An engine blade grinding and polishing method based on an industrial robot

Abstract

A method for grinding and polishing engine blades based on an industrial robot includes: designing and manufacturing a tooling fixture; formulating qualified standards for abrasive testing; adjusting the resilience of a flexible mechanism according to the blade profile and the thickness of the inlet and exhaust edges; assembling the blade according to the robot origin coordinates and planning the grinding path; performing simulation verification on the tooling fixture and the grinding trajectory and posture of the robot; planning the robot motion trajectory; importing a digital model, designing the blade cross-section and the detection height to be detected during blue light detection; setting basic grinding parameters to generate a grinding program; manually grasping and debugging the blade; verifying the grinding program and adjusting the grinding angle; verifying the blue light detection device; performing rough polishing, semi-finishing polishing, and finishing polishing on the blade profile; performing adaptive grinding on the inlet and exhaust edges of the blade; using blue light online detection on the inlet and exhaust edges of the blade; grinding the blade mounting plate; and performing overall glazing on the blade.

Description

Technical Field

[0001] The present invention belongs to the technical field of engine blade processing, and relates to a grinding and polishing method for engine blades based on an industrial robot. Background Art

[0002] Blades are key components of aeroengines. The accuracy of the blades directly determines the performance, life, and safety of the engine. At present, most blades are processed by manual grinding. Affected by manual operations, the surface integrity and consistency of the grinding area cannot be guaranteed. In addition, the rising labor costs, the scarcity of highly skilled workers, and the multi-process flow in blade processing. There are also cases where some components damage the substrate or the blades, which brings potential risks to both product quality and processing costs. At the same time, this also runs counter to the contemporary industrial development direction.

[0003] It can be seen that the conventional processing technology is difficult to meet the processing requirements of products. To improve the life and reliability of engine components, it is urgent to carry out research on the grinding technology of complex-shaped blades and improve product quality and processing efficiency with the assistance of relevant manufacturing processes and intelligent technologies. Summary of the Invention

[0004] To solve the above technical problems, the purpose of the present invention is to provide a grinding and polishing method for engine blades based on an industrial robot, which not only meets the accuracy and efficiency requirements, but also greatly improves the product consistency, significantly reduces the scrap rate, and improves the processing environment.

[0005] The present invention provides a grinding and polishing method for engine blades based on an industrial robot, including the following steps:

[0006] S1: Design and manufacture a tooling fixture based on the CAD model of the blade and the set grinding area;

[0007] S2: Formulate a qualified standard for abrasive testing according to the blade acceptance standard;

[0008] S3: Adjust the resilience of the flexible mechanism of the spindle for grinding the inlet and exhaust edges in advance according to the blade profile and the thickness of the inlet and exhaust edges;

[0009] S4: Establish a machining coordinate system based on the robot origin coordinates, assemble the blade, and plan the blade grinding path;

[0010] S5: Establish a 1:1 simulation environment to simulate and verify the tooling fixture, the grinding trajectory, and the posture of the robot. If there are problems, readjust the grinding path;

[0011] S6: Plan the robot motion trajectory, set transfer nodes in the robot control system, and manually teach;

[0012] S7: Import the assembled digital model and the robot grinding trajectory into the robot control system, and plan and design the blade cross-section and inspection height to be inspected during blue light inspection based on the theoretical digital model;

[0013] S8: Set the basic grinding parameters, including: force, linear velocity, and feed rate, and generate a grinding program;

[0014] S9: Based on the coordinates obtained from the simulation in the simulation, and in cooperation with the real-time coordinate system feedback function of the robot itself, perform manual grasping and debugging on the blade;

[0015] S10: Verify the grinding program and adjust the grinding angle;

[0016] S11: The robot calibrates the blue light inspection device through the calibration block carried by itself;

[0017] S12: The robot performs rough polishing, semi-finishing polishing, and finishing polishing on the blade surface;

[0018] S13: The robot uses a spindle tool with a flexible mechanism to perform adaptive grinding on the inlet and exhaust edges of the blade;

[0019] S14: The robot uses a blue light inspection device to perform on-line inspection on the profiles of the inlet and exhaust edges of the blade;

[0020] S15: The robot grinds the blade mounting plate;

[0021] S16: The robot performs overall glazing on the blade.

[0022] Further, in step S1, the fixture material is selected according to the hardness comparison table in combination with the actual hardness of the blade, and the fixture is installed at the end of the robot's robotic arm to achieve clamping of the blade.

[0023] Further, step S2 is specifically as follows:

[0024] S201: Select the abrasive according to the blade material;

[0025] S202: Conduct tests on the attenuation, life, and ultimate state of the abrasive during grinding.

[0026] Further, step S4 is specifically as follows:

[0027] S401: Use UG or Solidworks to assemble the blade, fixture, and robot with the robot origin as the center, establish a complete machining coordinate system with the robot origin as the center, and export the assembled digital model;

[0028] S402: Import the assembled digital model into Mastercam or Robotmaster for grinding path programming to generate a grinding path.

[0029] Further, the specific steps of step S5 are as follows:

[0030] Establish a simulation environment according to the tool module required for blade processing. Import the previously programmed blade grinding path and the assembled blade digital model into the simulation environment to simulate the robot grinding process and verify the robot grinding trajectory. If there are any problems, readjust the blade grinding path.

[0031] Further, the specific steps of step S6 are as follows:

[0032] Before the robot approaches the grinding point, it runs to the specified node and gradually approaches the target position through multiple nodes. The transfer node will compare the coordinates calculated by the simulation software with the coordinates reached by the robot during actual processing, and correct the error through multiple iterations to achieve high repeat positioning accuracy; if there is a deviation between the actual coordinates displayed on the Fanuc robot teach pendant and the actual coordinates in the simulation software, adjust the coordinates of the transfer point manually.

[0033] Further, the specific steps of step S8 are as follows:

[0034] S801: Understand the amount of material removed in a single grinding during manual grinding. At the same time, calculate the linear velocity with reference to the rotational speed of the grinding and polishing tool and apply it to the preliminary debugging of the program;

[0035] S802: When processing the inlet and exhaust edges, calculate the optimal processing tangent angle during processing; when there are three tangents:

[0036]

[0037] When there are four tangents:

[0038]

[0039]

[0040] Among them, θ 1 represents the first tangent angle, θ 2 represents the second tangent angle, θ 3 represents the third tangent angle, θ 4 represents the fourth tangent angle; the first tangent angle is between 25° and 40°, and the last tangent angle is less than 90°.

[0041] Further, the specific steps of step S10 are as follows:

[0042] Step S1001: The robot obtains the blue light detection angle and the movement trajectory of the robot during blue light detection according to the blade theoretical model. If there is a twist angle between the blade to be processed and the theoretical model, the robot control system calculates a new grinding and polishing tool vector, and then adjusts the grinding and polishing posture.

[0043] Step S1002: If the posture is inappropriate or interference occurs during blade grinding and polishing, the robot control system calculates a new grinding and polishing tool vector, and then adjusts the grinding and polishing posture.

[0044] Further, in step S10, the new polishing tool vector after rotation is calculated according to the following formula:

[0045] n' = n×cosα+(n×t')×t'×(1 - cosα)+t'×sinα

[0046] Where, n is the normal vector of the machining point, that is, the grinding and polishing tool vector, n is perpendicular to the tangential vector t in the direction of the blade surface. When adjusting the posture of the robot during grinding and polishing, n is rotated around the tangential vector t and adjusted by an angle α dynamically in combination with the right-hand rule to obtain the adjusted robot posture; t' is the unitized tangential vector, and n' is the new polishing tool vector after rotation.

[0047] Further, step S14 is specifically as follows:

[0048] S1401: Obtain the actual contour of the current blade and compare it with the theoretical contour, and calculate the difference area from the actual blade after fitting.

[0049] S1402: Determine whether the difference area is within the tolerance band according to the set tolerance, and obtain the conclusion of whether to process.

[0050] S1403: Calculate and select the machining angle suitable for the current blade according to the preset machining tangent angle, and calculate the matching feed speed at the same time.

[0051] After one round of machining, detect again. If the blade is completely qualified, jump out of the loop; if the blade is unqualified, first judge whether the machining cycle times are set. If the machining cycle times are greater than 1, continue to run steps S1401 - S1403 until the blade is machined to a qualified state or reaches the cycle limit.

[0052] A method for grinding and polishing engine blades based on an industrial robot of the present invention has at least the following beneficial effects:

[0053] Compared with traditional grinding and polishing blades, the grinding and polishing process based on industrial robots proposed by the present invention has the characteristics of high automation, high stability, high flexibility, and on-line detection. The consistent performance of products is reliably guaranteed, the processing quality and efficiency are improved, the rejection rate is reduced, the existing processing method is greatly improved, and the labor force is liberated. At the same time, the user-friendly visual interface reduces the programming difficulty, improves the accuracy of the program, and enhances the understanding of the blade process by programmers. In addition, the present invention is not limited to the grinding and polishing of a certain type of blade, but is applicable to the processing of other various complex curved surface parts. The automated processing of new parts can be achieved only by offline programming through the CAD digital model of the parts. Description of the Drawings

[0054] Figure 1 is a flowchart of a method for grinding and polishing engine blades based on an industrial robot according to the present invention. Detailed Embodiment

[0055] As Figure 1 shown, a method for grinding and polishing engine blades based on an industrial robot according to the present invention includes the following steps:

[0056] S1: Design and manufacture a tooling fixture based on the CAD model of the blade and the set grinding area;

[0057] The special tooling fixture designed based on the blade CAD model is an important step in the whole process. The tooling fixture is installed at the end of the robotic arm to clamp the blade. Its stable clamping can fit the path designed according to the theoretical model and the machining posture calculated by the robot to the greatest extent, which will greatly reduce the difficulty of later fine-tuning and improve the product quality during mass production. In addition, the hardness of the blade clamping surface needs to be understood in advance so as to select the appropriate tooling fixture material according to the hardness comparison table to avoid scratching the blade.

[0058] S2: Formulate qualified standards for abrasive testing according to the blade acceptance criteria. The selection of abrasives is directly related to the result of blade grinding and polishing. Before determining an abrasive as the abrasive that can be used in the final batch production, it is necessary to conduct life testing, ultimate heat-resistant temperature testing, attenuation testing, and visual surface evaluation on it. At the same time, the amount of abrasive removed also needs to be selected according to the average allowable stock removal of the blade. The specific steps of step S2 are as follows:

[0059] S201: Select abrasives according to the blade material;

[0060] For example, titanium alloy is processed using high-temperature resistant ceramic materials or silicon carbide material coiled wheels with special processes, and for superalloys, stacked wheels made of alumina material can be selected according to the blade stock removal requirements.

[0061] S202: Conduct tests on the attenuation, life, and ultimate state of the abrasives during grinding.

[0062] The test contents include but are not limited to the following: the difference in the amount of abrasive grinding between the first and the last blades exceeds 20%, whether the abrasive will thermally disintegrate when the robot air cooling system is not turned on, whether new machining marks will appear on the surface after grinding, the visual effect of the blade surface after grinding, etc.

[0063] S3: Adjust in advance the resilience of the flexible mechanism of the spindle for grinding the inlet and outlet edges according to the blade profile and the thickness of the inlet and outlet edges;

[0064] In specific implementation, the spindles for grinding the inlet and outlet edges of the blade adopt a floating form. When feeding, if the pressure applied by the robot exceeds the preset resilience of the spindle, the spindle will automatically retract, enabling the grinding tool to adaptively fit on the surface of the part and avoiding damaging the blade during feeding. The common resilience is 13.5N ± 10%. When the blade is thinner, the resilience can be appropriately reduced.

[0065] S4: Establish a machining coordinate system based on the robot origin coordinates, assemble the blade, and plan the blade grinding path. The specific steps of S4 are as follows:

[0066] S401: Use UG or Solidworks to assemble the blade, the tooling fixture, and the robot with the robot origin as the center, establish a complete machining coordinate system with the robot origin as the center, and export the digital model after assembly;

[0067] S402: Import the digital model after assembly into Mastercam or Robotmaster for grinding path programming to generate the grinding path; when programming, attention should be paid to the influence of the surface UV lines on the robot's posture, and at the same time, the grinding areas should be programmed separately to facilitate the subsequent grinding program design.

[0068] S5: Establish a 1:1 simulation environment to simulate and verify the tooling fixture and the robot grinding trajectory and posture. If there are problems, readjust the grinding path. The specific steps of S5 are as follows:

[0069] Establish a simulation environment according to the tool modules required for blade machining, import the previously programmed blade grinding path and the digital model of the blade after assembly into the simulation environment, simulate the robot grinding process, and simulate and verify the robot grinding trajectory. If there are problems, readjust the blade grinding path.

[0070] S6: Plan the robot motion trajectory, set transfer nodes in the robot control system, and manually teach. The specific steps of S6 are as follows:

[0071] Planning the robot trajectory includes how the robot approaches the machining point after grasping the blade. However, during the direct approach, the robot may have extremely slight shaking or deviation, resulting in a deviation between the final position coordinates and the ideal position coordinates, and also causing excessive differences in the machining between blades. Therefore, in order to ensure the accuracy of the robot when it reaches the machining position, multiple transfer nodes are added in the middle of the robot's running path. Before the robot approaches the grinding point, it will run to the specified nodes in sequence and gradually approach the target position through multiple nodes. The transfer nodes will compare the coordinates calculated by the simulation software with the coordinates reached by the robot during actual machining, and correct the error through multiple iterations to achieve high repeat positioning accuracy. The transfer nodes can adjust the specific coordinates according to their own needs, and during the test period, they can compare the difference between the actual coordinates and the calibrated coordinates of the transfer nodes and make appropriate adjustments.

[0072] If there is a deviation between the actual coordinates displayed on the Fanuc robot teach pendant and the actual coordinates in the simulation software, adjust the coordinates of the transfer point by manual teaching.

[0073] S7: Import the assembled digital model and the robot grinding trajectory into the robot control system, and based on the theoretical digital model, plan and design the blade cross-section and the detection height required for blue light detection.

[0074] When setting the blade cross-section to be detected, it needs to be set according to the position of the blade cross-section calibrated in the blade process specification. Due to different reference origins, it is necessary to convert the distance in the Z direction after fixing the X and Y axes. The specific reference is as follows:

[0075] z' = t + a + A i

[0076] Among them, z' is the cross-section distance from the robot origin coordinate to the cross-section to be detected, t is the projection distance from the original reference coordinate of the blade to the front panel of the robot. a is the distance from the origin of the blade assembly digital model to the front panel of the sixth joint of the robot. A i is the height from the blade reference coordinate in the blade digital model to each cross-section to be detected, and i is the serial number of the cross-section to be detected.

[0077] S8: Set the basic grinding parameters, including: force, linear velocity, and feed rate, and generate a grinding program. The specific steps of step S8 are as follows:

[0078] S801: Understand the amount of material removed in a single grinding during manual grinding, and at the same time calculate the linear velocity with reference to the rotational speed of the grinding and polishing tool, and apply it to the preliminary debugging of the program. The relationship between the linear velocity and the rotational speed is as follows:

[0079] v = 2πr × n

[0080] Among them, v represents the linear velocity, r represents the radius, and n represents the rotational speed respectively.

[0081] S802: When processing the intake and exhaust edges, the best processing tangent angle is calculated;

[0082] When there are three tangent lines:

[0083]

[0084] When there are four tangent lines:

[0085]

[0086]

[0087] Among them, θ 1 represents the first tangent angle, θ 2 represents the second tangent angle, θ 3 represents the third tangent angle, θ 4 Indicates the fourth tangent angle; the first and last tangent angles are determined based on the actual grindable angles and requirements of the blade. The first tangent angle is between 25° and 40°. The thinner the blade inlet and outlet edges, the closer the angle is to 40°, and vice versa. The last tangent angle is less than 90°. According to the blade shape and the size of the grinding wheel, the angle approaches 90° without interfering with the grinding position (inlet and outlet edges). 0° is the normal vector of the blade contact surface.

[0088] S9: Based on the coordinates obtained in the simulation, the blade is manually grasped and debugged with the robot's built-in real-time coordinate system feedback function;

[0089] In the specific implementation, the robot is manually taught to grasp and grasp. During grasping, the Fanuc robot teaching pendant can call the coordinates of the real-time joint coordinate system. During teaching, the robot coordinates calculated in the simulation software can be compared with the robot coordinates during teaching. By adjusting the actual coordinates and the coordinates in the simulation software, the coordinate matching can be automatically calibrated to minimize the possible deviation in the grasping process and prepare for subsequent processing.

[0090] S10: Verify the grinding program and adjust the grinding angle. When verifying the processing program, there may be uneven grinding or unsatisfactory visual surface. At this time, it is necessary to calculate the adjusted grinding and polishing tool vector and adjust the robot posture or grinding angle through Brainwave software, including but not limited to the robot's six-axis offset or rotation. The specific step S10 is:

[0091] Step S1001: The robot obtains the blue light detection angle and the movement trajectory of the robot during blue light detection according to the blade theoretical model. If there is a twist angle between the blade to be processed and the theoretical model, the robot control system calculates a new grinding and polishing tool vector, and then adjusts the grinding and polishing posture.

[0092] Step S1002: If the posture is inappropriate or interference occurs during blade grinding and polishing, the robot control system calculates a new grinding and polishing tool vector, and then adjusts the grinding and polishing posture.

[0093] During specific implementation, the new polished tool vector after rotation is calculated according to the following formula:

[0094] n' = n×cosα+(n×t')×t'×(1 - cosα)+t'×sinα

[0095] Where, n is the normal vector of the machining point, that is, the grinding and polishing tool vector, n is perpendicular to the tangential vector t in the direction of the blade surface. When adjusting the posture of the robot during grinding and polishing, n is rotated around the tangential vector t and adjusted by an angle α dynamically in combination with the right-hand rule to obtain the adjusted robot posture; t' is the unitized tangential vector, and n' is the new polished tool vector after rotation.

[0096] S11: The robot calibrates the blue light detection device through the calibration block carried by itself.

[0097] During the grinding and polishing process, the robot needs to clamp the blade and move it to a position where the blue light detection device can perform detection. The blue light detection device needs to be verified in advance to ensure that the detected contour section matches and conforms to the actual remaining amount of the current blade. At the same time, it is also necessary to confirm that the blade will not collide or interfere with the blue light detection device during detection. If interference or other situations occur, the robot posture needs to be adjusted appropriately.

[0098] During specific implementation, the robot moves to the blue light detection station, and the blue light detection device performs blue light detection on the calibration block carried by the robot itself. By comparing the theoretical contour of the calibration block with the actual contour of the calibration block detected by the blue light, the calibration of the blue light detection device is achieved.

[0099] S12: The robot performs rough polishing, semi-finishing polishing, and finishing polishing on the blade surface.

[0100] During semi-finishing polishing, it is necessary to ensure that there are no obvious grinding marks or defects on the blade surface and the surface roughness after grinding is not lower than Ra0.6.

[0101] During finishing polishing, it is necessary to ensure that there are no grinding marks on the blade surface, the blade surface is bright, there are no visual defects, and it is acceptable to leave fine tool marks at the edges of the inlet and exhaust sides for the next process to handle, and the roughness is not lower than Ra0.4.

[0102] S13: The robot uses a spindle tool with a flexible mechanism to adaptively grind the inlet and exhaust edges of the blade;

[0103] In specific implementation, the robot control system obtains the actual contour of the current blade and compares it with the theoretical contour. At the same time, it calculates the difference area with the actual blade after fitting. According to the set tolerance, it determines whether the difference area is within the tolerance band and draws a conclusion on whether to process. Then, according to the pre-set processing tangent angle, it calculates the processing angle suitable for the current blade, and calculates the matching feed speed to complete the adaptive grinding.

[0104] S14: The robot uses a blue light detection device to perform online detection of the contour of the inlet and outlet edges of the blades. The specific steps of step S14 are:

[0105] S1401: Obtain the actual profile of the current blade and compare it with the theoretical profile, and calculate the difference area between the actual blade and the actual blade after fitting;

[0106] S1402: Determine whether the difference area is within the tolerance zone according to the set tolerance, and draw a conclusion on whether to process;

[0107] S1403: Calculate and select a processing angle suitable for the current blade according to a preset processing tangent angle, and calculate a matching feed speed;

[0108] S1404: After one round of processing is completed, check again. If the blade is completely qualified, exit the loop; if the blade is unqualified, first determine whether the number of processing cycles is set. If the number of processing cycles is greater than 1, continue to run S1401-S1403 steps until the blade is processed to a qualified state or the cycle limit is reached.

[0109] S15: The robot polishes the blade mounting plate;

[0110] When grinding the mounting plate, the blade mounting plate and the adapter are usually polished with two different grinding wheels, which have different sizes and shapes depending on the area being polished. The rough polishing wheel is generally a 3M Rapid Cut 7XCRS. Depending on the feed rate and speed settings, this wheel can remove 0.025mm to 0.050mm of blade material. After rough polishing, a grinding wheel such as the 3M Scotch Brite Light Deburring Wheel 8SF grinding wheel sample is used for fine polishing to improve the surface quality and aesthetics of the flange.

[0111] The polishing of the mounting plate is done by an angled grinding wheel. The angled part of the grinding wheel will be in flat contact with the mounting plate, and the robot will polish the edge plate surface in a reciprocating motion at a pre-set distance between the mounting plate and the transition part. The surface polishing at this distance will be completed by the polishing process of the transition part.

[0112] S16: The robot performs overall polishing on the blade.

[0113] During the final polishing, the main purpose is to merge the multiple segmented polished areas of the blade together by means of a grinding wheel or an extremely fine abrasive belt, to improve the visual effect and to ensure that the final roughness is not less than Ra0.4.

[0114] The above description is only a preferred embodiment of the present invention and is not intended to limit the concept of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for grinding and polishing engine blade based on industrial robot, characterized in that, it includes the following steps: S1: Design and manufacture a tooling fixture based on the CAD model of the blade and the set grinding area; S2: Establish the qualified standard for abrasive testing according to the blade acceptance standard; S3: Adjust in advance the resilience of the flexible mechanism of the spindle for grinding the inlet and exhaust edges according to the blade profile and the thickness of the inlet and exhaust edges; S4: Establish a machining coordinate system based on the robot origin coordinates, assemble the blade and plan the blade grinding path; S5: Establish a 1:1 simulation environment to simulate and verify the tooling fixture and the robot grinding trajectory and posture. If there are problems, readjust the grinding path; S6: Plan the robot motion trajectory, set transfer nodes in the robot control system and manually teach; S7: Import the assembled digital model and the robot grinding trajectory into the robot control system, and plan and design the blade cross-section and the detection height to be detected during blue light detection based on the theoretical digital model; S8: Set the basic grinding parameters, including: force, linear velocity and feed rate, and generate a grinding program; S9: Based on the coordinates obtained from the simulation, cooperate with the real-time coordinate system feedback function of the robot itself to conduct manual grasping and debugging of the blade; S10: Verify the grinding program and adjust the grinding angle; S11: The robot calibrates the blue light detection device through the calibration block carried by itself; S12: The robot rough polishes, semi-finish polishes and finish polishes the blade profile; S13: The robot uses the spindle tool with a flexible mechanism to adaptively grind the inlet and exhaust edges of the blade; S14: The robot uses the blue light detection device to conduct on-line detection of the contour of the inlet and exhaust edges of the blade; S15: The robot grinds the blade mounting plate; S16: The robot conducts overall glazing on the blade; The specific step S8 is: S801: Understand the amount removed by a single grinding during manual grinding, and at the same time calculate the linear velocity with reference to the rotational speed of the grinding and polishing tool, and apply it to the preliminary debugging of the program; S802: When machining the inlet and exhaust edges, calculate the best machining tangent angle during machining; when there are three tangents: When there are four tangents: Among them, θ 1 represents the angle of the first tangent line, θ 2 represents the angle of the second tangent line, θ 3 represents the angle of the third tangent line, θ 4 represents the angle of the fourth tangent line; the angle of the first tangent line is between 25° and 40°, and the angle of the last tangent line is less than 90°.

2. The method for grinding and polishing engine blade based on industrial robot according to claim 1, characterized in that, in step S1, the tooling fixture material is selected according to the hardness comparison table in combination with the actual blade hardness, and the tooling fixture is installed at the end of the robot's robotic arm to realize the clamping of the blade.

3. The method for grinding and polishing engine blade based on industrial robot according to claim 1, characterized in that, the specific step S2 is: S201: Select the abrasive according to the blade material; S202: Conduct tests on the attenuation, life and ultimate state of the abrasive during grinding.

4. The method for grinding and polishing engine blade based on industrial robot according to claim 1, characterized in that, the specific step S4 is: S401: Use UG or Solidworks to assemble the blade, the tooling fixture and the robot with the robot origin as the center, establish a complete machining coordinate system with the robot origin as the center, and export the assembled digital model; S402: Import the assembled digital model into Mastercam or Robotmaster for grinding path programming to generate the grinding path.

5. The engine blade grinding and polishing method based on an industrial robot as claimed in claim 1, wherein, the specific steps of S5 are as follows: Establish a simulation environment according to the tool module required for blade processing. Import the previously programmed blade grinding path and the assembled blade digital model into the simulation environment to simulate the robot grinding process and verify the robot grinding trajectory. If there are any problems, readjust the blade grinding path.

6. The engine blade grinding and polishing method based on an industrial robot as claimed in claim 1, wherein, the specific steps of S6 are as follows: Before the robot approaches the grinding point, it runs to the specified node and gradually approaches the target position through multiple nodes. The transfer nodes will compare the coordinates calculated by the simulation software with the coordinates reached by the robot during actual processing, and correct the error through multiple iterations to achieve high repeat positioning accuracy; if there is a deviation between the actual coordinates displayed on the Fanuc robot teach pendant and the actual coordinates in the simulation software, adjust the coordinates of the transfer point manually by teaching.

7. The engine blade grinding and polishing method based on an industrial robot as claimed in claim 1, wherein, the specific steps of S10 are as follows: Step S1001: The robot obtains the blue light detection angle and the movement trajectory of the robot during blue light detection according to the blade theoretical model. If there is a twist angle between the blade to be processed and the theoretical model, the robot control system calculates a new grinding and polishing tool vector, and then adjusts the grinding and polishing posture; Step S1002: If there is an inappropriate posture or interference during blade grinding and polishing, the robot control system calculates a new grinding and polishing tool vector, and then adjusts the grinding and polishing posture.

8. The engine blade grinding and polishing method based on an industrial robot as claimed in claim 7, wherein, the new polished tool vector after rotation in step S10 is calculated according to the following formula: n' = n×cosα + (n×t')×t'×(1 - cosα) + t'×sinα where, n is the normal vector of the machining point, that is, the grinding and polishing tool vector, n is perpendicular to the tangential vector t in the direction of the blade surface. When adjusting the posture of the robot during grinding and polishing, n is rotated around the tangential vector t and adjusted dynamically by an angle α in combination with the right-hand rule to obtain the adjusted robot posture; t' is the unitized tangential vector, and n' is the new polished tool vector after rotation.

9. The engine blade grinding and polishing method based on an industrial robot as claimed in claim 1, wherein, the specific steps of S14 are as follows: S1401: Obtain the actual profile of the current blade and compare it with the theoretical profile, and calculate the difference area from the blade after fitting; S1402: Determine whether the difference area is within the tolerance band according to the set tolerance to obtain the machining conclusion; S1403: Calculate the machining angle suitable for the current blade according to the pre-set machining tangent angle and select it, and calculate the matching feed rate at the same time. S1404: After one round of processing is completed, conduct another inspection. If the blade is completely qualified, then exit the loop; if the blade is unqualified, first determine whether the processing loop count is set. If the processing loop count is greater than 1, then continue to execute steps S1401 - S1403 until the blade is processed to a qualified state or reaches the loop upper limit.

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