Calibration method of five-axis machine tool, computer device and storage medium

Abstract

This application provides a calibration method, computer equipment, and storage medium for a five-axis machine tool. The calibration method includes: determining measurement points on a calibration plate, wherein the measurement points are not on the rotary axes of the five-axis machine tool; determining the offset between the camera coordinate system and the tool tip coordinate system based on the measurement points; rotating the first and second rotary axes respectively, and recording the mechanical coordinates of the camera center facing the measurement points after rotation; calculating the coordinates of the rotation center points of the first and second rotary axes in the tool tip coordinate system based on the mechanical coordinates; and calculating the vector between the rotation center points of the first and second rotary axes and the rotation center point of the second rotary axis based on the coordinates of the rotation center points of the first and second rotary axes in the tool tip coordinate system. This application features a simple calibration process and a standardized method. Through this method, the cost of five-axis machine tool calibration can be reduced, and automatic calibration can be achieved.

Description

Technical Field

[0001] This application relates to the field of calibration technology, and in particular to a calibration method, computer equipment and storage medium for a five-axis machine tool. Background Technology

[0002] Rotational Tool Center Point (RTCP) is a crucial function of a five-axis CNC system. RTCP transforms workpiece-based coordinate system programming instructions into motion commands for the five axes of the machine tool coordinate system through kinematic transformations, freeing the user from understanding the complex movements of these axes during programming. To implement five-axis RTCP, the machine tool's motion structure, the vector relationships between the rotary axes, and the vector from the tool tip to the center of rotation must be known. This process is the five-axis calibration process for implementing RTCP on a five-axis CNC machine tool.

[0003] There are three main methods in the existing technology for realizing the vector relationship between the centers of the two rotary axes and the vector from the tool tip to the two rotary centers required for the five-axis linkage RTCP function. The first is that the machine tool manufacturer determines the vector relationship between the rotary axes and the offset vector from the tool tip to the rotary center during the mechanical structure design process. The second is to use the five-axis calibration measurement function provided by the CNC system manufacturer, such as the CYCLE996 measurement cycle function provided by the Siemens CNC system, to calculate the geometric vector required for the five-axis coordinate transformation by using a trigger probe and a standard ball. The third is to use manual measurement parameters using a gauge bar, dial indicator and square gauge.

[0004] However, existing technologies have the following drawbacks:

[0005] 1. There are deviations in the actual parts processing and assembly process, and there are deviations between the parameters in the design drawings and the actual RTCP parameters of the machine tool. The RTCP parameters obtained in this way are not very accurate.

[0006] 2. Trigger-type probes with standard balls are expensive, which will increase the manufacturer's usage costs in practical applications;

[0007] 3. The accuracy of parameters measured manually using gauge bars, dial indicators, and square gauges is not high, the operation steps are cumbersome, and the degree of automation is low. Summary of the Invention

[0008] The purpose of this application is to provide a calibration method, computer equipment, and storage medium for a five-axis machine tool, which can solve the technical problems of low parameter accuracy, cumbersome operation steps, and low degree of automation in the implementation of the five-axis linkage RTCP function in the prior art.

[0009] To address the aforementioned technical problems, this application provides a calibration method for a five-axis machine tool. The calibration method includes: determining a measurement point on a calibration plate, wherein the measurement point is not on the axis of rotation of the five-axis machine tool; determining the offset between the camera coordinate system and the tool tip coordinate system based on the measurement point; rotating a first rotation axis and a second rotation axis respectively, and recording the mechanical coordinates of the camera center facing the measurement point after rotation; calculating the coordinates of the rotation center points of the first and second rotation axes in the tool tip coordinate system based on the mechanical coordinates; and calculating the vector between the rotation center points of the first and second rotation axes and the rotation center point of the second rotation axis based on the coordinates of the rotation center points of the first and second rotation axes in the tool tip coordinate system.

[0010] The step of determining the offset between the camera coordinate system and the tool tip coordinate system based on the measurement point further includes: establishing a machine tool coordinate system, the camera coordinate system, and the tool tip coordinate system respectively; moving the first translation axis, the second translation axis, and the third translation axis of the machine tool coordinate system to obtain a first machine coordinate system in which the center of the camera is directly opposite the measurement point; moving the first translation axis, the second translation axis, and the third translation axis of the machine tool coordinate system to obtain a second machine coordinate system from the tool tip to the measurement point; and obtaining the offset between the camera coordinate system and the tool tip coordinate system based on the first machine coordinate system and the second machine coordinate system.

[0011] The step of obtaining the offset between the camera and the blade tip based on the first machine coordinates and the second machine coordinates further includes: obtaining the coordinates of the measurement point in the camera coordinate system based on the first machine coordinates; obtaining the coordinates of the measurement point in the blade tip coordinate system based on the second machine coordinates; and obtaining the offset between the camera coordinate system and the blade tip coordinate system based on the coordinates of the measurement point in both the camera coordinate system and the blade tip coordinate system.

[0012] The step of rotating the first and second rotation axes respectively and recording the mechanical coordinates of the camera center facing the measurement point after rotation further includes: rotating the first rotation axis to a first preset angle, the first preset angle being within the stroke range of the first rotation axis and not zero; driving the first, second, and third translation axes so that the camera center faces the measurement point, and recording the third mechanical coordinates of the measurement point; rotating the first rotation axis again to a second preset angle, the second preset angle being within the stroke range of the first rotation axis and not equal to the first preset angle and zero; driving the first, second, and third translation axes again so that the camera center faces the measurement point, and recording the fourth mechanical coordinates of the measurement point.

[0013] The step of calculating the coordinates of the rotation center points of the first and second rotating axes in the tool tip coordinate system based on the mechanical coordinates further includes: calculating the first coordinates of the measurement point in the camera coordinate system when the first rotating axis rotates to the first preset angle based on the third mechanical coordinates; obtaining the second coordinates of the measurement point in the tool tip coordinate system based on the first coordinates; and obtaining the coordinates of the rotation center point of the first rotating axis in the tool tip coordinate system based on the coordinates of the measurement point in the tool tip coordinate system before rotation, the second coordinates after rotation, and the first preset angle.

[0014] The step of rotating the first and second rotation axes respectively and recording the mechanical coordinates of the camera center facing the measurement point after rotation further includes: rotating the second rotation axis to a third preset angle, the third preset angle being within the travel range of the second rotation axis and not zero; driving the first, second, and third translational axes so that the camera center faces the measurement point, and recording the fifth mechanical coordinates of the measurement point; rotating the second rotation axis again to a fourth preset angle, the fourth preset angle being within the travel range of the second rotation axis and not equal to the third preset angle or zero; driving the first, second, and third translational axes again so that the camera center faces the measurement point, and recording the sixth mechanical coordinates of the measurement point.

[0015] The step of calculating the coordinates of the rotation center points of the first and second rotating axes in the blade tip coordinate system based on the mechanical coordinates further includes: obtaining the third coordinate of the measurement point in the camera coordinate system when the second rotating axis rotates to the third preset angle; obtaining the fourth coordinate of the measurement point in the blade tip coordinate system based on the third coordinate; obtaining the fifth coordinate of the measurement point in the camera coordinate system when the second rotating axis rotates to the fourth preset angle; calculating the sixth coordinate of the measurement point in the blade tip coordinate system based on the fifth coordinate; and obtaining the coordinates of the rotation center point of the second rotating axis in the blade tip coordinate system based on the coordinates of the measurement point in the blade tip coordinate system before rotation, the fourth and sixth coordinates after rotation, and the third and fourth preset angles.

[0016] To address the aforementioned technical problems, this application also provides a computer device, including a memory and a processor. The memory stores computer-readable instructions, and the processor executes the computer-readable instructions to implement the steps of the calibration method for a five-axis machine tool as described in any of the preceding claims.

[0017] To address the aforementioned technical problems, this application also provides a computer-readable storage medium, employing the following technical solution: the computer-readable storage medium stores computer-readable instructions, which, when executed by a processor, implement the steps of the above-described calibration method for a five-axis machine tool.

[0018] Compared with the prior art, the embodiments of this application have the following main advantages:

[0019] This application provides a calibration method, computer equipment, and storage medium for a five-axis machine tool. By determining the measurement points on the calibration plate, the offset between the camera coordinate system and the tool tip coordinate system is determined based on the measurement points. The first and second rotary axes are rotated respectively, and the mechanical coordinates of the camera center facing the measurement points after rotation are recorded. Based on the mechanical coordinates, the coordinates of the rotation center points of the first and second rotary axes in the tool tip coordinate system are calculated. Based on the coordinates of the rotation center points of the first and second rotary axes in the tool tip coordinate system, the vector between the rotation center points of the first and second rotary axes is calculated. The calibration process of this application is simple and the method is uniform. Through the above method, the cost of five-axis machine tool calibration can be reduced and automatic calibration can be achieved. Attached Figure Description

[0020] To more clearly illustrate the solutions in this application, the accompanying drawings used in the description of the embodiments of this application will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a flowchart illustrating one embodiment of the calibration method for a five-axis machine tool according to this application;

[0022] Figure 2 Figure 1 A flowchart illustrating an implementation method for step S200;

[0023] Figure 3 yes Figure 2 A flowchart illustrating an implementation method for step S240;

[0024] Figure 4 yes Figure 1 A flowchart illustrating the first embodiment of step S300;

[0025] Figure 5 yes Figure 1 A flowchart illustrating the second embodiment of step S300;

[0026] Figure 6 yes Figure 1A flowchart illustrating the first embodiment of step S400;

[0027] Figure 7 yes Figure 1 A flowchart illustrating the second embodiment of step S400;

[0028] Figure 8 This is a schematic diagram of a computer device according to an embodiment of the present application. Detailed Implementation

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The terms “comprising” and “having,” and any variations thereof, in the specification, claims, and foregoing drawings, are intended to cover non-exclusive inclusion. The terms “first,” “second,” etc., in the specification, claims, or foregoing drawings are used to distinguish different objects and not to describe a particular order.

[0030] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0031] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.

[0032] It is understood that the five-axis machine tool mentioned in this application has three translational axes (X-axis, Y-axis, and Z-axis) and two rotary axes (R1 axis and R2 axis). Among them, the X-axis, Y-axis, and Z-axis move in three-dimensional directions, and the R1 axis and R2 axis are rotary axes, and the R1 axis and R2 axis can be any two of the A-axis, B-axis, and C-axis.

[0033] Specifically, in this application, the rotation axis A is parallel to the X-axis, the rotation axis B is parallel to the Y-axis, and the rotation axis C is parallel to the Z-axis. It is understood that in the following description of this application, the three translational axes are referred to as the first translational axis, the second translational axis, and the third translational axis, where the first translational axis can be the X-axis, the second translational axis can be the Y-axis, and the third translational axis can be the Z-axis; the first rotational axis can be the C-axis, and the second rotational axis can be the A-axis. Of course, in other embodiments, the three translational axes and two rotational axes can also be in other combinations, which are not specifically limited here.

[0034] Please combine Figure 1 , Figure 1 This is a flowchart illustrating one embodiment of the calibration method for a five-axis machine tool according to this application. Figure 1 The calibration method for a five-axis machine tool provided in this application includes the following steps:

[0035] S100, determine the measurement point of the calibration plate. The measurement point is not on the axis of rotation of the five-axis machine tool.

[0036] Understandably, before determining the measurement points on the calibration plate, the camera needs to be mounted on the third translational axis (Z-axis) of the five-axis machine tool, and the optical axis of the camera needs to be adjusted to be parallel to and perpendicular to the base plane of the five-axis machine tool. Furthermore, the calibration plate is fixed on the worktable of the five-axis machine tool. With the first and second rotary axes in their initial states, and both axes at 0 degrees, the calibration plate is adjusted to be parallel to the base plane of the five-axis machine tool.

[0037] Furthermore, drive the five-axis machine tool to return to zero and clear the mechanical coordinates of the five-axis machine tool to zero, and select measurement point P on the calibration plate, wherein measurement point P is not on the axis of rotation of the five-axis machine tool.

[0038] S200 determines the offset between the camera coordinate system and the tool tip coordinate system based on the measurement point.

[0039] Please combine further Figure 2 , Figure 2 This is a flowchart illustrating an implementation method for step S200, as shown below. Figure 2 Step S200 further includes the following sub-steps:

[0040] S210, establish the machine tool coordinate system, camera coordinate system and tool tip coordinate system respectively.

[0041] Optionally, after the five-axis machine tool returns to zero, a machine tool coordinate system {M} is established as the reference coordinate system for the pose of all coordinate systems. The origin of the coordinate system is located at the machine origin, and the actual motion directions of the first, second, and third translational axes are parallel to the axes of the machine tool coordinate system {M}.

[0042] Furthermore, a camera coordinate system {C} is established, with the origin located at the projection point of the camera center point on the calibration plate plane after the five-axis machine tool returns to zero, and each axis parallel to the five-axis machine tool coordinate system {M}.

[0043] Establish a tool tip coordinate system {T}, with the origin located at the tool tip point after the five-axis machine tool returns to zero, and all its axes parallel to the machine tool coordinate system {M}.

[0044] S220, move the first translational axis, the second translational axis and the third translational axis of the machine tool coordinate system to obtain the first mechanical coordinate of the camera center facing the measurement point.

[0045] Move the first translational axis, the second translational axis, and the third translational axis (X-axis, Y-axis, Z-axis) to record the first mechanical coordinates when the camera center is directly facing the measurement point P. C x, C y, C z,0,0);

[0046] S230 moves the first, second, and third translational axes of the machine tool coordinate system to obtain the second machine coordinate from the tool tip to the measurement point.

[0047] Furthermore, by moving the first, second, and third translational axes (X-axis, Y-axis, and Z-axis) of the machine tool coordinate system again, the second machine coordinate from the tool tip to the measurement point P is obtained. T x, T y, T z,0,0).

[0048] S240, the offset between the camera coordinate system and the tool tip coordinate system is obtained based on the first machine coordinate and the second machine coordinate.

[0049] Further integration Figure 3 , Figure 3 This is a flowchart illustrating one embodiment of step S240, as shown below. Figure 3 Step S240 further includes the following sub-steps:

[0050] S241, obtain the coordinates of the measurement point in the camera coordinate system based on the first machine coordinates.

[0051] According to the first machine coordinate ( C x, C y, C The coordinates of the measurement point P in the camera coordinate system are obtained from z, 0, 0. C x, C y,0), where the value recorded when the camera center is directly facing the measurement point P. C z doesn't need to be accurate, just capture it clearly.

[0052] S242, the coordinates of the measurement point in the tool tip coordinate system are obtained according to the second machine coordinate.

[0053] Furthermore, according to the second machine coordinate ( T x, T y, T The coordinates of the measurement point P in the tool tip coordinate system are obtained from z, 0, 0. T x, T y, Tz).

[0054] S243, based on the coordinates of the measurement point in the camera coordinate system and the tool tip coordinate system respectively, obtain the offset between the camera coordinate system and the tool tip coordinate system.

[0055] Therefore, the vector of the camera coordinate system {C} in the knife-edge coordinate system {T} is:

[0056]

[0057] S300, rotate the first and second rotation axes respectively, and record the mechanical coordinates of the camera center facing the measurement point after rotation.

[0058] Further integration Figure 4 , Figure 4 This is a flowchart illustrating the first embodiment of step S300, as shown below. Figure 4 Step S300 further includes the following sub-steps:

[0059] S310, rotate the first rotating shaft to a first preset angle, the first preset angle being within the stroke range of the first rotating shaft and not zero.

[0060] After the five-axis machine tool returns to zero and the machine tool coordinates are cleared, the first rotary axis (C-axis) is rotated to the first preset angle θ1, where the first preset angle θ1 can be any angle within the range of the first rotary axis and is not zero.

[0061] S320 drives the first translational axis, the second translational axis, and the third translational axis so that the camera center is directly facing the measurement point and records the third mechanical coordinate of the measurement point.

[0062] Drive the first translation axis, the second translation axis, and the third translation axis (X-axis, Y-axis, Z-axis) so that the center of the camera is directly aligned with the measurement point P on the calibration plate. Record the third mechanical coordinates (x1, y1, z1, 0, θ1) of the measurement point P at this time, and let the measurement point P at this time be P1.

[0063] S330, rotate the first rotating shaft again to the second preset angle, the second preset angle being within the stroke range of the first rotating shaft and not equal to the first preset angle or zero.

[0064] Rotate the first rotation axis again to the second preset angle θ2, which is within the stroke range of the first rotation axis and is not equal to the first preset angle θ1 or zero.

[0065] S340, drive the first translation axis, the second translation axis and the third translation axis again, so that the center of the camera is facing the measurement point, and record the fourth mechanical coordinate of the measurement point.

[0066] Drive the first translation axis, the second translation axis, and the third translation axis (X-axis, Y-axis, Z-axis) again so that the center of the camera is directly aligned with the measurement point P on the calibration plate. Record the fourth mechanical coordinates (x2, y2, z2, 0, θ2) of the measurement point P at this time, and let the measurement point P at this time be P2.

[0067] Further integration Figure 5 , Figure 5 This is a flowchart illustrating the second embodiment of step S300, as shown below. Figure 5 Step S300 further includes the following sub-steps:

[0068] S310a, rotate the second rotating shaft to a third preset angle, the third preset angle being within the range formed by the second rotating shaft and not zero.

[0069] After the five-axis machine tool is homed and the machine tool coordinates are zeroed, rotate the second rotary axis (A-axis) to the third preset angle. Third preset angle Let be any angle that is not zero within the travel range of the second rotation axis.

[0070] S320a drives the first translational axis, the second translational axis, and the third translational axis so that the center of the camera is directly facing the measurement point and records the fifth mechanical coordinate of the measurement point.

[0071] Drive the first, second, and third translational axes (X-axis, Y-axis, and Z-axis) so that the camera center is directly facing the measurement point P, and record the fifth mechanical coordinate of the measurement point. Let the measurement point P at this moment be P3.

[0072] S330a, rotate the second rotating shaft again to the fourth preset angle, which is within the stroke range of the second rotating shaft and is not equal to the third preset angle or zero.

[0073] Rotate the second axis of rotation again to the fourth preset angle. Fourth preset angle It is any angle within the travel range of the second rotation axis that is not equal to the third preset angle or zero.

[0074] S340a drives the first translation axis, the second translation axis, and the third translation axis again, so that the center of the camera is directly facing the measurement point, and records the sixth mechanical coordinate of the measurement point.

[0075] Drive the first, second, and third translational axes again until the camera center is directly facing the measurement point P, and record the sixth mechanical coordinate of the measurement point P. Let the measurement point P at this time be P4.

[0076] S400, calculate the coordinates of the rotation center points of the first and second rotating axes in the tool tip coordinate system according to the machine coordinates.

[0077] Further integration Figure 6 , Figure 6 This is a flowchart illustrating the first embodiment of step S400, as shown below. Figure 6 Step S400 further includes the following sub-steps:

[0078] S410, calculate the first coordinate of the measurement point in the camera coordinate system when the first rotating axis rotates to the first preset angle according to the third mechanical coordinate.

[0079] Optionally, when the first rotation axis (C-axis) rotates to the first preset angle θ1, the first coordinate of the measurement point P1 in the camera coordinate system is ( C x1, C y1, C z1), where the first coordinate is expressed as follows:

[0080]

[0081] S420, based on the first coordinate, obtain the second coordinate of the measurement point in the tool tip coordinate system.

[0082] According to the first coordinate ( C x1, C y1, C z1) Obtain the second coordinate of the measurement point P1 in the tool tip coordinate system:

[0083]

[0084] S430: Based on the coordinates of the measurement point before rotation in the tool tip coordinate system, the second coordinates after rotation, and the first preset angle, the coordinates of the rotation center point of the first rotation axis in the tool tip coordinate system are obtained.

[0085] Let the coordinates of the center of rotation of the first rotation axis (C-axis) in the tool tip coordinate system {T} be o. c (x c ,y c ,z c ), where the vector from the rotation center point to the measurement point P before rotation and the vector from the rotation center point to the measurement point P1 after rotation are respectively and

[0086] in, for:

[0087]

[0088] for:

[0089]

[0090] Alternatively, since the first axis of rotation is the C-axis, the following relationship can be obtained:

[0091]

[0092] Expanding equation (1), we get:

[0093]

[0094] Solving formula (2), we get:

[0095]

[0096] Since the measuring point P rotates around the Z-axis, z c = T z.

[0097] In this way, the coordinates of the rotation center point of the first rotation axis in the tool tip coordinate system can be obtained.

[0098] Further integration Figure 7 , Figure 7 This is a flowchart illustrating the second embodiment of step S400, as shown below. Figure 7 Step S400 further includes the following sub-steps:

[0099] S410a, obtain the third coordinate of the measurement point in the camera coordinate system when the second rotation axis rotates to the third preset angle.

[0100] Optionally, when the second rotation axis (A-axis) rotates to a third preset angle At that time, the Z-axis coordinate of measurement point P3 in the camera coordinate system C z3. It is understandable that the Z-axis coordinate of measurement point P3 in the camera coordinate system cannot be obtained through the third mechanical coordinate system. Therefore, let the third coordinate of measurement point P3 in the camera coordinate system be (z3). C x3, C y3, C z3) is:

[0101]

[0102] S420a, based on the third coordinate, obtain the fourth coordinate of the measurement point in the tool tip coordinate system.

[0103] According to the third coordinate ( C x3, C y3, C z3) The fourth coordinate of the measurement point P3 in the tool tip coordinate system {T} is obtained as follows:

[0104]

[0105] S430a, obtain the fifth coordinate of the measurement point in the camera coordinate system when the second rotation axis rotates to the fourth preset angle.

[0106] Similarly, when the second rotation axis (A-axis) rotates to the fourth preset angle... At that time, the Z-axis coordinate of measurement point P4 in the camera coordinate system is: C z4, therefore, let the fifth coordinate of the measurement point P4 in the camera coordinate system be ( C x4, C y4, C z4) is:

[0107]

[0108] S440a, calculate the sixth coordinate of the measurement point in the tool tip coordinate system based on the fifth coordinate.

[0109] According to the fifth coordinate ( C x4, C y4, C z4) Calculate the sixth coordinate of the measurement point in the tool tip coordinate system {T} as follows:

[0110]

[0111] S450a, based on the coordinates of the measurement point before rotation in the tool tip coordinate system and the fourth and sixth coordinates after rotation, as well as the third and fourth preset angles, the coordinates of the rotation center point of the second rotation axis in the tool tip coordinate system are obtained.

[0112] Let the coordinates of the second rotation axis (A-axis) in the tool tip coordinate system {T} be o. A (x A ,y A ,z A ), where the vector from the center of rotation to the measurement point P before rotation. And the vectors from the center point of rotation to the measurement points P3 and P4 after two rotations are respectively and

[0113] in, for:

[0114]

[0115] for:

[0116]

[0117] for:

[0118]

[0119] Therefore, the following relationship can be obtained:

[0120]

[0121] as well as

[0122]

[0123] Expanding equations (3) and (4), we get:

[0124]

[0125] In equation (5), there exists a variable y A ,z A , T z3, T z4, solving the system of four linear equations, we can obtain the center of rotation as:

[0126]

[0127] Since the measuring point P rotates around the second rotation axis (axis A), x A = T x.

[0128] It should be noted that when a rotation axis B exists in a dual rotary table, the coordinates o of the rotation center point of axis B in the coordinate system {T} of the tool tip can be obtained as follows. B (x B ,y B ,z B ).

[0129] The five-axis machine tool is homed, the machine tool coordinates are zeroed, and the rotary axis B is rotated to φ1 degrees, where φ1 is any angle not equal to 0 degrees within the travel range of the B axis. The first translation axis, the second translation axis, and the third translation axis (X-axis, Y-axis, Z-axis) are driven so that the center of the camera is directly aligned with the measurement point P on the calibration plate. The machine coordinates at this time are recorded as (x5, y5, z5, φ1, 0), and the point P at this time is designated as P5.

[0130] Rotate the B-axis again to φ2 degrees, where φ2 is any angle within the B-axis's travel range that is neither 0 degrees nor φ1 degrees. Drive the translation axes X, Y, and Z so that the camera center is directly aligned with the calibration plate's measurement point P. Record the mechanical coordinates at this point as (x6, y6, z6, φ2, 0), and denote the measurement point P as P6.

[0131] When the rotation axis B rotates to φ1, the Z-axis coordinate of point P5 in the camera coordinate system {C} cannot be obtained through the mechanical coordinate system. Therefore, let the Z-axis coordinate of point P5 in the camera coordinate system {C} be... C z5, the coordinates of point P5 in the camera coordinate system are ( C x5, C y5, C z5), of which

[0132]

[0133] Therefore, the coordinates of point P5 in the tool tip coordinate system {T} can be obtained as follows:

[0134]

[0135] Similarly, when the rotation axis B rotates to φ2, let the Z-axis coordinate of point P6 in the camera coordinate system {C} be... C z6, the coordinates of point P6 in the camera coordinate system are ( C x6, C y6, C z6), where:

[0136]

[0137] Therefore, the coordinates of point P6 in the tool tip coordinate system {T} can be obtained as follows:

[0138]

[0139] Let the coordinates of the center of rotation of the B-axis in the tool tip coordinate system {T} be o. B (x B ,y B ,z B Before rotation After rotating to φ1 degree and φ2 degree and They are respectively

[0140]

[0141]

[0142] and

[0143]

[0144] Since the axis of rotation is the B-axis, the following relationship can be obtained:

[0145]

[0146] and

[0147]

[0148] Expanding equations (6) and (7), we get

[0149]

[0150] In equation (8), there exists a variable x B ,z B , T z5, T z6, Solving the system of four linear equations, we can obtain the center of rotation as:

[0151]

[0152] Since the measuring point P rotates around axis B, y B = T y.

[0153] S500, the vector between the rotation center points of the first and second rotation axes is calculated based on the coordinates of the rotation center points of the first and second rotation axes in the tool tip coordinate system.

[0154] Furthermore, based on the coordinates o of the rotation center point of the first rotation axis in the tool tip coordinate system {T}... c (x c ,y c ,z c The coordinates of the rotation center point of the second rotation axis in the tool tip coordinate system {T} are: A (x A ,y A ,z A The vector between the center points of the two rotation axes of the AC double turntable can then be obtained.

[0155] In the above embodiments, by determining the measurement points of the calibration plate, the offset between the camera coordinate system and the tool tip coordinate system is determined based on the measurement points. The first and second rotation axes are rotated respectively, and the mechanical coordinates of the camera center facing the measurement points after rotation are recorded. The coordinates of the rotation center points of the first and second rotation axes in the tool tip coordinate system are calculated based on the mechanical coordinates. The vector between the rotation center points of the first and second rotation axes and the rotation center points of the second rotation axis is calculated based on the coordinates of the rotation center points of the first and second rotation axes in the tool tip coordinate system. Compared with trigger probes, laser trackers, and interferometers, the calibration method of this application for five-axis machine tools has a simple calibration process and a unified method. Through the above method, the cost of five-axis machine tool calibration can be reduced and automatic calibration can be achieved.

[0156] To address the aforementioned technical problems, embodiments of this application also provide a computer device. Please refer to [link / reference needed]. Figure 8 , Figure 8 This is a basic structural block diagram of the computer device in this embodiment.

[0157] The computer device 300 includes a memory 301, a processor 302, and a network interface 303 that are interconnected via a system bus. It should be noted that... Figure 8 Only a computer device 300 with components 301-303 is shown in this document; however, it should be understood that implementation of all shown components is not required, and more or fewer components may be implemented alternatively. Those skilled in the art will understand that the computer device described herein is a device capable of automatically performing numerical calculations and / or information processing according to pre-set or stored instructions, and its hardware includes, but is not limited to, microprocessors, application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), digital signal processors (DSPs), embedded devices, etc.

[0158] The computer device can be a desktop computer, laptop, handheld computer, or cloud server, etc. The computer device can interact with the user via a keyboard, mouse, remote control, touchpad, or voice control.

[0159] The memory 301 includes at least one type of readable storage medium, including flash memory, hard disk, multimedia card, card-type memory (e.g., SD or DX memory), random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), programmable read-only memory (PROM), magnetic memory, magnetic disk, optical disk, etc. In some embodiments, the memory 301 may be an internal storage unit of the computer device 300, such as the hard disk or memory of the computer device 300. In other embodiments, the memory 301 may also be an external storage device of the computer device 300, such as a plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, etc., equipped on the computer device 300. Of course, the memory 301 may also include both the internal storage unit and the external storage device of the computer device 300. In this embodiment, the memory 301 is typically used to store the operating system and various application software installed on the computer device 300, such as computer-readable instructions for interface calling methods. Furthermore, the memory 301 can also be used to temporarily store various types of data that have been output or will be output.

[0160] In some embodiments, the processor 302 may be a central processing unit (CPU), controller, microcontroller, microprocessor, or other data processing chip. The processor 302 is typically used to control the overall operation of the computer device 300. In this embodiment, the processor 302 is used to execute computer-readable instructions stored in the memory 301 or to process data, such as computer-readable instructions for executing a calibration method for a five-axis machine tool.

[0161] The network interface 303 may include a wireless network interface or a wired network interface, which is typically used to establish communication connections between the computer device 300 and other electronic devices.

[0162] In the above embodiments, by determining the measurement points of the calibration plate, the offset between the camera coordinate system and the tool tip coordinate system is determined based on the measurement points. The first and second rotation axes are rotated respectively, and the mechanical coordinates of the camera center facing the measurement points after rotation are recorded. The coordinates of the rotation center points of the first and second rotation axes in the tool tip coordinate system are calculated based on the mechanical coordinates. The vector between the rotation center points of the first and second rotation axes and the rotation center points of the second rotation axis is calculated based on the coordinates of the rotation center points of the first and second rotation axes in the tool tip coordinate system. Compared with trigger probes, laser trackers, and interferometers, the calibration method of this application for five-axis machine tools has a simple calibration process and a unified method. Through the above method, the cost of five-axis machine tool calibration can be reduced and automatic calibration can be achieved.

[0163] This application also provides another embodiment, namely, providing a computer-readable storage medium storing computer-readable instructions that can be executed by at least one processor to cause the at least one processor to perform the steps of the five-axis machine tool calibration method described above.

[0164] In the above embodiments, by determining the measurement points of the calibration plate, the offset between the camera coordinate system and the tool tip coordinate system is determined based on the measurement points. The first and second rotation axes are rotated respectively, and the mechanical coordinates of the camera center facing the measurement points after rotation are recorded. The coordinates of the rotation center points of the first and second rotation axes in the tool tip coordinate system are calculated based on the mechanical coordinates. The vector between the rotation center points of the first and second rotation axes and the rotation center points of the second rotation axis is calculated based on the coordinates of the rotation center points of the first and second rotation axes in the tool tip coordinate system. Compared with trigger probes, laser trackers, and interferometers, the calibration method of this application for five-axis machine tools has a simple calibration process and a unified method. Through the above method, the cost of five-axis machine tool calibration can be reduced and automatic calibration can be achieved.

[0165] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods of the various embodiments of this application.

[0166] Obviously, the embodiments described above are only some embodiments of this application, not all embodiments. The accompanying drawings show preferred embodiments of this application, but do not limit the patent scope of this application. This application can be implemented in many different forms; rather, the purpose of providing these embodiments is to provide a more thorough and comprehensive understanding of the disclosure of this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing specific embodiments, or make equivalent substitutions for some of the technical features. Any equivalent structures made using the content of this application's specification and drawings, directly or indirectly applied to other related technical fields, are similarly within the scope of patent protection of this application.

Claims

1. A method for calibrating a five-axis machine tool, characterized in that, The calibration method includes: Determine the measurement points of the calibration plate, wherein the measurement points are not on the rotation axis of the five-axis machine tool; Determining the offset between the camera coordinate system and the tool tip coordinate system based on the measurement points includes: Establish the machine tool coordinate system, the camera coordinate system, and the tool tip coordinate system respectively; By moving the first translational axis, the second translational axis, and the third translational axis of the machine tool coordinate system, the first machine coordinates of the camera center facing the measurement point are obtained; By moving the first translational axis, the second translational axis, and the third translational axis of the machine tool coordinate system, the second machine coordinate from the tool tip to the measurement point is obtained; The offset between the camera coordinate system and the blade tip coordinate system is obtained based on the first machine coordinate and the second machine coordinate. Rotate the first and second rotation axes respectively, and record the mechanical coordinates of the camera center facing the measurement point after rotation; Calculate the coordinates of the rotation center points of the first and second rotating axes in the tool tip coordinate system based on the mechanical coordinates. The vector between the rotation center points of the first and second rotation axes in the tool tip coordinate system is calculated based on their coordinates.

2. The calibration method according to claim 1, characterized in that, The step of obtaining the offset between the camera coordinate system and the blade tip coordinate system based on the first machine coordinate and the second machine coordinate further includes: The coordinates of the measurement point in the camera coordinate system are obtained based on the first mechanical coordinates; The coordinates of the measuring point in the tool tip coordinate system are obtained based on the second mechanical coordinate system; The offset between the camera coordinate system and the blade tip coordinate system is obtained based on the coordinates of the measurement point in both the camera coordinate system and the blade tip coordinate system.

3. The calibration method according to claim 1, characterized in that, The step of rotating the first and second rotation axes respectively and recording the mechanical coordinates of the camera center facing the measurement point after rotation further includes: Rotate the first rotating shaft to a first preset angle, wherein the first preset angle is within the stroke range of the first rotating shaft and is not zero; Drive the first translational axis, the second translational axis, and the third translational axis so that the center of the camera is directly facing the measurement point, and record the third mechanical coordinate of the measurement point; Rotate the first rotating shaft again to a second preset angle, where the second preset angle is within the stroke range of the first rotating shaft and is not equal to the first preset angle or zero; Drive the first translation axis, the second translation axis, and the third translation axis again so that the center of the camera is directly facing the measurement point, and record the fourth mechanical coordinate of the measurement point.

4. The calibration method according to claim 3, characterized in that, The step of calculating the coordinates of the rotation center points of the first and second rotation axes in the tool tip coordinate system based on the mechanical coordinates further includes: Calculate the first coordinate of the measurement point in the camera coordinate system when the first rotating axis rotates to the first preset angle based on the third mechanical coordinate; The second coordinate of the measurement point in the tool tip coordinate system is obtained based on the first coordinate. The coordinates of the rotation center point of the first rotation axis in the blade tip coordinate system are obtained based on the coordinates of the measurement point before rotation in the blade tip coordinate system, the second coordinates after rotation, and the first preset angle.

5. The calibration method according to claim 3, characterized in that, The step of rotating the first and second rotation axes respectively and recording the mechanical coordinates of the camera center facing the measurement point after rotation further includes: Rotate the second rotating shaft to a third preset angle, wherein the third preset angle is within the stroke range of the second rotating shaft and is not zero; Drive the first translational axis, the second translational axis, and the third translational axis so that the center of the camera is directly facing the measurement point, and record the fifth mechanical coordinate of the measurement point; The second rotating axis is rotated again to a fourth preset angle, which is within the stroke range of the second rotating axis and is not equal to the third preset angle or zero; Drive the first translation axis, the second translation axis, and the third translation axis again so that the center of the camera is directly facing the measurement point, and record the sixth mechanical coordinate of the measurement point.

6. The calibration method according to claim 5, characterized in that, The step of calculating the coordinates of the rotation center points of the first and second rotation axes in the tool tip coordinate system based on the mechanical coordinates further includes: When the second rotation axis rotates to the third preset angle, the third coordinate of the measurement point in the camera coordinate system is obtained; The fourth coordinate of the measurement point in the tool tip coordinate system is obtained based on the third coordinate. When the second rotation axis rotates to the fourth preset angle, the fifth coordinate of the measurement point in the camera coordinate system is obtained; Calculate the sixth coordinate of the measurement point in the tool tip coordinate system based on the fifth coordinate; The coordinates of the rotation center point of the second rotation axis in the tool tip coordinate system are obtained based on the coordinates of the measurement point before rotation in the tool tip coordinate system, the fourth and sixth coordinates after rotation, and the third and fourth preset angles.

7. The calibration method according to claim 1, characterized in that, The determination of the measurement points on the calibration plate further includes: The camera is mounted on the third translational axis of the five-axis machine tool; The optical axis of the camera is adjusted to be parallel to and perpendicular to the base plane of the five-axis machine tool, and the direction of the third translation axis is adjusted to be parallel to and perpendicular to the base plane of the five-axis machine tool. The calibration plate is fixed to the worktable of the five-axis machine tool; Adjust the calibration plate to be parallel to the base plane of the five-axis machine tool; Drive the five-axis machine tool back to zero and clear the mechanical coordinates of the five-axis machine tool to zero.

8. A computer device, characterized in that, The system includes a memory and a processor, wherein the memory stores computer-readable instructions, and the processor executes the computer-readable instructions to implement the steps of the calibration method for a five-axis machine tool as described in any one of claims 1 to 7.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-readable instructions, which, when executed by a processor, implement the steps of the calibration method for a five-axis machine tool as described in any one of claims 1 to 7.

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