A method for finishing the peripheral surface of a workpiece using an angular positioning tool

Abstract

The application discloses a circumferential surface finishing method using an angular positioning tool, and relates to the technical field of grinding and polishing. The method comprises the following steps: in response to obtaining the real-time stress of a target workpiece, a first stress inhibition coefficient is determined based on the real-time stress of the workpiece and the average stress of the workpiece in a target machining stage; the basic thermal expansion coefficient of the workpiece in the target machining stage is corrected based on the first stress inhibition coefficient to obtain the real-time effective thermal expansion coefficient of the target workpiece; the theoretical angular displacement of the target workpiece is determined based on the real-time effective thermal expansion coefficient and the first workpiece temperature of the target workpiece; the monitoring angular displacement of the target workpiece obtained through monitoring and the theoretical angular displacement are weighted and summed to obtain the fusion angular displacement of the target workpiece; and the workpiece rotation angle of the target workpiece in the circumferential surface finishing process is adaptively compensated based on the fusion angular displacement of the target workpiece. The application can improve the finishing accuracy of the circumferential surface.

Description

Technical Field

[0001] This invention relates to the field of grinding and polishing technology, and specifically to a method for finishing circumferential surfaces using angular positioning fixtures. Background Technology

[0002] In the manufacturing of precision components such as bearings and gears, circumferential surface finishing is a core process to ensure product accuracy. Angular positioning fixtures are specialized tooling fixtures designed specifically for circumferential surface finishing scenarios such as grinding and polishing. Their core function is to precisely restrict the workpiece's rotational freedom around its own axis through specific mechanical structures and positioning logic, ensuring that the workpiece's angular position in the circumferential direction is perfectly aligned with the machining datum, providing a stable angular reference for subsequent high-precision circumferential surface machining.

[0003] Currently, angular positioning fixtures typically use clamping mechanisms and positioning elements to fix the workpiece at a preset angle position, thereby establishing a unified machining angle origin and reducing angular errors in circumferential surface machining.

[0004] However, existing technologies rely solely on mechanical structures for positioning, neglecting the dynamic correlation between temperature and positioning deviation. During grinding, polishing, and other machining processes, frictional heat causes thermal expansion and contraction of the tooling and workpiece, resulting in dynamic drift of the angular reference and thus reducing the finishing accuracy of the circumferential surface. Summary of the Invention

[0005] This invention provides a method for finishing circumferential surfaces using angular positioning fixtures, which can improve the finishing accuracy of circumferential surfaces.

[0006] A first aspect of the present invention provides a method for finishing a circumferential surface using an angular positioning fixture, comprising:

[0007] In response to obtaining the real-time stress of the target workpiece at the current moment, a first stress suppression coefficient is determined based on the real-time stress of the workpiece and the average stress of the workpiece at the current target processing stage; the first stress suppression coefficient is used to reflect the strength of the influence of the processing stress at the current moment on the thermal expansion effect.

[0008] Based on the first stress suppression coefficient, the basic thermal expansion coefficient of the workpiece in the target processing stage is corrected to obtain the real-time effective thermal expansion coefficient of the target workpiece at the current moment.

[0009] Based on the real-time effective thermal expansion coefficient and the first workpiece temperature of the target workpiece at the current moment, the theoretical angular offset of the target workpiece at the current moment is determined.

[0010] The monitored angle offset and the theoretical angle offset of the target workpiece at the current moment are weighted and summed to obtain the fused angle offset of the target workpiece at the current moment.

[0011] Based on the fusion angle offset of the target workpiece at the current moment, adaptive compensation is performed on the workpiece rotation angle during the circumferential surface finishing process.

[0012] Furthermore, the present invention also proposes determining a first stress suppression coefficient at the current moment based on the real-time stress of the workpiece and the average stress of the workpiece at the current target processing stage, including:

[0013] Get the current processing progress value;

[0014] Based on the current processing progress value and the real-time stress of the workpiece, determine the second stress suppression coefficient at the current moment;

[0015] The first correction factor is obtained by dividing the average stress of the workpiece in the target processing stage by the real-time stress of the workpiece.

[0016] Based on the first correction factor, the second stress suppression factor is corrected to obtain the first stress suppression factor at the current moment.

[0017] Furthermore, the present invention also proposes obtaining the processing progress value at the current moment, including:

[0018] Obtain the historical average feed rate and historical average number of revolutions for each historical processing cycle;

[0019] The first ratio is obtained by dividing the current real-time feed by the historical average feed, and the second ratio is obtained by dividing the current real-time rotation count by the historical average rotation count.

[0020] The processing progress value at the current moment is obtained by averaging the first ratio and the second ratio.

[0021] Furthermore, the present invention also proposes to correct the basic thermal expansion coefficient of the workpiece in the target processing stage based on the first stress suppression coefficient, so as to obtain the real-time effective thermal expansion coefficient of the target workpiece at the current moment, including:

[0022] The temperature change rate is obtained by dividing the difference between the temperature of the first workpiece and the temperature of the standard workpiece at the current moment by the temperature of the standard workpiece.

[0023] The second correction coefficient is determined based on the degree of temperature change and the temperature sensitivity coefficient of the target workpiece;

[0024] Multiply the first stress suppression coefficient, the workpiece's basic thermal expansion coefficient, and the second correction coefficient to obtain the target workpiece's real-time effective thermal expansion coefficient at the current moment.

[0025] Furthermore, the present invention also proposes that, before determining the theoretical angular offset of the target workpiece at the current moment based on the real-time effective thermal expansion coefficient and the first workpiece temperature of the target workpiece at the current moment, the invention further includes:

[0026] Based on the current ambient temperature and workpiece surface temperature, determine the internal temperature of the target workpiece at the current moment.

[0027] The temperature compensation value of the target workpiece at the current moment is obtained by multiplying the difference between the surface temperature and the internal temperature of the workpiece by the temperature distribution uniformity of the target workpiece.

[0028] Adding the internal temperature of the workpiece to the temperature compensation value, we obtain the first workpiece temperature of the target workpiece at the current moment.

[0029] Furthermore, the present invention also proposes that, before multiplying the difference between the workpiece surface temperature and the workpiece internal temperature by the temperature distribution uniformity of the target workpiece to obtain the temperature compensation value of the target workpiece at the current moment, the method further includes:

[0030] The variance of the internal temperature of the target workpiece during the i-th historical processing is calculated to obtain the temperature distribution coefficient of the target workpiece during the i-th historical processing; where i is a positive integer.

[0031] The temperature distribution uniformity of the target workpiece is obtained by averaging the various temperature distribution coefficients.

[0032] Furthermore, the present invention also proposes that, before correcting the basic thermal expansion coefficient of the workpiece in the target processing stage based on the first stress suppression coefficient to obtain the real-time effective thermal expansion coefficient of the target workpiece at the current moment, the invention further includes:

[0033] Based on the first workpiece temperature, the standard workpiece temperature, and the temperature sensitivity coefficient of the target workpiece at each moment in the target processing stage of the i-th historical processing process, the initial thermal expansion coefficient of the target workpiece at each moment in the target processing stage of the i-th historical processing process is determined; where i is a positive integer.

[0034] Based on the surface temperature of the target workpiece at each moment in the target processing stage of the i-th historical processing process, and the corresponding predicted surface temperature obtained by the temperature prediction model, the thermal expansion coefficient analysis weight of the target workpiece in the target processing stage of the i-th historical processing process is determined.

[0035] Based on the initial thermal expansion coefficient of the target workpiece at each moment in the target processing stage of each historical processing process, and the analysis weight of the thermal expansion coefficient of the target workpiece in the target processing stage of each historical processing process, the basic thermal expansion coefficient of the target workpiece in the target processing stage is determined.

[0036] Furthermore, the present invention also proposes that, before determining the thermal expansion coefficient analysis weight of the target workpiece in the target processing stage of the i-th historical processing process based on the workpiece surface temperature at each moment in the target processing stage of the i-th historical processing process and the corresponding predicted surface temperature obtained through the temperature prediction model, the method further includes:

[0037] Based on the surface temperature of the target workpiece at each moment in the target processing stage of the i-th historical processing process, determine the first temperature rise rate of the target workpiece in the target processing stage of the i-th historical processing process.

[0038] Based on the first temperature rise rate, average ambient temperature, and average workpiece surface temperature of the target workpiece in the target processing stage of each historical processing process, the second temperature rise rate of the target workpiece in the target processing stage is determined.

[0039] Based on the second temperature rise rate of the target workpiece in the target processing stage and the maximum temperature of the target workpiece in the target processing stage, a temperature prediction model for the target workpiece in the target processing stage is constructed.

[0040] Furthermore, the present invention also proposes that, before weighted summing the monitored angle offset and theoretical angle offset of the target workpiece at the current moment to obtain the fused angle offset of the target workpiece at the current moment, the method further includes:

[0041] The variance of the monitoring angle offset of the target workpiece during the historical processing is calculated to obtain the actual variance of the offset;

[0042] Based on the actual variance of the offset and the corresponding allowable variance of the offset, the first weight value of the monitored angle offset and the second weight value of the theoretical angle offset are determined.

[0043] Furthermore, the present invention also proposes that the method further includes:

[0044] In response to the triggering conditions of the quality sampling inspection process, a quality sampling inspection is carried out on the target workpiece that has completed the circumferential surface finishing, and the quality inspection results are obtained.

[0045] In response to the quality inspection results indicating that the workpiece is not up to standard, the parameter correction process for the circumferential surface finishing process is triggered.

[0046] The present invention has the following beneficial effects:

[0047] In the circumferential surface finishing method using angular positioning fixtures provided in this invention embodiment, a first stress suppression coefficient is first determined based on the workpiece's real-time stress and the workpiece's average stress at the current target machining stage. This coefficient reflects the strength of the influence of machining stress on thermal expansion. Next, the workpiece's basic thermal expansion coefficient is corrected using the first stress suppression coefficient to obtain the real-time effective thermal expansion coefficient, which more accurately reflects the degree of thermal expansion and contraction affecting the workpiece at the current moment. Then, a theoretical angle offset is determined based on the real-time effective thermal expansion coefficient and the first workpiece temperature. Finally, the monitored angle offset and the theoretical angle offset are weighted and summed to obtain the fused angle offset. Finally, the workpiece rotation angle is adaptively compensated based on the fused angle offset. Thus, through this series of operations, the influence of thermal expansion and contraction caused by temperature changes on the angle reference is considered, and dynamic adjustment and compensation are performed, thereby effectively reducing the dynamic drift of the angle reference and improving the finishing accuracy of the circumferential surface. Attached Figure Description

[0048] To more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0049] Figure 1 This is a flowchart illustrating a method for finishing a circumferential surface using an angular positioning fixture, as provided in an embodiment of the present invention.

[0050] Figure 2 This is a schematic diagram illustrating the process for determining the first stress suppression coefficient according to an embodiment of the present invention. Detailed Implementation

[0051] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effects of a circumferential surface finishing method using an angular positioning fixture proposed according to the present invention. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0052] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0053] In traditional angular positioning fixture applications, the workpiece's angular position is fixed solely by mechanical structure, without establishing a dynamic correlation model between temperature changes and positioning deviations. Furthermore, frictional heat during machining causes thermal expansion and contraction of the fixture and workpiece, resulting in dynamic drift of the angular reference, which in turn affects the accuracy and stability of the circumferential surface finishing.

[0054] If the aforementioned angular reference drift problem is not resolved, the workpiece will be unable to maintain a stable machining reference during the finishing process, which will cause the geometric deviation of the circumferential surface to exceed the tolerance range, thereby reducing the product qualification rate and causing assembly and fit problems.

[0055] In this regard, such as Figure 1 As shown, the present invention provides a flowchart of a method for finishing circumferential surfaces using an angular positioning fixture. This method for finishing circumferential surfaces using an angular positioning fixture is applied to electronic devices and includes the following steps S100 to S500:

[0056] S100, in response to obtaining the real-time stress of the target workpiece at the current moment, based on the real-time stress of the workpiece and the average stress of the workpiece at the current target processing stage, a first stress suppression coefficient is determined at the current moment; the first stress suppression coefficient is used to reflect the strength of the influence of the processing stress at the current moment on the thermal expansion effect.

[0057] S200, based on the first stress suppression coefficient, corrects the basic thermal expansion coefficient of the workpiece in the target processing stage to obtain the real-time effective thermal expansion coefficient of the target workpiece at the current moment.

[0058] S300, based on the real-time effective thermal expansion coefficient and the first workpiece temperature of the target workpiece at the current moment, determines the theoretical angular offset of the target workpiece at the current moment;

[0059] S400: The monitored angle offset and theoretical angle offset of the target workpiece at the current moment are weighted and summed to obtain the fused angle offset of the target workpiece at the current moment.

[0060] S500 adaptively compensates for the workpiece rotation angle during the circumferential surface finishing process based on the fusion angle offset of the target workpiece at the current moment.

[0061] For ease of understanding, the following explains some key terms in this embodiment:

[0062] An angular positioning fixture is a type of clamping tool specifically designed for precision machining of circumferential surfaces. Its main function is to precisely restrict the rotational freedom of the workpiece around its own axis through mechanical structure and positioning logic, thereby ensuring that the angular position of the workpiece in the circumferential direction is aligned with the machining datum, providing a stable angular datum for high-precision circumferential surface machining.

[0063] Circumferential surface finishing refers to the process of high-precision machining of the circumferential surfaces of precision parts such as bearings and gears, aiming to achieve strict dimensional accuracy and surface quality requirements.

[0064] Real-time stress in a workpiece refers to the internal or external stress state experienced by the target workpiece at a given moment during the finishing process of a circumferential surface. This stress can be monitored in real time using sensors installed on the workpiece or tooling, such as strain gauges or piezoelectric sensors.

[0065] The target machining stage refers to a specific time period or process stage in the finishing of a circumferential surface, such as the initial, middle, or final stage of machining. The physical properties and stress conditions of the workpiece may differ at different machining stages.

[0066] The average stress of a workpiece refers to the average stress experienced by the target workpiece during a specific target machining stage. This average value can be obtained through statistical analysis of historical machining data.

[0067] The first stress suppression coefficient is a quantitative indicator used to reflect the influence of stress generated during processing on the thermal expansion effect of the workpiece at the current moment. The magnitude of this first stress suppression coefficient indicates the strength of the stress's influence on the thermal expansion effect.

[0068] The basic coefficient of thermal expansion of a workpiece refers to the inherent coefficient of thermal expansion of the target workpiece material under standard conditions. For example, this basic coefficient of thermal expansion can be obtained through material testing or by consulting a material handbook, reflecting the fundamental characteristic of the material's deformation under temperature changes.

[0069] The real-time effective coefficient of thermal expansion refers to the actual coefficient of thermal expansion exhibited by the target workpiece at the current processing moment, after considering the effect of processing stress suppression. This real-time effective coefficient of thermal expansion is a modified version of the basic coefficient of thermal expansion, more accurately reflecting the thermal expansion characteristics of the workpiece under actual processing conditions.

[0070] The first workpiece temperature refers to the actual temperature of the target workpiece at the current moment. This first workpiece temperature can be measured in real time using temperature sensors such as non-contact infrared thermometers or contact thermocouples.

[0071] Theoretical angular offset refers to the angular deviation of the workpiece in the circumferential direction caused by the thermal expansion and contraction effect, calculated by a physical model based on the workpiece's real-time effective thermal expansion coefficient and current temperature.

[0072] Monitoring angular offset refers to the actual angular deviation of a target workpiece relative to a preset reference at a given moment, as monitored in real time by a high-precision angle sensor or vision measurement system.

[0073] The fused angle offset refers to the comprehensive angle deviation obtained by weighting and combining the theoretical angle offset and the monitored angle offset. This fused angle offset aims to reflect the actual angle deviation of the workpiece more comprehensively and accurately.

[0074] The workpiece rotation angle refers to the angle by which the target workpiece rotates around its own axis during the finishing process of a circular surface. Precise control of this angle is crucial for ensuring machining accuracy.

[0075] Adaptive compensation refers to the process of dynamically adjusting the workpiece rotation angle based on the fusion angle offset obtained through real-time monitoring and calculation. This compensation mechanism enables the machining process to be adjusted according to the actual state of the workpiece, thereby offsetting or reducing machining errors caused by angular offset.

[0076] To facilitate understanding, the main features of the above technical solution will be described in more detail below:

[0077] In the finishing process of a circular surface, it is necessary to respond to the real-time stress of the target workpiece at the current moment, and determine the first stress suppression coefficient based on the real-time stress and the average stress of the workpiece at the current machining stage. This first stress suppression coefficient reflects the strength of the influence of the machining stress on the thermal expansion effect. For example, it can be determined using a pre-established stress-suppression coefficient lookup table. When the real-time stress and the average stress of the workpiece are within a specific range, the corresponding first stress suppression coefficient value can be directly found in the lookup table. Alternatively, a simple linear model can be used to calculate the first stress suppression coefficient based on the real-time stress and the average stress of the workpiece.

[0078] Furthermore, based on the first stress suppression coefficient, the basic thermal expansion coefficient of the workpiece at the target processing stage is corrected to obtain the real-time effective thermal expansion coefficient of the target workpiece at the current moment. For example, a fixed correction factor can be set, and when the first stress suppression coefficient reaches a certain threshold, the basic thermal expansion coefficient of the workpiece is multiplied by the correction factor. Alternatively, the first stress suppression coefficient and the basic thermal expansion coefficient of the workpiece can be linearly superimposed or subtracted to obtain the real-time effective thermal expansion coefficient.

[0079] Based on this, the theoretical angular offset of the target workpiece at the current moment is determined using the real-time effective thermal expansion coefficient and the initial workpiece temperature. For example, the initial workpiece temperature can be directly measured by fixing a temperature sensor to the workpiece surface. The theoretical angular offset can be calculated using a simplified thermal expansion formula, based on the real-time effective thermal expansion coefficient, the initial workpiece temperature, and the workpiece's geometric dimensions, to estimate the angular change caused by thermal expansion, i.e., the theoretical angular offset. For instance, the theoretical angular offset can be determined by multiplying the real-time effective thermal expansion coefficient, the initial workpiece temperature, and the initial angle value of the target workpiece.

[0080] Simultaneously, the monitored angle offset and the theoretical angle offset of the target workpiece at the current moment are weighted and summed to obtain the fused angle offset of the target workpiece at the current moment. For example, a fixed weight value can be preset for the monitored angle offset and the theoretical angle offset, such as each accounting for 50%, or a fixed ratio can be set based on experience, and then the two are weighted and summed to obtain the fused angle offset.

[0081] Finally, based on the fusion angle offset of the target workpiece at the current moment, adaptive compensation is performed on the workpiece rotation angle during the circumferential surface finishing process. For example, a simple proportional controller can be used to directly multiply the fusion angle offset by a fixed proportional gain, and then the calculated compensation amount is directly applied to the workpiece rotation angle.

[0082] The following example will provide a more detailed explanation of the above technical solution:

[0083] Suppose that in a precision parts manufacturing plant, a target workpiece is undergoing circumferential surface finishing, such as high-precision grinding. During the grinding process, the friction between the tool and the workpiece generates heat, causing the workpiece temperature to rise. This, in turn, triggers the thermal expansion and contraction effect, causing the actual angular position of the workpiece to deviate, thus affecting the machining accuracy.

[0084] To address this issue, the method of this embodiment is applied to the finishing process. First, during machining, stress sensors mounted on the workpiece or fixture acquire the real-time stress of the target workpiece at the current moment. Simultaneously, the system retrieves the average stress of the workpiece at the current machining stage from historical data. Based on these real-time and average stress data, the system calculates a first stress suppression coefficient for the current moment. This first stress suppression coefficient can be calculated using a preset empirical formula or a lookup table method.

[0085] Subsequently, the calculated first stress suppression coefficient is used to correct the workpiece's basic thermal expansion coefficient preset for this target machining stage. This correction reflects the difference between the workpiece's thermal expansion behavior under actual machining stress and that under ideal conditions.

[0086] Next, the temperature of the target workpiece at the current moment is measured in real time using a non-contact infrared thermometer. Combining the corrected real-time effective thermal expansion coefficient and the real-time measured temperature of the first workpiece, the system calculates the theoretical angular deviation of the target workpiece at the current moment based on a preset physical model. This theoretical angular deviation quantifies the angular deviation of the workpiece due to thermal expansion and contraction under the current temperature and stress conditions.

[0087] Simultaneously, using a high-precision angle sensor or vision measurement system, the actual angular deviation of the target workpiece relative to the processing reference at the current moment is monitored in real time, resulting in the monitored angular offset. To obtain more accurate comprehensive angular information, the system performs a weighted summation of the monitored angular offset and the theoretical angular offset, for example, using a fixed weight ratio (e.g., 50% each), thus obtaining the fused angular offset of the target workpiece at the current moment. This fused angular offset integrates information from both actual measurement and theoretical prediction, providing a more comprehensive assessment of the workpiece's true angular deviation.

[0088] Finally, based on this fused angle offset, the system sends instructions to the machine tool control system to adaptively compensate for the workpiece rotation angle during the circumferential surface finishing process. Through this dynamic, real-time compensation mechanism, even if the workpiece experiences angular drift due to thermal effects during machining, it can be effectively and promptly offset, thereby ensuring that the workpiece always remains at the expected machining angle position, significantly improving the accuracy of circumferential surface finishing.

[0089] Based on the above examples, the technical concept of this embodiment demonstrates a significant technical contribution. In the finishing of circumferential surfaces, existing technologies primarily rely on mechanical structures for angular positioning of the workpiece. Their core limitation lies in their inability to effectively address the dynamic angular drift caused by thermal expansion and contraction of the workpiece due to frictional heat during machining. This static mechanical positioning method cannot provide real-time angular reference correction in the face of temperature changes, thus limiting the final precision of the finishing process.

[0090] In contrast, the technical solution of this embodiment incorporates consideration of the real-time stress of the workpiece and combines it with the average stress of the workpiece at the target machining stage to determine the first stress suppression coefficient, thereby quantifying the effect of machining stress on thermal expansion. This step goes beyond simple temperature compensation and delves into the influence of mechanical factors during machining on thermal deformation. For example, in the grinding example above, by analyzing real-time stress and average stress, the actual thermal expansion trend of the workpiece under the current machining state can be more accurately assessed, rather than simply using a fixed coefficient of thermal expansion.

[0091] Furthermore, this embodiment utilizes the first stress suppression coefficient to correct the workpiece's basic thermal expansion coefficient, obtaining a real-time effective thermal expansion coefficient. This correction process makes the thermal expansion coefficient no longer a static material property, but rather a dynamic reflection of the workpiece's thermal deformation characteristics under actual processing conditions. This significantly improves the accuracy of thermal deformation prediction compared to existing technologies that may use fixed thermal expansion coefficients or simple correction methods based solely on temperature.

[0092] Furthermore, this embodiment calculates the theoretical angle offset based on the real-time effective thermal expansion coefficient and the temperature of the first workpiece, and then weights and sums it with the actual monitored angle offset to form a fused angle offset. This fusion mechanism integrates physical model predictions and actual measurement data, effectively compensating for potential errors or limitations of a single data source.

[0093] Ultimately, the workpiece rotation angle is adaptively compensated based on this fused angle offset, enabling dynamic adjustment throughout the finishing process. This is significantly different from existing technologies where angle deviations are difficult to correct in real time once positioning is complete. The compensation mechanism in this embodiment can precisely adjust according to the real-time state of the workpiece, effectively offsetting angle drift caused by thermal expansion and contraction, thereby ensuring high precision and stability in circumferential surface finishing. Therefore, the technical solution of this embodiment demonstrates significant progress and innovation in solving the dynamic angle drift problem existing in the prior art.

[0094] In this embodiment, a first stress suppression coefficient is first determined based on the real-time stress of the workpiece and the average stress of the workpiece at the current target machining stage. This coefficient reflects the strength of the influence of machining stress on thermal expansion. Next, the first stress suppression coefficient is used to correct the workpiece's basic thermal expansion coefficient to obtain the real-time effective thermal expansion coefficient, which more accurately reflects the degree to which the workpiece is affected by thermal expansion and contraction at the current moment. Then, the theoretical angle offset is determined based on the real-time effective thermal expansion coefficient and the first workpiece temperature. Finally, the monitored angle offset and the theoretical angle offset are weighted and summed to obtain the fused angle offset. Finally, the workpiece rotation angle is adaptively compensated based on the fused angle offset. Thus, through this series of operations, the influence of thermal expansion and contraction caused by temperature changes on the angle reference is considered, and dynamic adjustment and compensation are performed, thereby effectively reducing the dynamic drift of the angle reference and improving the finishing accuracy of the circumferential surface.

[0095] In some embodiments of the present invention described above, a method for determining the first stress suppression coefficient based on the real-time stress of the workpiece and the average stress of the workpiece at the target machining stage is proposed. However, in actual machining processes, simply relying on the real-time stress and average stress of the workpiece may not fully reflect the dynamic changes in the machining state, resulting in an inaccurate determination of the first stress suppression coefficient, which in turn affects the accuracy of subsequent thermal expansion coefficient correction.

[0096] In this regard, such as Figure 2 As shown, the present invention further proposes that S100 includes the following S110 to S140:

[0097] S110, obtain the current processing progress value;

[0098] S120, based on the current processing progress value and the real-time stress of the workpiece, determine the second stress suppression coefficient at the current moment;

[0099] S130, divide the average stress of the workpiece in the target processing stage by the real-time stress of the workpiece to obtain the first correction coefficient;

[0100] S140, based on the first correction coefficient, the second stress suppression coefficient is corrected to obtain the first stress suppression coefficient at the current moment.

[0101] In this embodiment, obtaining the current processing progress value is an indicator of the degree of completion of the current processing task. This processing progress value can be obtained based on multiple dimensions. For example, it can be obtained by recording the ratio of the current processing time to the total processing time, or by calculating the ratio of the volume of processed material to the total volume of material to be processed. Alternatively, it can be obtained by monitoring the position of the tool on the preset processing path and comparing it with the total path length.

[0102] The second stress suppression coefficient is an intermediate parameter determined based on the machining progress value and the real-time stress of the workpiece. It is used to preliminarily assess the influence of machining stress on thermal expansion. It can be determined by interpolating the machining progress value and the real-time stress of the workpiece using a pre-defined lookup table; or by establishing a mathematical model, such as using multinomial regression or neural network algorithms, taking the machining progress value and the real-time stress of the workpiece as input, and outputting the second stress suppression coefficient.

[0103] The first correction factor is the ratio obtained by comparing the average stress of the workpiece at the target machining stage with the real-time stress of the workpiece at the current moment. This first correction factor reflects the degree of deviation of the current real-time stress of the workpiece from the average stress of the workpiece throughout the entire machining stage.

[0104] The correction of the second stress suppression coefficient involves adjusting the initially determined second stress suppression coefficient using the first correction coefficient to obtain the final first stress suppression coefficient. The correction method can be to multiply the second stress suppression coefficient by the first correction coefficient, or to adjust it using a more complex functional relationship.

[0105] The present invention first obtains the current processing progress value, providing dynamic contextual information about the processing process for determining the stress suppression coefficient. Then, based on this processing progress value and the real-time stress of the workpiece, a preliminary second stress suppression coefficient is determined, allowing the stress suppression assessment to take into account the characteristics of each processing stage. Simultaneously, by comparing the average stress of the workpiece at the target processing stage with the real-time stress of the workpiece, a first correction coefficient is obtained, which quantifies the degree of deviation between the current stress state and the average stress state. Finally, the second stress suppression coefficient is corrected using this first correction coefficient, resulting in a more accurate and dynamic first stress suppression coefficient. This multi-step, multi-parameter determination method enables the first stress suppression coefficient to more comprehensively and accurately reflect the strength of the processing stress in counteracting the thermal expansion effect at the current moment, thus providing a more reliable basis for subsequent correction of the thermal expansion coefficient, calculation of theoretical angle offsets, and adaptive compensation of the workpiece rotation angle.

[0106] As an example, the first stress suppression coefficient at the current moment can be determined using the following formula 1:

[0107] Formula 1

[0108] In formula 1, The first stress suppression coefficient is used to characterize the first stress suppression coefficient at time t in the j-th processing stage. The second stress suppression coefficient is used to characterize the time t-th moment. Used to characterize the average stress of the workpiece in the j-th processing stage. Used to characterize the real-time stress of the workpiece at time t.

[0109] The second stress suppression coefficient at the current moment can be determined using the following formula 2:

[0110] Formula 2

[0111] In formula 2, The second stress suppression coefficient is used to characterize the stress at time t, and max is used to characterize taking the maximum value. This is used to characterize a preset minimum thermal expansion retention ratio (e.g., 0.1) to ensure that the thermal expansion effect does not become negative even under extreme stress. The stress correction factor is used to characterize the workpiece material and is determined in a laboratory environment or by fitting historical data. This is used to characterize the real-time stress on the workpiece provided by the angular positioning fixture at time t. Used to characterize the maximum stress on the workpiece provided by the angular positioning fixture (i.e., the maximum value of the real-time stress of the workpiece at each historical moment). Used to characterize the processing progress value at time t.

[0112] It should be noted that, to ensure the calculation results are meaningful, in this embodiment of the invention, when performing fractional operations, if the denominator is 0, a parameter adjustment factor greater than 0 needs to be added to the denominator. To prevent the denominator from being zero, the values ​​of the parameter adjustment factors are set by the implementer according to the actual situation, and this invention does not impose any special restrictions.

[0113] The above technical solution, when determining the first stress suppression coefficient, not only considers the real-time stress of the workpiece and the average stress of the workpiece at the target machining stage, but also introduces the machining progress value as a key parameter. This multi-dimensional and dynamic consideration makes the determination of the first stress suppression coefficient more precise and accurate, and can more realistically reflect the strength of the influence of machining stress on thermal expansion. Therefore, when subsequently correcting the basic thermal expansion coefficient of the workpiece, a more accurate real-time effective thermal expansion coefficient can be obtained, thereby significantly improving the calculation accuracy of theoretical angle offset. Ultimately, this helps to improve the accuracy and effectiveness of adaptive compensation of workpiece rotation angle during circumferential surface finishing, effectively avoiding machining errors caused by thermal expansion and dynamic changes in machining stress, and ensuring the quality and precision of finishing.

[0114] In some embodiments of the present invention described above, in order to accurately determine the first stress suppression coefficient, it is necessary to obtain the machining progress value at the current moment. However, in the actual circumferential surface finishing process, the method of obtaining the machining progress value may be inaccurate or incomplete, thereby affecting the accuracy of the subsequent stress suppression coefficient and thus affecting the final machining accuracy.

[0115] In this regard, the present invention further proposes that S110 includes:

[0116] Obtain the historical average feed rate and historical average number of revolutions for each historical processing cycle;

[0117] The first ratio is obtained by dividing the current real-time feed by the historical average feed, and the second ratio is obtained by dividing the current real-time rotation count by the historical average rotation count.

[0118] The processing progress value at the current moment is obtained by averaging the first ratio and the second ratio.

[0119] In this embodiment, the historical average feed rate and historical average number of revolutions for each historical machining process are obtained to provide a benchmark reference for the current machining process. The historical average feed rate refers to the average distance the workpiece moves in multiple successful or representative machining processes in the past. The historical average number of revolutions refers to the average number of revolutions the workpiece completes in multiple successful or representative machining processes in the past. This historical data can be obtained through statistical analysis of past machining records.

[0120] The first ratio is obtained by dividing the current real-time feed rate by the historical average feed rate, and the second ratio is obtained by dividing the current real-time rotational revolutions by the historical average rotational revolutions. These ratios are used to quantify the relative difference between the current machining state and the historical baseline. The real-time feed rate refers to the actual feed distance of the workpiece at the current machining moment. The real-time rotational revolutions refer to the actual number of rotations of the workpiece at the current machining moment. By comparing the real-time values ​​with the historical averages, two dimensionless ratios are obtained, reflecting the degree of deviation of the current feed and rotational revolutions from the historical average levels, respectively.

[0121] The current machining progress value is obtained by averaging the first and second ratios. This aims to comprehensively consider information from both the feed and rotation dimensions to more fully and robustly represent the machining progress. Averaging can be performed in various ways, such as arithmetic mean, weighted mean, or geometric mean. The arithmetic mean is the simplest and most direct method, which involves adding the first and second ratios and then dividing by two. The weighted mean assigns different weights based on the influence of the feed rate and the number of rotations on the machining progress. For example, if the number of rotations is considered to have a greater impact on the machining progress, the second ratio can be given a higher weight.

[0122] The present invention uses historical average feed rate and historical average number of revolutions from each historical machining process as benchmark data. This historical data represents the typical performance of feed and rotation under stable and successful machining conditions. At the current machining moment, the system monitors the current feed rate and number of revolutions in real time. Subsequently, by comparing the current real-time feed rate with the historical average feed rate, a first ratio is obtained, which reflects the degree of deviation of the current feed state from the historical benchmark. Simultaneously, the current real-time number of revolutions is compared with the historical average number of revolutions, resulting in a second ratio, which reflects the degree of deviation of the current rotation state from the historical benchmark. Finally, the two ratios are averaged to comprehensively consider the impact of the two key machining parameters, feed and rotation, on the machining progress, thus obtaining the machining progress value at the current moment. This method avoids the limitations of single-parameter evaluation. By comprehensively considering multiple parameters and comparing with historical data, the determination of the machining progress value is more accurate and comprehensive. This processing progress value was then used to determine the second stress suppression coefficient, which in turn affected the calculation of the first stress suppression coefficient, ultimately improving the accuracy of reflecting the strength of the processing stress in offsetting the thermal expansion effect, and providing a more reliable basis for subsequent adaptive compensation.

[0123] As an example, the current processing progress value can be determined using the following formula 3:

[0124] Formula 3

[0125] In formula 3, The value used to characterize the processing progress at time t. Used to characterize the real-time feed rate at time t. Used to characterize historical average feed rate Used to characterize the real-time number of rotations at time t. Used to characterize the historical average number of rotations.

[0126] Furthermore, it should be noted that the division of processing stages can also be determined based on processing progress values. For example, This is the initial stage of processing ( ), It was during the middle of the processing period. ), This is during the later stages of processing ( ).

[0127] Through the above technical solution, this invention can obtain the current machining progress value more accurately and comprehensively. By comprehensively considering the real-time feed rate and real-time rotation number, and comparing them with historical average data, it effectively avoids the errors and limitations that may arise from evaluating a single machining parameter. This multi-dimensional evaluation method based on historical data makes the representation of the machining progress value more stable and reliable. Therefore, when determining the second stress suppression coefficient, more accurate input parameters can be obtained, thereby improving the calculation accuracy of the first stress suppression coefficient. Ultimately, this helps to more accurately reflect the strength of machining stress in offsetting thermal expansion effects, providing a more solid data foundation for adaptive compensation of workpiece rotation angle during circumferential surface finishing, thereby improving the overall machining accuracy and stability.

[0128] In some of the embodiments of the present invention described above, the temperature of the workpiece changes in real time. If only a basic thermal expansion coefficient of the workpiece is relied upon for correction, it may not be able to fully reflect the true thermal expansion characteristics of the workpiece under different temperature conditions, thereby affecting the accuracy of the real-time effective thermal expansion coefficient.

[0129] In this regard, the present invention further proposes that S200 includes:

[0130] The temperature change rate is obtained by dividing the difference between the temperature of the first workpiece and the temperature of the standard workpiece at the current moment by the temperature of the standard workpiece.

[0131] The second correction coefficient is determined based on the degree of temperature change and the temperature sensitivity coefficient of the target workpiece;

[0132] Multiply the first stress suppression coefficient, the workpiece's basic thermal expansion coefficient, and the second correction coefficient to obtain the target workpiece's real-time effective thermal expansion coefficient at the current moment.

[0133] In this embodiment, the temperature variation is obtained by dividing the difference between the target workpiece's current temperature (first workpiece temperature) and the standard workpiece temperature by the standard workpiece temperature. This step aims to quantify the difference between the workpiece's current thermal state and its reference thermal state. The first workpiece temperature refers to the actual temperature of the target workpiece at the current processing moment, which can be obtained in real time by arranging temperature sensors, such as thermocouples, thermistors, or infrared thermometers, on or inside the workpiece surface. The standard workpiece temperature is the reference temperature used to define the workpiece's basic thermal expansion coefficient. The temperature variation is a dimensionless relative value that provides temperature-related input for subsequent thermal expansion coefficient correction.

[0134] Based on the degree of temperature change and the temperature sensitivity coefficient of the target workpiece, a second correction coefficient is determined. This step is used to evaluate the direct impact of temperature changes on the coefficient of thermal expansion. The temperature sensitivity coefficient describes how sensitive the coefficient of thermal expansion of the workpiece material is to temperature changes; different materials respond differently to temperature changes. This temperature sensitivity coefficient can be obtained experimentally, such as by testing with a dilatometer, or by consulting a material handbook. It can be a constant or a function of temperature. As a specific example, the temperature sensitivity coefficient can be an empirical coefficient obtained by fitting the nonlinear characteristics of the material's thermal expansion. That is, by measuring the coefficient of thermal expansion of the workpiece material at different temperatures in the laboratory, using linear regression to obtain the slope of the coefficient of thermal expansion changing with temperature, and dividing this slope by the standard coefficient of thermal expansion of the workpiece at the standard workpiece temperature, the temperature sensitivity coefficient is obtained. The second correction coefficient is a factor used to adjust the basic coefficient of thermal expansion of the workpiece, which comprehensively considers the degree of deviation of the current temperature from the standard temperature and the material's sensitivity to temperature changes. For example, it can be defined as the product of the degree of temperature change and the temperature sensitivity coefficient, or calculated through a pre-defined functional relationship, such as a polynomial function or an exponential function.

[0135] Multiplying the first stress suppression coefficient, the workpiece's basic thermal expansion coefficient, and the second correction coefficient yields the target workpiece's real-time effective thermal expansion coefficient at the current moment. This step aims to comprehensively consider the combined effects of stress and temperature on the thermal expansion coefficient. The first stress suppression coefficient reflects the strength of the influence of processing stress on the thermal expansion effect at the current moment. The workpiece's basic thermal expansion coefficient is the coefficient of thermal expansion of the workpiece material measured under standard conditions, such as standard temperature and no stress; it is usually a reference value for an inherent material property. The real-time effective thermal expansion coefficient is obtained by correcting the workpiece's basic thermal expansion coefficient after considering the effects of processing stress suppression and the current actual temperature, thus more accurately reflecting the workpiece's current actual thermal expansion behavior.

[0136] The present invention determines a second correction coefficient by introducing a temperature change rate and a temperature sensitivity coefficient, and multiplies it by a first stress suppression coefficient and the workpiece's basic thermal expansion coefficient to obtain the real-time effective thermal expansion coefficient of the target workpiece at the current moment. In the circumferential surface finishing process, the workpiece's temperature and processing stress are key factors affecting its dimensional accuracy. This invention first calculates the temperature change rate by obtaining the target workpiece's current temperature and a preset standard workpiece temperature, directly reflecting the deviation of the workpiece's current thermal state from the reference thermal state. Secondly, combining this temperature change rate with the inherent temperature sensitivity coefficient of the target workpiece material, a second correction coefficient is determined, quantifying the direct impact of the current temperature deviation on the workpiece's thermal expansion coefficient, ensuring that the correction of the thermal expansion coefficient fully considers the material's response characteristics at different temperatures. Finally, the determined first stress suppression coefficient, the workpiece's basic thermal expansion coefficient, and the aforementioned second correction coefficient are multiplied to obtain the real-time effective thermal expansion coefficient of the target workpiece at the current moment. This multiplicative combination correction method ensures that the real-time effective thermal expansion coefficient not only considers the suppression effect of processing stress on thermal expansion but also further incorporates the influence of the workpiece's actual temperature deviating from the standard temperature. In this way, the workpiece's basic thermal expansion coefficient is no longer a static, single reference value, but is dynamically adjusted according to real-time stress state and real-time temperature changes, thus more accurately reflecting the workpiece's true thermal expansion characteristics under complex machining environments. This provides a more reliable input for the subsequent accurate calculation of theoretical angle offsets, thereby improving the accuracy of adaptive compensation for workpiece rotation angles throughout the entire circumferential surface finishing process.

[0137] As an example, the real-time effective coefficient of thermal expansion at the current moment can be determined using the following formula 4:

[0138] Formula 4

[0139] In formula 4, Used to characterize the real-time effective thermal expansion coefficient at time t in the j-th processing stage. Used to characterize the basic thermal expansion coefficient of the workpiece in the j-th processing stage. The first stress suppression coefficient is used to characterize the first stress suppression coefficient at time t in the j-th processing stage. Used to characterize the temperature sensitivity coefficient of the target workpiece Used to characterize the temperature of the first workpiece at time t. Used to characterize the temperature of standard workpieces.

[0140] The above technical solution, when determining the real-time effective thermal expansion coefficient of the target workpiece, not only considers the suppressive effect of processing stress on thermal expansion, but also further incorporates the influence of the actual workpiece temperature deviating from the standard workpiece temperature. This makes the correction of the workpiece's thermal expansion coefficient more refined and real-time, and can more accurately reflect the thermal expansion behavior of the workpiece under actual processing conditions. Therefore, the theoretical angle offset calculated based on this real-time effective thermal expansion coefficient will be closer to the actual situation, thereby significantly improving the accuracy of adaptive compensation for workpiece rotation angle during circumferential surface finishing, effectively avoiding processing errors caused by inaccurate estimation of the thermal expansion coefficient, and ultimately improving the quality and efficiency of finishing.

[0141] In some embodiments of the present invention described above, the theoretical angular offset is determined by the real-time effective coefficient of thermal expansion and the temperature of the first workpiece. However, in actual processing, the temperature distribution of the workpiece may be uneven, and relying solely on a single surface temperature or a simple measurement of the internal temperature is insufficient to accurately reflect the true overall thermal state of the workpiece, thus affecting the accuracy of the first workpiece temperature, leading to calculation errors in the theoretical angular offset, and ultimately affecting the compensation accuracy of the circumferential surface finishing.

[0142] In this regard, the present invention further proposes that, prior to S300, the following steps are also included:

[0143] Based on the current ambient temperature and workpiece surface temperature, determine the internal temperature of the target workpiece at the current moment.

[0144] The temperature compensation value of the target workpiece at the current moment is obtained by multiplying the difference between the surface temperature and the internal temperature of the workpiece by the temperature distribution uniformity of the target workpiece.

[0145] Adding the internal temperature of the workpiece to the temperature compensation value, we obtain the first workpiece temperature of the target workpiece at the current moment.

[0146] In this embodiment, the internal temperature of the target workpiece at the current moment is determined based on the current ambient temperature and the workpiece surface temperature, aiming to obtain the actual internal temperature of the workpiece at the current moment. During the finishing process, the internal temperature of the workpiece is often difficult to measure directly and accurately, and it has a complex heat exchange relationship with the ambient temperature and surface temperature. Accurately obtaining the internal temperature is the basis for subsequent calculations of the temperature compensation value and the first workpiece temperature. This step can be achieved by establishing a heat conduction model, combining data from ambient temperature sensors and workpiece surface temperature sensors, and using finite element analysis or numerical simulation methods to calculate the temperature distribution inside the workpiece in real time, thereby determining the average temperature inside the workpiece or the temperature at a specific point as the internal temperature of the workpiece. Alternatively, the internal temperature of the target workpiece at the current moment can also be determined using the following formula 5:

[0147] Formula 5

[0148] In formula 5, Used to characterize the internal temperature of the target workpiece at time t. Used to characterize the ambient temperature at time t. Used to characterize the surface temperature of the target workpiece at time t. The sampling time interval used to characterize temperature data (i.e., ambient temperature and workpiece surface temperature). Used to characterize the thermal conduction time constant of the target workpiece.

[0149] The temperature compensation value for the target workpiece at the current moment is obtained by multiplying the difference between the workpiece's surface temperature and its internal temperature by the uniformity of its temperature distribution. This aims to quantify the impact of the temperature difference between the workpiece's interior and surface on the overall thermal expansion effect and convert it into a compensation value. Since temperature gradients may exist in the workpiece during processing, simple internal or surface temperatures cannot fully represent the overall thermal expansion state of the workpiece. The temperature compensation value is used to correct for this non-uniformity.

[0150] Temperature distribution uniformity can be a preset empirical coefficient, obtained by analyzing a large amount of historical processing data and performing statistical regression on the temperature distribution characteristics under different materials, geometries, and processing parameters. This empirical coefficient reflects the weight of the temperature difference between the workpiece surface and interior on the overall thermal expansion under specific processing conditions. Alternatively, temperature distribution uniformity can also be a dynamically calculated parameter, for example, by performing variance analysis on the temperature distribution of the workpiece at different historical processing stages, or by using a machine learning model to learn the relationship between temperature gradient and thermal expansion effect, thereby adjusting the temperature distribution uniformity parameter in real time.

[0151] Adding a temperature compensation value to the internal temperature of the workpiece yields the first workpiece temperature at the current moment. This aims to comprehensively consider the influence of the workpiece's internal temperature and temperature distribution non-uniformity, thus obtaining a more accurate "first workpiece temperature" that better represents the overall thermal expansion state of the workpiece. This corrected temperature value will serve as input for subsequent theoretical angle offset calculations, improving the accuracy of the calculations. This step can be simply achieved by algebraically summing the calculated temperature compensation value with the workpiece's internal temperature. This method assumes that the temperature compensation value is a direct correction term for the internal temperature.

[0152] The present invention determines the internal temperature of the target workpiece at the current moment based on the ambient temperature and the workpiece surface temperature, providing fundamental data for subsequent temperature correction. Then, the difference between the workpiece surface temperature and the internal temperature is multiplied by the temperature distribution uniformity of the target workpiece to obtain the temperature compensation value for the target workpiece at the current moment. This step quantifies the impact of the temperature difference between the workpiece's interior and surface on the overall thermal expansion effect. Finally, the internal temperature is added to the temperature compensation value to obtain the first workpiece temperature at the current moment. In this way, the present invention comprehensively considers the influence of the workpiece's internal temperature and temperature distribution non-uniformity, enabling the obtained first workpiece temperature to more accurately reflect the overall thermal expansion state of the workpiece. This more accurate first workpiece temperature significantly improves the accuracy of calculations when subsequently used to determine theoretical angular offsets, thereby enhancing the accuracy of adaptive compensation for workpiece rotation angles during circumferential surface finishing.

[0153] As an example, the initial workpiece temperature at the current moment can be determined using the following formula 6:

[0154] Formula 6

[0155] In formula 6, Used to characterize the first workpiece temperature of the target workpiece at time t. Used to characterize the internal temperature of the target workpiece at time t. Used to characterize the surface temperature of the target workpiece at time t. Used to characterize the temperature distribution uniformity of the target workpiece.

[0156] Through the above technical solution, this invention can more accurately obtain the initial workpiece temperature during the machining process. By comprehensively considering the ambient temperature, workpiece surface temperature, and internal workpiece temperature, and introducing temperature distribution uniformity compensation, it effectively solves the problem of theoretical angle offset calculation errors caused by inaccurate workpiece temperature measurement in traditional methods. This makes the subsequent theoretical angle offset determined based on the real-time effective thermal expansion coefficient and the initial workpiece temperature more accurate, thereby significantly improving the accuracy and reliability of adaptive compensation for workpiece rotation angle during circumferential surface finishing, and ensuring machining quality.

[0157] In some embodiments of the present invention described above, the internal temperature of the workpiece is determined based on the current ambient temperature and the workpiece surface temperature. The difference between the workpiece surface temperature and the internal temperature is multiplied by the temperature distribution uniformity of the target workpiece to obtain the temperature compensation value of the target workpiece at the current moment. Then, the internal temperature of the workpiece is added to the temperature compensation value to obtain the first workpiece temperature of the target workpiece at the current moment. However, in actual processing, the internal temperature distribution of the workpiece is not always uniform, and its uniformity may be affected by various factors. If the temperature distribution uniformity is not accurately obtained, the temperature compensation value may be calculated inaccurately, thus affecting the accuracy of the theoretical angle offset.

[0158] To address this, the present invention further proposes that, before multiplying the difference between the workpiece surface temperature and the workpiece internal temperature by the temperature distribution uniformity of the target workpiece to obtain the temperature compensation value of the target workpiece at the current moment, the invention further includes:

[0159] The variance of the internal temperature of the target workpiece during the i-th historical processing is calculated to obtain the temperature distribution coefficient of the target workpiece during the i-th historical processing; where i is a positive integer.

[0160] The temperature distribution uniformity of the target workpiece is obtained by averaging the various temperature distribution coefficients.

[0161] In this embodiment, the variance of the internal temperature of the target workpiece during the i-th historical processing is calculated to quantify the dispersion or fluctuation of the internal temperature of the workpiece during a specific historical processing. This variance calculation can be achieved by continuously collecting temperature data at multiple preset temperature measurement points inside the workpiece during the historical processing, and then performing statistical variance calculations on these discrete temperature measurements. Alternatively, a numerical model of internal heat conduction can be established to simulate the temperature field distribution during the historical processing, and the temperature data from multiple representative points can be extracted from the simulation results for variance calculation.

[0162] The temperature distribution coefficient of the target workpiece during the i-th historical processing is obtained. This temperature distribution coefficient is a direct result of variance calculation and is used to intuitively reflect the uniformity of the internal temperature distribution of the workpiece during a certain historical processing. The larger the variance value, the more uneven the internal temperature distribution, and the larger the corresponding temperature distribution coefficient. This temperature distribution coefficient can be directly obtained from the calculated variance value, or, for ease of comparison and application, it can be normalized, for example, by dividing it by the square of a preset reference temperature or temperature range.

[0163] The purpose of averaging the temperature distribution coefficients is to comprehensively consider the temperature distribution characteristics across multiple historical processing stages, thereby obtaining a more representative and stable temperature distribution uniformity. This averaging process can be achieved using a simple arithmetic mean method, which involves summing the temperature distribution coefficients from all historical processing stages and dividing by the total number of historical processing stages.

[0164] The present invention systematically obtains the temperature distribution uniformity of a target workpiece by introducing the analysis of historical processing data. Specifically, during each historical processing, the internal temperature of the target workpiece is monitored and variance is calculated to obtain the temperature distribution coefficient for that historical processing. This temperature distribution coefficient directly reflects the dispersion of the internal temperature distribution of the workpiece. By averaging the temperature distribution coefficients obtained from multiple historical processing processes, random errors in single measurements or processing can be effectively eliminated, resulting in a more stable and reliable temperature distribution uniformity. This temperature distribution uniformity, verified and statistically processed by historical data, is then used in the above method to correct the difference between the workpiece surface temperature and the internal temperature, thereby obtaining a more accurate temperature compensation value. In this way, the present invention can more accurately assess the actual temperature distribution state inside the workpiece, making the determination of the first workpiece temperature closer to reality, thereby improving the accuracy of the theoretical angle offset calculation, and ultimately enhancing the accuracy and stability of the adaptive compensation of the workpiece rotation angle during circumferential surface finishing.

[0165] Through the above technical solution, this invention can systematically obtain the temperature distribution uniformity of the target workpiece based on statistical analysis of historical processing data. This method effectively avoids errors caused by empirical settings or rough estimations of temperature distribution uniformity, making the calculation of temperature compensation values ​​more accurate. Therefore, when determining the temperature of the first workpiece, it can more accurately reflect the true temperature distribution inside the workpiece, thereby significantly improving the calculation accuracy of theoretical angle offset. Ultimately, this helps to improve the accuracy and reliability of adaptive compensation of workpiece rotation angle during circumferential surface finishing, effectively suppressing thermal deformation errors caused by uneven temperature inside the workpiece, and thus ensuring the quality and precision of finishing.

[0166] In some embodiments of the present invention described above, a method is proposed to determine the theoretical angular offset based on the real-time effective thermal expansion coefficient and the temperature of the first workpiece, and to adaptively compensate for the workpiece rotation angle. However, in actual machining, accurate acquisition of the workpiece's basic thermal expansion coefficient is crucial for subsequent precise compensation. Traditional acquisition methods may not fully consider historical machining data and the influence of temperature at different times, resulting in an inaccurate setting of the workpiece's basic thermal expansion coefficient, which in turn affects the final machining accuracy.

[0167] In this regard, the present invention further proposes that, prior to S200, the following steps are also included:

[0168] Based on the first workpiece temperature, the standard workpiece temperature, and the temperature sensitivity coefficient of the target workpiece at each moment in the target processing stage of the i-th historical processing process, the initial thermal expansion coefficient of the target workpiece at each moment in the target processing stage of the i-th historical processing process is determined; where i is a positive integer.

[0169] Based on the surface temperature of the target workpiece at each moment in the target processing stage of the i-th historical processing process, and the corresponding predicted surface temperature obtained by the temperature prediction model, the thermal expansion coefficient analysis weight of the target workpiece in the target processing stage of the i-th historical processing process is determined.

[0170] Based on the initial thermal expansion coefficient of the target workpiece at each moment in the target processing stage of each historical processing process, and the analysis weight of the thermal expansion coefficient of the target workpiece in the target processing stage of each historical processing process, the basic thermal expansion coefficient of the target workpiece in the target processing stage is determined.

[0171] In this embodiment, the first workpiece temperature refers to the actual temperature measurement value of the target workpiece at a specific moment during the historical processing. This temperature can be obtained in real time or near real time during processing using a contact sensor, such as a thermocouple, or a non-contact sensor, such as an infrared thermometer. The standard workpiece temperature refers to a preset workpiece temperature value used as a reference. The temperature sensitivity coefficient reflects the degree to which the thermal expansion and contraction characteristics of the workpiece material respond to temperature changes. It is an inherent physical parameter of the material and can be obtained by consulting material handbooks, conducting experimental measurements (such as dilatometer testing), or performing theoretical calculations based on the material composition. The initial thermal expansion coefficient of the workpiece refers to the preliminary thermal expansion coefficient calculated based on the above parameters at a specific moment during the historical processing. Its purpose is to provide uncorrected raw thermal expansion data for subsequent analysis.

[0172] Specifically, the initial coefficient of thermal expansion of the workpiece can be determined using the following formula 7:

[0173] Formula 7

[0174] In formula 7, Used to characterize the initial thermal expansion coefficient of the target workpiece at time t. Used to characterize the standard thermal expansion coefficient of the target workpiece at the standard workpiece temperature. Used to characterize the temperature sensitivity coefficient of the target workpiece Used to characterize the first workpiece temperature of the target workpiece at time t. Used to characterize the temperature of standard workpieces.

[0175] Workpiece surface temperature refers to the measured external surface temperature of a workpiece at a specific moment during historical processing. This temperature can be monitored using non-contact devices such as infrared thermometers and thermal imagers. A temperature prediction model is a mathematical model used to predict changes in workpiece surface temperature under future or specific conditions. This model can be built based on historical temperature data, processing parameters (such as feed rate and rotational speed), and environmental conditions. It can be constructed using machine learning algorithms (such as support vector machines and neural networks) or physical heat transfer models (such as finite element analysis). Its purpose is to provide a predicted value that can be compared with the actual measured value to assess the accuracy of temperature measurement or the stability of the processing process. The thermal expansion coefficient analysis weight is a factor used to measure the contribution of the initial thermal expansion coefficient at different historical moments or different historical processing stages when calculating the basic thermal expansion coefficient. This thermal expansion coefficient analysis weight can be determined based on the degree of matching between the actual surface temperature and the predicted surface temperature.

[0176] Specifically, the weighting for the thermal expansion coefficient analysis can be determined using the following formula 8:

[0177] Formula 8

[0178] In formula 8, Weights used to characterize the coefficient of thermal expansion of the target workpiece in the i-th historical processing stage. Used to characterize the workpiece pass rate of the target workpiece in the i-th historical processing step. Used to characterize the average pass rate of a target workpiece in historical processing. Used to characterize the surface temperature of the target workpiece at time t. Used to characterize the predicted surface temperature of the target workpiece at time t. The total number of workpiece surface temperatures used to characterize the target workpiece during the i-th historical processing.

[0179] It should be noted that, to ensure the calculation results are meaningful, in this embodiment of the invention, when performing fractional operations, if the denominator is 0, a parameter adjustment factor greater than 0 needs to be added to the denominator. To prevent the denominator from being 0, the values ​​of the parameter adjustment factors are set by the implementer according to the actual situation. This invention does not impose any special restrictions; for example, it can be 0.01.

[0180] The basic thermal expansion coefficient of a workpiece refers to the reference thermal expansion coefficient obtained after comprehensive historical data and weighted analysis at the target processing stage, which is used for subsequent real-time correction. It represents the average or typical thermal expansion characteristics of the workpiece at that specific processing stage.

[0181] Specifically, the basic coefficient of thermal expansion of the workpiece can be determined using the following formula 9:

[0182] Formula 9

[0183] In formula 9, The coefficient of thermal expansion of the workpiece at the j-th processing stage is used to characterize the basic coefficient of thermal expansion, and n is used to characterize the total number of historical processing stages. Weights used to characterize the coefficient of thermal expansion of the target workpiece in the i-th historical processing stage. The total number of parameters used to characterize the surface temperature of the target workpiece in the i-th historical processing step. The coefficient of thermal expansion of the target workpiece is used to characterize the initial thermal expansion coefficient of the workpiece at time t in the j-th processing stage of the i-th historical processing process. The first stress suppression coefficient is used to characterize the target workpiece at time t in the j-th processing stage of the i-th historical processing process.

[0184] The present invention systematically utilizes historical processing data to determine the basic thermal expansion coefficient of the workpiece at the target processing stage. First, for each moment in the target processing stage of each historical processing process, the initial thermal expansion coefficient of the workpiece at that moment is calculated based on the temperature of the first workpiece, the temperature of the standard workpiece, and the temperature sensitivity coefficient. This provides raw thermal expansion data for subsequent analysis. Second, to ensure the reliability of the historical data used, the analysis weight of the thermal expansion coefficient is determined by comparing the workpiece surface temperature with the predicted surface temperature obtained from the temperature prediction model. Finally, the initial thermal expansion coefficients of the workpiece at each moment in all historical processing processes are combined with their corresponding analysis weights and processed to obtain the basic thermal expansion coefficient of the workpiece at the target processing stage. This method fully considers the influence of historical processing conditions and temperature changes on the thermal expansion coefficient, and uses a weighting mechanism to select more representative data, making the determined basic thermal expansion coefficient more accurate and reliable, providing a solid foundation for subsequent real-time correction of the effective thermal expansion coefficient.

[0185] Through the above technical solution, this invention can systematically utilize historical processing data and combine it with a temperature prediction model to perform weighted analysis on the data, thereby obtaining a more accurate and representative basic thermal expansion coefficient of the workpiece at the target processing stage. This significantly improves the accuracy of subsequent real-time effective thermal expansion coefficient calculations, thus making the determination of theoretical angle offsets more precise. Ultimately, this helps to improve the accuracy and reliability of adaptive compensation for workpiece rotation angle during circumferential surface finishing, effectively suppressing processing errors caused by thermal expansion effects, thereby significantly improving the processing quality and surface finish of the workpiece.

[0186] In some embodiments of the present invention, a method is proposed to determine the thermal expansion coefficient analysis weights based on the workpiece surface temperature during historical processing and the corresponding predicted surface temperature obtained through a temperature prediction model, thereby calculating the workpiece's basic thermal expansion coefficient. However, in actual processing, the workpiece's temperature changes are complex. If the temperature prediction model is not accurately constructed, the predicted surface temperature may deviate from the actual temperature, thus affecting the accuracy of the thermal expansion coefficient analysis weights and consequently the accuracy of the workpiece's basic thermal expansion coefficient.

[0187] In response, this invention further proposes that, before determining the thermal expansion coefficient analysis weight of the target workpiece in the target processing stage of the i-th historical processing process based on the workpiece surface temperature at each moment in the target processing stage of the i-th historical processing process and the corresponding predicted surface temperature obtained through the temperature prediction model, the invention further includes:

[0188] Based on the surface temperature of the target workpiece at each moment in the target processing stage of the i-th historical processing process, determine the first temperature rise rate of the target workpiece in the target processing stage of the i-th historical processing process.

[0189] Based on the first temperature rise rate, average ambient temperature, and average workpiece surface temperature of the target workpiece in the target processing stage of each historical processing process, the second temperature rise rate of the target workpiece in the target processing stage is determined.

[0190] Based on the second temperature rise rate of the target workpiece in the target processing stage and the maximum temperature of the target workpiece in the target processing stage, a temperature prediction model for the target workpiece in the target processing stage is constructed.

[0191] In this embodiment, the first temperature rise rate is used to quantify how quickly the surface temperature of the workpiece changes over time during a specific historical processing stage, reflecting the instantaneous thermal response characteristics of the workpiece. This can be achieved by performing time-series analysis on continuously collected workpiece surface temperature data from the historical processing process, for example, using the difference method or regression analysis to calculate the ratio of temperature change to the time interval between adjacent time points or over a period of time.

[0192] The second temperature rise rate is obtained by comprehensively considering instantaneous temperature changes, ambient thermal conditions, and the overall thermal state of the workpiece during historical processing. It is used to characterize the overall temperature change trend in the target processing stage. Its purpose is to provide a more macroscopic and stable temperature change index to overcome the randomness of a single historical process. Possible implementation methods include using the first temperature rise rate, the corresponding average ambient temperature, and the average workpiece surface temperature from multiple historical processing processes as inputs, training a machine learning model (such as a support vector machine or neural network) to learn the complex relationships between them, thereby predicting or calculating the second temperature rise rate in the target processing stage. Alternatively, the second temperature rise rate of the target workpiece in the target processing stage can be determined using the following formula 10:

[0193] Formula 10

[0194] In formula 10, The second temperature rise rate of the target workpiece in the j-th processing stage is used to characterize the total number of historical processing stages. Used to characterize the first temperature rise rate of the target workpiece in the j-th processing stage of the i-th historical processing process. This is used to characterize the average ambient temperature of the target workpiece in the j-th processing stage of the i-th historical processing process. This is used to characterize the average workpiece surface temperature in the j-th processing stage of the i-th historical processing process.

[0195] It should be noted that, to ensure the calculation results are meaningful, in this embodiment of the invention, when performing fractional operations, if the denominator is 0, a parameter adjustment factor greater than 0 needs to be added to the denominator. To prevent the denominator from being zero, the values ​​of the parameter adjustment factors are set by the implementer according to the actual situation, and this invention does not impose any special restrictions.

[0196] Temperature prediction models are used to predict the surface temperature of a workpiece during the target processing stage and are crucial for the accurate calculation of the thermal expansion coefficient analysis weights. Their role is to provide a dynamic and predictable temperature curve reflecting the thermal behavior of the workpiece during processing. Possible implementation methods include using thermodynamic principles and heat transfer equations, combined with a second temperature rise rate and temperature maxima as boundary or initial conditions, to establish a physical model (such as a finite element model) to simulate the temperature distribution and changes of the workpiece during processing. Alternatively, a temperature prediction model for the target workpiece can be constructed using the following formula 11:

[0197] Formula 11

[0198] In formula 11, Used to characterize the predicted surface temperature of the target workpiece at time t. Used to characterize the average workpiece surface temperature in the j-th processing stage. Used to characterize the second temperature rise rate of the target workpiece in the j-th processing stage. The value used to characterize the processing progress at time t. Used to characterize the initial processing progress value of the target workpiece in the j-th processing stage. Used to characterize the maximum temperature of the target workpiece in the j-th processing stage. Used to represent taking the minimum value.

[0199] Through the above technical solution, this invention can more accurately predict the surface temperature of the workpiece during the target machining stage. This makes the calculation of the thermal expansion coefficient analysis weight more precise, thereby improving the reliability of the workpiece's basic thermal expansion coefficient. Ultimately, this helps to more accurately determine the real-time effective thermal expansion coefficient, providing a more solid foundation for subsequent theoretical angle offset calculations and adaptive compensation of the workpiece rotation angle. This significantly improves the accuracy and stability of circumferential surface finishing and effectively avoids the problem of insufficient or excessive compensation for thermal expansion effects caused by inaccurate temperature prediction.

[0200] In some embodiments of the present invention, a weighted summation is proposed to obtain the fused angle offset of the target workpiece at the current moment by combining the monitored angle offset obtained at the current moment with the theoretical angle offset. However, in actual processing, the accuracy and stability of the monitored angle offset may be affected by various factors, such as sensor noise, environmental interference, or changes in workpiece material properties, leading to fluctuations in its reliability. Simply using fixed weights for weighting may not fully reflect the actual reliability of the monitored data, thus affecting the accuracy of the fused angle offset and consequently the accuracy of subsequent adaptive compensation for workpiece rotation angle.

[0201] In this regard, the present invention further proposes that, prior to S400, the following steps are also included:

[0202] The variance of the monitoring angle offset of the target workpiece during the historical processing is calculated to obtain the actual variance of the offset;

[0203] Based on the actual variance of the offset and the corresponding allowable variance of the offset, the first weight value of the monitored angle offset and the second weight value of the theoretical angle offset are determined.

[0204] In this embodiment, the variance of the monitoring angle offset of the target workpiece during historical processing is calculated to obtain the actual variance of the offset. This variance refers to the degree of dispersion of historical monitoring data relative to its average value, quantified using statistical methods. The magnitude of the variance directly reflects the volatility or stability of the monitoring data over a period of time. A larger variance indicates more drastic fluctuations in the monitoring data, potentially lower reliability; conversely, a smaller variance indicates more stable monitoring data and higher reliability. This variance calculation can be implemented in various ways. For example, monitoring angle offset data from each processing step can be continuously collected and stored in a database. When needed, a certain number of historical data points can be extracted from the database for standard variance calculation.

[0205] Based on the actual variance of the offset and the corresponding allowable variance of the offset, the first weight value of the monitoring angle offset and the second weight value of the theoretical angle offset are determined. This means dynamically adjusting the proportion of the monitoring angle offset and the theoretical angle offset in the fusion calculation according to the actual fluctuation of the monitoring data. The allowable variance of the offset is a preset threshold, representing the maximum degree of fluctuation of the monitoring angle offset within an acceptable range. By comparing the calculated actual variance of the offset with this allowable variance, the reliability level of the current monitoring data can be assessed. This weight determination mechanism can be implemented using various mathematical models. For example, a weight function can be designed that takes the ratio of the actual variance of the offset to the allowable variance of the offset as input and outputs the first weight value and the second weight value, with the sum of the two always being 1. This function can be a linear function, an exponential function, or a piecewise function to achieve a smooth transition of weights under different variance levels.

[0206] As an example, the first weight value for monitoring angular offset can be determined using the following formula 12:

[0207] Formula 12

[0208] In formula 12, The first weight value used to characterize the monitored angular offset Used to characterize the allowable variance of the offset. Used to characterize the actual variance of the offset Used to represent taking the maximum value.

[0209] Through the above technical solution, this invention can assess the reliability of monitoring data in real time and dynamically adjust the weights of monitoring angle offset and theoretical angle offset in the fusion calculation based on the assessment results. This adaptive weight adjustment mechanism effectively avoids calculation errors in the fusion angle offset caused by unstable monitoring data or noise interference, significantly improving the accuracy and robustness of the fusion angle offset. Furthermore, this makes the subsequent adaptive compensation for the workpiece rotation angle more accurate, ultimately improving the precision of circumferential surface finishing and product quality, and reducing the scrap rate.

[0210] In some of the embodiments of the present invention described above, the present invention proposes a method to improve the precision of circumferential surface finishing by adaptively compensating for the workpiece rotation angle. However, in actual production, even if a precise adaptive compensation mechanism is adopted, the processing quality may still fluctuate due to various unforeseen factors. There is a lack of effective feedback and continuous improvement mechanism for the final product quality, which affects the stability and pass rate of the overall production.

[0211] In this regard, the present invention further proposes that the method also includes:

[0212] In response to the triggering conditions of the quality sampling inspection process, a quality sampling inspection is carried out on the target workpiece that has completed the circumferential surface finishing, and the quality inspection results are obtained.

[0213] In response to the quality inspection results indicating that the workpiece is not up to standard, the parameter correction process for the circumferential surface finishing process is triggered.

[0214] In this embodiment, the triggering condition for the quality sampling inspection process refers to the preset conditions for initiating a quality inspection of the target workpiece that has completed finishing. These conditions can be set based on various factors, such as performing a sampling inspection after processing a certain number of workpieces, or performing a sampling inspection after processing workpieces for a certain period of time.

[0215] Quality sampling inspection refers to the random inspection of target workpieces that have undergone circumferential surface finishing to assess whether they meet predetermined quality standards. Quality sampling inspection can be conducted in various ways. For example, a coordinate measuring machine (CMM) can be used to measure key geometric parameters such as roundness, dimensional accuracy, and surface roughness of the workpiece. Another method is to use non-contact optical measuring equipment, employing laser scanning or image processing technology to quickly acquire surface morphology data of the workpiece and compare it with a standard model. Through quality sampling inspection, objective data on the workpiece's machining quality can be obtained, providing a basis for subsequent judgment.

[0216] Quality inspection results refer to the evaluation data or conclusions obtained through quality sampling inspection regarding the processing quality of a target workpiece. Quality inspection results can be expressed as quantitative data, such as deviations in a certain dimension or roundness errors, or as qualitative judgments, such as "qualified" or "unqualified." These results are important bases for judging whether a workpiece meets design requirements and process standards.

[0217] Workpiece machining non-conformity refers to the failure of quality inspection results to meet the preset acceptance standards for the actual machining quality of the target workpiece. The criteria for judging workpiece machining non-conformity are usually determined by design requirements, industry standards, or customer specifications. For example, when a critical dimension of the workpiece exceeds the tolerance range, or the surface roughness does not meet the requirements, it is judged as non-conformity.

[0218] The parameter correction process refers to the process of adjusting and optimizing relevant parameters during the finishing of the circumferential surface when a workpiece fails to meet machining standards. The parameter correction process can be implemented in various ways. For example, it can be manually adjusted by the operator based on experience. Another approach is that the system can automatically recommend or execute parameter adjustment schemes based on historical machining data and the specific characteristics of defective products, using a preset expert system or machine learning algorithm.

[0219] The present invention, based on the aforementioned method for finishing circumferential surfaces, further introduces a feedback and correction mechanism for machining quality. Specifically, after the target workpiece completes circumferential surface finishing, the system responds to the trigger conditions of a preset quality sampling inspection process, such as reaching a certain processing quantity or time node, to perform quality sampling inspection on the finished target workpiece. By detecting key dimensions, morphology, or surface quality, objective quality inspection results can be obtained. When these quality inspection results indicate that the workpiece is unqualified, the system will immediately trigger the parameter correction process for the circumferential surface finishing process. This means that it no longer relies solely on real-time compensation during the machining process, but forms a closed-loop quality control system through the inspection of the final product quality. This feedback correction based on actual machining results can effectively compensate for the potential limitations of real-time compensation, ensuring continuous optimization of the machining process and stability of product quality. In this way, the present invention combines adaptive compensation during the machining process with post-machining quality feedback to form a more robust and intelligent finishing control system, significantly improving the overall pass rate and accuracy of circumferential surface finishing.

[0220] Through the above technical solution, this invention introduces a feedback correction mechanism based on the final product quality, building upon the existing adaptive compensation finishing method. This allows the machining process to not only respond to internal changes in real time but also iteratively optimize based on the actual output quality results. When a workpiece is detected to be defective, parameter correction can be triggered promptly, effectively preventing the mass production of defective products and reducing scrap rate and production costs. Simultaneously, this closed-loop quality control system continuously improves the accuracy and adaptability of machining parameters, thereby significantly enhancing the overall pass rate and product quality stability of circumferential surface finishing, ensuring the reliability of high-precision machining.

[0221] It should be noted that the order of the above embodiments of the present invention is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. The processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0222] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

Claims

1. A method for finishing a circumferential surface using an angular positioning fixture, characterized in that, The method includes: In response to obtaining the real-time stress of the target workpiece at the current moment, a first stress suppression coefficient is determined based on the real-time stress of the workpiece and the average stress of the workpiece at the current target processing stage; the first stress suppression coefficient is used to reflect the strength of the influence of the processing stress at the current moment on the thermal expansion effect. Based on the first stress suppression coefficient, the basic thermal expansion coefficient of the workpiece in the target processing stage is corrected to obtain the real-time effective thermal expansion coefficient of the target workpiece at the current moment. Based on the real-time effective thermal expansion coefficient and the first workpiece temperature of the target workpiece at the current time, the theoretical angular offset of the target workpiece at the current time is determined, including: determining the theoretical angular offset by multiplying the real-time effective thermal expansion coefficient, the first workpiece temperature, and the initial angle value of the target workpiece. The monitored angle offset obtained from the target workpiece at the current moment and the theoretical angle offset are weighted and summed to obtain the fused angle offset of the target workpiece at the current moment. Based on the fusion angle offset of the target workpiece at the current moment, adaptive compensation is performed on the workpiece rotation angle during the circumferential surface finishing process. The step of determining the first stress suppression coefficient at the current moment based on the real-time stress of the workpiece and the average stress of the workpiece at the current target processing stage includes: Obtain the processing progress value at the current moment; Based on the current processing progress value and the real-time stress of the workpiece, determine the second stress suppression coefficient at the current moment; The first correction factor is obtained by dividing the average stress of the workpiece in the target processing stage by the real-time stress of the workpiece. Based on the first correction coefficient, the second stress suppression coefficient is corrected to obtain the first stress suppression coefficient at the current moment; The step of obtaining the processing progress value at the current moment includes: Obtain the historical average feed rate and historical average number of revolutions for each historical processing cycle; The first ratio is obtained by dividing the current real-time feed rate by the historical average feed rate, and the second ratio is obtained by dividing the current real-time rotation number by the historical average rotation number. The processing progress value at the current moment is obtained by averaging the first ratio and the second ratio. The second stress suppression coefficient is an intermediate parameter determined based on the processing progress value and the real-time stress of the workpiece. It is used to preliminarily assess the influence of processing stress on thermal expansion. It is determined by interpolation calculation based on the processing progress value and the real-time stress of the workpiece through a preset lookup table, or by establishing a mathematical model, taking the processing progress value and the real-time stress of the workpiece as input, and outputting the second stress suppression coefficient. The step of correcting the basic thermal expansion coefficient of the workpiece in the target processing stage based on the first stress suppression coefficient to obtain the real-time effective thermal expansion coefficient of the target workpiece at the current moment includes: The temperature change rate is obtained by dividing the difference between the temperature of the first workpiece and the temperature of the standard workpiece at the current moment by the temperature of the standard workpiece. Based on the temperature change rate and the temperature sensitivity coefficient of the target workpiece, a second correction coefficient is determined; Multiply the first stress suppression coefficient, the basic thermal expansion coefficient of the workpiece, and the second correction coefficient to obtain the real-time effective thermal expansion coefficient of the target workpiece at the current moment.

2. The method for finishing a circumferential surface using an angular positioning fixture according to claim 1, characterized in that, Before determining the theoretical angular offset of the target workpiece at the current time based on the real-time effective thermal expansion coefficient and the first workpiece temperature of the target workpiece at the current time, the method further includes: Based on the ambient temperature and workpiece surface temperature at the current moment, determine the internal temperature of the target workpiece at the current moment; The temperature difference between the surface temperature and the internal temperature of the workpiece is multiplied by the temperature distribution uniformity of the target workpiece to obtain the temperature compensation value of the target workpiece at the current moment. The temperature compensation value is added to the internal temperature of the workpiece to obtain the first workpiece temperature of the target workpiece at the current time.

3. The method for finishing a circumferential surface using an angular positioning fixture according to claim 2, characterized in that, Before multiplying the difference between the workpiece surface temperature and the workpiece internal temperature by the temperature distribution uniformity of the target workpiece to obtain the temperature compensation value of the target workpiece at the current moment, the method further includes: The variance of the internal temperature of the target workpiece during the i-th historical processing is calculated to obtain the temperature distribution coefficient of the target workpiece during the i-th historical processing; where i is a positive integer. The temperature distribution coefficients are averaged to obtain the temperature distribution uniformity of the target workpiece.

4. The method for finishing a circumferential surface using an angular positioning fixture according to claim 1, characterized in that, Before correcting the basic thermal expansion coefficient of the workpiece in the target processing stage based on the first stress suppression coefficient to obtain the real-time effective thermal expansion coefficient of the target workpiece at the current moment, the method further includes: Based on the first workpiece temperature, the standard workpiece temperature, and the temperature sensitivity coefficient of the target workpiece at each moment in the target processing stage of the i-th historical processing process, the initial thermal expansion coefficient of the target workpiece at each moment in the target processing stage of the i-th historical processing process is determined; where i is a positive integer. Based on the surface temperature of the target workpiece at each moment in the target processing stage of the i-th historical processing process, and the corresponding predicted surface temperature obtained by the temperature prediction model, the thermal expansion coefficient analysis weight of the target workpiece in the target processing stage of the i-th historical processing process is determined. Based on the initial thermal expansion coefficient of the target workpiece at each moment in the target processing stage of each historical processing process, and the thermal expansion coefficient analysis weight of the target workpiece in the target processing stage of each historical processing process, the basic thermal expansion coefficient of the target workpiece in the target processing stage is determined.

5. The method for finishing a circumferential surface using an angular positioning fixture according to claim 4, characterized in that, Before determining the thermal expansion coefficient analysis weight of the target workpiece in the target processing stage of the i-th historical processing process based on the workpiece surface temperature at each moment in the target processing stage of the i-th historical processing process and the corresponding predicted surface temperature obtained by the temperature prediction model, the method further includes: Based on the surface temperature of the target workpiece at each moment in the target processing stage of the i-th historical processing process, the first temperature rise rate of the target workpiece in the target processing stage of the i-th historical processing process is determined. Based on the first temperature rise rate, average ambient temperature, and average workpiece surface temperature of the target workpiece in each of the target processing stages of the historical processing process, the second temperature rise rate of the target workpiece in the target processing stage is determined. Based on the second temperature rise rate of the target workpiece in the target processing stage and the maximum temperature of the target workpiece in the target processing stage, a temperature prediction model for the target workpiece in the target processing stage is constructed.

6. The method for finishing a circumferential surface using an angular positioning fixture according to claim 1, characterized in that, Before performing a weighted summation of the monitored angle offset obtained from the target workpiece at the current moment and the theoretical angle offset to obtain the fused angle offset of the target workpiece at the current moment, the method further includes: The variance of the monitored angle offset of the target workpiece during the historical processing is calculated to obtain the actual variance of the offset; Based on the actual variance of the offset and the corresponding allowable variance of the offset, a first weight value for the monitored angle offset and a second weight value for the theoretical angle offset are determined.

7. The method for finishing a circumferential surface using an angular positioning fixture according to any one of claims 1-6, characterized in that, The method further includes: In response to the triggering conditions of the quality sampling inspection process being met, the target workpiece that has completed the finishing of the circumferential surface is subjected to quality sampling inspection to obtain the quality inspection results; In response to the quality inspection result indicating that the workpiece is not qualified, the parameter correction process of the circumferential surface finishing process is triggered.

Images