A parameterized crankshaft laser cladding robot machining control method and system

Abstract

In order to solve the problems of traditional crankshaft clamping precision, operation steps and low efficiency, the application provides a kind of parameterized crankshaft laser cladding robot processing control method and system, including the following steps; S1, the crankshaft model is measured by using laser scanner, the surface condition of each journal of crankshaft is analyzed, the surface repairability of crankshaft is analyzed, the worn journal is determined and marked; S2, the parameter information of the repaired journal is obtained, and the parameter extraction of the repaired workpiece is completed; S3, the processing sequence is formulated, and the target laser processing parameter is configured, the task of repair processing is realized; S4, the robot and servo turntable carry out online motion interpolation and laser process parameter follow-up control; S5, the surface light finishing and quality detection of journal are carried out, the laser cladding work of the robot along with the crankshaft under simple clamping can be realized, and the efficiency and quality of the crankshaft part laser cladding are ensured.

Description

Technical Field

[0001] This invention relates to the field of intelligent driving technology for vehicles, and in particular to a parametric crankshaft laser cladding robot processing control method and system. Background Technology

[0002] As the most important component of an engine, the crankshaft journals and connecting rods undergo high-speed relative motion during operation, making them prone to wear and failure after prolonged service. Therefore, preparing wear-resistant, corrosion-resistant, and fatigue-resistant coatings on the easily worn parts of the crankshaft journals can effectively improve the crankshaft's performance and greatly extend its service life. Laser cladding is a process in which the coating material is irradiated by a laser beam, causing it and the substrate surface layer to melt simultaneously and solidify rapidly, forming a cladding layer with extremely low dilution and metallurgical bonding with the substrate. This improves the wear resistance, corrosion resistance, heat resistance, oxidation resistance, and electrical properties of the substrate surface. It is a green and advanced metal coating preparation method suitable for surface modification of parts such as crankshafts. Robots have a series of advantages such as low cost, large working space, high spatial flexibility, and flexible production, making them particularly suitable for machining complex curved surfaces with large dimensions, low cutting forces, and low precision requirements.

[0003] Because crankshafts are irregular geometric shapes, traditional crankshaft cladding requires repeated, complex self-aligning clamping of each eccentric crankshaft segment. This process is cumbersome, inefficient, and the accuracy of self-aligning installation is difficult to guarantee, severely impacting processing efficiency and quality. In recent years, robotic processing systems using six-degree-of-freedom serial robots as the main motion unit and positioners or servo turntables as auxiliary motion devices, with high-power lasers mounted at the robot's end effector, have seen rapid development in the industrial manufacturing field. However, current solutions for crankshaft parts often require complex offline programming, especially when multi-end journal cladding is involved. This makes the programming task extremely cumbersome and prevents efficient parametric machining of crankshafts. Furthermore, due to the closed nature of the robot control system, precise synchronization of robot, servo turntable, and laser processing technology control is impossible, hindering the integrated development of the entire system. This is currently the biggest obstacle restricting the application of robots in crankshaft laser cladding. Summary of the Invention

[0004] To address the problems of low processing efficiency and quality caused by the repeated complex self-aligning and clamping of each eccentric crankshaft segment in traditional crankshaft cladding processes, which fail to consider actual wear and deformation, this invention provides a parametric crankshaft laser cladding robot processing control method and system. The technical solution adopted is as follows:

[0005] A parametric crankshaft laser cladding robot processing control method, characterized by comprising the following steps;

[0006] S1. Use a laser scanner to measure the crankshaft model, analyze the surface condition of each journal of the crankshaft, and perform a surface repairability analysis on the crankshaft to identify and mark the journals that have been worn.

[0007] S2. Referring to the crankshaft model measured in step S1, obtain the parameter information of the journal to be repaired and complete the parameter extraction of the workpiece to be repaired.

[0008] S3. Determine the processing sequence and configure the target laser processing parameters to realize the task formulation for repair processing;

[0009] S4. Based on the repair and processing sequence and process requirements, perform online motion interpolation and laser process parameter follow-up control:

[0010] By calculating the motion relationship between the position and attitude of the laser cladding head nozzle end and the rotation angle of the servo turntable, motion planning is performed on the target processing trajectory. The motion of the robot and the servo turntable is interpolated in real time to control the synchronous motion of each joint of the robot and the servo turntable. At the same time, based on the speed of the laser cladding nozzle relative to the crankshaft surface during the processing, the power of the laser and the powder feeding rate are controlled in real time to achieve equal laser energy ratio throughout the processing process.

[0011] S5. Perform surface finishing and quality inspection on the machined journal.

[0012] Furthermore, in step S1, the repairability analysis is implemented as follows: the crankshaft to be repaired is scanned from multiple angles using a laser scanner, the collected point cloud information is stitched together to obtain the actual three-dimensional geometric model of the worn crankshaft, and cylindrical fitting analysis is performed on different journals to obtain the wear deformation of each journal, thereby marking the worn journals.

[0013] Furthermore, in step S2, the method for extracting the parameters of the workpiece to be repaired is as follows: the actual crankshaft model measured in step S1 is simplified into a connecting rod shaft and a central shaft, the working journals with different wear are fitted, and the optimal cylindrical surface of different segments is fitted by the least squares method, thereby obtaining the specific parameters of that part.

[0014] Furthermore, the connecting rod shaft parameters include axial offset C(i), circumferential phase θ(i), center distance D, and journal length L(i), and the center shaft parameters include axial offset S(i) and journal length L(i)´.

[0015] Furthermore, in step S3, the task of repair processing is defined by the following method: by establishing a data list, the processing sequence and direction of each worn journal, the motion control parameter constraints of the robot and servo turntable are specified, and the target laser processing process parameters are configured.

[0016] Furthermore, the motion control parameter constraints for the robot and servo turntable include maximum speed, maximum acceleration, and maximum jerk.

[0017] Furthermore, the laser processing parameters include laser power, laser scanning speed, defocusing amount, overlap rate, powder feeding rate, and cladding layer thickness.

[0018] A parametric crankshaft laser cladding robot processing system, characterized in that it includes a robot, a servo turntable, a laser cladding head, a fiber laser, a powder feeder, a controller, and a motion and process control algorithm module, wherein the motion and process control algorithm module includes:

[0019] The crankshaft wear analysis module is used to create a three-dimensional geometric model of the worn crankshaft and analyze the wear deformation of each journal, and to mark the worn journals.

[0020] The crankshaft model parameterization module is used to obtain the repair parameters of each journal of the crankshaft model;

[0021] Repair the machining task specification module, which is used to specify the machining sequence, machining direction, control parameter constraints of the robot and servo turntable, and machining parameters of the laser process module for each journal of the crankshaft;

[0022] The robot-servo turntable motion control module consists of a robot motion trajectory control module and a servo turntable motion trajectory control module. It is used to perform motion interpolation on the motion of the robot and the servo turntable and control the robot to move synchronously with the servo turntable.

[0023] The cladding process follow-up control module consists of a laser power control module and a powder feeder flow control module. It controls the laser power and the powder feeder feed rate with the constraint of equal laser specific energy throughout the process.

[0024] The beneficial effects of this invention are as follows:

[0025] 1. This method solves the problem of low processing efficiency and quality caused by the traditional crankshaft cladding method, which requires repeated complex self-aligning and clamping of each eccentric crankshaft section without considering actual wear and deformation. The proposed parametric machining method avoids complex offline robot programming, enabling automatic generation of machining trajectories through simple parameter extraction. Precise synchronization of robot, servo turntable motion control, and laser processing technology control is achieved through system control methods, ensuring equal laser energy ratio throughout the entire machining process and thus guaranteeing processing quality.

[0026] 2. Compared with existing technologies, the model parameterization method proposed in this invention fully considers the geometric characteristics of actual worn crankshafts, providing accurate and lightweight parameter models for robot-servo turntable laser cladding. The proposed online motion interpolation and laser process follow-up control calculate the relative motion speed between the laser cladding nozzle and the machining journal in real time during interpolation. Based on constant laser specific energy constraints, the laser power is adjusted online, and the powder feeder rate is adjusted proportionally, ensuring that the laser process follows the relative motion speed in real time throughout the entire processing. This guarantees the thermal stability of the molten pool during processing and provides assurance for stable quality control. Attached Figure Description

[0027] Figure 1 Flowchart of a parametric crankshaft laser cladding robot machining control method

[0028] Figure 2 Schematic diagram of crankshaft model

[0029] Figure 3 Simplified front view of the crankshaft model

[0030] Figure 4 Simplified left view of the crankshaft model

[0031] Figure 5 Simplified model diagram of the first connecting rod shaft

[0032] Figure 6 Schematic diagram of the cladding trajectory of the first connecting rod shaft

[0033] Figure 7 Schematic diagram of synchronous cladding strategy

[0034] Figure 8 Schematic diagram of YOZ planar motion decomposition when α≠0

[0035] Figure 9 Schematic diagram of YOZ planar motion decomposition when α=0

[0036] Figure 10 A graph showing the velocity, acceleration, and jerk curves at the acceleration and deceleration points of the S-curve.

[0037] Figure 11 The curves of the robot's Cartesian coordinates and the rotation angle of the servo turntable were collected for the experiment.

[0038] Figure 12 The robot joint angle curves collected for the experiment

[0039] Figure 13 Actual surface morphology of crankshaft after experimental cladding

[0040] Figure 14 Schematic diagram of a parametric crankshaft laser cladding robotic processing system Detailed Implementation

[0041] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0042] A parametric crankshaft laser cladding robot processing control method includes the following steps:

[0043] S1. Use a laser scanner to measure the crankshaft model, analyze the surface condition of each journal of the crankshaft, and perform a surface repairability analysis on the crankshaft to identify and mark the journals that have been worn.

[0044] Surface repairability analysis specifically refers to the reverse modeling of crankshaft workpieces after actual service using a laser scanner, such as... Figure 2 As shown, and as Figure 3 As shown, the dimensions of each journal were measured, and the location and degree of wear of the worn journals were determined by referring to the crankshaft instruction manual and the original design model. A numerical list was created to mark the wear condition of each journal, which will guide subsequent crankshaft wear repair.

[0045] S2. Referring to the crankshaft model measured in step S1, obtain the parameter information of the journal to be repaired and complete the parameter extraction of the workpiece to be repaired.

[0046] The parameter information of the journal to be repaired specifically refers to the parameterization of the connecting rod shaft and the center shaft through model simplification for different journals of the crankshaft, including two different types of journals: eccentric connecting rod shaft and center shaft.

[0047] Simplified crankshaft models specifically refer to common practical models, such as Figure 2 As shown, the crankshaft model consists of connecting rod journals and a central journal connected in series via a crankshaft. From left to right, they can be named as the first main journal, first connecting rod journal, second main journal, second connecting rod journal, third main journal, third connecting rod journal, and so on. The actual crankshaft model is complex, containing many parameters unrelated to laser cladding. To simplify the model, considering both the motion and process requirements of laser processing, based on the crankshaft model obtained from actual scanning, the crankshaft model is simplified to a series connection of connecting rod journals and a central journal, as shown below. Figure 3 and Figure 4As shown, the crankshaft connecting rod journals and main journals are distributed alternately by the crankshaft. The origin O is taken as the center of the outer plane of the crankshaft gear journal. The y-axis is the direction of the main shaft centerline, with the direction pointing inwards towards the crankshaft as the positive y-axis. The z-axis is the line connecting the projections of the first connecting rod journal axis and the first main journal axis onto the y-axis, with the projection of the main shaft centerline pointing towards the connecting rod centerline as the positive z-axis. The x-axis is determined according to the right-hand rule, thus establishing the crankshaft workpiece coordinate system {G}. In the crankshaft workpiece coordinate system {G}, the main shaft and connecting rod axes are parameterized, where the i-th central axis uses an axial offset S(i), length L(i), and diameter d. c (i) The parameters used to describe the i-th link journal section are axial offset C(i), circumferential phase θ(i), center distance D, length L(i)´, and diameter d. c The parameters (i)´ are used to describe the entire crankshaft model after simplification. The connecting rod shaft parameters are relatively complex, including axial offset C(i), circumferential phase θ(i), center distance D, and journal length L(i). The central shaft parameters are relatively simple, including axial offset S(i) and journal length L´(i). Based on the actual wear workpiece three-dimensional reverse model obtained from the previous laser scanning, the parameters of the eccentric shaft and the central journal can be extracted by a simple cylindrical fitting method, providing accurate model parameters for the subsequent robotic laser repair of the crankshaft.

[0048] S3. Determine the processing sequence and configure the target laser processing parameters to realize the task formulation for repair processing;

[0049] The specific task of repair processing is to determine the processing sequence and direction of each worn journal, the laser cladding scanning speed, the motion control parameter constraints of the robot and servo turntable, and the laser processing process parameters. The parameter constraints include the maximum speed, the maximum acceleration, and the maximum jerk. The laser processing process parameters include the laser power, the scanning speed, the defocusing amount, the overlap rate, the powder feeder rate, and the cladding layer thickness.

[0050] S4. The robot control system performs online motion interpolation and laser process parameter follow-up control according to the repair and processing sequence and processing requirements.

[0051] By calculating the motion relationship between the position and attitude of the laser cladding head nozzle end and the rotation angle of the servo turntable, S-curve acceleration and deceleration motion planning is performed on the target processing trajectory to control the synchronous movement of each joint of the robot and the servo turntable. At the same time, based on the speed of the laser cladding nozzle relative to the crankshaft surface during processing, the power of the laser and the powder feeding rate are controlled in real time to achieve equal laser energy throughout the processing process.

[0052] Specifically, the motion planning of the robot-servo rotary table is as follows. To further clarify the motion control principle of the laser processing robot-servo rotary table, the model is further simplified based on the parametric model. Taking the motion control of the first journal machining as an example, as follows... Figure 5 As shown, for ease of analysis, in the workpiece coordinate system {G}, the origin O' of the first connecting rod journal coordinate system {G'} is taken as the center of the circle near the origin end face of the first connecting rod journal. The original coordinate system is translated to point O' to form a local coordinate system {G'}, as shown below. Figure 6 As shown, the relative position changes during the entire machining process are as follows: In the first connecting rod journal coordinate system {G´}, the machining trajectory is a helical motion, that is, it makes uniform circular motion in the x´O´z´ plane and moves in a straight line along the y´ axis. In the workpiece coordinate system {G}, the actual machining trajectory is an offset helical motion, that is, it makes offset uniform circular motion in the xOz plane and moves in a straight line along the y axis.

[0053] Furthermore, the attitude changes of relative motion throughout the entire processing are as follows: In the first connecting rod journal coordinate system {G´}, the axis of the robot end effector laser is always perpendicular to the surface of the first connecting rod journal to be processed during the processing motion. Similarly, in the workpiece coordinate system {G}, the axis of the robot end effector laser is always perpendicular to the surface of the first connecting rod journal to be processed. To meet the processing requirements, the laser cladding head is always perpendicular to the surface of the journal to be processed. A robot-servo turntable system is used as the motion system. A servo turntable coordinate system {S} is established, and a synchronous rotation model of the robot-servo turntable spindle is established, as follows. Figure 7 As shown, the main shaft rotates by an angle θ, and the robot rotates in the opposite direction by an angle θ relative to the axis of the connecting rod in the xOz plane, and moves in a straight line along the y direction in the yOz plane.

[0054] The online motion interpolation process for robot-servo turntable motion control is as follows:

[0055] The relative motion between the robot and the servo turntable is decomposed into yOz plane motion and xOz plane motion, and motion interpolation is performed separately to realize the growth and overlap of the cladding trajectory of the worn journal, and finally complete the preparation of the cladding layer on the entire journal surface.

[0056] The specific decomposition of the yOz plane motion is as follows, such as... Figure 8As shown, the initial position is with the connecting rod axis located on the z-axis. The robot's machining starting point is any point P on the upper surface of the connecting rod axis. At this point, the line connecting point P and the connecting rod axis makes an angle α with the z-axis. Starting from the starting point, the crankshaft's central axis moves in a circular motion under the drive of the servo motor. Based on the above assumptions, the robot rotates synchronously with the main spindle relative to the connecting rod axis, i.e., the main spindle rotates by an angle θ, and the robot's machining point rotates in the opposite direction by an angle θ relative to the connecting rod axis. From the motion relationship, it can be seen that when the main spindle rotates by any angle θ, the coordinate information of the robot's working point in the rotary table coordinate system {S} can be expressed as follows:

[0057] (1);

[0058] Where, λ o δ is the laser head defocusing amount determined above. o For the cladding layer thickness, specifically, when the starting point P is chosen as the highest point of the initial position connecting rod axis, α is exactly 0, such as... Figure 9 As shown, the coordinate information of the robot's working point in the rotary table coordinate system {S} can be further simplified to:

[0059] (2);

[0060] The yOz plane motion decomposition is as follows: the robot moves in a straight line along the x-axis, and its motion is constrained by the overlap rate α and the actual single-pass cladding width p of the laser cladding process. The robot's motion along the x-direction can be expressed as:

[0061] (3);

[0062] The robot's attitude control during real-time interpolation is as follows: During laser cladding, the laser cladding head must remain perpendicular to the journal surface to be repaired at all times, placing strict requirements on robot attitude control. Analysis shows that, based on the strategy of synchronous rotation between the robot and the spindle, the robot's end-effector attitude during the entire cladding process... The component remains constant, and its direction vector is always the same as the unit vector of vector P. To facilitate robot posture calculation, the fixed posture component can be simplified.

[0063] (4);

[0064] Solving the equation, we get:

[0065] (5);

[0066] Specifically, when the starting point P is chosen as the highest point of the initial position link axis, the end attitude... The component is the z-axis reverse direction vector of the rotary table coordinate system {S}, therefore:

[0067] (6);

[0068] and Freedom, for ease of calculation, take , Calculations show that α=π, β=0, and γ=0, indicating that the robot's end-effector posture remains constant throughout the machining process.

[0069] In this embodiment, S-curve acceleration and deceleration motion control is used to plan the machining trajectory of the robot and the servo turntable, such as... Figure 10 As shown, interpolation is performed on the target motion spiral. Based on the journal length L(i) or L(i)´ of each segment, the overlap ratio α, and the single-pass cladding width d0, the interpolated target rotation angle θ(i) can be obtained:

[0070] (7);

[0071] Then, based on the determined scanning speed V e and journal diameter d c (i) or dc(i)´ can determine the maximum angular velocity V during the machining process. max (i) Maximum angular acceleration A max (i) Maximum angular acceleration J max (i) Under the constraint parameter, the maximum angular velocity V max (i) Maximum angular acceleration A max (i) Maximum angular acceleration J max (i) Using the S-curve acceleration / deceleration algorithm to interpolate the target rotation angle θ(i) can yield continuous interpolated rotation angles θ(i,t).

[0072] Laser process parameter follow-up control specifically refers to the fact that when the laser nozzle moves relative to the journal to be repaired, it needs to undergo acceleration and deceleration phases, which changes the actual scanning speed of laser cladding. Therefore, online control of the laser process parameters is required to achieve follow-up control of the process. The ideal laser power P is determined based on the laser processing technology, production requirements, and processing materials. e Scanning speed V e Cladding laser specific energy E s and defocusing amount λ o This allows us to determine the laser specific energy under the current process parameters, i.e., the irradiation energy per unit area:

[0073] (8);

[0074] Where D is the laser beam diameter, and when the actual scanning speed V(t) is not equal to the project scanning speed V0... e At this time, the laser power P(t) needs to be adjusted appropriately to ensure a relatively constant cladding laser specific energy, that is:

[0075] (9);

[0076] By monitoring the relative speed between the laser cladding nozzle and the surface of the journal to be repaired in real time, the laser power is adjusted online while the powder feeder rate is changed proportionally to achieve the follow-up control of the laser specific energy of equal cladding, thereby ensuring the quality of the processing.

[0077] S5. Perform surface finishing and quality inspection on the machined journal.

[0078] This embodiment also discloses a parametric crankshaft laser cladding robotic processing system, such as... Figure 14 As shown, it includes a robot, a servo turntable, a laser cladding head, a fiber laser, a powder feeder, a controller, and a motion and process control algorithm module. The motion and process control algorithm module includes:

[0079] The crankshaft wear analysis module obtains the actual three-dimensional geometric model of the worn crankshaft through reverse modeling, and then analyzes the wear deformation of each journal and marks the worn journals.

[0080] The crankshaft model parameterization module fits working journals with different wear patterns, including the central shaft and connecting rod shaft, to obtain specific parameters for that part. The parameters for the connecting rod shaft include axial offset, circumferential phase, center distance, and journal length; the parameters for the central shaft include axial offset and journal length, which fully and completely describe the actual morphological characteristics of the crankshaft journal after actual wear.

[0081] The repair and processing task formulation module specifies the processing sequence and direction of each worn journal, as well as the motion control parameter constraints of the robot and servo turntable, including maximum speed, maximum acceleration, and maximum jerk, by establishing a data list, and laser processing parameters including laser power, scanning speed, defocusing amount, overlap rate, powder feeder rate, and cladding layer thickness.

[0082] The robot-servo turntable motion control module consists of a robot motion trajectory control module and a servo turntable motion trajectory control module. Based on the laser scanning speed and overlap rate information, it decomposes the complex robot cladding motion trajectory into motions in two directions: the rotation surface and the axis. It automatically generates motions in the two decomposed directions and performs motion interpolation using the S-curve acceleration and deceleration method according to the motion constraints of the robot and the servo turntable. This controls the synchronous motion of the robot and the servo turntable to achieve precise relative motion between the robot and the servo turntable, thus realizing the growth and overlap of the cladding trajectory.

[0083] The cladding process follow-up control module consists of a laser power control module and a powder feeder flow control module. By calculating the relative motion speed between the laser cladding nozzle and the processing journal in real time, and based on the constant laser specific energy constraint, the laser power is adjusted online and the powder feeder rate is adjusted proportionally. This enables the laser process to follow the relative motion speed in real time throughout the entire processing process, ensuring the thermal stability of the molten pool and providing a guarantee for stable quality control.

[0084] To verify the effectiveness of the parametric crankshaft laser cladding robot processing system and control method described in this invention, a crankshaft cladding experiment was conducted. The experimental platform consisted of a Kawasaki RS020N series 6-DOF industrial robot body and a servo turntable, which were serially connected to the controller via an EtherCAT protocol network cable. The controller was a standard PC equipped with an Intel® Core™ i5-4460 302GHz CPU, 4.00GB of memory, and a Windows 10 operating system. To ensure real-time performance, the Kithara RealTime Suite (KRTS) was used to achieve an industrial-grade 1ms real-time communication cycle for the controller. Figure 11 The Cartesian coordinate parameters [x,y,z,α,β,γ] of the robot and the feed angle θ of the servo turntable were obtained during the experiment. Figure 12 The information provided by the robot's 6-joint motor angles demonstrates that the method proposed in this patent enables precise and stable motion control of the robot and servo turntable. The S-curve acceleration / deceleration algorithm allows for rapid and smooth start-up and stopping of the robot and servo turntable. Figure 13 The final result of the actual cladding process shows that through the coordinated control of motion and process of this method, equal laser energy control can be achieved throughout the entire cladding process, thus ensuring the quality of laser cladding.

[0085] This invention solves the problems of low processing efficiency and quality caused by the traditional crankshaft cladding method, which requires repeated complex self-aligning and clamping of each eccentric crankshaft segment and does not consider actual wear and deformation. The proposed parametric machining method avoids complex offline robot programming, enabling automatic generation of machining trajectories through simple parameter extraction. A comprehensive control method achieves precise synchronization of robot and servo turntable motion control and laser processing process control, ensuring consistent laser energy ratio throughout the entire processing process and thus guaranteeing processing quality. Compared with existing technologies, the proposed model parametric method fully considers the geometric characteristics of the actual worn crankshaft, providing a precise and lightweight parameter model for robot-servo turntable laser cladding. The proposed online motion interpolation and laser process follow-up control calculate the relative speed between the laser cladding nozzle and the machining journal in real time during interpolation. Based on the constant laser energy constraint, the laser power is adjusted online and the powder feeder rate is adjusted proportionally, ensuring that the laser process follows the relative speed in real time throughout the entire processing process. This guarantees the thermal stability of the molten pool and provides assurance for stable quality control.

[0086] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements can be made without departing from the principle of the present invention, and these improvements should also be considered within the scope of protection of the present invention.

Claims

1. A parametric crankshaft laser cladding robot processing control method, characterized in that, Includes the following steps; S1. Use a laser scanner to measure the crankshaft model, analyze the surface condition of each journal of the crankshaft, and perform a surface repairability analysis on the crankshaft to identify and mark the journals that have been worn. S2. Referring to the crankshaft model measured in step S1, obtain the parameter information of the journal to be repaired, and complete the parameter extraction of the workpiece to be repaired. The parameter extraction method of the workpiece to be repaired is as follows: simplify the actual crankshaft model measured in step S1 into a series connecting rod shaft and a central shaft, fit the working journals with different wear, and fit the optimal cylindrical surface of different segments by the least squares method, and then obtain the specific parameters of the different segments. The connecting rod shaft parameters include axial offset C(i), circumferential phase θ(i), center distance D, and journal length L(i). The central shaft parameters include axial offset S(i) and journal length L(i)´. S3. Determine the processing sequence and configure the target laser processing parameters to realize the task formulation for repair processing; S4. Based on the repair and processing sequence and process requirements, perform online motion interpolation and laser process parameter follow-up control: By calculating the motion relationship between the position and attitude of the laser cladding head nozzle end and the rotation angle of the servo turntable, motion planning is performed on the target processing trajectory. The motion of the robot and the servo turntable is interpolated in real time to control the synchronous motion of each joint of the robot and the servo turntable. At the same time, based on the speed of the laser cladding nozzle relative to the crankshaft surface during the processing, the power of the laser and the powder feeding rate are controlled in real time to achieve equal laser energy ratio throughout the processing process. S5. Perform surface finishing and quality inspection on the machined journal.

2. The parametric crankshaft laser cladding robot processing control method according to claim 1, characterized in that, In step S1, the repairability analysis is performed as follows: the crankshaft to be repaired is scanned from multiple angles using a laser scanner, the collected point cloud information is stitched together to obtain the actual three-dimensional geometric model of the worn crankshaft, and cylindrical fitting analysis is performed on different journals to obtain the wear deformation of each journal, thereby marking the worn journals.

3. The parametric crankshaft laser cladding robot processing control method according to claim 1, characterized in that, In step S3, the task of repair processing is defined by the following method: by establishing a data list, the processing sequence and direction of each worn journal, the motion control parameters of the robot and servo turntable are specified, and the target laser processing process parameters are configured.

4. The parametric crankshaft laser cladding robot processing control method according to claim 3, characterized in that, The motion control parameter constraints for the robot and servo turntable include maximum speed, maximum acceleration, and maximum jerk.

5. The parametric crankshaft laser cladding robot processing control method according to claim 3, characterized in that, The laser processing parameters include laser power, laser scanning speed, defocusing amount, overlap rate, powder feeding rate, and cladding layer thickness.

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