Method for monitoring and compensating deformation of large ring-shaped workpiece during machining

Abstract

The embodiment of the application discloses a large ring part processing deformation multi-sensor monitoring compensation method; the embodiment of the application can generate a feedforward compensation amount based on the radial deformation amount of the stress mutation region in the surface radial deformation appearance time obtained by prediction when processing a large ring part, then generate a feedback compensation amount according to the deviation between the expected processing contour of the large ring part and the actual radial position data, generate a total compensation amount according to the feedback compensation amount and the feedforward compensation amount, and adjust the motion trail of the cutter on the processing machine tool according to the total compensation amount, the expected processing contour of the large ring part, the shape tolerance and the position tolerance. Thus, the embodiment of the application can compensate the deformation caused by stress release in real time during the processing of the large ring part, and improve the compensation efficiency.

Description

Technical Field

[0001] This application relates to the field of intelligent manufacturing technology, specifically to a multi-sensor monitoring and compensation method for deformation during the processing of large ring-shaped parts. Background Technology

[0002] Machining of large ring-shaped parts (such as wind turbine bearing rings, nuclear power pressure vessel flanges, aero-engine casings, and heavy-duty rolling mill support rolls) is widely used in high-end manufacturing fields such as energy, aerospace, rail transportation, and heavy equipment. During the cutting process, these workpieces often experience unpredictable local or overall deformation due to residual stress release, cutting force disturbance, and thermo-mechanical coupling.

[0003] Currently, the industry generally adopts an iterative process of "trial cutting-measurement-correction" to deal with machining deformation caused by stress release. That is, a trial machining is performed first, then the deformation is obtained through offline measurement, and finally the machining parameters or toolpath are corrected. However, this method is inefficient and cannot compensate for dynamic deformations that occur during machining in real time. Summary of the Invention

[0004] This application provides a multi-sensor monitoring and compensation method for deformation during the machining of large ring-shaped parts, which can compensate for deformation caused by stress release in real time during the machining of large ring-shaped parts, thereby improving the compensation efficiency.

[0005] This application provides a multi-sensor monitoring and compensation method for machining deformation of large ring-shaped parts, the method including:

[0006] Based on the change of the center wavelength reflected by multiple fiber Bragg grating sensors embedded in a large ring component over time, the strain time series corresponding to each fiber Bragg grating sensor is calculated, and the strain change rate of the strain time series corresponding to each fiber Bragg grating sensor is determined.

[0007] When the strain change rate corresponding to any fiber Bragg grating sensor exceeds a preset threshold, the stress change region is determined based on the position of any fiber Bragg grating sensor on the large ring component. Based on the stress change time corresponding to the stress change region and the preset time delay parameter from internal stress response to surface deformation, the surface radial deformation manifestation time of the stress change region is predicted.

[0008] Based on the strain rate of any fiber Bragg grating sensor and the preset mapping relationship between the strain rate and radial deformation, the radial deformation of the stress change region during the time of radial deformation manifestation on the surface is predicted.

[0009] Based on the radial deformation, a feedforward compensation amount is generated for the stress change region. At the same time, the actual radial position data of the large ring part measured by the laser displacement sensor arranged on the machine tool is obtained.

[0010] Based on the deviation between the expected machining profile and the actual radial position data of the large ring-shaped part, a feedback compensation amount is generated;

[0011] The total compensation amount is generated by fusing the feedback compensation amount and the feedforward compensation amount, and the motion trajectory of the tool on the machining tool is adjusted according to the total compensation amount, the expected machining contour of the large ring part, the shape tolerance and the position tolerance.

[0012] This application also provides an electronic device, including a processor and a memory, the memory storing multiple instructions; the processor loads instructions from the memory to execute the steps in any of the multi-sensor monitoring and compensation methods for deformation during the processing of large ring-shaped parts provided in this application.

[0013] This application also provides a computer-readable storage medium storing multiple instructions adapted for loading by a processor to execute the steps in any of the multi-sensor monitoring and compensation methods for machining deformation of large ring-shaped parts provided in this application.

[0014] This application also provides a computer program product, including a computer program / instructions, which, when executed by a processor, implement the steps in any of the multi-sensor monitoring and compensation methods for machining deformation of large ring-shaped parts provided in this application.

[0015] In this application, multiple fiber Bragg grating sensors are pre-embedded inside a large ring-shaped component. During the manufacturing process, these fiber Bragg grating sensors can sense the material strain state at their location in real time and output the corresponding strain time series (i.e., data on strain changes over time).

[0016] Furthermore, by analyzing the strain time series and calculating its strain change rate (i.e., the rate of change of strain per unit time), the moment when residual stress is suddenly released can be keenly captured.

[0017] Once the strain change rate corresponding to any fiber Bragg grating sensor is detected to exceed a preset threshold, the corresponding stress change region can be determined based on the position of the fiber Bragg grating sensor on the large ring component. This enables rapid location of the abnormal release of internal stress, focuses global monitoring on specific risk areas, and provides accurate spatial basis for subsequent compensation.

[0018] Based on this, by combining the stress abrupt change time corresponding to the stress abrupt change region and the preset time lag parameters from internal stress response to surface deformation, the manifestation time of radial deformation in the stress abrupt change region can be predicted, allowing for early prediction of the deformation occurrence time. Simultaneously, by substituting the strain change rate into the preset mapping relationship between strain change rate and radial deformation, the radial deformation amount in the stress abrupt change region during the surface radial deformation manifestation time can be predicted. Then, based on the radial deformation amount, a feedforward compensation amount is generated for the stress abrupt change region, enabling proactive intervention before actual surface deformation occurs, overcoming the lag of traditional methods that only respond after deformation has occurred.

[0019] Meanwhile, a laser displacement sensor mounted on the machine tool collects real-time data on the actual radial position of the large ring-shaped part. By comparing the deviation between the actual radial position data and the desired machining contour, a feedback compensation amount is generated to correct residual errors or external disturbances not covered by the feedforward.

[0020] Finally, the feedforward compensation and feedback compensation are spatially aligned and merged to generate a total compensation. The tool trajectory is then dynamically adjusted based on the total compensation, the desired machining profile of the large ring-shaped part, its shape tolerance, and its positional tolerance, thus achieving online, active, and collaborative compensation for the machining deformation of the large ring-shaped part.

[0021] Therefore, this application can compensate for deformation caused by stress release in real time during the processing of large ring parts, thus improving the compensation efficiency. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a flowchart illustrating the multi-sensor monitoring and compensation method for machining deformation of large ring-shaped parts provided in this application embodiment;

[0024] Figure 2 This is a schematic diagram of the structure of the multi-sensor monitoring and compensation device for machining deformation of large ring parts provided in the embodiments of this application. Detailed Implementation

[0025] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0026] This application provides a multi-sensor monitoring and compensation method for deformation during the machining of large ring-shaped parts.

[0027] The multi-sensor monitoring and compensation method for deformation during the machining of large ring-shaped parts can be executed in a multi-sensor monitoring and compensation device for deformation during the machining of large ring-shaped parts. This device can be integrated into an electronic device, such as a terminal or server. The terminal can be a mobile phone, tablet computer, smart Bluetooth device, laptop computer, or personal computer (PC); the server can be a single server or a server cluster consisting of multiple servers.

[0028] In some embodiments, the multi-sensor monitoring and compensation device for deformation of large ring-shaped parts can also be integrated into multiple electronic devices. For example, the multi-sensor monitoring and compensation device for deformation of large ring-shaped parts can be integrated into multiple servers, and the multi-sensor monitoring and compensation method for deformation of large ring-shaped parts of this application can be implemented by multiple servers.

[0029] In some embodiments, the server may also be implemented as a terminal.

[0030] The following sections provide detailed descriptions of each example. It should be noted that the sequence numbers of the following embodiments are not intended to limit the preferred order of the embodiments.

[0031] In this embodiment, a multi-sensor monitoring and compensation method for deformation during the machining of large ring-shaped parts is provided, such as... Figure 1 The specific process of this multi-sensor monitoring and compensation method for deformation during the processing of large ring-shaped parts is as follows:

[0032] 101. Based on the change of the center wavelength reflected by multiple fiber Bragg grating sensors embedded in a large ring component over time, calculate the strain time series corresponding to each fiber Bragg grating sensor and determine the strain change rate of the strain time series corresponding to each fiber Bragg grating sensor.

[0033] Large ring-shaped parts refer to heavy mechanical parts with hollow ring-shaped structures. They are widely used in wind power, nuclear power, aerospace and heavy equipment fields. They are characterized by large size, high wall thickness and complex residual stress distribution. During processing, they are prone to unpredictable radial deformation due to stress release.

[0034] A fiber optic grating (FBG) sensor is a passive optical sensor in which a periodic refractive index modulation structure is written into the core of an optical fiber. When external strain or temperature changes, the center wavelength of its reflected light will drift, and the strain state can be inverted by demodulating this wavelength change.

[0035] The center wavelength refers to the peak wavelength of the reflection spectrum of a fiber Bragg grating sensor under specific strain and temperature conditions, denoted as . ,in, The strain sensitivity coefficient, This is the wavelength offset relative to the initial state.

[0036] Strain time series refers to the strain data sequence continuously acquired by fiber optic grating sensors at their monitoring positions during the machining of large ring-shaped parts, in the form of... This is used to characterize the dynamic evolution of material strain at that location over time.

[0037] The rate of change of strain refers to the speed at which strain changes per unit time, and is used to characterize the drastic instantaneous change in strain. Mathematically, it can be expressed as the first derivative of strain with respect to time, and in discrete sampling, it is approximately the quotient of the difference between adjacent strain values.

[0038] Understandably, multiple fiber Bragg grating (FBG) sensors are pre-embedded circumferentially and / or radially inside the large annular blank. Specifically, during the casting or forging stage of the large annular blank, optical fibers with FBGs are embedded in key areas of the workpiece (such as high residual stress areas or thin-walled transition areas). For example, the optical fibers are arranged along the circumference of the large annular blank, with each FBG spaced at a certain angle (e.g., one every 30°), forming a distributed sensing network. The fiber leads are connected to an external demodulator to achieve real-time wavelength monitoring.

[0039] It should be noted that fiber Bragg grating (FBG) sensors are extremely small (typically 125–250 μm in diameter), with controllable embedding depth, and occupy only a minimal space. This does not compromise the overall structural integrity of large ring-shaped components, nor does it introduce additional stress concentration or affect subsequent heat treatment, machining, or service performance. Furthermore, as FBGs are passive, non-metallic devices, they possess excellent high-temperature resistance and electromagnetic interference immunity, allowing them to remain stable in harsh process environments such as casting, forging, and rough machining, ensuring the feasibility of strain monitoring throughout their entire lifecycle.

[0040] For example, in a large annular blank with a diameter of 2 meters, 12 FBG sensors are uniformly embedded along the circumference, located at 0°, 30°, 60°, ..., 330°, respectively, with a depth of 20 mm from the surface.

[0041] Calculation methods for strain time series corresponding to each fiber Bragg grating sensor:

[0042] The center wavelength reflected by each FBG sensor is acquired in real time using a fiber optic grating demodulator. According to the calibration formula The acquisition time was calculated. The corresponding dependent variable, where, The initial center wavelength before processing begins (zero strain reference state) is used to store ε(t) at each moment in the order of sampling time, forming a strain time series.

[0043] Methods for calculating the rate of change of strain:

[0044] For the strain time series corresponding to each fiber Bragg grating sensor ,in, ( (where the sampling time interval is), then the first rate of change of strain at time 1 This value, measured in με / s, reflects the rate of strain change.

[0045] 102. When the strain change rate corresponding to any fiber Bragg grating sensor exceeds a preset threshold, the stress change region is determined based on the position of any fiber Bragg grating sensor on the large ring component. Based on the stress change time corresponding to the stress change region and the preset time delay parameter from internal stress response to surface deformation, the surface radial deformation manifestation time of the stress change region is predicted.

[0046] In this context, "any fiber Bragg grating sensor" refers to any one of multiple fiber Bragg grating sensors embedded within a large ring-shaped component. It can be understood that during monitoring, all fiber Bragg grating sensors are scanned in parallel, and when any one of them (i.e., "any one") meets the trigger condition, the subsequent processing flow is initiated.

[0047] The strain change rate corresponding to any fiber Bragg grating sensor refers to the rate of change of material strain per unit time at the location monitored by any fiber Bragg grating sensor.

[0048] The preset threshold refers to a pre-defined critical value for the rate of strain change, used to determine whether a significant stress disturbance has occurred. This threshold can be determined through experimental calibration or simulation based on material properties, workpiece dimensions, processing technology, etc.

[0049] The position of any fiber Bragg grating sensor on a large ring refers to the spatial coordinates of any fiber Bragg grating sensor in the geometric coordinate system of the large ring, usually expressed as circumferential angle (e.g., 0°~360°) and / or radial depth (distance from the outer or inner surface). This position is recorded when the fiber Bragg grating sensor is embedded and associated with its unique identifier (e.g., wavelength code or channel number).

[0050] The stress abrupt change region refers to the workpiece region where the material strain changes drastically due to the rapid release of local residual stress.

[0051] The stress mutation time refers to the starting moment of a stress mutation event. It can be understood as the time when the strain rate of change first exceeds a preset threshold, corresponding to the acquisition time of the next strain variable in the strain time series. For example, if the strain rate of change exceeds the preset threshold at t=10.0s, then the stress mutation time is t=10.0s.

[0052] The preset time delay parameter from internal stress response to surface deformation refers to the time delay between the occurrence of internal stress abrupt change and the resulting radial surface deformation being clearly detectable by an external sensor (such as a laser displacement sensor). This parameter is obtained through a reference ring calibration experiment: the time of FBG strain abrupt change and the time of surface radial deformation manifestation measured by the laser displacement sensor are recorded simultaneously, and the difference between the two is the time delay parameter τ (typically tens of seconds to several minutes, depending on the material stiffness, thickness, and structural form).

[0053] The time when radial deformation of the surface becomes apparent refers to the moment when observable radial displacement begins to appear on the surface of the workpiece corresponding to the stress abrupt change region.

[0054] In some embodiments, by delineating stress change regions based on the location of fiber Bragg grating sensors, global monitoring can be focused on local high-risk areas, avoiding indiscriminate compensation of the entire ring component, thereby improving the targeting of compensation and resource utilization efficiency.

[0055] Specifically, based on the position of any fiber Bragg grating sensor on the large annular component, the stress abrupt change region is determined, including:

[0056] Obtain the preset radius of influence of internal stress;

[0057] Centered on the position of any fiber Bragg grating sensor on the large ring component, and based on the radius of influence of internal stress, a stress change region is delineated in the circumference and / or radial direction of the large ring component.

[0058] The radius of influence of internal stress refers to the maximum effective distance over which the strain disturbance caused by the rapid release of residual stress at a certain point propagates within the material and significantly affects the surrounding area. This radius reflects the spatial attenuation characteristics of stress disturbance and is usually determined by material properties (such as elastic modulus and Poisson's ratio), workpiece geometry (such as wall thickness and curvature), and processing history.

[0059] It is understandable that the radius of influence of internal stress can be determined in the following way:

[0060] Experimental calibration: Local stress release (such as local milling) was artificially introduced on the reference ring. The propagation range of strain disturbance was observed using a distributed FBG array. The farthest distance where the strain change rate was higher than the background noise threshold was taken as the influence radius.

[0061] Finite element simulation: Establish a mechanical model of a large ring-shaped component, simulate the strain field distribution after local stress unloading, and extract the effective influence area;

[0062] Experience setting: For similar workpieces (such as wind turbine bearing rings), typical values ​​can be set based on historical data (e.g., the circumferential influence range is ±30°~±60°, corresponding to an arc length of about 200~400mm).

[0063] For example, suppose a large ring-shaped component has 12 fiber Bragg grating sensors uniformly embedded circumferentially during the casting blank stage, located at 0°, 30°, 60°, ..., 330°, with a depth of 30mm from the outer surface. Through stress release experiments on a reference ring-shaped component used for calibration, the circumferential angle range corresponding to the radius of influence of internal stress on this type of workpiece is determined to be ±45° (i.e., an arc length of approximately 1.18 meters). During processing, the strain change rate of the fiber Bragg grating sensor located at 120° exceeds a preset threshold at t=25s. At this point, a fan-shaped region from 75° to 165° is defined circumferentially as the stress abrupt change region, centered at 120° and considering the influence range of ±45°. If the radial influence (e.g., an influence depth of ±20mm) is also considered, this region is further defined as a three-dimensional local area with a circumferential angle of 75°~165° and a radial depth of 10~50mm.

[0064] In some embodiments, by accurately calculating the strain change rate based on the strain time series and combining it with the preset time delay parameters of internal stress response to surface deformation, it is possible to achieve high-time-efficiency prediction of surface deformation, enabling compensation actions to intervene in advance and significantly improving processing accuracy and control foresight.

[0065] Specifically, the strain change rate is calculated based on the time interval between two adjacent strain variables in the strain time series;

[0066] Based on the stress abrupt change time corresponding to the stress abrupt change region and the preset time delay parameters from internal stress response to surface deformation, the manifestation time of surface radial deformation in the stress abrupt change region is predicted, including:

[0067] From the strain time series corresponding to any fiber Bragg grating sensor, determine the target adjacent strain corresponding to the strain change rate exceeding a preset threshold;

[0068] The time of acquisition of the next strain among the adjacent strains of the target is determined as the stress mutation time;

[0069] By fusing the stress abrupt change time and the preset time delay parameters of internal stress response to surface deformation, the manifestation time of surface radial deformation in the stress abrupt change region is predicted.

[0070] Among them, two adjacent dependent variables refer to those in continuous sampling time. and The two measured strain variables are used to calculate the instantaneous rate of change of strain.

[0071] The sampling time interval refers to the time interval between two consecutive strain data collections. Its value is determined by the sampling frequency of the fiber Bragg grating demodulator; for example, when the sampling frequency is 10 Hz, the sampling time interval is 0.1 seconds.

[0072] The target adjacent strain variables refer to the set of adjacent strain variables that cause the strain rate of change to exceed the preset threshold for the first time.

[0073] The time to manifestation of radial deformation on the surface refers to the initial moment when stress disturbance is expected to produce measurable radial displacement on the workpiece surface.

[0074] Understandably, due to the elasticity and inertia of materials, sudden changes in internal stress will not be immediately reflected in the surface morphology, but rather there will be a certain delay. By using the time delay parameters obtained through calibration (such as 60 seconds), the "internal warning" can be transformed into a "surface action command," achieving true predictive compensation.

[0075] For example, during the machining of large ring-shaped parts, an embedded fiber Bragg grating sensor collects strain data at a frequency of 10 Hz (i.e., Δt = 0.1 s). For any fiber Bragg grating sensor, the strain time series is: t = 8:10:49.9 seconds. =85 t=8:10:50 =115 Calculate the rate of change of strain. If the preset threshold is 250 If the strain rate exceeds the preset threshold, an early warning is triggered. At this time, the adjacent strain values ​​of the target are 85με and 115με. The acquisition time of the latter strain value, t=8:10:50, is taken as the stress mutation time. Assuming the time delay parameter τ=70s, the surface radial deformation manifestation time is 8:12:00.

[0076] In some embodiments, by calibrating the temporal relationship between internal stress disturbance and surface deformation on a reference ring, high-precision time delay parameters can be obtained, thereby providing a reliable basis for deformation prediction in actual processing and significantly improving the accuracy and timeliness of feedforward compensation.

[0077] Before predicting the manifestation time of surface radial deformation in the stress-induced region based on the stress-induced change time corresponding to the stress-induced change region and the preset time delay parameters from internal stress response to surface deformation, the following steps are also included:

[0078] Based on the change of the center wavelength reflected by multiple test fiber Bragg grating sensors embedded in the reference ring over time, the strain time series corresponding to each test fiber Bragg grating sensor is calculated, and the strain change rate of each test fiber Bragg grating sensor corresponding to the strain time series is determined.

[0079] When the strain change rate corresponding to any test fiber optic grating sensor exceeds the preset threshold, the acquisition time of the next strain variable corresponding to the strain change rate exceeding the preset threshold is determined as the stress change time corresponding to the reference ring.

[0080] By using a laser displacement sensor arranged on a machine tool, the radial position of a reference ring is detected at preset time intervals to obtain a radial position data sequence.

[0081] Based on the difference between two adjacent radial position data in the radial position data sequence, the surface radial deformation of the reference ring part and the deformation manifestation time corresponding to the surface radial deformation are determined. The deformation manifestation time is the time point when the difference between two adjacent radial position data in the radial position data sequence first exceeds the preset displacement change threshold.

[0082] Based on the time difference between the deformation manifestation time corresponding to the radial deformation of the reference annular part and the stress abrupt change time corresponding to the reference annular part, the time delay parameter from internal stress response to surface deformation is determined.

[0083] The reference ring-shaped part refers to a standard specimen that is highly consistent with the large ring-shaped part to be processed in terms of material composition, heat treatment state, geometric dimensions, and manufacturing process. Its function is to calibrate the dynamic response relationship between internal stress release and surface deformation offline or online, providing transferable model parameters for actual workpieces.

[0084] A test fiber Bragg grating sensor refers to a fiber Bragg grating sensor embedded inside a reference ring to collect strain signals. It has the same function as the fiber Bragg grating sensor used in the actual manufacturing process, but it is used specifically for the calibration stage, hence the name "test" fiber Bragg grating sensor.

[0085] The strain time series corresponding to a test fiber Bragg grating sensor refers to the continuous strain data sequence output by a specific test fiber Bragg grating sensor during the machining of a reference ring or the simulation of stress release. This reflects the evolution of material strain at that location over time.

[0086] The adjacent strain corresponding to the strain change rate exceeding the preset threshold refers to the strain time series corresponding to the tested fiber Bragg grating sensor that first caused the strain change rate. The set of continuous dependent variables that exceed the preset threshold and .

[0087] The stress abrupt change time for the reference annular component refers to the acquisition time of the subsequent strain among adjacent strains corresponding to strain change rates exceeding a preset threshold. This serves as the starting time for the occurrence of internal stress mutations.

[0088] Machine tools refer to CNC machine tools used for precision machining of large ring-shaped parts, such as turning and grinding, and can be integrated with monitoring devices such as laser displacement sensors.

[0089] Laser displacement sensors are non-contact optical measurement devices installed on machine tools to detect the distance from the workpiece surface to the sensor in real time, thereby inverting the radial position of the workpiece.

[0090] The preset time interval refers to the period during which the laser displacement sensor collects radial position data, for example, sampling once every 0.5 seconds. It is set by the system control strategy and needs to take into account both data density and processing load.

[0091] The radial position of the reference ring refers to the radial distance from the surface of the reference ring (such as the outer circle) to the machine tool reference coordinate system, as measured by the laser displacement sensor at a certain moment, and the unit is usually millimeters (mm).

[0092] Radial position data sequence refers to a set of radial position data recorded in chronological order. It is used to analyze surface deformation dynamics.

[0093] Difference between two adjacent radial position data It is used to reflect the change in radial displacement of the surface per unit time and to identify the starting point of deformation.

[0094] Surface radial deformation refers to the phenomenon where the radial dimension of a workpiece surface deviates from its initial state due to the release of internal stress. In this embodiment, during the calibration phase, it is achieved through... Identify by significant changes.

[0095] The deformation manifestation time corresponding to radial deformation of the surface refers to the difference between adjacent values ​​in the radial position data sequence. The time point at which the preset displacement change threshold is first exceeded This refers to the starting time when surface deformation becomes observable by external sensors.

[0096] The preset displacement change threshold is a critical value (e.g., 5μm / 0.5s) used to determine whether the surface has undergone significant deformation. It can be set according to the machine tool resolution, machining tolerance requirements and noise level to avoid misjudging the measured noise as real deformation.

[0097] Understandably, the above calibration process establishes a time mapping relationship between internal strain abrupt changes (sensed by the test fiber optic grating sensor) and surface deformation manifestation (captured by the laser displacement sensor). By calculating the time difference between the deformation manifestation time corresponding to the radial deformation of the reference ring and the stress abrupt change time corresponding to the reference ring, the time delay parameter τ from internal stress response to surface deformation can be obtained. This parameter has universality across workpiece types and can be directly used in the actual machining compensation of similar large ring parts without the need for repeated calibration.

[0098] In some embodiments, the time delay parameter of internal stress response to surface deformation is used as a preset time delay parameter of internal stress response to surface deformation.

[0099] 103. Based on the strain change rate corresponding to any fiber Bragg grating sensor and the preset mapping relationship between the strain change rate and the radial deformation, predict the radial deformation of the stress change region during the radial deformation manifestation time on the surface.

[0100] The preset mapping relationship between the strain rate of change and the radial deformation refers to a pre-established quantitative correspondence used to convert the internal strain rate of change into the surface radial deformation. This mapping relationship can be obtained through calibration experiments on a reference ring, and may take forms including but not limited to: table lookup, linear or nonlinear functions. Piecewise fitting curves and machine learning models, among which, For the rate of change of strain, This represents the corresponding radial deformation.

[0101] Radial deformation refers to the amount of displacement in the radial direction of a large annular part's surface (such as the outer circle or inner hole) relative to the desired machining contour or initial reference position at a certain time, usually measured in micrometers (μm). This value is the direct basis for generating feedforward compensation.

[0102] In some embodiments, by establishing a spatiotemporally aligned dataset between the strain rate of change and the radial deformation of the surface on a reference annular component, and constructing a mapping relationship accordingly, it is possible to achieve accurate conversion from internal stress disturbance signals to external compensation quantities, providing a highly reliable quantitative basis for feedforward control.

[0103] Before predicting the radial deformation of the stress-induced region during the surface radial deformation manifestation time, based on the strain change rate corresponding to any fiber Bragg grating sensor and a preset mapping relationship between the strain change rate and radial deformation, the method further includes:

[0104] For each test fiber Bragg grating sensor in the reference ring, based on the position of the test fiber Bragg grating sensor in the reference ring, a target laser displacement sensor corresponding to the test fiber Bragg grating sensor is determined from the laser displacement sensors arranged on the machine tool.

[0105] Based on the radial position data sequence collected by the target laser displacement sensor, the displacement change of each subsequent radial position data relative to the reference is calculated, and the displacement change is used as the radial deformation at the corresponding acquisition time point.

[0106] Based on each acquisition time point, the corresponding strain change rate is extracted from the strain time series of the test fiber grating sensor corresponding to the target laser displacement sensor.

[0107] Based on the radial deformation and its corresponding strain rate of change at each acquisition time point, a mapping relationship between the strain rate of change and the radial deformation is constructed, and this mapping relationship is used as the preset mapping relationship between the strain rate of change and the radial deformation.

[0108] The target laser displacement sensor refers to the test fiber Bragg grating sensor among multiple laser displacement sensors arranged on the machine tool, whose measurement direction is closest to or strictly aligned with the position of a certain test fiber Bragg grating sensor in the circumferential angle. Its function is to monitor the radial position of the workpiece surface directly opposite the area where the test fiber Bragg grating sensor is located, ensuring spatial consistency between internal (strain) and external (radial position) data.

[0109] The first radial position data refers to the first radial position value acquired by the target laser displacement sensor at the initial moment of the machining or calibration process of the reference ring (usually t=0 or the stabilization stage before stress release), denoted as... This data represents the baseline state of the workpiece when it is not subjected to significant stress disturbance.

[0110] The reference refers to the first radial position data mentioned above. This serves as the reference zero point for calculating all subsequent deformations.

[0111] The change in displacement refers to any subsequent time. Measured radial position data Compared with the benchmark The difference, This value reflects the cumulative radial displacement that has occurred on the workpiece surface from the initial state to the current moment.

[0112] The radial deformation at the time point of acquisition is the value at time... Corresponding displacement change This is directly regarded as the radial deformation of the surface at that moment, and the unit is usually micrometer (μm).

[0113] The strain change rate corresponding to the acquisition time point refers to the strain change rate at the same time. The strain rate of change was calculated by differential calculation from the strain time series of the test fiber grating sensor paired with the target laser displacement sensor. The test requires that the fiber Bragg grating sensor demodulation system and the laser displacement sensor acquisition system be synchronized in time to ensure data alignment.

[0114] Understandably, the above calibration process achieves spatial matching (target laser sensor ↔ test fiber optic grating sensor position) and temporal synchronization (same... Double alignment (extracting internal and external data). This is achieved by collecting multiple sets of (...). , A sample (where D = ΔR) can be fitted to obtain a mapping relationship reflecting the mechanical response characteristics of this type of workpiece. Once this relationship is established and stored, it can be directly used in actual processing to convert the real-time strain rate of change into the predicted deformation, without the need for repeated experiments, thus greatly improving engineering applicability.

[0115] 104. Generate feedforward compensation for stress abrupt change regions based on radial deformation, and simultaneously acquire the actual radial position data of the large ring-shaped part measured by a laser displacement sensor arranged on the machine tool.

[0116] The feedforward compensation is a control command generated based on the predicted radial deformation, used to correct the tool path in advance. This feedforward compensation is calculated and injected into the machining control system before the surface deformation actually appears, acting on the circumferential angular position corresponding to the stress abrupt change region to offset the impending machining error. Essentially, it is a predictive and proactive compensation strategy, distinct from feedback control that relies on post-measurement.

[0117] It should be noted that the amplitude of the feedforward compensation should not exceed the preset proportion of the current machining allowance. This prevents over-compensation from causing overcutting or scrapping of the workpiece, thus improving machining efficiency while ensuring machining safety.

[0118] Current machining allowance refers to the material thickness between the actual position of the surface of a large ring-shaped part and the final target contour (i.e., design dimension) at a certain machining moment. It reflects the amount of material that still needs to be removed.

[0119] The preset ratio is a dimensionless parameter between 0 and 1 (usually denoted as α, 0 < α ≤ 1), used to limit the maximum allowable amplitude of the feedforward compensation, ensuring that the compensation action does not lead to overcutting (i.e., cutting off more than the remaining material). In practical applications, α is often taken as 0.3 to 0.8, depending on process stability, measurement accuracy, and system response characteristics.

[0120] Actual radial position data refers to the distance from the surface of the large annular part to the laser displacement sensor, measured in real time during machining by a laser displacement sensor mounted on the machine tool. This distance is then transformed into coordinates to obtain the current radial position of the large annular part (e.g., outer radius or inner hole radius). This data reflects the current true geometric state of the workpiece surface, including the combined effects of residual stress release, thermal deformation, and clamping errors, and forms the basis for generating feedback compensation.

[0121] Understandably, while feedforward compensation offers foresight, it may not completely eliminate actual deformation due to limitations in model accuracy, material nonlinearity, or external disturbances (such as temperature fluctuations or cutting force variations). Therefore, it is necessary to simultaneously acquire actual radial position data to generate feedback compensation, dynamically correcting residuals not covered by the feedforward mechanism. Through the synergistic mechanism of feedforward and feedback, proactive intervention before deformation occurs and continuous correction of deviations during machining can be achieved, thus realizing high-precision and robust closed-loop compensation control.

[0122] In some embodiments, by combining the spatial location of the stress abrupt change region, the strain evolution trend, and the deformation direction, a feedforward compensation amount with directionality and amplitude is generated, enabling the tool to apply precise radial correction at the correct time and angle position, significantly improving the targeting of compensation and the machining contour accuracy.

[0123] Based on the radial deformation, a feedforward compensation amount is generated for the stress abrupt change region, including:

[0124] Based on the location of the stress abrupt change region on the large ring-shaped component, determine the circumferential angular coordinates corresponding to the radial deformation.

[0125] Based on the strain time series corresponding to any fiber Bragg grating sensor, determine the strain change trend in the stress abrupt change region;

[0126] Determine the radial deformation direction based on the strain change trend;

[0127] Based on the circumferential angular coordinates, radial deformation amount, radial deformation direction, and preset tool path compensation rules, the radial offset direction and offset amount that the tool should apply during the radial deformation manifestation time on the surface are determined, and the radial offset amount and offset direction are used as feedforward compensation amounts.

[0128] The location of the stress abrupt change region on the large ring-shaped component refers to the spatial description of the local area in the workpiece's geometric coordinate system, determined by the location of the fiber optic grating sensor that triggers the early warning and its internal stress influence radius. This is typically expressed as a circumferential angular range (e.g., 75°~165°) and / or radial depth (e.g., 20±10 mm from the outer surface). This location information is used to accurately map the compensation action to the corresponding physical area of ​​the workpiece.

[0129] The circumferential angular coordinates corresponding to the radial deformation refer to the center angle or dominant angle (such as 120°) of the stress abrupt change region in the circumferential direction of the large ring-shaped part, serving as a spatial anchor point for toolpath compensation. When the workpiece rotates to this angle, the control system executes the corresponding compensation command.

[0130] For example, if any grating sensor is located at 120° and the influence radius is ±30°, then the circumferential angular coordinate can be taken as 120° as the compensation point.

[0131] The strain change trend in the stress abrupt change region refers to the strain change before and after the strain abrupt change occurs, and is used to determine whether the material is under tension or compression.

[0132] Radial deformation direction refers to the radial displacement direction of the workpiece surface caused by stress release, which is divided into outward bulging (positive radial direction): usually caused by the release of internal residual tensile stress; and inward concavity (negative radial direction): usually caused by the release of internal residual compressive stress.

[0133] The preset toolpath compensation rule refers to the pre-set control strategy that converts the predicted deformation (direction + amplitude + position) into tool motion commands, including deformation outward → tool reduces radial feed (i.e., shifts inward), deformation inward → tool increases radial feed (i.e., shifts outward).

[0134] The radial offset direction refers to the direction in which the tool moves relative to its original trajectory along the radial axis to counteract the predicted deformation. "Inward" (negative direction): the tool moves towards the center of the workpiece; "Outward" (positive direction): the tool moves away from the center of the workpiece, in the opposite direction to the radial deformation, to achieve error cancellation.

[0135] Offset refers to the absolute distance the tool needs to be adjusted in the radial direction, which is numerically equal to the predicted radial deformation (unit: μm or mm). For example, if the predicted surface protrusion is 85 μm, then the offset is 85 μm, directed inwards.

[0136] For example, a fiber Bragg grating sensor detects a rapid increase in strain from 80 με to 110 με (tensile trend) at a 120° position, predicting that the surface will bulge outward by 90 μm at t=120s. Based on the compensation rule, a feedforward compensation is generated: circumferential angular coordinate: 120°, radial offset direction: inward, offset amount: 90 μm. When the workpiece rotates to 120° and the time is close to 120s, the CNC system of the machine tool drives the cutting tool to shift inward by 90 μm in advance, thereby counteracting the impending bulge.

[0137] In some embodiments, the stress release type (tension / compression) is automatically identified by the strain rate of change sign, and the surface deformation direction (inward / outward) is accurately determined accordingly, solving the problem of direction misjudgment in feedforward compensation and significantly improving the accuracy and reliability of active compensation.

[0138] Based on the strain time series corresponding to any fiber Bragg grating sensor, determine the strain change trend in the stress abrupt change region, including:

[0139] When the strain rate of change corresponding to any fiber Bragg grating sensor is greater than zero, the strain change trend in the stress abrupt region is determined to be a tensile trend.

[0140] When the strain rate of change corresponding to any fiber Bragg grating sensor is less than zero, the strain change trend in the stress abrupt region is determined to be a compressive trend.

[0141] Determining the radial deformation direction based on the strain change trend includes:

[0142] When the strain change trend in the stress abrupt change region is tensile, the radial deformation direction of the stress abrupt change region is determined to be inward.

[0143] When the strain change trend in the stress abrupt change region is a compressive trend, the radial deformation direction of the stress abrupt change region is determined to be outward.

[0144] Among them, the tensile tendency refers to the dynamic process in which the material undergoes elongation deformation along the axial direction of the fiber grating sensor due to the rapid release of internal residual tensile stress or the action of external load in a local area.

[0145] Compression tendency refers to the dynamic process by which a material shortens and deforms along the axial direction of a fiber optic grating sensor in a localized area due to the release of internal residual compressive stress or structural shrinkage.

[0146] "Inward" refers to the radial displacement of the surface of a large annular component toward its central axis. For example, the inward movement of the outer circular surface results in a decrease in the outer diameter; the inward movement of the inner hole surface results in a further reduction in the inner diameter. In this application, "inward," as a type of radial deformation direction, specifically refers to the deformation manifestation of surface concavity or contraction.

[0147] "Outward" refers to the radial displacement of the surface of a large annular component away from its central axis. For example, an outward bulge of the outer circular surface leads to an increase in the outer diameter; an outward expansion of the inner hole surface leads to an increase in the inner diameter. In this application, "outward" as a type of radial deformation direction specifically refers to the deformation manifestation of surface protrusion or expansion.

[0148] Understandably, when a material exhibits a tensile tendency (increased strain), it indicates that residual tensile stress is being released, and the material attempts to "spring back" and elongate. However, due to the overall constraint of the ring-shaped component, this internal elongation often leads to localized inward contraction to maintain force balance (especially in the outer circumference region), manifesting as inward surface deformation. Conversely, when a compressive tendency occurs (decreased strain), it indicates that residual compressive stress is being released, and the material "relaxes" and contracts, often causing localized outward bulging, manifesting as outward surface deformation. The aforementioned correspondence between "tension → inward" and "compression → outward" can be verified in advance through calibration experiments or finite element simulations and used as a criterion for determining the direction of radial deformation.

[0149] In this embodiment, the embedded fiber grating is arranged circumferentially along the annular component, and the measured strain is the circumferential strain. When the circumferential tensile strain increases (strain change rate > 0), it indicates that the local material is stretched, resulting in cross-sectional contraction, and the surface shows radial inward deformation.

[0150] 105. Generate feedback compensation based on the deviation between the expected machining profile and the actual radial position data of the large ring-shaped part.

[0151] The desired machining profile refers to the target geometry that a large ring-shaped part should achieve under ideal, deformation-free conditions, and is usually defined by machining process drawings or CNC programs (NC code). For rotating structures such as outer circles or inner holes, the desired machining profile can be expressed as a function R of the radial position with respect to the circumferential angle. ideal (θ), for example, a circle with a constant radius (R) ideal =constant) or a design curve within a specific tolerance zone. This desired machining profile serves as the benchmark for evaluating and compensating for machining accuracy.

[0152] Deviation refers to the difference between the actual radial position data and the desired machining contour at a certain moment and corresponding circumferential angular position. It can be understood that when the deviation is greater than zero, it indicates that the workpiece surface exceeds the desired machining contour (e.g., the outer circle is too large). When the deviation is less than zero, it indicates that the workpiece surface does not reach the desired machining contour (e.g., the outer circle is too small).

[0153] Feedback compensation refers to the control quantity used to correct the toolpath, calculated in real time based on the deviation. Its direction of action is opposite to the deviation, and its amplitude can be determined using proportional (P), integral (I), derivative (D), or a combination thereof (such as PID) strategies. A typical form is as follows: Where K is the gain coefficient. The feedback compensation is applied to the radial position of the tool in the current or next machining cycle to dynamically eliminate residual errors and compensate for disturbances not covered by the feedforward (such as thermal drift, clamping looseness, material inhomogeneity, etc.).

[0154] In some embodiments, by comparing the actual radial position measured by the laser displacement sensor with its corresponding theoretical value in the circumferential direction of the workpiece, a feedback compensation amount based on the contour deviation is generated, which realizes real-time closed-loop correction of machining errors, effectively suppresses geometric deviations caused by residual stress release, thermal deformation and system disturbance, and significantly improves the final contour accuracy of large ring parts.

[0155] Based on the deviation between the desired machining profile and the actual radial position data of the large ring-shaped part, a feedback compensation amount is generated, including:

[0156] Based on the position of the laser displacement sensor on the machine tool that collects actual radial position data, determine the corresponding circumferential angular coordinates of the large ring-shaped part.

[0157] Based on the circumferential angular coordinates, the corresponding theoretical radial position value is obtained from the expected machining contour of the large ring-shaped part;

[0158] The difference between the theoretical radial position value and the actual radial position data is calculated as the profile deviation;

[0159] Based on the contour deviation and the preset feedback control algorithm, a feedback compensation amount is generated.

[0160] Among them, the laser displacement sensor that collects actual radial position data refers to a sensor installed on a machine tool for non-contact measurement of the distance between the surface of a large annular part and the laser displacement sensor. Its output signal, after coordinate transformation, yields the actual radial position data of the workpiece at the laser displacement sensor. Typically, one or more of these laser displacement sensors are arranged around the circumference of the machine tool to cover the critical monitoring area.

[0161] The circumferential angular coordinate refers to the fixed installation azimuth angle of the laser displacement sensor in the coordinate system of the machining tool, corresponding to the circumferential angle of the measured point when the large ring-shaped part rotates to that position (such as 0°, 90°, 180°, etc.). When the workpiece rotates past the sensor, the collected data belongs to this circumferential angular coordinate and is used to align with the theoretical value of the desired contour at the same angle.

[0162] The theoretical radial position value refers to the ideal radius value corresponding to the aforementioned circumferential angular coordinates in the desired machining profile.

[0163] Contour deviation refers to the difference between the actual radial position data and the theoretical radial position value under the same circumferential angular coordinates. This deviation reflects the degree to which the current machining state deviates from the design target and serves as the input signal for feedback control. A positive value indicates that the workpiece is "out of tolerance outwards," while a negative value indicates "undercut inwards."

[0164] Feedback control algorithms refer to control strategies used to convert profile deviations into feedback compensation quantities. Typical forms include proportional control (P). Proportional-integral (PI) control: PID control or adaptive / fuzzy control (suitable for nonlinear systems), among which, , The preset gain parameter is used, and the negative sign ensures that the compensation direction is opposite to the deviation. This algorithm runs in a CNC system or host controller, outputting compensation commands in real time.

[0165] Understandably, the above process achieves a unification of spatial alignment (matching internal and external data through circumferential angular coordinates) and error quantification (calculated through contour deviation). Since large ring-shaped parts rotate continuously during machining, meaningful error signals can only be obtained by mapping measured data to their corresponding circumferential positions and comparing them with theoretical values ​​at the same positions. The feedback control algorithm then transforms this error into executable tool adjustment amounts, dynamically correcting the trajectory in subsequent cutting, forming a closed loop of "measurement → comparison → compensation → remeasurement." This effectively overcomes uncertainties not covered by the feedforward model, ensuring that the final contour meets high-precision requirements.

[0166] 106. Generate a total compensation amount by fusing the feedback compensation amount and the feedforward compensation amount, and adjust the motion trajectory of the tool on the machining tool according to the total compensation amount, the expected machining contour of the large ring part, the shape tolerance and the position tolerance.

[0167] The total compensation amount refers to the comprehensive compensation command obtained by fusing the feedforward compensation amount and the feedback compensation amount according to a preset strategy, which is used to drive the tool to correct the machining trajectory. Its mathematical expression is usually the algebraic sum of the two: ,in, This is the feedforward compensation amount. The positive and negative signs indicate the radial direction for the feedback compensation amount (positive values ​​indicate outward offset, and negative values ​​indicate inward offset, depending on the system coordinate system). The total compensation amount includes both active suppression of impending deformation and dynamic correction of existing errors, achieving coordinated control of "prediction + correction". It is important to emphasize that the application of the total compensation amount must ensure that the final machining result meets the shape and position tolerance requirements specified in the design—that is, the geometric features of the compensated workpiece must not exceed the allowable tolerance range of the tolerance zone.

[0168] Form tolerance refers to the allowable variation of a single actual measured feature (such as an outer cylindrical surface, inner hole surface, end face, or radial profile) on a large ring-shaped part with respect to its ideal geometry. It is used to limit the local or overall geometric deviation of the ring-shaped part under conditions without datum constraints.

[0169] Position tolerance refers to the maximum allowable positional deviation of a measured feature on a large ring-shaped component relative to the ideal theoretical position of one or more specified datum features. This tolerance is used to constrain the relative spatial relationships between various functional features on the ring-shaped component, ensuring that it meets the requirements of centering, coaxiality, and interface compatibility during assembly or use.

[0170] The tool's trajectory refers to the spatial path followed by the CNC system relative to a large ring-shaped part during machining, particularly the relationship between its radial position and the circumferential angle or time. When turning or grinding large ring-shaped parts, the ideal trajectory should strictly conform to the desired machining contour. When disturbances such as stress release occur, the trajectory needs to be adjusted in real time according to the total compensation amount to counteract the deformation. This adjustment process always uses the specified shape tolerances and position tolerances as accuracy boundaries to ensure that the compensation is both effective and compliant, thereby suppressing deformation during machining.

[0171] Understandably, feedforward compensation addresses "future problems," while feedback compensation addresses "past / current problems." Using either alone has limitations: feedforward relies on model accuracy and may result in undercompensation; feedback has a lag and cannot prevent first-round errors. Total compensation, by combining the advantages of both, enables the tool trajectory to possess foresight and adaptability. Under strict adherence to shape and position tolerance constraints, it significantly improves the machining consistency, contour accuracy, and process robustness of large ring-shaped parts under complex residual stress fields.

[0172] In some embodiments, by determining the positional consistency between the feedforward compensation amount and the feedback compensation amount in the circumferential space, and performing weighted fusion when the angle alignment condition is met, a high-confidence total compensation amount is generated, which effectively avoids compensation superposition errors caused by spatial misalignment (such as mis-superposition in different areas), thereby improving the accuracy and safety of tool path adjustment.

[0173] The total compensation amount is generated by fusing the feedback compensation amount and the feedforward compensation amount, including:

[0174] Determine the circumferential angular coordinates corresponding to the feedforward compensation amount and the circumferential angular coordinates corresponding to the feedback compensation amount;

[0175] When the absolute value of the difference between the circumferential angle coordinates corresponding to the feedforward compensation and the circumferential angle coordinates corresponding to the feedback compensation is less than or equal to the preset angle tolerance, the feedforward compensation and the feedback compensation are weighted and superimposed to generate the total compensation.

[0176] The circumferential angular coordinate corresponding to the feedforward compensation amount refers to the angular marker of the physical position of the large annular component affected by the feedforward compensation amount in the circumferential direction. This is determined by the position of the fiber Bragg grating sensor that triggers the early warning and the center of the stress abrupt change region it defines. For example, if the fiber Bragg grating sensor is located at 120° and the affected area is centered at 120°, then the circumferential angular coordinate corresponding to the feedforward compensation amount is 120°. This coordinate determines the feedforward offset performed by the tool when it rotates to this angle.

[0177] The circumferential angular coordinate corresponding to the feedback compensation amount refers to the circumferential angle of the workpiece at the moment the actual radial position data is acquired, which is determined by the fixed installation orientation of the laser displacement sensor on the machine tool. For example, if the laser sensor is installed at 90° on the machine tool, then the circumferential angular coordinate corresponding to its feedback compensation amount is 90°.

[0178] The absolute value of the difference between the circumferential angle coordinates corresponding to the feedforward compensation and the circumferential angle coordinates corresponding to the feedback compensation is used to determine whether the feedforward compensation and the feedback compensation act on the same or adjacent areas, and is a key criterion for determining whether they can be safely superimposed.

[0179] The preset angle tolerance refers to the maximum circumferential angle deviation threshold that allows the feedforward compensation and feedback compensation to be superimposed, expressed in degrees (°) or radians (rad). This parameter is set according to the workpiece size, stress influence range, and machining accuracy requirements, with typical values ​​ranging from ±5° to ±15°.

[0180] It is understandable that during the high-speed rotational machining of large ring-shaped parts, different sensors may collect data at different angles. If the feedforward compensation targets the 120° region, while the feedback data comes from the 180° region, direct superposition will lead to the erroneous introduction of 180° error correction at the 120° position, thus exacerbating machining deviations. Therefore, only when the two spatial positions are sufficiently close (i.e., the angle difference ≤ the preset angle tolerance) are they considered to reflect the deformation state of the same local area. In this case, weighted superposition (such as equal-weighted average, confidence-based weighting, etc.) can be safely performed to generate a reliable total compensation amount; otherwise, they should be applied independently, or only one of feedforward / feedback should be used.

[0181] For example, the feedforward compensation is triggered by a fiber Bragg grating sensor located at 120°, corresponding to the circumferential angular coordinates. The feedback compensation is provided by a laser sensor installed at 122°. The preset angle tolerance is 5°; the calculated Δθ = |120°−122°| = 2°≤5°, which meets the condition; the feedforward compensation (-90μm) and the feedback compensation (-80μm) are weighted and averaged (each with a weight of 0.5) to generate the total compensation: =0.5×(−90)+0.5×(−80)=−85μm, the tool performs this compensation in the 120°~122° range to achieve precise collaborative control.

[0182] In some embodiments, by precisely superimposing the total compensation amount onto the radial coordinates of the theoretical tool path point, a corrected target position is generated, and the CNC system drives the tool to track the trajectory in real time, thereby achieving high-precision spatial compensation for stress deformation of large ring parts and significantly improving the geometric consistency and dimensional stability of the machining profile.

[0183] Based on the circumferential angle coordinates corresponding to the total compensation, the theoretical tool path point corresponding to the current machining moment is obtained by interpolation from the expected machining profile of the large ring part.

[0184] Determine whether the total compensation amount meets the radial deformation limit allowed by the form tolerance;

[0185] If it is within the form tolerance tolerance range, then determine whether the total compensation amount simultaneously meets the position deviation constraint defined by the position tolerance;

[0186] If the total compensation amount meets the form tolerance but exceeds the position tolerance constraint, then the total compensation amount is limited according to the form tolerance, and the circumferential area corresponding to the total compensation amount is marked to be processed by the subsequent correction process.

[0187] If the total compensation amount satisfies both the form tolerance and position tolerance requirements, then the total compensation amount is applied as a radial offset to the radial coordinate of the theoretical path point to generate the corrected tool target position.

[0188] The CNC system that controls the machining tool drives the cutting tool to the corrected target position.

[0189] The theoretical tool path point refers to the discrete position point on the desired motion trajectory that the tool should follow under ideal conditions without any disturbances (such as residual stress release, thermal deformation, etc.). For the finishing of the outer circle or inner hole of a large ring-shaped part, this path is usually an ideal circle, and its radial coordinate at a certain circumferential angle θ is the theoretical radius value R corresponding to the desired machining profile. ideal (θ). The theoretical tool path point can be represented in polar coordinates (R). ideal (θ),θ) or convert to (x,y) points in a rectangular coordinate system.

[0190] Radial deviation tolerance refers to the maximum range of radial geometric deviations allowed during the machining of large ring-shaped parts, based on their specified form tolerances. This tolerance defines the maximum acceptable outward or inward offset of the workpiece surface relative to the ideal profile at any circumferential angular position.

[0191] Position deviation constraint refers to the maximum permissible positional offset in space of a specific feature on a large ring-shaped component relative to a design datum, as defined by position tolerance.

[0192] The alignment process refers to the non-cutting or micro-cutting correction process implemented after the main cutting is completed to address macroscopic geometric deviations caused by residual stress release, clamping deformation, or thermal effects.

[0193] It is understandable that form tolerances reflect the geometric integrity of the workpiece and must be strictly guaranteed during machining; while positional tolerances involve overall positional deviations that can be corrected through subsequent shaping processes. Therefore, this method uses form tolerance limits as the upper limit of compensation, and under the premise of ensuring contour quality, rationally allocates the task of ensuring positional accuracy to subsequent process steps, thereby improving the adaptability and reliability of the overall manufacturing system.

[0194] Radial offset refers to the amount of correction applied to the radial position of the tool to compensate for predicted or measured deformation, i.e., the aforementioned total compensation amount. Its direction is along the workpiece radius: a positive value indicates that the tool is offset outward (away from the center), and a negative value indicates that the tool is offset inward (closer to the center). This offset directly acts on the radial coordinates of the theoretical path point and is used to generate the actual machining command. The corrected tool target position refers to the new target coordinates obtained by superimposing the radial offset onto the theoretical tool path point. This position is the endpoint reached by the CNC system in actual control of the tool, ensuring that the workpiece surface approximates the ideal contour after cutting.

[0195] The CNC system of a machine tool refers to the digital control unit integrated into the machine tool. It is responsible for parsing the machining program, receiving external compensation commands, calculating the tool trajectory in real time through interpolation, and outputting servo control signals to drive the precise movement of each axis motor (such as the X / Z axis). In this embodiment, the CNC system receives the total compensation amount and dynamically modifies the radial coordinates of the tool to achieve online trajectory correction.

[0196] In summary, this application can compensate for deformation caused by stress release in real time during the processing of large ring parts, thus improving the compensation efficiency.

[0197] To better implement the above methods, this application also provides a multi-sensor monitoring and compensation device for deformation during the processing of large ring-shaped parts. This device can be integrated into an electronic device, such as a terminal or server. The terminal can be a mobile phone, tablet computer, smart Bluetooth device, laptop computer, or personal computer; the server can be a single server or a server cluster composed of multiple servers.

[0198] For example, in this embodiment, the method of this application embodiment will be described in detail by taking the integration of a multi-sensor monitoring and compensation device for deformation during the processing of a large ring-shaped part into an electronic device.

[0199] For example, such as Figure 2 As shown, the multi-sensor monitoring and compensation device for deformation during the machining of large ring-shaped parts may include a rate of change determination unit 201, a sudden change prediction unit 202, a deformation prediction unit 203, a coordination unit 204, a feedback determination unit 205, and a comprehensive determination unit 206, as follows:

[0200] (I) Determination of rate of change unit 201.

[0201] The rate of change determination unit 201 is used to calculate the strain time series corresponding to each fiber Bragg grating sensor based on the change of the center wavelength reflected by multiple fiber Bragg grating sensors embedded in a large ring component over time, and to determine the strain rate of change of the strain time series corresponding to each fiber Bragg grating sensor.

[0202] (ii) Mutation prediction unit 202.

[0203] The mutation prediction unit 202, when it detects that the strain change rate corresponding to any fiber Bragg grating sensor exceeds a preset threshold, determines the stress mutation region based on the position of any fiber Bragg grating sensor on the large ring component, and predicts the surface radial deformation manifestation time of the stress mutation region based on the stress mutation time corresponding to the stress mutation region and the preset time delay parameter from internal stress response to surface deformation.

[0204] In some embodiments, the strain rate of change is calculated based on two adjacent strain variables and the sampling time interval in the strain time series;

[0205] Based on the stress abrupt change time corresponding to the stress abrupt change region and the preset time delay parameters from internal stress response to surface deformation, the manifestation time of surface radial deformation in the stress abrupt change region is predicted, including:

[0206] From the strain time series corresponding to any fiber Bragg grating sensor, determine the target adjacent strain corresponding to the strain change rate exceeding a preset threshold;

[0207] The time of acquisition of the next strain among the adjacent strains of the target is determined as the stress mutation time;

[0208] By fusing the stress abrupt change time and the preset time delay parameters of internal stress response to surface deformation, the manifestation time of surface radial deformation in the stress abrupt change region is predicted.

[0209] In some embodiments, before predicting the surface radial deformation manifestation time of the stress abrupt change region based on the stress abrupt change time corresponding to the stress abrupt change region and a preset time delay parameter from internal stress response to surface deformation, the method further includes:

[0210] Based on the change of the center wavelength reflected by multiple test fiber Bragg grating sensors embedded in the reference ring over time, the strain time series corresponding to each test fiber Bragg grating sensor is calculated, and the strain change rate of each test fiber Bragg grating sensor corresponding to the strain time series is determined.

[0211] When the strain change rate corresponding to any test fiber optic grating sensor exceeds the preset threshold, the acquisition time of the next strain variable corresponding to the strain change rate exceeding the preset threshold is determined as the stress change time corresponding to the reference ring.

[0212] By using a laser displacement sensor arranged on a machine tool, the radial position of a reference ring is detected at preset time intervals to obtain a radial position data sequence.

[0213] Based on the difference between two adjacent radial position data in the radial position data sequence, the surface radial deformation of the reference ring part and the deformation manifestation time corresponding to the surface radial deformation are determined. The deformation manifestation time is the time point when the difference between two adjacent radial position data in the radial position data sequence first exceeds the preset displacement change threshold.

[0214] Based on the time difference between the deformation manifestation time corresponding to the radial deformation of the reference annular part and the stress abrupt change time corresponding to the reference annular part, the time delay parameter from internal stress response to surface deformation is determined.

[0215] In some embodiments, determining stress abrupt change regions based on the position of any fiber Bragg grating sensor on a large annular component includes:

[0216] Obtain the preset radius of influence of internal stress;

[0217] Centered on the position of any fiber Bragg grating sensor on the large ring component, and based on the radius of influence of internal stress, a stress change region is delineated in the circumference and / or radial direction of the large ring component.

[0218] (III) Deformation prediction unit 203.

[0219] The deformation prediction unit 203 is used to predict the radial deformation amount of the stress change region during the radial deformation manifestation time on the surface based on the strain change rate corresponding to any fiber Bragg grating sensor and the preset mapping relationship between the strain change rate and the radial deformation amount.

[0220] In some embodiments, before predicting the radial deformation of the stress abrupt change region during the surface radial deformation manifestation time based on the strain change rate corresponding to any fiber Bragg grating sensor and a preset mapping relationship between the strain change rate and the radial deformation, the method further includes:

[0221] For each test fiber Bragg grating sensor in the reference ring, based on the position of the test fiber Bragg grating sensor in the reference ring, a target laser displacement sensor corresponding to the test fiber Bragg grating sensor is determined from the laser displacement sensors arranged on the machine tool.

[0222] Based on the radial position data sequence collected by the target laser displacement sensor, the displacement change of each subsequent radial position data relative to the reference is calculated, and the displacement change is used as the radial deformation at the corresponding acquisition time point.

[0223] Based on each acquisition time point, the corresponding strain change rate is extracted from the strain time series of the test fiber grating sensor corresponding to the target laser displacement sensor.

[0224] Based on the radial deformation and its corresponding strain rate of change at each acquisition time point, a mapping relationship between the strain rate of change and the radial deformation is constructed, and this mapping relationship is used as the preset mapping relationship between the strain rate of change and the radial deformation.

[0225] (iv) Collaborative Unit 204.

[0226] The collaborative unit 204 is used to generate a feedforward compensation amount for the stress change region based on the radial deformation amount, and at the same time, acquire the actual radial position data of the large ring part measured by the laser displacement sensor arranged on the machine tool.

[0227] In some embodiments, generating a feedforward compensation amount for regions of sudden stress change based on the radial deformation includes:

[0228] Based on the location of the stress abrupt change region on the large ring-shaped component, determine the circumferential angular coordinates corresponding to the radial deformation.

[0229] Based on the strain time series corresponding to any fiber Bragg grating sensor, determine the strain change trend in the stress abrupt change region;

[0230] Determine the radial deformation direction based on the strain change trend;

[0231] Based on the circumferential angular coordinates, radial deformation amount, radial deformation direction, and preset tool path compensation rules, the radial offset direction and offset amount that the tool should apply during the radial deformation manifestation time on the surface are determined, and the radial offset amount and offset direction are used as feedforward compensation amounts.

[0232] In some embodiments, based on the strain time series corresponding to any fiber Bragg grating sensor, the strain change trend in the stress abrupt change region is determined, including:

[0233] When the strain rate of change corresponding to any fiber Bragg grating sensor is greater than zero, the strain change trend in the stress abrupt region is determined to be a tensile trend.

[0234] When the strain rate of change corresponding to any fiber Bragg grating sensor is less than zero, the strain change trend in the stress abrupt region is determined to be a compressive trend.

[0235] Determining the radial deformation direction based on the strain change trend includes:

[0236] When the strain change trend in the stress abrupt change region is tensile, the radial deformation direction of the stress abrupt change region is determined to be inward.

[0237] When the strain change trend in the stress abrupt change region is a compressive trend, the radial deformation direction of the stress abrupt change region is determined to be outward.

[0238] (v) Feedback confirmation unit 205.

[0239] Feedback determination unit 205 is used to generate feedback compensation amount based on the deviation between the expected machining profile and the actual radial position data of the large ring-shaped part.

[0240] In some embodiments, a feedback compensation amount is generated based on the deviation between the desired machining profile and the actual radial position data of the large annular part, including:

[0241] Based on the position of the laser displacement sensor on the machine tool that collects actual radial position data, determine the corresponding circumferential angular coordinates of the large ring-shaped part.

[0242] Based on the circumferential angular coordinates, the corresponding theoretical radial position value is obtained from the expected machining contour of the large ring-shaped part;

[0243] The difference between the theoretical radial position value and the actual radial position data is calculated as the profile deviation;

[0244] Based on the contour deviation and the preset feedback control algorithm, a feedback compensation amount is generated.

[0245] (vi) Comprehensive determination of unit 206.

[0246] The comprehensive determination unit 206 is used to generate a total compensation amount based on the feedback compensation amount and the feedforward compensation amount, and to adjust the motion trajectory of the cutting tool on the machining tool based on the total compensation amount, the expected machining profile of the large ring part, the shape tolerance and the position tolerance.

[0247] In some embodiments, the total compensation amount is generated by fusing the feedback compensation amount and the feedforward compensation amount, including:

[0248] Determine the circumferential angular coordinates corresponding to the feedforward compensation amount and the circumferential angular coordinates corresponding to the feedback compensation amount;

[0249] When the absolute value of the difference between the circumferential angle coordinates corresponding to the feedforward compensation and the circumferential angle coordinates corresponding to the feedback compensation is less than or equal to the preset angle tolerance, the feedforward compensation and the feedback compensation are weighted and superimposed to generate the total compensation.

[0250] In some embodiments, adjusting the motion trajectory of the tool on the machine tool based on the total compensation amount, the desired machining profile of the large ring-shaped part, the desired shape tolerance, and the positional tolerance includes:

[0251] Based on the circumferential angle coordinates corresponding to the total compensation, the theoretical tool path point corresponding to the current machining moment is obtained by interpolation from the expected machining profile of the large ring part.

[0252] Determine whether the total compensation amount meets the radial deformation limit allowed by the form tolerance;

[0253] If it is within the form tolerance tolerance range, then determine whether the total compensation amount simultaneously meets the position deviation constraint defined by the position tolerance;

[0254] If the total compensation amount meets the form tolerance but exceeds the position tolerance constraint, then the total compensation amount is limited according to the form tolerance, and the circumferential area corresponding to the total compensation amount is marked to be processed by the subsequent correction process.

[0255] If the total compensation amount satisfies both the form tolerance and position tolerance requirements, then the total compensation amount is applied as a radial offset to the radial coordinate of the theoretical path point to generate the corrected tool target position.

[0256] The CNC system that controls the machining tool drives the cutting tool to the corrected target position.

[0257] In practice, each of the above units can be implemented as an independent entity or can be arbitrarily combined to be implemented as the same or several entities. For the specific implementation of each of the above units, please refer to the previous method embodiments, which will not be repeated here.

[0258] Therefore, the embodiments of this application can compensate for deformation caused by stress release in real time during the processing of large ring parts, thereby improving the compensation efficiency.

[0259] Those skilled in the art will understand that all or part of the steps in the various methods of the above embodiments can be performed by instructions, or by instructions controlling related hardware. These instructions can be stored in a computer-readable storage medium and loaded and executed by a processor.

[0260] Therefore, embodiments of this application provide a computer-readable storage medium storing a plurality of instructions that can be loaded by a processor to execute the steps in any of the multi-sensor monitoring and compensation methods for deformation during the processing of large ring-shaped parts provided in embodiments of this application.

[0261] The storage medium may include: read-only memory (ROM), random access memory (RAM), disk or optical disk, etc.

[0262] Since the instructions stored in the storage medium can execute the steps in any of the trash rack cleaning path planning methods provided in the embodiments of this application, the beneficial effects that any of the large ring-shaped part processing deformation multi-sensor monitoring and compensation methods provided in the embodiments of this application can achieve can be realized. For details, please refer to the previous embodiments, which will not be repeated here.

[0263] According to one aspect of this application, a computer program product or computer program is provided, comprising a computer program / instructions stored in a computer-readable storage medium. A processor of an electronic device reads the computer program / instructions from the computer-readable storage medium and executes the computer program / instructions, causing the electronic device to perform the method provided in the above embodiments for multi-sensor monitoring and compensation of deformation during the processing of large annular parts.

[0264] The above provides a detailed description of a multi-sensor monitoring and compensation method for deformation during the processing of a large ring-shaped part, as provided in the embodiments of this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the method and its core ideas. At the same time, those skilled in the art will recognize that there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A multi-sensor monitoring and compensation method for deformation during the machining of large ring-shaped parts, characterized in that, The method includes: Based on the change of the center wavelength reflected by multiple fiber Bragg grating sensors embedded in a large ring component over time, the strain time series corresponding to each fiber Bragg grating sensor is calculated, and the strain change rate of the strain time series corresponding to each fiber Bragg grating sensor is determined. When the strain change rate corresponding to any fiber Bragg grating sensor exceeds a preset threshold, the stress change region is determined based on the position of the fiber Bragg grating sensor on the large ring component, and the surface radial deformation manifestation time of the stress change region is predicted based on the stress change time corresponding to the stress change region and the preset time delay parameter from internal stress response to surface deformation. Based on the strain change rate corresponding to any of the fiber Bragg grating sensors, and the preset mapping relationship between the strain change rate and the radial deformation, the radial deformation of the stress change region on the surface is predicted during the radial deformation manifestation time. Based on the radial deformation, a feedforward compensation amount is generated for the stress abrupt change region. At the same time, the actual radial position data of the large annular part measured by the laser displacement sensor arranged on the machine tool is obtained. A feedback compensation amount is generated based on the deviation between the expected machining profile of the large annular component and the actual radial position data. The total compensation amount is generated by fusing the feedback compensation amount and the feedforward compensation amount, and the motion trajectory of the tool on the machining tool is adjusted according to the total compensation amount, the expected machining contour of the large ring part, the shape tolerance and the position tolerance.

2. The method as described in claim 1, characterized in that, The strain change rate is calculated based on the two adjacent strain variables and the sampling time interval in the strain time series; The method of predicting the manifestation time of surface radial deformation in the stress-induced deformation region based on the stress-induced deformation time corresponding to the stress-induced deformation region and the preset time delay parameter from internal stress response to surface deformation includes: From the strain time series corresponding to any of the fiber Bragg grating sensors, determine the target adjacent strain corresponding to the strain change rate exceeding a preset threshold; The sampling time of the next strain among the adjacent strains of the target is determined as the stress mutation time; By fusing the stress abrupt change time and the preset time delay parameter from internal stress response to surface deformation, the manifestation time of surface radial deformation in the stress abrupt change region is predicted.

3. The method as described in claim 1, characterized in that, Before predicting the surface radial deformation manifestation time of the stress abrupt change region based on the stress abrupt change time corresponding to the stress abrupt change region and the preset time delay parameter from internal stress response to surface deformation, the method further includes: Based on the change of the center wavelength reflected by multiple test fiber Bragg grating sensors embedded in the reference ring over time, the strain time series corresponding to each test fiber Bragg grating sensor is calculated, and the strain change rate of each test fiber Bragg grating sensor corresponding to the strain time series is determined. When the strain change rate corresponding to any test fiber optic grating sensor exceeds a preset threshold, the acquisition time of the latter strain among the adjacent strains corresponding to the strain change rate exceeding the preset threshold is determined as the stress change time corresponding to the reference ring. The radial position of the reference ring is detected by a laser displacement sensor arranged on a machine tool at preset time intervals to obtain a radial position data sequence. Based on the difference between two adjacent radial position data in the radial position data sequence, the surface radial deformation of the reference ring is determined, and the deformation manifestation time corresponding to the surface radial deformation is determined. The deformation manifestation time is the time point when the difference between two adjacent radial position data in the radial position data sequence first exceeds a preset displacement change threshold. The time delay parameter from internal stress response to surface deformation is determined based on the time difference between the deformation manifestation time corresponding to the radial deformation of the reference annular component and the stress abrupt change time corresponding to the reference annular component.

4. The method as described in claim 3, characterized in that, Before predicting the radial deformation amount during the radial deformation manifestation time of the stress abrupt change region based on the strain change rate corresponding to any of the fiber Bragg grating sensors and the preset mapping relationship between the strain change rate and the radial deformation amount, the method further includes: For each test fiber Bragg grating sensor in the reference ring, based on the position of the test fiber Bragg grating sensor in the reference ring, a target laser displacement sensor corresponding to the test fiber Bragg grating sensor is determined from laser displacement sensors arranged on the machine tool. Based on the radial position data sequence collected by the target laser displacement sensor, taking the first radial position data as a reference, the displacement change of each subsequent radial position data relative to the reference is calculated, and the displacement change is used as the radial deformation at the corresponding acquisition time point. Based on each acquisition time point, the corresponding strain change rate is extracted from the strain time series of the test fiber optic grating sensor corresponding to the target laser displacement sensor; Based on the radial deformation and its corresponding strain rate of change at each acquisition time point, a mapping relationship between the strain rate of change and the radial deformation is constructed, and the mapping relationship is used as the preset mapping relationship between the strain rate of change and the radial deformation.

5. The method as described in claim 1, characterized in that, The determination of stress abrupt change regions based on the position of any of the fiber Bragg grating sensors on the large annular component includes: Obtain the preset radius of influence of internal stress; Centered on the position of any fiber optic grating sensor on the large annular component, and based on the radius of influence of the internal stress, a stress abrupt change region is delineated in the circumferential and / or radial direction of the large annular component.

6. The method as described in claim 1, characterized in that, The step of generating a feedforward compensation amount for the stress abrupt change region based on the radial deformation includes: Based on the location of the stress abrupt change region on the large annular component, determine the circumferential angular coordinates corresponding to the radial deformation. Based on the strain time series corresponding to any of the fiber Bragg grating sensors, the strain change trend in the stress abrupt change region is determined; The radial deformation direction is determined based on the strain change trend. Based on the circumferential angular coordinates, the radial deformation amount, the radial deformation direction, and the preset tool path compensation rules, the radial offset direction and offset amount that the tool should apply during the radial deformation manifestation time on the surface are determined, and the radial offset amount and offset direction are used as feedforward compensation amounts.

7. The method as described in claim 6, characterized in that, Determining the strain change trend in the stress abrupt change region based on the strain time series corresponding to any of the fiber Bragg grating sensors includes: When the strain change rate corresponding to any of the fiber Bragg grating sensors is greater than zero, the strain change trend of the stress change region is determined to be a tensile trend. When the strain change rate corresponding to any fiber Bragg grating sensor is less than zero, the strain change trend of the stress change region is determined to be a compressive trend. Determining the radial deformation direction based on the strain change trend includes: When the strain change trend of the stress abrupt change region is a tensile trend, the radial deformation direction of the stress abrupt change region is determined to be inward; When the strain change trend of the stress abrupt change region is a compression trend, the radial deformation direction of the stress abrupt change region is determined to be outward.

8. The method as described in claim 1, characterized in that, The step of generating a feedback compensation amount based on the deviation between the expected machining contour of the large annular component and the actual radial position data includes: Based on the position of the laser displacement sensor that collects the actual radial position data on the machine tool, the corresponding circumferential angular coordinates of the large ring-shaped part are determined. Based on the circumferential angular coordinates, the corresponding theoretical radial position value is obtained from the expected machining contour of the large annular part; The difference between the theoretical radial position value and the actual radial position data is calculated as the profile deviation; Based on the contour deviation and the preset feedback control algorithm, a feedback compensation amount is generated.

9. The method as described in claim 1, characterized in that, The step of generating a total compensation amount by fusing the feedback compensation amount and the feedforward compensation amount includes: Determine the circumferential angular coordinates corresponding to the feedforward compensation amount and the circumferential angular coordinates corresponding to the feedback compensation amount; When the absolute value of the difference between the circumferential angle coordinate corresponding to the feedforward compensation amount and the circumferential angle coordinate corresponding to the feedback compensation amount is less than or equal to the preset angle tolerance, the feedforward compensation amount and the feedback compensation amount are weighted and superimposed to generate the total compensation amount.

10. The method as described in claim 1, characterized in that, The step of adjusting the motion trajectory of the cutting tool on the machine tool based on the total compensation amount, the desired machining contour of the large ring-shaped part, the desired shape tolerance, and the positional tolerance includes: Based on the circumferential angle coordinates corresponding to the total compensation amount, the theoretical tool path point corresponding to the current machining moment is obtained by interpolation from the expected machining profile of the large annular part. Determine whether the total compensation amount meets the radial deformation limit allowed by the shape tolerance; If the shape tolerance is within the tolerance range, then determine whether the total compensation amount simultaneously satisfies the position deviation constraint defined by the position tolerance. If the total compensation amount meets the shape tolerance but exceeds the position tolerance constraint, then the total compensation amount is limited according to the shape tolerance, and the circumferential area corresponding to the total compensation amount is marked to be processed by the subsequent shape correction process. If the total compensation amount simultaneously meets the shape tolerance and position tolerance requirements, then the total compensation amount is applied as a radial offset to the radial coordinate of the theoretical path point to generate the corrected tool target position. The CNC system of the machine tool controls the movement of the cutting tool to the corrected target position.

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