An automated shearing system and method for steel grating

Abstract

This invention relates to the field of steel grating shearing technology, and discloses an automated steel grating shearing system and method. The method obtains the initial contact reaction force and three-dimensional morphology of the steel grating to be sheared; calculates the local equivalent section stiffness based on dimensional parameters; calculates the warping deviation caused by residual stress release by combining longitudinal distance and stiffness; calculates the dynamic compensation clamping force based on geometric projection using the warping deviation and stiffness; calculates the induced secondary nodal shear stress based on the clamping force; obtains the material's ultimate yield shear stress threshold, and calculates the critical cutting speed of the tool by combining the secondary shear stress; calculates the theoretical maximum nodal stiffness threshold; corrects the critical cutting speed based on the stiffness ratio and generates the final feed speed command. This method can effectively avoid warping and torsion caused by stress release and prevent microcrack damage at weld points.

Description

Technical Field

[0001] This invention relates to the field of steel grating shearing technology, specifically to an automated steel grating shearing system and method. Background Technology

[0002] Steel grating is made of flat steel and crossbars orthogonally welded together. In automated processing, steel grating shearing is an essential key process. Currently, most common automated shearing technologies use visual positioning correction or constant force feedback clamping control. These conventional technologies can only provide superficial control over a single surface physical deformation.

[0003] However, in actual automated steel grating shearing scenarios, the internal stress conditions are extremely complex. First, cutting off the preceding nodes will disrupt the original internal stress balance, and the internal residual stress will be released instantly. This will cause micro-warping deviation in the uncut parts. Existing technologies usually apply a reverse clamping force directly to eliminate this warping. However, there is a significant stiffness difference between the steel grating mesh nodes and non-node areas. Simply applying a single reverse clamping force is difficult to maintain mesh stability. The compensation force will deflect during transmission, which can easily cause secondary micro-torsional deformation of the crossbars.

[0004] Furthermore, after applying clamping force to suppress warping, the weld joint, as a stress concentration area, will bear additional secondary shear loads in advance. This will cause the load-bearing margin inside the weld joint to decrease sharply. When the tool contacts the weld joint, the material's shear impact threshold has been greatly reduced. If the actuator still cuts in at the conventional set speed, the instantaneous kinetic energy and the existing secondary strain energy will be superimposed, which will easily exceed the material's yield failure limit. This will eventually cause microcrack damage inside the weld joint, seriously affecting the product's mechanical properties. Existing technology lacks cross-physical domain coupling analysis of spatial static deformation and transient dynamic failure, and cannot dynamically feedforward limit the speed of the actuator.

[0005] Therefore, there is a need for an automated shearing method and system for steel grating that can comprehensively predict and eliminate residual stress warping, suppress local secondary torsion, and dynamically control the tool feed speed to avoid micro-cracks in the weld joints. Summary of the Invention

[0006] This invention provides an automated steel grating shearing system and method, which helps to solve the problems mentioned in the background art.

[0007] This invention provides the following technical solution: an automated shearing method for steel grating, comprising:

[0008] Obtain the initial contact reaction force and three-dimensional morphology of the steel grating to be sheared, and measure the height, thickness, adjacent spacing and longitudinal distance of the shearing starting point of the flat steel.

[0009] Calculate the local equivalent section stiffness at the current shearing node based on the height, thickness and adjacent spacing of the flat steel.

[0010] Combining the initial contact reaction force and the longitudinal distance, and using the local equivalent section stiffness and the flat steel height, the warping deviation is calculated;

[0011] Based on the warping deviation and the local equivalent section stiffness, and combined with the adjacent spacing, a geometric projection is performed to calculate the dynamic compensation clamping force.

[0012] The induced secondary nodal shear stress is calculated based on the dynamic compensation clamping force, the adjacent spacing, the flat steel thickness, and the flat steel height.

[0013] Obtain the material's ultimate yield shear stress threshold and density constant, and calculate the critical cutting speed of the tool by combining the secondary nodal shear stress and the flat steel dimensions;

[0014] Calculate the theoretical maximum nodal stiffness threshold based on the maximum permissible physical dimensions of the equipment;

[0015] Based on the ratio of the local equivalent cross-sectional stiffness to the theoretical maximum nodal stiffness threshold, the critical cutting speed is corrected, a final feed speed command is generated, and sent to the shearing mechanism.

[0016] Optionally, obtaining the initial contact reaction force and three-dimensional morphology of the steel grating to be sheared, and measuring the height, thickness, adjacent spacing, and longitudinal distance of the shearing starting point of the flat steel, includes:

[0017] Piezoelectric thin film stress sensors are arrayed on the bottom support base of the automated shearing platform;

[0018] The initial residual stress equivalent at the current shearing node is acquired by the piezoelectric thin film stress sensor and used as the initial contact reaction force.

[0019] A laser displacement sensor is installed at the position in front of the shearing blade holder;

[0020] The three-dimensional morphology of the steel grating is obtained by scanning using the laser displacement sensor;

[0021] Measure and record the height of the flat bar, the thickness of the flat bar, the spacing between adjacent flat bars, and the longitudinal distance from the shearing start point to the current node to be sheared.

[0022] Optionally, calculating the local equivalent section stiffness at the current shearing node based on the height, thickness, and adjacent spacing of the flat steel includes:

[0023] The height of the flat steel is calculated to the cube to obtain the height cube value;

[0024] Multiply the cubic value of the height by the measured thickness of the flat steel to obtain the stiffness numerator; square the measured distance between adjacent flat steel bars and multiply by a constant twelve to obtain the stiffness denominator.

[0025] Divide the stiffness numerator by the stiffness denominator to obtain the local equivalent cross-sectional stiffness at the current shear node.

[0026] Optionally, the step of combining the initial contact reaction force and the longitudinal distance, and using the local equivalent section stiffness and the flat steel height to calculate the warping deviation includes:

[0027] The measured longitudinal distance is calculated to the fourth power and multiplied by the initial contact reaction force to obtain the deviation numerator;

[0028] Multiply the local equivalent section stiffness by the measured flat steel height, and then multiply by a constant eight to obtain the deviation denominator;

[0029] Divide the numerator of the deviation by the denominator of the deviation to obtain the warping deviation amount.

[0030] Optionally, the step of calculating the dynamic compensation clamping force based on the warping deviation and the local equivalent cross-sectional stiffness, combined with the geometric projection of the adjacent spacing, includes:

[0031] Multiply the warping deviation by the local equivalent cross-sectional stiffness to obtain the first product;

[0032] Divide the first product by the square of the measured spacing between adjacent flat bars to obtain the basic compensation force;

[0033] Divide the warping deviation by the spacing between the adjacent flat bars to obtain the deviation ratio;

[0034] Calculate the square of the deviation ratio and subtract the square from the constant to obtain the correction margin;

[0035] The square root of the correction margin is used to obtain the projection correction coefficient;

[0036] Multiplying the basic compensation force by the projection correction coefficient yields the dynamic compensation clamping force.

[0037] Optionally, the step of calculating the induced secondary nodal shear stress based on the dynamic compensation clamping force, the adjacent spacing, the flat steel thickness, and the flat steel height includes:

[0038] Multiply the dynamic compensation clamping force by the measured distance between adjacent flat bars to obtain the stress molecule;

[0039] Multiply the measured thickness of the flat steel by the height of the flat steel, and then multiply by a constant two to obtain the stress denominator;

[0040] Dividing the stress numerator by the stress denominator yields the induced secondary nodal shear stress.

[0041] Optionally, the step of obtaining the material's ultimate yield shear stress threshold and density constant, and calculating the critical cutting speed of the tool in conjunction with the secondary nodal shear stress and the flat steel dimensions, includes:

[0042] Calculate the difference between the material's ultimate yield shear stress threshold and the secondary nodal shear stress;

[0043] Multiply the difference, constant 2, and the measured height of the flat steel by three factors to obtain the velocity numerator;

[0044] Multiply the density constant of the material by the measured thickness of the flat steel to obtain the velocity denominator;

[0045] Divide the velocity numerator by the velocity denominator to obtain the ratio;

[0046] The critical cutting speed of the tool is obtained by taking the square root of the ratio.

[0047] Optionally, calculating the theoretical maximum nodal stiffness threshold based on the maximum permissible physical size parameters of the device includes:

[0048] The maximum allowable flat steel height of the equipment is calculated to the cube and multiplied by the maximum allowable flat steel thickness of the equipment to obtain the ultimate stiffness numerator.

[0049] The minimum allowable grid spacing of the device is squared and multiplied by a constant of twelve to obtain the denominator of the ultimate stiffness.

[0050] Dividing the numerator of the ultimate stiffness by the denominator of the ultimate stiffness yields the theoretical maximum nodal stiffness threshold.

[0051] Optionally, the step of correcting the critical infeed speed based on the ratio of the local equivalent cross-sectional stiffness to the theoretical maximum nodal stiffness threshold, generating a final feed speed command, and sending it to the shearing mechanism includes:

[0052] Divide the local equivalent section stiffness by the theoretical maximum nodal stiffness threshold to obtain the stiffness ratio.

[0053] The final feed rate command is obtained by multiplying the critical cutting speed of the tool by the stiffness ratio.

[0054] The final feed rate command is sent to the shearing mechanism.

[0055] A system for implementing the automated shearing method for steel grating includes:

[0056] Data acquisition module: used to acquire the initial contact reaction force and three-dimensional morphology of the steel grating to be sheared, and to measure the height, thickness, adjacent spacing and longitudinal distance of the shearing starting point of the flat steel.

[0057] Stiffness calculation module: used to calculate the local equivalent section stiffness at the current shearing node based on the flat steel size parameters;

[0058] Warp deviation calculation module: used to calculate the warp deviation by combining the initial contact reaction force, longitudinal distance and local equivalent cross-sectional stiffness;

[0059] Compensation force calculation module: used to dynamically compensate for the clamping force based on the warping deviation, local equivalent cross-sectional stiffness, and adjacent spacing through geometric projection;

[0060] Secondary stress calculation module: used to calculate the induced secondary nodal shear stress based on the dynamic compensation clamping force and flat steel dimensions;

[0061] Critical speed calculation module: used to calculate the critical cutting speed of the tool by combining the material yield shear stress threshold, density constant and secondary nodal shear stress;

[0062] Maximum stiffness calculation module: used to calculate the theoretical maximum nodal stiffness threshold based on the maximum permissible physical size parameters of the equipment;

[0063] Command generation module: used to correct the critical cutting speed according to the theoretical maximum node stiffness threshold of the system, generate the final feed speed command and send it to the shearing mechanism.

[0064] The present invention has the following beneficial effects:

[0065] 1. This technical solution proposes a dynamic speed limiting control method for the specific processing environment of automated steel grating shearing. During the shearing process, the internal residual stress released by cutting off local nodes will cause microscopic warping deviations in the unsheared parts. To eliminate this deformation, a dynamic compensation clamping force must be calculated and applied. However, under the specific structure of non-uniform stiffness of steel grating, this compensation clamping force will cause the nodes to bear induced secondary node shear stress in advance. If the tool cuts in at a conventional constant speed, the instantaneous kinetic energy superimposed on the existing secondary shear load can easily exceed the material's ultimate yield shear stress threshold, causing microcrack damage at the weld joint. Therefore, this solution does not blindly cut in, but calculates the critical cutting speed of the tool that can avoid microcracks by deduce the physical coupling between the local equivalent section stiffness and multiple stresses. Based on this, flexible mapping control is performed to finally generate the feed rate command. Under the complex stress environment of steel grating, this solution realizes feedforward physical protection from deformation prediction to flexible speed limiting, fundamentally solving the stress surge problem caused by eliminating warping, avoiding mechanical damage, and ensuring the structural integrity of the processed parts.

[0066] 2. By arranging piezoelectric thin-film stress sensors in an array on the bottom support base of the automated shearing platform to specifically collect the initial contact reaction force of the nodes to be sheared, it is possible to capture minute mechanical fluctuations in the underlying structure with extremely high sensitivity. This contact-type array stress detection method is different from conventional optical external contour scanning. It can directly penetrate the obscuring of the metal's external shape and truly map the implicit residual stress equivalent left by welding cooling or pre-forming inside the steel grating. Since residual stress is the fundamental physical cause of uncontrollable deformation after shearing, its quantification and extraction at the initial station provides the most advanced and fundamental dynamic induction source data for the overall control algorithm.

[0067] 3. By accurately calculating the local equivalent section stiffness at the current shearing node based on the actual measured flat steel height, thickness, and spacing between adjacent flat steels, and by performing equivalent analysis based on the principle of rectangular section moment of inertia in classical mechanics of materials combined with mesh characteristics, the local equivalent section stiffness at the current shearing node is accurately calculated. This method of abstracting the complex steel grating mesh structure and equating it with a local bending stiffness model can profoundly reflect the inherent physical properties of the component resisting bending deformation under stress. Since the stress response of the steel grating at different mesh positions and different node regions has significant physical differences, accurately quantifying this stiffness parameter can provide the most core material mechanics benchmark for subsequent deformation and stress extrapolation. This allows the system to no longer rely on unified empirical predictions at the macro level, but to perform micro-dimensional mechanical deconstruction for each specific cutting node, thereby significantly improving the adaptive perception accuracy of the entire control algorithm for local structural differences and its response tracking capability for dynamic physical and mechanical properties.

[0068] 4. By combining the contact reaction force and longitudinal distance initially collected by the system, and using the obtained local equivalent section stiffness and flat steel height, and based on the mathematical model of deflection distribution of the cantilever beam under the action of concentrated force at the end, the microscopic spatial warping deviation caused by stress release is accurately calculated. This process fully considers the transient release effect of internal stress caused by the cutting off of the preceding node; it transforms the internal residual mechanical imbalance that was originally impossible to observe directly into spatial displacement data that can be accurately quantified; it effectively overcomes the technical bottleneck of the lag in traditional processing methods that can only deal with static surface unevenness; it enables the automated system to form accurate predictive feedback as soon as physical deformation begins or even in the microscopic accumulation stage; this forward-looking spatial deviation quantification mechanism provides a crucial target point for the subsequent application of precise clamping resistance force; it eliminates the risk of secondary mechanical damage caused by blindly applying constraints and significantly enhances the processing platform's ability to suppress dynamic displacement;

[0069] 5. Based on the previously derived warping deviation and local equivalent section stiffness, and combined with the trigonometric function geometric projection correction of the torsional angle based on the spacing between adjacent flat steel bars, a targeted dynamic compensation clamping force is calculated. This calculation logic strictly follows the principle of equivalent conversion between deformation energy and external force work, cleverly solving the technical problem that simply applying a large reverse force cannot maintain the stability of the grid space. Because there is a torsional force transmission attenuation phenomenon in the actual steel grating node area that is easily ignored, the introduction of trigonometric projection correction enables the compensation force to not only accurately offset the warping deformation of the target area, but also strictly prevent the transverse connecting rods from torsional yielding failure exceeding the bearing limit. This multi-dimensional compensation force synthesis mechanism ensures that the external clamping equipment can maintain the physical stability of the processing plane with the most appropriate energy input, greatly reducing the risk of incidental structural deformation caused by the deviation of the clamping force direction.

[0070] 6. By using the derived dynamic compensation clamping force, and in conjunction with the measured parameters of adjacent flat steel spacing, flat steel thickness, and flat steel height, the secondary nodal shear stress induced by external compensation is deeply analyzed and calculated based on the physical distribution relationship between the stress area and the concentrated load. This step breaks the blind spot in monitoring the incidental destructive effects in conventional control algorithms. When compensation constraints are applied to the steel grating to eliminate warping, the weld point, as a concentrated hub for stress transmission, will inevitably bear the hidden shear load in advance. Accurate calculation of this secondary shear stress enables the system to comprehensively evaluate and thoroughly understand the actual physical load-bearing margin of the weld point before the tool makes mechanical contact. This quantitative analysis, which transforms static constraint mechanics into microscopic material stress, provides key advance warning data for subsequent transient dynamic speed control, thereby fundamentally preventing the tearing of the matrix inside the weld area and the ultimate fracture of the material caused by insufficient estimation of the superimposed destructive load.

[0071] 7. By obtaining the preset material ultimate yield shear stress threshold and material density constant, and deeply integrating the derived secondary node shear stress and flat steel structure dimensions, and relying on the conversion and conservation mechanism of the instantaneous kinetic energy of the tool and the internal material strain energy, the critical cutting speed of the tool that can completely avoid the generation of microcracks at the weld point is accurately calculated. This control strategy realizes the dimensional reduction guidance from macroscopic material strength judgment to microscopic mechanical execution action. Since the kinetic energy brought by the tool impact must share the material's ultimate failure margin with the existing secondary strain energy in the material, the physical execution boundary is set using this energy difference, ensuring that the total impact energy is always limited within the structural safety envelope. This prevents the cutting equipment from forcibly cutting at a fixed and rigid blind constant rate, greatly enhancing the system's adaptive speed reduction protection efficiency for highly brittle node areas. It eliminates the expansion and derivation of microcracks at the moment of cutting from the source of mechanical kinetic energy input, extending the product's service life and structural reliability.

[0072] 8. By reading the physical limit parameters such as the maximum flat steel height, maximum flat steel thickness, and minimum grid spacing allowed by the mechanical structure of the automated shearing equipment, the basic equivalent section stiffness calculation principle is directly projected onto the extreme working state of the entire processing system, thereby deriving the theoretical maximum nodal stiffness threshold. This method avoids the control algorithm outputting erroneous electrical signals that cannot be executed when dealing with extreme abnormal deformation or special materials that exceed the upper limit of the equipment load. This enables the algorithm calculation framework to achieve a deep, underlying fit with the physical performance of the real mechanical structure, providing a global boundary guarantee for the safe mapping of the overall speed servo command and the long-term stable operation of the system.

[0073] 9. By proportionalizing the local equivalent cross-sectional stiffness calculated in real time at the current node with the theoretical maximum node stiffness threshold of the equipment system, and multiplying this flexibility ratio coefficient by the theoretical critical cutting speed of the tool, the final feed speed command that can be directly sent to the underlying shearing actuator is finally corrected and generated. This closed-loop end-to-end dimension reduction mapping control improves the mechanical impact problem of rigid critical commands in actual motor drive, so that the final output processing speed is not only absolutely lower than the limit red line that causes microcracks, but also can completely and smoothly adapt to the resistance fluctuations caused by local structural abrupt changes. The proportional dynamic correction mechanism allows the servo motor to intelligently adjust the torque burst mode in grid areas of different densities. While ensuring the flatness of the weld end face of the sheared steel grating reaches the extreme, it also greatly reduces the long-term wear of the transmission screw and guide rail components caused by heavy-duty cutting, and achieves the optimal balance between processing efficiency and equipment life. Attached Figure Description

[0074] Figure 1 This is a schematic diagram of the basic process of the present invention. Detailed Implementation

[0075] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0076] Example 1, refer to Figure 1 An automated shearing method for steel grating includes:

[0077] Obtain the initial contact reaction force and three-dimensional morphology of the steel grating to be sheared, and measure the height, thickness, adjacent spacing and longitudinal distance of the shearing starting point of the flat steel.

[0078] Calculate the local equivalent section stiffness at the current shearing node based on the height, thickness and adjacent spacing of the flat steel.

[0079] Combining the initial contact reaction force and the longitudinal distance, and using the local equivalent section stiffness and the flat steel height, the warping deviation is calculated;

[0080] Based on the warping deviation and the local equivalent section stiffness, and combined with the adjacent spacing, a geometric projection is performed to calculate the dynamic compensation clamping force.

[0081] The induced secondary nodal shear stress is calculated based on the dynamic compensation clamping force, the adjacent spacing, the flat steel thickness, and the flat steel height.

[0082] Obtain the material's ultimate yield shear stress threshold and density constant, and calculate the critical cutting speed of the tool by combining the secondary nodal shear stress and the flat steel dimensions;

[0083] Calculate the theoretical maximum nodal stiffness threshold based on the maximum permissible physical dimensions of the equipment;

[0084] Based on the ratio of the local equivalent cross-sectional stiffness to the theoretical maximum nodal stiffness threshold, the critical cutting speed is corrected, a final feed speed command is generated, and sent to the shearing mechanism.

[0085] The process of obtaining the initial contact reaction force and three-dimensional morphology of the steel grating to be sheared, and measuring the height, thickness, adjacent spacing, and longitudinal distance of the shearing starting point of the flat steel includes:

[0086] Piezoelectric thin film stress sensors are arrayed on the bottom support base of the automated shearing platform;

[0087] The initial residual stress equivalent at the current shearing node is acquired by the piezoelectric thin film stress sensor and used as the initial contact reaction force.

[0088] A laser displacement sensor is installed at the position in front of the shearing blade holder;

[0089] The three-dimensional morphology of the steel grating is obtained by scanning using the laser displacement sensor;

[0090] Measure and record the height of the flat bar, the thickness of the flat bar, the spacing between adjacent flat bars, and the longitudinal distance from the shearing start point to the current node to be sheared.

[0091] The step of calculating the local equivalent section stiffness at the current shearing node based on the height, thickness, and adjacent spacing of the flat steel includes:

[0092] The height of the flat steel is calculated to the cube to obtain the height cube value;

[0093] Multiply the cubic value of the height by the measured thickness of the flat steel to obtain the stiffness numerator; square the measured distance between adjacent flat steel bars and multiply by a constant twelve to obtain the stiffness denominator.

[0094] Divide the stiffness numerator by the stiffness denominator to obtain the local equivalent cross-sectional stiffness at the current shear node.

[0095] The calculation of warpage deviation, combining the initial contact reaction force and the longitudinal distance, using the local equivalent section stiffness and the flat steel height, includes:

[0096] The measured longitudinal distance is calculated to the fourth power and multiplied by the initial contact reaction force to obtain the deviation numerator;

[0097] Multiply the local equivalent section stiffness by the measured flat steel height, and then multiply by a constant eight to obtain the deviation denominator;

[0098] Divide the numerator of the deviation by the denominator of the deviation to obtain the warping deviation amount.

[0099] The calculation of the dynamic compensation clamping force based on the warping deviation and the local equivalent cross-sectional stiffness, combined with the geometric projection of the adjacent spacing, includes:

[0100] Multiply the warping deviation by the local equivalent cross-sectional stiffness to obtain the first product;

[0101] Divide the first product by the square of the measured spacing between adjacent flat bars to obtain the basic compensation force;

[0102] Divide the warping deviation by the spacing between the adjacent flat bars to obtain the deviation ratio;

[0103] Calculate the square of the deviation ratio and subtract the square from the constant to obtain the correction margin;

[0104] The square root of the correction margin is used to obtain the projection correction coefficient;

[0105] Multiplying the basic compensation force by the projection correction coefficient yields the dynamic compensation clamping force.

[0106] The calculation of the induced secondary nodal shear stress based on the dynamic compensation clamping force, the adjacent spacing, the flat steel thickness, and the flat steel height includes:

[0107] Multiply the dynamic compensation clamping force by the measured distance between adjacent flat bars to obtain the stress molecule;

[0108] Multiply the measured thickness of the flat steel by the height of the flat steel, and then multiply by a constant two to obtain the stress denominator;

[0109] Dividing the stress numerator by the stress denominator yields the induced secondary nodal shear stress.

[0110] The process of obtaining the material's ultimate yield shear stress threshold and density constant, combined with the secondary nodal shear stress and flat steel dimensions, to calculate the critical cutting speed of the tool includes:

[0111] Calculate the difference between the material's ultimate yield shear stress threshold and the secondary nodal shear stress;

[0112] Multiply the difference, constant 2, and the measured height of the flat steel by three factors to obtain the velocity numerator;

[0113] Multiply the density constant of the material by the measured thickness of the flat steel to obtain the velocity denominator;

[0114] Divide the velocity numerator by the velocity denominator to obtain the ratio;

[0115] The critical cutting speed of the tool is obtained by taking the square root of the ratio.

[0116] The calculation of the theoretical maximum nodal stiffness threshold based on the maximum permissible physical size parameters of the equipment includes:

[0117] The maximum allowable flat steel height of the equipment is calculated to the cube and multiplied by the maximum allowable flat steel thickness of the equipment to obtain the ultimate stiffness numerator.

[0118] The minimum allowable grid spacing of the device is squared and multiplied by a constant of twelve to obtain the denominator of the ultimate stiffness.

[0119] Dividing the numerator of the ultimate stiffness by the denominator of the ultimate stiffness yields the theoretical maximum nodal stiffness threshold.

[0120] The step of correcting the critical infeed speed based on the ratio of the local equivalent section stiffness to the theoretical maximum nodal stiffness threshold, generating a final feed speed command, and sending it to the shearing mechanism includes:

[0121] Divide the local equivalent section stiffness by the theoretical maximum nodal stiffness threshold to obtain the stiffness ratio.

[0122] The final feed rate command is obtained by multiplying the critical cutting speed of the tool by the stiffness ratio.

[0123] The final feed rate command is sent to the shearing mechanism. This technical solution proposes a dynamic speed limiting control method for the specific processing environment of automated steel grating shearing. During the shearing process, the internal residual stress released by cutting local nodes can cause microscopic warping deviations in the unsheared parts. To eliminate this deformation, a dynamic compensation clamping force must be calculated and applied. However, under the specific structure of non-uniform stiffness of steel grating, this compensation clamping force will cause the nodes to bear induced secondary node shear stress in advance. If the tool cuts in at a conventional constant speed, the instantaneous kinetic energy superimposed on the existing secondary shear load can easily exceed the material's ultimate yield shear stress threshold, causing microcrack damage at the weld joint. Therefore, this solution does not blindly cut in, but instead calculates the critical cutting speed of the tool that can avoid microcracks by deduce the physical coupling between the local equivalent section stiffness and multiple stresses. Based on this, flexible mapping control is performed to finally generate the feed rate command. Under the complex stress environment of steel grating, this solution realizes feedforward physical protection from deformation prediction to flexible speed limiting, fundamentally solving the stress surge problem caused by eliminating warping, avoiding mechanical damage, and ensuring the structural integrity of the processed parts.

[0124] Example 2: An automated shearing method for steel grating further includes:

[0125] The process of obtaining the initial contact reaction force and three-dimensional morphology of the steel grating to be sheared, and measuring the height, thickness, adjacent spacing, and longitudinal distance of the shearing starting point of the flat steel includes:

[0126] Piezoelectric thin-film stress sensors are arrayed on the bottom support base of the automated shearing platform to collect the initial residual stress equivalent at the current shearing node. As the initial contact reaction force;

[0127] A laser displacement sensor is installed in front of the shearing blade holder to scan and acquire the three-dimensional shape of the steel grating;

[0128] Measure and record the height of the flat steel. Flat steel thickness Spacing between adjacent flat steel bars And the distance from the starting point of the cut to the current node to be cut. Longitudinal distance By arranging piezoelectric thin-film stress sensors in an array on the bottom support base of the automated shearing platform to specifically collect the initial contact reaction force of the nodes to be sheared, it is possible to capture minute mechanical fluctuations in the underlying structure with extremely high sensitivity. This contact-type array stress detection method is different from conventional optical external contour scanning. It can directly penetrate the obscuring of the metal's external shape and truly map the implicit residual stress equivalent left by welding cooling or pre-forming inside the steel grating. Since residual stress is the fundamental physical cause of uncontrollable deformation after shearing, its quantification and extraction at the initial station provides the most advanced and fundamental dynamic induction source data for the overall control algorithm.

[0129] The step of calculating the local equivalent section stiffness at the current shearing node based on the height, thickness, and adjacent spacing of the flat steel includes:

[0130] Based on the principle of moment of inertia of rectangular sections in classical mechanics of materials and combined with the mesh spacing, the local equivalent section stiffness at the current node to be sheared is calculated:

[0131]

[0132] In the formula:

[0133] Represents the local equivalent cross-sectional stiffness of the node i to be sheared;

[0134] This represents the height of the flat steel obtained through direct measurement;

[0135] This represents the thickness of the flat steel obtained through direct measurement.

[0136] This represents the distance between adjacent flat bars obtained through direct measurement. By using the actual measured flat bar height, thickness, and distance between adjacent flat bars, and based on the principle of rectangular section moment of inertia in classical mechanics of materials combined with mesh characteristics for equivalent analysis, the local equivalent section stiffness at the current shearing node is accurately calculated. This approach, which abstracts the complex steel grating mesh structure and equates it to a local bending stiffness model, can profoundly reflect the inherent physical properties of the component resisting bending deformation under stress. Since the stress response of the steel grating varies significantly at different mesh locations and node regions, accurately quantifying this stiffness parameter can provide the most crucial material mechanics benchmark for subsequent deformation and stress extrapolation. This allows the system to move beyond macroscopic unified empirical predictions and instead perform microscopic mechanical deconstruction for each specific cutting node, thereby significantly improving the adaptive perception accuracy of the entire control algorithm for local structural differences and its ability to track dynamic physical and mechanical properties.

[0137] The calculation of warpage deviation, combining the initial contact reaction force and the longitudinal distance, using the local equivalent section stiffness and the flat steel height, includes:

[0138] Based on a mathematical model of the deflection distribution of a cantilever beam subjected to concentrated forces at its ends, the warping deviation caused by stress release in the microscopic spatial displacement is calculated:

[0139]

[0140] In the formula:

[0141] Represents the node to be cut The warping deviation;

[0142] This represents the initial residual stress equivalent obtained by measuring the initial values ​​using a piezoelectric thin-film stress sensor.

[0143] Represents the distance from the shear initiation point to the node obtained by direct measurement. The longitudinal distance;

[0144] This represents the calculated local equivalent cross-sectional stiffness.

[0145] This represents the height of the flat steel obtained through direct measurement. By combining the contact reaction force and longitudinal distance initially acquired by the system, and then using the obtained local equivalent section stiffness and flat steel height, and based on the mathematical model of deflection distribution of a cantilever beam under concentrated end force, the microscopic spatial warping deviation caused by stress release is accurately calculated. This process fully considers the transient release effect of internal stress caused by the cutting off of the preceding node; it transforms the internal residual mechanical imbalance that was originally impossible to directly observe into spatial displacement data that can be accurately quantified; it effectively overcomes the technical bottleneck of traditional processing methods that can only deal with static surface unevenness; it enables the automated system to form accurate predictive feedback as soon as physical deformation begins or even in the microscopic accumulation stage; this forward-looking spatial deviation quantification mechanism provides a crucial target point for subsequently applying precise clamping resistance force; it eliminates the risk of secondary mechanical damage caused by blindly applying constraints and significantly enhances the processing platform's ability to suppress dynamic displacement;

[0146] The calculation of the dynamic compensation clamping force based on the warping deviation and the local equivalent cross-sectional stiffness, combined with the geometric projection of the adjacent spacing, includes:

[0147] Based on the principle of equivalence between deformation energy and work done by external force, and by introducing trigonometric function projection correction of the torsional angle, the dynamic compensation clamping force that counteracts warping deformation and prevents the crossbar from tortuously yielding is calculated:

[0148]

[0149] In the formula:

[0150] Represents dynamic compensation clamping force;

[0151] This represents the calculated warpage deviation.

[0152] This represents the calculated local equivalent cross-sectional stiffness.

[0153] This represents the initial direct measurement of the spacing between adjacent flat bars. Based on the previously derived warping deviation and local equivalent section stiffness, and combined with the trigonometric function geometric projection correction of the torsional angle, a targeted dynamic compensation clamping force is calculated. This calculation logic strictly follows the principle of equivalent conversion between deformation energy and external force work, cleverly solving the technical problem that simply applying a large reverse force cannot maintain the stability of the grid space. Because there is a torsional force transmission attenuation phenomenon in the actual steel grating node area that is easily ignored, the introduction of trigonometric projection correction enables the compensation force to not only accurately offset the warping deformation of the target area, but also strictly prevent the transverse connecting members from torsional yielding failure exceeding the bearing limit. This multi-dimensional compensation force synthesis mechanism ensures that the external clamping equipment can maintain the physical stability of the processing plane with the most appropriate energy input, greatly reducing the risk of incidental structural deformation caused by the deviation of the clamping force direction.

[0154] The calculation of the induced secondary nodal shear stress based on the dynamic compensation clamping force, the adjacent spacing, the flat steel thickness, and the flat steel height includes:

[0155] Based on the relationship between the stress-bearing area and the distribution of concentrated force, assess the shear load state already borne by the weld joint before the tool enters the weld, and calculate the induced secondary nodal shear stress:

[0156]

[0157] In the formula:

[0158] This represents the calculated secondary nodal shear stress;

[0159] Represents dynamic compensation clamping force;

[0160] This represents the height of the flat steel obtained through direct measurement;

[0161] This represents the thickness of the flat steel obtained through direct measurement.

[0162] This represents the distance between adjacent flat bars obtained through direct measurement. By using the measured distance between adjacent flat bars, flat bar thickness, and flat bar height parameters in conjunction with the derived dynamic compensation clamping force, and leveraging the physical distribution relationship between the force-bearing area and the concentrated load, the secondary nodal shear stress induced by external compensation is deeply analyzed and calculated. This step breaks through the blind spot of monitoring incidental destructive effects in conventional control algorithms. When compensation constraints are applied to the steel grating to eliminate warping, the weld point, as a concentrated hub for stress transmission, will inevitably bear the hidden shear load in advance. Accurate calculation of this secondary shear stress allows the system to comprehensively evaluate and thoroughly understand the actual physical load-bearing margin of the weld point before the tool makes mechanical contact. This quantitative analysis, which transforms static constraint mechanics into microscopic material stress, provides key advance warning data for subsequent transient dynamic speed control, thereby fundamentally preventing the tearing of the matrix inside the weld area and the ultimate fracture of the material caused by insufficient estimation of the superimposed destructive load.

[0163] The process of obtaining the material's ultimate yield shear stress threshold and density constant, combined with the secondary nodal shear stress and flat steel dimensions, to calculate the critical cutting speed of the tool includes:

[0164] Calculate the critical cut speed of the tool by utilizing the conversion mechanism between kinetic energy and material strain energy:

[0165]

[0166] In the formula:

[0167] This represents the calculated critical cut speed of the tool.

[0168] The ultimate yield shear stress threshold of steel is determined based on the material properties of the steel.

[0169] This represents the calculated secondary nodal shear stress;

[0170] This represents the height of the flat steel obtained through direct measurement;

[0171] This represents the density constant of steel, and its value is determined based on the physical properties of steel.

[0172] This represents the thickness of the flat steel obtained through direct measurement. By acquiring the preset material ultimate yield shear stress threshold and material density constant, and deeply integrating the derived secondary node shear stress and flat steel structural dimensions, and relying on the conversion and conservation mechanism of the instantaneous kinetic energy of the tool and the internal material strain energy, the critical cutting speed of the tool that can completely avoid the generation of micro-cracks at the weld point is accurately calculated. This control strategy realizes the dimensional reduction guidance from macroscopic material strength judgment to microscopic mechanical execution action. Since the kinetic energy brought by the tool impact must share the material's ultimate failure margin with the existing secondary strain energy in the material, the physical execution boundary is set using this energy difference, ensuring that the total impact energy is always limited within the structural safety envelope. This prevents the cutting equipment from forcibly cutting at a fixed and rigid blind constant rate, greatly enhancing the system's adaptive deceleration protection efficiency for highly brittle node areas. It eliminates the expansion and derivation of micro-cracks at the moment of cutting from the source of mechanical kinetic energy input, extending the product's service life and structural reliability.

[0173] The calculation of the theoretical maximum nodal stiffness threshold based on the maximum permissible physical size parameters of the equipment includes:

[0174] Based on the maximum allowable dimensional parameters of the equipment's mechanical structure, the calculation principle of local equivalent section stiffness is projected onto the system's limit state to calculate the theoretical maximum nodal stiffness threshold:

[0175]

[0176] In the formula:

[0177] Represents the theoretical maximum nodal stiffness threshold;

[0178] This represents the maximum allowable height of flat steel in the equipment, which is directly obtained based on the design limits of the equipment's mechanical structure.

[0179] The maximum allowable flat steel thickness of the equipment is obtained directly from the design limits of the equipment's mechanical structure.

[0180] The minimum allowable grid spacing for the equipment is directly obtained based on the design limits of the equipment's mechanical structure. By reading the physical limit parameters such as the maximum allowable flat steel height, maximum flat steel thickness, and minimum grid spacing of the automated shearing equipment's mechanical structure, the basic equivalent section stiffness calculation principle is directly projected onto the extreme working state of the entire processing system, thereby deriving the theoretical maximum nodal stiffness threshold. This method avoids the control algorithm outputting erroneous electrical signals that cannot be executed when dealing with extreme abnormal deformations or special materials exceeding the equipment's load limit. This allows the algorithm's calculation framework to achieve a deep, underlying fit with the physical performance of the real mechanical structure, providing global boundary guarantees for the safe mapping of overall speed servo commands and the long-term stable operation of the system.

[0181] The step of correcting the critical infeed speed based on the ratio of the local equivalent section stiffness to the theoretical maximum nodal stiffness threshold, generating a final feed speed command, and sending it to the shearing mechanism includes:

[0182] Flexible mapping control is performed based on the ratio between the current node's local stiffness and the theoretical maximum stiffness threshold to correct the critical infeed speed and generate the final feed speed command.

[0183]

[0184] In the formula:

[0185] The final feed rate command is sent to the execution control system.

[0186] This represents the calculated critical cutting speed of the tool to avoid microcracks.

[0187] This represents the calculated local equivalent cross-sectional stiffness.

[0188] This represents the theoretical maximum node stiffness threshold calculated from the data. By proportionalizing the local equivalent cross-sectional stiffness of the current node calculated in real time with the theoretical maximum node stiffness threshold of the equipment system, and multiplying this flexibility ratio coefficient by the theoretical critical cutting speed of the tool, the final feed speed command that can be directly sent to the underlying shearing actuator is finally corrected and generated. This closed-loop end-to-end dimension reduction mapping control improves the mechanical impact problem of rigid critical commands under actual motor drive, ensuring that the final output processing speed is not only absolutely below the limit red line that causes microcracks, but also can completely and smoothly adapt to the resistance fluctuations caused by local structural abrupt changes. The proportional dynamic correction mechanism allows the servo motor to intelligently adjust the torque burst mode in grid areas of different densities, ensuring that the flatness of the weld end face of the sheared steel grating reaches the extreme, while significantly reducing the long-term wear of the transmission screw and guide rail components caused by heavy-duty cutting, achieving the optimal balance between processing efficiency and equipment lifespan.

[0189] Example 3: A system for implementing the automated shearing method for steel grating, comprising:

[0190] Data acquisition module: used to acquire the initial contact reaction force and three-dimensional morphology of the steel grating to be sheared, and to measure the height, thickness, adjacent spacing and longitudinal distance of the shearing starting point of the flat steel.

[0191] Stiffness calculation module: used to calculate the local equivalent section stiffness at the current shearing node based on the flat steel size parameters;

[0192] Warp deviation calculation module: used to calculate the warp deviation by combining the initial contact reaction force, longitudinal distance and local equivalent cross-sectional stiffness;

[0193] Compensation force calculation module: used to dynamically compensate for the clamping force based on the warping deviation, local equivalent cross-sectional stiffness, and adjacent spacing through geometric projection;

[0194] Secondary stress calculation module: used to calculate the induced secondary nodal shear stress based on the dynamic compensation clamping force and flat steel dimensions;

[0195] Critical speed calculation module: used to calculate the critical cutting speed of the tool by combining the material yield shear stress threshold, density constant and secondary nodal shear stress;

[0196] Maximum stiffness calculation module: used to calculate the theoretical maximum nodal stiffness threshold based on the maximum permissible physical size parameters of the equipment;

[0197] Command generation module: used to correct the critical cutting speed according to the theoretical maximum node stiffness threshold of the system, generate the final feed speed command and send it to the shearing mechanism.

[0198] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0199] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for automated shearing of steel grating, characterized in that, include: Obtain the initial contact reaction force and three-dimensional morphology of the steel grating to be sheared, and measure the height, thickness, adjacent spacing and longitudinal distance of the shearing starting point of the flat steel. Calculate the local equivalent section stiffness at the current shearing node based on the height, thickness and adjacent spacing of the flat steel. Combining the initial contact reaction force and the longitudinal distance, and using the local equivalent section stiffness and the flat steel height, the warping deviation is calculated; Based on the warping deviation and the local equivalent section stiffness, and combined with the adjacent spacing, a geometric projection is performed to calculate the dynamic compensation clamping force. The induced secondary nodal shear stress is calculated based on the dynamic compensation clamping force, the adjacent spacing, the flat steel thickness, and the flat steel height. Obtain the material's ultimate yield shear stress threshold and density constant, and calculate the critical cutting speed of the tool by combining the secondary nodal shear stress and the flat steel dimensions; Calculate the theoretical maximum nodal stiffness threshold based on the maximum permissible physical dimensions of the equipment; Based on the ratio of the local equivalent cross-sectional stiffness to the theoretical maximum nodal stiffness threshold, the critical cutting speed is corrected, a final feed speed command is generated, and sent to the shearing mechanism.

2. The method of claim 1, wherein, The process of obtaining the initial contact reaction force and three-dimensional morphology of the steel grating to be sheared, and measuring the height, thickness, adjacent spacing, and longitudinal distance of the shearing starting point of the flat steel includes: Piezoelectric thin film stress sensors are arrayed on the bottom support base of the automated shearing platform; The initial residual stress equivalent at the current shearing node is acquired by the piezoelectric thin film stress sensor and used as the initial contact reaction force. A laser displacement sensor is installed at the position in front of the shearing blade holder; The three-dimensional morphology of the steel grating is obtained by scanning using the laser displacement sensor; Measure and record the height of the flat bar, the thickness of the flat bar, the spacing between adjacent flat bars, and the longitudinal distance from the shearing start point to the current node to be sheared.

3. The method of claim 1, wherein, The step of calculating the local equivalent section stiffness at the current shearing node based on the height, thickness, and adjacent spacing of the flat steel includes: The height of the flat steel is calculated to the cube to obtain the height cube value; Multiply the cubic value of the height by the measured thickness of the flat steel to obtain the stiffness numerator; square the measured distance between adjacent flat steel bars and multiply by a constant twelve to obtain the stiffness denominator. Divide the stiffness numerator by the stiffness denominator to obtain the local equivalent cross-sectional stiffness at the current shear node.

4. The method of claim 1, wherein, The calculation of warpage deviation, combining the initial contact reaction force and the longitudinal distance, using the local equivalent section stiffness and the flat steel height, includes: The measured longitudinal distance is calculated to the fourth power and multiplied by the initial contact reaction force to obtain the deviation numerator; Multiply the local equivalent section stiffness by the measured flat steel height, and then multiply by a constant eight to obtain the deviation denominator; Divide the numerator of the deviation by the denominator of the deviation to obtain the warping deviation amount.

5. The method of claim 1, wherein, The calculation of the dynamic compensation clamping force based on the warping deviation and the local equivalent cross-sectional stiffness, combined with the geometric projection of the adjacent spacing, includes: Multiply the warping deviation by the local equivalent cross-sectional stiffness to obtain the first product; Divide the first product by the square of the measured spacing between adjacent flat bars to obtain the basic compensation force; Divide the warping deviation by the spacing between the adjacent flat bars to obtain the deviation ratio; Calculate the square of the deviation ratio and subtract the square from the constant to obtain the correction margin; The square root of the correction margin is used to obtain the projection correction coefficient; Multiplying the basic compensation force by the projection correction coefficient yields the dynamic compensation clamping force.

6. The method of claim 1, wherein, The calculation of the induced secondary nodal shear stress based on the dynamic compensation clamping force, the adjacent spacing, the flat steel thickness, and the flat steel height includes: Multiply the dynamic compensation clamping force by the measured distance between adjacent flat bars to obtain the stress molecule; Multiply the measured thickness of the flat steel by the height of the flat steel, and then multiply by a constant two to obtain the stress denominator; Dividing the stress numerator by the stress denominator yields the induced secondary nodal shear stress.

7. The automated shearing method for steel grating according to claim 1, characterized in that, The process of obtaining the material's ultimate yield shear stress threshold and density constant, combined with the secondary nodal shear stress and flat steel dimensions, to calculate the critical cutting speed of the tool includes: Calculate the difference between the material's ultimate yield shear stress threshold and the secondary nodal shear stress; Multiply the difference, constant 2, and the measured height of the flat steel by three factors to obtain the velocity numerator; Multiply the density constant of the material by the measured thickness of the flat steel to obtain the velocity denominator; Divide the velocity numerator by the velocity denominator to obtain the ratio; The critical cutting speed of the tool is obtained by taking the square root of the ratio.

8. The automated shearing method for steel grating according to claim 1, characterized in that, The calculation of the theoretical maximum nodal stiffness threshold based on the maximum permissible physical size parameters of the equipment includes: The maximum allowable flat steel height of the equipment is calculated to the cube and multiplied by the maximum allowable flat steel thickness of the equipment to obtain the ultimate stiffness numerator. The minimum allowable grid spacing of the device is squared and multiplied by a constant of twelve to obtain the denominator of the ultimate stiffness. Dividing the numerator of the ultimate stiffness by the denominator of the ultimate stiffness yields the theoretical maximum nodal stiffness threshold.

9. The automated shearing method for steel grating according to claim 1, characterized in that, The step of correcting the critical infeed speed based on the ratio of the local equivalent section stiffness to the theoretical maximum nodal stiffness threshold, generating a final feed speed command, and sending it to the shearing mechanism includes: Divide the local equivalent section stiffness by the theoretical maximum nodal stiffness threshold to obtain the stiffness ratio. The final feed rate command is obtained by multiplying the critical cutting speed of the tool by the stiffness ratio. The final feed rate command is sent to the shearing mechanism.

10. A system employing the automated steel grating shearing method of claim 1, characterized in that, include: Data acquisition module: used to acquire the initial contact reaction force and three-dimensional morphology of the steel grating to be sheared, and to measure the height, thickness, adjacent spacing and longitudinal distance of the shearing starting point of the flat steel. Stiffness calculation module: used to calculate the local equivalent section stiffness at the current shearing node based on the flat steel size parameters; Warp deviation calculation module: used to calculate the warp deviation by combining the initial contact reaction force, longitudinal distance and local equivalent cross-sectional stiffness; Compensation force calculation module: used to dynamically compensate for the clamping force based on the warping deviation, local equivalent cross-sectional stiffness, and adjacent spacing through geometric projection; Secondary stress calculation module: used to calculate the induced secondary nodal shear stress based on the dynamic compensation clamping force and flat steel dimensions; Critical speed calculation module: used to calculate the critical cutting speed of the tool by combining the material yield shear stress threshold, density constant and secondary nodal shear stress; Maximum stiffness calculation module: used to calculate the theoretical maximum nodal stiffness threshold based on the maximum permissible physical size parameters of the equipment; Command generation module: used to correct the critical cutting speed according to the theoretical maximum node stiffness threshold of the system, generate the final feed speed command and send it to the shearing mechanism.

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