Ultra-precision machine tool spindle rotation error in-situ detection system and detection method

Abstract

The invention relates to an ultra-precision machine tool spindle rotation error in-situ detection system and method, and the system comprises a first standard spherical reflector and a second standard spherical reflector which are respectively disposed at the two ends of a machine tool spindle, and the axis of the machine tool spindle passes through the sphere center of the first standard spherical reflector and the sphere center of the second standard spherical reflector; the optical axes of the first optical autocollimator, the second optical autocollimator, the third optical autocollimator and the fourth optical autocollimator are perpendicular to the axis of the machine tool spindle in the non-deflection state, and the optical axes of the optical autocollimators are divided into two groups and are perpendicular to the axis of the machine tool spindle in the non-deflection state. Compared with the prior art, the method has the advantages of high detection precision, fast response, strong data traceability, comprehensive detection and the like.

Description

Technical Field

[0001] The invention relates to the field of machine tool spindle rotation error detection, and in particular to an ultra-precision machine tool spindle rotation error in-situ detection system and detection method. Background Art

[0002] Ultra-precision CNC machine tools, as the "industrial mother machine" of high-end equipment manufacturing, are the basis for high-precision manufacturing of complex structural parts of large equipment in the fields of aviation, aerospace, navigation, etc. The high-speed spindle, as the core component of precision CNC machine tools, its rotation error is an important factor affecting the dimensional tolerance, shape and position accuracy and surface quality of machined parts. During precision machining, the spindle rotation error accounts for 30% to 70% of the total error, and the higher the machine tool accuracy level, the greater the proportion of spindle rotation error in the total error. During the machining process of the machine tool, the spindle is affected by periodic pulsating cyclic stress and symmetrical cyclic stress, and it has structural defects and performance decay. As a result, the current high-speed spindle rotation error detection faces problems such as inaccurate measurement, slow measurement, and incomplete measurement, which brings huge challenges to the service performance evaluation and dynamic control of ultra-precision machine tools.

[0003] At present, the common high-speed spindle rotation error monitoring technologies in the world are divided into contact and non-contact types. The contact force of the contact sensor will randomly change the rotation error morphology, and the measurement repeatability is poor. Therefore, ultra-precision rotary axis systems mainly use non-contact sensors such as capacitive displacement sensors, eddy current displacement sensors, scanning tunneling microscopes, atomic force microscopes, and laser interferometers. Capacitive displacement sensors and eddy current displacement sensors are easily restricted by factors such as electromagnetic environment interference and point data averaging. Laser interferometers, scanning tunneling microscopes, atomic force microscopes, and other instruments are limited by sampling rates and are only suitable for low-speed measurement scenarios. It is difficult to achieve comprehensive detection of radial rotation errors, axial play errors, and inclination swing errors. Summary of the invention

[0004] The purpose of the present invention is to provide an in-situ detection system and method for the rotation error of the spindle of an ultra-precision machine tool.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] An in-situ detection system for spindle rotation error of an ultra-precision machine tool, comprising:

[0007] A first standard spherical reflector and a second standard spherical reflector are respectively arranged at two ends of a machine tool spindle, and an axis of the machine tool spindle passes through the centers of the first standard spherical reflector and the second standard spherical reflector respectively;

[0008] The first optical autocollimator, the second optical autocollimator, the third optical autocollimator and the fourth optical autocollimator, the visual axes of all the optical autocollimators are perpendicular to the axis of the machine tool spindle in the non-deflection state, the visual axes of the first optical autocollimator and the second optical autocollimator are parallel to each other, the visual axes of the third optical autocollimator and the fourth optical autocollimator are parallel to each other, the visual axis of the first optical autocollimator is perpendicular to the visual axis of the third optical autocollimator, the visual axes of the first optical autocollimator and the fourth optical autocollimator pass through the center of the first standard spherical reflector in the non-deflection state, and the second optical autocollimator and the third optical autocollimator pass through the center of the second standard spherical reflector in the non-deflection state.

[0009] The two ends of the machine tool spindle are respectively installed at the centers of two mounting chucks.

[0010] A detection method based on the system as described above is used to detect radial play error and axial play error, and the detection method comprises:

[0011] Step A1: After installing the first standard spherical reflector and the second standard spherical reflector, as well as the first optical autocollimator, the second optical autocollimator, the third optical autocollimator and the fourth optical autocollimator;

[0012] Step A2: completing zeroing of the first optical autocollimator, the second optical autocollimator, the third optical autocollimator and the fourth optical autocollimator;

[0013] Step A3: Start the machine tool spindle and record the positions of all light spots collected by the optical autocollimator;

[0014] Step A4: determining a radial runout error along a second direction of the machine tool spindle based on the light spot positions collected by the first optical autocollimator and the second optical autocollimator and in combination with the radii of the first standard spherical reflector and the second standard spherical reflector, wherein the second direction is parallel to the visual axis of the third optical autocollimator;

[0015] Step A5: determining the radial runout error of the machine tool spindle along a first direction based on the light spot positions collected by the third optical autocollimator and the fourth optical autocollimator and in combination with the radii of the first standard spherical reflector and the second standard spherical reflector, wherein the first direction is parallel to the visual axis of the first optical autocollimator;

[0016] Step A6: Determine the axial movement of the machine tool spindle based on the light spot positions collected by the first optical autocollimator, the second optical autocollimator, the third optical autocollimator and the fourth optical autocollimator in combination with the radius of the first standard spherical reflector and the second standard spherical reflector.

[0017] The step A4 specifically includes:

[0018] Step A4-1: Determine the first radial error based on the light spot position collected by the first optical autocollimator and the radius of the first standard spherical reflector:

[0019] Δx 1 =R 1 sinθ 1

[0020]

[0021] Where: Δx 1 is the first radial error, R 1 is the radius of the first standard spherical reflector, θ 1 is the angle between the outgoing light of the first optical autocollimator and the normal of the reflecting surface of the first standard spherical reflector, X 1 (θ 1 ) is the component of the light spot coordinates collected by the first optical autocollimator in the direction perpendicular to the axis of the machine tool spindle, S 1 The distance from the light transmitting and receiving surface of the first standard spherical reflector to the axis of the machine tool spindle when there is no rotation error;

[0022] Step A4-2: determining a second radial error based on the light spot position collected by the second optical autocollimator and the radius of the second standard spherical reflector;

[0023] Step A4-3: Determine a radial rotation error along a second direction based on the first radial error and the second radial error, wherein the second direction is parallel to the visual axis of the third optical autocollimator.

[0024] The step A5 specifically includes:

[0025] Step A5-1: determining a fourth radial error based on the light spot position collected by the fourth optical autocollimator and the radius of the first standard spherical reflector;

[0026] Δx 4 =R 1 sinθ 4

[0027]

[0028] Where: Δx 4 is the fourth radial error, R 1 is the radius of the first standard spherical reflector, θ 4 is the angle between the outgoing light of the fourth optical autocollimator and the normal of the reflecting surface of the first standard spherical reflector, X 4 (θ 4 ) is the component of the light spot coordinates collected by the fourth optical autocollimator in the direction perpendicular to the axis of the machine tool spindle, S 4The distance from the light transmitting and receiving surface of the fourth optical autocollimator to the axis of the machine tool spindle when there is no error;

[0029] Step A5-2: determining a third radial error based on the light spot position collected by the third optical autocollimator and the radius of the second standard spherical reflector;

[0030] Step A5-3: Determine a radial rotation error along a first direction based on the third radial error and the fourth radial error, wherein the first direction is parallel to the visual axis of the first optical autocollimator.

[0031] The step A6 specifically includes:

[0032] Step A6-1: Based on the light spot position collected by each optical autocollimator and the radius of the corresponding standard spherical reflector, determine the axial error of each optical autocollimator:

[0033] Δz i =R j sinθ i

[0034]

[0035] Where: Δz i is the axial error of the ith optical autocollimator, R j is the radius of the jth standard spherical reflector corresponding to the i-th optical autocollimator, θ i is the angle between the outgoing light of the i-th optical autocollimator and the normal of the reflecting surface of the standard spherical reflector, Y i (θ i ) is the component of the light spot coordinates collected by the i-th optical autocollimator that is parallel to the axis of the machine tool spindle, S i The distance from the light transmitting and receiving surface of the i-th optical autocollimator to the axis of the machine tool spindle when there is no error;

[0036] Step A6-2: Determine the axial movement of the machine tool spindle based on the axial errors of each optical autocollimator.

[0037] The step A6-2 specifically includes:

[0038] Step A6-2-1: Determine whether the axial errors of all optical autocollimators are greater than a first set threshold value, if yes, execute step A6-2-2;

[0039] Step A6-2-3: Determine whether the variance of the axial errors of all optical autocollimators is greater than the second set threshold. If so, determine that axial movement exists, and determine the axial movement amount of the machine tool spindle based on the axial errors of each optical autocollimator.

[0040] A detection method based on the above system is used to detect the tilt swing error, and the detection method includes:

[0041] Step B1: After installing the first standard spherical reflector and the second standard spherical reflector, as well as the first optical autocollimator, the second optical autocollimator, the third optical autocollimator and the fourth optical autocollimator;

[0042] Step B2: completing zeroing of the first optical autocollimator, the second optical autocollimator, the third optical autocollimator and the fourth optical autocollimator;

[0043] Step B3: Start the machine tool spindle and record the positions of all light spots collected by the optical autocollimator;

[0044] Step B4: Based on the light spot positions collected by each optical autocollimator and in combination with the radius of each standard spherical reflector, the inclination swing error of the machine tool spindle is determined.

[0045] The step B4 comprises:

[0046] Step B4-1: Construct the offset angle model:

[0047]

[0048] S i =S i1 +S i2

[0049]

[0050] Where: d i Z is the distance from the intersection of the extended line of the outgoing light of the i-th optical autocollimator and the axis of the machine tool spindle when there is no inclination swing error to the center of the corresponding standard spherical reflector. j is the z-direction distance between the jth standard spherical reflector and the deflection center, Δc is the tilt swing error, and the angle value is taken, R j is the radius of the jth standard spherical reflector corresponding to the i-th optical autocollimator, S i When there is no error, the distance from the light transmitting and receiving surface of the i-th optical autocollimator to the axis of the machine tool spindle, S i1 For S i The first component, S i2 For S i The second component, θ i is the angle between the outgoing light of the i-th optical autocollimator and the normal of the reflecting surface of the standard spherical reflector, Y i (θ i ) is the z-component of the light spot coordinates collected by the i-th optical autocollimator;

[0051] Step B-2: Based on the first optical autocollimator, the second optical autocollimator, and the radius of each standard spherical reflector, determine the relationship between the tilt swing error and the z-component of the spot coordinates collected by the first optical autocollimator and the second optical autocollimator;

[0052] Step B-3: based on the third optical autocollimator, the fourth optical autocollimator, and the radius of each standard spherical reflector, determining the relationship between the tilt swing error and the z-component of the spot coordinates collected by the third optical autocollimator and the fourth optical autocollimator;

[0053] Step B-4: Determine the swing error based on the relationship between the tilt swing error and the z-component of the light spot coordinates collected by each optical autocollimator.

[0054] After the optical autocollimator is zeroed, the light spot of the laser hitting the surface of the standard spherical reflector is at the horizontal center position, and the light reflected by the spherical mirror returns along the original path.

[0055] Compared with the prior art, the present invention has the following beneficial effects:

[0056] 1. Taking advantage of the laser's collimation, high responsiveness, and traceability, the optical signal is combined with mathematical calculations to solve the problem of monitoring high-speed spindle rotation errors.

[0057] 2. A spindle rotation error analytical model integrating multi-channel monitoring signals was constructed to improve the robustness of the detection system and the comprehensiveness of detection, thus realizing comprehensive detection of radial rotation error, axial play error and inclination swing error.

[0058] 3. A spindle rotation state monitoring mechanism using surface geometric constraints and optical tracking has been established. The coupling relationship of high-speed spindle rotation errors has been revealed from the mathematical model level, and a high-precision, high-dynamic, multi-dimensional optical tracking monitoring theory and technology system has been constructed. This has important research significance and application value for accurately evaluating the spindle accuracy of ultra-precision CNC machine tools, comprehensively monitoring the spindle operating status, and timely predicting, discovering, and diagnosing spindle faults. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 It is a schematic diagram of the detection scheme of the present invention;

[0060] Figure 2 It is a zero adjustment schematic diagram of the present invention;

[0061] Figure 3 The radial movement detection principle of the present invention;

[0062] Figure 4 This is the axial movement detection principle of the present invention;

[0063] Figure 5The angle deviation detection principle of the present invention;

[0064] Figure 6 for Figure 5 An enlarged schematic diagram of region I;

[0065] Figure 7 for Figure 5 An enlarged schematic diagram of region II;

[0066] In the figure: 1, machine tool spindle, 2, first spherical reflector, 3, first optical autocollimator, 4, second spherical reflector, 5, second optical autocollimator, 6, third optical autocollimator, 7, fourth optical autocollimator, 8, mounting chuck, 301 and 501 are both normal lines. DETAILED DESCRIPTION

[0067] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0068] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0069] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "proximal", "distal", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance. Physical quantities in formulas, if not separately marked, should be understood as basic quantities of the base units of the International System of Units, or derived quantities derived from the basic quantities through mathematical operations such as multiplication, division, differentiation or integration.

[0070] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0071] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0072] In conjunction with the accompanying drawings, some embodiments of the present invention are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments may be combined with each other.

[0073] An in-situ detection system for the rotation error of the spindle of an ultra-precision machine tool, such as Figure 1 As shown, including:

[0074] A first standard spherical reflector 2 and a second standard spherical reflector 4 are respectively arranged at two ends of a machine tool spindle 1, and the axis of the machine tool spindle 1 passes through the centers of the first standard spherical reflector 2 and the second standard spherical reflector 4 respectively;

[0075] The first optical autocollimator 3, the second optical autocollimator 5, the third optical autocollimator 6 and the fourth optical autocollimator 7, the visual axes of all the optical autocollimators are perpendicular to the axis of the machine tool spindle 1 in the non-deflection state, the visual axes of the first optical autocollimator 3 and the second optical autocollimator 5 are parallel to each other, the visual axes of the third optical autocollimator 6 and the fourth optical autocollimator 7 are parallel to each other, the visual axis of the first optical autocollimator 3 is perpendicular to the visual axis of the third optical autocollimator 6, the visual axes of the first optical autocollimator 3 and the fourth optical autocollimator 7 pass through the center of the first standard spherical reflector 2 in the non-deflection state, and the second optical autocollimator 5 and the third optical autocollimator 6 pass through the center of the second standard spherical reflector 4 in the non-deflection state.

[0076] By utilizing the laser's collimation, high responsiveness, and traceability, the problem of monitoring high-speed spindle rotation errors can be solved by combining optical signals with mathematical calculations.

[0077] In general, such as Figure 2 As shown, both ends of the machine tool spindle 1 are respectively mounted at the centers of two mounting chucks 8 .

[0078] After the machine tool spindle is started, the laser emitted by the optical autocollimator is reflected by the spherical reflector and then the position signal is received by the autocollimator receiving module. The spherical reflector is a spherical surface reflector with an outer convex surface (not limited to this form). The detection principle of this system is based on optical reflection, so the processing accuracy of the spherical reflector will have a greater impact on the detection accuracy of the system.

[0079] In addition, the optical autocollimator adopts an orthogonal arrangement to avoid the detection blind area in specific scenarios; at the same time, the arrangement of multiple spherical reflectors can also provide support for the verification of error types and error data;

[0080] The detection system of this embodiment utilizes the characteristics of laser collimation, high responsiveness, traceability, etc., builds a spindle rotation error model that integrates multiple monitoring signals based on reflection information, analyzes error data through a data processing platform, and finally obtains the rotation error information of the high-speed machine tool spindle. Compared with the existing high-speed machine tool spindle detection system, the detection system of this embodiment can be installed on the machine tool spindle and detect in situ during operation. It does not require high-precision displacement or vibration sensors, and is not subject to the constraints of Western companies. It can simultaneously meet the performance requirements of high precision, high-speed response, and stable detection.

[0081] One aspect of the present embodiment provides a detection method based on the above system, which is used to detect radial play error and axial play error. The detection method includes:

[0082] Step A1: After installing the first standard spherical reflector 2 and the second standard spherical reflector 4, as well as the first optical autocollimator 3, the second optical autocollimator 5, the third optical autocollimator 6 and the fourth optical autocollimator 7;

[0083] Step A2: completing zeroing of the first optical autocollimator 3, the second optical autocollimator 5, the third optical autocollimator 6 and the fourth optical autocollimator 7;

[0084] like Figure 2 As shown, after the optical autocollimator is zeroed, the light spot of the laser hitting the surface of the standard spherical reflector is at the horizontal center position, and the light reflected by the spherical mirror returns along the original path.

[0085] Step A3: Start the machine tool spindle 1 and record the positions of all light spots collected by the optical autocollimator;

[0086] Step A4: Based on the light spot positions collected by the first optical autocollimator 3 and the second optical autocollimator 5, the radial runout error along the second direction of the machine tool spindle 1 is determined in combination with the radii of the first standard spherical reflector 2 and the second standard spherical reflector 4, wherein the second direction is parallel to the visual axis of the third optical autocollimator 6, specifically including:

[0087] Step A4-1: Based on the light spot position collected by the first optical autocollimator 3 and in combination with the radius of the first standard spherical reflector 2, determine the first radial error:

[0088] Δx 1 =R 1 sinθ 1

[0089]

[0090] Where: Δx 1 is the first radial error, R 1 is the radius of the first standard spherical reflector 2, θ 1 is the angle between the outgoing light of the first optical autocollimator 3 and the normal of the reflecting surface of the first standard spherical reflector 2, X 1 (θ 1 ) is the component of the light spot coordinates collected by the first optical autocollimator 3 in the direction perpendicular to the axis of the machine tool spindle 1, S 1 The distance from the light transmitting and receiving surface of the first standard spherical reflector 2 to the axis of the machine tool spindle 1 when there is no rotation error;

[0091] Specific as Figure 3 As shown in the figure, it can be seen that the angle between the incident light and the received light is twice the angle θ 1 , we can get:

[0092]

[0093] sinθ 1 =Δx 1 / R 1

[0094] Step A4-2: Similarly, based on the light spot position collected by the second optical autocollimator 5 and in combination with the radius of the second standard spherical reflector 4, the second radial error is determined;

[0095] Step A4 - 3 : Determine a radial rotation error along a second direction based on the first radial error and the second radial error, wherein the second direction is parallel to the visual axis of the third optical autocollimator 6 .

[0096] In some embodiments, the average of the first radial error and the second radial error may be used as the radial rotation error along the second direction.

[0097] Step A5: Based on the light spot positions collected by the third optical autocollimator 6 and the fourth optical autocollimator 7, the radial runout error of the machine tool spindle 1 along the first direction is determined in combination with the radii of the first standard spherical reflector 2 and the second standard spherical reflector 4, wherein the first direction is parallel to the visual axis of the first optical autocollimator 3, specifically including:

[0098] Step A5-1: Based on the spot position collected by the fourth optical autocollimator 7 and the radius of the first standard spherical reflector 2, the fourth radial error is determined. The specific principle is as follows: Figure 4 As shown, the fourth radial error is:

[0099] Δx 4 =R 1 sinθ 4

[0100]

[0101] Where: Δx 4 is the fourth radial error, R 1 is the radius of the first standard spherical reflector 2, θ 4 is the angle between the outgoing light of the fourth optical autocollimator 7 and the normal of the reflecting surface of the first standard spherical reflector 2, X 4 (θ 4 ) is the component of the light spot coordinates collected by the fourth optical autocollimator 7 in the direction perpendicular to the axis of the machine tool spindle 1, S 4 When there is no error, the distance from the light transmitting and receiving surface of the fourth optical autocollimator 7 to the axis of the machine tool spindle 1;

[0102] Step A5-2: Similarly, based on the light spot position collected by the third optical autocollimator 6 and in combination with the radius of the second standard spherical reflector 4, a third radial error is determined;

[0103] Step A5 - 3 : Determine a radial rotation error along a first direction based on the third radial error and the fourth radial error, wherein the first direction is parallel to the visual axis of the first optical autocollimator 3 .

[0104] Similarly, in some embodiments, the average of the third radial error and the fourth radial error is used as the radial rotation error along the first direction.

[0105] Step A6: Based on the light spot positions collected by the first optical autocollimator 3, the second optical autocollimator 5, the third optical autocollimator 6 and the fourth optical autocollimator 7, and combined with the radius of the first standard spherical reflector 2 and the second standard spherical reflector 4, the axial movement amount of the machine tool spindle 1 is determined.

[0106] Step A6 specifically includes:

[0107] Step A6-1: Based on the spot position collected by each optical autocollimator and the radius of the corresponding standard spherical reflector, the axial error of each optical autocollimator is determined. The specific principle is as follows: Figure 5 As shown, the axial error of each optical autocollimator is:

[0108] Δz i =R j sinθ i

[0109]

[0110] Where: Δz i is the axial error of the ith optical autocollimator, R j is the radius of the jth standard spherical reflector corresponding to the i-th optical autocollimator, θi is the angle between the outgoing light of the i-th optical autocollimator and the normal of the reflecting surface of the standard spherical reflector, Y i (θ i ) is the component of the light spot coordinates collected by the i-th optical autocollimator that is parallel to the axis of the machine tool spindle 1, S i When there is no error, the distance from the light transmitting and receiving surface of the i-th optical autocollimator to the axis of the machine tool spindle 1;

[0111] Step A6-2: Determine the axial movement of the machine tool spindle 1 based on the axial errors of each optical autocollimator. Step A6-2 specifically includes:

[0112] Step A6-2-1: Determine whether the axial errors of all optical autocollimators are greater than a first set threshold value, if yes, execute step A6-2-2;

[0113] Step A6-2-3: Determine whether the variance of the axial errors of all optical autocollimators is greater than a second set threshold. If so, determine that axial movement exists, and determine the axial movement amount of the machine tool spindle 1 based on the axial errors of each optical autocollimator.

[0114] In addition, another embodiment of the present application provides a detection method based on the above system for detecting a tilt swing error, the detection method comprising:

[0115] Step B1: After installing the first standard spherical reflector 2 and the second standard spherical reflector 4, as well as the first optical autocollimator 3, the second optical autocollimator 5, the third optical autocollimator 6 and the fourth optical autocollimator 7;

[0116] Step B2: completing the zeroing of the first optical autocollimator 3, the second optical autocollimator 5, the third optical autocollimator 6 and the fourth optical autocollimator 7;

[0117] After the optical autocollimator is zeroed, the laser spot on the surface of the standard spherical reflector is at the horizontal center, and the light reflected by the spherical mirror returns along the original path. The specific process is similar to step A2, so it will not be repeated here.

[0118] Step B3: start the machine tool spindle 1 and record the positions of all light spots collected by the optical autocollimator;

[0119] Step B4: Based on the light spot positions collected by each optical autocollimator and in combination with the radius of each standard spherical reflector, the inclination swing error of the machine tool spindle 1 is determined, specifically including:

[0120] Step B4-1: Construct the offset angle model:

[0121]

[0122] Si =S i1 +S i2

[0123]

[0124]

[0125] Where: d i Z is the distance from the intersection of the extended line of the outgoing light of the i-th optical autocollimator and the axis of the machine tool spindle 1 when there is no inclination swing error to the center of the corresponding standard spherical reflector, j is the z-direction distance between the jth standard spherical reflector and the deflection center, Δc is the tilt swing error, and the angle value is taken, R j is the radius of the jth standard spherical reflector corresponding to the i-th optical autocollimator, S i When there is no error, the distance from the light transmitting and receiving surface of the i-th optical autocollimator to the axis of the machine tool spindle 1 is S i1 For S i The first component, S i2 For S i The second component, θ i is the angle between the outgoing light of the i-th optical autocollimator and the normal of the reflecting surface of the standard spherical reflector, Y i (θ i ) is the z-component of the light spot coordinates collected by the i-th optical autocollimator;

[0126] For the offset angle model, the specific derivation process is as follows:

[0127] 1) First, if Figure 6 As shown, the red triangle is an isosceles triangle. By adding an auxiliary line as the perpendicular bisector of its base, we can get:

[0128]

[0129] After deformation, we can get:

[0130]

[0131] 2) In addition, for R, d 1 and S i1 The opposite angle of the side of the triangle with a length of R is △C / 2. Therefore, according to the cosine theorem, we can get:

[0132]

[0133] 3) According to the set relationship, the remaining formulas of the offset angle model can be obtained.

[0134] Step B-2: based on the first optical autocollimator 3, the second optical autocollimator 5, and the radius of each standard spherical reflector, determining the relationship between the tilt swing error and the z-component of the spot coordinates collected by the first optical autocollimator 3 and the second optical autocollimator 5;

[0135] Step B-3: based on the third optical autocollimator 6, the fourth optical autocollimator 7, and the radius of each standard spherical reflector, determine the relationship between the tilt swing error and the z-component of the spot coordinates collected by the third optical autocollimator 6 and the fourth optical autocollimator 7;

[0136] Step B-4: Determine the swing error based on the relationship between the tilt swing error and the z-component of the light spot coordinates collected by each optical autocollimator.

[0137] If the above functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program code.

Claims

1. An in-situ detection system for the rotation error of an ultra-precision machine tool spindle, characterized in that: include: A first standard spherical reflector (2) and a second standard spherical reflector (4) are respectively arranged at two ends of a machine tool spindle (1), and an axis of the machine tool spindle (1) passes through the sphere centers of the first standard spherical reflector (2) and the second standard spherical reflector (4); The first optical autocollimator (3), the second optical autocollimator (5), the third optical autocollimator (6) and the fourth optical autocollimator (7) have visual axes that are perpendicular to the axis of the machine tool spindle (1) in a non-deflection state; the visual axes of the first optical autocollimator (3) and the second optical autocollimator (5) are parallel to each other; the visual axes of the third optical autocollimator (6) and the fourth optical autocollimator (7) are parallel to each other; the visual axis of the first optical autocollimator (3) is perpendicular to the visual axis of the third optical autocollimator (6); the visual axes of the first optical autocollimator (3) and the fourth optical autocollimator (7) pass through the center of a first standard spherical reflector (2) in a non-deflection state; and the second optical autocollimator (5) and the third optical autocollimator (6) pass through the center of a second standard spherical reflector (4) in a non-deflection state.

2. The ultra-precision machine tool spindle rotation error in-situ detection system according to claim 1, characterized in that: The two ends of the machine tool spindle (1) are respectively mounted at the centers of two mounting chucks (8).

3. A detection method based on the system as claimed in claim 1 or 2, characterized in that: Used to detect radial and axial runout errors. The detection methods include: Step A1: After installing the first standard spherical reflector (2), the second standard spherical reflector (4), the first optical autocollimator (3), the second optical autocollimator (5), the third optical autocollimator (6) and the fourth optical autocollimator (7); Step A2: completing zeroing of the first optical autocollimator (3), the second optical autocollimator (5), the third optical autocollimator (6) and the fourth optical autocollimator (7); Step A3: starting the machine tool spindle (1) and recording the positions of all light spots collected by the optical autocollimator; Step A4: based on the light spot positions collected by the first optical autocollimator (3) and the second optical autocollimator (5), the radial runout error along the second direction of the machine tool spindle (1) is determined in combination with the radii of the first standard spherical reflector (2) and the second standard spherical reflector (4), wherein the second direction is parallel to the visual axis of the third optical autocollimator (6); Step A5: based on the light spot positions collected by the third optical autocollimator (6) and the fourth optical autocollimator (7), the radial runout error of the machine tool spindle (1) along a first direction is determined in combination with the radii of the first standard spherical reflector (2) and the second standard spherical reflector (4), wherein the first direction is parallel to the visual axis of the first optical autocollimator (3); Step A6: Based on the light spot positions collected by the first optical autocollimator (3), the second optical autocollimator (5), the third optical autocollimator (6) and the fourth optical autocollimator (7), the axial movement amount of the machine tool spindle (1) is determined in combination with the radius of the first standard spherical reflector (2) and the second standard spherical reflector (4).

4. The detection method according to claim 3, characterized in that: The step A4 specifically includes: Step A4-1: Based on the light spot position collected by the first optical autocollimator (3), the first radial error is determined in combination with the radius of the first standard spherical reflector (2): Δx1=R1 sinθ1 Wherein: Δx1 is the first radial error, R1 is the radius of the first standard spherical reflector (2), θ1 is the angle between the outgoing light of the first optical autocollimator (3) and the normal of the reflecting surface of the first standard spherical reflector (2), X1(θ1) is the component of the light spot coordinates collected by the first optical autocollimator (3) in the direction perpendicular to the axis of the machine tool spindle (1), and S1 is the distance from the light transmitting and receiving surface of the first standard spherical reflector (2) to the axis of the machine tool spindle (1) when there is no rotation error; Step A4-2: determining a second radial error based on the light spot position collected by the second optical autocollimator (5) and in combination with the radius of the second standard spherical reflector (4); Step A4-3: Determine a radial rotation error along a second direction based on the first radial error and the second radial error, wherein the second direction is parallel to the visual axis of the third optical autocollimator (6).

5. The detection method according to claim 3, characterized in that: The step A5 specifically includes: Step A5-1: Based on the light spot position collected by the fourth optical autocollimator (7), the fourth radial error is determined in combination with the radius of the first standard spherical reflector (2): Δx4=R1sinθ4 Wherein: Δx4 is the fourth radial error, R1 is the radius of the first standard spherical reflector (2), θ4 is the angle between the outgoing light of the fourth optical autocollimator (7) and the normal of the reflecting surface of the first standard spherical reflector (2), X4(θ4) is the component of the light spot coordinates collected by the fourth optical autocollimator (7) in the direction perpendicular to the axis of the machine tool spindle (1), and S4 is the distance from the light transmitting and receiving surface of the fourth optical autocollimator (7) to the axis of the machine tool spindle (1) when there is no error; Step A5-2: determining a third radial error based on the light spot position collected by the third optical autocollimator (6) and in combination with the radius of the second standard spherical reflector (4); Step A5-3: Determine a radial rotation error along a first direction based on the third radial error and the fourth radial error, wherein the first direction is parallel to the visual axis of the first optical autocollimator (3).

6. The detection method according to claim 3, characterized in that: The step A6 specifically includes: Step A6-1: Based on the light spot position collected by each optical autocollimator and the radius of the corresponding standard spherical reflector, determine the axial error of each optical autocollimator: Δz i =R j sinθ i Where: Δz i is the axial error of the ith optical autocollimator, R j is the radius of the jth standard spherical reflector corresponding to the i-th optical autocollimator, θ i is the angle between the outgoing light of the i-th optical autocollimator and the normal of the reflecting surface of the standard spherical reflector, Y i (θ i ) is the component of the light spot coordinates collected by the i-th optical autocollimator that is parallel to the axis of the machine tool spindle (1), S i When there is no error, the distance from the light transmitting and receiving surface of the i-th optical autocollimator to the axis of the machine tool spindle (1); Step A6-2: Determine the axial runout of the machine tool spindle (1) based on the axial errors of each optical autocollimator.

7. The detection method according to claim 6, characterized in that: The step A6-2 specifically includes: Step A6-2-1: Determine whether the axial errors of all optical autocollimators are greater than a first set threshold value, if yes, execute step A6-2-2; Step A6-2-3: Determine whether the variance of the axial errors of all optical autocollimators is greater than a second set threshold value. If so, determine that there is axial movement, and determine the axial movement amount of the machine tool spindle (1) based on the axial errors of each optical autocollimator.

8. A detection method based on the system as claimed in claim 1 or 2, characterized in that: Used to detect tilt swing error, the detection method includes: Step B1: After installing the first standard spherical reflector (2), the second standard spherical reflector (4), the first optical autocollimator (3), the second optical autocollimator (5), the third optical autocollimator (6) and the fourth optical autocollimator (7); Step B2: completing zeroing of the first optical autocollimator (3), the second optical autocollimator (5), the third optical autocollimator (6) and the fourth optical autocollimator (7); Step B3: starting the machine tool spindle (1) and recording the positions of all light spots collected by the optical autocollimator; Step B4: Based on the light spot positions collected by each optical autocollimator and in combination with the radius of each standard spherical reflector, the inclination swing error of the machine tool spindle (1) is determined.

9. The detection method according to claim 8, characterized in that: The step B4 comprises: Step B4-1: Construct the offset angle model: S i =S i1 +S i2 Where: d i Z is the distance from the intersection of the extended line of the outgoing light of the i-th optical autocollimator and the axis of the machine tool spindle (1) when there is no tilt swing error to the center of the corresponding standard spherical reflector. j is the z-direction distance between the jth standard spherical reflector and the deflection center, Δc is the tilt swing error, and the angle value is taken, R j is the radius of the jth standard spherical reflector corresponding to the i-th optical autocollimator, S i When there is no error, the distance from the light transmitting and receiving surface of the i-th optical autocollimator to the axis of the machine tool spindle (1) is S i1 For S i The first component, S i2 For S i The second component, θ i is the angle between the outgoing light of the i-th optical autocollimator and the normal of the reflecting surface of the standard spherical reflector, Y i (θ i ) is the z-component of the light spot coordinates collected by the i-th optical autocollimator; Step B-2: Based on the first optical autocollimator (3), the second optical autocollimator (5), and the radius of each standard spherical reflector, determining the relationship between the tilt swing error and the z-component of the light spot coordinates collected by the first optical autocollimator (3) and the second optical autocollimator (5); Step B-3: Based on the third optical autocollimator (6), the fourth optical autocollimator (7), and the radius of each standard spherical reflector, determining the relationship between the tilt swing error and the z-component of the light spot coordinates collected by the third optical autocollimator (6) and the fourth optical autocollimator (7); Step B-4: Determine the swing error based on the relationship between the tilt swing error and the z-component of the light spot coordinates collected by each optical autocollimator.

10. The detection method according to claim 3 or 8, characterized in that: After the optical autocollimator is zeroed, the light spot of the laser hitting the surface of the standard spherical reflector is at the horizontal center position, and the light reflected by the spherical mirror returns along the original path.

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