Method and system for compensating dynamic error of turning and milling swing head based on multi-axis linkage

Abstract

The invention discloses a dynamic error compensation method and system for a turn-milling swing head based on multi-axis linkage, and relates to the technical field of machine tools. The method comprises the following steps: extracting a task feature vector of a turn-milling swing head; identifying a plurality of linkage shafts associated with the turn-milling swing head; constructing a multi-axis reference coordinate system, performing coordinate system conversion on each axis in the plurality of linkage axes, and outputting a plurality of converted coordinate systems; carrying out multi-axis linkage error modeling, outputting a multi-axis linkage error model, carrying out multi-axis error analysis, and outputting a trajectory deviation vector; and solving a plurality of compensation angles corresponding to the plurality of linkage shafts according to the track deviation vector, wherein the plurality of linkage shafts execute correction of the plurality of compensation angles under the plurality of conversion coordinate systems. The technical problem that dynamic error compensation is difficult due to assembly angle error accumulation of multiple rotating shafts in the prior art is solved, the influence of error accumulation is eliminated by conducting coordinate system repositioning on the multiple shafts involved in the current task, and therefore the technical effect of dynamic error compensation is achieved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of machine tools, in particular to a turning-milling-swinging head dynamic error compensation method and system based on multi-axis linkage. BACKGROUND

[0002] As a key functional component of a turning-milling compound machine tool for realizing multi-axis linkage machining, a turning-milling-swinging head can flexibly adjust a tool posture and a machining path through the cooperative movement of multiple rotating shafts and a translating shaft, thereby providing great freedom and flexibility for complex curved surface machining and greatly expanding the machining range and process capability of the machine tool. However, during the assembly of the machine tool, assembly angle errors inevitably exist among the multiple rotating shafts. These initial errors continuously accumulate and transmit with the linkage movement of the shafts during the operation of the machine tool, thereby continuously accumulating dynamic errors. The existence of these dynamic errors causes significant deviation between an actual tool movement track and a theoretical programmed track, thereby leading to quality problems such as shape errors, size out-of-tolerance and surface waviness of the machined surface, and seriously restricting the machining precision and surface quality of complex parts. SUMMARY

[0003] The application provides a turning-milling-swinging head dynamic error compensation method and system based on multi-axis linkage, and solves the technical problem of difficult dynamic error compensation caused by the accumulation of assembly angle errors of multiple rotating shafts in the prior art.

[0004] In a first aspect, the application provides a turning-milling-swinging head dynamic error compensation method based on multi-axis linkage, which comprises the following steps: extracting a task feature vector of a turning-milling-swinging head; identifying, according to the task feature vector, a plurality of linkage shafts associated with the turning-milling-swinging head and a plurality of coordinate systems corresponding to the plurality of linkage shafts; constructing a multi-axis reference coordinate system, performing coordinate system conversion on each shaft in the plurality of linkage shafts according to the multi-axis reference coordinate system, and outputting a plurality of converted coordinate systems; performing multi-axis linkage error modeling according to the plurality of converted coordinate systems, outputting a multi-axis linkage error model, inputting the task feature vector into the constructed multi-axis linkage error model for multi-axis error analysis, and outputting a track deviation vector of the task feature vector; and solving a plurality of compensation angles corresponding to the plurality of linkage shafts according to the track deviation vector, and executing correction of the plurality of compensation angles by the plurality of linkage shafts under the plurality of converted coordinate systems.

[0005] In a second aspect, the application provides a turning-milling-swinging head dynamic error compensation system based on multi-axis linkage, which comprises the following steps: The feature extraction module is used for extracting a task feature vector of the swing head of the turning and milling machine; the identification module is used for identifying a plurality of linkage shafts associated with the swing head of the turning and milling machine and a plurality of coordinate systems corresponding to the plurality of linkage shafts according to the task feature vector; the coordinate conversion module is used for constructing a multi-shaft reference coordinate system, performing coordinate system conversion on each shaft in the plurality of linkage shafts according to the multi-shaft reference coordinate system, and outputting a plurality of converted coordinate systems; the error analysis module is used for performing multi-shaft linkage error modeling according to the plurality of converted coordinate systems, outputting a multi-shaft linkage error model, inputting the task feature vector into the constructed multi-shaft linkage error model to perform multi-shaft error analysis, and outputting a trajectory deviation vector of the task feature vector; and the correction module is used for solving a plurality of compensation angles corresponding to the plurality of linkage shafts according to the trajectory deviation vector, and the plurality of linkage shafts perform correction of the plurality of compensation angles under the plurality of converted coordinate systems.

[0006] One or more technical solutions provided in the present application have at least the following technical effects or advantages: First, the task feature vector of the swing head of the turning and milling machine is extracted. Then, a plurality of linkage shafts associated with the swing head of the turning and milling machine and a plurality of coordinate systems corresponding to the plurality of linkage shafts are identified according to the task feature vector. Then, a multi-shaft reference coordinate system is constructed, coordinate system conversion is performed on each shaft in the plurality of linkage shafts according to the multi-shaft reference coordinate system, and a plurality of converted coordinate systems are output. Further, multi-shaft linkage error modeling is performed according to the plurality of converted coordinate systems, a multi-shaft linkage error model is output, the task feature vector is input into the constructed multi-shaft linkage error model to perform multi-shaft error analysis, and a trajectory deviation vector of the task feature vector is output. Finally, a plurality of compensation angles corresponding to the plurality of linkage shafts are solved according to the trajectory deviation vector, and the plurality of linkage shafts perform correction of the plurality of compensation angles under the plurality of converted coordinate systems. The technical problem of difficulty in dynamic error compensation caused by error accumulation of a plurality of rotating shaft assembly angles in the prior art is solved. By repositioning the coordinate systems of the plurality of shafts involved in the current task, the influence of error accumulation is eliminated, thereby achieving the technical effect of dynamic error compensation. BRIEF DESCRIPTION OF DRAWINGS

[0007] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0008] Figure 1 A flowchart of a dynamic error compensation method for a swing head of a turning and milling machine based on multi-shaft linkage is provided for the embodiments of the present application. Figure 2 A structure diagram of a swing head of a turning and milling machine is provided for the embodiments of the present application. Figure 3 A schematic diagram of the structure of a multi-axis linkage-based milling and turning head dynamic error compensation system provided in an embodiment of this application.

[0009] Figure labeling: 1. Milling head; 2. Tool; 11. Feature extraction module; 12. Recognition module; 13. Coordinate transformation module; 14. Error analysis module; 15. Correction module. Detailed Implementation

[0010] This application provides a method and system for dynamic error compensation of milling and turning heads based on multi-axis linkage, which solves the technical problem in the prior art that dynamic error compensation is difficult due to the accumulation of assembly angle errors of multiple rotating axes.

[0011] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0012] It should be noted that the terms "comprising" and "having" are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or server that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or modules that are not explicitly listed or that are inherent to these processes, methods, products, or devices.

[0013] Example 1, as Figure 1 As shown, this application provides a dynamic error compensation method for milling and turning heads based on multi-axis linkage, wherein the method includes: Extract the task feature vector of the milling head.

[0014] By collecting the working parameters of the milling head, a task feature vector is obtained. The task feature vector includes, but is not limited to, the rotation angle of the milling head, feed rate, workpiece material, cutting force, depth of cut, rotation speed, and tool position.

[0015] Based on the task feature vector, identify multiple linkage axes associated with the milling head and multiple coordinate systems corresponding to the multiple linkage axes.

[0016] In the embodiments of this application, the multiple linkage axes of the milling head, such as Figure 2As shown, it includes three linkage shafts: A shaft, B shaft, C shaft, each corresponding to an independent motion degree of freedom in the turning and milling machine tool, wherein the A shaft rotates around the X axis, the B shaft rotates around the Y axis, and the C shaft rotates around the main shaft. Each linkage shaft has its own independent local coordinate system, which represents the rotation angle of the shaft and its position in the local coordinate system; each linkage shaft (A, B, C shaft) jointly acts during processing, determining the spatial position of the turning and milling head and the processing trajectory.

[0017] The task feature vector extracts various operating parameters of the turning and milling head, such as position, cutting force, and rotation speed. According to the data in these feature vectors, the motion state related to each linkage shaft (such as A shaft, B shaft, C shaft) is identified, where the X, Y, Z axes mainly control the position change, and the A, B, C axes are responsible for the change in rotation angle. Each linkage shaft has an independent local coordinate system, which reflects the dynamic behavior of each shaft. Through the coordinate transformation matrix, a mapping relationship between the local coordinate system and the global coordinate system is established, ensuring that the motion of each linkage shaft can be described in the global coordinate system.

[0018] A multi-axis reference coordinate system is constructed, and each axis in the plurality of linkage shafts is subjected to coordinate system conversion according to the multi-axis reference coordinate system, outputting a plurality of converted coordinate systems.

[0019] In the embodiments of the present application, a multi-axis reference coordinate system is constructed, which serves as a unified reference system for the motion of all linkage shafts. A stable reference point is usually selected as the reference, such as the fixed part of the turning and milling machine tool or the center point of the overall working space.

[0020] The system converts the coordinate system of each linkage shaft (such as A shaft, B shaft, C shaft) using a coordinate transformation matrix according to the multi-axis reference coordinate system, ensuring that all motion and position parameters can be processed and analyzed in a unified coordinate system. After coordinate conversion, a plurality of converted coordinate systems are output, each of which maintains an accurate spatial relationship with the reference coordinate system, allowing subsequent error modeling, compensation, and motion trajectory optimization to be based on a unified coordinate system.

[0021] Further, the method of converting the coordinate system of each axis in the plurality of linkage shafts according to the multi-axis reference coordinate system includes: According to the multi-axis reference coordinate system, the installation position error and translational and rotational deviation of each coordinate system in the plurality of coordinate systems are obtained; the transformation matrix corresponding to each coordinate system is represented according to the installation position error and translational and rotational deviation, and a plurality of transformation matrices are output; the coordinate system of each axis in the plurality of linkage shafts is converted according to the plurality of transformation matrices, and a plurality of converted coordinate systems are output.

[0022] Specifically, according to the multi-axis reference coordinate system, installation position errors and translational and rotational deviations of each coordinate system corresponding to the plurality of linkage axes are obtained, wherein the installation position error refers to the deviation position of the local coordinate system of each linkage axis relative to the reference coordinate system, and the translational and rotational deviation refers to the deviation between the direction and position of the local coordinate system of each axis and the expected ideal coordinate system. The system constructs a transformation matrix corresponding to each coordinate system according to the obtained installation position error and translational and rotational deviation, the transformation matrix including a translational matrix and a rotational matrix, wherein the translational matrix describes the position offset of the coordinate system in space, and the rotational matrix describes the rotation angle of the coordinate system in space. By substituting the error parameters of each linkage axis, the transformation matrix corresponding to each coordinate system can be calculated. The plurality of transformation matrices calculated are used to convert the coordinate systems of the plurality of linkage axes; each local coordinate system is transformed into the multi-axis reference coordinate system through matrix operation, and a plurality of converted coordinate systems are output.

[0023] Multi-axis linkage error modeling is performed according to the plurality of converted coordinate systems, and a multi-axis linkage error model is output. The task feature vector is input into the constructed multi-axis linkage error model for multi-axis error analysis, and a trajectory deviation vector of the task feature vector is output.

[0024] The system extracts error parameters in each converted coordinate system, and establishes an error vector in each converted coordinate system according to the error parameters. Each error vector reflects how the error of the linkage axis affects the overall motion trajectory in the coordinate system. The error vectors in all converted coordinate systems are concatenated to construct a multi-axis linkage error model. The multi-axis linkage error model comprehensively considers the error influence of each linkage axis and describes how the coupling error between the linkage axes is manifested in the overall task. The task feature vector is input into the constructed multi-axis linkage error model for multi-axis error analysis, and a trajectory deviation vector of the task feature vector is output. The trajectory deviation vector represents the deviation caused by the multi-axis linkage error during task execution, including position deviation and attitude deviation.

[0025] Further, multi-axis linkage error modeling is performed according to the plurality of converted coordinate systems, and a multi-axis linkage error model is output. The method comprises: Error parameters of the plurality of converted coordinate systems are extracted, the error parameters including transmission error, thermal error and stiffness error; an error vector formula in each converted coordinate system is established according to the error parameters; and a plurality of error vector formulas corresponding to the plurality of converted coordinate systems are concatenated to construct a multi-axis linkage error model.

[0026] Specifically, the system extracts linkage error parameters in multiple conversion coordinate systems. The linkage error parameters include transmission errors, thermal errors, and stiffness errors; the transmission errors refer to errors transmitted from one linkage shaft to another, which are usually caused by factors such as clearances and friction in the mechanical transmission system; the thermal errors are caused by material expansion or contraction due to temperature changes, resulting in changes in the geometric shape of the shaft; and the stiffness errors are caused by insufficient system stiffness, resulting in deformation of the linkage shaft and affecting the machining precision. The system establishes an error vector formula for each conversion coordinate system according to the extracted linkage error parameters, and the error vector formula is used to describe the error type and its size in the coordinate system. The error vector formula defines how errors affect the movement of the linkage shaft through mathematical expressions. The system cascades multiple error vector formulas corresponding to multiple conversion coordinate systems; by cascading the error vector formulas, local errors in each coordinate system can be gradually accumulated to reflect how errors of each linkage shaft propagate in the entire multi-axis system; by combining each error vector formula together, the mutual influence between the shafts is considered, and finally a complete multi-axis linkage error model is formed.

[0027] Further, the expression of the multi-axis linkage error model is: ; wherein, , is the Jacobian matrix of the i-th shaft, which is used to map the local error to the end shaft, is the pose of the end shaft during multi-axis linkage, is the current shaft angle of the i-th linkage shaft, and n is the number of linkage shafts; is the error vector formula of the i-th shaft, is the transmission error of the i-th linkage shaft, is the thermal drift error of the i-th linkage shaft, is the stiffness deformation error of the i-th linkage shaft.

[0028] Jacobian matrix is used to map the local error to the movement of the end shaft, specifically, represents the position and attitude (pose) of the end shaft during multi-axis linkage, and is the current shaft angle of the i-th linkage shaft. The role of the Jacobian matrix is to convert the errors on each linkage shaft according to their respective motion influences into actual motion errors of the end shaft. The system can accurately map the local error to the end pose by calculating the Jacobian matrix.

[0029] is the error vector formula of the i-th shaft, which represents the error source of the shaft. The error vector includes: is the transmission error of the i-th linkage shaft, thermal drift error of the ith linkage axis, stiffness deformation error of the ith linkage axis. By combining these error sources , , Combined into the error vector equation, the system can accurately calculate the error of each axis in actual motion and pass it to the end axis, building a complete multi-axis linkage error model.

[0030] The multi-axis linkage error model expresses how the local error of each linkage axis is mapped to the pose change of the end effector through the Jacobian matrix. Specifically, the Jacobian matrix converts the error of each axis (transmission error, thermal drift error, and stiffness deformation error) into the displacement and attitude deviation of the end effector. The errors of all axes form the total trajectory deviation , i.e., the multi-axis linkage error.

[0031] Further, inputting the task feature vector into the constructed multi-axis linkage error model for multi-axis error analysis, outputting the trajectory deviation vector of the task feature vector, the method comprises: Inputting the task feature vector into the constructed multi-axis linkage error model, obtaining a multi-axis transmission chain according to the multi-axis execution sequence; calculating the actual pose of each axis affected by the error according to the multi-axis transmission chain, comparing the actual pose of each axis with the expected pose to obtain a trajectory deviation vector, the trajectory deviation vector including position deviation and attitude deviation.

[0032] The system inputs the task feature vector into the constructed multi-axis linkage error model. Then, a multi-axis transmission chain is obtained according to the multi-axis execution sequence, which describes how each linkage axis transmits motion and error through interaction. These transmission chains reflect the mutual relationship and error transmission path between the axes. Next, the system calculates the actual pose of each axis affected by the error according to the multi-axis transmission chain, which represents the actual position and attitude of each axis in the multi-axis linkage system considering the error; the system obtains the pose of each axis affected by the error during operation by accurately calculating the motion of each axis. The system compares the actual pose of each axis with the expected pose to obtain a trajectory deviation vector, which includes position deviation and attitude deviation. The position deviation represents the position error of each axis in space, and the attitude deviation represents the angle or direction error of the axis.

[0033] Solving a plurality of compensation angles corresponding to the plurality of linkage axes according to the trajectory deviation vector, the plurality of linkage axes executing correction of the plurality of compensation angles in the plurality of conversion coordinate systems.

[0034] The system calculates the compensation angle required by each linkage shaft according to the obtained trajectory deviation vector. By analyzing the trajectory deviation vector, the system can determine the compensation angle of each linkage shaft, thereby adjusting the motion trajectory of each shaft. The system corrects in combination with multiple conversion coordinate systems according to the compensation angle of each linkage shaft. The compensation angle of each linkage shaft is applied in its corresponding conversion coordinate system, ensuring that the compensation angle can accurately reflect the relative relationship between the shafts and the motion state of the multi-axis system. By performing correction in the conversion coordinate system, the system can fine-tune the motion accuracy of each linkage shaft, compensating for deviations caused by linkage errors, thermal drift, transmission errors, and other factors.

[0035] Further, solving the plurality of compensation angles corresponding to the plurality of linkage shafts according to the trajectory deviation vector, the method comprises: constructing a target correction vector according to the trajectory deviation vector; and inversely solving the multi-axis linkage error model with the target correction vector as the target, and outputting the plurality of compensation angles corresponding to the plurality of linkage shafts.

[0036] The system constructs a target correction vector according to the trajectory deviation vector. The target correction vector describes the adjustment amount required by each shaft. Using the target correction vector, the compensation angle corresponding to each linkage shaft is solved by an inverse calculation method (such as pseudo-Jacobian matrix or weighted least squares method). The pseudo-Jacobian matrix, as the inverse matrix of error propagation, can map the trajectory deviation of the end effector back to each linkage shaft, thereby obtaining the compensation angle. After inverse solving, a plurality of compensation angles corresponding to each linkage shaft are output, which represent how each shaft should adjust its position and attitude to correct the trajectory deviation.

[0037] Further, inversely solving the multi-axis linkage error model with the target correction vector as the target, the expression is: ; wherein, is a plurality of compensation angles corresponding to a plurality of linkage shafts, is a pseudo-Jacobian matrix of the multi-axis linkage error model, is a trajectory deviation vector including position deviation and attitude deviation.

[0038] is a plurality of compensation angles corresponding to a plurality of linkage shafts, the compensation angle is calculated by the system according to the trajectory deviation vector, and is used to adjust the motion trajectory of each linkage shaft to compensate for the deviation caused by errors. is a pseudo-Jacobian matrix of the multi-axis linkage error model, the pseudo-Jacobian matrix is used to map between the error vector and the actual shaft angle. In a multi-axis linkage system, the pseudo-Jacobian matrix The pseudo-Jacobian matrix is used to solve the multi-axis linkage error adjustment problem caused by system errors. The trajectory deviation vector includes a position deviation and an attitude deviation; the position deviation represents the position deviation of the end effector in space caused by error accumulation during multi-axis linkage; and the attitude deviation reflects the deviation of the angle or direction of the end effector.

[0039] By using the pseudo-Jacobian matrix Through inverse calculation, the trajectory deviation of the end effector is converted into compensation angles of each linkage axis , so as to correct the trajectory deviation caused by errors.

[0040] Further, the method further comprises: Performing key axis analysis on the plurality of linkage axes to obtain a plurality of key indicators; configuring a plurality of key weights based on the plurality of key indicators; and performing inverse calculation feedback on the multi-axis linkage error model based on the weighted least squares method with the plurality of key weights to output updated compensation angles.

[0041] Preferably, the key axis analysis on the plurality of linkage axes obtains a plurality of key indicators, that is, the axes that have the greatest impact on the overall accuracy in the multi-axis linkage system are identified, which are usually the axes that are greatly affected by factors such as stress, stiffness, and thermal changes. For example, some axes may have a greater impact on the attitude change of the end effector, while other axes mainly affect the position accuracy. Through this analysis, a plurality of key indicators are extracted, including the sensitivity of the axis, the degree of influence of the error on the pose, and the role of each axis in the task.

[0042] Based on the plurality of key indicators, the system configures a plurality of key weights, which are used to reflect the relative contribution of each linkage axis to the system accuracy. By weighting the influence of different axes, the system can assign different priorities to each axis to ensure that the axes with greater impact on accuracy are compensated more accurately. The system performs inverse calculation feedback on the multi-axis linkage error model based on the weighted least squares method with the plurality of key weights; the weighted least squares method optimizes the calculation of the compensation angles by minimizing the weighted sum of squares of errors. After feedback solving by the weighted least squares method, the updated compensation angles are output. These compensation angles are optimized by weights, which more accurately correct the errors in the multi-axis linkage system and ensure that the motion accuracy of each linkage axis is maximally improved.

[0043] Further, the inverse calculation feedback on the multi-axis linkage error model based on the weighted least squares method with the plurality of key weights is expressed as: ; wherein, For multiple compensation angles corresponding to multiple linkage axes, Let be the transpose of the Jacobian matrix. For Jacobian matrices, A weight matrix constructed for multiple key weights. This is the trajectory deviation vector, which includes position and attitude deviations.

[0044] Specifically, using the Jacobian matrix and weight matrix Calculate the weighting matrix The weighted matrix combines the error propagation characteristics of each linked axis with the weight information of the critical axis. The inverse matrix of the weighted least squares method is calculated. and apply it to the trajectory deviation vector To calculate the compensation angle in reverse .

[0045] In summary, the embodiments of this application have at least the following technical effects: First, the task feature vector of the milling head is extracted. Next, multiple linkage axes associated with the milling head and their corresponding coordinate systems are identified based on the task feature vector. Then, a multi-axis reference coordinate system is constructed, and coordinate transformations are performed on each axis of the multiple linkage axes according to this system, outputting multiple transformed coordinate systems. Further, multi-axis linkage error modeling is performed according to the multiple transformed coordinate systems, outputting a multi-axis linkage error model. The task feature vector is input into this model for multi-axis error analysis, outputting the trajectory deviation vector of the task feature vector. Finally, multiple compensation angles corresponding to the multiple linkage axes are calculated based on the trajectory deviation vector, and the multiple linkage axes undergo multiple compensation angle corrections under the multiple transformed coordinate systems. This solves the technical problem of difficulty in dynamic error compensation caused by the accumulation of assembly angle errors of multiple rotary axes in existing technologies. By repositioning the coordinate systems of the multiple axes involved in the current task, the influence of error accumulation is eliminated, thereby achieving the technical effect of dynamic error compensation.

[0046] Example 2 is based on the same inventive concept as the multi-axis linkage-based milling head dynamic error compensation method in the previous examples, such as... Figure 3 As shown, this application provides a dynamic error compensation system for milling and turning heads based on multi-axis linkage, wherein the system includes: The feature extraction module 11 is configured to extract a task feature vector of the swing head of the road milling machine; the identification module 12 is configured to identify, according to the task feature vector, a plurality of linkage shafts associated with the swing head of the road milling machine and a plurality of coordinate systems corresponding to the plurality of linkage shafts; the coordinate conversion module 13 is configured to construct a multi-shaft reference coordinate system, perform coordinate system conversion on each shaft in the plurality of linkage shafts according to the multi-shaft reference coordinate system, and output a plurality of converted coordinate systems; the error analysis module 14 is configured to perform multi-shaft linkage error modeling according to the plurality of converted coordinate systems, output a multi-shaft linkage error model, input the task feature vector into the constructed multi-shaft linkage error model to perform multi-shaft error analysis, and output a trajectory deviation vector of the task feature vector; and the correction module 15 is configured to solve a plurality of compensation angles corresponding to the plurality of linkage shafts according to the trajectory deviation vector, and perform correction of the plurality of compensation angles on the plurality of linkage shafts under the plurality of converted coordinate systems.

[0047] Further, the coordinate conversion module 13 is configured to perform the following method: According to the multi-shaft reference coordinate system, the installation position error and the translational and rotational deviation of each coordinate system in the plurality of coordinate systems are obtained; a transformation matrix corresponding to each coordinate system is represented according to the installation position error and the translational and rotational deviation, and a plurality of transformation matrices are output; and coordinate system conversion is performed on each shaft in the plurality of linkage shafts according to the plurality of transformation matrices, and a plurality of converted coordinate systems are output.

[0048] Further, the error analysis module 14 is configured to perform the following method: Linkage error parameters of the plurality of converted coordinate systems are extracted, the linkage error parameters including transmission error, thermal error and stiffness error; an error vector formula under each converted coordinate system is established according to the linkage error parameters; and a plurality of error vector formulas corresponding to the plurality of converted coordinate systems are concatenated to construct a multi-shaft linkage error model.

[0049] Further, the error analysis module 14 is configured to perform the following method: The expression of the multi-shaft linkage error model is: ; wherein, , is the Jacobian matrix of the i th shaft, which is used to map the local error to the end shaft, is the pose of the end shaft during multi-shaft linkage, is the current shaft angle of the i th linkage shaft, and n is the number of linkage shafts; is the error vector formula of the i th shaft, is the transmission error of the i th linkage shaft, is the thermal drift error of the i th linkage shaft, is the stiffness deformation error of the i th linkage shaft.

[0050] Further, the error analysis module 14 is configured to perform the following method: inputting the task feature vector into the built multi-axis linkage error model, obtaining a multi-axis transmission chain according to a multi-axis execution sequence, calculating an actual pose of the task feature vector on each axis affected by an error according to the multi-axis transmission chain, comparing the actual pose of each axis with an expected pose to obtain a trajectory deviation vector, and the trajectory deviation vector including a position deviation and an attitude deviation.

[0051] Further, the correction module 15 is configured to perform the following method: constructing a target correction vector according to the trajectory deviation vector, and inversely solving the multi-axis linkage error model with the target correction vector as a target to output a plurality of compensation angles corresponding to the plurality of linkage axes.

[0052] Further, the correction module 15 is configured to perform the following method: inversely solving the multi-axis linkage error model with the target correction vector as the target, and the expression being: ; wherein, the plurality of compensation angles corresponding to the plurality of linkage axes, a pseudo-Jacobian matrix of the multi-axis linkage error model, a trajectory deviation vector including a position deviation and an attitude deviation.

[0053] Further, the correction module 15 is configured to perform the following method: performing key axis analysis on the plurality of linkage axes to obtain a plurality of key indicators, configuring a plurality of key weights based on the plurality of key indicators, and inversely solving the multi-axis linkage error model based on a weighted least squares method with the plurality of key weights for feedback to output updated plurality of compensation angles.

[0054] Further, the correction module 15 is configured to perform the following method: inversely solving the multi-axis linkage error model based on a weighted least squares method with the plurality of key weights for feedback, and the expression being: ; wherein, the plurality of compensation angles corresponding to the plurality of linkage axes, a transpose matrix of a Jacobian matrix, a Jacobian matrix, a weight matrix constructed based on the plurality of key weights, a trajectory deviation vector including a position deviation and an attitude deviation.

[0055] It should be noted that the above-mentioned embodiment sequences of the present application are merely for description only, but not for representing the advantages and disadvantages of the embodiments. And the above-mentioned embodiments of the present specification are described. The processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multi-task processing and parallel processing are also possible or can be advantageous.

[0056] The above only describes the preferred embodiments of the present application, and does not limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

[0057] The specification and drawings are merely exemplary of the present application, and any and all modifications, variations, combinations or equivalents that are within the scope of the present application should be included. Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the scope of the present application. Thus, if these modifications and variations of the present application belong to the scope of the present application and its equivalents, the present application is intended to include these modifications and variations.

Claims

1. A dynamic error compensation method for a turning-milling swing head based on multi-axis linkage, characterized in that, The method comprises: extracting the task feature vector of the turning-milling swing head; identifying a plurality of linkage shafts associated with the turning-milling swing head according to the task feature vector, and a plurality of coordinate systems corresponding to the plurality of linkage shafts; constructing a multi-axis reference coordinate system, performing coordinate system conversion on each shaft in the plurality of linkage shafts according to the multi-axis reference coordinate system, and outputting a plurality of converted coordinate systems; performing multi-axis linkage error modeling according to the plurality of converted coordinate systems, outputting a multi-axis linkage error model, inputting the task feature vector into the constructed multi-axis linkage error model for multi-axis error analysis, and outputting a trajectory deviation vector of the task feature vector; solving a plurality of compensation angles corresponding to the plurality of linkage shafts according to the trajectory deviation vector, and executing correction of the plurality of compensation angles by the plurality of linkage shafts under the plurality of converted coordinate systems.

2. The multi-axis based dynamic error compensation method for a turn-milling head as claimed in claim 1, wherein, The method for performing coordinate system conversion on each shaft in the plurality of linkage shafts according to the multi-axis reference coordinate system comprises: According to the multi-axis reference coordinate system, the installation position error and the translational and rotational deviation of each coordinate system in the plurality of coordinate systems are obtained; According to the installation position error and the translational and rotational deviation, a transformation matrix corresponding to each coordinate system is expressed, and a plurality of transformation matrices are outputted; According to the plurality of transformation matrices, coordinate system conversion is performed on each shaft in the plurality of linkage shafts, and a plurality of converted coordinate systems are outputted.

3. The multi-axis based dynamic error compensation method for a turn-milling head as claimed in claim 1, wherein, The method for performing multi-axis linkage error modeling according to the plurality of converted coordinate systems and outputting a multi-axis linkage error model comprises: extracting linkage error parameters of the plurality of converted coordinate systems, the linkage error parameters including transmission error, thermal error and stiffness error; establishing an error vector formula under each converted coordinate system according to the linkage error parameters; concatenating a plurality of error vector formulas corresponding to the plurality of converted coordinate systems to construct a multi-axis linkage error model.

4. The multi-axis linkage based dynamic error compensation method for a turning-milling-crane head as claimed in claim 3, wherein, The expression of the multi-axis linkage error model is: ； wherein, , Ji is the Jacobian matrix of the ith axis for mapping the local error to the end axis, is the pose of the end axis when the multiple axes are linked, ni is the current axis angle of the ith axis, and n is the number of axes. is the error vector for the ith axis, is the transmission error for the ith axis, is the thermal drift error for the ith axis, is the stiffness deformation error for the ith axis.

5. The multi-axis based dynamic error compensation method for a turn-milling head as claimed in claim 1, wherein, The method for inputting the task feature vector into the constructed multi-axis linkage error model for multi-axis error analysis and outputting a trajectory deviation vector of the task feature vector comprises: inputting the task feature vector into the constructed multi-axis linkage error model, and obtaining a multi-axis transmission chain according to the multi-axis execution sequence; calculating the actual pose of the task feature vector on each shaft affected by the error according to the multi-axis transmission chain, comparing the actual pose of each shaft with the expected pose, and obtaining a trajectory deviation vector, the trajectory deviation vector including a position deviation and an attitude deviation.

6. The multi-axis linkage based dynamic error compensation method for a turning-milling-crane head as claimed in claim 5, wherein, The method for solving a plurality of compensation angles corresponding to the plurality of linkage shafts according to the trajectory deviation vector comprises: constructing a target correction vector according to the trajectory deviation vector; performing inverse calculation on the multi-axis linkage error model with the target correction vector as the target, and outputting a plurality of compensation angles corresponding to the plurality of linkage shafts.

7. The multi-axis based dynamic error compensation method for a wobble head of a turning-milling machine according to claim 6, wherein, The expression of performing inverse calculation on the multi-axis linkage error model with the target correction vector as the target is: ； wherein, a plurality of compensation angles corresponding to the plurality of linkage axes, a pseudo-Jacobian matrix of the multi-axis linkage error model, a trajectory deviation vector including position deviation and attitude deviation.

8. The multi-axis linkage based dynamic error compensation method for a turning-milling-crane head as claimed in claim 6, wherein, The method for outputting a plurality of compensation angles corresponding to the plurality of linkage shafts further comprises: performing key shaft analysis on the plurality of linkage shafts to obtain a plurality of key indicators; configuring a plurality of key weights based on the plurality of key indicators; The multi-axis linkage error model is solved inversely and fed back based on the weighted least square method with the plurality of key weights, and updated plurality of compensation angles are output.

9. The multi-axis linkage based dynamic error compensation method for a turning-milling-crane head as claimed in claim 8, wherein, The multi-axis linkage error model is solved inversely and fed back based on the weighted least square method with the plurality of key weights, and the expression is: ； wherein, is a plurality of compensation angles corresponding to the plurality of linkage axes, is a transpose matrix of the Jacobian matrix, is the Jacobian matrix, is a weight matrix constructed from a plurality of key weights, is a trajectory deviation vector including a position deviation and a pose deviation.

10. A dynamic error compensation system for a turning-milling swing head based on multi-axis linkage, characterized in that, The system for implementing the multi-axis linkage-based dynamic error compensation method of the swing head of a turning and milling machine according to any one of claims 1-9 comprises: a feature extraction module configured to extract a task feature vector of the swing head of the turning and milling machine; an identification module configured to identify, according to the task feature vector, a plurality of linkage axes associated with the swing head of the turning and milling machine and a plurality of coordinate systems corresponding to the plurality of linkage axes; a coordinate conversion module configured to construct a multi-axis reference coordinate system, perform coordinate system conversion on each axis in the plurality of linkage axes according to the multi-axis reference coordinate system, and output a plurality of converted coordinate systems; an error analysis module configured to perform multi-axis linkage error modeling according to the plurality of converted coordinate systems, output a multi-axis linkage error model, input the task feature vector into the constructed multi-axis linkage error model, and perform multi-axis error analysis to output a trajectory deviation vector of the task feature vector; a correction module configured to solve a plurality of compensation angles corresponding to the plurality of linkage axes according to the trajectory deviation vector, and perform correction of the plurality of compensation angles by the plurality of linkage axes in the plurality of converted coordinate systems.

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