Stainless steel alignment auxiliary welding device and method

Abstract

The invention relates to a stainless steel alignment auxiliary welding device and method, and belongs to the technical field of stainless steel pipe alignment auxiliary welding. The stainless steel alignment auxiliary welding device comprises a positioning main machine, and the positioning main machine comprises an annular base and a synchronous clamping mechanism installed on the annular base; the annular base is provided with an inner ring used for rigidly fixing a reference tube and an outer ring capable of rotating around the axis of the inner ring, and the synchronous clamping mechanism is installed on the outer ring. The calibration execution unit comprises a fine adjustment execution arm and a displacement sensing system, a base of the fine adjustment execution arm is meshed and driven by the synchronous clamping mechanism, a piezoelectric fine adjustment device is arranged in the fine adjustment execution arm, and the displacement sensing system is fixed to the front end of the annular base; the controller is electrically connected with the displacement sensing system and the piezoelectric fine-tuning devices of the fine-tuning execution arms, micron-order high-precision alignment which is difficult to achieve in a traditional manual mode can be achieved, and meanwhile the alignment efficiency is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of auxiliary welding of stainless steel pipe joints, specifically to an auxiliary welding device and method for stainless steel joints. Background Technology

[0002] In the butt welding of stainless steel pipes, traditional manual butt welding relies heavily on the experience and skill of the operators, resulting in low efficiency and difficulty in guaranteeing butt welding accuracy. This makes it difficult to ensure the quality stability and consistency of the welded joints.

[0003] This situation arises because traditional methods lack precise automated control and real-time data support during the alignment process. Manual alignment cannot achieve micron-level precision displacement, and the calibration process is greatly affected by human factors. It is difficult to transform the complex alignment process into a standardized precision control procedure. As a result, it is impossible to effectively improve alignment efficiency and joint quality in the welding of stainless steel pipes with high alignment accuracy requirements.

[0004] The information disclosed in the background section above is only intended to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to provide a stainless steel butt welding auxiliary device and method to solve the problems mentioned in the background art; specifically, the technical solution of this invention is as follows:

[0006] A stainless steel butt welding auxiliary device, comprising:

[0007] The positioning host includes an annular base and a synchronous clamping mechanism mounted on the annular base. The annular base has an inner ring for rigidly fixing a reference tube and an outer ring that can rotate about the axis of the inner ring. The synchronous clamping mechanism is mounted on the outer ring.

[0008] The calibration execution unit includes a fine-tuning arm and a displacement sensing system. The base of the fine-tuning arm is engaged and driven by the synchronous clamping mechanism. The fine-tuning arm has a built-in piezoelectric fine-tuner. The displacement sensing system is fixed to the front end of the annular base.

[0009] A controller electrically connected to the displacement sensing system and the piezoelectric fine-tuning device of each of the fine-tuning actuators.

[0010] Preferably, the inner ring of the annular base has a locking screw on its inner wall for locking the reference tube; the outer ring is an annular component corresponding to the structure of the inner ring, which is rotatably connected to the annular base by a bearing and is located on the same axis as the inner ring, and a circumferential locking pin is provided between the outer ring and the annular base.

[0011] Preferably, the synchronous clamping mechanism is a three-jaw self-centering chuck structure. The synchronous clamping mechanism includes a planar threaded disk with an Archimedean spiral groove, and the base of each of the fine-tuning actuators engages in the spiral groove to realize the synchronous radial movement of the fine-tuning actuators.

[0012] Preferably, the displacement sensing system includes three eddy current sensors, which are evenly distributed at the front end of the annular base, with their probes pointing towards the outer wall of the tube to be calibrated.

[0013] Preferably, the calibration execution unit includes three fine-tuning execution arms, each of which is provided with a V-shaped clamping block at its end for contacting the tube to be calibrated, and the piezoelectric fine-tuner is a stacked piezoelectric ceramic actuator that is installed in series on the body of the fine-tuning execution arm.

[0014] A method for auxiliary butt welding of stainless steel, comprising:

[0015] The controller collects the initial distance readings of the displacement sensing system when the outer ring is in at least two different circumferential positions, and establishes an initial state model that defines the initial three-dimensional spatial attitude of the tube to be calibrated based on the initial distance readings.

[0016] The controller compares the initial state model with preset ideal attitude parameters to generate a multidimensional deviation vector describing the difference between the current attitude and the target attitude;

[0017] Based on the multidimensional deviation vector and the preset system response driving feature matrix, the controller calculates the optimal cooperative driving vector and generates a set of mutually compensating voltage commands to synchronously drive each of the piezoelectric trimmers.

[0018] The controller cyclically generates the multidimensional deviation vector and synchronously drives the piezoelectric fine-tuner until each component of the multidimensional deviation vector is less than a preset threshold. Then, the controller locks the driving voltage of each piezoelectric fine-tuner to enter the attitude holding and locking state.

[0019] Preferably, the establishment of the initial state model specifically includes:

[0020] The controller uses a rotational scanning and deviation consistency verification algorithm to identify abnormal data points caused by local defects on the pipe surface.

[0021] The controller reconstructs and corrects the abnormal data points based on normal sensor readings at the same time and a preset spatial cylindrical constraint model to generate the initial state model.

[0022] Preferably, the solution of the optimal cooperative driving vector is specifically as follows: the controller calculates the cooperative driving amount applied to the three piezoelectric tuners required to achieve the overall calibration target by solving the inverse operation of the system response driving feature matrix.

[0023] Preferably, the set of mutually compensating voltage commands are used to drive some of the piezoelectric trimmers to extend while simultaneously driving the remaining piezoelectric trimmers to shorten, thereby maintaining the center position of the tube while adjusting the tilt posture of the tube opening.

[0024] Preferably, the ideal attitude parameters are set to a state where the readings of the three sensors of the displacement sensing system are completely equal; the trigger condition for the attitude holding and locking state is that the controller continuously detects that each component of the multidimensional deviation vector is less than the preset threshold within a predetermined number of times.

[0025] This invention provides an improved auxiliary welding device and method for stainless steel butt joints, which has the following improvements and advantages compared with the prior art:

[0026] 1. The device transforms the complex alignment calibration process into an automated precision control process. The synchronous clamping mechanism adopts a three-jaw self-centering chuck structure, which can quickly perform synchronous initial clamping and automatic alignment of the tube to be calibrated, providing a good initial state for subsequent fine adjustment. The controller can calculate the optimal cooperative driving amount by solving the inverse operation of the system response driving feature matrix, thereby efficiently correcting the attitude and greatly improving the convergence speed of the calibration process. This enables the solution to achieve micron-level high-precision alignment that is difficult to achieve by traditional manual methods, while significantly improving alignment efficiency.

[0027] 2. This solution reduces reliance on operator experience through automation and precision control. The displacement sensing system uses a non-contact eddy current sensor, which can measure the pipe posture in real time with high precision, avoiding physical damage to the pipe surface. In addition, when establishing the initial state model, the controller can identify and correct abnormal data points caused by local defects on the pipe surface through a deviation consistency check algorithm, ensuring the accuracy of posture judgment. After calibration, the controller will enter the posture holding and locking state, rigidly fixing the calibrated pipe posture, providing stable mating conditions for subsequent welding operations. These measures work together to ensure the stability and repeatability of the mating process, thereby ensuring the stability and consistency of the weld joint quality.

[0028] 3. The controller can generate a set of mutually compensating voltage commands to drive some piezoelectric trimmers to extend while simultaneously driving the rest to shorten. This driving method can maintain the center position of the tube while adjusting the tilt attitude. This solves the problem of the coupling between attitude and position adjustment in the traditional adjustment process, making the adjustment path more direct and further improving the calibration efficiency. Attached Figure Description

[0029] The present invention will be further explained below with reference to the accompanying drawings and embodiments:

[0030] Figure 1 This is a schematic diagram of the overall structure of the device;

[0031] Figure 2 This is a schematic diagram of the positioning host and its connection structure;

[0032] Figure 3 This is a schematic diagram of the overall structure of the calibration execution unit;

[0033] Figure 4 This is a schematic diagram of a piezoelectric trimmer and its connection structure;

[0034] Figure 5 This is a schematic diagram of the process flow of the method of the present invention;

[0035] In the diagram: 100, positioning host; 110, ring base; 120, synchronous clamping mechanism; 200, calibration execution unit; 210, fine-tuning execution arm; 220, piezoelectric fine-tuner; 230, displacement sensing system; 300, controller. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0037] Example 1:

[0038] Please see Figure 1-4 The present invention provides a stainless steel butt welding auxiliary device, comprising:

[0039] The positioning host 100 includes an annular base 110 and a synchronous clamping mechanism 120 mounted on the annular base 110. The annular base 110 has an inner ring for rigidly fixing the reference tube and an outer ring that can rotate around the axis of the inner ring. The synchronous clamping mechanism 120 is mounted on the outer ring.

[0040] The calibration execution unit 200 includes a fine-tuning execution arm 210 and a displacement sensing system 230. The base of the fine-tuning execution arm 210 is engaged and driven by the synchronous clamping mechanism 120. The fine-tuning execution arm 210 has a built-in piezoelectric fine tuner 220. The displacement sensing system 230 is fixed to the front end of the annular base 110.

[0041] The controller 300 is electrically connected to the displacement sensing system 230 and the piezoelectric fine tuner 220 of each fine-tuning actuator arm 210.

[0042] In the butt welding of stainless steel pipes, the traditional manual butt welding method is inefficient and the butt welding accuracy depends on the operator's skill level, making it difficult to guarantee the stability and consistency of the weld joint quality. The stainless steel pipe butt welding auxiliary device provided in this embodiment aims to solve the above problems.

[0043] The positioning host 100 provides a stable mechanical reference and initial alignment function for the entire device. In actual operation, the annular base 110 of the positioning host 100 is first fixed to a stainless steel tube serving as a reference. Then, another stainless steel tube to be calibrated is introduced. Based on this, the calibration execution unit 200 performs high-precision attitude adjustment on the tube to be calibrated. The displacement sensing system 230 is responsible for monitoring the spatial position of the tube to be calibrated relative to the annular base 110 in real time and transmitting the measurement data to the controller 300. The controller 300 calculates the necessary adjustment amount based on this data and drives the piezoelectric fine adjusters 220 built into each fine-tuning execution arm 210 to perform micron-level precise displacement. The entire process, through the coordinated work of the positioning host 100, the calibration execution unit 200, and the controller 300, transforms the complex alignment calibration process into an automated precision control process, effectively improving the accuracy and efficiency of alignment.

[0044] The inner ring of the annular base 110 has a locking screw on its inner wall for locking the reference tube; the outer ring is an annular part corresponding to the structure of the inner ring, which is rotatably connected to the annular base 110 through a bearing and is located on the same axis as the inner ring, and a circumferential locking pin is provided between the outer ring and the annular base 110.

[0045] In this embodiment, the structure of the annular base 110 is further described. The inner ring of the annular base 110 can firmly fix the device to the outer wall of the reference tube through locking screws evenly distributed on its inner wall, providing a stable and unchanging reference coordinate system for all subsequent calibration actions. In order to avoid damaging the surface of the stainless steel tube, the ends of the locking screws can be made of materials with a certain degree of flexibility, such as polytetrafluoroethylene. The outer ring is fitted on the outside of the inner ring through a low-friction precision bearing. This connection relationship allows the synchronous clamping mechanism 120 and the displacement sensing system 230 installed on it to rotate smoothly around the central axis of the reference tube as a whole. This rotational capability is the basis for subsequent rotational scanning measurement, which aims to collect the position information of the tube to be calibrated at different circumferential angles. The function of the circumferential locking pin is to reliably lock the outer ring and the inner ring circumferentially after rotating to a specific angle, so as to ensure that the measurement system itself will not undergo unexpected angular displacement during data acquisition, thereby ensuring the stability of the acquired data.

[0046] The synchronous clamping mechanism 120 is a three-jaw self-centering chuck structure. The synchronous clamping mechanism 120 includes a planar threaded disk with an Archimedean spiral groove. The base of each fine-tuning actuator 210 is engaged in the spiral groove to realize the synchronous radial movement of the fine-tuning actuator 210.

[0047] In this embodiment, the synchronous clamping mechanism 120 adopts a three-jaw self-centering chuck structure. The core of this mechanism is a planar threaded disk with an Archimedean spiral groove machined inside. The base of each fine-tuning actuator 210 engages with the spiral groove. When the operator rotates the planar threaded disk, the geometric characteristics of the Archimedean spiral drive all three bases to move simultaneously and equidistantly radially inward or outward. The main purpose of this design is to achieve rapid and synchronous initial clamping and automatic centering of the tube to be calibrated. This synchronous movement ensures that after the tube to be calibrated is clamped, its centerline can be approximately coincident with the centerline of the reference tube, providing a good initial state for subsequent micron-level precise calibration and reducing the stroke and time of subsequent fine-tuning.

[0048] The displacement sensing system 230 includes three eddy current sensors, which are evenly distributed at the front end of the annular base 110, with their probes pointing towards the outer wall of the tube to be calibrated.

[0049] In this embodiment, the displacement sensing system 230 consists of three eddy current sensors, such as the EX-V series sensors from Keyence. These three eddy current sensors are fixedly mounted on the front end face of the annular base 110 in a 120-degree evenly distributed manner. Their probes point non-contactly at the outer wall of the tube to be calibrated. The purpose of selecting eddy current sensors is to achieve high-precision, high-frequency real-time distance measurement. Their non-contact characteristic avoids any physical damage to the surface of the tube. The evenly distributed layout of the three sensors in space allows their measurement values ​​to jointly define a plane. Through these three independent distance readings, the controller 300 can accurately calculate the complete attitude of the tube end face in three-dimensional space, including the radial offset of its center position and the tilt angle of the axis, providing the necessary input data for subsequent attitude calculation.

[0050] The calibration execution unit 200 includes three fine-tuning execution arms 210. Each fine-tuning execution arm 210 has a V-shaped clamping block at its end for contacting the tube to be calibrated. The piezoelectric fine-tuner 220 is a stacked piezoelectric ceramic actuator that is installed in series on the arm body of the fine-tuning execution arm 210.

[0051] The displacement sensing system 230 is preferably composed of three eddy current sensors, and the calibration execution unit 200 is preferably composed of three fine-tuning execution arms 210, so as to achieve precise control of the three-dimensional spatial attitude.

[0052] In this embodiment, the calibration execution unit 200 has three fine-tuning execution arms 210. The V-shaped clamping block at the end of each fine-tuning execution arm 210 is designed to form a stable and reliable two-point contact with the circular outer wall of the tube to be calibrated, preventing slippage during fine-tuning. The piezoelectric fine-tuning device 220 installed in series in the arm body is the core component for achieving precise adjustment. It can be a stacked piezoelectric ceramic actuator, such as the P-841.10B model from PI Company. This actuator can generate precise telescopic displacement at the micron or even submicron level under the drive of an applied voltage. When connected in series in the arm body, its telescopic displacement will be directly converted into radial micro-adjustment of the position of the V-shaped clamping block.

[0053] The controller 300 achieves the final precision calibration of the three-dimensional attitude of the tube to be calibrated by precisely controlling the voltage applied to each piezoelectric trimmer 220.

[0054] Example 2:

[0055] Please see Figure 5 A method for auxiliary butt welding of stainless steel, comprising:

[0056] The controller 300 acquires the initial distance reading set corresponding to the displacement sensing system 230 when the outer ring is in at least two different circumferential positions, and establishes an initial state model that defines the initial three-dimensional spatial attitude of the tube to be calibrated based on the initial distance reading set.

[0057] The controller 300 compares the initial state model with preset ideal attitude parameters to generate a multi-dimensional deviation vector describing the difference between the current attitude and the target attitude;

[0058] The controller 300 calculates the optimal cooperative driving vector based on the multi-dimensional deviation vector and the preset system response driving feature matrix, and generates a set of mutually compensating voltage commands to synchronously drive each piezoelectric trimmer 220.

[0059] The controller 300 cyclically executes the generation of the multidimensional deviation vector and the synchronous drive of the piezoelectric fine-tuner 220 until each component of the multidimensional deviation vector is less than the preset threshold, and then locks the drive voltage of each piezoelectric fine-tuner 220 to enter the attitude holding and locking state.

[0060] Function definition: The preset threshold is a micrometer-level distance difference quantification index, used to characterize the small residual deviation between the current posture of the tube to be calibrated and the ideal alignment posture. It is the key logical judgment basis for determining whether the alignment calibration process has achieved the predetermined accuracy.

[0061] Logical correlation and source: This threshold can be preset according to specific welding process requirements, pipe diameter and material properties. For example, for high-precision welding of stainless steel pipes for aerospace or medical devices, this threshold can be set to less than 10 micrometers, while for general industrial applications, it can be appropriately relaxed.

[0062] Decision function: When the controller 300 continuously detects that each component of the multidimensional deviation vector is less than the preset threshold, this serves as a logic trigger signal, causing the controller 300 to immediately stop fine-tuning and enter the attitude holding and locking state.

[0063] The method provided in this embodiment aims to automate and improve the precision of the matching process.

[0064] The controller 300 establishes an initial state model by collecting distance readings of the outer ring at different circumferential positions. The purpose of this rotational sampling is to comprehensively acquire the initial three-dimensional spatial attitude information of the pipe opening to be calibrated, rather than just a snapshot of a single position, thereby providing an accurate attitude starting point for subsequent calibration.

[0065] The controller 300 compares this model with the ideal attitude parameters and generates a multi-dimensional deviation vector. The purpose of generating this vector is to quantify the abstract spatial attitude difference into a set of specific deviation data that can be calculated, thus clarifying the direction and magnitude of the calibration.

[0066] Based on this deviation vector and the preset system response drive feature matrix, the controller 300 performs calculations and generates a set of mutually compensating voltage commands. This feature matrix pre-describes the linkage effect of the action of each piezoelectric fine tuner 220 on all sensor readings. The purpose of the calculation is to calculate an optimal, coordinated adjustment strategy, rather than simply adjusting a certain actuator arm in isolation, so as to efficiently correct the attitude.

[0067] The controller 300 executes the above-mentioned deviation calculation and collaborative drive process at a high frequency. The purpose of this cyclic process is to form a dynamic convergence adjustment so that the posture of the tube to be calibrated gradually approaches the ideal state. When the deviation is small enough, the controller 300 locks the voltage, so that the system enters the posture holding and locking state. The purpose is to rigidly fix the calibrated tube posture, so as to provide a stable and high-precision alignment for subsequent welding operations.

[0068] The establishment of the initial state model specifically includes:

[0069] The controller 300 uses a rotational scanning and deviation consistency verification algorithm to identify abnormal data points caused by local defects on the pipe surface.

[0070] The controller 300 reconstructs and corrects abnormal data points based on normal sensor readings at the same time and a preset spatial cylindrical constraint model to generate an initial state model.

[0071] Model Purpose: The purpose of the spatial cylindrical constraint model is to reconstruct and correct abnormal data points by utilizing the geometric characteristics of the pipe itself when there are local defects on the surface of the pipe to be calibrated, such as dents or welding slag, which cause abnormal sensor readings, thereby ensuring the accuracy of the overall attitude judgment.

[0072] Logical Structure and Data Flow: Logically, this model receives two other normal sensor readings at the same time as input, and combines them with the preset geometric parameters of the pipe, such as the pipe diameter; it uses mathematical algorithms to calculate the theoretical distance at the location of the third sensor based on the spatial position determined by the two valid readings.

[0073] Physical relationships represented: The model as a whole represents the physical and geometric constraints of the stainless steel pipe as a cylinder on a macroscopic scale. It assumes that even if there are local defects on the pipe surface, the overall shape still conforms to the cylindrical structure. Therefore, the coordinates of unknown points can be calculated using known valid points, thereby correcting abnormal data.

[0074] In this embodiment, the initial state model establishment process is further refined. When the controller 300 performs rotational scanning, it uses a deviation consistency check algorithm. The algorithm's judgment logic is as follows: a true pipe inclination will cause the sensor readings to change continuously and geometrically with the rotation angle; while local defects on the pipe surface, such as dents or weld slag, will cause sudden, discontinuous reading jumps when the sensor scans over that point. The purpose of this algorithm is to accurately distinguish between these two situations and identify abnormal data points caused by surface defects. After identifying abnormal data points, the controller 300 does not directly discard the measurement, but uses the readings of two other normal sensors at the same time, combined with a preset spatial cylindrical constraint model, to reconstruct the data. The calculation logic of this reconstruction process is: based on the spatial position determined by the two valid readings and the geometric constraint that the pipe itself is a cylinder, the theoretical distance that the third sensor should have is calculated in reverse. The purpose of data reconstruction and correction is to eliminate the interference of local surface defects on the overall attitude judgment, thereby establishing a more realistic and reliable initial state model.

[0075] The solution of the optimal cooperative driving vector is as follows: the controller 300 calculates the cooperative driving amount applied to the three piezoelectric tuners 220 to achieve the overall calibration target by solving the inverse operation of the system response driving feature matrix.

[0076] In this embodiment, the method for calculating the optimal cooperative driving vector is clearly defined. The controller 300 performs this calculation by solving the inverse operation of the system response driving feature matrix;

[0077] Input source: The input to this process is the readings from the three sensors of the displacement sensing system 230 and the ideal attitude parameters.

[0078] Logical steps:

[0079] Step 1: Generate a multidimensional deviation vector: The controller 300 compares the real-time sensor readings with preset ideal attitude parameters, for example, if the three readings are equal, and calculates the deviation at each sensor position to form a three-dimensional vector D; this vector represents the difference between the current attitude and the target attitude.

[0080] Step 2: Obtain the system response driving feature matrix: Use the system response driving feature matrix M obtained in advance through calibration experiments; this matrix characterizes the effect of the unit driving amount of each piezoelectric trimmer 220 on all sensor readings.

[0081] Step 3: Solving the inverse operation: The controller 300 performs the inverse operation on the feature matrix M to obtain its inverse matrix. .

[0082] Step 4: Calculate the optimal cooperative driving vector: The controller 300 will combine the deviation vector D generated in Step 1 with the inverse matrix Multiplication, that is, through the formula Calculate the optimal cooperative driving vector V; each component in vector V is the amount of driving voltage that needs to be applied to the corresponding piezoelectric trimmer 220.

[0083] Output and flow: The final output of the process is the optimal collaborative driving vector, which is then passed to the driving circuit of the piezoelectric fine tuner 220 for synchronously driving each fine tuner arm for precise calibration.

[0084] This feature matrix mathematically describes precisely how much linkage displacement each unit expansion of the piezoelectric trimmer 220 will produce at all three sensor locations.

[0085] The system response drive feature matrix is ​​usually pre-established through a one-time calibration experiment before the device leaves the factory or before use. The establishment logic is as follows: apply a known unit drive voltage to each piezoelectric trimmer 220 one by one, and simultaneously measure the displacement change caused by the single drive at all three eddy current sensor positions. For example, when the first piezoelectric trimmer 220 is driven, the displacement response of the three sensors will be measured. These three response values ​​are used as the first column of the matrix. By completing the test of all piezoelectric trimmers 220 in sequence, the complete feature matrix can be constructed.

[0086] When performing the calculation, this physical correspondence can be abstracted into a mathematical model: The calculation logic of controller 300 is to solve the inverse problem of this model, in order to calculate the required driving voltage vector based on the desired displacement correction amount, that is, the opposite vector of the current multidimensional deviation vector: .

[0087] in:

[0088] This represents the target displacement correction vector, which is composed of the deviations in the readings of the three sensors.

[0089] This is the system response driving feature matrix obtained through the above calibration experiment.

[0090] The controller 300 needs to calculate the coordinated drive voltage vector applied to the three piezoelectric trimmers 220.

[0091] Characteristic matrix The inverse matrix.

[0092] Through this calculation, the controller 300 can obtain a set of drive commands that can efficiently achieve the calibration target.

[0093] The purpose of performing matrix inverse operation is to transform the problem from applying a drive to generate displacement in the forward direction to applying a drive in the reverse direction to determine what kind of drive needs to be applied to achieve the target displacement. Through this reverse calculation, the controller 300 can directly calculate a set of optimal drive quantities that need to be applied to the three piezoelectric fine-tuners 220 simultaneously. This set of drive quantities can approach the overall calibration target with high efficiency in one go, rather than through multiple trial-and-error single-point adjustments, which greatly improves the convergence speed of the calibration process.

[0094] A set of mutually compensating voltage commands is used to drive some piezoelectric trimmers 220 to extend while driving the remaining piezoelectric trimmers 220 to shorten, thereby maintaining the center position of the tube while adjusting the tilt posture of the tube opening.

[0095] In this embodiment, the operation of a set of mutually compensating voltage commands is described. For example, to correct a tilt in a single direction, the controller 300 may command the piezoelectric trimmer 220 located at the highest point of the tilt to extend by a certain distance, while simultaneously commanding the other two piezoelectric trimmers 220 to shorten their calculated compensation distances. The purpose of this compensatory drive is to decompose the complex spatial attitude adjustment into two independent control dimensions: attitude adjustment and center position maintenance. In this way, while correcting the tilt of the pipe opening, it can be ensured that the center of the pipe opening will not shift unnecessarily due to the adjustment action, making the adjustment path more direct and avoiding coupling effects during the adjustment process.

[0096] The ideal attitude parameters are set to a state where the readings of the three sensors of the displacement sensing system 230 are completely equal; the trigger condition for attitude holding and locking is that the controller 300 continuously detects that each component of the multidimensional deviation vector is less than a preset threshold within a predetermined number of times.

[0097] In this embodiment, the boundary conditions of the method are defined, and the ideal attitude parameters are set to be that the readings of the three sensors are completely equal. The purpose of this setting is that, geometrically, the plane defined by the three equidistant points must be parallel to the mounting reference plane of the sensor, that is, the front end face of the annular base 110. This directly corresponds to the ideal alignment state in which the pipe opening to be calibrated is completely parallel to the pipe opening of the reference pipe. The triggering condition for attitude maintenance and locking state requires the controller 300 to detect that each component of the deviation vector is less than the threshold several times in a row. The purpose of adding this condition of several consecutive judgments is to ensure that the calibration system has entered a stable convergence state, rather than accidentally reaching the accuracy requirement once when oscillating near the target position, thereby improving the reliability and stability of the final locked attitude.

[0098] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A stainless steel butt joint auxiliary welding device, characterized by, The application relates to a calibration device for a reference tube, which comprises the following parts: a positioning host (100) comprising a ring-shaped base (110) and a synchronous clamping mechanism (120) mounted on the ring-shaped base (110), the ring-shaped base (110) has an inner ring for rigidly fixing a reference tube and an outer ring rotatable around the axis of the inner ring, and the synchronous clamping mechanism (120) is mounted on the outer ring; a calibration execution unit (200) comprising a fine-tuning execution arm (210) and a displacement sensing system (230), the base of the fine-tuning execution arm (210) is engaged and driven by the synchronous clamping mechanism (120), and the fine-tuning execution arm (210) is internally provided with a piezoelectric fine-tuner (220), and the displacement sensing system (230) is fixed to the front end of the ring-shaped base (110); a controller (300) electrically connected with the displacement sensing system (230) and the piezoelectric fine-tuner (220) of each fine-tuning execution arm (210).

2. The device according to claim 1, wherein The inner wall of the inner ring of the ring-shaped base (110) is provided with locking screws for locking the reference tube; the outer ring is a ring-shaped part corresponding to the structure of the inner ring, is rotatably connected on the ring-shaped base (110) through a bearing, is located on the same axis as the inner ring, and is provided with a circumferential locking pin between the outer ring and the ring-shaped base (110).

3. The device as claimed in claim 1, wherein the device is characterized by: The synchronous clamping mechanism (120) is a three-jaw self-centering chuck structure, the synchronous clamping mechanism (120) comprises a planar threaded disc with an Archimedes spiral groove, the base of each fine-tuning execution arm (210) is engaged in the spiral groove, and synchronous radial movement of the fine-tuning execution arm (210) is realized.

4. The device as claimed in claim 1, wherein, The displacement sensing system (230) comprises three eddy current sensors which are uniformly distributed at the front end of the ring-shaped base (110) and have probe heads pointing to the outer wall of a tube to be calibrated.

5. The device as claimed in claim 1, wherein, The calibration execution unit (200) comprises three fine-tuning execution arms (210), the end of each fine-tuning execution arm (210) is provided with a V-shaped clamping block for contacting a tube to be calibrated, and the piezoelectric fine-tuner (220) is a stacked piezoelectric ceramic actuator installed in series on the arm body of the fine-tuning execution arm (210).

6. A method for assisting welding of stainless steel butt joint, applied to the stainless steel butt joint assisting welding device of claim 1, characterized in that, The controller (300) collects a set of initial distance readings of the displacement sensing system (230) when the outer ring is located at at least two different circumferential positions, and establishes an initial state model defining the initial three-dimensional space posture of the tube to be calibrated based on the set of initial distance readings; The controller (300) compares the initial state model with preset ideal posture parameters to generate a multi-dimensional deviation vector describing the difference between the current posture and the target posture; The controller (300) calculates an optimal cooperative driving vector based on the multi-dimensional deviation vector and a preset system response driving characteristic matrix, and generates a set of mutually compensating voltage instructions to synchronously drive each piezoelectric fine-tuner (220). ​ The controller (300) cyclically performs the generation of the multi-dimensional deviation vector and the synchronous driving of the piezoelectric fine tuners (220) until each component of the multi-dimensional deviation vector is less than a preset threshold, and then locks the driving voltage of each piezoelectric fine tuner (220) to enter a posture holding and locking state.

7. The method of claim 6, wherein the method further comprises: The establishment of the initial state model specifically includes: The controller (300) identifies abnormal data points caused by local defects on the pipe surface through a rotation scanning and deviation consistency checking algorithm; The controller (300) reconstructs and corrects the abnormal data points based on normal sensor readings at the same time and a preset spatial cylindrical constraint model to generate the initial state model.

8. The method of claim 6, wherein the method further comprises: The calculation of the optimal collaborative driving vector specifically includes: the controller (300) reversely calculates the collaborative driving amount required to be applied to the three piezoelectric fine tuners (220) to achieve the overall calibration target by solving the inverse operation of the system response driving characteristic matrix.

9. The method of claim 6, wherein the method further comprises: The set of mutually compensating voltage instructions are used to drive some of the piezoelectric fine tuners (220) to elongate while driving the rest of the piezoelectric fine tuners (220) to shorten, so as to maintain the center position unchanged while adjusting the pipe opening inclination posture.

10. The method of claim 6, wherein the method further comprises: The ideal posture parameter is set as a state in which the three sensor readings of the displacement sensing system (230) are completely equal; and the trigger condition of the posture holding and locking state is that the controller (300) continuously detects that each component of the multi-dimensional deviation vector is less than the preset threshold within a predetermined number of times.

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