Method and device for calibrating machine tool

Abstract

The invention relates to a method and a device for calibrating a machine tool. The method comprises the following steps: a) at least one of a first axis and a second axis of the machine tool is made to move, at least three light spot positions are collected through a light spot collecting device, and at least three light spots corresponding to the at least three light spot positions are located on a light spot track formed by light beams emitted by a light beam emitting device of the machine tool during the movement, wherein at least two groups of first axis coordinates in the coordinates of the machine tool are different from each other when the at least three light spots are formed, and at least two groups of second axis coordinates in the coordinates of the machine tool are different from each other when the at least three light spots are formed; 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 acquired positions of the at least three light spots and the corresponding first axis coordinates and second axis coordinates of the machine tool when the at least three light spots are formed. The invention further provides a corresponding device.

Description

Technical Field

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

[0002] Machine tool processing plays a vital role in modern mechanical manufacturing. All 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 rotation direction should be Figure 2 However, in reality, due to errors in the manufacturing and installation process, the movement directions of the machine tool axes may not be coplanar (the movement directions of the axes are at a certain angle to each other), such as the above Figure 2 The X-axis movement direction is Figure 2 There is a component in the translation direction shown in the figure, and a component in the direction perpendicular to the paper, while the movement direction of the B axis is completely along the paper direction. At this time, if the machining is still carried out according to the preset ideal situation (that is, the movement directions of the various axes of the machine tool are coplanar), the machining trajectory will be deformed. Therefore, it is necessary to calibrate the angle between the movement directions of the various axes of the machine tool.

[0004] One existing calibration method is based on the measurement of a laser tracker to calculate the movement direction of each axis of the tool machine, and then to find the angle between them. This method is too expensive because it uses a laser tracker. Although this method can also use a camera instead of a laser tracker, the cost of camera shooting is also high and the accuracy is poor. Another existing calibration method uses marble and a dial indicator / micrometer to calculate the angle between the movement directions of each axis of the tool machine. This method is too complicated to operate, and it also requires the marble base to be flat, and the cost is also high.

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

[0006] The present invention aims to overcome the above and / or other problems in the prior art. Through the method and device for calibrating a machine tool provided by the present invention, only a spot acquisition device is needed to additionally implement the calibration of the angles between the movement directions of the axes of the machine tool, thereby improving the machining accuracy of the machine tool.

[0007] According to a first aspect of the present invention, there is provided a method for calibrating a machine tool, which may include 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 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 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 coordinates of the machine tool are different from each other; and 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.

[0008] According to the second aspect of the present invention, a device for calibrating a machine tool is also provided accordingly, which may include a spot collection device, a control unit and a calibration unit. The spot collection device can be used to collect the spot position of the light beam emitted from the light beam emitting device of the machine tool. The control unit can be configured to control the movement of at least one of the first axis and the second axis of the machine tool, and control the spot collection device to collect at least three spot positions, and at least three spots corresponding to the at least three spot positions are located on the spot trajectory formed by the light beam during the movement, wherein at least two groups of first axis coordinates in the coordinates of the machine tool when the at least three spots are formed are different from each other, and at least two groups of second axis coordinates in the coordinates of the machine tool when the at least three spots are formed are different from each other. The calibration unit can be configured to calibrate 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 spot positions and the corresponding first axis coordinates and second axis coordinates of the machine tool when the at least three spots are formed.

[0009] The present invention cleverly uses the light beam emitted by the light beam emitting device of 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 spot. On this basis, only an additional light spot acquisition device is needed to collect at least three light spot positions, and the 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 low. The stability and accuracy of the collected light spot position data are very high, so that the 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 invention, the step b) may include: calculating the first angle of the motion direction of the first axis relative to the coordinate system of the light spot acquisition device and the second angle of the motion direction of the second axis relative to the coordinate system of the light spot acquisition device based on the at least three light spot positions acquired 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 angle between the motion direction of the first axis and the motion direction of the second axis based on the first angle and the second angle. Correspondingly, in the calibration device of the present invention, the calibration unit may be further configured to: calculate the first angle of the motion direction of the first axis relative to the coordinate system of the light spot acquisition device and the second angle of the motion direction of the second axis relative to the coordinate system of the light spot acquisition device based on the at least three light spot positions acquired 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 angle between the motion direction of the first axis and the motion direction of the second axis based on the first angle and the second angle.

[0011] In the calibration method of the present invention, the step a) may include moving the first axis and the second axis simultaneously, or the step a) may also include moving the first axis and the second axis separately. Accordingly, in the calibration device of the present invention, the control unit may be 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 the light spot track formed by the light beam during the movement; or control the first axis and the second axis to move separately, and control the light spot acquisition device to acquire at least three light spot positions on the light spot track formed by the light beam during the movement.

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

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

[0014] According to a fourth aspect of the present invention, 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 invention.

[0015] Other features and aspects of the present invention will become more apparent from the following detailed description in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention may be better understood by describing exemplary embodiments of the present invention in conjunction with the accompanying drawings, in which:

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

[0018] Figure 2 A schematic diagram showing the movement of the machining head of a machine tool under the drive of each axis is shown;

[0019] Figure 3 A schematic diagram of a machine tool processing head for calibrating a machine tool according to the present invention is shown;

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

[0021] Figure 5 The figure is a structural block diagram of a device for calibrating a machine tool according to the present invention. DETAILED DESCRIPTION

[0022] The present invention will be further described below in conjunction with specific embodiments and drawings. More details are elaborated in the following description to facilitate a full understanding of the present invention. However, the present invention can obviously be implemented in a variety of other ways different from the description herein. Those skilled in the art can make similar generalizations and deductions based on actual application situations without violating the spirit of the present invention. Therefore, the scope of protection of the present invention should not be limited by the content of this specific embodiment.

[0023] Unless otherwise defined, the technical or scientific terms used in the claims and the specification shall have the usual meaning understood by persons with ordinary skills in the technical field to which the invention belongs. The words "first", "second" and similar words used in the specification 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 "one" do not indicate a quantitative limitation, but indicate the existence of at least one. Words such as "include" or "comprise" and similar words mean that the elements or objects appearing before "include" or "comprise" include the elements or objects listed after "include" or "comprise" and their equivalent elements, and do not exclude other elements or objects. Words such as "connect" or "connected" and similar words 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, and 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 a light beam emitted from a 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 may 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 translational axes, such as the X-axis and the Y-axis, or both can be rotational axes, such as the A-axis and the B-axis.

[0028] Can be as Figure 3 As shown, a light spot collection device is arranged under the processing 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 device. The light beam emitted from the light beam emitting device of the machine tool passes through the end of the processing head and reaches the format of the light spot collection device, thereby forming a light spot. Figure 2 For example, if the movement directions of the two axes are coplanar, the light spot on the frame of the light spot collection device will always be on a straight line or on parallel lines, that is, the light spot trajectory will be a straight line or several parallel 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 that of the B axis. Figure 2As shown in , there is a component in the translation direction, and a component in the direction perpendicular to the paper surface, while the movement direction of the B axis is completely along the paper surface. In this case, the light spot tracks formed when the X axis and the B axis move will also form an angle with each other. Therefore, the light spot track can map whether the movement direction of the X axis and the movement direction of the B axis are coplanar, and the light spot position data extracted from the light spot track can be used to calculate the angle between the movement direction of the X axis and the movement direction of the B axis.

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

[0030] In addition, during the formation of the light spot trajectory, the two axes of the machine tool to be calibrated do not need to move simultaneously all the time. 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 it is ensured that there are at least three light spot positions on the light spot trajectory to satisfy that when the corresponding light spots are formed, at least two groups of X-axis coordinates in the corresponding machine tool coordinates are different from each other (that is, the X-axis coordinates in the at least three groups of machine tool coordinates corresponding to the at least three light spot positions are not completely the same) and at least two groups of B-axis coordinates are different from each other (that is, the B-axis coordinates in the at least three groups of machine tool coordinates corresponding to the at least three light spot positions are not completely the same).

[0031] Taking the five-axis machine tool as an example, the axes to be calibrated are still the translation axis X axis and the rotation axis B axis. The coordinates of the three collected spot positions on the frame of the spot collection device are: [Cx1 Cy1] (spot 1), [Cx2 Cy2] (spot 2) and [Cx3 Cy3] (spot 3). The coordinates of the machine tool when spot 1 is formed are [X1 YZA B1], the coordinates of the machine tool when spot 2 is formed are [X2 YZA B2], and the coordinates of the machine tool when spot 3 is formed are [X3 YZA B3]. It needs to be ensured that the above 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 the above 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 X-axis movement direction and the B-axis movement direction is to be calibrated, the Y-axis translation axis, the Z-axis lifting axis, and the A-axis rotation axis are all kept stationary during the formation of the spot trajectory, and the Y-axis coordinate, the Z-axis coordinate, and the A-axis coordinate in the machine tool coordinate when the spots 1 to 3 are formed accordingly remain unchanged. If the angle between the movement directions of other combinations 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 when the spots 1 to 3 are formed remain unchanged, and no further explanation is given here.

[0033] Back 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 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.

[0034] The machine tool coordinate system and the format coordinate system of the light spot acquisition device can be converted to each other through a corresponding conversion matrix, and the above-mentioned collected light spot position is a two-dimensional coordinate in the format coordinate system of the light spot acquisition device, so it can also be converted to the machine tool coordinate system.

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

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

[0037] Among them, X and B are respectively the X-axis coordinate and the B-axis coordinate in the machine tool coordinate when forming the light spot, and the vector matrix [u0v0] represents the deviation between the zero point of the machine tool coordinate system and the zero point of the format coordinate system of the light spot acquisition 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] Among them, X1, X2 and X3 are respectively the X-axis coordinates of the machine tool coordinates when forming spot 1, spot 2 and spot 3, B1, B2 and B3 are respectively the B-axis coordinates of the machine tool coordinates when forming spot 1, spot 2 and spot 3, [Cx1 Cy1] is the two-dimensional coordinate of spot 1 in the format coordinate system of the spot acquisition device, [Cx2 Cy2] is the two-dimensional coordinate of spot 2 in the format coordinate system of the spot acquisition device, and [Cx3 Cy3] is the two-dimensional coordinate of spot 3 in the format coordinate system of the spot acquisition device. The above X1, X2 and X3 as well as B1, B2 and B3 can be obtained from the servo unit of the machine tool, and [Cx1 Cy1], [Cx2 Cy2] and [Cx3 Cy3] can be obtained from the light spot acquisition device. Therefore, the six unknowns ux, vx, ub, vb, u0 and v0 can be solved from the above three vector equations (2) to (4) (equivalent to six equations), and then based on the solved ux and vx (the components in the two-dimensional directions mapped to the light spot position when the X-axis moves) and ub and vb (the components in the two-dimensional directions mapped to the light spot position when the B-axis moves), the angle between the X-axis movement direction and the B-axis movement direction can be calculated.

[0043] The calibration method of the present invention cleverly maps the motion of the axis to be calibrated of the machine tool into the two-dimensional coordinate system of the light spot acquisition device, thereby converting the original calibration of the angle between the planes where the motion directions of the two axes are located into the calculation of the angle between two straight lines in the two-dimensional coordinate system, which brings great convenience to both data acquisition and calculation after data acquisition. Compared with the prior art, it not only significantly improves the calibration accuracy and calibration efficiency, but also reduces the calibration cost. By using the calibration method of the present invention to calibrate the angle between the motion directions of each axis of the machine tool, the machining accuracy of the machine tool can be significantly improved.

[0044] Optionally, step 140 may be performed as follows: Figure 4 As shown, sub-step 142 and sub-step 144 are included.

[0045] In sub-step 142, a first angle of the movement direction of the first axis relative to the coordinate system of the light spot collection device and a second angle of the movement direction of the second axis relative to the coordinate system of the light spot collection device can be calculated 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.

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

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

[0048] Optionally, the step 120 may include moving the first shaft and the second shaft separately.

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

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

[0051] Then the X-axis driven machining head can be moved a distance (the X-axis coordinate in the machine tool coordinate becomes X2) based on the position and posture of the above-mentioned light spot 1, and the B axis remains stationary. The vector equation of the light spot position 2 obtained is:

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

[0053] Next, the B-axis driven machining head is rotated by an angle (the B-axis coordinate in the machine tool coordinate becomes B2) based on the position and posture of the above-mentioned light spot 1, and the X-axis remains stationary. The vector equation of the light spot position 3 is obtained as follows:

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

[0055] Subtract the above vector equations (2) and (5) to obtain [ux vx] = [(Cx1-Cx2) / (X1-X2), (Cy1-Cy2) / (X1-X2)], X1, X2, Cx1, Cx2, Cy1 and Cy2 are all known, so the values ​​of ux and vx can be calculated. Similarly, the above vector equations (2) and (6) can be subtracted to calculate ub and vb. Then, by performing the inverse tangent function operation on ux and vx as well as ub and vb as described above, the angle between the X-axis motion direction and the light spot collection device coordinate system and the angle between the B-axis motion direction and the light spot collection device coordinate system can be obtained respectively, thereby calibrating the angle between the X-axis motion direction and the B-axis motion direction.

[0056] For the above-mentioned spot 3, the B-axis driven machining head can also be rotated by an angle based on the position and posture of the above-mentioned spot 2, and the X-axis remains stationary. The vector equation of the spot position 3 obtained thereby is:

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

[0058] In this case, the above vector equations (5) and (7) can be subtracted to calculate ub and vb.

[0059] Optionally, step 120 may include moving the first shaft and the second shaft simultaneously.

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

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

[0062] From spot 1 to spot 2, you can still only move the X axis or only move the B axis, that is, the vector equation of 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) However, in the process from spot 2 to spot 3, the X-axis and the B-axis can move simultaneously, that is, the X-axis moves a distance based on the position and posture of the spot 2 (the X-axis coordinate in the machine tool coordinate becomes X3), and at the same time, the B-axis drives the machining head to rotate an angle based on the position and posture of the spot 2 (the B-axis coordinate in the machine tool coordinate becomes B3), and the vector equation of the spot position 3 is obtained as follows:

[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 then the calculated ux and vx can be 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 then the calculated ub and vb can be substituted into the above vector equations (2) and (4) to calculate ux and vx.

[0067] By linking the two axes, the range of motion can be expanded, which dilutes the interference caused by random errors and significantly improves the stability of the calibration results. Moreover, the larger the range of motion when the two axes are linked, the smaller the error and the more stable the calibration results. Therefore, in the process from spot 2 to spot 3, not only can the X-axis and the B-axis move at the same time, but the amplitude of the simultaneous movement of the X-axis and the B-axis can be as large as possible, and the spot can even be moved out of the format of the spot acquisition device and then returned to the format, thereby further improving the calibration accuracy.

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

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

[0070] In addition, although the above description is mostly based on the calibration of the translational axis X-axis and the rotational axis B-axis in a five-axis machine tool as an example, those skilled in the art can understand that the method for calibrating a machine tool of the present invention is also applicable to the calibration of the angles between the motion directions of other axes in a five-axis machine tool, and is also applicable to the calibration of the angles between the motion directions of axes in other multi-axis machine tools.

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

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

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

[0074] refer to Figure 5 , which shows a device 500 for calibrating a machine tool according to the present invention, which may include a light spot collection device 520, a control unit 540 and a calibration unit 560.

[0075] The light spot acquisition device 520 may be used to acquire the light 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 the movement of at least one of the first axis and the second axis of the machine tool, and control the light spot collection device 520 to collect at least three light spot positions, and at least three light spots corresponding to the at least three light spot positions are located on the 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 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 coordinates of the machine tool are different from each other.

[0077] The calibration unit 560 can be configured to calibrate 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.

[0078] Optionally, the calibration unit 560 may be further configured to: calculate a first angle between the movement direction of the first axis and the coordinate system of the spot collection device 520 and a second angle between the movement direction of the second axis and the coordinate system of the spot collection device 520 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; and obtain the angle between the movement direction of the first axis and the movement direction of the second axis based on the first angle and the second angle.

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

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

[0081] The above-mentioned device for calibrating a machine tool can realize the method for calibrating a machine tool according to the present invention as described above. Many design concepts and details applicable to the method for calibrating a machine tool according to the present invention are also applicable to the above-mentioned device for calibrating a machine tool, and the same beneficial technical effects can be obtained, which will not be repeated here.

[0082] Various aspects of the present invention have been described above through some exemplary embodiments. However, it should be understood that various modifications may be made to the above exemplary embodiments without departing from the spirit and scope of the present invention. For example, if the described techniques are performed in a different order and / or if the components in the described system, architecture, device or circuit are combined in different ways and / or replaced or supplemented by other components or their equivalents, suitable results may be achieved, and accordingly, these modified other embodiments also fall within the scope of protection of the 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 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 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 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.

2. The method according to claim 1, characterized in that The step b) comprises: 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 movement direction of the first axis relative to the coordinate system of the light spot collection device and a second angle of the movement direction of the second axis relative to the coordinate system of the light spot collection device are calculated; and An angle between a moving direction of the first axis and a moving 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, characterized in that The step a) comprises moving the first shaft and the second shaft simultaneously.

4. The method according to claim 1 or 2, characterized in that: 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, used 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 at least one of the first axis and the second axis of the machine tool to move, 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 the 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 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 coordinates of the machine tool 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 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.

6. The device according to claim 5, characterized in that The calibration unit is further configured to: 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 movement direction of the first axis relative to the coordinate system of the light spot collection device and a second angle of the movement direction of the second axis relative to the coordinate system of the light spot collection device are calculated; and An angle between a moving direction of the first axis and a moving 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 located on a light spot trajectory 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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