A three-degree-of-freedom precision positioning platform and its positioning method based on inkjet printing

Abstract

This invention relates to the field of precision motion platform technology, and more particularly to a three-degree-of-freedom precision positioning platform and its positioning method based on inkjet printing. The platform includes a moving stage, a mounting frame, a Y-axis drive mechanism, and two X-axis drive mechanisms. The two X-axis drive mechanisms have the same driving direction, while the Y-axis drive mechanism is perpendicular to the X-axis drive mechanism. A bridge-type displacement amplification structure mechanically amplifies the micro-displacement of the piezoelectric ceramic actuator, achieving large-stroke motion at the hundred-micrometer level while maintaining nanometer-level positioning accuracy. This solves the problem of traditional platforms struggling to balance stroke and accuracy. A first and second flexible guide structure improves guiding accuracy and effectively suppresses parasitic motion. Furthermore, a first and second decoupling structure effectively isolates multi-axis motion crosstalk, improving structural reliability. The platform can perform XY-axis movement positioning and deflection positioning, enhancing its applicability.

Description

Technical Field

[0001] This invention relates to the field of precision motion platform technology, and in particular to a three-degree-of-freedom precision positioning platform based on inkjet printing and its positioning method. Background Technology

[0002] Inkjet printing technology has wide applications in high-precision micro-nano manufacturing, flexible electronics, and bioprinting. It demands extremely high precision in positioning between the printhead and the substrate. However, existing inkjet printing positioning platforms often face the following technical bottlenecks: 1. Difficulty in balancing large stroke and high precision: While piezoelectric ceramic actuators can achieve sub-nanometer precision, their stroke is typically less than 100μm, while large-stroke solutions such as linear motors struggle to achieve nanometer-level positioning; 2. Insufficient structural reliability: Poor motion guidance leads to parasitic motion, making it difficult to guarantee the unidirectional and controllable motion direction. Furthermore, traditional bridge-type displacement amplification mechanisms are prone to stress concentration at hinges, leading to fatigue fracture after long-term use and affecting system stability; 3. Severe coupling of multiple degrees of freedom: Existing platforms often employ multi-module series or parallel connections, resulting in complex structures, large volumes, and significant coupling errors between motion axes, making it difficult to achieve high-precision decoupled motion; 4. Limited degrees of freedom: Only X-axis or Y-axis movement positioning is possible, lacking deflection positioning, reducing applicability. Summary of the Invention

[0003] In order to overcome the shortcomings of the prior art, the purpose of this invention is to provide a three-degree-of-freedom precision positioning platform and positioning method based on inkjet printing that has the advantages of large stroke, high precision, high reliability, good decoupling performance and improved applicability.

[0004] The technical solution adopted in this invention is as follows:

[0005] A three-degree-of-freedom precision positioning platform based on inkjet printing includes a moving stage and a mounting frame, as well as a Y-axis drive mechanism and two X-axis drive mechanisms. The two X-axis drive mechanisms have the same driving direction, and the Y-axis drive mechanism is perpendicular to the X-axis drive mechanism. The Y-axis drive mechanism and the X-axis drive mechanism have the same structure, and each includes a bridge displacement amplification structure, a piezoelectric ceramic actuator, a first flexible guide structure, a first decoupling structure, a second flexible guide structure, and a second decoupling structure. The piezoelectric ceramic actuator is installed inside the bridge displacement amplification structure. One side of the bridge displacement amplification structure is connected to the mounting frame, and its other side is connected to the first flexible guide structure. One side of the first decoupling structure is connected to one side of the moving stage, and its other side is connected to the side of the first flexible guide structure away from the bridge displacement amplification structure. Both the first flexible guide structure and the second flexible guide structure are installed on the mounting frame. The other side of the moving stage is connected to one side of the second decoupling structure, and the other side of the second decoupling structure is connected to the second flexible guide structure.

[0006] Preferably, the bridge displacement amplification structure includes a rigid input block and a bridge amplification output component. Two rigid input blocks are symmetrically connected to both sides of the piezoelectric ceramic actuator. Two bridge amplification output components are symmetrically arranged on both sides of the piezoelectric ceramic actuator. Each bridge amplification output component includes a rigid output block and two inclined cantilever arms symmetrically arranged on both sides of the rigid output block. One end of the inclined cantilever arm is connected to the rigid output block through a rounded flexible hinge, and the other end is connected to the rigid input block through a rounded flexible hinge.

[0007] Preferably, the angle between the centerline of the tilting cantilever and the straight line containing the driving direction of the piezoelectric ceramic actuator is 30°.

[0008] Preferably, the first flexible guide structure and the second flexible guide structure have the same structure, and both include a guide body and a double parallelogram flexible hinge structure. The double parallelogram flexible hinge structure has two parts and is symmetrically connected to both sides of the guide body. The double parallelogram flexible hinge structure includes a first parallelogram flexible hinge structure and a second parallelogram flexible hinge structure. One side of the first parallelogram flexible hinge structure is connected to the guide body, and its other side is connected to one side of the second parallelogram flexible hinge structure. The other side of the second parallelogram flexible hinge structure is connected to the mounting bracket.

[0009] Preferably, the first decoupling structure and the second decoupling structure have the same structure, and both include a rigid connecting strip and a semi-circular flexible hinge. Two semi-circular flexible hinges are provided and symmetrically connected to both sides of the rigid connecting strip.

[0010] Preferably, the semi-circular flexible hinge has a micro-cavity at the end away from the rigid connecting strip, and the micro-cavity is filled with silicone gel with a high damping coefficient.

[0011] Preferably, there are several microcavities arranged in a three-dimensional rectangular array. Adjacent microcavities are connected by microchannels. The microchannels are filled with silicone gel with a high damping coefficient. The microcavities and microchannels form a cavity network. The cavity network is connected by a gel inlet and an exhaust port.

[0012] Preferably, the moving platform is provided with six grooves, and three first decoupling structures and three second decoupling structures are respectively disposed in the corresponding grooves. The ends of the first decoupling structures near the first flexible guide structure and the ends of the second decoupling structures near the second flexible guide structure are all connected to first buffer pads.

[0013] Preferably, the second flexible guide structure is connected to a second buffer pad on the side away from the second decoupling structure, and the second buffer pad is in movable contact with the mounting bracket.

[0014] This invention also provides a positioning method for a three-degree-of-freedom precision positioning platform based on inkjet printing, comprising the following steps:

[0015] S1 platform initialization and coordinate system establishment, including:

[0016] S11. Install the three-degree-of-freedom precision positioning platform on the motion base of the inkjet printer and ensure that the three-degree-of-freedom precision positioning platform is in a horizontal state.

[0017] S12. Establish the platform motion coordinate system: The two mutually perpendicular directions in the platform plane are the X-axis and Y-axis, the direction perpendicular to the platform plane is the Z-axis, and the rotation direction around the Z-axis is the θZ-axis.

[0018] S13. Set the initial voltage value of each piezoelectric ceramic actuator to the voltage corresponding to zero displacement, so as to perform zero-position calibration on each piezoelectric ceramic actuator.

[0019] S2 positioning command reception and motion decomposition, including:

[0020] S21. Receive target position command, which includes target displacement on the X-axis, target displacement on the Y-axis, and target deflection angle on the Z-axis;

[0021] S22. Decompose the target position command into control signals for each drive mechanism: decompose the target displacement of the X-axis into synchronous drive signals for the two X-axis drive mechanisms, decompose the target displacement of the Y-axis into drive signals for the Y-axis drive mechanism, and decompose the target deflection angle of the Z-axis into differential drive signals for the two X-axis drive mechanisms.

[0022] S3 drive signal output and displacement amplification, including:

[0023] S31. Apply driving voltage to the corresponding piezoelectric ceramic actuator according to the decomposed control signal;

[0024] S32. Each piezoelectric ceramic actuator generates a micro-displacement under the inverse piezoelectric effect, and the micro-displacement is mechanically amplified by the corresponding bridge displacement amplification structure.

[0025] S33. The amplified displacement is guided in a high-precision straight line through the first flexible guide structure and the second flexible guide structure, and the mutual crosstalk between the axial movements is isolated by the first decoupling structure and the second decoupling structure.

[0026] S4 pose adjustment includes:

[0027] S41. Under the coordinated drive of the Y-axis drive mechanism and two X-axis drive mechanisms, the moving stage realizes linear motion along the X-axis, linear motion along the Y-axis, or combined motion along the XY-axis in the plane.

[0028] S42. By controlling the two X-axis drive mechanisms to generate differential displacement, the moving table will generate θZ-direction deflection motion around the Z-axis to achieve planar three-degree-of-freedom positioning.

[0029] S5 position feedback and closed-loop control include:

[0030] S51. The actual displacement and deflection angle of the moving stage are detected in real time by the displacement sensor integrated on the three-degree-of-freedom precision positioning platform to obtain the actual position information;

[0031] S52. Compare the actual location information with the target location information to obtain the location deviation information;

[0032] S53. Adjust the driving voltage of each piezoelectric ceramic actuator in real time based on the position deviation information until the position deviation information is less than the preset tolerance threshold.

[0033] S54. After the mobile stage moves to the target position, lock the drive voltage to maintain the mobile stage's posture.

[0034] The beneficial effects of this invention are as follows:

[0035] This inkjet-printed three-degree-of-freedom precision positioning platform mechanically amplifies the micro-displacement of the piezoelectric ceramic actuator through a bridge-type displacement amplification structure. While maintaining nanometer-level positioning accuracy, it achieves large-stroke motion at the hundred-micrometer level and above, solving the problem of traditional platforms struggling to balance stroke and accuracy. The first and second flexible guide structures improve guiding accuracy and effectively suppress parasitic motion. Furthermore, the first and second decoupling structures effectively isolate multi-axis motion crosstalk, improving structural reliability. It can perform XY-axis movement positioning and deflection positioning, thus enhancing its applicability. Attached Figure Description

[0036] Figure 1 This is a three-dimensional schematic diagram of a three-degree-of-freedom precision positioning platform based on inkjet printing.

[0037] Figure 2 This is a top view of a three-degree-of-freedom precision positioning platform based on inkjet printing.

[0038] Figure 3 for Figure 2 Enlarged diagram of point A in the middle.

[0039] Figure 4 This is a cross-sectional view of the first and second decoupling structures.

[0040] Figure 5 for Figure 4 Enlarged diagram of point B in the middle.

[0041] Figure 6This is a schematic diagram of the first flexible guide structure and the second flexible guide structure.

[0042] Figure 7 This is a schematic diagram of a bridge-type displacement amplification structure and a piezoelectric ceramic actuator.

[0043] Figure 8 This is a flowchart of a positioning method for a three-degree-of-freedom precision positioning platform based on inkjet printing.

[0044] In the figure: 1. Moving stage; 2. Mounting frame; 3. Y-axis drive mechanism; 4. X-axis drive mechanism; 5. Bridge displacement amplification structure; 501. Rigid input block; 502. Bridge amplification output assembly; 5021. Rigid output block; 5022. Tilt cantilever; 5023. Rounded corner flexible hinge; 6. Piezoelectric ceramic actuator; 7. First flexible guide structure; 701. Guide body; 702. Double parallelogram flexible hinge structure; 7021. First parallelogram flexible hinge structure; 7022. Second parallelogram flexible hinge structure; 8. First decoupling structure; 801. Rigid connecting strip; 802. Semi-circular flexible hinge; 9. Second flexible guide structure; 10. Second decoupling structure; 11. Micro cavity; 12. Micro channel; 13. Groove; 14. First buffer pad; 15. Second buffer pad. Detailed Implementation

[0045] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] Please see Figures 1-7This invention provides a technical solution: a three-degree-of-freedom precision positioning platform based on inkjet printing, including a moving stage 1 and a mounting frame 2, and further including a Y-axis drive mechanism 3 and two X-axis drive mechanisms 4. The two X-axis drive mechanisms 4 have the same driving direction, and the Y-axis drive mechanism 3 is perpendicular to the driving direction of the X-axis drive mechanism 4. The Y-axis drive mechanism 3 and the X-axis drive mechanism 4 have the same structure, and both include a bridge displacement amplification structure 5, a piezoelectric ceramic actuator 6, a first flexible guide structure 7, a first decoupling structure 8, a second flexible guide structure 9, and a second decoupling structure. 10. The piezoelectric ceramic actuator 6 is installed inside the bridge displacement amplification structure 5. One side of the bridge displacement amplification structure 5 is connected to the mounting frame 2, and the other side is connected to the first flexible guide structure 7. One side of the first decoupling structure 8 is connected to one side of the moving stage 1, and the other side is connected to the side of the first flexible guide structure 7 away from the bridge displacement amplification structure 5. The first flexible guide structure 7 and the second flexible guide structure 9 are both installed on the mounting frame 2. The other side of the moving stage 1 is connected to one side of the second decoupling structure 10, and the other side of the second decoupling structure 10 is connected to the second flexible guide structure 9.

[0047] When the piezoelectric ceramic actuator 6 is energized, it generates a micro-displacement, which pushes the input end of the bridge displacement amplification structure 5. The bridge displacement amplification structure 5 amplifies the input micro linear displacement and outputs it to the first flexible guide structure 7. The first flexible guide structure 7 provides high-precision linear guidance for the amplified displacement, ensuring the singularity of the motion direction. The motion is transmitted to the moving stage 1 through the first decoupling structure 8. At the same time, the second flexible guide structure 9 and the second decoupling structure 10 provide support and guidance on the other side of the moving stage 1. The first decoupling structure 8 and the second decoupling structure 10 can effectively absorb and isolate motion components (crosstalk) in undesired directions, ensuring that the motion of each axis is independent. By coordinating the control of the two X-axis drive mechanisms 4 and the Y-axis drive mechanism 3, the moving stage 1 can realize linear motion in the X and Y directions and rotational motion around the Z-axis (θZ).

[0048] To facilitate efficient displacement amplification and extend structural lifespan, in this embodiment, preferably, the bridge-type displacement amplification structure 5 includes a rigid input block 501 and a bridge-type amplification output component 502. Two rigid input blocks 501 are symmetrically connected to both sides of the piezoelectric ceramic actuator 6. Two bridge-type amplification output components 502 are symmetrically arranged on both sides of the piezoelectric ceramic actuator 6. Each bridge-type amplification output component 502 includes a rigid output block 5021 and two inclined suspensions symmetrically arranged on both sides of the rigid output block 5021. Arm 5022, one end of the tilting cantilever 5022 is connected to the rigid output block 5021 through a rounded flexible hinge 5023, and the other end is connected to the rigid input block 501 through a rounded flexible hinge 5023. The purpose is to efficiently convert the axial thrust of the piezoelectric ceramic actuator 6 into an amplified displacement in the vertical direction of the output end through the geometric deformation of the bridge-type amplified output component 502. The use of a rounded flexible hinge 5023 instead of a traditional right-angle hinge can significantly reduce stress concentration, improve the compliance and fatigue life of the structure, and extend the structural life.

[0049] To facilitate optimization of geometric amplification efficiency and smooth force flow guidance, in this embodiment, preferably, the angle between the centerline of the tilted cantilever 5022 and the straight line containing the driving direction of the piezoelectric ceramic actuator 6 is 30°. The purpose is that this angle can achieve a high displacement amplification ratio while ensuring structural rigidity and motion stability. The choice of the tilt angle of the tilted cantilever 5022 directly affects the amplification factor and output force characteristics of the bridge displacement amplification structure 5. Geometrically, the 30° angle causes the cantilever to produce a large lateral bending deformation under the action of input displacement, thereby effectively amplifying the output displacement. At the same time, it avoids stress concentration caused by too small an angle or output force attenuation caused by too large an angle. In addition, this angle is conducive to the uniform transmission of force flow along the cantilever, reducing local stress concentration, improving the fatigue life and motion stability of the structure, and ensuring that stable amplification performance and guiding accuracy can still be maintained under long-term high-frequency working conditions.

[0050] To facilitate achieving nanometer-level guiding precision and suppressing parasitic motion, in this embodiment, preferably, the first flexible guiding structure 7 and the second flexible guiding structure 9 have identical structures, both including a guiding body 701 and a double parallelogram flexible hinge structure 702. The double parallelogram flexible hinge structure 702 has two components symmetrically connected to both sides of the guiding body 701. The double parallelogram flexible hinge structure 702 includes a first parallelogram flexible hinge structure 7021 and a second parallelogram flexible hinge structure 7022. One side of the first parallelogram flexible hinge structure 7021 is connected to the guiding body 701, and its other side is connected to the second parallelogram flexible hinge structure 7022. One side of the first parallelogram flexible hinge structure 7022 is connected to the first parallelogram flexible hinge structure 7021, and the other side of the second parallelogram flexible hinge structure 7022 is connected to the mounting bracket 2. The purpose is to achieve symmetrical motion constraints by symmetrically connecting the two double parallelogram flexible hinge structures 702 on both sides of the guide body 701, eliminating parasitic displacement in the guide motion, and ensuring high-precision linear guidance in the output displacement direction. The first parallelogram flexible hinge structure 7021 and the second parallelogram flexible hinge structure 7022 are linked in series, which expands the stroke range of linear motion. Moreover, the series arrangement reduces the overall structural stiffness and the driving force requirement, which is beneficial for precise control and energy consumption reduction.

[0051] To facilitate effective isolation of motion crosstalk between different motion axes and improve motion decoupling performance, in this embodiment, preferably, the first decoupling structure 8 and the second decoupling structure 10 have the same structure, and both include a rigid connecting strip 801 and a semi-circular flexible hinge 802. Two semi-circular flexible hinges 802 are provided and symmetrically connected to both sides of the rigid connecting strip 801. The purpose is to make the radial stiffness of the first decoupling structure 8 and the second decoupling structure 10 high by symmetrically providing two semi-circular flexible hinges 802 on both sides of the rigid connecting strip 801, so as to effectively transmit the force and displacement in the driving direction (axial direction) and make the tangential stiffness of the first decoupling structure 8 and the second decoupling structure 10 low, so as to allow compliant deformation in the non-driving direction, thereby absorbing and isolating crosstalk forces or displacements from other axes and realizing motion decoupling.

[0052] To facilitate the suppression of high-frequency vibrations and improve the dynamic stability of the platform, in this embodiment, preferably, a micro cavity 11 is provided at the end of the semi-circular flexible hinge 802 away from the rigid connecting strip 801. The micro cavity 11 is filled with silicone gel with a high damping coefficient. The purpose is that when the platform moves at high frequency or is disturbed by external forces, the root of the semi-circular flexible hinge 802 will undergo slight deformation, squeezing the internal silicone gel. The silicone gel is repeatedly sheared, and the viscoelastic hysteresis effect of the silicone gel is used to convert the vibration mechanical energy into heat energy for dissipation, thereby filtering out high-frequency harmful vibrations from the source and improving the platform's motion smoothness and positioning stability.

[0053] To facilitate enhanced damping, in this embodiment, preferably, several microcavities 11 are arranged in a three-dimensional rectangular array. Adjacent microcavities 11 are connected by microchannels 12, which are filled with high-damping-coefficient silica gel. The microcavities 11 and microchannels 12 form a cavity network. The cavity network is connected by a gel inlet and an exhaust port. The purpose is to inject liquid silica gel into the cavity network through the gel inlet using vacuum-assisted infusion technology, while simultaneously exhausting the gas inside the cavity network through the exhaust port. This allows the liquid silica gel to be fully filled into the entire complex cavity network, ensuring uniform distribution of the damping material. After curing, it becomes integrated with the semi-circular flexible hinge 802, thereby specifically enhancing the dynamic damping performance of key parts without excessively affecting the macroscopic static stiffness of the structure.

[0054] To facilitate a compact layout and overload protection, in this embodiment, preferably, the mobile platform 1 is provided with six grooves 13. Three first decoupling structures 8 and three second decoupling structures 10 are respectively disposed in the corresponding grooves 13. The ends of the first decoupling structures 8 near the first flexible guide structure 7 and the ends of the second decoupling structures 10 near the second flexible guide structure 9 are connected to first buffer pads 14. The purpose is to embed the decoupling structures into the grooves 13, making the overall structure more compact and improving the platform space utilization. The first buffer pads 14 are made of elastic materials (such as polyurethane). When the platform moves beyond its limit or an accidental impact occurs, it can play a buffering role to prevent the right-angle corners of the mobile platform 1 from forming a hard collision with the first decoupling structure 8 or the second decoupling structure 10 and causing damage.

[0055] To facilitate the prevention of overtravel and end-of-travel buffering, in this embodiment, preferably, a second buffer pad 15 is connected to the side of the second flexible guide structure 9 away from the second decoupling structure 10. The second buffer pad 15 is in movable contact with the mounting frame 2. The purpose of the second buffer pad 15 is to limit the movement and prevent overtravel. The second buffer pad 15 is made of an elastic material (such as polyurethane). When the platform moves close to the limit position, the second buffer pad 15 can gradually absorb the impact energy through its nonlinear stiffness characteristics, thereby achieving end-of-travel buffering and smooth limiting, ensuring the stability of the platform's movement at the limit position, and preventing the second flexible guide structure 9 from forming a hard collision with the mounting frame 2 and causing damage.

[0056] Please see Figure 8 The present invention also provides a positioning method for a three-degree-of-freedom precision positioning platform based on inkjet printing, comprising the following steps:

[0057] S1 platform initialization and coordinate system establishment, including:

[0058] S11. Install the three-degree-of-freedom precision positioning platform on the motion base of the inkjet printer and ensure that the three-degree-of-freedom precision positioning platform is in a horizontal state.

[0059] S12. Establish the platform motion coordinate system: The two mutually perpendicular directions in the platform plane are the X-axis and Y-axis, the direction perpendicular to the platform plane is the Z-axis, and the rotation direction around the Z-axis is the θZ-axis.

[0060] S13. Set the initial voltage value of each piezoelectric ceramic actuator 6 to the voltage corresponding to zero displacement, so as to perform zero-position calibration on each piezoelectric ceramic actuator 6.

[0061] S2 positioning command reception and motion decomposition, including:

[0062] S21. Receive target position command, which includes target displacement on the X-axis, target displacement on the Y-axis, and target deflection angle on the Z-axis;

[0063] S22. Decompose the target position command into control signals for each drive mechanism: decompose the target displacement of the X-axis into synchronous drive signals for the two X-axis drive mechanisms 4, decompose the target displacement of the Y-axis into drive signals for the Y-axis drive mechanism 3, and decompose the target deflection angle of the Z-axis into differential drive signals for the two X-axis drive mechanisms 4.

[0064] S3 drive signal output and displacement amplification, including:

[0065] S31. Apply driving voltage to the corresponding piezoelectric ceramic actuator 6 according to the decomposed control signal;

[0066] S32. Each piezoelectric ceramic actuator 6 generates a micro-displacement under the inverse piezoelectric effect, and the micro-displacement is mechanically amplified by the corresponding bridge displacement amplification structure 5.

[0067] S33. The amplified displacement is guided in a high-precision straight line through the first flexible guide structure 7 and the second flexible guide structure 9, and the crosstalk between each axial movement is isolated by the first decoupling structure 8 and the second decoupling structure 10.

[0068] S4 pose adjustment includes:

[0069] S41. Under the coordinated drive of the Y-axis drive mechanism 3 and two X-axis drive mechanisms 4, the moving stage 1 realizes linear motion in the X-axis, linear motion in the Y-axis, or combined motion in the XY-axis in the plane.

[0070] S42. By controlling the two X-axis drive mechanisms 4 to generate differential displacement, the moving stage 1 generates θZ-direction deflection motion around the Z-axis to achieve planar three-degree-of-freedom positioning.

[0071] S5 position feedback and closed-loop control include:

[0072] S51. The actual displacement and deflection angle of the moving stage 1 are detected in real time by the displacement sensor integrated on the three-degree-of-freedom precision positioning platform to obtain the actual position information.

[0073] S52. Compare the actual location information with the target location information to obtain the location deviation information;

[0074] S53. Adjust the driving voltage of each piezoelectric ceramic actuator 6 in real time based on the position deviation information until the position deviation information is less than the preset tolerance threshold.

[0075] S54. After the mobile stage 1 moves to the target position, lock the drive voltage to maintain the pose of the mobile stage 1.

[0076] The working principle of this invention: The three-degree-of-freedom precision positioning platform adopts a series modular design of "bridge displacement amplification structure 5 + first flexible guide structure 7 + first decoupling structure 8", and utilizes piezoelectric ceramic actuator 6 to provide high-precision micro-displacement input under the inverse piezoelectric effect, forming a modular "drive-amplification-guide-decoupling" combination unit, which synergistically leverages the advantages of each component. The bridge displacement amplification structure 5 solves the problem of the small stroke of the piezoelectric ceramic actuator 6. The double composite parallelogram flexible guide structure of the first flexible guide structure 7 and the second flexible guide structure 9 ensures the pure linearity of the motion direction and suppresses parasitic motion. The first decoupling structure 8 and the second decoupling structure 10 effectively filter the motion coupling between multiple axes. Combined with the differential drive principle, planar deflection is achieved, and closed-loop precision control is achieved through sensor feedback. Thus, within a compact structure, a large stroke of hundreds of micrometers, nanometer-level positioning accuracy, and planar three-degree-of-freedom (X, Y, θZ) motion capability are simultaneously achieved, perfectly meeting the stringent requirements of inkjet printing equipment for large stroke and high-precision positioning.

[0077] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An inkjet printing based three-degree-of-freedom precision positioning platform comprising a moving table (1) and a mounting frame (2), characterized in that: Also include Y axial drive mechanism (3) and two X axial drive mechanism (4), the driving direction of two X axial drive mechanism (4) is same, the driving direction of Y axial drive mechanism (3) and X axial drive mechanism (4) is perpendicular to set, the structure of Y axial drive mechanism (3) and X axial drive mechanism (4) is same, and all include bridge type displacement amplification structure (5), piezoelectric ceramic actuator (6), first flexible guide structure (7), first decoupling structure (8), second flexible guide structure (9) and second decoupling structure (10), piezoelectric ceramic actuator (6) is installed in the inside of bridge type displacement amplification structure (5), one side of bridge type displacement amplification structure (5) is connected with mounting bracket (2), and its other side is connected with first flexible guide structure (7), one side of first decoupling structure (8) is connected with one side of moving platform (1), and its other side is connected with the side of first flexible guide structure (7) away from bridge type displacement amplification structure (5), first flexible guide structure (7) and second flexible guide structure (9) are all installed on mounting bracket (2), the other side of moving platform (1) is connected with one side of second decoupling structure (10), the other side of second decoupling structure (10) is connected with second flexible guide structure (9), the structure of first decoupling structure (8) and second decoupling structure (10) is same, and all include rigid connection strip (801) and semicircular flexible hinge (802), the semicircular flexible hinge (802) is provided with two and is symmetrically connected to the two sides of rigid connection strip (801), one end of semicircular flexible hinge (802) away from rigid connection strip (801) is provided with microcavity (11), the microcavity (11) is filled with high damping coefficient silicon gel, the microcavity (11) is three-dimensional rectangular array arrangement several, two adjacent microcavities (11) are communicated by microchannel (12), the microchannel (12) is filled with high damping coefficient silicon gel, several microcavities (11) and several microchannels (12) constitute cavity network, the cavity network is connected and communicated and is provided with gel perfusion port and vent; The positioning method of the three-degree-of-freedom precision positioning platform based on inkjet printing comprises the following steps: S1 platform initialization and coordinate system establishment, comprising: S11, install the three-degree-of-freedom precision positioning platform on the motion base of the inkjet printing equipment, and ensure that the three-degree-of-freedom precision positioning platform is in a horizontal state; S12, establish the platform motion coordinate system: take two directions perpendicular to each other in the platform plane as the X and Y axes, and the direction perpendicular to the platform plane as the Z axis, and the rotation direction around the Z axis as the θZ axis; S13, set the initial voltage value of each piezoelectric ceramic actuator (6) to zero displacement corresponding voltage to zero mark each piezoelectric ceramic actuator (6); S2 positioning instruction receiving and motion decomposition, comprising: S21, receive the target position instruction, which includes the X-axis target displacement, the Y-axis target displacement and the θZ-axis target deflection angle; S22, decompose the target position instruction into control signals for each driving mechanism: decompose the X-axis target displacement into synchronous driving signals for the two X-axis driving mechanisms (4), decompose the Y-axis target displacement into a driving signal for the Y-axis driving mechanism (3), and decompose the θZ-axis target deflection angle into differential driving signals for the two X-axis driving mechanisms (4); S3 driving signal output and displacement amplification, comprising: S31, according to the decomposed control signals, respectively apply driving voltages to the corresponding piezoelectric ceramic actuators (6); S32, each piezoelectric ceramic actuator (6) generates a micro-displacement under the inverse piezoelectric effect, which is mechanically amplified by the corresponding bridge-type displacement amplification structure (5); S33, the amplified displacement is guided in a straight line with high precision through the first flexible guide structure (7) and the second flexible guide structure (9), and the mutual crosstalk between the axial movements is isolated through the first decoupling structure (8) and the second decoupling structure (10); S4 pose adjustment, comprising: S41, the moving table (1) realizes X-axis linear motion, Y-axis linear motion or XY-axis compound motion in the plane under the cooperative driving of the Y-axis driving mechanism (3) and the two X-axis driving mechanisms (4); S42, by controlling the two X-axis driving mechanisms (4) to generate differential displacement, the moving table (1) generates θZ-axis deflection motion around the Z-axis to realize three degrees of freedom positioning in the plane; S5 position feedback and closed-loop control, comprising: S51, the actual displacement and deflection angle of the moving table (1) are detected in real time by the displacement sensor integrated on the three-degree-of-freedom precision positioning platform to obtain actual position information; S52, compare the actual position information with the target position information to obtain position deviation information; S53, based on the position deviation information, adjust the driving voltage of each piezoelectric ceramic actuator (6) in real time until the position deviation information is less than a preset tolerance threshold; S54, after the moving table (1) moves to the target position, lock the driving voltage to maintain the pose of the moving table (1).

2. The three degree of freedom precision positioning platform based on inkjet printing according to claim 1, characterized in that: The bridge-type displacement amplification structure (5) comprises a rigid input block (501) and a bridge-type amplification output assembly (502), the rigid input block (501) is provided with two and symmetrically connected to the two sides of the piezoelectric ceramic actuator (6), the bridge-type amplification output assembly (502) is provided with two and symmetrically arranged on the two sides of the piezoelectric ceramic actuator (6), each bridge-type amplification output assembly (502) comprises a rigid output block (5021) and two inclined cantilevers (5022) symmetrically arranged on the two sides of the rigid output block (5021), one end of the inclined cantilever (5022) is connected with the rigid output block (5021) through a round corner flexible hinge (5023), and the other end is connected with the rigid input block (501) through a round corner flexible hinge (5023).

3. The three degree of freedom precision positioning platform based on inkjet printing according to claim 2, characterized in that: The angle between the center line of the inclined cantilever (5022) and the straight line where the driving direction of the piezoelectric ceramic actuator (6) is located is 30°.

4. The three degree of freedom precision positioning platform based on inkjet printing according to claim 1, characterized in that: The first flexible guide structure (7) and the second flexible guide structure (9) are identical in structure and each comprises a guide main body (701) and double parallelogram flexible hinge structures (702), two of which are symmetrically connected to the two sides of the guide main body (701), the double parallelogram flexible hinge structures (702) comprise first parallelogram flexible hinge structures (7021) and second parallelogram flexible hinge structures (7022), one side of the first parallelogram flexible hinge structure (7021) is connected with the guide main body (701), and the other side thereof is connected with one side of the second parallelogram flexible hinge structure (7022), and the other side of the second parallelogram flexible hinge structure (7022) is connected with the mounting rack (2).

5. The three degree of freedom precision positioning platform based on inkjet printing according to claim 1, characterized in that: The mobile station (1) is provided with six grooves (13), three first decoupling structures (8) and three second decoupling structures (10) are arranged in the corresponding grooves (13) respectively, and the first decoupling structure (8) is connected with the first buffer pad (14) on both sides of the end portion close to the first flexible guide structure (7), and the second decoupling structure (10) is connected with the second buffer pad (14) on both sides of the end portion close to the second flexible guide structure (9).

6. The three degree of freedom precision positioning platform based on inkjet printing according to claim 1, characterized in that: The second flexible guide structure (9) is connected with the second buffer pad (15) on the side away from the second decoupling structure (10), and the second buffer pad (15) is movably abutted against the mounting rack (2).

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