Method and device for calibrating a machine tool

Abstract

The present invention relates to a method and an apparatus for calibrating a machine tool. The method comprises the steps of: a) moving at least one of a first axis and a second axis of the machine tool and acquiring at least three light spot positions by a light spot acquisition device, the at least three light spots corresponding to the at least three light spot positions being located on a light spot track formed by a light beam emitted from a light beam emitting device of the machine tool during the movement, wherein a first axis coordinate of at least two sets of coordinates of the machine tool when the at least three light spots are formed is different from each other, and a second axis coordinate of at least two sets of coordinates of the machine tool when the at least three light spots are formed is different from each other; and b) calibrating an included angle between a movement direction of the first axis and a movement direction of the second axis based on the acquired at least three light spot positions and the corresponding first axis coordinates and second axis coordinates of the machine tool when the at least three light spots are formed. The present invention also provides a corresponding apparatus.

Description

Technical Field

[0001] The present invention relates to the field of machine tool processing, and more particularly to a method and device for calibrating a machine tool. Background Art

[0002] Machine tool processing plays a vital role in modern mechanical manufacturing. Parts with high precision requirements and fine surface roughness requirements generally need to be finally processed on machine tools.

[0003] For multi-axis machine tools, the machining head can be moved by at least one translation axis, or the posture of the machining head can be rotated by at least one rotation axis. Ideally, the movement directions of the axes should be coplanar. For example, Figure 2 As described above, the machining head is driven by the translation axis X axis to translate from position 1 to position 2, and then driven by the rotation axis B axis to rotate from posture 2 to posture 3. Ideally, the translation direction and the rotation direction should be Figure 2 However, in reality, due to errors in the manufacturing and installation process, the movement directions of the various axes of the machine tool may not be coplanar (the movement directions of the various axes are at a certain angle to each other), such as the above Figure 2 The X-axis movement direction is as follows Figure 2 The translational component shown in the figure also has a component perpendicular to the paper, while the B-axis's motion is completely along the paper. At this point, if machining is still performed according to the ideal assumption (i.e., the motion directions of all machine tool axes are coplanar), the machining path will be deformed. Therefore, it is necessary to calibrate the angles between the motion directions of the machine tool's axes.

[0004] One existing calibration method uses laser tracker measurements to calculate the motion directions of each tool's axes and, in turn, the angles between them. However, this method is prohibitively expensive due to the use of a laser tracker. While this method can also use a camera instead of a laser tracker, camera photography is equally expensive and offers poor accuracy. Another existing calibration method uses a marble and a dial / micrometer indicator to calculate the angles between the motion directions of each tool's axes. This method is complex, requires a flat marble base, and is also costly.

[0005] Therefore, there is an urgent need for a new technology that can calibrate the angles between the motion directions of each axis of a multi-axis machine tool conveniently and accurately at a low cost. Summary of the Invention

[0006] The present application aims to overcome the above and / or other problems in the prior art. The method and device for calibrating a machine tool provided by the present application can calibrate the included angle between the movement directions of each axis of the machine tool very conveniently and accurately by additionally using a light spot collecting device, thereby improving the machining accuracy of the machine tool.

[0007] According to a first aspect of the present application, a method for calibrating a machine tool is provided, which can comprise the following steps: a) moving at least one of a first axis and a second axis of the machine tool, and collecting at least three light spot positions by a light spot collecting device, the at least three light spots corresponding to the at least three light spot positions being located on a light spot track formed by a light beam during the movement, wherein the first axis coordinates of at least two groups of coordinates of the machine tool when the at least three light spots are formed are different from each other, and the second axis coordinates of at least two groups of coordinates of the machine tool when the at least three light spots are formed are different from each other; and b) calibrating the included angle between the movement direction of the first axis and the movement direction of the second axis based on the collected at least three light spot positions and the corresponding first axis coordinates and second axis coordinates of the machine tool when the at least three light spots are formed.

[0008] According to a second aspect of the present application, a device for calibrating a machine tool is also correspondingly provided, which can comprise a light spot collecting device, a control unit and a calibration unit. The light spot collecting device can be used to collect the light spot positions of a light beam emitted from a light beam emitting device of the machine tool. The control unit can be configured to control the movement of at least one of a first axis and a second axis of the machine tool, and control the light spot collecting device to collect at least three light spot positions, the at least three light spots corresponding to the at least three light spot positions being located on a light spot track formed by the light beam during the movement, wherein the first axis coordinates of at least two groups of coordinates of the machine tool when the at least three light spots are formed are different from each other, and the second axis coordinates of at least two groups of coordinates of the machine tool when the at least three light spots are formed are different from each other. The calibration unit can be configured to calibrate the included angle between the movement direction of the first axis and the movement direction of the second axis based on the collected at least three light spot positions and the corresponding first axis coordinates and second axis coordinates of the machine tool when the at least three light spots are formed.

[0009] The present application ingeniously utilizes the light beam emitted by the light beam emitting device carried by the machine tool itself to map the movement of the two axes of the machine tool to be calibrated to the movement of the light spots. On this basis, only the additional light spot collecting device is needed to collect at least three light spot positions, and the included angle between the movement directions of the two axes to be calibrated can be calculated based on the collected light spot positions and the known machine tool coordinates corresponding to the light spot positions. The operation of the calibration process is very convenient, and the cost is also low, and the stability and accuracy of the collected light spot position data are very high, so that the included angle between the movement directions of the two axes to be calibrated can be calibrated very accurately.

[0010] In the calibration method of the present application, step b) can include: calculating a first included angle of the movement direction of the first axis relative to the coordinate system of the light spot collecting device and a second included angle of the movement direction of the second axis relative to the coordinate system of the light spot collecting device based on the collected at least three light spot positions and the corresponding first axis coordinates and second axis coordinates of the machine tool when the at least three light spots are formed; and obtaining the included angle between the movement direction of the first axis and the movement direction of the second axis based on the first included angle and the second included angle. Accordingly, in the calibration device of the present application, the calibration unit can be further configured to: calculate a first included angle of the movement direction of the first axis relative to the coordinate system of the light spot collecting device and a second included angle of the movement direction of the second axis relative to the coordinate system of the light spot collecting device based on the collected at least three light spot positions and the corresponding first axis coordinates and second axis coordinates of the machine tool when the at least three light spots are formed; and obtain the included angle between the movement direction of the first axis and the movement direction of the second axis based on the first included angle and the second included angle.

[0011] In the calibration method of the present application, step a) can include simultaneously moving the first axis and the second axis, or step a) can also include moving the first axis and the second axis respectively. Accordingly, in the calibration device of the present application, the control unit can be further configured to: control the first axis and the second axis to move simultaneously, and control the light spot collecting device to collect at least three light spot positions located on the light spot track formed by the light beam during the movement; or control the first axis and the second axis to move respectively, and control the light spot collecting device to collect at least three light spot positions located on the light spot track formed by the light beam during the movement.

[0012] By moving the two axes to be calibrated together, the interference caused by the random errors of the two axes respectively can be diluted, thereby further improving the stability and accuracy of the calibration.

[0013] According to a third aspect of the present application, there is provided a computer readable storage medium having encoded instructions recorded thereon, which when executed implement the method for calibrating a machine tool according to the present application.

[0014] According to a fourth aspect of the present application, there is provided a computer program product comprising a computer program which when executed implements the method for calibrating a machine tool according to the present application.

[0015] Other features and aspects of the present application will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the application. BRIEF DESCRIPTION OF DRAWINGS

[0016] The application can be better understood with reference to the following examples in conjunction with the accompanying drawings, in which:

[0017] Figure 1 A flow chart of the method for calibrating a machine tool according to the present application is shown;

[0018] Figure 2 A schematic diagram of a machine tool machining head in motion under drive of the various axes is shown;

[0019] Figure 3 A schematic diagram of a machine tool machining head when calibrating a machine tool according to the present application is shown;

[0020] Figure 4 A flow chart of an extended embodiment of the method for calibrating a machine tool according to the present application; and

[0021] Figure 5 A block diagram of the structure of an apparatus for calibrating a machine tool according to the present application. DETAILED DESCRIPTION

[0022] The application will be further described with reference to the drawings, in which:

[0023] Unless otherwise defined, the technical or scientific terms used in the claims and description shall have the ordinary meaning understood by persons of ordinary skill in the technical field to which the invention belongs. The words "first", "second" and similar terms used in the description and claims of this application do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "one" or "a" do not indicate a quantity limitation, but rather indicate the presence of at least one. Words such as "include" or "comprising" mean that the elements or objects appearing before "include" or "comprising" cover the elements or objects listed after "include" or "comprising" and their equivalents, and do not exclude other elements or objects. Words such as "connected" or "connected" and similar terms are not limited to physical or mechanical connections, nor are they limited to direct or indirect connections.

[0024] According to an embodiment of the present invention, a method for calibrating a machine tool is provided.

[0025] Figure 1 A method 100 for calibrating a machine tool according to an embodiment of the present invention is shown, which includes step 120 and step 140 .

[0026] In step 120, at least one of the first axis and the second axis of the machine tool is moved, and at least three light spot positions are collected by a light spot collection device, and at least three light spots corresponding to the at least three light spot positions are located on a light spot trajectory formed by the light beam emitted from the light beam emitting device of the machine tool during the movement.

[0027] Taking a five-axis machine tool as an example, the first axis and the second axis can be a translation axis and a rotation axis, for example Figure 2 The X-axis and B-axis in the figure, or both can be translation axes, such as the X-axis and the Y-axis, or both can be rotation axes, such as the A-axis and the B-axis.

[0028] Ke Ru Figure 3 As shown, a light spot collection device is provided below the machining head of the machine tool. The light spot collection device can be, for example, a camera (such as a CCD camera), a PSD photoelectric position sensor, or other sensing devices. The light beam emitted from the beam emitting device of the machine tool passes through the end of the machining head and reaches the surface of the light spot collection device, thereby forming a light spot. Figure 2 For example, if the X-axis and B-axis in the image are coplanar, the light spot on the image acquisition device will always be on a straight line or parallel to each other, that is, the light spot trajectory will be a straight line or several parallel straight lines. However, if the movement directions of the two axes form an angle, for example, the movement direction of the X-axis is different from the direction of the image acquisition device. Figure 2In this case, the movement directions of the X-axis and the B-axis are not coplanar, and the spot trajectory formed by the movement of the X-axis and the B-axis is also not a straight line. Therefore, the spot trajectory formed by the movement of the X-axis and the B-axis can be used to determine whether the movement directions of the X-axis and the B-axis are coplanar. In this case, the spot trajectory formed by the movement of the X-axis and the B-axis is not a straight line, and the movement directions of the X-axis and the B-axis are not coplanar. Therefore, the spot trajectory formed by the movement of the X-axis and the B-axis can be used to determine whether the movement directions of the X-axis and the B-axis are coplanar.

[0029] It should be particularly noted that since the spot trajectory during the movement of the machine tool axis to be calibrated has been recorded by the spot acquisition device during the movement, although the spot acquisition device needs to acquire at least three spot positions on the spot trajectory formed during the movement of the axis to be calibrated, the acquisition operation does not necessarily need to be performed during the movement of the axis to be calibrated, but can also be performed after the movement.

[0030] In addition, during the formation of the spot trajectory, the two axes of the machine tool to be calibrated do not need to move at the same time all the time, but can be Figure 2 For example, sometimes only the X-axis moves, sometimes only the B-axis moves, or sometimes both the X-axis and the B-axis move, as long as there are at least three spot positions on the spot trajectory, and the X-axis coordinates of at least two groups of machine tool coordinates corresponding to the formation of the corresponding spots are different from each other (i.e., the X-axis coordinates of at least three groups of machine tool coordinates corresponding to the at least three spot positions are not completely the same), and the B-axis coordinates of at least two groups of machine tool coordinates corresponding to the formation of the corresponding spots are different from each other (i.e., the B-axis coordinates of at least three groups of machine tool coordinates corresponding to the at least three spot positions are not completely the same).

[0031] For example, the machine tool to be calibrated is a five-axis machine tool, and the axes to be calibrated of the machine tool are the translational axis X-axis and the rotational axis B-axis. The coordinates of the three acquired spot positions on the surface of the spot acquisition device are [Cx1 Cy1] (spot 1), [Cx2 Cy2] (spot 2), and [Cx3 Cy3] (spot 3). The coordinates of the machine tool when forming the spot 1 are [X1 Y Z A B1], the coordinates of the machine tool when forming the spot 2 are [X2 Y Z A B2], and the coordinates of the machine tool when forming the spot 3 are [X3 Y Z A B3]. It needs to be ensured that X1, X2, and X3 are not completely the same, for example, X1 = X2 ≠ X3, or X1 ≠ X2 = X3, or X1 = X3 ≠ X2, or X1 ≠ X2 ≠ X3, and B1, B2, and B3 are not completely the same, for example, B1 = B2 ≠ B3, or B1 ≠ B2 = B3, or B1 = B3 ≠ B2, or B1 ≠ B2 ≠ B3.

[0032] It can be understood that, because the angle between the movement direction of the X-axis and the movement direction of the B-axis is to be calibrated, the translation axis Y-axis, the lifting axis Z-axis and the rotation axis A-axis are all kept still during the formation of the spot trajectories, and correspondingly, the Y-axis coordinate, the Z-axis coordinate and the A-axis coordinate in the machine tool coordinate are all kept unchanged when the spots 1-3 are formed. If the angle between the movement direction of another combination of two axes (for example, the X-axis and the Y-axis) is to be calibrated, the coordinates of the remaining three axes (for example, the Z-axis, the A-axis and the B-axis) in the machine tool coordinate are kept unchanged when the spots 1-3 are formed, and thus will not be described herein.

[0033] Returning to Figure 1 , then in step 140, the angle between the movement direction of the first axis and the movement direction of the second axis is calibrated based on the collected at least three spot positions and the corresponding first axis coordinate and second axis coordinate of the machine tool when the at least three spots are formed.

[0034] For the machine tool coordinate system and the area coordinate system of the spot collecting device, they can be converted to each other through a corresponding conversion matrix, and the collected spot positions are two-dimensional coordinates in the area coordinate system of the spot collecting device, and thus can be converted to each other with the machine tool coordinate.

[0035] Still taking the above five-axis machine tool as an example, and the axes to be calibrated of the machine tool are still the translation axis X-axis and the rotation axis B-axis. When the machining head moves or changes the posture under the driving of the X-axis or the B-axis, the X-axis coordinate or the B-axis coordinate in the machine tool coordinate will change, and correspondingly, the two-dimensional coordinates [Cx Cy] of the collected spot positions will also change. The vector matrix [ux vx] can be used to represent the relationship between the change of the X-axis coordinate and the change of the two-dimensional coordinates [Cx Cy], and the vector matrix [ub vb] can be used to represent the relationship between the change of the B-axis coordinate and the change of the two-dimensional coordinates [Cx Cy]. Thus, for each collected spot position, the following vector equation (1) is established:

[0036] X*[ux vx] + B*[ub vb] + [u0 v0] = [Cx Cy] (1)

[0037] Wherein, X and B are respectively the X-axis coordinate and the B-axis coordinate in the machine tool coordinate when the spot is formed, and the vector matrix [u0 v0] represents the deviation between the zero point of the machine tool coordinate system and the zero point of the area coordinate system of the spot collecting device.

[0038] When three spot positions are collected as described in step 120, the following vector equation can be obtained:

[0039] X1*[ux vx] + B1*[ub vb] + [u0 v0] = [Cx1 Cy1] (2)

[0040] X2*[ux vx] + B2*[ub vb] + [u0 v0] = [Cx2 Cy2] (3)

[0041] X3*[ux vx] + B3*[ub vb] + [u0 v0] = [Cx3 Cy3] (4)

[0042] Wherein, X1, X2 and X3 are respectively X-axis coordinates in the machine tool coordinate when forming the light spot 1, the light spot 2 and the light spot 3, B1, B2 and B3 are respectively B-axis coordinates in the machine tool coordinate when forming the light spot 1, the light spot 2 and the light spot 3, [Cx1 Cy1] is two-dimensional coordinates of the light spot 1 under the plane coordinate system of the light spot acquisition device, [Cx2 Cy2] is two-dimensional coordinates of the light spot 2 under the plane coordinate system of the light spot acquisition device, [Cx3 Cy3] is two-dimensional coordinates of the light spot 3 under the plane coordinate system of the light spot acquisition device. The above X1, X2 and X3 and B1, B2 and B3 can be obtained from the servo unit of the machine tool, [Cx1 Cy1], [Cx2 Cy2] and [Cx3 Cy3] can be obtained from the light spot acquisition device, so that the six unknown numbers of ux, vx, ub, vb, u0 and v0 can be solved from the above three vector equations (2)-(4) (equivalent to six equations), and the angle between the X-axis movement direction and the B-axis movement direction can be calculated based on the solved ux and vx (respectively, the components of the two-dimensional direction mapped to the light spot position when the X-axis moves) and ub and vb (respectively, the components of the two-dimensional direction mapped to the light spot position when the B-axis moves).

[0043] The calibration method of the present application ingeniously maps the movement of the machine tool axis to be calibrated to the two-dimensional plane coordinate system of the light spot acquisition device, thereby converting the calibration of the angle between the movement directions of the two axes into the calculation of the angle between two straight lines in the two-dimensional coordinate system, which brings great convenience to data acquisition and calculation after data acquisition, and significantly improves the calibration accuracy and efficiency, and reduces the calibration cost compared with the prior art. By using the calibration method of the present application to calibrate the angle between the movement directions of each axis of the machine tool, the machining precision of the machine tool can be significantly improved.

[0044] Optionally, the step 140 can include sub-step 142 and sub-step 144 as shown in the figure. Figure 4

[0045] ​In sub-step 142, a first included angle between the movement direction of the first axis and a coordinate system of the light spot collecting device and a second included angle between the movement direction of the second axis and the coordinate system of the light spot collecting device can be calculated based on the collected at least three light spot positions and the corresponding first axis coordinate and second axis coordinate of the machine tool when the at least three light spots are formed.

[0046] In sub-step 144, an included angle between the movement direction of the first axis and the movement direction of the second axis can be obtained based on the first included angle and the second included angle.

[0047] Continuing with the above five-axis machine tool as an example, and the axes of the machine tool to be calibrated are still the translational axis X-axis and the rotational axis B-axis. As previously described, ux and vx are respectively the components of the two dimensional directions (x-axis direction and y-axis direction in the plane coordinate system of the light spot collecting device) of the light spot position when the X-axis moves, and ub and vb are respectively the components of the two dimensional directions (x-axis direction and y-axis direction in the plane coordinate system of the light spot collecting device) of the light spot position when the B-axis moves, so after ux and vx and ub and vb are solved based on the above vector equations (2)-(4), the included angle 1 between the movement direction of the light spot when the X-axis moves and the x-axis of the plane coordinate system of the light spot collecting device can be obtained by calculating arctan(vx / ux), and the included angle 1 represents the included angle between the movement direction of the X-axis and the x-axis of the plane coordinate system of the light spot collecting device. The included angle 2 between the movement direction of the light spot when the B-axis moves and the x-axis of the plane coordinate system of the light spot collecting device can be obtained by calculating arctan(vb / ub), and the included angle 2 represents the included angle between the movement direction of the B-axis and the x-axis of the plane coordinate system of the light spot collecting device. Alternatively, the included angle 1 between the movement direction of the light spot when the X-axis moves and the y-axis of the plane coordinate system of the light spot collecting device can be obtained by calculating arctan(ux / vx), and the included angle 1 represents the included angle between the movement direction of the X-axis and the y-axis of the plane coordinate system of the light spot collecting device. The included angle 2 between the movement direction of the light spot when the B-axis moves and the y-axis of the plane coordinate system of the light spot collecting device can be obtained by calculating arctan(ub / vb), and the included angle 2 represents the included angle between the movement direction of the B-axis and the y-axis of the plane coordinate system of the light spot collecting device. The above included angles 1 and 2 are the included angles under the same reference (the plane coordinate system of the light spot collecting device), so the included angle between the movement direction of the X-axis and the movement direction of the B-axis can be obtained based on the two included angles.

[0048] Optionally, the step 120 can include moving the first axis and the second axis respectively.

[0049] Continuing with the above five-axis machine tool as an example, and the axes of the machine tool to be calibrated are still the translational axis X-axis and the rotational axis B-axis. In step 120, if the vector equation of the collected light spot position 1 is still:

[0050] X1*[ux vx] + B1*[ub vb] + [u0 v0] = [Cx1 Cy1] (2)

[0051] Then, the X-axis drives the machining head to move a distance (the X-axis coordinate in the machine coordinate becomes X2) based on the position and posture of the above-mentioned light spot 1, and the B-axis is not moved, and thus the vector equation of the light spot position 2 is:

[0052] X2*[ux vx] + B1*[ub vb] + [u0 v0] = [Cx2 Cy2] (5)

[0053] Next, the B-axis drives the machining head to rotate an angle (the B-axis coordinate in the machine coordinate becomes B2) based on the position and posture of the above-mentioned light spot 1, and the X-axis is not moved, and thus the vector equation of the light spot position 3 is:

[0054] X1*[ux vx] + B2*[ub vb] + [u0 v0] = [Cx3 Cy3] (6)

[0055] Subtracting the above-mentioned vector equations (2) and (5) from each other, [(Cx1-Cx2) / (X1-X2), (Cy1-Cy2) / (X1-X2)] is obtained, and X1, X2, Cx1, Cx2, Cy1 and Cy2 are all known, and thus the values of ux and vx can be calculated. Similarly, the above-mentioned vector equations (2) and (6) can be subtracted from each other, and ub and vb can be calculated. As described above, the arctangent function is operated on ux and vx and ub and vb, and thus the angle between the X-axis movement direction and the light spot collecting device coordinate system and the angle between the B-axis movement direction and the light spot collecting device coordinate system can be obtained, and thus the angle between the X-axis movement direction and the B-axis movement direction can be calibrated.

[0056] For the above-mentioned light spot 3, the B-axis drives the machining head to rotate an angle based on the position and posture of the above-mentioned light spot 2, and the X-axis is not moved, and thus the vector equation of the light spot position 3 is:

[0057] X2*[ux vx] + B2*[ub vb] + [u0 v0] = [Cx3 Cy3] (7)

[0058] In this case, the above-mentioned vector equations (5) and (7) can be subtracted from each other, and ub and vb can be calculated.

[0059] Alternatively, the step 120 can include moving the first axis and the second axis simultaneously.

[0060] Continuing with the above five-axis machine tool as an example, and the axes of the machine tool to be calibrated are still the translational axis X-axis and the rotational axis B-axis. In step 120, if the vector equation of the collected light spot position 1 is still:

[0061] X1*[ux vx] + B1*[ub vb] + [u0 v0] = [Cx1 Cy1] (2)

[0062] From light spot 1 to light spot 2, only the X-axis or only the B-axis can still be moved, i.e. the vector equation of the light spot position 2 is still:

[0063] X2*[ux vx] + B1*[ub vb] + [u0 v0] = [Cx2 Cy2] (5)

[0064] Or X1*[ux vx]+B2*[ub vb]+[u0 v0]=[Cx2 Cy2](8) but from light spot 2 to light spot 3, the X-axis and the B-axis can be moved simultaneously, i.e. the X-axis is moved a distance (the X-axis coordinate in the machine tool coordinate is changed to X3) on the basis of the position and posture of forming the light spot 2, and the B-axis drives the machining head to rotate an angle (the B-axis coordinate in the machine tool coordinate is changed to B3) on the basis of the position and posture of forming the light spot 2, and the vector equation of the light spot position 3 obtained is:

[0065] X3*[ux vx] + B3*[ub vb] + [u0 v0] = [Cx3 Cy3] (4)

[0066] Similarly, the above vector equations (2) and (5) can be subtracted to calculate ux and vx, and the calculated ux and vx are substituted into the above vector equations (2) and (4) to calculate ub and vb; or the above vector equations (2) and (8) can be subtracted to calculate ub and vb, and the calculated ub and vb are substituted into the above vector equations (2) and (4) to calculate ux and vx.

[0067] Through the linkage of two axes, the motion range can be expanded, which makes the interference caused by random errors be diluted, and the stability of the calibration result is significantly improved. Moreover, the larger the motion range of the linkage of two axes is, the smaller the error is, and the more stable the calibration result is. Therefore, in the process from light spot 2 to light spot 3, not only the X-axis and the B-axis can be moved simultaneously, but also the amplitude of the linkage of the X-axis and the B-axis can be as large as possible, and even the light spot can be moved out of the amplitude of the light spot collecting device and then returned to the amplitude, so as to further improve the calibration accuracy.

[0068] In the process from spot 1 to spot 2, only the X-axis or only the B-axis is moved, but in fact, the X-axis and the B-axis can also be moved together in this process, thereby further improving the calibration accuracy.

[0069] The calibration method of the present application only needs to collect 3 spot positions to complete the calibration of the included angle between different axis movement directions, but it can be understood that the more spot positions collected on this basis, the higher the fitting accuracy, and the more accurate the final calibration result.

[0070] In addition, although the above mainly describes the calibration of the X-axis and the B-axis in the five-axis machine tool, it can be understood by those skilled in the art that the method for calibrating the machine tool of the present application is also applicable to the calibration of the included angle between other axes in the five-axis machine tool, and is also applicable to the calibration of the included angle between axes in other multi-axis machine tools.

[0071] According to an embodiment of the present application, a computer readable storage medium is also provided, on which encoded instructions are recorded, which when executed can implement the above-mentioned method for calibrating the machine tool according to the present application. The computer readable storage medium can include a hard disk drive, a floppy disk drive, a compact disc read / write (CD-R / W) drive, a digital versatile disc (DVD) drive, a flash drive, and / or a solid state storage device, etc.

[0072] According to an embodiment of the present application, a computer program product is also provided, which includes a computer program that when executed can implement the above-mentioned method for calibrating the machine tool according to the present application. The computer program product can be implemented using various programming languages, such as C, C++, Java, Python, JavaScript, etc., to adapt to different development environment and platform requirements.

[0073] According to an embodiment of the present application, a device for calibrating the machine tool is also correspondingly provided.

[0074] Reference Figure 5 wherein a device 500 for calibrating the machine tool according to the present application is shown, which can include a spot collection device 520, a control unit 540 and a calibration unit 560.

[0075] The spot collection device 520 can be used to collect the spot position of the light beam emitted from the light beam emitting device of the machine tool.

[0076] The control unit 540 can be configured to control at least one of the first axis and the second axis of the machine tool to move, and control the spot acquisition device 520 to acquire at least three spot positions, the at least three spots corresponding to the at least three spot positions being located on a spot track formed by the light beam during the movement, wherein the first axis coordinates of at least two groups of coordinates of the machine tool when the at least three spots are formed are different from each other, and the second axis coordinates of at least two groups of coordinates of the machine tool when the at least three spots are formed are different from each other.

[0077] The calibration unit 560 can be configured to calibrate an included angle between a movement direction of the first axis and a movement direction of the second axis based on the acquired at least three spot positions and corresponding first axis coordinates and second axis coordinates of the machine tool when the at least three spots are formed.

[0078] Optionally, the calibration unit 560 can be further configured to: calculate a first included angle of the movement direction of the first axis relative to a coordinate system of the spot acquisition device 520 and a second included angle of the movement direction of the second axis relative to the coordinate system of the spot acquisition device 520 based on the acquired at least three spot positions and corresponding first axis coordinates and second axis coordinates of the machine tool when the at least three spots are formed; and obtain the included angle between the movement direction of the first axis and the movement direction of the second axis based on the first included angle and the second included angle.

[0079] Optionally, the control unit 540 can be further configured to: control the first axis and the second axis to move simultaneously, and control the spot acquisition device 520 to acquire at least three spot positions located on a spot track formed by the light beam during the movement.

[0080] Optionally, the control unit 540 can be further configured to: control the first axis and the second axis to move respectively, and control the spot acquisition device 520 to acquire at least three spot positions located on a spot track formed by the light beam during the movement.

[0081] The above-described device for calibrating a machine tool can implement the above-described method for calibrating a machine tool according to the present application. Many design concepts and details applicable in the above-described method for calibrating a machine tool according to the present application are also applicable to the above-described device for calibrating a machine tool, and the same beneficial technical effects can be achieved, and thus will not be described here again.

[0082] Various aspects of the application have been described through a number of example embodiments. It is to be understood that various alterations to the described examples will occur to the reader. For example, it will be appreciated that the described technology can be performed in different orders and / or that the components of the described systems, architectures, devices or circuits can be combined in different ways and / or replaced or supplemented with other components or their equivalents, and that suitable results can still be achieved, without departing from the spirit and scope of the claims. Accordingly, other implementations are within the scope of the following claims.

Claims

1. A method for calibrating a machine tool, comprising the following steps: a) moving at least one of the first axis and the second axis of the machine tool, and collecting at least three light spot positions by a light spot collection device, wherein at least three light spots corresponding to the at least three light spot positions are located on a light spot trajectory formed by a light beam emitted from a light beam emitting device of the machine tool during the movement, wherein: When the at least three light spots are formed, at least two groups of first-axis coordinates of the machine tool are different from each other, and when the at least three light spots are formed, at least two groups of second-axis coordinates of the machine tool are different from each other; as well as b) calibrating the angle between the movement direction of the first axis and the movement direction of the second axis based on the collected at least three light spot positions and the corresponding first axis coordinates and second axis coordinates of the machine tool when the at least three light spots are formed.

2. The method according to claim 1, wherein The step b) comprises: calculating, based on the at least three light spot positions collected and the corresponding first-axis coordinates and second-axis coordinates of the machine tool when the at least three light spots are formed, a first angle of the motion direction of the first axis relative to the coordinate system of the light spot collection device and a second angle of the motion direction of the second axis relative to the coordinate system of the light spot collection device; and An angle between the movement direction of the first axis and the movement direction of the second axis is obtained based on the first angle and the second angle.

3. The method according to claim 1 or 2, wherein: Said step a) comprises moving said first shaft and said second shaft simultaneously.

4. The method according to claim 1 or 2, wherein: The step a) includes moving the first shaft and the second shaft separately.

5. A device for calibrating a machine tool, comprising: a light spot acquisition device for acquiring the light spot position of the light beam emitted from the light beam emitting device of the machine tool; a control unit configured to control the movement of at least one of the first axis and the second axis of the machine tool, and control the light spot acquisition device to acquire at least three light spot positions, wherein at least three light spots corresponding to the at least three light spot positions are located on a light spot trajectory formed by the light beam during the movement, wherein when the at least three light spots are formed, at least two groups of first-axis coordinates of the machine tool coordinates are different from each other, and when the at least three light spots are formed, at least two groups of second-axis coordinates of the machine tool coordinates are different from each other; as well as The calibration unit is configured to calibrate the angle between the movement direction of the first axis and the movement direction of the second axis based on the at least three collected light spot positions and the corresponding first axis coordinates and second axis coordinates of the machine tool when the at least three light spots are formed.

6. The device according to claim 5, characterized in that The calibration unit is further configured to: calculating, based on the at least three light spot positions collected and the corresponding first-axis coordinates and second-axis coordinates of the machine tool when the at least three light spots are formed, a first angle of the motion direction of the first axis relative to the coordinate system of the light spot collection device and a second angle of the motion direction of the second axis relative to the coordinate system of the light spot collection device; and An angle between the movement direction of the first axis and the movement direction of the second axis is obtained based on the first angle and the second angle.

7. The device according to claim 5 or 6, characterized in that The control unit is further configured to control the first axis and the second axis to move simultaneously, and control the light spot acquisition device to acquire at least three light spot positions on a light spot track formed by the light beam during the movement.

8. The device according to claim 5 or 6, characterized in that The control unit is further configured to control the first axis and the second axis to move respectively, and control the light spot acquisition device to acquire at least three light spot positions located on a light spot track formed by the light beam during the movement.

9. A computer-readable storage medium having encoded instructions recorded thereon, which implement the method according to any one of claims 1 to 4 when the instructions are executed.

10. A computer program product comprising a computer program, which implements the method according to any one of claims 1 to 4 when the computer program is executed.

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