An ultra-high precision multi-wire cutting machine and control method

Abstract

The present invention discloses an ultra-high precision multi-wire cutting machine and control method, comprising a frame, a lifting table, a translation table, a workpiece loading position and a multi-wire cutting assembly, wherein the lifting table is slidably mounted on the frame in the up-down direction and driven to lift by a lifting drive mechanism; a lower support platform is fixedly connected to the lower part of the lifting table, the translation table is slidably mounted on the lower support platform in the horizontal direction and driven to translate by a translation drive mechanism; a workpiece loading position is arranged on the lower side of the translation table; the multi-wire cutting assembly is mounted on the frame and located on the lower side of the workpiece loading position, and a plurality of parallelly distributed cutting lines are formed on the upper side of the multi-wire cutting assembly, and the cutting lines are distributed in the horizontal direction; the direction of the cutting lines is perpendicular to the translation direction of the translation table. The present invention can actively compensate for the horizontal offset during the lifting and lowering of the table by adopting a translation table and a translation drive mechanism.

Description

Technical Field

[0001] The present invention relates to cutting equipment, and more specifically, to an ultra-high precision multi-wire cutting machine, and also to a control method for the ultra-high precision multi-wire cutting machine. Background Art

[0002] At present, multi-wire cutting is the most advanced brittle and hard material processing technology in the world. It is a cutting method that cuts the workpiece into hundreds or even thousands of thin slices at a time through the high-speed reciprocating movement of the cutting wire. It is widely used in the IC (integrated circuit), IT (information technology), PV (photovoltaic) industries, such as single (multi) crystalline silicon, sapphire, magnetic materials, optical glass and quartz crystals and other brittle and hard materials precision slicing processing dedicated equipment.

[0003] With the advancement of technology and the increasingly higher requirements for the performance indicators of processed products, customers using multi-wire cutting machines have increasingly higher requirements for cutting accuracy, especially the total thickness deviation (TTV) requirement for the cutting blade, which is required to be ≤5μm. Therefore, the mechanical accuracy of the lifting worktable for loading and cutting workpieces is required to be higher.

[0004] At present, the lifting platform of conventional multi-wire cutting equipment usually moves up and down. During the lifting process, although it is theoretically vertical, due to the tolerance of the slider, slide rail and screw transmission structure, the lifting of the lifting platform will produce deviations in the horizontal direction. When the workpiece is installed on the lifting platform, it will also deviate with the lifting platform, resulting in deviations in cutting accuracy.

[0005] During the lifting process of the lifting platform, the horizontal deviation can be decomposed into two vertical directions. The first is the direction parallel to the cutting line and the cutting surface. The deviation in this direction will not affect the cutting; the second is the direction perpendicular to the cutting line. The deviation in this direction will affect the cutting. Once the deviation occurs, it will affect the accuracy of the cutting surface.

[0006] However, in current multi-wire cutting equipment, the final cutting accuracy is usually improved by improving the accuracy of the equipment, such as the matching accuracy of the slide rail and the slider. However, the improvement of hardware accuracy is limited, and when it reaches a certain level, it will be difficult to improve.

[0007] Therefore, a new solution needs to be proposed to solve this problem. Summary of the invention

[0008] The purpose of the present invention is to overcome the above-mentioned deficiencies of the prior art and to provide an ultra-high precision multi-wire cutting machine and a control method.

[0009] In order to achieve the above object, the present invention adopts the following technical solution:

[0010] An ultra-high precision multi-wire cutting machine comprises a frame, a lifting table, a translation table, a workpiece loading position and a multi-wire cutting assembly, wherein the lifting table is slidably mounted on the frame in the up-down direction and driven to lift by a lifting drive mechanism; a lower support table is fixedly connected to the lower part of the lifting table, the translation table is slidably mounted on the lower support table in the horizontal direction and driven to translate by a translation drive mechanism; a workpiece loading position is arranged at the lower side of the translation table;

[0011] The multi-wire cutting assembly is installed on the frame and is located at the lower side of the workpiece loading position. A plurality of parallel cutting lines are formed on the upper side of the multi-wire cutting assembly. The cutting lines are distributed in a horizontal direction. The direction of the cutting lines is perpendicular to the translation direction of the translation worktable.

[0012] It also includes a grating ruler 1, a displacement sensor 1, a grating ruler 2, a displacement sensor 2 and a detection reference surface. The grating ruler 1 is installed between the frame and the lifting worktable, and is used to detect the lifting displacement of the lifting worktable; the grating ruler 2 is installed between the lower support platform and the translation worktable, and is used to detect the horizontal displacement of the translation worktable; the frame is provided with a detection reference surface, and the detection reference surface is a plane, parallel to the lifting displacement direction of the lifting worktable, and perpendicular to the translation direction of the translation worktable; the displacement sensor 1 is installed on the lifting worktable, and senses the detection reference surface; the displacement sensor 2 is installed on the translation worktable, and senses the detection reference surface.

[0013] The present invention is further configured such that the lifting workbench is slidably connected to the frame via a lifting slide rail, and the translation workbench is slidably connected to the lower support platform via a translation slide rail.

[0014] The present invention is further configured such that the translation drive mechanism includes a screw, a drive motor and a screw seat, the screw is rotatably connected to the lower support platform, the screw is externally threadedly connected to the screw seat, and the screw seat is fixedly connected to the translation workbench.

[0015] The present invention is further configured such that the translation drive mechanism also includes two groups of push springs, which are respectively located on both sides of the axial direction of the screw seat and elastically act on the screw seat, and the elastic action direction is along the axial direction of the screw and is axially opposite.

[0016] The present invention also provides a control method for an ultra-high precision multi-wire cutting machine, which controls the ultra-high precision multi-wire cutting machine as described above; the lifting worktable has a horizontal offset during the lifting process, and during the lifting process of the lifting worktable, the translation worktable is driven horizontally by a translation drive mechanism to compensate for the horizontal offset of the lifting worktable during the lifting process.

[0017] The present invention is further configured such that the displacement of the horizontal movement of the translation workbench and the offset of the lifting workbench in the horizontal direction during the lifting process are opposite in direction and equal in magnitude.

[0018] The present invention is further configured to define variable parameters, h[i][j]: used to record the height position value of the lifting worktable; γ[i][j]: used to record the translation compensation feedback value of the translation worktable; δ1[i][j]: used to record the horizontal position change value of the lifting worktable; δ2[i][j]: used to record the horizontal position change value of the translation worktable; σ[i][j]: used to record the translation compensation value of the translation drive mechanism to the translation worktable; i is the height position value, j is the number of records, and each time a full stroke lifting is performed, the historical data is recorded once;

[0019] The control method comprises the following steps:

[0020] Step 1: Initially perform lifting operation, recorded as j=0. No compensation is performed during the initial lifting operation. The grating ruler second feedback data γ[i][j] is 0. As the original data during the lifting process, record the initial deviation value; record the initial detection data values: h[i][0], δ1[i][0], δ2[i][0];

[0021] Step 2: Perform linearity fitting on the calculated δ1[i][0] and δ2[i][0] to calculate the deviation relationship coefficient of the translation table: Q= ;

[0022] Step 3: Perform the full compensation open-loop lifting operation for the first time, denoted as j=1. According to the initial detection data value, directly drive the translation drive mechanism to operate, σ[i][1]= δ2[i][0], as the driving compensation amount of the lifting drive mechanism; record the detection data values: h[i][1], δ1[i][1], δ2[i][1], γ[i][1];

[0023] Step 4: Calculate the relationship between the given compensation value and the actual compensation coefficient based on the data values ​​γ[i][1] and σ[i][1] recorded in step 3: P = ;

[0024] Step 5: Execute the compensation feedback closed-loop lifting operation for the first time, denoted as j=2.

[0025] Calculate the feedback closed-loop compensation value: σ[i][2]=σ[i][1]+δ2[i][1]×P, which is used as the drive compensation value of the lifting drive mechanism;

[0026] Record the test data values: h[i][2], δ1[i][2], δ2[i][2], γ[i][2];

[0027] Step 6: Repeat step 5, continue iterating the calculation 3 times, and continue to record the detection data values.

[0028] The present invention is further configured to, during step 6, extract the values ​​in δ2[i][j] that exceed the preset interval range, record them as unstable positions, and perform corrections;

[0029] When correcting an unstable position, take the values ​​of the first three δ2[i][j], record them as δ2[i][j-1], δ2[i][j-2], δ2[i][j-3], and set the proportion coefficient to obtain the correction compensation value of the unstable position:

[0030] σ[i][j]=σ[i][j-1] +(δ2[i][j-1]×50%+δ2[i][j-2] ×30%+δ2[i][j-3] ×20%)×P

[0031] The present invention is further configured to include: Step 7: repeating step 6, and continuing the iterative calculation until the output value δ2[i][j] meets the required range and δ2[i][j] reaches the accuracy range.

[0032] The present invention is further configured such that the position change of the lifting and lowering of the translation worktable is continuous, and a continuous compensation value can be obtained by using a straight line fitting function, and the output value gives a continuous compensation value to the translation mechanism.

[0033] In summary, the present invention has the following beneficial effects:

[0034] The lifting workbench has a horizontal offset during the lifting process. During the lifting process, the translation workbench is driven horizontally by the translation drive mechanism to compensate for the horizontal offset of the lifting workbench during the lifting process, thereby reducing the offset during the lifting process.

[0035] In this solution, the vertical height trajectory is the theoretical height position of the lifting table, which is a straight line running vertically up and down. The position of each point reflects the height position of the lifting table. The actual trajectory is the actual lifting trajectory of the lifting table, which may be tilted in the horizontal direction, affecting the accuracy of the equipment. The compensation trajectory is the compensation trajectory of the translation table, which is opposite to the inclination direction of the actual trajectory and equal in size. By combining the compensation trajectory with the actual trajectory, a compensated running trajectory can be obtained, which is close to the vertical height trajectory, thereby improving the accuracy of the equipment's running trajectory and improving the cutting accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A three-dimensional diagram of an ultra-high precision multi-wire cutting machine in this embodiment Figure 1 ;

[0037] Figure 2 A three-dimensional diagram of an ultra-high precision multi-wire cutting machine in this embodiment Figure 2 ;

[0038] Figure 3 is a three-dimensional cross-sectional view of an ultra-high precision multi-wire cutting machine in this embodiment;

[0039] Figure 4 for Figure 3 Enlarged view of point A in the middle;

[0040] Figure 5 Schematic diagram of the structure of the translation drive mechanism in this embodiment;

[0041] Figure 6 Schematic diagram of the lifting workbench and the moving structure of the lifting workbench in this embodiment;

[0042] Figure 7 Schematic diagram of the structure of the lifting track, offset track and compensation track of the lifting workbench in this embodiment;

[0043] Figure 8 This is a logical schematic diagram of the control method in this embodiment.

[0044] Figure numerals: frame 1; detection reference surface 11; mounting plate 12; lifting workbench 2; lifting slide rail 21; lifting drive mechanism 22; grating ruler 23; scale grating 231; reading head 232; lower support platform 24; displacement sensor 25; translation workbench 3; translation slide rail 31; translation drive mechanism 32; screw rod 321; drive motor 322; screw rod seat 323; push spring 324; grating ruler 33; scale grating 331; reading head 332; displacement sensor 34; workpiece loading position 4; workpiece 5; multi-wire cutting assembly 6; cutting line 61; vertical line height trajectory 100; actual trajectory 101; compensation trajectory 102. DETAILED DESCRIPTION

[0045] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] This embodiment discloses an ultra-high precision multi-wire cutting machine. Figure 1-Figure 5As shown, it includes a frame 1, a lifting workbench 2, a translation workbench 3, a workpiece loading position 4 and a multi-wire cutting component 6. The frame 1 has a vertically arranged mounting plate 12. The lifting workbench 2 and the multi-wire cutting component 6 are both installed on one side of the mounting plate 12, and the multi-wire cutting component 6 is located below the lifting workbench 2.

[0047] The mounting plate 12 is provided with two lifting rails 21 , and the lifting workbench 2 is slidably mounted on the frame 1 along the up-and-down direction through the lifting rails 21 and driven to move up and down through the lifting driving mechanism 22 .

[0048] A lower support platform 24 is fixedly connected to the lower part of the lifting workbench 2, and two translation rails 31 are installed on the lower support platform 24. The translation workbench 3 is slidably installed on the lower support platform 24 along the horizontal direction through the translation rails 31, and is driven to translate by the translation driving mechanism 32.

[0049] The lifting rail 21 is vertical, so that the lifting direction of the lifting platform 2 is also vertical. The translation platform 3 is installed on the lower side of the lifting platform 2 and can slide up and down synchronously with the lifting platform 2. The translation rail 31 is arranged in the horizontal direction, and the translation platform 3 can slide horizontally in the horizontal direction.

[0050] A workpiece loading position 4 is installed at the lower side of the translation workbench 3 , and the workpiece loading position 4 is used to install a workpiece 5 to be cut.

[0051] In this embodiment, the multi-wire cutting assembly 6 is mounted on the mounting plate 12 of the frame 1 and is located at the lower side of the workpiece loading position 4. A plurality of parallel cutting lines 61 are formed on the upper side of the multi-wire cutting assembly 6, and the cutting lines 61 are distributed in a horizontal direction. The multiple cutting lines 61 form a cutting line network, which is located directly below the workpiece loading position 4 and plays a role in multi-wire cutting of the workpiece. The cutting lines 61 are directed in a horizontal direction and are perpendicular to the translation direction of the translation table 3.

[0052] In this embodiment, a grating scale 1 23 , a displacement sensor 1 25 , a grating scale 2 33 , a displacement sensor 2 34 and a detection reference surface 11 are also provided.

[0053] The grating ruler 23 is installed between the frame 1 and the lifting platform 2, and can detect the lifting displacement of the lifting platform 2. Specifically, the grating ruler 23 includes a scale grating 231 and a reading head 232. The scale grating 231 is fixedly installed on the mounting plate 12 of the frame 1 and is in a fixed state. The reading head 232 is installed on the lifting platform 2 and is in an active state. The reading head 232 and the scale grating 231 sense each other to obtain the height position parameters of the lifting platform 2.

[0054] The grating ruler 2 33 is installed between the lower support table 24 and the translation table 3, and can detect the horizontal displacement of the translation table 3. Specifically, the grating ruler 2 33 includes a scale grating 2 331 and a reading head 2 332, the scale grating 2 331 is installed on the lower translation table 3; the reading head 2 332 is installed on the lower support table 24, and the scale grating 2 331 and the reading head 2 332 are mutually induced, so that the horizontal displacement parameters of the translation table 3 can be obtained.

[0055] Reference Figure 3 As shown, the frame 1 is provided with a detection reference surface 11 , which is a plane, parallel to the lifting displacement direction of the lifting workbench 2 , and perpendicular to the translation direction of the translation workbench 3 .

[0056] The detection reference surface 11 is formed on the mounting plate 12 of the frame 1, and a sink is milled around the detection reference surface 11 to form a floating island structure to ensure that the grinding wheel of the grinding machine does not contact other positions of the detection reference surface 11 during processing, so as not to affect the accuracy of the detection reference surface 11. The detection reference surface 11 shall not be processed by cutting, that is, the surface grinding wheel of the surface grinder passes the tool once to ensure that the flatness of the reference surface is within 1μm.

[0057] Reference Figure 4 As shown, the displacement sensor 25 is installed on the lifting workbench 2. The installation position of the displacement sensor 2 is close to the detection reference plane 11, and can sense the detection reference plane 11. The horizontal offset can be detected through the distance change of the displacement sensor 2.

[0058] Reference Figure 5 As shown, the displacement sensor 2 34 is installed on the translation workbench 3. The installation position of the displacement sensor 2 34 is close to the detection reference surface 11, and can sense the detection reference surface 11. The horizontal offset can be detected through the distance change of the displacement sensor 2 34. Since the workpiece 5 is installed on the translation workbench 3, the distance change of the displacement sensor 2 34 can mainly reflect the horizontal offset.

[0059] Reference Figure 5 As shown, the translation drive mechanism 32 is a threaded screw structure, including a screw 321, a drive motor 322 and a screw seat 323. The screw 321 is rotatably connected to the lower support platform 24, and the direction of the screw 321 is consistent with the translation direction of the translation workbench 3. The screw 321 is externally threadedly connected to the screw seat 323, and the screw seat 323 is fixedly connected to the translation workbench 3, and the translation workbench 3 moves following the screw seat 323.

[0060] In the translation drive mechanism 32, the driving motor 322 is a harmonic reducer driven by a servo motor, and the output end is connected to the screw 321, which can drive the screw 321 to rotate. The screw 321 and the screw seat 323 are threaded together to produce threaded linkage and realize horizontal movement. The screw structure has clearance during the driving process, and high precision requirements are required, which must be eliminated during the driving process. Therefore, two push springs 324 of the same specification are installed at both ends of the screw seat 323. The push spring 324 is in a semi-compressed state. The compressed elastic force of the push spring 324 is used to eliminate the screw gap and resist the reverse torque of the cutting line 61 on the workpiece 5. Through this structure, the clearance in the driving structure can be eliminated to ensure the response speed and response accuracy during the adjustment process.

[0061] This embodiment also discloses a control method for an ultra-high precision multi-wire cutting machine, which controls the ultra-high precision multi-wire cutting machine in the above embodiment, and then combines Figure 6-Figure 8 A detailed description is given, and the control method can be used to control the equipment, realize cutting, and maintain the accuracy during the cutting process.

[0062] The lifting platform 2 has a horizontal offset during the lifting process. During the lifting process of the lifting platform 2, the translation drive mechanism 32 drives the translation platform 3 to move horizontally to compensate for the horizontal offset of the lifting platform 2 during the lifting process, thereby reducing the offset during the lifting process. Theoretically, if the displacement of the horizontal movement of the translation platform 3 is opposite to the horizontal offset of the lifting platform 2 during the lifting process and is equal in magnitude, the offset can be completely eliminated.

[0063] Reference Figure 6 , Figure 7 As shown, in this embodiment, the vertical height trajectory 100 is the theoretical height position of the lifting table 2, which is a straight line running vertically up and down, and the position of each point reflects the height position of the lifting table 2. The actual trajectory 101 is the actual lifting trajectory of the lifting table 2, which may be tilted in the horizontal direction, affecting the accuracy of the equipment. The compensation trajectory 102 is the compensation trajectory of the translation table 3, which is opposite to the tilt direction of the actual trajectory 101 and equal in size. By combining the compensation trajectory 102 with the actual trajectory 101, a compensated running trajectory can be obtained, which is close to the vertical height trajectory 100, thereby improving the accuracy of the running trajectory of the equipment and improving the cutting accuracy.

[0064] The vertical line height track 100 can be detected and obtained by the grating ruler 1 23 . The compensation track 102 can be detected and obtained by the grating ruler 2 33 .

[0065] The actual trajectory 101 can be obtained by sensing and detecting the displacement sensor 1 25 , the displacement sensor 2 34 and the detection reference surface 11 , and is mainly detected by the displacement sensor 2 34 .

[0066] During the up and down movement of the lifting workbench 2, the height point and the vertical deviation value of the corresponding height point are recorded, and a certain position point is marked, for example: the height position is 1mm, the deviation value is: 0.1mm; the height position is 2mm, the deviation value is: -0.1mm;

[0067] The translation table 3 can compensate for the deviation value by horizontal movement, for example, reverse compensation of -0.1mm at a height position of 1mm and positive compensation of 0.1mm at a height position of 2mm; the offset of the translation table 3 can be compensated by reverse translation of the translation table 3 at the corresponding position.

[0068] However, in actual operation, when the lifting platform rises to the 1mm position, the offset detection value obtained at this time is 0.1mm. If the output compensation value is 0.1mm when reaching this position, it is already delayed and accurate compensation cannot be achieved. Moreover, the delayed compensation not only cannot be corrected, but may also cause worse consequences.

[0069] In this embodiment, historical data during the operation of the equipment (i.e., the detection value of the last displacement position, or even the detection value before) is recorded to calculate compensation data for the translation compensation of the translation workbench 3.

[0070] The control method in this embodiment refers to Figure 8 As shown, the controller of the equipment reads the grating scale signal and displacement sensor signal of the lifting table 2 and the translation table 3. After logical analysis and judgment, the translation drive mechanism 32 drives the translation table 3 to perform translation compensation. Finally, the output compensation value is judged by the feedback grating scale and displacement sensor signal, so as to achieve the required operating accuracy requirement.

[0071] The height value h of the lifting table 2 is detected and recorded by the grating ruler 23, which is an absolute value type. During each lifting process, the absolute value is recorded to clarify the height position of the lifting table 2. The resolution of the grating ruler 23 is 0.5μm.

[0072] The lifting platform 2 is equipped with a displacement sensor 25, which can detect the horizontal position of the lifting platform 2 and the detection reference surface 11, thereby obtaining the lifting verticality of the lifting platform 2 and detecting the distance between the displacement sensor 25 and the detection reference surface 11. The detection stroke of the displacement sensor 25 is 0-2mm, and the distance between the installation position and the detection reference surface 11 is maintained within the range of 1±0.1mm.

[0073] A grating ruler 33 is installed between the translation worktable 3 and the lower support table 24 to record the execution value γ of the compensation position of the translation worktable 3. The grating ruler 33 is an absolute value type and records the absolute position each time compensation is performed. The resolution of the grating ruler 33 is 0.5 μm.

[0074] The translation table 3 is equipped with a displacement sensor 2 34, which has a measurement accuracy of 0.4μm. The displacement sensor 2 34 is used to measure the verticality of the translation table 3 and the reference surface after movement compensation, and detect the distance between the displacement sensor 2 34 and the reference surface. The workpiece loading position 4 is installed on the translation table 3, and the offset of the detection distance can directly reflect the verticality of the lifting of the workpiece 5 during cutting. The detection stroke of the displacement sensor 2 34 is 0-2mm, and the distance between the installation position and the detection reference surface 11 is maintained within the range of 1±0.1mm.

[0075] As for the height, at every certain height position (generally 0.1 mm), read the absolute position h of the grating ruler 1 23, the absolute position γ of the grating ruler 2 33, the displacement detection values ​​δ1 and δ2 of the displacement sensor 1 25 and the displacement sensor 2 34, and transmit the recorded values ​​to the controller. Since the height of the translation table 3 and the lifting table 2 does not change, the corresponding height and the corresponding horizontal position of the translation table 3 are mentioned in the subsequent embodiments.

[0076] Define variable parameters to represent the position parameters of the translation table 3, which are used to record values ​​and calculations, where h[i][j] is used to record the height position value of the lifting table 2; γ[i][j] is used to record the translation compensation feedback value of the translation table 3; δ1[i][j] is used to record the horizontal position change value of the lifting table 2; δ2[i][j] is used to record the horizontal position change value of the translation table 3; σ[i][j] is used to record the translation compensation value of the translation drive mechanism 32 on the translation table 3; where i is the height position value (for example, the total height stroke is 200mm, and 200mm can be divided into 2000 parts, each part is 0.1mm); j is the number of records, and the historical data is recorded once each full stroke lifting is performed, that is, j=j+1).

[0077] The displacement sensor 2 34 detects data, obtains the horizontal offset of the translation table 3, and transmits it to the controller. After analyzing and calculating the value, the translation drive mechanism 32 is controlled. The driving motor 322 drives the translation drive mechanism 32 to run, drive the translation table 3 to translate, and perform position compensation.

[0078] The control method in this embodiment includes the following steps:

[0079] Step 1: Initially perform the lifting operation, recorded as j=0, but do not perform the compensation operation (that is, the feedback data of the grating ruler 233γ[i][j] is 0). Record the initial deviation value as the original data during the lifting process.

[0080] When the lifting operation is initially performed, a full-stroke lifting action is performed starting from the lowest point of the translation table 3 (i.e., the origin 0). In this embodiment, the lifting stroke is 200 mm. The initial detection data values ​​are recorded: h[i][0], δ1[i][0], δ2[i][0]. For example, h[0][0], δ1[0][0], δ2[0][0] are used as position data of a height of 0 mm; h[1][0], δ1[1][0], δ2[1][0] are used as position data of a height of 0.1 mm... h

[2000] [0], δ1

[2000] [0], δ2

[2000] [0] are used as position data of a height of 200.0 mm.

[0081] Step 2: Calculate the linearity fitting of the calculated δ1[i][0] and δ2[i][0]. Calculate the relationship coefficient between the displacement sensor detection deviation of the translation stage and the displacement sensor detection deviation of the lifting stage: Q= .

[0082] Step 3: The first full compensation open-loop lifting operation is performed, denoted as j=1, that is, according to the initial detection data value, the translation mechanism is directly driven to operate with the initial detection data value, σ[i][1]= δ2[i][0]. For example, at position h

[100] [1] (height position at 10.0mm), the full compensation value is calculated: σ

[100] [1]= δ2

[100] [0], and the σ

[100] [1] value is used as the driving compensation amount of the lifting drive mechanism 22.

[0083] Similarly, starting from the lowest point of the translation table 3 (i.e., origin 0), a full stroke of 200 mm lifting action is performed, and the detection data values ​​are recorded in sequence: h[i][1], δ1[i][1], δ2[i][1], γ[i][1]. The detection data values ​​are the parameters after one compensation.

[0084] Step 4: Calculate the relationship between the given compensation value and the actual compensation coefficient based on the recorded data values ​​γ[i][1] and σ[i][1]: P = .

[0085] Step 5: The first execution of the compensation feedback closed-loop lifting operation is recorded as j=2. After the full compensation open-loop operation is executed, there is still a deviation between the compensation value and the compensation value required for the translation table 3. At this time, continue to superimpose the δ2[i][1] deviation value and the deviation coefficient, calculate the feedback closed-loop compensation value: σ[i][2]=σ[i][1]+δ2[i][1]×P, and use the σ[i][2] value as the drive compensation amount of the lifting drive mechanism 22.

[0086] Again, starting from the lowest point of the translation table 3 (i.e., the origin 0), a full-stroke lifting action of 200 mm is performed, and the detection data values ​​are recorded in sequence: h[i][2], δ1[i][2], δ2[i][2], γ[i][2].

[0087] Step 6: Repeat step 5 and continue iterating the calculation for 3 times, record them as j=3, 4, and 5 respectively, and continue to record the detection data values. Extract the values ​​that exceed the interval range in δ2[i][j] (generally ±2μm, the highest control accuracy is related to the sensor accuracy). The positions corresponding to these values ​​that exceed the interval range are still in an unstable state after continuous iteration, indicating that there is an overcompensation problem at this position, and this position is an overcompensation position.

[0088] When correcting these compensation values, the first three compensation values ​​are taken, and the coefficients are 50%, 30%, and 20% respectively. The corresponding drive compensation amount is obtained through the coefficient, that is:

[0089] σ[i][j]=σ[i][j-1] +(δ2[i][j-1]×50%+δ2[i][j-2] ×30%+δ2[i][j-3] ×20%)×P

[0090] Step 7: Repeat step 6 and continue iterative calculation until the output value δ2[i][j] meets the required range and δ2[i][j] reaches the accuracy range.

[0091] Furthermore, since the position change of the translation workbench 3 can be continuous during the actual operation of the lifting process, the interval between the two recording points is reduced during recording. Theoretically, the interval between the two recording points can be reduced to zero, that is, continuous recording can be achieved. For example, the interval between the two recording points can be shortened on the basis of the above, and reduced by 1 / 10. According to the above method, the position value and compensation value that can be obtained can be obtained by using a straight line fitting function, and a continuous compensation value can be obtained. The output value gives a continuous compensation value to the translation mechanism, that is:

[0092] σ[h][j]= (σ[i+1][j-1]-σ[i][j-1]) / 0.1×(hi×0.1)+σ[i][j-1]

[0093] Where h is a continuous height position value, and h∈(i×0.1, (i+1)×0.1), i=0,1…2000.

[0094] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A control method for an ultra-high precision multi-wire cutting machine, characterized in that: The ultra-high precision multi-wire cutting machine is controlled. The ultra-high precision multi-wire cutting machine is controlled with a lifting table (2). The lower part of the lifting table (2) is fixedly connected to a lower support table (24). The translation table (3) is slidably installed on the lower support table (24) in the horizontal direction. The lower side of the translation table (3) is provided with a workpiece loading position (4). The lifting table (2) has a horizontal displacement during the lifting process. During the lifting process of the lifting table (2), the translation table (3) is driven to move horizontally by a translation drive mechanism (32) to compensate for the horizontal displacement of the lifting table (2) during the lifting process. Define variable parameters, h[i][j]: used to record the height position value of the lifting platform (2); γ[i][j]: used to record the translation compensation feedback value of the translation platform (3); δ1[i][j]: used to record the horizontal position change value of the lifting platform (2); δ2[i][j]: used to record the horizontal position change value of the translation platform (3); σ[i][j]: used to record the translation compensation value of the translation drive mechanism (32) on the translation platform (3); i is the height position value, j is the number of records, and each time a full stroke lifting is performed, the historical data is recorded once; The control method comprises the following steps: Step 1: Initially perform the lifting operation, denoted as j=0. No compensation is performed during the initial lifting operation. The feedback data γ[i][j] of the grating ruler 2 (33) is 0. As the original data during the lifting process, record the initial deviation value; record the initial detection data values: h[i][0], δ1[i][0], δ2[i][0]; Step 2: Perform linearity fitting on the calculated δ1[i][0] and δ2[i][0], and calculate the deviation relationship coefficient of the translation table (3): Q = ; Step 3: Perform full compensation open-loop lifting operation for the first time, denoted as j=1, and directly drive the translation drive mechanism (32) to operate according to the initial detection data value, σ[i][1]= δ2[i][0], as the driving compensation amount of the lifting drive mechanism (22); record the detection data values: h[i][1], δ1[i][1], δ2[i][1], γ[i][1]; Step 4: Calculate the relationship between the given compensation value and the actual compensation coefficient based on the data values ​​γ[i][1] and σ[i][1] recorded in step 3: P = ; Step 5: Execute the compensation feedback closed-loop lifting operation for the first time, denoted as j=2. Calculate the feedback closed loop compensation value: σ[i][2]=σ[i][1]+δ2[i][1]×P, as the driving compensation amount of the lifting driving mechanism (22); Record the test data values: h[i][2], δ1[i][2], δ2[i][2], γ[i][2]; Step 6: Repeat step 5, continue iterating the calculation 3 times, and continue to record the detection data values.

2. The control method of the ultra-high precision multi-wire cutting machine according to claim 1, characterized in that: The displacement of the horizontal movement of the translation workbench (3) and the offset of the lifting workbench (2) in the horizontal direction during the lifting process are opposite in direction and equal in magnitude.

3. The control method of the ultra-high precision multi-wire cutting machine according to claim 1, characterized in that: In step 6, the values ​​in δ2[i][j] that are beyond the preset interval are extracted, recorded as unstable positions, and corrected; When correcting an unstable position, take the values ​​of the first three δ2[i][j], record them as δ2[i][j-1], δ2[i][j-2], δ2[i][j-3], and set the proportion coefficient to obtain the correction compensation value of the unstable position: σ[i][j]=σ[i][j-1] + (δ2[i][j-1]×50%+δ2[i][j-2] ×30%+δ2[i][j-3] ×20%)×P.

4. The control method of the ultra-high precision multi-wire cutting machine according to claim 3, characterized in that: It also includes: Step 7: Repeat step 6 and continue iterative calculation until the output value δ2[i][j] meets the required range and δ2[i][j] reaches the accuracy range.

5. The control method of the ultra-high precision multi-wire cutting machine according to claim 1, characterized in that: The lifting and lowering position change of the translation workbench (3) is continuous, and a continuous compensation value can be obtained by adopting a straight line fitting function, and the output value is used to give a continuous compensation value to the translation mechanism.

6. An ultra-high precision multi-wire cutting machine, characterized in that: The invention comprises a frame (1), a lifting worktable (2), a translation worktable (3), a workpiece loading position (4) and a multi-wire cutting assembly (6); the lifting worktable (2) is slidably mounted on the frame (1) in the up-down direction and driven to lift by a lifting drive mechanism (22); a lower support platform (24) is fixedly connected to the lower part of the lifting worktable (2); the translation worktable (3) is slidably mounted on the lower support platform (24) in the horizontal direction and driven to translate by a translation drive mechanism (32); a workpiece loading position (4) is arranged on the lower side of the translation worktable (3); The multi-wire cutting assembly (6) is installed on the frame (1) and is located at the lower side of the workpiece loading position (4); a plurality of parallel cutting lines (61) are formed on the upper side of the multi-wire cutting assembly (6); the cutting lines (61) are distributed in a horizontal direction; the direction of the cutting lines (61) is perpendicular to the translation direction of the translation worktable (3); It also includes a grating ruler 1 (23), a displacement sensor 1 (25), a grating ruler 2 (33), a displacement sensor 2 (34) and a detection reference surface (11), wherein the grating ruler 1 (23) is installed between the frame (1) and the lifting worktable (2) and is used to detect the lifting displacement of the lifting worktable (2); the grating ruler 2 (33) is installed between the lower support platform (24) and the translation worktable (3) and is used to detect the horizontal displacement of the translation worktable (3); the frame (1) is provided with a detection reference surface (11), and the detection reference surface (11) is a plane, parallel to the lifting displacement direction of the lifting worktable (2) and perpendicular to the translation direction of the translation worktable (3); the displacement sensor 1 (25) is installed on the lifting worktable (2) and senses the detection reference surface (11); the displacement sensor 2 (34) is installed on the translation worktable (3) and senses the detection reference surface (11); The control is performed by adopting the control method of the ultra-high precision multi-wire cutting machine as described in any one of claims 1 to 5.

7. The ultra-high precision multi-wire cutting machine according to claim 6, characterized in that: The lifting workbench (2) is slidably connected to the frame (1) via a lifting slide rail (21), and the translation workbench (3) is slidably connected to the lower support platform (24) via a translation slide rail (31).

8. The ultra-high precision multi-wire cutting machine according to claim 6, characterized in that: The translation drive mechanism (32) comprises a screw rod (321), a drive motor (322) and a screw rod seat (323); the screw rod (321) is rotatably connected to the lower support platform (24); the screw rod (321) is externally threadedly connected to the screw rod seat (323); and the screw rod seat (323) is fixedly connected to the translation workbench (3).

9. The ultra-high precision multi-wire cutting machine according to claim 8, characterized in that: The translation drive mechanism (32) further comprises two groups of push springs (324), which are respectively located on both axial sides of the screw seat (323) and elastically act on the screw seat (323), with the elastic acting direction being along the axial direction of the screw (321) and axially opposite.

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