A six-degree-of-freedom motion error measurement system and method for a rotating axis

Abstract

This invention discloses a six-degree-of-freedom motion error measurement system and method for a rotating axis. The system includes a rotating axis and angular position error measurement components and tilt motion and radial runout error measurement components respectively connected to the rotating axis. The tilt motion and radial runout error measurement components include a first laser optical path and also include an axial runout error measurement component, which is integrated into the first laser optical path. The six-degree-of-freedom motion error measurement system of this invention has a simple structure, occupies little space, and is easy to operate. It can accurately measure two tilt motion errors, two radial runout errors, angular positioning errors, and axial runout errors.

Description

Technical Field

[0001] This invention relates to the field of precision measurement technology, and more specifically, to a system and method for measuring the motion error of a six-degree-of-freedom rotating axis. Background Technology

[0002] Rotary axes, as core components in precision mechanical structures, occupy an indispensable position in numerous instruments and precision manufacturing equipment. For example, the azimuth and pitch axes of instruments such as theodolites and laser trackers, and the rotary axes of manufacturing equipment such as five-axis machining centers and industrial robots—any minute deviation can lead to serious errors in positioning data. Due to inherent manufacturing errors and external interference, six motion errors are unavoidable during the operation of rotary axes (two tilt motion errors, two radial runout errors, angular positioning error, and axial runout error). The existence of these errors poses a severe challenge to the high accuracy and precision of precision mechanical structures; therefore, accurate measurement of rotary axis motion errors is particularly crucial.

[0003] Currently, methods for measuring the motion error of rotating shafts fall into two categories: contact measurement and non-contact measurement. Contact measurement typically employs devices such as ballbars and R-tests, using linear displacement sensors to detect minute changes during the rotation of the shaft. Data processing, combined with an error separation model, is then used to obtain various motion errors. This method requires multiple setups of the device, and the error separation model is complex, making it inconvenient for error measurement. Non-contact measurement is usually based on optical detection, reflecting the motion error of the rotating shaft onto sensors such as photodetectors. The relevant errors are measured based on principles such as laser interferometry, diffraction, and collimation. However, existing methods typically require numerous optical components, and the integrated measurement system is bulky, making online measurement inconvenient. Summary of the Invention

[0004] The purpose of this invention is to provide a six-degree-of-freedom motion error measurement system and method for a rotating shaft, which uses a simplified structure to measure the six-degree-of-freedom motion error of the rotating shaft.

[0005] To achieve the above objectives, the six-degree-of-freedom motion error measurement system for a rotating axis of the present invention includes a rotating axis and an angular position error measurement component and a tilt motion and radial runout error measurement component respectively connected to the rotating axis. The tilt motion and radial runout error measurement component includes a first laser optical path and further includes an axial runout error measurement component, which is integrated into the first laser optical path.

[0006] In one embodiment of the above-mentioned six-degree-of-freedom motion error measurement system for a rotating shaft, the tilt motion and radial runout error measurement component includes a first laser emitting module, a first sensing module, and a first adjustment frame. The first laser emitting module is connected to the end of the rotating shaft through the first adjustment frame, and the first laser emitting module and the first sensing module are arranged sequentially along the first laser optical path.

[0007] In one embodiment of the above-mentioned six-degree-of-freedom motion error measurement system for a rotating axis, the first laser emitting module includes a first laser, a first reflector, a first beam splitter, and a first quarter-wave plate arranged along the first laser optical path.

[0008] In one embodiment of the above-mentioned six-degree-of-freedom motion error measurement system for a rotating axis, the axial runout error measurement component includes a second reflector, a first position sensor, and a first beam splitter. The second reflector and the first position sensor are respectively disposed on both sides of the first beam splitter, and the first beam splitter is disposed between the first quarter-wave plate and the first sensing module.

[0009] In one embodiment of the above-described six-degree-of-freedom motion error measurement system for a rotating axis, the light beams reflected by the second reflector and the first beam splitter form an equilateral triangle.

[0010] In one embodiment of the above-mentioned six-degree-of-freedom motion error measurement system for a rotating axis, the axial runout error measurement component further includes a beam splitter calibration component, which includes a cornerstone prism, a first convex lens, and a second position sensor. The cornerstone prism is disposed on one side of the first beam splitter along the first laser optical path, and the first convex lens and the second position sensor are disposed on the other side of the first beam splitter opposite to the cornerstone prism.

[0011] In one embodiment of the above-described six-DOF motion error measurement system for a rotating axis, the tilt motion and radial runout error measurement component further includes a second adjustment frame connected to the first sensing module.

[0012] In one embodiment of the above-mentioned six-degree-of-freedom motion error measurement system for a rotating axis, the first sensing module includes a second beam splitter, a third position sensor, a second convex lens, and a fourth position sensor. The transmitted light, split by the second beam splitter, reaches the third position sensor, and the reflected light, split by the second beam splitter, reaches the fourth position sensor via the second convex lens.

[0013] In one embodiment of the above-mentioned six-degree-of-freedom motion error measurement system for a rotating axis, the angular position error measurement component includes a correspondingly arranged second laser emission sensing module and a polyhedral prism, the polyhedral prism being disposed at the end of the rotating axis.

[0014] In one embodiment of the above-mentioned six-degree-of-freedom motion error measurement system for a rotating axis, the second laser emission sensing module includes a second laser, a third beam splitter, a second quarter-plate, a third convex lens, and a fifth position sensor, and the second laser, the third beam splitter, the polyhedral prism, the second quarter-plate, the third convex lens, and the fifth position sensor are arranged sequentially along the second laser optical path.

[0015] The six-degree-of-freedom motion error measurement method for a rotating shaft of the present invention includes the following steps:

[0016] Set up an angle position error measurement component to measure the angle position error;

[0017] Set up a tilt motion and radial runout error measurement component to measure tilt motion error and radial runout error;

[0018] Set up an axial runout error measurement component to measure axial runout error;

[0019] The axial runout error measurement component is integrated into the first laser optical path of the tilt motion and radial runout error measurement component.

[0020] In one embodiment of the above-mentioned six-degree-of-freedom motion error measurement method for a rotating shaft, a first laser emitting module equipped with tilt motion and radial runout error measurement components is connected to the end of the rotating shaft via a first adjustment frame. The first laser emitting module consists of a first laser, a first reflector, a first beam splitter, and a first quarter-wave plate arranged along the first laser optical path. The first sensing module is arranged after the first quarter-wave plate along the first laser optical path.

[0021] The second reflector and the first position sensor of the axial runout error measurement component are respectively disposed on both sides of the first beam splitter, and the first beam splitter plate is disposed between the first quarter-wave plate and the first sensing module.

[0022] In one embodiment of the above-mentioned six-degree-of-freedom motion error measurement method for a rotating axis, the transmitted light beam split by the first beam splitter is further reflected by the second mirror and reaches the first beam splitter plate, and then reflected by the first beam splitter plate to reach the first position sensor. The axial runout error is measured by sensing the change in the position of the laser spot.

[0023] In one embodiment of the above-described method for measuring the six-degree-of-freedom motion error of a rotating axis, the light beam reflected by the second mirror and the first beam splitter forms an equilateral triangle.

[0024] In one embodiment of the above-described method for measuring the six-degree-of-freedom motion error of a rotating axis, the step of eliminating the tilt angle of the first beam splitter is further included when measuring the axial runout error.

[0025] In one embodiment of the above-described method for measuring the six-degree-of-freedom motion error of a rotating axis, a cornerstone prism is placed directly in front of the first laser emitting module. A first convex lens and a second position sensor are positioned on the opposite side of the first beam splitter relative to the cornerstone prism. The laser beam is split and transmitted through the first beam splitter to the cornerstone prism. The tilt angle and position of the laser beam are adjusted by a first adjustment frame so that the reflected beam from the cornerstone prism passes through the first convex lens and is focused at the center of the second position sensor, making the reading of the second position sensor zero. Then, the cornerstone prism is replaced with a first beam splitter, and a third adjustment frame is adjusted so that the reading of the second position sensor is zero again. The axial runout error is then measured.

[0026] In one embodiment of the above-described method for measuring the six-degree-of-freedom motion error of a rotating shaft, the method for measuring axial runout error further includes a step of eliminating the influence of the tilting motion error of the rotating shaft on the measurement of axial runout error.

[0027] In one embodiment of the above-described method for measuring the six degrees of freedom motion error of a rotating axis, the first sensing module is configured as a second beam splitter, a third position sensor, a second convex lens, and a fourth position sensor. A laser beam emitted from a first laser reaches a first reflecting mirror. The reflected laser beam passes through the first beam splitter for beam splitting, and the reflected light reaches the second beam splitter, where the laser beam is split again. The split transmitted light goes to the third position sensor, and two radial runout errors during the rotation axis motion are measured by sensing the change in the position of the laser spot. The split reflected light is focused by the second convex lens onto the fourth position sensor, and two tilting motion errors during the rotation axis motion are measured by sensing the change in the position of the laser spot.

[0028] In one embodiment of the above-described six-degree-of-freedom motion error measurement method for a rotating axis, the two tilting motion errors ε during the rotation axis motion process are... x and ε z The axial runout error Δx satisfies the following relationship:

[0029]

[0030] Where, Δy QPD This refers to the position change of the light spot on the first position sensor;

[0031] L is the distance between the first beam splitter and the first position sensor;

[0032] This is the nominal rotation angle of the rotation axis.

[0033] In one embodiment of the above-described method for measuring the six degrees of freedom motion error of a rotation axis, the angular position error measurement component is set as a corresponding second laser emission sensing module and a polyhedral prism. The second laser emission sensing module is set as a second laser, a third beam splitter, a second quarter-wave plate, a third convex lens, and a fifth position sensor. The polyhedral prism rotates with the rotation axis. The laser emitted by the second laser passes through the third beam splitter, and its transmitted light reaches the reflecting surface of the polyhedral prism. The reflected beam passes through the third beam splitter again, and the reflected light passes through the second quarter-wave plate and the third convex lens to reach the fifth position sensor. The rotation angle position error is measured by sensing the change in the position of the laser spot.

[0034] The beneficial effects of this invention are that the six-degree-of-freedom motion error measurement system for the rotating shaft has a simple structure, occupies little space, and is easy to operate. It can accurately measure two tilt motion errors, two radial runout errors, angular positioning errors, and axial runout errors.

[0035] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the present invention. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the overall structure of the six-degree-of-freedom motion error measurement system for the rotating axis of the present invention;

[0037] Figure 2 This is a schematic diagram of the measurement optical path structure of the angle position error measurement component of the six-degree-of-freedom motion error measurement system for the rotating axis of the present invention;

[0038] Figure 3 This is a schematic diagram of the measurement optical path structure of the tilt motion and radial runout error measurement component and the axial runout error measurement component of the six-degree-of-freedom motion error measurement system for the rotating shaft of the present invention;

[0039] Figure 4 This is a schematic diagram illustrating the principle of measuring axial runout error of a rotating shaft.

[0040] Figure 5 This is a schematic diagram illustrating the principle of tilt error during the installation of the first beam splitter.

[0041] Figure 6 and Figure 7 This is a schematic diagram of the optical lens assembly adjustment for axial runout error;

[0042] Figure 8 This is a schematic diagram illustrating the principle of crosstalk analysis during the measurement of axial runout error of a rotating shaft.

[0043] In the picture:

[0044] 1: Rotating shaft

[0045] 2: Angle position error measurement component

[0046] 21: Second laser emission sensing module

[0047] 22: Polyhedral prism

[0048] 211: Second Laser

[0049] 212: Third beam splitter

[0050] 213: Second Quarter Pick

[0051] 214: Third convex lens

[0052] 215: Fifth Position Sensor

[0053] 3: Measurement component for tilting motion and radial runout error

[0054] 31: First laser emission module

[0055] 311: The First Laser

[0056] 312: First reflecting mirror

[0057] 313: First beam splitter

[0058] 314: First quarter-wave plate

[0059] 32: First sensing module

[0060] 321: Second beam splitter

[0061] 322: Third position sensor

[0062] 323: Second convex lens

[0063] 324: Fourth position sensor

[0064] 33: First Adjustment Frame

[0065] 34: Second Adjustment Frame

[0066] 4: Axial runout error measurement component

[0067] 401: Second reflecting mirror

[0068] 402: First position sensor

[0069] 403: First spectrophotometer

[0070] 404: Cornerstone Prism

[0071] 405: First convex lens

[0072] 406: Second position sensor

[0073] 407: Third Adjustment Frame Detailed Implementation

[0074] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments to further understand the purpose, solution and effect of the present invention, but it is not intended to limit the scope of protection of the appended claims.

[0075] References to "embodiment," "another embodiment," "this embodiment," etc., in the specification refer to embodiments that may include specific features, structures, or characteristics, but not every embodiment must include these specific features, structures, or characteristics. Furthermore, such expressions do not refer to the same embodiment. Moreover, when describing specific features, structures, or characteristics in connection with embodiments, whether or not explicitly described, it is indicated that incorporating such features, structures, or characteristics into other embodiments is within the knowledge of those skilled in the art.

[0076] The specification and subsequent claims use certain terms to refer to specific components or parts. Those skilled in the art will understand that users or manufacturers may use different names or terms to refer to the same component or part. This specification and subsequent claims do not distinguish components or parts by differences in name, but rather by differences in function. The terms "comprising" and "including" used throughout the specification and subsequent claims are open-ended and should be interpreted as "including but not limited to." Furthermore, the term "connection" here includes any direct and indirect means of connection.

[0077] It should be noted that in the description of this invention, terms such as "lateral," "longitudinal," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are used only for the convenience of describing this invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting this invention. For clarity, the sequential terms such as "first," "second," "third," and "fourth" used herein are used to distinguish an element, region, or part from another identical or similar element, region, or part, and are not used to limit specific elements, regions, or parts.

[0078] like Figure 1As shown, the six-DOF motion error measurement system for a rotating axis of the present invention includes a rotating axis 1 and an angular position error measurement component 2, a tilt motion and radial runout error measurement component 3, and an axial runout error measurement component 4, respectively connected to the rotating axis 1. The tilt motion and radial runout error measurement component 3 includes a first laser optical path, and the axial runout error measurement component 4 is integrated into the first laser optical path of the tilt motion and radial runout error measurement component 3. Specifically, the angular position error measurement component 2 is used to measure the angular position error of the rotating axis 1, the tilt motion and radial runout error measurement component 3 is used to measure two tilt motion errors and two radial runout errors of the rotating axis 1, and the axial runout error measurement component 4 is used to measure the axial runout error of the rotating axis 1.

[0079] The tilt motion and radial runout error measurement component 3 includes a first laser emitting module 31, a first sensing module 32, and a first adjustment frame 33. The first laser emitting module 31 is connected to the end of the rotating shaft 1 through the first adjustment frame 33. The first laser emitting module 31 and the first sensing module 32 are arranged sequentially along the first laser optical path, and the first sensing module 32 is connected to a second adjustment frame 34. The second adjustment frame 34 is, for example, a four-degree-of-freedom (two-dimensional angle and two-dimensional offset) adjustment mechanism.

[0080] like Figure 1 and Figure 3 As shown, the first laser emitting module 31 includes a first laser 311, a first reflector 312, a first beam splitter 313, and a first quarter-wave plate 314 arranged along the first laser optical path.

[0081] The axial runout error measurement component 4 includes a second reflector 401, a first position sensor 402, and a first beam splitter 403. The second reflector 401 and the first position sensor 402 are respectively disposed on both sides of the first beam splitter 313, and the first beam splitter 403 is disposed between the first quarter-wave plate 314 and the first sensing module 32.

[0082] like Figure 6 As shown, the axial runout error measurement component 4 also includes a beam splitter calibration component, which includes a corner bevel prism 404, a first convex lens 405, and a second position sensor 406. The corner bevel prism 404 is disposed on one side of the first beam splitter 313 along the first laser optical path, and the first convex lens 405 and the second position sensor 406 are disposed on the other side of the first beam splitter 313 opposite to the corner bevel prism 404.

[0083] like Figure 1 and Figure 3 As shown, the first sensing module 32 includes a second beam splitter 321, a third position sensor 322, a second convex lens 323, and a fourth position sensor 324.

[0084] like Figure 1 and Figure 2 As shown, the angle position error measurement component 2 includes a second laser emission sensing module 21 and a polyhedral prism 22, which are respectively disposed at the end of the rotation shaft 1.

[0085] The second laser emission sensing module 21 includes a second laser 211, a third beam splitter 212, a second quarter-paddle 213, a third convex lens 214, and a fifth position sensor 215, which are arranged sequentially along the second laser optical path.

[0086] This invention is used to simultaneously measure the six degrees of freedom motion error of a rotating axis, such as... Figure 1 and Figure 2 As shown, the system includes a rotating part and a fixed part. The rotating part is mounted on a moving rotating shaft 1 and includes a polyhedral prism 22 and a first laser emitting module 31 mounted on a first adjustment frame 33. The fixed part is fixed to a base and includes a second laser emitting sensing module 21 for measuring angular position error and a first sensing module 32 mounted on a second adjustment frame 34.

[0087] The process of measuring the angular position error of rotating shaft 1 is as follows: (Combined with...) Figure 1 and Figure 2 The polyhedral prism 22 is mounted on the rotation axis 1 and rotates with the rotation axis 1. The laser emitted by the second laser 211 of the second laser emission sensing module 21 passes through the third beam splitter 212, and its transmitted light P reaches the reflecting surface of the polyhedral prism 22. The reflected beam passes through the third beam splitter 212 again, and the split reflected light passes through the second quarter-wave plate 213 and the third convex lens 214 (focal length f1) to reach the fifth position sensor 215. By sensing the change in the position of the laser spot Δy1, and combining the following formula, the rotation angle position error ε is realized. y Measurement.

[0088]

[0089] The measurement process for the tilting motion and radial runout error of rotating shaft 1 is as follows: (Combined with...) Figure 1 and Figure 3The first adjustment frame 33 carries the first laser 311 of the first laser emitting module 31, the first reflector 312, the first beam splitter 313, the first quarter-wave plate 314, and the second reflector 401 of the axial runout error measuring component 4. The fixed part of the second adjustment frame 34 carries the first beam splitter 403 of the axial runout error measuring component 4, the second beam splitter 321 of the first sensing module 32, the third position sensor 322, the second convex lens 323, and the fourth position sensor 324. The laser beam emitted by the first laser 311 reaches the first reflector 312. The reflected laser beam passes through the first beam splitter 313 for beam splitting. The reflected light reaches the second beam splitter 321, where the laser beam is split again. The split transmitted light reaches the third position sensor 322 to measure two radial runout errors during the movement of the rotating shaft 1. The split reflected light is focused by the second convex lens 323 onto the fourth position sensor 324 to measure two tilting motion errors during the movement of the rotating shaft 1.

[0090] This invention adds a second reflector 401 and a first position sensor 402 to the first adjustment frame 33 of the rotating part, and adds a first beam splitter 403 in front of the second beam splitter 321 on the second adjustment frame 34 of the fixed part. The projected transmitted light split by the first beam splitter 313 reaches the second reflector 402, and the further reflected beam Q reaches the first beam splitter 403, and is then reflected by the first beam splitter 403 to reach the first position sensor 402, thereby realizing the measurement of axial runout error. The beams reflected by the second reflector 401 and the first beam splitter 403 form an equilateral triangle.

[0091] The measurement principle of axial runout error is as follows: Figure 4 As shown, when the shaft end produces a runout error δ y At that time, the light spot incident on the first beam splitter 403 will also undergo displacement, which in turn will cause the reflected beam to shift, and the light spot incident on the first position sensor 402 will undergo position change Δy. QPD Therefore, according to trigonometric relations, δ y and △y QPD The relationship between them is shown in the following formula.

[0092]

[0093] Axial runout error measurement must ensure that the incident light is perpendicular to the first beam splitter 403, such as... Figure 5 As shown, if the beam splitter is tilted by θ, in order to make the light spot hit the center of the semi-reflecting mirror, the end-runout measurement optical path will be tilted. Therefore, the axial runout error relationship will become as shown in the following formula, resulting in inaccurate final measurement results.

[0094]

[0095] Since θ is an unknown quantity, the tilt angle θ of the first beam splitter 403 must be eliminated to ensure the accuracy of the axial runout error measurement results. The elimination scheme is as follows: Figure 6 As shown, a cornerstone prism 404 is placed directly in front of the first laser emitting module 31. The light beam, after being split and transmitted by the first beam splitter 313, reaches the cornerstone prism 404. Based on the characteristic that the light reflected from the cornerstone prism 404 is parallel to the incident light, the tilt angle and position of the laser beam are adjusted by the first adjustment bracket 33, so that the reflected beam from the cornerstone prism 404 passes through the first convex lens 405 and is focused at the center of the second position sensor 406. At this time, the reading of the second position sensor 406 is zero. Then, the cornerstone prism 404 is replaced by the first beam splitter 403 in front of the first sensing module 32, as shown... Figure 7 As shown, by adjusting the third adjustment frame 407 after the first beam splitter 403, the reading of the second position sensor 406 is also 0. At this time, it can be considered that the tilt angle θ is eliminated and the incident light is perpendicular to the first beam splitter.

[0096] During the measurement of axial runout error, the tilting motion error of rotating shaft 1 will also cause crosstalk to the measurement results of axial runout error, such as... Figure 8 As shown, assume that the rotation axis 1 has a tilting motion error ε about the X direction. x The deviation caused by this error in the axial runout error is approximately calculated as follows:

[0097] Δδ QPD =L·tanε x

[0098] Where L is the distance between the first beam splitter 403 and the first position sensor 402.

[0099] Therefore, in the actual measurement process, when the rotation axis is set to 0 degrees, the tilting motion error ε of the first sensing module 32 around the X direction is... x Corresponding to the X direction of the first position sensor 402, the tilt motion error ε of the first sensing module 32 around the Z direction z Corresponding to the Y direction of the first position sensor 402, the rotation axis rotates counterclockwise, and during the rotation, it rotates with the nominal rotation angle. The change in the angle value in the Y direction of the first position sensor 402 will also change. The tilt motion errors around the X and Z directions are decomposed in the Y direction of the first position sensor 402 respectively, and then synthesized into the Y direction of the first position sensor 402. Therefore, the actual axial runout error value Δx is:

[0100]

[0101] All six motion errors of the rotating shaft 1 are sensed by a position sensor. The laser beam generates photocurrent on the sensing surface of the sensor. The photocurrent is amplified and converted into voltage by the circuit board and then converted into digital signal by the data acquisition card. The data is then transmitted to the computer for data acquisition and analysis, thereby obtaining the measurement values ​​of each error.

[0102] The embedded rotary shaft axial runout error measurement method and system proposed in this invention can perform six-degree-of-freedom error measurement and takes into account various crosstalk phenomena in the axial runout error measurement process, thus realizing accurate measurement of axial runout error.

[0103] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the appended claims.

Claims

1. A rotary shaft six degree of freedom motion error measurement system comprising a rotary shaft and an angular position error measurement assembly and a tilt motion and runout error measurement assembly connected to the rotary shaft, respectively, the tilt motion and runout error measurement assembly comprising a first laser light path, characterized in that, It also includes an axial runout error measurement component, which is integrated into the first laser optical path; The tilt motion and radial runout error measurement component includes a first laser emitting module, a first sensing module, and a first adjustment frame. The first laser emitting module is connected to the end of the rotating shaft through the first adjustment frame. The first laser emitting module includes a first laser, a first reflector, a first beam splitter, and a first quarter-wave plate arranged along the first laser optical path. The first sensing module is arranged after the first quarter-wave plate along the first laser optical path. The first sensing module includes a second beam splitter, a third position sensor, a second convex lens, and a fourth position sensor. A laser beam emitted from the first laser reaches the first reflecting mirror. The reflected laser beam passes through the first beam splitter for beam splitting. The reflected light reaches the second beam splitter, where the laser beam is split again. The split transmitted light goes to the third position sensor. By sensing the change in the position of the laser spot, two radial runout errors during the rotation axis movement are measured. The split reflected light is focused by the second convex lens onto the fourth position sensor. By sensing the change in the position of the laser spot, two tilting motion errors during the rotation axis movement are measured. The axial runout error measurement component includes a second reflector, a first position sensor, and a first beam splitter. The second reflector and the first position sensor are respectively disposed on opposite sides of the first beam splitter, and the first beam splitter is disposed between the first quarter-wave plate and the first sensing module. The transmitted light beam split by the first beam splitter is further reflected by the second reflector to reach the first beam splitter, and then reflected by the first beam splitter to reach the first position sensor. The axial runout error is measured by sensing the change in the position of the laser spot. The light beams reflected by the second reflector and the first beam splitter form an equilateral triangle. The angular position error measurement component includes a correspondingly configured second laser emission sensing module and a polyhedral prism. The second laser emission sensing module includes a second laser, a third beam splitter, a second quarter-wave plate, a third convex lens, and a fifth position sensor. The polyhedral prism rotates with the rotation axis. The laser emitted by the second laser passes through the third beam splitter, and its transmitted light reaches the reflecting surface of the polyhedral prism. The reflected beam passes through the third beam splitter again, and the reflected light passes through the second quarter-wave plate and the third convex lens to reach the fifth position sensor. The rotational angular position error is measured by sensing the change in the position of the laser spot.

2. The six-degree-of-freedom motion error measurement system for a rotating axis according to claim 1, characterized in that, The axial runout error measurement component further includes a beam splitter calibration component, which includes a cornerstone prism, a first convex lens, and a second position sensor. The cornerstone prism is disposed on one side of the first beam splitter along the first laser optical path, and the first convex lens and the second position sensor are disposed on the other side of the first beam splitter opposite to the cornerstone prism.

3. The six-degree-of-freedom motion error measurement system for a rotating axis according to claim 1, characterized in that, The tilt motion and radial runout error measurement component also includes a second adjustment frame connected to the first sensing module.

4. The six-degree-of-freedom motion error measurement system for a rotating axis according to claim 1, characterized in that, The polyhedral prism is disposed at the end of the rotation axis.

5. A method for measuring the motion error of a six-degree-of-freedom rotating axis, characterized in that, Using the measurement system of claim 1 includes the following steps: Set up an angle position error measurement component to measure the angle position error; Set up a tilt motion and radial runout error measurement component to measure tilt motion error and radial runout error; Set up an axial runout error measurement component to measure axial runout error; The axial runout error measurement component is integrated into the first laser optical path of the tilt motion and radial runout error measurement component.

6. The method for measuring the six-degree-of-freedom motion error of a rotating axis according to claim 5, characterized in that, The measurement of axial runout error also includes a step of eliminating the tilt angle of the first beam splitter.

7. The method for measuring the motion error of a six-degree-of-freedom rotating axis according to claim 6, characterized in that, A corner prism is placed directly in front of the first laser emitting module. A first convex lens and a second position sensor are positioned on the opposite side of the first beam splitter relative to the corner prism. The laser beam is split and transmitted through the first beam splitter to the corner prism. The tilt angle and position of the laser beam are adjusted by a first adjustment frame so that the reflected beam from the corner prism passes through the first convex lens and is focused at the center of the second position sensor so that the reading of the second position sensor is zero. Then, the corner prism is replaced by a first beam splitter, and a third adjustment frame is adjusted so that the reading of the second position sensor is zero again. The axial runout error is then measured.

8. The method for measuring the motion error of a six-degree-of-freedom rotating axis according to claim 6, characterized in that, When measuring axial runout error, the procedure also includes a step to eliminate the influence of the tilting motion error of the rotating shaft on the measurement of axial runout error.

9. The method for measuring the motion error of a six-degree-of-freedom rotating axis according to claim 5, characterized in that, Two tilting motion errors during the rotation axis motion process and Axial runout error The following relationship must be satisfied: in, This refers to the position change of the light spot on the first position sensor; L is the distance between the first beam splitter and the first position sensor; φ is the nominal rotation angle of the rotation axis.

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