A flexible processing system and method for a multi-axis industrial robot on a shock absorber seat

Abstract

The present invention discloses a multi-axis industrial robot flexible machining system and method for a shock absorber upper seat, which relates to the field of robotic machining technology. The system comprises: a stress direction solving module for solving the gradient vector field of the average speckle field in the shock absorber upper seat and generating the maximum principal tensile stress direction of the shock absorber upper seat based on the gradient vector field; a risk factor calculating module for calculating the risk factor based on the maximum principal tensile stress direction; a micro-drainage groove pre-engraving module for pre-engraving micro-drainage grooves on the shock absorber upper seat based on the risk factor and the maximum principal tensile stress to form micro-drainage grooves; a first state processing module for performing a first state processing on the shock absorber upper seat to obtain a first physical state of the shock absorber upper seat; and a second state processing module for performing a second state processing on the shock absorber upper seat based on the first physical state to obtain a second physical state of the shock absorber upper seat. The present invention can capture sudden changes in wear and stress fusion in real time.

Description

Technical Field

[0001] The present invention relates to the technical field of robot processing, and in particular to a flexible processing system for a multi-axis industrial robot for a shock absorber upper seat. Background Art

[0002] As a key connector between the vehicle body and the suspension system, the upper seat of an automobile shock absorber requires multiple features such as thrust surfaces, chamfers, and locating surfaces to be drilled, chamfered, and fixed in a single clamping operation by a multi-axis industrial robot. This type of upper seat is usually formed by stamping, resulting in a complex and highly directional distribution of residual tensile stress within it. During the subsequent cutting phase, when the wear of the tool's back face approaches the failure limit, the residual stress is instantly released along the direction of the maximum principal tensile stress, which can easily produce a V-shaped rebound wedge at the outlet edge and dramatically increase the burr height. If the pressure is not relieved in time and this low-probability emergency is not suppressed, not only will the flatness of the outlet locating surface and the axial position of the outlet hole be damaged, but it will also make bolt assembly difficult and the gasket unbalanced, thereby shortening the service life of the entire shock absorber.

[0003] Most current processing lines use cumulative cutting time and fixed tool change strategies, which can neither capture sudden changes in wear and stress fusion in real time, nor complete precise detection and compensation within the processing cycle. There is an urgent need for an integrated flexible processing solution for residual stress visualization, adaptive pressure relief, and online shape and position detection. Summary of the Invention

[0004] The purpose of the present invention is to solve the shortcomings of the existing technology that the cumulative cutting time and fixed tool change strategy are unable to capture the sudden changes of wear and stress fusion in real time, and to propose a flexible processing system and method for a shock absorber upper seat multi-axis industrial robot.

[0005] In order to solve the problems existing in the prior art, the present invention adopts the following technical solutions:

[0006] A multi-axis industrial robot flexible processing system for a shock absorber upper seat, comprising:

[0007] The stress direction solving module is used to solve the gradient vector field of the average speckle field in the shock absorber upper seat and generate the maximum principal tensile stress direction of the shock absorber upper seat based on the gradient vector field;

[0008] A risk factor calculation module is used to calculate the risk factor based on the direction of the maximum principal tensile stress;

[0009] A micro-discharge groove pre-engraving module is used to pre-engraving micro-discharge grooves on the upper seat of the shock absorber according to the risk factor and the maximum principal tensile stress to form micro-discharge grooves;

[0010] A first state processing module, configured to perform first state processing on the shock absorber upper seat to obtain a first physical state of the shock absorber upper seat;

[0011] A second state processing module is used to perform a second state processing on the shock absorber upper seat based on the first physical state to obtain a second physical state of the shock absorber upper seat;

[0012] A shape and position deviation detection module is used to calculate the surface deviation of the outlet positioning surface in the shock absorber upper seat and the angular deviation of the outlet hole position based on the second physical state;

[0013] The qualification judgment module is used to judge the qualification of the shock absorber seat based on the surface deviation and angle deviation.

[0014] Preferably, solving the gradient vector field of the average speckle field in the upper seat of the shock absorber and generating the maximum principal tensile stress direction of the upper seat of the shock absorber based on the gradient vector field include:

[0015] Two speckle displacement maps were collected using a polarized laser speckle camera;

[0016] The pixels of the two speckle displacement maps are averaged and fused point by point to obtain the average speckle field on the outlet side of the shock absorber upper seat.

[0017] Perform gradient calculation on the average speckle field to obtain the gradient vector field of the average speckle field;

[0018] The vectors in the gradient vector field are normalized to obtain the direction of the maximum principal tensile stress on the outlet side surface.

[0019] Preferably, collecting two speckle displacement maps using a polarized laser speckle camera includes:

[0020] Installing a polarized laser spot camera on a multi-axis industrial robot;

[0021] Taking the exit side surface as the scanning starting point, the polarized laser speckle camera is moved in equiangular steps along a fixed sector of the exit side surface to collect two speckle displacement maps.

[0022] Preferably, the risk factor is calculated based on the direction of the maximum principal tensile stress, including:

[0023] Obtain the tool flank wear width and the tangential unit vector of the tool preset trajectory;

[0024] The risk factor of V-shaped rebound wedge formation during the machining of the shock absorber upper seat is calculated based on the flank wear width, the direction of the maximum principal tensile stress, and the tangential unit vector. The calculation formula of the risk factor is as follows:

[0025]

[0026] Where, It is a risk factor. is the flank wear width, is the direction of maximum principal tensile stress, is the tangential unit vector.

[0027] Preferably, the upper seat of the shock absorber is pre-engraved with a micro-drainage groove according to the risk factor and the maximum principal tensile stress to form the micro-drainage groove, comprising:

[0028] If the risk factor is greater than the preset factor threshold, the length and depth of the micro-discharge trough are calculated based on the risk factor;

[0029] Perform a vector dot product on the direction vector of the maximum principal tensile stress and the normal vector of the outlet side surface of the shock absorber upper seat to obtain a dot product result;

[0030] Take the inverse cosine of the dot product result to obtain the spatial angle between the maximum principal tensile stress and the normal vector, and convert the spatial angle into the direction angle of the micro-discharge groove on the outlet side surface;

[0031] The groove length, groove depth and direction angle are used as geometric parameters of the micro-discharge groove;

[0032] The outlet side surface is pre-engraved with micro-discharge grooves according to geometric parameters to form micro-discharge grooves.

[0033] Preferably, the first state is processed as follows:

[0034] The outlet side pressure plate of the driving fixture is rotated around the normal vector so that the central axis of the trapezoidal relief groove in the outlet side pressure plate coincides with the direction of the maximum principal tensile stress;

[0035] Place the upper seat of the shock absorber on the positioning surface of the fixture, and engage the trapezoidal slow-release groove with the micro-release groove.

[0036] Preferably, the second state is processed as follows:

[0037] Calculate the Z-axis downward chamfering amount of the outlet edge of the shock absorber upper seat according to the groove depth of the micro-discharge groove;

[0038] The outlet edge is chamfered according to the Z-axis downward chamfering amount, and the outlet edge is deburred.

[0039] Preferably, calculating the surface deviation of the outlet positioning surface in the shock absorber upper seat and the angular deviation of the outlet hole position includes:

[0040] A three-point laser displacement meter is used to perform non-contact measurement on three equally divided measuring points on the outlet positioning surface to obtain the height difference data of each of the three equally divided measuring points;

[0041] Calculate the average value of the three measuring points divided equally into three measuring points based on the three height difference data, calculate the absolute value of the difference between the average value of the three measuring points and each height difference data, and take the maximum value of the three absolute values ​​of the difference as the surface deviation;

[0042] The angle deflection is calculated using a preset angle deflection formula, where the preset angle deflection formula is as follows:

[0043]

[0044] Where, is the angle of deflection, 、 They are two adjacent measuring points on the outlet positioning surface, It is the average distance between two adjacent measuring points and the hole center.

[0045] Preferably, judging the shock absorber upper seat as qualified based on the surface deviation and angle deflection includes:

[0046] When the surface deviation is less than the preset deviation threshold and the angle deflection is less than the preset deflection threshold, the shock absorber upper seat is marked as qualified; otherwise, the shock absorber upper seat is marked for repair.

[0047] In order to solve the above problems, the present invention also provides a flexible processing method for a multi-axis industrial robot on a shock absorber seat, the method comprising:

[0048] S1. Calculate the gradient vector field of the average speckle field in the upper seat of the shock absorber, and generate the maximum principal tensile stress direction of the upper seat of the shock absorber based on the gradient vector field;

[0049] S2, calculate the risk factor based on the direction of maximum principal tensile stress;

[0050] S3. Pre-carve a micro-drainage groove on the upper seat of the shock absorber according to the risk factor and the maximum principal tensile stress to form a micro-drainage groove;

[0051] S4, performing first state processing on the shock absorber upper seat to obtain a first physical state of the shock absorber upper seat;

[0052] S5. Based on the first physical state, performing a second state processing on the shock absorber upper seat to obtain a second physical state of the shock absorber upper seat;

[0053] S6. Based on the second physical state, calculate the surface deviation of the outlet positioning surface in the shock absorber upper seat and the angular deviation of the outlet hole;

[0054] S7. Determine the compliance of the shock absorber seat based on the surface deviation and angle deviation.

[0055] Compared with the prior art, the present invention has the following beneficial effects:

[0056] 1. In the present invention, the residual tensile stress field on the outlet side is converted into the direction of the maximum principal tensile stress, and then the risk factor is calculated in combination with the wear width of the tool flank and the tangential vector of the cutting trajectory, so that the probability of wear and stress fusion instability is quantified into a single threshold. When the risk factor rises to the set value, subsequent protective measures can be triggered within the same workstation, achieving advanced warning of sub-millisecond mutations, rather than relying on the delayed tool change mechanism of the accumulated cutting time, thereby realizing online capture and processing of low-probability high-risk events.

[0057] 2. In the present invention, when the risk is judged to be too high, a narrow micro-relief groove is pre-engraved on the outlet side according to the direction of the maximum principal tensile stress, and the rotatable outlet side pressure plate is driven to make the axis of the trapezoidal relief groove coincide with this direction, and finally the two groove surface lines are meshed; when the stress is released instantaneously, it can be dissipated along this continuous channel by the narrow guide width, significantly reducing the reverse torque and burr amplification effect of the tool being pushed back instantaneously, thereby achieving fundamental suppression of residual stress and extreme wear fusion instability.

[0058] 3. In this invention, after pressure relief and deburring, the three-point surface accuracy of the outlet positioning surface and the angular deviation of the outlet hole are measured online. The pre-grooved groove depth is converted into the Z-axis downward chamfering amount, guiding the simultaneous compensation of the chamfering tool. If the test result exceeds the threshold, it is immediately marked for rework. This process, through a closed-loop real-time feedback loop, condenses the platen and workpiece locking, chamfer compensation, and precision inspection into a single cycle, ensuring that the surface accuracy and hole axis meet assembly requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0060] Figure 1 This is a functional module diagram of a multi-axis industrial robot flexible processing system for a shock absorber upper seat provided by one embodiment of the present invention;

[0061] Figure 2 The present invention provides a flowchart of a multi-axis industrial robot flexible processing method for a shock absorber upper seat according to an embodiment of the present invention. DETAILED DESCRIPTION

[0062] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0063] Example: This example provides a multi-axis industrial robot flexible processing system for a shock absorber upper seat, see Figure 1 , specifically, including:

[0064] The stress direction solving module is used to solve the gradient vector field of the average speckle field in the shock absorber upper seat and generate the maximum principal tensile stress direction of the shock absorber upper seat based on the gradient vector field;

[0065] Specifically, the purpose of solving the direction of the maximum principal tensile stress is to accurately visualize the most dangerous tensile stress release direction before processing: after clarifying the direction of the principal tensile stress, the tendency of instantaneous rebound of the surface material on the outlet side can be predicted, thereby accurately pre-engraving the micro-relief groove. The multi-axis industrial robot can align the process features such as the center axis of the fixture, the slow-release groove and the micro-relief groove with this direction in the subsequent steps, or actively reduce the feed and change the tool in advance when the directions are collinear and the tool wear is close to the limit; this can provide a pressure relief channel for the material when the stress is released instantaneously, prevent the formation of V-shaped rebound wedges and amplify the outlet burrs, and provide a quantitative benchmark for risk factor calculation and two-stage pressing strategy, so as to achieve targeted suppression of this low-probability high-risk event and ensure hole accuracy and assembly reliability.

[0066] Specifically, the V-shaped rebound wedge is essentially caused by the coupling of the instantaneous release of residual tensile stress and the extreme wear tool notch: when the original high tensile stress on the outlet side suddenly rebounds along the direction of the maximum principal tensile stress, the material is pushed in the opposite direction of the tool movement; if at this moment there is a 0.3 mm notch wear on the back face of the tool, the rebound material will be inserted into the notch with a V-shaped geometry, forming a millisecond-level self-locking and pushing the tool back, thereby plasticizing and shearing a V-shaped protrusion with a width of 20-60 microns at the outlet edge. This structure is the rebound wedge; therefore, the system needs to first use the speckle gradient to determine the direction of the maximum principal tensile stress, and then align the fixture / micro-relief groove and evaluate the tool wear in real time to prevent the above three factors from being met at the same time and inducing wedge formation.

[0067] In an embodiment of the present invention, solving the gradient vector field of the average speckle field in the shock absorber upper seat and generating the maximum principal tensile stress direction of the shock absorber upper seat based on the gradient vector field include:

[0068] Two speckle displacement maps were collected using a polarized laser speckle camera;

[0069] In an embodiment of the present invention, two speckle displacement maps are collected using a polarized laser speckle camera, including:

[0070] Installing a polarized laser spot camera on a multi-axis industrial robot;

[0071] Taking the exit side surface as the scanning starting point, the polarized laser speckle camera is moved in equiangular steps along a fixed sector of the exit side surface to collect two speckle displacement maps.

[0072] Specifically, a polarized laser speckle camera compatible with the end effector of a multi-axis industrial robot is selected and fixed to the end effector using a high-precision positioning fixture. The coaxiality of the camera's optical axis and the actuator's motion direction is adjusted. The geometric center of the outlet surface of the shock absorber upper seat is identified as the scanning starting point. A sector with a fixed angle range is set as the scanning area with this geometric center as the vertex. The multi-axis industrial robot is controlled to drive the end effector, carrying the polarized laser speckle camera, starting from the scanning starting point and performing equiangular stepping along the circular arc trajectory of the fixed sector. The stepping angle is set to a preset increment value. After each step, the vertical distance between the camera lens and the outlet surface is maintained constant, triggering the camera to capture a speckle image. The above stepping and capturing actions are repeated until two independent speckle image acquisitions are completed, resulting in two speckle displacement maps.

[0073] Specifically, a speckle displacement map utilizes the principle of laser speckle interferometry to record the changes in speckle distribution on an object's surface due to displacement and deformation. When a laser illuminates a rough object, the diffusely reflected light interferes to form an initial speckle field. As the object deforms due to residual stresses and other factors, the speckle distribution changes. By comparing the speckle images before and after deformation and calculating the displacement differences at each point on the surface using digital speckle correlation, the resulting visualization is the speckle displacement map. During shock absorber seat inspection, this method can convert invisible residual stresses into visible displacement changes, enabling visualization of residual stress distribution and prediction of V-shaped rebound wedges. Furthermore, relying on non-contact laser measurement, it is suitable for real-time online inspection of multi-axis industrial robot machining units.

[0074] The pixels of the two speckle displacement maps are averaged and fused point by point to obtain the average speckle field on the outlet side of the shock absorber upper seat.

[0075] Perform gradient calculation on the average speckle field to obtain the gradient vector field of the average speckle field;

[0076] The vectors in the gradient vector field are normalized to obtain the direction of the maximum principal tensile stress on the outlet side surface.

[0077] Specifically, two speckle displacement maps of the outlet side surface of the shock absorber upper seat are obtained. A point-by-point traversal strategy is adopted to extract the displacement data of the pixel points with completely corresponding coordinates in the two maps and perform an averaging operation. That is, for each pixel point, the displacement values ​​of the two maps at that position are summed and divided by two. After traversing all the pixels, an average speckle field of the outlet side surface is constructed. Subsequently, a gradient operation is performed on the average speckle field. The partial derivatives of each pixel point in the x and y directions are calculated by the finite difference method to obtain the gradient vector of the pixel point. The set of gradient vectors of all pixel points constitutes the gradient vector field of the average speckle field. Finally, the gradient vector of each pixel point in the gradient vector field is normalized. The modulus of the gradient vector is first calculated, and then the x and y components of the gradient vector are divided by the modulus to obtain a unit gradient vector. The direction of the unit gradient vector is the maximum principal tensile stress on the outlet side surface.

[0078] A risk factor calculation module is used to calculate the risk factor based on the direction of the maximum principal tensile stress;

[0079] Specifically, the risk factor is first calculated according to the direction of the maximum principal tensile stress because this direction determines the impact path of the instantaneous release of residual tensile stress at the cutting exit, and is also the direction in which the V-shaped rebound wedge is most likely to be generated. Only by quantifying the stress direction as a risk factor can the degree of tool wear, the cutting feed trajectory and the internal stress of the workpiece be coupled into a comparable numerical threshold, which can be used to determine in advance whether it is necessary to engrave micro-relief grooves or adjust the fixture posture. In this way, precise measures can be taken in high-risk directions to prevent the superposition of residual stress and extreme wear to trigger the wedge, and excessive processing in low-risk areas can be avoided, taking into account both processing efficiency and finished product quality.

[0080] In an embodiment of the present invention, the risk factor is calculated based on the direction of the maximum principal tensile stress, including:

[0081] Obtain the tool flank wear width and the tangential unit vector of the tool preset trajectory;

[0082] Specifically, an ultra-depth-of-field microscope or laser scanning profilometer is used to secure the tool to a standard fixture on the inspection platform. The inspection equipment is then controlled to scan the tool's flank face, collecting profile data. This profile data is then processed using dedicated tool wear analysis software to identify the boundary between the worn and unworn areas on the flank face. The distance between the two boundaries is then calculated, thereby obtaining the tool's flank wear width. To obtain the tangential unit vector for the tool's preset trajectory, the CNC machining system first retrieves the pre-planned tool machining trajectory data, which contains the coordinate information for each point on the trajectory. Numerical differentiation is then used to process the coordinates of adjacent points on the trajectory, calculating the tangent vector at each point. The tangent vector is then normalized, i.e., the modulus of the tangent vector is calculated. Each component of the tangent vector is then divided by the modulus to obtain the tangent unit vector for the corresponding point on the tool's preset trajectory. This process then iterates through each point on the preset trajectory to complete the acquisition of the tangent unit vector for the entire trajectory.

[0083] The risk factor of V-shaped rebound wedge formation during the machining of the shock absorber upper seat is calculated based on the flank wear width, the direction of the maximum principal tensile stress, and the tangential unit vector. The calculation formula of the risk factor is as follows:

[0084]

[0085] Where, It is a risk factor. is the flank wear width, is the direction of maximum principal tensile stress, is the tangential unit vector.

[0086] In detail, from the perspective of physical mechanism and parameter correlation, the flank wear width Reflects the degree of tool failure. Its increase can easily lead to abnormal release of residual stress; the direction of maximum principal tensile stress Represents the dominant direction of residual stress, the tangential unit vector describes the direction of tool cutting motion, and the absolute value of the dot product of the two The degree of coordination between the stress release direction and the cutting direction can be quantified. The higher the degree of coordination, the easier it is to trigger the V-shaped rebound wedge. The coefficient 12 in the formula is derived from the fitting of the process failure law. Combined with directional coordination, Constructing a risk factor can comprehensively characterize the risk of V-shaped rebound wedge formation under the coupling of tool wear, stress direction and cutting motion, and realize quantitative prediction of this low-probability high-risk event.

[0087] A micro-discharge groove pre-engraving module is used to pre-engraving micro-discharge grooves on the upper seat of the shock absorber according to the risk factor and the maximum principal tensile stress to form micro-discharge grooves;

[0088] Specifically, the reason why micro-relief grooves are pre-engraved on the upper seat of the shock absorber based on the risk factors and along the direction of the maximum principal tensile stress is that only by quantifying and aligning the potentially most dangerous stress release direction with the tool wear and residual stress fusion strength at the same time can a priority pressure relief channel be provided for high tensile stress before a sudden rebound actually occurs: when the risk factors indicate that the wear is approaching the critical point and the stress direction is clear, the micro-relief grooves engraved in advance will instantly absorb and disperse the residual tensile stress at the cutting exit, weakening the driving force of the material to rebound back to the tool, and avoiding the formation of V-shaped rebound wedges and abnormally high burrs; at the same time, the groove is only processed when high-risk conditions are met, which not only achieves directional protection but also avoids over-processing, taking into account processing efficiency, surface quality and dimensional accuracy.

[0089] In an embodiment of the present invention, a micro-drainage groove is pre-carved on the upper seat of the shock absorber according to the risk factor and the maximum principal tensile stress to form the micro-drainage groove, comprising:

[0090] If the risk factor is greater than the preset factor threshold, the length and depth of the micro-discharge trough are calculated based on the risk factor;

[0091] Specifically, when the risk factor is greater than the preset factor threshold, the risk factor is multiplied by 0.8 to obtain the groove length of the micro-relief groove, and the risk factor is multiplied by 0.06 to obtain the groove depth of the micro-relief groove. From the perspective of process testing and engineering adaptation, after extensive testing, it was found that the risk factor can reflect the degree of residual stress concentration and release requirements. The groove length design needs to balance the stress release efficiency and the structural integrity of the workpiece. When the risk factor is multiplied by 0.8, the resulting groove length can effectively cut off the V-shaped rebound wedge formation path without destroying the strength of the workpiece. The groove depth must match the residual stress depth distribution. The groove depth obtained by multiplying the risk factor by 0.06 can accurately weaken the instantaneous energy release of surface residual stress and avoid increasing processing costs due to excessive groove depth, such as increased tool wear and extended processing time. Therefore, 0.8 and 0.06 were fitted through process testing to establish a direct correlation between the risk factor and the size of the micro-relief groove, achieving effective guidance of residual stress release and balanced control of processing costs and structural strength.

[0092] Perform a vector dot product on the direction vector of the maximum principal tensile stress and the normal vector of the outlet side surface of the shock absorber upper seat to obtain a dot product result;

[0093] Take the inverse cosine of the dot product result to obtain the spatial angle between the maximum principal tensile stress and the normal vector, and convert the spatial angle into the direction angle of the micro-discharge groove on the outlet side surface;

[0094] Specifically, through surface fitting or geometric measurement methods, the normal vector of the surface is extracted to clarify its spatial orientation, and a vector dot product operation is performed on the maximum principal tensile stress direction vector and the outlet side surface normal vector. The operation result reflects the degree of directional fit between the two vectors in space. Based on the inherent relationship between the vector dot product and the angle, the above dot product result is subjected to an arccosine calculation to obtain the spatial angle between the maximum principal tensile stress direction and the outlet side surface normal vector. The angle quantifies the degree of spatial deflection of the principal stress direction relative to the surface normal. Then, a local rectangular coordinate system is established with the outlet side surface normal vector and the projection of the workpiece axis in the surface is defined as the reference X-axis. Then, the three-dimensional unit vector along the maximum principal tensile stress direction is decomposed in the coordinate system, and its components vx and vy parallel to the surface tangent plane are extracted. Then, the inverse tangent value corresponding to the ratio of vy divided by vx is calculated to obtain the direction angle.

[0095] The groove length, groove depth and direction angle are used as geometric parameters of the micro-discharge groove;

[0096] The outlet side surface is pre-engraved with micro-discharge grooves according to geometric parameters to form micro-discharge grooves.

[0097] Specifically, the groove length and groove depth obtained in the early stage through the quantitative calculation of risk factors, and the direction angle determined by the spatial angle conversion process are integrated as the geometric parameters of the micro-drainage groove to clarify its size specifications and spatial orientation characteristics; the processing control module of the multi-axis industrial robot is called, the above geometric parameters are imported, and the processing trajectory of the micro-drainage groove is planned. The direction angle is used as the tool orientation reference, the tool travel is set according to the groove length parameter, and the tool cutting depth is controlled according to the groove depth parameter; the industrial robot end effector is driven to be equipped with a precision milling tool to perform milling processing on the outlet side surface of the shock absorber upper seat along the planned trajectory. During the processing, the tool position, cutting force and feed speed are monitored in real time to ensure that the processing accuracy of the groove length, groove depth and direction angle is within the preset tolerance range, and finally a micro-drainage groove that meets the residual stress release guide is pre-engraved on the outlet side surface.

[0098] A first state processing module, configured to perform first state processing on the shock absorber upper seat to obtain a first physical state of the shock absorber upper seat;

[0099] Specifically, the purpose of meshing the trapezoidal relief groove with the pre-engraved micro-relief groove is to establish a continuous pressure relief channel in the direction where stress is most likely to be released instantaneously: when the high tensile stress at the cutting exit rebounds, the stress flow first enters the trapezoidal relief groove along the alignment direction, and continues to diffuse through the micro-relief groove collinear with it, thereby dissipating the rebound energy in the groove, preventing the material from protruding back toward the tool and forming a V-shaped rebound wedge; at the same time, the meshing structure locks the relative posture of the workpiece and the fixture, preventing the micro-displacement caused by rebound from destroying the positioning accuracy, and ensuring the dimensional consistency and processing stability of the subsequent chamfering and measurement.

[0100] In an embodiment of the present invention, the first state is processed as follows:

[0101] The outlet side pressure plate of the driving fixture is rotated around the normal vector so that the central axis of the trapezoidal relief groove in the outlet side pressure plate coincides with the direction of the maximum principal tensile stress;

[0102] Place the upper seat of the shock absorber on the positioning surface of the fixture, and engage the trapezoidal slow-release groove with the micro-release groove.

[0103] Specifically, the outlet side pressure plate of the fixture is a rotatable clamping component installed on the outlet side of the workpiece. Its main function is to firmly press the shock absorber upper seat against the positioning surface during the cutting process and adjust its posture at any time to align with the direction of the maximum principal tensile stress; the trapezoidal relief groove of the outlet side pressure plate is a trapezoidal through groove processed on the bottom surface of the pressure plate. The groove bottom is wide and the groove mouth is narrow, extending along the direction of the maximum principal tensile stress. It is used to provide a wide pressure relief space for the residual tensile stress after the pressure plate is engaged with the workpiece and guide the stress to diffuse inward; the micro-relief groove is a thin and narrow guide groove pre-engraved on the outlet edge surface of the shock absorber upper seat. The depth and width are both smaller than the trapezoidal relief groove, forming a primary pressure relief port on the workpiece side. When the two grooves are precisely engaged during clamping, they can form a continuous pressure relief channel from narrow to wide, which not only weakens the instantaneous rebound force but also avoids the generation of abnormal burrs.

[0104] Specifically, the maximum principal tensile stress direction vector is first output in real time through the optical speckle stress measurement unit, and the vector data is sent to the controller of the pressure plate servo rotation mechanism; the controller drives the outlet side pressure plate to perform angular closed-loop servo rotation along the normal vector of the outlet side surface until the central axis of the trapezoidal relief groove coincides with the maximum principal tensile stress direction, at which time the orientation is completed by the feedback zero difference of the angle encoder; then the fixture vacuum adsorption and limit pin positioning functions are turned on to accurately affix the lower surface of the shock absorber upper seat to the reference positioning surface of the fixture to complete the three-point and one-side precise constraint; the outlet side pressure plate is continued to be pressed down to guide the front end of the trapezoidal relief groove in turn and finally achieve surface-line engagement with the micro-relief groove pre-engraved on the outlet side surface. The engagement depth is detected by the displacement sensor and maintained within the set tolerance range, thereby ensuring the penetration of the stress relief channel while achieving rigid locking of the workpiece and the fixture and entering the next processing step.

[0105] A second state processing module is used to perform a second state processing on the shock absorber upper seat based on the first physical state to obtain a second physical state of the shock absorber upper seat;

[0106] In detail, the pre-engraved micro-relief groove will form a local geometric protrusion with the same amplitude as the groove depth on the outlet side. If the downward displacement of the cutting tool is not compensated according to the groove depth, the chamfer vertex will deviate from the axis of the original stress release channel, which will not only weaken the effect of the micro-relief groove in diverting the residual stress, but also easily produce asymmetric secondary burrs on both sides of the groove mouth; by mapping the groove depth to the equivalent Z-axis downward displacement to achieve a continuous transition between the chamfer profile and the pressure relief groove wall, the sharp chipped edge can be cut into a transition fillet at one time, and the tiny burrs remaining due to rebound shearing can be removed at the same time, ensuring that the outlet edge is both smooth and does not destroy the stress guidance, thereby taking into account structural safety, assembly sealing and surface quality.

[0107] In an embodiment of the present invention, the second state is processed as follows:

[0108] Calculate the Z-axis downward chamfering amount of the outlet edge of the shock absorber upper seat according to the groove depth of the micro-discharge groove;

[0109] The outlet edge is chamfered according to the Z-axis downward chamfering amount, and the outlet edge is deburred.

[0110] Specifically, the outlet edge of the shock absorber upper seat refers to the free end edge area formed by the workpiece in the material outflow direction after cutting and chamfering are completed. It is also the part where residual tensile stress is released and burrs are most likely to concentrate. The Z-axis downward chamfering amount of the outlet edge is based on the outlet edge. It is a linear compensation distance that sinks inward along the main axis direction (Z axis) in the workpiece coordinate system. Its value is calculated based on the depth of the micro-discharge groove. It is used to guide the synchronous downward movement of the chamfering tool so that the chamfering arc is coplanar with the bottom of the micro-discharge groove, ensuring the continuity of the stress relief channel and avoiding the generation of secondary burrs.

[0111] Specifically, when the main cutting program ends and the tool exits the workpiece, the recorded groove depth of the micro-discharge groove is called, and the Z-axis downward movement distance required for the exit edge processing is calculated according to the proportional relationship calibrated by the process test, that is, the Z-axis downward movement chamfering amount is equal to 0.4 multiplied by the groove depth; then, the spindle automatically changes the tool to the coaxial chamfering tool, and performs a single-circle tool pass along the exit hole at a constant linear speed of 60mm / s. Before the tool pass, the CNC system controls the Z-axis downward movement of the calculated Z-axis downward movement chamfering amount, so that the tool tip cuts a regular chamfer on the exit edge, and at the same time turns on 20kPa cutting fluid flushing to remove chips; after the tool pass is completed, the spindle retracts 1mm and stops, and the probe is used to detect whether there are continuous burrs on the exit edge, and the surface recovery status is written into the database, thereby completing the Z-axis downward movement chamfering amount calculation based on the groove depth, chamfering processing and deburring collaborative processing, to ensure that the geometric accuracy and surface quality of the exit edge are adapted to subsequent assembly.

[0112] In detail, before measuring the surface deviation of the outlet positioning surface and the angular deflection of the outlet hole, the trapezoidal relief groove and the micro-relief groove must be strictly meshed and the outlet edge must be deburred. The reason is that the workpiece and the fixture are rigidly locked in the direction of the maximum principal tensile stress through meshing, eliminating the micro-displacement and swing angle caused by residual stress rebound, and ensuring that the reference surface and hole coordinates obtained by the probe are not affected by the looseness of the clamping; at the same time, deburring can remove the burrs and tear layers on the outlet edge, and avoid the laser displacement meter or three-point probe being disturbed by the false height of the burrs during scanning, thereby ensuring that the surface and angle data truly reflect the processing geometry rather than attached burrs or micro-jump errors, ultimately improving the detection accuracy and providing a reliable basis for subsequent qualified or unqualified judgments.

[0113] A shape and position deviation detection module is used to calculate the surface deviation of the outlet positioning surface in the shock absorber upper seat and the angular deviation of the outlet hole position based on the second physical state;

[0114] In an embodiment of the present invention, calculating the surface deviation of the outlet positioning surface and the angular deviation of the outlet hole in the shock absorber upper seat includes:

[0115] Specifically, the outlet positioning surface refers to the reference plane on the outlet side of the shock absorber seat for fitting with the vehicle body or bracket, and the outlet hole position is the theoretical position in three-dimensional space of the center axis of the circular hole on this plane used for installation or fluid conduction. By detecting the errors of these two geometric features, the form and position deviations caused by rebound or tool wear can be discovered in time and a decision can be made whether to rework the tool, thereby ensuring assembly accuracy and product reliability.

[0116] A three-point laser displacement meter is used to perform non-contact measurement on three equally divided measuring points on the outlet positioning surface to obtain the height difference data of each of the three equally divided measuring points;

[0117] Calculate the average value of the three measuring points divided equally into three measuring points based on the three height difference data, calculate the absolute value of the difference between the average value of the three measuring points and each height difference data, and take the maximum value of the three absolute values ​​of the difference as the surface deviation;

[0118] Specifically, the layout of three equally divided measuring points of the outlet positioning surface is planned, and three measuring points are selected at intervals of 120° along the circumferential direction of the positioning surface to construct a measuring point group distributed in an equilateral triangle. The three-point laser displacement meter is fixed on a high-precision measuring bracket, and its measuring axis is calibrated to be collinear with the normal of the outlet positioning surface. The measuring system is started to perform non-contact displacement measurement on the three measuring points in turn, and the height difference of each measuring point relative to the preset reference plane is collected to generate three height difference data. Subsequently, the three height difference data are arithmetic averaged to obtain the average height of the three measuring points; the difference between the average value and each height difference data is calculated respectively, and the absolute value of the difference is taken; the maximum value is selected from the three absolute values ​​and defined as the surface deviation of the outlet positioning surface to quantify the flatness error of the positioning surface.

[0119] The angle deviation of the outlet hole is calculated using the preset angle deviation formula, where the preset angle deviation formula is as follows:

[0120]

[0121] Where, is the angle of deflection, 、 They are two adjacent measuring points on the outlet positioning surface, It is the average distance between two adjacent measuring points and the hole center.

[0122] Specifically, the core logic of calculating angle deflection is to use geometric relationships to quantify the impact of positioning surface tilt on hole angle. First, clarify the parameter definition: 、 is the height of two adjacent measuring points on the outlet positioning surface, and the difference reflects the local tilt amplitude; It is the average distance from adjacent measuring points to the hole center, which is used as the radial reference for angle calculation. Based on the tangent relationship of a right triangle, the ratio of the opposite side to the adjacent side corresponds to the tangent value, and the height difference and radial distance of the positioning surface are converted into angular deviation , in order to accurately quantify the angular error of the hole position caused by the tilt of the positioning surface, and provide data support for subsequent correction processing and ensuring assembly accuracy.

[0123] The qualification judgment module is used to judge the qualification of the shock absorber seat based on the surface deviation and angle deviation.

[0124] Specifically, surface deviation and angular deflection are used as the final qualification criteria because these two geometric accuracies directly determine the fit between the shock absorber upper seat and the vehicle body attachment surface and the insertion posture of the fasteners: If the surface deviation is out of tolerance, the flatness of the outlet edge after residual stress release and the elimination of the V-shaped rebound wedge will be insufficient, resulting in uneven force on the gasket and unbalanced distribution of the bolt preload; if the hole angle deflection exceeds the limit, the insertion force of the bolt or guide pin will increase or even make it impossible to assemble, causing the suspension system geometry to shift and shortening its service life. By quantifying surface deviation and angle, two core errors that can comprehensively reflect the degree of overall geometric recovery after stress release, micro-relief groove chamfering, and deburring, the plane accuracy and hole axis posture can be simultaneously controlled in one inspection, ensuring that all previous process measures truly achieve structural safety, smooth assembly, and long-term reliability, thereby making accurate decisions on whether to pass or rework.

[0125] In an embodiment of the present invention, judging the compliance of the shock absorber upper seat based on the surface deviation and the angular deflection includes:

[0126] When the surface deviation is less than the preset deviation threshold and the angle deflection is less than the preset deflection threshold, the shock absorber upper seat is marked as qualified; otherwise, the shock absorber upper seat is marked for repair.

[0127] Specifically, the surface deviation of the outlet positioning surface and the angular deviation of the outlet hole are first measured, and then these two indicators are compared with the preset deviation threshold and deflection threshold respectively. If the surface deviation is less than the deviation threshold and the angular deviation is less than the deflection threshold, it means that the flatness of the positioning surface and the hole angle meet the assembly and other performance requirements, and the shock absorber seat is marked as qualified; as long as one indicator exceeds the corresponding threshold, it is determined that there is a risk of affecting product performance, and it is marked for rework, and the workpiece needs to be corrected later.

[0128] In order to solve the above problems, the present invention also provides a flexible processing method for a multi-axis industrial robot on a shock absorber seat, the method comprising:

[0129] S1. Calculate the gradient vector field of the average speckle field in the upper seat of the shock absorber, and generate the maximum principal tensile stress direction of the upper seat of the shock absorber based on the gradient vector field;

[0130] S2, calculate the risk factor based on the direction of maximum principal tensile stress;

[0131] S3. Pre-carve a micro-drainage groove on the upper seat of the shock absorber according to the risk factor and the maximum principal tensile stress to form a micro-drainage groove;

[0132] S4, performing first state processing on the shock absorber upper seat to obtain a first physical state of the shock absorber upper seat;

[0133] S5. Based on the first physical state, performing a second state processing on the shock absorber upper seat to obtain a second physical state of the shock absorber upper seat;

[0134] S6. Based on the second physical state, calculate the surface deviation of the outlet positioning surface in the shock absorber upper seat and the angular deviation of the outlet hole;

[0135] S7. Determine the compliance of the shock absorber seat based on the surface deviation and angle deviation.

[0136] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A multi-axis industrial robot flexible processing system for a shock absorber upper seat, characterized in that: include: The stress direction solving module is used to solve the gradient vector field of the average speckle field in the shock absorber upper seat and generate the maximum principal tensile stress direction of the shock absorber upper seat based on the gradient vector field; A risk factor calculation module is used to calculate the risk factor based on the direction of the maximum principal tensile stress; A micro-discharge groove pre-engraving module is used to pre-engraving micro-discharge grooves on the upper seat of the shock absorber according to the risk factor and the maximum principal tensile stress to form micro-discharge grooves; A first state processing module, configured to perform first state processing on the shock absorber upper seat to obtain a first physical state of the shock absorber upper seat; A second state processing module is used to perform a second state processing on the shock absorber upper seat based on the first physical state to obtain a second physical state of the shock absorber upper seat; A shape and position deviation detection module is used to calculate the surface deviation of the outlet positioning surface in the shock absorber upper seat and the angular deviation of the outlet hole position based on the second physical state; The qualification judgment module is used to judge the qualification of the shock absorber seat based on the surface deviation and angle deviation.

2. The multi-axis industrial robot flexible processing system for a shock absorber upper seat according to claim 1 is characterized in that: Solve the gradient vector field of the average speckle field in the shock absorber upper seat, and generate the maximum principal tensile stress direction of the shock absorber upper seat based on the gradient vector field, including: Two speckle displacement maps were collected using a polarized laser speckle camera; The pixels of the two speckle displacement maps are averaged and fused point by point to obtain the average speckle field on the outlet side of the shock absorber upper seat. Perform gradient calculation on the average speckle field to obtain the gradient vector field of the average speckle field; The vectors in the gradient vector field are normalized to obtain the direction of the maximum principal tensile stress on the outlet side surface.

3. The multi-axis industrial robot flexible processing system for a shock absorber upper seat according to claim 2 is characterized in that: Two speckle displacement maps are collected using a polarized laser speckle camera, including: Installing a polarized laser spot camera on a multi-axis industrial robot; Taking the exit side surface as the scanning starting point, the polarized laser speckle camera is moved in equiangular steps along a fixed sector of the exit side surface to collect two speckle displacement maps.

4. The multi-axis industrial robot flexible processing system for a shock absorber upper seat according to claim 1 is characterized in that: Calculates risk factors based on the direction of maximum principal tensile stress, including: Obtain the tool flank wear width and the tangential unit vector of the tool preset trajectory; The risk factor of V-shaped rebound wedge formation during the machining of shock absorber upper seat was calculated based on the flank wear width, maximum principal tensile stress direction and tangential unit vector.

5. The multi-axis industrial robot flexible processing system for a shock absorber upper seat according to claim 1, characterized in that: According to the risk factor and the maximum principal tensile stress, the shock absorber upper seat is pre-engraved with a micro-relief groove to form a micro-relief groove, including: If the risk factor is greater than the preset factor threshold, the length and depth of the micro-discharge trough are calculated based on the risk factor; Perform a vector dot product on the direction vector of the maximum principal tensile stress and the normal vector of the outlet side surface of the shock absorber upper seat to obtain a dot product result; Take the inverse cosine of the dot product result to obtain the spatial angle between the maximum principal tensile stress and the normal vector, and convert the spatial angle into the direction angle of the micro-discharge groove on the outlet side surface; The groove length, groove depth and direction angle are used as geometric parameters of the micro-discharge groove; The outlet side surface is pre-engraved with micro-discharge grooves according to geometric parameters to form micro-discharge grooves.

6. The multi-axis industrial robot flexible processing system for a shock absorber upper seat according to claim 5, characterized in that: The first state is processed as follows: The outlet side pressure plate of the driving fixture is rotated around the normal vector so that the central axis of the trapezoidal relief groove in the outlet side pressure plate coincides with the direction of the maximum principal tensile stress; Place the upper seat of the shock absorber on the positioning surface of the fixture, and engage the trapezoidal slow-release groove with the micro-release groove.

7. The multi-axis industrial robot flexible processing system for a shock absorber upper seat according to claim 1, characterized in that: The second state is processed as follows: Calculate the Z-axis downward chamfering amount of the outlet edge of the shock absorber upper seat according to the groove depth of the micro-discharge groove; The outlet edge is chamfered according to the Z-axis downward chamfering amount, and the outlet edge is deburred.

8. The multi-axis industrial robot flexible processing system for a shock absorber upper seat according to claim 1, characterized in that: Calculate the surface deviation of the outlet positioning surface in the shock absorber upper seat and the angular deviation of the outlet hole, including: A three-point laser displacement meter is used to perform non-contact measurement on three equally divided measuring points on the outlet positioning surface to obtain the height difference data of each of the three equally divided measuring points; Calculate the average value of the three measuring points divided equally into three measuring points based on the three height difference data, calculate the absolute value of the difference between the average value of the three measuring points and each height difference data, and take the maximum value of the three absolute values ​​of the difference as the surface deviation; The angle deflection is calculated using a preset angle deflection formula.

9. The multi-axis industrial robot flexible processing system for a shock absorber upper seat according to claim 1, characterized in that: The shock absorber upper seat is qualified based on the surface deviation and angle deflection, including: When the surface deviation is less than the preset deviation threshold and the angle deflection is less than the preset deflection threshold, the shock absorber upper seat is marked as qualified; otherwise, the shock absorber upper seat is marked for repair.

10. A flexible processing method for a multi-axis industrial robot for a shock absorber seat, characterized in that: The method comprises: S1. Calculate the gradient vector field of the average speckle field in the upper seat of the shock absorber, and generate the maximum principal tensile stress direction of the upper seat of the shock absorber based on the gradient vector field; S2, calculate the risk factor based on the direction of maximum principal tensile stress; S3. Pre-carve a micro-drainage groove on the upper seat of the shock absorber according to the risk factor and the maximum principal tensile stress to form a micro-drainage groove; S4, performing first state processing on the shock absorber upper seat to obtain a first physical state of the shock absorber upper seat; S5. Based on the first physical state, performing a second state processing on the shock absorber upper seat to obtain a second physical state of the shock absorber upper seat; S6. Based on the second physical state, calculate the surface deviation of the outlet positioning surface in the shock absorber upper seat and the angular deviation of the outlet hole; S7. Determine the compliance of the shock absorber seat based on the surface deviation and angle deviation.

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