A three-axis ultra-precision motion ruling device for microstructure processing and a control method thereof

Abstract

The application discloses a three-axis ultra-precision motion ruling device and a control method for microstructure processing, which comprises an air floating support assembly, a base, a motion platform and an air floating guide rail. The air floating support assembly is arranged at both ends of the air floating guide rail, and the air floating support assembly is mounted on the base. The motion platform is arranged on the air floating guide rail, so that the internal vibration of the system is effectively isolated, and a motion structure without reverse force is formed. The driving magnet is arranged in the air floating guide rail, and there is no ferrous structure, so that the precision of coreless design and zero tooth slot effect are realized. The coil and the magnet are arranged in the motion platform, and the non-contact driving is adopted to realize the ultra-precision motion. The piezoelectric driving device is arranged at the bottom of the motion platform, the piezoelectric driving device drives the cutter to move, the three-axis collaborative control strategy is adopted, and the dynamic precision compensation of the ruling straightness is realized.

Description

Technical Field

[0001] This invention belongs to the technical field of microstructure processing, and in particular relates to a three-axis high-speed motion device and control method for ultra-precision machining. Background Technology

[0002] Microstructure fabrication refers to the creation of geometric or functional structures with micron to nanometer-scale feature dimensions on or within materials using precisely controlled physical or chemical methods. This enables the control of specific optical, electrical, and mechanical properties of devices, and is a core foundation for the manufacturing of microelectronic devices, optical components, and precision sensors. In the current field of ultra-precision microstructure fabrication, the fabrication of microstructure gratings, due to its stringent periodic accuracy and morphological requirements, has become a critical technical challenge that urgently needs to be overcome.

[0003] Currently, grating manufacturing mainly employs various technical routes, including mechanical scribing, lamination replication, holographic lithography, X-ray exposure, wet etching, and scanning interference field exposure. Among these, mechanical scribing technology is widely used due to its relatively perfect processing effect. However, this technology still faces significant technical bottlenecks in achieving higher precision, mainly in key aspects such as maintaining processing accuracy, controlling thermal stability, and multi-degree-of-freedom coordination. As micro-nano manufacturing processes develop towards higher precision and more complex structures, the processing accuracy and high-speed processing stability of traditional mechanical scribing devices under high-speed motion conditions face severe challenges.

[0004] While a considerable foundation has been established in the fabrication of microstructures such as diffraction gratings, existing diffraction grating ruling systems still suffer from significant technical drawbacks during high-speed operation due to their rigid mechanical frames. The rigid coupling between the drive system and the mechanical frame generates a significant reaction force, which, when transmitted to the processing area, causes two main problems: firstly, it intensifies system vibration, affecting the accuracy of the ruling trajectory; secondly, it causes a sharp rise in temperature in the processing area. To address the temperature rise issue, current technologies generally employ active cooling systems (such as circulating water cooling or oil cooling) combined with high-energy-consuming vibration-damping platforms. This approach not only increases system complexity and energy consumption but also limits cooling efficiency due to inherent physical characteristics. Of particular concern is that while direct-drive systems based on linear motors possess high dynamic response characteristics (acceleration > 2g), the motion platform still experiences thermal deformation of up to 0.5 μm / m due to electromagnetic heat dissipation. This thermo-mechanical coupling effect is even more pronounced when processing high-reflectivity materials such as single-crystal silicon and gallium nitride, directly leading to defects such as burrs at the microstructure edges and uneven ruling depth.

[0005] To overcome the precision loss caused by traditional mechanical friction, air-bearing and liquid-bearing guide rail technologies have been applied in the field of precision motion. Among them, air-bearing guide rail technology, with its non-contact support characteristics, has accumulated considerable technical expertise in China, demonstrating significant advantages in reducing frictional resistance and vibration transmission. However, this technology still faces prominent bottlenecks in practical applications: the grating marking process requires the motion platform to maintain extremely high trajectory accuracy during high-speed reciprocating motion. Although traditional air-bearing guide rails can achieve low-friction motion, their air film stiffness is limited, making them prone to air hammer vibration and micro-drift under high-speed reversal or external disturbances. Uneven stiffness distribution amplifies the yaw effect, leading to a decrease in marking straightness. In traditional layouts, the force between the drive system and the motion platform is transmitted to the base through the guide rail, generating a reaction force excitation. This reaction force is particularly significant during high-speed reversal, easily triggering system structural resonance, causing micro-chatter of the marking tool, thus forming burrs or periodic errors at the edge of the grating groove. Existing air-bearing guide rail structures lack effective internal force balance mechanisms, relying solely on external damping or vibration reduction platforms for passive suppression. This not only increases system complexity but also limits vibration reduction effectiveness due to the inherent characteristics of the mechanical structure. Furthermore, the grating ruling process typically involves long periods of continuous operation, making system thermal stability crucial for ensuring consistent processing. During high-speed motion, traditional air-bearing guide rails generate significant heat due to gas viscous friction and electromagnetic losses in the drive system. Given the poor thermal conductivity of the air-bearing structure itself, heat easily accumulates in the contact area between the guide rail and the platform, causing structural thermal deformation. Particularly in the ruling of high-reflectivity materials such as single-crystal silicon and gallium nitride, even micron-level thermal expansion can lead to uneven ruling depth and distortion of periodic structures. These problems urgently need to be overcome in grating ruling applications.

[0006] Meanwhile, although piezoelectric actuation technology can achieve micro-displacement output with nanometer-level resolution, when used as an independent actuator in a grating ruling system, it still suffers from problems such as limited output displacement, difficulty in coordinating dynamic response with the macro-motion system, and insufficient long-term stability due to temperature drift. Especially in high-speed reciprocating ruling processes, piezoelectric actuators need to complete high-frequency force or displacement control in an extremely short time, and traditional structures cannot simultaneously achieve large stroke, high stiffness, and low thermal drift. In addition, the hysteresis, nonlinearity, and creep characteristics inherent in piezoelectric ceramics also pose challenges to closed-loop control, affecting the uniformity of ruling depth and edge morphology quality.

[0007] In terms of motion degree-of-freedom architecture, existing single-axis scribing systems in China have significant limitations. When machining intersecting grooves, curved surface arrays, or asymmetric microstructures, multi-step splicing processes are necessary, which introduces accumulated positioning errors and significantly reduces machining efficiency. Furthermore, due to the lack of multi-axis collaborative control capabilities, even during the machining of basic grooves, when the system is in a high-speed motion state, the combined effects of vibration, forces from structural stiffness, and thermal influences make it difficult to reliably guarantee the machining accuracy of straightness. Moreover, existing systems are significantly inadequate in meeting the demand for precise control of the sidewall morphology of high aspect ratio structures. These technical deficiencies severely restrict the applicability and development potential of microstructure machining.

[0008] It is evident that existing scribing devices suffer from significant technical deficiencies in areas such as reaction force suppression, thermal management efficiency, and multi-degree-of-freedom coordinated control. These systemic shortcomings make it difficult to guarantee dynamic accuracy during machining, especially under high-speed reciprocating motion conditions, where the cumulative error effect is particularly pronounced. Therefore, overcoming the limitations of traditional single-axis motion modes and constructing a multi-degree-of-freedom precision motion system to achieve internal balance of reaction forces, active compensation for thermal deformation, and precise coordination of multi-axis motions, thereby effectively suppressing error accumulation and improving machining consistency and shape accuracy, has become a crucial problem urgently needing to be solved in the field of microstructure machining. Summary of the Invention

[0009] To address the technical problems existing in the prior art, this invention proposes a three-axis ultra-precision motion scribing device. By employing a scheme combining piezoelectric ceramic drive and air-bearing guide rails, the motion platform is mounted on the air-bearing guide rails, which are in turn mounted on an air-bearing support assembly. Utilizing the magnets and iron cores built into the guide rails, a constant thrust is generated by the current flowing through the shuttle-side coils via magnetic lines of force output from the iron core, achieving a low-heat, non-reactive effect. Simultaneously, based on the nanometer-level resolution of the piezoelectric ceramic micro-stage and V / W-axis linkage, the micro-displacement of the tool is controlled by two-axis piezoelectric vibration, achieving real-time compensation for guide rail straightness errors and realizing the cutting motion.

[0010] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0011] In a first aspect, the present invention provides a three-axis ultra-precision motion scribing device for microstructure machining, comprising an air-bearing support assembly, a base, a motion platform, and an air-bearing guide rail; air-bearing support assemblies are provided at both ends of the air-bearing guide rail, the air-bearing support assemblies are mounted on the base, and the motion platform is provided on the air-bearing guide rail, thus effectively isolating internal vibrations of the system and forming a motion structure without reverse force; a driving magnet is provided inside the air-bearing guide rail, without iron structure, achieving the precision of a coreless design and zero cogging effect; a coil and a magnet are provided inside the motion platform, enabling non-contact drive and thus achieving ultra-precision motion; a piezoelectric drive device is provided at the bottom of the motion platform, the piezoelectric drive device comprising a piezoelectric actuator, the bottom of the piezoelectric actuator being vertically embedded in a symmetrical leaf spring piezoelectric head structure via a pre-tightening device; simultaneously, the symmetrical leaf spring piezoelectric head structure is embedded in a bridge-type displacement amplification mechanism, and a cutting tool is mounted at the bottom of the symmetrical leaf spring piezoelectric head structure.

[0012] The aforementioned motion platform enables the diamond tool to move in the U-axis direction, the piezoelectric actuator to drive the tool to move in the V-axis direction, and the bridge displacement amplification mechanism to drive the tool to move in the W-axis direction, thus realizing the U / V / W three-axis linkage control and achieving dynamic precision compensation for the straightness of the engraving.

[0013] As a further technical solution, the air-bearing guide rail is a hollow structure. Inside the air-bearing guide rail, from one end to the other, are sequentially arranged a first limiting block, a first driving magnet, a second driving magnet, a third adjusting magnet, a fourth adjusting magnet, a fifth driving magnet, a sixth driving magnet, and a second limiting block. A fifth permanent magnet and a sixth permanent magnet are symmetrically arranged vertically within the air-bearing guide rail body at the corresponding positions where the first and second driving magnets connect. A seventh permanent magnet and an eighth permanent magnet are symmetrically arranged vertically within the air-bearing guide rail body at the corresponding positions where the fifth and sixth driving magnets connect.

[0014] As a further technical solution, air-bearing guide rail end caps are installed at both ends of the air-bearing guide rail.

[0015] As a further technical solution, the first driving magnet, the second driving magnet, and the third regulating magnet have their S and N poles arranged in the same direction; the fourth regulating magnet, the fifth driving magnet, and the sixth driving magnet have their S and N poles arranged in the same direction; and the first driving magnet, the second driving magnet, and the third regulating magnet have their S and N poles arranged in opposite directions to the fourth regulating magnet, the fifth driving magnet, and the sixth driving magnet.

[0016] As a further technical solution, inside the motion platform, a first permanent magnet and a second permanent magnet are symmetrically arranged vertically at one end, and a third permanent magnet and a fourth permanent magnet are symmetrically arranged vertically at the other end; a coil is arranged in the middle of the motion platform.

[0017] As a further technical solution, the first permanent magnet and the fifth permanent magnet repel each other, the second permanent magnet and the sixth permanent magnet repel each other; the third permanent magnet and the eighth permanent magnet repel each other, and the fourth permanent magnet and the seventh permanent magnet repel each other.

[0018] As a further technical solution, both the air flotation support assembly and the motion platform are equipped with throttling plugs.

[0019] As a further technical solution, the piezoelectric drive device includes an upper piezoelectric ceramic sheet and a lower piezoelectric ceramic sheet, which are tightly attached to a copper substrate. The upper piezoelectric ceramic sheet, the lower piezoelectric ceramic sheet, and the copper substrate are placed in a heat-insulating ceramic sleeve to form a piezoelectric actuator. The bottom of the piezoelectric actuator is vertically embedded in a symmetrical leaf spring piezoelectric head structure through a butterfly preload spring. At the same time, the symmetrical leaf spring piezoelectric head structure is embedded in a bridge displacement amplification mechanism, and a diamond tool is installed at the bottom.

[0020] As a further technical solution, both the symmetrical leaf spring piezoelectric head structure and the bridge displacement amplification mechanism adopt a mirror symmetrical layout.

[0021] Secondly, based on the aforementioned three-axis ultra-precision motion scribing device for microstructure processing, the present invention also provides a control method, as follows:

[0022] The coil inside the motion platform is connected to a three-phase AC current, simultaneously activating the piezoelectric drive. First, V-axis marking control is performed. Based on a preset V-axis piezoelectric drive force threshold and the force-voltage characteristic curve of this drive force and the V-axis piezoelectric drive, an initial voltage is applied to the piezoelectric drive. The symmetrical leaf spring piezoelectric head drives the tool to approach the workpiece surface to a safe distance. Then, the tool position is fed back in real-time by tracking the real-time force change curve of the piezoelectric drive. A PID algorithm is used to dynamically adjust the drive voltage to ensure marking depth accuracy. Next, W-axis dynamic compensation is executed, tracking the offset of the motion platform on the W-axis in real time. The compensation amount is calculated based on the offset, generating a reverse displacement command. The W-axis bridge-type flexible hinge amplifier responds in microseconds to drive the tool's lateral offset, compensating for path deviation and achieving high-precision marking.

[0023] The beneficial effects of this invention are as follows:

[0024] 1. Three-axis linkage and real-time error compensation improve the straightness of the engraving and support efficient machining of complex microstructures.

[0025] To address the shortcomings of traditional air-bearing guides, such as limited air film stiffness leading to air hammer vibration and slight drift under high-speed reversal or external disturbances, resulting in decreased scribing straightness, this invention achieves three-axis linkage control (U / V / W) through a motion platform, piezoelectric actuator, and bridge-type displacement amplification mechanism. Compensation perpendicular to the scribing direction (W-axis direction) is achieved using a bridge-type flexible amplification hinge, combined with the nanometer-level resolution (±5nm) of the piezoelectric actuator, enabling real-time dynamic compensation of the tool position. This effectively compensates for the high-speed stability shortcomings of air-bearing guides and improves straightness stability (straightness error <100nm / 200mm). Furthermore, traditional single-axis scribing systems require multi-stage splicing to process cross grooves or asymmetrical structures, easily introducing cumulative errors and resulting in low efficiency. This invention, in conjunction with a grating encoder, grating measuring scale, and PID algorithm installed at the rear of the motion platform, can correct W-axis offset during high-speed reversal (acceleration up to 5g), significantly reducing positioning errors. This technological breakthrough makes it possible to form high aspect ratio structures, non-periodic gratings, and biomimetic textures in a single step, significantly improving processing efficiency.

[0026] The non-reaction symmetrical structural design enhances system stability and compactness. Addressing the lack of an effective internal force balance mechanism in existing air-bearing guide rail structures, where the drive system and mechanical frame are rigidly coupled, the reaction force is transmitted to the machining area, leading to increased system vibration, decreased scribing trajectory accuracy, and micro-chatter of the scribing tool. This invention employs a non-contact support structure combining an air-bearing guide rail and an air-bearing support component. Combined with a self-balancing design where the motion platform and guide rail move in opposite directions, it achieves non-reaction force transmission, fundamentally preventing vibration transmission to the machining area during high-speed reversal. Through a symmetrical permanent magnet array and electromagnetic drive system, non-contact drive and limiting are achieved, further reducing mechanical shock and micro-chatter, effectively suppressing burrs and periodic errors at the scribing edges.

[0027] 3. Low heat generation and high thermal stability significantly improve machining accuracy.

[0028] To address the issue of uneven marking depth and periodic structure distortion caused by electromagnetic heat dissipation and frictional heat leading to thermal deformation of the motion platform during the coupling process between the air-bearing guide structure and the motion platform, this invention constructs a symmetrical air-bearing support system by combining piezoelectric ceramic drive with the air-bearing guide. This system, combined with self-balancing electromagnetic drive technology, effectively suppresses the transmission of reaction force and electromagnetic heat dissipation. Compared to traditional technologies relying on active cooling systems (such as water / oil cooling) and high-energy-consuming vibration-damping platforms, this device achieves low heat generation. Furthermore, by utilizing air dampers and thermally insulating ceramic sleeves, the thermal deformation is controlled within ±0.1 μm / m. This design not only reduces energy consumption but also significantly improves the temperature stability of the processing area, avoiding microstructure edge burrs and uneven depth issues, making it particularly suitable for the ultra-precision processing of high-reflectivity materials (such as single-crystal silicon and gallium nitride).

[0029] 4. Collaborative optimization of the piezoelectric drive system overcomes performance bottlenecks and ensures long-term reliability.

[0030] To address the limitations of piezoelectric actuators, such as limited output displacement, difficulties in dynamic coordination, hysteresis nonlinearity, and temperature drift, this invention designs a high-performance piezoelectric drive structure within the V / W axis configuration. This structure combines a piezoelectric stack with a bridge-type flexible amplification mechanism, increasing output displacement while maintaining high-frequency response. A disc-type preload spring is introduced to counteract torque in non-target directions through an elastic preload force (10-20% of the maximum output force of the piezoelectric stack), reducing hysteresis. Furthermore, the combination of a thermally insulating ceramic sleeve and a copper substrate minimizes the impact of temperature drift on V-axis displacement (temperature drift error <1 nm / ℃). This collaborative design extends the piezoelectric actuator's lifespan by more than double, ensuring the device's accuracy and stability under long-term high-speed operation.

[0031] 5. Setting up a force feedback control loop represents a paradigm shift from "geometric accuracy" to "process physical accuracy".

[0032] The ultra-precision marking system of this invention, by introducing a force feedback control loop into piezoelectric control, produces significant beneficial technical effects compared to traditional systems that rely solely on displacement sensors installed near the diamond tool. Traditional displacement feedback can only passively follow geometric positions and cannot compensate for fluctuations in actual marking force caused by uneven material microhardness, tool "deflection" effect, and thermomechanical errors in the transmission chain, resulting in inconsistent marking depths. This invention achieves active "constant force" marking by real-time monitoring of the marking force and dynamically adjusting the piezoelectric actuator output based on a force-voltage equivalent model. This not only effectively suppresses the aforementioned interferences and ensures uniformity of marking depth and morphology across the entire workpiece, but also extends the control dimension from geometric space to the physical process, thereby fundamentally improving process consistency. Attached Figure Description

[0033] Figure 1 A schematic diagram of the overall structure of a three-axis ultra-precision motion scribing device for microstructure processing;

[0034] Figure 2 This is a schematic diagram of a non-reactive structure;

[0035] Figure 3 Internal structure for motion platform and guide rail drive;

[0036] Figure 4 Schematic diagram of the internal magnetic pole distribution of the guide rail drive;

[0037] Figure 5 Schematic diagram of V-axis piezoelectric scribing structure Figure 1 ;

[0038] Figure 6 Schematic diagram of V-axis piezoelectric scribing structure Figure 2 ;

[0039] Figure 7 Schematic diagram of V-axis piezoelectric scribing structure Figure 3 ;

[0040] Figure 8 This is a schematic diagram of the structure of a symmetrical leaf spring piezoelectric head;

[0041] Figure 9 This is a schematic diagram of the W-axis compensation structure;

[0042] Figure 10 A schematic diagram of a W-axis bridge-type flexible hinge structure;

[0043] Figure 11 A geometric calculation model for magnification;

[0044] Figure 12 A schematic diagram of triaxial piezoelectric marking compensation logic;

[0045] Figure 13 To depict the actual processing data without compensation;

[0046] Figure 14 A diagram showing the actual machining data for the three-piezoelectric compensation;

[0047] In the diagram: 1. Air-bearing guide rail cover; 2. Air nozzle; 3. Air-bearing support assembly; 4. Motion platform; 5. Air-bearing guide rail; 6. Air-bearing support assembly; 7. Air nozzle; 8. Air-bearing guide rail cover; 9. Base; 10. Diamond cutting tool; 11. Symmetrical leaf spring piezoelectric head; 12. Bridge-type flexible hinge amplifier; 13. Upper piezoelectric ceramic plate; 14. Copper substrate; 15. Lower piezoelectric ceramic plate; 16. Thermal insulation ceramic sleeve; 17. Disc preload spring; 18. Piezoelectric actuator;

[0048] 3-1. Throttling plug; 3-2. Throttling plug; 3-3. Throttling plug; 3-4. Throttling plug;

[0049] 4-1, First permanent magnet; 4-2, Coil; 4-3, Throttling plug; 4-4, Second permanent magnet; 4-5, Wire frame; 4-6, Third permanent magnet; 5-1, Fifth permanent magnet; 5-2, Seventh permanent magnet; 5-3, Sixth permanent magnet; 5-4, Eighth permanent magnet; 5-5, First limiting block; 5-6, First driving magnet; 5-7, Second driving magnet; 5-8, Third regulating magnet; 5-9, Fourth regulating magnet; 5-10, Fifth driving magnet; 5-11, Sixth driving magnet; 5-12, Second limiting block; 6-1, Throttling plug; 6-2, Throttling plug; 6-3, Throttling plug; 6-4, Throttling plug; 12-1, Disc preload spring; 12-2, Disc preload spring; 12-3, Spacer block; 12-4, Spacer block; 12-5, Piezoelectric ceramic; 12-6, Piezoelectric ceramic; Detailed Implementation

[0050] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0051] 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, unless otherwise expressly indicated by the invention, the singular form is also intended to include the plural form. 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.

[0052] For ease of description, the words "up," "down," "left," and "right" appearing in this invention only indicate that they are consistent with the up, down, left, and right directions of the accompanying drawings themselves, and do not limit the structure. They are merely for the purpose of facilitating the description of this invention and simplifying the description, and do not indicate or imply that the device or component 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.

[0053] Furthermore, in this invention, the vertical direction of the piezoelectric drive device is defined as the V-axis direction, the horizontal plane and the motion direction of the motion platform are defined as the U-axis direction, and the motion direction of the bridge displacement amplification mechanism is defined as the W-axis direction; the purpose is to correspond to the XYZ axes of the machine tool after installation, and not to repeat them.

[0054] This embodiment proposes a three-axis ultra-precision motion scribing device for microstructure machining, such as... Figure 1As shown, the device includes an air-bearing support assembly, a base, a motion platform, an air-bearing guide rail, and a piezoelectric drive device. Air-bearing support assemblies are installed at both ends of the air-bearing guide rail of the scribing device. The air-bearing support assembly is mounted on the base, and a motion platform is mounted on the air-bearing guide rail. A piezoelectric drive device is installed on the motion platform, and the piezoelectric drive device drives the cutting tool. The overall mechanism of this invention aims to process micro-grooves and micro-depressions with high precision and in a short time. As an accessory device, it is mounted on an ultra-precision machining machine via connectors on the base. Furthermore, the air-bearing guide rail, which is typically not fixed as a motion platform and bearing guide, is instead supported by an air-bearing support assembly between the air-bearing guide rail and the base. The air-bearing guide rail bears all acceleration and deceleration of the motion platform. This innovative structure combines rigid force transmission with flexible vibration isolation, which can effectively suppress the transmission of vibration to the precision machining area, especially reducing the micro-vibration of the cutting edge during high-speed reversal and improving machining accuracy. "Rigid force transmission" refers to the mechanism of directly transmitting driving force and acceleration / deceleration load through the air-bearing guide rail and motion platform; "flexible vibration isolation" refers to the isolation of external vibration and internal impact through the air-bearing support components to prevent high-frequency micro-vibration from being transmitted to the machining area.

[0055] Specifically, such as Figure 1 , Figure 3 As shown, the air-bearing guide rail in this embodiment is a hollow structure. Air-bearing guide rail caps 1 and 8 are provided at both ends of the air-bearing guide rail. From left to right, the air-bearing guide rail is provided with a first limiting block 5-5, a first driving magnet 5-6, a second driving magnet 5-7, a third adjusting magnet 5-8, a fourth adjusting magnet 5-9, a fifth driving magnet 5-10, a sixth driving magnet 5-11, and a second limiting block 5-12. A fifth permanent magnet 5-1 and a sixth permanent magnet 5-3 are symmetrically arranged vertically within the air-bearing guide rail body at the corresponding positions where the first driving magnet 5-6 and the second driving magnet 5-7 are connected. A seventh permanent magnet 5-2 and an eighth permanent magnet 5-4 are symmetrically arranged vertically within the air-bearing guide rail body at the corresponding positions where the fifth driving magnet 5-11 and the sixth driving magnet 5-12 are connected.

[0056] The main function of the first driving magnet 5-6, the second driving magnet 5-7, the third regulating magnet 5-8, the fourth regulating magnet 5-9, the fifth driving magnet 5-10, and the sixth driving magnet 5-11 mentioned above is to provide a magnetic field to interact with the current in the coil inside the motion platform.

[0057] The third regulating magnet 5-8 and the fourth regulating magnet 5-9 serve as the main processing motion area. Along this path, the current is regulated to make the motion platform move at a constant speed.

[0058] The air-bearing guide rail 5 and the motion platform 4 mentioned above do not contain any iron core structure, thus achieving the precision of the coreless design and zero cogging effect.

[0059] The coil of the linear magnetic shaft inside the aforementioned motion platform 4 forms an iron core, thereby achieving the rigidity of the iron core motor;

[0060] Furthermore, the motion platform 4 in this embodiment includes a body, within which a first permanent magnet 4-1, a second permanent magnet 4-4, a third permanent magnet 4-6, a coil 4-2, and a throttle plug 4-3 are disposed; the first permanent magnet 4-1 and the second permanent magnet 4-4 are symmetrically arranged vertically; the second permanent magnet 4-6 and another fourth permanent magnet are symmetrically arranged vertically; due to the cross-sectional position relationship, the fourth permanent magnet is not shown in the figure;

[0061] During the leftward movement of the motion platform, the first permanent magnet 4-1 and the second permanent magnet 4-4 form an upward and downward repulsive force with the fifth permanent magnet 5-1 and the sixth permanent magnet 5-3 (the first permanent magnet 4-1 and the fifth permanent magnet 5-1 repel each other, and the second permanent magnet 4-4 and the sixth permanent magnet 5-3 repel each other); thus limiting and buffering the movement of the motion platform.

[0062] The third permanent magnet 4-6 and the fourth permanent magnet are symmetrically arranged vertically during the movement of the platform to the right. They form a repulsive force with the seventh permanent magnet 5-2 and the eighth permanent magnet 5-4 (the third permanent magnet 4-6 and the eighth permanent magnet 5-4 repel each other, and the fourth permanent magnet and the seventh permanent magnet 5-2 repel each other). This plays a role in limiting and buffering the movement of the platform.

[0063] The aforementioned permanent magnets do not have a specific magnetic pole arrangement. It is only required that the magnetic poles on the lower surface of the permanent magnet in the motion platform are the same as the magnetic poles on the upper surface of the permanent magnet in the guide rail, forming mutual repulsion; and that the magnetic poles on the upper surface of the permanent magnet are the same as the magnetic poles on the lower surface of the permanent magnet in the guide rail, forming mutual repulsion.

[0064] The aforementioned throttle plugs 4-3 are arranged symmetrically in the top, bottom, left, and right. By venting, the moving platform is essentially suspended like a guide rail, ensuring that there is no friction between the two.

[0065] Furthermore, in this embodiment, the air-float support assembly 3 and air-float support assembly 6 are mounted on the base 9. The air-float support assembly 3 includes a body containing four throttling plugs: throttling plug 3-1, throttling plug 3-2, throttling plug 3-3, and throttling plug 3-4. The air-float support assembly 6 also includes a body containing four throttling plugs: throttling plug 6-1, throttling plug 6-2, throttling plug 6-3, and throttling plug 6-4. Air is supplied to the guide rail through throttling plugs 3-1, 3-2, 3-3, 3-4, 6-1, 6-2, 6-3, and 6-4, allowing the air-float guide rail to float relative to the air-float support assembly 3 and air-float support assembly 6, ensuring no friction between them.

[0066] Furthermore, the magnetic poles of the aforementioned magnets are arranged as follows: the first driving magnet 5-6 has an S pole on the left and an N pole on the right; the second driving magnet 5-7 has an S pole on the left and an N pole on the right; the third regulating magnet 5-8 has an S pole on the left and an N pole on the right; the fourth regulating magnet 5-9 has an N pole on the left and an S pole on the right; the fifth driving magnet 5-10 has an N pole on the left and an S pole on the right; and the fourth driving magnet 5-11 has an N pole on the left and an S pole on the right, forming a symmetrical distribution.

[0067] In this embodiment, the aforementioned motion platform and air-bearing guide rail will always move in opposite directions due to the action and reaction forces. According to formula (1), theoretically, no matter how high the motion platform moves, its reaction force will not be transmitted to the base, thus becoming a reaction-free structure. The weight of the motion platform is m. s The weight of the guide rail is m. g If the speed of the motion platform is set to v s (t), let the speed of the guide rail be v g Since the amount of motion is ideally preserved, equation (1) holds true. Strictly speaking, a tiny force, negligible in magnitude, is applied to the motion platform by cables or similar means connected to it. The travel s of the motion platform... s Travel s of the guide rail g According to formula (2), the heavier the guide rail, the less the guide rail moves, so the length of the guide rail can be shortened and the device becomes more compact.

[0068] (1)

[0069] (2)

[0070] The main structure of the device adopts a symmetrical design, such as... Figure 3By using the outer working surface of the guide rail body as a double-sided symmetrical air-bearing bearing surface, and constructing a mirror layout of two air-bearing support components, a unique coaxial bidirectional air-bearing support system is formed. Compared with the traditional single-sided air-bearing system, this structure allows the guide rail cross-section to be optimized into a continuously closed hollow box-shaped structure, improving bending stiffness and reducing mass.

[0071] Meanwhile, the guide rail has a built-in drive magnet, and the motion platform is equipped with a drive permanent magnet that constitutes a linear motor, forming an iron core structure. By allowing current to flow through the shuttle-side coil with magnetic lines of force output from the iron core structure, the magnetic force of the drive permanent magnet and the coil mounted on the motion platform generate a thrust, thus forming a linear motor that drives the motion platform.

[0072] A symmetrically distributed permanent magnet array is constructed between the motion platform and the guide rail, combined with multi-phase winding pulse modulation technology inside the slider, to form a self-balancing electromagnetic drive system. When the actuator triggers non-contact commutation at the end of its stroke (position detection accuracy ±0.1μm), the current vector is instantaneously switched through the phase compensation module (commutation time <0.8ms), allowing the system to maintain a peak acceleration of 5g. In this way, the motion platform reciprocates between the driving permanent magnet and the guide rail. Since the driving force is generated between the motion platform and the guide rail, due to the aforementioned action-reaction relationship, the motion platform and the guide rail move in opposite directions, and the reaction force generated by the acceleration and deceleration of the motion platform is not transmitted to the outside (e.g., machine tool).

[0073] In motion platforms, compared to traditional single-axis marking mechanisms that only control the horizontal movement of the tool (U-axis), the inertial vibration of the workpiece stage during acceleration / deceleration can cause the marking path to deviate. Furthermore, the marking trajectory can only be generated through the macro motion of the workpiece stage, making it impossible to achieve local high-frequency fine-tuning and limiting the processing capability of complex microstructures (such as non-periodic gratings and biomimetic textures).

[0074] The specific control process for achieving the reciprocating motion of the motion platform is as follows:

[0075] When the motion platform 4 moves to the right, the coil (three-phase winding) 4-2 inside the motion platform 4 is connected to three-phase current. Unlike the static magnetic field, the three-phase winding coil 4-2 is supplied with alternating current according to a specific pattern. The current of each phase changes periodically with time, causing the magnetic field generated by the winding to not be fixed at a certain position, but to continuously "move" along the direction of the guide rail, forming a "traveling wave magnetic field". The current in the coil 4-2 mainly interacts electromagnetically with the first driving magnet 5-6 and the second driving magnet 5-7 built into the air-bearing guide rail 5, forming a Lorentz force along the axis of the air-bearing guide rail 5 in a non-contact manner. The resultant force vector direction is parallel to the direction of the air-bearing guide rail, thereby driving the motion platform 4 to move to the right along the air-bearing guide rail 5. Due to the action and reaction forces, the air-bearing guide rail 5 moves in the opposite linear motion, thus achieving the effect of canceling the reaction force inside the mechanism. When the motion platform 4 moves to the control magnet area inside the air-bearing guide rail 5, according to the law of electromagnetic force, the direction of the thrust on the motion platform is consistent with the direction of movement of the traveling wave magnetic field. As long as the current continues to be input, the traveling wave magnetic field will continue to move, and the thrust will continue to be generated. Therefore, the control system adjusts the current in real time so that the motion platform 4 can overcome the slight resistance given by the workpiece and move in uniform linear motion to perform ultra-precision machining of the workpiece. When the motion platform 4 is about to reach the right limit position of the air-bearing guide rail 5, the current in the coil 4-2 mainly interacts with the fifth drive magnet 5-10 and the sixth drive magnet 5-11 built into the air-bearing guide rail 5. Since the magnetic poles of the drive magnets on both sides are symmetrically distributed, the motion platform 4 is subjected to a repulsive force in the left direction and begins to decelerate. At the same time, the third permanent magnet 4-6 and the fourth permanent magnet symmetrically distributed therewith generate a repulsive force with the seventh permanent magnet 5-2 and the eighth permanent magnet 5-4 distributed on the right side of the air-bearing guide rail 5, which limits the motion platform 4. Finally, the speed of the motion platform 4 is reduced to 0.

[0076] At this time, to make the motion platform 4 move to the left, the current vector in the coil 4-2 inside the motion platform 4 is instantaneously switched. The current in the coil (three-phase winding) 4-2 mainly interacts electromagnetically with the fifth drive magnet 5-10 and the sixth drive magnet 5-11 built into the air-bearing guide rail 5, forming a Lorentz force along the axis of the air-bearing guide rail 5. The resultant force vector direction is parallel to the direction of the air-bearing guide rail 5, thereby driving the motion platform 4 to move to the left along the air-bearing guide rail 5. The air-bearing guide rail 5, due to the action and reaction forces, moves in the opposite linear motion. When the motion platform 4 moves to the control magnet area inside the air-bearing guide rail 5, according to the law of electromagnetic force, the direction of the thrust on the motion platform 4 is consistent with the direction of movement of the traveling wave magnetic field, and as long as the current continues to be input, the traveling wave magnetic field will continue to move. The thrust will continue to be generated, so the control system adjusts the current in real time to enable the motion platform 4 to overcome the slight resistance from the workpiece and move in a uniform linear motion to perform ultra-precision machining of the workpiece. When the motion platform 4 is about to reach the left limit position of the air-bearing guide rail 5, the current in the coil 4-2 mainly interacts with the first drive magnet 5-6 and the second drive magnet 5-7 built into the air-bearing guide rail 5. Due to the symmetrical magnetic distribution of the drive magnets on both sides, the motion platform 4 is subjected to a repulsive force in the right direction and begins to decelerate. At the same time, the first permanent magnet 4-1 and the second permanent magnet 4-4 generate a repulsive force with the fifth permanent magnet 5-1 and the sixth permanent magnet 5-3 distributed on the left side of the air-bearing guide rail 5, which limits the motion platform 4. Finally, the speed of the motion platform 4 is reduced to 0, realizing the non-contact reversal of the motion platform 4.

[0077] When the motion platform 4 moves to a position approximately 10 mm away from the fifth permanent magnet 5-1 and the seventh permanent magnet 5-2, a repulsive force is generated due to electromagnetic interaction, causing the motion platform 4 to trigger a non-contact commutation at the end of its stroke, reducing its speed to zero. At the same time, the vector current in the coil 4-2 undergoes instantaneous phase commutation, causing the motion platform 4 to move in the opposite direction, thus achieving ultra-fast and ultra-precise reciprocating scribing on three axes.

[0078] For the aforementioned motion, before connecting current to the three-phase winding (coil) 4-2 inside the motion platform 4, the main body of the system is installed on a stable marble base platform. The air pump is started, injecting 0.5MPa compressed gas into the internal cavity of the device through the air inlet ports of air nozzles 2 and 7. Under the regulation of the throttle plugs 3-1, 3-2, 3-3, and 3-4 support structures, after the air pressure stabilizes for approximately two minutes, the generated gas lubrication layer effect achieves a non-contact suspension state between the air-bearing guide rail 5 mechanism and the double-sided air-bearing support components 6 and 3, and between the motion platform 4 and the air-bearing guide rail 5. Ultimately, this allows the motion platform 4 and the air-bearing guide rail 5 system to form a stable air film lubrication working mode.

[0079] Furthermore, the piezoelectric drive device proposed in this embodiment is built into the aforementioned motion platform. One axis of the piezoelectric drive device is used to control the vertical movement of the tool's V-axis, such as... Figure 5 , Figure 6 , Figure 7 As shown, because the displacement generated by the inverse piezoelectric effect of cylindrical piezoelectric ceramics is very small, this invention utilizes the piezoelectric stacking effect and tightly attaches the piezoelectric ceramic sheet to a highly elastic copper substrate to increase the possible displacement. Specifically, the piezoelectric actuator in this embodiment includes an upper piezoelectric ceramic sheet 13 and a lower piezoelectric ceramic sheet 15, which are tightly attached to the copper substrate 14. The upper piezoelectric ceramic sheet 13, the lower piezoelectric ceramic sheet 15, and the copper substrate 14 are placed inside a heat-insulating ceramic sleeve 15 to form a piezoelectric actuator 18. The bottom of the piezoelectric actuator 17 presses against a butterfly preload spring 16, which is vertically embedded in the center of the symmetrical leaf spring piezoelectric head 10 (the symmetrical leaf spring piezoelectric head 10 is symmetrically distributed on both sides of the tool, suppressing U-axis yaw and rotational freedom through geometric constraints), reducing the impact of temperature drift on displacement accuracy. The structure of the aforementioned symmetrical leaf spring piezoelectric head 11 is as follows... Figure 7 As shown; the bottom of the symmetrical leaf spring piezoelectric head 10 is inserted into the bridge-type flexible hinge amplifier 12;

[0080] The other axis (W axis) is used for real-time compensation of straightness during the scribing process, such as... Figure 9 , Figure 10 As shown, a bridge-type symmetrical hinge design is adopted to drive the transverse fine-tuning platform to correct the tool position. Specifically, the aforementioned bridge-type flexible hinge amplifier 12 includes a butterfly preload spring 12-1, a butterfly preload spring 12-2, a pad 12-3, a pad 12-4, a piezoelectric ceramic 12-5, and a piezoelectric ceramic 12-6. Two piezoelectric actuators 12-5 and 12-6 are horizontally embedded in the bridge-type displacement amplification mechanism through the butterfly preload spring 12-2, with an adjustment pad 12-4 in the middle. At the same time, the V-axis leaf spring and the W-axis bridge structure both adopt a mirror symmetrical layout to counteract non-target direction torques (such as U-axis yaw and rotation around the V-axis). The W-axis compensation principle is to output through the bridge-type flexible amplification hinge, as follows: Figure 7 At the input, the piezoelectric actuator's output displacement is Δx, moving along the x-axis; at the output, the output displacement is Δy, moving along the y-axis. Then, theoretically, the amplification factor of the bridge amplifier mechanism (AB approximately equal to BO) is (e.g.) Figure 11 )yes:

[0081]

[0082] Figure 5The pre-tightening structure utilizes a butterfly pre-tightening spring 17 to provide the pre-tightening amount. The flexible mechanism interacts with the piezoelectric stack to achieve a balanced state, thus pre-tightening the piezoelectric stack. The pre-tightening mechanism ensures that the piezoelectric stack is protected from tensile forces and non-axial forces, and provides a certain elastic restoring force, reducing the hysteresis of the piezoelectric stack and improving its working performance. Generally, the pre-tightening force is 10-20% of the maximum output force of the piezoelectric stack, which provides sufficient protection while minimizing displacement loss. The pre-tightening process requires multiple adjustments to achieve the desired effect.

[0083] The specific control logic of this invention is as follows: Figure 12 The first step is V-axis engraving control.

[0084] The first approach is a traditional detection feedback design. Based on a preset marking depth (e.g., 5μm), an initial voltage (e.g., 80V) is applied to the V-axis piezoelectric actuator 18 to drive the tool to approach the workpiece surface to a safe distance (e.g., 10μm). Then, a capacitive displacement sensor installed near the diamond tool provides real-time feedback on the tool position, and a PID algorithm is used to dynamically adjust the voltage to ensure a marking depth accuracy of ±5nm.

[0085] The second approach is the innovative dual-end integrated design of this patent. Based on a preset V-axis piezoelectric driving force threshold (e.g., 5N) and according to the "force-voltage" characteristic curve of this driving force and the V-axis piezoelectric actuator 18, an initial voltage (e.g., 80V) is applied to the V-axis piezoelectric actuator 18 to drive the tool to approach the workpiece surface to a safe distance (e.g., 10μm). Then, by tracking the real-time force change curve through the piezoelectric actuator, a PID algorithm is used to dynamically adjust the voltage to ensure a depth of cut accuracy of ±5nm. Unlike the first approach which compensates based on displacement feedback, this approach utilizes the principle of mechanical equivalence, allowing the piezoelectric actuator to act as both a driving force output end, directly transmitting the axial force required for cutting to the tool, and a force feedback input end, sensing the dynamic force changes at the cutting interface in real time.

[0086] Next, dynamic compensation is performed on the W-axis. A trajectory capture device (such as a laser interferometer) installed on the outside of the piezoelectric actuator tracks the trajectory of the motion platform on the W-axis at a sampling rate of 1MHz, detecting the offset of the motion platform on the W-axis (e.g., ±0.5μm). The main control system calculates the compensation amount based on the offset and generates a reverse displacement command (e.g., +0.5μm). The W-axis piezoelectric actuator 12-6 drives the tool to shift laterally with a μs-level response, offsetting the path deviation and ensuring that the straightness error of the marking is <100nm / 200mm.

[0087] During the movement of the motion platform 4, the piezoelectric drive is activated synchronously. First, V-axis marking control is performed. Based on the preset V-axis piezoelectric drive force threshold and the force-voltage characteristic curve of this drive force and the V-axis piezoelectric actuator 18, an initial voltage is applied to the V-axis piezoelectric actuator (composed of an upper piezoelectric ceramic plate 13, a copper base plate 14, a lower piezoelectric ceramic plate 15, and a heat-insulating ceramic sleeve 16). This drives the tool to approach the workpiece surface to a safe distance via the symmetrical leaf spring piezoelectric head 11. Subsequently, the tool position is fed back in real-time by tracking the real-time force change curve of the piezoelectric actuator, and the voltage is dynamically adjusted using a PID algorithm to ensure marking depth accuracy. Next, W-axis dynamic compensation is performed. A trajectory capture device tracks the linear trajectory of the motion platform 4 at a high-frequency sampling rate and detects the lateral offset. The main control system calculates the compensation amount based on the error signal and generates a reverse displacement command. The W-axis bridge-type flexible hinge amplifier 12 responds in microseconds to drive the tool's lateral offset, compensating for path deviation and achieving high-precision marking.

[0088] The specific operating method is as follows:

[0089] Preparation: First, install the main body of the system on a stable marble base platform. Start the air pump device and inject 0.5MPa compressed gas into the internal cavity through the air inlet ports 2 and 7. Under the regulation of the throttle plug support structure, after the air pressure stabilizes for about two minutes, the generated gas lubrication layer effect achieves a non-contact suspension state between the guide rail mechanism and the double-sided air-bearing support components, and between the motion platform and the air-bearing guide rail, ultimately enabling the motion platform and the guide rail system to form a stable air film lubrication working mode.

[0090] Subsequently, an optical encoder and an optical scale were installed at the rear of the motion platform as position sensors. The power to the optical encoder and motion platform was then turned on, and a manual displacement calibration procedure was executed. The consistency of the measurement distance between the optical scale and the optical encoder was verified by observing the display mode of the optical encoder's status indicator light, ensuring that standard testing conditions were met. Simultaneously, in the V-axis piezoelectric drive system at the bottom of the motion platform, a preload system consisting of disc preload springs 17, 12-1, and 12-2 provides the initial load configuration for the piezoelectric ceramic, effectively enhancing system rigidity.

[0091] Startup process:

[0092] The first step is to install an adapter driver on the outside of the invention to drive the motion platform and the air bearing guide rail. The driver and the motion platform are connected through power lines, Hall effect lines and encoder lines to realize motion content detection. Then, the computer is connected to the driver through the driver debugging line for subsequent adjustment of the device.

[0093] The second step is to activate the piezoelectric actuator, execute the piezoelectric actuator configuration and motion control program, fill in the specific parameters of the device's coil into the system, and enable the device.

[0094] The third step is to find the phase angle, locate the initial position or phase angle information of the device, zero it, and ensure that the device and driver can correctly generate control signals.

[0095] The fourth step involves inputting the initialization current loop script into the device, running it, and verifying the device status. If the desired outcome is achieved, the control parameters are input into the controller and the device is run. At this point, the external power supply applies voltage to the coil through the power line, forming a current and generating a magnetic field. The coil's magnetic field interacts with the static magnetic field of the permanent magnet used for driving, generating a force that drives the coil to move, thus achieving effective movement between the motion platform and the guide rail. Simultaneously, the motion trajectory is recorded in real time, and data images (such as speed, acceleration, and position) are output. If any problems arise, the PID parameters are adjusted.

Claims

1. A three-axis ultra-precision motion scribing device for microstructure machining, characterized in that, The system includes an air-bearing support assembly, a base, a motion platform, and an air-bearing guide rail. Air-bearing support assemblies are installed at both ends of the air-bearing guide rail, and these assemblies are mounted on the base. The motion platform is mounted on the air-bearing guide rail. A driving magnet and a regulating magnet are installed within the air-bearing guide rail. A coil and a permanent magnet are installed within the motion platform. Throttling plugs are installed on both the air-bearing support assembly and the motion platform, ensuring that the motion platform is suspended relative to the air-bearing guide rail. The regulating magnet causes the motion platform to move at a uniform speed within the processing area. The driving magnet provides a magnetic field that interacts with the current in the coil within the motion platform. The permanent magnet provides limiting and buffering functions for the movement of the motion platform. The motion direction of the motion platform is the U-axis direction; A piezoelectric drive device is installed at the bottom of the motion platform to drive the tool movement. The piezoelectric drive device drives in the V-axis direction. The piezoelectric drive device includes a piezoelectric actuator, the bottom of which is vertically embedded in a symmetrical leaf spring piezoelectric head structure via a pre-tightening spring; simultaneously, the symmetrical leaf spring piezoelectric head structure is embedded in a bridge-type displacement amplification mechanism, and a cutting tool is installed at the bottom of the symmetrical leaf spring piezoelectric head structure; the movement direction of the bridge-type displacement amplification mechanism is the W-axis direction. The piezoelectric actuator includes an upper piezoelectric ceramic sheet and a lower piezoelectric ceramic sheet, which are closely attached to a copper substrate. The upper piezoelectric ceramic sheet, the lower piezoelectric ceramic sheet, and the copper substrate are placed inside a heat-insulating ceramic sleeve to form the piezoelectric actuator.

2. The three-axis ultra-precision motion scribing device for microstructure machining as described in claim 1, characterized in that, The air-bearing guide rail is a hollow structure. Inside the air-bearing guide rail, from one end to the other, a first limiting block, a first driving magnet, a second driving magnet, a third adjusting magnet, a fourth adjusting magnet, a fifth driving magnet, a sixth driving magnet, and a second limiting block are arranged in sequence. At the corresponding positions where the first driving magnet and the second driving magnet are connected, a fifth permanent magnet and a sixth permanent magnet are arranged symmetrically. At the corresponding positions where the fifth driving magnet and the sixth driving magnet are connected, a seventh permanent magnet and an eighth permanent magnet are arranged symmetrically.

3. The three-axis ultra-precision motion scribing device for microstructure machining as described in claim 2, characterized in that, Air flotation guide rail end caps are installed at both ends of the air flotation guide rail.

4. The three-axis ultra-precision motion scribing device for microstructure machining as described in claim 2, characterized in that, The first driving magnet, the second driving magnet, and the third regulating magnet have their S and N poles set in the same direction; the fourth regulating magnet, the fifth driving magnet, and the sixth driving magnet have their S and N poles set in the same direction; the first driving magnet, the second driving magnet, and the third regulating magnet have their S and N poles set in opposite directions to the fourth regulating magnet, the fifth driving magnet, and the sixth driving magnet.

5. The three-axis ultra-precision motion scribing device for microstructure machining as described in claim 2, characterized in that, Inside the motion platform, a first permanent magnet and a second permanent magnet are symmetrically arranged vertically at one end, and a third permanent magnet and a fourth permanent magnet are symmetrically arranged vertically at the other end; a coil is arranged in the middle of the motion platform.

6. The three-axis ultra-precision motion scribing device for microstructure machining as described in claim 5, characterized in that, The first permanent magnet and the fifth permanent magnet repel each other; the second permanent magnet and the sixth permanent magnet repel each other; the third permanent magnet and the eighth permanent magnet repel each other; and the fourth permanent magnet and the seventh permanent magnet repel each other.

7. The three-axis ultra-precision motion scribing device for microstructure machining as described in claim 1, characterized in that, Both the symmetrical leaf spring piezoelectric head structure and the bridge displacement amplification mechanism adopt a mirror symmetrical layout.

8. The control method for the three-axis ultra-precision motion scribing device for microstructure machining as described in any one of claims 2-7, characterized in that, The coil inside the motion platform is connected to a three-phase AC current, and the piezoelectric drive of the piezoelectric drive device is started simultaneously. First, V-axis marking control is performed. According to the preset V-axis piezoelectric drive force threshold and based on the "force-voltage" characteristic curve of the drive force and the V-axis piezoelectric drive, an initial voltage is applied to the piezoelectric drive. The tool is driven to approach the workpiece surface to a safe distance through the symmetrical leaf spring piezoelectric head. Then, the tool position is fed back in real time by tracking the real-time change curve of the force by the piezoelectric drive. The drive voltage is dynamically adjusted by a PID algorithm to ensure the marking depth accuracy. Then, W-axis dynamic compensation is performed to track the offset of the motion platform on the W-axis in real time. The compensation amount is calculated based on the offset, and a reverse displacement command is generated. The W-axis bridge flexible hinge amplifier drives the tool to shift laterally with a microsecond-level response, which cancels the path deviation and achieves high-precision engraving.

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