Flexible clamping method for aviation composite part machining

Abstract

The invention belongs to the field of clamping and positioning of aviation composite material part numerical control machining, and relates to a flexible clamping method for aviation composite material part machining, and the method comprises the steps: S1, importing a workpiece three-dimensional model into a point location planning system, automatically analyzing features, and generating an optimized supporting point location file based on mechanical constraints; s2, the three-axis flexible motion platform drives a suction cup assembly to be positioned, and after the suction cup assembly is attached to the curved surface of the workpiece, workpiece clamping is completed; s3, the on-machine measurement system collects the actual profile and thickness data of the workpiece, the intelligent process module reconstructs the actual geometrical shape of the workpiece, comparative analysis is conducted, and tool path compensation data is generated; s4, machining is executed based on the tool path compensation data, the management platform is driven to conduct real-time monitoring, and self-adaptive protection is triggered when abnormity occurs; and S5, after machining is completed, vacuum is released, the supporting assembly is taken back, and meanwhile whole-process data are recorded. According to the clamping device, the clamping stability and safety can be effectively improved.

Description

Technical Field

[0001] This invention relates to the field of clamping and positioning technology for CNC machining of aerospace composite material parts, and specifically to a flexible clamping method for machining aerospace composite material parts. Background Technology

[0002] In the existing technology, aerospace composite material parts are usually characterized by large size, complex curvature, thin walls and easy deformation. Traditional rigid fixtures are difficult to achieve stable and self-adaptive clamping, and the changeover efficiency is low, making it difficult to meet the high-efficiency processing needs of multiple varieties and small batches.

[0003] To this end, the invention patent with publication number WO 2025 / 103427 A1 discloses a multi-process flexible clamping method, which is implemented using a flexible fixture with multiple clamping devices. The clamping devices include a multi-jaw chuck and a multi-process clamping device. The implementation steps of the multi-process flexible clamping method include: S1 comparing the external structure of different types of workpieces, finding common features and determining a unified positioning and clamping method; S2 unifying the process datum between different types of workpieces, the required process datum being determined according to the highest process datum among different types of parts; S3 adjusting the position of the clamping device for workpieces of different specifications; S4 controlling the loading and unloading operations by a digital control program: S41 The clamping components of the multi-process clamping device are switched and the position of the multi-process clamping device is adjusted according to the required process: the clamping component switching steps are as follows: the clamping components of the multi-process clamping device are divided into a first clamping component and a second clamping component; when the workpiece of the first process needs to be clamped, the clamping surface of the first clamping component is parallel to the workpiece to be clamped position, and the clamping surface of the second clamping component is not parallel to the workpiece to be clamped position; when the workpiece of the second process needs to be clamped, the second clamping component rotates around the first clamping component so that the clamping surface of the second clamping component is parallel to the workpiece to be clamped position and higher than the clamping surface of the first clamping component; S42 loading; S43 unloading. Progress has been made in improving the versatility of fixtures and reducing investment costs.

[0004] However, the above technical solutions still have the following technical problems: their clamping method is mechanical pressing, which cannot adapt to the large curved surface, thin wall and easy deformation characteristics of aerospace composite parts, lacks the ability to adapt to complex curved surfaces, and cannot solve the problem of reduced processing accuracy of composite parts due to springback and deformation.

[0005] In view of this, it is very necessary to provide a flexible clamping method for processing aerospace composite material parts to solve the above-mentioned defects in the prior art. Summary of the Invention

[0006] The purpose of this invention is to address the technical problems of existing flexible clamping methods being unable to adapt to the large curved surfaces, thin walls, and easily deformable characteristics of aerospace composite parts, lacking adaptive fitting capabilities for complex curved surfaces, and failing to solve the technical problems of decreased processing accuracy caused by springback and deformation of composite parts. This invention provides a flexible clamping method for processing aerospace composite parts to solve the technical problems in the prior art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a flexible clamping method for machining aerospace composite material parts, comprising the following steps: Step S1: The step of point planning involves importing the 3D model of the workpiece into the point planning system, automatically parsing the features, and generating an optimized support point file based on mechanical constraints. Step S2: Positioning and adsorption step. The three-axis flexible motion platform drives the suction cup assembly to position and fit the workpiece surface, thus completing the workpiece clamping. Step S3: The toolpath compensation step involves collecting the actual surface and thickness data of the workpiece from the machine measurement system, reconstructing the actual geometry of the workpiece using the intelligent process module, performing comparative analysis, and generating toolpath compensation data. Step S4: The monitoring and protection step involves performing machining based on toolpath compensation data, driving the management platform to monitor in real time, and triggering adaptive protection when an anomaly occurs. Step S5: Data archiving step. After processing is completed, the vacuum is released and the support components are retrieved. At the same time, the entire process data is recorded to form a processing process archive.

[0008] The beneficial effects of this invention are as follows: This invention establishes a highly digitized, flexible clamping process, achieving full-cycle automation and traceability management, and improving the automation level of the clamping process in composite parts processing. The angle-adaptive suction cup module and the height-adaptive module enable the suction cup to automatically conform to complex free-form surfaces, making the workpiece more adaptable. Because the support point layout is automatically planned by software, taking into account processing avoidance and mechanical constraints, it is more scientific and reasonable than manual experience-based placement, which is beneficial for improving processing quality. The valve island system integrates multiple solenoid valves and a negative pressure monitoring device, enabling reliable adsorption and holding, positive pressure purging, and prevention of leakage suction, improving the stability and safety of clamping.

[0009] This invention automatically analyzes the 3D model of the workpiece and generates optimized support point files based on mechanical constraints, making the flexible support position more reasonable and effectively avoiding local stress concentration and deformation problems caused by improper manual point placement. This improves the adaptability to the large curved surface, thin wall and easily deformable characteristics of aerospace composite parts and solves the problem of difficult stable clamping of complex curved surface parts in the prior art.

[0010] This invention achieves adaptive adjustment of position, angle, and height by driving the suction cup assembly, enabling the adsorption surface to automatically conform to the actual curved surface of the workpiece, thus achieving reliable adsorption of complex free-form surfaces. This effectively overcomes the problem of insufficient adhesion in traditional clamping methods and improves the support stability of composite material parts during processing.

[0011] This invention reconstructs the actual shape of a workpiece by collecting its actual surface and thickness data. Through toolpath compensation, it significantly improves machining accuracy and reduces safety risks caused by forming errors or springback. It effectively compensates for deviations in composite material parts caused by springback or forming errors, thereby improving machining accuracy.

[0012] This invention uses real-time monitoring to take timely protective actions when vacuum abnormalities or positional deviations occur, ensuring that the clamping state is controllable during processing, reducing processing risks caused by adsorption failure or part deformation, and improving the safety and stability of the processing process.

[0013] This invention records and archives the entire clamping and processing data after processing to form a complete processing archive, enabling traceable process management and providing a basis for subsequent process analysis and quality control. This invention also addresses the problem of missing processing data for composite parts in existing technologies.

[0014] Furthermore, this invention does not rely on dedicated rigid fixtures and can quickly change between different workpiece models through software switching, greatly shortening the clamping preparation time, reducing manufacturing costs, and improving the automation, adaptability, reliability, and safety of composite material parts processing. It is suitable for multi-variety, small-batch aerospace composite material processing scenarios.

[0015] Therefore, it is evident that the present invention has outstanding substantive features and significant progress compared with the prior art, and the beneficial effects of its implementation are also obvious. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0017] Figure 1 This is a flowchart of a flexible clamping method for machining aerospace composite parts; Figure 2 This is an architecture diagram of a flexible clamping method for machining aerospace composite parts; Figure 3 This is a structural diagram of a three-axis flexible motion platform; Figure 4 This is a structural diagram of the valve island system; Figure 5 This is a structural diagram of an in-machine measurement system; Figure 6 This is a diagram of the driver management platform architecture; Detailed Implementation The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The following embodiments are explanations of the present invention, but the present invention is not limited to the following implementation methods.

[0018] Example 1: like Figure 1 and Figure 2 As shown in the figure, this embodiment provides a flexible clamping method for machining aerospace composite material parts, including the following steps: Step S1: The step of point planning involves importing the 3D model of the workpiece into the point planning system, automatically parsing the features, and generating an optimized support point file based on mechanical constraints. Step S2: Positioning and adsorption step. The three-axis flexible motion platform drives the suction cup assembly to position and fit the workpiece surface, thus completing the workpiece clamping. Step S3: The toolpath compensation step involves collecting the actual surface and thickness data of the workpiece from the machine measurement system, reconstructing the actual geometry of the workpiece using the intelligent process module, performing comparative analysis, and generating toolpath compensation data. Step S4: The monitoring and protection step involves performing machining based on toolpath compensation data, driving the management platform to monitor in real time, and triggering adaptive protection when an anomaly occurs. Step S5: Data archiving step. After processing is completed, the vacuum is released and the support components are retrieved. At the same time, the entire process data is recorded to form a processing process archive.

[0019] In step S1: the 3D model of the aerospace composite material part to be processed is imported into the point planning system. The point planning system automatically analyzes the surface features of the workpiece in the 3D model, identifies curvature variation areas, reinforcing structures, opening positions, weak areas, and potential interference areas. Based on the identification results, the system obtains the stress characteristics and processing requirements of the workpiece. Combining the workpiece mass, stiffness distribution, processing area, and tool interference requirements, the system automatically generates preliminary support points. Based on the travel range of the three-axis flexible motion platform and the workpiece's supportable area, the preliminary support points are screened to select those within the executable range. The point planning system optimizes the stress on the support points within the executable range based on mechanical constraints, making the stress distribution of each support point more uniform, thereby reducing the deformation of the composite material structure during processing. After stress optimization is completed, the point planning system generates optimized support point files and outputs them to the PLC control system. At the same time, the point planning system stores the optimized support point files corresponding to each machining program in a programmed manner. When different parts or machining processes are changed, the operator can quickly switch and execute the optimized support point files by calling the corresponding program.

[0020] The optimized support point file includes the spatial location information of the support points on the workpiece's 3D model, the corresponding surface features and structural attribute identifiers, the force distribution information of the support points, the executability identifier, and their association information with the machining program. This information is used to determine the support layout of the workpiece during machining. The support points are planned points calculated by the point-location planning system based on the workpiece's 3D model and force characteristics, used to determine the workpiece's support positions. The suction cup points are execution points formed by corresponding the support points with specific suction cups on the three-axis flexible motion platform, used to guide the suction cup assembly to complete positioning and adsorption.

[0021] Step S1 optimizes the support points, which are automatically generated based on the actual geometric features and stress requirements of the workpiece. This avoids uneven stress and local deformation caused by manual point placement, improves the rationality of the support layout, and provides a reliable foundation for subsequent flexible bonding and stable adsorption.

[0022] In step S2: the three-axis flexible motion platform receives the optimized support point file, drives the suction cup assembly to move along the X, Y, and Z directions to the target position, and lifts the workpiece. As the suction cup approaches the workpiece surface, the valve island system performs a positive pressure blowing function to clean the workpiece contact surface. When the workpiece is lifted and lowered to initially contact the suction cup, the valve island system switches the positive pressure blowing function to vacuum negative pressure adsorption. The angle adaptive unit adjusts the posture through the universal ball joint structure. For suction cups that fail the negative pressure test, the height adaptive module is activated, and the suction cups are passively lifted under the action of the spring, so that all suction cups naturally fit with the workpiece surface. The rotation angle is locked by the air lock structure of the angle adaptive unit to complete the workpiece clamping.

[0023] The three-axis flexible motion platform includes a three-axis motion system, an angle-adaptive suction cup module, and a height-adaptive module. In the three-axis motion system, the gantry enables the X-axis movement of the suction cup array, the slider enables Y-axis positioning, and the servo electric cylinder enables precise Z-axis contact height control.

[0024] The height adaptive module is installed on top of the electric cylinder and connected to positive pressure air. It includes a piston rod, a spring, and a locking mechanism. When positive pressure air is supplied, the piston rod in the height adaptive module remains at its lowest position. When the air supply is cut off, the piston rod can be raised a certain distance under the force of the spring, achieving height adaptation. After the height adaptation is completed, the locking mechanism of the height adaptive module locks the piston rod in place. The height adaptive module works as follows: after the operator issues a clamping command, the flexible clamp is activated to pre-evacuate and detect the vacuum level. If the vacuum level is not up to standard, it indicates that the suction cup at that point is not in contact with the bottom surface of the workpiece. The PLC control system disconnects the positive pressure air at that point, and the spring raises the suction cup position until the vacuum sensor indicates that a steady vacuum has been established. The height is then locked through the locking mechanism.

[0025] The angle-adaptive suction cup module is mounted above the height-adaptive module and directly contacts the workpiece. The height-adaptive module automatically adjusts upon contact, ensuring a natural fit with the workpiece surface. The angle-adaptive suction cup module includes a suction cup assembly, an angle-adaptive unit, and a rigid limiting support. The suction cup assembly can fit the workpiece and create a vacuum. Equipped with specially shaped suction cups, the assembly can be fitted with different shaped suction cups for edge locations to adapt to curved surfaces and contact conditions. The angle-adaptive unit includes an airlock structure and a universal ball joint structure. The universal ball joint structure allows the suction cup to adapt to workpieces with various curvatures. When compressed air is supplied, the universal ball joint structure is adjustable, allowing for angle adjustment. When the compressed air is cut off, the airlock structure locks the angle, fixing the suction cup's posture. The rigid limiting support is made of steel and its height exceeds the suction cup plane, ensuring rigid support between the suction cup and the workpiece.

[0026] The valve island system includes a three-position five-way center-sealed valve, a vacuum pump, a compressed air pump, and a pressure detection switch. The three-position five-way center-sealed valve is a normally closed solenoid valve. Before the suction cups contact the workpiece, the workpiece surface is cleaned by positive pressure purging to improve adsorption reliability. After the suction cups are attached, the system switches to negative pressure adsorption mode. When the power is off, the solenoid valve immediately closes to maintain the existing negative pressure. The vacuum pump and compressed air pump provide negative and positive pressure to the valve island system, respectively. The pressure detection switch detects the vacuum value of each suction cup in real time and feeds it back to the drive management platform. Subsequent steps can only be performed when the set vacuum threshold is reached.

[0027] Through step S2, the suction cup can conform to the curved surface of multi-curvature composite materials, reduce local stress concentration, and improve adsorption stability. At the same time, positive pressure purging and vacuum detection ensure that the adsorption process is controllable and effectively reduce the risk of leakage.

[0028] In step S3: the in-machine measurement system measures the clamped workpiece, collects point cloud data and thickness data, and the intelligent process module reconstructs the actual geometry of the workpiece based on the collected point cloud data and thickness data, compares and analyzes it with the workpiece's three-dimensional model, automatically calculates the deviation, generates toolpath compensation data based on the actual surface, automatically corrects the machining trajectory, and performs adaptive adjustment of the machining toolpath to improve machining accuracy.

[0029] The on-machine measurement system includes a laser probe / trigger probe, a medium-free ultrasonic probe, and an intelligent process module, used to reconstruct the true shape of the workpiece. The laser probe / trigger probe is mounted on the spindle and acquires surface point cloud data according to the planned path. The medium-free ultrasonic probe measures the thickness data of the composite material at each optimized support point and transmits it to the intelligent process module. The intelligent process module reversely reconstructs the actual geometry of the workpiece and compares it with the theoretical 3D model of the workpiece. It automatically calculates the deviation and generates toolpath compensation data based on the actual model, automatically corrects the machining trajectory, and performs adaptive adjustment of the machining toolpath to improve machining accuracy. The intelligent process module detects the actual center coordinates of the predefined positioning holes on the workpiece through the probe, executes the alignment program, and realizes the deflection of the machining coordinate system and the alignment of the part.

[0030] By combining the machine measurement system with the intelligent process module, the toolpath adaptive correction based on the actual shape of the workpiece is realized, which effectively reduces the impact of forming error, springback and clamping deviation on machining accuracy and improves the machining consistency of composite material parts.

[0031] In step S4: Based on the toolpath compensation data, the CNC machine tool performs machining. The drive management platform uses an electrical cabinet and a large-size touchscreen to control and monitor in real time data such as the vacuum adsorption status of each chuck, the movement position of each axis, and the status of the three-axis flexible motion platform. When the drive management platform detects that the vacuum of a certain chuck has dropped to the warning value, or that the position of the three-axis flexible motion platform has drifted, it generates an abnormal alarm message and automatically triggers protective measures such as local replenishment of suction, short-term tool pause, posture realignment, or suspension of machining according to a preset strategy to ensure workpiece stability and equipment safety during machining. During machining, the operator can view the vacuum adsorption status of each chuck in real time through the large-size touchscreen and summarize the vacuum adsorption pass rate. It supports operation and monitoring in automatic, electric, or manual modes.

[0032] The drive management platform includes an electrical cabinet and a large touchscreen. The large touchscreen enables servo motor drive, valve island system control, positive pressure blowing switching control, and detection. The drive management platform can perform position control, air source control, height compensation control, and angle locking control in automatic, manual, and electric modes. The automatic mode is used for production, where operators call the drive management platform to automatically complete the positioning, vacuum adsorption, and status monitoring of all suction cups. The manual mode is used for debugging or maintenance, and individual electric cylinders can be precisely controlled through the drive management platform interface. The large touchscreen displays the vacuum adsorption status of each suction cup in a graphic and color-coded manner, summarizing the vacuum adsorption pass rate. Operators can use the large touchscreen to call up the entire automatic program with one click, or enter manual mode to select any suction cup point individually and control its air / vacuum switching.

[0033] Step S4 enables real-time safety protection and intelligent monitoring of the machining process. This step ensures the reliability of the suction cup adsorption, reduces the risk of workpiece detachment, enables dynamic adjustment of the workpiece machining process, ensures the effectiveness of toolpath compensation, and allows operators to intervene flexibly in automatic or manual modes, improving machining stability and safety.

[0034] In step S5: After machining is completed, the control valve island system switches to the air blowing mode, so that each suction cup is safely detached from the workpiece surface. The workpiece is then hoisted and transported to a safe position away from the machine tool. After the workpiece is unloaded, the three-axis flexible motion platform gradually retracts the support components to the initial standby position. The drive management platform collects and records data during the machining cycle, including suction cup vacuum curves, motion trajectories of each axis, on-machine measurement system data, toolpath compensation data, and abnormal alarm information. These data are summarized, organized, and archived within the drive management platform to form a traceable machining process archive, which can accurately reflect the entire process status from clamping, measurement, toolpath compensation to machining completion.

[0035] This step allows operators or subsequent quality management systems to trace the processing records of any workpiece at any time, achieving transparency, controllability, and historical data tracking in the processing process, providing a reliable basis for quality verification, process optimization, and anomaly analysis.

[0036] Furthermore, such as Figure 3 As shown, the three-axis flexible motion platform 2 includes a three-axis motion system 21, an angle adaptive suction cup module 22, and a height adaptive module 23. Multiple Z-axis servo electric cylinders are installed on the X / Y gantry and slider of the three-axis flexible motion platform 2. The height adaptive module 23 is mounted on the top of the electric cylinders, and the angle adaptive suction cup module 22 is installed above the height adaptive module 23. like Figure 4As shown, the valve island system 3 is connected to each suction cup assembly through air pipelines. It integrates a three-position five-way center-sealed valve 31, a vacuum pump 32, a compressed air pump 33, and a pressure detection switch 34, and is controlled by the drive management platform 5. like Figure 5 As shown, the in-machine measurement system 4 includes a laser probe / trigger probe 41, a medium-free ultrasonic probe 42, and an intelligent process module 43. The laser probe / trigger probe 41 is mounted on the machine tool spindle, and the medium-free ultrasonic probe 42 is integrated into the in-machine measurement system 4. The collected data is transmitted to the intelligent process module 43 through a communication interface. like Figure 6 As shown, the drive management platform 5 includes an electrical cabinet 51 and a large-size touch screen 52. The electrical cabinet 51 integrates a PLC control system and a servo motor driver, and the large-size touch screen 52 provides a human-machine interface.

[0037] The point-position planning system 1 identifies the 3D model of the workpiece and automatically analyzes the surface features of the workpiece in the 3D model, identifying curvature variation areas, reinforcement structures, opening positions, weak areas, and potential interference areas. Based on the identification results, it obtains the stress characteristics and processing requirements of the workpiece, automatically generates preliminary support points, and selects support points within the executable range based on the travel range of the three-axis flexible motion platform 2 and the workpiece support range. Based on mechanical constraints, the point-position planning system 1 optimizes the stress distribution of the support points within the executable range, making the stress distribution of each support point more uniform, reducing structural deformation during processing, generating the optimized final support point file and outputting it to the PLC control system. The point-position planning system 1 has built-in program management, and the point coordinates corresponding to each processing program and part are pre-stored in the point-position planning system 1. When changing parts or processing technology, the operator can execute the corresponding program by calling it. After the operator confirms the clamping, the three-axis flexible motion platform 2 is started.

[0038] The three-axis flexible motion platform 2 includes a three-axis motion system 21, an angle-adaptive suction cup module 22, and a height-adaptive module 23. Multiple Z-axis servo electric cylinders are mounted on the X / Y axis truss and slider of the three-axis flexible motion platform 2. The height-adaptive module 23 is mounted on top of the electric cylinders, and the angle-adaptive suction cup module 22 is mounted above the height-adaptive module 23. The angle-adaptive suction cup module 22 includes a suction cup assembly 221, an angle-adaptive unit 222, and a rigid limit support 223; the angle-adaptive unit 222 contains a pneumatic lock structure 2221 and a universal ball joint structure 2222; the height-adaptive module 23 is mounted on top of the electric cylinders, connected to positive pressure air, and includes a piston rod 231, a spring 232, and a locking mechanism 233. When air is introduced, the piston rod 231 remains at its lowest position. When the air is cut off, the piston rod 231 can be lifted a certain distance under the force of the spring 232 to achieve height self-adaptation. The locking mechanism 233 of the height self-adaptation module 23 locks the piston rod 231 after the height self-adaptation is completed. The working mode of the height self-adaptation module 23 is as follows: after the operator issues the clamping command, the flexible clamp opens the pre-vacuum and detects the vacuum degree. If the vacuum degree does not meet the standard, it proves that the suction cup at that point is not in contact with the bottom surface of the workpiece. The PLC control system disconnects the positive pressure air at that point, and the spring 232 actively lifts the position of the suction cup until the vacuum sensor shows that a steady vacuum has been established. The height is locked by the locking mechanism 233.

[0039] The angle-adaptive suction cup module 22 directly contacts the workpiece and automatically adjusts upon contact with the workpiece via the height-adaptive module 23, naturally adhering to the workpiece surface. The suction cup assembly 221 can adhere to the workpiece and draw a vacuum. The suction cup assembly 221 is equipped with a specially shaped suction cup. For edge points, the suction cup assembly 221 can be replaced with a specially shaped suction cup to adapt to the curved surface and contact conditions of the edge area. The angle-adaptive unit 222 contains an airlock structure 2221 and a universal ball joint structure 2222. The universal ball joint structure 2222 enables the suction cup to adapt to workpieces with various curvatures. When compressed air is introduced, the universal ball joint structure 2222 is in an adjustable state and can be rotated to adjust the angle. When the compressed air is cut off, the airlock structure 2221 locks the angle, fixing the suction cup posture. The rigid limit support 223 is made of steel and its height is higher than the suction cup plane, ensuring that the support between the middle of the suction cup and the workpiece is rigid.

[0040] The three-position five-way center-sealed valve 31 of the valve island system 3 is a normally closed solenoid valve. When the power is off, the solenoid valve closes immediately to maintain the existing negative pressure. The vacuum pump 32 and the compressed air pump 33 provide negative pressure and positive pressure to the valve island system 3, respectively. The pressure detection switch 34 detects the vacuum value of each suction cup in real time and feeds it back to the drive management platform 5.

[0041] The laser probe / trigger probe 41 of the on-machine measurement system 4 is mounted on the spindle and acquires surface point cloud data according to the planned path. The medium-free ultrasonic probe 42 measures the thickness data of the composite material at each optimized support point and transmits it to the intelligent process module 43. The intelligent process module 43 reversely reconstructs the actual geometry of the workpiece and compares it with the theoretical three-dimensional model of the workpiece. It automatically calculates the deviation and generates toolpath compensation data based on the actual model. It automatically corrects the machining trajectory and performs adaptive adjustment of the machining toolpath to improve machining accuracy. The intelligent process module 43 detects the actual center coordinates of the predefined positioning holes on the workpiece through the probe and executes the alignment program to realize the deflection of the machining coordinate system and the alignment of the part.

[0042] The drive management platform 5 includes an electrical cabinet 51 and a large-size touch screen 52. The electrical cabinet 51 is responsible for servo motor drive, valve island system 3 control, positive pressure blowing switching control, and detection. The drive management platform 5 can perform position control, air source control, height compensation control, and angle locking control in automatic, manual, and electric modes. The automatic mode is used for production, where operators call the drive management platform 5 to automatically complete the positioning, vacuum adsorption, and status monitoring of all suction cups. The manual mode is used for debugging or maintenance, and individual electric cylinders can be precisely controlled through the interface of the drive management platform 5. The large-size touch screen 52 displays the vacuum adsorption status of each suction cup in a graphic and color-coded manner, summarizing the vacuum adsorption pass rate. Operators can use the large-size touch screen 52 to call up the entire automatic program with one click, or enter the manual mode to select any suction cup point individually and control its air / vacuum switching.

[0043] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. The methods disclosed in the embodiments are described simply because they correspond to the systems disclosed in the embodiments; relevant details can be found in the method section.

[0044] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0045] In the embodiments provided by this invention, it should be understood that the disclosed systems, methods, and approaches can be implemented in other ways. For example, the system embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between systems or units may be electrical, mechanical, or other forms.

[0046] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0047] In addition, the functional modules in the various embodiments of the present invention can be integrated into one processing unit, or each module can exist physically separately, or two or more modules can be integrated into one unit.

[0048] Similarly, in the various embodiments of the present invention, each processing unit can be integrated into a functional module, or each processing unit can exist physically, or two or more processing units can be integrated into a functional module.

[0049] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0050] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0051] The above-disclosed embodiments are merely preferred embodiments of the present invention, but the present invention is not limited thereto. Any non-creative variations that can be conceived by those skilled in the art, as well as any improvements and modifications made without departing from the principles of the present invention, should fall within the protection scope of the present invention.

Claims

1. A flexible clamping method for machining aerospace composite material parts, characterized in that, Includes the following steps: Step S1: The step of point planning involves importing the 3D model of the workpiece into the point planning system, automatically parsing the features, and generating an optimized support point file based on mechanical constraints. Step S2: Positioning and adsorption step. The three-axis flexible motion platform drives the suction cup assembly to position and fit the workpiece surface, thus completing the workpiece clamping. Step S3: The toolpath compensation step involves collecting the actual surface and thickness data of the workpiece from the machine measurement system, reconstructing the actual geometry of the workpiece using the intelligent process module, performing comparative analysis, and generating toolpath compensation data. Step S4: The monitoring and protection step involves performing machining based on toolpath compensation data, driving the management platform to monitor in real time, and triggering adaptive protection when an anomaly occurs. Step S5: Data archiving step. After processing is completed, the vacuum is released and the support components are retrieved. At the same time, the entire process data is recorded to form a processing process archive.

2. The flexible clamping method for machining aerospace composite material parts according to claim 1, characterized in that, In step S1: the 3D model of the aerospace composite material part to be processed is imported into the point-position planning system. The point-position planning system automatically analyzes the surface features of the workpiece in the 3D model, identifies curvature variation areas, reinforcing structures, opening positions, weak areas, and potential interference areas. Based on the identification results, the system obtains the stress characteristics and processing requirements of the workpiece. Combining the workpiece mass, stiffness distribution, processing area, and tool interference requirements, the system automatically generates preliminary support points. The preliminary support points are then filtered based on the travel range of the three-axis flexible motion platform and the workpiece's supportable area, selecting those within the executable range. The point-position planning system optimizes the stress on the support points within the executable range based on mechanical constraints. The system generates optimized support point files and outputs them to the PLC control system. Simultaneously, the point-position planning system programmatically stores the optimized support point files corresponding to each processing program. When changing different parts or processing techniques, the corresponding program can be called to quickly switch and execute the optimized support point files.

3. A flexible clamping method for machining aerospace composite material parts according to claim 1 or 2, characterized in that, The optimized support point file includes the spatial location information of the support points on the workpiece's three-dimensional model, the corresponding surface features and structural attribute identifiers, the force distribution information of the support points, the executability identifier, and its association information with the machining program.

4. The flexible clamping method for machining aerospace composite material parts according to claim 3, characterized in that, In step S2: the three-axis flexible motion platform receives the optimized support point file, drives the suction cup assembly to move along the X, Y, and Z directions to the target position, and lifts the workpiece. As the suction cup approaches the workpiece surface, the valve island system performs a positive pressure blowing function to clean the workpiece contact surface. When the workpiece is lifted and lowered to initially contact the suction cup, the valve island system switches the positive pressure blowing function to vacuum negative pressure adsorption. The angle adaptive unit adjusts the posture through the universal ball joint structure. For suction cups that fail the negative pressure test, the height adaptive module is activated, and the suction cups are passively lifted under the action of the spring, so that all suction cups naturally fit with the workpiece surface. The rotation angle is locked by the air lock structure of the angle adaptive unit to complete the workpiece clamping.

5. A flexible clamping method for machining aerospace composite material parts according to claim 4, characterized in that, In step S3: the in-machine measurement system measures the clamped workpiece, collects point cloud data and thickness data, and the intelligent process module reconstructs the actual geometry of the workpiece based on the collected point cloud data and thickness data, compares and analyzes it with the workpiece's three-dimensional model, calculates the deviation, and generates toolpath compensation data based on the actual surface.

6. A flexible clamping method for machining aerospace composite material parts according to claim 5, characterized in that, In step S4: Based on the toolpath compensation data, the CNC machine tool performs machining. The drive management platform controls and monitors the vacuum adsorption status of each chuck, the movement position of each axis, and the status of the three-axis flexible motion platform in real time through the electrical cabinet and a large-size touch screen. When the drive management platform detects that the vacuum of a certain chuck drops to the warning value, or that the position of the three-axis flexible motion platform drifts, it generates an abnormal alarm message and automatically triggers protective measures such as local replenishment of suction and short-term tool pause, posture realignment, or suspension of machining according to the preset strategy. During the machining process, the vacuum adsorption status of each chuck is viewed in real time through the large-size touch screen, and the vacuum adsorption pass rate is summarized.

7. A flexible clamping method for machining aerospace composite material parts according to claim 6, characterized in that, In step S5: After processing is completed, the control valve island system switches to the air blowing mode to safely detach each suction cup from the workpiece surface, and the workpiece is hoisted and transported to a safe position away from the machine tool. After the workpiece is unloaded, the three-axis flexible motion platform gradually retracts the support components to the initial standby position. The drive management platform collects and records data during the processing cycle, including suction cup vacuum curves, motion trajectories of each axis, on-machine measurement system data, toolpath compensation data, and abnormal alarm information. The data is summarized, organized, and archived within the drive management platform to form a traceable processing process archive.

8. A flexible clamping method for machining aerospace composite material parts according to claim 7, characterized in that, The three-axis flexible motion platform (2) includes a three-axis motion system (21), an angle adaptive suction cup module (22), and a height adaptive module (23). The valve island system (3) integrates a three-position five-way center-sealed valve (31), a vacuum pump (32), a compressed air pump (33), and a pressure detection switch (34). The in-machine measurement system (4) includes a laser probe / trigger probe (41), a medium-free ultrasonic probe (42), and an intelligent process module (43). The laser probe / trigger probe (41) is installed on the machine tool spindle, and the medium-free ultrasonic probe (42) is integrated into the in-machine measurement system (4). The collected data is transmitted to the intelligent process module (43) through a communication interface. The drive management platform (5) includes an electrical cabinet (51) and a large-size touch screen (52). The electrical cabinet (51) integrates a PLC control system and a servo motor driver, and the large-size touch screen (52) provides a human-machine interface.

9. A flexible clamping method for machining aerospace composite material parts according to claim 8, characterized in that, The three-axis flexible motion platform (2) has multiple Z-axis servo electric cylinders installed on the X / Y truss and slider. The top of the electric cylinder is equipped with a height adaptive module (23), and the angle adaptive suction cup module (22) is installed above the height adaptive module (23). The angle-adaptive suction cup module (22) includes a suction cup assembly (221), an angle-adaptive unit (222), and a rigid limit support (223); the angle-adaptive unit (222) contains a gas lock structure (2221) and a universal ball joint structure (2222). The height adaptive module (23) includes a piston rod (231), a spring (232), and a locking mechanism (233).

10. A flexible clamping method for machining aerospace composite material parts according to claim 9, characterized in that, The point planning system (1) identifies the three-dimensional model of the workpiece and automatically analyzes the surface features of the workpiece in the three-dimensional model of the workpiece, identifying the curvature change area, reinforcement structure, opening position, weak area and potential interference area; based on the identification results, it obtains the force characteristics and processing requirements of the workpiece, automatically generates preliminary support points, selects support points within the executable range based on the stroke range of the three-axis flexible motion platform (2) and the workpiece support range, and optimizes the force of the support points within the executable range based on mechanical constraints, generates the optimized final support point file and outputs it to the PLC control system; the point planning system (1) comes with program management, and the point coordinates corresponding to each processing program and part are pre-stored in the point planning system (1). When changing parts or processing technology, the corresponding program is called to execute, and after confirming clamping, the three-axis flexible motion platform (2) is started. The height adaptive module (23) of the three-axis flexible motion platform is installed on the top of the electric cylinder and connected to positive pressure air. When air is introduced, the piston rod (231) is kept at the lowest position. When the air is cut off, the piston rod (231) can be lifted a distance under the action of the spring (232). The locking mechanism (233) of the height adaptive module (23) locks the piston rod (231) after the height adaptation is completed. The height adaptive module (23) works as follows: after the operator issues the clamping command, the soft clamp opens the pre-vacuum and detects the vacuum degree. If the vacuum degree does not meet the standard, it proves that the suction cup at that point is not in contact with the bottom surface of the workpiece. The PLC control system disconnects the positive pressure air at that point, and the spring (232) actively lifts the position of the suction cup until the vacuum sensor shows that a steady vacuum has been established. The height is locked by the locking mechanism (233). The angle-adaptive suction cup module (22) is in direct contact with the workpiece. It automatically adjusts itself when in contact with the workpiece through the height-adaptive module (23) and naturally fits the workpiece surface. The suction cup assembly (221) can fit the workpiece and draw a vacuum. The suction cup assembly (221) is equipped with a special-shaped suction cup. For edge points, the suction cup assembly (221) can be replaced with a special-shaped suction cup. When compressed air is introduced, the universal ball joint structure (2222) is in an adjustable state and can be rotated to adjust the angle. When the compressed air is cut off, the air lock structure (2221) locks the angle to fix the suction cup posture. The hard limit support (223) is made of steel. The three-position five-way center-sealed valve (31) of the valve island system (3) is a normally closed solenoid valve. The vacuum pump (32) and the compressed air pump (33) provide negative pressure and positive pressure to the valve island system (3) respectively. The pressure detection switch (34) detects the vacuum value of each suction cup in real time and feeds it back to the drive management platform (5). The laser probe / trigger probe (41) of the on-machine measurement system (4) is installed on the spindle and acquires surface point cloud data according to the planned path. The medium-free ultrasonic probe (42) measures the thickness data of the composite material at each optimized support point and transmits it to the intelligent process module (43). The intelligent process module (43) reversely reconstructs the actual geometry of the workpiece and compares it with the theoretical three-dimensional model of the workpiece. It automatically calculates the deviation and generates toolpath compensation data based on the actual model. It automatically corrects the machining trajectory and performs adaptive adjustment of the machining toolpath. The intelligent process module (43) detects the actual center coordinates of the predefined positioning holes on the workpiece through the probe and executes the alignment procedure. The drive management platform (5) includes an electrical cabinet (51) and a large-size touch screen (52). The electrical cabinet (51) is responsible for the servo motor drive, valve island system (3) control, positive pressure blowing switching control and detection. The drive management platform (5) performs position control, air source control, height compensation control and angle locking control in automatic mode, manual mode and electric mode. The automatic mode is used for production. The operator calls the drive management platform (5) to automatically complete the positioning, vacuum adsorption and status monitoring of all suction cups. The manual mode is responsible for debugging or maintenance. The interface of the drive management platform (5) can be used to finely control a single electric cylinder. The large-size touch screen (52) displays the vacuum adsorption status of each suction cup in graphic color and summarizes the vacuum adsorption qualification rate.

Images