A femtosecond laser three-dimensional seven-axis linkage machining system

Abstract

This invention discloses a femtosecond laser three-dimensional seven-axis linkage machining system, belonging to the field of laser precision machining technology. The system integrates a femtosecond laser pulse train temporal characteristic detection module, a three-dimensional seven-axis linkage motion control module, a laser processing execution module, and an intelligent control module. First, the detection module accurately acquires temporal characteristic parameters of the femtosecond laser pulse train, such as the sub-pulse time difference and polarization direction. Then, the motion control module achieves high-precision spatial positioning across seven axes. Combined with the control module, the laser processing parameters and motion trajectory are optimized in real time based on the detected parameters, achieving high-precision, highly adaptable three-dimensional machining with femtosecond lasers. This system combines precise laser characteristic detection with multi-axis linkage machining control capabilities, exhibiting high processing accuracy, strong adaptability, and good stability. It can be widely applied in precision manufacturing, micro-nano fabrication, and biomedical device fabrication.

Description

Technical Field

[0001] This invention relates to the field of laser precision machining technology, specifically to a femtosecond laser three-dimensional seven-axis linkage machining system. Background Technology

[0002] Femtosecond lasers, with their ultrashort pulse width, ultra-high peak power, and extremely small heat-affected zone, have become a core technology for precision micro- and nano-fabrication and the fabrication of complex structural devices, and are widely used in aerospace, precision electronics, and biomedicine. However, existing femtosecond laser processing equipment mostly employs simple single-axis or multi-axis linkage control methods, resulting in low degrees of freedom and making it difficult to achieve high-precision processing of complex three-dimensional curved surfaces and irregularly shaped microstructures. Furthermore, existing equipment lacks the ability to detect and control the temporal characteristics of femtosecond laser pulse trains in real time; even minute changes in laser output characteristics can directly affect processing accuracy and consistency, leading to unstable processing quality.

[0003] Furthermore, traditional femtosecond laser processing systems often use preset, fixed values ​​for laser and motion control parameters, making real-time optimization impossible based on the actual temporal characteristics of the laser and the workpiece's processing status, resulting in poor adaptability. Moreover, the lack of precise visual positioning of the workpiece and real-time monitoring of the processing status during the process easily leads to processing deviations, making it difficult to meet the demands for high precision and high consistency. Therefore, developing a femtosecond laser processing system that combines precise detection of laser temporal characteristics, high-precision multi-axis linkage control, and intelligent adjustment of processing parameters has become a pressing technical problem to be solved in this field. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a femtosecond laser three-dimensional seven-axis linkage machining system, which solves the problems of low motion freedom, lack of real-time detection and control of laser characteristics, and mismatch between machining parameters and laser characteristics in existing femtosecond laser processing equipment, and realizes high-precision, high-stability, and high-adaptability three-dimensional precision machining with femtosecond laser.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a femtosecond laser three-dimensional seven-axis linkage machining system, comprising a femtosecond laser emitting module, a time-domain characteristic detection module, a three-dimensional seven-axis linkage motion control module, a laser processing execution module, an intelligent control module, and a workpiece clamping module; the femtosecond laser emitting module is a femtosecond laser, the output optical path of which is sequentially connected to a beam splitter, which splits the laser into a detection beam and a processing beam; the time-domain characteristic detection module is connected to the detection beam optical path and is used to detect the time-domain characteristic parameters of the femtosecond laser pulse train; the three-dimensional seven-axis linkage motion control module includes X / Y / Z linear axes, A / B / C rotary axes, and a W precision fine-tuning axis to realize seven-axis linkage spatial motion control; the laser processing execution module is connected to the processing beam optical path and is also connected to the three-dimensional seven-axis linkage motion control module; the intelligent control module is electrically connected to the time-domain characteristic detection module, the three-dimensional seven-axis linkage motion control module, and the laser processing execution module respectively, receiving detection parameters and adjusting processing parameters and motion trajectory in real time; the workpiece clamping module is located at the processing station of the laser processing execution module.

[0006] Furthermore, the time-domain characteristic detection module includes a time-domain shaping module, a polarizer, a dispersive crystal, a focusing lens group, a BBO nonlinear crystal, a time delay line, a filter, a photodetector, and a host computer detection unit. The photodetector is electrically connected to the host computer detection unit, and the host computer detection unit is communicatively connected to the intelligent control module.

[0007] Furthermore, the laser processing execution module includes a laser beam expander, an adjustable polarization controller, a processing focusing head, and a laser power regulator, both of which are electrically connected to the intelligent control module.

[0008] Furthermore, the three-dimensional seven-axis linkage motion control module includes a servo drive unit, a motion controller, a grating ruler displacement detection unit, and an angle encoder. The grating ruler displacement detection unit and the angle encoder are respectively matched with the X / Y / Z linear axes, the A / B / C rotary axes, and the W precision fine-tuning axis, and are all electrically connected to the motion controller. The motion controller is electrically connected to the intelligent control module.

[0009] Furthermore, the intelligent control module includes a data processing unit, a parameter matching unit, a trajectory optimization unit, and a real-time control unit. The data processing unit receives the detection parameters from the time-domain characteristic detection module, the parameter matching unit matches the optimal machining parameters according to the detection parameters, the trajectory optimization unit generates a seven-axis linkage machining trajectory, and the real-time control unit outputs control signals to each module.

[0010] Furthermore, the workpiece clamping module includes a vacuum adsorption platform, a precision chuck, and tooling fixtures. The tooling fixtures are connected to the motion end of the three-dimensional seven-axis linkage motion control module to realize multi-position clamping and linkage motion of the workpiece.

[0011] Furthermore, the machining focusing head is a telecentric focusing head with an adjustable focusing focal length, and the machining focusing head is connected to the Z-axis and W-axis of the three-dimensional seven-axis linkage motion control module to achieve precise adjustment of the focusing position.

[0012] Furthermore, it also includes a visual positioning module, which comprises an industrial camera, a microscopic imaging unit, and an image recognition unit. It is set next to the processing station and electrically connected to the intelligent control module to achieve precise positioning of the workpiece and real-time monitoring of the processing process.

[0013] Furthermore, the beam splitter is an adjustable beam splitter with a splitting ratio adjustment range of 1:99 to 99:1. The beam splitter is electrically connected to the intelligent control module to realize automatic adjustment of the splitting ratio between the probe beam and the processing beam.

[0014] Furthermore, it also includes a cooling and dust prevention module, which includes a water-cooled unit, a gas protection unit, and a dust removal unit. The water-cooled unit is connected to the femtosecond laser and the processing focusing head. The gas protection unit and the dust removal unit are both located at the processing station and are electrically connected to the intelligent control module.

[0015] Beneficial effects: (1) It has both laser time domain characteristic detection and processing functions, and can acquire parameters such as laser sub-pulse time difference and polarization direction in real time, so as to avoid processing quality fluctuations caused by changes in laser characteristics and greatly improve processing stability; (2) The three-dimensional seven-axis linkage motion control of X / Y / Z / A / B / C / W is adopted, which has high motion freedom, high positioning accuracy and angle adjustment accuracy, and can realize high-precision spatial processing of complex three-dimensional curved surfaces and irregular microstructures, and significantly improves processing adaptability; (3) The intelligent control module establishes a real-time matching and optimization mechanism between laser parameters, processing parameters, and motion trajectory, realizing automated and intelligent control of the processing process without manual intervention, thereby improving processing efficiency and consistency; (4) Integrate auxiliary modules such as visual positioning and cooling and dust prevention to achieve precise workpiece positioning, real-time monitoring of the processing process and all-round protection of equipment, further ensuring processing accuracy and equipment service life; (5) Each module adopts a modular design, which is convenient for disassembly, assembly and maintenance. The splitting ratio, processing parameters and motion trajectory can be flexibly adjusted according to processing needs, which can adapt to the precision processing needs of different industries and structures and has a wide range of applications.

[0016] The above description is merely an overview of the technical solutions of the embodiments of this application. In order to better understand the technical means of the embodiments of this application and to implement them in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the embodiments of this application more apparent and understandable, specific implementation methods of this application are described below. Attached Figure Description Figure 1 is a schematic diagram of the overall structure of the femtosecond laser three-dimensional seven-axis linkage machining system of the present invention; Figure 2 is a schematic diagram of the working process of the intelligent control module of the present invention.

[0017] Explanation of reference numerals in the attached figures: 1- Femtosecond laser, 2- Adjustable beam splitter, 3- Temporal characteristic detection module, 4- Laser processing execution module, 5- Three-dimensional seven-axis linkage motion control module, 6- Intelligent control module, 61- Data processing unit, 62- Parameter matching unit, 63- Trajectory optimization unit, 64- Real-time control unit, 7- Workpiece clamping module, 8- Vision positioning module, 9- Cooling and dust prevention module. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0020] Please see Figure 1 , Figure 2 The present invention provides a femtosecond laser three-dimensional seven-axis linkage machining system, including a femtosecond laser emission module, a time domain characteristic detection module 3, a three-dimensional seven-axis linkage motion control module 5, a laser processing execution module 4, an intelligent control module 6, a workpiece clamping module 7, a vision positioning module 8, and a cooling and dust prevention module 9; The femtosecond laser emitting module is a femtosecond laser 1, whose output optical path is connected to an adjustable beam splitter 2. The beam splitting ratio is adjustable from 1:99 to 99:1, which splits the laser into a probe beam and a processing beam. The probe beam enters the time domain characteristic detection module 3, and the processing beam enters the laser processing execution module 4. The adjustable beam splitter 2 is electrically connected to the intelligent control module 6 to realize automatic adjustment of the beam splitting ratio. The time-domain characteristic detection module 3 includes a time-domain shaping module, a polarizer, a dispersive crystal, a focusing lens group, a BBO nonlinear crystal, a time delay line, a filter, a photodetector, and a host computer detection unit. The photodetector converts the optical signal into an electrical signal and transmits it to the host computer detection unit. The host computer detection unit processes and analyzes the signal to obtain time-domain characteristic parameters such as the time difference between sub-pulses of the femtosecond laser pulse train, polarization direction, short-time average power, and long-term stability, and transmits the parameters to the intelligent control module 6. The laser processing execution module 4 includes a laser beam expander, an adjustable polarization controller, a laser power regulator, and a telecentric focusing head. The processing beam is expanded by the laser beam expander, the polarization direction is adjusted by the adjustable polarization controller, and the output power is adjusted by the laser power regulator. Then, it is focused onto the processing surface of the workpiece by the telecentric focusing head. The focusing focal length of the telecentric focusing head is adjustable and is connected to the Z-axis and W-axis of the three-dimensional seven-axis linkage motion control module 5 to achieve micron-level precision adjustment of the focusing position. The adjustable polarization controller and the laser power regulator are both electrically connected to the intelligent control module 6 to receive real-time control signals. The three-dimensional seven-axis linkage motion control module 5 includes X / Y / Z linear axes, A / B / C rotary axes, W precision fine-tuning axis, servo drive unit, motion controller, grating ruler displacement detection unit, and angle encoder. The grating ruler displacement detection unit works with the X / Y / Z linear axes and W precision fine-tuning axis to achieve real-time displacement detection. The angle encoder works with the A / B / C rotary axes to achieve real-time rotation angle detection. All detection signals are transmitted to the motion controller. The motion controller is electrically connected to the intelligent control module 6, receives trajectory optimization signals, and drives each axis to move in linkage through the servo drive unit to achieve high-precision spatial motion control. The positioning accuracy of the X / Y / Z linear axes is ≤0.001mm, the angle adjustment accuracy of the A / B / C rotary axes is ≤1 arcsecond, and the fine-tuning accuracy of the W precision fine-tuning axis is ≤0.0005mm. Please see Figure 2 The intelligent control module 6 includes a data processing unit 61, a parameter matching unit 62, a trajectory optimization unit 63, and a real-time control unit 64. The data processing unit 61 receives laser time-domain characteristic parameters from the time-domain characteristic detection module 3 and workpiece positioning and processing monitoring information from the vision positioning module 8, and performs noise reduction and normalization processing on the data. The parameter matching unit 62 has a built-in laser parameter-processing parameter matching database, and matches the optimal laser power, polarization direction, focusing focal length, and other processing parameters according to the processed laser parameters. The trajectory optimization unit 63 generates the optimal spatial processing trajectory according to the workpiece's processing structure requirements and the motion characteristics of the seven-axis linkage, and performs real-time fine-tuning according to the laser parameters. The real-time control unit 64 converts the matched processing parameters and the optimized motion trajectory into electrical signals, which are transmitted to the laser processing execution module 4 and the three-dimensional seven-axis linkage motion control module 5, respectively, to realize closed-loop intelligent control of the processing process. The workpiece clamping module 7 is set at the processing station of the laser processing execution module 4. It includes a vacuum adsorption platform, a precision chuck, and a tooling fixture. The vacuum adsorption platform is suitable for flat workpieces, the precision chuck is suitable for shaft workpieces, and the tooling fixture is suitable for irregularly shaped workpieces. The tooling fixture is connected to the motion end of the three-dimensional seven-axis linkage motion control module 5 to realize the synchronous linkage motion between the workpiece and the laser processing head. The visual positioning module 8 includes an industrial camera, a microscopic imaging unit, and an image recognition unit. It is set next to the processing station. The industrial camera works with the microscopic imaging unit to perform high-definition imaging of the workpiece. The image recognition unit performs feature extraction and positioning analysis on the imaging to obtain the precise position information of the workpiece and transmits it to the intelligent control module 6. At the same time, it monitors the processing process in real time and promptly feeds back the processing deviation to the intelligent control module 6 to realize real-time correction of the processing trajectory. The cooling and dust prevention module 9 includes a water-cooled unit, a gas protection unit, and a dust removal unit. The water-cooled unit adopts a closed-loop water cooling method and is connected to the femtosecond laser 1 and the processing focusing head to provide constant temperature cooling, ensuring the stability of laser output and the life of the focusing head. The gas protection unit uses inert gas (such as nitrogen or argon) to form a sealed gas protection atmosphere at the processing station to prevent oxidation of the workpiece processing surface. The dust removal unit adopts a negative pressure dust removal method to remove dust generated during processing in a timely manner, preventing dust from adhering to the focusing head and workpiece surface and affecting processing accuracy.

[0021] The working process of this invention is as follows: Workpiece clamping: Select the appropriate clamping method according to the shape and size of the workpiece, fix the workpiece on the workpiece clamping module 7, start the vision positioning module 8 to accurately position the workpiece, and transmit the positioning information to the intelligent control module 6. Laser emission and beam splitting: The femtosecond laser 1 is started and outputs a femtosecond laser pulse train. The intelligent control module 6 adjusts the splitting ratio of the adjustable beam splitter 2 according to the processing requirements, splitting the laser into a probe beam and a processing beam. Laser temporal characteristic detection: The detection beam enters the temporal characteristic detection module 3, and after optical path shaping, dispersion, and frequency conversion, it is converted into an electrical signal by the photodetector. The host computer detection unit processes and analyzes the signal to obtain the laser temporal characteristic parameters, and transmits them to the intelligent control module 6. Parameter matching and trajectory optimization: The data processing unit 61 of the intelligent control module 6 processes the laser parameters and workpiece positioning information, the parameter matching unit 62 matches the optimal processing parameters, and the trajectory optimization unit 63 generates a seven-axis linkage processing trajectory; Seven-axis linkage machining: The real-time control unit 64 of the intelligent control module 6 outputs control signals to drive the three-dimensional seven-axis linkage motion control module 5 to realize seven-axis linkage motion. At the same time, it controls the laser processing execution module 4 to adjust parameters such as laser polarization direction and power. After the laser is focused, it performs three-dimensional precision machining on the workpiece. Real-time monitoring and control: During the processing, the vision positioning module 8 monitors the processing status in real time, and the time domain characteristic detection module 3 continuously detects the laser time domain characteristics. If there is a change in laser parameters or processing deviation, the intelligent control module 6 immediately corrects the processing parameters and motion trajectory in real time. Processing Protection: The cooling and dustproof module 9 provides cooling for the equipment throughout the process, and provides gas protection and dust removal for the processing station, ensuring the stability and quality of the processing. The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit it. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

[0022] The innovation of this invention lies in: The femtosecond laser pulse train time-domain characteristic detection module is integrated with the processing system to achieve real-time and accurate detection of laser time-domain characteristics, providing data support for processing parameter control and solving the problem of unstable processing quality caused by changes in laser characteristics. The X / Y / Z / A / B / C / W three-dimensional seven-axis linkage motion control module is designed to break through the degree of freedom limitation of traditional multi-axis linkage, realize high-precision spatial machining of complex three-dimensional curved surfaces and irregular microstructures, and greatly improve machining adaptability. An intelligent control module is set up to establish a real-time matching and optimization mechanism between laser time-domain characteristic parameters, processing parameters, and motion trajectory, thereby realizing closed-loop intelligent control of the processing process and improving processing accuracy and consistency. By integrating auxiliary modules such as visual positioning and cooling and dust prevention, an integrated processing system is formed, which realizes precise workpiece positioning, real-time monitoring of the processing process and equipment protection, further ensuring processing quality and equipment stability.

[0023] The femtosecond laser three-dimensional seven-axis linkage machining system of the present invention has high machining accuracy, good stability and strong adaptability. It can be widely used in three-dimensional precision machining of aerospace precision parts, microelectronic chips, biomedical devices, micro-nano sensors and other fields. It can meet the high precision and high consistency machining requirements of various fields for complex structural devices and has significant industrial application value and market prospects.

[0024] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A femtosecond laser three-dimensional seven-axis linkage machining system, characterized in that, The system comprises a femtosecond laser emitting module, a time-domain characteristic detection module, a three-dimensional seven-axis linkage motion control module, a laser processing execution module, an intelligent control module, and a workpiece clamping module. The femtosecond laser emitting module is a femtosecond laser, whose output optical path is sequentially connected to a beam splitter, which divides the laser into a detection beam and a processing beam. The time-domain characteristic detection module is connected to the detection beam optical path and is used to detect the time-domain characteristic parameters of the femtosecond laser pulse train. The three-dimensional seven-axis linkage motion control module includes X / Y / Z linear axes, A / B / C rotary axes, and a W precision fine-tuning axis, realizing seven-axis linkage spatial motion control. The laser processing execution module is connected to the processing beam optical path and is also drive-connected to the three-dimensional seven-axis linkage motion control module. The intelligent control module is electrically connected to the time-domain characteristic detection module, the three-dimensional seven-axis linkage motion control module, and the laser processing execution module, respectively, receiving detection parameters and adjusting processing parameters and motion trajectories in real time. The workpiece clamping module is located at the processing station of the laser processing execution module.

2. The femtosecond laser three-dimensional seven-axis linkage machining system according to claim 1, characterized in that: The time-domain characteristic detection module includes a time-domain shaping module, a polarizer, a dispersive crystal, a focusing lens group, a BBO nonlinear crystal, a time delay line, a filter, a photodetector, and a host computer detection unit. The photodetector is electrically connected to the host computer detection unit, and the host computer detection unit is communicatively connected to the intelligent control module.

3. The femtosecond laser three-dimensional seven-axis linkage machining system according to claim 1, characterized in that: The laser processing execution module includes a laser beam expander, an adjustable polarization controller, a processing focusing head, and a laser power regulator. The adjustable polarization controller and the laser power regulator are both electrically connected to the intelligent control module.

4. The femtosecond laser three-dimensional seven-axis linkage machining system according to claim 1, characterized in that: The three-dimensional seven-axis linkage motion control module includes a servo drive unit, a motion controller, a grating ruler displacement detection unit, and an angle encoder. The grating ruler displacement detection unit and the angle encoder are respectively matched with the X / Y / Z linear axes, A / B / C rotary axes, and W precision fine-tuning axis, and are all electrically connected to the motion controller. The motion controller is electrically connected to the intelligent control module.

5. The femtosecond laser three-dimensional seven-axis linkage machining system according to claim 1, characterized in that: The intelligent control module includes a data processing unit, a parameter matching unit, a trajectory optimization unit, and a real-time control unit. The data processing unit receives the detection parameters from the time-domain characteristic detection module, the parameter matching unit matches the optimal machining parameters according to the detection parameters, the trajectory optimization unit generates a seven-axis linkage machining trajectory, and the real-time control unit outputs control signals to each module.

6. The femtosecond laser three-dimensional seven-axis linkage machining system according to claim 1, characterized in that: The workpiece clamping module includes a vacuum adsorption platform, a precision chuck, and a tooling fixture. The tooling fixture is connected to the motion end of the three-dimensional seven-axis linkage motion control module to realize multi-position clamping and linkage motion of the workpiece.

7. The femtosecond laser three-dimensional seven-axis linkage machining system according to claim 3, characterized in that: The processing focusing head is a telecentric focusing head with an adjustable focusing focal length. The processing focusing head is connected to the Z-axis and W-axis of the three-dimensional seven-axis linkage motion control module to achieve precise adjustment of the focusing position.

8. The femtosecond laser three-dimensional seven-axis linkage machining system according to claim 1, characterized in that: It also includes a visual positioning module, which comprises an industrial camera, a microscopic imaging unit, and an image recognition unit. The module is located next to the processing station and is electrically connected to the intelligent control module to achieve precise positioning of the workpiece and real-time monitoring of the processing process.

9. The femtosecond laser three-dimensional seven-axis linkage machining system according to claim 1, characterized in that: The beam splitter is an adjustable beam splitter with a splitting ratio adjustment range of 1:99 to 99:

1. The beam splitter is electrically connected to the intelligent control module to realize automatic adjustment of the splitting ratio between the detection beam and the processing beam.

10. A femtosecond laser three-dimensional seven-axis linkage machining system according to claim 1, characterized in that: It also includes a cooling and dust prevention module, which includes a water-cooled unit, a gas protection unit, and a dust removal unit. The water-cooled unit is connected to the femtosecond laser and the processing focusing head. The gas protection unit and the dust removal unit are both located at the processing station and are electrically connected to the intelligent control module.

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