A multi-source data compensation method for positioning accuracy of a motion unit of a complex micro-component ultra-precision controlled-shape machining system

Abstract

The application discloses a multi-source data compensation method for positioning precision of a motion unit of a complex micro-component ultra-precision controlled-shape machining system, relates to the technical field of complex micro-component ultra-precision controlled-shape machining, and is proposed to meet the requirement of high-precision creation of surface characteristic structures of a thin-wall spherical shell micro-component under the constraint of a narrow space. Technical points: a linear motion unit is controlled by a numerical control system program to reciprocate several times in a constant increment form in a full stroke and a working area, respectively; the position of the linear motion unit in the motion process is collected by a high-frequency laser interferometer; and multi-source error data in the whole area and the region are obtained through data processing. Based on the multi-source data compensation method, a multi-source data error compensation table is established, compensation is carried out through a numerical control program, and the positioning precision of the linear motion unit is calibrated. For a rotary motion unit, an autocollimator is used to calibrate the error, and further compensation is carried out in the program through the error table by an error synthesis method, so that the calibration and compensation of the positioning precision of each motion unit of the complex micro-component ultra-precision controlled-shape machining system are completed, and high-precision equipment support is provided for micro-structure high-precision creation.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of complex micro-component ultra-precision controlled shape machining technology, and particularly relates to a complex micro-component ultra-precision controlled shape machining system motion unit positioning precision multi-source data compensation method. BACKGROUND

[0002] With the rapid development of related industries, it has triggered the urgent demand for various high-precision, complex micro components in large quantities. For example, a kind of micro-thin-walled spherical shell complex micro-component has been widely used in the field of energy exploration. The ball diameter of this kind of component is usually in the order of millimeter to sub-millimeter, and the engineering application requires that ultra-precision micro-milling controlled shape machining method is used to process dozens to hundreds of cross-scale feature structures on the whole surface, and the surface shape reaches sub-millimeter level shape accuracy and nanometer level surface roughness, which puts forward higher requirements for the motion performance and positioning accuracy of the controlled shape machining system.

[0003] Under the constraint of narrow space, the special structural features, fine surface defects, millimeter-level motion stroke and micrometer-level material removal depth of the thin-walled spherical shell micro-component pose a severe challenge to the improvement of the motion accuracy of the ultra-precision controlled shape machining system. For the nanometer-level precision removal of space structure materials under such complex working conditions, it is necessary to rely on a multi-axis linkage controlled shape machining system, and the positioning accuracy of the linear motor driven guide rail motion unit needs to reach the sub-micron to nanometer level. Improving the manufacturing process of the motion unit, error compensation and optimization of the compensation strategy are the key measures to improve the positioning accuracy. The common precision compensation methods are reverse gap compensation method and pitch compensation method, which mainly face the ball screw transmission components and cannot be applied to linear motor transmission precision compensation. At the same time, the current five-axis precision manufacturing system with high technical maturity mainly faces the precision level material removal of conventional basic parts, and the positioning accuracy of the motion unit is in the order of millimeter, which cannot realize high-precision surface creation; while the two-axis and three-axis ultra-precision manufacturing system can improve the positioning accuracy through global error compensation, but is limited by the manufacturing process and error compensation method of the motion unit, and the positioning accuracy after compensation is very limited; and in the local area, especially in the millimeter-level actual working stroke, it still cannot meet the requirements.

[0004] In view of the problem that the current multi-axis linkage system cannot meet the high-precision creation requirements of micro-structures due to insufficient manufacturing process capability and poor precision compensation method, the positioning accuracy multi-source data compensation method of the motion unit of the complex micro-component ultra-precision controlled shape machining system is researched, so as to meet the urgent practical engineering demand for large quantities of complex micro components in the field of energy exploration, which has important practical significance. SUMMARY

[0005] The technical problem to be solved by the present application is:

[0006] Aiming at the problem that the five-axis precision manufacturing system with high technical maturity and the ultra-precision manufacturing system mainly with two-axis and three-axis cannot meet the high-precision creation of the surface feature structure of the thin-walled spherical shell micro component under the constraint of narrow space due to the insufficient manufacturing process capability of the motion unit component, the poor precision compensation method and other reasons, a motion unit positioning precision multi-source data compensation method of a complex micro component ultra-precision controlled shape machining system is provided.

[0007] The technical scheme adopted by the present application to solve the above technical problems is:

[0008] A motion unit positioning precision multi-source data compensation method of a complex micro component ultra-precision controlled shape machining system, the implementation process of the method is:

[0009] A plurality of target positions are selected in the full stroke and working range of the linear motion unit, and a numerical control program is compiled in combination with the structural characteristics of the controlled shape machining system, so that each linear motion unit moves to the target position in incremental form, and this reciprocating motion is repeated multiple times; at each target position, the target position coordinates are collected in real time by a high-frequency laser interferometer to construct a shaft system running position data set; after data processing, the multi-source error data set in the global and regional range is obtained;

[0010] Based on the multi-source error data compensation method, a multi-source data error collaborative compensation table is established; for the rotary motion unit, the positioning accuracy of the controlled shape machining system hydraulic B-axis and workpiece C-axis rotary motion unit is calibrated by using an optical self-collimation instrument and a regular polyhedral prism, and an error compensation table is established by the error synthesis method after data processing;

[0011] Based on the upper computer software of the controlled shape machining system, the above multi-source data error collaborative compensation table of the linear motion unit and the error compensation table of the rotary motion unit are downloaded into the motion controller, and the compensation table is enabled through the numerical control program, so as to complete the motion error calibration and positioning accuracy improvement of each motion unit of the ultra-precision controlled shape machining system;

[0012] The multi-source data compensation method provided is based on the global motion error of the motion unit, and the global positioning accuracy compensation is performed on the numerical control program; on this basis, the regional motion error of the motion unit is calibrated, and the regional motion error data set is obtained;

[0013] The global motion error and the regional motion error and other multi-source error data are coupled to establish a multi-source error data compensation table, and the compensation is performed through the numerical control program; when the error calibration and precision compensation are performed in the global and actual working stroke region, the multi-source data compensation method needs to be used for multiple iterative calibration and compensation to meet the global and regional precision index requirements, so as to realize the positioning accuracy improvement of the motion unit.

[0014] This invention offers the following beneficial technical effects: The method of this invention is geared towards ultra-precision controlled machining systems for complex micro-components. A CNC system program controls linear motion units to reciprocate several times within their full stroke and working range in a constant increment. The positions of the linear motion units during motion are collected using a high-frequency laser interferometer, and data processing yields multi-source error data for both global and regional operations. Based on a multi-source data compensation method, a multi-source data error compensation table is established, and compensation is performed through the CNC program to complete the calibration of the positioning accuracy of the linear motion units. For rotary motion units, an autocollimator is used for error calibration, and further compensation is performed in the program using an error synthesis method through the error table. This completes the calibration and compensation of the positioning accuracy of each motion unit in the ultra-precision controlled machining system for complex micro-components, providing high-precision positioning equipment support for the high-precision creation of microstructures.

[0015] This invention focuses on a multi-source data compensation method. The accuracy compensation method provided by this invention can meet the high-precision creation requirements of surface feature structures of thin-walled spherical shell micro-components under confined space constraints. The multi-source error in this method mainly includes two aspects: first, the coupling between global motion error and regional motion error; second, the coupling between the multiple positioning error data (multi-source iterative errors) involved when performing global and regional positioning accuracy calibration and compensation separately, which is limited by the manufacturing accuracy of the motion unit. The equipment used for error detection can also be implemented using existing technologies. Attached Figure Description

[0016] Figure 1 A schematic diagram illustrating a multi-source data compensation method for the positioning accuracy of motion units in an ultra-precision form control machining system for complex micro-components. Figure 2 A flowchart illustrating the operation of a multi-source data compensation method for the positioning accuracy of motion units in an ultra-precision form control machining system for complex micro-components. Figure 3 The diagram shows the structure of a complex micro-component ultra-precision form control machining system. In the diagram: (a) is the front view of the complex micro-component ultra-precision form control machining system, and (b) is the top view of the complex micro-component ultra-precision form control machining system. Detailed Implementation

[0017] The present invention relates to a multi-source data compensation method for the positioning accuracy of motion units in an ultra-precision form control machining system for complex micro-components, the implementation process of which is combined with... Figures 1-3 To illustrate: The flowchart of the multi-source data compensation method for the positioning accuracy of the motion unit in the ultra-precision form control machining system for complex micro-components is shown below. Figure 1 As shown in the figure, the operation flowchart of the multi-source data compensation method for the positioning accuracy of the motion unit in the ultra-precision shape control machining system for complex micro-components is as follows. Figure 2 As shown. The provided multi-source data compensation method for motion unit positioning accuracy is geared towards ultra-precision form control machining systems for complex micro-components, such as...Figure 3 as shown.

[0018] The motion unit positioning accuracy multi-source data compensation method is proposed for the complex micro component ultra-precision controlled shape machining system, which mainly comprises a marble table 1, an X-axis linear motion unit 2, a Y-axis linear motion unit 3, a Z-axis linear motion unit 9, a hydraulic B-axis rotary motion unit 8, a workpiece C-axis rotary motion unit 4, a milling shaft 7, a thin-walled spherical shell micro component 5, a micro-diameter milling cutter 6 and the like. The marble table 1 is connected to the controlled shape machining system bed through a vibration isolation air cushion, so as to weaken the influence of environmental vibration on machining precision. The horizontal X-axis linear motion unit 2 and the Y-axis linear motion unit 3 are arranged on the marble table 1 in a perpendicular manner, the vertical Y-axis linear motion unit 3 is arranged on the X-axis motion unit 2, and the directions of the X / Y / Z-axis linear motion units are as shown in the figure.

[0019] Figure 3 As shown, all are supported by high-precision hydraulic guide rails and driven by linear motors. The hydraulic B-axis rotary motion unit 8 adopts a hydrostatic bearing and is arranged on the Z-axis 9 tail plate, and the negative Y-axis clockwise direction is the positive direction of the B-axis. The milling shaft 7 is connected to the hydraulic B-axis transition plate 8, and the micro-diameter milling cutter 6 is connected to the end of the milling shaft 7 through pneumatic clamping. The workpiece C-axis rotary motion unit 4 adopts a gas static bearing and is connected to the Y-axis 3 tail plate; the thin-walled spherical shell micro component 5 is connected to the end of the workpiece C-axis 4 through a vacuum suction clamp.

[0020] The operation method of the present application and the working principle are as follows:

[0021] The above-mentioned motion unit positioning accuracy multi-source data compensation method for the complex micro component ultra-precision controlled shape machining system is directed to the complex micro component ultra-precision controlled shape machining system (in the prior art), mainly comprising three parts of shafting error calibration, multi-source data precision compensation and shafting positioning accuracy checking, as shown in the figure. The specific operation process of the method is as shown in the figure. Figure 3 Figure 1 Figure 2 ​​As shown, a plurality of target positions are selected in the full stroke and working range of the linear motion unit, and a numerical control program is compiled according to the structural characteristics of the shape control machining system, so that each linear motion unit moves to the target position in an incremental form, and such reciprocating motion is repeated multiple times. At each target position, the target position coordinates are collected in real time by the high-frequency laser interferometer to construct a shaft system running position data set; further data processing is performed to obtain a multi-source error data set in the global and regional range. Based on the multi-source error data compensation method, a multi-source data error collaborative compensation table is established; for the rotary motion unit, the positioning accuracy of the hydraulic B shaft and the workpiece C shaft rotary motion unit of the shape control machining system is calibrated by using the photoelectric autocollimator and the regular polyhedral prism, and the error compensation table is established by the error synthesis method through data processing. Based on the upper computer software of the shape control machining system, the above-mentioned multi-source data error collaborative compensation table of the linear motion unit and the error compensation table of the rotary motion unit are downloaded into the motion controller, and the compensation table is enabled through the numerical control program, so as to complete the motion error calibration and positioning accuracy improvement of each motion unit of the ultra-precision shape control machining system.

[0022] The multi-source data compensation method provided is based on the global motion error of the motion unit, and the global positioning accuracy compensation of the numerical control program is performed; on this basis, the regional motion error is calibrated to obtain a regional motion error data set. Further, the multi-source error data such as global motion error and regional motion error are coupled to establish a multi-source error data compensation table, and compensation is performed through the numerical control program. Limited by the manufacturing process of the motion unit components, when the global and actual working stroke region error calibration and accuracy compensation are performed, the multi-source data compensation method needs to be used for multiple iterative calibration and compensation to meet the global and regional accuracy index requirements, so as to realize the positioning accuracy improvement of the motion unit.

[0023] The specific description and operation process are as follows:

[0024] I. Shaft system error calibration: the high-frequency laser interferometer is used for linear motion unit motion error calibration, and the photoelectric autocollimator and the regular polyhedral prism are used for rotary motion unit positioning accuracy test. The numerical control program is compiled by the upper computer software, the motion unit is controlled to move to the target position in a constant incremental form, and the real-time position coordinates are collected to construct a shaft system running position data set, and the global and regional range motion error is obtained through data processing, so as to complete the shaft system error calibration. The specific operation steps are as follows:

[0025] Step 1.1: the laser interferometer is used for linear motion unit motion error calibration, the interferometer is fixed on the transition plate and connected with the shape control machining system bed; the interferometer mirror is installed on the X / Y / Z sliding table of the shape control machining system;

[0026] Further, the laser interferometer is XL-80 series of Renishaw, with a resolution of 0.01 μm, and the point acquisition interface unit is unified as μm;

[0027] Further, the environmental condition requirement is that the environmental temperature is 20±0.5℃, the temperature change rate is ≤0.5℃ / h, and the relative humidity is 40-60%.

[0028] Step 1.2: The laser detection light path design is performed, the interferometer is placed in the light path of the interferometer and the mirror, and the reciprocating linear motion unit is moved to adjust the laser detection light path, so that the light path transmission is normal in the full stroke of the X / Y / Z linear motion unit, and the interferometer has a high signal strength;

[0029] Further, particularly, because the Y-axis linear motion unit moves up and down in the vertical plane, a 45° refractor is added to change the light path transmission direction by 90°.

[0030] Step 1.3: A plurality of target points are selected in the full stroke of each linear shaft system, a numerical control program is compiled to make the linear shaft system move to the target points in an incremental form, the interferometer collects the actual coordinates of the target positions in real time, the linear shaft system motion position data set is constructed, and the linear motion shaft system motion error in the global range is obtained through data processing;

[0031] Further, the shaft system adopts a cyclic inspection mode, and is detected from positive and negative directions respectively, and is detected in the positive and negative directions for 5 times continuously;

[0032] Further, the full stroke of the linear motion unit is L i , a target point n i is selected, and the movement is performed in an incremental ΔL i .

[0033] Further, the motion speed of each shaft system in the numerical control program and the point position staying time are matched with the parameter settings of the laser interferometer.

[0034] Step 1.4: The positioning accuracy of the rotary motion unit is tested by using the photoelectric autocollimator and the regular polygonal prism, the 23-face prism is clamped on the hydraulic B-axis and the workpiece C-axis to be tested by a special clamp, the photoelectric autocollimator is installed on the system bed, and the special clamp is adjusted to make the signal transmission normal;

[0035] Further, the photoelectric autocollimator is ELCOMAT3000 series of Moeller, with a resolution of 0.001" and an accuracy of 0.1";

[0036] Further, the 23-face prism is a 2-equal prism, with a flatness of 0.03 μm;

[0037] Further, the eccentric error between the prism and the axis of the rotary shaft system is required to be less than 0.2 μm during the adjustment of the special fixture.

[0038] Step 1.5: A numerical control program is compiled to rotate the hydraulic B shaft and the workpiece C shaft by a constant angle at a constant angular velocity, the rotary motion unit position angle is measured by the photoelectric autocollimator measurement software, the rotary shaft system motion angle position data set is constructed, and the B / C shaft rotary motion error is obtained through data processing;

[0039] Further, the rotary shaft system rotation angular velocity and angle position residence time in the numerical control program are matched with the measurement software parameter settings.

[0040] II. Multi-source data accuracy compensation:

[0041] The general idea of compensation is as follows:

[0042] Taking the X linear motion unit as an example, first, the full-stroke positioning accuracy is calibrated, then the error program is compensated, and then it is checked whether the accuracy after compensation meets the requirements. If not, the compensation is continued (which can be cumulative for multiple times). When the full-stroke accuracy meets the requirements, the local working interval accuracy is calibrated based on the compensation table of the full-stroke accuracy. If the accuracy meets the requirements, the process is ended. If not, the compensation is performed in the local interval. When the local interval accuracy meets the requirements, the full-stroke and local interval accuracy both meet the requirements. Therefore, it can be seen that the multi-source error compensation mainly involves two parts: one is the coupling and collaborative compensation of the full-stroke and local interval error data; the other is the collaborative compensation between the multiple calibration iteration errors when the full-stroke or local interval is calibrated and compensated separately.

[0043] Based on the global motion error of the motion unit, the global positioning accuracy of the numerical control program is compensated until the positioning accuracy meets the global index requirements. On this basis, the regional motion error data set is obtained by regionalizing the motion error in the actual working stroke interval of the motion unit. Further, the multi-source error data such as the global motion error and the regional motion error are coupled to establish a multi-source error data compensation table, and the positioning accuracy of the motion unit is improved through the compensation of the numerical control program. As shown in the following formula: Figure 2 The specific operation steps are as follows:

[0044] Step 2.1: Based on the collected global error data set of each motion unit, the error data set is converted into accuracy compensation data set according to the corresponding relationship, and n i target point accuracy compensation data are obtained; in the integrated development environment, a new error compensation table C i is created according to the number of points to be compensated n i , a unit conversion coefficient is set, and the accuracy compensation data of each motion unit are written; in the upper computer software, a numerical control program is compiled, and the compensation table C i, further precision calibration by (1) shaft system error calibration method;

[0045] Further, the global error data set is the difference between the actual motion position of each motion unit and the program instruction position, and the error compensation is compensated for the program instruction position. The precision compensation data and the error data have an inverse number relationship;

[0046] Further, the integrated development environment adopts the international unit system mm. When writing precision compensation data, a conversion coefficient x10 -3 ;

[0047] Further, in the host computer software, a compensation table enabling program is compiled to start the compensation control through the interface to enable the compensation table C1. The compensation enabling program is as follows:

[0048]

[0049] Further, in step 2.1, after the compensation table C i is enabled, the shaft system precision is calibrated by (1) shaft system error calibration method. If the precision does not meet the global positioning precision requirement, step 2.1 is executed until the motion precision meets the index requirement, and the next step is entered; if the precision meets the requirement, the next step is entered;

[0050] Further, considering that N (i) times of calibration error data ε (i) is based on the overall performance of the motion unit after N (i-1) times of compensation, which covers N (i-1) times of error compensation data ε (i-1) , based on the multi-source data collaborative compensation method, N (i) times of precision compensation, the error data ε (i) mathematically superimposes N (i-1) times of error compensation data ε (i-1) ;

[0051] Explanation of subscript: i represents the random i-th motion unit, and r represents the i-th rotary motion unit;

[0052] Step 2.2: On the basis that the global positioning precision meets the index requirement, the actual working interval positioning precision of each motion unit is calibrated and compensated, the laser detection light path is adjusted according to steps 1.2 and 1.2, and a plurality of target points are selected in the actual working interval of the linear motion unit according to the error detection method of step 1.3. A numerical control program is compiled to make the linear shaft system move to the target point in incremental form. The interferometer collects the target position coordinates to construct the motion position data set. After data processing, the regional linear shaft system motion error is obtained;

[0053] Further, the actual working stroke range of the linear motion unit is L i-1 , a target point n i-1 is selected, and motion is performed with an increment ΔL i-1 .

[0054] Step 2.3: Based on the collected actual working stroke error data set of each motion unit, the error data set is converted into an accuracy compensation data set according to the corresponding relationship, n i-1 target point compensation data are obtained; in the integrated development environment, an error compensation table C i is newly created according to the number n i-1 of points to be compensated, a unit conversion coefficient is set, and the accuracy compensation data are written; in the upper computer software, a numerical control program is compiled, the compensation table C i-1 is enabled, and further regional positioning accuracy calibration is performed through step 2.2.

[0055] Further, in step 2.3, after the compensation table C i-1 is enabled, the shaft system accuracy is calibrated by the method of step 2.2. If the accuracy does not meet the actual working stroke positioning accuracy requirement, step 2.3 is executed until the motion accuracy meets the index requirement, and step 2.4 is entered; if the accuracy meets the requirement, step 2.4 is entered.

[0056] Further, considering that N (i)-1 calibration error data ε (i)-1 is based on the actual performance of the motion unit after N (i-1)-1 compensations, which covers N (i-1)-1 error compensation data ε (i-1)-1 , based on the multi-source data collaborative compensation method, N (i)-1 accuracy compensations, the error data ε (i)-1 mathematically superimposes N (i-1)-1 error compensation data ε (i-1)-1 .

[0057] Step 2.4: Based on steps 2.1 and 2.3, accuracy compensation data ε (i-1) and ε (i-1)-1 that meet the accuracy index requirements of each motion unit in the global / total stroke and the actual engineering interval stroke are obtained, based on the multi-source data collaborative compensation method, a numerical control program is compiled in the upper computer software, compensation tables C i and C i-1 are enabled, and the global and regional errors are written into the motion controller according to the multi-source data collaborative compensation method.

[0058] Further, when the compensation table is enabled in the upper computer numerical control program, the compensation table enabling instruction is downward compatible. Specifically, if compensation table C i is enabled, compensation table C(i-1) , C (i-2) …C0 are enabled.

[0059] Step 2.5: Based on the slewing motion unit motion error data set collected in step 1.4, the error data set is converted into an accuracy compensation data set according to the correspondence by the error synthesis method, and in the integrated development environment, an error compensation table C ri is newly created according to the number n ri of points to be compensated, and accuracy compensation data is written; in the upper computer software, a numerical control program is compiled, the compensation table C ri is enabled, and further error calibration is performed through step 1.5;

[0060] Further, in step 2.5, after the compensation table C ri is enabled, the slewing shaft system accuracy is calibrated by the (1) shaft system error calibration method. If the accuracy does not meet the global positioning accuracy requirement, step 2.5 is executed until the motion accuracy meets the index requirement, and the next step is entered; if the accuracy meets the requirement, the next step is entered;

[0061] Further, considering that the N (ri) times calibration error data ε (ri) is based on the overall performance of the motion unit after N (ri-1) times compensation, which covers N (ri-1) times error compensation data ε (ri-1) , based on the multi-source data collaborative compensation method, N (ri) times accuracy compensation, the error data ε (ri) mathematically superimposes N (ri-1) times error compensation data ε (ri-1) .

[0062] Three, shaft system positioning accuracy check: high-frequency laser interferometer is used to check the linear motion unit motion error, and photoelectric autocollimator and regular polyhedral prism are used to check the positioning accuracy of the slewing motion unit. The upper computer software compiles a numerical control program to control each motion unit to move to the target position in a constant increment form, and collects real-time position coordinates to construct a shaft system running position data set, and through data processing, global and regional range motion errors are obtained.

[0063] Further, the motion unit uses a cyclic test method to detect from both positive and negative directions, and detects in the positive and negative directions for 3 times in succession.

[0064] Implementation case:

[0065] A multi-source data compensation method for the positioning accuracy of motion units in a complex micro-component ultra-precision shape control machining system is proposed to address the problem of high-precision creation of surface feature structures of thin-walled spherical shell micro-components under confined space constraints due to insufficient manufacturing process capabilities and inadequate accuracy compensation methods in current technologically mature five-axis precision manufacturing systems and ultra-precision manufacturing systems mainly based on two-axis and three-axis systems. A specific implementation example is as follows, taking the X-axis linear motion unit as an example:

[0066] Step 6.1: Under an environment of 23.5℃ and 55% humidity, fix the detection equipment such as the laser interferometer and photoelectric autocollimator to the system bed, and adjust the optical path to ensure that the detection equipment has a high signal strength;

[0067] Step 6.2: Taking the X-axis linear motion unit as an example, select 6 points within its full stroke of -130mm to 130mm, compile a CNC program (see Appendix 1 at the end of the instruction manual), move to the target points of -130 / -78 / -26 / 26 / 78 / 130 in increments of 52mm and stay for 5s, collect the position coordinates with a laser interferometer, and perform 3 cyclic detections from both positive and negative directions to obtain the full stroke motion error (raw) of the X-axis linear motion unit, as shown in Table 1.

[0068] Table 1. X-axis linear motion unit (-130~130) mm full stroke motion error (original)

[0069]

[0070] Step 6.3: After data processing, the original motion error of the X-axis full stroke was obtained as 5.886μm. The bidirectional average position deviation and accuracy compensation data of each target point were obtained, as shown in Table 2.

[0071] Table 2. Average Bidirectional Position Deviation and Accuracy Compensation Data for the X-axis Full Travel (Original)

[0072] Position -130 -78 -26 26 78 130 Two-way mean bias -0.177 -0.774 -1.826 -2.960 -4.138 -5.637 Accuracy compensation data 0.177 0.774 1.826 2.960 4.138 5.637

[0073] Step 6.4: Create compensation table C1 in the integrated development environment and set the unit conversion ratio factor to 10. -3 Set the number of regions to 6 and the total span to 260. Write the accuracy compensation data in Table 2 and save it. Compile the CNC program in the host computer (see Appendix 2), enable the compensation table C1, and perform the axis positioning accuracy calibration after one compensation in step 6.2. Obtain the full stroke motion error of the X-axis linear motion unit (one compensation), as shown in Table 3.

[0074] Table 3. X-axis linear motion unit (-130~130) mm full stroke motion error (compensated once)

[0075]

[0076]

[0077] Step 6.5: After data processing, the X-axis full stroke one-time compensation motion error is 0.387 μm, and the bidirectional uniform deviation of each target point is obtained, as shown in Table 4.

[0078] Table 4 X-axis full stroke bidirectional uniform deviation and precision compensation data (one-time compensation)

[0079] Position -130 -78 -26 26 78 130 Two-way mean bias -0.127 -0.112 -0.094 -0.101 -0.094 -0.077

[0080] Step 6.6: Based on the multi-source iterative error compensation method, the positioning precision secondary compensation data is obtained by coupling the precision compensation data (original), as shown in Table 5.

[0081] Table 5 X-axis full stroke bidirectional uniform deviation and precision compensation data (original)

[0082] Position -130 -78 -26 26 78 130 Accuracy compensation (primary) 0.177 0.774 1.826 2.960 4.138 5.637 Two-way mean bias (compensated once) -0.127 -0.112 -0.094 -0.101 -0.094 -0.077 Accuracy compensation data (secondary) 0.304 0.886 1.92 3.061 4.232 5.714

[0083] Step 6.7: Refer to step 6.4, update the compensation table C1 iteratively, and enable it to obtain the X-axis linear motion unit full stroke motion error (two-time compensation), as shown in Table 6.

[0084] Table 6 X-axis linear motion unit (-130~130) mm full stroke motion error (two-time compensation)

[0085]

[0086] Step 6.8: After data processing, the X-axis full stroke two-time compensation motion error is 0.250 μm, which meets the precision index requirements.

[0087] Step 6.9: Enable compensation table C1, select 6 points at equal intervals within the actual working stroke 120 mm~130 mm of the X-axis linear motion unit, compile the numerical control program (see Appendix Three), move to the target points 120 / 122 / 124 / 126 / 128 / 130 with 2 mm increments and stop for 5 s, and collect the position coordinates by laser interferometer. The X-axis linear motion unit 120 mm~130 mm working stroke motion error is obtained by detecting 3 times in the positive and negative directions respectively, as shown in Table 7.

[0088] Table 7 X-axis linear motion unit (120~130) mm working stroke motion error (original)

[0089]

[0090] Step 6.10: Through data processing, the original motion error of the X-axis 120mm~130mm working stroke is obtained as 0.133μm, and the bidirectional average deviation and precision compensation data of each target point are obtained, as shown in Table 8.

[0091] Table 8 Bidirectional average deviation and precision compensation data of X-axis full stroke (original)

[0092] Position 120 122 124 126 128 130 Two-way mean bias 0.000 0.006 0.025 0.027 0.043 0.050 Accuracy compensation data 0.000 -0.006 -0.025 -0.027 -0.043 -0.050

[0093] Step 6.11: In the integrated development environment, the compensation table C2 is established, the unit conversion ratio coefficient 10 is set, the number of regions is set as 6, the total span is set as 10, the precision compensation data in Table 8 is written, and saved. -3

[0094] Step 6.12: Based on step 6.6 and step 6.11, the X-axis linear motion unit full stroke precision compensation data and 120mm~130mm working stroke precision compensation data and corresponding compensation tables C1 and C2 are obtained, based on the global and regional multi-source error compensation method, the numerical control program is compiled in the host computer, and the compensation table C1 and the compensation table C2 are enabled.

[0095] Step 6.13: The laser interferometer is used to calibrate the multi-source data compensation X-axis linear motion unit full stroke and working interval motion error, the full stroke positioning precision is 0.248μm, the working interval positioning precision is 0.131μm, which meets the precision index requirement, and the full stroke positioning precision is improved by 35.9% compared with the first compensation.

[0096] Step 6.14: For the Y-axis, Z-axis linear motion unit and B-axis, C-axis rotary motion unit positioning precision multi-source data compensation, the above steps can also be implemented according to the specific implementation case analysis.

[0097] The present application includes but is not limited to the above specific implementation cases. It should be understood that the steps can be reordered, added or deleted using the various forms of processes shown above. For example, the steps described in the present application can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solutions disclosed in the present application can be achieved, which are within the protection scope of the present application.

[0098] Advantages of the method of the present application:

[0099] ​The method of the application aims at the problem that the five-axis precision manufacturing system and the ultra-precision manufacturing system mainly with two-axis and three-axis cannot meet the high-precision creation of the surface feature structure of the thin-walled spherical shell microstructure under the constraint of narrow space due to the insufficient manufacturing process capability and poor manufacturing precision of the motion unit components, and proposes to improve the positioning precision of the motion unit of the shape control processing system from three aspects of shafting error calibration, multi-source data precision compensation and shafting positioning precision checking, so as to provide equipment support with high positioning precision for the high-precision creation of the microstructure. The method cooperatively compensates the multi-source motion errors of the global stroke and the actual working interval of each motion unit and the iterative errors introduced by the multiple calibration of the global stroke and the actual working interval, the positioning precision of the global stroke is improved by 35.9% compared with the one-time compensation, and the positioning precision of the actual working interval reaches 0.131 μm, which can well meet the high-precision processing requirements of the sub-millimeter level shape precision and nanometer level surface roughness of the surface feature structure of the thin-walled spherical shell microstructure with a millimeter to sub-millimeter spherical diameter. The method is based on high-precision motion unit position detection equipment such as Renishaw high-precision XL80 series laser interferometer with a resolution of 0.01 μm, Moeller ELCOMAT3000 photoelectric autocollimator with a resolution of 0.001" and an accuracy of 0.1", and 2 equal 23 surface prisms with a flatness of 0.03 μm, which ensures the accuracy of the detection results. The method has a certain universality and is not only suitable for multi-source data compensation of the positioning precision of the motion area of the ultra-precision shape control processing system of complex small components, but also can be further popularized in the specific practice of the global stroke error compensation and the working interval error compensation of the precision level multi-axis linkage machine tool.

[0100] It should be understood that the various forms of flow shown above can be reordered, added to, or deleted from. For example, the steps described in the present application can be executed in parallel, in sequence, or in a different order, as long as the desired results of the technical solutions disclosed in the present application can be achieved, which are within the protection scope of the present application.

[0101] Annex I: X-axis linear motion unit full stroke range incremental form reciprocating motion 3 times NC program:

[0102]

[0103]

[0104] Annex II: X-axis linear motion unit full stroke positioning error compensation table enabling program:

[0105]

[0106] Annex III: X-axis linear motion unit 120mm-130mm stroke incremental form reciprocating motion 3 times NC program:

[0107]

[0108]

Claims

1. A multi-source data compensation method for the positioning accuracy of motion units in an ultra-precision form control machining system for complex micro-components, characterized in that, The implementation process of the method is as follows: Several target positions are selected in the entire stroke and working range of the linear motion unit. A CNC program is compiled in combination with the structural characteristics of the shape control machining system so that each linear motion unit moves to the target position in an incremental manner, and repeats this motion multiple times. At each target position, the target position coordinates are collected in real time by a high-frequency laser interferometer to construct a dataset of axis running positions. After data processing, multi-source error datasets are obtained in the global and regional ranges; Based on the multi-source error data compensation method, a multi-source data error collaborative compensation table is established; for the rotary motion unit, the positioning accuracy of the hydraulic B-axis and workpiece C-axis rotary motion units of the shape control machining system is calibrated using an opto-autocollimator and a regular polyhedron, and after data processing, an error compensation table is established by the error synthesis method; Based on the host computer software of the form control machining system, the above-mentioned multi-source data error collaborative compensation table of linear motion unit and error compensation table of rotary motion unit are downloaded into the motion controller, and the compensation table is activated through the CNC program to complete the motion error calibration and positioning accuracy improvement of each motion unit of the ultra-precision form control machining system. The provided multi-source data compensation method is based on the global motion error of the motion unit to compensate for the global positioning accuracy of the CNC program; on this basis, the motion error of the actual working stroke range of the motion unit is calibrated regionally to obtain a regional motion error dataset; By coupling global motion error and regional motion error multi-source error data, a multi-source error data compensation table is established, and compensation is performed through CNC program. When performing error calibration and accuracy compensation for the global and actual working stroke areas, multiple iterations of calibration and compensation are required based on the multi-source data compensation method to meet the global and regional accuracy index requirements and improve the positioning accuracy of the motion unit.

2. The multi-source data compensation method for the positioning accuracy of motion units in a complex micro-component ultra-precision shape control machining system according to claim 1, characterized in that, The process of shaft system error calibration is as follows: The shaft system error calibration employs a high-frequency laser interferometer to calibrate the motion error of the linear motion units, and a photoelectric autocollimator and a regular polyhedron to test the positioning accuracy of the rotary motion units. A numerical control program is written in the host computer software to control each motion unit to move to the target position in a constant increment, and real-time position coordinates are collected to construct a shaft system running position dataset. After data processing, the global and regional motion errors are obtained, completing the shaft system error calibration. The specific operational steps are as follows: Step 1.1: Use a laser interferometer to calibrate the motion error of the linear motion unit. Fix the interferometer on the transition plate and integrate it with the bed of the form control machining system; install the interferometer reflector on the X / Y / Z slide of the form control machining system; Step 1.2: Design the laser detection optical path, place the interferometer at the interferometer end of the interferometer and reflector optical path; reciprocate the linear motion unit to adjust the laser detection optical path, so that the optical path transmission is normal throughout the entire stroke of the X / Y / Z linear motion unit, and the interferometer has a high signal strength; Step 1.3: Select several target points within the full stroke of each linear axis system, compile a CNC program to make the linear axis system move to the target points in an incremental manner, and use an interferometer to collect the actual coordinates of the target positions in real time to construct a linear axis system motion position dataset. After data processing, obtain the motion error of the linear motion axis system in the global range. Step 1.4: Use an opto-autocollimator and a regular polyhedron to test the positioning accuracy of the rotary motion unit. The 23-faceted prism is clamped onto the hydraulic B-axis and the workpiece C-axis of the test object respectively using a special fixture. The opto-autocollimator is installed on the system bed, and the special fixture is adjusted to ensure normal signal transmission. Step 1.5: Compile a CNC program to make the hydraulic B-axis and the workpiece C-axis rotate at a constant angular velocity and a constant angle. The motion position angle of the rotary motion unit is recorded by the photoelectric autocollimator measurement software to construct a dataset of the motion angle position of the rotary axis system. After data processing, the rotational motion error of the B / C axis is obtained.

3. The multi-source data compensation method for the positioning accuracy of motion units in a complex micro-component ultra-precision shape control machining system according to claim 2, characterized in that, The specific process for implementing the shaft system error calibration is as follows: In step 1.1, the laser interferometer is a Renishaw XL-80 series with a resolution of 0.01 μm, and the unit for point acquisition is uniformly μm; the environmental conditions are as follows: ambient temperature 20±0.5℃, temperature change rate ≤0.5℃ / h, and relative humidity 40-60%. In step 1.2, based on the Y-axis linear motion unit moving up and down in the vertical plane, a 45° refracting mirror is set to change the direction of light path transmission by 90°; In step 1.3, the shaft system is inspected using a cyclic inspection method, performing tests in both forward and reverse directions five times consecutively; the total stroke of the linear motion unit is L. i Select target point n i With increment ΔL i The motion is performed; the motion speed and dwell time of each axis in the CNC program are matched with the parameter settings of the laser interferometer. In step 1.4, the photoelectric autocollimator is a Moeller ELCOMAT3000 series with a resolution of 0.001" and an accuracy of 0.1"; the 23-faceted prism is a second-order prism with a flatness of 0.03μm; when adjusting the special fixture, the eccentricity error between the prism and the axis of rotation system is required to be better than 0.2μm; In step 1.5, the rotational angular velocity and angular position dwell time of the rotary shaft system in the CNC program are matched with the measurement software parameter settings.

4. The multi-source data compensation method for the positioning accuracy of motion units in a complex micro-component ultra-precision shape control machining system according to claim 2, characterized in that, The process of multi-source data precision compensation is as follows: Based on the global motion error of the motion unit, global positioning accuracy compensation is performed by the CNC program until the positioning accuracy meets the global index requirements. The running error within the actual working stroke range of the motion unit is regionally calibrated to obtain a regional motion error dataset. Multi-source error data of global and regional motion errors are coupled to establish a multi-source error data compensation table. Compensation is then performed through the CNC program to improve the positioning accuracy of the motion unit. The specific operation steps are as follows: Step 2.1: Based on the collected global error dataset of each motion unit, convert the global error dataset into a precision compensation dataset according to the correspondence, and obtain n. i Accuracy compensation data for each target point; in the integrated development environment, based on the number of points to be compensated, n... i Create a new error compensation table C i Set the unit conversion factor and write the accuracy compensation data for each motion unit; in the host computer software, write the CNC program and enable the compensation table C. i The accuracy was calibrated using the shaft system error calibration method; Step 2.2: Based on the global positioning accuracy meeting the requirements, calibrate and compensate the positioning accuracy of each motion unit in the actual working range. Adjust the laser detection optical path according to Step 1.2 and Step 1.

3. Referring to the error detection method in Step 1.3, select several target points in the actual working range of the linear motion unit, compile a CNC program to make the linear axis system move to the target point in an incremental manner, and use the interferometer to collect the target position coordinates to construct a motion position dataset. After data processing, obtain the motion error of the linear axis system in the region. Step 2.3: Referring to Step 2.1, based on the collected actual working stroke error dataset of each motion unit, convert the working stroke error dataset into a precision compensation dataset according to the correspondence relationship, and obtain n. i-1 Compensation data for each target point; in the integrated development environment, based on the number of points to be compensated, n... i Create a new error compensation table C i-1 Set the unit conversion factor and write the precision compensation data; in the host computer software, write the CNC program and enable the compensation table C. i-1 Then, the regional positioning accuracy is further calibrated in step 2.2; In step 2.3, compensation table C is enabled. i-1 Then, the shaft system accuracy is calibrated using the method in step 2.2; if the accuracy does not meet the positioning accuracy requirements of the actual working stroke, then step 2.3 is executed until the motion accuracy meets the index requirements, and then step 2.4 is executed; if the accuracy meets the requirements, then step 2.4 is executed. Considering N (i)-1 Sub-calibration error data ε (i)-1 Based on N (i-1)-1 The overall performance of the motion unit after compensation was measured, covering N. (i-1)-1 Error compensation data ε (i-1)-1 Based on the multi-source data collaborative compensation method, N (i)-1 During sub-precision compensation, its error data ε (i)-1 Mathematical superposition to N (i-1)-1 Error compensation data ε (i-1)-1 ; Step 2.4: Based on Steps 2.1 and 2.3, obtain the accuracy compensation data ε for each motion unit's global / full stroke and actual engineering interval stroke, ensuring that the accuracy requirements are met. (i-1) and ε (i-1)-1 Based on the multi-source data collaborative compensation method, a numerical control program is compiled in the host computer software to enable compensation table C. i and C i-1 The global and regional errors are written into the motion controller based on the multi-source data collaborative compensation method; When enabling the compensation table in the CNC program on the host computer, the compensation table enabling command is backward compatible, such as enabling compensation table C. i Then compensation table C (i-1) C (i-2) …C0 is enabled; Step 2.5: Based on the rotary motion unit motion error dataset collected in Step 1.4, the rotary motion unit motion error dataset is converted into a precision compensation dataset according to the correspondence relationship using the error synthesis method. Then, in the integrated development environment, based on the number of points to be compensated (n)... ri Create a new error compensation table C ri Write the precision compensation data; in the host computer software, write the CNC program and enable the compensation table C. ri Then, error calibration is performed in step 1.

5. In step 2.5, compensation table C is enabled. ri Then, the accuracy of the rotary shaft system is calibrated using the shaft system error calibration method; if the accuracy does not meet the global positioning accuracy requirements, proceed to step 2.5 until the motion accuracy meets the index requirements, then proceed to the next step; if the accuracy meets the requirements, then proceed to the next step. Considering N (ri) Sub-calibration error data ε (ri) Based on N (ri-1) The overall performance of the motion unit after compensation was measured, covering N. (ri-1) Error compensation data ε (ri-1) Based on the multi-source data collaborative compensation method, N (ri) During sub-precision compensation, its error data ε (ri) Mathematical superposition to N (ri-1) Error compensation data ε (ri-1) .

5. The multi-source data compensation method for the positioning accuracy of motion units in a complex micro-component ultra-precision shape control machining system according to claim 4, characterized in that, In step 2.1 of multi-source data accuracy compensation, The global error dataset is the difference between the actual position of each motion unit and the position of the program instruction. Error compensation is performed on the position of the program instruction. There is an inverse relationship between the accuracy compensation data and the error data. The integrated development environment uses the International System of Units (SI) mm. When writing precision-compensated data, a conversion factor of ×10 needs to be set. -3 ; In the host computer software, a compensation table activation program is written. The compensation control is activated through the interface. The program determines the compensation status of the motion unit. If the positioning accuracy of the motion unit is not compensated, compensation table C is activated. i Perform procedural compensation; In step 2.1, compensation table C is enabled. i Then, the shaft system accuracy is calibrated using the shaft system error calibration method; if the accuracy does not meet the global positioning accuracy requirements, proceed to step 2.1 until the motion accuracy meets the index requirements, then proceed to the next step; if the accuracy meets the requirements, then proceed to the next step. Considering N (i) Sub-calibration error data ε (i) Based on N (i-1) The overall performance of the motion unit after compensation was measured, covering N. (i-1) Error compensation data ε (i-1) Based on the multi-source data collaborative compensation method, N (i) During sub-precision compensation, its error data ε (i) Mathematical superposition to N (i-1) Error compensation data ε (i-1) ; i represents the i-th random motion unit, and ri represents the i-th rotational motion unit.

6. The multi-source data compensation method for the positioning accuracy of motion units in a complex micro-component ultra-precision shape control machining system according to claim 5, characterized in that, In step 2.2 of the multi-source data accuracy compensation, the actual working stroke range of the linear motion unit is L. i-1 Select target point n i-1 With increment ΔL i-1 Engage in exercise.

7. The multi-source data compensation method for the positioning accuracy of motion units in a complex micro-component ultra-precision shape control machining system according to claim 6, characterized in that, It also includes shaft system positioning accuracy verification, the implementation process of which is as follows: A high-frequency laser interferometer was used to verify the motion error of the linear motion unit, and a photoelectric autocollimator and a regular polyhedron were used to verify the positioning accuracy of the rotary motion unit. A numerical control program was written by the host computer software to control each motion unit to move to the target position in a constant increment, and real-time position coordinates were collected to construct a dataset of axis running positions. After data processing, the global and regional motion errors were obtained.

8. The multi-source data compensation method for the positioning accuracy of motion units in a complex micro-component ultra-precision shape control machining system according to claim 7, characterized in that, The motion unit adopts a cyclic testing method, which performs testing from both the forward and reverse directions, and performs testing three times in each direction.

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