Control method and device for laser in-situ composite cladding

Abstract

The invention provides a laser in-situ composite cladding control method and device, and relates to the field of laser powder feeding repairing, and the method comprises the following steps: a detection module obtains a molten pool image and a molten pool infrared image of a to-be-repaired part, and sends the molten pool image and the molten pool infrared image to a decision module; the decision-making module determines the width-depth ratio of the molten pool of the to-be-repaired component according to the molten pool image; according to the molten pool infrared image, the molten pool temperature of the to-be-repaired part is determined; determining a repair control strategy according to a preset control rule base in combination with the width-depth ratio of the molten pool and the temperature of the molten pool; based on the repair control strategy, a control signal is sent to the execution module; and the execution module adjusts repairing parameters according to the control signal, in-situ composite cladding repairing is conducted on the to-be-repaired part, and the repairing parameters comprise the laser output power, the laser scanning speed and / or the powder feeding flow. According to the in-situ composite cladding repairing method, automatic feedback adjustment of the repairing parameters is achieved, and the repairing precision of in-situ composite cladding repairing is improved.

Description

Technical Field

[0001] This application relates to the field of laser powder feeding repair, and more specifically, to a control method and apparatus for laser in-situ composite cladding. Background Technology

[0002] With the development of high-end equipment manufacturing, the demand for micro-damage repair of precision metal parts, such as aero-engine blades and medical device components, is becoming increasingly urgent. Laser cladding technology, due to its advantages such as high metallurgical bonding strength and controllable heat input, has become the mainstream solution for micro-damage repair.

[0003] However, traditional laser cladding technology and its derivative methods have many shortcomings. The cladding method using continuous long-pulse lasers and premixed cladding materials has low repair accuracy. Summary of the Invention

[0004] In view of this, the purpose of this application is to overcome the shortcomings of the prior art and provide a repair method and apparatus for ultrafast laser in-situ composite cladding. This application provides the following technical solution: In a first aspect, this application provides a control method for laser in-situ composite cladding, applied to a control device for laser in-situ composite cladding. The device includes: a detection module, a decision module, and an execution module, wherein the decision module is electrically connected to the detection module and the execution module, respectively; the method includes: The detection module acquires the molten pool image and the molten pool infrared image of the component to be repaired, and sends the molten pool image and the molten pool infrared image to the decision module; The decision module determines the aspect ratio of the molten pool to be repaired based on the molten pool image; determines the molten pool temperature of the molten pool to be repaired based on the molten pool infrared image; determines a repair control strategy based on a preset control rule base, combined with the molten pool aspect ratio and the molten pool temperature; and sends a control signal to the execution module based on the repair control strategy. The execution module adjusts the repair parameters according to the control signal to perform in-situ composite cladding repair on the component to be repaired. The repair parameters include: laser output power, laser scanning speed and / or powder flow rate.

[0005] In one embodiment, determining the aspect ratio of the molten pool of the component to be repaired based on the molten pool image includes: Based on the camera calibration parameters, the pixel coordinates of each image feature point in the molten pool image are converted into three-dimensional coordinates in the world coordinate system. Each image feature point includes: multiple edge feature points. The width of the molten pool is determined based on the three-dimensional coordinates of each edge feature point in the transformed world coordinates. The depth of the molten pool is determined based on the three-dimensional coordinates of each image feature point in the transformed world coordinates. The width-to-depth ratio of the molten pool is determined based on the width of the molten pool and the depth of the molten pool.

[0006] In one embodiment, the molten pool temperature includes: the highest molten pool temperature and the molten pool temperature gradient, and determining the molten pool temperature of the component to be repaired based on the molten pool infrared image includes: A molten pool temperature matrix is ​​determined based on the infrared image of the molten pool, wherein each element in the molten pool temperature matrix corresponds to the temperature value of a pixel in the infrared image of the molten pool. The target temperature matrix is ​​obtained by performing spatial filtering on the molten pool temperature matrix. The maximum value is extracted from the target temperature matrix and taken as the highest temperature of the molten pool. The temperature change rate between adjacent elements in the target temperature matrix is ​​determined using a differential algorithm, and the average value of each temperature change rate is determined as the molten pool temperature gradient of the component to be repaired.

[0007] In one embodiment, the preset control rule base includes the following preset rules: If the aspect ratio of the molten pool is less than a first preset threshold, then increase the laser output power or decrease the laser scanning speed; If the aspect ratio of the molten pool is greater than the second preset threshold, then reduce the laser output power or increase the laser scanning speed; If the temperature of the molten pool is greater than the preset melting point, the powder feeding flow rate is reduced. The preset melting point is a preset multiple of the melting point of the matrix material of the component to be repaired. If the temperature of the molten pool exceeds a preset temperature threshold, a shutdown is triggered. If the temperature gradient of the molten pool is greater than the preset gradient value, then the inert gas pressurization is triggered.

[0008] In one embodiment, the laser output power includes: cladding laser head output power and pulsed laser head output power; the laser scanning speed includes: cladding laser scanning speed and pulsed laser head scanning speed; the execution module includes: cladding laser head and pulsed laser head; the execution module adjusts the repair parameters according to the control signal to perform in-situ composite cladding repair on the component to be repaired, including: The cladding laser head adjusts its output power and scanning speed according to the control signal, and outputs the adjusted output power based on the adjusted scanning speed. The pulsed laser head adjusts its output power and scanning speed according to the control signal, and outputs the adjusted output power based on the adjusted scanning speed.

[0009] In one embodiment, the powder feeding flow rate includes: a first channel powder feeding flow rate and a second channel powder feeding flow rate; the execution module further includes: a coaxial dual-channel powder feeder; the execution module adjusts the repair parameters according to the control signal to perform in-situ composite cladding repair on the component to be repaired, and further includes: The coaxial dual-channel powder feeder adjusts the powder feeding flow rate of the first channel and the powder feeding flow rate of the second channel according to the control signal, and controls the powder feeding of the first channel based on the adjusted powder feeding flow rate of the first channel, and controls the powder feeding of the second channel based on the adjusted powder feeding flow rate of the second channel.

[0010] Secondly, this application provides a control device for laser in-situ composite cladding, comprising: a detection module, a decision module, and an execution module, wherein the decision module is electrically connected to the detection module and the execution module respectively; The detection module is used to acquire the molten pool image and the molten pool infrared image of the component to be repaired, and send the molten pool image and the molten pool infrared image to the decision module; The decision module is used to determine the aspect ratio of the molten pool of the component to be repaired based on the molten pool image; determine the molten pool temperature of the component to be repaired based on the molten pool infrared image; determine a repair control strategy based on a preset control rule base, combined with the molten pool aspect ratio and the molten pool temperature; and send a control signal to the execution module based on the repair control strategy. The execution module is used to adjust the repair parameters according to the control signal to perform in-situ composite cladding repair on the component to be repaired. The repair parameters include: laser output power, laser scanning speed and / or powder flow rate.

[0011] In one embodiment, the decision-making module includes a signal processing unit; The signal processing unit is used to convert the pixel coordinates of each image feature point in the molten pool image into three-dimensional coordinates in the world coordinate system based on the camera calibration parameters. Each image feature point includes multiple edge feature points. The width of the molten pool is determined based on the three-dimensional coordinates of each edge feature point in the transformed world coordinates. The depth of the molten pool is determined based on the three-dimensional coordinates of each image feature point in the transformed world coordinates. The width-to-depth ratio of the molten pool is determined based on the width of the molten pool and the depth of the molten pool.

[0012] In one embodiment, the signal processing unit is further configured to determine a molten pool temperature matrix based on the molten pool infrared image, wherein each element in the molten pool temperature matrix corresponds to the temperature value of a pixel in the molten pool infrared image. The target temperature matrix is ​​obtained by performing spatial filtering on the molten pool temperature matrix. The maximum value is extracted from the target temperature matrix as the highest temperature of the molten pool. The temperature change rate between adjacent elements in the target temperature matrix is ​​determined using a differential algorithm, and the average value of each temperature change rate is determined as the molten pool temperature gradient of the component to be repaired.

[0013] In one embodiment, the execution module includes: a cladding laser head and a pulsed laser head; The cladding laser head is used to adjust the output power and scanning speed of the cladding laser head according to the control signal, and to output the adjusted output power of the cladding laser head based on the adjusted scanning speed of the cladding laser head; The pulsed laser head is used to adjust the output power and scanning speed of the pulsed laser head according to the control signal, and to output the adjusted output power of the pulsed laser head based on the adjusted scanning speed.

[0014] The laser in-situ composite cladding control method and apparatus provided in this application acquires a molten pool image and a molten pool infrared image of the component to be repaired through the detection module, and sends the molten pool image and the molten pool infrared image to the decision module; the decision module determines the aspect ratio of the molten pool of the component to be repaired based on the molten pool image; determines the molten pool temperature of the component to be repaired based on the molten pool infrared image; determines a repair control strategy based on a preset control rule base, combined with the molten pool aspect ratio and the molten pool temperature; and sends a control signal to the execution module based on the repair control strategy; the execution module adjusts the repair parameters according to the control signal to perform in-situ composite cladding repair on the component to be repaired. The repair parameters include: laser output power, laser scanning speed, and / or powder flow rate, realizing automated feedback adjustment of repair parameters and improving the repair accuracy of in-situ composite cladding repair.

[0015] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A schematic flowchart of the control method for laser in-situ composite cladding provided in an embodiment of this application is shown. Figure 2 A schematic diagram of the control device for laser in-situ composite cladding provided in an embodiment of this application is shown; Figure 3 Another structural schematic diagram of the control device for laser in-situ composite cladding provided in an embodiment of this application is shown; Figure 4 A schematic diagram of the structure of the support platform provided in an embodiment of this application is shown; Figure 5 A schematic diagram of the coaxial dual-channel powder feeder and cladding laser head provided in an embodiment of this application is shown.

[0018] Explanation of key component symbols: 200-Control device for laser in-situ composite cladding; 210-Detection module; 211-High-speed camera; 212-Infrared detector; 220-Decision module; 221-PLC; 222-Industrial computer; 230-Execution module; 231-Clad laser head; 232-Pulsed laser head; 233-Coaxial dual-channel powder feeder; 2331-First channel; 2332-Second channel; 240-Worktable; 250-Bearing platform; 251-Ball screw; 252-Screw slider; 253-Bearing seat; 254-Drive motor; 260-Truss. Detailed Implementation

[0019] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown 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 are only used to explain the present invention, and should not be construed as limiting the present invention.

[0020] 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.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the template description is for the purpose of describing particular embodiments only and is not intended to limit the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0022] Example 1 Existing laser cladding technologies mostly employ continuous long-pulse lasers and premixed cladding materials. Continuous long-pulse lasers have a high heat input, which can easily cause uncontrollable thermal damage to the parts being repaired. Premixed cladding materials have poor uniformity, making them prone to segregation and even burning, both of which negatively impact repair accuracy. For further information, please refer to [link to relevant documentation]. Figure 1 This application provides a control method for laser in-situ composite cladding, applicable to, for example... Figure 2 The control device 200 for laser in-situ composite cladding shown includes: a detection module 210, a decision module 220, and an execution module 230. The decision module 220 is electrically connected to the detection module 210 and the execution module 230, respectively. The method includes steps S110 to S160.

[0023] In step S110, the detection module 210 acquires the molten pool image and the molten pool infrared image of the component to be repaired, and sends the molten pool image and the molten pool infrared image to the decision module 220.

[0024] In this embodiment, the detection module 210 includes a high-speed camera 211 and an infrared detector 212. The high-speed camera captures images of the component to be repaired at a preset frequency, such as 10,000 frames per second, and acquires the molten pool image of the component to be repaired in real time. At the same time, the infrared detector 212 collects an infrared image of the molten pool reflecting the temperature distribution of the component to be repaired.

[0025] In step S120, the decision module 220 determines the aspect ratio of the molten pool of the component to be repaired based on the molten pool image.

[0026] In this embodiment, the decision module 220 includes a signal processing unit. The signal processing unit performs coordinate transformation based on the acquired molten pool image, converting each image feature point in the molten pool image from its original pixel coordinates to three-dimensional coordinates in the world coordinate system. Then, based on the transformed three-dimensional coordinates, it determines the molten pool width and molten pool depth, and calculates the molten pool width-to-depth ratio.

[0027] It is understandable that coordinate transformation avoids the dimensional errors of traditional two-dimensional visual inspection and improves the accuracy of the molten pool width-to-depth ratio.

[0028] In one embodiment, determining the aspect ratio of the molten pool of the component to be repaired based on the molten pool image includes: converting the pixel coordinates of each image feature point in the molten pool image into three-dimensional coordinates in the world coordinate system based on camera calibration parameters, wherein each image feature point includes multiple edge feature points; determining the molten pool width based on the three-dimensional coordinates of each edge feature point in the converted world coordinates; determining the molten pool depth based on the three-dimensional coordinates of each image feature point in the converted world coordinates; and determining the aspect ratio of the molten pool based on the molten pool width and the molten pool depth.

[0029] In this embodiment, coordinate transformation is first performed based on camera calibration parameters, which include: camera intrinsic parameters (focal length). / Image center coordinates / Camera depth reference ) and the extrinsic parameters (rotation matrix) obtained through prior calibration R Translation vector T Edge feature points in each image feature point need to be filtered out first by gradient calculation of the horizontal and vertical Sobel operators, and then the pixel coordinates of all feature points are substituted into a specific matrix algorithm, combined with the rotation matrix. R The inverse operation completes the conversion from pixel coordinates to three-dimensional coordinates in the world coordinate system.

[0030] Specifically, based on the camera imaging model, the mapping relationship between pixel coordinates and world coordinates is determined by a specific matrix algorithm, the expression of which is shown below:

[0031] in, , This represents the pixel coordinates of image feature points. , , This represents the world coordinates of image feature points. , This represents the focal length of a high-speed camera. , This represents the center coordinates of the molten pool image. This represents a rotation matrix. This represents the translation vector. This represents the camera depth reference.

[0032] In one embodiment, based on the specific matrix algorithm described above, the pixel coordinates of each image feature point in the molten pool image are converted into three-dimensional coordinates in the world coordinate system, providing a coordinate basis for the subsequent calculation of the molten pool width and depth.

[0033] When determining the width of the molten pool, the horizontal direction is extracted based on the three-dimensional coordinates of the transformed edge feature points. - The coordinate differences between the leftmost and rightmost, and the frontmost and backmost feature points on the plane are used to determine the molten pool width; when determining the molten pool depth, the three-dimensional coordinates of all image feature points are combined to locate the molten pool surface ( (maximum coordinate) and the bottom of the molten pool ( The minimum coordinate value (i.e., the lowest point of penetration on the substrate surface) is used to calculate the difference between the two coordinates as the molten pool depth; finally, the molten pool width-to-depth ratio is obtained by calculating the ratio of "molten pool width ÷ molten pool depth".

[0034] Step S130: Determine the molten pool temperature of the component to be repaired based on the infrared image of the molten pool.

[0035] In this embodiment, the information processing unit included in the decision module 220 converts the radiation intensity corresponding to each pixel of the molten pool infrared image into the corresponding temperature value, constructs a molten pool temperature matrix covering the entire molten pool area, and determines the molten pool temperature of the component to be repaired based on the temperature matrix, specifically including: the maximum molten pool temperature and the molten pool temperature gradient.

[0036] It is understandable that by detecting the temperature of the molten pool with high precision, the errors of traditional temperature measurement methods are avoided, providing a reliable basis for subsequent parameter adjustments.

[0037] In one embodiment, the molten pool temperature includes: a maximum molten pool temperature and a molten pool temperature gradient. Determining the molten pool temperature of the component to be repaired based on the molten pool infrared image includes: determining a molten pool temperature matrix based on the molten pool infrared image, where each element of the molten pool temperature matrix corresponds to the temperature value of a pixel in the molten pool infrared image; performing spatial filtering on the molten pool temperature matrix to obtain a target temperature matrix; extracting the maximum value from the target temperature matrix as the maximum molten pool temperature; determining the temperature change rate between adjacent elements in the target temperature matrix using a differential algorithm; and determining the average value of each temperature change rate as the molten pool temperature gradient of the component to be repaired.

[0038] In this embodiment, based on the hardware calibration parameters of the infrared detector 212, a fixed infrared radiation intensity-actual temperature mapping relationship is established. The radiation intensity of each pixel in the infrared image of the molten pool is converted into the corresponding actual temperature value, and a molten pool temperature matrix is ​​constructed (the matrix elements correspond one-to-one with the image pixels, completely covering the molten pool area). Then, the temperature matrix is ​​spatially filtered to remove abnormal temperature values ​​caused by laser reflection, ambient light interference, etc., and retain the true temperature distribution of the molten pool to obtain the target temperature matrix. The maximum value is selected from the target temperature matrix and determined as the highest temperature of the molten pool to ensure the capture of the instantaneous high temperature state of the molten pool. Finally, the temperature difference between adjacent elements (corresponding to adjacent measuring points of the molten pool) in the target temperature matrix is ​​calculated using a differential algorithm. The actual spatial distance between adjacent measuring points is calculated by combining the world coordinates corresponding to each element to obtain the temperature change rate of each adjacent measuring point. The average value of all change rates is then taken as the molten pool temperature gradient to achieve a quantitative determination of the temperature distribution uniformity.

[0039] It is understandable that the pixel-level construction of the temperature matrix ensures that there are no blind spots in the detection of the molten pool temperature and fully captures the details of the temperature distribution; spatial filtering effectively improves the reliability of temperature data and avoids misjudgments in adjustment caused by outliers; the maximum temperature and temperature gradient of the molten pool obtained by step-by-step calculation reflect the temperature field of the molten pool and provide a basis for adjusting and repairing parameters.

[0040] Step S140: Determine the repair control strategy based on the preset control rule library, combined with the molten pool width-to-depth ratio and the molten pool temperature.

[0041] In this embodiment, the decision module 220 first synchronously receives the molten pool width-to-depth ratio output in step S120 and the molten pool temperature output in step S130, then calls the preset control rule library to compare the real-time collected molten pool width-to-depth ratio and molten pool temperature with the threshold conditions in the preset control rule library; and calculates the parameter adjustment amount through the PID discretization algorithm to finally determine the repair control strategy. The entire decision-making process is synchronously connected with data acquisition and parameter calculation to ensure that a set of control instructions adapted to the current molten pool state is output every preset time, such as 5ms.

[0042] It should be noted that the basic form of the PID fine-tuning formula is as follows:

[0043] The discretized form is:

[0044] in, u(t) The physical meaning it represents is controlling the output, that is, adjusting the laser power. This represents the k-th control output quantity after discretization. e(t) represents the current error value, which is the difference between the target width-to-depth ratio and the actual width-to-depth ratio. T s The physical meaning it represents is the sampling period. e i The variable in the summation symbol represents the historical error value from the 0th to the kth sampling time, that is, the error at each time step. e k This represents the current error value at the k-th sampling time, which is the difference between the target value and the current measured value. The physical meaning it represents is the proportionality coefficient. =0.8, The physical meaning it represents is the integral coefficient. K i =0.2, K d The physical meaning represented is the differential coefficient. K d =0.05, the discretized formula is composed of three terms added together. From left to right, the three terms are the proportional term, integral term, and derivative term. Their respective characteristics are: fast and oscillating, eliminating steady-state error but slow response, needing to guard against integral saturation, enhancing stability but sensitive to noise. When the system fails to obtain the corresponding aspect ratio, the PID controller will be activated for discretization fine-tuning, thereby calculating the... This allows us to obtain the adjustment parameters for the laser power.

[0045] Further details on PID fine-tuning, including the proportional term. Adjust the current error Directly outputting the adjustment amount quickly reduces the deviation. In this project, when the actual aspect ratio is less than the target value, the proportional term quickly outputs a positive laser power adjustment amount to increase the laser energy input, and the integral term... The cumulative error of historical sampling periods is used to gradually eliminate static deviations. When small aspect ratio deviations persist for a long time, the integral term is continuously adjusted to ensure steady-state accuracy during the repair process. The differential term... The method predicts the deviation trend based on the error change rate and suppresses and adjusts oscillations. In this project, when the error increases rapidly, the differential term outputs a reverse adjustment amount to avoid the laser power from increasing too much and causing the molten pool to become too deep.

[0046] It is understandable that by making decisions in tandem with aspect ratio and temperature data, the unintended consequences of adjusting a single parameter are avoided, achieving precise control over both the molten pool morphology and the temperature field. The combination of a preset rule base and a PID algorithm ensures standardized adjustment actions and effectively reduces defects such as cracks and porosity in the repair layer by dynamically fine-tuning to adapt to real-time changes in the molten pool. The dynamic matching of decision results with the molten pool state takes into account both metallurgical bonding strength and forming accuracy, significantly improving the stability and yield of the repair process.

[0047] In one embodiment, the preset control rule base includes the following preset rules: if the width-to-depth ratio of the molten pool is less than a first preset threshold, then the laser output power is increased or the laser scanning speed is decreased; if the width-to-depth ratio of the molten pool is greater than a second preset threshold, then the laser output power is decreased or the laser scanning speed is increased; if the temperature of the molten pool is greater than a preset melting point, then the powder feeding flow rate is reduced, wherein the preset melting point is a preset multiple of the melting point of the matrix material of the component to be repaired; if the temperature of the molten pool is greater than a preset temperature threshold, then a shutdown is triggered; if the temperature gradient of the molten pool is greater than a preset gradient value, then inert gas pressurization is triggered.

[0048] In this embodiment, the preset rule base quantifies the thresholds and corresponding actions for each control scenario based on the characteristics of the cladding process and safety requirements: the first preset threshold is set to 1.0, and the second preset threshold is set to 2.0, corresponding to a reasonable preset range for the molten pool width-to-depth ratio. When the molten pool width-to-depth ratio is less than 1.0, the output power of the cladding laser head 231 and the pulsed laser head 232 is increased to enhance the molten pool energy input, making the molten pool deeper and more concentrated; when the molten pool width-to-depth ratio is greater than 2.0... At the same time, the heat input is reduced by lowering the laser output power to avoid thermal deformation of the substrate caused by an excessively wide molten pool; the preset melting point is 1.2 times the melting point of the substrate material of the part to be repaired. When the highest temperature of the molten pool exceeds this value, the conveying rate of the reinforcing phase powder in the coaxial dual-channel powder feeder 233 is reduced to avoid ablation and segregation of the reinforcing phase; the preset temperature threshold is set to 1600℃. When the temperature of the molten pool exceeds this value, a shutdown is triggered to ensure the safety of the workpiece; the preset gradient value is set to 500K / mm. When the temperature gradient exceeds the standard, the inert gas pressurization of the outer layer of the coaxial multi-channel powder feeder is activated to reduce the temperature gradient by expanding the coverage of the umbrella-shaped gas curtain and optimizing the heat dissipation uniformity of the molten pool.

[0049] Step S150: Based on the repair control strategy, send a control signal to the execution module 230.

[0050] In this embodiment, the repair control strategy is converted into standardized digital instructions and sent to the execution module 230.

[0051] In step S160, the execution module 230 adjusts the repair parameters according to the control signal and performs in-situ composite cladding repair on the component to be repaired. The repair parameters include: laser output power, laser scanning speed and / or powder flow rate.

[0052] In this embodiment, the execution module 230 includes a cladding laser head 231, a pulsed laser head 232, and a coaxial dual-channel powder feeder 233. The cladding laser head 231 dynamically adjusts its output power within a power range and its scanning speed within a scanning speed range according to a control signal, moving along the damaged area of ​​the component to be repaired. The pulsed laser head 232 synchronously responds to the control signal, adjusting its additional laser energy output and scanning speed to form a composite cladding energy field in conjunction with the cladding laser head 231. The coaxial dual-channel powder feeder 233 adjusts the powder feeding flow rates of the metal base powder in the inner annular channel and the reinforcing phase powder in the outer annular channel according to the control signal. When the molten pool temperature exceeds a preset multiple of the melting point of the matrix material, it automatically reduces the reinforcing phase powder delivery rate. At the same time, the outer inert gas protective layer adjusts the gas pressure according to the temperature gradient signal to form a stable umbrella-shaped gas curtain covering the molten pool.

[0053] In one embodiment, the laser output power includes the output power of the cladding laser head 231 and the output power of the pulsed laser head 232; the laser scanning speed includes the cladding laser scanning speed and the pulsed laser head 232 scanning speed; the execution module 230 includes the cladding laser head 231 and the pulsed laser head 232; the execution module 230 adjusts the repair parameters according to the control signal to perform in-situ composite cladding repair on the component to be repaired, including: The cladding laser head 231 adjusts its output power and cladding laser scanning speed according to the control signal, and outputs the adjusted output power of the cladding laser head 231 based on the adjusted cladding laser scanning speed; The pulsed laser head 232 adjusts its output power and scanning speed according to the control signal, and outputs its adjusted output power based on the adjusted scanning speed.

[0054] The independent parameter adjustment of the dual laser heads ensures precise and controllable core cladding energy of the cladding laser head 231, while the auxiliary energy supplementation of the pulsed laser head 232 makes the molten pool deeper and more concentrated, synergistically improving the metallurgical bonding effect. Based on the logic of adjusting the output power corresponding to the scanning speed, the two avoid the instability of the molten pool caused by the mismatch between power and speed, effectively reducing defects such as cracks and pores. Combined with the low heat input characteristics of ultrafast lasers, the risk of thermal deformation of the substrate is significantly reduced, which is suitable for the repair needs of precision aerospace components and further improves the mechanical properties of the repaired parts and the yield of batch repairs.

[0055] In one embodiment, the powder feeding flow rate includes: the powder feeding flow rate of the first channel 2331 and the powder feeding flow rate of the second channel 2332. The execution module 230 further includes: a coaxial dual-channel powder feeder 233. The execution module 230 adjusts the repair parameters according to the control signal to perform in-situ composite cladding repair on the component to be repaired, and further includes: The coaxial dual-channel powder feeder 233 adjusts the powder feeding flow rate of the first channel 2331 and the powder feeding flow rate of the second channel 2332 according to the control signal, and controls the powder feeding of the first channel 2331 based on the adjusted powder feeding flow rate of the first channel 2331, and controls the powder feeding of the second channel 2332 based on the adjusted powder feeding flow rate of the second channel 2332.

[0056] Dual-channel independent flow regulation avoids the segregation and burn-off problems caused by traditional premixed powders, achieving instantaneous and uniform mixing of metal-based powder and reinforcing phase powder. Combined with the rapid solidification characteristics of ultrafast laser, it forms a non-equilibrium reinforced structure, improving the mechanical properties of the repair layer. The flow regulation is linked with real-time monitoring data such as melt pool temperature and aspect ratio, effectively reducing porosity and crack defects caused by powder supply imbalance.

[0057] The laser in-situ composite cladding control method provided in this application embodiment acquires a molten pool image and a molten pool infrared image of the component to be repaired through the detection module 210, and sends the molten pool image and the molten pool infrared image to the decision module 220; the decision module 220 determines the aspect ratio of the molten pool of the component to be repaired based on the molten pool image; determines the molten pool temperature of the component to be repaired based on the molten pool infrared image; determines a repair control strategy based on a preset control rule base, combined with the molten pool aspect ratio and the molten pool temperature; and sends a control signal to the execution module 230 based on the repair control strategy; the execution module 230 adjusts the repair parameters according to the control signal to perform in-situ composite cladding repair on the component to be repaired. The repair parameters include: laser output power, laser scanning speed, and / or powder flow rate, realizing automated feedback adjustment of repair parameters and improving the repair accuracy of in-situ composite cladding repair.

[0058] Example 2 In addition, please see again Figure 2 , Figure 2 A schematic diagram of a control device 200 for laser in-situ composite cladding provided in an embodiment of this application is shown. The control device 200 for laser in-situ composite cladding includes: a detection module 210, a decision module 220, and an execution module 230. The decision module 220 is electrically connected to the detection module 210 and the execution module 230, respectively. The detection module 210 is used to acquire the molten pool image and the molten pool infrared image of the component to be repaired, and send the molten pool image and the molten pool infrared image to the decision module 220; The decision module 220 is used to determine the aspect ratio of the molten pool of the component to be repaired based on the molten pool image; determine the molten pool temperature of the component to be repaired based on the molten pool infrared image; determine a repair control strategy based on a preset control rule base, combined with the molten pool aspect ratio and the molten pool temperature; and send a control signal to the execution module 230 based on the repair control strategy. The execution module 230 is used to adjust the repair parameters according to the control signal to perform in-situ composite cladding repair on the component to be repaired. The repair parameters include: laser output power, laser scanning speed and / or powder flow rate.

[0059] In this embodiment, the detection module 210 includes a high-speed camera 211 and an infrared detector 212; the decision module 220 includes a signal processing unit and a control unit, wherein the signal processing unit is specifically a programmable logic controller (PLC 221) and the control unit is specifically an industrial computer 222; the execution module 230 includes a cladding laser head 231, a pulsed laser head 232 and a coaxial dual-channel powder feeder 233.

[0060] Please see Figure 3 , Figure 3 This paper shows another structural schematic diagram of the control device 200 for laser in-situ composite cladding provided in an embodiment of this application. Figure 3 The diagram shows the positional relationships between the high-speed camera 211, infrared detector 212, signal processing unit, cladding laser head 231, pulsed laser head 232, coaxial dual-channel powder feeder 233, etc.

[0061] Specifically, a support platform 250 is provided on the upper side of the workbench 240, and the parts to be repaired are placed on the support platform 250. The specific structure of the support platform 250 can be found in [reference needed]. Figure 4 As shown, the support platform 250 includes a ball screw 251 and a screw slider 252. The ball screw 251 is fixed in the bearing seat 253 inside the support platform 250, and one end is electrically connected to the drive motor 254. When the drive motor 254 drives the ball screw 251 to rotate, the screw slider 252, which meshes with the ball screw 251, slides along the direction of the ball screw 251 to fix the part to be repaired placed on the support platform 250. The high-speed camera 211 is set at one end of the support platform 250.

[0062] The PLC 221 and industrial computer 222 are housed inside the workbench 240. Multiple trusses 260 are fixedly connected to the workbench 240 for mounting the cladding laser head 231, pulsed laser head 232, coaxial dual-channel powder feeder 233, and infrared detector 212. The specific structures of the coaxial dual-channel powder feeder 233 and the cladding laser head 231 can be found in [reference needed]. Figure 5 .

[0063] In one embodiment, the decision module 220 includes a signal processing unit; The signal processing unit is used to convert the pixel coordinates of each image feature point in the molten pool image into three-dimensional coordinates in the world coordinate system based on the camera calibration parameters. Each image feature point includes multiple edge feature points. The width of the molten pool is determined based on the three-dimensional coordinates of each edge feature point in the transformed world coordinates. The depth of the molten pool is determined based on the three-dimensional coordinates of each image feature point in the transformed world coordinates. The width-to-depth ratio of the molten pool is determined based on the width of the molten pool and the depth of the molten pool.

[0064] In one embodiment, the signal processing unit is further configured to determine a molten pool temperature matrix based on the molten pool infrared image, wherein each element in the molten pool temperature matrix corresponds to the temperature value of a pixel in the molten pool infrared image. The target temperature matrix is ​​obtained by performing spatial filtering on the molten pool temperature matrix. The maximum value is extracted from the target temperature matrix as the highest temperature of the molten pool. The temperature change rate between adjacent elements in the target temperature matrix is ​​determined using a differential algorithm, and the average value of each temperature change rate is determined as the molten pool temperature gradient of the component to be repaired.

[0065] In one embodiment, the execution module 230 includes: a cladding laser head 231 and a pulsed laser head 232; The cladding laser head 231 is used to adjust the output power and cladding laser scanning speed of the cladding laser head 231 according to the control signal, and output the adjusted output power of the cladding laser head 231 based on the adjusted cladding laser scanning speed; The pulsed laser head 232 is used to adjust the output power and scanning speed of the pulsed laser head 232 according to the control signal, and to output the adjusted output power of the pulsed laser head 232 based on the adjusted scanning speed of the pulsed laser head 232.

[0066] The laser in-situ composite cladding control device 200 provided in this embodiment can realize the laser in-situ composite cladding control method provided in Embodiment 1. To avoid repetition, it will not be described again here.

[0067] In all examples shown and described herein, any specific values ​​should be interpreted as merely exemplary and not as limitations; therefore, other examples of exemplary embodiments may have different values.

[0068] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0069] The above-described embodiments are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A method for controlling laser in-situ composite cladding, characterized in that, A control device for laser in-situ composite cladding, the device comprising: a detection module, a decision module, and an execution module, wherein the decision module is electrically connected to the detection module and the execution module respectively; the method comprising: The detection module acquires the molten pool image and the molten pool infrared image of the component to be repaired, and sends the molten pool image and the molten pool infrared image to the decision module; The decision module determines the aspect ratio of the molten pool to be repaired based on the molten pool image; determines the molten pool temperature of the molten pool to be repaired based on the molten pool infrared image; determines a repair control strategy based on a preset control rule base, combined with the molten pool aspect ratio and the molten pool temperature; and sends a control signal to the execution module based on the repair control strategy. The execution module adjusts the repair parameters according to the control signal to perform in-situ composite cladding repair on the component to be repaired. The repair parameters include: laser output power, laser scanning speed and / or powder flow rate.

2. The control method for laser in-situ composite cladding according to claim 1, characterized in that, The step of determining the aspect ratio of the molten pool of the component to be repaired based on the molten pool image includes: Based on the camera calibration parameters, the pixel coordinates of each image feature point in the molten pool image are converted into three-dimensional coordinates in the world coordinate system. Each image feature point includes: multiple edge feature points. The width of the molten pool is determined based on the three-dimensional coordinates of each edge feature point in the transformed world coordinates. The depth of the molten pool is determined based on the three-dimensional coordinates of each image feature point in the transformed world coordinates. The width-to-depth ratio of the molten pool is determined based on the width of the molten pool and the depth of the molten pool.

3. The control method for laser in-situ composite cladding according to claim 2, characterized in that, The molten pool temperature includes: the highest molten pool temperature and the molten pool temperature gradient. Determining the molten pool temperature of the component to be repaired based on the molten pool infrared image includes: A molten pool temperature matrix is ​​determined based on the infrared image of the molten pool, wherein each element in the molten pool temperature matrix corresponds to the temperature value of a pixel in the infrared image of the molten pool. The target temperature matrix is ​​obtained by performing spatial filtering on the molten pool temperature matrix. The maximum value is extracted from the target temperature matrix and taken as the highest temperature of the molten pool. The temperature change rate between adjacent elements in the target temperature matrix is ​​determined using a differential algorithm, and the average value of each temperature change rate is determined as the molten pool temperature gradient of the component to be repaired.

4. The control method for laser in-situ composite cladding according to claim 3, characterized in that, The preset control rule base includes the following preset rules: If the aspect ratio of the molten pool is less than a first preset threshold, then increase the laser output power or decrease the laser scanning speed; If the aspect ratio of the molten pool is greater than the second preset threshold, then reduce the laser output power or increase the laser scanning speed; If the temperature of the molten pool is greater than the preset melting point, the powder feeding flow rate is reduced. The preset melting point is a preset multiple of the melting point of the matrix material of the component to be repaired. If the temperature of the molten pool exceeds a preset temperature threshold, a shutdown is triggered. If the temperature gradient of the molten pool is greater than the preset gradient value, then the inert gas pressurization is triggered.

5. The control method for laser in-situ composite cladding according to claim 4, characterized in that, The laser output power includes: cladding laser head output power and pulsed laser head output power; the laser scanning speed includes: cladding laser scanning speed and pulsed laser head scanning speed; the execution module includes: cladding laser head and pulsed laser head; the execution module adjusts the repair parameters according to the control signal to perform in-situ composite cladding repair on the component to be repaired, including: The cladding laser head adjusts its output power and scanning speed according to the control signal, and outputs the adjusted output power based on the adjusted scanning speed. The pulsed laser head adjusts its output power and scanning speed according to the control signal, and outputs the adjusted output power based on the adjusted scanning speed.

6. The control method for laser in-situ composite cladding according to claim 5, characterized in that, The powder feeding flow rate includes: a first channel powder feeding flow rate and a second channel powder feeding flow rate. The execution module further includes: a coaxial dual-channel powder feeder. The execution module adjusts the repair parameters according to the control signal to perform in-situ composite cladding repair on the component to be repaired, and further includes: The coaxial dual-channel powder feeder adjusts the powder feeding flow rate of the first channel and the powder feeding flow rate of the second channel according to the control signal, and controls the powder feeding of the first channel based on the adjusted powder feeding flow rate of the first channel, and controls the powder feeding of the second channel based on the adjusted powder feeding flow rate of the second channel.

7. A control device for laser in-situ composite cladding, characterized in that, include: The system comprises a detection module, a decision module, and an execution module, wherein the decision module is electrically connected to both the detection module and the execution module. The detection module is used to acquire the molten pool image and the molten pool infrared image of the component to be repaired, and send the molten pool image and the molten pool infrared image to the decision module; The decision module is used to determine the aspect ratio of the molten pool of the component to be repaired based on the molten pool image; determine the molten pool temperature of the component to be repaired based on the molten pool infrared image; determine a repair control strategy based on a preset control rule base, combined with the molten pool aspect ratio and the molten pool temperature; and send a control signal to the execution module based on the repair control strategy. The execution module is used to adjust the repair parameters according to the control signal to perform in-situ composite cladding repair on the component to be repaired. The repair parameters include: laser output power, laser scanning speed and / or powder flow rate.

8. The control device for laser in-situ composite cladding according to claim 7, characterized in that, The decision-making module includes a signal processing unit; The signal processing unit is used to convert the pixel coordinates of each image feature point in the molten pool image into three-dimensional coordinates in the world coordinate system based on the camera calibration parameters. Each image feature point includes multiple edge feature points. The width of the molten pool is determined based on the three-dimensional coordinates of each edge feature point in the transformed world coordinates. The depth of the molten pool is determined based on the three-dimensional coordinates of each image feature point in the transformed world coordinates. The width-to-depth ratio of the molten pool is determined based on the width of the molten pool and the depth of the molten pool.

9. The control device for laser in-situ composite cladding according to claim 8, characterized in that, The signal processing unit is further configured to determine a molten pool temperature matrix based on the molten pool infrared image, wherein each element in the molten pool temperature matrix corresponds to the temperature value of a pixel in the molten pool infrared image. The target temperature matrix is ​​obtained by performing spatial filtering on the molten pool temperature matrix. The maximum value is extracted from the target temperature matrix as the highest temperature of the molten pool. The temperature change rate between adjacent elements in the target temperature matrix is ​​determined using a differential algorithm, and the average value of each temperature change rate is determined as the molten pool temperature gradient of the component to be repaired.

10. The control device for laser in-situ composite cladding according to claim 9, characterized in that, The execution module includes: a cladding laser head and a pulsed laser head; The cladding laser head is used to adjust the output power and scanning speed of the cladding laser head according to the control signal, and to output the adjusted output power of the cladding laser head based on the adjusted scanning speed of the cladding laser head; The pulsed laser head is used to adjust the output power and scanning speed of the pulsed laser head according to the control signal, and to output the adjusted output power of the pulsed laser head based on the adjusted scanning speed.

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