Longitudinal-torsional ultrasonic milling surface topography modeling and surface roughness prediction method and system based on Z-MAP method, terminal and storage medium

Abstract

The invention discloses a Z-MAP method-based longitudinal-torsional ultrasonic milling surface topography modeling and surface roughness prediction method and system, a terminal and a storage medium, and the method comprises the steps: determining a machining method, geometric features of a cutter, cutting parameters and ultrasonic vibration parameters, and measuring the axial run-out and radial run-out of the cutter in the machining process; discretizing a workpiece, a cutter and time to obtain a cutter movement track of each stage; dividing the workpiece into u parts and v parts along an x axis and a y axis; comparing the Z coordinate at each moment with the Z coordinate of the workpiece point, if the former is smaller than the latter, indicating that the cutting edge infinitesimal at the current moment has a cutting effect on the workpiece, and updating the Z coordinate of the workpiece, and if the former is not smaller than the latter, indicating that the cutting edge infinitesimal at the current moment has no interference on the workpiece, and keeping the Z coordinate of the workpiece unchanged; and the whole simulation machining process is completed. According to the method, the surface topography and the surface roughness of different machining processes are predicted.

Description

Technical Field

[0001] The present invention relates to the field of mechanical processing technology, and in particular to a method, system, terminal and computer-readable storage medium for longitudinal-torsional ultrasonic milling surface topography modeling and surface roughness prediction based on a Z-MAP method. Background Art

[0002] Surface topography and surface roughness are important indicators for describing workpiece quality in milling, and have a significant impact on the surface integrity and service life of the workpiece.

[0003] The ultrasonic milling system consists of an ultrasonic transmitter, a transducer, a horn, a controller and related processing tools. In recent years, ultrasonic milling has become an important processing method that can adapt to the processing of difficult-to-process materials and can effectively reduce the surface roughness and surface defects of the workpiece.

[0004] Longitudinal-torsional ultrasonic machining is a special machining method that introduces longitudinal vibration along the tool axis and torsional vibration along the tool arc in traditional tool milling. The tool trajectory in longitudinal-torsional ultrasonic machining is complex, and the prediction of surface morphology and surface roughness becomes more difficult.

[0005] Therefore, the existing technology still needs to be improved and developed. Summary of the Invention

[0006] The main purpose of the present invention is to provide a method, system, terminal and computer-readable storage medium for longitudinal-torsional ultrasonic milling surface morphology modeling and surface roughness prediction based on the Z-MAP method, aiming to solve the problem in the prior art that the prediction of surface morphology and surface roughness is increased due to the complexity of the tool trajectory in longitudinal-torsional ultrasonic machining.

[0007] To achieve the above objectives, the present invention provides a method for longitudinal-torsional ultrasonic milling surface topography modeling and surface roughness prediction based on the Z-MAP method, the method comprising the following steps: Determine machining methods, tool geometry, cutting parameters, and ultrasonic vibration parameters, and measure tool axial and radial runout during machining; Discretize the workpiece, tool and time to obtain the tool motion trajectory at each stage; Place the workpiece along x Axis and y Axis is divided into u Share v In the unit time element, the sweep arc length of the tool discrete point is controlled to sweep only one discrete unit of the workpiece; The Z coordinate at each moment is compared with the Z coordinate of the workpiece point. If the former is smaller than the latter, it means that the cutting edge element at the current moment has a cutting effect on the workpiece, and the Z coordinate of the workpiece is updated. If the former is not smaller than the latter, it means that the cutting edge element at the current moment has no interference with the workpiece, and the Z coordinate of the workpiece remains unchanged until the entire simulated machining process is completed to achieve the prediction of surface morphology and surface roughness.

[0008] Optionally, the longitudinal torsional ultrasonic milling surface topography modeling and surface roughness prediction method based on the Z-MAP method further comprises: Considering the spindle coordinate system as the tool coordinate system, the coordinate of any point on the cutting edge in the spindle coordinate system is P a = [ x a , y a , z a ] T Expressed as: ; (1) in, r for P a The actual rotation radius of the point, n is the spindle speed, t For the current moment, z is the number of teeth of the tool, i is the sequence of the current tooth, T Indicates transpose.

[0009] Optionally, the longitudinal torsional ultrasonic milling surface topography modeling and surface roughness prediction method based on the Z-MAP method further comprises: When ultrasound is added, the coordinates of any point on the blade in the spindle coordinate system are Pa= [ x a1 , y a1 ，z a1 ] T Expressed as: ; (2) in, A f is the amplitude of the tool torsional vibration, A z is the amplitude of the tool's longitudinal vibration, fis the vibration frequency of ultrasonic vibration; The transformation matrix from the spindle coordinate system to the workpiece coordinate system is expressed as: ; (3) in, f z Indicates the feed per tooth, f s Indicates the feed amount each time in the intermittent feed direction. j Indicates the current feed number in the intermittent feed direction; The trajectory of the cutting edge points in ultrasonic vibration-assisted milling is finally expressed as: ; (4).

[0010] Optionally, the longitudinal torsional ultrasonic milling surface topography modeling and surface roughness prediction method based on the Z-MAP method further comprises: Divide the tool into several segments along the Z-axis direction and divide the tool into several segments along the arc direction of the tool; Deviation between tool axis and machine axis Deviation from the origin of the two coordinate systems ρ Describe tool runout, determine the spindle coordinate system and tool coordinate system, and transform the tool coordinate system to the spindle coordinate system through a matrix transformation: , ; (5) in, ρ x and ρ y Respectively represent the tool center x Axis and y Deviation between the axis and the spindle axis, Indicates the position change of the coordinate origin from the tool coordinate system to the spindle coordinate system. Indicates the angular change between the tool coordinate system and the spindle coordinate system.

[0011] Optionally, the longitudinal torsional ultrasonic milling surface topography modeling and surface roughness prediction method based on the Z-MAP method further comprises: Place the workpiece along x Axis and y Axis is divided into u Share v share; The motion of the cutting edge from the initial state to the first time element: ; (6) ; (7) in, Represents the motion transformation matrix from the initial state to the first time element cutting edge, Indicates unit time, and They represent the initial coordinate position in the workpiece coordinate system and the coordinate position after a time element respectively; The position reached after the time difference with the initial position is obtained by formula (6), and the trajectory change within any time difference is obtained by formula (7).

[0012] Optionally, in the longitudinal-torsional ultrasonic milling surface topography modeling and surface roughness prediction method based on the Z-MAP method, in the process of discretizing the workpiece, tool and time, the discretization condition is: ; (8) in, l x Indicates that the workpiece is x The length on the axis, l y Indicates the length of the workpiece on the y-axis, Indicates the tool trajectory within a time element x The projection on the axis, Indicates the tool trajectory within a time element y Projection on the axis.

[0013] Optionally, in the longitudinal-torsional ultrasonic milling surface topography modeling and surface roughness prediction method based on the Z-MAP method, the surface roughness calculation formula is: ; (9) in, S a Indicates surface roughness, h Indicates the unit height of a workpiece. represents the average height of all cells, m Indicates the number of all units.

[0014] In addition, to achieve the above-mentioned purpose, the present invention also provides a longitudinal torsional ultrasonic milling surface topography modeling and surface roughness prediction system based on the Z-MAP method, wherein the longitudinal torsional ultrasonic milling surface topography modeling and surface roughness prediction system based on the Z-MAP method comprises: An information confirmation module is used to determine the machining method, tool geometry, cutting parameters, and ultrasonic vibration parameters, and to measure the tool axial and radial runout during machining; Discretization module, used to discretize the workpiece, tool and time to obtain the tool motion trajectory at each stage; Workpiece division module is used to divide the workpiece along x Axis and y Axis is divided into u Share v In the unit time element, the sweep arc length of the tool discrete point is controlled to sweep only one discrete unit of the workpiece; The surface prediction module is used to compare the Z coordinate at each moment with the Z coordinate of the workpiece point. If the former is smaller than the latter, it means that the cutting edge element at the current moment has a cutting effect on the workpiece, and the Z coordinate of the workpiece is updated. If the former is not smaller than the latter, it means that the cutting edge element at the current moment has no interference with the workpiece, and the Z coordinate of the workpiece remains unchanged until the entire simulated processing process is completed to realize the prediction of surface morphology and surface roughness.

[0015] In addition, to achieve the above-mentioned purpose, the present invention also provides a terminal, wherein the terminal includes: a memory, a processor, and a longitudinal torsional ultrasonic milling surface morphology modeling and surface roughness prediction program based on the Z-MAP method stored in the memory and runnable on the processor. When the longitudinal torsional ultrasonic milling surface morphology modeling and surface roughness prediction program based on the Z-MAP method is executed by the processor, the steps of the longitudinal torsional ultrasonic milling surface morphology modeling and surface roughness prediction method based on the Z-MAP method as described above are implemented.

[0016] In addition, to achieve the above-mentioned purpose, the present invention also provides a computer-readable storage medium, wherein the computer-readable storage medium stores a longitudinal torsional ultrasonic milling surface morphology modeling and surface roughness prediction program based on the Z-MAP method, and when the longitudinal torsional ultrasonic milling surface morphology modeling and surface roughness prediction program based on the Z-MAP method is executed by the processor, the steps of the longitudinal torsional ultrasonic milling surface morphology modeling and surface roughness prediction method based on the Z-MAP method as described above are implemented.

[0017] In the present invention, the machining method, tool geometry, cutting parameters and ultrasonic vibration parameters are determined, and the axial runout and radial runout of the tool during the machining process are measured; the workpiece, tool and time are discretized to obtain the tool motion trajectory at each stage; the workpiece is moved along the x Axis and y Axis is divided into u Share vIn the unit time unit, the sweep arc length of the tool discrete point is controlled to sweep only one discrete unit of the workpiece; the Z coordinate at each moment is compared with the Z coordinate of the workpiece point. If the former is less than the latter, it means that the cutting edge element at the current moment has a cutting effect on the workpiece, and the Z coordinate of the workpiece is updated. If the former is not less than the latter, it means that the cutting edge element at the current moment has no interference with the workpiece, and the Z coordinate of the workpiece remains unchanged until the entire simulation process is completed to achieve the prediction of surface morphology and surface roughness. The present invention can more accurately predict the motion trajectory of the tool, retains sufficient scalability, and by changing the tool transformation matrix, it can achieve the prediction of surface morphology and surface roughness of different processing processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a flow chart of a preferred embodiment of the method for longitudinal torsional ultrasonic milling surface topography modeling and surface roughness prediction based on the Z-MAP method of the present invention; Figure 2 It is a flow chart of surface topography prediction for different machining processes in a preferred embodiment of the longitudinal torsional ultrasonic milling surface topography modeling and surface roughness prediction method based on the Z-MAP method of the present invention; Figure 3 It is a schematic diagram of the machining process in a preferred embodiment of the longitudinal-torsional ultrasonic milling surface topography modeling and surface roughness prediction method based on the Z-MAP method of the present invention; Figure 4 This is a schematic diagram of a preferred embodiment of the longitudinal torsional ultrasonic milling surface morphology modeling and surface roughness prediction method based on the Z-MAP method of the present invention, in which the tool is divided into several segments along the Z-axis direction and the tool is divided into several segments along the arc direction of the tool.

[0019] Figure 5 Schematic diagram of tool runout in a preferred embodiment of the longitudinal-torsional ultrasonic milling surface topography modeling and surface roughness prediction method based on the Z-MAP method of the present invention; Figure 6 This is a schematic diagram of dividing a workpiece into u parts and v parts along the x-axis and y-axis in a preferred embodiment of the longitudinal-torsional ultrasonic milling surface topography modeling and surface roughness prediction method based on the Z-MAP method of the present invention; Figure 7 It is a structural diagram of a preferred embodiment of the longitudinal-torsional ultrasonic milling surface topography modeling and surface roughness prediction system based on the Z-MAP method of the present invention; Figure 8 FIG. 4 is a structural diagram of a preferred embodiment of the terminal of the present invention. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the present invention more clear and distinct, the present invention is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0021] The present invention provides a method for longitudinal-torsional ultrasonic milling surface morphology modeling and surface roughness prediction based on the Z-MAP method. This method is based on Z-MAP surface reconstruction technology. After the tool geometry characterization modeling, tool runout error and processing process parameters are collected, it can realize tool motion trajectory and simulation, and realize surface morphology modeling under different cutting parameters and ultrasonic vibration parameters.

[0022] The preferred embodiment of the present invention is a method for modeling the surface topography and predicting the surface roughness of longitudinal torsional ultrasonic milling based on the Z-MAP method, as shown in FIG. Figure 1 and Figure 2 As shown, the longitudinal torsional ultrasonic milling surface topography modeling and surface roughness prediction method based on the Z-MAP method includes the following steps: Step S10: Determine the machining method, tool geometric characteristics, cutting parameters, and ultrasonic vibration parameters, and measure the tool axial runout and radial runout during the machining process.

[0023] Step S20: discretize the workpiece, tool, and time to obtain the tool motion trajectory at each stage; Step S30: Move the workpiece along x Axis and y Axis is divided into u Share v In the unit time element, the sweep arc length of the tool discrete point is controlled to sweep only one discrete unit of the workpiece; Step S40, compare the Z coordinate at each moment with the Z coordinate of the workpiece point. If the former is smaller than the latter, it means that the cutting edge element at the current moment has a cutting effect on the workpiece, and the Z coordinate of the workpiece is updated. If the former is not smaller than the latter, it means that the cutting edge element at the current moment has no interference with the workpiece, and the Z coordinate of the workpiece remains unchanged until the entire simulated processing process is completed to achieve the prediction of surface morphology and surface roughness.

[0024] Specifically, the motion trajectory of the cutting edge point during milling is very complex. In addition to the influence of spindle speed and feed rate, the existence of tool runout will also have an impact, and the trajectory will become more complicated after adding ultrasonic vibration. In this case, the surface morphology and surface roughness obtained by the model prediction will have a large deviation compared with the relevant data measured in the experiment, reducing the accuracy of the model. The present invention will take all the above factors into consideration at the same time to ensure the accuracy of the model. The processing process is as follows Figure 3As shown in (a) in the figure, by establishing different coordinate systems and matrix transformations between different coordinate systems, the tool path description can accurately represent the motion state of the cutting edge point under different circumstances. Figure 3 As shown in (b), the workpiece coordinate system / global coordinate system O w X w Y w Z w : Take the front point of the workpiece as the coordinate origin, the normal direction of the workpiece surface as the Z axis, and the tool feed direction as the X axis to establish a rectangular coordinate system, where O w Indicates the origin of the coordinate system, X w Indicates the X axis of the coordinate system, Y w Represents the Y axis of the coordinate system, Z w Indicates the Z axis of the coordinate system. A X A Y A Z A Establish a rectangular coordinate system with the spindle as the origin, the axis as the Z axis, and the feed direction as the X axis. A Indicates the origin of the coordinate system, X A Indicates the X axis of the coordinate system, Y A Represents the Y axis of the coordinate system, Z A Indicates the Z axis of the coordinate system. Tool coordinate system O T X T Y T Z T : Establish a rectangular coordinate system with the axis of the tool end face as the origin, the tool axis direction as the Z axis, and the normal direction of the cutting edge with a phase angle of 0 as the X axis, where O T Indicates the origin of the coordinate system, X T Indicates the X axis of the coordinate system, Y T Represents the Y axis of the coordinate system, Z T Indicates the Z axis of the coordinate system.

[0025] Without considering tool runout and ultrasonic, the spindle coordinate system can be regarded as the tool coordinate system. At this time, the coordinate of any point on the blade in the spindle coordinate system is P a = [ x a , y a , z a ] T Expressed as: ; (1) in, r for Pa The actual rotation radius of the point, n is the spindle speed, t For the current moment, z is the number of teeth of the tool, i is the sequence of the current tooth, T Indicates transpose.

[0026] When ultrasonic wave is added, the motion trajectory of the tool in the spindle coordinate system is expressed as formula (2). At this time, the coordinate of any point on the blade in the spindle coordinate system is Pa= [ x a1 , y a1 ，z a1 ] T Expressed as: ; (2) in, A f is the amplitude of the tool torsional vibration, A z is the amplitude of the tool's longitudinal vibration, f is the vibration frequency of ultrasonic vibration.

[0027] The transformation matrix from the spindle coordinate system to the workpiece coordinate system is expressed as: ; (3) in, f z Indicates the feed per tooth, f s Indicates the feed amount each time in the intermittent feed direction. j Indicates the current feed number in the intermittent feed direction.

[0028] The trajectory of the cutting edge points in ultrasonic vibration-assisted milling is finally expressed as: ; (4) Divide the tool into several segments along the Z axis direction and the tool into several segments along the arc direction, such as Figure 4 shown.

[0029] Deviation between tool axis and machine axis Deviation from the origin of the two coordinate systems ρ To describe tool runout, after determining the spindle coordinate system and tool coordinate system, it is only necessary to convert the tool coordinate system to the spindle coordinate system through a matrix transformation. Figure 5 As shown: , ; (5) in, ρ x and ρ y Respectively represent the tool center x Axis and y Deviation between the axis and the spindle axis, Indicates the position change of the coordinate origin from the tool coordinate system to the spindle coordinate system. Indicates the angular change between the tool coordinate system and the spindle coordinate system.

[0030] Place the workpiece along x Axis and y Axis is divided into u Share v copies, such as Figure 6 As shown in the figure, in order to ensure the smooth completion of the morphology reconstruction, it is necessary to ensure that the sweep arc length of the discrete points of the tool in the unit time element only sweeps to one time unit, so that all discrete units of the workpiece can be searched.

[0031] The motion of the cutting edge from the initial state to the first time element: ; (6) ; (7) in, Represents the motion transformation matrix from the initial state to the first time element cutting edge, Indicates unit time, and They represent the initial coordinate position in the workpiece coordinate system and the coordinate position after a time element respectively.

[0032] Based on the position reached after the time difference from the initial position obtained by formula (6), the trajectory change within any time difference is obtained by formula (7).

[0033] Will i The Z coordinate of the workpiece point is compared with the Z coordinate of the workpiece point. If the former is smaller than the latter, it means that the cutting edge element at the current moment has a cutting effect on the workpiece, and the Z coordinate of the workpiece is updated; otherwise, it means that the cutting edge element at the current moment has no interference with the workpiece, and the Z coordinate of the workpiece remains unchanged. This method can be used to obtain the complete surface morphology of the workpiece.

[0034] The whole process is as follows Figure 2 As shown below: In the first step, the specific parameters of spindle speed, feed per tooth, cutting depth, ultrasonic vibration frequency and ultrasonic vibration amplitude are input; The second step is to discretize the workpiece, tool and time; The third step is to establish each coordinate system, measure the tool runout, and calculate the transformation matrix between each coordinate system; The fourth step is to obtain the coordinates of the cutting edge trajectory point at the current moment in the workpiece coordinate system and compare them with the workpiece unit coordinates corresponding to the current coordinates. If the trajectory point height is less than the workpiece unit height, it means that the cutting edge element at the current moment has a cutting effect on the workpiece, and the workpiece unit height is updated to the trajectory point height. If the trajectory point height is greater than the workpiece unit height, it means that the cutting edge at the current moment has no interference with the workpiece, and the workpiece unit height remains unchanged. Step 5: Repeat step 4 until the loop end condition is met.

[0035] Figure 2 middle, i Indicates the current time, Z w Indicates the current workpiece unit height, Z T Indicates the current tool cutting edge height, t max Indicates the set processing time, l Indicates the tool unit number, l max Represents the discrete number of tools, c Indicates the current number of teeth.

[0036] In addition, in the process of discretizing the workpiece, tool and time, the discretization conditions are: ; (8) in, l x Indicates that the workpiece is x The length on the axis, l y Indicates the length of the workpiece on the y-axis, Indicates the tool trajectory within a time element x The projection on the axis, Indicates the tool trajectory within a time element y Projection on the axis.

[0037] In addition, the calculation formula of the surface roughness is: ; (9) in, S a Indicates surface roughness, h Indicates the unit height of a workpiece. represents the average height of all cells, m Indicates the number of all units.

[0038] The present invention solves the problem that the tool motion trajectory is complex and difficult to characterize during the ultrasonic vibration process, and can more accurately predict the tool motion trajectory; it fully considers the secondary cutting effect caused by the rotation of the ultrasonic tool, and provides a more accurate method for comparing the contact between the tool sweep trajectory and the workpiece unit; the present invention retains sufficient scalability, and by changing the tool transformation matrix, it can realize the prediction of the surface morphology of different processing processes.

[0039] Further, if Figure 7 As shown, based on the above-mentioned longitudinal torsional ultrasonic milling surface topography modeling and surface roughness prediction method based on the Z-MAP method, the present invention also provides a longitudinal torsional ultrasonic milling surface topography modeling and surface roughness prediction system based on the Z-MAP method, wherein the longitudinal torsional ultrasonic milling surface topography modeling and surface roughness prediction system based on the Z-MAP method includes: An information confirmation module 51 is used to determine the machining method, tool geometry, cutting parameters, and ultrasonic vibration parameters, and to measure the tool axial runout and radial runout during machining; a discretization module 52 for discretizing the workpiece, the tool, and time to obtain the tool motion trajectory at each stage; The workpiece dividing module 53 is used to divide the workpiece along x Axis and y Axis is divided into u Share v In the unit time element, the sweep arc length of the tool discrete point is controlled to sweep only one discrete unit of the workpiece; The surface prediction module 54 is used to compare the Z coordinate at each moment with the Z coordinate of the workpiece point. If the former is smaller than the latter, it means that the cutting edge element at the current moment has a cutting effect on the workpiece, and the Z coordinate of the workpiece is updated. If the former is not smaller than the latter, it means that the cutting edge element at the current moment has no interference with the workpiece, and the Z coordinate of the workpiece remains unchanged until the entire simulated processing process is completed to realize the prediction of surface morphology and surface roughness.

[0040] Further, if Figure 8 As shown, based on the above-mentioned longitudinal torsional ultrasonic milling surface morphology modeling and surface roughness prediction method and system based on the Z-MAP method, the present invention also provides a terminal, which includes a processor 10, a memory 20 and a display 30. Figure 8 Only some of the components of the terminal are shown, but it should be understood that implementation of all of the shown components is not required, and more or fewer components may be implemented instead.

[0041] In some embodiments, the memory 20 may be an internal storage unit of the terminal, such as a hard drive or memory of the terminal. In other embodiments, the memory 20 may also be an external storage device of the terminal, such as a plug-in hard drive, a Smart Media Card (SMC), a Secure Digital (SD) card, a flash card, etc. equipped with the terminal. Furthermore, the memory 20 may include both the internal storage unit of the terminal and an external storage device. The memory 20 is used to store application software installed in the terminal and various types of data, such as program code of the installed terminal. The memory 20 may also be used to temporarily store data that has been output or is about to be output. In one embodiment, the memory 20 stores a program 40 for longitudinal-torsional ultrasonic milling surface topography modeling and surface roughness prediction based on the Z-MAP method. The program 40 for longitudinal-torsional ultrasonic milling surface topography modeling and surface roughness prediction based on the Z-MAP method can be executed by the processor 10, thereby implementing the longitudinal-torsional ultrasonic milling surface topography modeling and surface roughness prediction method based on the Z-MAP method described in this application.

[0042] In some embodiments, the processor 10 can be a central processing unit (CPU), a microprocessor or other data processing chip, used to run the program code or process data stored in the memory 20, such as executing the longitudinal torsional ultrasonic milling surface morphology modeling and surface roughness prediction method based on the Z-MAP method.

[0043] In some embodiments, the display 30 may be an LED display, a liquid crystal display, a touch-sensitive liquid crystal display, or an OLED (Organic Light-Emitting Diode) touchscreen. The display 30 is used to display information on the terminal and to display a visual user interface. The processor 10, memory 20, and display 30 of the terminal communicate with each other via a system bus.

[0044] In one embodiment, when the processor 10 executes the longitudinal torsional ultrasonic milling surface morphology modeling and surface roughness prediction program 40 based on the Z-MAP method in the memory 20, the steps of the longitudinal torsional ultrasonic milling surface morphology modeling and surface roughness prediction method based on the Z-MAP method are implemented.

[0045] The present invention also provides a computer-readable storage medium, wherein the computer-readable storage medium stores a longitudinal torsional ultrasonic milling surface morphology modeling and surface roughness prediction program based on the Z-MAP method, and when the longitudinal torsional ultrasonic milling surface morphology modeling and surface roughness prediction program based on the Z-MAP method is executed by a processor, the steps of the longitudinal torsional ultrasonic milling surface morphology modeling and surface roughness prediction method based on the Z-MAP method as described above are implemented.

[0046] In summary, the present invention provides a method, system, terminal and computer-readable storage medium for surface topography modeling and surface roughness prediction of longitudinal torsional ultrasonic milling based on the Z-MAP method. The method comprises: determining the machining method, tool geometric characteristics, cutting parameters and ultrasonic vibration parameters, and measuring the axial runout and radial runout of the tool during the machining process; discretizing the workpiece, tool and time to obtain the tool motion trajectory at each stage; moving the workpiece along the x Axis and y Axis is divided into u Share v In the unit time unit, the sweep arc length of the tool discrete point is controlled to sweep only one discrete unit of the workpiece; the Z coordinate at each moment is compared with the Z coordinate of the workpiece point. If the former is less than the latter, it means that the cutting edge element at the current moment has a cutting effect on the workpiece, and the Z coordinate of the workpiece is updated. If the former is not less than the latter, it means that the cutting edge element at the current moment has no interference with the workpiece, and the Z coordinate of the workpiece remains unchanged until the entire simulation process is completed to achieve the prediction of surface morphology and surface roughness. The present invention can more accurately predict the motion trajectory of the tool, retains sufficient scalability, and by changing the tool transformation matrix, it can achieve the prediction of surface morphology and surface roughness of different processing processes.

[0047] It should be noted that, in this document, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or terminal comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or terminal. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or terminal comprising the element.

[0048] Of course, those skilled in the art will appreciate that all or part of the processes in the above-described method embodiments can be implemented by instructing related hardware (such as a processor, controller, etc.) through a computer program. The program can be stored in a computer-readable storage medium that can be read by a computer. When executed, the program can include the processes in the above-described method embodiments. The computer-readable storage medium can be a memory, a magnetic disk, an optical disk, etc.

[0049] It should be understood that the application of the present invention is not limited to the above examples. For those skilled in the art, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A method for surface topography modeling and surface roughness prediction of longitudinal torsional ultrasonic milling based on the Z-MAP method, characterized in that: The longitudinal torsional ultrasonic milling surface topography modeling and surface roughness prediction method based on the Z-MAP method includes: Determine machining methods, tool geometry, cutting parameters, and ultrasonic vibration parameters, and measure tool axial and radial runout during machining; Discretize the workpiece, tool and time to obtain the tool motion trajectory at each stage; Place the workpiece along x Axis and y Axis is divided into u Share v In the unit time element, the sweep arc length of the tool discrete point is controlled to sweep only one discrete unit of the workpiece; The Z coordinate at each moment is compared with the Z coordinate of the workpiece point. If the former is smaller than the latter, it means that the cutting edge element at the current moment has a cutting effect on the workpiece, and the Z coordinate of the workpiece is updated. If the former is not smaller than the latter, it means that the cutting edge element at the current moment has no interference with the workpiece, and the Z coordinate of the workpiece remains unchanged until the entire simulated machining process is completed to achieve the prediction of surface morphology and surface roughness.

2. The method for longitudinal torsional ultrasonic milling surface topography modeling and surface roughness prediction based on the Z-MAP method according to claim 1 is characterized in that: The longitudinal torsional ultrasonic milling surface topography modeling and surface roughness prediction method based on the Z-MAP method also includes: Considering the spindle coordinate system as the tool coordinate system, the coordinate of any point on the cutting edge in the spindle coordinate system is P a = [ x a , y a , z a ] T Expressed as: ；（1） in, r for P a The actual rotation radius of the point, n is the spindle speed, t For the current moment, z is the number of teeth of the tool, i is the sequence of the current tooth, T Indicates transpose.

3. The method for longitudinal torsional ultrasonic milling surface topography modeling and surface roughness prediction based on the Z-MAP method according to claim 2 is characterized in that: The longitudinal torsional ultrasonic milling surface topography modeling and surface roughness prediction method based on the Z-MAP method also includes: When ultrasound is added, the coordinates of any point on the blade in the spindle coordinate system are Pa= [ x a1 , y a1 ，z a1 ] T Expressed as: ；（2） in, A f is the amplitude of the tool torsional vibration, A z is the amplitude of the tool's longitudinal vibration, f is the vibration frequency of ultrasonic vibration; The transformation matrix from the spindle coordinate system to the workpiece coordinate system is expressed as: ；（3） in, f z Indicates the feed per tooth, f s Indicates the feed amount each time in the intermittent feed direction. j Indicates the current feed number in the intermittent feed direction; The trajectory of the cutting edge points in ultrasonic vibration-assisted milling is finally expressed as: ；（4）。 4. The method for longitudinal torsional ultrasonic milling surface topography modeling and surface roughness prediction based on the Z-MAP method according to claim 3 is characterized in that: The longitudinal torsional ultrasonic milling surface topography modeling and surface roughness prediction method based on the Z-MAP method also includes: Divide the tool into several segments along the Z-axis direction and divide the tool into several segments along the arc direction of the tool; Deviation between tool axis and machine axis Deviation from the origin of the two coordinate systems ρ Describe tool runout, determine the spindle coordinate system and tool coordinate system, and transform the tool coordinate system to the spindle coordinate system through a matrix transformation: ， ；（5） in, ρ x and ρ y Respectively represent the tool center x Axis and y Deviation between the axis and the spindle axis, Indicates the position change of the coordinate origin from the tool coordinate system to the spindle coordinate system. Indicates the angular change between the tool coordinate system and the spindle coordinate system.

5. The method for longitudinal torsional ultrasonic milling surface topography modeling and surface roughness prediction based on the Z-MAP method according to claim 4 is characterized in that: The longitudinal torsional ultrasonic milling surface topography modeling and surface roughness prediction method based on the Z-MAP method also includes: Place the workpiece along x Axis and y Axis is divided into u Share v share; The motion of the cutting edge from the initial state to the first time element: ；（6） ；（7） in, Represents the motion transformation matrix from the initial state to the first time element cutting edge, Indicates unit time, and They represent the initial coordinate position in the workpiece coordinate system and the coordinate position after a time element respectively; The position reached after the time difference with the initial position is obtained by formula (6), and the trajectory change within any time difference is obtained by formula (7).

6. The method for longitudinal torsional ultrasonic milling surface topography modeling and surface roughness prediction based on the Z-MAP method according to claim 1, characterized in that: In the process of discretizing the workpiece, tool and time, the discretization conditions are: ；（8） in, l x Indicates that the workpiece is x The length on the axis, l y Indicates the length of the workpiece on the y-axis, Indicates the tool trajectory within a time element x The projection on the axis, Indicates the tool trajectory within a time element y Projection on the axis.

7. The method for longitudinal torsional ultrasonic milling surface topography modeling and surface roughness prediction based on the Z-MAP method according to claim 1, characterized in that: The calculation formula of the surface roughness is: ； （9） in, S a Indicates surface roughness, h Indicates the unit height of a workpiece. represents the average height of all cells, m Indicates the number of all units.

8. A surface topography modeling and surface roughness prediction system for longitudinal torsional ultrasonic milling based on the Z-MAP method, characterized in that: The longitudinal torsional ultrasonic milling surface topography modeling and surface roughness prediction system based on the Z-MAP method includes: An information confirmation module is used to determine the machining method, tool geometry, cutting parameters, and ultrasonic vibration parameters, and to measure the tool axial runout and radial runout during machining; Discretization module, used to discretize the workpiece, tool and time to obtain the tool motion trajectory at each stage; Workpiece division module is used to divide the workpiece along x Axis and y Axis is divided into u Share v In the unit time element, the sweep arc length of the tool discrete point is controlled to sweep only one discrete unit of the workpiece; The surface prediction module is used to compare the Z coordinate at each moment with the Z coordinate of the workpiece point. If the former is smaller than the latter, it means that the cutting edge element at the current moment has a cutting effect on the workpiece, and the Z coordinate of the workpiece is updated. If the former is not smaller than the latter, it means that the cutting edge element at the current moment has no interference with the workpiece, and the Z coordinate of the workpiece remains unchanged until the entire simulated processing process is completed to realize the prediction of surface morphology and surface roughness.

9. A terminal, characterized in that: The terminal includes: a memory, a processor, and a longitudinal torsional ultrasonic milling surface morphology modeling and surface roughness prediction program based on the Z-MAP method stored in the memory and runnable on the processor. When the longitudinal torsional ultrasonic milling surface morphology modeling and surface roughness prediction program based on the Z-MAP method is executed by the processor, the steps of the longitudinal torsional ultrasonic milling surface morphology modeling and surface roughness prediction method based on the Z-MAP method are implemented.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a longitudinal torsional ultrasonic milling surface morphology modeling and surface roughness prediction program based on the Z-MAP method. When the longitudinal torsional ultrasonic milling surface morphology modeling and surface roughness prediction program based on the Z-MAP method is executed by the processor, the steps of the longitudinal torsional ultrasonic milling surface morphology modeling and surface roughness prediction method based on the Z-MAP method are implemented as described in any one of claims 1 to 7.

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