A four-layer half-hole plate precision drilling trajectory measurement system
By combining image acquisition and deformation analysis technologies with dynamic monitoring of the trajectory measurement module, a self-collimation measurement system for a four-layer half-hole plate was constructed. This system solves the problems of depth deviation and directional distortion in existing measurement systems under dynamic cutting environments, and achieves high-precision drilling and cutting trajectory monitoring.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- GANZHOU ZHONGSHENGLONG ELECTRONIC CO LTD
- Filing Date
- 2026-02-13
- Publication Date
- 2026-06-02
AI Technical Summary
Existing technologies make it difficult to perceive the local strain field of the material and the tool position distortion in real time during the drilling and cutting of four-layer half-hole plates. This results in depth deviation and directional distortion in the metering system when cutting deep half-holes, and adding hardware sensors will increase costs.
The image acquisition module acquires random texture images of the surface and dynamic projection contours of the cutting tool. The deformation analysis unit identifies the displacement vectors of feature points and local deformation correction parameters. Combined with the trajectory measurement module, grayscale gradient data and shadow shortening rate are extracted to construct a self-collimating dynamic closed-loop measurement framework, enabling real-time monitoring and path correction of the cutting tool.
Without adding hardware sensors, the system achieves the coordinated inversion of the local strain field of the substrate and the tool position distortion, ensuring the spatial consistency and trajectory accuracy of the measurement system under dynamic cutting environment, and avoiding axial measurement distortion caused by mechanical precision decay and sudden changes in medium resistance.
Smart Images
Figure CN121708040B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of precision geometric measurement technology, and in particular relates to a measurement system for the precision drilling and cutting trajectory of a four-layer half-hole plate. Background Technology
[0002] Establishing a precise mapping between the drilling tool and the substrate space is fundamental to ensuring the quality of semi-hole forming. The current industry-standard technical strategy is to use global markers on the surface of the plate to construct a virtual reference model. The projection coordinates of the processing path in three-dimensional space are determined through linear affine transformation or fitting algorithms. This method exhibits stable positioning performance on an overall scale. However, many improvement schemes involve mechanical structure integration and modularization. For example, Chinese invention patent CN119388146A discloses a precision drilling and cutting system for a four-layer semi-hole plate. It uses an L-shaped bracket, a lead screw, and a hydraulic cylinder to achieve physical integration of drilling and cutting functions. This scheme is based on the geometric mapping of a rigid mechanical coordinate system. The accuracy depends on the physical stroke of the machine tool guide elements. It ignores the dynamic displacement caused by the release of internal stress in the substrate under cutting load. Due to the lack of real-time inversion methods for the local strain field and dynamic yaw of the spindle at the processing site, it is difficult to perceive the surface topological distortion caused by material anisotropy.
[0003] However, with the increase in the number of circuit board layers and the improvement of process precision, there is a core constraint on the physical properties of materials: the universality of overall positioning and the fidelity of local positioning cannot be achieved simultaneously. This is because the difference in the warp and weft density of the internal fiberglass cloth and the uneven distribution of resin in the four-layer board lamination process cause the local deformation induced by the drilling and cutting thermal effect to exhibit nonlinearity and discreteness. This deformation characteristic causes the metrology model to become disconnected from the actual physical topology. In addition, the radial runout and axial tilt generated by the high-speed rotation of the spindle accumulate in the thickness direction, causing the surface entry hole coordinates and the inner layer invasion boundary to deviate vectorly. To address the above challenges, the industry has tried to remedy the situation by increasing the sampling point density or using high-dimensional pure data smoothing algorithms. However, adding hardware sensors will increase the integration cost and is limited by the physical space of the machine tool. Statistical smoothing without physical mechanism constraints cannot restore the instantaneous spatial distortion caused by the release of internal stress in the material, and cannot detect the axial yaw caused by uneven tool force. As a result, the metrology system has depth deviation and directional distortion when processing deep half-hole notches.
[0004] Therefore, the technical problem to be solved by this invention is how to achieve the coordinated inversion of the local strain field of the substrate and the tool position distortion by utilizing the feature flow generated by optical sensing without introducing additional hardware sensing, thereby constructing a dynamic closed-loop metrology framework with self-collimation capability. Summary of the Invention
[0005] This invention provides a measurement system for the precision drilling trajectory of a four-layer half-hole plate, comprising:
[0006] The image acquisition module is used to acquire random surface texture images around the drilling points of the four-layer half-hole plate and the dynamic projection contour of the cutting tool in the cutting state.
[0007] The deformation analysis unit is used to identify the displacement vectors of feature points in the random texture image of the surface when the cutting tool applies cutting force, and to determine the local deformation correction parameters of the drilling site based on the displacement vectors of the feature points. This is used to perform non-uniform mesh reconstruction on the preset linear reference model to generate a correction reference surface that characterizes the spatial distortion caused by the release of internal stress in the substrate. The deformation analysis unit is also used to convert the transient geometric deformation of the drilling site under pressure into the local coordinate offset of the correction reference surface by establishing the mapping logic between the sub-pixel offset of the displacement vector of the feature points and the local curvature of the linear reference model.
[0008] The trajectory measurement module extracts grayscale gradient data from the edges of the dynamically projected contour and determines the deflection vector characterizing the dynamic yaw of the cutting tool spindle based on the grayscale gradient data. The module also calculates the instantaneous spatial tilt angle of the cutting tool spindle by identifying the brightness span of the edge blurring region generated by the cutting tool in the rotating projection. Furthermore, the module performs pose compensation on the projected trajectory in the correction reference surface using the instantaneous spatial tilt angle and identifies the cutting tool's position using the shadow shortening rate at the moment of contact with the four-layer half-hole plate surface. The zero point of displacement in the axial direction, and the actual penetration depth of the cutting tool in the inner layer of the four-layer half-hole plate determined by the phase difference sequence of the shadow length, generate a three-dimensional coordinate measurement conclusion characterizing the actual movement path of the cutting tool inside the four-layer half-hole plate.
[0009] Preferably, the image acquisition module includes an industrial camera and a coaxial cold light source; the coaxial cold light source is used to create a dark field lighting environment around the drilling site so that the industrial camera can capture the random fabric texture of the fiberglass cloth distribution inside the semi-cured sheet of the four-layer semi-perforated plate as a surface random texture image; the sampling frequency of the industrial camera is 3 to 5 times the spindle speed of the cutting tool.
[0010] Preferably, when determining local deformation correction parameters, the deformation analysis unit uses feature region matching logic to determine the amount of movement of the surface random texture image between consecutive frames, and bases this on the formula... Determine the local deformation coefficient of the drilling site. ;in, The coefficient of local deformation. The average magnitude of the displacement vector of the feature point, in mm. This is the preset elastic modulus of the substrate, in MPa. The real-time cutting force exerted by the cutting tool on the drilling site is expressed in N; the deformation analytical unit utilizes the local deformation coefficient. Position corrections are performed on the mesh nodes in the linear reference model to generate a corrected reference surface.
[0011] Preferably, when determining the deflection vector, the trajectory measurement module performs sub-pixel edge extraction on the edge of the dynamic projection contour, removes air disturbance interference caused by the rotation of the cutting tool, and determines the dynamic deflection variable of the cutting tool under the action of cutting torque based on the angle between the center line of the cutting tool projection and the normal of the correction reference surface.
[0012] Preferably, when determining the actual intrusion depth, the trajectory measurement module uses the shadow shortening rate at the moment the cutting tool contacts the surface of the four-and-a-half-hole plate for calibration. The starting point of the axis is determined, and the real-time depth coordinates of the cutting tool between the inner copper foils inside the four-layer half-hole plate are inverted based on the linear dependence of the cutting tool feed rate and the phase difference sequence of the shadow length.
[0013] Preferably, the metering system further includes: a trajectory correction control unit; the trajectory correction control unit is connected to the trajectory metering module and is used to compare the three-dimensional coordinate metering results with the preset drilling and cutting trajectory. When the spatial position indicated by the three-dimensional coordinate metering results deviates from the preset drilling and cutting trajectory by more than 10 μm in Euclidean distance, the trajectory correction control unit outputs a feed parameter adjustment command to correct the feed rate or spindle speed.
[0014] Preferably, the linear reference model is constructed by the deformation analysis unit based on the coordinates of the global reference marker points on the surface of the four-layer half-hole plate acquired by the image acquisition module; the coordinates of the global reference marker points are the spatial absolute coordinate reference of the four-layer half-hole plate under the condition of no cutting force.
[0015] Preferably, the dynamic projection contour captured by the image acquisition module includes the reflected projection area formed by the cutting tool on the surface of the four-layer half-hole plate; the trajectory measurement module measures the local depression displacement of the four-layer half-hole plate under pressure at the drilling point by analyzing the geometric distance between the reflected projection area and the projection of the cutting tool body, and uses the local depression displacement as... Dynamic correction increments in the axial direction are used to compensate for zero displacement.
[0016] Preferably, the trajectory measurement module is also used to analyze the frequency oscillation characteristics in the grayscale gradient data, so as to help determine the type of medium currently penetrated by the cutting tool based on the difference in vibration frequency generated during cutting of different material layers, and call the material stiffness coefficient matching the medium type to perform numerical verification of the deflection vector.
[0017] Preferably, the measurement system uses the deformation analysis unit to quantify the displacement vector of the feature point, and combines the trajectory measurement module to dynamically invert the rotating light and shadow features, thereby realizing closed-loop measurement of the actual movement path of the cutting tool inside the four-layer half-hole plate.
[0018] Compared with existing technologies, the metering system for precision drilling and cutting trajectories of four-layer half-hole plates of the present invention has the following advantages:
[0019] 1. In the metrology of precision drilling and cutting trajectories of four-layer half-hole plates, the system realizes the transformation of the metrology reference model from global linear fitting to local anisotropic mapping based on the adjoint extraction of random texture features of the surface layer around the drilling and cutting point. It uses the substrate strain information generated during processing as a self-feedback calibration source, enabling the topological unit to capture and compensate for nonlinear deformation caused by resin flow or uneven distribution of glass fiber in real time. This eliminates the metrology residuals in areas far from the global marker point under complex pressing structures, ensuring the spatial consistency of trajectory metrology conclusions in dynamic cutting environments.
[0020] 2. By performing symmetry arbitration on the dynamic geometric envelope contour formed by the high-speed rotating tool in the projection area, this invention constructs a non-contact real-time pose compensation path. The dynamic runout of the tool spindle and the slight yaw caused by the force are converted into the distortion characteristics of the optical envelope for quantitative analysis. This allows the trajectory calculation engine to perform coordinate reconstruction on the actual intrusion position of the tool in each inner layer circuit based on the calculated instantaneous axis tilt vector, avoiding axial measurement distortion caused by the decay of spindle mechanical precision or the sudden change in resistance of multi-layer media.
[0021] 3. By utilizing the sequence of projected length changes and edge grayscale gradient features during the cutting process, the system achieves self-collimation monitoring of the force deflection and depth reference, and constructs a fully closed-loop metrology framework covering three-dimensional coordinates and vector attitude. This technical logic, based on the inversion of the tool's intrinsic force state and spatial position using light and shadow features, enables the system to enhance its operational reliability under extreme dynamic conditions by deeply mining optical sensing information and adapting to environmental disturbances and mechanical wear based on the metrology model, without the need to deploy external physical strain gauges or height measurement hardware. Attached Figure Description
[0022] Figure 1 This is a flowchart of the data flow and logical processing of the metering system of this invention;
[0023] Figure 2 This is an analysis diagram of the key technical elements affecting the measurement accuracy of precision drilling and cutting trajectories in this invention;
[0024] Figure 3 This is a diagram of the hardware integration architecture and signal interaction topology of the present invention. Detailed Implementation
[0025] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.
[0026] It should be noted that all directional and positional terms used in this invention, such as: up, down, left, right, front, back, vertical, horizontal, inner, outer, top, bottom, transverse, longitudinal, center, etc., are only used to explain the relative positional relationship and connection between components in a specific state (as shown in the accompanying drawings). They are only for the convenience of describing this invention and do not require that this invention be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention. In addition, the descriptions of "first," "second," etc., in this invention are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated.
[0027] In the description of this invention, unless otherwise explicitly specified and limited, the terms installation, connection, and linking should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to the internal communication between two components. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.
[0028] In the description of this specification, references to the terms "an embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example, and the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0029] A metrology system for precision drilling and cutting trajectories of a four-layer half-hole plate comprises an image acquisition module, a deformation analysis unit, a trajectory measurement module, and a trajectory correction control unit. The image acquisition module acquires random surface texture images around the drilling point of the four-layer half-hole plate and the dynamic projection contour of the cutting tool under cutting conditions. The deformation analysis unit, connected to the image acquisition module, identifies the displacement vectors of characteristic points in the random surface texture image when the cutting tool applies cutting force. Based on these displacement vectors, it determines the local deformation correction parameters for the drilling point, performing non-uniform mesh reconstruction on a preset linear reference model to generate a corrected reference surface characterizing the spatial distortion caused by stress release within the substrate. During non-uniform mesh reconstruction, the deformation analysis unit imports the captured displacement vectors as displacement boundary conditions into the elastic strain field model, calculating the spatial distortion of mesh nodes under anisotropic constraints. The system determines the local topological parameters of the corrected reference surface and uses the magnitude and direction of the feature point displacement vector to drive the coordinate repositioning of the mesh nodes, so that the reconstructed corrected reference surface is spatially aligned with the physical morphology of the substrate after loading. When calculating the node coordinates, the system executes a coordinate weighted offset program based on the influence radius, establishing a circular influence area with a radius of 5 mm centered on the drilling site. For each mesh node within this area, its three-dimensional coordinate offset is determined by multiplying the average magnitude of the feature point displacement vector by the local deformation coefficient. The system performs linear attenuation compensation based on the Euclidean distance between the node and the drilling site. The closer the node is to the center, the higher the offset weight, with the weight coefficient decreasing linearly from 1.0 at the center to 0.1 at the edge. By superimposing the calculated offset increment onto the original coordinate values of the linear reference model, point-by-point repositioning of non-uniform mesh nodes is achieved.
[0030] The trajectory measurement module, connected to the deformation analysis unit, determines the deflection vector characterizing the dynamic yaw of the cutting tool spindle by extracting grayscale gradient data from the edge of the dynamic projection contour. It also identifies the depth zero point by combining the shadow shortening rate, generating a three-dimensional coordinate measurement conclusion. The trajectory correction control unit, connected to the trajectory measurement module, performs closed-loop adjustment of the feed parameters based on the three-dimensional coordinate measurement conclusion. When adjusting the feed parameters, the trajectory correction control unit applies a multi-level decision-making strategy based on error amplitude. When the Euclidean distance between the real-time position indicated by the three-dimensional coordinate measurement conclusion and the preset drilling trajectory is within a certain range... to When the distance is within a certain range, the trajectory correction control unit outputs a feed rate reduction command to decrease the cutting force load by reducing the feed amount per unit time; when the Euclidean distance exceeds a certain range... Simultaneously, the trajectory correction control unit sends a speed compensation command while reducing the execution rate, increasing the spindle speed of the cutting tool to maintain a constant linear velocity and suppress radial runout of the tool until the real-time measured Euclidean distance returns to the preset tolerance range. The image acquisition module includes an industrial camera and a coaxial cold light source. The coaxial cold light source provides a dark field illumination environment around the drilling site, enabling the industrial camera to capture the random fabric texture of the fiberglass cloth warp and weft distribution inside the semi-cured sheet of the four-layer semi-perforated plate. This texture is used as the feature pattern for substrate deformation analysis. The sampling frequency of the industrial camera is [missing information - likely a percentage of the cutting tool spindle speed]. Doubled Times, when the spindle speed is At that time, the sampling frequency is set to It is used to capture the instantaneous dynamic projection contour during the cutting process, providing a data basis for geometric dimension measurement.
[0031] The deformation analysis unit is used to identify the displacement vectors of feature points in a random surface texture image when a cutting force is applied by a cutting tool. Addressing the non-uniform deformation during substrate pressing, the unit establishes a mapping logic between the sub-pixel offsets of the feature point displacement vectors and the local curvature of the linear reference model. This converts the transient geometric deformation under pressure into local coordinate offsets of the corrected reference surface. The deformation analysis unit utilizes local deformation coefficients... The grid node positions in the linear reference model are corrected using the following formula: ,in, This is the local deformation coefficient; The average magnitude of the displacement vector of the feature point, in units of ; The preset elastic modulus of the substrate, in units of ; This refers to the real-time cutting force exerted by the cutting tool on the drilling site, expressed in units of... This procedure converts the geometric deformation of the drilling site under pressure into the local coordinate offset of the correction reference surface to eliminate the measurement residual caused by the release of pressure stress. Before performing non-uniform mesh reconstruction, the deformation analysis unit selects global reference markers on the surface of the four-layer half-hole plate under no-load conditions. The image acquisition module collects random fabric textures of fiberglass cloth in a dark environment and establishes an original pose template of texture features as the initial spatial coordinate reference before being subjected to force. When the cutting tool applies real-time cutting force, the deformation analysis unit identifies the displacement vector of feature points through feature region matching logic. The sub-pixel offset of the feature point displacement vector is mapped to the local curvature change of the linear reference model. The local deformation coefficient is determined by multiplying the average amplitude of the feature point displacement vector by the preset elastic modulus of the substrate and dividing by the real-time cutting force. The specific calculation formula is as follows: ,in The coefficient of local deformation. The average amplitude of the displacement vector at the feature point, in millimeters. The elastic modulus of the substrate is preset in megapascals. The real-time cutting force of the cutting tool applied to the drilling site is measured in Newtons. The system uses the local deformation coefficient to correct the position of the grid nodes in the linear reference model. The spatial response of the grid nodes under anisotropic constraints is used as the displacement boundary condition to drive the repositioning of the grid node coordinates and generate a corrected reference surface that characterizes the spatial distortion caused by the release of internal stress in the substrate.
[0032] The trajectory measurement module is used to determine the spatial orientation of the cutting tool during the drilling process. It extracts grayscale gradient data from the edges of the dynamic projection contour to identify the yaw characteristics of the cutting tool caused by spindle radial runout or bending under stress. The module calculates the angle between the projected centerline of the cutting tool and the normal to the correction reference surface to determine the spindle deflection vector. This module also utilizes the shadow shortening rate at the moment the cutting tool contacts the surface of the four-and-a-half-layer perforated plate to identify the cutting tool's position within the perforated area. The zero point of displacement in the axial direction and the rate of shadow shortening are determined by the rate of change of the geometric distance between the cutting tool body projection and the reflected projection area. The trajectory measurement module measures the local depression displacement caused by the pressure on the four-layer half-hole plate at the drilling point, and uses the local depression displacement as... The dynamic correction increment in the axial direction is used to compensate for the zero displacement point.
[0033] The trajectory measurement module monitors the geometric distance between the body projection and the reflection projection areas during the downward movement of the cutting tool. It performs a first-order difference operation on the geometric distance over five consecutive sampling periods to generate a shadow shortening rate sequence. When the amplitude of the shadow shortening rate sequence changes between adjacent sampling points exceeding a preset rate threshold, that sampling moment is determined as a feature point of the cutting tool contacting the surface, establishing the zero point of displacement in the Z-axis direction. Here, the preset rate threshold is taken as the point where the shadow shortening rate produces a 50% step change. The trajectory measurement module identifies the brightness span of the blurred area at the edge of the cutting tool's rotating projection, calculates the pixel span covering the peak brightness from 10% to 90% to determine the sub-pixel edge width, and combines the physical size of a single pixel in the industrial camera with the effective extension length of the cutting tool. It then uses the arctangent function to calculate the instantaneous spatial tilt angle of the cutting tool spindle. The calculation formula is: ,in For instantaneous spatial tilt angle, In pixels, the unit is pixels. The physical size of a single pixel in an industrial camera, measured in micrometers. The effective extension length of the cutting tool is measured in millimeters. The system uses the instantaneous spatial tilt angle to perform pose compensation on the projection trajectory of the correction reference surface. Based on the linear dependence of the shadow length phase difference sequence and the feed rate, a three-dimensional coordinate measurement conclusion characterizing the actual motion path of the cutting tool inside the four-layer half-hole plate is generated.
[0034] The trajectory measurement module determines the actual penetration depth of the cutting tool in the inner layer of the four-and-a-half-layer perforated plate based on the shadow length phase difference sequence, generating a three-dimensional coordinate measurement conclusion. This conclusion characterizes the vector attitude of the cutting tool's actual movement path within the four-and-a-half-layer perforated plate. The trajectory correction control unit adjusts the feed parameters based on the three-dimensional coordinate measurement conclusion. When the spatial position indicated by the three-dimensional coordinate measurement conclusion deviates from the preset drilling trajectory by a greater than [amount missing] Euclidean distance, the tool will be corrected. At that time, the trajectory correction control unit adjusts the output frequency of the servo driver to correct the feed rate or spindle speed until the real-time measured Euclidean distance returns to the preset tolerance range. Through the analysis of the displacement vector by the deformation analysis unit, combined with the dynamic inversion of the rotational light and shadow characteristics by the trajectory measurement module, the measurement of the movement path of the cutting tool inside the four-layer half-hole plate is realized.
[0035] Example 1: For a total thickness of The spindle speed of the four-layer half-hole plate is In drilling and cutting scenarios, the system needs to address localized deformation caused by uneven warp and weft density of the fiberglass cloth during the pressing process, as well as radial runout of the tool under high-speed load. The image acquisition module uses a coaxial cold light source to capture random fabric texture inside the prepreg, and the deformation analysis unit identifies the displacement vector of the random fabric texture between consecutive frames and averages the amplitude of the displacement vector. Combined with the preset elastic modulus With real-time cutting force Import the calculation procedure and determine the local deformation coefficient. The system corrects the mesh node positions of the preset linear reference model to generate a corrected reference surface that characterizes the spatial distortion caused by stress release within the substrate. The trajectory measurement module extracts grayscale gradient data from the edges of the dynamic projection contour, identifies the brightness span of the blurred edge region to calculate the deflection vector of the cutting tool spindle, and coordinates the pose reference provided by the corrected reference surface with the tool yaw state represented by the deflection vector. By calculating the angle between the projected centerline of the cutting tool and the normal to the corrected reference surface, the vector attitude of the actual movement path of the cutting tool within the four-layer half-hole plate is determined. When the cutting tool contacts the surface of the four-layer half-hole plate, the trajectory measurement module monitors the feature points of the shadow shortening rate and establishes... The zero point of displacement in the axial direction is used to acquire the vector attitude of the trajectory correction control unit, and to calculate the Euclidean distance of the real-time spatial position deviating from the preset drilling and cutting trajectory. When the Euclidean distance exceeds... At that time, the trajectory correction control unit adjusts the output frequency of the servo driver to correct the feed rate, so that the drilling trajectory returns to the tolerance range.
[0036] The real-time cutting force experienced by the cutting tool during the drilling and cutting into the inner copper foil stage. When a step change occurs, the deformation analytical unit synchronously acquires the average magnitude of the displacement vector. The change in the value of the local deformation coefficient is determined according to the calculation formula. : ,in, The coefficient of local deformation. The average magnitude of the displacement vector of the feature point, in units of , The preset elastic modulus of the substrate, in units of , This refers to the real-time cutting force exerted by the cutting tool on the drilling site, expressed in units of... The deformation analysis unit utilizes the updated local deformation coefficients. The local coordinate offset of the correction reference surface is redefined. The trajectory measurement module uses the local coordinate offset to check the fluctuation of the shadow length phase difference sequence caused by the sudden change in material resistance. The light and shadow distortion features captured by vision are converted into geometric compensation amounts characterizing the bending of the tool under stress. Without deploying external physical height measurement hardware, the axial measurement residual caused by the decrease in spindle accuracy and the fluctuation of medium resistance is controlled within a certain range. Within; the feed parameter adjustment command drives the cutting tool to complete the path traversal of the four-and-a-half-hole plate, and the profile of the machined hole wall and the preset trajectory maintain the same coordinates in three-dimensional space.
[0037] Example 2: For a four-layer half-hole plate in The challenge of interlayer alignment deviation under high-speed drilling and cutting conditions; this experiment addresses this challenge in the context of… The effectiveness of the metrology system was verified on a CNC machining platform with high positioning accuracy. The test platform was equipped with a spindle radial runout of less than [missing information]. High-precision electric spindle, feed driver has The current loop refresh frequency, the image acquisition module uses an effective pixel count of For industrial cameras, set key parameters such as sampling frequency. At that time, the consideration lies in balancing the high-rate coverage of the tool spindle rotation cycle with the real-time load of the data processing unit, since the spindle operating frequency is To satisfy the sampling theorem and achieve sub-pixel edge reconstruction of the cutting edge, a sampling frequency is selected. for To simulate vibration and lighting fluctuations in a real industrial environment, a signal-to-noise ratio of [value missing] was superimposed on the experimental signal source. Gaussian white noise, and turn on the power frequency lighting to generate Background flickering.
[0038] The total thickness collected during the test process was... The sample's surface random texture image under no-load conditions was used to start the cutting tool and apply a programmed gradient-varying real-time cutting force. The deformation analysis unit extracts the feature point displacement vector based on the acquired loaded texture displacement, and calculates the local deformation coefficient using the calculation procedure in the specific implementation method. During the verification process, a control group and an experimental group were set up for accuracy comparison. The control group used a conventional linear reference model and did not perform deformation correction, while the experimental group performed correction based on local deformation coefficients. The non-uniform mesh was reconstructed, and the local deformation coefficient was determined by formula. The evolution trend.
[0039] Table 1: Performance Verification Data of Precision Drilling and Cutting Trajectory Measurement System
[0040]
[0041] Based on the test results in Table 1, when the real-time cutting force exist to When the value increases within a preset range, the experimental group uses the updated local deformation coefficient. The local coordinate offset of the correction reference surface is redefined, and its final trajectory measurement error stabilizes at... In comparison, the control group without nonlinear compensation had an error under the same operating conditions of: Observe the data of the over-range sample group, when the real-time cutting force Increase to That is, the average amplitude of the displacement vector of the characteristic point after exceeding the elastic limit of the substrate. The growth exhibits a nonlinear transition, and the local deformation coefficient... The compensation efficiency reached a performance inflection point, confirming that the parameter range defined by the present invention is adaptable to the elastic deformation region of the substrate. After removing the displacement vector recognition step of the random texture image on the surface, the error of some missing groups increased, which confirms the role of micro-area texture flow characteristics in offsetting the compression stress distortion.
[0042] The experiment investigated The accuracy of zero-point depth identification in the axial direction is assessed. The trajectory measurement module monitors the characteristic points of the shadow shortening rate during the downward movement of the cutting tool and verifies the zero-point displacement determined at that moment with the readings of the mechanical contact sensor. This is relevant to the surface of the four-layer half-hole plate. In fluctuating scenarios, the displacement zero-point identification deviation based on light and shadow inversion is no greater than [value missing]. This demonstrates that the metrology system, through the coordinated operation of the deformation analysis unit and the trajectory metrology module, achieves deterministic quantification of the actual movement path of the cutting tool inside the four-and-a-half-layer hole plate. The three-dimensional topological features of the hole wall after machining are consistent with the preset drilling and cutting trajectory in spatial coordinates. By deeply mining the visual perception information, the metrology system incorporates the measurement deviation caused by environmental disturbances into the closed-loop compensation path, thus meeting the metrology resolution requirements under precision manufacturing processes.
[0043] Example 3: This example combines Figures 1 to 3 A description of a metering system for precision drilling and cutting trajectories of a four-layer half-hole plate, such as... Figure 1 As shown, the operating logic of this metrology system begins with the physical input of a random texture image source on the surface of the drilling site and a dynamic projection contour source of the cutting tool. The image acquisition module is responsible for acquiring the texture image and the dynamic projection contour and importing the data stream into the subsequent processing unit. After receiving the image data, the deformation analysis unit performs a series of operations, including identifying the displacement vector of feature points, reconstructing the non-uniform mesh, and generating a correction reference surface. The generated correction reference surface parameters are then output as the calibration basis. Meanwhile, after receiving the dynamic projection contour, the trajectory metrology module extracts grayscale gradient data to determine the principal axis deflection vector and performs pose compensation in conjunction with the received correction reference surface parameters. Finally, based on the above processing, the system outputs a three-dimensional coordinate metrology conclusion containing the actual motion path.
[0044] like Figure 2 As shown, achieving the core goal of precision drilling and cutting trajectory measurement accuracy is supported by four dimensions of factors: substrate physical properties, deformation analysis technology mechanism, optomechanical hardware system support, and trajectory inversion algorithm logic. Among them, substrate physical properties mainly involve the material characteristics of the semi-cured sheet's random texture and compression stress release. The deformation analysis technology mechanism covers three algorithm steps: feature point displacement vector, non-uniform mesh reconstruction, and correction reference surface generation. Optomechanical hardware system support depends on the physical environment construction of coaxial cold light source dark field and industrial camera magnification sampling. The trajectory inversion algorithm logic is based on the comprehensive calculation of dynamic projection contour, principal axis deflection vector, and shadow shortening rate.
[0045] like Figure 3As shown, the high-performance industrial control computing workstation serves as the computing and control hub of the entire system, integrating four core functional blocks: an image acquisition module, a deformation analysis unit, a trajectory measurement module, and a trajectory correction control unit. This hub is connected to the vision acquisition terminal on the left via a high-speed data transmission link, serving as an optical sensing device that includes an industrial camera for high-magnification sampling and a coaxial cold light source for providing dark-field illumination, responsible for transmitting texture images and projected contours. Simultaneously, the computing and control hub is connected to the CNC machining platform on the right via an industrial Ethernet, serving as a motion execution device that includes a servo driver and a high-precision electric spindle, used to receive feed parameters and speed compensation commands issued by the hub, thereby achieving frequency control of the drive signal and precise adjustment of the high-speed rotation of the spindle.
[0046] Example 4: In the calibration scenario of performing the first drilling and cutting trial machining of a four-layer half-hole plate containing an inner layer of buried blind holes, the system should address the inconsistency in initial projection features caused by differences in the geometric cutting edge shape of the cutting tool. The image acquisition module extracts the initial state parameters under the condition that the spindle drives the cutting tool to rotate unloaded to the set speed. The industrial camera acquires the reference projection sequence of the cutting tool under coaxial cold light source dark field illumination, and uses the reference projection sequence as a reference template for subsequent dynamic deviation identification. The trajectory measurement module executes the algorithm path procedure, extracts the original brightness distribution data of the cutting tool rotation envelope edge in the reference projection sequence, and calculates the brightness from the initial state. Rise to The pixel span covered by the peak determines the subpixel edge width. The real-time edge width during drilling and cutting is compared with... Perform differential calculations to determine the edge spread increment caused by tool yaw under load, and calculate the instantaneous spatial tilt angle of the cutting tool spindle based on the formula. : ,in, It is the instantaneous spatial tilt angle; The span is in pixels, in units of ; This refers to the physical size of a single pixel in an industrial camera, in units of... ; The effective extension length of the cutting tool, in units of .
[0047] To identify the depth reference, the trajectory measurement module monitors the shadow length change sequence in real time during the downward feed of the cutting tool, and applies a process judgment quantization procedure. The trajectory measurement module continuously... The shadow length within each sampling period is subjected to a first-order difference operation to generate a shadow shortening rate sequence. When the amplitude of the change in the shadow shortening rate sequence between two adjacent sampling points exceeds a preset rate threshold... When the sampling time is determined to be a characteristic singularity point touching the surface, the system allocates a circular sampling buffer with a length of 64 data points in memory to store high-frequency projection data from the industrial camera. The system triggers a calculation task every 8 sampling points, selecting the latest 16 sampling points in the buffer to form a sliding evaluation window, achieving a 50% data overlap rate to suppress random noise. The shadow shortening rate within the window is obtained by calculating the displacement difference between the start and end points of the window and dividing it by the sampling period. When the average rate mutation increment calculated by three consecutive sliding windows exceeds 1.5 times the average value of the previous steady state, the system latches the current counter value and maps it to the physical zero point coordinate of the Z-axis, setting the sampling frequency. for When the cutting tool penetrates the surface of the four-and-a-half-hole plate from the air medium, the length of the shadow changes from... Zeroing and shortening the rate of production The above step change establishes the system at this point. The zero displacement point in the axial direction is identified by the deformation analysis unit, which simultaneously identifies the feature point displacement vectors of the fiberglass cloth interlacing points in the random texture image of the surface, and uses the calculated local deformation coefficient. The non-uniform mesh of the linear reference model is corrected, and the zero displacement point is projected from the surface physical plane to the stress equilibrium surface inside the substrate to generate a three-dimensional coordinate measurement conclusion. The trajectory correction control unit receives the three-dimensional coordinate measurement conclusion and performs closed-loop adjustment of the feed parameters. This unit performs Euclidean distance calculation between the real-time measured vector attitude and the preset drilling trajectory. When it detects that the cutting tool is penetrating the inner copper foil due to a sudden change in material hardness, the unit will correct the deviation. When there is radial deviation, the trajectory correction control unit sends a frequency compensation command to the servo drive via industrial Ethernet, adjusting the feed rate from... Downgraded to Until the real-time measured Euclidean distance returns to Within tolerance range.
[0048] Example 5: In the optical calibration scenario before performing drilling trajectory measurement on a four-layer half-hole plate, the measurement system identifies the standard scale target located at the workbench reference position. The image acquisition module captures the geometric dot matrix image of the surface of the standard scale target, and the trajectory measurement module extracts the pixel distance between adjacent marker points in the geometric dot matrix image. And combined with the preset physical spacing value Determine the physical size calibration coefficient corresponding to a unit pixel. Physical dimension calibration factor The calculation formula is as follows: ,in, This is the physical dimension calibration factor, in units of ; The preset physical spacing of the standard scale target sheet, in units of ; The pixel distance between adjacent markers, in units of The trajectory measurement module uses physical size calibration coefficients. For the edge width extracted subsequently Perform dimensional transformation to map the displacement of visual feature points in the image plane into a physical length vector in three-dimensional space, and establish a linear mapping benchmark between pixel grayscale space and physical geometric space.
[0049] When the system encounters material stiffness fluctuations caused by differences in substrate composition between different production batches, the deformation analysis unit retrieves the initial state parameters of the four-and-a-half-layer perforated plate before executing the drilling and cutting path. The deformation analysis unit applies stress to the non-circuit area at the edge of the four-and-a-half-layer perforated plate. The quasi-static preload is applied, and the displacement increment of the random texture image on the surface under the quasi-static preload is measured. Based on the linear correlation logic between the displacement increment and the quasi-static preload, the real-time elastic modulus of the batch of substrates is determined. and real-time elastic modulus Importing the local deformation coefficient calculation procedure, when the cutting tool performs high-speed feed, the deformation analysis unit calls the real-time elastic modulus that matches the current material properties. Corrected local deformation coefficient The calculation weights are used to maintain the reconstruction accuracy of the correction reference surface under different material properties. The metering system eliminates the influence of raw material physical property fluctuations on the metering conclusions by calibrating the initial parameters on site, so that the output three-dimensional coordinate metering conclusions are kept within the preset tolerance range.
[0050] Example 6: In a production scenario involving continuous drilling and cutting, the deformation analysis unit applies a force of magnitude [value missing] to the non-circuit area of the four-and-a-half-layer perforated plate every preset processing cycle. Test cutting force By recording the response displacement vector of the surface random texture image between consecutive frames And according to the formula Update the real-time elastic modulus stored in the processing engine. The value of, among which, This is the real-time elastic modulus, in units of... , As the reference stiffness constant, To test cutting force, the unit is . , The average magnitude of the response displacement vector, in units of The deformation analysis unit will update the real-time elastic modulus. Injection of local deformation coefficient calculation procedure, correction of local deformation coefficient The calculated weights ensure that the corrected reference surface maintains physical consistency with the internal stress state of the substrate; in the visual noise environment generated by cutting fluid spray, the dynamic projection contour captured by the image acquisition module undergoes time-dimension-based sliding window filtering before being input to the trajectory measurement module, and the trajectory measurement module performs continuous... Subpixel edge width calculated from frame image Perform variance checking when the subpixel edge width of the current frame... The deviation from the mean of the preceding window exceeds When an instantaneous visual occlusion occurs, the system identifies it and uses the deflection rate of change from the preceding steady state to perform trajectory prediction and completion. This data cleaning logic based on temporal correlation suppresses the interference of stray environmental light and shadow on edge gradient features, controlling the trajectory measurement error of the cutting tool when penetrating each material layer within a certain range. Within.
[0051] In a static calibration scenario to verify the accuracy of subpixel edge extraction, the trajectory measurement module processes a tool projection image with known geometric dimensions, identifies the brightness gradient distribution of the edge region, and calculates the subpixel edge width. By comparing the physically measured values with the visually calculated values, the measurement results show... Edge positioning accuracy at resolution better than The system converts the original pixel grayscale step into the geometric width characterizing the tool yaw, establishing the physical traceability of the deflection vector calculation process and eliminating the quantization residuals generated by discrete pixel sampling in the dynamic measurement process of the four-layer half-hole plate. For auxiliary identification of the medium type, the trajectory measurement module has a built-in vibration frequency feature library based on the material stiffness difference. When the cutting tool penetrates the resin layer, the main frequency of the frequency oscillation feature in the grayscale gradient data is concentrated in the range of 800 Hz to 1200 Hz. When the tool touches and cuts the inner copper foil, the main frequency of the micro-vibration generated in the image will instantly jump to the range of 2500 Hz to 3200 Hz due to the influence of metal hardness feedback. The system performs a 128-point fast Fourier transform on the current grayscale features to identify the peak frequency with the highest energy proportion in the spectrum, and automatically calls the corresponding material correction coefficient according to the range to which the frequency belongs to perform a secondary verification of the three-dimensional coordinate measurement conclusion.
[0052] The embodiments of this application have been described above with reference to the accompanying drawings. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. This application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit of this application and the scope of protection of this invention, and all of these forms are within the protection scope of this application.
Claims
1. A metering system for precision drilling and cutting trajectory of a four-layer half-hole plate, characterized in that, include: The image acquisition module is used to acquire random surface texture images around the drilling points of the four-layer half-hole plate and the dynamic projection contour of the cutting tool in the cutting state. The deformation analysis unit is used to identify the displacement vectors of feature points in the random texture image of the surface when the cutting tool applies cutting force, and to determine the local deformation correction parameters of the drilling site based on the displacement vectors of the feature points. This is used to perform non-uniform mesh reconstruction on the preset linear reference model to generate a correction reference surface that characterizes the spatial distortion caused by the release of internal stress in the substrate. The deformation analysis unit is also used to convert the transient geometric deformation of the drilling site under pressure into the local coordinate offset of the correction reference surface by establishing the mapping logic between the sub-pixel offset of the displacement vector of the feature points and the local curvature of the linear reference model. The trajectory measurement module extracts grayscale gradient data from the edges of the dynamically projected contour and determines the deflection vector characterizing the dynamic yaw of the cutting tool spindle based on the grayscale gradient data. The module also calculates the instantaneous spatial tilt angle of the cutting tool spindle by identifying the brightness span of the edge blurring region generated by the cutting tool in the rotating projection. Furthermore, the module performs pose compensation on the projected trajectory in the correction reference surface using the instantaneous spatial tilt angle and identifies the cutting tool's position using the shadow shortening rate at the moment of contact with the four-layer half-hole plate surface. The zero point of displacement in the axial direction, and the actual penetration depth of the cutting tool in the inner layer of the four-layer half-hole plate determined by the shadow length phase difference sequence, generate a three-dimensional coordinate measurement conclusion characterizing the actual movement path of the cutting tool inside the four-layer half-hole plate; wherein, the shadow length phase difference sequence is generated by the trajectory measurement module performing a first-order difference operation on the shadow length in a continuous sampling period to generate a shadow shortening rate sequence; the trajectory measurement module identifies the brightness span of the blurred area at the edge of the cutting tool's rotation projection, and calculates the pixel span covering the peak brightness from 10% to 90% to determine the sub-pixel edge width.
2. The metering system for precision drilling trajectory of a four-layer half-hole plate according to claim 1, characterized in that, The image acquisition module includes an industrial camera and a coaxial cold light source. The coaxial cold light source is used to create a dark field lighting environment around the drilling site so that the industrial camera can capture the random fabric texture of the fiberglass cloth distribution inside the semi-cured sheet of the four-layer semi-perforated plate as a surface random texture image.
3. The metering system for precision drilling trajectory of a four-layer half-hole plate according to claim 1, characterized in that, When determining local deformation correction parameters, the deformation analysis unit uses feature region matching logic to determine the amount of movement of the surface random texture image between consecutive frames, and bases this on the formula... Determine the local deformation coefficient of the drilling site. ;in, The coefficient of local deformation. The average magnitude of the displacement vector of the feature point, in mm. This is the preset elastic modulus of the substrate, in MPa. The real-time cutting force exerted by the cutting tool on the drilling site is expressed in N; the deformation analytical unit utilizes the local deformation coefficient. Position corrections are performed on the mesh nodes in the linear reference model to generate a corrected reference surface.
4. The metering system for precision drilling trajectory of a four-layer half-hole plate according to claim 1, characterized in that, When determining the deflection vector, the trajectory measurement module performs sub-pixel edge extraction on the edge of the dynamic projection contour, removes air disturbance interference caused by the rotation of the cutting tool, and determines the dynamic deflection variable of the cutting tool under the action of cutting torque based on the angle between the center line of the cutting tool projection and the normal of the correction reference surface.
5. The metering system for precision drilling trajectory of a four-layer half-hole plate according to claim 1, characterized in that, When determining the actual intrusion depth, the trajectory measurement module uses the shadow shortening rate at the moment the cutting tool contacts the surface of the four-and-a-half-hole plate for calibration. The starting point of the axis is determined, and the real-time depth coordinates of the cutting tool between the inner copper foils inside the four-layer half-hole plate are inverted based on the linear dependence of the cutting tool feed rate and the phase difference sequence of the shadow length.
6. The metering system for precision drilling trajectory of a four-layer half-hole plate according to claim 1, characterized in that, The metering system also includes: a trajectory correction control unit; the trajectory correction control unit is connected to the trajectory metering module and is used to compare the three-dimensional coordinate metering results with the preset drilling and cutting trajectory. When the spatial position indicated by the three-dimensional coordinate metering results deviates from the preset drilling and cutting trajectory by more than 10μm in Euclidean distance, the trajectory correction control unit outputs a feed parameter adjustment command to correct the feed rate or spindle speed.
7. The metering system for precision drilling trajectory of a four-layer half-hole plate according to claim 1, characterized in that, The linear reference model is constructed by the deformation analysis unit based on the coordinates of the global reference marker points on the surface of the four-layer half-hole plate acquired by the image acquisition module; the coordinates of the global reference marker points are the spatial absolute coordinate reference of the four-layer half-hole plate under the condition of no cutting force.
8. The metering system for precision drilling trajectory of a four-layer half-hole plate according to claim 1, characterized in that, The dynamic projection contour captured by the image acquisition module includes the reflected projection area formed by the cutting tool on the surface of the four-layer half-hole plate; the trajectory measurement module measures the local subsidence displacement of the four-layer half-hole plate under pressure at the drilling point by analyzing the geometric distance between the reflected projection area and the cutting tool body projection, and uses the local subsidence displacement as... Dynamic correction increments in the axial direction are used to compensate for zero displacement.