360-degree precise angle correction device and method based on autocollimation tracking compensation

Abstract

This invention relates to the field of precision angle measurement and error correction technology, specifically to a 360° precision angle correction device and method based on autocollimation tracking compensation. The device includes a mounting and fixing assembly for mounting and fixing the object to be corrected; a rotary correction assembly whose main housing is connected to the rotation output end of the object to be corrected; a reflector connected to the rotation output end of the rotary correction assembly; an autocollimator, configured in conjunction with the reflector, for acquiring the deflection angle value of the reflector; and a host computer connected to the object to be corrected, the rotary correction assembly, and the autocollimator. The rotary correction assembly includes a reference encoder. This device, through the rotary correction assembly with its built-in high-precision reference encoder, provides real-time reverse compensation for the motion angle of the object to be corrected, ensuring that the reflector mounted on the rotary correction assembly remains aligned with the autocollimator in space, indirectly achieving precise measurement and correction data generation of the angle error within a 360° full-circle range of the object to be corrected.

Description

Technical Field

[0001] This invention relates to the field of precision angle measurement and error correction technology, specifically to a 360° precision angle correction device and method based on self-collimation tracking compensation. Background Technology

[0002] In fields such as precision machining, robotics manufacturing, and CNC equipment, the angular positioning accuracy of rotary axes directly affects the performance of the overall system. High-precision angular error calibration and correction of rotating bodies such as machine tool rotary tables and robot joint modules is a core step in ensuring product quality. However, current mainstream angle calibration and correction solutions face the following significant problems in practical engineering applications:

[0003] The widespread reliance on and limitations of coaxial alignment for calibration: In the angle calibration and correction of rotary tables and robot joint modules, the coaxial alignment method is currently widely used in engineering. A high-precision angle reference (such as a calibration encoder or reference shaft system) is coaxially installed with the measured rotating shaft through mechanical interfaces such as couplings and transition flanges. Error curves are obtained by synchronously rotating and comparing the readings of both, and then compensation is implemented. This method is simple in structure and relatively cost-effective, and is widely used in small to medium-sized shaft systems with high installation precision. However, in many practical scenarios, the measured rotary component is large and bulky, or its housing does not have a precise mounting reference surface, with only the rotation center possessing accuracy. In such cases, the reference shaft system required for coaxial alignment is difficult to align accurately. Additional adapters not only fail to guarantee coaxiality but also introduce significant additional errors such as eccentricity and deflection, making on-site calibration difficult or even impossible. This has become a major engineering obstacle for the precision calibration of large rotary devices and highly integrated joint modules.

[0004] The need for overall precision correction in robot joint modules is prominent: In fields such as collaborative robots, where high absolute positioning accuracy is required, the final angular output accuracy of the joint module depends not only on the resolution and accuracy of the encoder itself, but also on a series of system factors such as reducer transmission errors, backlash, bearing runout, structural elastic deformation, and assembly eccentricity. Simply improving encoder accuracy is not only costly, but also cannot compensate for the aforementioned system-level errors.

[0005] Technical Bottlenecks of Autocollimators in 360° Full-Circle Correction: An autocollimator is a precision angle measuring instrument with an angular resolution of up to 0.01 arcseconds and a repeatability better than 0.1 arcseconds, making it an ideal tool for high-precision small-angle measurements. Using an autocollimator-polyhedron combination as the measurement reference, coupled with a stepper motor, small-angle precision detection is achieved. This method has been applied in the angle measurement error detection of absolute photoelectric encoders, achieving an expanded uncertainty of 1.6 arcseconds. However, the measurement field of view of the autocollimator is limited—typically, its effective field of view is approximately 4200 arcseconds (about 1.17°). When the target rotates 360° in a full circle, the autocollimator quickly loses alignment, making continuous, automated detection difficult. Therefore, it is limited to detection methods and cannot perform full-circle compensation. For high-precision applications, the overall output error is usually much smaller than the autocollimator's field of view. Therefore, after initial alignment, if only fixed-point measurement and adjustment of the error are needed, the angular offset of the reflector remains within the measurable range of the autocollimator. However, to achieve automated error calibration at multiple points within the entire circle, the problem of "cross-field of view" tracking of the reflector during the stepping process still needs to be solved. Summary of the Invention

[0006] The purpose of this invention is to provide a 360° precision angle correction device and method based on self-collimation tracking compensation. By using a rotary correction component with a built-in high-precision reference encoder, the motion angle of the object to be corrected is compensated in real time, so that the reflector installed on the rotary correction component is always aligned with the autocollimator in space. Thus, by utilizing the high-precision small-angle measurement capability of the autocollimator, the precise measurement and correction data generation of the angle error of the object to be corrected within a 360° full circle range can be indirectly realized.

[0007] In a first aspect of the present invention, a 360° precision angle correction device based on self-collimation tracking compensation is provided, comprising:

[0008] Mounting and fixing components are used to mount and fix the object to be calibrated;

[0009] The rotary straightening assembly has its main housing connected to the rotational output end of the object to be straightened.

[0010] A reflector is connected to the rotation output end of the rotary correction assembly;

[0011] An autocollimator, used in conjunction with a reflector, is used to obtain the deflection angle value of the reflector.

[0012] The host computer is connected to the object to be calibrated, the rotary correction component, and the autocollimator.

[0013] The rotation correction components include:

[0014] The reference encoder is located inside the main housing of the rotary correction assembly. The accuracy level of the reference encoder is better than that of the encoder being corrected on the object to be corrected.

[0015] The servo rotary system is located inside the main housing of the rotary correction component, and the drive shaft of the servo rotary system is connected to the reflector.

[0016] As a preferred embodiment of the present invention, the main housing of the rotary straightening assembly is connected to the rotation output end of the object to be straightened through a concentric tooling.

[0017] As a preferred embodiment of the present invention, the rotation correction component further includes:

[0018] The control circuit and communication module are located outside the main housing of the slewing correction assembly. The control circuit is connected to the reference encoder and servo slewing system via cables. The main housing of the slewing correction assembly is provided with a support structure that allows the cables to rotate 360°.

[0019] Alternatively, the rotation correction component may also include:

[0020] The control circuit and wireless communication module are located inside the main housing of the slewing correction assembly. The main housing of the slewing correction assembly is equipped with an electric slip ring that connects to an external cable.

[0021] Alternatively, the rotation correction component may also include:

[0022] The control circuit, wireless communication module, and battery are housed inside the main housing of the slewing correction assembly.

[0023] In a second aspect of the present invention, a 360° precision angle correction method based on self-collimation tracking compensation is provided, employing the apparatus of the first aspect, the method comprising:

[0024] Step 11. Set the angle interval value via the host computer;

[0025] Step 12. The host computer determines the target angle value based on the current angle value and the angle interval value; the host computer sends a first rotation command to the object to be corrected based on the target angle value, and at the same time sends a second rotation command to the rotary correction component;

[0026] Step 13. The object to be calibrated controls the motor to rotate along the first direction based on the first rotation command until the detection angle value of the encoder to be calibrated is the target angle value. At the same time, the rotary correction component controls the servo rotary system to rotate along the second direction based on the second rotation command until the detection angle value of the reference encoder is the target angle value. The first direction and the second direction are opposite.

[0027] Step 14. The host computer obtains the deflection angle value through the autocollimator and combines the deflection angle value, the detection angle value of the reference encoder, and the detection angle value of the encoder to be calibrated into a data group.

[0028] Repeat steps 12 through 14 until the current angle value is 360°;

[0029] Step 15. Calculate the corresponding error compensation value based on each data set; generate an error compensation curve or error compensation table based on all error compensation values, and write the error compensation curve or error compensation table into the encoder or controller of the object to be calibrated.

[0030] As a preferred embodiment of the present invention, step 15, calculating the corresponding error compensation value based on each data set, specifically includes:

[0031] The sum of the deflection angle value and the detection angle value of the reference encoder is calculated as the actual rotation angle value of the object to be calibrated. The detection angle value of the encoder to be calibrated is then subtracted from the actual rotation angle value to obtain the error compensation value corresponding to the detection angle value of the encoder to be calibrated.

[0032] As a preferred embodiment of the present invention, in step 15, an error compensation curve or error compensation table is generated based on all error compensation values ​​and using an interpolation method.

[0033] In a third aspect of the present invention, a 360° precision angle correction method based on self-collimation tracking compensation is provided, employing the apparatus of the first aspect, the method comprising:

[0034] Step 21. Set the motor rotation speed of the object to be calibrated, the sampling frequency, and the target deflection angle value via the host computer;

[0035] Step 22. The host computer sends a rotation command to the object to be corrected based on the motor's rotation speed;

[0036] Step 23. The object to be calibrated controls the motor to rotate along the first direction at the set motor rotation speed based on the rotation command. The host computer controls the servo rotation system of the rotation correction component to rotate along the second direction so that the deflection angle value of the autocollimator is the target deflection angle value. The first direction and the second direction are opposite. At the same time, the host computer acquires the detection angle value of the reference encoder, the detection angle value of the encoder to be calibrated, and the actual deflection angle value of the autocollimator at the set sampling frequency, and combines the detection angle value of the reference encoder, the detection angle value of the encoder to be calibrated, and the actual deflection angle value of the autocollimator corresponding to the same sampling as a data group.

[0037] Step 24. Calculate the corresponding error compensation value based on each data set; generate an error compensation curve based on all error compensation values, and write the error compensation curve into the encoder or controller of the object to be calibrated.

[0038] As a preferred embodiment of the present invention, step 24, calculating the corresponding error compensation value based on each data set, specifically includes:

[0039] The sum of the actual deflection angle value and the detection angle value of the reference encoder is calculated as the actual rotation angle value of the object to be calibrated. The detection angle value of the encoder to be calibrated is then subtracted from the actual rotation angle value to obtain the error compensation value corresponding to the detection angle value of the encoder to be calibrated.

[0040] As a preferred embodiment of the present invention, in step 24, an error compensation curve is generated based on all error compensation values ​​and using a filtering and smoothing method.

[0041] As a preferred embodiment of the present invention, before performing step 11 or step 21, the method further includes: installing the object to be calibrated, the rotary correction component, the reflector, and the autocollimator; connecting the object to be calibrated, the rotary correction component, and the autocollimator to the host computer; and aligning the autocollimator with the center of the reflector.

[0042] In summary, the present invention has the following beneficial effects:

[0043] The device in this invention is not only an angle error measurement device, but also a precision correction device. After the measurement is completed, an error compensation curve can be directly generated and written into the encoder or controller of the object being corrected, which makes up for the shortcomings of traditional solutions that focus on testing while relying on third-party systems for the correction process.

[0044] The device of this invention has a wide range of applications and strong adaptability. It is not only suitable for single encoder accuracy correction, but also for robot joint module whole machine correction, and also for on-site correction of the rotary spindle of an assembled machine tool. The rotary correction component can be directly connected to the output end of the device under test without the need to connect to the frame, which greatly simplifies the correction and installation in this scenario.

[0045] The method of this invention provides two working modes: step-by-step high-precision full-point correction and continuous rapid calibration. The former uses indexing stepping combined with point-by-point precision measurement to obtain a high-precision error compensation curve, while the latter uses servo real-time tracking combined with synchronous sampling to greatly shorten the measurement time. The two modes can be flexibly selected according to accuracy requirements and cycle time requirements.

[0046] The method of this invention can improve the overall system-level accuracy of the calibrated object. The object to be calibrated is the actual angle of the output end of the rotating body, which includes all system factors such as encoder error, reducer transmission error, and assembly error. By performing error calibration and compensation at the whole machine level, the absolute positioning accuracy of the joint module can be significantly improved without replacing the high-precision encoder, achieving the goal of "medium-precision device + system calibration = high-precision whole machine".

[0047] Further or more detailed beneficial effects will be described in conjunction with specific embodiments in the detailed implementation. Attached Figure Description

[0048] Figure 1 This diagram shows the overall structure of a 360° precision angle correction device based on self-collimation tracking compensation according to an embodiment of the present invention.

[0049] Figure 2 An exploded view of a 360° precision angle correction device based on self-collimation tracking compensation according to an embodiment of the present invention is shown. Detailed Implementation

[0050] Embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. While some embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the invention. It should be understood that the accompanying drawings and embodiments are for illustrative purposes only and are not intended to limit the scope of protection of the invention.

[0051] In the description of embodiments of the present invention, the term "comprising" and similar terms should be understood as open-ended inclusion, i.e., "including but not limited to". The term "based on" should be understood as "at least partially based on". The term "one embodiment" or "the embodiment" should be understood as "at least one embodiment". The terms "first", "second", etc., may refer to different or the same objects. Other explicit and implicit definitions may also be included below.

[0052] This invention proposes a 360° precision angle correction device based on self-collimation tracking compensation, such as... Figure 1 and Figure 2 As shown, the device includes:

[0053] Mounting and fixing assembly 200 is used to mount and fix the object to be calibrated 100. The object to be calibrated 100 can be a single encoder, a robot joint, or an assembled machine tool rotary spindle, etc. Figure 1 , Figure 2This is a schematic diagram of the installation of a certain robot joint. In this embodiment, since the object to be corrected 100 is not of a unique type, the specific structure of the mounting and fixing component 200 is not limited, as long as it can be used to install and fix the object to be corrected 100.

[0054] The rotary straightening assembly 300 has its main housing connected to the rotational output end of the object to be straightened 100 via a concentric tool 600. In this embodiment, after the concentric tool 600 is connected to the object to be straightened 100, the central axis of the concentric tool 600 and the central axis of the object to be straightened 100 are collinear. When the output shaft of the object to be straightened 100 rotates, it can drive the main housing of the rotary straightening assembly 300 to rotate synchronously.

[0055] In this embodiment, the slewing correction component 300 specifically includes a reference encoder and a servo slewing system.

[0056] The reference encoder is located inside the main housing of the rotary correction assembly 300. The accuracy level of the reference encoder is more than an order of magnitude better than that of the encoder being corrected on the object to be corrected 100. In this embodiment, the reference encoder is a high-precision encoder (of course, the reference encoder can also be replaced by high-precision angle reference devices such as circular gratings, inductive synchronizers, and multi-tooth indexing tables), which can accurately detect the rotation angle of the drive shaft of the servo rotary system.

[0057] The servo rotation system is housed inside the main housing of the rotation correction assembly 300, and its drive shaft is connected to the reflector 400. In this embodiment, the servo rotation system is a high-precision motor, capable of precisely controlling the rotation of its drive shaft.

[0058] The reflector 400 is connected to the rotation output end of the rotation correction assembly 300, that is, connected to the drive shaft of the servo rotation system. The central axis of the drive shaft of the servo rotation system is perpendicular to the mirror normal of the reflector 400. In this embodiment, the reflector 400 is a plane reflector (of course, the reflector 400 can also be replaced by optical elements with self-collimating characteristics such as right-angle prisms or corner prisms).

[0059] The autocollimator 500, configured in conjunction with the reflector 400, is used to acquire the deflection angle value of the reflector 400. In this embodiment, the autocollimator 500 is a photoelectric autocollimator (of course, the autocollimator 500 can also be replaced by a laser autocollimator or a photoelectric goniometer with autocollimation function), with an angular resolution of 0.01 arcseconds and an effective measurement field of view of 4200 arcseconds (approximately 1.17°). When the normal of the plane reflector is aligned with the center of the photoelectric autocollimator (i.e., the reflector 400 is not deflected), the deflection angle value acquired by the autocollimator 500 is 0°; when the plane reflector is deflected (even by a very small amount), the photoelectric autocollimator can still accurately acquire the deflection angle value.

[0060] The host computer is connected to the object to be calibrated 100, the rotary correction component 300, and the autocollimator 500. In this embodiment, the host computer can be connected to the object to be calibrated 100 via cable, can be wirelessly connected to the rotary correction component 300, and can be connected to the autocollimator 500 via cable.

[0061] Working principle:

[0062] Taking a target angle value (e.g., 8°) as an example, initially, the mirror normal of the reflector 400 is aligned with the center of the autocollimator 500, and the deflection angle value obtained by the autocollimator 500 is 0°. At this time, the detection angle value of the encoder to be calibrated is 0°, and the detection angle value of the reference positive encoder is also 0°.

[0063] Then, the host computer controls the output shaft of the object to be calibrated 100 to rotate clockwise to 8°. The encoder of the object to be calibrated 100 can determine whether the output shaft of the object to be calibrated 100 has rotated clockwise to 8° (when the angle value of the encoder is 8°, it means that the output shaft of the object to be calibrated 100 has rotated to 8°). At the same time, the host computer controls the drive shaft of the servo rotary system of the rotary correction component 300 to rotate counterclockwise to 8°. The reference encoder of the rotary correction component 300 can determine whether the drive shaft of the servo rotary system has rotated counterclockwise to 8° (when the angle value of the reference positive encoder is 8°, it means that the drive shaft of the servo rotary system has rotated to 8°).

[0064] When the output shaft of the object to be calibrated 100 rotates clockwise by 8°, the main housing of the rotary correction assembly also rotates clockwise by 8° synchronously, and consequently, the reflector 400 also rotates clockwise by 8° synchronously. When the drive shaft of the servo rotary system rotates counterclockwise by 8°, the reflector 400 is simultaneously rotated counterclockwise by 8°. Theoretically, since the reflector 400 has been rotated both clockwise and counterclockwise by 8°, the reflector 400 has not deflected, and the deflection angle value obtained by the collimator 500 remains 0°.

[0065] However, there may be a deviation between the detected angle value of the encoder to be calibrated and the actual rotation angle value of the object 100 to be calibrated. Although the detected angle value of the encoder to be calibrated is 8°, the actual rotation angle value of the object 100 to be calibrated may not be 8°. Therefore, the reflector 400 deflects, resulting in the deflection angle value obtained by the autocollimator 500 being non-zero. The deflection angle value obtained by the autocollimator 500 can determine the error value when the detected angle value of the encoder to be calibrated is 8°. The error compensation value when the detected angle value of the encoder to be calibrated is 8° can then be determined.

[0066] For example, assuming the deflection angle value obtained by the autocollimator 500 is 0.1°, adding the detection angle value of the reference positive encoder (i.e., 8°) to the deflection angle value obtained by the autocollimator 500 (i.e., 0.1°) yields the actual rotation angle value of the object to be calibrated 100, which is 8.1°. Subtracting the detection angle value of the encoder to be calibrated (i.e., 8°) from the actual rotation angle value of the object to be calibrated 100 (i.e., 8.1°) yields the error compensation value (i.e., 0.1°) when the detection angle value of the encoder to be calibrated is 8°.

[0067] This can also be understood as the deflection angle value obtained by the autocollimator 500 being the error compensation value of the encoder to be calibrated. In other words, the device in this embodiment only needs to control the output end of the object to be calibrated 100 to rotate clockwise to the target angle value, and simultaneously control the drive shaft of the servo rotary system to rotate counterclockwise to the target value. This allows the error compensation value of the encoder to be calibrated when the detection angle value is the target angle value to be determined using the deflection angle value obtained by the autocollimator 500.

[0068] Furthermore, the rotation correction component 300 in this embodiment also includes:

[0069] The control circuit and communication module are located outside the main housing of the slewing correction assembly 300. The control circuit is connected to the reference encoder and servo slewing system via cables. The main housing of the slewing correction assembly 300 has a support structure that allows the cables to rotate 360°. Because the communication module is located outside the main housing of the slewing correction assembly 300 and can be fixed in place, the communication module can communicate wirelessly or via wired connection with the host computer.

[0070] Alternatively, the slewing correction assembly 300 may also include:

[0071] The control circuit and wireless communication module are located inside the main housing of the slewing correction assembly 300. The main housing of the slewing correction assembly 300 is provided with an electric slip ring that connects to an external cable.

[0072] Alternatively, the slewing correction assembly 300 may also include:

[0073] The control circuit, wireless communication module, and battery are housed inside the main housing of the slewing correction assembly 300.

[0074] This invention proposes a 360° precision angle correction method based on self-collimation tracking compensation, employing the device described in the first embodiment. The method includes:

[0075] Step 11. Set the angle interval value via the host computer.

[0076] This embodiment assumes an angle interval of 10°.

[0077] Step 12. The host computer determines the target angle value based on the current angle value and the angle interval value; the host computer sends a first rotation command to the object to be corrected 100 based on the target angle value, and at the same time sends a second rotation command to the rotary correction component 300.

[0078] In this embodiment, the target angle value is equal to the current angle value plus the angle interval value. Assuming the current angle value is 0°, then the target angle value is 10°. Specifically, the first rotation command can be a rotation along a first direction (e.g., clockwise) to the target angle value, and the second rotation command can be a rotation along a second direction (e.g., counterclockwise) to the target angle value. The first and second directions need to be opposite.

[0079] Step 13. The object to be calibrated 100 controls the motor to rotate along the first direction based on the first rotation command until the detection angle value of the encoder to be calibrated is the target angle value. At the same time, the rotary correction component 300 controls the servo rotary system to rotate along the second direction based on the second rotation command until the detection angle value of the reference encoder is the target angle value. The first direction and the second direction are opposite.

[0080] In this embodiment, the motor of the object to be calibrated 100 stops rotating when the detection angle value of the encoder to be calibrated is 10°, and the servo rotary system of the rotary correction component 300 stops rotating when the detection angle value of the reference encoder is 10°.

[0081] Step 14. The host computer obtains the deflection angle value through the autocollimator 500 and combines the deflection angle value, the detection angle value of the reference encoder, and the detection angle value of the encoder to be calibrated into a data group.

[0082] In this embodiment, assuming that the deflection angle value currently acquired by the autocollimator 500 is 0.2°, then "0.2°, 10°, 10°" will be treated as a data group.

[0083] Repeat steps 12 through 14 until the current angle value is 360°.

[0084] The method in this embodiment requires repeating steps 12 to 14 until the detection angle value of the encoder to be calibrated and the reference encoder is 360°. At this point, a total of 36 data sets have been acquired.

[0085] Step 15. Calculate the corresponding error compensation value based on each data set; generate an error compensation curve or error compensation table based on all error compensation values, and write the error compensation curve or error compensation table into the encoder or controller of the object to be calibrated 100.

[0086] In step 15 of this embodiment, calculating the corresponding error compensation value based on each data set specifically includes:

[0087] The sum of the deflection angle value and the detection angle value of the reference encoder is calculated as the actual rotation angle value of the object to be calibrated 100. The detection angle value of the encoder to be calibrated is subtracted from the actual rotation angle value to obtain the error compensation value corresponding to the detection angle value of the encoder to be calibrated.

[0088] Assuming a data set is "0.1°, 20°, 20°", the deflection angle is 0.1°, the detection angle of the reference encoder is 20°, and the actual rotation angle of the object to be calibrated 100 is 20.1° (the deflection angle is added to the detection angle of the reference encoder). The detection angle of the encoder to be calibrated is 20°, and the error compensation value for the encoder to be calibrated corresponding to "20°" is 0.1° (the actual rotation angle of the object to be calibrated 100 is subtracted from the detection angle value of the encoder to be calibrated). The error compensation values ​​for other detection angle values ​​of the encoder to be calibrated are calculated similarly. This embodiment ultimately yields 36 error compensation values.

[0089] In this embodiment, after obtaining 36 error compensation values, the host computer generates an error compensation curve (which can be represented by a formula) or an error compensation table through interpolation, and directly writes the error compensation curve or table into the encoder or controller of the object to be calibrated 100. In subsequent use, assuming the detection angle of the encoder to be calibrated is 6.6°, substituting 6.6° into the formula of the error compensation curve or using a lookup table yields the corresponding error compensation value. Adding the corresponding error compensation value to 6.6° gives the actual rotation angle of the object to be calibrated 100.

[0090] In addition, this embodiment includes the following steps before performing step 11: installing the object to be calibrated 100, the rotary correction component 300, the reflector 400, and the autocollimator 500; connecting the object to be calibrated 100, the rotary correction component 300, and the autocollimator 500 to the host computer; and aligning the autocollimator 500 with the center of the reflector 400. This ensures that before performing step 11, the deflection angle value obtained by the autocollimator 500 is 0°, the detection angle value of the encoder to be calibrated is 0°, and the detection angle value of the reference positive encoder is also 0°.

[0091] This invention proposes a 360° precision angle correction method based on self-collimation tracking compensation, employing the device described in the first embodiment. The method includes:

[0092] Step 21. Set the motor rotation speed of the object to be calibrated 100, the sampling frequency, and the target deflection angle value through the host computer.

[0093] This embodiment assumes that the set motor rotation speed is 0.5 rpm, the set sampling frequency is 100 Hz, and the set target deflection angle is 0°.

[0094] Step 22. The host computer sends a rotation command to the object to be corrected 100 based on the motor rotation speed.

[0095] In this embodiment, the rotation command can specifically be to rotate in a first direction (e.g., clockwise) at a rotation speed of 0.5 rpm.

[0096] Step 23. The object to be calibrated 100 controls the motor to rotate along the first direction at the set motor rotation speed based on the rotation command. The host computer controls the servo rotation system of the rotation correction component 300 to rotate along the second direction so that the deflection angle value of the autocollimator 500 is the target deflection angle value. The first direction and the second direction are opposite. At the same time, the host computer acquires the detection angle value of the reference encoder, the detection angle value of the encoder to be calibrated, and the actual deflection angle value of the autocollimator 500 at the set sampling frequency, and combines the detection angle value of the reference encoder, the detection angle value of the encoder to be calibrated, and the actual deflection angle value of the autocollimator 500 corresponding to the same sampling as a data group.

[0097] In this embodiment, the motor of the object to be calibrated 100 rotates at a speed of 0.5 rpm along a first direction (e.g., clockwise) until the detection angle value of the encoder to be calibrated is 360°. In order to make the deflection angle value of the autocollimator 500 0°, the host computer will control the servo rotation system of the rotation correction component 300 to rotate along a second direction (e.g., counterclockwise), or in other words, the host computer will try to keep the deflection angle value of the autocollimator 500 stable at 0° by using a combination of feedforward and feedback control of the servo rotation system.

[0098] From the moment the motor of the object to be calibrated 100 starts rotating until it stops rotating, the host computer acquires the detection angle value of the reference encoder, the detection angle value of the encoder to be calibrated, and the actual deflection angle value of the autocollimator 500 at a sampling frequency of 100Hz (i.e., once every 0.01 seconds). Although the target deflection angle value of the autocollimator 500 is 0°, in actual execution, there may be a slight deviation from 0°. For example, the actual deflection angle value of the autocollimator 500 may be 0.01°.

[0099] For example, during a certain sampling, the obtained detection angle value of the reference encoder is 8°, the obtained detection angle value of the encoder to be calibrated is 7.96°, and the obtained actual deflection angle value of the autocollimator 500 is 0.01°. In this embodiment, "8°, 7.96°, 0.01°" is treated as a data group.

[0100] When the rotation speed of the motor of the object to be calibrated 100 is 0.5 rpm and the frequency is 100 Hz, the final number of data sets obtained is 12,000.

[0101] Step 24. Calculate the corresponding error compensation value based on each data set; generate an error compensation curve based on all error compensation values, and write the error compensation curve into the encoder or controller of the object to be calibrated 100.

[0102] In step 24 of this embodiment, the sum of the actual deflection angle value and the detection angle value of the reference encoder is calculated as the actual rotation angle value of the object to be corrected 100. The detection angle value of the encoder to be corrected is subtracted from the actual rotation angle value to obtain the error compensation value corresponding to the detection angle value of the encoder to be corrected.

[0103] Assuming a data set is "8°, 7.96°, 0.01°", the reference encoder's detection angle is 8°, the actual deflection angle is 0.01°, and the actual rotation angle of the object to be calibrated 100 is 8.01° (the actual deflection angle is added to the reference encoder's detection angle). The encoder to be calibrated has a detection angle of 7.96°, and the error compensation value corresponding to "7.96°" is 0.05° (the actual rotation angle of the object to be calibrated 100 is subtracted from the encoder's detection angle). The error compensation values ​​for other detection angle values ​​of the encoder to be calibrated are calculated similarly. This embodiment ultimately yields 12,000 error compensation values.

[0104] In this embodiment, after acquiring 12,000 error compensation values, the host computer generates an error compensation curve (which can be represented by a formula) through filtering and smoothing, and directly writes the error compensation curve into the encoder or controller of the object to be calibrated 100. In subsequent use, assuming the detection angle of the encoder to be calibrated is 7.7°, substituting 7.7° into the formula for the error compensation curve yields the corresponding error compensation value. Adding the corresponding error compensation value to 7.7° gives the actual rotation angle of the object to be calibrated 100.

[0105] In addition, before performing step 21, this embodiment further includes: installing the object to be calibrated 100, the rotary correction component 300, the reflector 400, and the autocollimator 500; connecting the object to be calibrated 100, the rotary correction component 300, and the autocollimator 500 to the host computer; and aligning the autocollimator 500 with the center of the reflector 400. This ensures that before performing step 21, the deflection angle value obtained by the autocollimator 500 is 0°, the detection angle value of the encoder to be calibrated is 0°, and the detection angle value of the reference positive encoder is also 0°.

[0106] Although the subject matter has been described using language specific to structural features and / or methodological logic, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or actions described above. Rather, the specific features and actions described above are merely illustrative examples of implementing the claims.

Claims

1. A 360° precision angle correction device based on self-collimation tracking compensation, characterized in that, include: Mounting and fixing components (200) are used to mount and fix the object to be calibrated (100); A rotary correction assembly (300) has its main housing connected to the rotation output end of the object to be corrected (100); A reflector (400) is connected to the rotation output end of the rotary correction assembly (300); An autocollimator (500) is configured in conjunction with the reflector (400) to obtain the deflection angle value of the reflector (400); The host computer is connected to the object to be calibrated (100), the rotary correction component (300), and the autocollimator (500); The rotation correction assembly (300) includes: A reference encoder is disposed inside the main housing of the rotary correction assembly (300), and the accuracy level of the reference encoder is better than that of the encoder to be corrected of the object to be corrected (100). A servo rotation system is disposed inside the main housing of the rotation correction component (300), and the drive shaft of the servo rotation system is connected to the reflector (400).

2. The apparatus according to claim 1, characterized in that, The main housing of the rotary straightening assembly (300) is connected to the rotation output end of the object to be straightened (100) via a concentric tooling (600).

3. The apparatus according to claim 1, characterized in that, The rotary correction assembly (300) also includes: The control circuit and communication module are located outside the main housing of the slewing correction assembly (300). The control circuit is connected to the reference encoder and the servo slewing system via a cable. The main housing of the slewing correction assembly (300) is provided with a support structure that allows the cable to rotate 360°. Alternatively, the slewing correction assembly (300) may further include: The control circuit and wireless communication module are disposed inside the main housing of the rotary straightening assembly (300), and the main housing of the rotary straightening assembly (300) is provided with an electric slip ring connected to an external cable; Alternatively, the slewing correction assembly (300) may further include: The control circuit, wireless communication module, and battery are disposed inside the main housing of the slewing correction assembly (300).

4. A 360° precision angle correction method based on self-collimation tracking compensation, employing the device described in any one of claims 1 to 3, characterized in that, include: Step 11. Set the angle interval value via the host computer; Step 12. The host computer determines the target angle value based on the current angle value and the angle interval value; the host computer sends a first rotation command to the object to be corrected (100) based on the target angle value, and at the same time sends a second rotation command to the rotary correction component (300); Step 13. The object to be calibrated (100) controls the motor to rotate along the first direction based on the first rotation command until the detection angle value of the encoder to be calibrated is the target angle value. At the same time, the rotary correction component (300) controls the servo rotary system to rotate along the second direction based on the second rotation command until the detection angle value of the reference encoder is the target angle value. The first direction and the second direction are opposite. Step 14. The host computer obtains the deflection angle value through the autocollimator (500) and combines the deflection angle value, the detection angle value of the reference encoder, and the detection angle value of the encoder to be calibrated into a data group; Repeat steps 12 through 14 until the current angle value is 360°; Step 15. Calculate the corresponding error compensation value based on each data set; generate an error compensation curve or error compensation table based on all error compensation values, and write the error compensation curve or error compensation table into the encoder or controller of the object to be calibrated (100).

5. The method according to claim 4, characterized in that, In step 15, calculating the corresponding error compensation value based on each data set specifically includes: The sum of the deflection angle value and the detection angle value of the reference encoder is calculated as the actual rotation angle value of the object to be calibrated (100). The detection angle value of the encoder to be calibrated is subtracted from the actual rotation angle value to obtain the error compensation value corresponding to the detection angle value of the encoder to be calibrated.

6. The method according to claim 4, characterized in that, In step 15, an error compensation curve or error compensation table is generated based on all error compensation values ​​and using interpolation.

7. A 360° precision angle correction method based on self-collimation tracking compensation, employing the device described in any one of claims 1 to 3, characterized in that, include: Step 21. Set the motor rotation speed of the object to be corrected (100), the sampling frequency, and the target deflection angle value through the host computer; Step 22. The host computer sends a rotation command to the object to be corrected (100) based on the motor's rotation speed; Step 23. The object to be calibrated (100) controls the motor to rotate along the first direction at the set motor rotation speed based on the rotation command. The host computer controls the servo rotation system of the rotation correction component (300) to rotate along the second direction so that the deflection angle value of the autocollimator (500) is the target deflection angle value. The first direction and the second direction are opposite. At the same time, the host computer obtains the detection angle value of the reference encoder, the detection angle value of the encoder to be calibrated, and the actual deflection angle value of the autocollimator (500) at the set sampling frequency, and takes the detection angle value of the reference encoder, the detection angle value of the encoder to be calibrated, and the actual deflection angle value of the autocollimator (500) corresponding to the same sampling as a data group. Step 24. Calculate the corresponding error compensation value based on each data set; generate an error compensation curve based on all error compensation values, and write the error compensation curve into the encoder or controller of the object to be calibrated (100).

8. The method according to claim 7, characterized in that, In step 24, calculating the corresponding error compensation value based on each data set specifically includes: The sum of the actual deflection angle value and the detection angle value of the reference encoder is calculated as the actual rotation angle value of the object to be calibrated (100). The detection angle value of the encoder to be calibrated is subtracted from the actual rotation angle value to obtain the error compensation value corresponding to the detection angle value of the encoder to be calibrated.

9. The method according to claim 7, characterized in that, In step 24, an error compensation curve is generated based on all error compensation values ​​and using a filtering and smoothing method.

10. The method according to claim 4 or 7, characterized in that, Before performing step 11 or step 21, the following steps are also included: installing the object to be calibrated (100), the rotary correction component (300), the reflector (400), and the autocollimator (500); connecting the object to be calibrated (100), the rotary correction component (300), and the autocollimator (500) to the host computer; and aligning the autocollimator (500) with the center of the reflector (400).

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