Five-axis machine tool rotating shaft error compensation method and system, electronic equipment and readable medium

Abstract

The embodiment of the invention discloses a five-axis machine tool rotating shaft error compensation method and system, electronic equipment and a readable medium, and the five-axis machine tool rotating shaft error compensation method comprises the steps: machining a measurement workpiece with a measurement groove, obtaining the coordinates of measurement points around the measurement groove, and calculating the size error of the measurement groove in a five-axis coordinate system, according to the method, the error of the five-axis machine tool is compensated, the compensation precision and universality are high, and error compensation can be carried out on all types of five-axis machine tools. The five-axis machine tool error compensation method is high in compensation precision and universality, and error compensation can be conducted on all types of five-axis machine tools.

Description

Technical Field

[0001] The present invention belongs to the technical field of numerical control machine tools, and particularly relates to a method, a system, an electronic device and a readable medium for compensating the errors of the rotating axes of a five-axis machine tool. Background Art

[0002] Improving the machining accuracy of a numerical control machine tool is a key factor in ensuring the accuracy of machined parts. Geometric errors caused by factors such as the manufacturing, assembly and wear of machine tool components account for 20% - 30% of the total machine tool errors, seriously restricting the machine tool accuracy. Error compensation, as a highly efficient and low-cost technical method, plays an important role in improving the machine tool accuracy.

[0003] The errors of a five-axis machine tool include 21 linear axis errors and 22 rotating axis errors. Among them, the error compensation of the rotating axes is more complex than that of the linear axes. One reason is that there is currently no good measuring equipment for rotating axis errors, making it difficult to quickly measure out the 22 errors. The other reason is that a comprehensive error model needs to be established for each structure of the five-axis machine tool, which is not universal.

[0004] The information disclosed in this background art section is only intended to enhance the overall understanding of the present invention and should not be regarded as an admission or any form of suggestion that this information constitutes prior art already known to those of ordinary skill in the art. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for compensating the errors of a five-axis machine tool, which is used to solve the problems of poor universality and low compensation accuracy of the existing error compensation methods.

[0006] To achieve the above purpose, the technical solution provided by the present invention is as follows:

[0007] In a first aspect, a specific embodiment of the present invention provides a method for compensating the errors of a five-axis machine tool, including the following steps:

[0008] Rotate the first rotating axis, and machine a measuring groove on one side of the measuring workpiece. A plurality of measuring points are formed around the measuring groove;

[0009] Rotate the second rotating axis, and machine a measuring groove on the other side of the measuring workpiece;

[0010] Repeat the step of rotating the second rotating axis until measuring grooves are machined on all the preset sides of the measuring workpiece;

[0011] Measure the coordinate values (x ij , y ij , z ij ) of the plurality of measuring points around each measuring groove in a three-axis coordinate system, where i represents the serial number of the measuring groove and j represents the serial number of the measuring point;

[0012] Based on the coordinate values (x ij , y ij , z ij ) of each of the said measurement points in a three-axis coordinate system, calculate the machining error (Δx αβi , Δy αβi , Δz αβi ) of each of the said measurement grooves in a five-axis coordinate system;

[0013] Based on the machining error (Δx αβi , Δy αβi , Δz αβi ) of each of the said measurement grooves in a five-axis coordinate system, the angle α i of the first rotating axis and the angle β i of the second rotating axis during machining of each measurement groove, compensate for the machine tool error.

[0014] In one or more embodiments of the present invention, the measurement workpiece includes a top surface, a bottom surface and a plurality of side surfaces, the shape of the measurement groove is generally a cuboid or a cube, and the recessed direction is perpendicular to the side surface of the measurement workpiece, and the measurement groove also penetrates through to the top surface of the detection workpiece, and a spacing portion is formed between two adjacent said measurement grooves.

[0015] In one or more embodiments of the present invention, there are 8 measurement points around each of the said measurement grooves. When the measurement workpiece is placed horizontally, measurement point one and measurement point two are on the same side surface of the measurement workpiece and are respectively located on both sides of the measurement groove, measurement point three is on the rear side wall of the measurement groove, measurement point four and measurement point five are respectively on the left and right side walls of the measurement groove, measurement point six and measurement point seven are respectively on the top surfaces of the two spacing portions on both sides of the measurement groove, and measurement point eight is on the bottom side wall of the measurement groove.

[0016] In one or more embodiments of the present invention, the calculating the machining error (Δx αβi , Δy αβi , Δz αβi ) of each of the said measurement grooves in a five-axis coordinate system includes: converting the coordinate values (x ij , y ij , z ij ) of the measurement points in the three-axis coordinate system into coordinate values (x βij , y βij , z βij ) relative to the second rotating axis; based on the coordinate values (x βij , y βij , z βij ) of each of the said measurement points relative to the second rotating axis, calculate the machining error (Δx βi , Δyβi , Δz βi ); Based on the machining errors (Δx βi , Δy βi , Δz βi ) of each of the measurement grooves relative to the second rotation axis, calculate the machining errors (Δx αβi , Δy αβi , Δz αβi ) of each of the measurement grooves in the five-axis coordinate system.

[0017] In one or more embodiments of the present invention, convert the coordinate values (x ij , y ij , z ij ) of the measurement point in the three-axis coordinate system to the coordinate values (x βij , y βij , z βij ) relative to the second rotation axis according to the following formula:

[0018] (x βij , y βij , z βij ) = (x ij , y ij , z ij )·R β ;

[0019] where R β is the rotation matrix of the second rotation axis of the five-axis machine tool.

[0020] In one or more embodiments of the present invention, when the second rotation axis is the turntable rotation axis, the angle value β in its rotation matrix is β = -β i , β i is the angle of the second rotation axis when machining the i-th measurement groove.

[0021] In one or more embodiments of the present invention, when measuring the coordinates of the measurement point, the measurement workpiece is placed horizontally. Calculate the machining errors (Δx βi , Δy βi , Δz βi ) of each of the measurement grooves relative to the second rotation axis according to the following formula;

[0022]

[0023] where L X is the designed horizontal depression depth of the measurement groove when the measurement workpiece is placed horizontally, and L Z is the designed vertical depression depth of the measurement groove when the workpiece is placed horizontally.

[0024] In one or more embodiments of the present invention, the machining error (Δx αβi , Δy αβi , Δz αβi ):

[0025] (Δx αβi , Δy αβi , Δz αβi )=(Δx βi , Δy βi , Δz βi )·R α ;

[0026] Among them, R α is the rotation matrix of the first rotation axis of the five-axis machine tool.

[0027] In one or more embodiments of the present invention, when the first rotation axis is the turntable rotation axis, the angle value α in the rotation matrix is -α i , α i is the angle of the first rotation axis when machining the i-th measuring groove.

[0028] In a second aspect, the present invention provides a five-axis machine tool error compensation system, comprising a data acquisition module, a data processing module, and a compensation module. The data acquisition module is used to obtain the coordinate values (x ij ,y ij , z ij ), i represents the serial number of the measuring groove, j represents the serial number of the measuring point, the measuring groove is obtained by rotating the first rotation axis and the second rotation axis on the side of the measuring workpiece, and a plurality of measuring points are formed around the measuring groove. The data processing module is used to calculate the coordinate value (x ij ,y ij , z ij ), calculate the machining error (Δx αβi , Δy αβi , Δz αβi The compensation module is used to compensate for the machining error (Δx αβi , Δy αβi , Δz αβi ), the angle α of the first rotation axis when machining each measuring groove i and the angle β of the second rotation axis i Compensate for machine tool errors.

[0029] In a third aspect, the present invention provides an electronic device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, the method for compensating the errors of a five-axis machine tool as described above is implemented.

[0030] In a fourth aspect, the present invention provides a computer-readable medium carrying computer-executable instructions. When the computer-executable instructions are executed by a processor, they are used to implement the method for compensating the errors of a five-axis machine tool as described above.

[0031] Compared with the prior art, the present invention processes a measurement workpiece with measurement grooves, obtains the coordinates of measurement points around the measurement grooves, calculates the dimensional errors of the measurement grooves in a five-axis coordinate system, and compensates the errors of the five-axis machine tool accordingly. Its compensation accuracy and versatility are relatively high, and it can compensate for the errors of all types of five-axis machine tools. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0033] Figure 1 It is a flowchart of the method for compensating the errors of a five-axis machine tool in an embodiment of the present invention;

[0034] Figure 2 It is a three-dimensional structure diagram of a measurement workpiece in an embodiment of the present invention;

[0035] Figure 3 It is a top view structure diagram of a measurement workpiece in an embodiment of the present invention;

[0036] Figure 4 It is a schematic diagram of a five-axis machine tool error compensation system in an embodiment of the present invention;

[0037] Figure 5 It is a schematic diagram of an electronic device in an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0038] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0039] In the rapid development of modern manufacturing, the accuracy of numerically controlled machine tools directly affects product quality and production efficiency. The current mainstream numerically controlled machine tools include five-axis machine tools, and the errors of five-axis machine tools include 21 linear axis errors and 22 rotary axis errors. At present, the traditional error measurement methods for five-axis machine tools are roughly divided into two types: direct measurement and indirect measurement. Direct measurement requires error measurement equipment with relatively high accuracy. However, the current measurement equipment is not accurate enough for measuring rotary axis errors to meet the actual requirements. Indirect measurement mainly compensates for errors by establishing a spatial error compensation model, but it is difficult to meet the error compensation requirements of various five-axis machine tools and does not have universality. Therefore, how to quickly and accurately compensate for the errors of five-axis machine tools has become the main obstacle to improving the accuracy of five-axis machine tools.

[0040] To solve this problem, the present invention aims to establish an error compensation method that is basically applicable to all types of five-axis machine tools, and to improve the machining accuracy of five-axis machine tools as much as possible without increasing costs and operation complexity.

[0041] The core idea of the present invention is: machining a measurement workpiece on a five-axis machine tool, adjusting the angles of the corresponding rotary axes of the five-axis machine tool during machining, machining multiple detection grooves at different positions of the measurement workpiece, calculating the dimensional errors of each detection groove in the five-axis coordinate system, and establishing a corresponding error compensation table to accurately compensate for the machine tool errors.

[0042] Refer to Figure 1 As shown, it is a flowchart of the error compensation method for a five-axis machine tool in an embodiment of the present invention. This error compensation method for a five-axis machine tool is basically applicable to all five-axis machine tools, and specifically includes the following steps:

[0043] S1. Machine a measurement workpiece.

[0044] Specifically, in this step, a measurement workpiece 1 needs to be pre-designed. The measurement workpiece 1 includes a top surface, a bottom surface, and multiple side surfaces. The top surface, the bottom surface, and the side surfaces are configured as planes or at least have planar parts. The top surface and the bottom surface are parallel to each other, and the side surfaces are perpendicular to both the top surface and the bottom surface. Measurement grooves 11 are machined on each side surface of the measurement workpiece 1 by the machine tool.

[0045] The designed shape and designed dimensions of each measurement groove 11 are the same. The groove body of the measurement groove 11 is roughly designed in the shape of a cuboid or a cube. The top of the measurement groove 11 penetrates through to the top surface of the measurement workpiece 1. The recessed direction of the measurement groove 11 is perpendicular to the corresponding side surface of the measurement workpiece 1, so that the bottom groove wall of the measurement groove 11 is parallel to the top surface of the measurement workpiece 1, and the left and right groove walls of the measurement groove 11 are perpendicular to the side surface of the measurement workpiece 1 where they are located and also perpendicular to the top surface of the measurement workpiece 1.

[0046] It should be noted that the angular range of the first rotating axis of the five-axis machine tool in this step includes at least -90° to 90°, and the angular range of the second rotating axis is generally -180° to 180°.

[0047] When machining and measuring the workpiece 1, the first rotating axis of the five-axis machine tool first rotates to a preset angle so that one side of the measuring workpiece 1 faces the tool, and the tool mills a measuring groove 11 on this side.

[0048] Optionally, the preset angle of the first rotating axis of the five-axis machine tool can be set to -90° or 90°.

[0049] After the first measuring groove 11 is machined, the second rotating axis of the five-axis machine tool rotates to adjust the angle of the measuring workpiece 1 on the second rotating axis so that another side of the measuring workpiece 1 faces the tool, and the tool mills a measuring groove 11 on this side.

[0050] Then repeat the above steps until measuring grooves 11 are milled on all sides of the measuring workpiece 1.

[0051] In an exemplary embodiment, the measuring workpiece 1 can be machined from a regular octagonal prism-shaped or a workpiece similar to a regular octagonal prism-shaped workpiece, and measuring grooves 11 are machined on all 8 sides of the regular octagonal prism-shaped workpiece. When machining the measuring groove 11, the angle of each rotation of the second rotating axis is 45°. When machining 8 measuring grooves 11, the angles of the second rotating axis are 0°, 45°, 90°, 135°, 180°, 225°, 270°, 315° and 330° in sequence.

[0052] In other embodiments, the measuring workpiece 1 can be machined from a regular polygonal prism-shaped workpiece of other shapes, such as a regular quadrangular prism-shaped, regular pentagonal prism-shaped or regular hexagonal prism-shaped workpiece.

[0053] It should be noted that with reference to Figure 2 As shown, there are 8 measuring points around each measuring groove 11, and the distribution positions of the 8 measuring points are as follows:

[0054] Measuring point one 111 and measuring point two 112 are located on the same side of the measuring workpiece 1, and measuring point one 111 and measuring point two 112 are respectively located on both sides of the measuring groove 11.

[0055] Measuring point three 113 is located on the rear groove wall of the measuring groove 11.

[0056] Measuring point four 114 and measuring point five 115 are respectively located on the left and right groove walls of the same measuring groove 11.

[0057] The measuring point six 116 and the measuring point seven 117 are respectively located on the top surfaces of two spaced parts on both sides of the measuring groove 11. The spaced part represents the structure formed between two adjacent measuring grooves 11.

[0058] The measuring point eight 118 is located on the bottom wall of the measuring groove 11.

[0059] It should be noted that the measuring point can be located at any point on the plane where it is located, and its position is not limited to the central area or the edge area of the plane where it is located. During actual measurement, it is only necessary to ensure that the probe can contact the corresponding plane where the measuring point is located.

[0060] In the following steps, taking the measuring workpiece 1 in the shape of a regular octagonal prism as an example, the subsequent steps will be further introduced.

[0061] S2. Measure the coordinate values (x ij , y ij , z ij ) of each measuring point around each of the measuring grooves 11 in a three-axis coordinate system, where i represents the serial number of the measuring groove 11 and j represents the serial number of the measuring point.

[0062] Specifically, in this step when detecting the coordinate values of the measuring points, the first rotation axis and the second rotation axis of the measuring workpiece 1 are restored to the 0° position, and the measuring workpiece 1 is in a horizontal placement position, that is, the top surface and the bottom surface of the measuring workpiece 1 are perpendicular to the Z axis. During the measurement process, the measuring workpiece 1 remains stationary, and the coordinate values (x ij , y ij , z ij ) of 8 detection points around each measuring point are detected by using a moving probe.

[0063] S3. Based on the coordinate values (x ij , y ij , z ij ) of each measuring point in the three-axis coordinate system, calculate the machining error (Δx αβi , Δy αβi , Δz αβi ) of each measuring groove 11 in a five-axis coordinate system.

[0064] Specifically, in this step, considering that the coordinate values obtained by the probe are the coordinate values in the three-axis coordinate system, if the dimensional error of the measuring groove 11 is calculated using the coordinate values in the three-dimensional coordinate system in the subsequent steps, the errors of the first rotation axis and the second rotation axis during the machining of the measuring groove 11 cannot be reflected.

[0065] Therefore, in this step, the dimensional error (Δx i , Δy i , Δz i ) of each measuring groove 11 in the five-axis coordinate system is specifically calculated according to the following steps.

[0066] S31. Convert the coordinate values (x ij , y ij , z ij ) of the measurement points in the three-axis coordinate system into the coordinate values (x βij , y βij , z βij ) relative to the second rotation axis.

[0067] Specifically, convert the coordinate values (x ij , y ij , z ij ) of the measurement points in the three-axis coordinate system into the coordinate values (x βij , y βij , z βij ) relative to the second rotation axis according to the following formula:

[0068] (x βij , y βij , z βij ) = (x ij , y ij , z ij ) · R β ;

[0069] where R β is the rotation matrix of the second rotation axis of the five-axis machine tool.

[0070] Furthermore, considering that the rotation direction of the turntable structure in the five-axis machine tool conforms to the left-hand rule, when the second rotation axis is the turntable rotation axis, the angle value in its rotation matrix is the negative value of the angle of the second rotation axis when machining the measurement groove 11.

[0071] Specifically, when the second rotation axis is the turntable rotation axis, the angle value β in its rotation matrix is β = -β i , and β i is the angle of the second rotation axis when machining the i-th measurement groove 11.

[0072] As an example, when the second rotation axis is the turntable rotation axis, the angle of the second rotation axis when the machine tool machines the second measurement groove 11 is 45°. When calculating the coordinate values (x βij , y βij , z βij ) of the measurement points relative to the second rotation axis, the angle value in the rotation matrix of the second rotation axis is taken as -45°.

[0073] S32. Calculate the machining error (Δx βij , Δy βij , z βij ) of the measurement groove 11 relative to the second rotation axis based on the coordinate values (x βi , Δyβi , Δz βi ), where β represents the angle of the second rotating shaft when machining the i-th measuring groove 11.

[0074] Specifically, the measurement points should be distributed as much as possible in the three dimensional directions of the measuring groove 11. To a certain extent, it can be understood that the measurement points are distributed as much as possible in the length, width, and height directions of the measuring groove 11. The length of the measuring groove 11 can be calculated by the difference in the measurement points in the length direction, the width of the measuring groove 11 can be calculated by the difference in the measurement points in the width direction, and the height of the measuring groove 11 can be calculated by the difference in the measurement points in the height direction.

[0075] As an example, referring to Figure 2 and Figure 3 shown, when measuring the coordinates of the measurement points, the workpiece to be measured is placed horizontally. At this time, the first measuring groove 11 is recessed along the X-axis direction and penetrates the top surface of the workpiece to be measured along the Z-axis. The two groove walls of the first measuring groove 11 on both sides of the X-axis are symmetrically distributed along the X-axis.

[0076] At this time, the machining error of each measuring groove 11 relative to the second rotating shaft can be calculated according to the following formula (Δx βi , Δy βi , Δz βi );

[0077]

[0078] Among them, L X is the designed horizontal depression depth of the measuring groove 11 when the workpiece to be measured 1 is placed horizontally (i.e., the theoretical dimension of the measuring groove 11 on the X-axis), and L Z is the designed vertical depression depth of the measuring groove 11 when the workpiece is placed horizontally (i.e., the theoretical dimension of the measuring groove 11 on the Z-axis).

[0079] The calculation principle of the above formula is: subtracting the designed dimension (i.e., the theoretical dimension) of the measuring groove 11 from the actual dimension of the measuring groove 11. The average value of the X-axis coordinate values of the first measurement point 111 and the second measurement point 112 can be used as the actual coordinate of the side surface of the measuring groove 11 on the X-axis. To a certain extent, it can be understood as the actual coordinate of the front groove wall (the front groove wall is a fictional groove wall) of the measuring groove 11 on the X-axis. The X-axis coordinate of the third measurement point 113 is the actual coordinate of the rear groove wall of the measuring groove 11 on the X-axis. Therefore, subtracting the actual coordinate of the rear groove wall of the measuring groove 11 on the X-axis from the actual coordinate of the front groove wall of the measuring groove 11 on the X-axis can obtain the actual dimension of the measuring groove 11 on the X-axis. Then, subtracting the theoretical dimension of the measuring groove 11 on the X-axis can obtain the X-axis dimension error of the measuring groove 11.

[0080] Similarly, the Z-axis dimensional error of the measurement groove 11 can also be calculated in the above manner. At this time, it is necessary to measure the Z-axis coordinate values of measurement point six 116, measurement point seven 117, and measurement point eight 118, and convert them into coordinate values relative to the second rotation axis, and then calculate the dimensional error of the measurement groove 11 on the Z-axis.

[0081] The Y-axis dimensional error of the measurement groove 11 can be obtained by measuring the Y-axis coordinate values of measurement point four 114 and measurement point five 115. Specifically, the average value of the Y-axis coordinates of measurement point four 114 and measurement point five 115 can be regarded as the actual coordinate of the Y-axis zero point. After subtracting the theoretical coordinate of the Y-axis zero point (the theoretical coordinate of the Y-axis zero point is 0), the Y-axis dimensional error of the measurement groove can be obtained.

[0082] S33. Based on the machining errors (Δx βi , Δy βi , Δz βi ) of each measurement groove 11 relative to the second rotation axis, calculate the machining errors (Δx αβi , Δy αβi , Δz αβi ) of each measurement groove 11 in the five-axis coordinate system. α represents the angle of the first rotation axis when machining the i-th measurement groove 11.

[0083] Specifically, calculate the machining errors (Δx αβi , Δy αβi , Δz αβi ) of each measurement groove 11 in the five-axis coordinate system according to the following formula:

[0084] (Δx αβi , Δy αβi , Δz αβi ) = (Δx βi , Δy βi , Δz βi ) · R α ;

[0085] Among them, R α is the rotation matrix of the first rotation axis of the five-axis machine tool.

[0086] Furthermore, considering that the rotation direction of the turntable structure in the five-axis machine tool applies the left-hand rule, when the first rotation axis is the turntable rotation axis, the angle value in its rotation matrix is the negative value of the angle of the first rotation axis when machining the measurement groove 11.

[0087] Specifically, when the first rotation axis is the turntable rotation axis, the angle value α in its rotation matrix = -α i , α i is the angle of the first rotation axis when machining the i-th measurement groove 11.

[0088] S4. Compensate for the machine tool error based on the machining error (Δx αβi , Δy αβi , Δz αβi ) of each measurement groove 11 in the five-axis coordinate system, the angle α i of the first rotation axis and the angle β i of the second rotation axis when machining each measurement groove 11.

[0089] Specifically, in this step, based on the machining error (Δx αβi , Δy αβi , Δz αβi ) of each measurement groove 11 in the five-axis coordinate system, the angle α i of the first rotation axis and the angle β i of the second rotation axis when machining each measurement groove 11, an error compensation table is established. For the angles of the first rotation axis and the second rotation axis not recorded in the error compensation table, the corresponding error compensation values can be obtained by using conventional interpolation methods and symmetry methods. The method of interpolating discrete error compensation data is well-known to those skilled in the art and will not be elaborated in the present invention.

[0090] The above are the specific steps of a five-axis machine tool error compensation method proposed by the present invention. Below, taking the machining of a regular octahedron measurement workpiece 1 by a five-axis machine tool as an example, the error compensation method of the present invention will be introduced.

[0091] 1. BC double-turntable five-axis machine tool

[0092] S1. Place the measurement workpiece 1 horizontally on the workbench, rotate the B axis to 90°, the C axis angle is 0°, the first side of the measurement workpiece 1 faces the tool, and the tool processes the first measurement groove 11 on the first side according to a pre-set program. The shape of the measurement groove 11 is approximately a cuboid or a cube.

[0093] Then the C axis rotates to 45°, 90°, 135°, 180°, 225°, 270° and 315° in sequence, and processes the measurement grooves 11 on the second to seventh sides of the measurement workpiece 1 respectively.

[0094] S2. The B axis and the C axis return to the 0° position, and the coordinate values (x ij , y ij , z ij ) of 8 measurement points around each measurement groove 11 in the three-axis coordinate system are detected by using a probe.

[0095] [[ID=(47]]S31. According to the calculation formula (x βij , y βij , z βij ) = (x ij , y ij , z ij)·R β The coordinate value (x ij ,y ij , z ij ) is converted to the coordinate value relative to the second rotation axis (x βij ,y βij , z βij ). The second rotation axis in this example is the C axis, and the rotation matrix of the C axis is as follows:

[0096]

[0097] Considering that the C axis is the rotary axis of the turntable in this example, the calculation formula (x βij ,y βij , z βij )=(x ij ,y ij , z ij )·R β The following calculation formula can be obtained by deduction:

[0098] x βij =x ij cos(-β i )-y ij sin(-β i )

[0099] y βij =x ij sin(-β i )+y ij cos(-β i ).

[0100] S32, calculate the machining error (Δx βi , Δy βi , Δz βi ):

[0101]

[0102] S33, according to the calculation formula (Δx αβi , Δy αβi , Δz αβi )=(Δx βi , Δy βi , Δz βi )·R α Calculate the machining error (Δx αβi , Δy αβi , Δz αβi ), the first rotation axis in this example is the B axis, and the rotation matrix of the B axis is as follows:

[0103]

[0104] Considering that the B-axis is the rotary axis of the turntable in this example, the calculation formula (Δx αβi , Δy αβi , Δz αβi ) = (Δx βi , Δy βi , Δz βi ) · R α is derived to obtain the following calculation formula:

[0105]

[0106] The error compensation data in the following table are the actual compensation data obtained based on the error compensation method of the present invention.

[0107] Table 1 - X-axis compensation

[0108]

[0109]

[0110] Table 2 - Y-axis compensation

[0111]

[0112] Table 3 - Z-axis compensation

[0113]

[0114] Based on the above compensation data, it can be seen that at least 50% of the rotary axis error can be compensated by the error compensation method of the present invention, greatly improving the machining accuracy of the five-axis machine tool.

[0115] In addition, it should be noted that the B-axis angle does not appear in the compensation table because the B-axis angle is always 90° when machining the measurement groove 11. In the actual machining process, when the B-axis angle is 90° and the C-axis angle is a multiple of 0° or 45°, the corresponding error compensation data in the above table can be directly used to compensate the machine tool error. When the B-axis angle is -90° and the C-axis angle is a multiple of 0° or 45°, the corresponding error compensation data in the above table is taken as a negative value, and then the machine tool error is compensated. When the B-axis angle is 30° and the C-axis angle is a multiple of 0° or 45°, the corresponding error compensation data in the above table is multiplied by (1 / 3), and then the machine tool error is compensated. And so on, when the C-axis angle does not appear in the above table, the corresponding error compensation data can be obtained by interpolation using the error compensation data corresponding to the two adjacent angles of this angle.

[0116] 2. B-axis swivel head and C-axis rotary table five-axis machine tool

[0117] The machining method for measuring workpiece 1 in this example is similar to that of a BC dual-turret five-axis machine tool. The difference is that the B-axis is a swing head rotation axis and is applicable to the right-hand rule. The calculation formula finally derived in step S33 is as follows:

[0118]

[0119] 3. CB double-swing head five-axis machine tool

[0120] The machining method for measuring workpiece 1 in this example is similar to that of a BC dual-turret five-axis machine tool. The difference is that the B-axis and C-axis are swing head rotation axes and are applicable to the right-hand rule. The calculation formula finally derived in step S31 is as follows:

[0121]

[0122] The calculation formula finally derived in step S33 is as follows:

[0123]

[0124] The above examples mainly show the corresponding calculation steps for a five-axis machine tool with a B-axis and a C-axis. For a five-axis machine tool with an A-axis and a B-axis, or with an A-axis and a C-axis, the calculation steps are similar to the above examples. The only difference is that the corresponding rotation matrix needs to be selected according to the rotation axis. The rotation matrix in the corresponding calculation formula is simply replaced, and the essence of the corresponding technical solution does not deviate from the spirit and scope of the technical solution of the embodiment of the present invention.

[0125] Reference Figure 4 As shown, based on the same inventive concept as the aforementioned five-axis machine tool error compensation method, an embodiment of the present invention further provides a five-axis machine tool error compensation system 2, which includes a data acquisition module 21, a data processing module 22 and a compensation module 23.

[0126] The data acquisition module 21 is used to obtain the coordinate values (x ij ,y ij , z ij The data processing module 21 is used to process the coordinate value (x ij ,y ij , z ij ), calculate the machining error (Δx αβi , Δy αβi , Δz αβi The compensation module 23 is used to compensate for the machining error (Δx αβi , Δyαβi , Δz αβi ), the angle α of the first rotating shaft when machining each measuring groove 11 i and the angle β of the second rotating shaft i Compensate for the machine tool error.

[0127] Referring to Figure 5 As shown, an embodiment of the present invention further provides an electronic device 3. The electronic device 3 includes at least one processor 31, a memory 32 (such as a non-volatile memory), a memory 33, and a communication interface 34, and the at least one processor 31, the memory 32, the memory 33, and the communication interface 34 are connected together via an internal bus 35. The at least one processor 31 is configured to call at least one program instruction stored or encoded in the memory, so that the at least one processor 31 performs various operations and functions of the five-axis machine tool error compensation method described in each embodiment of this specification.

[0128] In an embodiment of the present invention, the electronic device 3 may include, but is not limited to: a personal computer, a server computer, a workstation, a desktop computer, a laptop computer, a notebook computer, a mobile electronic device, a smart phone, a tablet computer, a cellular phone, a personal digital assistant (PDA), a handheld device, a messaging device, a wearable electronic device, a consumer electronic device, and the like.

[0129] An embodiment of the present invention further provides a computer-readable storage medium. The computer-readable storage medium may have instructions (i.e., the above elements implemented in software form), and when the instructions are executed by a machine, the machine is caused to perform various operations and functions described above in connection with Figures 1 to 5 each embodiment of this specification. Specifically, a system or device equipped with a readable storage medium may be provided, and a software program code for implementing the functions of any one of the above embodiments is stored on the readable storage medium, and the computer or processor of the system or device is caused to read and execute the instructions stored in the readable storage medium.

[0130] The computer-readable medium in the present invention can be a computer-readable signal medium, a computer-readable storage medium, or any combination of the two. A computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the above. More specific examples of the computer-readable storage medium can include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present invention, the computer-readable storage medium can be any tangible medium that contains or stores a program, which can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0131] In the present invention, a computer-readable signal medium can include a data signal propagated in a baseband or as part of a carrier wave, which carries computer-readable program code. Such a propagated data signal can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. The computer-readable signal medium can also be any computer-readable medium other than a computer-readable storage medium, which can send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium can be transmitted using any appropriate medium, including but not limited to: wireless, wire, optical fiber, RF, etc., or any suitable combination of the above.

[0132] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a system, or a computer program product. Therefore, the present invention can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memory, CD-ROM, optical memory, etc.) that contain computer-usable program code.

[0133] The present invention is described with reference to the flowcharts and / or block diagrams of methods, apparatuses, systems, and computer program products according to embodiments of the present invention. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of flows and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate for implementing the processFigure 1 means for the functions specified in one process or a plurality of processes and / or boxes Figure 1 or a plurality of boxes.

[0134] The foregoing description of specific exemplary embodiments of the invention has been presented for purposes of illustration and example. Such descriptions are not intended to limit the invention to the precise forms disclosed, and it is apparent that, in light of the above teaching, many modifications and variations are possible. The purpose of selecting and describing the exemplary embodiments was to explain the specific principles of the invention and its practical application so as to enable others skilled in the art to make and utilize various different exemplary embodiments of the invention, as well as various different selections and modifications. The scope of the invention is intended to be defined by the claims and their equivalents.

[0135] It will be apparent to those skilled in the art that the invention is not limited to the details of the foregoing exemplary embodiments, and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics thereof. Accordingly, in all respects, the embodiments are to be regarded as illustrative and not restrictive, the scope of the invention being defined by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. No reference signs in the claims should be construed as limiting the claims concerned.

[0136] In addition, it should be understood that although this specification is described in terms of embodiments, not every embodiment contains only a single independent technical solution, and this narrative manner of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A five-axis machine tool error compensation method, characterized in that, Including: Rotate the first rotation axis to machine a measurement groove on one side of the workpiece to be measured, and a plurality of measurement points are formed around the measurement groove; Rotate the second rotation axis to machine a measurement groove on the other side of the workpiece to be measured; Repeat the step of rotating the second rotation axis until measurement grooves are machined on all of the preset sides of the workpiece to be measured; Measure the coordinate values (x ij , y ij , z ij ) of multiple measurement points around each of the measurement slots, where i represents the serial number of the measurement slot and j represents the serial number of the measurement point; Based on the coordinate values (x ij , y ij , z ij ) of each of the said measurement points in a three-axis coordinate system, calculate the machining errors (Δx αβi , Δy αβi , Δz αβi ) of each of the said measurement grooves in a five-axis coordinate system; Based on the machining errors (Δx αβi , Δy αβi , Δz αβi ) of each of the said measurement slots in a five-axis coordinate system, the angle α i of the first rotating axis and the angle β i of the second rotating axis during machining of each measurement slot, compensate for the machine tool errors.

2. The error compensation method for a five-axis machine tool according to claim 1, wherein, The workpiece to be measured includes a top surface, a bottom surface and a plurality of side surfaces. The shape of the measurement groove is generally a cuboid or a cube, and the depression direction is perpendicular to the side surface of the workpiece to be measured. The measurement groove also penetrates through the top surface of the workpiece to be detected, and a spacing portion is formed between two adjacent measurement grooves; Eight measurement points are provided around each measurement groove. When the workpiece to be measured is placed horizontally, measurement point one and measurement point two are on the same side surface of the workpiece to be measured and are respectively located on both sides of the measurement groove, measurement point three is on the rear side wall of the measurement groove, measurement point four and measurement point five are respectively on the left and right side walls of the measurement groove, measurement point six and measurement point seven are respectively on the top surfaces of the two spacing portions on both sides of the measurement groove, and measurement point eight is on the bottom side wall of the measurement groove.

3. The error compensation method for a five-axis machine tool according to claim 2, wherein Calculating the machining error (Δx αβi , Δy αβi , Δz αβi ) of each of the measurement grooves in the five-axis coordinate system, including: Convert the coordinate values (x ij , y ij , z ij ) of the measurement point in the three-axis coordinate system into the coordinate values (x βij , y βij , z βij ) relative to the second rotation axis; Based on the coordinate values (x βij , y βij , z βij ) of each of the said measurement points relative to the second rotation axis, calculate the machining error (Δx βi , Δy βi , Δz βi ) of the measurement groove relative to the second rotation axis; Based on the machining errors (Δx βi , Δy βi , Δz βi ) of each of the measurement slots relative to the second rotation axis, calculate the machining errors (Δx αβi , Δy αβi , Δz αβi ) of each of the measurement slots in the five-axis coordinate system.

4. The error compensation method for a five-axis machine tool according to claim 3, wherein Convert the coordinate values (x ij , y ij , z ij ) of the measurement point in the three-axis coordinate system into the coordinate values (x βij , y βij , z βij ) relative to the second rotation axis according to the following formula: (x βij , y βij , z βij ) = (x ij , y ij , z ij ) · R β ; Among them, R β is the rotation matrix of the second rotating axis of the five-axis machine tool.

5. The error compensation method for a five-axis machine tool according to claim 4, characterized in that, When the second rotation axis is the rotary table rotation axis, the angle value β in its rotation matrix is β = -β i , β i is the angle of the second rotation axis when machining the i-th measurement groove.

6. The error compensation method for a five-axis machine tool according to claim 3, wherein When measuring the coordinates of the measurement points, the workpiece to be measured is placed horizontally; Calculate the machining error (Δx βi , Δy βi , Δz βi ) of each of the said measurement grooves relative to the second rotation axis according to the following formula; Among them, L X is the designed horizontal depression depth of the measurement groove when the workpiece is placed horizontally, and L Z is the designed vertical depression depth of the measurement groove when the workpiece is placed horizontally.

7. The error compensation method for a five-axis machine tool according to claim 3, characterized in that Calculate the machining error (Δx αβi , Δy αβi , Δz αβi ) of each of the said measurement grooves in the five-axis coordinate system according to the following formula: (Δx αβi , Δy αβi , Δz αβi ) = (Δx βi , Δy βi , Δz βi ) · R α ; wherein, R α is the rotation matrix of the first rotating axis of the five-axis machine tool.

8. The error compensation method for a five-axis machine tool according to claim 7, characterized in that, When the first rotation axis is the rotary table rotation axis, the angle value α in its rotation matrix is α = -α i , α i is the angle of the first rotation axis when machining the i-th measurement groove.

9. A five-axis machine tool error compensation system, characterized in that, Including: A data acquisition module for obtaining the coordinate values (x ij , y ij , z ij ) of multiple measurement points around a measurement groove of a measured workpiece, where i represents the serial number of the measurement groove and j represents the serial number of the measurement point. The measurement groove is obtained by machining on the side surface of the measured workpiece after rotating a first rotating shaft and a second rotating shaft, and a plurality of the measurement points are formed around the measurement groove; A data processing module, which is used to calculate the machining error (Δx ij , Δy ij , Δz ij ) of each measurement slot in a five-axis coordinate system based on the coordinate values (x αβi , y αβi , z αβi ) of each measurement point in a three-axis coordinate system; Compensation module, for compensating for machine tool errors based on the machining errors (Δx αβi , Δy αβi , Δz αβi ) of each of the measurement slots in a five-axis coordinate system, the angle α i of the first rotating axis and the angle β i of the second rotating axis when machining each measurement slot.

10. An electronic device, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the five-axis machine tool error compensation method according to any one of claims 1 to 8.

11. A computer-readable medium, characterized in that, The computer-readable medium carries computer-executable instructions, and when the computer-executable instructions are executed by a processor, they are used to implement the five-axis machine tool error compensation method according to any one of claims 1 to 8.

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