Intelligent auxiliary assembly pose measurement method for large workpiece

Abstract

The invention belongs to the related technical field of workpiece assembly measurement, and discloses a large workpiece intelligent auxiliary assembly pose measurement method comprising the following steps: installing a first target ball of a laser tracker on a parallel mechanism used for controlling an assembly body, scanning to generate a three-dimensional point cloud model, and obtaining the position distance of each preset key feature point on the assembly body; resolving absolute coordinates of each preset key feature point on the assembly, and recording the absolute coordinates as a first coordinate set; mounting a second target ball on the mounting base, acquiring the position distance of each preset feature point on the mounting base, resolving absolute coordinates and recording the absolute coordinates as a second coordinate set; and the first coordinate set and the second coordinate set are used for respectively calculating the required translation adjustment amount and the required rotation adjustment amount. According to the invention, rapid three-dimensional modeling and precise space coordinate measurement can be organically fused, and the problem that measurement efficiency and precision cannot be considered at the same time by a single measurement means in the prior art is effectively solved, so that high-efficiency and precise integrated acquisition of pose adjustment data of a large workpiece is realized.

Description

Technical Field

[0001] This invention belongs to the technical field of workpiece assembly measurement, and more specifically, relates to an intelligent assisted assembly posture measurement method for large workpieces. Background Technology

[0002] In the construction of high-end equipment such as aerospace and shipbuilding, the key to achieving precise assembly of large workpieces and mounting bases lies in the accurate measurement and adjustment of their relative positions and orientations. By integrating optical measurement equipment and constructing an intelligent assisted assembly orientation measurement system, the spatial six-degree-of-freedom deviation of the workpiece relative to the base can be obtained efficiently and accurately, i.e., the required orientation adjustment amount.

[0003] In existing technologies, this type of high-precision measurement mainly relies on laser trackers. This approach indirectly fits the overall pose of the workpiece by repeatedly moving and measuring the spatial coordinates of a discrete target. However, for large workpieces with complex surfaces, this method requires frequent station changes and aiming, resulting in a cumbersome and inefficient operation. Furthermore, its accuracy largely depends on the selection of feature points and the standardization of measurement operations, making it prone to human error. Another solution is to use 3D optical scanning technology, which can quickly acquire a complete point cloud model of the workpiece surface, offering high modeling efficiency and rich detail. However, the absolute measurement accuracy of this technology is usually difficult to match that of laser trackers, and in the global measurement environment of large industrial sites, it often cannot directly meet the stringent requirements of high-precision pose adjustment.

[0004] Therefore, all existing solutions face the following technical challenges: a single measurement method is difficult to achieve both high-efficiency global spatial relationship reconstruction and high-precision absolute coordinate measurement in the same process flow, which often leads to a dilemma in practice: either sacrifice efficiency for accuracy, resulting in a long assembly cycle; or compromise accuracy in pursuit of efficiency, affecting the final assembly quality. Summary of the Invention

[0005] In response to one or more of the above-mentioned defects or needs of the existing technology, the present invention provides a method for intelligent assisted assembly pose measurement of large workpieces. By redesigning the entire process flow, it can organically integrate rapid 3D modeling and precise spatial coordinate measurement, effectively solving the problem that the single measurement method in the existing technology cannot take into account both measurement efficiency and accuracy, thereby realizing efficient and accurate integrated acquisition of pose adjustment data of large workpieces.

[0006] To achieve the above objectives, according to the present invention, a method for intelligent assisted assembly pose measurement of large workpieces is provided, characterized in that the method includes the following steps: S1. Construction and Data Acquisition of Digital Model of Assembly For large workpieces that are assemblies, the first target ball of the laser tracker is mounted on the parallel mechanism used to control the assembly. Then, the assembly, the parallel mechanism and the first target ball are scanned to obtain three-dimensional point cloud data of its surface. The surface three-dimensional point cloud data is processed to generate a corresponding three-dimensional point cloud model, and the size information of the assembly itself, as well as the three-dimensional relative coordinates (ΔX1, ΔY1, ΔZ1) from the center of the first target ball to each preset key feature point on the assembly are obtained. S2, Generation of the first coordinate set The laser tracker is set up in a common working area where the assembly and its mounting base can be observed simultaneously. Then, the laser tracker is used to measure the actual three-dimensional coordinates (X1, Y1, Z1) of the first target ball in the laser tracker coordinate system. Using the actual three-dimensional coordinates (X1, Y1, Z1) of the first target ball as a reference, and combining the three-dimensional relative coordinates (ΔX1, ΔY1, ΔZ1) obtained in step S1, the absolute coordinates of each preset key feature point on the assembly are obtained and recorded as the first coordinate set. S3, Generation of the Second Coordinate Set The second target ball of the laser tracker is installed on the mounting base, and the actual three-dimensional coordinates (X2, Y2, Z2) of the second target ball in the coordinate system of the laser tracker, as well as the three-dimensional relative coordinates (ΔX2, ΔY2, ΔZ2) from the center of the second target ball to each preset feature point on the mounting base are obtained. Using the actual three-dimensional coordinates (X2, Y2, Z2) of the second target ball as a reference, and combining the three-dimensional relative coordinates (ΔX2, ΔY2, ΔZ2) from the center of the second target ball to each preset feature point on the mounting base, the absolute coordinates of each preset feature point on the mounting base are obtained and recorded as the second coordinate set; S4. Calculation of Assembly Position Adjustment Parameters By comparing the absolute coordinates between the corresponding feature points in the first and second coordinate sets, the coordinate difference between the two is calculated, thereby obtaining the translation adjustment amount in the XYZ three-axis directions; At the same time, the corresponding planes or feature lines are fitted according to the first and second coordinate sets respectively, and the tilt deviation angle between the two is calculated, thereby obtaining the spatial rotation adjustment amount.

[0007] As a further preferred embodiment of the present invention, in step S1, a spherical scanner with optical markers is preferably used in conjunction with a laser tracker to scan the assembly, the parallel mechanism and the first target ball.

[0008] As a further preferred embodiment of the present invention, in step S1, each preset key feature point on the assembly preferably corresponds to a mounting hole or a positioning surface.

[0009] As a further preferred embodiment of the present invention, in step S2, the actual three-dimensional coordinates (X1, Y1, Z1) of the first target ball are preferably directly superimposed with the three-dimensional relative coordinates (ΔX1, ΔY1, ΔZ1) to obtain the absolute coordinates of each preset key feature point on the assembly.

[0010] As a further preferred embodiment of the present invention, in step S3, the second target ball may also be installed on the rigid connection structure of the mounting base, and the three-dimensional relative coordinates (ΔX2, ΔY2, ΔZ2) from the center of the second target ball to each preset feature point on the rigid connection structure are obtained accordingly.

[0011] As a further preferred embodiment of the present invention, in step S3, the actual three-dimensional coordinates (X2, Y2, Z2) of the second target ball are preferably directly superimposed with the three-dimensional relative coordinates (ΔX2, ΔY2, ΔZ2) to obtain the absolute coordinates of each preset feature point on the mounting base.

[0012] As a further preferred embodiment of the present invention, in step S4, the least squares method is preferably used to fit two three-dimensional equations of planes corresponding to the bottom surface of the assembly and the surface of the mounting base, respectively. Then, the angle between the normal vectors of the two planes, i.e. the required tilt deviation angle, is calculated by the vector dot product formula.

[0013] As a further preferred embodiment of the present invention, the large workpiece is a large workpiece with a complex shape in the fields of aerospace and shipbuilding.

[0014] In summary, compared with the prior art, the above-described technical solutions conceived by this invention mainly possess the following technical advantages: 1. This invention redesigns the entire process flow, making full use of optical scanning technology to quickly obtain the complete three-dimensional model and spatial relationships of the assembly, while also using laser tracking technology to provide a high-precision absolute coordinate reference. On this basis, it organically integrates rapid three-dimensional modeling and precise spatial coordinate measurement, achieving a balance between high efficiency and high precision. 2. This invention can obtain all the necessary relative distance data through a single scan modeling, eliminating the need for repeated target movement and tedious point-by-point measurements. Subsequent measurement processes are fast and direct, significantly improving the overall efficiency of assembly operations. 3. The present invention also provides a unified and high-precision measurement coordinate system for the entire field through a laser tracker, avoiding the cumulative error caused by multiple station changes or fitting, ensuring the accuracy of pose adjustment calculation, and thus directly improving the final assembly accuracy. 4. The pose measurement method of the present invention is easy to operate and has good reliability. It does not depend on a specific assembly structure and is applicable to the assembly scenarios of large components with various complex surfaces. Therefore, it has good versatility and promotion value. Attached Figure Description

[0015] Figure 1 This is a basic flowchart of the intelligent assisted assembly posture measurement method for large workpieces according to the present invention; Figure 2 This is an illustration of an application scenario for intelligent assisted assembly pose measurement according to the present invention; In all the accompanying drawings, the same reference numerals are used to denote the same elements or structures, wherein: 1-First target ball; 2-Second target ball; 3-Laser tracker; 4-Large workpiece and parallel mechanism; 6-Mounting base. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0017] It should be understood that expressions such as "comprising" and "may include" as used in this application indicate the existence of the disclosed functions, operations, or constituent elements, and do not limit one or more additional functions, operations, and constituent elements. In this application, terms such as "comprising" and / or "having" may be interpreted as indicating a specific characteristic, number, operation, constituent element, component, or combination thereof, but should not be interpreted as excluding the existence or possibility of adding one or more other characteristics, numbers, operations, constituent elements, components, or combinations thereof.

[0018] It should be understood that the terms “center,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “inner,” “outer,” “clockwise,” “counterclockwise,” “axial,” “radial,” and “circumferential” indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0019] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0020] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0021] Figure 1 This is a basic flowchart of the intelligent assisted assembly posture measurement method for large workpieces according to the present invention. Figure 2 This is an illustrative diagram demonstrating an application scenario of intelligent assisted assembly pose measurement according to the present invention. The following will be combined with... Figure 1 and Figure 2 This will be explained in more detail to illustrate the present invention.

[0022] like Figure 1 As shown, the intelligent assisted assembly pose measurement method for large workpieces according to the present invention mainly includes the following steps: Step 1: Construction and data acquisition of the digital model of the assembly.

[0023] In this step, for a large workpiece that is an assembly, the first target ball of the laser tracker is installed on the parallel mechanism used to control the assembly, and then the assembly, the parallel mechanism and the first target ball are scanned to obtain three-dimensional point cloud data of its surface. The surface three-dimensional point cloud data is processed to generate a corresponding three-dimensional point cloud model, and the size information of the assembly itself, as well as the three-dimensional relative coordinates (ΔX1, ΔY1, ΔZ1) from the center of the first target ball to each preset key feature point on the assembly are obtained.

[0024] Step 2: Generation of the first coordinate set.

[0025] In this step, the laser tracker is set up in a common working area where the assembly and its mounting base can be observed simultaneously, and then the laser tracker is used to measure the actual three-dimensional coordinates (X1, Y1, Z1) of the first target ball in the laser tracker coordinate system. Using the actual three-dimensional coordinates (X1, Y1, Z1) of the first target ball as a reference, and combining the three-dimensional relative coordinates (ΔX1, ΔY1, ΔZ1) obtained in step S1, the absolute coordinates of each preset key feature point on the assembly are obtained and recorded as the first coordinate set.

[0026] The following provides a more detailed explanation of the two steps above.

[0027] For example, a spherical scanner with optical markers can be used to scan the assembly, parallel mechanism and first target ball 1. The optical tracker receives the optical marker points and can use software to generate a three-dimensional point cloud model. The three-dimensional relative coordinates of the key feature points of the assembly (such as mounting holes and positioning surfaces) relative to the center of the first target ball 1 can be directly read from the model. That is, the distance ΔX1 in the X direction, the distance ΔY1 in the Y direction, and the distance ΔZ1 in the Z direction. They only reflect the position difference and have no absolute spatial positioning. Next, an absolute coordinate reference is taken, in which the laser tracker can be set up in the common work area to measure the actual three-dimensional coordinates of the center of the target ball 1 in real space (denoted as X1, Y1, Z1), and use this as a unified reference; Next, according to a preferred embodiment of the present invention, the coordinates of the first target ball 1 can be directly superimposed with the relative coordinates of each key feature point on the assembly, that is, the absolute coordinates of the feature points of the assembly = the absolute coordinates of the target ball 1 + the relative coordinates (formula: X_feature1 = X1 + ΔX1, Y_feature1 = Y1 + ΔY1, Z_feature1 = Z1 + ΔZ1), and the absolute coordinates of all feature points are summed to form the first coordinate set.

[0028] Step 3: Generation of the second coordinate set.

[0029] In this step, the second target ball of the laser tracker is installed on the mounting base, and the actual three-dimensional coordinates (X2, Y2, Z2) of the second target ball in the coordinate system of the laser tracker, as well as the three-dimensional relative coordinates (ΔX2, ΔY2, ΔZ2) from the center of the second target ball to each preset feature point on the mounting base are obtained. Using the actual three-dimensional coordinates (X2, Y2, Z2) of the second target ball as a reference, and combining the three-dimensional relative coordinates (ΔX2, ΔY2, ΔZ2) from the center of the second target ball to each preset feature point on the mounting base, the absolute coordinates of each preset feature point on the mounting base are obtained and denoted as the second coordinate set.

[0030] More specifically, a simplified logic similar to the previous steps can be adopted: place the second target ball 2 on the mounting base or its rigid connection structure, read the three-dimensional relative coordinates (ΔX2, ΔY2, ΔZ2) of each preset feature point on the base relative to the second target ball 2 using a spherical scanner, and then measure the absolute coordinates (X2, Y2, Z2) of the target ball 2 using a laser tracker. After superimposing, the absolute coordinates of the feature points of the base are obtained (X_t2 = X2 + ΔX2, Y_t2 = Y2 + ΔY2, Z_t2 = Z2 + ΔZ2), and sum them up to form the second coordinate set.

[0031] Step 4: Calculation of assembly pose adjustment parameters.

[0032] In this step, the absolute coordinates between corresponding feature points in the first and second coordinate sets are compared, and the coordinate difference between the two is calculated, thereby obtaining the translation adjustment amount in the XYZ three-axis directions; At the same time, the corresponding planes or feature lines are fitted according to the first and second coordinate sets respectively, and the tilt deviation angle between the two is calculated, thereby obtaining the spatial rotation adjustment amount.

[0033] More specifically, by comparing the absolute coordinates of the corresponding feature points in the first and second coordinate sets and calculating the coordinate difference between them, the amount of translation adjustment required on the X, Y, and Z axes can be obtained.

[0034] For the rotation adjustment amount, it can be achieved using the following process: First, the least squares method can be used to fit the plane equation: AX+BY+CZ+D=0. Then, the angle between the two planes can be calculated using the plane angle formula, which is the amount of rotation to be adjusted.

[0035] The formula for fitting the plane equation using the least squares method is as follows: (1) Calculate the centroid of the point cloud

[0036] (2) Construct the covariance matrix

[0037] Expand as

[0038] (3) Eigenvalue decomposition Perform eigenvalue decomposition on matrix M:

[0039] Where λ1≤λ2≤λ3 are the eigenvalues, and v1,v2,v3 are the corresponding unit eigenvectors.

[0040] (4) Determine the plane normal vector The plane normal vector takes the eigenvector corresponding to the smallest eigenvalue λ1:

[0041] (5) Calculate the plane constant term

[0042] (6) The plane equation is obtained as AX+BY+CZ+D=0 Formula for calculating the angle between two planes, assuming the equations of the two planes are:

[0043] The corresponding normal vector is:

[0044] The angle between the two planes is:

[0045] It should be noted that the above theoretical formulas and derivation processes are conventional knowledge in this field, and therefore only a brief explanation is given here.

[0046] Based on this, the calculation process for the rotation adjustment of the assembly can be summarized as follows: (1) Extraction and fitting of three-dimensional point cloud in two planes: Extract the three-dimensional point cloud data of the bottom surface of the workpiece to be assembled and the surface of the mounting base respectively (select 10-20 evenly distributed points in each plane), and use the least squares method to fit the three-dimensional equations of the two planes. (2) Calculation of rotation adjustment amount: The angle between the normal vectors of the two planes is the tilt deviation angle between the bottom surface of the workpiece and the surface of the base. This angle is the required rotation adjustment amount, which can be calculated by the vector dot product formula. (3) The attitude calibration control parallel mechanism drives the workpiece to rotate until the angle between the refitted workpiece bottom plane normal vector and the base surface plane normal vector approaches 0, thus completing the horizontal attitude calibration.

[0047] The following specific examples are given to explain the invention more clearly and in more detail.

[0048] Specific example 1: docking and assembly of ship cabins and upper-level equipment.

[0049] In this embodiment, the large workpiece is an upper-level device to be assembled on the raft, the mounting base is a ship raft structure, and the supporting equipment is a hoisting device.

[0050] The corresponding pose measurement method includes the following steps.

[0051] S1: Scanning and Modeling The first target ball 1 is fixed to the upper equipment hoisting device, and the second target ball 2 is placed on the ship's raft structure. Using a spherical scanner with optical markers and an optical tracker, the docking surface of the upper equipment, the fixing point of the first target ball, the docking area of ​​the raft, and the placement point of the second target ball 2 are scanned to obtain high-precision 3D point cloud data. A 3D model containing the feature points of each docking bolt hole on the upper equipment and the raft is generated. During this process, the fixed relative positional relationships between the key feature points of the first target ball 1 and the upper equipment, and between the second target ball 2 and the feature points of the raft structure, are simultaneously recorded.

[0052] S2: Coordinate Measurement A laser tracker was placed in the assembly work area that could be covered by both the raft and the upper equipment to measure the precise coordinates of the first target ball 1 and the second target ball 2 in space.

[0053] S3: Feature point coordinate calculation Based on the pre-defined positional relationship between the first target ball 1 and the feature points of the upper equipment, and the measured coordinates of the first target ball 1, the actual coordinates of the feature points on the upper equipment are calculated. Simultaneously, based on the measured coordinates of the second target ball 2 and the previously obtained fixed relative positional relationship between the second target ball 2 and the feature points of the raft structure, the actual coordinates of the corresponding docking feature points on the raft structure are calculated. S4: Pose Adjustment Calculation By comparing the coordinates of corresponding docking feature points on the upper-level equipment and the raft structure, the required pose adjustment parameters for the upper-level equipment in six degrees of freedom (three translations and three rotations) are calculated. Based on these parameters, operators drive the hoisting device to achieve precise and rapid positioning and docking of the upper-level equipment with the raft structure.

[0054] Specific example 2: docking and assembly between tower sections of wind turbine generator sets.

[0055] In this embodiment, the large workpiece is the upper tower section, and the mounting base is the flange face of the lower tower section.

[0056] The corresponding pose measurement method includes the following steps.

[0057] S1: Scanning and Modeling The first target ball 1 is fixed to the parallel adjustment mechanism of the upper tower section during hoisting, and the second target ball 2 is placed on the stable platform inside the lower tower section. The measuring system is used to scan the mating flange surfaces and bolt holes of the upper and lower tower sections to obtain point cloud data and generate a three-dimensional model containing the center position of the flange hole group.

[0058] S2: Coordinate Measurement A laser tracker is installed inside the tower to ensure that it can simultaneously track the first target ball 1 and the second target ball 2 and measure their spatial coordinates.

[0059] S3: Feature point coordinate calculation Based on the relative positions of the first target ball 1 and the centers of each flange bolt hole as marked in the upper tower model, and combined with the measured coordinates of the first target ball 1, the actual coordinates of each feature point on the upper flange surface are calculated. Similarly, based on the measured coordinates of the second target ball 2 and the previously obtained fixed relative positional relationship between the second target ball 2 and the feature points on the lower flange surface, the coordinates of the corresponding feature points on the lower flange surface are obtained.

[0060] S4: Pose Adjustment Calculation By comparing the center coordinates of the bolt hole groups on the upper and lower flanges, the required adjustments for lifting, translation, and deflection of the upper tower section are calculated. The hoisting system then makes fine adjustments based on these parameters to ensure that dozens of bolts can be smoothly inserted, greatly improving the efficiency and safety of tower connection.

[0061] Specific example 3: The docking and assembly of the ship's superstructure and main deck.

[0062] In this embodiment, the large workpiece is a ship's superstructure (such as a bridge), and the mounting base is a predetermined installation area on the ship's main deck.

[0063] The corresponding pose measurement method includes the following steps.

[0064] S1: Scanning and Modeling The first target ball 1 is fixed to the parallel support mechanism supporting the superstructure, and the second target ball 2 is placed at the reference point on the main deck. The bottom structure of the superstructure and the corresponding welding positions of the main deck are scanned using a measurement system to obtain point cloud data and generate a 3D model with bottom mounting holes and deck pad features.

[0065] S2: Coordinate Measurement A laser tracker was placed in the dock to measure the coordinates of the first target ball 1 and the second target ball 2 in the coordinate system.

[0066] S3: Feature point coordinate calculation The actual coordinates of each installation feature point at the bottom of the superstructure are calculated based on the measured coordinates of the first target ball 1. Simultaneously, the coordinates of the corresponding feature points on the deck are calculated based on the measured coordinates of the second target ball 2 and the previously obtained fixed relative positional relationship between the second target ball 2 and the feature points on the deck.

[0067] S4: Pose Adjustment Calculation By comparing the coordinates of upper and lower feature points, the fit deviation between the superstructure and the deck is calculated and converted into position adjustment parameters. Based on these parameters, the parallel support mechanism is controlled to achieve precise positioning of the superstructure weighing thousands of tons, laying a perfect foundation for subsequent welding work and effectively avoiding structural stress caused by forced assembly.

[0068] In summary, the intelligent assisted assembly pose measurement method for large workpieces according to the present invention fully utilizes optical scanning technology to quickly obtain the complete three-dimensional model and spatial relationships of the assembly, while also using laser tracking technology to provide a high-precision absolute coordinate reference. On this basis, it organically integrates rapid three-dimensional modeling and precise spatial coordinate measurement, achieving a balance between high efficiency and high precision. This measurement method is easy to operate, has good reliability, and does not depend on a specific assembly structure. It is applicable to assembly scenarios of large components with various complex surfaces, thus possessing good versatility and promotional value.

[0069] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for intelligent assisted assembly pose measurement of large workpieces, characterized in that, The method includes the following steps: S1. Construction and Data Acquisition of Digital Model of Assembly For large workpieces that are assemblies, the first target ball of the laser tracker is mounted on the parallel mechanism used to control the assembly. Then, the assembly, the parallel mechanism and the first target ball are scanned to obtain three-dimensional point cloud data of its surface. The surface three-dimensional point cloud data is processed to generate a corresponding three-dimensional point cloud model, and the size information of the assembly itself, as well as the three-dimensional relative coordinates (ΔX1, ΔY1, ΔZ1) from the center of the first target ball to each preset key feature point on the assembly are obtained. S2, Generation of the first coordinate set The laser tracker is set up in a common working area where the assembly and its mounting base can be observed simultaneously. Then, the laser tracker is used to measure the actual three-dimensional coordinates (X1, Y1, Z1) of the first target ball in the laser tracker coordinate system. Using the actual three-dimensional coordinates (X1, Y1, Z1) of the first target ball as a reference, and combining the three-dimensional relative coordinates (ΔX1, ΔY1, ΔZ1) obtained in step S1, the absolute coordinates of each preset key feature point on the assembly are obtained and recorded as the first coordinate set. S3, Generation of the Second Coordinate Set The second target ball of the laser tracker is installed on the mounting base, and the actual three-dimensional coordinates (X2, Y2, Z2) of the second target ball in the coordinate system of the laser tracker, as well as the three-dimensional relative coordinates (ΔX2, ΔY2, ΔZ2) from the center of the second target ball to each preset feature point on the mounting base are obtained. Using the actual three-dimensional coordinates (X2, Y2, Z2) of the second target ball as a reference, and combining the three-dimensional relative coordinates (ΔX2, ΔY2, ΔZ2) from the center of the second target ball to each preset feature point on the mounting base, the absolute coordinates of each preset feature point on the mounting base are obtained and recorded as the second coordinate set; S4. Calculation of Assembly Position Adjustment Parameters By comparing the absolute coordinates between the corresponding feature points in the first and second coordinate sets, the coordinate difference between the two is calculated, thereby obtaining the translation adjustment amount in the XYZ three-axis directions; At the same time, the corresponding planes or feature lines are fitted according to the first and second coordinate sets respectively, and the tilt deviation angle between the two is calculated, thereby obtaining the spatial rotation adjustment amount.

2. The method as described in claim 1, characterized in that, In step S1, a spherical scanner with optical markers is preferably used in conjunction with a laser tracker to scan the assembly, the parallel mechanism, and the first target ball.

3. The method as described in claim 1 or 2, characterized in that, In step S1, for each preset key feature point on the assembly, it preferably corresponds to the mounting hole, positioning surface, etc.

4. The method according to any one of claims 1-3, characterized in that, In step S2, it is preferable to directly superimpose the actual three-dimensional coordinates (X1, Y1, Z1) of the first target ball with the three-dimensional relative coordinates (ΔX1, ΔY1, ΔZ1) to obtain the absolute coordinates of each preset key feature point on the assembly.

5. The method according to any one of claims 1-4, characterized in that, In step S3, the second target ball can also be replaced and installed on the rigid connection structure of the mounting base, and the three-dimensional relative coordinates (ΔX2, ΔY2, ΔZ2) from the center of the second target ball to each preset feature point on the rigid connection structure are obtained accordingly.

6. The method according to any one of claims 1-5, characterized in that, In step S3, it is preferable to directly superimpose the actual three-dimensional coordinates (X2, Y2, Z2) of the second target ball with the three-dimensional relative coordinates (ΔX2, ΔY2, ΔZ2) to obtain the absolute coordinates of each preset feature point on the mounting base.

7. The method according to any one of claims 1-6, characterized in that, In step S4, the least squares method is preferably used to fit two three-dimensional equations corresponding to the bottom surface of the assembly and the surface of the mounting base, respectively. Then, the angle between the normal vectors of the two planes, which is the required tilt deviation angle, is calculated by the vector dot product formula.

8. The method according to any one of claims 1-7, characterized in that, The large workpieces mentioned are large workpieces with complex shapes in the fields of aerospace and shipbuilding.

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