Ultrasonic impact strengthening method and device for cylindrical weldment

Abstract

The application provides a cylindrical welding piece ultrasonic impact strengthening method and device, relates to the technical field of metal welding, collects the clamping center of two ends of the cylindrical welding piece, the axial direction and the initial angle of the active chuck, establishes the test piece coordinate system, and forms the test piece coordinate reference by the clamping center of two ends, the axial line of the test piece and the active rotation angle, so that the length adjustment, the transverse centering and the circumferential rotation become the common constraints of the path conversion; the force sensor is arranged on the actual axial force transmission path at the rear end of the rotatable impact gun, the impact enablement is controlled by three conditions of the position, the posture and the contact force, the contact force stability and the impact consistency are improved, the test piece rotation, the two-dimensional displacement of the clamp, the rotation and the feeding of the gun body are cooperatively controlled, the girth weld, the straight weld and the fillet weld can be processed on the same device, the actual execution state is recorded by using the structured path point and the set of points to be re-impacted, and local compensation and process tracing of abnormal points are facilitated.

Description

Technical Field

[0001] This invention relates to the field of metal welding technology, and in particular to a method and apparatus for ultrasonic impact strengthening of cylindrical welded parts. Background Technology

[0002] Ultrasonic impact strengthening involves using an impact needle to subject the metal surface to high-frequency mechanical impact at ultrasonic frequencies. This induces plastic deformation and beneficial residual compressive stress in the weld toe and adjacent areas, thereby improving the fatigue performance of the welded joint. Cylindrical welded components typically include round bars, round tubes, and rotating components with circumferential welds, axial straight welds, or fillet welds. The weld position and surface normal vary with the circumferential position, axial position, and local geometry.

[0003] Existing rotary ultrasonic impact devices typically utilize a chuck and tailstock to clamp and rotate cylindrical welded parts, and a linear motion mechanism to move the impact gun. Devices facing circumferential welds can also use a ring-shaped guide rail to move the impact mechanism circumferentially along the pipe. While these devices can achieve partial automation, the clamping centers at both ends, the axis of the cylindrical welded part, the active rotation angle, and the gun's posture are often not uniformly defined as coordinate references for path changes. When the length, diameter, clamping eccentricity, or weld type of the cylindrical welded part changes, re-teaching or manual correction is still required. Furthermore, some devices use counterweights, elastic elements, or single force sensors to maintain preload. When the impact gun changes posture, the load measured by the sensor cannot stably reflect the actual contact force of the impact pin acting on the weld along the gun's axis. If the control system executes only according to the offline path, local under-impact, over-impact, or missed impacts are prone to occur, and anomalies are difficult to trace and resolve. Summary of the Invention

[0004] In view of this, the present invention proposes an ultrasonic impact strengthening method and apparatus for cylindrical welded parts, in order to solve the technical problems of insufficient path reproduction accuracy, contact force fluctuation and limited applicable weld types in the prior art of cylindrical welded parts caused by size changes, double-end clamping deviations, diverse weld directions and changes in gun posture.

[0005] The technical solution of this invention is implemented as follows: In a first aspect, the present invention proposes an ultrasonic impact strengthening method for cylindrical welded parts, comprising: Collect the clamping center, axial direction, and initial angle of the active chuck at both ends of the cylindrical weldment, and establish the specimen coordinate system; A structured path point sequence is generated based on the weld model, scan data, or teaching data. Each structured path point includes at least the target position, target tangential direction, target normal direction, target contact force, and weld category identifier in the specimen coordinate system. The structured path point sequence is mapped to the active chuck rotation angle, the two-dimensional displacement of the clamping cooperative movement mechanism, the feed position of the ultrasonic impact gun, and the target angle of the gun body rotation unit, so that the impact direction of the ultrasonic impact gun corresponds to the target normal direction. At the current structured path point, the actual position, actual impact posture, and actual contact force collected by the force sensor set on the axial force transmission path at the rear end of the ultrasonic impact gun are obtained, and an ultrasonic impact enable signal is output when the preset conditions are met. Compensation is performed on structured path points that do not meet the preset conditions. If compensation fails, the process is paused and abnormal points are recorded to form a set of impact points to be recompensated.

[0006] In some optional embodiments, preferably, the step of collecting the clamping centers at both ends of the cylindrical weldment, the axial direction, and the initial angle of the active clamp, and establishing the specimen coordinate system, includes: The clamping centers at both ends are adjusted by using a first guide rail pair set along the axis of the cylindrical welded part and a second guide rail pair set along the direction perpendicular to the axis of the cylindrical welded part, so that the clamping centers at both ends coincide with the preset axis of the cylindrical welded part or meet the preset coaxiality threshold. The specimen coordinate system uses the line connecting the centers of the two clamping ends as the axial coordinate axis, the initial angle of the active clamp as the circumferential zero position, and is updated according to the actual rotation angle of the active clamp and the actual displacement of the clamping and coordinating movement mechanism.

[0007] In some optional implementations, preferably, mapping the structured path point sequence to the active gripper rotation angle and the two-dimensional displacement of the gripping cooperative movement mechanism includes: A zero-position rotation matrix for the specimen is constructed using the axial unit vector, radial y-axis unit vector, and radial z-axis unit vector of the cylindrical weldment. ; By using the axial coordinate s along the axis of the cylindrical welded part i The radial distance ρ from the path point to the axis of the cylindrical weldment i And the circumferential angle φ relative to the zero position of the active chuck i The target position is calculated. Surface normal unit vector unit vector of weld tangential direction ; According to the active end clamping center Specimen zero-position rotation matrix Target location Surface normal unit vector unit vector of weld tangential direction Active clamp target rotation angle θ s,i The target displacement u of the first guide rail pair and the second guide rail pair i and υ iThe corresponding unit vector of the device coordinate direction is and Calculate the target position of the path point in the device coordinate system. Surface normal unit vector unit vector of weld tangential direction It is the two-dimensional displacement of the active gripper rotation angle and the gripping cooperative movement mechanism.

[0008] In some optional implementations, preferably, mapping the structured path point sequence to the target angle of the gun body rotation unit includes: Define the gun body impact axis k g Calculate the target impact direction vector from the rear of the gun body to the tip of the impact needle. ; Let the gun body rotation axis be The zero-position impact axis of the gun body is ,Will and Projected onto perpendicular to The plane yields u0 and u i ; pass , u0 and u i Calculate the target angle θ of the gun body rotation unit g,i .

[0009] In some optional implementations, preferably, mapping the structured path point sequence to the feed position of the ultrasonic impact gun includes: Based on the execution variable q i The transformation of the gun body base after movement via the guide rail and feed axis is as follows: Fixed offset of the impact pin tip in the gun body coordinate system Gun body rotation axis The target angle θ of the gun body rotation unit g,i Calculate the actual needle tip position ; Using the travel of each axis, the soft limit of the active chuck and the gun body, the collision envelope of the clamp / cylindrical welded parts / gun body, the cumulative torsion of the cable, and the minimum obstacle avoidance distance as constraint parameters, a constraint model for the feed position of the ultrasonic impact gun is constructed. With the goal of prioritizing combinations that have small position and attitude errors, small changes in relative angles at the previous point, large obstacle avoidance margins, and do not cause cable entanglement, the optimal solution of the constraint model for the feed position of the ultrasonic impact gun is sought.

[0010] In some optional implementations, preferably, the preset conditions include: the position deviation, attitude deviation, and contact force deviation all meet preset thresholds.

[0011] In some alternative implementations, preferably, the positional deviation is calculated using the following method: The target needle tip position vector is obtained by transforming the specimen coordinates from the target position obtained from CAD, scan, or taught path points. ; The actual needle tip position vector is calculated by directly reading the actual linear axis position, active chuck angle, and gun body angle from the servo encoder. ; Through the actual needle tip position vector and the target needle tip position vector The difference in modulus length yields the positional deviation e. p,i .

[0012] In some alternative implementations, preferably, the attitude deviation is calculated by the following method: The target impact direction vector is calculated using the normal, tangential, and preset tilt angle of the structured path point sequence. ; The actual impact direction vector is calculated from the active clamp angle, the gun body angle, and the calibration matrix. ; Through the target impact direction vector and the actual impact direction vector Calculate the attitude deviation e a,i .

[0013] In some alternative implementations, preferably, the contact force deviation is calculated by the following method: The target contact force F is obtained from the process database or pre-experiment corresponding to the material, plate / pipe wall thickness, weld type, impact needle type, ultrasonic power, and target strengthening effect. tar,i ; The actual contact force F is obtained from the measurement value of the gun rear force sensor after calibration, attitude baseline compensation and filtering. act,i ; Through actual contact force F act,i Contact force F with the target tar,i The difference is used to obtain the contact force deviation e. F,i .

[0014] Secondly, this invention proposes an ultrasonic impact strengthening device for cylindrical welded parts, comprising a frame, a display and control device, an active clamping module, a driven clamping module, a clamping and cooperative movement mechanism, an ultrasonic impact actuator, and a controller, wherein: The display control device is located on one side of the frame and is used to input the size of the cylindrical welded part, the weld type, the target contact force and the path accuracy threshold, and to display the clamping status, the contact force curve, the path execution progress and abnormal information. The active clamping module includes an active chuck, a rotary drive, and a first angle detection component. The active chuck is disposed on one side of the cylindrical welded part and is used to clamp the cylindrical welded part. The rotary drive is driven to the active chuck and is used to drive the cylindrical welded part to rotate around its axis. The first angle detection component is mounted on the active chuck. The driven clamping module includes a driven chuck and a follower support. The driven chuck is located on the other side of the cylindrical welded part and is used to clamp the cylindrical welded part. The follower support is mounted on the frame and is used to support the driven chuck and rotate together with the cylindrical welded part. The clamping and cooperative moving mechanism includes a first guide rail pair and a second guide rail pair. The first guide rail pair is arranged along the axis of the cylindrical welded part and is used to adjust the clamping span between the active chuck and the driven chuck. The second guide rail pair is arranged along the direction perpendicular to the axis of the cylindrical welded part and is used to adjust the lateral position of the clamping centers at both ends. The ultrasonic impact actuator includes a feeding unit, a gun body rotation unit, an ultrasonic impact gun, and a force sensor. The feeding unit is connected to the gun body rotation unit. The ultrasonic impact gun is installed at the end of the gun body rotation unit. The force sensor is located on the axial force transmission path between the gun body rotation unit and the rear end of the ultrasonic impact gun. The controller is electrically connected to the rotary drive, the clamping and coordinating movement mechanism, the feeding unit, the gun body rotation unit, the force sensor, and the display and control device.

[0015] The ultrasonic impact strengthening method and apparatus for cylindrical welded parts of the present invention have the following advantages over the prior art: (1) By collecting the clamping center, axial direction and initial angle of the active chuck at both ends of the cylindrical welded part, and establishing the specimen coordinate system, the clamping center at both ends, the specimen axis and the active rotation angle together constitute the specimen coordinate reference, so that length adjustment, lateral centering and circumferential rotation become the common constraints of path transformation; the force sensor is arranged on the actual axial force transmission path at the rear end of the rotatable impact gun, and the impact enable is controlled by the three conditions of position, attitude and contact force, which is conducive to improving the stability of contact force and the consistency of impact; through the coordinated control of specimen rotation, two-dimensional displacement of fixture, gun body rotation and feed, circumferential welds, straight welds and fillet welds can be processed on the same device; the actual execution status is recorded by using the structured path points and the set of impact points to be repeated, which facilitates local compensation of abnormal points and process traceability; (2) By using the first guide rail pair set along the axis of the cylindrical weldment and the second guide rail pair set perpendicular to the axis of the cylindrical weldment, the clamping centers at both ends are adjusted so that the clamping centers at both ends coincide with the preset axis of the cylindrical weldment or meet the preset coaxiality threshold; the specimen coordinate system takes the line connecting the clamping centers at both ends as the axial coordinate axis, the initial angle of the active chuck as the circumferential zero position, and is updated according to the actual rotation angle of the active chuck and the actual displacement of the clamping cooperative movement mechanism; the clamping centers at both ends, the specimen axis and the active rotation angle together constitute the specimen coordinate reference, so that length adjustment, lateral centering and circumferential rotation become the common constraints of path transformation; (3) The preset conditions include: the position deviation, attitude deviation and contact force deviation all meet the preset threshold. When the three conditions meet the corresponding preset threshold, the ultrasonic impact enable signal is output to perform ultrasonic impact. The impact enable is controlled by the three conditions of position, attitude and contact force, which is beneficial to improve the contact force stability and impact consistency. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic flowchart of the ultrasonic impact strengthening method for cylindrical welded parts in an embodiment of the present invention. Figure 2 This is a schematic diagram illustrating the control principle of the controller in an embodiment of the present invention; Figure 3 This is a flowchart illustrating the execution process of the ultrasonic impact strengthening method for cylindrical welded parts in an embodiment of the present invention. Figure 4 This is a schematic diagram of the ultrasonic impact strengthening device for cylindrical welded parts in an embodiment of the present invention; Figure 5 This is a schematic diagram of the active clamping module, the driven clamping module, and the clamping cooperative movement mechanism in an embodiment of the present invention; Figure 6 This is a schematic diagram of the ultrasonic impact actuator in an embodiment of the present invention.

[0018] Explanation of reference numerals in the attached figures: 1-Frame, 2-Display and control device, 3-Active clamping module, 4-Slave clamping module, 5-Clamping and cooperative movement mechanism, 6-Ultrasonic impact actuator; 100 - Cylindrical welded parts; 31-Active chuck, 32-Rotary drive component; 41-Driven chuck, 42-Follower support; 51 - First guide rail pair, 52 - Second guide rail pair; 61-Feed unit, 611-Coarse feed unit, 612-Micro feed unit, 62-Gun body rotation unit, 621-Rotary motor, 622-Reduction transmission component, 63-Ultrasonic impact gun, 64-Force sensor. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0020] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0021] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention.

[0022] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0023] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0024] The following disclosure provides numerous different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. Additionally, examples of various specific processes and materials are provided in this invention; however, those skilled in the art will recognize the applicability of other processes and / or the use of other materials.

[0025] The technical solution will now be explained in detail: Reference Figures 1-3 As shown, a first aspect of the present invention provides a method for ultrasonic impact strengthening of cylindrical welded parts, comprising: Step S1: Collect the clamping center, axial direction and initial angle of the active chuck 31 at both ends of the cylindrical welded part 100, and establish the specimen coordinate system; Step S1 specifically includes: The clamping centers at both ends are adjusted by using the first guide rail pair 51 arranged along the axis of the cylindrical welded part 100 and the second guide rail pair 52 arranged perpendicular to the axis of the cylindrical welded part 100, so that the clamping centers at both ends coincide with the preset axis of the cylindrical welded part 100 or meet the preset coaxiality threshold. The specimen coordinate system uses the line connecting the centers of the two clamping ends as the axial coordinate axis, the initial angle of the active chuck 31 as the circumferential zero position, and is updated based on the actual rotation angle of the active chuck 31 and the actual displacement of the clamping cooperative movement mechanism 5. This coordinate system is denoted as Σ. D Read the active end clamping center and driven end clamping center Specimen axial unit vector for: (1); The active chuck 31 is equipped with a zero-position mark, positioning groove, or angle detection element, which provides a radial reference vector when it is at the zero position. In order to eliminate Errors caused by non-perpendicularity to the specimen axis are first projected and then normalized to obtain a unit vector in the radial y-direction. for: (2); Radial z-axis unit vector for: (3); This yields the zero-position rotation matrix of the specimen. and with The origin of the specimen coordinate system ΣW is used. If the clamping centers at both ends change after the guide rail moves, the reading is re-read. , And update Instead of simply adding the guide rail displacements, this method can unify the changes in clamping span, lateral centering, and active end rotation into the same specimen pose.

[0026] Step S2: Generate a structured path point sequence based on the weld model, scan data, or teaching data. Each structured path point includes at least the target position, target tangential direction, target normal direction, target contact force, and weld type identifier in the specimen coordinate system. Step S2 specifically includes: Define the i-th structured path point as: (4); In equation (4), s i Let ρ be the axial coordinate along the axis of the cylindrical weldment 100. i φ is the radial distance from the path point to the axis of the cylindrical weldment 100. i The circumferential angle of the relative active clamp at position 31 is the zero position. For the target location, The unit vector in the tangential direction of the weld. F is the unit vector normal to the surface. tar,i For the target contact force, β i υ is the preset tilt angle of the impact axis relative to the surface normal. i For path velocity, A i For ultrasonic amplitude or power level, m i For marking circumferential welds, straight welds, fillet welds, or composite welds; For a nominal cylindrical surface, the target position can be directly expanded from the cylinder parameters: (5); The nominal radial normal vector is: (6); For the circumferential weld, the tangent vector is: (7); For straight welds, the tangent vector is: (8); For weld toes, fillet welds, diameter changes, or irregular surfaces obtained from scanning, the nominal cylindrical normal is not used to replace the measured normal; instead, the normal obtained from scanning or CAD model calculations is directly saved. , and .

[0027] Step S3: Map the structured path point sequence to the rotation angle of the active chuck 31, the two-dimensional displacement of the clamping cooperative moving mechanism 5, the feed position of the ultrasonic impact gun 63, and the target angle of the gun body rotating unit 62, so that the impact direction of the ultrasonic impact gun 63 corresponds to the target normal direction. In step S3, mapping the structured path point sequence to the two-dimensional displacement of the active gripper 31's rotation angle and the gripping cooperative movement mechanism 5 includes: The zero-position rotation matrix of the specimen is constructed using the axial unit vector, radial y-axis unit vector, and radial z-axis unit vector of the cylindrical welded part 100. For the specific construction formula, please refer to formulas (1) to (3); By using the axial coordinate s along the axis of the cylindrical weldment 100 i The radial distance ρ from the path point to the axis of the cylindrical weldment 100 i The circumferential angle φ of the relative active chuck 31 zero position i The target position is calculated. Surface normal unit vector unit vector of weld tangential direction For specific calculation formulas, please refer to formulas (5) to (8); According to the active end clamping center Specimen zero-position rotation matrix Target location Surface normal unit vector unit vector of weld tangential direction Active gripper 31 target rotation angle θ s,i The target displacement u of the first guide rail pair 51 and the second guide rail pair 52 i and υ i The corresponding unit vector of the device coordinate direction is and Calculate the target position of the path point in the device coordinate system. Surface normal unit vector unit vector of weld tangential direction This represents the two-dimensional displacement of the active gripper 31's rotation angle and the gripping cooperative movement mechanism 5. The target position of the path point in the device coordinate system is calculated using the following formula: (9); In equation (9), R x(θ s,i ) indicates the direction around the specimen axis e x The rotation; The unit vector of the weld tangential direction of the path point in the device coordinate system is calculated using the following formula: (10); The surface normal unit vector of the path point in the device coordinate system is calculated using the following formula: (11); If the first guide rail pair 51 is only used to change the clamping span between the driving end and the driven end, without driving the entire specimen to move axially, then in the above formula... It should not be directly used as path displacement; in this case, it should be based on the displacement after movement. , The specimen coordinate system was recalculated, and the tool feed was handled by another axial actuator.

[0028] In step S3, mapping the structured path point sequence to the target angle of the gun body rotation unit 62 includes: Define the gun body impact axis k g Calculate the target impact direction vector from the rear of the gun body to the tip of the impact needle. : During normal impact, the target impact direction vector is: ; There is a preset tilt angle β i First, construct the lateral unit vector: (12); Then calculate the target impact direction vector: (13); In equation (13), η i This is a constant coefficient, taking values ​​of +1 or -1, used to select the side with the larger obstacle clearance between the two sides of the weld. Let the gun body rotation axis be The zero-position impact axis of the gun body is ,Will and Projected onto perpendicular to The plane yields u0 and u i ; (14); (15); pass , u0 and u i Calculate the target angle θ of the gun body rotation unit 62 g,i The formula for calculating the target angle of the gun body rotation unit 62 is as follows: (16); If the target direction cannot be fully reached under a single rotation axis of the gun body, the controller changes the target rotation angle θ of the active chuck 31. s,i The specimen's normal direction is first rotated into the gun body to reach the plane of rotation, and then θ is recalculated. g,i This demonstrates the synergistic effect of the active chuck 31 rotation and the gun body rotation.

[0029] In step S3, mapping the structured path point sequence to the feed position of the ultrasonic impact gun 63 includes: Based on the execution variable q i The transformation of the gun body base after movement via the guide rail and feed axis is as follows: Fixed offset of the impact pin tip in the gun body coordinate system Gun body rotation axis The target angle θ of the gun body rotation unit 62 g,i Calculate the actual needle tip position The formula for calculating the actual needle tip position is as follows: (17); In equation (17), the execution variable Before contact, the needle tip is positioned at ,in To determine the approach distance, then along Low-speed feed and enter force closed loop; Using the travel of each axis, the active chuck 31 and the soft limit of the gun body, the collision envelope of the fixture / cylindrical welded part 100 / gun body, the cumulative torsion of the cable, and the minimum obstacle avoidance distance as constraint parameters, a constraint model for the feed position of the ultrasonic impact gun 63 is constructed; the specific expression of the constraint model is as follows: (18); When multiple equivalent solutions exist, the optimal solution of the constraint model for the feed position of the ultrasonic impact gun 63 is obtained by prioritizing the combination with small position and attitude errors, small change in rotation angle relative to the previous point, large obstacle avoidance margin, and no cable entanglement.

[0030] For different weld types: Circumferential weld: s i =s0,φ i Increasing along the circumference, if the impactable orientation is fixed at φ a Then the target rotation angle of the active clamp 31 can be taken as θ. s,i =wrap(φ a -φ i The gun body and axial guide rail maintain the reference position, the feed axis compensates for roundness and eccentricity errors, and in continuous rotation mode, the active chuck's angular velocity of 31° is satisfied, and the path linear velocity is approximately υ. i= ρi ω s ; Straight weld: φ i =φ0,s i Increasing along the axial direction, first let θ s =wrap(φ a -φ i ), rotate the weld to an impact-resistant position, and then maintain θ. s Basically unchanged, guided by the axis to the guide rail according to u i= s i -s ref The weapon's rotation angle is adjusted slightly based on local changes in the normal direction. Spiral weld or bevel weld: s i and φ i Simultaneously changing, the rotation angle and axial displacement of the active chuck 31 are executed synchronously; their speed relationship is as follows: , And keep synchronized through the timestamps of adjacent path points; Fillet weld: Path points are obtained using CAD or scanning. and The controller first selects a reachable and collision-free combination from the candidates of the active chuck angle 31 and the gun body angle, and then performs the feed; it cannot be calculated using only the nominal radial normal vector.

[0031] Step S4: At the current structured path point, obtain the actual position, actual impact posture, and actual contact force collected by the force sensor 64 set on the axial force transmission path at the rear end of the ultrasonic impact gun 63. When the preset conditions are met, output the ultrasonic impact enable signal. In step S4, the preset conditions include: the position deviation, attitude deviation, and contact force deviation all meet preset thresholds. Specifically, the position deviation is calculated using the following method: The target needle tip position vector is obtained by transforming the specimen coordinates from the target position obtained from CAD, scan, or taught path points. ; The actual needle tip position vector is calculated by directly reading the actual linear axis position, the active chuck angle 31°, and the gun body angle from the servo encoder. ; Through the actual needle tip position vector and the target needle tip position vector The difference in modulus length yields the positional deviation e. p,i The formula for calculating positional deviation is as follows: (19); The attitude deviation is calculated using the following method: The target impact direction vector is calculated using the normal, tangential, and preset tilt angle of the structured path point sequence. ; The actual impact direction vector is calculated using the active chuck angle 31°, the gun body angle, and the calibration matrix. ; Through the target impact direction vector and the actual impact direction vector Calculate the attitude deviation e a,i The formula for calculating attitude deviation is as follows: (20); The contact force deviation is calculated using the following method: The target contact force F is obtained from the process database or pre-experiment corresponding to the material, plate / pipe wall thickness, weld type, impact needle type, ultrasonic power, and target strengthening effect. tar,i ; The actual contact force F is obtained by calibrating, compensating for attitude baseline, and filtering the values ​​measured by the gun rear force sensor 64. act,i ; Through actual contact force F act,i Contact force F with the target tar,i The difference is used to obtain the contact force deviation e. F,i， The formula for calculating contact force deviation is as follows: (twenty one); Determining the preset threshold for positional deviation: "Not greater than 1 mm" should be understood as the upper limit allowed by the process, not that all equipment should be directly set to 1 mm. The actual positional tolerance ε p It should be greater than or equal to the lower limit of the statistical error that the system can achieve, and less than or equal to the allowable deviation of the process, as shown in the following formula: (twenty two); In equation (22), σ center For the double-ended center identification error, σ reg σ represents the registration error from CAD scanning to the specimen coordinate system. tcp For the calibration error of the needle tip tool center, σ enc For the encoder and tracking error of each axis, σ fixture ε represents the repeatability error during clamping. process This represents the allowable deviation from the process parameters; during implementation, the standard round bar and standard path should be run repeatedly at least 10 times, and the standard deviation or maximum value of each error term should be used for estimation; ε can only be written when the total error meets the conditions. p ≤1mm; Determining the preset threshold for attitude deviation: Attitude tolerance ε aThe sensitivity of the impact pin tip geometry, weld toe angle, and process to the incident angle is determined. Comparative tests can be conducted with angular deviations of 0°, ±2°, ±5°, and ±8° under fixed material and target force conditions. Surface plastic deformation width, residual compressive stress, roughness, or fatigue life are used as evaluation metrics. The maximum angle that meets the quality indicators is selected as ε. a It is recommended that the initial embodiment use 2° to 5°, and the smaller value be used for fillet welds or narrow weld toes; Determination of the preset threshold for contact force deviation: Force tolerance ε F It should at least cover sensor resolution, no-load noise, and temperature drift, but not so much that it masks under-contact or overload issues. Recommended approach: (twenty three); In equation (23), λ F 5% to 10% can be taken, σ F ε is the standard deviation of the filtered force signal under no-load or stable contact conditions. res To ensure resolution and calibration margin; in addition to the average force error, the standard deviation of the force within the stability window should not exceed 2% to 5% of the target force; Position, orientation, and contact force conditions should be maintained continuously at T stable Only then is an impact permitted, T stable The recommended duration is 0.2–1.0 s, and the following conditions must be met: (twenty four); In equation (24), τ f f is the time constant of the force filter. s Where N is the sampling frequency. min T represents the number of consecutive qualified sampling points. settle,test The settling time is the time measured during the prototype contact step test; Step S5: Perform compensation for structured path points that do not meet the preset conditions. If the compensation fails, pause and record the abnormal points to form a set of impact points to be recompensated.

[0032] Step S5 specifically includes: when the contact force deviation exceeds the limit, compensation is preferentially performed through the micro-feed unit 612; when the position deviation or attitude deviation exceeds the limit, the controller adjusts the guide rail position, the active chuck 31 rotation angle, or the gun body rotation angle; if the threshold is still not met after a preset number of compensations, the impact at the current path point is paused, the anomaly type, actual position, actual attitude, and actual contact force are recorded, and the path point is added to the set of impact points to be repeated. Each anomaly point forms a record: (25); In equation (25), r i The exception cause code, N local,i D represents the number of local compensation attempts at the current point.i The cumulative impact dose already applied at this point, status i At least include: pending re-impact, re-impact qualified, manual confirmation, and prohibited re-impact; The cumulative dose can be expressed as the integral of ultrasonic power or amplitude with the enable time: (26); In equation (26), P us For ultrasonic power; if gating fails at the current point before ultrasonic output, then D i =0; If the impact is interrupted due to excessive force or posture, the applied dose is retained, and the re-impact only replenishes the remaining dose to avoid repeated impact on the treated points or some treated points. In step S5, after forming the set of impact points to be repeated, impacts on those points should not continue until conditions are restored. The controller should first shut down the ultrasonic output, retract the impact gun, and record the reason. If it is a non-hard fault and the subsequent path is safe and executable, the next normal point in the current continuous path segment can be processed. After completing the path segment or main path, the set of impact points to be repeated is reassembled into a local repeated impact path. Repeated impacts do not "automatically continue to the next round of impacts," but must be re-established or registered, the pose is recalculated, the contact force is re-established, and the gating is re-passed before it can be enabled again.

[0033] Anomaly classification and subsequent actions: Level A: Recoverable deviations include minor force deviations, short-term position following errors, or switchable equivalent attitudes. The controller allows for 2-3 attempts at local compensation at the current point; if it still fails, it is added to the queue, and can continue to the next normal point after a safe retreat. Grade B: Geometric or accessibility anomalies include local weld scan deviations, collision risks, insufficient shaft travel, or no feasible gun body angle; the controller shuts off ultrasonic output, marks the point and adjacent points as awaiting replanning, and does not directly perform automatic re-impact; it re-enters the queue after updating the local scan, coordinate registration, or alternative posture. Level C: Hard faults include loose clamping, sudden changes in the axis of the active / slave end, disconnection or over-range of force sensor 64, servo faults, and safety input triggering; the controller should stop the entire task and lift the gun, and should not continue to the next point until manual troubleshooting and system reconstruction are completed.

[0034] Complex impact queue generation and execution: Merge outlier points with consecutive path numbers or spatial distances no greater than 2 to 3 times the point spacing into a local outlier segment to avoid frequent start-stop operations point by point. Add 1-2 guide points before and after the abnormal segment, which are only used for acceleration, deceleration and attitude transition; keep the ultrasonic output off for qualified guide points and do not apply impact dose again; For Class A anomalies, prioritize reducing the tool feed speed, decreasing the micro-feed step size, extending the stabilization time, or switching the equivalent gun body attitude; for Class B anomalies, first update the local point cloud and registration matrix, and then resolve the multi-axis execution quantity. Each impact point to be re-impacted must re-execute the "safe approach - position verification - attitude verification - force closed loop - stabilization time determination - impact enable" process, and must not skip the gating because it is already in the queue; After a successful re-impact, the status will be changed to "Re-impact Qualified" and the actual parameters will be written back; if one or two re-impacts fail, manual confirmation will be required, and the loop will no longer be infinite. When the main task ends, the output includes the first-round pass rate, the second-round pass rate, the manual confirmation points, the actual contact force curve, the cumulative dose, and the statistics of abnormal causes.

[0035] The recommended implementation procedure for ultrasonic impact strengthening of cylindrical welded parts is as follows: (1) Clamping and centering: Select arc-shaped clamps or V-shaped clamps, and put the two ends of the specimen into the active clamping module 3 and the driven clamping module 4 respectively. Adjust the axial span and lateral position so that the center line of the two ends meets the coaxiality threshold. (2) Two-end system establishment: reading , And the zero mark of the active clamp 31, calculate , , and Perform a low-speed test rotation once, and use a probe or displacement sensor to estimate the eccentricity and circular runout; (3) Force sensor 64 calibration: Perform zero-point calibration and gun body angle-no-load baseline calibration in a non-contact state; verify sensitivity, linearity and overload condition using standard load; (4) Path generation: Generate Q from CAD, scan, or teaching data. i Nominal cylinder uses si and ρ i φ i For irregular weld toes, the measured position, tangent vector, and normal vector are used directly; the point spacing is set according to the curvature and normal variation.

[0036] (5) Multi-axis solution: For each Q i Solve for the active chuck angle 31, guide rail position, gun body angle, and pre-approach feed position, and check the stroke of each axis, cumulative cable torsion, collision envelope, and continuity of adjacent points.

[0037] (6) Dry run: Keep the ultrasonic output off, execute key points and attitude transition points, and verify the needle tip position, gun body attitude, minimum obstacle avoidance distance and double-end clamping stability.

[0038] (7) Formal impact: After the needle tip reaches the pre-approach position, it makes contact at low speed. The sensor signal completes attitude compensation and filtering, and the PI controls the micro-feed. After the position, attitude, force and stabilization time are qualified at the same time, the ultrasonic output is enabled.

[0039] (8) Online monitoring: During the impact process, the average and fluctuation of contact force, position following error, posture deviation and cumulative dose are continuously calculated; if the limit is exceeded continuously, the ultrasonic output is shut down within 50 to 200 ms and classified and handled. (9) Abnormal processing: After the local compensation reaches the upper limit of the number of times, R is generated. i Level A allows the main path to continue, Level B requires replanning, and Level C requires shutdown; after the main path segment is completed, a local re-impact queue is executed. (10) Output results: Generate point-by-point planned and actual values, contact force curve, first / second impact status, cumulative dose, cause of abnormality and manual confirmation items.

[0040] Based on the same concept, a second aspect of the present invention, combined with... Figures 4-6 As shown, an ultrasonic impact strengthening device for cylindrical welded parts is proposed, comprising a frame 1, a display and control device 2, an active clamping module 3, a driven clamping module 4, a clamping and cooperative movement mechanism 5, an ultrasonic impact actuator 6, and a controller, wherein: The display control device 2 is located on one side of the frame 1 and is used to input the dimensions of the cylindrical welded part 100, the weld type, the target contact force and the path accuracy threshold, and to display the clamping status, the contact force curve, the path execution progress and abnormal information. The active clamping module 3 includes an active clamp 31, a rotary drive 32, and a first angle detection component. The active clamp 31 is disposed on one side of the cylindrical welded part 100 and is used to clamp the cylindrical welded part 100. The rotary drive 32 is drivenly connected to the active clamp 31 and is used to drive the cylindrical welded part 100 to rotate around its axis. The first angle detection component is mounted on the active clamp 31. The driven clamping module 4 includes a driven chuck 41 and a follower support 42. The driven chuck 41 is disposed on the other side of the cylindrical welded part 100 and is used to clamp the cylindrical welded part 100. The follower support 42 is mounted on the frame 1 and is used to support the driven chuck 41 and rotate together with the cylindrical welded part 100. The driving chuck 31 and the driven chuck 41 can be equipped with replaceable arc-shaped or V-shaped jaws to adapt to round bars or tubes of different diameters within the design clamping range. The clamping and cooperative moving mechanism 5 includes a first guide rail pair 51 and a second guide rail pair 52. The first guide rail pair 51 is arranged along the axial direction of the cylindrical welded part 100 and is used to adjust the clamping span between the active chuck 31 and the driven chuck 41. The second guide rail pair 52 is arranged in a direction perpendicular to the axial direction of the cylindrical welded part 100 and is used to adjust the lateral position of the clamping centers at both ends. At least one of the first guide rail pair 51 and the second guide rail pair 52 is provided with a linear position detection element to feed back the actual displacement to the controller. After clamping the cylindrical welding part 100, the controller reads the clamping center positions of the active clamping module 3 and the driven clamping module 4, and controls the first guide rail pair 51 and the second guide rail pair 52 to perform axial adjustment and lateral alignment. When the line connecting the clamping centers of the two ends coincides with the preset specimen axis or meets the preset coaxiality threshold, the axial coordinate axis of the specimen coordinate system is established with the line connecting the clamping centers of the two ends, and the circumferential zero position is established with the initial angle of the active chuck 31. Thereafter, the position and attitude of the specimen relative to the device coordinate system are updated according to the actual rotation angle of the active chuck 31 and the actual displacement of the guide rail. The ultrasonic impact actuator 6 includes a feed unit 61, a gun body rotation unit 62, an ultrasonic impact gun 63, and a force sensor 64. The feed unit 61 is connected to the gun body rotation unit 62, and the feed unit 61 includes a coarse feed unit 611 and a micro feed unit 612. The ultrasonic impact gun 63 is installed at the end of the gun body rotation unit 62. The force sensor 64 is located on the axial force transmission path between the gun body rotation unit 62 and the rear end of the ultrasonic impact gun 63. The gun body rotation unit 62 includes a rotary motor 621, a reduction transmission component 622, and a second angle detection component, which can adjust the impact direction of the ultrasonic impact gun 63 within a range of not less than 360°. The controller is electrically connected to the rotary drive unit 32, the clamping and coordinating movement mechanism 5, the feeding unit 61, the gun body rotation unit 62, the force sensor 64, and the display control device 2.

[0041] The ultrasonic impact strengthening device for cylindrical welded parts proposed in this embodiment arranges the force sensor 64 on the actual axial force transmission path at the rear end of the rotatable impact gun, and uses three conditions of position, attitude and contact force to control the impact enable, which is beneficial to improve the stability of contact force and the consistency of impact. Through the coordinated control of specimen rotation, two-dimensional displacement of fixture, gun body rotation and feed, circumferential welds, straight welds and fillet welds can be processed on the same device.

[0042] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for ultrasonic impact strengthening of cylindrical welded parts, characterized in that, include: Collect the clamping center, axial direction, and initial angle of the active chuck at both ends of the cylindrical weldment, and establish the specimen coordinate system; A structured path point sequence is generated based on the weld model, scan data, or teaching data. Each structured path point includes at least the target position, target tangential direction, target normal direction, target contact force, and weld category identifier in the specimen coordinate system. The structured path point sequence is mapped to the active chuck rotation angle, the two-dimensional displacement of the clamping cooperative movement mechanism, the feed position of the ultrasonic impact gun, and the target angle of the gun body rotation unit, so that the impact direction of the ultrasonic impact gun corresponds to the target normal direction. At the current structured path point, the actual position, actual impact posture, and actual contact force collected by the force sensor set on the axial force transmission path at the rear end of the ultrasonic impact gun are obtained, and an ultrasonic impact enable signal is output when the preset conditions are met. Compensation is performed on structured path points that do not meet the preset conditions. If compensation fails, the process is paused and abnormal points are recorded to form a set of impact points to be recompensated.

2. The ultrasonic impact strengthening method for cylindrical welded parts as described in claim 1, characterized in that, The process involves collecting the clamping centers at both ends of the cylindrical welded component, the axial direction, and the initial angle of the active clamp, and establishing a coordinate system for the specimen, including: The clamping centers at both ends are adjusted by using a first guide rail pair set along the axis of the cylindrical welded part and a second guide rail pair set along the direction perpendicular to the axis of the cylindrical welded part, so that the clamping centers at both ends coincide with the preset axis of the cylindrical welded part or meet the preset coaxiality threshold. The specimen coordinate system uses the line connecting the centers of the two clamping ends as the axial coordinate axis, the initial angle of the active clamp as the circumferential zero position, and is updated according to the actual rotation angle of the active clamp and the actual displacement of the clamping and coordinating movement mechanism.

3. The ultrasonic impact strengthening method for cylindrical welded parts as described in claim 2, characterized in that, The process of mapping the structured path point sequence to the active gripper rotation angle and the two-dimensional displacement of the gripping cooperative movement mechanism includes: A zero-position rotation matrix for the specimen is constructed using the axial unit vector, radial y-axis unit vector, and radial z-axis unit vector of the cylindrical weldment. ; By using the axial coordinate s along the axis of the cylindrical welded part i The radial distance ρ from the path point to the axis of the cylindrical weldment i And the circumferential angle φ relative to the zero position of the active chuck i The target position is calculated. Surface normal unit vector unit vector of weld tangential direction ; According to the active end clamping center Specimen zero-position rotation matrix Target location Surface normal unit vector unit vector of weld tangential direction Active clamp target rotation angle θ s,i The target displacement u of the first guide rail pair and the second guide rail pair i and υ i The corresponding unit vector of the device coordinate direction is and Calculate the target position of the path point in the device coordinate system. Surface normal unit vector unit vector of weld tangential direction It is the two-dimensional displacement of the active gripper rotation angle and the gripping cooperative movement mechanism.

4. The ultrasonic impact strengthening method for cylindrical welded parts as described in claim 3, characterized in that, The step of mapping the structured path point sequence to the target angle of the gun body rotation unit includes: Define the gun body impact axis k g Calculate the target impact direction vector from the rear of the gun body to the tip of the impact needle. ; Let the gun body rotation axis be The zero-position impact axis of the gun body is ,Will and Projected onto perpendicular to The plane yields u0 and u i ; pass , u0 and u i Calculate the target angle θ of the gun body rotation unit g,i .

5. The ultrasonic impact strengthening method for cylindrical welded parts as described in claim 3, characterized in that, The step of mapping the structured path point sequence to the feed position of the ultrasonic impact gun includes: Based on the execution variable q i The transformation of the gun body base after movement via the guide rail and feed axis is as follows: Fixed offset of the impact pin tip in the gun body coordinate system Gun body rotation axis The target angle θ of the gun body rotation unit g,i Calculate the actual needle tip position ; Using the travel of each axis, the soft limit of the active chuck and the gun body, the collision envelope of the clamp / cylindrical welded parts / gun body, the cumulative torsion of the cable, and the minimum obstacle avoidance distance as constraint parameters, a constraint model for the feed position of the ultrasonic impact gun is constructed. With the goal of prioritizing combinations that have small position and attitude errors, small changes in relative angles at the previous point, large obstacle avoidance margins, and do not cause cable entanglement, the optimal solution of the constraint model for the feed position of the ultrasonic impact gun is sought.

6. The ultrasonic impact strengthening method for cylindrical welded parts as described in claim 1, characterized in that, The preset conditions include: the position deviation, posture deviation, and contact force deviation all meet the preset thresholds.

7. The ultrasonic impact strengthening method for cylindrical welded parts as described in claim 6, characterized in that, The positional deviation is calculated using the following method: The target needle tip position vector is obtained by transforming the specimen coordinates from the target position obtained from CAD, scan, or taught path points. ; The actual needle tip position vector is calculated by directly reading the actual linear axis position, active chuck angle, and gun body angle from the servo encoder. ; Through the actual needle tip position vector and the target needle tip position vector The difference in modulus length yields the positional deviation e. p,i .

8. The ultrasonic impact strengthening method for cylindrical welded parts as described in claim 7, characterized in that, The attitude deviation is calculated using the following method: The target impact direction vector is calculated using the normal, tangential, and preset tilt angle of the structured path point sequence. ; The actual impact direction vector is calculated from the active clamp angle, the gun body angle, and the calibration matrix. ; Through the target impact direction vector and the actual impact direction vector Calculate the attitude deviation e a,i .

9. The ultrasonic impact strengthening method for cylindrical welded parts as described in claim 7, characterized in that, The contact force deviation is calculated using the following method: The target contact force F is obtained from the process database or pre-experiment corresponding to the material, plate / pipe wall thickness, weld type, impact needle type, ultrasonic power, and target strengthening effect. tar,i ; The actual contact force F is obtained from the measurement value of the gun rear force sensor after calibration, attitude baseline compensation and filtering. act,i ; Through actual contact force F act,i Contact force F with the target tar,i The difference is used to obtain the contact force deviation e. F,i .

10. An ultrasonic impact strengthening device for cylindrical welded parts, characterized in that, It includes a frame, a display and control device, an active clamping module, a driven clamping module, a clamping and cooperative movement mechanism, an ultrasonic impact actuator, and a controller, wherein: The display control device is located on one side of the frame and is used to input the size of the cylindrical welded part, the weld type, the target contact force and the path accuracy threshold, and to display the clamping status, the contact force curve, the path execution progress and abnormal information. The active clamping module includes an active chuck, a rotary drive, and a first angle detection component. The active chuck is disposed on one side of the cylindrical welded part and is used to clamp the cylindrical welded part. The rotary drive is driven to the active chuck and is used to drive the cylindrical welded part to rotate around its axis. The first angle detection component is mounted on the active chuck. The driven clamping module includes a driven chuck and a follower support. The driven chuck is located on the other side of the cylindrical welded part and is used to clamp the cylindrical welded part. The follower support is mounted on the frame and is used to support the driven chuck and rotate together with the cylindrical welded part. The clamping and cooperative moving mechanism includes a first guide rail pair and a second guide rail pair. The first guide rail pair is arranged along the axis of the cylindrical welded part and is used to adjust the clamping span between the active chuck and the driven chuck. The second guide rail pair is arranged along the direction perpendicular to the axis of the cylindrical welded part and is used to adjust the lateral position of the clamping centers at both ends. The ultrasonic impact actuator includes a feeding unit, a gun body rotation unit, an ultrasonic impact gun, and a force sensor. The feeding unit is connected to the gun body rotation unit. The ultrasonic impact gun is installed at the end of the gun body rotation unit. The force sensor is located on the axial force transmission path between the gun body rotation unit and the rear end of the ultrasonic impact gun. The controller is electrically connected to the rotary drive, the clamping and coordinating movement mechanism, the feeding unit, the gun body rotation unit, the force sensor, and the display and control device.

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