High-precision segmented cutting system and method for flexible helical wire based on axis following

Abstract

The present application relates to flexible spiral wire high-precision segmented cutting equipment technical field, specifically to a kind of flexible spiral wire high-precision segmented cutting system and method based on axis following.System includes portal frame, bearing and unloading mechanism, non-contact scanning positioning mechanism, adaptive clamping mechanism and multi-degree-of-freedom shearing mechanism.Through non-contact scanning positioning mechanism, obtain the three-dimensional space curved trajectory data of workpiece, based on this data, the axial tangential vector at cutting point is solved, and the shearing plane of multi-degree-of-freedom shearing mechanism is adjusted in real time, so that it is strictly perpendicular to the current axis of workpiece;At the same time, adaptive clamping mechanism dynamically centers and clamps workpiece according to scanning data.The method realizes the closed-loop control of "scanning-solution-following shearing".The present application effectively overcomes the influence of flexible material form uncertainty, realizes the high-precision, automated segmented cutting with cutting surface perpendicularity error less than ±1°.

Description

Technical Field

[0001] This invention relates to the field of high-precision segmented cutting equipment for flexible spiral wires, specifically a high-precision segmented cutting system and method for flexible spiral wires based on axis following. Background Technology

[0002] Precision automated shearing technology is a core component of modern manufacturing, particularly in the processing of medical catheters, precision electronic coils, and aerospace flexible tubing. As industrial production demands increasingly higher levels of integration and precision in components, achieving high-precision segmented shearing of strip-shaped objects such as thin tubes and coils—characterized by flexibility and easy deformation—has become a key technical challenge restricting production efficiency and yield. These materials are highly susceptible to random spatial bending due to residual stress during storage or loading. Traditional fixed or simple feeding shearing equipment often struggles to detect and compensate for this morphological deviation, leading to inaccurate shearing positions. More importantly, the cut surface cannot be guaranteed to be perpendicular to the local axis of the workpiece, severely impacting subsequent welding, assembly, or sealing performance.

[0003] Currently, there are several automated devices in the industry designed to improve the shearing quality of flexible materials. For example, Chinese patent application CN202222783726.X discloses a cutting machine for cutting flexible materials. This device uses sequentially arranged transverse and longitudinal guiding mechanisms to constrain the material, attempting to avoid unidirectional compressive deformation during transport. While this design improves transport stability, its cutting assembly uses a fixed-angle rotating disc cutter, which cannot flexibly adjust the geometric angle of the cutting surface according to the actual spatial posture of the workpiece. More importantly, it lacks an effective real-time detection and compensation mechanism for the actual three-dimensional orientation of the flexible material before entering the cutting zone. Therefore, for workpieces with initial bending or helical characteristics, the perpendicularity of the cut cannot be guaranteed.

[0004] Another improved solution is found in Chinese patent application CN202210036635.1, which discloses an automatic conveying and cutting device for flexible strip materials. This device utilizes a master-slave drive wheel assembly with a connecting belt for smooth traction and obtains material end position information through photoelectric sensors to achieve fixed-length cutting. This device significantly improves the automation level of feeding and cutting linkage. However, its cutter is restricted to moving within a fixed limiting groove and cutting hole, resulting in a single cutting trajectory and limited degrees of freedom, making it difficult to handle complex spatial angle cutting requirements. Furthermore, the limiting adjustment achieved by the device through moving plates and elastic bodies mainly targets linear compensation for different size specifications. When dealing with coils and spiral tubes with complex spatial curvature, simple physical limiting cannot achieve dynamic and precise alignment between the workpiece centerline and the cutting tool centerline, resulting in insufficient cutting accuracy in demanding scenarios.

[0005] In summary, existing flexible material shearing equipment generally suffers from the following limitations: First, they lack high-precision online three-dimensional posture detection capabilities, making it impossible to acquire the real-time spatial axis trajectory of the workpiece; second, their shearing actuators have insufficient degrees of freedom or lack angle adjustment capabilities, making it impossible to dynamically adjust the shearing plane based on detected posture data; finally, the clamping mechanisms are mostly passive or coarse-adjustment type, making it difficult to achieve precise adaptive alignment with the bending axis while avoiding damage to the workpiece. This has led to the industry facing long-standing technical bottlenecks such as "low positioning accuracy, large perpendicularity deviation of the cutting surface, and poor adaptability to irregular and curved workpieces." Summary of the Invention

[0006] To overcome the shortcomings of the prior art, this invention provides a high-precision segmented cutting system and method for flexible spiral wires based on axis following. It integrates non-contact three-dimensional scanning, real-time attitude calculation, dynamic clamping compensation, and multi-degree-of-freedom precision variable angle shearing into one system, fundamentally solving the technical problem of high-precision segmented cutting of flexible spiral wires while ensuring high efficiency.

[0007] To achieve the above objectives, the present invention employs the following technical solution: A high-precision segmented cutting system for flexible helical wire based on axis following includes a gantry, a load-bearing and unloading mechanism installed below the gantry, a non-contact scanning and positioning mechanism installed on the gantry, an adaptive clamping mechanism, and a multi-degree-of-freedom shearing mechanism. The load-bearing and unloading mechanism supports and positions the flexible helical wire. The non-contact scanning and positioning mechanism moves along the axial direction of the flexible helical wire and acquires its three-dimensional spatial bending trajectory data. The adaptive clamping mechanism performs adaptive centering clamping on the flexible helical wire based on the feedback data from the non-contact scanning and positioning mechanism. The multi-degree-of-freedom shearing mechanism includes an angle-adjusting servo motor, a circumferential rotation adjustment mechanism, and a pneumatic shearing actuator. The circumferential rotation adjustment mechanism drives the pneumatic shearing actuator to rotate around its axis, and the servo motor adjusts the angle of the circumferential rotation adjustment mechanism. The angle-adjusting servo motor adjusts the shearing plane of the pneumatic shearing actuator in real time based on the axial tangential vector at the cutting point calculated from the three-dimensional spatial bending trajectory data, making it perpendicular to the axis of the flexible helical wire at the cutting point.

[0008] Furthermore, the non-contact scanning positioning mechanism includes a mounting beam, a non-contact scanning sensor, and a non-contact scanning sensor slide; the non-contact scanning sensor slide is slidably connected to the mounting beam and reciprocates along the mounting beam; the non-contact scanning sensor is fixed to the non-contact scanning sensor slide and is a line laser profile sensor, which moves along the axial direction of the flexible helical wire with the non-contact scanning sensor slide to obtain continuous cross-sectional profile data and construct a continuous spatial helical model.

[0009] Furthermore, the adaptive clamping mechanism includes a gripper cylinder mounting plate, a lead screw, a through-type linear drive motor, a contour chuck, and a chuck cylinder; the chuck cylinder drives the contour chuck, the chuck cylinder is fixed to the gripper cylinder mounting plate, the gripper cylinder mounting plate is threadedly connected to the lead screw, the through-type linear drive motor drives the lead screw to rotate, thereby moving the gripper cylinder mounting plate; the through-type linear drive motor drives the contour chuck to move according to the position information fed back by the non-contact scanning and positioning mechanism, so as to compensate for the radial position deviation of the flexible spiral wire.

[0010] Furthermore, the shearing mechanism also includes a Z-axis lifting drive module and a shearing mechanism feed adjustment slide; the Z-axis lifting drive module drives the shearing mechanism to move in the vertical direction; the shearing mechanism feed adjustment slide drives the shearing mechanism to move horizontally along the axial direction of the flexible spiral wire.

[0011] Furthermore, the bearing and unloading mechanism includes an unloading guide plate and a tilting cylinder; the upper surface of the unloading guide plate is provided with a V-shaped positioning groove for supporting the flexible spiral wire; the tilting cylinder is connected to the unloading guide plate and drives the unloading guide plate to tilt around the axis to achieve unloading.

[0012] Furthermore, the circumferential rotation adjustment mechanism is a hollow rotary platform, and the angle adjustment servo motor is a servo motor equipped with a multi-turn absolute encoder. The two constitute a direct drive architecture, and the air pipe and cable of the pneumatic shear actuator are arranged through the axis of the hollow rotary platform.

[0013] A high-precision segmented cutting method for flexible spiral wires, employing the aforementioned system, includes the following steps: 1) Placement and scanning: The flexible spiral wire is placed on the bearing and unloading mechanism, and its three-dimensional spatial bending trajectory data is obtained by scanning along its axis through a non-contact scanning and positioning mechanism. 2) Modeling and calculation: Based on the three-dimensional spatial bending trajectory data, construct a spatial curve model of the workpiece and calculate the axial tangential vector at the predetermined cutting point; 3) Follow-up adjustment and clamping: The adaptive clamping mechanism is controlled to perform position compensation according to the space curve model and perform adaptive centering clamping on the flexible spiral wire; at the same time, the angle adjustment servo motor of the multi-degree-of-freedom shearing mechanism is controlled to drive the pneumatic shearing actuator to rotate according to the tangential vector so that its shearing plane is perpendicular to the axis. 4) Perform shearing: Control the shearing mechanism to move to the cutting point and perform the shearing action; 5) Unloading and resetting: After shearing is completed, the clamps are released, and the cut workpiece is unloaded through the bearing and unloading mechanism, and each mechanism is reset.

[0014] Further, in step 2), the step of solving the tangential vector of the axis includes: selecting a sliding window containing multiple adjacent data points on the spatial curve model with the cut-off point as the center; performing polynomial curve fitting on the data points in the sliding window using the least squares method; and calculating the derivative of the fitted curve at the cut-off point as the accurate tangential vector of that point.

[0015] Further, in step 3), the control process for driving the pneumatic shear actuator to rotate is a closed-loop control, specifically including: using the actual rotation angle fed back by the built-in encoder of the angle adjustment servo motor as a feedback signal; comparing the target rotation angle calculated in step 2) with the actual rotation angle to obtain the angle deviation; using a proportional-integral-derivative control algorithm to calculate the angle deviation and generate a control command to drive the angle adjustment servo motor to eliminate steady-state error and ensure that the shearing angle error is within the set range.

[0016] Further, the specific steps of adaptive centering clamping in step 3) include: calculating the lateral coordinate deviation between the actual center line of the workpiece and the mechanical center line of the equipment at the clamping point according to the space curve model; controlling the through-type linear drive motor of the adaptive clamping mechanism to drive the contour chuck to move to compensate for the lateral coordinate deviation, and after centering, controlling the chuck cylinder to perform a closing clamping action.

[0017] Compared with the prior art, the beneficial effects of the present invention are: 1. The accuracy of the shearing angle has been greatly improved, fundamentally ensuring the quality of the cut surface. Existing technologies, due to their inability to sense the actual spatial posture of the workpiece, or the lack of a high-degree-of-freedom actuator for dynamic compensation, result in significant and uncontrollable deviations between the shearing surface and the theoretical perpendicular plane. This invention acquires high-density three-dimensional spatial bending trajectories of the workpiece in real time through a non-contact scanning and positioning mechanism, and employs a least-squares fitting algorithm based on a local sliding window to accurately calculate the axial tangential vector at each shearing point. This algorithm, through multi-point data smoothing, effectively suppresses interference from sensor noise and microscopic undulations on the workpiece surface, obtaining smoother and more accurate axial direction information than the traditional differential method. Subsequently, the angle adjustment servo motor of the multi-degree-of-freedom shearing mechanism drives a high-precision, low-backlash circumferential rotation adjustment mechanism based on this vector signal, ensuring that the cutting edge plane of the pneumatic shearing actuator is aligned with and perpendicular to the actual axis at that point in real time. This proactive "axis following" mechanism eliminates, in principle, angular errors caused by workpiece placement curvature, its own helical characteristics, or clamping deformation. The implementation results show that the system can stably control the perpendicularity error between the cut surface and the local axis of the workpiece within ±1°, and in the best case it can reach ±0.2°, which meets the stringent requirements for cut quality in fields such as medical catheters and precision coils, and solves the core problem of cut deviation in the existing technology.

[0018] 2. Enhanced adaptability to complex spatial shapes and specifications of workpieces. Traditional shearing equipment is typically designed for straight or near-straight workpieces, with extremely limited capability in processing wires with significant helical or random bends. This invention, through a combination of global scanning and local modeling, eliminates the assumption that the workpiece is in an ideal straight line. Regardless of whether the workpiece is a regular helix or irregularly curved, the system can first acquire its overall spatial model, and then perform independent angle calculations and adjustments for any selected cutting point. Simultaneously, the modular and adjustable design of the device greatly expands the processing range: by adjusting the span of the gantry, replacing guide plates of different lengths, and linear modules, it can adapt to different workpiece lengths, from short micro-components to ultra-long cables; by flexibly adding or removing the number of shearing units on the crossbeam, single-point cutting or multi-segment synchronous cutting can be achieved, allowing for flexible configuration of production efficiency. This changes the limitation of traditional equipment being "one machine for one use," realizing "one machine for multiple uses," and significantly improving equipment utilization and economy.

[0019] 3. Achieved non-destructive and precise clamping of workpieces with irregular cross-sections. For flexible workpieces with non-circular cross-sections (such as rectangular, elliptical, and "E"-shaped sealing strips), traditional V-blocks or flat-mouth grippers are difficult to achieve stable centering and are prone to crushing or deformation. The adaptive clamping mechanism of this invention employs a "first follow-up centering, then closing clamping" strategy. Specifically, a through-type linear drive motor first drives the grippers to the centering position based on the actual coordinates of the workpiece's centerline obtained from scanning, compensating for lateral deviations caused by bending. Then, a chuck cylinder drives a quickly replaceable contour-following chuck to perform the closing action. The inner cavity shape of this contour-following chuck matches the workpiece's cross-section, ensuring a uniform distribution of clamping force. While providing sufficient clamping force, it effectively avoids workpiece surface damage or cross-sectional distortion caused by stress concentration, providing a stable process foundation for subsequent high-precision shearing.

[0020] 4. Improved production automation and efficiency, and reduced overall costs. This invention integrates multiple processes such as feeding and positioning, online detection, adaptive clamping, variable angle shearing, and automatic unloading into one unit, and achieves fully automated continuous operation through a central control system. The carrying and unloading mechanism integrates a flipping function. After shearing, a flipping cylinder drives a guide plate with a V-groove to flip, and the finished product automatically slides into the material box by gravity, eliminating the need for manual material handling and shortening the work cycle. Compared to traditional single-machine equipment or manual cutting that relies on manual measurement, alignment, and step-by-step operation, this device reduces the single-cycle time by more than 60%, and in multi-segment synchronous shearing examples, efficiency can be improved by up to 300%. Simultaneously, high precision and automation reduce scrap rates and reliance on highly skilled workers, thereby reducing raw material waste and labor costs, and improving the overall efficiency of the production line.

[0021] 5. The control system has high robustness and reliability. This invention constructs a complete three-layer control architecture, from information perception (scanning) to intelligent decision-making (vector computation) and then to precise execution (servo closed loop). At the decision layer, the least squares fitting algorithm enhances the system's resistance to data interference. At the execution layer, real-time PID position closed-loop control based on a high-resolution encoder, combined with feedforward compensation, not only achieves rapid dynamic response but also completely eliminates steady-state error through the integral term, enabling the system to maintain angle lock even when facing disturbances such as instantaneous pneumatic shearing impact and mechanical friction. This dual error elimination mechanism, combining hardware and software, ensures that the system's accuracy does not decay during long-term operation, and its process stability is far superior to open-loop or simple feedback control systems. Attached Figure Description

[0022] Figure 1 This is a three-dimensional structural diagram of the present invention.

[0023] Figure 2 This is a three-dimensional structural diagram of the Z-axis lifting drive module of the present invention.

[0024] Figure 3 This is a schematic diagram of the three-dimensional structure of the multi-degree-of-freedom shearing mechanism and gantry frame of the present invention.

[0025] Figure 4 This is a three-dimensional structural diagram of the multi-degree-of-freedom shearing mechanism of the present invention.

[0026] Figure 5 This is a three-dimensional structural diagram of the non-contact scanning and positioning mechanism of the present invention.

[0027] Figure 6 This is a three-dimensional structural diagram of the material-bearing and unloading mechanism of the present invention.

[0028] Figure 7 This is a three-dimensional structural diagram of the tilting cylinder of the material-carrying and unloading mechanism of the present invention.

[0029] Figure 8 This is a three-dimensional structural diagram of the adaptive clamping mechanism of the present invention.

[0030] Figure 9 This is a three-dimensional structural diagram of the contour-following chuck portion of the adaptive clamping mechanism of the present invention.

[0031] Figure 10 This is a schematic diagram of the shearing state of the present invention.

[0032] Figure 11 This is a schematic diagram of the shearing state of a flexible spiral wire.

[0033] Figure 12 This is a schematic diagram of the electrical control principle of the present invention.

[0034] The diagram shows the following components: 1. Gantry frame; 2. Non-contact scanning and positioning mechanism; 3. Multi-degree-of-freedom shearing mechanism; 4. Adaptive clamping mechanism; 5. Loading and unloading mechanism; 6. Flexible spiral wire; 7. Z-axis lifting drive module; 8. Shearing mechanism guide rail; 9. Shearing mechanism mounting bracket; 10. Shearing mechanism feed adjustment slide; 11. Angle adjustment servo motor; 12. Circumferential rotation adjustment mechanism; 13. Pneumatic shearing actuator; 14. Pneumatic shearing actuator mounting bracket; 15. Mounting beam; 16. Non-contact scanning sensor; 17. Non-contact scanning sensor slide; 18. V-shaped positioning groove; 19. Unloading guide plate; 20. Loading and unloading mechanism mounting bracket; 21. Tilting cylinder; 22. Tilting cylinder mounting plate; 23. Gripper cylinder mounting plate; 24. Lead screw; 25. Clamping mechanism mounting plate; 26. Through-type linear drive motor; 27. Contouring chuck; 28. Chuck cylinder. Detailed Implementation

[0035] The embodiments of the present invention are described in detail below. To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0037] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0038] In the description of this invention, it should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0039] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention. Furthermore, it should be understood that, for ease of description, the various parts shown in the accompanying drawings... The dimensions of the drawings are not based on actual proportional relationships. For techniques and methods known to those skilled in the art in the relevant field... The methods and devices may not be discussed in detail, but where appropriate, the techniques, methods, and devices described should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0040] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0041] like Figure 1-12 As shown, a high-precision segmented cutting system for flexible spiral wire based on axis following adopts a modular, high-rigidity gantry architecture. Its core components include: a gantry frame (1) serving as the overall support foundation; a non-contact scanning and positioning mechanism (2) installed at the front of the gantry frame (1); an adaptive clamping mechanism (4) symmetrically arranged on both sides of the workpiece axis; a multi-degree-of-freedom shearing mechanism (3) located at the center of the crossbeam of the gantry frame (1) and capable of vertical and horizontal feeding; and a load-bearing and unloading mechanism (5) located at the bottom of the equipment, which has both positioning and unloading functions. The flexible spiral wire (6) to be processed is placed on the load-bearing and unloading mechanism (5).

[0042] like Figure 5As shown, the non-contact scanning positioning mechanism (2) is a prerequisite for achieving "axis following". It includes a mounting beam (15) fixed on the gantry (1), a non-contact scanning sensor slide (17) set along the mounting beam (15), and a non-contact scanning sensor (16) fixed on the non-contact scanning sensor slide (17). The non-contact scanning sensor (16) is preferably a high-precision line laser profile sensor (e.g., Keyence LJ-X8000 series). Its working principle is to project a laser line onto the surface of the workpiece and obtain the profile data of the workpiece on the scanning section (XZ plane) by triangulation.

[0043] When the non-contact scanning sensor slide (17) drives the sensor (16) to move at a constant speed along the axial direction (Y-axis) of the flexible helical wire (6), the system continuously acquires the cross-sectional profile at a frequency of not less than 2kHz. Through data processing, the coordinates of the center point of each cross-section can be fitted, and the sequence of center points of all cross-sections can be connected to reconstruct a complete and continuous three-dimensional helical model of the workpiece. The advantages of using a line laser sensor compared with a single-point laser are: First, it can completely cover the entire cross-section of a small-diameter workpiece, accurately fit the center of the circle, and avoid the error introduced by the uncertainty of the highest point position in single-point measurement; Second, for irregular cross-sections, a complete profile can be obtained to determine whether the workpiece is twisted, which is the basis for subsequent calculation of the true normal vector; Third, line lasers of specific wavelengths (such as 405nm blue light) have better adaptability to semi-transparent or highly reflective materials, which can ensure the quality of the point cloud. The measurement accuracy (Z-axis) of this sensor can reach ±5μm (optimal ±2μm), thus providing hardware guarantee for high-precision modeling.

[0044] like Figure 2 , 3 As shown in Figure 4, the multi-degree-of-freedom shearing mechanism (3) is the core execution unit for achieving precision variable-angle shearing. The shearing mechanism guide rail (8) is vertically set and fixed to the left and right sides of the gantry frame (1). The shearing mechanism mounting frame (9) is mounted on both sides of the shearing mechanism guide rail (8) and moves up and down along the shearing mechanism guide rail (8). The shearing mechanism feed adjustment slide (10) is mounted on the shearing mechanism mounting frame (9). The main body of the multi-degree-of-freedom shearing mechanism (3) is driven by the shearing mechanism feed adjustment slide (10) to achieve positioning along the workpiece axis (Y direction). The entire mechanism is driven by the Z-axis lifting drive module (7) to achieve vertical (Z direction) feed and tool lifting.

[0045] The execution of the shearing action relies on a pneumatic shearing actuator (13). To ensure that its shearing plane is always perpendicular to the local axis of the workpiece, this invention designs a precision circumferential angle adjustment unit: an angle adjustment servo motor (11) directly drives a circumferential rotation adjustment mechanism (12) through a coupling. The circumferential rotation adjustment mechanism (12) is preferably a high-rigidity, low-backlash hollow rotary platform (e.g., GIGAGERGSB series), with a mechanical repeatability better than ±15 arcseconds (approximately ±0.004°) and a backlash less than 1 arcminute. The angle adjustment servo motor (11) is preferably equipped with a 23-bit multi-turn absolute encoder (e.g., Panasonic A6 series), with a single-turn resolution of up to 8,388,608 pulses. This "high-resolution encoder + direct-drive hollow rotary table" architecture makes the theoretical hardware angle adjustment resolution of the system much higher than the process requirement (±1°), providing sufficient accuracy redundancy for software closed-loop control. The air pipe and signal cable of the pneumatic shearing actuator (13) can pass through the axis of the hollow rotary platform, avoiding the problem of entanglement during rotation.

[0046] like Figure 8 , 9 As shown, the adaptive clamping mechanism (4) is responsible for providing stable and damage-free clamping at the moment of shearing. It includes a through-type linear drive motor (26) fixed on the clamping mechanism mounting plate (25). The output shaft of the through-type linear drive motor (26) is connected to the lead screw (24) through a coupling, driving the gripper cylinder mounting plate (23) with its threaded engagement to move linearly. The chuck cylinder (28) is fixed on the mounting plate (23), and the end of its piston rod is connected to the contour chuck (27).

[0047] Its working logic is "first follow-up centering, then closing and clamping": The control system calculates the coordinate deviation in the lateral (X direction) between the actual center line of the flexible spiral wire (6) and the mechanical center line of the equipment at the predetermined clamping point based on the spatial model obtained by scanning. Subsequently, the through-type linear drive motor (26) drives the contour chuck (27) to move, accurately compensating for this deviation, so that the symmetry center of the two contour chucks (27) coincides with the actual center of the workpiece. After centering is completed, the chuck cylinder (28) is activated to drive the contour chuck (27) to close and complete the clamping. The contour chuck (27) is a quick-replaceable module, and its inner cavity shape is precisely matched with the cross-section of the workpiece (circular, rectangular, elliptical, etc.) to ensure uniform distribution of clamping force and effectively avoid crushing or scratching of irregular flexible workpieces caused by traditional clamping methods.

[0048] like Figure 6 , 7As shown, the carrying and unloading mechanism (5) integrates initial positioning and finished product discharge functions. The unloading guide plate (19) is supported by the carrying and unloading mechanism mounting bracket (20), and its upper surface is machined with a V-shaped positioning groove (18) for supporting and initially centering the workpiece (6) before scanning and shearing. After all shearing actions are completed, the tilting cylinder (21) mounted on the tilting cylinder mounting plate (22) is activated, driving the unloading guide plate (19) to rotate about 90 degrees around its axis towards the hopper. The cut workpiece segment slides into the collection device along the inclined guide plate under the action of gravity, realizing fully automatic unloading and greatly shortening the auxiliary time.

[0049] Core implementation methods of control algorithms and logic To achieve high-precision shearing with the aforementioned hardware and eliminate the influence of surface roughness and minor vibrations on the scanning data of flexible workpieces, this invention abandons the traditional two-point difference method and adopts a least-squares fitting algorithm based on a local sliding window to calculate the high-precision tangential vector. The specific calculation steps are as follows: 1. Construction of discrete point data. A non-contact sensor scans at a frequency f, and the system acquires a series of discrete spatial coordinate points P. i , denoted as: Where N is the total number of scan points, and i is the sampling point number.

[0050] 2. Establishing a local window. This involves setting the current shear point P to be calculated. k A sliding window containing 2m+1 data points is selected centered on this point (for example, if m=5, then 5 points are taken before and after, for a total of 11 points): 3. Local polynomial fitting of space curves. Within a sliding window W... k Internally, the least squares method is used to perform a quadratic polynomial fitting on the data points to construct the local parametric equation P(u): Where u is a local parameter (which can be taken as a normalized coordinate along the axis), and a0, a1, and a2 are the fitting coefficient vectors to be solved. This is achieved by minimizing the difference between the point P(uj) on the fitted curve and the actual observation point P within the sliding window. j Sum of squares of Euclidean distance between them: This allows us to calculate the optimal coefficient vector.

[0051] 4. Tangential vector T k The exact solution is obtained by taking the first derivative of the fitted equation P(u) at the center point (i.e., u=0), thus obtaining the exact tangential vector T at that point. k : Compared to the traditional central difference method, this fitting algorithm effectively filters out high-frequency noise from the sensor through multi-point smoothing, ensuring the smoothness and accuracy of the tangential vector.

[0052] 5. Conversion and execution of shear angle θ. Based on the calculated tangential vector T... k The control system calculates the target rotation angle θ of the pneumatic shear actuator in the XY plane (assuming the shear plane is perpendicular to the direction of gravity). t Where δ is the initial installation compensation angle of the shearing mechanism. The control system will... t The signal is converted into a pulse signal and sent to the angle adjustment servo motor, driving the circumferential rotation adjustment mechanism to rotate, so that the normal of the shear blade edge is always aligned with the tangential vector T. k Parallel (i.e., the shear plane is perpendicular to the axis).

[0053] To ensure the actuator can accurately respond to the tangential vector angle calculated by the above algorithm, this invention constructs a high-frequency position closed-loop control system based on a servo kernel. The specific signal flow and control logic are as follows: 1. Feedback signal source: This system uses a high-resolution multi-turn absolute encoder (e.g., a 23-bit magnetic encoder or optical encoder, with a single-turn resolution of 8,388,608 pulses) built into the servo motor (11) as the core signal source for angle feedback. The controller does not rely on visual verification after shearing (which is a type of hysteresis control), but instead uses real-time position feedback. Before the shearing action is executed, the driver reads the actual rotation angle θ fed back by the encoder in real time at a period of 100µs. a and the angle θ calculated by the algorithm. t The comparison is performed to form a hard real-time position deviation signal e(t).

[0054] 2) PID control algorithm and its steady-state error elimination mechanism: To ensure that the steady-state error during dynamic following is less than 1 degree, this invention introduces a feedforward compensation combined with position-based PID control algorithm in the servo drive layer: Where u(t) is the motor current command. K p Its function is to achieve high rigidity locking. By setting a high proportional gain, the shearing mechanism forms a large "electromagnetic rigidity" after reaching the target angle, preventing the pneumatic shearing actuator from deflecting due to the reaction force at the moment of performing the shearing action. K i The purpose is to eliminate static error, addressing the mechanical friction and air pipe resistance torque present during the rotation of the pneumatic shear actuator. The integral term K iIt automatically accumulates minute angular deviations until sufficient corrective torque is generated to bring the deviation e(t) close to zero. This mathematically guarantees that the theoretical error at the final stopping position is zero, thus ensuring that the actual physical error is far less than 1°. K d This is the differential gain.

[0055] This invention eliminates errors from both geometric calculation and physical execution dimensions through a three-layer architecture of "line laser scanning to establish a model (feedforward reference) - least squares method to solve vectors (path planning) - encoder real-time feedback PID control (execution closed loop)", thereby achieving true "axis following" precision shearing.

[0056] To address the spatial curvature (i.e., workpiece axis deviating from the machine's mechanical centerline) problem inherent in flexible workpieces under natural placement, this invention employs a "first follow-up centering, then closing clamping" control strategy to prevent additional internal stress or displacement damage to the workpiece due to forced correction during clamping. The specific calculation and execution logic is as follows: Based on the workpiece spatial spiral model P(u) constructed using the aforementioned algorithm, the control system first determines the fixed longitudinal position Y of the clamping mechanism in the gantry coordinate system. c Substituting the values ​​into the curve equation, the actual transverse center coordinates (X) of the workpiece at that cross-section can be calculated. c : Among them, P x (u) is the component function of the fitted curve in the X-axis direction.

[0057] The workflow of this invention is as follows: 1. Placement and Scanning: Place the flexible spiral wire (6) into the V-shaped positioning groove (18). Start the system, and the non-contact scanning sensor (16) moves along the entire length of the workpiece to acquire three-dimensional point cloud data and construct a spatial model.

[0058] 2. Setting and Calculation: Input the number of cutting segments and their lengths. The system calculates the precise spatial coordinates and tangential vector of each cutting point based on the model.

[0059] 3. Follow-up centering and clamping: The adaptive clamping mechanism (4) drives the contour chuck (27) to move and center and clamp the workpiece according to the center position calculated by the model.

[0060] 4. Variable Angle Positioning and Shearing: The multi-degree-of-freedom shearing mechanism (3) moves to the first cutting point. The angle adjustment servo motor (11) drives the pneumatic shearing actuator (13) to rotate to the corresponding angle according to the tangential vector of that point. The Z-axis lifting drive module (7) descends, and the pneumatic shearing actuator completes the shearing.

[0061] 5. Unloading and resetting: Repeat step 4 until all segments are cut. The clamping mechanism is released, the flipping cylinder (21) drives the unloading guide plate (19) to flip and unload, and then each mechanism is reset to prepare for the next cycle.

[0062] Example 1: Precision oblique cutting of medical TPU catheters This embodiment addresses the precision machining requirements for the tip forming of catheters used in minimally invasive interventional surgery. The workpiece is a transparent TPU flexible catheter with an outer diameter of 3.0 mm and a wall thickness of 0.5 mm, requiring a precision bevel cut at its end at a 45.0° angle to the axis.

[0063] During operation, the conduit is naturally placed into the V-shaped positioning groove (18), which has a slight bend. After the system is started, the non-contact scanning sensor (16) scans the entire length of the conduit and reconstructs its three-dimensional model. Based on the input 45.0° angle requirement and the model data, the control system calculates the precise rotation angle of the pneumatic shearing actuator (13) required to achieve the inclined plane. After the angle adjustment servo motor (11) drives the shearing mechanism to rotate to the target angle, the adaptive clamping mechanism (4) moves to gently and precisely clamp the conduit at the predetermined position through the contoured circular chuck. Finally, the shearing mechanism descends to complete the shearing.

[0064] Performance Verification: A high-precision optical projector was used to inspect the cut catheter cross-section. Measurement results showed that the actual angle of the cut surface deviated from the theoretically required 45.0° target by less than 0.2°. This precision fully meets the assembly requirements of high-end medical devices. Compared to manual cutting relying on the technician's feel or traditional clamp cutting, this process significantly increases the finished product qualification rate of such catheters from approximately 70% to over 95%, with extremely high processing consistency.

[0065] Example 2: Multi-segment synchronous high-precision shearing of long-size aviation induction coils This embodiment demonstrates the equipment's capability in processing long workpieces and multi-segment synchronously. The workpiece is a 1500mm long aircraft induction coil made of copper wire with an insulating layer, and its overall shape is a relaxed spiral. It needs to be divided into four equal segments, and the length tolerance of each segment must be strictly controlled.

[0066] Before implementation, the span of the gantry (1) was adjusted according to the length of the workpiece, and the unloading guide plate (19) of the corresponding length was replaced. At the same time, four independent pneumatic shearing actuator (13) units were installed in parallel on the shearing mechanism mounting frame (9). After the coil was placed into the equipment, the scanning mechanism quickly obtained its overall shape and precise length. The control system automatically calculated and positioned the four shearing points according to the equal division requirements. The four sets of adaptive clamping mechanisms (4) synchronously performed adaptive centering and clamping on the coil segments they were responsible for according to the model data. After preparation, the four shearing units synchronously rotated to their calculated angles, and then synchronously cut down under the drive of the Z-axis lifting drive module (7), completing the four-segment shearing in one go.

[0067] Verification of Results: The lengths of the four cut coil segments were measured using a digital caliper. The results showed that the deviation of each segment's length from the set value was controlled within ±0.04mm. Previously, the method of manually marking lines and then cutting sequentially at single points typically resulted in length deviations of around ±1.2mm. This embodiment not only improves dimensional accuracy by an order of magnitude, but also, due to the use of multi-segment synchronous cutting technology, increases processing efficiency by approximately 300% compared to the traditional single-blade sequential cutting method.

[0068] Example 3: Vertical cutting of irregular cross-section rubber sealing strip This embodiment demonstrates the equipment's ability to handle workpieces with complex cross-sectional shapes. The workpiece is an "E"-shaped cross-section rubber strip used for sealing. It is made of soft, easily deformable material and requires vertical cutting to ensure a smooth cross-section.

[0069] Before processing, a contour chuck (27) that perfectly matches the shape of the "E"-shaped cross-section is selected and installed from the series of chucks. After the rubber strip is placed on the equipment, the scanning mechanism not only obtains its axial trajectory but also identifies the cross-sectional direction. During clamping, the through-type linear drive motor (26) first drives the contour chuck (27) to move precisely, ensuring that the inner cavity of the chuck is completely aligned with the cross-section of the rubber strip before clamping, perfectly avoiding cross-sectional distortion caused by improper clamping. The shearing mechanism performs shearing at a 0 (vertical) angle according to calculation. After completion, the flip cylinder (21) automatically unloads the material.

[0070] Performance Verification: The cross-section of the sheared rubber sealing strip was inspected. The perpendicularity error between the cross-section and the side of the workpiece (which reflects the axial direction) was less than 0.5°. The cross-section was flat, without tearing or crushing. This process enables fully automated, high-precision, and non-destructive processing of such easily deformable irregular-shaped workpieces. It transforms a task that previously required repeated adjustments by skilled workers into one-click automated production, reducing the estimated overall labor cost per piece by approximately 80%.

[0071] In summary, this invention, through the coordinated implementation of the aforementioned hardware architecture and software algorithms, achieves high-precision "axis-following" cutting of flexible helical wires. The system stably controls the perpendicularity error of the cutting surface within ±1° (optimally reaching ±0.2°), reduces the single-operation cycle time by more than 60%, and possesses excellent workpiece adaptability, fundamentally solving the bottleneck problems in existing technologies.

[0072] The above description is only a part of the specific embodiments of the present invention. The scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A high-precision segmented cutting system for flexible spiral wire based on axis following, characterized in that, It includes a gantry (1), a load-bearing and unloading mechanism (5) installed below the gantry (1), a non-contact scanning and positioning mechanism (2) installed on the gantry (1), an adaptive clamping mechanism (4), and a multi-degree-of-freedom shearing mechanism (3). The bearing and unloading mechanism (5) supports and positions the flexible spiral wire (6). The non-contact scanning and positioning mechanism (2) moves along the axial direction of the flexible spiral wire (6) and acquires its three-dimensional spatial bending trajectory data; The adaptive clamping mechanism (4) performs adaptive centering clamping on the flexible spiral wire (6) based on the feedback data from the non-contact scanning and positioning mechanism (2); The multi-degree-of-freedom shearing mechanism (3) includes an angle adjustment servo motor (11), a circumferential rotation adjustment mechanism (12), and a pneumatic shearing actuator (13); the circumferential rotation adjustment mechanism (12) drives the pneumatic shearing actuator (13) to rotate around its axis, and the servo motor (11) adjusts the angle of the circumferential rotation adjustment mechanism (12); The angle adjustment servo motor (11) adjusts the shearing plane of the pneumatic shearing actuator (13) in real time based on the axial tangential vector at the cutting point calculated by the three-dimensional spatial bending trajectory data, so that it is perpendicular to the axis of the flexible spiral wire (6) at the cutting point.

2. The high-precision segmented cutting system for flexible spiral wire based on axis following according to claim 1, characterized in that, The non-contact scanning positioning mechanism (2) includes a mounting beam (15), a non-contact scanning sensor (16), and a non-contact scanning sensor slide. The non-contact scanning sensor slide (17) is slidably connected to the mounting beam (15) and moves back and forth along the mounting beam (15); The non-contact scanning sensor (16) is fixed to the non-contact scanning sensor slide (17) and is a line laser profile sensor. It moves along the axial direction of the flexible helical wire (6) with the non-contact scanning sensor slide (17) to obtain continuous cross-sectional profile data and construct a continuous spatial helical model.

3. The high-precision segmented cutting system for flexible spiral wire based on axis following according to claim 1, characterized in that, The adaptive clamping mechanism (4) includes a gripper cylinder mounting plate (23), a lead screw (24), a through-type linear drive motor (26), a contour chuck (27), and a chuck cylinder (28). The chuck cylinder (28) drives the contour chuck (27). The chuck cylinder (28) is fixed to the gripper cylinder mounting plate (23). The gripper cylinder mounting plate (23) is threadedly connected to the lead screw (24). The through-type linear drive motor (26) drives the lead screw (24) to rotate, thereby driving the gripper cylinder mounting plate (23) to move. The through-type linear drive motor (26) drives the contour chuck (27) to move based on the position information fed back by the non-contact scanning and positioning mechanism (2) in order to compensate for the radial position deviation of the flexible spiral wire (6).

4. The high-precision segmented cutting system for flexible spiral wire based on axis following according to claim 1, characterized in that, The shearing mechanism (3) also includes a Z-axis lifting drive module (7) and a shearing mechanism feed adjustment slide (10). The Z-axis lifting drive module (7) drives the shearing mechanism (3) to move in the vertical direction; The feed adjustment slide (10) of the shearing mechanism is driven to move horizontally along the axis of the flexible spiral wire (6) along the shearing mechanism (3).

5. The high-precision segmented cutting system for flexible spiral wire based on axis following according to claim 1, characterized in that, The loading and unloading mechanism (5) includes an unloading guide plate (19) and a tilting cylinder (21). The upper surface of the unloading guide plate (19) is provided with a V-shaped positioning groove (18) to support the flexible spiral wire (6). The tilting cylinder (21) is connected to the unloading guide plate (19) and drives the unloading guide plate (19) to tilt around the axis to achieve unloading.

6. The high-precision segmented cutting system for flexible spiral wire based on axis following according to claim 1, characterized in that, The circumferential rotation adjustment mechanism (12) is a hollow rotating platform, and the angle adjustment servo motor (11) is a servo motor equipped with a multi-turn absolute encoder. The two constitute a direct drive architecture, and the air pipe and cable of the pneumatic shear actuator (13) are arranged through the axis of the hollow rotating platform.

7. A method for high-precision segmented cutting of flexible spiral wire, employing the system described in any one of claims 1-6, characterized in that, Includes the following steps: 1) Placement and scanning: The flexible spiral wire (6) is placed on the bearing and unloading mechanism (5), and its three-dimensional spatial bending trajectory data is obtained by scanning along its axis through the non-contact scanning positioning mechanism (2); 2) Modeling and calculation: Based on the three-dimensional spatial bending trajectory data, construct a spatial curve model of the workpiece and calculate the axial tangential vector at the predetermined cutting point; 3) Follow-up adjustment and clamping: Control the adaptive clamping mechanism (4) to perform position compensation according to the space curve model, and perform adaptive centering clamping on the flexible spiral wire (6); at the same time, control the angle adjustment servo motor (11) of the multi-degree-of-freedom shearing mechanism (3) to drive the pneumatic shearing actuator (13) to rotate according to the tangential vector, so that its shearing plane is perpendicular to the axis. 4) Perform cutting: Control the cutting mechanism (3) to move to the cutting point and perform the cutting action; 5) Unloading and resetting: After shearing is completed, the clamp is released and the cut workpiece is unloaded through the bearing and unloading mechanism (5), and each mechanism is reset.

8. A high-precision segmented cutting method for flexible spiral wire according to claim 7, characterized in that, Step 2), the step of calculating the tangential vector of the axis includes: Centered on the cut-off point, a sliding window containing multiple adjacent data points is selected on the spatial curve model; The least squares method is used to perform polynomial curve fitting on the data points within the sliding window; Calculate the derivative of the fitted curve at the cut-off point, which is used as the precise tangential vector at that point.

9. A high-precision segmented cutting method for flexible spiral wire according to claim 7, characterized in that, The control process for driving the pneumatic shear actuator (13) to rotate in step 3) is a closed-loop control, specifically including: The actual rotation angle fed back by the built-in encoder of the angle-adjusting servo motor (11) is used as the feedback signal; Compare the target turning angle calculated in step 2) with the actual turning angle to obtain the angle deviation; The angle deviation is calculated using a proportional-integral-derivative control algorithm to generate control commands to drive the angle adjustment servo motor (11) in order to eliminate steady-state error and ensure that the shear angle error is within the set range.

10. A high-precision segmented cutting method for flexible spiral wire according to claim 7, characterized in that, The specific steps of adaptive centering clamping described in step 3) include: Based on the space curve model, calculate the lateral coordinate deviation between the actual centerline of the workpiece and the mechanical centerline of the equipment at the clamping point; The through-type linear drive motor (26) of the adaptive clamping mechanism (4) is controlled to drive the contour chuck (27) to move to compensate for the lateral coordinate deviation. After centering, the chuck cylinder (28) is controlled to perform the closing clamping action.

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