A laser ablation and milling collaborative machining system and method for hard and brittle materials

Abstract

This invention discloses a laser ablation and milling collaborative machining system and method for hard and brittle materials. The system includes a machine tool milling system, a laser ablation system, and a collaborative control device. The laser ablation system utilizes a six-degree-of-freedom robotic arm to mount the ablation mechanism. The collaborative control device generates collaborative data based on the machining program, achieving collaborative machining with laser ablation leading and milling lagging. The method calculates the milling lag time interval using Newton's law of cooling, combines G-code parsing to generate the laser ablation trajectory and adds a non-ablation segment, and incorporates modules such as visual obstacle avoidance and laser focus adjustment to ensure machining safety and accuracy. This system and method solve problems such as tool wear, low efficiency, and difficulty in controlling thermal damage in the machining of hard and brittle materials, achieving efficient, high-precision, and low-damage machining, meeting the needs of complex surface machining, and quantifying the laser ablation lead time to balance machining efficiency and accuracy.

Description

Technical Field

[0001] This invention relates to the field of hard and brittle material processing technology, and in particular to a laser ablation and milling collaborative processing system and method for hard and brittle materials. Background Technology

[0002] With the development of aerospace manufacturing technology, hard and brittle materials, represented by reaction-bonded silicon carbide and ceramic matrix composites, have become core materials for high-performance hot-end structural components in aircraft due to their high temperature resistance, high specific strength, lightweight, and high damage tolerance. The application of these materials involves four key stages: material forming, machining, component assembly, and overall aircraft assembly. Among these, machining is the core step that determines the final performance of the component. However, the inherent characteristics of hard and brittle materials, such as high hardness, high brittleness, anisotropy, and heterogeneity, pose severe challenges to the machining process: severe tool wear and chipping, high machining loads, susceptibility to edge chipping and vibration defects, and a significantly increased risk of material damage due to fiber orientation and weak interfaces. Traditional solutions aim to ensure machining quality by reducing material removal rates, but this results in low machining efficiency and cannot meet the mass production needs of complex structural components in the aerospace field.

[0003] To address the aforementioned issues, laser-assisted machining technology has become a research hotspot in recent years. For example, laser-assisted grinding, turning, and milling technologies reduce material hardness through the laser thermal softening effect, thereby improving processing quality. However, existing technologies still have significant limitations: on the one hand, the thermal softening effect is limited for high-temperature resistant materials, and the melting, oxidation, and resolidification of the material surface during high-energy laser ablation can lead to changes in properties, requiring precise control of the damage level; on the other hand, traditional laser-assisted machining focuses primarily on single-process optimization and lacks multi-process collaborative mechanisms. For instance, the mobile ultrafast laser processing robot equipment proposed in patent CN112060103B, while achieving laser hole making on large-sized workpieces, is only suitable for simple hole processing and cannot meet the requirements of high-precision milling; the laser-ultrasonic dual-assisted milling device disclosed in patent CN215941632U, although combining laser and ultrasonic technologies, lacks a multi-field collaborative processing method, making it difficult to handle the precision machining of complex surfaces.

[0004] Furthermore, while the combination of ultrafast lasers and five-axis linkage technology has achieved breakthroughs in micron-level machining accuracy, problems such as insufficient real-time performance of dynamic coupling algorithms and imperfect subsurface crack suppression mechanisms still need to be addressed. For example, although femtosecond laser processing can reduce surface damage, its nonlinear energy absorption mechanism is still unclear, making it difficult to guarantee the consistency of large-format machining quality. Although existing research has proposed partial ablation-milling strategies to improve surface quality, the quantitative relationship between laser pre-ablation time and material removal rate has not been established, making it difficult to achieve a balance between machining efficiency and accuracy. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by achieving efficient, high-precision, and low-damage machining of hard and brittle materials. It proposes a laser ablation and milling collaborative machining system and method for hard and brittle materials, ensuring machining accuracy and meeting the requirements for machining complex surfaces. Furthermore, by calculating the minimum laser ablation time, the minimum laser ablation time is obtained, thereby ensuring the machining efficiency of hard and brittle composite materials.

[0006] This application achieves the above objectives through the following technical solution:

[0007] A laser ablation and milling collaborative machining system for hard and brittle materials is characterized by comprising a machine tool milling system, a laser ablation system, and a collaborative control device; the machine tool milling system includes a machine tool CNC mechanism, a machine tool main body mechanism, and a machine tool spindle unit; the laser ablation system includes a six-degree-of-freedom robotic arm and a laser ablation mechanism; and the collaborative control device includes a central control unit, a robotic arm control module, and a laser ablation control module.

[0008] The central control unit establishes physical communication connections with the machine tool CNC mechanism, the laser ablation control module, and the robotic arm control module, respectively. It is used to generate ablation end collaborative data and milling end collaborative data based on the machining program of hard and brittle material workpieces, and send drive collaborative instructions and ablation collaborative instructions to the robotic arm control module and the laser ablation control module respectively according to the ablation end collaborative data, and send milling collaborative instructions to the machine tool CNC mechanism according to the milling end collaborative data.

[0009] The robotic arm control module establishes a physical control connection with the six-degree-of-freedom robotic arm, which is used to parse the drive coordination command into drive control signals for the six-degree-of-freedom robotic arm; the six-degree-of-freedom robotic arm is installed at the front end of the worktable of the machine tool body, and is used to execute the joint actions according to the drive control signals issued by the robotic arm control module.

[0010] The laser ablation control module establishes a physical control connection with the laser ablation mechanism to parse the ablation coordination command into a drive and control signal for the laser ablation mechanism. The laser ablation mechanism is mounted on the end effector of a six-degree-of-freedom robotic arm and is used to perform laser ablation processing on hard and brittle material workpieces according to the drive and control signal issued by the laser ablation control module, in coordination with the joint movements of the six-degree-of-freedom robotic arm, and according to a specified trajectory and speed.

[0011] The machine tool spindle unit is mounted on the main body of the machine tool, and a milling tool assembly for milling hard and brittle material workpieces is installed on the machine tool spindle unit; the machine tool CNC mechanism is physically connected to the machine tool spindle unit through a servo control circuit, and is used to control the movement of the machine tool spindle unit according to the milling coordination command, so that the milling tool assembly performs milling of hard and brittle material workpieces according to a specified trajectory and speed, which is lagging behind the laser ablation process.

[0012] Preferably, the laser ablation system further includes a visual obstacle avoidance unit, which includes a camera device and an image pose recognition unit. The camera device is physically connected to the image pose recognition unit and is used to acquire image data of the machine tool spindle unit and the hard and brittle material workpiece in real time, and transmit the image data to the image pose recognition unit. The image pose recognition unit is physically connected to the central control unit and is used to identify the real-time dynamic pose information of the machine tool spindle unit and the hard and brittle material workpiece through the image data, and transmit the real-time dynamic pose information to the central control unit, so that the central control unit controls the six-degree-of-freedom robotic arm to avoid the machine tool spindle unit and the hard and brittle material workpiece through the robotic arm control module.

[0013] Preferably, the laser ablation mechanism includes a laser processing head and a laser generator; the laser generator is connected to the laser ablation control module and is used to emit a laser beam according to the drive signal issued by the laser ablation control module; the laser processing head is connected to the laser generator and is used to focus the laser beam emitted by the laser generator onto the hard and brittle material workpiece.

[0014] Preferably, the collaborative control device further includes a laser focusing adjustment unit and a laser rangefinder; the laser rangefinder is mounted on a six-degree-of-freedom robotic arm and establishes a physical communication connection with the laser focusing adjustment unit, used to measure the real-time distance between the laser processing head and the hard and brittle material workpiece based on the projection of the laser beam emitted by the laser processing head on the surface of the hard and brittle material workpiece, and transmits the real-time distance to the laser focusing adjustment unit; the laser focusing adjustment unit establishes a physical communication connection with the robotic arm control module, used to obtain the distance adjustment signal based on the real-time distance between the laser processing head and the hard and brittle material workpiece, and transmit the distance adjustment signal to the robotic arm control module, through which the robotic arm control module controls the six-degree-of-freedom robotic arm to adjust the distance between the laser processing head and the hard and brittle material workpiece, so that the laser beam emitted by the laser processing head is always focused on the surface of the hard and brittle material workpiece.

[0015] Preferably, the laser ablation system further includes a refrigerated dryer, and the refrigerated dryer is physically connected to the central control unit to provide a drying gas source for the laser generator.

[0016] Preferably, it also includes a power distribution cabinet, which is connected to the power supply of both the laser ablation system and the collaborative control device.

[0017] A laser ablation and milling co-processing method for hard and brittle materials specifically employs the aforementioned laser ablation and milling co-processing system to implement the following processing control steps:

[0018] The laser ablation and milling co-processing system is started and initialized;

[0019] The central control unit acquires the machining program for hard and brittle material workpieces and generates ablation end collaborative data and milling end collaborative data based on the machining program for hard and brittle material workpieces;

[0020] The central control unit sends drive coordination commands and ablation coordination commands to the robotic arm control module and the laser ablation control module respectively, based on the ablation end coordination data.

[0021] The robotic arm control module parses the drive coordination instructions into drive control signals for the six-degree-of-freedom robotic arm, and the laser ablation control module parses the ablation coordination instructions into drive control signals for the laser ablation mechanism, so that the laser ablation mechanism cooperates with the six-degree-of-freedom robotic arm to perform laser ablation processing on hard and brittle material workpieces according to the specified trajectory and speed.

[0022] The central control unit sends milling coordination instructions to the CNC mechanism of the machine tool based on the milling end coordination data. The CNC mechanism of the machine tool runs the machining program for hard and brittle material workpieces according to the milling coordination instructions. By controlling the movement of the machine tool spindle unit, the milling tool assembly performs milling machining on the hard and brittle material workpieces according to the specified trajectory and speed, which is lagging behind the laser ablation process.

[0023] Preferably, the method for the central control unit to acquire the machining program of a hard and brittle material workpiece includes active acquisition and passive acquisition. Active acquisition involves the central control unit sending a machining program read command to the machine tool CNC mechanism based on a physical connection established with the machine tool CNC mechanism via an industrial communication interface; the machine tool CNC mechanism responds to the command and transmits the workpiece machining program to the central control unit in binary or text format. Passive acquisition involves the machine tool CNC mechanism directly transmitting the workpiece machining program to the central control unit in binary or text format based on a physical connection established with the central control unit via an industrial communication interface. After receiving the workpiece machining program, the central control unit performs an integrity verification on the workpiece machining program; if the verification passes, it proceeds to the next step of the parsing process; if the verification fails, it sends error feedback to the machine tool CNC mechanism.

[0024] Preferably, in the process of generating milling end collaborative data based on the machining program for hard and brittle material workpieces, the process includes generating the lag time interval between milling and laser ablation. That is: Formula 1 is obtained based on Newton's law of cooling. ;in This is the minimum lag time interval. For the current ablation zone of a workpiece made of hard and brittle material, For the specific heat capacity of a workpiece made of hard and brittle materials, The convective heat transfer coefficient, The surface area of ​​the current ablation zone of the hard and brittle material workpiece; This represents the current average temperature of the ablation zone. This is the highest temperature at which milling can be performed. The ambient temperature is set. The current ablation zone of the hard, brittle material workpiece is defined as a region with dimensions of [length, width, and height]. , , A cuboid, then has , , This represents the density of a workpiece made of hard and brittle materials; thus, Formula 1 is transformed into... Calculate the minimum lag time interval. ,make .

[0025] Preferably, in the process of generating collaborative data for the ablation end based on the workpiece machining program for hard and brittle materials, the process includes generating a laser ablation machining trajectory. Generating the laser ablation machining trajectory includes the following steps: The central control unit calls a G-code parser to scan the workpiece machining program line by line, identifies milling-related instructions, filters out non-trajectory instructions, and retains only trajectory instructions related to the movement of the milling tool assembly. The trajectory instructions are interpolated, and then discrete trajectory instruction segments are converted into a continuous sequence of trajectory points, forming the basic data structure of the workpiece milling machining trajectory. After smoothing the basic data structure of the milling machining trajectory, the central control unit transforms the trajectory coordinate data from the machine tool coordinate system to the reference coordinate system of the laser ablation system, generating the basic ablation trajectory. A non-ablation segment is added to the end of the basic ablation trajectory, ultimately generating the laser ablation machining trajectory.

[0026] Preferably, adding a non-ablation segment trajectory at the end of the basic ablation trajectory includes: calculating the minimum distance between the ablation area and the milled area at the same time, i.e. ,in This indicates the feed rate in milling operations; taking into account the diameter of the milling tool assembly... Under the given conditions, calculate the length of the non-ablation segment trajectory. ,Right now Based on the coordinates of the endpoint of the basic ablation trajectory, a vector extension is made along the direction of ablation movement, with an extension length of... .

[0027] Preferably, in the process of generating ablation end collaborative data based on the workpiece processing program of hard and brittle materials, the process also includes generating trajectory segmentation markers, which are used as the basis for the laser ablation control module to control the operation of the laser ablation mechanism. The trajectory segmentation markers include traversing the laser ablation processing trajectory point set, marking the points in the basic ablation trajectory as "ablation task segments", and marking the points in the non-ablation segment trajectory as "non-ablation segments".

[0028] Compared to the problems of severe tool wear, low processing efficiency, lack of multi-process synergy mechanism, and insufficient thermal damage control in traditional hard and brittle material processing techniques in the background art, the "laser ablation and milling synergistic processing system and method for hard and brittle materials" proposed in this invention brings the following beneficial technical effects:

[0029] I. Multi-process synergy improves processing efficiency and precision

[0030] Timing synergy between laser ablation and milling: Laser ablation is performed in advance, while milling is executed with a lag. The lag time interval is calculated using Newton's law of cooling to ensure the ablation area cools to a safe temperature, avoiding tool wear and workpiece breakage caused by high temperatures. This breaks through the limitations of traditional single processes by quantifying the synergistic relationship (e.g., (Relationship with material thermophysical parameters) to improve material removal efficiency while ensuring processing quality.

[0031] Trajectory planning and dynamic obstacle avoidance: Based on G-code parsing, a laser ablation trajectory is generated. Conflicts with the milling trajectory are avoided through a combination of a basic ablation trajectory and non-ablation segment extension. The visual obstacle avoidance unit identifies the machine tool spindle and workpiece pose in real time and dynamically adjusts the robotic arm path. This solves the problem in existing technologies where "traditional laser-assisted machining trajectories are singular and unable to handle complex surfaces," enabling precision machining of complex surfaces.

[0032] II. Thermal Damage Control and Processing Stability Optimization

[0033] Dynamic laser focusing adjustment: The laser rangefinder measures the distance between the processing head and the workpiece in real time, and the focusing adjustment unit controls the robotic arm to adjust its height, ensuring that the laser is always focused on the workpiece surface and avoiding uneven energy density caused by distance fluctuations. This improves upon the problems of "unclear nonlinear energy absorption mechanism and poor processing quality consistency" in existing technologies, thus enhancing surface processing quality.

[0034] Cooling and air supply guarantee: The refrigerated dryer provides a dry air source for the laser generator to prevent damage to optical components caused by moisture; the power distribution cabinet provides unified power supply to ensure system stability.

[0035] III. System Integration and Intelligent Control

[0036] Multi-module linkage of the collaborative control device: The central control unit uniformly generates collaborative data between the ablation end and the milling end, and achieves precise driving of multiple actuators through the robotic arm control module and the laser ablation control module, supporting active / passive acquisition and integrity verification of the machining program. It solves the problem of "lack of multi-process collaborative mechanism in traditional laser-assisted machining" in existing technologies, and achieves dynamic matching of process parameters through integrated control.

[0037] Quantitative design based on physical models: A hysteresis time calculation model is established using Newton's law of cooling, simplifying the ablation region into a cuboid, and deriving the model by combining parameters such as material density and specific heat capacity. The minimum value is achieved, realizing a quantitative balance between processing efficiency and thermal damage. Unlike existing technologies that lack a quantitative relationship between laser pre-ablation time and material removal rate, this invention improves process controllability through physical modeling.

[0038] IV. Enhanced Adaptability and Safety

[0039] The flexible movement of the six-DOF robotic arm: Equipped with a laser ablation mechanism, the robotic arm adapts to complex trajectories through six-DOF joint movements. Combined with visual obstacle avoidance, it prevents collisions with the machine tool spindle, making it suitable for processing large workpieces. It overcomes the problem of insufficient real-time performance of the dynamic coupling algorithm in existing five-axis linkage technology, improving motion accuracy and environmental adaptability.

[0040] Trajectory segmentation and laser output control: The laser ablation trajectory is marked as "ablation task segment" and "non-ablation segment," and the laser output is precisely controlled according to the segmentation markings, reducing ineffective ablation and energy waste. Compared with the problem of "difficulty in controlling the degree of laser ablation damage" in the prior art, this invention achieves precise control of the processing area through trajectory subdivision. Attached Figure Description

[0041] Figure 1 A schematic diagram of the spatial layout structure of a laser ablation and milling co-processing system;

[0042] Figure 2 A schematic diagram of the structural layout and installation of a laser ablation system;

[0043] Figure 3 A schematic diagram showing the trajectory relationship between laser ablation and milling combined.

[0044] Figure 4 This is a schematic diagram of the laser focusing trajectory in a single ablation region;

[0045] Figure 5 This is the electrical control schematic diagram of a laser ablation and milling co-processing system.

[0046] 1. Machine tool main body; 1.1 Worktable; 2. Machine tool spindle unit; 3. Cooperative control device; 4. Six-degree-of-freedom robotic arm; 5. Camera device; 6. Laser processing head; 7. Laser generator; 8. Laser rangefinder; 9. Power distribution cabinet; 10. Refrigerated dryer; 11. Cable; 12. Hard and brittle material workpiece; 13. Basic ablation trajectory; 14. Laser ablation processing trajectory starting position; 15. Laser ablation processing trajectory ending position; 16. Laser focusing trajectory; 17. Area to be processed; 18. Milling trajectory starting position; 19. Milling trajectory ending position; 20. Ablation area. Detailed Implementation

[0047] To make the purpose, technical solution and advantages of the invention clearer, the technical solution of the invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the invention, but not all embodiments.

[0048] Therefore, the following detailed description of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0049] Example 1

[0050] This embodiment discloses a laser ablation and milling collaborative machining system and method for hard and brittle materials (hereinafter referred to as "collaborative machining system" and "collaborative machining method"), as a preferred embodiment of the present invention, such as... Figure 1 and Figure 5 As shown, the collaborative machining system includes a machine tool milling system, a laser ablation system, and a collaborative control device 3. The machine tool milling system includes a machine tool CNC mechanism, a machine tool main body mechanism 1, and a machine tool spindle unit 2; the laser ablation system includes a six-degree-of-freedom robotic arm 4 and a laser ablation mechanism; and the collaborative control device 3 includes a central control unit, a robotic arm control module, and a laser ablation control module.

[0051] The central control unit establishes physical communication connections (such as via cables) with the machine tool CNC mechanism, the laser ablation control module, and the robotic arm control module, respectively. It is used to generate ablation end collaborative data and milling end collaborative data based on the machining program of the hard and brittle material workpiece 12. Based on the ablation end collaborative data, it sends drive collaborative instructions and ablation collaborative instructions to the robotic arm control module and the laser ablation control module, respectively. Based on the milling end collaborative data, it sends milling collaborative instructions to the machine tool CNC mechanism.

[0052] The robotic arm control module establishes a physical control connection with the six-degree-of-freedom robotic arm 4, which is used to parse the drive coordination command into drive control signals for the six-degree-of-freedom robotic arm 4; the six-degree-of-freedom robotic arm 4 is installed at the front end of the worktable 1.1 of the machine tool body mechanism 1, and is used to execute the joint actions according to the drive control signals issued by the robotic arm control module.

[0053] The laser ablation control module establishes a physical control connection with the laser ablation mechanism to parse ablation coordination commands into drive and control signals for the laser ablation mechanism; such as Figure 2As shown, the laser ablation mechanism is mounted on the end effector of the six-degree-of-freedom robotic arm 4. It is used to perform laser ablation processing on the hard and brittle material workpiece 12 according to the drive and control signals issued by the laser ablation control module, in coordination with the joint movements of the six-degree-of-freedom robotic arm 4, and according to the specified trajectory and speed.

[0054] The machine tool spindle unit 2 is mounted on the machine tool body mechanism 1, and a milling tool assembly for milling the hard and brittle material workpiece 12 is installed on the machine tool spindle unit 2; the machine tool CNC mechanism and the machine tool spindle unit 2 are physically connected through a servo control circuit, which is used to control the movement of the machine tool spindle unit 2 according to the milling coordination command, so that the milling tool assembly performs milling on the hard and brittle material workpiece 12 according to the specified trajectory and speed, which is lagging behind the laser ablation process.

[0055] Based on the above-mentioned collaborative processing system, the collaborative processing method of this technical solution includes the following steps:

[0056] Step 1: Start and initialize the collaborative processing system.

[0057] The central control unit of the collaborative control device 3 establishes a physical communication connection with the machine tool CNC mechanism through an industrial communication interface (such as EtherCAT, Modbus, OPCUA, or TCP / IP) to ensure unimpeded data transmission. Taking OPCUA as an example, it is based on a service-client model and relies on the DiscoveryService defined in the OPCUA protocol. Through this service, the central control unit can automatically identify and connect to the address space exposed by the machine tool CNC mechanism, thereby establishing a data interaction channel. If data is transmitted via the TCP / IP protocol, it supports secure communication between cross-platform and cross-vendor devices, ensuring the compatibility and stability of the data transmission channel. The communication link between the central control unit and the machine tool CNC mechanism is established.

[0058] The central control unit sends a communication protocol handshake signal (such as authentication and data transmission format agreement) to the CNC mechanism of the machine tool to confirm that the communication parameters of both parties are consistent. This process follows the standardized procedures of industrial communication. Taking the Modbus protocol as an example, the communication status can be confirmed through function codes and exception codes to ensure that parameters such as baud rate, data bits, stop bits, and parity are consistent between the two parties, thus avoiding data transmission errors caused by mismatched communication parameters.

[0059] Step 2: The central control unit acquires the machining program for the hard and brittle material workpiece 12, and generates ablation end collaborative data and milling end collaborative data based on the machining program for the hard and brittle material workpiece 12. The acquisition of the machining program for the hard and brittle material workpiece 12 can be achieved through import via the machine tool's CNC mechanism or through other external tools (such as a USB flash drive) or a client application.

[0060] Step 3: The central control unit sends drive coordination commands and ablation coordination commands to the robotic arm control module and the laser ablation control module respectively, based on the ablation end coordination data.

[0061] Step 4: The robotic arm control module parses the drive coordination command into drive control signals for the six-degree-of-freedom robotic arm 4, and the laser ablation control module parses the ablation coordination command into drive control signals for the laser ablation mechanism, so that the laser ablation mechanism cooperates with the six-degree-of-freedom robotic arm 4 to perform laser ablation processing on the hard and brittle material workpiece 12 according to the specified trajectory and speed.

[0062] Step 5: The central control unit sends milling coordination commands to the machine tool CNC mechanism based on the milling end coordination data. The machine tool CNC mechanism runs the machining program for the hard and brittle material workpiece 12 according to the milling coordination commands, and controls the movement of the machine tool spindle unit 2 to make the milling tool assembly follow the specified trajectory (e.g., ...). Figure 3 As shown, starting from the milling trajectory start station 18, passing through the basic ablation trajectory 13, and finally landing at the milling trajectory end station 19, the entire process covers the entire processing area 17 of the hard and brittle material workpiece 12, and the speed of the milling process on the hard and brittle material workpiece 12 is lagging behind the laser ablation process.

[0063] Example 2

[0064] This embodiment discloses a laser ablation and milling collaborative machining system and method for hard and brittle materials. As a preferred embodiment of the present invention, based on Embodiment 1, in step two of the collaborative machining method, the machining program for the hard and brittle material workpiece 12 is preferably obtained by importing the program through a machine tool CNC mechanism. Furthermore, it also includes active acquisition and passive acquisition.

[0065] Passive acquisition refers to the physical connection established between the CNC mechanism of a machine tool and the central control unit based on the industrial communication interface, which directly transmits the workpiece machining program to the central control unit in binary or text format.

[0066] Active acquisition involves the central control unit (CCU) sending a workpiece machining program read instruction to the machine tool's CNC mechanism using a "producer-consumer model." In this model, the machine tool's CNC mechanism acts as the data producer, and the CCU acts as the consumer. The CCU specifies the storage path or number of the target program (e.g., by searching through G-code program names). For example, in a custom communication protocol based on TCP / IP, the CCU sends a request data packet containing program path information. Upon receiving the request, the machine tool's CNC mechanism parses the data packet and locates the target program. Responding to the instruction, the machine tool's CNC mechanism transmits the workpiece machining program in binary or text format (e.g., NC code files) to the CCU's buffer or storage module.

[0067] To ensure reliable data transmission, a segmented transmission + verification mechanism, such as LRC (Longitudinal Redundancy Check) or CRC (Cyclic Redundancy Check), is used between the machine tool CNC mechanism and the central control unit. Taking CRC verification as an example: before sending data, the machine tool CNC mechanism calculates the CRC checksum based on the data content and appends it to the end of the data packet. After receiving the data, the central control unit performs an integrity check on the workpiece machining program, that is, it recalculates the CRC checksum of the data and compares it with the received checksum. If the comparison matches, the verification is deemed successful, and the process proceeds to the next parsing step; if the comparison does not match, an error feedback is sent to the machine tool CNC mechanism, which then retransmits the workpiece machining program, thus ensuring that no data is lost or tampered with.

[0068] Example 3

[0069] This embodiment discloses a laser ablation and milling collaborative machining system and method for hard and brittle materials. As a preferred embodiment of the present invention, based on embodiment 1 or 2, in step two of the collaborative machining method, during the process of generating milling end collaborative data based on the machining program of the hard and brittle material workpiece 12, the method includes generating a lag time interval between the milling process and the laser ablation process. Assume the average temperature of the current ablation zone 20 is... The highest temperature at which milling can be performed is According to Newton's law of cooling, the temperature of hard and brittle materials can be calculated from... Cool to The required time is also the minimum lag time. Specifically:

[0070] Newton's law of cooling formula is In this formula, Indicates the rate of heat loss. Indicates the convective heat transfer coefficient. Represents the surface area of ​​an object. Indicates the current temperature of the object. Indicates ambient temperature.

[0071] Applying Newton's law of cooling to this technical solution, to simplify calculations, it is assumed that the specific heat capacity, mass, surface area, and ambient temperature of the object are constant. Integrating Newton's law of cooling yields Formula 1. In this formula, This is the minimum lag time interval. For the mass of the current ablation zone 20 of the hard and brittle material workpiece 12, The specific heat capacity of the hard and brittle material workpiece 12. The convective heat transfer coefficient, The surface area of ​​the current ablation zone 20 of the hard and brittle material workpiece 12; The average temperature of the current ablation zone is 20. This is the highest temperature at which milling can be performed. The ambient temperature.

[0072] Because the laser focal point is nanometer-sized and moves quickly along a specific trajectory, such as Figure 3 The laser ablation processing trajectory starting station 14 and Figure 4 The ablation region 20 shown is typically defined as a region with length, width, and height of 12 for a hard and brittle material workpiece 12. , , cuboid ( Figure 4 The image shows the length and width of the ablation zone 20. , , This represents the density of the hard and brittle material workpiece 12; thus, Formula 1 is transformed into... Then, the minimum value of the lag time interval is calculated. Then let .

[0073] Ceramic matrix composites are typical hard and brittle materials. They are a class of composite materials with ceramics as the matrix and various fibers as the reinforcing phase, exhibiting characteristics of hard and brittle materials such as high brittleness, high hardness, and thermal stability. Taking the combined laser ablation and milling processing of ceramic matrix composites as an example:

[0074] First, a milling program (i.e., a machining program for hard and brittle material workpiece 12) is compiled based on the machining process characteristics of ceramic matrix composite workpieces, which includes CNC milling machining trajectories.

[0075] Then, based on the processing requirements of the ceramic matrix composite workpiece, parameters such as laser ablation power, ultrasonic vibration frequency and amplitude are set in the collaborative control device 3, as well as the following parameters related to the ceramic matrix composite: specific heat capacity of the ceramic matrix composite. The convective heat transfer coefficient between the ceramic matrix composite and air is: Ambient temperature Density of ceramic matrix composite workpiece Average temperature of the ablated area 20 The ablated area 20 is a region with dimensions of [length and width are missing]. Height is A rectangular prism; the highest temperature at which milling can be performed. .

[0076] Finally, the collaborative processing of laser ablation and milling is implemented according to the collaborative processing method of this technical solution. This involves generating a lag time interval between the milling process and the laser ablation process. During the process, the minimum lag time interval .Right now Milling should lag behind laser ablation by at least 28 seconds. After laser ablation, the surface temperature of the ceramic matrix composite workpiece rises sharply. Direct milling would reduce the lifespan of the milling tool assembly. Therefore, milling should begin at least 28 seconds after laser ablation to allow sufficient time for the ablated area 20 to cool.

[0077] Example 4

[0078] This embodiment discloses a laser ablation and milling collaborative machining system and method for hard and brittle materials. As a preferred embodiment of the present invention, based on embodiment 1 or 2, in step two of the collaborative machining method, during the process of generating milling end collaborative data based on the machining program of the hard and brittle material workpiece 12, the method includes generating a lag time interval between the milling process and the laser ablation process. The difference from Embodiment 3 is that in this embodiment, the central control unit in the collaborative control device 3 retrieves the workpiece material database to obtain thermodynamic property parameters such as thermal conductivity, specific heat capacity, and melting point of the target material, while simultaneously reading processing characteristic data such as the heat resistance limit temperature of the milling tool assembly. Based on the Fourier heat conduction equation and combined with ablation parameters such as laser energy density and spot diameter, the temperature field change process of the laser ablation region 20 is simulated using a finite element thermal analysis algorithm. For example, for hard and brittle materials such as ceramics, a three-dimensional heat conduction model is established using simulation software such as ANSYS to calculate the time required for the ablation region 20 to drop from its highest temperature to the milling safety temperature, thereby determining the execution time interval (i.e., the lag time interval). .

[0079] Example 5

[0080] This embodiment discloses a laser ablation and milling collaborative machining system and method for hard and brittle materials. As a preferred embodiment of the present invention, based on embodiment 3 or 4, the process of generating ablation end collaborative data based on the machining program of the hard and brittle material workpiece 12 includes generating a laser ablation machining trajectory, and generating the laser ablation machining trajectory includes the following steps:

[0081] The central control unit invokes the G-code parser to scan the workpiece machining program line by line, identifying milling-related instructions (such as G00 / G01 linear interpolation, G02 / G03 circular interpolation, F feed rate, S spindle speed, etc.). Taking the recursive descent parser as an example, it decomposes the G-code string into lexical units (tokens) according to the G-code syntax rules, such as coordinate values, instruction codes, and parameters. During the parsing process, the parser verifies the legality of the instructions by matching syntax rules (such as the requirement that G01 instructions must be followed by X, Y, and Z coordinate parameters). For the identified milling-related instructions, the parser extracts and stores them, filtering out non-trajectory instructions (such as M-code auxiliary functions, T-code tool change instructions, etc.), and retaining only trajectory instructions related to the movement of the milling tool assembly.

[0082] The trajectory commands are processed using interpolation. Linear interpolation: Using the coordinates of the start and end points, an interpolation algorithm is used to calculate intermediate interpolation points, forming a continuous straight-line trajectory. For example, for commands G01, X10, Y20, Z30, and F100, the parser generates a series of tiny line segments between the start and end points based on the start and end point coordinates (X10, Y20, Z30) and a feed rate of F100. Connecting these segments forms the straight-line trajectory. Circular interpolation: Based on the center coordinates, radius, and rotation direction (clockwise / counterclockwise), an arc-shaped trajectory is generated using an arc interpolation algorithm. For example, for commands G02, X20, Y30, I10, and J0, the parser calculates the offset of the center relative to the start point (I10, J0) and combines this with the end point coordinates (X20, Y20) to generate discrete points on the arc-shaped trajectory.

[0083] Discrete trajectory command segments are converted into a continuous sequence of trajectory points, forming the basic data structure of the workpiece milling trajectory (such as a point set + motion parameter array). During the conversion process, motion attributes such as velocity and acceleration are assigned to each trajectory point according to the motion type and parameters to ensure the accuracy and stability of subsequent machining processes.

[0084] The central control unit smooths the basic data structure of the milling machining trajectory, specifically using cubic spline interpolation or B-spline curve fitting algorithms. Taking cubic spline curves as an example, it requires that the positions, first derivatives, and second derivatives of adjacent curve segments at the connection points be continuous. This eliminates sudden velocity changes at the connection points of command segments, ensuring the continuity and stability of the milling motion and reducing the impact of motion shocks on the workpiece and equipment.

[0085] For the smoothed milling trajectory data, the trajectory coordinate data is transformed from the machine tool coordinate system to the reference coordinate system of the laser ablation system to generate the basic ablation trajectory. This transformation is based on a homogeneous transformation matrix. In practical applications, the coordinates of at least three non-collinear points in the two coordinate systems can be measured using a high-precision calibration tool (such as a laser tracker). The homogeneous transformation matrix is ​​then optimized using the least squares method to control the coordinate transformation error within ±0.01mm, ensuring the consistency of the trajectory spatial position.

[0086] Finally, since the milling trajectory overlaps with the basic ablation trajectory, in order to avoid the delayed milling, a non-ablation segment trajectory is added at the end of the basic ablation trajectory, thereby generating the laser ablation trajectory (which includes the laser ablation trajectory start station 14 and the laser ablation trajectory end station 15).

[0087] Example 6

[0088] This embodiment discloses a laser ablation and milling collaborative machining system and method for hard and brittle materials. As a preferred embodiment of the present invention, based on embodiment 5, a non-ablation segment trajectory is added to the end of the basic ablation trajectory, including:

[0089] Based on the lag time interval and the machining feed rate of machine tool spindle unit 2 Using formula Calculate the distance before and after execution This calculation is based on the kinematic relationship between velocity, time, and displacement, ensuring that the milling operation is performed after the laser ablation zone 20 has cooled. Simultaneously, the diameter of the milling tool assembly is taken into account. ( (Determines the contact range and heat-affected zone when the tool enters the material, using the formula) Calculate the length of the non-ablation segment trajectory ,in The introduction of this feature is to prevent the milling cutter from cutting into the high-temperature ablation zone 20, which could lead to tool wear or workpiece breakage.

[0090] Based on the coordinates of the endpoint of the basic ablation trajectory, a vector extension is performed along the direction of ablation movement (determined by the tangent direction of the trajectory point), with an extension length of [length missing]. This generates the laser ablation processing trajectory.

[0091] Furthermore, in practical applications, trajectory planning and control verification can be incorporated. For example, the central control unit can utilize virtual simulation technology to simulate and verify the generated laser ablation machining trajectory and control logic in a digital twin environment. By importing the 3D model of the hard and brittle material workpiece 12, the virtual models of the laser ablation system and the machine tool milling system, machining parameters and motion constraints are set, and the simulation program is run. Based on collision detection algorithms in computer graphics (such as the hierarchical bounding box method), it is checked whether the laser ablation machining trajectory will cause a collision risk between the laser ablation system and the machine tool spindle unit 2, and the hard and brittle material workpiece 12, while verifying the rationality of the ablation-milling time interval and trajectory connection. If problems are found in the trajectory planning or control logic during the simulation (such as collision risk, incomplete cooling of the ablation area 20, etc.), the central control unit automatically adjusts the relevant parameters (such as...). , (or trajectory path), regenerate the laser ablation processing trajectory, and perform simulation verification again until the processing requirements are met, ensuring the safety and efficiency of the actual processing process.

[0092] Example 7

[0093] This embodiment discloses a laser ablation and milling collaborative machining system and method for hard and brittle materials. As a preferred embodiment of the present invention, based on Embodiment 5 or Embodiment 6, in the process of generating collaborative data for the ablation end based on the machining program of the hard and brittle material workpiece 12, the system further includes generating trajectory segmentation markers, which serve as the basis for the laser ablation control module to control the operation of the laser ablation mechanism. The trajectory segmentation markers include traversing the laser ablation machining trajectory point set, marking points in the basic ablation trajectory as "ablation task segments," and marking points in the non-ablation segment trajectory as "non-ablation segments."

[0094] Therefore, during the laser ablation mechanism and the six-degree-of-freedom robotic arm 4, which cooperate to perform laser ablation processing on the hard and brittle material workpiece 12 according to a specified trajectory and speed, the control logic is as follows: The central control unit simultaneously sends ablation coordination commands and drive coordination commands to the laser ablation control module and the robotic arm control module, respectively. After receiving the drive coordination command, the robotic arm control module, based on the planned laser ablation processing trajectory data (including trajectory point coordinates and movement speed), converts the trajectory data into motion control commands for each joint of the six-degree-of-freedom robotic arm 4 based on G-code parsing and motion control principles. Specifically, the DH parameter method can be used to establish the kinematic model of the robotic arm, and the trajectory points in the Cartesian coordinate system can be converted into a sequence of angle values ​​for each joint through inverse kinematics solving algorithms (such as the Newton-Raphson iteration method). These angle values ​​are then converted into pulse signals or analog voltage signals to drive the servo motors of each joint to control the movement of the six-degree-of-freedom robotic arm 4. After receiving the ablation coordination command, the laser ablation control module controls the power output of the laser ablation mechanism while the six-degree-of-freedom robotic arm 4 moves along the laser ablation processing trajectory. This control is based on the trajectory segment marking information ("ablation task segment" or "non-ablation segment") and laser ablation parameters (such as laser power parameters). When in the "ablation task segment," the module outputs a corresponding laser power control signal (drive signal) according to the preset laser ablation parameters, thereby controlling the operation of the laser ablation mechanism. When entering the "non-ablation segment," the module immediately cuts off the power supply to the laser ablation mechanism, stopping the laser output.

[0095] Simultaneously, the laser ablation control module and / or the robotic arm control module record the start time of the laser ablation task. This timestamp is then synchronized to the system clock of the central control unit, subsequently controlling the CNC mechanism of the machine tool. Start the milling task, where Based on this, the control logic of the collaborative control device 3 for the machine tool milling system is as follows: when the system clock arrives... Before the scheduled start time, the central control unit sends a pre-start command to the machine tool's CNC mechanism, notifying it to prepare to receive the milling task. Upon receiving the pre-start command, the machine tool's CNC mechanism allocates internal resources (such as toolpath buffering and spindle acceleration preparation). When the system clock reaches [time missing], [action missing]. At any given moment, the central control unit sends a formal milling start signal (i.e., a milling coordination command) to the machine tool's CNC mechanism. Upon receiving the command, the machine tool's CNC mechanism immediately initiates the milling task (i.e., step five). During the machining process, the machine tool's CNC mechanism monitors parameters such as spindle load and feed rate in real time, and ensures machining accuracy and stability through a feedback control mechanism.

[0096] Example 8

[0097] This embodiment discloses a laser ablation and milling collaborative machining system and method for hard and brittle materials. As a preferred embodiment of the present invention, based on any one of embodiments 1 to 7, the laser ablation system further includes a visual obstacle avoidance unit, which includes a camera device 5 and an image pose recognition unit. The camera device 5 is physically connected to the image pose recognition unit and is used to collect image data of the machine tool spindle unit 2 and the hard and brittle material workpiece 12 in real time, and transmit the image data to the image pose recognition unit. The image pose recognition unit is physically connected to the central control unit and is used to identify the real-time dynamic pose information of the machine tool spindle unit 2 and the hard and brittle material workpiece 12 through the image data, and transmit the real-time dynamic pose information to the central control unit, so that the central control unit controls the six-degree-of-freedom robotic arm 4 to avoid the machine tool spindle unit 2 and the hard and brittle material workpiece 12 through the robotic arm control module.

[0098] The camera device 5 can employ an industrial-grade high-resolution camera to ensure the capture of rapid dynamic changes in the machine tool spindle unit 2 and the workpiece. Initialization commands can be sent via the collaborative control device 3 to set parameters such as exposure time, gain, and white balance of the camera device 5, adapting it to the lighting conditions of the processing environment and ensuring the clarity and accuracy of the acquired images. During the collaborative machining task, the camera device 5 continuously acquires image data of the machine tool spindle unit 2 and the workpiece area at a set frame rate and transmits the image data to the image pose recognition unit.

[0099] After receiving the raw image data, the image pose recognition unit first performs image preprocessing. Digital image processing techniques are used, including grayscale conversion, to transform the color image into a grayscale image, reducing the amount of data processing. Gaussian filtering or median filtering algorithms are employed to remove noise from the image and smooth image edges. Histogram equalization is used to enhance image contrast, highlighting the contour features of the machine tool spindle unit 2 and the hard, brittle material workpiece 12, providing high-quality image data for subsequent pose recognition.

[0100] The image pose recognition unit utilizes feature extraction algorithms from computer vision, such as SIFT (Scale Invariant Feature Transform), SURF (Speed ​​Robust Feature Transform), or ORB (Oriented to Fast Feature Points and Rotation Brief Descriptors), to extract key feature points (such as corner points and edge points) of the machine tool spindle unit 2 and the hard and brittle material workpiece 12. Simultaneously, a deep learning-based object detection model (such as YOLO or Faster R-CNN) is used to identify the machine tool spindle unit 2 and the hard and brittle material workpiece 12 in the image through a pre-trained model, determining their position and range within the image. The extracted feature points are combined with the object detection results to construct a feature descriptor for the target object, which is then used for subsequent pose calculations.

[0101] Pose calculation: Based on the extracted feature points and the 3D model of the target object (pre-stored in the image pose recognition unit), the PnP (Perspective-n-Point) algorithm is used to calculate the six-degree-of-freedom pose (3D position and 3D attitude) of the machine tool spindle unit 2 and the hard and brittle material workpiece 12. The PnP algorithm, based on the principle of perspective projection, solves for the pose parameters of the target object in the coordinate system of the camera device 5 by establishing the correspondence between feature points on the image plane and points on the 3D model. Then, using the pre-calibrated transformation relationship between the camera device 5 and the reference coordinate system, the pose parameters are transformed into the reference coordinate system of the laser ablation system, obtaining the real-time dynamic pose information of the machine tool spindle unit 2 and the hard and brittle material workpiece, which is then sent to the central control unit.

[0102] The central control unit constructs a collision detection model based on the 3D models of the machine tool spindle unit 2, the hardened material workpiece, and the laser ablation system (six-DOF robotic arm 4 and laser ablation mechanism). A hierarchical bounding box method is used to simplify the complex 3D model, dividing it into multiple levels of bounding box structures to reduce the computational complexity of collision detection. Based on the real-time pose information of the machine tool spindle unit 2, the hardened material workpiece, and the laser ablation system, the central control unit updates the position and orientation of each component in the collision detection model in real time. Collision interference is determined by calculating whether the motion trajectory of the laser ablation system intersects with the bounding boxes of the machine tool spindle unit 2 and the central control unit workpiece. A spatial segmentation algorithm is used to divide the machining space into multiple subspaces, and intersection detection is only performed on the bounding boxes within the subspaces where collisions may occur, further improving detection efficiency. If an intersection of bounding boxes is detected, a collision risk is determined; otherwise, the system is considered to be operating normally without collision interference.

[0103] When the central control unit detects a collision, it triggers obstacle avoidance path planning. Based on motion planning algorithms, such as RRT (Rapid Expanding Random Tree), a collision-free obstacle avoidance path is searched in the processing space, starting from the current pose of the laser ablation system and aiming at a safe pose after avoiding the collision area. Considering the kinematic constraints of the six-DOF robotic arm 4 (such as joint angle limitations and motion speed limitations), the generated path is optimized during the path planning process to ensure that the six-DOF robotic arm 4 can move safely and quickly according to the planned path.

[0104] The robotic arm control module converts the obstacle avoidance path planned by the central control unit into joint motion commands for the six-DOF robotic arm 4, which are then sent to the servo drives of each joint. The servo drives drive the joints of the robotic arm according to the commands, causing the laser ablation system to move along the obstacle avoidance path, avoiding the machine tool spindle unit 2 and the workpiece. During obstacle avoidance, the camera device 5 continuously monitors environmental changes, and the collaborative control device 3 updates pose information and collision detection in real time to ensure the effectiveness and safety of the obstacle avoidance action. Once the laser ablation system successfully avoids the collision area, the central control unit reassesses the processing task. If conditions permit, the normal collaborative processing flow is resumed; otherwise, the obstacle avoidance strategy is continued or the processing task is paused.

[0105] Example 9

[0106] This embodiment discloses a laser ablation and milling collaborative machining system and method for hard and brittle materials. As a preferred embodiment of the present invention, based on any of embodiments 1 to 8, the collaborative control device 3 further includes a human-machine interface unit. The human-machine interface unit is physically connected to the central control unit and is used to input corresponding machining parameters and control commands, as well as display the collaborative machining parameters. Based on this, during the machining preparation stage, machining can be started automatically or manually.

[0107] Automatic machining start: After the central control unit completes the generation of collaborative data for the ablation end and the milling end, it automatically triggers the automated workflow trigger command, entering the machining task start stage (i.e., step three). The advantage of automatic machining start is that it saves time and eliminates the need for personnel to constantly monitor and advance the machining process.

[0108] Manual Start-up: After the central control unit completes the generation of collaborative data for both the ablation and milling ends, a "Loading Complete" message is displayed on the human-machine interface (HMI). When the operator sends a manual start signal via the "Start" button on the HMI, the signal is transmitted to the central control unit through the PLC (Programmable Logic Controller) or a dedicated I / O interface. Upon recognizing the signal, the central control unit initiates the machining task startup phase (i.e., step three). The advantage of manual start-up is that it allows technicians time to check the equipment and machining parameters.

[0109] Example 10

[0110] This embodiment discloses a laser ablation and milling collaborative machining system and method for hard and brittle materials. As a preferred embodiment of the present invention, it is based on any of the embodiments 1-9, such as... Figure 2As shown, its laser ablation mechanism includes a laser processing head 6 and a laser generator 7; the laser generator 7 is connected to the laser ablation control module and is used to emit a laser beam according to the drive control signal issued by the laser ablation control module; the laser processing head 6 is connected to the laser generator 7 and is used to focus the laser beam emitted by the laser generator 7 onto the hard and brittle material workpiece 12.

[0111] After receiving control signals (including power, pulse frequency, etc.) from the laser ablation control module, laser generator 7 operates based on the principle of stimulated emission. Taking a solid-state laser as an example, its internal gain medium achieves population inversion under the excitation of the pump source. The control system of laser generator 7 adjusts the current of the pump source according to the input command, thereby controlling the laser energy generated by the gain medium. For example, when it is necessary to increase the laser power, the pump source current is increased, causing more particles to achieve energy level transitions, thereby increasing the laser output power. At the same time, the pulse frequency and pulse width of the laser are controlled by the modulation circuit to meet the needs of different processing stages.

[0112] The laser processing head 6 has a built-in optical focusing system, including optical components such as lenses and mirrors. After the laser beam output from the laser generator 7 enters the laser processing head 6, it first passes through a collimating lens to adjust the diverging beam into parallel light, and then through a focusing lens to focus the parallel light onto the workpiece surface. The focal length of the focusing lens is selected according to the processing requirements; the shorter the focal length, the smaller the focused spot and the higher the energy density, making it suitable for precision machining. The laser processing head 6 uses a servo motor-driven two-dimensional galvanometer system to achieve rapid scanning and guidance of the laser beam. The galvanometer precisely adjusts the mirror angle according to the trajectory coordinate commands sent by the laser ablation control module, ensuring that the laser beam follows a preset trajectory within the current ablation area (e.g., ...). Figure 4 The laser focusing trajectory 16 shown moves until the laser ablation processing of the current ablation area 20 is completed. After the laser ablation processing of the current ablation area 20 is completed, the six-degree-of-freedom robotic arm 4 moves the laser processing head 6 to the next ablation area 20 along the laser ablation processing trajectory.

[0113] Example 11

[0114] This embodiment discloses a laser ablation and milling collaborative processing system and method for hard and brittle materials. As a preferred embodiment of the present invention, based on embodiment 9 or 10, the collaborative control device 3 further includes a laser focusing adjustment unit and a laser rangefinder 8. The laser rangefinder 8 is mounted on a six-degree-of-freedom robotic arm 4 and establishes a physical communication connection with the laser focusing adjustment unit. It is used to measure the real-time distance between the laser processing head 6 and the hard and brittle material workpiece 12 based on the projection of the laser beam emitted by the laser processing head 6 onto the surface of the hard and brittle material workpiece 12, and transmits the real-time distance to the laser focusing adjustment unit. The laser focusing adjustment unit establishes a physical communication connection with the robotic arm control module. It is used to obtain the distance adjustment signal based on the real-time distance between the laser processing head 6 and the hard and brittle material workpiece 12, and transmit the distance adjustment signal to the robotic arm control module. The robotic arm control module controls the six-degree-of-freedom robotic arm 4 to adjust the distance between the laser processing head 6 and the hard and brittle material workpiece 12, so that the laser beam emitted by the laser processing head 6 is always focused on the surface of the hard and brittle material workpiece 12.

[0115] The raw data collected by the laser rangefinder needs to be filtered to remove noise interference. Median filtering or Kalman filtering algorithms are used to improve the accuracy and stability of the data. Since manufacturing errors of optical components and changes in ambient temperature can affect measurement accuracy, the laser focusing adjustment unit has a built-in calibration module that performs periodic self-calibration. During calibration, the measurement error is calculated by measuring a reference object at a known standard distance, and an error compensation table is generated. In actual measurements, the measurement data is corrected according to the error compensation table to ensure that the distance data accuracy meets processing requirements.

[0116] The laser focusing adjustment unit compares the processed and calibrated distance data with the preset focusing distance. If a deviation exists, the laser focusing self-adjustment module is triggered. Based on a PID control algorithm, the laser focusing self-adjustment module calculates the adjustment amount of each joint of the six-DOF robotic arm 4. Through the robotic arm control module, it drives the six-DOF robotic arm 4 to adjust its movements, thereby adjusting the position of the laser processing head 6. This restores the distance between the laser processing head 6 and the workpiece surface to the optimal focusing distance, ensuring that the laser beam is always focused on the workpiece surface and guaranteeing the accuracy and quality of the laser ablation process.

[0117] Example 12

[0118] This embodiment discloses a laser ablation and milling co-processing system and method for hard and brittle materials. As a preferred embodiment of the present invention, based on embodiment 11, the laser ablation system further includes a refrigerated dryer 10, and the refrigerated dryer 10 establishes a physical control connection with the central control unit to provide a drying gas source for the laser generator 7.

[0119] Example 13

[0120] This embodiment discloses a laser ablation and milling collaborative processing system and method for hard and brittle materials. As a preferred embodiment of the present invention, based on any one of the embodiments 1 to 12, it further includes a power distribution cabinet 9, and the power distribution cabinet 9 is connected to the laser ablation system and the collaborative control device 3 for power supply.

Claims

1. A method for combined laser ablation and milling machining of hard and brittle materials, characterized in that, A laser ablation and milling collaborative machining system for hard and brittle materials is adopted. The collaborative machining system includes a machine tool milling system, a laser ablation system, and a collaborative control device (3). The machine tool milling system includes a machine tool CNC mechanism, a machine tool main body mechanism (1), and a machine tool spindle unit (2). The laser ablation system includes a six-degree-of-freedom robotic arm (4) and a laser ablation mechanism. The collaborative control device (3) includes a central control unit, a robotic arm control module, and a laser ablation control module. The central control unit establishes physical communication connections with the machine tool CNC mechanism, the laser ablation control module, and the robotic arm control module, respectively. The robotic arm control module establishes a physical control connection with the six-degree-of-freedom robotic arm (4), which is installed at the front end of the worktable (1.1) of the main machine tool mechanism (1). The laser ablation control module establishes a physical control connection with the laser ablation mechanism, which is mounted on the execution end of the six-degree-of-freedom robotic arm (4). The machine tool spindle unit (2) is mounted on the machine tool body mechanism (1). The machine tool CNC mechanism and the machine tool spindle unit (2) are physically connected through a servo control line. The machine tool spindle unit (2) is equipped with a milling tool assembly for milling hard and brittle material workpieces (12). The collaborative processing method includes the following processing control steps: The laser ablation and milling co-processing system is started and initialized; The central control unit acquires the machining program for the hard and brittle material workpiece (12) and generates ablation end coordination data and milling end coordination data based on the machining program for the hard and brittle material workpiece (12). The coordination data includes the lag time interval of milling machining relative to laser ablation machining. That is: Formula 1 is obtained based on Newton's law of cooling. ;in This is the minimum lag time interval. For the mass of the current ablation zone (20) of the hard and brittle material workpiece (12), The specific heat capacity of the hard and brittle material workpiece (12) is... The convective heat transfer coefficient, The surface area of ​​the current ablation zone (20) of the hard and brittle material workpiece (12); The average temperature of the current ablation zone (20) is... This is the highest temperature at which milling can be performed. The ambient temperature is set; the current ablation area (20) of the hard and brittle material workpiece (12) is set as a length, width, and height of [missing information]. , , A cuboid, then has , , This represents the density of the hard and brittle material workpiece (12); thus, Formula 1 is transformed into... Calculate the minimum lag time interval. ,make ; The central control unit sends drive coordination commands and ablation coordination commands to the robotic arm control module and the laser ablation control module respectively, based on the ablation end coordination data. The robotic arm control module parses the drive coordination command into drive control signals for the six-degree-of-freedom robotic arm (4). The six-degree-of-freedom robotic arm executes the joint actions according to the drive control signals issued by the robotic arm control module. The laser ablation control module parses the ablation coordination command into drive control signals for the laser ablation mechanism, so that the laser ablation mechanism and the joint actions of the six-degree-of-freedom robotic arm (4) cooperate to perform laser ablation processing on the hard and brittle material workpiece (12) according to the specified trajectory and speed. The central control unit sends milling coordination instructions to the machine tool CNC mechanism based on the milling end coordination data. The machine tool CNC mechanism runs the machining program for the hard and brittle material workpiece (12) according to the milling coordination instructions. By controlling the action of the machine tool spindle unit (2), the milling tool assembly performs milling machining on the hard and brittle material workpiece (12) according to the specified trajectory and speed, which is lagging behind the laser ablation machining.

2. The laser ablation and milling combined machining method for hard and brittle materials as described in claim 1, characterized in that: In the collaborative processing system, the laser ablation system also includes a visual obstacle avoidance unit, which includes a camera device (5) and an image pose recognition unit. The camera device (5) is physically connected to the image pose recognition unit and is used to collect image data of the machine tool spindle unit (2) and the hard and brittle material workpiece (12) in real time, and transmit the image data to the image pose recognition unit. The image pose recognition unit is physically connected to the central control unit and is used to identify the real-time dynamic pose information of the machine tool spindle unit (2) and the hard and brittle material workpiece (12) through image data, and transmit the real-time dynamic pose information to the central control unit, so that the central control unit controls the six-degree-of-freedom robotic arm (4) to avoid the machine tool spindle unit (2) and the hard and brittle material workpiece (12) through the robotic arm control module.

3. The laser ablation and milling combined machining method for hard and brittle materials as described in claim 1, characterized in that: In the collaborative processing system, the laser ablation mechanism includes a laser processing head (6) and a laser generator (7); the laser generator (7) is connected to the laser ablation control module and is used to emit a laser beam according to the drive control signal issued by the laser ablation control module; the laser processing head (6) is connected to the laser generator (7) and is used to focus the laser beam emitted by the laser generator (7) onto the hard and brittle material workpiece (12).

4. The laser ablation and milling co-processing method for hard and brittle materials as described in claim 3, characterized in that: In the collaborative processing system, the collaborative control device (3) further includes a laser focusing adjustment unit and a laser rangefinder (8). The laser rangefinder (8) is mounted on a six-degree-of-freedom robotic arm (4) and establishes a physical communication connection with the laser focusing adjustment unit. It is used to measure the real-time distance between the laser processing head (6) and the hard and brittle material workpiece (12) based on the projection of the laser beam emitted by the laser processing head (6) onto the surface of the hard and brittle material workpiece (12), and transmit the real-time distance to the laser focusing adjustment unit. The laser focusing adjustment unit establishes a physical communication connection with the robotic arm control module. It is used to obtain the adjustment signal based on the real-time distance between the laser processing head (6) and the hard and brittle material workpiece (12), and transmit the adjustment signal to the robotic arm control module. The robotic arm control module controls the six-degree-of-freedom robotic arm (4) to adjust the distance between the laser processing head (6) and the hard and brittle material workpiece (12), so that the laser beam emitted by the laser processing head (6) is always focused on the surface of the hard and brittle material workpiece (12).

5. The laser ablation and milling co-processing method for hard and brittle materials as described in claim 4, characterized in that: In the collaborative processing system, the laser ablation system also includes a refrigerated dryer (10), and the refrigerated dryer (10) is physically connected to the central control unit to provide a drying gas source for the laser generator (7).

6. The laser ablation and milling co-processing method for hard and brittle materials as described in claim 1, characterized in that: The collaborative processing system also includes a power distribution cabinet (9), which is connected to the laser ablation system and the collaborative control device (3) for power supply.

7. The laser ablation and milling combined machining method for hard and brittle materials as described in claim 1, characterized in that, The methods for the central control unit to acquire the machining program of hard and brittle material workpieces (12) include active acquisition and passive acquisition; The active acquisition is as follows: the central control unit sends a machining program reading instruction to the machine tool CNC mechanism based on the physical connection established between the central control unit and the machine tool CNC mechanism through the industrial communication interface; the machine tool CNC mechanism responds to the instruction and transmits the workpiece machining program to the central control unit in binary or text format; The passive acquisition refers to the machine tool CNC mechanism directly transmitting the workpiece machining program to the central control unit in binary or text format based on the physical connection established between the machine tool CNC mechanism and the central control unit through the industrial communication interface. After receiving the workpiece processing program, the central control unit performs an integrity check on the program; if the check passes, it proceeds to the next step of the parsing process. If the verification fails, an error feedback is sent to the CNC mechanism of the machine tool.

8. The laser ablation and milling co-processing method for hard and brittle materials as described in claim 1, characterized in that, In the process of generating ablation end collaborative data based on the machining program of hard and brittle material workpiece (12), the process includes generating laser ablation machining trajectory, and generating laser ablation machining trajectory includes the following steps: The central control unit calls the G-code parser to scan the workpiece machining program line by line, identify instructions related to milling, filter out non-trajectory instructions, and retain only trajectory instructions related to the movement of the milling tool assembly. The trajectory commands are interpolated, and then the discrete trajectory command segments are converted into a continuous sequence of trajectory points to form the basic data structure of the workpiece milling operation trajectory. After smoothing the basic data structure of the milling operation trajectory, the central control unit transforms the trajectory coordinate data from the machine tool coordinate system to the reference coordinate system of the laser ablation system to generate the basic ablation trajectory of the laser ablation (13). A non-ablation segment trajectory is added at the end of the basic ablation trajectory (13) to finally generate the laser ablation processing trajectory.

9. The laser ablation and milling co-processing method for hard and brittle materials as described in claim 8, characterized in that, Adding a non-ablation segment trajectory at the end of the basic ablation trajectory (13) includes: calculating the minimum distance between the ablation region (20) and the milled area at the same time, i.e. ,in This indicates the feed rate in milling operations; taking into account the diameter of the milling tool assembly... Under the given conditions, calculate the length of the non-ablation segment trajectory. ,Right now Based on the coordinates of the endpoint of the basic ablation trajectory (13), a vector extension is made along the direction of ablation movement, with an extension length of... .

10. The laser ablation and milling co-processing method for hard and brittle materials as described in claim 8, characterized in that, In the process of generating collaborative data for the ablation end based on the machining program of the hard and brittle material workpiece (12), the process also includes generating trajectory segment markers, which are used as the basis for the laser ablation control module to control the operation of the laser ablation mechanism. The trajectory segment markers include traversing the laser ablation machining trajectory point set, marking the points in the basic ablation trajectory (13) as "ablation task segment", and marking the points in the non-ablation segment trajectory as "non-ablation segment".

Images