordinary skill in the technical field to which this application belongs. The words "one", "a", "the" and the like used in this application do not indicate a limit on quantity and may indicate the singular or plural. The terms "include", "comprise", "have" and any variations thereof used in this application are intended to cover non-exclusive inclusions; for example, a process, method, system, product or device that includes a series of steps or modules (units) is not limited to the listed steps or units, but may also include steps or units that are not listed, or may also include other steps or units that are inherent to these processes, methods, products or devices. The words "connect", "connected", "coupled" and the like used in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The word "multiple" used in this application refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships can exist. For example, "A and / or B" can mean: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the objects before and after are in an "or" relationship. The terms "first", "second", "third", etc. involved in this application are only used to distinguish similar objects and do not represent a specific order for the objects.

[0055] The purpose of this application is to use a high-precision six-degree-of-freedom (6DOF) translation stage as a reference for the position and posture of the object being measured, assisting a three-dimensional vision measurement system in performing real-time position corrections, thereby improving the accuracy and reliability of the three-dimensional vision measurement system. This application can be used in a three-dimensional vision measurement system to improve the measurement accuracy of the feature points of the measured object. It can also be combined with a multi-view three-dimensional vision measurement system and high-precision standard parts to form a three-dimensional vision measurement field. Using standard parts with known structural information and high-precision six-degree-of-freedom position output, the measurement accuracy of the measurement field can be corrected in real time.

[0056] An embodiment of the present application provides a six-degree-of-freedom displacement positioning auxiliary correction method for a three-dimensional vision measurement system, which is applicable to a three-dimensional vision measurement system. Figure 1 A flow chart of a six-degree-of-freedom displacement positioning auxiliary correction method for a three-dimensional vision measurement system provided in an embodiment of the present application is shown as follows: Figure 1 As shown, the method includes the following steps:

[0057] Calibrate the 3D vision measurement system;

[0058] The object to be measured is fixedly connected to the six-degree-of-freedom translation stage, and the coordinates of the feature points of the object to be measured in the world coordinate system and the coordinates of the feature points of the object to be measured in the six-degree-of-freedom translation stage coordinate system are obtained based on the three-dimensional vision measurement system. The first pose between the two coordinate systems is solved according to the coordinates of the feature points of the object to be measured in the two coordinate systems, including the first rotation matrix and the first translation vector;

[0059] The six-degree-of-freedom translation stage moves the object under test and outputs six-degree-of-freedom displacement information, including rotation matrix components and displacement matrix components;

[0060] According to the coordinates of the feature points of the measured object in the two coordinate systems after the movement, the second posture between the two coordinate systems after the movement is solved, including the second rotation matrix and the second translation vector;

[0061] The posture change information is determined according to the first posture and the second posture, and the three-dimensional vision measurement system is corrected in combination with the six-degree-of-freedom displacement information, including: determining the rotation matrix change value of the two coordinate systems according to the first rotation matrix and the second rotation matrix, and then correcting the rotation matrix of the three-dimensional vision measurement system in combination with the rotation matrix components; determining the displacement matrix change value of the two coordinate systems according to the first translation vector and the second translation vector, and then correcting the translation vector of the three-dimensional vision measurement system in combination with the displacement matrix components.

[0062] Based on the existing technical system of three-dimensional vision measurement system, this application uses a high-precision six-degree-of-freedom translation stage as the position reference of the object to be measured. The three-dimensional vision measurement system is corrected in real time through the high-precision position output of the six-degree-of-freedom translation stage, which can effectively realize the rapid determination or correction of the position of the feature points of the measured object, thereby improving the accuracy and reliability of the three-dimensional vision measurement system.

[0063] Specifically, the six-degree-of-freedom displacement positioning auxiliary correction method for a three-dimensional vision measurement system according to an embodiment of the present application includes the following steps:

[0064] Step 1: Use the calibration tool to calibrate the 3D vision measurement system and establish the world coordinate system Ow;

[0065] Step 2: Obtain the coordinates P(X) of a feature point P of the object to be measured in the world coordinate system Ow through binocular vision imaging calculation of the 3D vision measurement system. w ,Y w ,Z w ); Connect the measured object to the six-degree-of-freedom translation platform and obtain the coordinates P(X s ,Y s ,Z s ), according to the coordinates of point P in the two coordinate systems, the position and posture of the six-degree-of-freedom translation stage coordinate system in the world coordinate system are obtained, including the rotation matrix and the translation vector;

[0066] Step 3: The six-degree-of-freedom platform moves the object to be measured, so that point P moves to point P', and outputs the six-degree-of-freedom displacement information ΔP s ; Six-degree-of-freedom displacement information ΔP s Covers rotation matrix components as well as displacement matrix components;

[0067] Step 4: Obtain the coordinates P′(X′) of point P′ in the world coordinate system Ow through binocular vision imaging calculation of the 3D vision measurement system. w ,Y′ w ,Z′ w ) and the coordinates of the six-degree-of-freedom translation platform coordinate system Os. Similarly, according to the coordinates of point P' in the two coordinate systems, the position and posture of the six-degree-of-freedom translation platform coordinate system in the world coordinate system after the six-degree-of-freedom translation platform moves are obtained;

[0068] Step 5: Use the six-degree-of-freedom displacement information to assist in correcting the positioning information of the three-dimensional vision measurement system to obtain the corrected rotation matrix and translation vector of the three-dimensional vision measurement system. Then, the corrected rotation matrix and translation vector can be used to update the positions of P and P′ to make the positioning of the three-dimensional vision measurement system more accurate.

[0069] In some embodiments, step S1 includes:

[0070] The world coordinate system Ow is established for the 3D vision measurement system by using specific marks on tools such as calibration plates and calibration rods. By moving the calibration plates and calibration rods and changing the position and orientation of specific marks, the internal and external parameters of the camera used in 3D vision measurement can be calibrated, and the relationship between the world coordinate system and the camera image coordinate system can be determined. According to the camera imaging model, the following relationship exists between the 3D space points in the world coordinate system and the coordinates in the camera image coordinate system:

[0071]

[0072] Among them, A is the intrinsic parameter matrix of the camera, R and T are the rotation matrix and translation vector (collectively referred to as extrinsic parameters) from the world coordinate system to the camera image coordinate system, and f x ,f y are the scale factors of the u-axis and v-axis, respectively, and f s is the non-perpendicularity factor of the two coordinate axes, (c x ,c y ) is the principal point of the image, (u,v) is the spatial point P(X w ,Y w ,Z w ) is projected into the camera image coordinate system. Since the marker information on the calibration plate and calibration rod is known, the camera parameters can be obtained and the world coordinate system established. The object being measured is fixed to the 6DOF translation stage, and similarly, the 6DOF translation stage coordinate system Os is linked to the world coordinate system.

[0073] In some embodiments, step S2 includes:

[0074] Assume that the point set {P1,P2,...,P n} are all feature points on the object being measured, and their coordinates in the world coordinate system Ow are {P 1w ,P 2w ,...,P nw According to the imaging pixel (u, v) information of the feature point P of the object to be measured in the camera image coordinate system, the coordinates P (X w ,Y w ,Z w ).

[0075] The object to be measured is fixedly connected to the six-degree-of-freedom translation stage. The coordinates of point P on the six-degree-of-freedom translation stage coordinate system Os are P(X s ,Y s ,Z s ), point set {P1,P2,...,P n The coordinates of the six-degree-of-freedom platform coordinate system Os are {P 1s ,P 2s ,...,P ns}. is the position of the six-degree-of-freedom translation stage coordinate system in the world coordinate system, is the rotation matrix, is the translation vector, and the following relationship exists:

[0076]

[0077] By solving the above equation using the singular value decomposition method, the position and posture of the object being measured can be obtained. The objective function is solved as follows:

[0078]

[0079] Where i represents the i-th feature point on the object being measured, and n represents the total number of feature points.

[0080] It should be noted that there are at least 3 feature points.

[0081] In some embodiments, step S3 includes:

[0082] like Figure 2 As shown, the six-degree-of-freedom translation stage moves the object to be measured, so that point P moves to point P', and outputs the six-degree-of-freedom displacement information ΔP s Taking the center point position of the platform on the six-degree-of-freedom translation stage as the target, the lengths of the six electric cylinders are calculated based on the inverse solution. The controller of the electric cylinder branch chain performs closed-loop control according to the command length, so that the electric cylinder is extended and retracted to the command length, the object being measured moves to the specified position, the feature point P moves to P', and the six-degree-of-freedom translation stage outputs the displacement information ΔP s ={δX s ,δY s ,δZ s ,δP s ,δR s ,δH s}. Among them, δX s ,δY s ,δZ s is the displacement matrix component, δP s ,δR s ,δH s are the rotation matrix components.

[0083] In some embodiments, step S4 includes:

[0084] Assume that the point set {P1,P2,...,P n}Move to {P′1,P′2,...,P′ n}, whose coordinates in the world coordinate system Ow are {P′ 1w ,P′ 2w ,...,P′ nwAccording to the imaging pixel (u′, v′) information of the feature point P′ of the object to be measured in the camera image coordinate system, the coordinates P′ (X′) of the point P′ in the world coordinate system Ow can be calculated by formula (1). w ,Y′ w ,Z′ w ).

[0085] The object to be measured is fixedly connected to the six-degree-of-freedom translation stage. The coordinates of point P on the six-degree-of-freedom translation stage coordinate system Os are P(X s ,Y s ,Z s ), point set {P′1,P′2,...,P′ n The coordinates of the six-degree-of-freedom platform coordinate system Os are {P′ 1s ,P′ 2s ,...,P′ ns}. is the position of the six-degree-of-freedom translation stage coordinate system in the world coordinate system, is the rotation matrix, is the translation vector, and the following relationship exists:

[0086]

[0087] By solving the above equation using the singular value decomposition method, the position and posture of the object being measured can be obtained. The objective function is solved as follows:

[0088]

[0089] Where i represents the i-th feature point on the object being measured, and n represents the total number of feature points.

[0090] In some embodiments, step S5 is used to use six-degree-of-freedom displacement information to assist in correcting the positioning information of the three-dimensional vision measurement system, including:

[0091] For the feature point P, when the six-degree-of-freedom platform drives it to move to point P', the following relationship should be met:

[0092]

[0093] Similarly, for the feature point set {P1,P2,...,P n} also satisfies the above relationship, namely:

[0094]

[0095] in, is the rotation matrix change value of the six-degree-of-freedom translation stage coordinate system relative to the world coordinate system, is the displacement matrix change value of the six-degree-of-freedom translation platform coordinate system relative to the world coordinate system,

[0096] Since the measurement accuracy of the six-degree-of-freedom position change of the six-degree-of-freedom translation stage is higher than that of the binocular vision measurement method, the six-degree-of-freedom displacement information can be used to assist in correcting the positioning information of the three-dimensional vision measurement system by minimizing the residual root mean square of the visual position change value of the feature point set and the measured change value of the six-degree-of-freedom translation stage, that is:

[0097]

[0098] Where ΔP sR ΔP s The rotation matrix component, ΔP sT ΔP s The displacement matrix components are n', and n' is the total number of feature point sets. By iteratively optimizing and solving the above equation, the error parameters of the 3D vision measurement system can be corrected to improve its measurement accuracy.

[0099] In order to further improve the correction accuracy, the six-degree-of-freedom translation stage can move the object to be measured multiple times. Every time the object to be measured moves, the rotation matrix and translation vector of the three-dimensional vision measurement system are corrected once, making the result more accurate.

[0100] In addition, combined Figure 1 The six-degree-of-freedom displacement positioning auxiliary correction method for a three-dimensional vision measurement system described in the embodiments of the present application can be implemented by a computer device. Figure 3 Schematic diagram of the hardware structure of the computer device of the embodiment of the present application. Figure 3 As shown, the device may include a processor 301 and a memory 302 storing computer program instructions.

[0101] Specifically, the processor 301 may include a central processing unit (CPU), or an application-specific integrated circuit (ASIC), or may be configured to implement one or more integrated circuits of the embodiments of the present application.

[0102] Among them, the memory 302 may include a large-capacity memory for data or instructions. By way of example and not limitation, the memory 302 may include a hard disk drive (HDD), a floppy disk drive, a solid-state drive (SSD), a flash memory, an optical disk, a magneto-optical disk, a magnetic tape, or a universal serial bus (USB) drive, or a combination of two or more of these. Where appropriate, the memory 302 may include a removable or non-removable (or fixed) medium. Where appropriate, the memory 302 may be inside or outside the data processing device. In a specific embodiment, the memory 302 is a non-volatile memory. In a specific embodiment, the memory 302 includes a read-only memory (ROM) and a random access memory (RAM). Where appropriate, the ROM may be a mask-programmed ROM, a programmable ROM (PROM), an erasable PROM (EPROM), an electrically erasable PROM (EEPROM), an electrically alterable ROM (EAROM) or a flash memory (FLASH), or a combination of two or more of these. Under appropriate circumstances, the RAM can be a static random access memory (SRAM) or a dynamic random access memory (DRAM), where the DRAM can be a fast page mode dynamic random access memory (FPMDRAM), an extended data output dynamic random access memory (EDODRAM), a synchronous dynamic random access memory (SDRAM), etc.

[0103] The memory 302 may be used to store or cache various data files that need to be processed and / or used for communication, as well as possible computer program instructions executed by the processor 301 .

[0104] The processor 301 reads and executes computer program instructions stored in the memory 302 to implement any one of the six-degree-of-freedom displacement positioning auxiliary correction methods for a three-dimensional vision measurement system in the above embodiments.

[0105] In some embodiments, the point cloud generation device may further include a communication interface 303 and a bus 300. Figure 3 As shown, the processor 301 , the memory 302 , and the communication interface 303 are connected via a bus 300 and communicate with each other.

[0106] The communication interface 303 is used to implement communication between the various modules, devices, units, and / or devices in the embodiments of the present application. The communication interface 303 can also implement data communication with other components such as: external devices, image / data acquisition equipment, databases, external storage, and image / data processing workstations.

[0107] Bus 300 includes hardware, software, or both, and couples the components of the point cloud generation device to each other. Bus 300 includes, but is not limited to, at least one of the following: a data bus, an address bus, a control bus, an expansion bus, and a local bus. By way of example, and not limitation, bus 300 may include an Accelerated Graphics Port (AGP) or other graphics bus, an Extended Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), a Hyper Transport (HT) interconnect, an Industry Standard Architecture (ISA) bus, an InfiniBand interconnect, a Low Pin Count (LPC) bus, a memory bus, a Micro Channel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a Video Electronics Standards Association Local Bus (VLB) bus, or other suitable buses, or a combination of two or more of these. Bus 300 may include one or more buses, where appropriate. Although embodiments herein describe and illustrate a particular bus, this application contemplates any suitable bus or interconnect.

[0108] The computer device can execute the six-degree-of-freedom displacement positioning auxiliary correction method for the three-dimensional vision measurement system in the embodiment of the present application based on the three-dimensional vision measurement system and the high-precision six-degree-of-freedom displacement stage, thereby realizing the combination of Figure 1 A six-degree-of-freedom displacement positioning auxiliary correction method for a three-dimensional vision measurement system is described.

[0109] In addition, in conjunction with the six-degree-of-freedom displacement positioning assisted correction method for a three-dimensional vision measurement system in the above-mentioned embodiments, embodiments of the present application may provide a computer-readable storage medium for implementation. The computer-readable storage medium stores computer program instructions; when executed by a processor, the computer program instructions implement any of the six-degree-of-freedom displacement positioning assisted correction methods for a three-dimensional vision measurement system in the above-mentioned embodiments.

[0110] It should be noted that the various technical features of the above-described embodiments can be combined in any manner. To simplify the description, not all possible combinations of the various technical features in the above-described embodiments are described. However, as long as there are no contradictions in the combination of these technical features, they should be considered to be within the scope of this specification. In addition, according to the needs of implementation, the various steps / components described in this application can be split into more steps / components, and two or more steps / components or partial operations of steps / components can be combined into new steps / components to achieve the purpose of the present invention.

[0111] Those skilled in the art will readily understand that the above-described embodiments merely represent several implementation methods of the present application, and their descriptions are relatively specific and detailed, but should not be construed as limiting the scope of the invention. It should be noted that a person of ordinary skill in the art may make several variations and improvements without departing from the concept of the present application, and these variations and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be based on the appended claims.

Claims

1. A six-degree-of-freedom displacement positioning auxiliary correction method for a three-dimensional vision measurement system, characterized in that: The method includes: Calibrate the 3D vision measurement system; The object to be measured is fixedly connected to the six-degree-of-freedom translation stage, and the coordinates of the feature points of the object to be measured in the world coordinate system and the coordinates of the feature points of the object to be measured in the six-degree-of-freedom translation stage coordinate system are obtained based on the three-dimensional vision measurement system. The first pose between the two coordinate systems is solved according to the coordinates of the feature points of the object to be measured in the two coordinate systems, including the first rotation matrix and the first translation vector; The six-degree-of-freedom translation stage moves the object under test and outputs six-degree-of-freedom displacement information, including rotation matrix components and displacement matrix components; According to the coordinates of the feature points of the measured object in the two coordinate systems after the movement, the second posture between the two coordinate systems after the movement is solved, including the second rotation matrix and the second translation vector; The posture change information is determined according to the first posture and the second posture, and the three-dimensional vision measurement system is corrected in combination with the six-degree-of-freedom displacement information, including: determining the rotation matrix change value of the two coordinate systems according to the first rotation matrix and the second rotation matrix, and then correcting the rotation matrix of the three-dimensional vision measurement system in combination with the rotation matrix components; determining the displacement matrix change value of the two coordinate systems according to the first translation vector and the second translation vector, and then correcting the translation vector of the three-dimensional vision measurement system in combination with the displacement matrix components.

2. The six-degree-of-freedom displacement positioning auxiliary correction method for a three-dimensional vision measurement system according to claim 1, characterized in that: Calibrate the 3D vision measurement system, including: Establish the world coordinate system Ow and the camera image coordinate system. According to the camera imaging model, the three-dimensional space point in the world coordinate system and the coordinate in the camera image coordinate system have the following relationship: Among them, A is the intrinsic parameter matrix of the camera, R and T are the rotation matrix and translation vector from the world coordinate system to the camera image coordinate system, (c x ,c y ) is the principal point of the image, (u,v) is the spatial point P(X w ,Y w ,Z w ) is projected into the camera image coordinate system, f x ,f y are the scale factors of the u-axis and v-axis, respectively, and f s is the non-perpendicular factor of the two coordinate axes, s is the spatial point P(X w ,Y w ,Z w ) is the projection along the optical axis in the camera image coordinate system; r ij is the element of the rotation matrix; t i are the elements of the translation vector.

3. The six-degree-of-freedom displacement positioning auxiliary correction method for a three-dimensional vision measurement system according to claim 1, characterized in that: Based on the three-dimensional vision measurement system, the coordinates of the feature points of the measured object in the world coordinate system are obtained, and the coordinates of the feature points of the measured object in the six-degree-of-freedom translation stage coordinate system are obtained. The first position between the two coordinate systems is solved according to the coordinates of the feature points of the measured object in the two coordinate systems, including: Assume that the point set {P1,P2,...,P n } are all feature points on the object being measured, and their coordinates in the world coordinate system Ow are {P 1w ,P 2w ,...,P nw According to the imaging pixel (u, v) information of the feature point P of the object to be measured in the camera image coordinate system, the coordinates P (X w ,Y w ,Z w ); Assume that the point set {P1,P2,...,P n The coordinates of the six-degree-of-freedom platform coordinate system Os are {P 1s ,P 2s ,...,P ns }, then the following relationship exists: Where, is the first rotation matrix, is the first translation vector, and the two together constitute the first position of the six-degree-of-freedom translation stage coordinate system in the world coordinate system. Solve the above equation by singular value decomposition method to obtain the first rotation matrix and the first translation vector The objective function is solved as follows: Where i represents the i-th feature point on the object being measured, and n represents the total number of feature points.

4. The six-degree-of-freedom displacement positioning auxiliary correction method for a three-dimensional vision measurement system according to claim 1, characterized in that: According to the coordinates of the feature points of the measured object in the two coordinate systems after the movement, the second posture between the two coordinate systems after the movement is solved, including: Assume that the feature point set {P1,P2,...,P n }Move to {P1′,P2′,...,P n ′}, its coordinates in the world coordinate system Ow are {P1′ w ,P2′ w ,...,P n ' w According to the imaging pixel (u′, v′) information of the feature point P′ of the object to be measured in the camera image coordinate system, the coordinates P′ (X′ w ,Y w ′,Z′ w ); Assume that the point set {P1′,P2′,...,P n The coordinates of P1′ on the six-degree-of-freedom platform coordinate system Os are {P1′ s ,P2′ s ,...,P n ' s }, then the following relationship exists: Where, is the second rotation matrix, is the second translation vector, and the two together constitute the second posture of the six-degree-of-freedom translation stage coordinate system in the world coordinate system after movement Solve the above equation by singular value decomposition method to obtain the second rotation matrix and the second translation vector The objective function is solved as follows: Where i represents the i-th feature point on the object being measured, and n represents the total number of feature points.

5. The six-degree-of-freedom displacement positioning auxiliary correction method for a three-dimensional vision measurement system according to claim 1, characterized in that: Determine the rotation matrix change values ​​of the two coordinate systems according to the first rotation matrix and the second rotation matrix, and then correct the rotation matrix of the three-dimensional vision measurement system in combination with the rotation matrix components; Determining the displacement matrix change values ​​of the two coordinate systems according to the first translation vector and the second translation vector, and then correcting the translation vector of the three-dimensional vision measurement system in combination with the displacement matrix components, including: For the characteristic point P of the object being measured, when the six-degree-of-freedom translation stage drives it to move to point P', the following relationship should be met: Similarly, for the feature point set {P1, P2, ..., P n } also satisfies the above relationship, namely: Among them, Δ s w R is the rotation matrix change value of the six-degree-of-freedom translation stage coordinate system relative to the world coordinate system, is the second rotation matrix, is the first rotation matrix; is the displacement matrix change value of the six-degree-of-freedom translation platform coordinate system relative to the world coordinate system, is the second translation vector, is the first translation vector; P(X w ,Y w ,Z w ) is the coordinate of point P in the world coordinate system, P′(X′ w ,Y w ′,Z′ w ) is the coordinate of point P′ in the world coordinate system; the point set {P1,P2,...,P n }Move to {P1′,P2′,...,P n ′}, its coordinates in the world coordinate system Ow are {P1′ w ,P2′ w ,...,P n ' w }, n represents the total number of feature points; By minimizing the residual root mean square of the visual pose change value of the feature point set and the measured change value of the six-degree-of-freedom displacement platform, the six-degree-of-freedom displacement information ΔP is used. s Assist in correcting the positioning information of the 3D vision measurement system, namely: Among them, R is the rotation matrix of the three-dimensional vision measurement system, T is the translation vector of the three-dimensional vision measurement system, ΔP sR ΔP s The rotation matrix component, ΔP sT ΔP s The displacement matrix component of , n' is the total number of feature point sets.

6. The six-degree-of-freedom displacement positioning auxiliary correction method for a three-dimensional vision measurement system according to claim 1, characterized in that: The method further includes: The coordinates of the feature points of the measured object in the world coordinate system are updated using the rotation matrix and translation vector of the calibrated 3D vision measurement system.

7. The six-degree-of-freedom displacement positioning auxiliary correction method for a three-dimensional vision measurement system according to claim 1, characterized in that: The method further includes: The six-degree-of-freedom translation stage moves the object to be measured multiple times. Every time the object to be measured moves, the rotation matrix and translation vector of the three-dimensional vision measurement system are corrected once.

8. A three-dimensional visual measurement system, characterized in that: The three-dimensional vision measurement system includes the steps of the six-degree-of-freedom displacement positioning auxiliary correction method for a three-dimensional vision measurement system as described in any one of claims 1 to 7.

9. An electronic device, characterized in that: include: A processor and a memory, wherein the memory stores programs or instructions that can be run on the processor, and when the programs or instructions are executed by the processor, the steps of the six-degree-of-freedom displacement positioning auxiliary correction method for a three-dimensional vision measurement system as described in any one of claims 1 to 7 are implemented.

10. A readable storage medium, characterized in that: Programs or instructions are stored thereon, and when the programs or instructions are executed by the processor, the steps of the six-degree-of-freedom displacement positioning auxiliary correction method for a three-dimensional vision measurement system as described in any one of claims 1 to 7 are implemented.

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