Laser dynamic curved surface machining precision control method based on six-axis robot arm

Abstract

This invention discloses a laser dynamic surface machining accuracy control method based on a six-axis robotic arm, comprising the following steps: Step 1: Powering the transformer and connecting it to the robot, then sequentially opening the development software for the laser, robot, and computer. Step 2: Placing the sample, starting the robot to focus on each machining surface sequentially, and setting the program to control the laser's alignment with the marking points on each machining surface. Step 3: Importing the design pattern into the development software, setting the laser parameters, and performing a no-load run (pre-machining) on ​​the sample. After verifying the toolpath is correct, machining can begin. This laser dynamic surface machining accuracy control method based on a six-axis robotic arm can be widely applied to machining scenarios involving various difficult-to-machine materials. This innovative technology provides a more reliable and efficient technical solution for related complex laser machining scenarios.

Description

Technical Field

[0001] This invention belongs to the field of laser precision control and processing technology, specifically relating to robotic arm control technology, and also to methods for optimizing the precision control of laser inclined and curved surface processing. Background Technology

[0002] Ultra-precision machining technology, often hailed as the "crown jewel of industry," includes laser processing, a type of ultra-precision machining widely used in key industrial sectors such as aerospace, automotive manufacturing, and high-end equipment. Currently, domestic laser processing technology has achieved mature applications in planar machining, but significant technological gaps and shortcomings remain in the core scenario of complex curved surface machining. The most critical issues are insufficient positioning accuracy and unstable machining precision—difficulty in achieving precise positioning and fit to complex curved surfaces, resulting in substandard surface contour accuracy and surface roughness. Furthermore, poor path planning and surface adaptability severely hinder the high-quality development of my country's high-end manufacturing industry. The deep integration of robotic arm control and laser processing technology has become a key breakthrough path. This technology integrates the high flexibility and adaptability of industrial robotic arms with the high precision and non-contact advantages of laser processing, forming a flexible, high-precision complex curved surface machining system. This significantly improves the positioning accuracy and machining precision stability of curved surfaces, effectively solving the complex curved surface machining problems that traditional processing methods struggle to overcome. This fusion technology provides strong support for the high-precision machining of products such as aero-engine blades, automotive curved parts, and precision electronic housings, helping related industries to upgrade products, improve efficiency, and optimize costs. It has significant industrial application value and broad development prospects.

[0003] The existing laser inclined / curved surface processing technology still has the following technical defects: (1) In the process of inclined surface processing, traditional three-axis laser processing equipment lacks rotational degrees of freedom and must use complex tooling fixtures for auxiliary positioning, which not only significantly increases the equipment cost and clamping time, but also the positioning accuracy is greatly affected by the manufacturing accuracy and installation error of the fixture, making it difficult to meet the requirements of high-precision processing. (2) The existing inclined surface processing path planning method mainly relies on manual teaching or offline programming, resulting in low path generation efficiency and poor repeatability. (3) Traditional laser processing systems lack an effective real-time accuracy control mechanism when performing dynamic inclined surface processing. (4) Existing six-axis robotic arm laser processing systems often do not fully consider the kinematic constraints and dynamic characteristics of the robotic arm when planning the path. Summary of the Invention

[0004] The purpose of this invention is to provide a laser dynamic curved surface machining accuracy control method based on a six-axis robotic arm, and to develop a six-axis robotic arm control technology to improve the machining accuracy of laser inclined / curved surface machining.

[0005] The technical solution adopted in this invention is a laser dynamic surface machining accuracy control method based on a six-axis robotic arm, comprising the following steps:

[0006] Step 1: Power the transformer and connect it to the robot. Turn on the laser, robot control cabinet and computer development software in sequence according to the specifications.

[0007] Step 2: Securely clamp and position the sample, start the robot to focus on each surface to be processed in sequence, control the focus position and the accuracy of the surface to be processed by precisely adjusting the laser height and the robot posture, and then set the marking points of the laser on each surface to be processed through the program.

[0008] Step 3: Import the design pattern into the control software, set the laser power, scanning speed and other parameters according to the material and processing requirements, perform a no-load pre-processing on the sample first, check the processing path and point accuracy, and after confirming that the tool path is correct, start the laser for formal processing.

[0009] The specific sequence for opening the equipment in Step 1 is as follows: First, open the transformer circuit breaker; second, open the main circuit breaker; third, press the computer power button; fourth, press the air conditioning button; fifth, open the laser control box circuit breaker; sixth, activate the emergency stop by pressing the galvanometer button; seventh, press the laser button; eighth, press the control button; ninth, open the I / O control box circuit breaker; eleventh, open the robot control box circuit breaker; eleventh, wait for the teach pendant to turn on and check for any abnormalities; eleventh, activate the robot emergency stop on the bottom of the display screen; eleventh, activate the teach pendant emergency stop; eleventh, open the development software on the computer; and eleventh, click the robot automation button.

[0010] The specific focusing process of the robot in step 2 is as follows: First, the robot (1-6) is in a bent, rear-positioned state, and a high-precision focusing device (1-5-3) mounted on the 6th axis performs parallel focusing on the processing surface 1 (2-1). After reaching point 1 (2-1), the focusing operation is performed. Second, the robot (1-6) is in a straight, forward-positioned state, with the 6th axis aligned with the 5th and 4th axes. A high-precision focusing device (1-5-3) mounted on the 5th axis performs parallel focusing on the processing surface 2 (2-2). After reaching point 2 (2-2), the focusing operation is performed. Third, the robot (1-6) is in a bent, forward-positioned state, and a high-precision focusing device (1-5-3) mounted on the 6th axis performs parallel focusing on the processing surface 3 (2-3). After reaching point 3 (2-3), the focusing operation is performed.

[0011] The robot posture control and position accuracy control methods in step 2 are as follows: Step A: Establish the kinematic model of the robotic arm and perform kinematic modeling of the six-axis robotic arm using the DH parameter method; Step B: Use a dual laser displacement sensor feedback system to monitor the focal position of the laser displacement sensor in real time, and trigger the position compensation program when the deviation exceeds the preset threshold; Step C: Calculate the optimal laser incident angle based on the surface geometric features; Step D: Use the Jacobian matrix method to perform motion conversion between joint space and Cartesian space, and detect and avoid singular configuration regions in real time; Step E: Tilt error compensation model to automatically compensate for loading position errors.

[0012] The specific advantages of the program control method in step 2 are as follows: The control program has the following characteristics and advantages: (1) It adopts a modular program architecture design, and the path planning module, motion control module, accuracy compensation module and human-computer interaction module are independently encapsulated; (2) The path planning algorithm adopts a hybrid optimization strategy of improved RRT* algorithm and genetic algorithm, and the path planning time is shortened by more than 40% compared with the traditional method; (3) The accuracy compensation program adopts a hierarchical compensation strategy, and the comprehensive processing accuracy can reach within ±0.05mm; (4) The program supports the switching of multiple processing scheme templates, and the average fault-free running time of the system exceeds 2000 hours.

[0013] The beneficial effects of this invention are:

[0014] This invention successfully integrates robotics technology to achieve a precise planning method for laser dynamic inclined / curved surface machining paths, consistently meeting specified manufacturing accuracy requirements. The developed laser dynamic inclined / curved surface machining method exhibits excellent machining performance and can be widely applied to machining various difficult-to-machine materials. This innovative technology provides a more reliable and efficient technical solution for related complex laser machining scenarios. Attached Figure Description

[0015] Figure 1 This is an overall diagram of the equipment used in the laser dynamic surface machining accuracy control method based on a six-axis robotic arm;

[0016] Figure 2 This is the first step in robot focusing in the laser dynamic surface processing accuracy control method based on a six-axis robotic arm;

[0017] Figure 3 This is the second step of robot focusing in the laser dynamic surface processing accuracy control method based on a six-axis robotic arm;

[0018] Figure 4 This is the third step of robot focusing in the laser dynamic surface processing accuracy control method based on a six-axis robotic arm;

[0019] Figure 5This is a robot model diagram in the laser dynamic surface processing accuracy control method based on a six-axis robotic arm;

[0020] Figure 6 This is the main interface of the machining system in the laser dynamic surface machining accuracy control method based on a six-axis robotic arm;

[0021] Figure 7 This is a partial operation procedure diagram of a laser dynamic surface machining accuracy control method based on a six-axis robotic arm;

[0022] Figure 8 This is a circuit diagram of a laser dynamic surface machining accuracy control method based on a six-axis robotic arm.

[0023] Figure 9 This is a test report on the accuracy verification of a six-axis robotic arm system in the laser dynamic surface processing accuracy control method based on a six-axis robotic arm.

[0024] Figure 10 This is a finished product image of a laser dynamic surface machining accuracy control method based on a six-axis robotic arm. Detailed Implementation

[0025] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0026] Step 1: Power the transformer and connect it to the robot. Turn on the laser, robot control cabinet and computer development software in sequence according to the specifications.

[0027] Step 2: Securely clamp and position the sample, start the robot to focus on each surface to be processed in sequence, control the focus position and the accuracy of the surface to be processed by precisely adjusting the laser height and the robot posture, and then set the marking points of the laser on each surface to be processed through the program.

[0028] Step 3: Import the design pattern into the control software, set the laser power, scanning speed and other parameters according to the material and processing requirements, perform a no-load pre-processing on the sample first, check the processing path and point accuracy, and after confirming that the tool path is correct, start the laser for formal processing.

[0029] like Figure 1 As shown, in steps 1 and 2, the equipment control cabinet 1 and the robot control cabinet 2 are opened in sequence. The robot body 6 is controlled by setting the program. The workpiece 4 is fixed by the processing platform 3. The robot body 6 drives the galvanometer 5 to control the focal length (the system focal length is 170mm, the focal depth is ±1mm, and the laser displacement sensor in front of the galvanometer is adjusted by controlling the robot end effector, and the accuracy can reach ±0.1mm).

[0030] like Figure 2As shown, the method for adjusting the focal length of the processing plane 1 is as follows: the robot (1-6) is in a bent, rearward position, and a high-precision focusing device (1-5-3) is installed on the 6th axis to perform parallel focusing on the processing plane 1 (2-1). After reaching the point 1 (2-1), the focusing operation is performed.

[0031] like Figure 3 As shown, to adjust the focal length of the processing plane 2, the robot (1-6) is in a straight, forward position, with the 6th axis and the 5th and 4th axes in a straight line. A high-precision focusing device (1-5-3) is installed on the 5th axis to perform parallel focusing on the processing plane 2 (2-2). After reaching the point 2 (2-2), the focusing operation is performed.

[0032] like Figure 4 As shown, to adjust the focal length of the processing plane 3, the robot (1-6) is in a bent, forward position, and a high-precision focusing device (1-5-3) is installed on the 6th axis to perform parallel focusing on the processing plane 3 (2-3). After reaching the point 3 (2-3), the focusing operation is performed.

[0033] like Figure 5 The diagram shows the main structure of the six-axis robotic arm. This robotic arm adopts a serial structure design with six rotary joints (J1-J6), enabling six degrees of freedom of spatial motion. The base (J1 axis) can rotate ±180° around the vertical axis; the shoulder joint (J2 axis) has a range of motion from -135° to +135°; the elbow joint (J3 axis) has a range of motion from -150° to +150°; the wrist joint (J4 axis) can rotate ±200°; the wrist joint (J5 axis) has a range of motion from -130° to +130°; and the end effector flange joint (J6 axis) can rotate continuously ±360°. A laser galvanometer system is installed at the end effector of the robotic arm, achieving a repeatability accuracy of ±0.02mm.

[0034] Figure 6 This is the main interface of the processing system, integrating three core functions: processing task parameter input, real-time equipment status monitoring, and operation log traceability. It can accurately record production information such as melting number and production sequence number, and provide real-time feedback on the execution status and error information of robot motion commands through the log bar. This provides a visual basis for path planning and precision control in dynamic laser processing, offering crucial support for ensuring the stability and reliability of complex surface processing.

[0035] Figure 7 This diagram illustrates a portion of the operating procedure, demonstrating how conditional statements and command combinations enable logic for starting, pausing, and resetting the equipment. The code includes detection of signal states and mode switches, as well as calls to motion control commands such as MC_POWER, ensuring the safety and stability of the automated processing flow.

[0036] Figure 8 The circuit diagram of the equipment is divided into a system architecture diagram, an external power supply diagram, and an internal power supply grounding diagram. Figure 3 This section clearly illustrates the power supply links and grounding schemes for core modules such as PLCs, robots, and servo drives, providing crucial information for the electrical installation, troubleshooting, and safe operation of the equipment.

[0037] Figure 9 This is a precision verification test report for a six-axis robotic arm system. The precision control method includes the following steps: Step A: Establishing a kinematic model of the robotic arm, using the DH parameter method to perform kinematic modeling of the six-axis robotic arm; Step B: Using a dual-laser displacement sensor feedback system to monitor the focal position of the laser displacement sensor in real time, triggering a position compensation program when the deviation exceeds a preset threshold; Step C: Calculating the optimal laser incident angle based on the surface geometric features; Step D: Using the Jacobian matrix method to perform motion conversion between joint space and Cartesian space, detecting and avoiding singular configuration regions in real time; Step E: A tilt error compensation model to automatically compensate for loading position errors.

[0038] Figure 10 This is a finished product image of a laser-processed curved workpiece. The surface displays exquisite concentric circle patterns, with a multi-layered ring at the center extending outwards as a continuous and complex scrollwork decoration. The strong black and white contrast and the fine, uniform texture demonstrate the high precision and stability of laser dynamic curved surface processing technology in engraving complex patterns.

[0039] Example 1

[0040] This embodiment uses a planar metal block as the processing object to verify the planar processing benchmark of the laser dynamic curved surface processing accuracy control method based on a six-axis robotic arm of the present invention. The specific implementation is carried out according to the following steps:

[0041] Step 1: Power the transformer and connect the robot. Turn on the main circuit breaker, start the computer, turn on the air conditioner, turn on the laser control box circuit breaker, activate the emergency stop button and press the galvanometer button, press the laser button, press the control button, turn on the I / O control box circuit breaker, turn on the robot control box circuit breaker, wait for the teach pendant to open and check for any abnormalities, activate the robot control cabinet emergency stop, activate the robot emergency stop button on the lower side of the display screen, activate the teach pendant emergency stop, open the development software on the computer, and click the robot automation button. The laser is a 1064nm wavelength fiber laser with an adjustable rated power of 0-100W.

[0042] Step 2: Securely clamp and position the planar metal block sample on processing platform 3, with the upper surface plane being the surface to be processed. Start the robot and perform kinematic modeling of the six-axis robotic arm using the DH parameter method; as... Figure 1As shown, the robot is in a bent rear position, with a high-precision focusing device (1-5-3) mounted on the 6th axis to perform parallel focusing on the processing surface 1 (2-1). After reaching point 1 (2-1), the laser focuses on the processing surface. The robotic arm uses the Jacobian matrix method for motion transformation, detects and avoids singular configuration areas, and ensures that the robotic arm is always in the optimal motion configuration during processing. The tilt error compensation model automatically compensates for the loading position deviation. The measured loading deviation is 0.08mm, which is eliminated after compensation.

[0043] The sample is made of 304 stainless steel and measures 120mm×80mm×15mm. The system focal length is set to 170mm and the defocusing amount is ±1mm. A dual laser displacement sensor feedback system is used to monitor the focal position in real time. The deviation threshold is set to ±0.05mm. When the deviation exceeds the threshold, the position compensation program is triggered.

[0044] Step 3: Import the design pattern (sine curve array pattern, line width 0.1mm, spacing 0.5mm) into the control software and set the laser processing parameters: laser power 40W, scanning speed 500mm / s, pulse width 20ns, repetition frequency 30kHz. First, perform a no-load pre-processing on the sample to verify the processing path and point accuracy. After confirming that the toolpath is correct, start the laser for formal processing.

[0045] The laser dynamic inclined / curved surface machining method for a six-axis robotic arm of this invention achieves a planar machining positioning accuracy of ±0.02mm, a machining contour accuracy of ±0.03mm, and an overall machining accuracy within ±0.05mm. The surface roughness Ra is 1.2μm. Example 2

[0046] This embodiment uses a sloping metal block as the processing object to verify the accuracy control method for laser dynamic curved surface processing based on a six-axis robotic arm of the present invention through dynamic machining of sloping surfaces. The specific implementation is carried out according to the following steps:

[0047] Step 1: The equipment startup process is the same as in Example 1. The laser is a 1064nm wavelength fiber laser with an adjustable rated power of 0-100W.

[0048] Step 2: Securely clamp the inclined metal block sample onto processing platform 3 and position it. Start the robot and use the DH parameter method to perform kinematic modeling of the six-axis robotic arm. Since the processing surface is a 30° incline, the robot needs to dynamically adjust its posture along the incline, such as... Figure 1 , 2As shown: The robot (1-6) is in a bent-forward state. A high-precision focusing device is installed on the 6th axis to focus on the top layer, obtain the contrast height after focusing, calculate the height of point 1, and move the high-precision focusing device to the workpiece processing surface in world coordinates. The high-precision focusing device (1-5-3) installed on the 6th axis is used to perform parallel focusing on the processing surface 1 (2-1). After reaching point 1 (2-1), the focusing operation is performed. Then the robot (1-6) is in a straight-forward state, with the 6th axis in a straight line with the 5th and 4th axes. The high-precision focusing device (1-5-3) installed on the 5th axis is used to perform parallel focusing on the processing surface 2 (2-2). After reaching point 2 (2-2), the focusing operation is performed.

[0049] The sample is made of 304 stainless steel and measures 120mm×80mm×15mm. The upper surface is machined as a 30° single bevel with a length span of 120mm and a height difference of 60mm. The defocusing amount is ±1mm, and the set deviation threshold is ±0.03mm. When the deviation exceeds the threshold, the position compensation program is triggered.

[0050] Soft limits are set: the safe movement range of the J2 axis is -120° to +90°, and the safe movement range of the J3 axis is -130° to +120°. The tilt error compensation model jointly compensates for the loading position deviation and the inclined plane angle installation error, ensuring that the workpiece loading deviation and inclined plane angle deviation are within 0.02mm and 0.1°, respectively. Figure 7 As shown, the path planning algorithm adopts a hybrid optimization strategy of improved RRT* algorithm and genetic algorithm to optimize path generation for slopes with constant inclination angle.

[0051] Step 3: Import the design pattern (equally spaced parallel line array pattern, line width 0.15mm, spacing 1.0mm, arranged along the inclined plane) into the control software, and set the laser processing parameters: laser power 55W, scanning speed 450mm / s, pulse width 25ns, repetition frequency 32kHz. First, perform a no-load pre-processing on the sample to verify the processing path and point accuracy. After confirming that the toolpath is correct, start the laser for formal processing.

[0052] This invention discloses a laser dynamic inclined / curved surface machining method for a six-axis robotic arm. The positioning accuracy of each measurement point during inclined surface machining is within ±0.03mm, the machining contour accuracy is ±0.04mm, the difference in machining accuracy between the upper and lower ends of the inclined surface is controlled within 0.01mm, and the overall machining accuracy is within ±0.05mm. The surface roughness Ra is 1.4μm.

[0053] Example 3

[0054] This embodiment uses a curved metal block as the processing object to verify the accuracy control method for laser dynamic curved surface processing based on a six-axis robotic arm of the present invention through complex curved surface dynamic processing. The specific implementation is carried out according to the following steps:

[0055] Step 1: The equipment startup process is the same as in Example 1. The laser is a 1064nm wavelength fiber laser with an adjustable rated power of 0-100W.

[0056] Step 2: Stably clamp the curved metal block sample onto processing platform 3 and position it. Start the robot and use the DH parameter method to perform kinematic modeling of the six-axis robotic arm. The focusing process is as follows: Figure 1-3 As shown: Step 1, the robot (1-6) is in a bent rear position. A high-precision focusing device (1-5-3) mounted on the 6th axis is used to perform parallel focusing on the machining surface 1 (2-1), which is the starting end of the curved surface. The focusing operation is performed after reaching point 1 (2-1). Step 2, the robot (1-6) is in a straight front position. The 6th axis is in a straight line with the 5th and 4th axes. A high-precision focusing device (1-5-3) mounted on the 5th axis is used to perform parallel focusing on the machining surface 2 (2-2), which is the midpoint of the curved surface. The focusing operation is performed after reaching point 2 (2-2). Step 3, the robot (1-6) is in a bent front position. A high-precision focusing device (1-5-3) mounted on the 6th axis is used to perform parallel focusing on the machining surface 3 (2-3), which is the end of the curved surface. The focusing operation is performed after reaching point 3 (2-3). The focal lengths at the two ends and the midpoint of the curved surface are calibrated in three steps to establish a focal length reference for the curved surface.

[0057] The sample is made of 304 stainless steel, with dimensions of 120mm × 80mm × 15mm. The upper surface is machined into an arc surface with a radius of curvature R = 150mm, a height difference of 20mm, and a span of 120mm. The defocusing amount is ±0.02mm. Due to the continuous change of the surface normal vector along the path, dual sensors are set to sample the focus deviation in real time at 500Hz and trigger position compensation.

[0058] In curved surface machining, the normal vector changes non-linearly with the position of the curved surface. The posture of the robotic arm's end effector needs to be dynamically adjusted in real time to ensure that the laser axis is always aligned with the surface normal vector, and the incident angle deviation is controlled within ±1.5°. The six-axis linkage is the most drastic during curved surface machining, with the J4 and J5 axes requiring frequent oscillations to track changes in the surface normal vector. Singular configuration regions need to be detected and avoided in real time. In this example, the safety margin for each joint is set to 15% of its extreme position. The tilt error compensation model jointly compensates for the loading position deviation and the surface shape deviation. The loading deviation is 0.02mm, and the surface shape deviation is within 0.05mm. The path planning algorithm employs a hybrid optimization strategy combining the improved RRT* algorithm and a genetic algorithm. It performs path smoothing optimization for continuously changing surface curvature, generating a machining path that is 18% shorter than the traditional equidistant planning path.

[0059] Step 3: Import the design pattern (concentric arc array pattern, line width 0.12mm, spacing 0.8mm, unfolded along the curvature of the surface) into the control software, and set the laser processing parameters: laser power 65W, scanning speed 400mm / s, pulse width 30ns, repetition frequency 28kHz. First, perform a no-load pre-processing on the sample to verify the processing path and point accuracy. After confirming that the toolpath is correct, start the laser for formal processing.

[0060] The quality inspection of the machined parts was carried out by uniformly selecting 15 measurement points along the arc length of the curved surface, measuring the machining trajectory using a laser image measuring instrument, and characterizing the surface morphology of the machined area using a laser confocal microscope. The precision control of curved surface machining is the most challenging, mainly in the following aspects: (1) the continuous change of the surface normal vector requires real-time dynamic adjustment of the laser incident angle; (2) the complexity of avoiding singular configurations during six-axis linkage is significantly increased; (3) the surface shape deviation needs to be incorporated into the layered compensation strategy. Through the synergistic effect of DH parameter kinematic modeling, real-time feedback from dual sensors, Jacobian matrix motion transformation, and layered precision compensation, the comprehensive machining accuracy within ±0.05mm of the curved surface was achieved, verifying the high-precision control capability and wide engineering applicability of the method of this invention in complex curved surface dynamic machining scenarios.

[0061] This invention discloses a laser dynamic inclined / curved surface machining method for a six-axis robotic arm. The positioning accuracy of each measurement point in the curved surface machining is within ±0.04mm, the machining contour accuracy is ±0.05mm, and the difference in machining accuracy between the top of the curved surface (the area with the greatest change in incident angle) and both ends is controlled within 0.02mm. The overall machining accuracy meets the control requirement of ±0.05mm. The surface roughness Ra is 1.5μm. The present invention uses a six-axis robotic arm to process curved surface finished products, such as... Figure 10As shown, laser scanning is used to mark curved workpieces, revealing fine and uniform machining textures and high machining accuracy. This demonstrates the high-precision fabrication of curved surfaces using laser multi-axis dynamic machining technology.

Claims

1. A method for controlling the accuracy of laser dynamic surface machining based on a six-axis robotic arm, characterized in that, The specific steps are as follows: Step 1: Power the transformer and connect it to the robot. Turn on the laser, robot control cabinet and computer development software in sequence according to the specifications. Step 2: Securely clamp and position the sample, start the robot to focus on each surface to be processed in sequence, control the focus position and the accuracy of the surface to be processed by precisely adjusting the laser height and the robot posture, and then set the marking points of the laser on each surface to be processed through the program. Step 3: Import the design pattern into the control software, set the laser power, scanning speed and other parameters according to the material and processing requirements, perform a no-load pre-processing on the sample first, check the processing path and point accuracy, and after confirming that the tool path is correct, start the laser for formal processing.

2. The specific focusing process of the robot according to claim 1 is as follows: Step 1, the robot (1-6) is in a bent, rear-positioned state, and a high-precision focusing device (1-5-3) mounted on the 6th axis performs parallel focusing on the processing surface 1 (2-1). After reaching point 1 (2-1), the focusing operation is performed. Step 2, the robot (1-6) is in a straight, forward-positioned state, the 6th axis is in a straight line with the 5th and 4th axes, and a high-precision focusing device (1-5-3) mounted on the 5th axis performs parallel focusing on the processing surface 2 (2-2). After reaching point 2 (2-2), the focusing operation is performed. Step 3, the robot (1-6) is in a bent, forward-positioned state, and a high-precision focusing device (1-5-3) mounted on the 6th axis performs parallel focusing on the processing surface 3 (2-3). After reaching point 3 (2-3), the focusing operation is performed.

3. The robot posture control and point-to-point accuracy control method according to claim 1, characterized in that, The precision control method includes the following steps: Step A: Establish a kinematic model of the robotic arm, and perform kinematic modeling of the six-axis robotic arm using the DH parameter method; Step B: Use a dual laser displacement sensor feedback system to monitor the focal position of the laser displacement sensor in real time, and trigger a position compensation program when the deviation exceeds a preset threshold; Step C: Calculate the optimal laser incident angle based on the surface geometric features; Step D: Use the Jacobian matrix method to perform motion conversion between joint space and Cartesian space, and detect and avoid singular configuration regions in real time; Step E: Tilt error compensation model to automatically compensate for loading position errors.

4. The program control method according to claim 1, characterized in that, The control program has the following features and advantages: (1) It adopts a modular program architecture design, and the path planning module, motion control module, accuracy compensation module and human-computer interaction module are independently encapsulated; (2) The path planning algorithm adopts a hybrid optimization strategy of improved RRT* algorithm and genetic algorithm, and the path planning time is shortened by more than 40% compared with the traditional method; (3) The accuracy compensation program adopts a hierarchical compensation strategy, and the comprehensive processing accuracy can reach within ±0.05mm; (4) The program supports the switching of multiple processing scheme templates, and the average fault-free running time of the system exceeds 2000 hours.

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