A method for calibrating and compensating installation error of rotary shaft of ultra-precision five-axis linkage machine tool for complex micro-component machining

Abstract

This invention provides a method for calibrating and compensating for the installation error of the rotary axis of an ultra-precision five-axis CNC machine tool used for machining complex micro-components. It relates to the field of ultra-precision machining technology and addresses the problem in existing methods where installation errors are directly mapped to subsequent machining trajectories and cannot be eliminated through tool setting. This invention determines error calibration and compensation methods for both rigid and weak-rigidity machining systems. Considering the weak rigidity of the tool / workpiece and the precision error caused by deformation during contact, the installation error of the rotary axis of the ultra-precision five-axis CNC machine tool is determined by the geometric relationships of the ball end mill radius, workpiece radius, X-axis motion unit travel distance, and the distance between the ball end mill's ball center and the B-axis rotary table axis. The installation error of the machine tool rotary axis is then compensated to improve machining accuracy. This invention can comprehensively and accurately eliminate rotary axis installation errors, significantly improving the machining accuracy of the machine tool.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ultra-precision machining, in particular to a rotary shaft installation error calibration and compensation method for an ultra-precision five-axis linkage machine tool for complex micro-component machining. BACKGROUND

[0002] In the fields of national defense, military affairs, aerospace, electronic information, etc., with the upgrading of equipment, various complex micro-components with precision, miniaturization and integration have been widely applied, and their manufacturing feasibility and machining precision are closely related to the service performance and machining precision of equipment. In the field of energy exploration, a kind of thin-walled spherical shell micro-component with a diameter of several millimeters and a shell thickness of several tens of microns is widely used, and dozens to hundreds of micro-pit structures with a feature size of microns need to be machined on its surface, and high requirements are put forward for machining precision and surface quality. Based on the ultra-precision five-axis linkage machine tool, combined with the specific ultra-precision machining process of micro-components, the corresponding machining requirements can be met.

[0003] Ultra-precision five-axis linkage is the most difficult and the most controlled axis equipment in ultra-precision machining process, and its machining precision directly affects the surface quality of the workpiece. There are many factors affecting the accuracy of the machine tool, including machining principle error, geometric error, thermal deformation, tool wear, working environment, human factors, etc. Among them, the external factors such as temperature, humidity and human interference can be eliminated or kept within a small range by strictly controlling the environmental conditions. Among the internal factors such as machining principle error, geometric error, thermal deformation and tool wear, geometric error occupies a large proportion, especially the installation error of the workpiece rotary shaft, which will directly reflect on the machined surface of the workpiece and affect the machining surface quality. In the existing ultra-precision five-axis linkage machine tool machining process, the coordinate axis error calibration, especially the rotary shaft error calibration and compensation, is integrated with the processing of the tool, and the narrow error in the field of view before processing is eliminated through CCD tooling process. Since the installation error of the rotary shaft directly causes the deviation of the coordinate system origin during subsequent program editing, the error is directly mapped to the subsequent machining trajectory, and the installation error of the rotary shaft cannot be eliminated through the CCD tooling process, which limits the machining precision and surface quality of the workpiece, and cannot meet the high machining precision requirement. Therefore, it is urgent to design a novel error calibration and compensation method to calibrate the installation error of the rotary shaft after the machine tool is built and before formal processing, and further compensate through the program to improve the machining precision of the ultra-precision five-axis machine tool and realize the ultra-precision machining of the workpiece with higher surface quality. SUMMARY

[0004] The technical problem to be solved by the present application is:

[0005] The existing method directly causes the deviation of the coordinate system origin due to the installation error of the rotary shaft, and the installation error is directly mapped to the subsequent machining track, which cannot be eliminated by tooling process.

[0006] The present application adopts the technical scheme to solve the above technical problems:

[0007] The present application provides a kind of complex microstructure processing with ultra-precision five-axis linkage machine tool rotary shaft installation error calibration and compensation method, which is based on ultra-precision five-axis linkage machine tool, including three linear motion axes X axis movement unit, Y axis movement unit and Z axis movement unit, two rotary axes B axis rotary table and gas bearing workpiece C axis, also including tool spindle, horizontal CCD camera and vertical CCD camera, X axis movement unit and Z axis movement unit are horizontally perpendicular to each other, Y axis movement unit is vertically arranged on X axis movement unit guide rail, gas bearing workpiece C axis is installed in Y axis movement unit middle part, B axis rotary table is installed in Z axis movement unit middle part, tool spindle is installed above B axis rotary table, and it is opposite to gas bearing workpiece C axis, horizontal CCD camera is installed on B axis rotary table, lens axis points to the ball center of machining tool ball head;Vertical CCD camera is installed on Y axis movement unit, above gas bearing workpiece C axis;

[0008] The method is for rigid body complex microstructure, including the following steps:

[0009] Step A1, complex microstructure is clamped on gas bearing workpiece C axis, and machining tool is installed on tool spindle;

[0010] Step A2, the distance l1 between the ball center of machining tool ball head and the straight line where the axis of machine tool B axis rotary table is located is measured;

[0011] Step A3, each axis of machine tool is initialized, B axis rotary table is controlled to rotate clockwise by 90 °, X axis movement unit, Y axis movement unit and Z axis movement unit are adjusted, and machining tool and complex microstructure are just contacted by observing through vertical CCD camera and horizontal CCD camera, the distance x1 that X axis movement unit moves is obtained, and the radius R1 of complex microstructure is extracted;

[0012] Step A4, according to the geometric relationship between rotary shaft installation error δ and complex microstructure radius R1, the distance l1 between the ball center of machining tool ball head and the straight line where the axis of machine tool B axis rotary table is located, machining tool ball head radius r1 and the distance x1 that X axis movement unit moves, rotary shaft installation error δ of complex microstructure processing with ultra-precision five-axis linkage machine tool is solved;

[0013] Step A5, according to the obtained rotary shaft installation error δ, the center position of machine tool initialization origin B axis rotary table is compensated along X axis direction- δ;

[0014] The method is for weak stiffness complex micro-structure, comprising the following steps:

[0015] Step B1, clamping the complex micro-structure on the air floating workpiece C shaft, and installing the machining tool on the tool spindle;

[0016] Step B2, measuring the distance l1 between the ball center of the machining tool ball head and the straight line where the B shaft rotary table axis of the machine tool is located;

[0017] Step B3, initializing the machine tool axes, controlling the B shaft rotary table to rotate 90° clockwise, adjusting the X axis movement unit, the Y axis movement unit and the Z axis movement unit, and observing through the vertical CCD camera and the horizontal CCD camera to make the machining tool just contact with the complex micro-structure, recording the distance x1 of the X axis movement unit movement, and extracting the complex micro-structure radius R1, and recording the error ε introduced by the weak rigidity of the machining tool / complex micro-structure and the elastic deformation in the contact process;

[0018] Step B4, initializing the machine tool axes again, controlling the B shaft rotary table to rotate 90° counterclockwise, adjusting the X axis movement unit, the Y axis movement unit and the Z axis movement unit, and observing through the vertical CCD camera and the horizontal CCD camera to make the machining tool just contact with the complex micro-structure, recording the distance x2 of the X axis movement unit movement, and extracting the complex micro-structure radius R2;

[0019] Step B5, according to the geometric relationship between the rotation axis installation error δ and the clockwise rotating complex micro-structure radius R1, the distance l1 between the ball center of the machining tool ball head and the straight line where the B shaft rotary table axis of the machine tool is located, the machining tool ball head radius r1, the error ε introduced by the elastic deformation, and the distance x1 of the X axis movement unit movement, and the geometric relationship between the counterclockwise rotating complex micro-structure radius R2, the distance l1 between the ball center of the machining tool ball head and the straight line where the B shaft rotary table axis of the machine tool is located, the machining tool ball head radius r1, the error ε introduced by the elastic deformation, and the distance x2 of the X axis movement unit movement, solving the rotation axis installation error δ of the complex micro-structure machining ultra-precision five-axis linkage machine tool;

[0020] Step B6, compensating the center position of the B shaft rotary table along the X axis direction by-δ according to the obtained rotation axis installation error δ.

[0021] Further, in step A4, the following relationship is used to solve the rotation axis installation error δ of the complex micro-structure machining ultra-precision five-axis linkage machine tool;

[0022] x1+δ=l1+r1+R1.

[0023] Further, in step B5, the following relationship is used to solve the rotation axis installation error δ of the complex micro-structure machining ultra-precision five-axis linkage machine tool;

[0024]

[0025] Further, the pixels of the vertical CCD camera and the horizontal CCD camera are all 2600 million.

[0026] Further, the method for extracting the radius of the complex micro component in steps A3, B3 and B4 is as follows: the vertical CCD camera is used to acquire the image of the contact area between the machining tool and the complex micro component, the image is subjected to gray scale processing, the component is separated from the image background, and finally the classic Hough transform method is used to extract the radius of the complex micro component.

[0027] Further, the gray scale processing of the image is specifically as follows: the R, G and B components in the image are subjected to weighted average to obtain a gray value Gray(m, n);

[0028] The gray image is subjected to binary processing, the component is separated from the image background, and then a Canny edge detection operator is used, a Gaussian filter is used to filter the image, the image is convolved by Sobel horizontal and vertical direction detection operators, the direction angle and gradient are calculated, and the arc contour edge of the workpiece is extracted;

[0029] The classic Hough transform method is used, each straight line in the image is associated with a pair of parameters (rho, theta), rho represents the precision of the straight line distance from the origin in the Hough space in pixels, theta represents the precision of the rotation angle of the straight line in the Hough space, the parameters (rho, theta) form a Hough plane, each point in the image space is mapped to the Hough space through the Hough transform, the complex micro component radius is extracted according to the iterative calculation of the arc contour points.

[0030] Compared with the prior art, the present application has the following advantages:

[0031] The present application discloses a method for calibrating and compensating installation errors of a rotary shaft of an ultra-precision five-axis linkage machine tool for machining complex micro components.

[0032] The method has certain universality, is suitable for calibrating errors of rotary shafts of ultra-precision multi-axis linkage machine tools, and can be further applied to calibrating errors of rotary shafts of conventional multi-axis machine tools, thereby further improving machining precision of the machine tool. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1The figure is a rotation axis installation error calibration and compensation flow chart of the ultra-precision five-axis linkage machine tool for complex micro-component processing in the embodiment of the present application.

[0034] Figure 2 The figure is a structure schematic diagram of the ultra-precision five-axis linkage machine tool in the embodiment of the present application.

[0035] Figure 3 The figure is a top view schematic diagram of the B-axis rotary table relative to the air-floating workpiece C-axis offset error in the embodiment of the present application.

[0036] Figure 4 The figure is a schematic diagram of the distance between the B-axis rotary table axis and the ball head milling cutter ball center in the embodiment of the present application.

[0037] Figure 5 The figure is a schematic diagram of the B-axis rotary table rotating clockwise by 90 degrees in the embodiment of the present application.

[0038] Figure 6 The figure is a schematic diagram of the rigid body system coordinate axis installation error calibration method in the embodiment of the present application.

[0039] Figure 7 The figure is a schematic diagram of the weak rigidity system coordinate axis installation error calibration method in the embodiment of the present application (rotating clockwise by 90 degrees).

[0040] Figure 8 The figure is a schematic diagram of the weak rigidity system coordinate axis installation error calibration method in the embodiment of the present application (rotating counterclockwise by 90 degrees).

[0041] Explanation of reference signs:

[0042] 1-base, 2-Z-axis motion unit, 3-B-axis rotary table, 4-tool spindle, 5-horizontal CCD camera, 6-ball head milling cutter, 7-vertical CCD camera, 8-Y-axis motion unit, 9-complex micro-component, 10-air-floating workpiece C-axis, 11-X-axis motion unit. DETAILED DESCRIPTION

[0043] In the description of the present application, it should be explained that the terms and nouns in each embodiment, such as "upper", "lower", "front", "rear", "left", "right", etc., are words indicating the position relationship based on the position relationship of the drawings in the description, and do not represent that the elements and devices, etc. must be operated according to the specific position and limited operation and method, structure in the description, and such positional terms do not constitute a limitation on the present application.

[0044] In the description of the present application, it should be noted that the terms "first", "second", "third" mentioned in the embodiments of the present application are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second", "third" can be explicitly or implicitly included one or more of the features.

[0045] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0046] Embodiment 1:

[0047] A complex micro-structure machining ultra-precision five-axis linkage machine tool rotary shaft installation error calibration and compensation method, as shown in Figure 2 The method is based on a "T" layout-ultra-precision five-axis five-linkage machine tool for thin-walled spherical shell micro-milling machining, which includes three linear motion axes X-axis motion unit 11, Y-axis motion unit 8 and Z-axis motion unit 2, two rotary axes B-axis rotary table 3 and gas bearing workpiece C-axis 10, and base 1, tool spindle 4, ball end mill 6, horizontal CCD camera 5 and vertical CCD camera 7. The pixels of the vertical CCD camera (7) and the horizontal CCD camera (5) are 26 million. The X-axis motion unit 11 and the Z-axis motion unit 2 are installed on the base 1 and arranged perpendicular to each other, and are driven by liquid static pressure guide rail linear motors respectively. The Y-axis motion unit 8 is vertically arranged on the X-axis guide rail and is driven by a liquid static pressure guide rail linear motor. The gas bearing workpiece C-axis 10 is arranged in the middle of the Y-axis motion unit and adopts a gas static pressure bearing, which is controlled by a circular grating feedback. The B-axis rotary table 3 is arranged on the Z-axis motion unit 2 guide rail and is driven by a liquid static pressure bearing. The tool spindle 4 is installed above the B-axis rotary table 3, and the ball end mill 6 is installed at the front end of the tool spindle 4 and is arranged opposite to the gas bearing workpiece C-axis 10. The horizontal CCD camera 5 is fixed on the transition plate on the B-axis rotary table 3 through a high-precision micro-displacement platform, and the lens axis points to the ball center of the ball end mill. The vertical CCD camera 7 is fixed on the Y-axis transition plate through a high-precision micro-displacement platform, and the Y-axis transition plate is coupled to the Y-axis drag plate through an internal hexagonal screw and can move with the Y-axis motion unit 8. The workpiece installation error of the present application is the deviation between the rotary center of the gas bearing workpiece C-axis 10 and the plane where the B-axis rotary table 3 axis and the tool milling axis are located.

[0048] As shown in Figure 3 The rotary shaft installation error of the ultra-precision five-axis linkage machine tool is the offset error δ of the machine tool B-axis rotary table 3 axis relative to the plane where the gas bearing workpiece C-axis 10 axis is located. After installation, the B-axis rotary table 3 axis is taken as the origin. Since the errors between the rotary shafts in the vertical direction and the feeding direction will not cause coordinate deviation, they are not considered.

[0049] Example 2:

[0050] For rigid complex micro-structure, the five-axis machine tool of Example 1 is used to illustrate the method of the present application according to the following process, as shown in Figure 1 , comprising the following steps:

[0051] Step A1, clamp the complex micro-structure 9 on the air-floating workpiece C-axis 10, and install the ball-end mill 6 at the end of the tool spindle 4;

[0052] Step A2, as shown in Figure 4 , as shown in Figure 4 , during the installation of the machine tool, the distance l1 between the ball center of the ball-end mill 6 and the straight line where the axis of the B-axis rotary table 3 is located is measured by the vernier caliper as 80mm;

[0053] Step A3, initialize the settings of each axis of the machine tool, and return each axis to the coordinate origin, as shown in Figure 5 and Figure 6 , control the B-axis rotary table 3 to rotate clockwise by 90°, so that the vertical plane where the milling tool shaft 4 is located is perpendicular to the axis of the air-floating workpiece C-axis 10, adjust the X-axis motion unit 11, Y-axis motion unit 8 and Z-axis motion unit 2 to move by distances x1, y1 and z1, and observe through the vertical CCD camera 7 and the horizontal CCD camera 5 to make the ball-end mill 6 just contact with the complex micro-structure 9;

[0054] According to the tool parameters, the ball-end mill 6 ball head radius r1 is determined as 0.25mm, and through the cumulative calculation of the movement trajectory of the X-axis motion unit 11 in the machine tool control system, x1 is obtained as 79.500mm; the radius R1 of the complex micro-structure 9 is extracted as 2.36mm;

[0055] Step A4, according to the geometric relationship between the rotary axis installation error δ and the radius R1 of the complex micro-structure 9, the distance l1 between the ball center of the ball-end mill 6 and the straight line where the axis of the B-axis rotary table 3 is located, the ball-end mill 6 ball head radius r1 and the distance x1 moved by the X-axis motion unit 11, the rotary axis installation error δ of the ultra-precision five-axis machine tool for machining the complex micro-structure 9 is solved by using the following relationship;

[0056] x1+δ=l1+r1+R1.

[0057] The rotary axis installation error of the ultra-precision five-axis machine tool for machining the complex micro-structure 9 is obtained as 3.11mm.

[0058] Step A5, according to the obtained rotary axis installation error δ=3.11mm, compensate the center position of the B-axis rotary table 3 along the X-axis direction by -δ, i.e. eliminate the influence of the rotary axis installation error on the machining precision.

[0059] Since the cutter / workpiece is defined as a rigid body system, the elastic deformation of the workpiece is small when it is in contact with the ball-end mill 6, and the influence of the deformation on the error is small, so the influence of the deformation of the workpiece is ignored.

[0060] Example 3:

[0061] As shown in Figure 1 , for a weak stiffness process system, the five-axis machine tool of Example 1 is used to illustrate the method of the present application according to the following process, including the following steps:

[0062] Step B1, clamp the complex microstructure 9 on the air-floating workpiece C-axis 10, and install the ball-end mill 6 at the end of the tool spindle 4;

[0063] Step B2, as shown in Figure 4 , during the installation of the machine tool, the distance l1 between the ball center of the ball head of the ball-end mill 6 and the straight line where the axis of the B-axis rotary table 3 is located is measured by using a vernier caliper, which is 80mm;

[0064] Step B3, initialize the settings of the axes of the machine tool, as shown in Figure 7 , control the B-axis rotary table 3 to rotate clockwise by 90°, so that the vertical plane where the milling tool shaft 4 is located is perpendicular to the axis of the air-floating workpiece C-axis 10, adjust the X-axis motion unit 11, Y-axis motion unit 8 and Z-axis motion unit 2 to move by distances x1, y1 and z1, and observe through the vertical CCD camera 7 and the horizontal CCD camera 5 to make the ball-end mill 6 just contact the complex microstructure 9; record the error introduced by the weak rigidity of the ball-end mill 6 / complex microstructure 9 and the elastic deformation during the contact process as ε;

[0065] According to the cutter parameters, the ball head radius r1 of the ball-end mill 6 is determined to be 0.25mm, and the cumulative calculation of the movement trajectory of the X-axis motion unit 11 in the machine tool control system gives x1 as 79.231mm, and the radius R1 of the complex microstructure 9 is extracted as 3.25mm.

[0066] Step B4, as shown in Figure 8 , initialize the settings of the axes of the machine tool again, control the B-axis rotary table 3 to rotate counterclockwise by 90°, so that the vertical plane where the milling tool shaft 4 is located is perpendicular to the axis of the air-floating workpiece C-axis 10, adjust the X-axis motion unit 11, Y-axis motion unit 8 and Z-axis motion unit 2 to move by distances x1, y1 and z1, and observe through the vertical CCD camera 7 and the horizontal CCD camera 5 to make the ball-end mill 6 just contact the complex microstructure 9;

[0067] In the same way as in Example 2, x2 is obtained as 82.233mm, and the radius R2 of the complex microstructure 9 is extracted as 3.16mm.

[0068] Step B5, according to the geometric relationship between the rotary shaft installation error δ and the clockwise rotating complex microstructure 9 radius R1, the distance l1 between the ball head center of the ball head milling cutter 6 and the axis line of the machine tool B-axis rotary table 3, the ball head radius r1 of the ball head milling cutter 6, the error ε introduced by elastic deformation and the distance x1 moved by the X-axis movement unit 11, and the geometric relationship between the counterclockwise rotating complex microstructure 9 radius R2, the distance l1 between the ball head center of the ball head milling cutter 6 and the axis line of the machine tool B-axis rotary table 3, the ball head radius r1 of the ball head milling cutter 6, the error ε introduced by elastic deformation and the distance x2 moved by the X-axis movement unit 11, the following relationship is used to solve the rotary shaft installation error δ of the ultra-precision five-axis linkage machine tool for complex microstructure machining:

[0069]

[0070] That is,

[0071] The result of the error δ is:

[0072]

[0073] That is,

[0074] Step B6, according to the obtained rotary shaft installation error δ = 3.11 mm, the center position of the machine tool initialization origin B-axis rotary table 3 is compensated along the X-axis direction by -δ, that is, the influence of the rotary shaft installation error on the machining precision is eliminated.

[0075] For the complex microstructure of thin-walled spherical shell type with diameter of 1-5 mm, shell thickness of 20-120 μm, and micro-pit structure with longitudinal size of 0.5-20 μm and transverse size of 50-200 μm, the obtained micro-pit structure profile error is less than 0.3 μm, and the surface roughness Ra is less than 20 nm. Compared with the result without error compensation.

[0076] Example 4

[0077] The method for extracting the radius of the complex microstructure is:

[0078] The image of the contact area between the machining tool and the complex microstructure is obtained by the vertical CCD camera (7), the image is grayed, the structure and the image background are separated, and finally the classic Hough transform method is used to extract the radius of the complex microstructure.

[0079] The gray processing of the image is specifically: the R, G and B components in the image are weighted and averaged to obtain the gray value Gray(m, n):

[0080] Gray(m, n) = 0.299 * R(m, n) + 0.578 * G(m, n) + 0.114 * B(m, n)

[0081] In the formula, R(m, n), G(m, n) and B(m, n) represent the R, G and B values of the pixel point at coordinate (m, n) in the image collected by the vertical CCD camera (7) respectively; the image is converted into a gray image.

[0082] The gray image is binarized: the 24-bit gray image is converted into an 8-bit gray image, and then based on the peak-valley method of the gray distribution histogram, when the gray histogram of the image is bimodal distribution, the value of the bottom point between the two peaks is selected as the segmentation threshold, the gray value less than the threshold is taken as 0, and the gray value greater than the threshold is taken as 255, the image is segmented into two parts, and the component and the image background are separated. Then a Canny edge detection operator is used, a Gaussian filter is used to filter the image, a Sobel horizontal and vertical direction detection operator is used to convolve the image, the direction angle and the gradient are calculated, and the circular arc profile edge of the workpiece is extracted.

[0083] The Sobel operator uses a 3x3 convolution kernel to perform convolution operation on the image, and the horizontal and vertical direction operators are as follows:

[0084]

[0085] After the convolution operation, the gradient amplitude and the gradient direction of the image are obtained:

[0086] Gradient amplitude

[0087] Gradient direction

[0088] A classic Hough transformation method is used, each straight line in the image is associated with a pair of parameters (p, q), p represents the precision of the straight line distance from the origin in the Hough space in pixels, q represents the precision of the rotation angle of the straight line in the Hough space, and the parameters (p, q) form a Hough plane. Through Hough transformation, each point in the image space is mapped to the Hough space, and the radius of the complex micro-component is extracted according to the iterative calculation of the circular arc profile points.

[0089] For a weak rigidity process system, the installation error of the rotary shaft is about δ=1μm, without the installation error compensation of the application, for the machining of the micro-pit structure with the diameter of 1-5mm, the shell thickness of 20-120μm, the thin-walled spherical shell complex micro member with the full surface of tens to hundreds of longitudinal dimension of 0.5-20μm and the transverse dimension of 50-200μm, the profile error is about 1μm and the surface roughness is about 70nm. The installation error compensation is carried out by the method of the application, the X direction displacement compensation of the machine tool initialization origin position is -δ, the machining of the micro-pit structure with the diameter of 1-5mm, the shell thickness of 20-120μm, the thin-walled spherical shell complex micro member with the full surface of tens to hundreds of longitudinal dimension of 0.5-20μm and the transverse dimension of 50-200μm, the profile error of the micro-pit structure is better than 0.3μm and the surface roughness R a is better than 20nm, and the machining precision is obviously improved.

[0090] Although the application is disclosed as above, the protection scope of the application is not limited to this. The person skilled in the art can make various changes and modifications without departing from the spirit and scope of the application, and these changes and modifications will fall into the protection scope of the application.

Claims

1. A method for calibrating and compensating the installation error of the rotary shaft of an ultra-precision five-axis linkage machine tool for complex microstructure machining, characterized in that, The method is based on a super-precision five-axis linkage machine tool, including three linear motion axes X-axis motion unit (11), Y-axis motion unit (8) and Z-axis motion unit (2), two rotary axes B-axis rotary table (3) and air floating workpiece C-axis (10), and further including a tool spindle (4), a horizontal CCD camera (5) and a vertical CCD camera (7), the X-axis motion unit (11) and the Z-axis motion unit (2) are arranged horizontally and perpendicularly to each other, the Y-axis motion unit (8) is arranged vertically on the guide rail of the X-axis motion unit (11), the air floating workpiece C-axis (10) is installed in the middle of the Y-axis motion unit, the B-axis rotary table (3) is installed in the middle of the Z-axis motion unit (2), the tool spindle (4) is installed above the B-axis rotary table (3) and is arranged opposite to the air floating workpiece C-axis (10), the horizontal CCD camera (5) is installed on the B-axis rotary table (3) and the lens axis points to the center of the ball head of the machining tool, and the vertical CCD camera (7) is installed on the Y-axis motion unit (8) and is located above the air floating workpiece C-axis (10); The method is aimed at rigid complex micro components and includes the following steps: Step A1, clamping the complex micro component on the air floating workpiece C-axis (10) and installing the machining tool on the tool spindle (4); Step A2, measuring the distance l1 between the center of the ball head of the machining tool and the straight line where the axis of the B-axis rotary table (3) of the machine tool is located; Step A3, initializing the machine tool axes, controlling the B-axis rotary table (3) to rotate clockwise by 90°, adjusting the X-axis motion unit (11), the Y-axis motion unit (8) and the Z-axis motion unit (2) and observing through the vertical CCD camera (7) and the horizontal CCD camera (5) to make the machining tool just contact with the complex micro component, obtaining the distance x1 by which the X-axis motion unit (11) moves, and extracting the radius R1 of the complex micro component; Step A4, solving the installation error δ of the rotary axis of the super-precision five-axis linkage machine tool for complex micro component machining according to the geometric relationship between the installation error δ of the rotary axis, the radius R1 of the complex micro component, the distance l1 between the center of the ball head of the machining tool and the straight line where the axis of the B-axis rotary table (3) of the machine tool is located, the radius r1 of the ball head of the machining tool and the distance x1 by which the X-axis motion unit (11) moves; Step A5, compensating the center position of the B-axis rotary table (3) at the initialization origin of the machine tool by -δ along the X-axis direction according to the obtained installation error δ of the rotary axis; The method is aimed at weak-rigidity complex micro components and includes the following steps: Step B1, clamping the complex micro component on the air floating workpiece C-axis (10) and installing the machining tool on the tool spindle (4); Step B2, measuring the distance l1 between the center of the ball head of the machining tool and the straight line where the axis of the B-axis rotary table (3) of the machine tool is located; Step B3, initialize the machine tool axes, control the B-axis rotary table (3) to rotate clockwise by 90°, adjust the X-axis motion unit (11), the Y-axis motion unit (8) and the Z-axis motion unit (2) and make the machining tool just contact with the complex microstructure by observing through the vertical CCD camera (7) and the horizontal CCD camera (5), record the distance of the X-axis motion unit (11) movement as x1, and extract the complex microstructure radius R1, and record the error introduced by the weak rigidity of the machining tool / complex microstructure and the elastic deformation in the contact process as ε; Step B4, initialize the machine tool axes again, control the B-axis rotary table (3) to rotate counterclockwise by 90°, adjust the X-axis motion unit (11), the Y-axis motion unit (8) and the Z-axis motion unit (2) and make the machining tool just contact with the complex microstructure by observing through the vertical CCD camera (7) and the horizontal CCD camera (5), record the distance of the X-axis motion unit movement as x2, and extract the complex microstructure radius R2; Step B5, according to the geometric relationship between the rotation axis installation error δ and the clockwise rotating complex microstructure radius R1, the distance l1 between the center of the machining tool ball head and the straight line where the B-axis rotary table (3) axis of the machine tool is located, the machining tool ball head radius r1, the error introduced by the elastic deformation ε and the distance x1 of the X-axis motion unit (11) movement, and the geometric relationship between the rotation axis installation error δ and the counterclockwise rotating complex microstructure radius R2, the distance l1 between the center of the machining tool ball head and the straight line where the B-axis rotary table (3) axis of the machine tool is located, the machining tool ball head radius r1, the error introduced by the elastic deformation ε and the distance x2 of the X-axis motion unit (11) movement, solve the rotation axis installation error δ of the ultra-precision five-axis linkage machine tool for complex microstructure machining; Step B6, according to the obtained rotation axis installation error δ, compensate the center position of the B-axis rotary table (3) along the X-axis direction by -δ; In step A4, the rotation axis installation error δ of the ultra-precision five-axis linkage machine tool for complex microstructure machining is solved by using the following relationship: x1+δ=l1+r1+R1; In step B5, the rotation axis installation error δ of the ultra-precision five-axis linkage machine tool for complex microstructure machining is solved by using the following relationship: 。 2. The method according to claim 1, wherein the method is characterized in that, The pixels of the vertical CCD camera (7) and the horizontal CCD camera (5) are all 26 million.

3. The method according to claim 1, wherein the method is characterized in that, In steps A3, B3 and B4, the method for extracting the radius of the complex microstructure is as follows: the vertical CCD camera (7) is used to obtain the image of the contact area of the machining tool and the complex microstructure, the image is subjected to gray scale processing to separate the structure from the image background, and finally the classic Hough transform method is used to extract the radius of the complex microstructure.

4. The method according to claim 3, wherein the method is characterized in that, The gray scale processing of the image is specifically as follows: the R, G and B components in the image are subjected to weighted average to obtain the gray value Gray(m, n); The gray image is subjected to binaryzation processing to separate the structure from the image background, and then the Canny edge detection operator is used to filter the image by using a Gaussian filter, the image is convolved by Sobel horizontal and vertical direction detection operators, the direction angle and gradient are calculated, and the arc contour edge of the workpiece is extracted; Using the classic Hough transform method, each straight line in the image is associated with a pair of parameters , The accuracy of the straight line distance from the origin in the Hough space is represented by pixels, and the accuracy of the rotation angle of the straight line in the Hough space is represented by θ, and the parameters Form a Hough plane, map each point in the image space to the Hough space by Hough transform, and extract the radius of complex microstructure according to the iterative calculation of circular arc contour points.

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