Portable detection method and instrument for flatness and machining allowance of large ring

Abstract

The present application relates to large ring piece detection technical field, especially to a kind of portable detection method and instrument of large ring piece flatness and machining allowance, the method includes first establishing the workpiece coordinate system being fixed with ring piece, and based on the coordinate system, the circumferential thickness distribution is quickly obtained, the upper end surface profile curve is generated, the defects types such as whole inclination, local concave-convex or periodic wave deformation are diagnosed synchronously by real-time analysis to profile curve, then, different fine scanning strategies are adaptively triggered according to the diagnosis result, to obtain corresponding high-precision topographic data, finally, the end surface flatness error and global minimum machining allowance are calculated by fusing multi-source data, and the process machinability of ring piece is directly judged accordingly.The present application realizes closed loop from rapid detection, intelligent diagnosis to process decision, solves the problems of low efficiency, inaccurate defect judgment, detection and machining decision disjointedness in large ring piece field detection.

Description

Technical Field

[0001] This invention relates to the field of large ring component testing technology, and in particular to a portable testing method and instrument for the flatness and machining allowance of large ring components. Background Technology

[0002] The flatness of the end face and the radial machining allowance of large ring components are key fundamental indicators for their subsequent finishing. Currently, existing testing technologies cannot achieve efficient, comprehensive, and intelligent closed-loop testing of large ring component blanks on-site, specifically exhibiting the following limitations:

[0003] Fixed or large-scale equipment: high precision but not portable, long testing cycle, high cost, and the data results cannot directly provide intelligent process judgment.

[0004] Traditional manual or portable measuring tools are inefficient, have incomplete coverage, rely on experience, and are difficult to obtain comprehensive and quantitative morphology and allowance distribution. Furthermore, the data cannot be automatically integrated and analyzed.

[0005] Automated scanning equipment: sensitive to the environment, complex and time-consuming data processing, and disconnected from subsequent processing decisions.

[0006] The common shortcomings of these existing technologies can be summarized as follows: they cannot quickly complete comprehensive testing under portable conditions; they cannot perform intelligent cause diagnosis on the test data to distinguish between overall tilt, local concavity and convexity, and periodic deformation; and they cannot adaptively plan fine re-inspection based on the diagnostic results and ultimately directly output process decisions regarding "manufacturability".

[0007] Chinese Patent Publication No. CN111015366A discloses a laser detection device and method for machining allowances in complex box-shaped internal cavities. The detection device mainly consists of a handheld detection gauge, a laser projection device, a measuring rod, and a connecting ring. Through the handheld detection gauge and the blue light-emitting laser projection device, online, non-test-tool detection on machine tools is achieved. This invention is mainly used for detecting machining allowances in the internal cavity hole systems of box-shaped parts and for detecting the internal dimensions of large structural components, particularly solving the problem of detecting contour surface dimensions that are difficult to detect using conventional methods. In principle, measurements can be taken at any position where the laser beam can penetrate and the handheld detection gauge can be placed. This enables non-test-tool online detection on CNC machine tools, effectively solving the problem of online detection of high-precision hole system allowances in box-shaped internal cavities, improving the efficiency of box-shaped hole system machining, and also effectively detecting the internal dimensions of large structural components.

[0008] Therefore, it can be seen that the aforementioned laser detection device and method for machining allowance in complex box cavities has the following characteristics:

[0009] 1. The inspection process involves using a handheld device to check the machining allowance inside the box, which greatly reduces the stability of the inspection process and results in low inspection accuracy.

[0010] 2. The surface defects that may occur in the inner cavity of the box were not considered during the inspection process, and no targeted inspection strategies were developed for different defects, resulting in low accuracy of the inspection results and a high degree of misjudgment in the inspection of machining allowance. Summary of the Invention

[0011] Therefore, the present invention provides a portable method and instrument for detecting the flatness and machining allowance of large ring parts, in order to overcome the problems of low detection accuracy and efficiency and delayed process decision-making in the prior art for flatness and machining allowance.

[0012] To achieve the above objectives, on the one hand, the present invention provides a portable method for detecting the flatness and machining allowance of large ring parts, comprising:

[0013] The testing instrument is fixed to the reference area of ​​the ring through the positioning component, at least three inherent feature points on the ring are identified, and the workpiece coordinate system for a single measurement is established.

[0014] Based on the workpiece coordinate system, a pair of axially arranged cylindrical laser displacement sensors are controlled to move along the ring axis to obtain the actual thickness uniformity coefficient of the ring in the circumferential direction, so as to determine whether the thickness uniformity of the ring meets the standard, and output the contour curve of the axial height of the upper end face contour minus the circumferential angle if the standard is not met.

[0015] Real-time feature analysis is performed based on the contour curve to obtain the maximum tilt angle and residual value sequence, and spectrum analysis is performed on the residual value sequence to simultaneously determine whether there is at least one type of defect on the end face of the ring, including overall tilt, local bulge or depression, and periodic wave deformation.

[0016] Based on different defect types, corresponding fine scanning strategies are executed. For example, if the defect is an overall tilt, a planar verification scan is performed to obtain a high-precision coordinate data set; if the defect is a local bulge or depression, a regional microscopic scan is performed to obtain microscopic three-dimensional topographic point cloud data; and if the defect is a periodic wave deformation, a characteristic wavelength sampling is performed to obtain a characteristic contour line dataset.

[0017] Based on the acquired high-confidence data, a synthetic 3D topography dataset is generated, and the final flatness error value of the upper end face of the ring and the global minimum machining allowance from all points on the current end face to the target theoretical machining surface are obtained to determine whether the ring can be used for subsequent grinding and finishing.

[0018] Furthermore, the process of determining whether the thickness uniformity of the ring meets the standard includes,

[0019] Multiple sets of measurement points are evenly distributed along the circumference of the ring component;

[0020] By moving along the axial direction of the ring using a pair of axially opposed cylindrical laser displacement sensors, the distance between the upper and lower end faces of the ring is measured and converted into the thickness value at the current measurement point.

[0021] Extract the maximum and minimum thickness values ​​from all measurement points;

[0022] Calculate the difference between the maximum and minimum values, and the average of the thickness values ​​at all measurement points;

[0023] The actual thickness uniformity coefficient is calculated based on the difference and the average value.

[0024] The actual thickness uniformity coefficient is compared with the preset thickness uniformity coefficient;

[0025] In response to the actual thickness uniformity coefficient being less than the preset thickness uniformity coefficient, it is determined that the thickness uniformity of the ring is substandard.

[0026] Furthermore, the process of simultaneously determining whether the end face of the ring component exhibits at least one type of defect, including overall tilt, local bulges or depressions, and periodic wave deformation, includes,

[0027] Based on a series of upper surface spatial points corresponding to the contour curve, a spatial reference plane and its normal vector are fitted to obtain the spatial reference plane;

[0028] Extract the length component and vertical component of the projection of the normal vector in the horizontal direction;

[0029] The maximum tilt angle is obtained by calculating the ratio of the absolute value of the length component of the horizontal projection to the absolute value of the vertical component and performing an arctangent operation.

[0030] The maximum tilt angle is compared with the tilt angle threshold.

[0031] The ring end face is determined to be tilted as the maximum tilt angle is greater than the tilt angle threshold.

[0032] Furthermore, the process of simultaneously determining whether the end face of the ring component has at least one type of defect, including overall tilt, local bulges or depressions, and periodic wave deformation, also includes...

[0033] Based on the spatial reference plane, the vertical distance from each measurement point on the contour curve to the spatial reference plane is taken as the residual value of the corresponding point;

[0034] The residual values ​​are arranged in the order of measurement to form a residual value sequence;

[0035] The absolute value of the residual is compared with the residual threshold.

[0036] In response to the absolute value of the residual value being greater than the residual value threshold, it is determined that there is a local protrusion or depression on the end face of the ring component, wherein a positive residual value corresponds to a local protrusion and a negative residual value corresponds to a local depression.

[0037] Furthermore, the process of simultaneously determining whether the end face of the ring component has at least one type of defect, including overall tilt, local bulges or depressions, and periodic wave deformation, also includes...

[0038] The residual value sequence is preprocessed to remove the mean, and the frequency domain spectrum is obtained.

[0039] Calculate the magnitude of each frequency component in the spectrum, and use it as the amplitude of the spectral component.

[0040] The amplitude of the spectral component is compared with the spectral amplitude threshold;

[0041] In response to the presence of at least one of the spectral components with an amplitude greater than a spectral amplitude threshold, it is determined that there is significant periodic wave deformation on the end face of the ring.

[0042] Furthermore, the process of determining to perform a planar verification scan to obtain a high-precision coordinate data set includes,

[0043] Several verification points are evenly distributed along the circumference of the upper end face of the ring.

[0044] The control end-face laser displacement sensor is moved to the positions of several verification points;

[0045] Multiple distance measurements are performed at several of the aforementioned verification point locations, and the results are converted into three-dimensional coordinates in the workpiece coordinate system.

[0046] All coordinates are aggregated to form the coordinate dataset used to correct the plane equation.

[0047] Furthermore, the process of determining the execution area for microscopic scanning to obtain microscopic three-dimensional topographic point cloud data includes,

[0048] The starting point is the center point of the identified local protrusion or depression;

[0049] Estimate the span of the local protrusion or depression on the end face and calculate the side length of the scanning area to form a rectangular area covering the local protrusion or depression.

[0050] The end-face laser displacement sensor is controlled to move to the rectangular area and perform a two-dimensional grid scan;

[0051] The distance measurement value and planar coordinates are recorded synchronously at each grid point to generate the microscopic three-dimensional topographic point cloud data.

[0052] Furthermore, the process of determining to perform feature wavelength sampling to obtain a feature contour line dataset includes,

[0053] The sampling interval is set based on the main characteristic wavelength of the periodic wave deformation;

[0054] The end face sensor is controlled to perform linear scanning along at least three radial paths along the end face of the ring component.

[0055] The radial position and distance value of each sampling point are recorded synchronously to form the feature contour line dataset that characterizes the wave shape.

[0056] Furthermore, the process of determining whether the ring can be used for subsequent grinding and finishing includes,

[0057] The coordinate data set, the microscopic three-dimensional topography point cloud data, and the feature contour line dataset and contour curve are fused together in the workpiece coordinate system to form the synthetic three-dimensional topography dataset.

[0058] The final flatness error is calculated using the minimum region method;

[0059] The synthetic 3D topography dataset is aligned with the theoretical design model based on shared inherent features;

[0060] Calculate the shortest distance from each point to the surface of the theoretical model, and take the minimum value as the global minimum machining allowance;

[0061] The final flatness error value is compared with the flatness error threshold, as well as the global minimum machining allowance and the safety allowance threshold;

[0062] In response to the final flatness error being less than or equal to the flatness error threshold and the global minimum machining allowance being greater than or equal to the safety allowance threshold, the ring is determined to be a machinable forging blank that can be used for subsequent fine grinding.

[0063] On the other hand, the present invention also provides a portable testing instrument for the flatness and machining allowance of large ring parts, comprising:

[0064] A positioning assembly includes a positioning groove and a measuring rod disposed inside the positioning groove for mounting a detection assembly;

[0065] The support assembly includes a plurality of support rods disposed at the upper end of the measuring rod for supporting the detection assembly, the ends of the plurality of support rods being provided with magnetic support legs for attracting the detection instrument to the upper end face of the ring, and support leg slides disposed at the ends of the plurality of support rods for moving the magnetic support legs to adapt to the ring of the same diameter, and the ends of the measuring rods also being provided with a pair of telescopic rods for mounting the detection assembly.

[0066] The detection assembly includes a first cylindrical laser displacement sensor disposed at the upper end of the measuring rod for panoramic scanning of the cylindrical surface of the inner hole of the ring, a second cylindrical laser displacement sensor disposed at the lower end of the measuring rod for forming a thickness detection reference end, and an end face laser displacement sensor disposed at the end of the telescopic rod and facing the upper end face of the ring for detecting the upper end face of the ring.

[0067] The control component includes a digital display screen and a data transmitter disposed on the back of the first cylindrical laser displacement sensor for reading detection values ​​and transmitting signals.

[0068] Compared with existing technologies, the beneficial effects of this invention are as follows: Firstly, through a two-level adaptive detection strategy of "rapid general survey – intelligent diagnosis – precise verification," this invention significantly improves detection efficiency while ensuring a high detection rate for typical defects such as overall tilt, local unevenness, and periodic wave deformation. This avoids the time waste and insufficient accuracy problems of traditional uniform scanning or manual sampling methods, enabling rapid on-site assessment. Secondly, this invention integrates the identification, location, and precise quantification of multiple defects, and can directly output two key process parameters: flatness error and global minimum machining allowance. This makes the detection results no longer abstract data point clouds, but clear conclusions that can be directly used to guide production decisions, effectively solving the technical problem of the disconnect between the detection and processing stages. Finally, based on a unified workpiece coordinate system and clear judgment thresholds, this invention achieves automation and intelligence in the detection process, as well as objectivity and traceability of the judgment results. This significantly reduces reliance on operator experience and improves the consistency of batch production quality and the level of intelligence in the manufacturing process.

[0069] Furthermore, this invention achieves a rapid, stable, and repeatable mechanical connection between the testing instrument and the ultra-large, ultra-heavy ring by physically clamping the positioning groove at the bottom of the instrument to the pre-machined annular process boss on the lower end face of the ring, combined with the adsorption support of the automatically leveling magnetic support legs at the top. This fundamentally solves the core problem of portable instruments being difficult to install stably on large workpieces and easily affected by shaking, laying a physical foundation for high-precision on-site measurement. Secondly, a cylindrical laser displacement sensor performs a 360-degree panoramic scan of the inner hole, and a point cloud processing algorithm is used to automatically identify inherent feature points, such as forging marks and process holes, achieving... The intelligent capture and positioning of the ring's own true geometric features completely avoids the subjective errors and inefficiencies caused by relying on external auxiliary markers or manual visual alignment. Finally, based on the spatial spherical intersection algorithm, multiple feature points are precisely calculated, and a workpiece coordinate system is established with the fitted inner hole axis and the geometric center of the feature points as the reference. The coordinate system established by this method is uniquely bound to the ring entity, has high accuracy, and has clear physical meaning, ensuring that all subsequent scanning data can be unified under this stable and accurate spatial reference system, providing a fundamental guarantee for the data consistency, result reliability, and process decision credibility of the entire inspection process.

[0070] Furthermore, this invention utilizes a pair of axially opposed cylindrical laser displacement sensors and employs a unique method of "fixing the lower sensor and measuring the movement distance of the upper sensor" to obtain thickness values. This cleverly transforms the difficult-to-measure absolute thickness into the sum of a relative displacement and a fixed gauge length, which is easily and precisely measured. This enables efficient and reliable measurement of the wall thickness of large ring components in a portable device. Secondly, by defining and calculating the actual thickness uniformity coefficient and setting a clear preset threshold for automatic comparison, the system can provide an objective and quantitative rapid diagnosis of the overall thickness uniformity of the ring component within one minute, realizing a transformation from "measurement" to "process." The leap in "preliminary status assessment" avoids the lag of traditional methods that only record data without providing immediate conclusions. Crucially, when uniformity is deemed unacceptable, the system can simultaneously and automatically generate and output the "axial height of the upper surface profile - circumferential angle profile curve." This curve is not obtained through separate post-measurement but is generated in real-time from the raw data of the upper sensor during thickness measurement. This provides a direct and accurate data foundation for subsequent defect analysis, forming a highly efficient closed loop of "rapidly identifying problems while simultaneously preparing core data for precise problem localization," greatly optimizing the overall efficiency and logical coherence of the inspection process.

[0071] Furthermore, this invention performs three types of analysis simultaneously on the same contour curve data: by obtaining the maximum tilt angle through plane fitting and vector operations and comparing it with a threshold, the macroscopic "overall tilt" is objectively determined; by calculating the residual values ​​of each point and comparing them with a threshold, the microscopic "local bulges or depressions" are accurately located and quantified; even further, by performing fast Fourier transform spectrum analysis on the residual sequence, periodic wave deformations that are difficult for the human eye to detect but seriously affect processing quality can be keenly identified; this multi-dimensional parallel diagnosis completely changes the limitation of traditional detection that only outputs a single flatness error value and cannot reveal the root cause of defects; secondly, the entire diagnostic process is based entirely on preset, quantifiable thresholds for automatic judgment, which transforms the identification of defects from a vague perception that relies on personal experience to an objective, consistent, and traceable digital decision, significantly improving the accuracy and reliability of process judgment.

[0072] Furthermore, this invention directly transforms intelligent diagnostic conclusions into optimal detection actions, achieving efficient and precise allocation of detection resources. First, this method completely changes the crude mode of "uniform scanning of all areas" in traditional detection, establishing an intelligent mapping rule of "defect type - scanning strategy": For macroscopic overall tilt, efficient planar verification scanning is performed, requiring only high-confidence coordinates at a few key points to accurately correct the planar equation, avoiding unnecessary time consumption across the entire area; for microscopic local protrusions or depressions, regional microscopic scanning is initiated, performing two-dimensional rasterized high-density measurements of the defect area like a microscope, thereby obtaining microscopic three-dimensional morphology sufficient to guide local repair; for regular periodic wave deformation, characteristic wavelength sampling is used, scanning radially at a density conforming to the Nyquist law, accurately capturing the shape and amplitude of the wave with minimal sampling data; fundamentally solving the inherent contradiction between "unacceptable time consumption of comprehensive high-precision scanning" and "the possibility of missing key details with rapid scanning" in the detection of large workpieces.

[0073] Furthermore, this invention integrates all preceding detection and analysis results to generate a unified, high-precision synthetic 3D topography dataset, and directly calculates two ultimate process parameters: final flatness error and global minimum machining allowance. By automatically comparing these two parameters with preset flatness error thresholds and safety allowance thresholds, the system can output clear "machinable" or "unmachinable" process instructions. This completely solves the core pain point of traditional detection methods, which can only provide data but cannot directly give reliable processing conclusions, realizing a closed loop from "measurement" to "reliable decision-making." It enables seamless connection between the detection stage and subsequent processing stages, effectively intercepting unqualified blanks and preventing them from entering expensive and time-consuming finishing processes, thus avoiding huge waste. At the same time, it provides a quantified quality pass for machinable blanks, significantly improving the economy and intelligence level of the manufacturing process. Attached Figure Description

[0074] Figure 1 This is a schematic diagram illustrating the steps of a portable detection method for the flatness and machining allowance of large ring components according to an embodiment of the present invention.

[0075] Figure 2 This is a logic block diagram illustrating how the thickness uniformity of a ring is determined based on the actual thickness uniformity coefficient in an embodiment of the present invention.

[0076] Figure 3 This is a top view schematic diagram of a portable testing instrument for the flatness and machining allowance of large ring parts according to an embodiment of the present invention.

[0077] Figure 4 This is a front cross-sectional view of a portable testing instrument for the flatness and machining allowance of large ring parts according to an embodiment of the present invention.

[0078] Figure 5 This is an enlarged structural diagram of part A of the portable testing instrument for the flatness and machining allowance of large ring parts according to an embodiment of the present invention.

[0079] In the diagram, 1 - ring, 2 - support leg slide, 3 - magnetic support leg, 4 - carbon fiber base, 5 - measuring rod, 6 - first cylindrical laser displacement sensor, 7 - second cylindrical laser displacement sensor, 8 - positioning groove, 9 - telescopic rod, 10 - measured value laser mark, 11 - zero point laser mark, 12 - end face laser displacement sensor, 13 - digital display screen, 14 - data transmitter, 15 - support rod, 16 - slide, 17 - drive motor. Detailed Implementation

[0080] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0081] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0082] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0083] Please see Figure 1The diagram shown illustrates the steps of a portable detection method for the flatness and machining allowance of large ring components according to an embodiment of the present invention.

[0084] An embodiment of the present invention provides a portable method for detecting the flatness and machining allowance of large ring components, comprising:

[0085] Step S1: Fix the positioning groove of the testing instrument in the preset reference area on the lower end face of the ring, and identify at least three inherent feature points on the forging blank to establish a workpiece coordinate system unique to a single measurement.

[0086] Step S2: Based on the workpiece coordinate system, a rapid detection mode is activated. Using a pair of axially opposed laser displacement sensors, the distance data between the upper and lower end faces of multiple sets of measurement points evenly distributed along the circumference of the ring are simultaneously acquired, and the actual thickness value of each point is calculated in real time. Based on the thickness values ​​of all points, an actual thickness uniformity coefficient is calculated. The uniformity of the ring's thickness is then determined based on this coefficient. If the uniformity is not met, the contour curve of the upper end face profile (axial height - circumferential angle) is output.

[0087] Step S3: Perform real-time feature analysis based on the contour curve, simultaneously obtain the maximum tilt angle and residual value, and form a residual value sequence. Simultaneously execute the following steps: determine whether there is an overall tilt on the end face of the ring component based on the maximum tilt angle, determine whether there is a local protrusion or depression based on the residual value, and perform rapid spectrum analysis on the residual value sequence to determine whether there is periodic wave deformation.

[0088] Step S4: Execute corresponding detection strategies based on different defect types. If the defect type is overall tilt, determine to perform planar verification scanning and obtain a set of coordinate data for accurately correcting the tilt plane equation. If the defect type is local convexity or depression, determine to perform regional microscopic scanning and obtain microscopic three-dimensional topographic point cloud data of the local convexity or depression area. If the defect type is periodic wave deformation, determine to perform characteristic wavelength sampling and obtain a dataset of feature contour lines that accurately reflect the wave topographic features.

[0089] Step S5: Based on the acquired high-confidence data, data fusion is performed in the workpiece coordinate system to generate a synthetic three-dimensional topography dataset for final evaluation. The final flatness error value of the upper end face of the ring and the global minimum machining allowance from all points on the current end face to the target theoretical machining surface are calculated to determine whether the ring can be used for subsequent grinding and finishing based on the final flatness error value and the global minimum machining allowance.

[0090] Specifically, this invention employs a two-level adaptive detection strategy of "rapid general survey - intelligent diagnosis - precise verification," which significantly improves detection efficiency while ensuring a high detection rate for typical defects such as overall tilt, local concavity and convexity, and periodic wave deformation. This avoids the time waste and insufficient accuracy problems of traditional uniform scanning or manual sampling methods, enabling rapid on-site assessment. Secondly, this invention integrates the identification, location, and precise quantification of multiple defects, and can directly output two key process parameters: flatness error and global minimum machining allowance. This makes the detection results no longer abstract data point clouds, but clear conclusions that can be directly used to guide production decisions, effectively solving the technical problem of the disconnect between the detection and processing stages. Finally, based on a unified workpiece coordinate system and clear judgment thresholds, it achieves automation and intelligence in the detection process, as well as objectivity and traceability of the judgment results. This significantly reduces reliance on operator experience and improves the consistency of batch production quality and the level of intelligence in the manufacturing process.

[0091] In this embodiment of the invention, step S1 includes:

[0092] Step S11: Place the ring at the inspection station, align the positioning groove at the bottom of the inspection instrument with and clamp it onto a pre-machined annular process boss on the lower end face of the ring. The inspection instrument includes an end face laser displacement sensor for subsequent fine scanning of the end face and a cylindrical laser displacement sensor for panoramic scanning of the cylindrical surface of the inner hole of the ring. Subsequently, unfold the four self-leveling magnetic support legs at the top of the instrument, which are distributed at 90 degrees. Each support leg has an independent force sensor and a micro-drive motor. When the support leg contacts the upper end face of the ring, the system controls the corresponding micro-drive motor to adjust the extension length of the support leg according to the feedback signal of each force sensor until the force on the four support legs is balanced, so that the main body of the instrument achieves stable support and automatic leveling relative to the upper end face of the ring.

[0093] Step S12: After the instrument is fixed, the cylindrical laser displacement sensor at the top of the instrument is turned on to perform a 360-degree panoramic scan of the cylindrical surface of the inner hole of the ring, obtaining the three-dimensional contour point cloud of the inner wall. Using a point cloud processing algorithm, the point cloud is first denoised and fitted to the cylindrical surface. Considering the rough surface of the forging blank, the presence of oxide scale and random textures, adaptive preprocessing is performed on the point cloud before feature recognition: based on the local point cloud density and curvature distribution, the neighborhood search radius used to calculate the normal vector and feature descriptor is dynamically adjusted. Specifically, for areas with low point cloud density or gentle curvature changes, the neighborhood radius is increased to obtain more stable statistical features; for areas with high point cloud density or drastic curvature changes, the neighborhood radius is decreased to preserve details and... To avoid interference between different features, the true structural features are enhanced and noise is suppressed. Subsequently, based on curvature change or eigenvalue analysis, at least three inherent feature points that are not on the same straight line are automatically identified and initially located from the three-dimensional contour. The feature identification can use the SHOT three-dimensional feature descriptor with rotation and translation invariance. However, due to the sparse and irregular characteristics of forging surface features, a higher matching threshold and geometric constraints are set. For example, the feature points should be roughly located on the fitted cylindrical surface to eliminate false matches. The inherent feature points are forging marks with unique shapes formed naturally during the forging process, the intersection of process holes or engravings left in the processing steps, and the edge vertices of lifting holes or keyways inherent on the ring.

[0094] The local point cloud density and the curvature distribution are quantified by calculating the number of points per unit volume and the standard deviation of the point cloud normal vector.

[0095] Step S13: After initial positioning, the high-precision single-point ranging function of the cylindrical laser displacement sensor is activated, and it moves sequentially to the estimated center position of each feature point. A laser beam is emitted to the surface of each feature point and the reflected signal is received. The spatial straight-line distance from the center of the ranging reference point of the cylindrical laser displacement sensor to each feature point is accurately measured by the time-of-flight method. At the same time, the high-resolution dual-axis tilt sensor and rotary encoder built into the instrument synchronously record the current horizontal azimuth and pitch angles of the cylindrical laser displacement sensor relative to the carbon fiber base of the instrument.

[0096] Step S14: Based on the acquired distance-angle dataset and the fixed calibration parameters of the cylindrical laser displacement sensor and the carbon fiber base of the instrument, the three-dimensional coordinates of each feature point in the instrument's own coordinate system are accurately calculated using the spatial spherical intersection algorithm. Subsequently, based on the current non-collinear spatial points, the feature point set is first fitted with a spatial cylindrical surface using the least squares method to obtain the direction of the central axis of the cylindrical surface. This direction is defined as the positive direction of the Z-axis of the workpiece coordinate system, pointing towards the upper end face of the ring. At the same time, the geometric center of the coordinates of all feature points is calculated, and this point is defined as the origin O of the workpiece coordinate system. A plane is drawn through the origin O, perpendicular to the determined Z-axis. In the plane perpendicular to the Z-axis, the vector direction pointing from the origin to one of the most recognizable feature points, such as the center of the largest lifting hole, is selected as the X-axis. Finally, the Y-axis is determined according to the right-hand rule, thereby establishing the workpiece coordinate system.

[0097] Specifically, this invention achieves a rapid, stable, and repeatable mechanical connection between the testing instrument and ultra-large, ultra-heavy ring components by physically clamping the positioning groove at the bottom of the instrument to the pre-machined annular process boss on the lower end face of the ring component, combined with the adsorption support of the automatically leveling magnetic support legs at the top. This fundamentally solves the core problem of portable instruments being difficult to install stably on large workpieces and being easily affected by shaking, laying a physical foundation for high-precision on-site measurement. Secondly, a cylindrical laser displacement sensor performs a 360-degree panoramic scan of the inner hole, and a point cloud processing algorithm is used to automatically identify inherent feature points, such as forging marks and process holes, achieving... The intelligent capture and positioning of the ring's own true geometric features completely avoids the subjective errors and inefficiencies caused by relying on external auxiliary markers or manual visual alignment. Finally, based on the spatial spherical intersection algorithm, multiple feature points are precisely calculated, and a workpiece coordinate system is established with the fitted inner hole axis and the geometric center of the feature points as the reference. The coordinate system established by this method is uniquely bound to the ring entity, has high accuracy, and has clear physical meaning, ensuring that all subsequent scanning data can be unified under this stable and accurate spatial reference system, providing a fundamental guarantee for the data consistency, result reliability, and process decision credibility of the entire inspection process.

[0098] Please see Figure 2 As shown, it is a logic block diagram of an embodiment of the present invention for determining whether the thickness uniformity of the ring meets the standard based on the actual thickness uniformity coefficient.

[0099] Specifically, based on the workpiece coordinate system, a rapid detection mode is activated. Using a pair of axially opposed laser displacement sensors, the distance data between the upper and lower end faces of multiple measurement points evenly distributed along the circumference of the ring are simultaneously acquired, and the actual thickness value of each point is calculated in real time. Based on the thickness values ​​of all points, an actual thickness uniformity coefficient is calculated. The comparison between the actual thickness uniformity coefficient and a preset thickness uniformity coefficient determines whether the thickness uniformity of the ring meets the standard. If the standard is not met, the contour curve of the upper end face profile, representing the axial height minus the circumferential angle, is output.

[0100] If the actual thickness uniformity coefficient is less than the preset thickness uniformity coefficient, it is determined that the thickness uniformity of the ring is not up to standard, and the contour curve of the axial height of the upper end face profile minus the circumferential angle is output.

[0101] If the actual thickness uniformity coefficient is greater than or equal to the preset thickness uniformity coefficient, then the thickness uniformity of the ring is determined to meet the standard.

[0102] In this embodiment of the invention, the calculation process of the actual thickness uniformity coefficient is as follows: First, find the maximum and minimum values ​​among all the thickness values ​​of all measurement points and calculate the difference between them; then, calculate the average value of the thickness of all measurement points; finally, calculate the value 1 minus the ratio of the difference to the average value, and the result is the actual thickness uniformity coefficient.

[0103] Specifically, the distance data between the upper and lower end faces is acquired through a pair of axially opposed laser displacement sensors. The acquisition process is as follows: the laser displacement sensor at the lower end of the coaxial axis is moved to the lowest point of the machined inner diameter surface of the ring, serving as the thickness detection reference end. Then, the measurement is initiated, and the first cylindrical laser displacement sensor at the upper end of the coaxial axis moves uniformly upward along the ring axis from its initial position adjacent to the second cylindrical laser displacement sensor at the lower end until it detects the highest point of the machined inner diameter surface of the ring. During this process, the precise distance the first cylindrical laser displacement sensor moves along the axis is measured in real time using a high-precision grating ruler. The actual thickness value at the measurement point is the sum of the precise distance moved and the calibrated inherent installation distance between the optical centers of the first and second cylindrical laser displacement sensors.

[0104] In this embodiment of the invention, the preset thickness uniformity coefficient ranges from 0.92 to 0.98, and the preferred value is 0.95. The preferred range and preferred value can be determined according to the actual situation, and are not specifically limited here.

[0105] In this embodiment of the invention, the specific process of outputting the contour curve of the axial height-circumferential angle of the upper end face is as follows: In the fast detection mode, when the first cylindrical laser displacement sensor moves along the axis to each circumferential measurement point, it synchronously and accurately measures and records an original value of the normal distance to the upper end face of the ring; for each measurement point, the axial movement distance of the first cylindrical laser displacement sensor from the reference position to the current position is known, as well as the initial zero point position of the second cylindrical laser displacement sensor in the workpiece coordinate system. By comparing the axial movement distance with the initial zero point... By adding the positions, the axial coordinate of the sensor's optical center in the workpiece coordinate system at that moment can be obtained. Then, the original value of the normal distance to the upper end face measured by the sensor itself is subtracted from this axial coordinate, and the calculated result is the absolute axial height value of the upper end face of the ring at the current measurement point in the workpiece coordinate system. Simultaneously, the precise circumferential angle corresponding to the measurement point is obtained through the circumferential angle encoder in the instrument. Finally, a series of "circumferential angle - absolute axial height value" data pairs are stored and connected according to the measurement sequence, that is, the axial height - circumferential angle contour curve of the upper end face contour is generated and output.

[0106] Specifically, this invention utilizes a pair of axially opposed cylindrical laser displacement sensors and employs a unique method of "fixing the lower sensor and measuring the movement distance of the upper sensor" to obtain thickness values. This cleverly transforms the difficult-to-measure absolute thickness into the sum of a relative displacement and a fixed gauge length, which is easily and precisely measured. This enables efficient and reliable measurement of the wall thickness of large ring components in a portable device. Secondly, by defining and calculating the actual thickness uniformity coefficient and setting a clear preset threshold for automatic comparison, the system can provide an objective and quantitative rapid diagnosis of the overall thickness uniformity of the ring component within one minute, realizing a transformation from "measurement" to "process." The leap in "preliminary status assessment" avoids the lag of traditional methods that only record data without providing immediate conclusions. Crucially, when uniformity is deemed unacceptable, the system can simultaneously and automatically generate and output the "axial height of the upper surface profile - circumferential angle profile curve." This curve is not obtained through separate post-measurement but is generated in real-time from the raw data of the upper sensor during thickness measurement. This provides a direct and accurate data foundation for subsequent defect analysis, forming a highly efficient closed loop of "rapidly identifying problems while simultaneously preparing core data for precise problem localization," greatly optimizing the overall efficiency and logical coherence of the inspection process.

[0107] Specifically, real-time feature analysis is performed based on the contour curve to simultaneously acquire the maximum tilt angle and residual values, forming a residual value sequence. This sequence is then used to determine whether the end face of the ring component exhibits overall tilt based on the comparison between the maximum tilt angle and a tilt angle threshold.

[0108] If the maximum tilt angle is less than or equal to the tilt angle threshold, it is determined that the end face of the ring does not have an overall tilt.

[0109] If the maximum tilt angle is greater than the tilt angle threshold, it is determined that the end face of the ring component has an overall tilt.

[0110] In this embodiment of the invention, the process of obtaining the maximum tilt angle is as follows: First, a spatial reference plane is fitted using the least squares method for a series of upper surface spatial points represented by the contour curve. The specific process of the least squares fitting is as follows: The three-dimensional coordinate values ​​of the series of spatial points are input into a plane fitting algorithm. This algorithm calculates a unique spatial plane that minimizes the sum of the squares of the perpendicular distances from all points to the plane to be determined. Mathematically, this spatial plane is described by a standard equation containing four parameters. The first three parameters are usually denoted as A, B, and C, which together form a vector perpendicular to the fitted plane, i.e., the normal vector of the plane; the fourth parameter is denoted as D. The specific values ​​of parameters A, B, C, and D are automatically calculated by the plane fitting algorithm based on the coordinates of all input spatial points. After obtaining the parameters A, B, and C of the fitted plane, the specific direction of the normal vector in space is uniquely determined; the steepest tilt direction is the direction pointed to by the projection of the normal vector onto the workpiece coordinate system; the calculation process of the maximum tilt angle is as follows: based on the parameters A, B, and C of the normal vector, first calculate the sum of the squares of parameter A and parameter B, then take the square root of the sum to obtain an intermediate value; this intermediate value geometrically represents the length of the horizontal projection of the normal vector; finally, calculate the ratio of the absolute value of this intermediate value to the absolute value of parameter C, and perform an arctangent function operation on this ratio to obtain the angle value, which is the maximum tilt angle.

[0111] In this embodiment of the invention, the value range of the tilt angle threshold is 0.1° to 0.3°, preferably 0.2°. The preferred value range and preferred value can be determined according to the actual situation, and are not specifically limited here.

[0112] Specifically, the existence of local protrusions or depressions is determined based on the comparison between the absolute value of the residual value and the residual value threshold.

[0113] If the absolute value of the residual value is less than or equal to the residual value threshold, then it is determined that there is no local protrusion or depression on the end face of the ring component;

[0114] If the absolute value of the residual value is greater than the residual value threshold, it is determined that there is a local protrusion or depression on the end face of the ring component. A positive residual value corresponds to a local protrusion, and a negative residual value corresponds to a local depression.

[0115] In this embodiment of the invention, the process of obtaining the residual value is as follows: after fitting the spatial reference plane using the least squares method and obtaining its plane equation, for each measurement point on the contour curve, its three-dimensional coordinates in the workpiece coordinate system are substituted into the left side of the plane equation for calculation. The absolute value of the obtained value is the vertical distance from the measurement point to the fitted reference plane, and this distance value is the residual value of that point. The residual values ​​of all measurement points are arranged in the measurement order to form the residual value sequence.

[0116] In this embodiment of the invention, the residual value threshold is determined based on the diameter of the ring, surface quality requirements, and subsequent machining allowance. Its typical value range is 0.5mm to 2.0mm, preferably 1.0mm. The preferred value range and preferred value can be adjusted according to the actual situation, and are not specifically limited here.

[0117] Specifically, a rapid spectral analysis is performed on the residual value sequence. The presence of periodic wave deformation is determined by comparing the amplitudes of the analyzed spectral components with spectral amplitude thresholds.

[0118] If the amplitude of all the spectral components is less than or equal to the spectral amplitude threshold, then it is determined that there is no significant periodic wave deformation on the end face of the ring.

[0119] If at least one of the spectral components has an amplitude greater than the spectral amplitude threshold, then it is determined that there is significant periodic wave deformation on the end face of the ring.

[0120] In this embodiment of the invention, the specific process for obtaining the amplitude of the spectral component is as follows: the residual value sequence sampled at equal angular intervals is used as the input signal; firstly, mean-reduction preprocessing is performed, that is, the arithmetic mean of all values ​​in the sequence is calculated, and the average value is subtracted from each value in the sequence to eliminate the DC component; then, the length of the preprocessed sequence is adjusted to the nearest integer power of 2, and the Fast Fourier Transform algorithm is applied to transform the sequence from the spatial angular domain to the spatial frequency domain, resulting in a spectrum in the form of a complex array; each complex number corresponding to each index position in the spectrum represents a specific spatial frequency component; finally, for each complex component, the sum of the square of its real part and the square of its imaginary part is calculated, and the square root operation is performed on the sum, and the result is the amplitude representation of the frequency component in the original residual sequence.

[0121] In this embodiment of the invention, the spectral amplitude threshold is determined based on the process allowable limit of the surface waviness of the ring component, and its typical value range is 0.05mm to 0.15mm, preferably 0.10mm; the preferred value range and preferred value can be adjusted according to the ring component specifications and processing requirements, and are not specifically limited here.

[0122] Specifically, this invention performs three types of analysis simultaneously on the same contour curve data: by obtaining the maximum tilt angle through plane fitting and vector operations and comparing it with a threshold, the macroscopic "overall tilt" is objectively determined; by calculating the residual values ​​of each point and comparing them with a threshold, the microscopic "local bulges or depressions" are accurately located and quantified; furthermore, by performing fast Fourier transform spectrum analysis on the residual sequence, periodic wave deformations that are difficult for the human eye to detect but seriously affect processing quality can be keenly identified; this multi-dimensional parallel diagnosis completely changes the limitation of traditional detection that only outputs a single flatness error value and cannot reveal the root cause of defects; secondly, the entire diagnostic process is based entirely on preset, quantifiable thresholds for automatic judgment, which transforms the identification of defects from a vague perception that relies on personal experience to an objective, consistent, and traceable digital decision, significantly improving the accuracy and reliability of process judgment.

[0123] Specifically, corresponding detection strategies are implemented based on different defect types, among which...

[0124] If the defect type is overall tilt, then a plane verification scan is performed to obtain a set of coordinate data for accurately correcting the tilt plane equation;

[0125] If the defect type is a local protrusion or depression, then determine the area to be scanned microscopically and obtain the microscopic three-dimensional topographic point cloud data of the local protrusion or depression area.

[0126] If the defect type is periodic wave deformation, then characteristic wavelength sampling is performed, and a feature contour line dataset that accurately reflects the wave morphology is obtained.

[0127] In this embodiment of the invention, the execution process of the planar verification scan is as follows: the end-face laser displacement sensor and its two-dimensional translation stage on the upper end face of the ring are controlled to move to N verification point positions evenly distributed in the circumferential direction of the upper end face of the ring, where N is an even number greater than or equal to 4; at each verification point position, the end-face laser displacement sensor performs multiple high-precision distance measurements and records the results, and converts the distance value measured each time into three-dimensional coordinates in the workpiece coordinate system according to the spatial pose of the sensor at that point; finally, the multiple three-dimensional coordinates obtained at all verification points are collected to form the high-precision coordinate data set used to accurately correct the equation of the inclined plane.

[0128] In this embodiment of the invention, the execution process of the regional microscopic scanning is as follows: starting from the center point of the identified local protrusion or depression, the end face laser displacement sensor and its two-dimensional translation stage are controlled to perform two-dimensional gridded path movement within a rectangular area covering the defect area; firstly, based on the circumferential angle range corresponding to the continuous data segments in the residual value sequence whose amplitude exceeds the residual value threshold, combined with the radius of the ring, the approximate span of the defect on the end face is estimated; subsequently, the product of the approximate span and the safety factor is used as the side length of the scanning area to ensure that the scanning range can completely cover the defect and its transition area; at each stopping node of the grid path, the end face laser displacement sensor performs a high-precision distance measurement, and records the distance value together with the two-dimensional plane coordinates of the sensor node in the workpiece coordinate system as a three-dimensional data point; after traversing all grid nodes, the set of all recorded three-dimensional data points constitutes the microscopic three-dimensional topography point cloud data.

[0129] In this embodiment of the invention, the characteristic wavelength sampling process is as follows: based on the identified main characteristic wavelength of the periodic wave deformation, the end face laser displacement sensor and its two-dimensional translation stage are controlled to perform one-dimensional linear scanning along at least three radial paths of different radii on the end face of the ring; the sampling point spacing of each radial path is no greater than one-quarter of the characteristic wavelength; during the scanning process, the end face laser displacement sensor moves at a constant speed and continuously performs high-precision ranging, while recording the precise position on the radial path corresponding to each ranging value; the sequence of "position-distance" data pairs obtained on each radial path constitutes a characteristic contour line that can accurately reflect the wave undulation pattern at that radius, and the contour lines of all radial paths constitute the characteristic contour line dataset.

[0130] The two-dimensional translation stage includes an end-face laser displacement sensor for detecting the upper end face of the ring, a pair of telescopic rods for supporting the end-face laser displacement sensor and adapting to rings of different diameters, and a drive motor for driving the end-face laser displacement sensor and the telescopic rods to rotate in a two-dimensional plane along the end face of the ring.

[0131] Specifically, this invention directly transforms intelligent diagnostic conclusions into optimal detection actions, achieving efficient and precise allocation of detection resources. First, this method completely changes the traditional crude mode of "uniform scanning of all areas" in detection, establishing an intelligent mapping rule of "defect type - scanning strategy": For macroscopic overall tilt, efficient planar verification scanning is performed, requiring only high-confidence coordinates at a few key points to accurately correct the planar equation, avoiding unnecessary time consumption across the entire area; for microscopic local protrusions or depressions, regional microscopic scanning is initiated, performing two-dimensional rasterized high-density measurements of the defect area like a microscope, thereby obtaining microscopic three-dimensional morphology sufficient to guide local repair; for regular periodic wave deformation, characteristic wavelength sampling is used, scanning radially at a density conforming to the Nyquist law, accurately capturing the shape and amplitude of the wave with minimal sampling data; fundamentally solving the inherent contradiction between "unacceptable time consumption of comprehensive high-precision scanning" and "the possibility of missing key details with rapid scanning" in the inspection of large workpieces.

[0132] Specifically, based on the acquired high-confidence data, data fusion is performed in the workpiece coordinate system to generate a synthetic three-dimensional topography dataset for final evaluation. The final flatness error value of the upper end face of the ring and the global minimum machining allowance from all points on the current end face to the target theoretical machining surface are calculated. The suitability of the ring for subsequent grinding and finishing is determined based on the comparison results between the final flatness error value and the flatness error threshold, and between the global minimum machining allowance and the safety allowance threshold.

[0133] If the final flatness error is less than or equal to the flatness error threshold and the global minimum machining allowance is greater than or equal to the safety allowance threshold, then the ring is determined to be a machinable forging blank that can be used for subsequent grinding and finishing.

[0134] If the final flatness error is greater than the flatness error threshold, or the global minimum machining allowance is less than the safety allowance threshold, then the ring is determined to be an unmachinable forging blank, and a process alarm command is generated.

[0135] In this embodiment of the invention, the specific process for obtaining the final flatness error is as follows: First, all the high-precision data obtained in step S4, including the coordinate data set, the microscopic three-dimensional topography point cloud data, and the feature contour line dataset, are spliced ​​and fused with the fast-scanning contour curve obtained in step S2 in the workpiece coordinate system to form a complete synthetic three-dimensional topography dataset of the upper end face of the ring; then, the flatness error is calculated using the minimum region method on this synthetic dataset. The goal is to find a pair of parallel planes such that all data points in the synthetic dataset are located between these two parallel planes, and the distance between these two planes is the minimum value among all possible solutions, which is the final flatness error.

[0136] The specific process of splicing and fusion is as follows: First, coordinate alignment is performed; for the microscopic three-dimensional topography point cloud data and the feature contour line dataset, all their data points are directly incorporated into the synthetic dataset as high-precision feature points; for the coordinate data set, it is combined with the data points of the contour curve of the corresponding position through fast scanning, and a local weighted surface fitting method is used to generate the optimized three-dimensional coordinate points of that position; for the regions in the contour curve that are not covered by any fine data, their original data points are retained as the basic topography description.

[0137] In this embodiment of the invention, the specific process for obtaining the global minimum machining allowance is as follows: First, the pre-imported theoretical three-dimensional design model representing the final machining completion state of the ring component is aligned with the synthetic three-dimensional topography dataset representing the current actual state. The theoretical three-dimensional design model is usually a triangular mesh model. After alignment, for each three-dimensional data point in the synthetic three-dimensional topography dataset, the shortest Euclidean distance from it to the surface of the triangular mesh of the theoretical three-dimensional design model is calculated using a spatial nearest neighbor search algorithm, which is taken as the instantaneous machining allowance of that point. After traversing and calculating the instantaneous machining allowance of all data points in the synthetic three-dimensional topography dataset, the minimum value among them is found and taken as the global minimum machining allowance.

[0138] The alignment process is as follows: A common, geometrically defined inherent feature shared by the theoretical model and the measured dataset is selected as the alignment reference, preferably an inner cylindrical surface. The theoretical axis of the inner cylindrical surface is extracted from the theoretical model, and data points of the measured inner surface are extracted from the synthetic 3D topography dataset and fitted to the cylindrical surface to obtain the measured axis. A spatial rigid body transformation, including rotation and translation, is calculated to make the measured axis coincide with the theoretical axis. Simultaneously, the distance between the point set representing the reference region of the lower end face of the ring in the measured dataset and the corresponding reference plane in the theoretical model is minimized, thereby completing the precise spatial alignment of the theoretical model and the measured data in the workpiece coordinate system.

[0139] In this embodiment of the invention, the flatness error threshold is set based on the specifications, materials and assembly accuracy requirements of the ring component, and is used to distinguish between acceptable flatness fluctuations and unacceptable deformations. The value range is 0.1mm to 0.5mm, preferably 0.3mm. The preferred value range and preferred value can be determined according to the actual situation, and are not specifically limited here.

[0140] In this embodiment of the invention, the safety margin threshold is determined comprehensively based on the process margin of subsequent CNC machining, the tool wear tolerance, and the stability of the machining system. It is used to ensure that the machining process is reliable and no scrap occurs. The value range is 1.0mm to 5.0mm, preferably 4mm. The preferred value range and preferred value can be determined according to the actual situation, and are not specifically limited here.

[0141] Specifically, this invention integrates all preceding detection and analysis results to generate a unified, high-precision synthetic 3D topography dataset. Based on this dataset, it directly calculates two ultimate process parameters: the final flatness error and the global minimum machining allowance. By automatically comparing these two parameters with preset flatness error thresholds and safety allowance thresholds, the system can output clear "machinable" or "unmachinable" process instructions. This completely solves the core pain point of traditional detection methods, which can only provide data but cannot directly give reliable machining conclusions, realizing a closed loop from "measurement" to "reliable decision-making." It enables seamless connection between the detection stage and subsequent processing stages, effectively intercepting unqualified blanks and preventing them from entering expensive and time-consuming finishing processes, thus avoiding huge waste. At the same time, it provides a quantified quality pass for machinable blanks, significantly improving the economy and intelligence level of the manufacturing process.

[0142] Please see Figures 3 to 5 As shown, Figure 3 This is a top view schematic diagram of a portable testing instrument for the flatness and machining allowance of large ring parts according to an embodiment of the present invention. Figure 4 This is a front cross-sectional view of a portable testing instrument for the flatness and machining allowance of large ring parts according to an embodiment of the present invention. Figure 5 This is an enlarged structural diagram of part A of the portable testing instrument for the flatness and machining allowance of large ring parts according to an embodiment of the present invention.

[0143] Specifically, embodiments of the present invention also provide a portable testing instrument for the flatness and machining allowance of large ring components, including,

[0144] The positioning component includes a positioning groove 8 with a pre-machined annular process boss on the lower end face of the ring 1. A carbon fiber base 4 for stabilizing the testing instrument is provided at the bottom of the positioning groove 8. A measuring rod 5 for mounting the testing component is provided inside the positioning groove 8.

[0145] The support assembly includes four support rods 15 disposed on the upper end of the measuring rod 5 to support the testing instrument. Each support rod 15 has four magnetic legs 3, the same number as the support rods 15, for adhering to the upper surface of the ring 1. The surface of the support rod 15 is also provided with a leg slide 2 for moving the magnetic legs 3 in a plane so that the testing instrument can adapt to rings of different diameters. A pair of telescopic rods 9 are disposed on the top of the measuring rod 5 to support the testing assembly.

[0146] In this embodiment of the invention, when the support rod 15 is working, each adjacent support rod forms a 90° angle to guide the magnetic support leg 3 and the support leg slide 2 into the working position, and adjusts the position of the magnetic support leg 3 through the support leg slide 2 so that the distance between the two opposing magnetic support legs 3 matches the diameter of the ring to be tested. The force sensor (not shown in the figure) built into the magnetic support leg 3 and the first micro drive motor (not shown in the figure) automatically level and fix it to the upper end face of the ring.

[0147] The detection assembly includes a first cylindrical laser displacement sensor 6 disposed at the upper end of the measuring rod 5 for panoramic scanning of the cylindrical surface of the inner hole of the ring, a second cylindrical laser displacement sensor 7 disposed at the lower end of the measuring rod 5 for forming a thickness detection reference end, and an end face laser displacement sensor 12 disposed at the end of the telescopic rod 9 and facing the upper end face of the ring for detecting the upper end face of the ring.

[0148] In this embodiment of the invention, the end of the telescopic rod 9 is provided with a slide rail 16 for allowing the detection component to slide on the surface of the telescopic rod 9 to adapt to rings of different diameters, and a drive motor 17 is provided in the middle of the telescopic rod and rotatably connected to the measuring rod 5 for driving the end face laser displacement sensor 12 and the telescopic rod 9 to rotate in a two-dimensional plane along the end face of the ring.

[0149] In this embodiment of the invention, the end face laser displacement sensor 12 can be moved through the slide rail 16 during operation, and the end face laser displacement sensor 12 can also rotate around the telescopic rod 9 within a preset angle range via a built-in second micro-drive motor (not shown in the figure) to form a grid-type scanning mode.

[0150] In this embodiment of the invention, the first cylindrical laser displacement sensor 6 is detected by emitting a measurement value laser mark 10, and the second cylindrical laser displacement sensor 7 is calibrated by emitting a zero-point laser mark 11, forming a thickness detection reference end.

[0151] The preset angle range is 0° to 20°.

[0152] The control components include a digital display screen 13 and a data transmitter 14 disposed on the back of the first cylindrical laser displacement sensor 6 for reading detection values ​​and transmitting signals.

[0153] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A portable method for measuring the flatness and the machining allowance of a large ring, characterized in that, The application relates to a method for detecting the thickness uniformity of a ring workpiece. The detection instrument is fixed to the reference area of the ring workpiece through a positioning assembly, at least three inherent feature points on the ring workpiece are identified, and a workpiece coordinate system for single measurement is established; Based on the workpiece coordinate system, a pair of axially arranged cylindrical laser displacement sensors are controlled to move along the axis of the ring workpiece, the actual thickness uniformity coefficient of the ring workpiece in the circumferential direction is obtained, whether the thickness uniformity of the ring workpiece meets the standard is determined, and an axial height-circumferential angle profile curve of the upper end surface profile is output under the condition that the thickness uniformity of the ring workpiece does not meet the standard; Based on the profile curve, real-time feature analysis is carried out, the maximum inclination angle and a residual value sequence are obtained, and spectrum analysis is carried out on the residual value sequence, so that at least one defect type of overall inclination, local protrusion or depression, and periodic wave deformation of the end surface of the ring workpiece is synchronously determined; Based on different defect types, corresponding fine scanning strategies are executed, wherein if the defect type is overall inclination, plane verification scanning is determined to be executed to obtain a high-precision coordinate data set; If the defect type is local protrusion or depression, regional microscopic scanning is determined to be executed to obtain micro three-dimensional topography point cloud data; if the defect type is periodic wave deformation, characteristic wavelength sampling is determined to be executed to obtain a characteristic profile line data set; Based on the obtained high-confidence data, a synthesized three-dimensional topography data set is generated, and the final flatness error value of the upper end surface of the ring workpiece and the global minimum machining allowance of all points on the current end surface to the target theoretical machining surface are obtained, so that whether the ring workpiece can be used for subsequent grinding finishing is determined.

2. The portable method for inspecting the flatness and the machining allowance of a large ring member according to claim 1, characterized by, The process of determining whether the thickness uniformity of the ring workpiece meets the standard comprises the following steps: A plurality of groups of measurement points are uniformly distributed in the circumferential direction of the ring workpiece; A pair of axially opposite cylindrical laser displacement sensors are moved along the axial direction of the ring workpiece to measure the distance between the upper end surface and the lower end surface of the ring workpiece, and the distance is converted into a thickness value of the current measurement point position; The maximum value and the minimum value of the thickness values of all measurement points are extracted; The difference between the maximum value and the minimum value and the average value of the thickness values of all measurement points are calculated; The actual thickness uniformity coefficient is calculated according to the difference and the average value; The actual thickness uniformity coefficient is compared with a preset thickness uniformity coefficient; In response to the actual thickness uniformity coefficient being smaller than the preset thickness uniformity coefficient, it is determined that the thickness uniformity of the ring workpiece does not meet the standard.

3. The portable method of inspecting the flatness and the machining allowance of a large ring member according to claim 2, characterized by, The process of synchronously determining whether the end surface of the ring workpiece has at least one defect type of overall inclination, local protrusion or depression, and periodic wave deformation comprises the following steps: Based on a series of upper end surface space points corresponding to the profile curve, a space reference plane and a normal vector thereof are fitted; The length component and the vertical component of the horizontal direction projection of the normal vector are extracted; The maximum inclination angle is obtained by calculating the ratio of the absolute values of the length component and the vertical component of the horizontal direction projection and performing an inverse tangent operation; The maximum inclination angle is compared with an inclination angle threshold value; In response to the maximum inclination angle being greater than the inclination angle threshold value, it is determined that the end surface of the ring workpiece has overall inclination.

4. The portable method for inspecting the flatness and the machining allowance of a large ring member according to claim 3, characterized by, The process of synchronously determining whether the end surface of the ring workpiece has at least one defect type of overall inclination, local protrusion or depression, and periodic wave deformation further comprises the following steps: Based on the spatial reference plane, a vertical distance from each measuring point on the profile curve to the spatial reference plane is taken as a residual value of the corresponding point; The residual values are arranged in a measuring sequence to form a residual value sequence; An absolute value of the residual value is compared with a residual value threshold; In response to the absolute value of the residual value being greater than the residual value threshold, it is determined that there is a local protrusion or depression on the end face of the ring, wherein the residual value is positive when corresponding to a local protrusion, and the residual value is negative when corresponding to a local depression.

5. The method of claim 4, wherein The process of synchronously determining whether the end face of the ring has at least one defect type of overall tilt, local protrusion or depression, and periodic wave deformation further comprises, The residual value sequence is preprocessed by removing the mean value, and a frequency domain spectrum is obtained; A modulus value corresponding to each frequency component in the frequency domain spectrum is calculated as a spectrum component amplitude; The spectrum component amplitude is compared with a spectrum amplitude threshold; In response to at least one spectrum component amplitude being greater than the spectrum amplitude threshold, it is determined that there is significant periodic wave deformation on the end face of the ring.

6. The method for portable detection of flatness and machining allowance of large rings according to claim 5, characterized in that, The process of determining to perform a plane verification scan to obtain a high-precision coordinate data set comprises, A plurality of verification point positions are uniformly distributed in the circumferential direction of the upper end face of the ring; The end face laser displacement sensor is controlled to move to the plurality of verification point positions; Multiple distance measurements are performed at the plurality of verification point positions, and the results are converted into three-dimensional coordinates in the workpiece coordinate system; All coordinates are collected to form the coordinate data set for correcting the plane equation.

7. The method of claim 6, wherein the method further comprises: The process of determining to perform a regional microscopic scan to obtain microscopic three-dimensional topography point cloud data comprises, The center point position of the identified local protrusion or depression is taken as a starting point; The span of the local protrusion or depression region on the end face is estimated, and the scanning region side length is calculated to form a rectangular region covering the local protrusion or depression; The end face laser displacement sensor is controlled to move to the rectangular region, and a two-dimensional grid scan is performed; And the distance measurement value and the plane coordinate are recorded synchronously at each grid point to generate the microscopic three-dimensional topography point cloud data.

8. The portable method of inspecting the flatness and the machining allowance of a large ring member according to claim 7, characterized by, The process of determining to perform characteristic wavelength sampling to obtain a characteristic profile line data set comprises, A sampling interval is set based on the main characteristic wavelength of the periodic wave deformation; The end face laser displacement sensor is controlled to perform a straight-line scan along at least three radial paths of the ring end face; The radial position and the distance measurement value of each sampling point are recorded synchronously to form the characteristic profile line data set representing the wave topography.

9. The portable method of inspecting the flatness and the machining allowance of a large ring member according to claim 8, characterized by, The process of determining whether the ring can be used for subsequent grinding finishing comprises, The coordinate data set, the microscopic three-dimensional topography point cloud data, and the characteristic profile line data set are fused with the profile curve in the workpiece coordinate system to form the synthesized three-dimensional topography data set; The minimum zone method is used to calculate the final flatness error value; The synthesized three-dimensional topography data set is aligned with a theoretical design model based on common inherent characteristics; The shortest distance of each point to the surface of the theoretical model is calculated, and the minimum value is taken as the global minimum machining allowance; The final flatness error value is compared with a flatness error threshold, and the global minimum machining allowance is compared with a safety allowance threshold; In response to the final flatness error value being less than or equal to a flatness error threshold and the global minimum machining allowance being greater than or equal to a safety allowance threshold, the ring piece is determined to be a processable forging blank, which can be used for subsequent fine polishing processing.

10. A measuring instrument suitable for use in the portable measuring method of flatness and machining allowance of large rings according to any one of claims 1 to 9, characterized in that, Comprise, A positioning assembly comprising a positioning slot and a measuring rod arranged inside the positioning slot for mounting a detection assembly; A supporting assembly comprising a plurality of supporting rods arranged at the upper end of the measuring rod for supporting the detection assembly, the end of the plurality of supporting rods is provided with a magnetic attraction leg for attracting the detection instrument to the upper end surface of the ring piece, and a leg sliding channel is arranged at the end of the plurality of supporting rods for moving the magnetic attraction leg to adapt to the ring piece with the same diameter, and the end of the measuring rod is also provided with a pair of telescopic rods for mounting the detection assembly; A detection assembly comprising a first cylindrical laser displacement sensor arranged at the upper end of the measuring rod for panoramic scanning of the cylindrical surface of the inner hole of the ring piece, and a second cylindrical laser displacement sensor arranged at the lower end of the measuring rod for forming a thickness detection reference end, and an end surface laser displacement sensor arranged at the end of the telescopic rod and opposite to the upper end surface of the ring piece for detecting the upper end surface of the ring piece; A control assembly comprising a digital display screen and a data transmitter arranged at the back of the first cylindrical laser displacement sensor for reading detection values and transmitting signals.

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