A novel decoupled dual-axis elliptical vibration-assisted cutting platform and its control method

Abstract

The present invention discloses a novel decoupled dual-axis elliptical vibration assisted cutting platform and a control method thereof. The device includes a base, a corner mounting seat, a middle mounting seat, two drive units arranged vertically at a 90° angle, and a tool mounting block. The drive unit includes a piezoelectric actuator, a pendulum block, a mobile constraint block, an amplifying output block, and a fixed block. The two opposite side surfaces of the pendulum block are respectively connected to the corner mounting seat and the middle mounting seat by flexible hinges. Two groups of mobile constraint blocks and the amplifying output block are respectively connected to the two sides of the opposite surface of the pendulum block and the fixed block by flexible hinges. The amplifying output block is flexibly connected to the tool mounting block. The present invention adopts a double parallel straight plate hinge as an input guide mechanism and a double parallelogram mechanism as an output guide mechanism. By adopting such a guide mechanism, the device can achieve the advantages of good flexibility, high precision, and controllable motion trajectory.

Description

Technical Field

[0001] The present invention relates to the fields of elliptical vibration-assisted cutting (EVC) technology and mechanism motion modeling and design, and more specifically, to the theory and method of flexible mechanism design and the application of piezoelectrically actuated high-precision micro-nano positioning platforms and other related fields. Background Art

[0002] Elliptical Vibration-Assisted Cutting (EVC) is an advanced manufacturing technology that has been widely used in various fields, including micro-nanostructure fabrication, optical mold manufacturing, and composite material processing, due to its superior precision machining performance when machining difficult-to-machine materials. However, with the growing demand for high-precision and complex structures in the manufacturing industry, the design of high-performance EVC devices faces several new challenges.

[0003] First, the spatial complexity of micro- and nanostructured surfaces inevitably requires cutting tools with multiple degrees of freedom to match the desired geometry. Second, the extreme miniaturization of equipment requires cutting tools with higher operating bandwidth and relative stability. Finally, in addition to ensuring high precision and performance, design must also consider cost-effectiveness, finding a balance between accuracy requirements and manufacturing costs.

[0004] The driving force in EVCs is primarily provided by piezoelectric actuators, which offer advantages such as high rigidity, fast frequency response, and precise positioning accuracy. Motion guidance mechanisms are generally categorized into four types: flexure hinge mechanisms, high-precision gas bearings, ultrasonic levitation, and magnetic levitation. Due to factors such as structural size and cost, flexure hinge mechanisms are primarily used to achieve force transmission and motion guidance at the submillimeter and millimeter scales. Currently, the main theoretical frameworks and methods for kinematic modeling and design of EVC mechanisms include pseudo-rigid body theory, the second integral calculus theorem (ICST), finite element analysis (FEA), inverse kinematics modeling (IKM) based on Lagrange's equations, screw theory (ST), and matrix-based compliance modeling (MCM). However, the coupled nature of the kinematics presents challenges in the design of EVC mechanisms, limiting the performance improvement of dual-axis EVC worktables.

[0005] In summary, given the geometric intuition and efficiency of screw theory (ST) in kinematic analysis, and the superior accuracy and simplicity of matrix-based flexibility modeling in static analysis and small-deformation behavior description, this paper proposes a method that combines the stiffness matrix approach with screw theory. This integrated approach is used to reconstruct the mathematical model of the EVC worktable's flexible mechanism to analyze its kinematic, static, and dynamic characteristics. To further improve the precision and efficiency of ultra-precision auxiliary equipment, the development of cutting platforms requires not only mechanical structure design but also motion control. Considering the simplicity, ease of parameter adjustment, and effective control capabilities of PID controllers, as well as their strong compatibility with other control algorithms, a coupled PID control strategy combined with dynamic feedforward control solves the challenge of achieving high-performance motion control in EVC systems. Therefore, this invention not only provides important reference and guidance for various fields, such as precision engineering, elliptical vibration-assisted cutting, and topology optimization design of flexible mechanisms, but also possesses considerable academic and practical value. Summary of the Invention

[0006] The purpose of the present invention is to provide a novel decoupled dual-axis elliptical vibration assisted cutting platform and a structural design method thereof.

[0007] In the first aspect, the present invention provides a novel decoupled dual-axis elliptical vibration assisted cutting platform, which includes a base, a corner mounting seat, a middle mounting seat, two drive units arranged vertically at a 90° angle, and a tool mounting block. The corner mounting seat and the middle mounting seat are both fixed at the corners of the base. The two drive units are both connected between the corner mounting seat and the middle mounting seat. The drive unit includes a piezoelectric actuator, a pendulum block, a movable constraint block, an amplifying output block, and a fixed block. The two opposite side surfaces of the pendulum block are respectively connected to the corner mounting seat and the middle mounting seat by flexible hinges. The fixed block is fixed on the base. Two groups of movable constraint blocks and the amplifying output block are respectively connected to the two sides of the opposite surfaces of the pendulum block and the fixed block by flexible hinges. The piezoelectric actuator is connected between the fixed block and the pendulum block. The amplifying output block is flexibly connected to the tool mounting block.

[0008] During operation, the piezoelectric actuator's telescopic motion is amplified and rotated 90 degrees by the pendulum block, the motion constraint block, and the amplified output block. The two drive units jointly drive the tool mounting block to move in two degrees of freedom.

[0009] Preferably, the drive unit further includes two directional constraint beams disposed between the amplifying output block and the tool mounting block. One end of the two mutually parallel directional constraint beams is connected to two locations on the same side of the corresponding amplifying output block via a flexible hinge. The other end of the two mutually parallel directional constraint beams is connected to two locations on the same side of the corresponding tool mounting block via a flexible hinge.

[0010] Preferably, the tool further includes a displacement detection assembly comprising two displacement sensors. Both displacement sensors are fixed to the base and face the tool mounting block or a displacement detection identification block fixed to the tool mounting block. The detection directions of the two displacement sensors are perpendicular to each other.

[0011] Preferably, the flexible hinges between the pendulum block and the movable constraint block, between the movable constraint block and the amplifying output block, between the amplifying output block and the direction constraint beam, and between the direction constraint beam and the tool mounting block are semicircular flexible hinges; the hinge thickness of the semicircular flexible hinge is 0.4mm~0.8mm, and more preferably 0.5mm.

[0012] Preferably, the radius of the semicircular flexible hinge is 1 mm to 2 mm, more preferably 1.5 mm.

[0013] Preferably, the flexible hinges between the pendulum block and the corner mounting seats and the middle mounting seat are connected by double parallel straight plate hinges.

[0014] Preferably, the flexible hinge between the amplifying output block and the fixed block is connected by a double parallel straight plate hinge.

[0015] Preferably, two ends of the piezoelectric actuator respectively abut against the opposite ends of the pendulum block and the fixed block and are pre-tightened by bolts.

[0016] In a second aspect, the present invention provides a cutting platform structure optimization method for optimizing the aforementioned novel decoupled dual-axis elliptical vibration-assisted cutting platform. The cutting platform structure optimization method is as follows:

[0017] Construct the stiffness matrix for the first drive unit;

[0018] According to the 90° rotational symmetry between the two drive units, the stiffness matrix of the second drive unit is obtained by rotating the stiffness matrix of the first drive unit.

[0019] The stiffness matrix corresponding to the two drive units is used to form the stiffness model of the entire cutting platform;

[0020] Based on the stiffness model, the objective function of structural optimization is established, the structural parameters of the drive unit are adjusted, the overall stiffness of the cutting platform is optimized, the ability of the cutting platform to withstand cutting forces is enhanced, and while ensuring stiffness control, the frequency is optimized to facilitate error compensation in subsequent cutting processes.

[0021] Preferably, the optimized structural parameters include the sizes of the pendulum block, the mobile constraint block, the amplified output block, the fixed block and the direction constraint beam, as well as the sizes of each flexible hinge.

[0022] In a third aspect, the present invention provides a cutting control method using the aforementioned novel decoupled dual-axis elliptical vibration assisted cutting platform. The cutting control method is as follows: two drive units are used as two controlled systems respectively; the two controlled systems are dynamically controlled according to the displacement error of the tool mounting block (6).

[0023] Preferably, the dynamic control of the two controlled systems is performed by means of PID controllers.

[0024] The present invention has the following beneficial effects.

[0025] 1. The present invention provides two drive units with orthogonal arrangement, and uses a new decoupling bridge amplification structure in the drive unit, which realizes the two-axis drive of the tool and effectively suppresses the axial coupling of the output displacement of the two-axis cutting platform.

[0026] 2. The present invention performs stiffness matrix modeling on a single drive unit and obtains the stiffness matrix of the second drive unit by rotating 90° around the z-axis and flipping 180° around the x-axis, thereby conveniently and accurately obtaining the stiffness model of the entire dual-axis cutting platform. The stiffness model is then used to rapidly optimize the structural parameters of the drive unit, thereby improving hardware performance. While increasing the stiffness to resist cutting forces, the optimal frequency is obtained to facilitate error compensation. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to better interpret the patent of the present invention, the following will briefly introduce the implementation of the technical solution of the present invention with drawings. Obviously, the following drawings are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 It is a schematic diagram of the overall structure of Example 1 of the present invention.

[0029] Figure 2 It is a schematic diagram of the back structure of Example 1 of the present invention.

[0030] Figure 3 This is a schematic diagram of the connection structure between the two drive units and the tool mounting block in Example 1 of the present invention.

[0031] Figure 4 It is a schematic diagram of the positions of the coordinate systems of the respective rigid bodies when the stiffness model is established in Example 2 of the present invention.

[0032] Figure 5 This is a system block diagram of a PID controller with a feedforward compensator used in Example 2 of the present invention.

[0033] Figure 6 This is a Y-axis drive simulation diagram of Example 2 of the present invention.

[0034] Figure 7 This is an x-axis drive simulation diagram of Example 2 of the present invention.

[0035] Figure 8 This is a sinusoidal trajectory tracking diagram of the driving cutting platform in different directions in Example 2 of the present invention.

[0036] Figure 9 This is a trajectory tracking diagram of the nano-stepping experiment of driving the cutting platform in different directions in Example 2 of the present invention.

[0037] Figure 10 This is a trajectory tracking diagram of the harmonic superposition signal experiment for driving the cutting platform in Example 2 of the present invention.

[0038] Figure markings: 1. base; 2. corner mounting seat; 3. driving unit; 3-1. piezoelectric actuator; 3-2. pendulum block; 3-3. moving constraint block; 3-4. amplifying output block; 3-5. fixed block; 3-6. direction constraint beam; 4. middle mounting seat; 5. displacement detection assembly; 5-1. sensor mounting seat; 5-2. displacement sensor; 6. tool mounting block; 7. diamond tool. DETAILED DESCRIPTION

[0039] In order to more clearly illustrate the objectives, technical solutions and advantages of the present invention, embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0040] Example 1

[0041] like Figure 1 、 Figure 2 As shown, a novel decoupled dual-axis elliptical vibration-assisted cutting platform comprises a base 1, a corner mounting seat 2, a middle mounting seat 4, two drive units 3 arranged vertically at a 90° angle, a tool mounting block 6, and a displacement detection assembly 5. The corner mounting seats 2 are bolted to the corners of the base 1. Both drive units 3 are movably connected between the corner mounting seats 2 and the middle mounting seat 4. The two drive units 3 jointly drive the tool mounting block 6 for planar free movement in the x- and y-axis directions. The displacement detection assembly 5 is used to detect the displacement of the tool mounting block 6 within the xy plane.

[0042] The driving unit 3 includes a piezoelectric actuator 3-1, and a pendulum block 3-2, two movement constraint blocks 3-3, two amplification output blocks 3-4, a fixed block 3-5 and two direction constraint beams 3-6 that constitute a decoupled bridge amplification structure.

[0043] The specific connection method of the decoupled bridge amplification structure is as follows: the two opposing side surfaces of the pendulum block 3-2 are connected to the corner mounting seat 2 and the middle mounting seat 4 respectively via double parallel straight plate hinges. The fixed block 3-5 is fixed to the base 1 via bolts. The two movement constraint blocks 3-3 and the two amplification output blocks 3-4 are disposed between the pendulum block 3-2 and the fixed block 3-5. One end of the two movement constraint blocks 3-3 is connected to the two ends of the same side surface of the pendulum block 3-2 respectively via flexible hinges. One end of the two movement constraint blocks 3-3 is connected to one end of the two amplification output blocks 3-4 respectively via flexible hinges.

[0044] The two ends of the piezoelectric actuator 3-1 rest against the opposite ends of the pendulum block 3-2 and the fixed block 3-5, respectively, and are pre-tightened with bolts. The two ends of the same side of the amplifying output block 3-4, located near the tool mounting block 6, are connected to one end of two directional restraining beams 3-6 via a flexible hinge. The two ends of the side of the tool mounting block 6 facing the amplifying output block 3-4 are connected to the other ends of the two directional restraining beams 3-6 via a flexible hinge.

[0045] In this embodiment's decoupled bridge-type amplification structure, the pendulum block 3-2, two motion-constraining blocks 3-3, two amplifying output blocks 3-4, and one fixed block 3-5 form an input guide mechanism, ensuring that the motion direction of the amplifying output block 3-4 of the tool mounting block 6 is perpendicular to the piezoelectric actuator 3-1. Two parallel directional constraint beams 3-6 form a parallelogram mechanism, helping to maintain the motion direction of the tool mounting block 6 aligned with that of the connected amplifying output block 3-4.

[0046] The two drive units 3 are rotationally symmetrical at 90°, and the piezoelectric actuators 3-1 in each drive unit 3 extend and retract parallel to the x-axis and y-axis, respectively. The input guide mechanism enables the amplified output block 3-4, located near the tool mounting block 6, to provide stable, precise amplified motion perpendicular to the direction of extension and retraction of the piezoelectric actuator 3-1. This allows the drive unit 3 with the piezoelectric actuator 3-1 extending and retracting parallel to the x-axis to translate the tool mounting block 6 along the y-axis. The drive unit 3 with the piezoelectric actuator 3-1 extending and retracting parallel to the y-axis also translates the tool mounting block 6 along the x-axis.

[0047] The displacement detection assembly 5 includes a sensor mounting base 5-1 and two displacement sensors 5-2. The sensor mounting base 5-1 is fixed to the central mounting base 4. The two displacement sensors 5-2 are bolted to either end of the sensor mounting base 5-1, each facing the tool mounting block 6. The detection directions of the two displacement sensors 5-2 are perpendicular to each other and, in this embodiment, parallel to the x-axis and y-axis, respectively.

[0048] In this embodiment, the displacement sensor 5 - 2 is a capacitive displacement sensor 5 - 2 ; in some other embodiments, the displacement sensor 5 - 2 may also be other existing displacement sensors 5 - 2 such as a laser displacement sensor 5 - 2 .

[0049] In this embodiment, a diamond tool 7 is mounted on the tool mounting block 6. A displacement detection identification block fixed at the front end of the diamond tool 7 cooperates with two displacement sensors 5-2 to measure the displacement of the diamond tool 7 in two axial directions.

[0050] Example 2

[0051] A cutting platform control method combines the stiffness matrix method with screw theory. This method is used to reconstruct a mathematical model of the EVC worktable's flexible mechanism to analyze its kinematic, static, and dynamic characteristics, thereby precisely driving the novel decoupled dual-axis elliptical vibration-assisted cutting platform provided in Example 1.

[0052] The cutting platform control method comprises the following steps:

[0053] Step 1: Establish the stiffness matrix model of the entire cutting platform as follows:

[0054] Based on the Lagrange equation, the dynamic differential equation describing the cutting platform can be expressed as:

[0055] Formula (1)

[0056] in, and denote the displacement vector and acceleration vector respectively; and denote the mass matrix and stiffness matrix respectively; Represents the external force vector.

[0057] Next, the cutting platform stiffness matrix Use the observation method to derive the stiffness matrix mid-diagonal elements represents the total stiffness calculated from all elastic elements connected to the front of the i-th rigid body. Represents the composite stiffness calculated by the elastic element connecting the i-th rigid body and the j-th rigid body.

[0058] Establish , mass matrix , stiffness matrix , external force vector as follows:

[0059] Formula (2)

[0060] in, Extract the diagonal matrix.

[0061] matrix and The i-th element of is represented as:

[0062] Formula (3)

[0063] When only free vibration is considered, is set to zero. By Set to zero, the static force-displacement relationship can be derived from Equation (1). When the force vector When , the output displacement vector can be expressed as:

[0064] Formula (4)

[0065] Stiffness matrix in The diagonal submatrix of is derived as follows:

[0066] Assume there is The flexible element is connected to the i-th rigid body. The coordinate system is a coordinate system with a point on the i-th rigid body as the origin; for the j-th rigid body In the case of one-way translation on the coordinate axis of the coordinate system Coordinate system, get the origin On the j-th rigid body Coordinate system. For the j-th rigid body not in In the case of coordinate system axis; bidirectional translation Coordinate system, get the origin on the j-th rigid body Coordinate system.

[0067] The displacement of the i-th rigid body is from Coordinate system conversion to The coordinate system is expressed as:

[0068] Formula (5)

[0069] in, For the i-th rigid body Displacement spinor in the coordinate system; It is from Coordinate system to Coordinate transformation matrix of the coordinate system; and represent the rotation matrix and position matrix respectively.

[0070] Formula (6)

[0071] When the force vector Acting on the point When, about The additional torque vector for:

[0072] Formula (7)

[0073] in, for point to The direction vector.

[0074] express The force component acts on The equivalent spinor It can be described as:

[0075] Formula (8)

[0076] Therefore, the matrix Has the following form:

[0077] Formula (9)

[0078] Stiffness matrix The matrix in Derivation of the non-diagonal matrix: Assume that there is A flexible element connects the i-th rigid body and the j-th rigid body, and the displacement of the j-th rigid body is from Coordinate system conversion to The expression of the coordinate system is:

[0079] Formula (10)

[0080] in, It is from Coordinate system to The coordinate transformation matrix of the coordinate system. and represent the rotation matrix and position matrix respectively.

[0081] Acting on the point The force torque is:

[0082] Formula (11)

[0083] Rotate the force from Coordinate system conversion to Coordinate system, we get:

[0084] Formula (12)

[0085] Therefore, the matrix It can be expressed as:

[0086] Formula (13)

[0087] Step 2: Kinematic modeling description:

[0088] like Figure 4 As shown, the coordinate origins of the coordinate systems of the pendulum block 3-2, the two mobile constraint blocks 3-3, the two amplifying output blocks 3-4, the fixed block 3-5, the two direction constraint beams 3-6 and the tool mounting block 6 are set to O1~O8 respectively, and the forces are set to F1~F8 respectively.

[0089] According to the static equilibrium condition, the elastic model of the bridge-type amplification structure can be expressed as:

[0090] Formula (14)

[0091] in, Indicates from point Arrive Stiffness; Indicates force Under the effect, point Horizontal displacement; Indicates force Under the effect, point Vertical displacement of and It can be expressed as:

[0092] Formula (15)

[0093] in, It is from Coordinate system to Coordinate transformation matrix of the coordinate system; It is from Coordinate system to Coordinate transformation matrix of the coordinate system; It is from the point Arrive Stiffness; It is from the point Arrive Stiffness. Point The center point of the flexible hinge connecting the mobile constraint block 3-3 to the pendulum block 3-2; The center point of the flexible hinge of the mobile constraint block 3-3 is connected to the amplified output block 3-4.

[0094] Amplification factor of the input guide mechanism in the drive unit , calculated using the following formula:

[0095] Formula (16)

[0096] in, , .

[0097] Step 3, Stiffness Modeling Description: First, perform stiffness modeling on the output end. To coordinate system The stiffness matrix can be expressed as:

[0098] Formula (17)

[0099] in, ,express Hinge stiffness on the right side; ,express and Hinge stiffness between coordinate systems; ,express and Hinge stiffness between coordinate systems.

[0100] From the coordinate system To coordinate system The stiffness matrix can be expressed as:

[0101] Formula (18)

[0102] in, express The stiffness of the hinge below the coordinate system; express and Hinge stiffness between coordinate systems; express and Hinge stiffness between coordinate systems. It is from arrive The coordinate transformation matrix.

[0103] Considering that the two drive units of the cutting platform have a symmetrical structure, the stiffness of the first drive unit at the output end calculated above can be converted to the stiffness of the second drive unit at the output end by first rotating it 90° counterclockwise around the z-axis and then rotating it 180° clockwise around the x-axis to obtain the stiffness matrix of the input guide mechanism in the second drive unit. as follows:

[0104] Formula (20)

[0105] Therefore, the output stiffness of the input guide mechanism in the drive unit It can be expressed as:

[0106] (twenty one)

[0107] Then, the input end stiffness modeling is carried out. from The stiffness concentration is converted to The stiffness can be divided into two steps.

[0108] (1) Confirm to The stiffness can be described as:

[0109] Formula (22)

[0110] in , , as well as .

[0111] (2) Calculate from arrive The stiffness of and The relationship between is in series. Therefore, the stiffness can be described as:

[0112] Formula (23)

[0113] in , .

[0114] Therefore, the input guide mechanism in the drive unit is at point The input stiffness is:

[0115] Formula (24)

[0116] in , .

[0117] Aluminum alloy was selected as the structural material for the cutting platform in this paper. Its elastic modulus is E = 71 GPa and its density is ρ = 2.7 × 10⁻³ kg / m³. To solve the multi-parameter minimization problem, a differential evolution (DE) algorithm was employed to determine the optimal dimensions. The design goal was to achieve high bandwidth and high output stiffness. Therefore, the objective function was defined as:

[0118] (29)

[0119] in, , 、 are the first and second order natural frequencies of the cutting platform respectively; 、 is the stiffness matrix of the input guide mechanism in the two drive units; 、 、 、 are four weight vectors.

[0120] Considering the overall size of the cutting platform, the constraints of the dimensional parameters are listed in Table 1. As shown in the table, according to the dimensional and geometric constraints imposed by SPA, the ranges of all 11 optimization parameters are set accordingly to ensure the compactness of the overall mechanical structure of the dual-axis EVC platform. The increase of will inevitably improve some characteristics. Therefore, the weight vector : : : The final choice is 2:2:1:2 to effectively balance these weights and obtain the optimal structural parameters. Input stiffness ( , ) is 20.02N / µm, the first-order frequency ( ) is 1641.4Hz, the second-order frequency ( ) is 1641.4Hz.

[0121] surface Structural optimization results, unit: mm.

[0122]

[0123] Among them (see Figure 9 ): is the width of the constrained beam; is the length of the constrained beam; is the radius of the semicircular flexible hinge connected to the other end of the beam constrained in two directions; The width of the hinge connecting the two enlarged output blocks and the fixed block; is the length of the hinge connecting the two amplified output blocks and the fixed block; is the radius of the semicircular flexible hinge between the two amplified output blocks and the fixed block; To enlarge the width of the output block; To enlarge the length of the output block; The width of the double parallel straight plate hinge connecting the swing block and the middle mounting seat; It is the length of the double parallel straight plate hinge connecting the swing block and the middle mounting seat.

[0124] Step 4: Closed-loop test description:

[0125] In this embodiment, a classic PID controller combined with a dynamic feedforward compensator based on an inverse hysteresis model is used as the main controller, such as Figure 5 As shown. G(s) represents the unfiltered controlled system and The parameters of the PID controller are obtained by repeated trial and error, and the transfer functions of the feedforward compensator are expressed as and .

[0126] In order to test the trajectory tracking capability of the cutting platform, a simulation was carried out to track a sinusoidal trajectory with an amplitude of 10 μm and a frequency of 100 Hz. The simulation results of driving the tool mounting block along the y direction are shown in the figure below. Figure 6 As shown in the figure, the simulation results along the x direction are as follows Figure 7 As shown;

[0127] The trajectory tracking results of the nano-stepping experiment of the cutting platform are as follows Figure 9 shown; from Figure 9 As can be seen from the figure, the cutting platform tracks the trajectory along the x-axis and y-axis simultaneously, with corresponding tracking errors of ±0.09μm and ±0.08μm, respectively. The tracking accuracy is approximately ±0.9% and ±0.8%, respectively. In addition, in order to verify the motion resolution and positioning accuracy of the cutting platform under closed-loop conditions, a nanometer-level step tracking experiment was carried out, with a position change of 5nm per second. The tracking results are shown in Figure 2. Figure 6 The designed controller can reliably achieve stable closed-loop positioning with a resolution of 5nm, effectively realizing nanometer-level positioning. To further demonstrate the high precision of the designed device, a harmonic superposition signal is used to drive the two axes separately.

[0128] Formula (25)

[0129] The experimental trajectory tracking results of the harmonic superposition signal of the cutting platform are as follows: Figure 10 The results show that the maximum tracking errors for the x-axis and y-axis are ±0.08µm and ±0.11µm, respectively. Given a 15µm x-axis motion range, the maximum tracking error is approximately 0.79% of the total motion range. Similarly, the maximum tracking error for the y-axis is approximately 1.33%. These results demonstrate that the learning platform provided in this embodiment can effectively track complex trajectories used for layered surface texturing.

Claims

1. A new type of decoupled dual-axis elliptical vibration assisted cutting platform, characterized in that: The invention comprises a base (1), a corner mounting seat (2), a middle mounting seat (4), two drive units (3) arranged vertically at a 90° angle, and a tool mounting block (6); the corner mounting seat (2) and the middle mounting seat (4) are both fixed at the corners of the base (1); the two drive units (3) are both connected between the corner mounting seat (2) and the middle mounting seat (4); the drive unit (3) comprises a piezoelectric actuator (3-1), a pendulum block (3-2), a moving constraint block (3-3), an amplifying output block, and a fixing block (3-4). -5); two opposite side surfaces of the pendulum block (3-2) are connected to the corner mounting seat (2) and the middle mounting seat (4) respectively through flexible hinges; the fixed block (3-5) is fixed on the base (1); two groups of movement constraint blocks (3-3) and the amplifying output block are respectively connected to the two sides of the opposite surfaces of the pendulum block (3-2) and the fixed block (3-5) through flexible hinges; the piezoelectric actuator (3-1) is connected between the fixed block (3-5) and the pendulum block (3-2); the amplifying output block is connected to the tool mounting block (6) through flexible transmission; The novel decoupled dual-axis elliptical vibration assisted cutting platform further comprises a displacement detection component (5); the displacement detection component (5) comprises two displacement sensors (5-2); the two displacement sensors (5-2) are both fixed to the base (1) and both face the tool mounting block (6) or the displacement detection identification block fixed on the tool mounting block (6); the detection directions of the two displacement sensors (5-2) are perpendicular to each other; The drive unit (3) further comprises two directional constraint beams (3-6) arranged between the amplifying output block and the tool mounting block (6); one end of the two mutually parallel directional constraint beams (3-6) is connected to two positions on the same side of the corresponding amplifying output block via flexible hinges; and the other end of the two mutually parallel directional constraint beams (3-6) is connected to two positions on the same side of the corresponding tool mounting block (6) via flexible hinges.

2. The novel decoupled dual-axis elliptical vibration assisted cutting platform according to claim 1 is characterized by: The flexible hinges between the pendulum block (3-2) and the movement constraint block (3-3), between the movement constraint block (3-3) and the amplifying output block, between the amplifying output block and the direction constraint beam (3-6), and between the direction constraint beam (3-6) and the tool mounting block (6) are semicircular flexible hinges; the hinge thickness of the semicircular flexible hinge is 0.4 mm to 0.8 mm.

3. The novel decoupled dual-axis elliptical vibration assisted cutting platform according to claim 2 is characterized by: The radius of the semicircular flexible hinge is 1 mm to 2 mm.

4. The novel decoupled dual-axis elliptical vibration assisted cutting platform according to claim 1 is characterized by: The flexible hinges between the pendulum block (3-2) and the corner mounting seat (2) and the middle mounting seat (4) are connected by double parallel straight plate hinges.

5. The novel decoupled dual-axis elliptical vibration assisted cutting platform according to claim 1 is characterized by: The flexible hinge between the amplifying output block and the fixed block (3-5) is connected by a double parallel straight plate hinge.

6. The novel decoupled dual-axis elliptical vibration assisted cutting platform according to claim 1 is characterized by: The two ends of the piezoelectric actuator (3-1) respectively abut against the opposite ends of the pendulum block (3-2) and the fixed block (3-5), and are pre-tightened by bolts.

7. A cutting platform structure optimization method, characterized in that: Used to optimize a novel decoupled dual-axis elliptical vibration assisted cutting platform as claimed in claim 1; the cutting platform structure optimization method is as follows: Construct the stiffness matrix for the first drive unit (3); According to the 90° rotationally symmetrical relative positions of the two drive units (3), the stiffness matrix of the second drive unit (3) is obtained by rotating the stiffness matrix of the first drive unit (3); The stiffness matrix corresponding to the two drive units (3) is used to form a stiffness model of the entire cutting platform; The objective function of structural optimization is established according to the stiffness model, the structural parameters of the drive unit (3) are adjusted, and the overall stiffness of the cutting platform is optimized.

8. A cutting control method, characterized in that: Using a novel decoupled dual-axis elliptical vibration assisted cutting platform as described in claim 1; The cutting control method is as follows: two driving units (3) are used as two controlled systems respectively; and the two controlled systems are dynamically controlled by a PID controller according to the displacement error of a tool mounting block (6).

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