Spatial multi-degree-of-freedom pose vision ultra-precision measurement system and method

Abstract

The invention discloses a spatial multi-degree-of-freedom pose vision ultra-precision measurement system and method, the system is mainly composed of a multi-view imaging system and a pose measurement algorithm, in the multi-view imaging system, a low-distortion telecentric lens is selected as a lens, and auxiliary industrial cameras are distributed around a main industrial camera, so that the multi-view imaging system is differentiated into multiple groups of binocular systems; the method comprises the following steps of: fixing a mark plate printed with any mark pattern on a target plane in a position and posture measurement algorithm, and extracting a position and posture through the position and posture measurement algorithm corresponding to the observed mark pattern. And due to the parallel projection characteristic of the telecentric lens, at most five-degree-of-freedom pose measurement is realized, so that a sixth degree of freedom is obtained by utilizing complementary information provided by the binocular system, and space six-degree-of-freedom ultra-precision measurement is realized. The method can be applied to the field of precision measurement and robots, and visual ultra-precision measurement of spatial multi-degree-of-freedom poses can be realized by selecting proper cameras and lenses and combining the algorithm.

Description

Technical Field

[0001] This invention belongs to the field of precision measurement, and in particular relates to a spatial multi-degree-of-freedom pose vision ultra-precision measurement system and method. Background Technology

[0002] With the development of micro-assembly and micro-robots, as well as the research and development of various precision instruments, manufacturing technologies are constantly evolving towards micro-nano and ultra-precision directions, leading to an increasing demand for precision positioning platforms and micro-nano manipulators. To achieve real-time monitoring and closed-loop control of various precision motion devices, higher requirements are placed on precise posture measurement.

[0003] Currently, sensors used for pose measurement can be divided into two categories: optical and non-optical. Optical sensors mainly include laser trackers and laser interferometers. Due to their advantages such as non-contact operation, high resolution, and high bandwidth, they are widely used in precision pose measurement. However, while laser trackers can measure multiple degrees of freedom, their accuracy is relatively low. Although laser interferometers can achieve nanometer-level accuracy, they typically only measure 2 to 3 degrees of freedom and require complex optical path structures. Besides optical sensors, camera-based visual pose measurement systems are also a common approach. Visual pose measurement systems can be divided into monocular and multi-view systems. Monocular systems typically provide a large field of view, but a single viewpoint is not sensitive to depth perception, especially with telecentric lenses. Because telecentric lenses have lower distortion and a greater depth of field, they greatly improve the performance and accuracy of optical systems. Therefore, to improve measurement accuracy, telecentric lenses or inherently orthographic projection microscope objectives are widely used in precision measurement. However, because telecentric lenses use orthographic projection, they are less able to perceive changes in depth and struggle to measure all six degrees of freedom. Therefore, they are currently mainly used for in-plane measurements. Compared to monocular systems, multi-view systems offer significant advantages in reconstructing the object and its pose for solving multiple degrees of freedom. However, if a binocular system is used, the binocular vision system needs to ensure a common field of view between the two industrial cameras and that the target being measured is simultaneously within the depth of field of both cameras, further reducing the space that can be accurately measured compared to a single industrial camera. Clearly, ultra-precision measurements suffer from a trade-off between measurement accuracy, degrees of freedom, and measurement range.

[0004] Existing visual measurement methods can be divided into spatial domain-based methods and frequency domain-based methods. Spatial domain-based methods refer to recovering the pose by using features present in the image or studying pixel changes between images. The literature (Hai Li, Xianmin Zhang, Benliang Zhu, Sergej Fatikow. Online precise motion measurement of 3-DOF nanopositioners based on image correlation. IEEE Transactions on Instrumentation and Measurement, 2019, 68(3):782-790.) proposes an optimization algorithm based on inverse combination Gaussian-Newton search to determine the template position in the input image based on the pixel value of the marker feature, realizing real-time motion tracking of the nanopositioner. However, due to the limitation that template matching can only intuitively obtain planar pose information, this method only realizes the precise measurement of 3-DOF pose. For frequency domain-based methods, the pose changes of two frames of images at any time during the measurement process are mainly converted into phase changes in the frequency domain through Fourier transform for measurement. Existing literature (Ahmad B, Sandoz P, Laurent G J. 6-DoF Motion Capture with Nanometric Resolutions over Millimetric Ranges Using a Pseudo-Periodic Encoded Pattern[J]. IEEE Transactions on Instrumentation and Measurement, 2024.) proposes a complementary method that uses digital holographic microscopy to solve out-of-plane motion and phase-based motion estimation to solve in-plane motion. However, the out-of-plane measurement range of this method is limited by the digital holographic microscopy, resulting in a small measurement range, especially for z-direction displacement, which is only 0.2 mm. A common problem with these existing ultra-precision measurement methods is the contradiction between measurement accuracy, measurable degrees of freedom, and measurement range.

[0005] Therefore, there is a need in this field to develop a spatial multi-degree-of-freedom pose vision ultra-precision measurement system and method, which can perform ultra-precision measurement of 6 degrees of freedom while having a large measurable space. Summary of the Invention

[0006] To address the constraints between measurement accuracy, degrees of freedom, and measurement range in the field of ultra-precision measurement, this invention proposes a spatial multi-degree-of-freedom pose vision ultra-precision measurement system and method. This overcomes the contradiction between multi-view systems and measurement space in existing vision measurement technologies, providing a larger common measurement range and depth of field. Furthermore, by utilizing relevant algorithms and binocular stereo vision, it extends ultra-precision in-plane measurement under a telecentric lens, achieving complete six-degree-of-freedom ultra-precision measurement.

[0007] The present invention is achieved by at least one of the following technical solutions.

[0008] A spatial multi-degree-of-freedom pose vision ultra-precision measurement system includes a main industrial camera, multiple auxiliary industrial cameras, a lens fixing bracket, a marking device, a precision motion device, and a base;

[0009] The main industrial camera and multiple auxiliary industrial cameras are connected to telecentric lenses, which are respectively mounted on lens mounting brackets. The marking device is mounted on a precision motion device located inside the base. The lens mounting bracket is fixed on the base and located above the marking device, ensuring that the marking pattern of the marking device is within the field of view of the main industrial camera and the auxiliary industrial cameras.

[0010] Furthermore, the marking device includes a marking plate and a backlight plate. The marking plate is fixed on the backlight plate, and the backlight plate is installed on the moving end of the precision motion device. The marking plate is printed with marking patterns.

[0011] Furthermore, the precision motion device is a robotic arm capable of multi-degree-of-freedom motion with a repeatability accuracy at the micrometer level. The backlight plate is fixed to the moving end of the robotic arm, enabling the moving end to drive the marking plate to move synchronously.

[0012] Furthermore, the lens mounting bracket includes a bracket with mounting holes corresponding to a plurality of telecentric lenses. The telecentric lenses are mounted on the mounting holes via lens mounting rings, and the bracket is mounted on a base via a slide rail.

[0013] Furthermore, the main industrial camera is vertically downward, and the auxiliary industrial cameras surround the main industrial camera. The optical axes of all the industrial cameras intersect at a point, and the distance between the intersection point and the telecentric lens is the working distance of the lens. The main industrial camera is divided into multiple directions with the image center as the origin and parallel to the coordinate axis. Each direction and the corresponding auxiliary industrial camera constitute a binocular system, forming a local binocular measurement model composed of the main industrial camera and the corresponding auxiliary industrial cameras.

[0014] The method for implementing the aforementioned spatial multi-degree-of-freedom pose vision ultra-precision measurement system includes the following steps:

[0015] S1. Adjust the position of the lens fixing bracket so that the center of the marking board pattern is located in the center of the main industrial camera image, and make the images of each industrial camera clear.

[0016] S2, the main industrial camera and the auxiliary industrial camera simultaneously acquire images of the marking board pattern in its initial pose and transmit the images to the computer for processing;

[0017] S3. Select any one of the auxiliary industrial cameras to form the initial binocular system;

[0018] S4. The precision motion device moves, and the main industrial camera and auxiliary industrial camera capture images of the marking board pattern in its current pose and transmit the images to the computer for processing.

[0019] S5. By using the image of the pattern on the marker board, establish the relationship between the pattern features or phase and the pose of the pattern, thereby obtaining the pose;

[0020] S6. Based on the pose relationship between the main industrial camera and the selected auxiliary industrial camera, obtain the positive and negative directions of the off-axis angle, and combine the pose information of the two cameras to calculate the displacement in the z direction.

[0021] S7. Based on the pose of the current moment relative to the initial state obtained by measurement, evaluate the motion trend of the next moment, and when approaching the measurement boundary, select new auxiliary industrial cameras through the theoretical measurement area of ​​each camera to form a binocular system.

[0022] Further, step S7 includes the following steps:

[0023] Based on the field of view and depth of field parameters of the industrial camera and the telecentric lens, the spatial coordinate system of the system is established with the sensor center of the main industrial camera as the origin, thus obtaining the theoretical measurement boundary equation for each lens.

[0024] A cubic region is constructed from the theoretical measurement boundary of each lens, which is the theoretical measurement space of each industrial camera.

[0025] Furthermore, based on the intersection of the theoretical measurement spaces of the main industrial camera and different auxiliary industrial cameras, the measurement space of the main industrial camera is divided into multiple binocular measurement areas. After the precision motion device performs precision motion, it combines the boundary equation to determine the binocular measurement area where the pattern is located at the current moment: if the distance between the pattern and the boundary of the area is less than the threshold, then a suitable auxiliary industrial camera is selected again to form a new binocular system for the next moment, and the measurement area is switched.

[0026] A computer device according to the present invention includes a memory and a processor, the memory being electrically connected to the processor, the memory storing a computer program, characterized in that: when the computer program is executed by the processor, the processor causes the processor to implement the method described thereon.

[0027] The present invention provides a computer-readable storage medium storing a computer program, characterized in that: when the computer program is executed by a processor, the processor implements the method described thereon.

[0028] Compared with existing technologies, the beneficial effects of the present invention are as follows:

[0029] (1) In multi-view vision, it is necessary to ensure a common field of view between two industrial cameras, and also to ensure that the target being measured is simultaneously within the depth of field of both cameras, which further reduces the space that can be accurately measured compared to a single industrial camera. This invention proposes a spatial multi-degree-of-freedom pose vision ultra-precision measurement system, which overcomes the contradiction between multi-view systems and measurement space in existing vision measurement technologies, and ensures a larger measurement space range.

[0030] (2) In the currently used ultra-precise pose measurement methods, there are few measurable degrees of freedom. This invention proposes a spatial multi-degree-of-freedom pose visual ultra-precise measurement method, which realizes the complete six degrees of freedom under orthogonal projection through binocular vision multi-view fusion. Attached Figure Description

[0031] Figure 1 This is a structural diagram of a spatial multi-degree-of-freedom pose vision ultra-precision measurement system according to an embodiment;

[0032] Figure 2 This is a schematic diagram of an identification device for a spatial multi-degree-of-freedom pose vision ultra-precision measurement system, as shown in the embodiment.

[0033] Figure 3 Example of a marking pattern for a spatial multi-degree-of-freedom pose vision ultra-precision measurement system;

[0034] Figure 4 This is a flowchart illustrating a spatial multi-degree-of-freedom pose vision-based ultra-precision measurement method as an example.

[0035] Figure 5 This is a schematic diagram of the measurement space of a spatial multi-degree-of-freedom pose vision ultra-precision measurement system according to an embodiment;

[0036] The diagram shows: 1-telecentric lens, 2-main industrial camera, 3-auxiliary industrial camera, 4-lens mounting bracket, 5-marking device, 6-marking plate, 7-backlight plate, 8-precision motion device, 9-base, 10-lens mounting ring, 11-panel, 12-bracket. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0038] Example 1

[0039] like Figure 1 As shown, this embodiment provides a spatial multi-degree-of-freedom pose vision ultra-precision measurement system, including: multiple telecentric lenses 1, a main industrial camera 2, multiple auxiliary industrial cameras 3, a lens fixing bracket 4, a marking device 5, a precision motion device 8, and a base 9.

[0040] The lens mounting bracket 4 is mounted on the base 9, and the precision motion device 8 is located inside the base 9. The main industrial camera 2 and multiple auxiliary industrial cameras 3 are fixed above the precision motion device 8 via the lens mounting bracket 4. The marking device 5 is fixed on the moving end of the precision motion device 8 so that the coordinate system of the marking device 5 coincides with the coordinate system of the moving end platform of the precision motion device 8.

[0041] The marking device 5 includes a marking plate 6 and a backlight plate 7. To further expand the measurement range, in this embodiment, an absolutely encoded pattern is selected as an example. The marking plate 6 is printed with a light-transmitting marking pattern, such as a checkerboard pattern, a dot pattern, or an encoded pattern. Pose measurement is performed based on the geometric features, geometric constraints, or phase relationships present in the marking pattern. The marking plate 6 is processed onto the backlight plate 7 to provide a light source for camera imaging, thereby making the pattern brighter and clearer.

[0042] The marking pattern in this embodiment is as follows: Figure 3 As shown, since the pattern is absolutely encoded, the marked pattern can be larger than the field of view, with a length and width of 100mm. By inserting binary sequence encoding into the periodic coded pattern, the relative pose measurement provided by the periodic pattern is transformed into an absolute pose measurement. The marking plate 6 is located on the backlight plate 7, providing a certain brightness for the marking pattern to ensure clear imaging. The backlight plate 7 is fixed to the moving end of the precision motion device 8, so that the moving end drives the marking plate 6 to move synchronously.

[0043] The main industrial camera 2 and multiple auxiliary industrial cameras 3 are each connected to a telecentric lens 1. The main industrial camera 2 is vertically downward to provide the best viewing angle. The telecentric lens 1, the main industrial camera 2, and the multiple auxiliary industrial cameras 3 are connected as one unit by threads. The main industrial camera 2 and the auxiliary industrial cameras 3 transmit the collected data to the computer for processing via USB cable.

[0044] The telecentric lens 1 is mounted on the lens mounting bracket 4 via a lens mounting ring. The lens mounting ring is coaxially fitted with the outer wall of the telecentric lens 1 and the two are fixed together by fastening screws on the side of the lens mounting ring 10. Simultaneously, the lens mounting ring is fixed to the lens mounting bracket 4 by bolts. The lens mounting bracket 4 is connected to the base 9 via a slide rail, allowing it to move along the slide rail to adjust the field of view. The lens mounting bracket 4 has a topology-optimized hemispherical structure to ensure that the optical axes of the main industrial camera 2 and the auxiliary industrial cameras 3 distributed around the main industrial camera 2 intersect at a single point, and the distance between the intersection point and the telecentric lens 1 is the same as the lens's working distance. The field of view of the main industrial camera 2 is divided into four directions with the center of the field of view as the origin and parallel to the coordinate axis. Each direction forms a different binocular system with the corresponding auxiliary industrial camera 3. The main industrial camera 2 and the corresponding auxiliary industrial camera 3 form a local binocular measurement model, thereby dividing the measurement space of the central main industrial camera 2 into multiple regions. This allows full utilization of the field of view of the main industrial camera 2 at the optimal observation position. The multi-industry camera differentially divides into multiple binocular vision systems to ensure complete six-degree-of-freedom ultra-precision measurement and to fully utilize the measurement space of the main industrial camera 2, ensuring a large common measurement range and depth of field.

[0045] The initial position of the center of the marking plate 6 is located at the intersection of the optical axes, ensuring that the marking pattern is simultaneously in the center of the field of view of the main industrial camera 2 and the auxiliary industrial camera 3 at the initial moment.

[0046] In one embodiment, the lens mounting bracket 4 includes a hemispherical bracket 12 and a panel 11. The hemispherical bracket 12 is used to mount the telecentric lens 1. The bracket 12 has mounting holes corresponding to multiple telecentric lenses 1, and the telecentric lenses 1 are mounted on the mounting holes via lens mounting rings 10. The hemispherical bracket 12 is fixed to the panel 11, and the panel 11 is connected to the base 9 via a slide rail, allowing it to move along the slide rail to adjust the field of view. The panel 11 has a through hole, and the hemispherical bracket 12 is located on the through hole, ensuring that the marking pattern is within the field of view of the main industrial camera 2 and the auxiliary industrial camera 3.

[0047] In a preferred embodiment, this embodiment uses four auxiliary industrial cameras 3, with the optical axis angle between the main industrial camera 2 and each of the auxiliary industrial cameras 3 being 40 degrees.

[0048] In this example, the industrial camera is the MER2-502-79U3M from Daheng Imaging, with a resolution of 2448×2048 and a pixel size of 3.45μm×3.45μm; the telecentric lens 1 is an MTL-8018C-023 telecentric lens, the overall imaging system has a magnification of 0.228x, a theoretical field of view of 37.04mm×30.99mm for a single lens, and a depth of field of 12.3mm.

[0049] The precision motion device 8 is a robotic arm that can achieve multi-degree-of-freedom motion and has a repeatability of 10 micrometers. The backlight plate 7 is fixed to the moving end of the robotic arm, so that the moving end drives the marking plate 6 to move synchronously.

[0050] Example 2

[0051] like Figure 4 As shown, this embodiment provides a spatial multi-degree-of-freedom pose vision ultra-precision measurement method, which mainly includes the following steps:

[0052] Step 1: Adjust the lens fixing bracket 4 so that the center of the pattern on the marking plate 6 is located in the center of the image of the main industrial camera 2, and so that the marking device 5 is within the depth of field of each lens to ensure clear imaging.

[0053] The second step involves the main industrial camera 2 and the auxiliary industrial camera 3 simultaneously acquiring images of the pattern on the marker board 6 in its initial pose, and then transmitting the images to the computer via a USB interface.

[0054] The third step is to combine any one auxiliary industrial camera 3 with the main industrial camera 2 to form the initial binocular system.

[0055] Fourth step: The precision motion device 8 drives the marker plate 6 to move, and the main industrial camera 2 and the auxiliary industrial camera 3 acquire the image of the current pose marker plate, and then transmit it to the computer again through the USB interface.

[0056] Step 5: Using the image of the pattern on marker board 6, establish the relationship between the pattern features or phase and the pose of the pattern, and retrieve the 5-DOF pose (x,y,α,β,γ).

[0057] Specifically, the pose matrix is ​​obtained from the pattern information using an algorithm corresponding to the pattern, such as the PnP algorithm for chessboard patterns and the phase method for coded patterns. At this time, since the telecentric lens adopts a parallel projection model, only the truncated 2×2 rotation matrix and the displacement in the x and y directions can be obtained. Then, the rotation matrix is ​​restored by combining the characteristics of the rotation matrix to obtain the 5-DOF pose (x, y, α, β, γ). In this embodiment, since the coded pattern is used, the pose measurement under parallel projection is performed using the existing method (André AN, Sandoz P, Jacquot M, et al. Pose measurement at small scale by spectral analysis of periodic patterns[J]. International Journal of Computer Vision, 2022, 130(6): 1566-1582.).

[0058] Step 6: Obtain relevant constraints from the pose relationship between the main industrial camera 2 and the selected auxiliary industrial camera 3, obtain the positive and negative directions of the off-axis angle, and combine the pose information of the two cameras to calculate the displacement in the z direction.

[0059] Specifically, the process involves: first, performing telecentric lens calibration (Li H, Liao Z, Cai W, et al. Flexible calibration of the telecentric vision systems using only planar calibration target[J]. IEEE Transactions on Instrumentation and Measurement, 2023, 73: 1-10.) to obtain the pose between the main industrial camera 2 and the auxiliary industrial camera 3. Then, based on the pose transformation relationship between the two cameras, the following constraints are established regarding the angular relationship between the main industrial camera 2, the auxiliary industrial camera 3, and the measured plane:

[0060]

[0061] Where a represents the main industrial camera 2, and b represents the auxiliary industrial camera 3. It is the 2-row, 3-column truncated submatrix above the rotation matrix of the main industrial camera 2 relative to the auxiliary industrial camera 3. The 3x2 truncated submatrix to the left of the rotation matrix of the measured plane relative to the main industrial camera 2. It is the top left 2x2 truncated submatrix of the rotation matrix of the measured plane relative to the auxiliary industrial camera 3. express The element in the i-th row and j-th column. Since the sign of the off-axis angles (β, γ) is affected by the r in the rotation matrix... 31 r 32 The sign of the symbol has an effect, therefore R can be calculated. aw middle The estimated values ​​can be used to determine the signs of the off-axis angles β and γ, thereby resolving the ambiguity of the signs.

[0062] Simultaneously, based on the pose relationship between the main industrial camera 2 and the auxiliary industrial camera 3, constraints are established on the displacement vectors of the measured plane relative to the main industrial camera 2 and the auxiliary industrial camera 3:

[0063]

[0064] Among them, t a t b These are the displacement vectors of the measured plane relative to the main industrial camera 2 and the auxiliary industrial camera 3, respectively. xa t ya tza ], [t xb t yb t zb ] are respectively t a t b The displacement components in the x, y, and z directions. Solving this equation allows us to calculate the displacement t in the z direction of the last degree of freedom. z .

[0065] Step 7: Based on the pose of the current moment relative to the initial state obtained by measurement, evaluate the motion trend of the next moment. When approaching the measurement boundary, select new auxiliary industrial cameras 3 through the theoretical measurement area of ​​each camera to form a binocular system.

[0066] Specifically: Based on the field of view, depth of field, and other parameters of the industrial cameras and lenses, the theoretical measurement space of each industrial camera can be obtained. By establishing the system's spatial coordinate system with the sensor center of the main industrial camera 2 as the origin, the theoretical measurement boundary equations for each industrial camera can be derived. Taking the auxiliary industrial camera 3, located in the xz plane, as an example, it satisfies:

[0067]

[0068] Where θ is the optical axis angle between the main industrial camera and the auxiliary industrial camera, dof is the depth of field, w is the width of the field of view of a single camera lens, wd is the working distance of the telecentric lens 1, and l is the lens length of the telecentric lens 1.

[0069] A cubic region, or theoretical measurement space of each industrial camera, can be constructed from the theoretical measurement boundary of each lens. Except for the central region, the measurement spaces of different auxiliary industrial cameras 3 and the main industrial camera 2 intersect in different ways. Therefore, the measurement space of the main industrial camera 2 can be divided into multiple binocular measurement regions, such as... Figure 5 As shown in (a) and (b). After the precision motion device 8 performs precision motion, a mathematical model of the target being measured at the current moment can be established based on the obtained current pose:

[0070] p i ′=T cw ·p i i = 1, 2, 3, 4

[0071]

[0072] Among them, T cw p represents the transformation relationship between the target being measured and the image sensor. i p i ′, i = 1, 2, 3, 4 represent the initial posture and the spatial coordinates of the four vertices of the measured pattern after motion, i represents the vertex number, and tw and th are the length and width of the pattern;

[0073] By combining the boundary equation, the binocular measurement area where the pattern is located at the current moment can be determined: if the distance between the pattern and the boundary of the area is less than the set threshold, then a suitable auxiliary industrial camera 3 is selected to form a new binocular system for the next moment, and the measurement area is switched.

[0074] The above steps enable precise pose measurement of a planar target with six degrees of freedom. This invention can be applied to the fields of precision measurement and robotics. By selecting different types of cameras and lenses and combining them with the measurement method, ultra-precise measurement of planar six-degree-of-freedom motion can be achieved. In this embodiment, the common field of view and depth of field of the multi-view system are expanded. The common field of view in the x-direction is 37.04 mm, in the y-direction it is 30.99 mm, and in the z-direction it is 12.3 mm. The theoretical resolution of pose measurement depends on the selected marking pattern and the measurement algorithm. Taking the selected coding pattern and corresponding phase correlation method in this embodiment as an example, the displacement can reach 15 nm, and the α angle measurement is less than 0.2 × 10⁻⁶. -6 rad, off-axis angles β and γ can reach 5.10 rad. -6 rad.

[0075] The above are merely embodiments of the present invention and do not limit the scope of protection of the present invention. Any equivalent structure made using the content of the present invention specification, or any direct or indirect application in other related technical fields, are similarly included within the scope of protection of the present invention.

Claims

1. A spatial multi-degree-of-freedom pose vision ultra-precision measurement system, characterized in that: The application relates to a multi-camera industrial measurement device, which comprises a main industrial camera (2), multiple auxiliary industrial cameras (3), a lens fixing support (4), an identification device (5), a precision motion device (8) and a base (9). The main industrial camera (2) and the multiple auxiliary industrial cameras (3) are respectively connected with a telecentric lens (1), the multiple telecentric lenses (1) are arranged on the lens fixing support (4), the identification device (5) is installed on the precision motion device (8), the precision motion device (8) is located in the base (9), the lens fixing support (4) is fixed on the base (9) and located above the identification device (5), and the marking pattern of the identification device (5) is ensured to be located in the field of view of the main industrial camera (2) and the auxiliary industrial cameras (3). 2.The spatial multi-degree-of-freedom pose vision ultra-precision measurement system according to claim 1, characterized in that: The identification device (5) comprises a marking plate (6) and a backlight plate (7), the marking plate (6) is fixed on the backlight plate (7), the backlight plate (7) is installed on the moving end of the precision motion device (8), and the marking plate (6) is provided with a marking pattern.

3. The spatial multi-degree-of-freedom pose vision ultra-precision measurement system according to claim 2, characterized in that: The precision motion device (8) is a mechanical arm, can realize multi-degree-of-freedom motion, and has a micron-level repeat positioning precision, the backlight plate (7) is fixed on the moving end of the mechanical arm, and the moving end drives the marking plate (6) to move synchronously.

4. The spatial multi-degree-of-freedom pose vision ultra-precision measurement system according to claim 1, characterized in that: The lens fixing support (4) comprises a support (12), the support (12) is provided with mounting holes corresponding to the multiple telecentric lenses (1), the telecentric lenses (1) are installed on the mounting holes through lens mounting rings (10), and the support (12) is installed on the base (9) through sliding rails.

5. The spatial multi-degree-of-freedom pose vision ultra-precision measurement system according to claim 1, characterized in that: The main industrial camera (2) is vertically downward, the auxiliary industrial cameras (3) surround the main industrial camera (2), the optical axes of all the industrial cameras intersect at a point, the distance between the intersection point and the telecentric lens (1) is the working distance of the lens, the main industrial camera is divided into multiple directions with the image center as the origin and parallel to the coordinate axes, each direction and the corresponding auxiliary industrial camera form a binocular system, and the local binocular measurement model is formed by the main industrial camera and the corresponding auxiliary industrial camera.

6. The method for realizing the spatial multi-degree-of-freedom pose vision ultra-precision measurement system of claim 1, characterized in that: The application further discloses a multi-camera industrial measurement method, which comprises the following steps: S1, adjusting the position of the lens fixing support (4) so that the pattern center of the marking plate (6) is located in the imaging center of the main industrial camera (2) and the imaging of the industrial cameras is clear; S2, the main industrial camera (2) and the auxiliary industrial cameras (3) simultaneously collect the images of the marking plate (6) pattern in the initial pose, and transmit the images to a computer for processing; S3, the main industrial camera (2) selects any one of the auxiliary industrial cameras (3) to form an initial binocular system; S4, the precision motion device (8) moves, the main industrial camera (2) and the auxiliary industrial cameras (3) collect the images of the marking plate (6) pattern in the current pose, and transmit the images to the computer for processing; S5, the pattern features or phases and the poses of the pattern are connected through the images of the marking plate (6) pattern, so that the poses are obtained; S6, the positive and negative directions of the off-axis angle are obtained according to the pose relationship between the main industrial camera (2) and the selected auxiliary industrial camera (3), and the z direction displacement is obtained by combining the pose information of the two cameras. S7, according to the measured current time relative to the initial state of the pose, the motion trend of the next moment is evaluated, and when approaching the measurement boundary, the new auxiliary industrial camera (3) is screened through the theoretical measurement area of each camera to form a binocular system.

7. The method of claim 6, wherein: Step S7 includes the following steps: According to the field of view and the depth of field parameters of the industrial camera and the telecentric lens (1), a spatial coordinate system of the system is established with the center of the sensor of the main industrial camera (2) as the origin, that is, the theoretical measurement boundary equation of each lens is obtained; A cubic region is constructed from the theoretical measurement boundary of each lens, that is, the theoretical measurement space of each industrial camera.

8. The method of claim 7, wherein: According to the intersection of the theoretical measurement space of the main industrial camera (2) and different auxiliary industrial cameras (3), the measurement space of the main industrial camera (2) is divided into multiple binocular measurement regions. After the precise motion device (8) performs precise motion, the binocular measurement region where the pattern is currently located is judged in combination with the boundary equation: if the distance of the pattern from the region boundary is less than a threshold, then the next moment is selected to select a suitable auxiliary industrial camera (3) to form a new binocular system, and the measurement region is switched.

9. A computer device comprising a memory and a processor, the memory and the processor being electrically connected, the memory storing a computer program, characterized in that: The computer program is executed by the processor, so that the processor implements the method of any one of claims 6-8.

10. A computer readable storage medium storing a computer program, characterized in that: The computer program is executed by the processor, so that the processor implements the method of any one of claims 6-8.

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