Machine tool, correction method, correction device and computer readable storage medium

Abstract

The present application provides a machine tool, a correction method, a correction device and a computer-readable storage medium. A ball-end mandrel is installed on the main shaft of the machine tool, and a spectral confocal displacement sensor is installed on the workbench of the machine tool. The spectral confocal displacement sensor is used to collect the position offset of the ball-end mandrel during movement. The correction method includes: running the machine tool program so that the machine tool drives the ball-end mandrel to move; obtaining the position offset of the ball-end mandrel collected by the spectral confocal displacement sensor; generating a position compensation table according to the position offset collected by the ball-end mandrel; and performing position compensation on the movement of the machine tool according to the position compensation table. The correction method for the spatial position point deviation of the machine tool in the present application can effectively compensate for the motion error of the machine tool, realize the adjustment of the spatial position accuracy, and thus improve the processing accuracy.

Description

Technical Field

[0001] The present application belongs to the field of mechanical processing detection, and specifically relates to a machine tool, a correction method, a correction device and a computer-readable storage medium. Background Art

[0002] Five-axis linkage means that there are at least five coordinate axes (three linear coordinates and two rotational coordinates) on a machine tool, and they can coordinate movement simultaneously for processing under the control of a computer numerical control (CNC) system.

[0003] The five-axis linkage CNC machine tool is a high-tech, high-precision machine tool specially used for processing complex surfaces. This machine tool system has a significant influence on a country's aviation, aerospace, military, scientific research, precision machinery, high-precision medical equipment and other industries.

[0004] There will also be errors in the movement of five-axis linkage CNC machine tools. How to calibrate the five-axis linkage CNC machine tools to eliminate the errors is a common problem in the industry. Summary of the invention

[0005] The present application provides a machine tool, a calibration method, a calibration device and a computer-readable storage medium to solve the problem that the calibration of current five-axis linkage CNC machine tools is difficult.

[0006] In order to solve the above technical problems, a technical solution adopted in the present application is: to provide a method for correcting the spatial position point deviation of a machine tool, a ball head mandrel is installed on the main shaft of the machine tool, and a spectral confocal displacement sensor is installed on the workbench of the machine tool, and the spectral confocal displacement sensor is used to collect the position offset of the ball head mandrel during movement. The method includes: running the machine tool program so that the machine tool drives the ball head mandrel to move; obtaining the position offset of the ball head mandrel collected by the spectral confocal displacement sensor; generating a position compensation table according to the position offset collected by the ball head mandrel; and performing position compensation on the movement of the machine tool according to the position compensation table.

[0007] Among them, the step of obtaining the position offset of the ball head core rod collected by the spectral confocal displacement sensor includes: obtaining the position offset of the ball head core rod at multiple preset sampling position points collected by the spectral confocal displacement sensor; wherein different preset sampling position points correspond to different A-axis angles and C-axis angles.

[0008] Wherein, the step of generating a position compensation table according to the position offset collected by the ball-end mandrel comprises: determining the maximum position offset among the multiple position offsets collected by the ball-end mandrel; and generating the position compensation table according to the maximum position offset.

[0009] Wherein, before generating the position compensation table according to the maximum position offset, it also includes: judging whether the maximum position offset is greater than a first preset threshold; in response to the maximum position offset being greater than the first preset threshold, executing the step of generating the position compensation table according to the maximum position offset.

[0010] Among them, in response to the maximum position offset being less than the first preset threshold, the step of returning to execute the running machine tool program so that the machine tool drives the ball head mandrel to move is performed until the number of times the step of returning to execute the running machine tool program so that the machine tool drives the ball head mandrel to move reaches a number threshold.

[0011] Wherein, the step of generating a position compensation table according to the position offset of the ball-end mandrel comprises: determining an average offset according to a plurality of position offsets collected by the ball-end mandrel; and generating the position compensation table according to the average offset.

[0012] Wherein, the step of generating a position compensation table according to the position offset of the ball-end mandrel comprises: generating a position offset curve according to the position offset collected by the ball-end mandrel; generating the position compensation table according to the position offset curve.

[0013] Another technical solution adopted in the present application is: providing a machine tool, which includes a spindle, a workbench, a ball-end mandrel, a spectral confocal displacement sensor and a controller, wherein the ball-end mandrel is installed on the spindle, the spectral confocal displacement sensor is installed on the workbench, and the spectral confocal displacement sensor is used to collect the position offset of the ball-end mandrel during movement; the controller is used to run a machine tool program so that the machine tool drives the ball-end mandrel to move; obtain the position offset of the ball-end mandrel collected by the spectral confocal displacement sensor; generate a position compensation table according to the position offset collected by the ball-end mandrel; and perform position compensation on the movement of the machine tool according to the position compensation table.

[0014] Another technical solution adopted in the present application is to provide a correction device, which includes a memory and a processor connected to each other, wherein the memory is used to store a computer program, and when the computer program is executed by the processor, it is used to implement the method described in the above embodiment.

[0015] Another technical solution adopted by the present application is: providing a computer-readable storage medium, the computer-readable storage medium storing a computer program, and the computer program can be executed by a processor to implement any of the steps in the above method embodiments.

[0016] The beneficial effect of the present application is that in the method for correcting the spatial position point deviation of the machine tool of the present application, the spectral confocal displacement sensor is used to collect the position offset of the ball head mandrel, which has the advantage of accurate data. At the same time, a compensation table is generated according to the position offset, and the movement of the machine tool is positionally compensated according to the obtained position compensation table, so as to reduce the movement error of the machine tool, realize the adjustment of the spatial position accuracy, and thus improve the processing accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work, among which:

[0018] Figure 1 It is a flow chart of an embodiment of a correction method in the present application;

[0019] Figure 2 It is a structural schematic diagram of an embodiment of a machine tool in the present application;

[0020] Figure 3 It is a structural schematic diagram of an implementation method of a correction device in the present application;

[0021] Figure 4 It is a structural schematic diagram of an implementation method of a computer-readable storage medium of the present application. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0023] See also Figure 1 and Figure 2 The present application provides a method for correcting the spatial position point deviation of a machine tool 100. A ball-end mandrel 20 is installed on the spindle 10 of the machine tool 100, and a spectral confocal displacement sensor 30 is installed on the workbench 40 of the machine tool 100. The spectral confocal displacement sensor 30 is used to collect the position deviation of the ball-end mandrel 20 when it moves. The method includes:

[0024] S10: Run the machine tool program so that the machine tool 100 drives the ball end mandrel 20 to move.

[0025] Specifically, by running the machine tool program, the machine tool 100 drives the ball-end mandrel 20 on the spindle 10 to move. In one embodiment, the machine tool program can use a machine tool program with a tool tip point following (TCP) function, or a machine tool program on a computer software for controlling the movement of the machine tool 100. The machine tool program is used to plan the movement position of the ball-end mandrel 20 so that the ball-end mandrel 20 moves according to a predetermined trajectory.

[0026] S20: Acquire the position offset of the ball-end mandrel 20 collected by the spectral confocal displacement sensor 30.

[0027] When the ball-end mandrel 20 moves, the spectral confocal displacement sensor 30 can move with the ball-end mandrel 20 or remain stationary. The spectral confocal displacement sensor 30 collects the position offset of the ball-end mandrel 20 during its movement in a non-contact manner. The spectral confocal displacement sensor 30 uses the principle of optical dispersion to extend the focal halo range of light of different colors through a special lens to form a special amplified chromatic aberration, so that a precise wavelength of light corresponding to the distance from the object to be measured to the lens is focused on the object to be measured. By measuring the wavelength of the reflected light, the precise distance from the object to be measured to the lens can be obtained. Due to the use of confocal technology, this method has good tomographic characteristics, improved resolution, and is insensitive to the characteristics of the object to be measured and stray light. Therefore, the use of the spectral confocal displacement sensor 30 to collect the position offset of the ball-end mandrel 20 in a non-contact manner has the advantages of accurate measurement and can avoid damage to the ball-end mandrel 20.

[0028] S30: Generate a position compensation table according to the position offset of the ball-end mandrel 20.

[0029] Specifically, the position offset of the ball-end mandrel 20 refers to the deviation between the actual position and the ideal position of the ball-end mandrel 20 during the movement. The existence of position offset in the movement of the ball-end mandrel 20 indicates that the accuracy of the machine tool 100 needs to be improved. According to the position offset of the ball-end mandrel 20 and by using the preset compensation principle, the compensation parameters of the machine tool 100 at each spatial position point can be determined, and each spatial position point and the corresponding compensation parameter are saved in correspondence, thereby forming a position compensation table.

[0030] S40: Perform position compensation on the movement of the machine tool 100 according to the position compensation table.

[0031] The motion of the machine tool 100 is positionally compensated according to the obtained position compensation table to reduce the motion error of the machine tool 100 and adjust the spatial position accuracy, thereby improving the machining accuracy.

[0032] In one embodiment, step S20 includes:

[0033] S21: Obtaining the position offset of the ball-end mandrel 20 at a plurality of preset sampling positions collected by the spectral confocal displacement sensor 30; wherein different preset sampling positions correspond to different A-axis angles and C-axis angles.

[0034] Specifically, the five axes of the five-axis machining center are X, Y, Z, A, and C axes. Among them, the X, Y, and Z axes represent the movement of the workpiece in the horizontal direction, vertical direction, and feed direction, respectively. These three axes are called basic axes, and most machines can realize the movement of these three axes. They are the basic skeleton of the five-axis machining center. A and C axes are two additional axes of the five-axis machining center. A axis represents the rotation of the workpiece in the horizontal direction, and C axis represents the rotation of the workpiece in the vertical direction. With the rotation of A and C axes, the cutting tool can be moved more flexibly, improving the processing efficiency and accuracy. In the actual processing process, these five axes do not have fixed positions and directions, and their movement is relative. Therefore, the five-axis machining center has a high degree of freedom and can process workpieces of various shapes. Therefore, a plurality of preset sampling position points are set, and at the same time, the combination of the A-axis angle and the C-axis angle of different preset sampling position points is different, so as to realize the change of the motion trajectory of the ball head mandrel 20. Among them, at each preset sampling position point, the spectral confocal displacement sensor 30 collects the position offset of the ball head mandrel 20. It can be understood that the more the number of preset sampling position points, the more accurate the compensation can be achieved later.

[0035] In one embodiment, the angle range of the A axis is -90°~90°; the angle range of the C axis is -250°~250°; and a corresponding combination of measured angle values ​​is selected within the above angle range. In one embodiment, 19 measured angle values ​​are selected for the A axis; 51 measured angle values ​​are selected for the C axis; the measured angle values ​​are in an arithmetic progression with a difference of 10. Specifically, the angles selected for the A axis include -90, -80, -70, -60, -50, -40, -30, -20, -10, 0, 10, 20, 30, 40, 50, 60, 70, 80, 90°; the angles selected for the C axis include -250, -240, -230, -220, -210, -200, -190, -180, -170, -160, -150, -140, - 130, -120, -110, -100, -90, -80, -70, -60, -50, -40, -30, -20, -10, 0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250°. Combine an A-axis angle and a C-axis angle to get a preset sampling position point. When the A-axis and C-axis angles change, the X, Y, and Z axes all change position.

[0036] In one embodiment, step S30 includes:

[0037] S31: Among the multiple position deviations of the ball-end mandrel 20, determine the maximum position deviation.

[0038] Specifically, the positional deviation of the ball-end mandrel 20 in each axial direction is determined, and the maximum positional deviation is determined.

[0039] S32: Generate a position compensation table according to the maximum position offset.

[0040] The position compensation table is generated using the maximum position offset, which improves the correction efficiency and has the advantage of good compensation effect.

[0041] In one embodiment, before step S32, the method further includes:

[0042] S321: Determine whether the maximum position offset is greater than a first preset threshold.

[0043] Specifically, the magnitude relationship between the maximum value of the position offset and the first preset threshold is compared. In one embodiment, the first preset threshold may be 0.035 um.

[0044] S322: In response to the maximum position offset being greater than a first preset threshold, executing a step of generating a position compensation table according to the maximum position offset.

[0045] Specifically, when the maximum value of the position offset is greater than the first preset threshold, it means that the motion parameters of the position need to be adjusted and cannot meet the production needs temporarily. At this time, a position compensation table is generated according to the maximum position offset.

[0046] In one embodiment, before step S32, the method further includes:

[0047] S323: In response to the maximum position offset being less than a first preset threshold, return to executing the step of running the machine tool program so that the machine tool 100 drives the ball head mandrel 20 to move, until the step of returning to executing the step of running the machine tool program so that the machine tool 100 drives the ball head mandrel 20 to move reaches a number threshold.

[0048] Specifically, when the maximum value in the position offset is less than the first preset threshold, in order to avoid inaccurate single detection effect, return to step S10 and confirm the maximum value in the position offset again. If the maximum value of the position offset is still less than the first preset threshold, continue to execute S10 until the number of times of returning to execute step S10 reaches the number threshold. That is, when the maximum value in the position offset is relatively small, multiple detections are performed to obtain accurate measurement results. At the same time, the number of times is limited. Within the number threshold, you can return to execute S10. When the number threshold is exceeded, there is no need to continue to confirm, thereby improving the correction efficiency.

[0049] In one embodiment, step S30 includes:

[0050] S33: Determine an average offset according to multiple position offsets collected by the ball-end mandrel.

[0051] Specifically, a plurality of position offsets collected by the ball-end mandrel are summed and divided by the number of position offsets to determine an average offset.

[0052] S34: Generate a position compensation table based on the average offset.

[0053] The average offset represents the overall offset level of the ball-end mandrel 20 , so using the average offset to generate a corresponding position compensation table can also ensure the accuracy of subsequent corrections.

[0054] In other implementations, the position compensation table may be generated using a median value, a mode value, etc. among a plurality of position offsets.

[0055] In another embodiment, step S30 includes:

[0056] S35: Generate a position offset curve according to the position offset of the ball-end mandrel 20.

[0057] Specifically, according to the position offset of the ball-end mandrel 20, the corresponding relationship between the position of the ball-end mandrel 20 and the position offset can be known, and a position offset curve is generated according to the corresponding relationship, and the position offset curve includes the A-axis and C-axis angles and the position offset of the ball-end mandrel 20. S36: Generate a position compensation table according to the position offset curve.

[0058] Specifically, the spectral confocal displacement sensor 30 transmits the voltage signal of the position offset curve to the computer, and the computer converts the voltage signal into a digital signal, so that the computer can read the position offset, determine the compensation value according to the position offset, and form a position compensation table. Compared with discrete data, generating a position compensation table according to the position offset curve can improve the efficiency of subsequent compensation. Of course, in other embodiments, a position compensation table can also be generated according to multiple discrete position offsets.

[0059] Please continue reading Figure 2 The present application also provides a machine tool 100, which includes a spindle 10, a workbench 40, a ball-end mandrel 20, a spectral confocal displacement sensor 30 and a controller (not shown), wherein the ball-end mandrel 20 is mounted on the spindle 10, the spectral confocal displacement sensor 30 is mounted on the workbench 40, and the spectral confocal displacement sensor 30 is used to collect the position offset of the ball-end mandrel 20 during movement; the controller is used to run a machine tool program so that the machine tool 100 drives the ball-end mandrel 20 to move; obtain the position offset of the ball-end mandrel 20 collected by the spectral confocal displacement sensor 30; generate a position compensation table according to the position offset collected by the ball-end mandrel 20; and perform position compensation on the movement of the machine tool 100 according to the position compensation table.

[0060] Specifically, the spindle 10 in the machine tool 100 is used to move according to the instructions in the machine tool program. When the ball-end mandrel 20 is installed on the spindle 10, after the machine tool program is executed, the ball-end mandrel 20 moves with the spindle 10. In addition, the spectral confocal displacement sensor 30 is located on the workbench 40, which moves with the ball-end mandrel 20 and can be used to collect the position offset of the ball-end mandrel 20 when it moves. The controller is used to run the machine tool program, execute the calibration method in the above embodiment, and complete the calibration of the machine tool 100.

[0061] See also Figure 3 The present application also provides a correction device 200, which includes a memory 210 and a processor 220 connected to each other, wherein the memory 210 is used to store a computer program, and when the computer program is executed by the processor 220, it is used to implement the method in any of the above-mentioned embodiments.

[0062] See also Figure 4 The present application also provides a computer-readable storage medium 300, wherein the computer-readable storage medium 300 stores a computer program 310, and the computer program 310 can be executed by a processor to implement the steps as described in any one of the above method embodiments.

[0063] The computer-readable storage medium 300 may specifically be a device that can store the computer program 310, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, or may be a server that stores the computer program 310. The server may send the stored computer program 310 to other devices for execution, or may also execute the stored computer program 310 by itself.

[0064] The above description is only an embodiment of the present application and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for correcting the spatial position point deviation of a machine tool, characterized in that: A ball-end mandrel is installed on the main shaft of the machine tool, and a spectral confocal displacement sensor is installed on the workbench of the machine tool. The spectral confocal displacement sensor is used to collect the position offset of the ball-end mandrel when it moves. The method includes: Running a machine tool program so that the machine tool drives the ball head mandrel to move; Acquire the position offset of the ball-end core rod collected by the spectral confocal displacement sensor; generating a position compensation table according to the position offset of the ball-end mandrel; Performing position compensation on the movement of the machine tool according to the position compensation table; Wherein, the step of obtaining the position offset of the ball-end mandrel collected by the spectral confocal displacement sensor comprises: Acquire the position offset of the ball-end core rod at a plurality of preset sampling positions collected by the spectral confocal displacement sensor; Wherein, different preset sampling position points correspond to different A-axis angles and C-axis angles; Wherein, the step of generating a position compensation table according to the position offset of the ball-end mandrel comprises: Determine the maximum position offset among the plurality of position offsets collected by the ball-end mandrel; generating the position compensation table according to the maximum position offset; Wherein, before generating the position compensation table according to the maximum position offset, the method further includes: Determining whether the maximum position offset is greater than a first preset threshold; In response to the maximum position offset being greater than the first preset threshold, the step of generating the position compensation table according to the maximum position offset is performed.

2. The calibration method according to claim 1, characterized in that: The method further comprises: In response to the maximum position offset being less than the first preset threshold, the step of returning to execute the running machine tool program so that the machine tool drives the ball head mandrel to move is performed until the number of times the step of returning to execute the running machine tool program so that the machine tool drives the ball head mandrel to move reaches a number threshold.

3. The calibration method according to claim 1, characterized in that: The step of generating a position compensation table according to the position offset of the ball-end mandrel comprises: Determine an average offset according to the plurality of position offsets collected by the ball-end mandrel; The position compensation table is generated according to the average offset.

4. The calibration method according to claim 1, characterized in that: The step of generating a position compensation table according to the position offset of the ball-end mandrel comprises: generating a position offset curve according to the position offset collected by the ball-end mandrel; The position compensation table is generated according to the position offset curve.

5. A machine tool, characterized in that: It comprises a main shaft, a workbench, a ball-end mandrel, a spectral confocal displacement sensor and a controller, wherein the ball-end mandrel is mounted on the main shaft, the spectral confocal displacement sensor is mounted on the workbench, and the spectral confocal displacement sensor is used to collect the position offset of the ball-end mandrel when it moves; The controller is used to: Running a machine tool program so that the machine tool drives the ball head mandrel to move; Acquire the position offset of the ball-end core rod collected by the spectral confocal displacement sensor; Generating a position compensation table according to the position offset collected by the ball-end mandrel; According to the position compensation table, position compensation is performed on the movement of the machine tool.

6. A calibration device, characterized in that: The method comprises a memory and a processor connected to each other, wherein the memory is used to store a computer program, and when the computer program is executed by the processor, it is used to implement the method according to any one of claims 1 to 4.

7. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and the computer program can be executed by a processor to implement the steps in the method according to any one of claims 1 to 4.

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