Three-degree-of-freedom precision positioning platform based on ink-jet printing and positioning method thereof

Abstract

The invention relates to the technical field of precision motion platforms, in particular to a three-degree-of-freedom precision positioning platform based on ink-jet printing and a positioning method thereof.The three-degree-of-freedom precision positioning platform comprises a moving table, a mounting frame, a Y-axis driving mechanism and two X-axis driving mechanisms, and the driving directions of the two X-axis driving mechanisms are the same; the driving direction of the Y-axis driving mechanism is perpendicular to the driving direction of the X-axis driving mechanism, mechanical amplification is conducted on micro displacement of the piezoelectric ceramic actuator through the bridge type displacement amplification structure, large-stroke movement of hundred microns or above is achieved while the nanoscale positioning precision is kept, the problem that the stroke and precision of a traditional platform are difficult to consider at the same time is solved, and the working efficiency is improved. The guide precision is improved through the first flexible guide structure and the second flexible guide structure, parasitic motion is effectively inhibited, multi-axis motion crosstalk is effectively isolated through the first decoupling structure and the second decoupling structure, the structural reliability is improved, XY axial movement positioning and deflection positioning can be carried out, and the applicability is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of precision motion platform, and particularly relates to a three-degree-of-freedom precision positioning platform based on inkjet printing and a positioning method thereof. BACKGROUND

[0002] The inkjet printing technology has wide application in the fields of high-precision micro-nano manufacturing, flexible electronics, biological printing and the like, and high precision positioning between a printing head and a substrate is required, and the existing inkjet printing positioning platform often faces the following technical bottlenecks: 1. It is difficult to balance large stroke and high precision: although the piezoelectric ceramic driver can reach sub-nanometer level in precision, the stroke is usually less than 100 microns, and the large stroke scheme such as linear motor is difficult to realize nanometer level positioning; 2. Insufficient structural reliability: poor motion guiding effect, easy to produce parasitic motion, unable to guarantee the singleness and controllability of the motion direction, and the traditional bridge type displacement amplification mechanism is easy to produce stress concentration at the hinge, and is easy to fatigue fracture in long-term use, affecting the stability of the system; 3. Serious coupling of multi-degree-of-freedom motion: the existing platform usually adopts multi-module series connection or parallel connection, and the structure is complex, large in size, and the coupling error between the motion axes is significant, and it is difficult to realize high-precision decoupling motion; 4. Few degrees of freedom: only X-axis or Y-axis movement positioning can be performed, and deflection positioning cannot be performed, reducing the applicability. SUMMARY

[0003] In order to overcome the deficiencies of the prior art, the purpose of the present application is to provide a three-degree-of-freedom precision positioning platform based on inkjet printing and a positioning method thereof, which have large stroke, high precision, high reliability, good decoupling performance and improved applicability.

[0004] The technical scheme adopted by the present application is as follows: A three-degree-of-freedom precision positioning platform based on inkjet printing, comprising a moving table and a mounting frame, further comprising a Y-axis driving mechanism and two X-axis driving mechanisms, the driving directions of the two X-axis driving mechanisms are the same, the driving directions of the Y-axis driving mechanism and the X-axis driving mechanism are vertically arranged, the Y-axis driving mechanism and the X-axis driving mechanism have the same structure, and both comprise a bridge type 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 on the inner side of the bridge type displacement amplification structure, one side of the bridge type displacement amplification structure is connected with the mounting frame, and the other side thereof is connected with the first flexible guide structure, one side of the first decoupling structure is connected with one side of the moving table, and the other side thereof is connected with the side of the first flexible guide structure away from the bridge type displacement amplification structure, the first flexible guide structure and the second flexible guide structure are both installed on the mounting frame, the other side of the moving table is connected with one side of the second decoupling structure, and the other side of the second decoupling structure is connected with the second flexible guide structure.

[0005] As preferred, the bridge type displacement amplification structure comprises a rigid input block and a bridge type amplification output assembly, the rigid input block is provided with two and symmetrically connected to the two sides of the piezoelectric ceramic actuator, the bridge type amplification output assembly is provided with two and symmetrically arranged on the two sides of the piezoelectric ceramic actuator, each bridge type amplification output assembly comprises a rigid output block and two inclined cantilevers symmetrically arranged on the two sides of the rigid output block, one end of the inclined cantilever is connected with the rigid output block through a round corner flexible hinge, and the other end is connected with the rigid input block through a round corner flexible hinge.

[0006] As preferred, the angle between the center line of the inclined cantilever and the straight line where the driving direction of the piezoelectric ceramic actuator is located is 30°.

[0007] As preferred, the first flexible guide structure and the second flexible guide structure are the same in structure, and each comprises a guide body and a double parallelogram flexible hinge structure, the double parallelogram flexible hinge structure is provided with two and symmetrically connected to the two sides of the guide body, the double parallelogram flexible hinge structure comprises a first parallelogram flexible hinge structure and a second parallelogram flexible hinge structure, one side of the first parallelogram flexible hinge structure is connected with the guide body, and the other side is connected with one side of the second parallelogram flexible hinge structure, the other side of the second parallelogram flexible hinge structure is connected with the mounting frame.

[0008] As preferred, the first decoupling structure and the second decoupling structure are the same in structure, and each comprises a rigid connecting strip and a semicircular flexible hinge, the semicircular flexible hinge is provided with two and symmetrically connected to the two sides of the rigid connecting strip.

[0009] As preferred, one end of the semicircular flexible hinge away from the rigid connecting strip is provided with a micro cavity, and the micro cavity is filled with silicone gel with high damping coefficient.

[0010] As preferred, the micro cavities are arranged in a three-dimensional rectangular array, two adjacent micro cavities are connected through a micro channel, the micro channel is filled with silicone gel with high damping coefficient, and the plurality of micro cavities and the plurality of micro channels form a cavity network, and the cavity network is connected and communicated through a gel filling port and an exhaust port.

[0011] As preferred, six grooves are arranged on the moving platform, three first decoupling structures and three second decoupling structures are arranged in the corresponding grooves, and the first decoupling structure is connected with the first buffer pad on both sides of the end portion close to the first flexible guide structure, and the second decoupling structure is connected with the second buffer pad on both sides of the end portion close to the second flexible guide structure.

[0012] As preferred, the second flexible guide structure is connected with the second buffer pad on the side away from the second decoupling structure, and the second buffer pad is in movable abutment with the mounting frame.

[0013] The application further provides a positioning method of a three-degree-of-freedom precision positioning platform based on inkjet printing, comprising the following steps: S1, platform initialization and coordinate system establishment, comprising: S11, mounting the three-degree-of-freedom precision positioning platform on a motion base of an inkjet printing device, and ensuring that the three-degree-of-freedom precision positioning platform is in a horizontal state; S12, establishing a platform motion coordinate system: taking two directions perpendicular to each other in the platform plane as the X-axis and the Y-axis, and taking the direction perpendicular to the platform plane as the Z-axis, and taking the rotation direction around the Z-axis as the θZ-axis; S13, setting the initial voltage value of each piezoelectric ceramic actuator as the voltage corresponding to zero displacement, so as to calibrate the zero position of each piezoelectric ceramic actuator; S2, positioning instruction receiving and motion decomposition, comprising: S21, receiving a target position instruction, the target position instruction comprising an X-axis target displacement amount, a Y-axis target displacement amount and a θZ-axis target deflection angle; S22, decomposing the target position instruction into control signals for each driving mechanism: decomposing the X-axis target displacement amount into synchronous driving signals for two X-axis driving mechanisms, decomposing the Y-axis target displacement amount into a driving signal for the Y-axis driving mechanism, and decomposing the θZ-axis target deflection angle into differential driving signals for two X-axis driving mechanisms; S3, driving signal output and displacement amplification, comprising: S31, applying driving voltages to corresponding piezoelectric ceramic actuators according to the decomposed control signals; S32, each piezoelectric ceramic actuator generates a micro-displacement under the inverse piezoelectric effect, and the micro-displacement is mechanically amplified through a corresponding bridge-type displacement amplification structure; 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 motions is isolated through the first decoupling structure and the second decoupling structure; S4, pose adjustment, comprising: S41, moving the stage to realize 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 and the two X-axis driving mechanisms; S42, generating differential displacements by controlling the two X-axis driving mechanisms to make the moving stage produce θZ-direction deflection motion around the Z-axis, so as to realize three-degree-of-freedom positioning in the plane; S5, position feedback and closed-loop control, comprising: S51, detecting the actual displacement and deflection angle of the moving stage in real time through a 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, real-time adjust the driving voltage of each piezoelectric ceramic actuator until the position deviation information is less than a preset tolerance threshold; S54, when the mobile station moves to the target position, lock the driving voltage to maintain the pose of the mobile station.

[0014] The beneficial effects of the present application are: The three-degree-of-freedom precision positioning platform based on inkjet printing realizes mechanical amplification of the micro-displacement of the piezoelectric ceramic actuator through the bridge displacement amplification structure, realizes large stroke movement of more than 100 microns while maintaining nanometer-level positioning accuracy, solves the problem that the stroke and precision of the traditional platform are difficult to balance, improves the guiding accuracy through the first flexible guiding structure and the second flexible guiding structure, effectively suppresses parasitic motion, effectively isolates multi-axis motion crosstalk through the first decoupling structure and the second decoupling structure, improves the structural reliability, can realize XY axial movement positioning and deflection positioning, and improves the applicability. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 It is a three-dimensional schematic view of the three-degree-of-freedom precision positioning platform based on inkjet printing.

[0016] Figure 2 It is a top view of the three-degree-of-freedom precision positioning platform based on inkjet printing.

[0017] Figure 3 It is Figure 2 An enlarged schematic view of position A in FIG.

[0018] Figure 4 It is a structural sectional view of the first decoupling structure and the second decoupling structure.

[0019] Figure 5 It is Figure 4 An enlarged schematic view of position B in FIG.

[0020] Figure 6 It is a structural schematic view of the first flexible guiding structure and the second flexible guiding structure.

[0021] Figure 7 It is a structural schematic view of the bridge displacement amplification structure and the piezoelectric ceramic actuator.

[0022] Figure 8 It is a flowchart of the positioning method of the three-degree-of-freedom precision positioning platform based on inkjet printing.

[0023] In the figure: 1. mobile station; 2. mounting frame; 3. Y-axis drive mechanism; 4. X-axis drive mechanism; 5. bridge type displacement amplification structure; 501. rigid input block; 502. bridge type amplification output assembly; 5021. rigid output block; 5022. inclined cantilever; 5023. round 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. semicircular 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 DESCRIPTION

[0024] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0025] Please refer to Figures 1-7 The present application provides a technical solution: a three-degree-of-freedom precision positioning platform based on inkjet printing, comprising a mobile station 1 and a mounting frame 2, further comprising a Y-axis drive mechanism 3 and two X-axis drive mechanisms 4, the driving directions of the two X-axis drive mechanisms 4 are the same, the driving directions of the Y-axis drive mechanism 3 and the X-axis drive mechanism 4 are perpendicular, the structures of the Y-axis drive mechanism 3 and the X-axis drive mechanism 4 are the same, and both comprise a bridge type 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 on the inner side of the bridge type displacement amplification structure 5, one side of the bridge type displacement amplification structure 5 is connected with the mounting frame 2, and the other side thereof is connected with the first flexible guide structure 7, one side of the first decoupling structure 8 is connected with one side of the mobile station 1, and the other side thereof is connected with the side of the first flexible guide structure 7 away from the bridge type 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 mobile station 1 is connected with one side of the second decoupling structure 10, and the other side of the second decoupling structure 10 is connected with the second flexible guide structure 9; The piezoelectric ceramic actuator 6 generates micro displacement after being powered on, and pushes the input end of the bridge type displacement amplification structure 5. The bridge type displacement amplification structure 5 amplifies the input micro linear displacement and then outputs to the first flexible guide structure 7. The first flexible guide structure 7 guides the amplified displacement with high precision, ensures the singularity of the movement direction, and transmits the movement to the moving table 1 through the first decoupling structure 8. Meanwhile, the second flexible guide structure 9 and the second decoupling structure 10 provide support and guidance on the other side of the moving table 1. The first decoupling structure 8 and the second decoupling structure 10 can effectively absorb and isolate the motion components (cross talk) in the non-desired direction, ensure the independent movement of each axis, and realize the linear movement of the moving table 1 in the X and Y directions and the rotary movement around the Z axis (θZ) through the coordinated control of the two X-axis and Y-axis driving mechanisms 4 and 3.

[0026] In order to facilitate efficient displacement amplification and prolong the service life of the structure, preferably, the bridge type displacement amplification structure 5 includes a rigid input block 501 and a bridge type amplification output assembly 502 in the embodiment. The rigid input block 501 is provided with two symmetrically connected sides of the piezoelectric ceramic actuator 6. The bridge type amplification output assembly 502 is provided with two symmetrically arranged sides of the piezoelectric ceramic actuator 6. Each bridge type amplification output assembly 502 includes a rigid output block 5021 and two inclined cantilever arms 5022 symmetrically arranged on both sides of the rigid output block 5021. One end of the inclined cantilever arm 5022 is connected with the rigid output block 5021 through a round flexible hinge 5023, and the other end is connected with the rigid input block 501 through a round flexible hinge 5023. The purpose is to efficiently convert the axial thrust of the piezoelectric ceramic actuator 6 into amplified displacement in the vertical direction of the output end through the geometric deformation of the bridge type amplification output assembly 502. The round flexible hinge 5023 is used to replace the traditional right-angle hinge, which can significantly reduce stress concentration, improve the flexibility and fatigue life of the structure, and prolong the service life of the structure.

[0027] In order to facilitate the optimization of geometric amplification efficiency and smoothness of force flow guidance, preferably, the angle between the center line of the inclined cantilever arm 5022 and the straight line where the driving direction of the piezoelectric ceramic actuator 6 is located is 30° in the embodiment. The purpose is that this angle can realize higher displacement amplification ratio under the premise of ensuring the structural stiffness and movement stability. The selection of the inclination angle of the inclined cantilever arm 5022 directly affects the amplification multiple and output force characteristics of the bridge type displacement amplification structure 5. The 30° angle makes the cantilever produce larger lateral bending deformation under the action of input displacement, thereby effectively amplifying the output displacement, while avoiding stress concentration caused by too small angle or output force attenuation caused by too large angle. In addition, this angle is conducive to uniform transmission of force flow along the cantilever, reduces local stress concentration, improves the fatigue life and movement stability of the structure, and ensures that the stable amplification performance and guidance precision can be maintained under long-term high-frequency working conditions.

[0028] In order to facilitate the realization of nanometer level guiding precision and inhibit parasitic motion, in the embodiment, preferably, the first flexible guiding structure 7 and the second flexible guiding structure 9 are identical in structure and each comprises a guiding body 701 and a double parallelogram flexible hinge structure 702, two double parallelogram flexible hinge structures 702 are symmetrically connected to the two sides of the guiding body 701, the double parallelogram flexible hinge structure 702 comprises 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 with the guiding 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 frame 2, the purpose is to realize symmetric motion constraint by symmetrically connecting two double parallelogram flexible hinge structures 702 on the two sides of the guiding body 701, eliminate parasitic displacement in guiding motion, and ensure to provide high-precision linear guiding in the output displacement direction, the first parallelogram flexible hinge structure 7021 and the second parallelogram flexible hinge structure 7022 are connected in series, the stroke range of linear motion is expanded, and the overall structure stiffness is reduced due to the series arrangement, the driving force demand is reduced, which is beneficial to precise control and energy saving.

[0029] In order to facilitate effective isolation of motion crosstalk between different motion axes and improve motion decoupling performance, in the embodiment, preferably, the first decoupling structure 8 and the second decoupling structure 10 are identical in structure and each comprises a rigid connecting strip 801 and a semicircular flexible hinge 802, two semicircular flexible hinges 802 are symmetrically connected to the two 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 arranging two semicircular flexible hinges 802 on the two sides of the rigid connecting strip 801, effectively transmit the driving direction (axial) force and displacement, make the tangential stiffness of the first decoupling structure 8 and the second decoupling structure 10 low, allow soft deformation in the non-driving direction, thereby absorbing and isolating the crosstalk force or displacement from other axes, and realizing motion decoupling.

[0030] In order to facilitate the inhibition of high-frequency vibration and improve the dynamic stability of the platform, in the embodiment, preferably, the semicircular flexible hinge 802 away from one end of the rigid connecting strip 801 is provided with a micro cavity 11, and the micro cavity 11 is filled with silica gel with high damping coefficient, the purpose is that when the platform is high-frequency motion or disturbed by external disturbance, the root of the semicircular flexible hinge 802 will be deformed slightly, extruding the internal silica gel, the silica gel is repeatedly sheared, and the viscoelastic hysteresis effect of the silica gel is utilized to convert the vibration mechanical energy into heat energy dissipation, thereby filtering out the high-frequency harmful vibration from the source, and improving the motion smoothness and positioning stability of the platform.

[0031] In order to facilitate the enhancement of damping effect, preferably, the micro cavities 11 are arranged in a three-dimensional rectangular array in the embodiment, two adjacent micro cavities 11 are communicated through the micro channel 12, the micro channel 12 is filled with silica gel with high damping coefficient, and the plurality of micro cavities 11 and the plurality of micro channels 12 form a cavity network, the cavity network is connected and communicated with the gel pouring port and the exhaust port, the purpose is to fill the liquid silica gel into the entire complex cavity network through the vacuum assisted pouring technology at the gel pouring port, and the gas in the cavity network is discharged through the exhaust port, so that the liquid silica gel can be fully filled into the entire complex cavity network, the uniform distribution of the damping material is ensured, the silica gel is integrated with the semicircular flexible hinge 802 after solidification, and the dynamic damping performance of the key position is enhanced on the premise that the macroscopic static stiffness of the structure is not excessively affected.

[0032] In order to facilitate compact layout and overload protection, preferably, six grooves 13 are arranged on the moving table 1, three first decoupling structures 8 and three second decoupling structures 10 are arranged in the corresponding grooves 13, the first buffer pad 14 is connected to the two sides of the end portion of the first flexible guide structure 7 close to the first decoupling structure 8 and the two sides of the end portion of the second flexible guide structure 9 close to the second decoupling structure 10, and the purpose is to embed the decoupling structure into the groove 13, so that the overall structure is more compact, the platform space utilization is improved, the first buffer pad 14 is made of elastic material (such as polyurethane), and when the platform motion exceeds the limit or an accidental impact occurs, the first buffer pad 14 can play a buffering role to prevent the right-angle corner of the moving table 1 from being damaged by hard collision with the first decoupling structure 8 or the second decoupling structure 10.

[0033] In order to facilitate the prevention of motion overtravel and end buffering, preferably, the 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 abutment with the mounting frame 2, and the purpose is to limit the travel through the second buffer pad 15, prevent overtravel, and the second buffer pad 15 is made of elastic material (such as polyurethane), when the platform motion approaches the limit position, the second buffer pad 15 can gradually absorb impact energy through its nonlinear stiffness characteristics, realize end buffering and stable limiting, ensure the motion stability of the platform at the limit position, and prevent the second flexible guide structure 9 from being damaged by hard collision with the mounting frame 2.

[0034] Please refer to Figure 8 The application also provides a positioning method of the three-degree-of-freedom precision positioning platform based on inkjet printing, including the following steps: S1, platform initialization and coordinate system establishment, including: 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 a platform motion coordinate system: two directions perpendicular to each other in the platform plane are respectively X axis and Y axis, and the direction perpendicular to the platform plane is Z axis, and the rotation direction around Z axis is θZ axis; S13, set the initial voltage value of each piezoelectric ceramic actuator 6 as the zero displacement corresponding voltage, so as to calibrate the zero position of each piezoelectric ceramic actuator 6; S2 positioning instruction receiving and motion decomposition, comprising: S21, receiving target position instruction, the target position instruction includes X axis target displacement, Y axis target displacement and θZ axis target deflection angle; S22, decomposing the target position instruction into control signals for each driving mechanism: decomposing the X axis target displacement into synchronous driving signals for two X axis driving mechanisms 4, decomposing the Y axis target displacement into a driving signal for the Y axis driving mechanism 3, and decomposing the θZ axis target deflection angle into differential driving signals for two X axis driving mechanisms 4; S3 driving signal output and displacement amplification, comprising: S31, according to the decomposed control signal, respectively applying driving voltage to the corresponding piezoelectric ceramic actuator 6; S32, each piezoelectric ceramic actuator 6 generates micro displacement under the inverse piezoelectric effect, and the micro displacement is mechanically amplified through the corresponding bridge type displacement amplification structure 5; S33, the amplified displacement is guided in high precision straight line through the first flexible guide structure 7 and the second flexible guide structure 9, and the mutual crosstalk between the axial motions 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 direction deflection motion around Z axis, so as 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 through the displacement sensor integrated on the three degrees of freedom precision positioning platform, and the actual position information is obtained; S52, comparing the actual position information with the target position information to obtain position deviation information; S53, based on the position deviation information, the driving voltage of each piezoelectric ceramic actuator 6 is adjusted in real time until the position deviation information is less than the preset tolerance threshold; S54, when the moving table 1 moves to the target position, the driving voltage is locked to maintain the pose of the moving table 1.

[0035] The working principle of the present application: the three-degree-of-freedom precision positioning platform is designed by the series modularization of "bridge type displacement amplification structure 5 + first flexible guide structure 7 + first decoupling structure 8", and utilizes the piezoelectric ceramic actuator 6 to provide high-precision micro-displacement input under the inverse piezoelectric effect, forms the modularized "drive-amplification-guide-decoupling" combined unit, and cooperates to play respective advantages. The bridge type displacement amplification structure 5 solves the problem of 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 straight line of the movement direction, and suppresses the parasitic motion. The first decoupling structure 8 and the second decoupling structure 10 effectively filter the motion coupling between multiple axes, realize plane deflection combined with the differential drive principle, and realize closed-loop precision control through sensor feedback, so as to realize the hundred-micron large stroke, nanometer positioning precision and plane three-degree-of-freedom (X, Y, θZ) motion ability in a compact structure, and perfectly meet the strict requirements of inkjet printing equipment on large stroke and high-precision positioning.

[0036] Finally, it should be pointed out that: the above-mentioned is only the preferred example of the present application, and is not used to limit the present application, although the present application has been described in detail with reference to the foregoing embodiments, for those skilled in the art, the technical solutions recorded in the foregoing embodiments can still be modified, or some technical features can be replaced. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the protection scope of the present application.

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: The Y-axis driving mechanism (3) and two X-axis driving mechanisms (4) are further included, the driving directions of the two X-axis driving mechanisms (4) are the same, the Y-axis driving mechanism (3) is arranged perpendicularly to the driving directions of the X-axis driving mechanisms (4), the Y-axis driving mechanism (3) and the X-axis driving mechanisms (4) are the same in structure and each include a bridge type 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 on the inner side of the bridge type displacement amplification structure (5), one side of the bridge type displacement amplification structure (5) is connected with the mounting frame (2), and the other side thereof is connected with the first flexible guide structure (7), one side of the first decoupling structure (8) is connected with one side of the moving table (1), and the other side thereof is connected with the side of the first flexible guide structure (7) away from the bridge type displacement amplification structure (5), the first flexible guide structure (7) and the second flexible guide structure (9) are each installed on the mounting frame (2), the other side of the moving table (1) is connected with one side of the second decoupling structure (10), and the other side of the second decoupling structure (10) is connected with the second flexible guide structure (9).

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) includes rigid input blocks (501) and bridge type amplification output assemblies (502), the rigid input blocks (501) are provided with two and are symmetrically connected to the two sides of the piezoelectric ceramic actuator (6), the bridge type amplification output assemblies (502) are provided with two and are symmetrically arranged on the two sides of the piezoelectric ceramic actuator (6), each bridge type amplification output assembly (502) includes 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 thereof 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 included 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 the same in structure and each include a guide main body (701) and a double parallelogram flexible hinge structure (702), the double parallelogram flexible hinge structures (702) are provided with two and are symmetrically connected to the two sides of the guide main 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 with the guide main body (701), and the other side thereof is connected with one side of the second parallelogram flexible hinge structure (7022), the other side of the second parallelogram flexible hinge structure (7022) is connected with the mounting frame (2).

5. The three degree-of-freedom precision positioning platform based on inkjet printing according to claim 1, wherein: The first decoupling structure (8) and the second decoupling structure (10) are identical in structure and each include a rigid connecting strip (801) and two symmetrical semicircular flexible hinges (802) connected to the two sides of the rigid connecting strip (801).

6. The three degree of freedom precision positioning platform based on inkjet printing according to claim 5, characterized in that: The semicircular flexible hinge (802) is provided with a micro cavity (11) at one end away from the rigid connecting strip (801), and the micro cavity (11) is filled with silicone gel with a high damping coefficient.

7. The three degree of freedom precision positioning platform based on inkjet printing according to claim 6, characterized in that: The micro cavities (11) are arranged in a three-dimensional rectangular array, and two adjacent micro cavities (11) are connected through a micro channel (12) filled with silicone gel with a high damping coefficient, and the micro cavities (11) and the micro channels (12) form a cavity network, which is connected and communicated through a gel pouring port and an exhaust port.

8. 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), and 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 a first buffer pad (14) on both sides of the end close to the first flexible guide structure (7), and the second decoupling structure (10) is connected with a second buffer pad (15) on both sides of the end close to the second flexible guide structure (9).

9. 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 a second buffer pad (15) on one side away from the second decoupling structure (10), and the second buffer pad (15) is in movable abutment with the mounting rack (2).

10. A method of positioning based on the three-degree-of-freedom precision positioning platform based on inkjet printing according to any one of claims 1-9, characterized in that, The method comprises the following steps: S1, platform initialization and coordinate system establishment, comprising: S11, install the three-degree-of-freedom precision positioning platform on the moving base of the inkjet printing equipment, and ensure that the three-degree-of-freedom precision positioning platform is in a horizontal state; S12, establish a platform motion coordinate system: take two directions perpendicular to each other in the platform plane as the X-axis and the Y-axis, and take the direction perpendicular to the platform plane as the Z-axis, and take the rotation direction around the Z-axis as the θZ-axis; S13, set the initial voltage value of each piezoelectric ceramic actuator (6) as the voltage corresponding to zero displacement, and perform zero position calibration on each piezoelectric ceramic actuator (6); S2, positioning instruction receiving and motion decomposition, comprising: S21, receive a target position instruction, which includes an X-axis target displacement amount, a Y-axis target displacement amount, and a θZ-axis target deflection angle; S22, decompose the target position instruction into control signals for each drive mechanism: decompose the X-axis target displacement amount into synchronous drive signals for two X-axis drive mechanisms (4), decompose the Y-axis target displacement amount into a drive signal for the Y-axis drive mechanism (3), and decompose the θZ-axis target deflection angle into differential drive signals for two X-axis drive mechanisms (4); S3, drive signal output and displacement amplification, comprising: S31, apply drive voltages to corresponding piezoelectric ceramic actuators (6) according to the decomposed control signals; S32, each piezoelectric ceramic actuator (6) generates a micro displacement under the inverse piezoelectric effect, which is mechanically amplified through a corresponding bridge-type displacement amplification structure (5). 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 mutual crosstalk between each axial movement is isolated through the first decoupling structure (8) and the second decoupling structure (10); S4, pose adjustment, comprising: S41, the moving table (1) is driven by the Y-axis driving mechanism (3) and the two X-axis driving mechanisms (4) to realize X-axis linear motion, Y-axis linear motion or XY-axis compound motion in the plane; S42, differential displacement is generated by controlling the two X-axis driving mechanisms (4) to make the moving table (1) produce θZ 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 degrees of freedom precision positioning platform to obtain actual position information; S52, the actual position information is compared with the target position information to obtain position deviation information; S53, the driving voltage of each piezoelectric ceramic actuator (6) is adjusted in real time based on the position deviation information until the position deviation information is less than a preset tolerance threshold; S54, when the moving table (1) moves to the target position, the driving voltage is locked to maintain the pose of the moving table (1).

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