A method and system for laser additive data processing of rail defects

Abstract

This application provides a method and system for processing laser additive manufacturing data for rail defects, relating to the field of laser additive repair technology for rail defects. It analyzes the velocity variation curve of the laser head along the predicted motion path and generates laser power adjustment commands by combining the velocity-power function. During the execution of the laser head movement, the actual instantaneous velocity corresponding to a specific motion command point is acquired in real time, and the laser output power is adjusted synchronously, effectively compensating for the deviation between the actual and predicted motion, ensuring the uniformity and stability of laser energy input. Compared with existing technologies, this method can pre-plan a more reasonable laser power adjustment strategy, avoiding blindness in the repair process; it effectively compensates for the influence of the dynamic characteristics of mechanical motion on energy input, ensuring the uniformity and stability of laser energy input. The overall solution can significantly reduce structural defects within the repair layer, improving repair quality and reliability.

Description

Technical Field

[0001] This application relates to the field of laser additive repair technology for rail defects, and more specifically, to a method and system for processing laser additive data on rail defects. Background Technology

[0002] In the field of modern rail maintenance, laser additive repair technology is widely used to repair surface defects in rails to extend their service life and ensure operational safety. The core of this type of repair system lies in its data processing software, which is responsible for converting the acquired three-dimensional information of the defects into executable motion trajectories and process parameters for the laser additive equipment. However, in practical applications, due to material properties, equipment kinematic limitations, and shortcomings in existing data processing logic, hidden structural defects may form within the repair layer, thus affecting the long-term reliability of the repair.

[0003] Specifically, in modern laser additive manufacturing systems for rail defects, the core data processing software plays a crucial role. It is responsible for converting the acquired 3D defect data into motion trajectories and process parameters that the laser additive manufacturing equipment can execute. To ensure repair efficiency, the "laser filling path generation logic" of such software typically prioritizes processing speed from the outset. Therefore, a common and computationally efficient strategy is to employ a "reciprocating grating" filling path, where the laser head scans back and forth across the area to be repaired in a zigzag pattern. The advantages of this path are its simple geometry, ease of algorithm implementation, and ability to quickly cover large areas, thus shortening the overall repair time. Complementing this path strategy is a standard "correlation function between laser power and scanning speed." This function is based on an ideal state, assuming that laser energy can be uniformly applied to the material surface and that the powder supply is stable and uniform. It binds the laser output power to the scanning speed through a pre-defined mathematical relationship, aiming to maintain a relatively constant energy density input throughout the repair process. However, when the equipment begins executing the pre-defined "reciprocating grating" filling path, an inherent physical limitation presents new challenges. At the edges of the filling area, when the laser head needs to make a 180-degree turn to change the scanning direction, the motion control system cannot achieve instantaneous turning. It must instruct the laser head to "decelerate to zero, reverse, and then accelerate" to complete this action. This deceleration-stop-acceleration process causes the laser spot to remain on these corner points for a significantly longer time. However, the standard power function design in current data processing software is not fully correlated with the motion state; it does not correspondingly and significantly reduce the output power when the laser head decelerates. This means that at these corners, the laser still outputs power at the same rate as during uniform scanning, but the spot remains on the local area for a longer time, resulting in a sudden surge in energy input per unit area.

[0004] The combined effect of "power not adjusted in time" and "long-term stagnation of the light spot" at the corner point creates a local "heat spike." This energy spike not only causes the substrate to be over-melted in that area, but more importantly, it instantly vaporizes the "fine particles" that are located on the periphery of the powder beam and are more sensitive to heat due to their fine size. These particles, due to their large surface area, would normally melt and integrate into the molten pool under normal power, but under the influence of this energy spike, they rapidly reach their vaporization temperature, directly transforming into metal vapor and forming tiny bubbles inside the molten pool. As the molten pool rapidly solidifies, these tiny bubbles formed at the heat spike are "frozen" inside the repair layer. Due to the regularity of the "reciprocating grating" path, these bubbles are regularly distributed along all the "corners" of the filling path, forming linear "microscopic loose bands." From the outside of the repaired rail, its surface is smooth and its dimensions are precise; no visible flaws can be detected by the naked eye or conventional surface inspection methods. However, the repaired area actually contains structural "weak ribs" due to the regularly distributed micropores. During the long-term service of the rail, these weak ribs will become the starting points of stress concentration under the repeated action of train loads, significantly reducing the fatigue resistance of the repaired area and thus creating potential failure risks.

[0005] Therefore, providing a laser additive data processing method and system for rail defects to solve the above problems is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this application provides a method and system for processing laser additive data on rail defects. The aim is to solve the problem that, due to material properties, equipment kinematic limitations, and deficiencies in existing data processing logic, hidden structural defects may form inside the repair layer, thus affecting the long-term reliability of the repair.

[0007] Based on the above objectives, the technical solution provided in this application is as follows:

[0008] In a first aspect, this application discloses a method for processing laser additive manufacturing data of rail defects, applied to the laser additive repair of rail defects, comprising the following steps:

[0009] Acquire the three-dimensional geometric data of the target rail defect, and generate the motion trajectory command of the laser head according to the preset strategy;

[0010] Analyze the motion trajectory command to generate the velocity change curve of the laser head on the predicted motion path;

[0011] Based on the velocity change curve and velocity power function along the predicted motion path, the laser power adjustment command is obtained;

[0012] During the movement of the laser head, it receives motion trajectory instructions and laser power adjustment instructions, obtains the actual instantaneous speed corresponding to a specific motion instruction point based on the motion trajectory instructions, and adjusts the laser output power synchronously.

[0013] This technical solution enables the synchronous adjustment of the laser head movement speed and laser power, effectively preventing the formation of hidden structural defects inside the repair layer, thereby improving the long-term reliability of the repair.

[0014] Furthermore, in this laser additive data processing method for rail defects, the velocity power function is obtained based on the following steps:

[0015] Design laser heads to scan target rail defects at various first scanning speeds;

[0016] Metallographic analysis was performed on the defects in the target rail.

[0017] Based on the metallographic analysis results, the first ideal power corresponding to each first scanning speed is determined, and the first scanning speed and the first ideal power are fitted to obtain the speed power function.

[0018] This technical solution allows for the fitting of experimental data to obtain a velocity-power function, providing a data basis for precise adjustment of subsequent laser power and thus improving repair quality.

[0019] Based on the above, this application further proposes to obtain laser power adjustment commands based on the velocity change curve and velocity power function on the predicted motion path, including the following steps:

[0020] Based on the velocity change curve, obtain the first instantaneous velocity corresponding to each motion command point on the predicted motion path;

[0021] Based on the first instantaneous velocity and the velocity power function, obtain the first power corresponding to each motion command point;

[0022] By integrating the first power corresponding to all motion command points in chronological order, a laser power adjustment command is generated.

[0023] This technical solution enables the dynamic calculation and generation of laser power adjustment commands based on speed changes along the predicted path, ensuring precise delivery of laser energy and further improving the repair effect.

[0024] In some preferred embodiments, in this laser additive data processing method for rail defects, specific motion command points are obtained based on the following steps:

[0025] Based on the velocity change curve, obtain the first instantaneous velocity corresponding to each motion command point on the predicted motion path;

[0026] Calculate the first and second derivatives of the velocity at the first instant corresponding to each motion command point;

[0027] Determine the extreme points based on the first derivative;

[0028] The first determination is whether the second derivative has opposite signs on both sides at the extreme point;

[0029] If the first judgment result is yes, it is defined as a specific motion command point.

[0030] This technical solution enables the precise identification of key motion command points through mathematical analysis of the velocity change curve, providing a more accurate reference point for subsequent synchronous adjustment of laser power, thereby improving the response speed and accuracy of the adjustment.

[0031] As an optional approach, after obtaining the velocity power function, the following steps are also included:

[0032] Design laser heads to scan target rail defects at various second scanning speeds;

[0033] Metallographic analysis was performed on the defects in the target rail.

[0034] Based on the metallographic analysis results, the second ideal power corresponding to each second scanning speed was determined;

[0035] The second optical radiation intensity obtained under different combinations of second scanning speed and second ideal power is analyzed and fitted to establish an optical radiation reference function to compensate for the first power.

[0036] This technical solution enables the establishment of a light radiation reference function, introducing light radiation intensity as a compensation factor, further optimizing the adjustment of laser power, and improving the stability and consistency of the repair process.

[0037] To enhance functionality, after obtaining the first power corresponding to each motion command point based on the first instantaneous velocity and the velocity power function, the following steps are also included:

[0038] The first light radiation intensity is obtained based on the first instantaneous velocity and the first power.

[0039] The optical radiation residual value is obtained based on the optical radiation reference function and the preprocessed first optical radiation intensity.

[0040] Based on the optical radiation residual value and the preset historical residual accumulation, the power compensation value is obtained to compensate for the first power.

[0041] This technical solution enables the dynamic calculation of power compensation values ​​using optical radiation residual values ​​and historical residual accumulation, achieving real-time and precise adjustment of laser power, effectively addressing uncertainties in the actual repair process, and further improving repair quality.

[0042] To improve the solution, after obtaining the power compensation value based on the optical radiation residual value and the preset historical residual accumulation to compensate for the first power, the following steps are also included:

[0043] Based on the first power and the power compensation value, obtain the compensated first power;

[0044] By integrating the compensated first power corresponding to all motion command points in chronological order, a new laser power adjustment command is generated to update the laser power adjustment command.

[0045] This technical solution allows the calculated power compensation value to be applied to the original power, generating more precise laser power adjustment commands, ensuring the accuracy of laser energy delivery, and thus achieving a more ideal repair effect.

[0046] In practical applications, the laser head movement process also includes the following steps:

[0047] When the laser head moves a unit distance, the corresponding digital pulse signal is obtained by the grating encoder installed on the laser head's motion axis and input to the controller;

[0048] During the movement of the laser head, the controller controls the laser to deliver energy based on the digital pulse signal corresponding to each unit distance and the currently synchronized laser output power, so as to ensure that the energy density delivered within the unit distance is consistent with the expected laser power adjustment command.

[0049] This technical solution enables real-time monitoring of the laser head's movement distance via a grating encoder, combined with the synchronously adjusted laser output power, to achieve precise laser energy delivery, ensuring uniform energy density during the repair process and effectively preventing overheating or underheating.

[0050] Secondly, this application also discloses a laser additive data processing system for rail defects, applied to the laser additive repair of rail defects, including:

[0051] The motion trajectory instruction module is used to acquire the three-dimensional geometric data of the target rail defect and generate the motion trajectory instruction of the laser head according to the preset strategy.

[0052] The velocity change curve module is used to analyze motion trajectory commands and generate velocity change curves of the laser head along the predicted motion path.

[0053] The laser power adjustment command module is used to obtain laser power adjustment commands based on the velocity change curve and velocity power function on the predicted motion path.

[0054] The power adjustment module is used to receive motion trajectory commands and laser power adjustment commands during the movement of the laser head, obtain the actual instantaneous speed corresponding to a specific motion command point based on the motion trajectory command, and synchronously adjust the laser output power.

[0055] This technical solution provides a system for implementing the aforementioned laser additive data processing method for rail defects. This system can work collaboratively to achieve synchronous adjustment of the laser head movement speed and laser power, effectively solving the problem of internal structural defects in the repair layer in the prior art and improving the long-term reliability of the repair.

[0056] Preferably, it further includes:

[0057] An optical encoder, mounted on the laser head's motion axis, is used to acquire the corresponding digital pulse signal every time the laser head moves a unit distance.

[0058] A controller is configured to control the energy delivery of the laser during laser head movement, based on the digital pulse signal corresponding to each unit distance and the currently synchronized laser output power, to ensure that the energy density delivered per unit distance is consistent with the expected laser power adjustment command.

[0059] This technical solution introduces spatial domain closed-loop control based on physical displacement, irrefutably achieving theoretical energy uniformity on real machined parts. It compensates for all underlying errors and external disturbances, ultimately translating the technical advantages directly into a significant improvement in the microstructure and macroscopic performance of the repair layer, thereby greatly enhancing the reliability, accuracy, and industrial applicability of the entire technical solution.

[0060] This application discloses a laser additive data processing method for rail defects. It acquires the three-dimensional geometric data of the target rail defect and generates a motion trajectory command for the laser head, then analyzes the velocity variation curve generated by this command. Based on this, a laser power adjustment command is obtained according to the velocity variation curve and the velocity power function. During the laser head movement, this method can receive the motion trajectory command and the laser power adjustment command, and obtain the actual instantaneous velocity corresponding to a specific motion command point based on the motion trajectory command, synchronously adjusting the laser output power. This method effectively solves the problem of internal structural defects in the repair layer caused by material properties, equipment kinematic limitations, and insufficient existing data processing logic in the laser additive repair process of existing technologies. By synchronously adjusting the laser head's motion speed and the laser's output power in real time, this application can ensure uniform laser energy distribution throughout the entire repair path, avoiding local overheating or insufficient energy, thereby significantly improving the quality and uniformity of the repair layer, effectively extending the service life of the rail, and enhancing operational safety. Attached Figure Description

[0061] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0062] Figure 1 A schematic flowchart illustrating a laser additive data processing method for rail defects provided in this application embodiment;

[0063] Figure 2 A flowchart for obtaining the speed power function provided in an embodiment of this application;

[0064] Figure 3 A flowchart of step S3 provided in the embodiments of this application;

[0065] Figure 4 A flowchart for obtaining a specific motion command point provided in an embodiment of this application;

[0066] Figure 5 A flowchart illustrating the laser head movement process provided in this application embodiment;

[0067] Figure 6 This is a schematic diagram of a laser additive data processing system for rail defects provided in an embodiment of this application. Detailed Implementation

[0068] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0069] The embodiments in this application are written in a progressive manner.

[0070] In the field of modern rail maintenance, laser additive repair technology is widely used to repair surface defects in rails to extend their service life and ensure operational safety. The core of this type of repair system lies in its data processing software, which is responsible for converting the acquired three-dimensional information of the defects into executable motion trajectories and process parameters for the laser additive equipment. However, in practical applications, due to material properties, equipment kinematic limitations, and shortcomings in existing data processing logic, hidden structural defects may form within the repair layer, thus affecting the long-term reliability of the repair.

[0071] like Figure 1 As shown, based on this, a method for processing laser additive manufacturing data of rail defects is provided, which is applied to the laser additive repair of rail defects, and includes the following steps:

[0072] S1. Acquire the three-dimensional geometric data of the target rail defect, and generate the motion trajectory command of the laser head according to the preset strategy;

[0073] S2. Analyze the motion trajectory command and generate the velocity change curve of the laser head on the predicted motion path;

[0074] S3. Based on the velocity change curve and velocity power function on the predicted motion path, obtain the laser power adjustment command;

[0075] S4. During the laser head movement, receive motion trajectory instructions and laser power adjustment instructions, obtain the actual instantaneous speed corresponding to a specific motion instruction point based on the motion trajectory instructions, and synchronously adjust the laser output power.

[0076] Rail defects, as defined in laser additive data processing methods for rail defects, refer to various damages existing on or inside the rail surface, such as wear, cracks, and spalling. These defects affect the normal use of the rail and traffic safety. Laser additive repair is a technology that uses a laser as a heat source to melt and deposit metal powder layer by layer to repair or rebuild damaged components. This technology has advantages such as high repair precision, small heat-affected zone, and high material utilization.

[0077] Step S1, acquiring the three-dimensional geometric data of the target rail defect, can be achieved in various ways. For example, a 3D scanner can be used to scan the rail defect area, generating point cloud data, and then data processing software can be used to reconstruct the three-dimensional geometric model of the defect. Another method is to use industrial CT (computed tomography) technology to perform non-destructive testing on the rail defect and obtain its internal three-dimensional information. Furthermore, high-precision three-dimensional data of the defect surface can be obtained using laser rangefinders or structured light projection technology. Preset strategies can be set according to factors such as the type, size, depth of the defect, and the characteristics of the repair material. For example, for linear defects, the laser head can be set to scan in a straight line along the defect direction; for planar defects, the laser head can be set to perform reciprocating or spiral scanning. Motion trajectory instructions typically include a series of coordinate points of the laser head in three-dimensional space and the velocity information of each point. These instructions can be pre-programmed G-code or similar numerical control instructions used to directly control the motion system of the laser additive manufacturing equipment.

[0078] Step S2, analyzing the motion trajectory command and generating the velocity change curve of the laser head along the predicted motion path, refers to the fact that in actual laser additive manufacturing, the laser head's velocity is not constant, especially at corners or acceleration / deceleration phases, where significant velocity changes occur. Therefore, it is necessary to parse the preset motion trajectory command and calculate the instantaneous velocity of the laser head at each point along the entire predicted motion path, thus obtaining a continuous velocity change curve. This can be accurately calculated using kinematic models or simulation software.

[0079] The velocity-power function in step S3 describes the relationship between the laser head's movement speed and the required laser power. This function can be obtained through experimental calibration or theoretical modeling. For example, when the laser head moves at a high speed, the laser power may need to be increased to ensure sufficient energy input; conversely, when the speed is slow, the power may need to be reduced to avoid overheating. By substituting the predicted velocity change curve into the velocity-power function, the ideal laser power at each point along the entire movement path can be calculated, thereby generating laser power adjustment commands. These commands are typically in the form of time series or position series and are used to control the laser's output power in real time.

[0080] In step S4, during the laser head movement process, motion trajectory commands and laser power adjustment commands are received. The actual instantaneous speed corresponding to a specific motion command point is obtained based on the motion trajectory command. Synchronously adjusting the laser output power is necessary because, during the actual movement of the laser head, due to factors such as mechanical inertia and friction, its actual speed may deviate from the preset predicted speed. Therefore, it is necessary to monitor the actual instantaneous speed of the laser head in real time. For example, real-time position and speed information can be obtained through an encoder or displacement sensor installed on the laser head's motion axis. When a deviation between the actual instantaneous speed and the predicted speed is detected, the system synchronously adjusts the laser output power according to the pre-generated laser power adjustment command to ensure that the energy density of the laser energy input to the rail defect area remains stable at different speeds, thereby avoiding defects in the repair layer caused by uneven energy input.

[0081] Steps S1 to S4 involve analyzing the velocity change curve of the laser head along the predicted motion path and generating laser power adjustment commands based on the velocity-power function, thus achieving precise control of the laser energy input. During the laser head movement, the actual instantaneous velocity corresponding to a specific motion command point is acquired in real time, and the laser output power is adjusted synchronously to effectively compensate for the deviation between the actual and predicted motion, ensuring the uniformity and stability of the laser energy input.

[0082] Compared to traditional constant power or simple empirical adjustment methods, this application has the following advantages: First, by analyzing the velocity change curve along the predicted motion path, a more reasonable laser power adjustment strategy can be planned in advance, avoiding blindness in the repair process; second, during actual execution, by acquiring the actual instantaneous velocity of the laser head in real time and adjusting the laser power synchronously, the influence of the dynamic characteristics of mechanical motion on energy input is effectively compensated, ensuring the uniformity and stability of laser energy input. This refined control method can significantly reduce structural defects within the repair layer, improving repair quality and reliability.

[0083] like Figure 2 As shown, further, in this laser additive data processing method for rail defects, the velocity power function is obtained based on the following steps:

[0084] A1. Design a laser head to scan target rail defects at various first scanning speeds;

[0085] A2. Perform metallographic analysis on the defects in the target rail;

[0086] A3. Based on the metallographic analysis results, determine the first ideal power corresponding to each first scanning speed, fit the first scanning speed and the first ideal power, and obtain the speed power function.

[0087] Step A1, which involves designing laser head scanning of the target rail defect at various first scanning speeds, refers to experimentally scanning the target rail defect at different laser head scanning speeds before actual additive repair. The first scanning speed can be understood as the movement speed of the laser head relative to the rail defect during the scanning process. Its purpose is to simulate various speed conditions that may be encountered during the actual repair process, thereby obtaining experimental data on the material response at different speeds.

[0088] The metallographic analysis of the target rail defect in step A2 refers to the microstructural analysis of the defective area of ​​the rail repaired by laser additive manufacturing after completing scanning experiments at different speeds. Metallographic analysis typically involves grinding, polishing, and etching the cross-section of the repaired area, followed by observation of its microstructure, grain size, and defect distribution (such as porosity and cracks) using an optical microscope or scanning electron microscope. Its purpose is to evaluate the metallurgical quality and defect status of the additive layer under different scanning speeds and power combinations, providing an objective basis for subsequently determining the ideal power.

[0089] Step A3, determining the first ideal power corresponding to each first scanning speed based on the metallographic analysis results, refers to judging which power can achieve the best repair effect at a specific first scanning speed based on the additive layer quality revealed by the metallographic analysis, such as density, hardness, and grain structure. The first ideal power is the laser output power that enables the additive layer to achieve a preset quality standard (e.g., no obvious pores or cracks, and uniform and dense structure). Fitting the first scanning speed and the first ideal power to obtain the speed-power function refers to performing curve fitting on the various first scanning speeds and their corresponding first ideal power data points obtained in the experiment using mathematical methods. The fitting process can use various mathematical models such as linear regression, polynomial fitting, and exponential fitting to establish a function that can describe the relationship between speed and ideal power. This speed-power function will serve as an important basis for the subsequent generation of laser power adjustment commands, ensuring that the laser power can be adjusted in real time and accurately when the laser head movement speed changes, so as to maintain stable additive quality.

[0090] Steps A1 to A3 detail the specific implementation of obtaining the velocity-power function, which is systematically acquired through experimental design, metallographic analysis, and data fitting. Specifically, by designing laser heads to scan the target rail defects at various first scanning speeds, the system comprehensively covers all possible speed conditions during laser additive repair, thereby obtaining raw data on the material response at different speeds. Subsequently, metallographic analysis of the target rail defects allows for an objective assessment of the repair quality under different scanning parameters at a microscopic level, thus accurately determining the first ideal power corresponding to each first scanning speed. It is precisely this rigorous method based on actual experiments and microscopic analysis that ensures the obtained velocity-power function accurately reflects the intrinsic relationship between speed and ideal power, providing a reliable basis for subsequent precise adjustment of laser power.

[0091] In some preferred embodiments, a specific example is given below. Suppose that when obtaining the velocity-power function, the following experiment can be designed: First, set multiple first scanning speeds for the laser head to perform additive scanning on the target rail defect, for example, 5 mm / s, 10 mm / s, 15 mm / s, and 20 mm / s. For each first scanning speed, try different laser powers through multiple experiments, and perform metallographic analysis on the additive region after each experiment. For example, at a first scanning speed of 10 mm / s, metallographic analysis reveals that when the laser power is 1500 watts, the additive layer structure is dense, without obvious pores and cracks, and the grains are fine and uniform; this is determined to be the first ideal power at this speed. Similarly, the first ideal power at other speeds can be determined. For example, 5 mm / s corresponds to 1200 watts, 15 mm / s corresponds to 1800 watts, and 20 mm / s corresponds to 2200 watts. Finally, the data points (5, 1200), (10, 1500), (15, 1800), and (20, 2200) of these velocities and ideal power are input into data processing software. Using methods such as polynomial fitting or linear regression, a mathematical function describing the relationship between velocity and ideal power—the velocity-power function—is obtained. For example, this function might be expressed as P = aV + b, where P is the laser power, V is the scanning velocity, and a and b are fitting coefficients. This function will be used for subsequent real-time adjustment of the laser power.

[0092] like Figure 3 As shown above, this application further proposes to obtain laser power adjustment commands based on the velocity change curve and velocity power function on the predicted motion path, including the following steps:

[0093] B1. Based on the velocity change curve, obtain the first instantaneous velocity corresponding to each motion command point on the predicted motion path;

[0094] B2. Based on the first instantaneous velocity and the velocity power function, obtain the first power corresponding to each motion command point;

[0095] B3. Integrate the first power corresponding to all motion command points in chronological order to generate laser power adjustment commands.

[0096] The velocity change curve in step B1 can be understood as a function or data set showing the change in the laser head's velocity with time or position along a predetermined motion path. This curve reflects the expected velocity of the laser head at different points during the repair process. Motion command points are discretized points on the laser head's trajectory; each point corresponds to a specific position and time and can be associated with an instantaneous velocity. The first instantaneous velocity refers to the instantaneous velocity value of the laser head at each specific motion command point along the predicted motion path.

[0097] The velocity power function in step B2 describes the relationship between the laser scanning speed and the required laser power. It is usually obtained through experimental calibration and data fitting to ensure that the ideal additive manufacturing effect can be obtained at different scanning speeds. The first power refers to the laser output power required at that instantaneous speed, obtained by consulting or calculating the velocity power function based on the first instantaneous speed of the laser head at a specific motion command point.

[0098] The laser power adjustment command in step B3 is a series of commands formed by integrating the first power corresponding to all motion command points in chronological order. It is used to control the output power of the laser in real time during the actual movement of the laser head so that it matches the instantaneous speed of the laser head.

[0099] Steps B1 to B3 detail the implementation of step S3, refining the generation process of laser power adjustment commands to ensure the accuracy of power output during laser additive repair. Specifically, firstly, by analyzing the velocity change curve of the laser head along the predicted motion path, the first instantaneous velocity at each motion command point can be obtained. Since the quality of laser additive repair is closely related to laser energy density, which is affected by both laser power and scanning speed, the laser power needs to be adjusted accordingly to maintain stable energy input when the laser head speed changes. Secondly, using a pre-acquired velocity-power function, the required first power can be accurately calculated based on the first instantaneous velocity at each motion command point. This velocity-power function is fitted based on a large amount of experimental data and reflects the optimal power required to achieve the ideal additive effect at different scanning speeds. Finally, these calculated first power values ​​are integrated in chronological order to form a complete laser power adjustment command. These commands are executed in real time when the laser head actually moves, thus achieving dynamic matching between laser power and the instantaneous velocity of the laser head. This refined power adjustment mechanism effectively avoids uneven energy density caused by speed variations, thereby improving the quality and stability of additive repair. This effectively solves the problem of unstable additive quality caused by the mismatch between laser power and scanning speed in traditional methods. Therefore, it ensures that the laser energy density remains within the optimal range throughout the entire repair process, significantly improving the quality, uniformity, and reliability of laser additive repair of rail defects, reducing the need for secondary processing after defect repair, and extending the service life of the repaired components.

[0100] like Figure 4 As shown, in some preferred embodiments, in this laser additive data processing method for rail defects, specific motion command points are obtained based on the following steps:

[0101] C1. Based on the velocity change curve, obtain the first instantaneous velocity corresponding to each motion command point on the predicted motion path;

[0102] C2. Calculate the first and second derivatives of the velocity at the first instant corresponding to each motion command point;

[0103] C3. Determine the extreme points based on the first derivative;

[0104] C4. First, determine whether the second derivative has opposite signs on both sides at the extreme point;

[0105] C5. If the first judgment result is yes, it is defined as a specific motion command point.

[0106] Specifically, a specific motion command point refers to a key point on the laser head's motion path where the velocity change trend changes significantly. These points typically correspond to the laser head's position during operations such as acceleration, deceleration, or turning. The first instantaneous velocity refers to the instantaneous velocity value of the laser head at each motion command point on the predicted motion path. By acquiring these instantaneous velocities, the motion state of the laser head can be quantitatively described.

[0107] Step C2, which calculates the first and second derivatives of the velocity at the first instant, aims to analyze the rate and trend of velocity change. The first derivative reflects how fast the velocity changes, i.e., the acceleration; the second derivative reflects how fast the acceleration changes, i.e., the inflection point of the velocity change trend.

[0108] Step C3, determining the extreme points based on the first derivative, means identifying the points where the velocity reaches a local maximum or minimum. These extreme points are key turning points in the velocity change;

[0109] Step C4 involves determining whether the second derivative has opposite signs on both sides of the extreme point. This determination is used to further confirm whether the extreme point is a true inflection point, i.e., the point where the velocity change trend changes. For example, when the second derivative changes from positive to negative or from negative to positive on both sides of the extreme point, it indicates that the point is an inflection point of the rate of velocity change, and the motion state of the laser head has undergone a fundamental change at this point.

[0110] If the first judgment result in step C5 is yes, then that point is defined as a specific motion command point. This allows for the precise identification of key control points of the laser head on complex motion paths.

[0111] Steps C1 to C5 detail the specific implementation of obtaining specific motion command points. This involves in-depth analysis of the laser head's velocity change curve along the predicted motion path, particularly utilizing the first and second derivatives to identify these specific motion command points. This solves the problem of accurately capturing key velocity change points during high-speed or complex laser head movements. Furthermore, calculating the first derivative of the initial instantaneous velocity reveals the velocity's increasing or decreasing trend, while the second derivative reveals the inflection point of the velocity change rate. When the second derivative shows opposite signs on both sides of an extreme point, it indicates a true turning point in the velocity change trend, such as a change from acceleration to deceleration, or from a convex curve to a concave curve. These points are crucial locations where the laser head's motion state undergoes significant changes. Accurate identification of these points provides a more precise basis for subsequent synchronous adjustment of laser power. This ensures a closer match between laser power and actual instantaneous velocity during laser head movement, especially in regions of drastic velocity changes, thereby guaranteeing the uniformity and quality of additive repair.

[0112] In actual laser additive repair processes, due to various factors such as batch-to-batch material differences, ambient temperature fluctuations, and laser performance degradation, relying solely on a pre-fitted velocity-power function may not fully guarantee the accuracy and stability of laser power, potentially leading to inconsistencies or defects in the additive repair quality. Failure to address these issues could affect the metallurgical quality, bonding strength, and final repair outcome of the repair layer.

[0113] Based on this, as an optional solution, after obtaining the velocity power function, the following steps are also included:

[0114] Design laser heads to scan target rail defects at various second scanning speeds;

[0115] Metallographic analysis was performed on the defects in the target rail.

[0116] Based on the metallographic analysis results, the second ideal power corresponding to each second scanning speed was determined;

[0117] The second optical radiation intensity obtained under different combinations of second scanning speed and second ideal power is analyzed and fitted to establish an optical radiation reference function to compensate for the first power.

[0118] The design of laser head scanning targets for rail defects at various second scanning speeds involves conducting additional experiments after obtaining the initial velocity power function to further optimize power control. These experiments involve setting a second scanning speed, different from the first scanning speed used to obtain the velocity power function, to allow the laser head to scan the target rail defects. The second scanning speed can be a series of preset speed values ​​designed to cover the speed range that may be encountered during actual repair, in order to obtain more comprehensive data. Metallographic analysis of the target rail defects involves a detailed inspection and evaluation of the microstructure of the additive repair area after completing laser scanning at different second scanning speeds. Metallographic analysis typically includes grinding, polishing, and etching the repair layer cross-section, and observing its morphology, grain size, and defects (such as pores and cracks) under a metallographic microscope to determine the repair quality. Determining the second ideal power corresponding to each second scanning speed based on the metallographic analysis results means deriving the laser power value that achieves the best repair effect at a specific second scanning speed, i.e., the second ideal power, based on the repair quality revealed by the metallographic analysis. This process may involve multiple iterative experiments and analyses to precisely pinpoint the ideal power point. Analyzing and fitting the second optical radiation intensity obtained under different combinations of second scanning speeds and second ideal powers to establish an optical radiation reference function means that after determining the second ideal power, it is necessary to simultaneously measure the second optical radiation intensity generated by the laser when outputting these second ideal powers. Optical radiation intensity is a direct physical manifestation of the laser's output power and can be monitored in real time using devices such as photodetectors. By collecting data on different second scanning speeds, second ideal powers, and their corresponding second optical radiation intensities, data analysis and mathematical fitting are performed to establish an optical radiation reference function that reflects the relationship between laser power and actual optical radiation intensity. This function can be used for subsequent power compensation to ensure consistency between the actual output power and the desired power. Its purpose is to compensate for the first power by using the established optical radiation reference function to correct the first power previously calculated based on the speed-power function. This compensation mechanism can correct power deviations caused by various uncertainties, making the laser energy actually applied to the rail defects more accurate, thereby improving the quality and stability of additive repair.

[0119] The above steps detail the implementation after obtaining the velocity-power function. This is achieved by introducing additional experimental steps: designing laser heads to scan the target rail defects at various second scanning speeds and determining the second ideal power using metallographic analysis. This yields actual ideal power data under different operating conditions. Based on this, a light radiation benchmark function is established by analyzing and fitting the second light radiation intensity obtained under these second ideal powers. This benchmark function more accurately reflects the output characteristics of the laser under actual operating conditions, including potential nonlinearities, drift, or deviations influenced by the environment. Because this benchmark function based on actual light radiation intensity is established, it can be used to compensate for the initial power calculated from the velocity-power function. This compensation mechanism effectively corrects the actual deviation of the laser output power, ensuring that the laser energy applied to the rail defects during laser additive repair more closely matches the expected ideal energy. This overcomes the limitations of relying solely on a preset velocity-power function and significantly improves the accuracy and robustness of laser power control during laser additive repair of rail defects.

[0120] In some preferred embodiments, a specific example is given below. Assuming that after obtaining the initial velocity-power function, a series of second scanning speeds, such as 50 mm / s, 60 mm / s, and 70 mm / s, can be designed to further refine power control. At each second scanning speed, the corresponding second ideal power is determined through multiple experiments combined with metallographic analysis; for example, at 50 mm / s, the second ideal power is 1000 W; at 60 mm / s, it is 1200 W; and at 70 mm / s, it is 1400 W. While the laser outputs these second ideal powers, the corresponding second optical radiation intensity is measured in real time using a high-precision photodetector. For example, at 1000 W power, the measured optical radiation intensity is X units; at 1200 W power, it is Y units; and at 1400 W power, it is Z units. After collecting these data points, the relationship between the second scanning speed, the second ideal power, and the second optical radiation intensity can be fitted into an optical radiation reference function, such as a polynomial or exponential function, using the least squares method or other fitting algorithms. When the first power corresponding to a certain motion command point is subsequently calculated based on the speed-power function, for example, 1100W, a compensation value can be calculated using this optical radiation reference function and the actual optical radiation intensity of the current laser. This corrects the 1100W first power, making it closer to the actual required precise power and ensuring repair quality.

[0121] In actual laser additive repair processes, slight fluctuations in material properties, laser status, or environmental factors can lead to deviations between the actual optical radiation intensity and the ideal state, even with power adjustments based on preset velocity-power functions and optical radiation reference functions. This can affect the quality and stability of the additive repair. Failure to address these issues may result in weak bonding between the additive layer and the substrate, uneven microstructure, or other defects.

[0122] To enhance functionality, after obtaining the first power corresponding to each motion command point based on the first instantaneous velocity and the velocity power function, the following steps are also included:

[0123] The first light radiation intensity is obtained based on the first instantaneous velocity and the first power.

[0124] The optical radiation residual value is obtained based on the optical radiation reference function and the preprocessed first optical radiation intensity.

[0125] Based on the optical radiation residual value and the preset historical residual accumulation, the power compensation value is obtained to compensate for the first power.

[0126] Specifically, obtaining the first optical radiation intensity based on the first instantaneous velocity and the first power means that, during the movement of the laser head, the actual optical radiation intensity emitted by the laser at the current instantaneous velocity and the calculated first power is measured in real time by an optical radiation sensor (e.g., a photodiode or a spectrometer) installed on or near the laser head. The measured value represents the actual energy density acting on the workpiece, and its purpose is to obtain real-time feedback information of the laser output. Obtaining the optical radiation residual value based on the optical radiation reference function and the pre-processed first optical radiation intensity involves performing necessary pre-processing (e.g., filtering, denoising, or calibration) on the real-time acquired first optical radiation intensity, and then comparing it with the ideal optical radiation intensity predicted by the pre-established optical radiation reference function (which describes the ideal optical radiation intensity at different speeds and powers). The optical radiation residual value is the deviation between the actual measured value and the ideal predicted value; this residual value quantifies the real-time difference between the laser output and the expected target. In practical applications, obtaining a power compensation value based on the optical radiation residual value and a preset historical residual accumulation to compensate for the first power means that after calculating the current optical radiation residual value, the system combines preset historical residual accumulation information (e.g., through moving average, integral term, or more complex control algorithms, such as the integral part of a proportional-integral-derivative (PID) controller) to comprehensively evaluate the trend and cumulative effect of the power deviation. Based on this comprehensive evaluation, a power compensation value is calculated. The compensation value can be positive (when the actual light radiation is too low) or negative (when the actual light radiation is too high). Its purpose is to correct the original first power in real time so as to ensure that the actual energy output by the laser can more accurately match the optimal energy level required for the additive repair process.

[0127] The above steps detail the implementation after obtaining the first power corresponding to each motion command point. By introducing a real-time optical radiation intensity measurement and feedback mechanism, the lag and inaccuracy issues that may exist in power adjustment in traditional methods are solved. Specifically, during the laser head movement, the first optical radiation intensity is obtained in real time and compared with a pre-established optical radiation reference function to dynamically calculate the optical radiation residual value. This residual value directly reflects the deviation between the current laser output and the ideal state. Furthermore, combined with the preset historical residual accumulation, the system can more comprehensively evaluate the trend and cumulative effect of power deviation, thereby generating a more accurate power compensation value. Thus, this power compensation value is used to adjust the first power in real time, ensuring that the energy output of the laser can accurately match the needs of additive repair, effectively dealing with various uncertainties that may occur in the actual processing, ensuring the stability and consistency of the laser additive repair process for rail defects, and significantly improving the overall performance and reliability of the repaired parts.

[0128] In some preferred embodiments, a specific example is given below. Assume that during laser additive repair, the laser head moves at a certain instantaneous speed, and a first power is calculated based on the speed-power function. At this time, the actual first light radiation intensity at the current moment can be obtained through a real-time light radiation sensor installed near the laser head. For example, if the light radiation intensity predicted by the light radiation reference function at this instantaneous speed and first power is X, and the actual measured pre-processed first light radiation intensity is Y, then the light radiation residual value is YX. If Y is greater than X, it indicates that the actual energy output is too high; if Y is less than X, it indicates that the actual energy output is too low. The system calculates a power compensation value based on this residual value and combined with residual data accumulated over a period of time (e.g., through a moving average window or the integral term in a PID controller). For example, if the residual value is consistently negative (actual energy is too low), the system calculates a positive power compensation value and adds it to the original first power, thereby increasing the laser's output power and bringing it closer to the ideal state. Conversely, if the residual value remains positive (actual energy is too high), a negative power compensation value is calculated, reducing the laser output power. Through this real-time feedback and compensation mechanism, even under complex repair paths or changes in material properties, the precise delivery of laser energy can be ensured, thereby guaranteeing the quality of additive repair.

[0129] To improve the solution, after obtaining the power compensation value based on the optical radiation residual value and the preset historical residual accumulation to compensate for the first power, the following steps are also included:

[0130] Based on the first power and the power compensation value, obtain the compensated first power;

[0131] By integrating the compensated first power corresponding to all motion command points in chronological order, a new laser power adjustment command is generated to update the laser power adjustment command.

[0132] The process of obtaining the compensated first power involves combining the first power corresponding to each motion command point previously obtained based on the velocity power function with the power compensation value accumulated from the optical radiation residual value and preset historical residuals. This combination is typically achieved through mathematical operations. For example, if the power compensation value represents an increment or decrement, it can be directly added to or subtracted from the first power to obtain a corrected and more accurate compensated first power. The purpose is to perform real-time, dynamic correction of the initially calculated laser power to adapt to various uncertainties in the actual additive manufacturing process. Integrating the compensated first powers corresponding to all motion command points in chronological order generates a new laser power adjustment command. This can be understood as arranging and encapsulating all compensated and corrected first power values ​​according to the time sequence of the laser head's motion command points on the predicted motion path, forming a complete command sequence that can be directly executed by the laser controller. This new laser power adjustment command will replace or update the original laser power adjustment command, ensuring that the laser can adjust its output based on the latest compensated power value during subsequent movement. The aim is to provide an immediately available and accurate power control scheme to guide the actual operation of the laser head.

[0133] The above steps detail the implementation after obtaining the power compensation value. By explicitly applying the calculated power compensation value to the original first power and further generating new laser power adjustment commands, it solves the problem of merely obtaining the compensation value without specifying its application. Specifically, by combining the power compensation value with the first power, it ensures that the laser output power at each motion command point has undergone fine correction, thus more accurately reflecting the needs of the actual additive repair process. Subsequently, by integrating these compensated power values ​​in chronological order, a complete and executable command sequence is formed, enabling the laser to output according to these real-time adjusted power commands. This achieves precise control of laser energy delivery, effectively compensating for power deviations caused by environmental changes, material property fluctuations, and other factors. It realizes a closed-loop compensation mechanism and its practical application, providing a more reliable and efficient solution for laser additive repair of rail defects, ultimately improving repair efficiency and quality.

[0134] In some preferred embodiments, a specific example is given below. Assume that at a certain motion command point, the initial first power calculated from the velocity power function is 1000 watts. Through light radiation intensity analysis and historical residual accumulation, the calculated power compensation value is +50 watts (indicating that an additional 50 watts of power is needed to achieve the desired effect). According to the scheme of this application, the compensated first power will be calculated as 1000 watts + 50 watts = 1050 watts.

[0135] For all motion command points along the predicted motion path of the laser head, their respective compensated first power will be calculated in a similar manner. For example, if there are multiple motion command points corresponding to time points T1, T2, T3...Tn on the path, and each point has a corresponding compensated first power P1', P2', P3'...Pn' calculated, this application integrates these compensated power values ​​P1', P2', P3', ..., Pn' in chronological order to form a continuous power command sequence. This sequence is then encapsulated into a new laser power adjustment command, such as an array or data stream containing timestamps and corresponding power values. When the laser head actually moves to point T1, the laser will output the power of P1'; when it moves to point T2, it will output the power of P2', and so on. In this way, the laser's output power can respond to speed changes and environmental feedback on the path in real time and accurately, ensuring that the energy input during the additive repair process is always in an optimal state, thereby obtaining a high-quality repair layer.

[0136] In actual laser additive repair processes, the actual instantaneous speed of the laser head may deviate slightly from the predicted speed due to factors such as mechanical inertia, control precision, or external interference. This deviation can lead to uneven energy distribution per unit distance, thereby affecting the metallurgical quality and mechanical properties of the additive repair layer. If these issues are not addressed, it may result in uneven microstructure, hardness fluctuations, or insufficient bonding strength in the repaired area, thus reducing the overall reliability of the repaired part.

[0137] like Figure 5 As shown, based on this, the following steps are also included in the process of moving the laser head:

[0138] D1. When the laser head moves a unit distance, the corresponding digital pulse signal is obtained by the grating encoder installed on the laser head's motion axis and input to the controller;

[0139] D2. During the movement of the laser head, the controller controls the energy output of the laser based on the digital pulse signal corresponding to each unit distance and the currently synchronized laser output power, so as to ensure that the energy density output within the unit distance is consistent with the expected laser power adjustment command.

[0140] The unit distance in step D1 refers to the minimum measurable distance increment in which the laser head moves along the motion axis. This can be set to values ​​such as 0.1 mm, 0.05 mm, or even smaller, to provide precise distance feedback. The grating encoder is a high-precision displacement sensor that converts mechanical displacement into electrical signals using optical principles, thereby accurately detecting the actual movement distance of the laser head and generating corresponding digital pulse signals. Each digital pulse signal represents a preset unit distance movement of the laser head. These digital pulse signals are input to the controller in real time. The controller is the core control unit of the entire laser additive manufacturing system, responsible for processing various sensor data and issuing control commands.

[0141] The energy density in step D2 refers to the laser energy acting on a unit area of ​​the rail defect when the laser head moves one "unit distance" along the repair path; the expected laser power adjustment command refers to a series of power values ​​calculated in advance to maintain an "ideal and constant" energy density when the laser head moves at a "predicted instantaneous speed".

[0142] Steps D1 to D2 detail the specific implementation of the laser head movement process. By introducing a grating encoder to monitor the actual displacement of the laser head in real time, and based on this, adjusting the laser output power synchronously, energy distribution per unit distance is achieved, effectively solving the problem of uneven energy distribution that may exist in traditional solutions. Specifically, when the laser head executes the motion trajectory command, the grating encoder can accurately sense each unit distance it moves and immediately send a digital pulse signal to the controller. After receiving these signals, the controller executes the following closed-loop control process:

[0143] 1. Displacement-time conversion and velocity confirmation:

[0144] The controller records the time interval between receiving two consecutive unit distance pulse signals. Based on preset, precise unit distance The controller calculates the actual average velocity of the laser head within this displacement range. .

[0145] This move aims to obtain an undisputed true velocity value based on physical displacement for subsequent accurate calculations.

[0146] 2. Actual energy density calculation:

[0147] Controller synchronous reading here The actual average output power of the laser during the time interval (This value can be obtained from feedback from the sensors inside the laser or from the command value output by the controller after calibration.)

[0148] The controller then calculates the unit distance that has just been completed. Above, the actual energy density deployed The essence of its calculation formula is:

[0149] ;

[0150] Due to the area of ​​the light spot and If it is a constant within a specific period, this calculation is logically equivalent to... Here It represents a true measure of the energy deposited on the workpiece.

[0151] 3. Comparison and deviation generation between expected and actual values:

[0152] Simultaneously, the controller queries the pre-generated laser power adjustment command based on the current position of the laser head to obtain the expected laser power at that position. and expected speed of movement .

[0153] Based on these expected values, the controller calculates the expected energy density. (Similarly, ).

[0154] The controller then calculates the energy density deviation. .Should It quantifies the sum of all errors between theoretical design and actual implementation.

[0155] 4. Generation of power compensation amount:

[0156] The controller applies a proportional-integral (PI) control algorithm to this deviation value. To generate a real-time power compensation amount. .

[0157] Its control law can be expressed as:

[0158] ;

[0159] Among them: Kp (proportional gain) provides a fast, instantaneous response to correct for the current deviation; Ki (integral gain) is used to accumulate and eliminate persistent static deviations to ensure long-term accuracy.

[0160] This compensation amount is a dynamic value, which can be positive or negative.

[0161] 5. Real-time update and look-ahead output of power commands:

[0162] The controller does not modify past instructions; instead, it makes proactive adjustments. Based on the motion path, it obtains the expected reference power required for the next control cycle. .

[0163] The calculated power compensation amount is added to it to generate and output a new, closed-loop corrected power command:

[0164] ;

[0165] The new instruction was immediately sent to the laser, guiding it to execute the movement over the next unit distance.

[0166] Through the cyclical execution of the above steps, the system achieves a high-frequency closed-loop control based on physical displacement triggering. Its technical effect is that, regardless of any deviation between the actual and expected speeds caused by mechanical inertia, transmission errors, or external interference, the system can continuously and in real-time fine-tune the laser power through the aforementioned feedback mechanism. This ensures that the laser energy density deposited on the rail defects within each tiny unit distance segment remains highly consistent with the ideal value, thereby fundamentally eliminating overburning, underburning, and microstructural defects caused by uneven energy distribution. This significantly improves the uniformity, density, and final mechanical properties of the additive repair layer.

[0167] like Figure 6 As shown, in a second aspect, this application also discloses a rail defect laser additive data processing system, applied to rail defect laser additive repair scenarios, including:

[0168] The motion trajectory instruction module is used to acquire the three-dimensional geometric data of the target rail defect and generate the motion trajectory instruction of the laser head according to the preset strategy.

[0169] The velocity change curve module is used to analyze motion trajectory commands and generate velocity change curves of the laser head along the predicted motion path.

[0170] The laser power adjustment command module is used to obtain laser power adjustment commands based on the velocity change curve and velocity power function on the predicted motion path.

[0171] The power adjustment module is used to receive motion trajectory commands and laser power adjustment commands during the movement of the laser head, obtain the actual instantaneous speed corresponding to a specific motion command point based on the motion trajectory command, and synchronously adjust the laser output power.

[0172] The motion trajectory instruction module can be a computer system equipped with a 3D scanning interface and a data processing unit. It receives point cloud data from a 3D scanner and runs a preset path planning algorithm to generate a series of CNC instructions containing position and velocity information. In some implementations, this module can also generate motion trajectory instructions through manual input or by loading defect models and repair strategies from a preset database.

[0173] The velocity curve variation module can be a motion controller or a standalone computing unit, configured to parse the position and time information in the motion trajectory command and calculate the instantaneous velocity of the laser head along the entire predicted path based on a kinematic model, thereby forming a continuous velocity variation curve. For example, this module can use interpolation algorithms or motion simulation software to accurately calculate the velocity curve;

[0174] The laser power adjustment command module can be a digital signal processor (DSP) or an embedded controller, internally storing a pre-calibrated velocity-power function. Upon receiving a velocity change curve, this module substitutes each velocity value in the curve into the velocity-power function to calculate the corresponding ideal laser power value and generates a laser power adjustment command according to a time series or position series. For example, this module can quickly calculate the power value using a lookup table or mathematical model.

[0175] The power adjustment module can be a real-time controller integrated into the laser additive manufacturing equipment control system. It is configured to receive commands from the motion trajectory command module and the laser power adjustment command module. This module is also connected to a speed sensor or encoder to monitor the actual instantaneous speed of the laser head in real time. When a deviation between the actual and predicted speed is detected, the module adjusts the laser's output power in real time according to a preset power adjustment algorithm to ensure uniform energy input. For example, the module can use a PID controller or other feedback control algorithms to achieve precise power adjustment.

[0176] This application aims to provide a laser additive data processing system for rail defects. Through the coordinated operation of its various internal functional modules, it achieves precise control over the laser head's motion trajectory and laser power, aiming to solve the problem of potential hidden structural defects forming within the repair layer in existing technologies, thereby improving repair quality and reliability. The core of this system lies in its modular design, effectively integrating functions such as laser head motion speed change prediction, laser power adjustment command generation, and real-time power adjustment to ensure the uniformity and stability of laser energy input.

[0177] Compared to traditional systems, this application offers the following advantages: First, by combining the motion trajectory command module and the velocity change curve module, a more reasonable laser power adjustment strategy can be pre-planned, avoiding blindness during the repair process. Second, the laser power adjustment command module can generate precise power adjustment commands based on the predicted velocity change curve and velocity-power function. Finally, during actual execution, the power adjustment module effectively compensates for the impact of the dynamic characteristics of mechanical motion on energy input by acquiring the actual instantaneous velocity of the laser head in real time and adjusting the laser power synchronously, ensuring the uniformity and stability of the laser energy input. This refined control method can significantly reduce structural defects within the repair layer, improving repair quality and reliability.

[0178] Preferably, it further includes:

[0179] An optical encoder, mounted on the laser head's motion axis, is used to acquire the corresponding digital pulse signal every time the laser head moves a unit distance.

[0180] The controller is used to control the energy delivered by the laser during the movement of the laser head, based on the digital pulse signal corresponding to each unit distance and the currently synchronized laser output power, so as to ensure that the energy density delivered per unit distance is consistent with the expected laser power adjustment command.

[0181] In practical applications, a grating encoder and controller are also set up. The closed-loop control process from step D1 to D2 is realized through the design of the grating encoder and controller. The technical implementation method and effect are as described above. It realizes the leap from control in the "time-command domain" to control in the "space-physical domain", which further improves the reliability and robustness of the rail defect laser additive data processing system.

[0182] In the embodiments provided in this application, it should be understood that the disclosed methods and systems can be implemented in other ways. The system embodiments described above are merely illustrative. For example, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods, such as: multiple modules or components can be combined, or integrated into another system, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the various components shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or modules, and can be electrical, mechanical, or other forms.

[0183] In addition, each functional module in the various embodiments of this application can be fully integrated into a processor, or each module can be a separate device, or two or more modules can be integrated into a device; each functional module in the various embodiments of this application can be implemented in hardware or in the form of hardware plus software functional units.

[0184] Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by program instructions and related hardware. The aforementioned program instructions can be stored in a computer-readable storage medium. When the program instructions are executed, they perform the steps of the above method embodiments. The aforementioned storage medium includes various media that can store program code, such as mobile storage devices, read-only memory (ROM), magnetic disks, or optical disks.

[0185] Hereinafter, 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.

[0186] If a flowchart is used in this application, it is used to illustrate the operations performed by the system according to embodiments of this application. It should be understood that the preceding or following operations are not necessarily performed in exact order. Instead, the steps can be processed in reverse order or simultaneously. Furthermore, other operations can be added to these processes, or one or more steps can be removed from them.

[0187] The foregoing provides a detailed description of a laser additive data processing method and system for rail defects provided in this application. The above description of the disclosed embodiments enables those skilled in the art to implement or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A steel rail defect laser additive data processing method applied to a steel rail defect laser additive repair scene, characterized in that, The method comprises the following steps: acquiring three-dimensional geometric data of a target rail defect, and generating a movement trajectory instruction of a laser head according to a preset strategy; analyzing the movement trajectory instruction to generate a speed change curve of the laser head on a predicted movement path; obtaining a laser power adjustment instruction according to the speed change curve on the predicted movement path and a speed-power function; during the movement of the laser head, receiving the movement trajectory instruction and the laser power adjustment instruction, acquiring an actual instantaneous speed corresponding to a specific movement instruction point according to the movement trajectory instruction, and synchronously adjusting the output power of the laser; the speed-power function is obtained based on the following steps: designing the laser head to scan the target rail defect at a plurality of first scanning speeds; performing metallographic analysis on the target rail defect; determining a first ideal power corresponding to each first scanning speed according to the metallographic analysis result, fitting the first scanning speed and the first ideal power, and obtaining the speed-power function; the laser power adjustment instruction is obtained according to the speed change curve on the predicted movement path and the speed-power function, comprising the following steps: acquiring a first instantaneous speed corresponding to each movement instruction point on the predicted movement path according to the speed change curve; acquiring a first power corresponding to each movement instruction point according to the first instantaneous speed and the speed-power function; integrating the first power corresponding to all the movement instruction points in time sequence to generate the laser power adjustment instruction; the specific movement instruction point is obtained based on the following steps: acquiring the first instantaneous speed corresponding to each movement instruction point on the predicted movement path according to the speed change curve; calculating the first derivative and the second derivative of the first instantaneous speed corresponding to each movement instruction point; determining an extreme point according to the first derivative; firstly judging whether the second derivative is of opposite signs on both sides of the extreme point; if the first judgment result is yes, the specific movement instruction point is defined.

2. The method of claim 1, wherein, after obtaining the speed-power function, the following steps are further included: designing the laser head to scan the target rail defect at a plurality of second scanning speeds; performing metallographic analysis on the target rail defect; determining a second ideal power corresponding to each second scanning speed according to the metallographic analysis result; analyzing and fitting a second light radiation intensity obtained under the combination of different second scanning speeds and second ideal powers to establish a light radiation reference function to compensate the first power.

3. The method of claim 2, wherein, after obtaining the first power corresponding to each movement instruction point according to the first instantaneous speed and the speed-power function, the following steps are further included: acquiring a first light radiation intensity according to the first instantaneous speed and the first power; acquiring a light radiation residual value according to the light radiation reference function and the preprocessed first light radiation intensity; acquiring a power compensation value according to the light radiation residual value and a preset historical residual accumulation to compensate the first power.

4. The steel rail defect laser additive data processing method of claim 3, wherein, after obtaining the power compensation value according to the light radiation residual value and the preset historical residual accumulation to compensate the first power, the following steps are further included: According to the first power and the power compensation value, a compensated first power is obtained; In time sequence, the compensated first powers corresponding to all the motion instruction points are integrated to generate a new laser power adjustment instruction to update the laser power adjustment instruction.

5. The rail defect laser additive data processing method of claim 1 wherein, In the process of moving the laser head, the following steps are further included: When the laser head moves a unit distance, a corresponding digital pulse signal is obtained by a grating encoder installed on the motion shaft of the laser head and input into the controller; In the process of moving the laser head, the controller controls the laser to deliver energy according to the digital pulse signal corresponding to each unit distance and the current synchronously adjusted laser output power, to ensure that the energy density delivered in a unit distance is consistent with the expectation of the laser power adjustment instruction.

6. A steel rail defect laser additive data processing system applied to a steel rail defect laser additive repair scene, characterized in that, Comprise: a motion trajectory instruction module for obtaining three-dimensional geometric data of a target rail defect, and generating a motion trajectory instruction of a laser head according to a preset strategy; a speed change curve module for analyzing the motion trajectory instruction and generating a speed change curve of the laser head on a predicted motion path; a laser power adjustment instruction module for obtaining a laser power adjustment instruction according to the speed change curve on the predicted motion path and a speed-power function; a power adjustment module for receiving the motion trajectory instruction and the laser power adjustment instruction in the process of moving the laser head, obtaining an actual instantaneous speed corresponding to a specific motion instruction point according to the motion trajectory instruction, and synchronously adjusting the output power of the laser; wherein the speed-power function is obtained based on the following steps: designing the laser head to scan the target rail defect at a plurality of first scanning speeds; performing metallographic analysis on the target rail defect; determining a first ideal power corresponding to each of the first scanning speeds according to the metallographic analysis result, and fitting the first scanning speeds and the first ideal powers to obtain the speed-power function; the laser power adjustment instruction is obtained according to the speed change curve on the predicted motion path and the speed-power function, including the following steps: obtaining a first instantaneous speed corresponding to each of the motion instruction points on the predicted motion path according to the speed change curve; obtaining a first power corresponding to each motion instruction point according to the first instantaneous speed and the speed-power function; integrating all the first powers corresponding to all the motion instruction points in time sequence to generate the laser power adjustment instruction; the specific motion instruction point is obtained based on the following steps: obtaining the first instantaneous speed corresponding to each of the motion instruction points on the predicted motion path according to the speed change curve; calculating the first derivative and the second derivative of the first instantaneous speed corresponding to each of the motion instruction points; determining an extreme point according to the first derivative; firstly judging whether the second derivative is of opposite signs on both sides of the extreme point; if the first judgment result is yes, the specific motion instruction point is defined.

7. The rail defect laser additive data processing system of claim 6, wherein, Further comprise: a grating encoder installed on the motion shaft of the laser head, for obtaining a corresponding digital pulse signal when the laser head moves a unit distance; A controller is configured to control the laser to emit energy according to the digital pulse signal corresponding to each unit distance and the laser output power adjusted in real time during the movement of the laser head, so as to ensure that the energy density emitted in the unit distance is consistent with the expected laser power adjustment instruction.

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