A spatial geometric error iterative compensation method and system for five-axis CNC machine tools

Abstract

The present invention relates to the technical field of error compensation for numerically controlled machine tools, and in particular to a method and system for iterative compensation of spatial geometric errors of five-axis numerically controlled machine tools. The method comprises the steps of: constructing a tool motion chain topology model and a workpiece motion chain topology model of the five-axis numerically controlled machine tool, establishing a theoretical positive kinematics model and an actual positive kinematics model of the tool relative to the workpiece; measuring and identifying the geometric errors of each motion axis of the five-axis numerically controlled machine tool; separating the tool axis direction vector part and the tool tip point position part during iteration; calculating the tool posture deviation according to the correction model of the tool axis direction vector and the tool tip point position; continuously iterating and generating the corrected running position of each axis, and realizing the error compensation of the spatial posture of the tool of the five-axis linkage numerically controlled machine tool. The present invention directly corrects the actual spatial posture of the tool through an iterative algorithm in an offline state, so that it continuously approaches the theoretical posture, thereby improving the accuracy and efficiency of error compensation.

Description

Technical Field

[0001] The present invention relates to the technical field of error compensation for numerically controlled machine tools, and in particular to a method and system for iteratively compensating spatial geometric errors of a five-axis numerically controlled machine tool. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] In recent years, with the increasing development of computer numerical control (CNC) technology, the demand for machined parts with complex shapes and high precision has increased dramatically. Five-axis machine tools have two more rotation axes than three-axis machine tools, which can change the position and direction of the tool more easily and directly. However, the increase in the number of motion axes will introduce more error sources to the machine tool, resulting in the accumulation of geometric errors and a significant reduction in the overall machining accuracy. Therefore, it is crucial to efficiently and accurately reduce the geometric errors of each axis of the five-axis machine tool to improve the machining accuracy. At present, the strategies for controlling and reducing the geometric errors of five-axis machine tools and improving the machining accuracy of machine tools are divided into two categories: error avoidance and error compensation. Due to the increased requirements for machine tool machining accuracy and the increase in manufacturing costs, error compensation strategies have become a research hotspot for controlling machine tool accuracy in recent years.

[0004] At present, the error compensation function embedded in most domestic machine tool CNC systems is only for the positioning error of the linear axis, including pitch error compensation function and backlash error compensation function. This error compensation function has a certain effect, but it cannot completely compensate for the coupling error of the multi-axis linkage of the five-axis CNC machine tool.

[0005] The existing error compensation method for NC codes of five-axis CNC machine tools is to develop a separate compensation process for each rotary and linear axis according to the topological relationship between the axes in the machine tool kinematic chain. However, since the tool positioning error caused by the compensation of the rotary axis requires additional compensation, the precise decoupling mechanism is difficult to derive. Moreover, the error iterative compensation algorithm implemented using Newton's method is effective for calculating the correct compensation data, but its efficiency is limited by the lengthy and time-consuming iteration process.

[0006] Therefore, how to improve the error compensation calculation speed and accuracy of the tool spatial posture in five-axis CNC machine tools has become a problem that needs to be urgently solved in the existing technology. Summary of the invention

[0007] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a method and system for iterative compensation of spatial geometric errors of a five-axis CNC machine tool, which directly corrects the actual spatial posture of the tool through an iterative algorithm in an offline state, so that it continuously approaches the theoretical posture, thereby improving the accuracy and efficiency of error compensation.

[0008] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0009] A first aspect of the present invention provides a method for iteratively compensating spatial geometric errors of a five-axis CNC machine tool, comprising the following steps:

[0010] Based on the structure of the five-axis CNC machine tool, the tool kinematic chain topology model and the workpiece kinematic chain topology model of the five-axis CNC machine tool are respectively constructed. Based on the multi-body theory and homogeneous coordinate transformation, the theoretical forward kinematics model and the actual forward kinematics model of the tool relative to the workpiece are respectively established.

[0011] Measure and identify the geometric errors of each moving axis of the five-axis CNC machine tool according to the stroke of each axis of the five-axis CNC machine tool;

[0012] According to the theoretical forward kinematics model and the actual forward kinematics model, the tool axis direction vector part and the tool tip point position part during iteration are separated, and correction models of the tool axis direction vector and tool tip point position are established respectively;

[0013] An iterative correction algorithm for tool spatial posture is established, and the tool posture deviation is calculated based on the correction model of tool axis direction vector and tool tip position.

[0014] The new corrected tool posture is continuously generated iteratively until the allowable spatial error range is reached, and the corrected operating position of each axis is generated to achieve error compensation for the spatial posture of the tool of the five-axis linkage CNC machine tool.

[0015] A second aspect of the present invention provides a spatial geometric error iterative compensation system for a five-axis CNC machine tool, comprising:

[0016] The topological model and kinematic model building modules are configured to respectively build a tool kinematic chain topological model and a workpiece kinematic chain topological model of the five-axis CNC machine tool based on the structure of the five-axis CNC machine tool, and respectively establish a theoretical forward kinematic model and an actual forward kinematic model of the tool relative to the workpiece based on multi-body theory and homogeneous coordinate transformation;

[0017] The error acquisition module is configured to measure and identify the geometric error of each motion axis of the five-axis CNC machine tool according to the stroke of each axis of the five-axis CNC machine tool;

[0018] The correction model building module is configured to separate the tool axis direction vector part and the tool tip point position part during iteration according to the theoretical forward kinematics model and the actual forward kinematics model, and respectively establish correction models of the tool axis direction vector and the tool tip point position;

[0019] The error correction module is configured to establish an iterative correction algorithm for the tool spatial posture and calculate the tool posture deviation according to the correction model of the tool axis direction vector and the tool tip point position;

[0020] The error compensation module is configured to iteratively generate new corrected tool postures continuously until the allowable spatial error range is reached, generate corrected operating positions of each axis, and realize error compensation of the spatial posture of the tool of the five-axis linkage CNC machine tool.

[0021] The third aspect of the present invention provides a medium having a program stored thereon, which, when executed by a processor, implements the steps of the iterative compensation method for spatial geometric errors of a five-axis CNC machine tool as described in the first aspect of the present invention.

[0022] The fourth aspect of the present invention provides a device, including a memory, a processor, and a program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps in the iterative compensation method for spatial geometric errors of a five-axis CNC machine tool as described in the first aspect of the present invention are implemented.

[0023] One or more of the above technical solutions have the following beneficial effects:

[0024] The present invention discloses a method and system for iteratively compensating the spatial geometric errors of a five-axis CNC machine tool, which reduces the steps for compensating the spatial geometric errors of a tool of a five-axis CNC machine tool. The error compensation efficiency is improved by directly correcting the spatial posture of the tool to obtain the operating position of each axis after error compensation.

[0025] The tool space geometric error compensation method of the present invention adopts a posture iterative correction algorithm to generate a new spatial posture based on the corrected actual spatial posture of the tool, thereby improving the error compensation accuracy.

[0026] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0028] Figure 1 Schematic diagram of a five-axis machine tool according to Embodiment 1 of the present invention;

[0029] Figure 2 This is a flow chart of geometric error compensation for a five-axis CNC machine tool according to Embodiment 1 of the present invention;

[0030] Figure 3 It is a schematic diagram for updating the tool axis direction vector;

[0031] Figure 4 This is a comparison chart of compensation accuracy of different compensation methods;

[0032] Figure 5The figure below is a comparison chart of compensation time for different compensation methods. DETAILED DESCRIPTION

[0033] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0034] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "include" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or their combinations;

[0035] Embodiment 1:

[0036] Embodiment 1 of the present invention provides a method for iteratively compensating spatial geometric errors of a five-axis CNC machine tool, comprising the following steps:

[0037] S1: Based on the structure of the five-axis CNC machine tool, the tool motion chain topology model and the workpiece motion chain topology model of the five-axis CNC machine tool are constructed respectively. Based on the multi-body theory and homogeneous coordinate transformation, the theoretical forward kinematics model and the actual forward kinematics model of the tool relative to the workpiece are established respectively.

[0038] Among them, the establishment of the forward kinematics model includes the machine tool assembly relationship and geometric errors. The coordinate system of the linear axis is established on the respective guide surfaces, and the origin of the coordinate system of the rotary axis is established at the intersection of the two rotary axis axes. The spatial error model established based on the Denavit-Hartenberg matrix combines the machine tool size parameters, and the coordinate position parameters in the model are consistent with the machine tool coordinate parameters in the CNC system.

[0039] The specific steps are as follows:

[0040] S101: Figure 1As shown in the figure, a right-hand coordinate system is established according to the machine tool structure, with the origin located at the rotation center of the worktable. The horizontal movement direction of the milling spindle is the X-axis, the horizontal movement direction of the worktable is the Y-axis, the vertical movement direction of the milling spindle is the Z1-axis, the vertical movement direction of the turning turret is the Z2-axis, the swing direction of the milling spindle is the B-axis, and the rotation direction of the worktable is the C-axis. The tool motion chain topology model and the workpiece motion chain topology model are constructed respectively. The intersection of the end of the tool motion chain and the end of the workpiece motion chain is the cutting forming point during actual processing. Among them, in the tool motion chain topology model, the tool motion chain includes the bed, X-axis, Z1-axis, B-axis and tool in sequence, and the tool includes the tool tip part and the tool shaft part. In the workpiece motion chain topology model, the workpiece motion chain includes the bed, Y-axis, C-axis and workpiece in sequence.

[0041] S102: According to multi-body theory and Denavit-Hartenberg matrix, the theoretical expression of the position transformation of the tool coordinate system relative to the workpiece coordinate system is:

[0042] .

[0043] The actual position transformation expression of the tool coordinate system relative to the workpiece coordinate system is:

[0044] .

[0045] in, and They are the ideal homogeneous coordinate transformation matrix and the actual homogeneous coordinate transformation matrix of the tool relative to the workpiece, Represents the homogeneous coordinate transformation matrix from bed M to X axis, Represents the homogeneous coordinate transformation matrix from the X axis to the Z1 axis, Represents the homogeneous coordinate transformation matrix from the Z1 axis to the B axis, Represents the homogeneous coordinate transformation matrix from the B axis to the tool T, Represents the homogeneous coordinate transformation matrix from the bed M to the Y axis, Represents the homogeneous coordinate transformation matrix from the Y axis to the C axis, Represents the homogeneous coordinate transformation matrix from the C axis to the workpiece W, is the corresponding error matrix.

[0046] S2: Measure and identify the geometric errors of each moving axis of the five-axis CNC machine tool based on the stroke of each axis calibrated in the five-axis CNC machine tool system.

[0047] In a specific implementation, all motion-related geometric errors of each motion axis of a five-axis CNC machine tool are measured and identified, totaling 30 items, including 15 linear errors and 15 angular errors, which can comprehensively reflect the changes in machining accuracy when the operating position of each axis changes. The 15 linear errors include the positioning errors, horizontal straightness errors, and vertical straightness errors of the X-axis, Y-axis, Z-axis, B-axis, and C-axis, respectively, and the 15 angular errors include the pitch angle errors, yaw angle errors, and roll angle errors of the X-axis, Y-axis, Z-axis, B-axis, and C-axis, respectively.

[0048] The specific steps are as follows:

[0049] S201: Use a multi-beam laser interferometer to measure 18 geometric errors of the three linear axes, including six geometric errors of linearity, pitch, tilt, yaw, horizontal and vertical straightness of each axis.

[0050] S202: Use the ballbar to measure the 12 geometric errors of the two rotation axes respectively, establish the geometric error identification equation according to the installation position of the ballbar, and decouple the specific values ​​of each error, including the six geometric errors of linearity, pitch, tilt, yaw, horizontal and vertical straightness of each axis.

[0051] S3: According to the theoretical forward kinematics model and the actual forward kinematics model, the tool axis direction vector part and the tool tip point position part at the kth iteration are separated, and correction models of the tool axis direction vector and the tool tip point position are established respectively.

[0052] S301: Define the theoretical position of the machine tool coordinate system relative to the workpiece coordinate system as ( , ), the actual pose is ( , ). They can be obtained by the following formulas:

[0053] .

[0054] in, and are the theoretical and actual spatial positions of the tool tip in the workpiece coordinate system, and They respectively represent the theoretical and actual direction vectors of the tool axis in the workpiece coordinate system.

[0055] S302: The corrected but not fully compensated posture is defined as “residual posture ( , )".

[0056] S303: Use addition and subtraction or multiplication and division to correct the deviation of the tool axis direction vector:

[0057] (1) Addition and subtraction. According to the forward kinematic transformation, the theoretical direction vector of the tool axis corresponding to a certain set of operating positions is obtained. , the actual direction vector in the k-1th iteration and the residual direction vector , the residual direction vector is updated by addition and subtraction, as shown below:

[0058] .

[0059] (2) Multiplication and division. In order to ensure the validity of the residual pose during the iteration process, the tool axis direction vector update strategy of “multiplication and division” is defined, as follows: Figure 3 shown.

[0060] First, calculate the differential motion matrix between the actual direction vector of the tool axis and the theoretical direction vector at the k-1th iteration :

[0061] .

[0062] Then, the differential motion matrix is ​​applied to the "residual direction vector" at the k-1th iteration to generate the "residual direction vector" at the kth iteration:

[0063] .

[0064] S4: Establish an iterative correction algorithm for tool spatial posture, such as Figure 2 As shown, the tool posture deviation is calculated based on the correction model of the tool axis direction vector and the tool tip point position.

[0065] S401: Set the initial iteration value and start the iteration. The initial iteration number k = 0, and the corrected running position of each axis The initial value is set to the initial operating position , the initial residual pose ( , ) is set as the theoretical pose ( , ). Introducing variables To record the minimum tool posture deviation, the variable Record the running position corresponding to the minimum posture deviation. is the minimum tool posture deviation in each iteration. Set the error threshold to , the iteration number threshold is In this embodiment, The initial value of is set to 10 mm. Set the error threshold , the iteration number threshold .

[0066] S402: Calculate the corrected running position in the kth iteration based on the theoretical and actual forward kinematics models Corresponding theoretical tool pose and actual tool pose.

[0067] .

[0068] S403: Calculate the deviation between the actual tool posture and the theoretical tool posture in the kth iteration. In order to more comprehensively evaluate the spatial geometric error of the tool, the evaluation index shown in the following formula is introduced, including the tool tip position deviation and the tool axis direction vector deviation.

[0069] .

[0070] in, is the total error, , , , , , As an intermediate quantity, it is obtained by the following formula:

[0071] .

[0072] in, For the k The actual homogeneous coordinate transformation matrix of the tool relative to the workpiece in the iteration, is the ideal homogeneous coordinate transformation matrix of the tool relative to the workpiece.

[0073] S5: Continuously iterate and generate new corrected tool postures until the allowable spatial error range is reached, generate the corrected operating positions of each axis, and realize the error compensation of the tool spatial posture of the five-axis linkage CNC machine tool.

[0074] S501: Calculate total error After that, if the total error is less than the minimum tool posture deviation, that is, , then update the minimum tool posture deviation and the corresponding operating position ; Otherwise, continue to iterate and update the number of iterations If the minimum tool posture deviation is updated , while minimizing tool posture deviation Less than the set error threshold or number of iterations Greater than the iteration threshold , then stop the iteration and output the current corresponding running position As the final running position of each axis; otherwise, continue to iterate and update the number of iterations .

[0075] S502: Calculate the running position of each axis corresponding to the residual posture in the previous iteration through the inverse kinematics function.

[0076] In order to verify the accuracy and efficiency of the error compensation strategy, a tool running trajectory is designed in the machine tool workspace, including 200 sampling points. The tool posture deviation before and after compensation on the trajectory is recorded. The results are shown in Figure 2. Figure 4 As shown; the compensation time of different compensation methods is as follows Figure 5 As shown. The average posture error of the trajectory before compensation is 0.053mm; the average posture error of the trajectory after compensation using the traditional strategy is 0.018mm, the single compensation time is 0.09s, and the iterative compensation time is 23.74s; the average posture error of the trajectory after compensation using the posture iterative correction strategy is 2.77×10-5mm, and the compensation time is 1.24s. Therefore, the error compensation algorithm proposed in the present invention can well correct the continuous trajectory points by directly correcting the tool posture, with high correction efficiency and the corrected trajectory close to the expected trajectory.

[0077] Embodiment 2:

[0078] Embodiment 2 of the present invention provides a spatial geometric error iterative compensation system for a five-axis CNC machine tool, comprising:

[0079] The topological model and kinematic model building modules are configured to respectively build a tool kinematic chain topological model and a workpiece kinematic chain topological model of the five-axis CNC machine tool based on the structure of the five-axis CNC machine tool, and respectively establish a theoretical forward kinematic model and an actual forward kinematic model of the tool relative to the workpiece based on multi-body theory and homogeneous coordinate transformation;

[0080] The error acquisition module is configured to measure and identify the geometric error of each motion axis of the five-axis CNC machine tool according to the stroke of each axis of the five-axis CNC machine tool;

[0081] The correction model building module is configured to separate the tool axis direction vector part and the tool tip point position part during iteration according to the theoretical forward kinematics model and the actual forward kinematics model, and respectively establish correction models of the tool axis direction vector and the tool tip point position;

[0082] The error correction module is configured to establish an iterative correction algorithm for the tool spatial posture and calculate the tool posture deviation according to the correction model of the tool axis direction vector and the tool tip point position;

[0083] The error compensation module is configured to iteratively generate new corrected tool postures continuously until the allowable spatial error range is reached, generate corrected operating positions of each axis, and realize error compensation of the spatial posture of the tool of the five-axis linkage CNC machine tool.

[0084] Embodiment three:

[0085] Embodiment 3 of the present invention provides a medium on which a program is stored. When the program is executed by a processor, the steps of the iterative compensation method for spatial geometric errors of a five-axis CNC machine tool as described in Embodiment 1 of the present invention are implemented.

[0086] Embodiment 4:

[0087] Embodiment 4 of the present invention provides a device, including a memory, a processor, and a program stored in the memory and executable on the processor. When the processor executes the program, the steps in the iterative compensation method for spatial geometric errors of a five-axis CNC machine tool as described in Embodiment 1 of the present invention are implemented.

[0088] The steps involved in the above embodiments 2, 3 and 4 correspond to the method embodiment 1. For the specific implementation methods, please refer to the relevant description part of embodiment 1.

[0089] Those skilled in the art should understand that the modules or steps of the present invention described above can be implemented by a general-purpose computer device, or alternatively, they can be implemented by a program code executable by a computing device, so that they can be stored in a storage device and executed by the computing device, or they can be made into individual integrated circuit modules, or multiple modules or steps therein can be made into a single integrated circuit module for implementation. The present invention is not limited to any specific combination of hardware and software.

[0090] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A method for iterative compensation of spatial geometric errors of a five-axis CNC machine tool, characterized in that: The following steps are involved: Based on the structure of the five-axis CNC machine tool, the tool kinematic chain topology model and the workpiece kinematic chain topology model of the five-axis CNC machine tool are respectively constructed. Based on the multi-body theory and homogeneous coordinate transformation, the theoretical forward kinematics model and the actual forward kinematics model of the tool relative to the workpiece are respectively established. Measure and identify the geometric errors of each moving axis of the five-axis CNC machine tool according to the stroke of each axis of the five-axis CNC machine tool; Measure and identify 30 geometric errors of each motion axis of a five-axis CNC machine tool, including 15 linear errors and 15 angular errors; According to the theoretical forward kinematics model and the actual forward kinematics model, the tool axis direction vector part and the tool tip point position part during iteration are separated, and correction models of the tool axis direction vector and tool tip point position are established respectively; An iterative correction algorithm for tool spatial posture is established, and the tool posture deviation is calculated based on the correction model of tool axis direction vector and tool tip position. Evaluation indicators are introduced, including tool tip position deviation and tool axis direction vector deviation: ； in, is the total error, , , , , , As an intermediate quantity, it is obtained by the following formula: ， in, For the k The actual homogeneous coordinate transformation matrix of the tool relative to the workpiece in the iteration, is the ideal homogeneous coordinate transformation matrix of the tool relative to the workpiece; The new corrected tool posture is continuously generated iteratively until the allowable spatial error range is reached, and the corrected operating position of each axis is generated to achieve error compensation for the spatial posture of the tool of the five-axis linkage CNC machine tool.

2. The iterative compensation method for spatial geometric errors of a five-axis CNC machine tool according to claim 1, characterized in that: The forward kinematics model is established including the machine tool assembly relationship and geometric errors.

3. The iterative compensation method for spatial geometric errors of a five-axis CNC machine tool according to claim 1, characterized in that: In the tool motion chain topology model, the tool motion chain includes the bed, X-axis, Z1-axis, B-axis and tool in sequence; in the workpiece motion chain topology model, the workpiece motion chain includes the bed, Y-axis, C-axis and workpiece in sequence.

4. The iterative compensation method for spatial geometric errors of a five-axis CNC machine tool according to claim 1, characterized in that: The specific steps to establish the correction model of the tool axis direction vector and tool tip position are: Define the theoretical and actual positions of the machine tool coordinate system relative to the workpiece coordinate system; The corrected but not fully compensated pose is defined as the residual pose; Use addition, subtraction or multiplication and division to correct the deviation of the tool axis direction vector.

5. The iterative compensation method for spatial geometric errors of a five-axis CNC machine tool according to claim 1, characterized in that: The specific steps for calculating the tool posture deviation based on the correction model of the tool axis direction vector and the tool tip point position are as follows: Set the initial value of the iteration and the iteration starts; Calculate the theoretical tool pose and the actual tool pose corresponding to the corrected running position in the kth iteration according to the theoretical and actual forward kinematics models; Calculate the deviation between the actual tool pose and the theoretical tool pose in the kth iteration.

6. The iterative compensation method for spatial geometric errors of a five-axis CNC machine tool according to claim 1, characterized in that: The new corrected tool posture is continuously generated iteratively until the allowable spatial error range is reached. The specific steps for generating the corrected running position of each axis are as follows: After calculating the total error, if the total error is less than the minimum tool posture deviation, the minimum tool posture deviation and the corresponding running position are updated; otherwise, the iteration continues and the number of iterations is updated; If the minimum tool posture deviation is updated, and the minimum tool posture deviation is less than the set error threshold or the number of iterations is greater than the number of iterations threshold, the iteration is stopped and the current corresponding running position is output as the final running position of each axis; The inverse kinematics function is used to calculate the running position of each axis corresponding to the residual posture in the previous iteration.

7. A spatial geometric error iterative compensation system for a five-axis CNC machine tool, characterized in that: include: The topological model and kinematic model building modules are configured to respectively build a tool kinematic chain topological model and a workpiece kinematic chain topological model of the five-axis CNC machine tool based on the structure of the five-axis CNC machine tool, and respectively establish a theoretical forward kinematic model and an actual forward kinematic model of the tool relative to the workpiece based on multi-body theory and homogeneous coordinate transformation; The error acquisition module is configured to measure and identify the geometric error of each motion axis of the five-axis CNC machine tool according to the stroke of each axis of the five-axis CNC machine tool; Measure and identify 30 geometric errors of each motion axis of a five-axis CNC machine tool, including 15 linear errors and 15 angular errors; The correction model building module is configured to separate the tool axis direction vector part and the tool tip point position part during iteration according to the theoretical forward kinematics model and the actual forward kinematics model, and respectively establish correction models of the tool axis direction vector and the tool tip point position; The error correction module is configured to establish an iterative correction algorithm for the tool spatial posture and calculate the tool posture deviation according to the correction model of the tool axis direction vector and the tool tip point position; Evaluation indicators are introduced, including tool tip position deviation and tool axis direction vector deviation: ； in, is the total error, , , , , , As an intermediate quantity, it is obtained by the following formula: ， in, For the k The actual homogeneous coordinate transformation matrix of the tool relative to the workpiece in the iteration, is the ideal homogeneous coordinate transformation matrix of the tool relative to the workpiece; The error compensation module is configured to iteratively generate new corrected tool postures continuously until the allowable spatial error range is reached, generate corrected operating positions of each axis, and realize error compensation of the spatial posture of the tool of the five-axis linkage CNC machine tool.

8. A computer-readable storage medium, characterized in that: A plurality of instructions are stored therein, and the instructions are suitable for being loaded by a processor of a terminal device and executing the spatial geometric error iterative compensation method for a five-axis CNC machine tool according to any one of claims 1-6.

9. A terminal device, characterized in that: It includes a processor and a computer-readable storage medium, the processor is used to implement various instructions; the computer-readable storage medium is used to store multiple instructions, and the instructions are suitable for being loaded by the processor and executing the spatial geometric error iterative compensation method for a five-axis CNC machine tool according to any one of claims 1-6.

Images