Digital twin five-axis machine tool kinematic transformation methods, systems, equipment and media

Abstract

This invention provides a method, system, device, and medium for kinematic transformation of a five-axis machine tool using digital twin technology, belonging to the interdisciplinary field of CNC technology and digital twin technology. The method includes: acquiring axis parameters from the five-axis machine tool controller; constructing a unified five-axis parameter set containing axis type, axis reference point, and direction vector; constructing a hierarchical homogeneous transformation chain in the machine tool base coordinate system based on this parameter set to achieve a forward kinematic transformation from the machine coordinate system to the workpiece coordinate system; and inversely solving the axis position vector from the tool position command in the workpiece coordinate system based on the unified parameter set and transformation chain, and mapping it back to the controller coordinates. This invention, employing the aforementioned method, system, device, and medium for kinematic transformation of a five-axis machine tool using digital twin technology, solves the problems of poor model reusability and inconsistent virtual-real mapping caused by differences in machine tool structure and the diversity of CNC systems. It achieves universal reversible kinematic transformation across platforms and machine types, improving the engineering applicability and deployment efficiency of the digital twin model.

Description

Technical Field

[0001] This invention relates to the field of CNC technology and digital twin technology, and in particular to a method, system, device and medium for kinematic transformation of a digital twin five-axis machine tool. Background Technology

[0002] Five-axis CNC machine tools, with their advantages in machining complex curved surfaces and forming multiple surfaces in a single clamping, have become core equipment in high-end manufacturing fields such as aerospace, energy equipment, precision molds, and medical devices. With the development of digital twin technology, it is playing an increasingly important role in the entire life cycle management of machine tools, including design verification, process planning, work-in-process monitoring, and quality traceability.

[0003] To effectively apply digital twin technology in five-axis machining scenarios, the key lies in ensuring the consistency of coordinate semantics between the virtual and physical spaces. Specifically, the same machining program or tool position data should achieve consistent and reversible coordinate mapping and execution results in both the digital twin and the physical machine tool. However, current technological practices face several prominent technical challenges in realizing digital twins for five-axis machine tools:

[0004] (1) Lack of a unified and parameterized coordinate transformation model: Five-axis machine tools have diverse structural forms (such as double rotary tables, double swivel heads, and head-table hybrids), and their rotary axes often have non-orthogonal layouts and offset hinge structures. At the same time, multi-level parameters involved in the machining process, such as tool length and radius compensation, workpiece coordinate system offset (such as G54~G59), and fixture offset, are usually implicitly and dispersedly configured in the controller, post-processing program, and simulation software. This situation makes it difficult to construct a readable, verifiable, and interchangeable standard parameter set, thus failing to provide a universal and reliable mathematical model for the transformation between WCS (workpiece coordinate system) and MCS (machine coordinate system).

[0005] (2) Poor compatibility between controller platforms and attitude representation: Different CNC systems (such as Fanuc, Siemens, etc.) have significant differences in key conventions such as coordinate axis definition, motion command semantics (such as the implementation of RTCP function), coordinate system chirality, and axis motion direction. In addition, the coexistence of multiple attitude representation methods in engineering practice (such as Euler angles, spinors, quaternions) further exacerbates the complexity and inconsistency of tool position data migration between different platforms, making it difficult to reuse the same machining intention on different controllers or machine models without loss.

[0006] (3) The simulation on the WCS side and the monitoring on the MCS side are disconnected: In digital twin applications, WCS usually serves the cutting simulation oriented towards part geometry and process, while MCS is used for online monitoring, collision protection and stroke verification oriented towards machine tool physical state. Due to the lack of a stable and reversible parametric mapping bridge, the conclusions and optimization strategies obtained from the simulation are difficult to be directly and reliably applied to the online monitoring side, which seriously hinders the realization of virtual and real closed-loop control of the machining process and the traceability of the entire process quality.

[0007] The aforementioned issues collectively lead to difficulties in the actual deployment of five-axis machine tool digital twin systems, including a large workload for adaptation, high maintenance costs, and poor model reusability. Each new machine tool or change to a process plan requires tedious simultaneous modifications and verifications across multiple stages, including CAM post-processing, simulation software, and controller configuration, significantly hindering the efficiency of large-scale application and continuous evolution of digital twin technology in the five-axis machining field.

[0008] Therefore, there is an urgent need in this field for a parameterized, reversible, universal kinematic transformation method for five-axis machine tools that can be decoupled from specific controllers, is friendly to machine tool structure types, and supports direct reuse across platforms. Summary of the Invention

[0009] The purpose of this invention is to provide a method, system, device and medium for kinematic transformation of digital twin five-axis machine tools, so as to solve technical problems such as poor model reusability, inconsistent virtual-real mapping and complex adaptation and deployment caused by differences in machine tool structure and diversity of CNC systems, and realize universal, reversible and high-fidelity kinematic transformation across platforms and machine models.

[0010] To achieve the above objectives, this invention provides a kinematic transformation method for a digital twin five-axis machine tool, comprising the following steps:

[0011] Step S1: Collect axis parameters from the five-axis machine tool controller, including three linear axes and two rotary axes;

[0012] Step S2: Based on the collected axis parameters, construct a unified five-axis parameter set;

[0013] Step S3: Based on the unified five-axis parameter set, construct a hierarchical homogeneous transformation chain in the machine tool base coordinate system to realize the positive kinematic transformation from the machine coordinate system to the workpiece coordinate system, and calculate the position of the tool center point in the workpiece coordinate system and the tool axis direction vector.

[0014] Step S4: Based on the unified five-axis parameter set and homogeneous transformation chain, the corresponding axis position vector is solved in reverse from the tool position command in the workpiece coordinate system, and the axis position vector is mapped back to the controller coordinate to generate the axis command that can be issued.

[0015] Preferably, in step S1, any two rotary axes are selected from the table-side rotary axis and the spindle-side rotary axis, and the collected axis parameters include axis type, positive axis direction, zero point position, tool center point control RTCP parameters, workpiece coordinate system parameters G54 to G59, and tool compensation parameters.

[0016] Preferably, in step S2, the unified five-axis parameter set includes the axis type, axis reference point, axis unit direction vector, and axis attitude deviation vector for each axis, wherein the axis type includes linear axes and rotation axes.

[0017] Preferably, in step S2, for the rotating axis, the position of the tool center point is measured by calibration test, and the rotation center and axis of the rotating axis are identified by least squares method to form a unified set of geometric parameters.

[0018] Preferably, in step S3, for the linear axis, its homogeneous transformation matrix is... for:

[0019] ;

[0020] in, Indicates the axis position. Represents the unit direction vector of the axis. express The identity matrix, Indicates transpose;

[0021] For the rotation axis, its homogeneous transformation matrix for:

[0022] ;

[0023] ;

[0024] in, Indicates the reference point for the axis.

[0025] Preferably, step S4 specifically includes:

[0026] Step S41: Based on the machine structure, including dual rotary tables, dual swing heads, or a combination of head tables and the rotation axis numbering in a unified parameter set, construct the tool axis direction constraint, and solve the rotation axis angle using analytical geometry or numerical iteration methods.

[0027] Step S42: Given a fixed rotation axis angle, solve for the position of the linear axis based on the tool center point position constraint.

[0028] Step S43: Map the axis position vector under the unified model back to the controller coordinates, superimpose the workpiece coordinate offset and tool compensation, and generate the final axis command.

[0029] Preferably, in step S4, the tool position command includes the tool center point position and the tool axis direction.

[0030] This invention also provides a digital twin five-axis machine tool kinematics transformation system, comprising:

[0031] The five-axis machine tool controller interface module is used to acquire axis parameters from the five-axis machine tool controller, including three linear axes and two rotary axes. Any two rotary axes can be selected from the table-side rotary axis and the spindle-side rotary axis. The acquired axis parameters include axis type, positive axis direction, zero point position, tool center point control RTCP parameters, workpiece coordinate system parameters G54 to G59, and tool compensation parameters.

[0032] The five-axis motion unified model configuration module is used to construct a unified five-axis parameter set based on the collected axis parameters. The unified five-axis parameter set includes the axis type, axis reference point, axis unit direction vector, and axis attitude deviation vector for each axis. The axis types include linear axes and rotation axes.

[0033] The Unified Kinematic Transformation Module is used to construct a hierarchical homogeneous transformation chain in the machine tool base coordinate system based on a unified five-axis parameter set. It realizes the forward kinematic transformation from the machine coordinate system to the workpiece coordinate system to calculate the position of the tool center point in the workpiece coordinate system and the tool axis direction vector. It is also used to solve the corresponding axis position vector in reverse from the tool position command in the workpiece coordinate system.

[0034] The digital twin simulation and optimization module is used for tool position simulation, stroke interference verification, tool center point control RTCP behavior verification, and process parameter optimization based on the unified kinematic transformation module.

[0035] The present invention also provides a computer device, including: a memory and a processor; the memory stores a computer program, and the processor executes the computer program to implement the steps of the above-described digital twin five-axis machine tool kinematic transformation method.

[0036] The present invention also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the steps of the above-described digital twin five-axis machine tool kinematic transformation method.

[0037] Therefore, the present invention employs the above-mentioned digital twin five-axis machine tool kinematics transformation method, system, equipment, and medium, and the beneficial technical effects are as follows:

[0038] (1) This invention constructs a unified parametric five-axis motion model, abstracting the coordinate conventions, axis parameters, and offset information of different structural types (such as dual rotary tables and dual oscillating heads) and different controllers (such as Fanuc and Siemens) into a standardized set of configuration parameters and a hierarchical homogeneous transformation chain. This enables tool position data under the same workpiece coordinate system to be stably and reversibly mapped to the mechanical coordinate system axis commands of different machine tools through a unified inverse solution algorithm, fundamentally solving the problems of model reuse difficulties and high adaptation costs caused by platform differences in the prior art, and improving the universality and portability of the digital twin model.

[0039] (2) This invention provides an explicit and hierarchical unified management of the multi-level offsets (such as workpiece zero point, tool compensation, and fixture offset) and their combination order that were previously scattered in controller parameters and post-processing scripts. Users only need to configure a unified set of parameters to adapt to new models or change process schemes, without having to perform scattered and error-prone modifications and regression verifications in multiple stages such as CAM post-processing, simulation software, and controller configuration. This simplifies the deployment, debugging, and long-term maintenance process of the digital twin system, and reduces the technical threshold and labor costs for large-scale applications.

[0040] (3) The forward and inverse kinematic transformation algorithms provided by this invention realize stable and reversible coordinate mapping between the workpiece coordinate system and the machine coordinate system based on a unified parameter model. This not only ensures the consistency of the pose results of the same NC program on the digital twin and the physical machine tool, but also enables the cutting simulation conclusions based on the workpiece coordinate system to be reliably used for online collision monitoring, stroke verification and error analysis based on the machine coordinate system. This connects the process planning and online monitoring links, and lays a key technical foundation for achieving accurate virtual-real closed-loop control and full-process quality traceability. Attached Figure Description

[0041] Figure 1 The process for establishing / identifying a five-axis unified motion model;

[0042] Figure 2 The flowchart shows the coordinate transformation and mapping methods.

[0043] Figure 3 Flowcharts for online parsing and optimization;

[0044] Figure 4 This is a flowchart for offline parsing and optimization. Detailed Implementation

[0045] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0046] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0047] Example 1

[0048] like Figure 1 and Figure 2 As shown, this embodiment details the kinematic transformation method for a digital twin five-axis machine tool provided by the present invention, which is implemented through the following steps:

[0049] Step S1: Controller parameter acquisition and machine structure identification.

[0050] This step uses the five-axis machine tool controller interface module to collect and identify the following key parameters and structural information from the machine tool CNC system:

[0051] Axis sequence and axis type: Identify and record three linear axes ( ) and two rotating axes (e.g., the worktable side) or spindle side The rotary axis can be selected from either the table-side rotary axis or the spindle-side rotary axis, and its corresponding axis number in the controller (such as X, Y, Z, A, B, C, etc.) should be specified.

[0052] Positive axis direction and zero point: Obtain the physical positive direction definition, mechanical zero point position, and soft limit for each axis.

[0053] RTCP and tool compensation parameters: Acquisition controller parameters such as tool pivot point definition and reference point offset used in RTCP (such as G43.4, PLANE SPATIAL, TCPM, etc.) mode.

[0054] Workpiece coordinate system parameters: Read the offsets of workpiece coordinate systems (WCS) from G54 to G59, as well as additional offset values ​​such as fixture and jig coordinates.

[0055] Tool parameters: Obtain the current tool's length, radius compensation value, and how it is applied in the controller.

[0056] The above information can be obtained by parsing the controller's parameter file, accessing the system diagnostic interface, or reading the configuration document provided by the machine tool manufacturer.

[0057] Step S2: Construction of a unified five-axis parameter set and identification of axis parameters.

[0058] Based on the information collected in step S1, this step constructs a standardized, unified five-axis parameter set decoupled from the controller. First, the machine tool kinematic chain is abstracted into a unified axis position vector. :

[0059] ;

[0060] in, This indicates transpose.

[0061] Subsequently, for each axis in the kinetic chain Define the following parameters to form a unified parameter set:

[0062] Shaft type This is used to identify whether the axis is a linear axis (P) or a rotational axis (R).

[0063] Axis reference point This indicates that the axis is in the machine tool base coordinate system. The spatial coordinates below.

[0064] Axis unit direction vector , indicating the direction of the axis in space.

[0065] Axis attitude deviation vector (Optional) Used to describe non-orthogonal installation errors, etc.

[0066] For linear axes, their parameters can usually be determined directly from the machine tool assembly model or controller manual.

[0067] For the rotary axis, in order to obtain a more accurate model, this embodiment preferably measures the position of the tool center point (TCP) in multiple known postures in the workpiece coordinate system through calibration experiments (e.g., using probes and standard balls), and uses numerical optimization methods such as least squares method to accurately identify the rotation center and axis of the rotary axis, thereby forming a high-precision unified set of geometric parameters.

[0068] Step S3: Construct a unified homogeneous transformation chain (to achieve forward mapping from MCS to WCS).

[0069] This step is based on the unified parameter set constructed in step S2, in the machine tool base coordinate system ( A hierarchical homogeneous transformation chain is constructed in the model to realize the forward kinematic transformation from the machine coordinate system (MCS) to the workpiece coordinate system (WCS).

[0070] For the linear axis, its homogeneous transformation matrix is ​​defined as:

[0071] ;

[0072] in, Indicates the axis command position. express The identity matrix.

[0073] For the rotation axis, its homogeneous transformation matrix is ​​defined as:

[0074] ;

[0075] ;

[0076] in, Indicates the reference point for the axis.

[0077] Following the inherent motion chain sequence of the machine tool (e.g., "table-linear axis-spindle-tool"), the homogeneous transformation matrices of each axis are multiplied sequentially and then incorporated into the workpiece coordinate system offset. and tool geometry transformation This allows us to obtain the complete transformation from the machine coordinate system (MCS) to the workpiece coordinate system (WCS) with the tool center point (TCP). :

[0078] ;

[0079] in, Represents the set of axes involved (e.g.) (In the order from bed to workpiece / spindle to tool); the tool's position vector in the WCS can be extracted from the translation portion of this transformation matrix. The tool axis direction vector can be extracted from the rotating part. .

[0080] Step S4: Reverse solution from WCS to MCS and controller mapping.

[0081] In digital twin simulation or when NC instructions need to be generated, the target tool position in the WCS, i.e., the TCP position, must be obtained ( ) and tool axis direction ( The positions of each axis in the machine coordinate system (MCS) are solved in reverse. This step is achieved through the following sub-steps:

[0082] 1. Solving for the rotary axis: Based on the specific structural type of the machine tool (double rotary table, double swivel head, or a combination of headrest and rotary table) and the two rotary axis numbers determined by a unified parameter set, establish the functional relationship between the tool axis direction and the rotary axis angle:

[0083] ;

[0084] in, Indicates the position of a given axis At that time, the TCP tool axis unit direction vector calculated by the unified kinematic model ( (rotation part in) Represents the mapping "from the four rotational axis angles to the tool axis direction" (forward kinematics) (The rotation part) (This describes the homogeneous transformation matrix, that is, in 3D, a rigid body pose = rotation + translation) , It means yes matrix, express The rotation matrix represents the rotation part. express The translation matrix (i.e., the translation part).

[0085] The combination of rotation axis angles that satisfy the tool axis direction constraint is solved by analytical geometric methods or numerical iterative algorithms (such as Newton's method), and the soft limit of the axis and the avoidance of singular postures are considered in the process.

[0086] 2. Solving for the linear axis: After the rotation axis angle is determined, the TCP position becomes a function only of the linear axis:

[0087] ;

[0088] in, Indicates the position of a given axis At that time, the TCP position vector in the workpiece coordinate system WCS calculated by the unified kinematic model (i.e., ), This represents a mapping from all axis positions to TCP spatial positions (i.e.) ). The known and unknown quantities are only It can be solved directly using linear algebra or least squares.

[0089] 3. Controller coordinate mapping: Mapping the axis vectors obtained from solving under the unified model. Based on the controller-specific conventions (such as axis sequence, symbol, and zero point) collected in step S1, the coordinates are mapped back to the axis coordinates (such as X, Y, Z, A, C, etc.) that the controller can recognize. At the same time, the activated workpiece coordinate offset (such as G54) and tool compensation value in the controller are superimposed on the final instruction to generate NC code or axis instructions that can be directly issued to the controller for execution.

[0090] Through steps S1 to S4 above, this embodiment realizes a stable and reversible high-precision coordinate transformation between the machine coordinate system (MCS) and the workpiece coordinate system (WCS) of a five-axis machine tool in a digital twin environment, providing a reliable kinematic core for subsequent online monitoring, offline simulation and process optimization.

[0091] Example 2

[0092] This embodiment corresponds to Figure 3 The online analysis and optimization application scenario shown illustrates in detail how the present invention utilizes a unified kinematic transformation method for real-time monitoring, trajectory analysis, and process optimization during the actual operation of a five-axis machine tool.

[0093] Step S1: Online data collection.

[0094] During machine tool processing or idle operation, the following data from the controller is read in real time via fieldbus (such as EtherCAT, PROFIBUS, etc.) or high-speed data acquisition card:

[0095] Real-time position feedback of each axis .

[0096] The controller's operating mode status includes the start / stop status of the RTCP function and the currently active workpiece coordinate system (such as G54~G59).

[0097] The currently active tool number and its corresponding length and radius compensation values.

[0098] Information about the NC program segment and instructions currently being executed.

[0099] Step S2: Real-time TCP reconstruction and trajectory analysis.

[0100] Using the unified kinematics forward transformation model constructed in step S3 of Example 1, the axis position vectors collected at each sampling time are... Real-time mapping to the tool center point (TCP) position in the workpiece coordinate system (WCS) and tool axis direction vector This allows for the precise reconstruction of real-time toolpaths that are completely synchronized with the physical machine tool within a digital twin environment.

[0101] Step S3: Online monitoring, comparison and optimization.

[0102] Based on the reconstructed real-time trajectory, the following online analysis and optimization functions are performed in the digital twin platform:

[0103] Trajectory consistency verification: The reconstructed actual trajectory is compared with the nominal theoretical trajectory defined by the NC program in real time. This can be used to verify whether the RTCP function is implemented correctly, whether the workpiece coordinate system offset (such as G54) is configured accurately, and whether the tool compensation parameters are effective as expected, so as to promptly detect parameter configuration errors or controller malfunctions.

[0104] Travel and Collision Monitoring: Utilizing the geometric model of a digital twin, real-time interference detection and soft limit verification are performed on the current axis position of the machine tool and a "look-forward" future trajectory. This allows for early warning of potential interference risks between the tool and workpiece, the tool and fixture, or machine tool components, as well as axis overtravel risks, before physical collisions occur.

[0105] Process parameter optimization: In a virtual environment, process parameters such as feed rate and spindle speed of the CAM path can be safely modified, or virtual tool geometry can be adjusted. The impact of these changes on workpiece surface finish, tool cutting load, and the smoothness of each axis's motion can be quickly assessed. Based on the assessment results, optimization suggestions for feed rate adjustment or tool change strategies can be provided to operators, improving machining safety and efficiency without directly interfering with the physical machine tool's PLC logic.

[0106] Step S4: Comparison of virtual and real data and source of error.

[0107] By combining the actual geometric data of the workpiece acquired by an online probe or external measuring device installed on the machine tool, and aligning and comparing it with the corresponding nominal geometry in the digital twin model, the deviation between the measured point and the theoretical point can be substituted back into the axis space of the machine tool to analyze the source of error, for example:

[0108] The problem is determined to be a geometric error inherent in the machine tool itself (such as inter-axis perpendicularity error).

[0109] Or is it a systematic deviation caused by inaccurate rotation center parameters of the rotating shaft?

[0110] Or it could be due to deviations in the workpiece clamping and positioning.

[0111] The analysis results provide accurate data support and decision-making basis for subsequent machine tool geometric parameter compensation, clamping scheme optimization, or process parameter adjustment.

[0112] As can be seen from this embodiment, the unified kinematic transformation method of the present invention can be linked with the physical machine tool in real time, which not only achieves high-fidelity virtual-real synchronization, but more importantly, provides in-depth analysis, monitoring and optimization capabilities for the online machining process, and improves the transparency, safety and intelligence level of five-axis CNC machining.

[0113] Example 3

[0114] This embodiment corresponds to Figure 4 The offline process planning and multi-machine adaptation application process shown in this paper specifically illustrates the method of the present invention for unified process evaluation and program generation for multiple five-axis machine tools in an offline environment.

[0115] 1. Offline device configuration.

[0116] For multiple five-axis machine tools with different structural types (such as double rotary table, double swing head, and head-table hybrid) and different CNC systems, the kinematic model and configuration parameters of each machine tool are established through the parameter acquisition and unified parameter set construction steps in this invention, and finally a reusable "machine configuration library" is formed.

[0117] 2. CAM toolpath import and WCS toolpath simulation.

[0118] Export the toolpath file, represented in the workpiece coordinate system, from the CAM system. This file contains the tool center point trajectory and tool axis vector information. After importing the toolpath file into the digital twin platform, perform geometrical machinability simulation in the workpiece coordinate system, including allowance checking, tool interference judgment, surface quality assessment, and machining time evaluation.

[0119] 3. Unified model-driven multi-machine mapping and comparison.

[0120] For the same workpiece coordinate system toolpath, the inverse kinematics solution steps of this invention map it to each machine tool in the machine configuration library, generating axis command trajectories corresponding to different machine tools. For each machine tool, a unified kinematics model is further used for execution:

[0121] Stroke and limit checks determine the reachability of the toolpath on this machine model;

[0122] Joint space velocity / acceleration estimation to assess servo load and vibration risk;

[0123] By combining the machine tool dynamic characteristic model, the potential contour error and machining time are estimated.

[0124] By comparing the simulation results of various machine models, the optimal machine tool solution can be selected during the offline stage, or the workpiece clamping posture, workpiece coordinate system zero point and tool parameters can be automatically adjusted for specific machine models to meet the machining stroke and accuracy requirements.

[0125] 4. Generate a dedicated NC program for the controller.

[0126] After offline optimization is completed, the axis trajectories and offset information calculated by the unified model are converted into corresponding dedicated NC programs based on the coordinate conventions and instruction syntax of each controller. These programs include G-code, plane / RTCP instructions, coordinate system settings, etc., enabling one-click program generation and distribution from the unified digital twin model to different actual machine tools.

[0127] This embodiment demonstrates that the unified kinematic transformation method of the present invention can perform consistent process evaluation and parameter optimization for multiple five-axis machine tools in an offline environment, reducing the cost of multi-machine adaptation and maintenance.

[0128] Example 4

[0129] A digital twin five-axis machine tool kinematics transformation system includes:

[0130] The five-axis machine tool controller interface module is used to acquire axis parameters from the five-axis machine tool controller, including three linear axes and two rotary axes. Any two rotary axes can be selected from the table-side rotary axis and the spindle-side rotary axis. The acquired axis parameters include axis type, positive axis direction, zero point position, tool center point control RTCP parameters, workpiece coordinate system parameters G54 to G59, and tool compensation parameters.

[0131] The five-axis motion unified model configuration module is used to construct a unified five-axis parameter set based on the collected axis parameters. The unified five-axis parameter set includes the axis type, axis reference point, axis unit direction vector, and axis attitude deviation vector for each axis. The axis types include linear axes and rotation axes.

[0132] The Unified Kinematic Transformation Module is used to construct a hierarchical homogeneous transformation chain in the machine tool base coordinate system based on a unified five-axis parameter set. It realizes the forward kinematic transformation from the machine coordinate system to the workpiece coordinate system to calculate the position of the tool center point in the workpiece coordinate system and the tool axis direction vector. It is also used to solve the corresponding axis position vector in reverse from the tool position command in the workpiece coordinate system.

[0133] The digital twin simulation and optimization module is used for tool position simulation, stroke interference verification, tool center point control RTCP behavior verification, and process parameter optimization based on the unified kinematic transformation module.

[0134] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0135] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-including system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device.

[0136] More specific examples of computer-readable media (a non-exhaustive list) include: electrical connections (electronic devices) having one or more wires, portable computer disk drives (magnetic devices), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Furthermore, computer-readable media can even be paper or other suitable media on which the program can be printed, because the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in computer memory.

[0137] It is worth noting that all contents not described in detail in this invention are existing technologies and are well known to those skilled in the art.

[0138] Therefore, this invention adopts the above-mentioned digital twin five-axis machine tool kinematic transformation method, system, equipment and medium. By constructing a unified parameter set and hierarchical transformation chain, it solves the problems of poor model universality and inconsistent virtual-real mapping caused by structural diversity and control system heterogeneity in five-axis machine tool digital twins. It realizes stable and reversible high-precision coordinate transformation between the workpiece coordinate system and the machine coordinate system, and improves the cross-platform reuse capability and engineering deployment efficiency of the digital twin model.

[0139] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for kinematic transformation of a digital twin five-axis machine tool, characterized in that, Includes the following steps: Step S1: Collect axis parameters from the five-axis machine tool controller, including three linear axes and two rotary axes; Two rotary axes can be selected from the table-side rotary axis and the spindle-side rotary axis. The collected axis parameters include axis type, positive axis direction, zero point position, tool center point control RTCP parameters, workpiece coordinate system parameters G54 to G59, and tool compensation parameters. Step S2: Based on the collected axis parameters, construct a unified five-axis parameter set; The unified five-axis parameter set includes the axis type, axis reference point, axis unit direction vector, and axis attitude deviation vector for each axis, where the axis type includes linear axes and rotation axes; For the rotary axis, the position of the tool center point is measured by calibration test, and the rotation center and axis of the rotary axis are identified by least squares method to form a unified five-axis parameter set; Step S3: Based on the unified five-axis parameter set, construct a hierarchical homogeneous transformation chain in the machine tool base coordinate system to realize the positive kinematic transformation from the machine coordinate system to the workpiece coordinate system, and calculate the position of the tool center point in the workpiece coordinate system and the tool axis direction vector. For the linear axis, its homogeneous transformation matrix is... for: ； in, Indicates the axis position. Represents the unit direction vector of the axis. express The identity matrix, Indicates transpose. It is an index variable used to iterate through each axis in the kinematic chain; For the rotation axis, its homogeneous transformation matrix for: ； ； in, Indicates the reference point for the axis; Step S4: Based on the unified five-axis parameter set and homogeneous transformation chain, solve the corresponding axis position vector from the tool position command in the workpiece coordinate system in reverse, and map the axis position vector back to the controller coordinate to generate the axis command that can be issued. Step S41: Based on the machine structure, including dual rotary tables, dual swing heads, or a combination of head tables and the rotation axis numbers in the unified five-axis parameter set, construct the tool axis direction constraints, and solve the rotation axis angles using analytical geometry or numerical iteration methods. Step S42: Given a fixed rotation axis angle, solve for the position of the linear axis based on the tool center point position constraint. Step S43: Map the axis position vector under the unified model back to the controller coordinates, superimpose the workpiece coordinate offset and tool compensation, and generate the final axis command.

2. The kinematic transformation method for a digital twin five-axis machine tool according to claim 1, characterized in that, In step S4, the tool position command includes the tool center point position and the tool axis direction.

3. A digital twin five-axis machine tool kinematics transformation system, characterized in that, A method for performing kinematic transformation of a digital twin five-axis machine tool as described in any one of claims 1-2, comprising: The five-axis machine tool controller interface module is used to acquire axis parameters from the five-axis machine tool controller, including three linear axes and two rotary axes. Any two rotary axes can be selected from the table-side rotary axis and the spindle-side rotary axis. The acquired axis parameters include axis type, positive axis direction, zero point position, tool center point control RTCP parameters, workpiece coordinate system parameters G54 to G59, and tool compensation parameters. The five-axis motion unified model configuration module is used to construct a unified five-axis parameter set based on the collected axis parameters. The unified five-axis parameter set includes the axis type, axis reference point, axis unit direction vector, and axis attitude deviation vector for each axis. The axis types include linear axes and rotation axes. The Unified Kinematic Transformation Module is used to construct a hierarchical homogeneous transformation chain in the machine tool base coordinate system based on a unified five-axis parameter set. It realizes the forward kinematic transformation from the machine coordinate system to the workpiece coordinate system to calculate the position of the tool center point in the workpiece coordinate system and the tool axis direction vector. It is also used to solve the corresponding axis position vector in reverse from the tool position command in the workpiece coordinate system. The digital twin simulation and optimization module is used for tool position simulation, stroke interference verification, tool center point control RTCP behavior verification, and process parameter optimization based on the unified kinematic transformation module.

4. A computer device, comprising: Memory and processor; The memory stores a computer program, characterized in that when the processor executes the computer program, it implements the steps of the digital twin five-axis machine tool kinematic transformation method as described in any one of claims 1-2.

5. A computer-readable storage medium having a computer program stored thereon, characterized in that, When a computer program is executed by a processor, it implements the steps of the digital twin five-axis machine tool kinematic transformation method as described in any one of claims 1-2.

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