X-ray reflector mandrel angular resolution in-situ evaluation method

Abstract

The invention relates to an X-ray reflector mandrel angular resolution in-situ evaluation method, and belongs to the technical field of precision measurement. Bus data mA (z) and bus data mB (z) measured twice are obtained; calculating an error edz caused by the deviation of the measurement starting point; obtaining a straightness error component f (z) of the profile of the measured X-ray reflector mandrel; f (z) is made to be equal to 0, and the installation error angle lambda 0 and the measurement starting point offset dz0 of the X-ray reflector mandrel relative to the axis are obtained through fitting; x-ray reflector mandrel contour error data f0 (z) are obtained; fitting the measurement angle error eangle into a fourth-order polynomial through the measurement angle theta; obtaining the relation between the included angle between the measurement angle theta and the measuring head and the generatrix formula F (z) of the X-ray reflector mandrel; obtaining contour error data f1 (z) after correction of the measurement angle error; geometric evaluation of the X-ray reflector mandrel is completed; optical performance evaluation of the X-ray reflector mandrel is completed; the problem that in-situ measurement and optical performance evaluation cannot be achieved in ultra-precision machining of the X-ray reflector mandrel is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of precision measurement, and relates to a method for on-site evaluation of the angular resolution of an X-ray mirror mandrel. Background Technique

[0002] The grazing-incidence X-ray pulsar optical system plays an important role in the fields of spacecraft autonomous navigation in space, establishment of a space-time reference based on space, deep space exploration, etc., and is one of the key technologies developed by advanced technology countries. The X-ray mirror is an important optical element of the grazing-incidence X-ray pulsar optical system, and its manufacturing error directly affects the imaging accuracy of the optical system. At present, the X-ray mirror is mainly prepared by successively depositing an optical film and a lens substrate on an X-ray mirror mandrel with requirements of micron-level surface shape accuracy and nanometer-level surface roughness, and then separating the X-ray mirror lens from the X-ray mirror mandrel. Therefore, the X-ray mirror mandrel is the basis for the manufacturing accuracy of X-ray optical lenses, and its surface shape accuracy and surface roughness will directly affect the reflectivity and angular resolution of the X-ray mirror.

[0003] In the current ultra-precision machining of X-ray mirror mandrels, in order to obtain an accurate geometric surface shape, generally in the machining, an iterative machining strategy of machining - measuring - correcting errors is selected, that is, machining with a margin on an ultra-precision machining center, measuring the surface shape accuracy by off-line detection with a profilometer to obtain the error from the theoretical optical surface, then reinstalling the X-ray mirror mandrel on the ultra-precision machining center, aligning to reduce the error introduced by reinstalling the X-ray mirror mandrel, and machining according to the correction value measured off-line. The machining process is complex, the machining efficiency is low, and the repeated positioning error is inevitably introduced.

[0004] In addition, in the ultra-precision machining of X-ray mirror mandrels, the existing measurement methods can only obtain the geometric errors of the X-ray mirror mandrels. Optical performance indicators such as angular resolution can only be measured by optical methods after the X-ray mirror is separated from the X-ray mirror mandrel and the X-ray mirror optical system is assembled. The direct relationship between the machining error of the X-ray mirror mandrel and the angular resolution of the X-ray mirror cannot be directly obtained. Summary of the Invention

[0005] The technical problem solved by the present invention is: overcoming the deficiencies of the prior art, a method for improving the bonding strength between rubber and fiber fabric is proposed, and the problem that on-site measurement and optical performance evaluation cannot be realized in the ultra-precision machining of X-ray mirror mandrels is solved.

[0006] The technical solution adopted by the present invention is:

[0007] A method for on-site evaluation of the angular resolution of an X-ray mirror mandrel, comprising:

[0008] Measure the generatrix of the X-ray mirror mandrel twice on the ultra-precision machining center to obtain the generatrix data m A (z) and m B (z);

[0009] Calculate the error e dz ;

[0010] Superimpose the generatrix data m A (z) and m B (z), and remove the guideway error e guide and the spindle error e spindle , to obtain the straightness error component f(z) of the profile of the measured X-ray mirror mandrel;

[0011] Let f(z)=0, and fit to obtain the installation error angle λ0 of the X-ray mirror mandrel relative to the axis and the measurement starting point offset dz0;

[0012] Substitute the installation error angle λ0 and the measurement starting point offset dz0 into the straightness error component f(z) to obtain the profile error data f0(z) of the X-ray mirror mandrel;

[0013] Scan the horizontal profile line along the path of the standard sphere offset by △Z through the spectral confocal probe to obtain the measurement angle error e angle and the measurement angle θ. Fit the measurement angle error e angle to a fourth-order polynomial through the measurement angle θ;

[0014] Obtain the slope of the generatrix of the X-ray mirror mandrel through the generatrix formula of the rotary surface. The included angle corresponding to the slope is the included angle between the spectral confocal probe and the normal of the ideal surface, so as to obtain the relationship between the measurement angle θ, the probe included angle and the generatrix formula F(z) of the X-ray mirror mandrel;

[0015] According to the profile error data f0(z) of the X-ray mirror mandrel, the fourth-order polynomial of the measurement angle error e angle , and the relationship between the measurement angle θ, the probe included angle and the generatrix formula F(z) of the X-ray mirror mandrel, obtain the profile error data f1(z) after correcting the measurement angle error;

[0016] According to the profile error data f1(z) after correcting the measurement angle error, establish the calculation formula of the root mean square error RMS and the calculation formula of the maximum profile error f max ; Substitute each point of the generatrix of the X-ray mirror mandrel into the calculation formula of RMS and the calculation formula of the maximum profile error f max to obtain the value of RMS and the value of f max , which are the geometric errors of the generatrix of the X-ray mirror mandrel, and complete the geometric evaluation of the X-ray mirror mandrel;

[0017] In the form of a third-order spline curve, each point on the generatrix of the X-ray mirror mandrel is fitted into m curves along the axial direction, and a closed curve is formed at the center position and the two shaft end positions of the X-ray mirror mandrel to obtain the fitted surface of the actually measured X-ray mirror mandrel; the fitted surface of the X-ray mirror mandrel is brought into the optical simulation software to obtain the angular resolution value formed by the in-situ measurement data of the X-ray mirror mandrel, and the optical performance evaluation of the X-ray mirror mandrel is completed.

[0018] In the above method for in-situ evaluation of the angular resolution of an X-ray mirror mandrel, the measurement method for the generatrix of the X-ray mirror mandrel is as follows:

[0019] Fix the X-ray mirror mandrel horizontally along the axis on the ultra-precision machining center; set the axial direction of the X-ray mirror mandrel as the z direction, the vertical direction as the y direction, and the x direction is determined by the right-hand rule; install 1 spectral confocal probe on the Y axis of the ultra-precision machining center and 1 spectral confocal probe on the Z axis of the ultra-precision machining center; measure the generatrix data m A (z) and m B (z).

[0020] In the above method for in-situ evaluation of the angular resolution of an X-ray mirror mandrel, the maximum linear error of the spectral confocal probe is ±40 nm;

[0021] m A (z) = f(z) + e guide (z) + e spindle (z) + zλ + e dz

[0022] m B (z) = f(z) - e guide (z) - e spindle (z) + zλ + e dz

[0023] In the formula, f(z) is the straightness error component of the profile of the measured X-ray mirror mandrel;

[0024] e guide is the guideway error;

[0025] e spindle is the spindle error;

[0026] λ is the installation error angle of the workpiece relative to the axis;

[0027] e dz is the error caused by the offset of the measurement starting point;

[0028] z is the coordinate value in the z direction.

[0029] In the above method for on-site evaluation of the angular resolution of the X-ray mirror core axis, the error e caused by the measurement starting point offset dz is calculated as follows:

[0030] e dz = [F(z) - F1(z)] - [F(z - dz) - F1(z)] = F(z) - F(z - dz)

[0031] where, F(z) - F1(z) is the measured value when the measurement starting point is accurate; F(z - dz) - F1(z) is the measured value with the measurement starting point offset;

[0032] In the formula, F(z) is the generatrix formula of the X-ray mirror core axis;

[0033] F1(z) is the actual surface after processing;

[0034] dz is the measurement starting point offset amount;

[0035] F(z - dz) is the generatrix expression of the X-ray mirror core axis after substituting the starting point offset amount.

[0036] In the above method for on-site evaluation of the angular resolution of the X-ray mirror core axis, the calculation method of the straightness error component f(z) is as follows:

[0037]

[0038] In the above method for on-site evaluation of the angular resolution of the X-ray mirror core axis, the X-ray mirror core axis profile error data f0(z) is:

[0039]

[0040] In the above method for on-site evaluation of the angular resolution of the X-ray mirror core axis, the measured angle error e angle The fourth-order polynomial of is:

[0041] e angle = Intercept + B1·θ + B2·θ 2 + B3·θ 3 + B4·θ 4

[0042] In the formula, Intercept is the constant term;

[0043] B1 is the coefficient of the first-order term of the fourth-order polynomial;

[0044] B2 is the coefficient of the second-order term of the fourth-order polynomial;

[0045] B3 is the coefficient of the cubic term of the fourth-order polynomial;

[0046] B4 is the coefficient of the fourth-order term of the fourth-order polynomial.

[0047] In the above method for on-site evaluation of the angular resolution of the X-ray mirror mandrel, the relationship between the measured angle θ, the angle between the probe and the generatrix formula F(z) of the X-ray mirror mandrel is:

[0048] θ = arctan(F′(z)).

[0049] In the above method for on-site evaluation of the angular resolution of the X-ray mirror mandrel, the contour error data f1(z) after correcting the measurement angle error is:

[0050] f1(z) = f0(z) - [Intercept + B1·arctan(F′(z)) + B2·arctan 2 (F′(z)) + B3·arctan 3 (F′(z)) + B4·arctan 4 (F′(z))].

[0051] In the above method for on-site evaluation of the angular resolution of the X-ray mirror mandrel, the calculation formula for the root mean square error RMS is:

[0052]

[0053] Where N is the number of acquisition data of the contour error of the X-ray mirror mandrel;

[0054] The calculation formula for the maximum contour error f max is:

[0055] f max = max(f1(z)) - min(f1(z))

[0056] Where max(f1(z)) is the maximum value in the contour error data f1(z);

[0057] min(f1(z)) is the minimum value in the contour error data f1(z).

[0058] The beneficial effects of the present invention compared with the prior art are:

[0059] (1) The present invention adopts the on-site measurement technology of the ultra-precision machining center, eliminates the repeated positioning error caused by off-line measurement of the X-ray mirror mandrel, and improves the measurement accuracy compared with the existing off-line measurement technology;

[0060] (2) The present invention adopts the on-site measurement technology of the ultra-precision machining center, and can realize the integration of processing and measurement of the X-ray mirror mandrel;

[0061] (3) The present invention adopts the in-situ measurement technology of a ultra-precision machining center, which can realize the in-situ error compensation in the ultra-precision machining process of an X-ray mirror, and improve the ultra-precision machining accuracy and efficiency of the X-ray mirror;

[0062] (4) The present invention adopts the in-situ measurement technology of a ultra-precision machining center, which can evaluate the angular resolution optical index during the ultra-precision machining process, eliminating the lag of the prior art that the evaluation of the angular resolution index can only be realized after the X-ray mirror is prepared and an optical system is formed;

[0063] (5) The present invention adopts the in-situ measurement technology of a ultra-precision machining center, which can solve the problem that the optical performance index does not correspond to the machining accuracy index of the core axis of the X-ray mirror;

[0064] (6) The present invention adopts the in-situ measurement technology of a ultra-precision machining center, which can simultaneously realize the evaluation of the geometric surface form accuracy and the optical performance of the core axis of the X-ray mirror, making up for the blank of the existing measurement technology;

[0065] (7) The present invention adopts the in-situ measurement technology of a ultra-precision machining center, which can replace existing precision measuring instruments such as profilometers. Description of the Drawings

[0066] Figure 1 is the flow chart of the in-situ evaluation of the angular resolution of the core axis of the X-ray mirror of the present invention;

[0067] Figure 2 is the schematic diagram of the inherent error of the ultra-precision machining center of the present invention;

[0068] Figure 3 is the schematic diagram of the error caused by the offset of the measurement starting point of the present invention;

[0069] Figure 4 is the schematic diagram of the process of fitting the measured data into a surface of the present invention;

[0070] Figure 5 is the simulation diagram of the angular resolution obtained from the measurement curve of the core axis of the X-ray mirror of the present invention. Detailed Embodiments

[0071] The present invention will be further described below in conjunction with embodiments.

[0072] The present invention provides a method for in-situ evaluation of the angular resolution of the core axis of an X-ray mirror, which solves the problems of in-situ measurement in the ultra-precision machining process of the core axis of the X-ray mirror and directly associating the geometric accuracy with the angular resolution of the X-ray mirror.

[0073] The method for in-situ evaluation of the angular resolution of the core axis of the X-ray mirror, as Figure 1 shown, specifically includes the following steps:

[0074] Measure the generatrix of the X-ray mirror mandrel twice on an ultra-precision machining center to obtain the generatrix data m A (z) and m B (z).

[0075] The measuring method for the generatrix of the X-ray mirror mandrel is as follows:

[0076] Fix the X-ray mirror mandrel horizontally axially on the ultra-precision machining center; set the axial direction of the X-ray mirror mandrel as the z direction, the vertical direction as the y direction, and the x direction is determined by the right-hand rule; install 1 spectral confocal probe on the Y-axis of the ultra-precision machining center and 1 spectral confocal probe on the Z-axis of the ultra-precision machining center; measure through the 2 spectral confocal probes to obtain the generatrix data m A (z) and m B (z).

[0077] Among them, the maximum linear error of the spectral confocal probe is ±40 nm;

[0078] m A (z) = f(z) + e guide (z) + e spindle (z) + zλ + e dz

[0079] m B (z) = f(z) - e guide (z) - e spindle (z) + zλ + e dz

[0080] In the formula, f(z) is the straightness error component of the profile of the measured X-ray mirror mandrel;

[0081] e guide is the guideway error;

[0082] e spindle is the spindle error;

[0083] λ is the installation error angle of the workpiece relative to the axis;

[0084] e dz is the error caused by the offset of the measurement starting point;

[0085] z is the coordinate value in the z direction.

[0086] In the present invention, the generatrix expression of the X-ray mirror mandrel is x = F(z). The X-ray mirror mandrel rotates with the spindle, and the spectral confocal probe 4 moves along the path of offsetting △Z along the horizontal generatrix to obtain the measurement data m A(z). Restore the X-ray mirror mandrel to the angle before measurement, then rotate it 180° along the C-axis of the ultra-precision machining center, and move the spectral confocal probe along the path of offsetting ΔZ along the horizontal generatrix on the other side to obtain the measurement data m B (z).

[0087] Calculate the error e caused by the offset of the measurement starting point dz .

[0088] In the present invention, the error caused by the offset of the measurement starting point is as Figure 2 Can be expressed as: the difference between the measured value F(z)-F1(z) when the measurement starting point is accurate and the measured value F(z-dz)-F1(z) with the measurement starting point offset

[0089] The error e caused by the offset of the measurement starting point dz The calculation method is:

[0090] e dz =[F(z)-F1(z)]-[F(z-dz)-F1(z)] = F(z)-F(z-dz)

[0091] Among them, F(z)-F1(z) is the measured value when the measurement starting point is accurate; F(z-dz)-F1(z) is the measured value with the measurement starting point offset.

[0092] In the formula, F(z) is the generatrix formula of the X-ray mirror mandrel.

[0093] F1(z) is the actual surface after processing.

[0094] dz is the measurement starting point offset amount.

[0095] F(z-dz) is the generatrix expression of the X-ray mirror mandrel after substituting the starting point offset amount.

[0096] The guideway error e guide and the spindle error e spindle in the measurement data can be removed by superimposing the two sets of data m A (z), m B (z) measured at 0° and 180° of the C-axis of the ultra-precision machining center respectively, to obtain the measurement data of the X-ray mirror mandrel generatrix that only contains the installation error angle λ and the measurement offset amount dz.

[0097] Superimpose the generatrix data m A (z) and m B (z) of the two measurements, and remove the guideway error e guide and the spindle error e spindle ,, to obtain the straightness error component f(z) of the profile of the measured X-ray mirror mandrel.

[0098] The calculation method of the straightness error component f(z) is as follows:

[0099]

[0100] Let f(z)=0, and the installation error angle λ0 of the X-ray mirror mandrel relative to the axis and the measurement starting point offset dz0 are obtained by fitting.

[0101] Substitute the installation error angle λ0 and the measurement starting point offset dz0 into the straightness error component f(z) to obtain the profile error data f0(z) of the X-ray mirror mandrel.

[0102] The profile error data f0(z) of the X-ray mirror mandrel is:

[0103]

[0104] When the spectral confocal displacement sensor measures the rotating surface with a non-straight busbar of the X-ray mirror, there is a measurement error that varies with the measurement angle. Therefore, the spectral confocal displacement sensor is calibrated with a standard ball before measurement, as Figure 3 shown.

[0105] The measurement angle error e angle and the measurement angle θ are obtained by scanning the horizontal profile line along the path of the standard ball offset by △Z through the spectral confocal probe. The measurement angle error e angle is fitted to a fourth-order polynomial through the measurement angle θ.

[0106] The fourth-order polynomial of the measurement angle error e angle is:

[0107] e angle = Intercept + B1·θ + B2·θ 2 + B3·θ 3 + B4·θ 4

[0108] In the formula, Intercept is the constant term;

[0109] B1 is the coefficient of the first-order term of the fourth-order polynomial;

[0110] B2 is the coefficient of the second-order term of the fourth-order polynomial;

[0111] B3 is the coefficient of the third-order term of the fourth-order polynomial;

[0112] B4 is the coefficient of the fourth-order term of the fourth-order polynomial.

[0113] The slope of the generatrix of the X-ray mirror mandrel is obtained through the generatrix formula of the surface of revolution. The angle corresponding to the slope is the angle between the spectral confocal probe and the normal direction of the ideal surface, thereby obtaining the relationship between the measurement angle θ, the probe angle, and the generatrix formula F(z) of the X-ray mirror mandrel.

[0114] The relationship between the measurement angle θ, the probe angle, and the generatrix formula F(z) of the X-ray mirror mandrel is:

[0115] θ = arctan(F′(z)).

[0116] According to the X-ray mirror mandrel profile error data f0(z), the fourth-order polynomial of the measurement angle error e angle and the relationship between the measurement angle θ, the probe angle, and the generatrix formula F(z) of the X-ray mirror mandrel, the profile error data f1(z) after correcting the measurement angle error is obtained.

[0117] The profile error data f1(z) after correcting the measurement angle error is:

[0118] f1(z) = f0(z) - [Intercept + B1·arctan(F′(z)) + B2·arctan 2 (F′(z)) + B3·arctan 3 (F′(z)) + B4·arctan 4 (F′(z))].

[0119] According to the profile error data f1(z) after correcting the measurement angle error, the calculation formula for the root mean square error RMS and the maximum profile error f max are established; each point of the generatrix of the X-ray mirror mandrel is substituted into the calculation formula for RMS and the calculation formula for the maximum profile error f max to obtain the value of RMS and the value of f max , which are the geometric errors of the generatrix of the X-ray mirror mandrel, completing the geometric evaluation of the X-ray mirror mandrel.

[0120] The calculation formula for the root mean square error RMS is:

[0121]

[0122] In the formula, N is the number of acquisition data of the X-ray mirror mandrel profile error.

[0123] The calculation formula for the maximum profile error f max is:

[0124] f max = max(f1(z)) - min(f1(z))

[0125] Wherein, max(f1(z)) is the maximum value in the contour error data f1(z);

[0126] min(f1(z)) is the minimum value in the contour error data f1(z).

[0127] Adopting the cubic spline curve method, each point on the generatrix of the X-ray mirror mandrel is fitted into m curves along the axial direction, and a closed curve is formed at the center position and the two shaft end positions of the X-ray mirror mandrel to obtain the actually measured fitted surface of the X-ray mirror mandrel, as Figure 4 shown. Substituting the fitted surface of the X-ray mirror mandrel into the optical simulation software, the angular resolution value formed by the in-situ measurement data of the X-ray mirror mandrel is obtained, as Figure 5 shown, and the optical performance evaluation of the X-ray mirror mandrel is completed.

[0128] The present invention adopts the in-situ measurement technology of the ultra-precision machining center, eliminates the repeated positioning error brought by the off-line measurement of the X-ray mirror mandrel, and improves the measurement accuracy compared with the existing off-line measurement technology; the present invention adopts the in-situ measurement technology of the ultra-precision machining center, and can realize the integration of the processing and measurement of the X-ray mirror mandrel.

[0129] The present invention adopts the in-situ measurement technology of the ultra-precision machining center, can realize the in-situ error compensation in the ultra-precision machining process of the X-ray mirror, and improve the ultra-precision machining accuracy and efficiency of the X-ray mirror; the present invention adopts the in-situ measurement technology of the ultra-precision machining center, can realize the evaluation of the angular resolution optical index in the ultra-precision machining process, and eliminates the lag that the existing technology needs to wait until the X-ray mirror is prepared and the optical system is formed to realize the evaluation of the angular resolution index.

[0130] The present invention adopts the in-situ measurement technology of the ultra-precision machining center, can solve the problem that the optical performance index does not correspond to the machining accuracy index of the X-ray mirror mandrel; the present invention adopts the in-situ measurement technology of the ultra-precision machining center, can simultaneously realize the geometric surface form accuracy evaluation and optical performance evaluation of the X-ray mirror mandrel, make up for the existing measurement technology blank; the present invention adopts the in-situ measurement technology of the ultra-precision machining center, and can replace the existing precision measuring instruments such as contour meters.

[0131] Although the present invention has been disclosed above with preferred embodiments, it is not used to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the technical solution of the present invention all belong to the protection scope of the technical solution of the present invention.

Claims

1. An in-situ evaluation method for the core axis angular resolution of an X-ray reflector, characterized in that: include: The generatrix of the X-ray reflector mandrel is measured twice on the ultra-precision machining center to obtain the generatrix data m of the two measurements. A (z) and m B (z); Calculate the error e caused by the offset of the measurement starting point dz ; Superimpose the busbar data m of the two measurements A (z) and m B (z), remove the guide rail error e in the measurement data guide and spindle error e spindle ,, obtain the straightness error component f(z) of the profile of the measured X-ray reflector core axis; Let f(z) = 0, and obtain the installation error angle λ0 of the X-ray reflector core axis relative to the axis and the measurement starting point offset dz0 by fitting; Substitute the installation error angle λ0 and the measurement starting point offset dz0 into the straightness error component f(z) to obtain the X-ray reflector core shaft profile error data f0(z); The spectral confocal probe scans the horizontal contour line along the path of the standard sphere offset △Z to obtain the measured angle error e angle and the measured angle θ, the angle error e is measured by measuring the angle θ angle The fit was a fourth-order polynomial; The slope of the generatrix of the X-ray reflector core axis is obtained by the generatrix formula of the revolution surface. The angle corresponding to the slope is the angle between the spectral confocal probe and the normal of the ideal surface, thereby obtaining the relationship between the measurement angle θ and the probe angle and the generatrix formula F(z) of the X-ray reflector core axis; According to the X-ray reflector core axis profile error data f0(z), the measured angle error e angle The fourth-order polynomial of , the relationship between the measurement angle θ and the probe angle and the generatrix formula F(z) of the X-ray reflector core axis, the contour error data f1(z) after correcting the measurement angle error is obtained; According to the contour error data f1(z) after correcting the measured angle error, the calculation formula of the root mean square error RMS and the maximum contour error f max Calculate the formula; Substitute each point of the generatrix of the X-ray reflector core axis into the calculation formula of RMS and the maximum profile error f max The calculation formula is used to obtain the RMS value and f max The value of is the geometric error of the X-ray reflector core axis generatrix, completing the geometric evaluation of the X-ray reflector core axis; Using the third-order spline curve method, the points on the generatrix of the X-ray mirror core axis are fitted into m curves along the axial direction, and closed curves are formed at the points at the center position and the two axial ends of the X-ray mirror core axis to obtain the actually measured X-ray mirror core axis fitting surface; the X-ray mirror core axis fitting surface is brought into the optical simulation software to obtain the angular resolution value formed by the in-situ measurement data of the X-ray mirror core axis, thereby completing the optical performance evaluation of the X-ray mirror core axis.

2. The in-situ evaluation method of the core axis angular resolution of an X-ray reflector according to claim 1, characterized in that: The method for measuring the generatrix of the X-ray reflector mandrel is: The X-ray reflector core shaft is fixed horizontally on the ultra-precision machining center; the X-ray reflector core shaft is set to the z direction, the vertical direction is set to the y direction, and the x direction is determined by the right-hand rule; a spectral confocal probe is installed on the Y axis of the ultra-precision machining center, and a spectral confocal probe is installed on the Z axis of the ultra-precision machining center; The busbar data m of two measurements are obtained by measuring with two spectral confocal probes A (z) and m B (z).

3. The in-situ evaluation method of the core axis angular resolution of an X-ray reflector according to claim 1, characterized in that: The maximum linear error of the spectral confocal probe is ±40nm; m A (z)=f(z)+e guide (z)+e spindle (z)+zλ+e dz m B (z)=f(z)-e guide (z)-e spindle (z)+zλ+e dz Where, f(z) is the straightness error component of the profile of the measured X-ray reflector core axis; e guide is the guide rail error; e spindle is the spindle error; λ is the installation error angle of the workpiece relative to the axis; e dz The error caused by the offset of the measurement starting point; z is the coordinate value in the z direction.

4. The in-situ evaluation method of the core axis angular resolution of an X-ray reflector according to claim 3, characterized in that: The error caused by the deviation of the measurement starting point is dz The calculation method is: e dz =[F(z)-F1(z)]-[F(z-dz)-F1(z)]=F(z)-F(z-dz) Among them, F(z)-F1(z) is the measured value when the measurement starting point is accurate; F(z-dz)-F1(z) is the measured value when the measurement starting point is offset; Where, F(z) is the generatrix formula of the X-ray reflector core axis; F1(z) is the actual surface after machining; dz is the offset of the measurement starting point; F(z-dz) is the generatrix expression of the X-ray reflector core axis after substituting the starting point offset.

5. The in-situ evaluation method of the core axis angular resolution of an X-ray reflector according to claim 3, characterized in that: The calculation method of the straightness error component f(z) is:

6. The in-situ evaluation method of the core axis angular resolution of an X-ray reflector according to claim 5, characterized in that: The X-ray reflector core axis profile error data f0(z) is:

7. The in-situ evaluation method of the core axis angular resolution of an X-ray reflector according to claim 6, characterized in that: Measuring angle error e angle The fourth-order polynomial of is: e angle =Intercept+B1·θ+B2·θ 2 +B3·θ 3 +B4·θ 4 In the formula, Intercept is a constant term; B1 is the coefficient of the first-order term of the fourth-order polynomial; B2 is the coefficient of the quadratic term of the fourth-order polynomial; B3 is the cubic coefficient of the fourth-order polynomial; B4 is the coefficient of the fourth-order polynomial.

8. The in-situ evaluation method of the core axis angular resolution of an X-ray reflector according to claim 7, characterized in that: The relationship between the measuring angle θ, the probe angle and the generatrix formula F(z) of the X-ray reflector core axis is: θ = arctan(F′(z)).

9. The in-situ evaluation method of the core axis angular resolution of an X-ray reflector according to claim 8, characterized in that: The contour error data f1(z) after correcting the measurement angle error is: f1(z)=f0(z)-[Intercept+B1·arctan(F′(z))+B2·arctan 2 (F′(z))+B3·arctan 3 (F′(z))+B4·arctan 4 (F′(z))]。 10. The in-situ evaluation method of the core axis angular resolution of an X-ray reflector according to claim 1, characterized in that: The calculation formula of root mean square error RMS is: Where N is the number of collected data of the X-ray reflector core axis profile error; Maximum contour error f max The calculation formula is: f max =max(f1(z))-min(f1(z)) Where max(f1(z)) is the maximum value of the contour error data f1(z); min(f1(z)) is the minimum value in the contour error data f1(z).

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