Space orthogonal pressure-torsion coupling flexible piezoelectric stick-slip driver and driving method thereof

Abstract

The invention provides a spatial orthogonal pressure-torsion coupling flexible piezoelectric stick-slip driver and a driving method thereof. The spatial orthogonal pressure-torsion coupling flexible piezoelectric stick-slip driver comprises a fixed base; the stator comprises a piezoelectric stack and a flexible driving assembly, and the flexible driving assembly comprises a first hinge, a second hinge and a third hinge; the rotor comprises a fixed guide rail and a movable guide rail. Precise driving of the mover is achieved through the contact effect between the piezoelectric stack and the flexible driving assembly, and in the lifting process of the piezoelectric stack, based on the mutual matching linkage effect among the first hinge, the second hinge and the third hinge which are of special structures, the piezoelectric stack is driven to move up and down. The effect of efficiently converting the strain of the piezoelectric stack in the height direction into horizontal lateral displacement output is achieved, so that the friction force between the stator and the rotor is accurately regulated and controlled in combination with the unique characteristics of pressure-torsion coupling; and therefore, the structure is ingenious, the controllability is high, the response speed is high, the driving process is precise, the application range is wide, and the like.

Description

Technical Field

[0001] The present invention relates to the field of micro-nano precision driving and positioning technology, and in particular to a spatial orthogonal pressure-torsion coupling flexible piezoelectric stick-slip driver and a driving method thereof. Background Art

[0002] As an important form of piezoelectric drive technology, piezoelectric stick-slip actuators rely on the inverse piezoelectric effect of piezoelectric materials and exhibit excellent performance characteristics, including high positioning accuracy, fast response time, sub-nanometer resolution, and strong driving force output capabilities. These characteristics make it play an indispensable role in cutting-edge technology fields such as scanning probe microscopy, micro-nanorobotics technology, adaptive optical systems, and micro-nano measurement platforms. The design of piezoelectric actuators is flexible and diverse, covering a variety of types such as direct drive, inertial drive, and inchworm type. Piezoelectric stick-slip actuators stand out among many types for their relatively simple structural design, convenient operation, and stable output performance.

[0003] The piezoelectric stick-slip drive mechanism uses a sawtooth excitation electrical signal to excite the piezoelectric element. This excitation method enables the stator to produce fast and slow alternating motion deformations, thereby carefully regulating the conversion between the "adhesion" and "sliding" motion modes of the stator and the mover. In this process, the clever use of friction is the key to achieving precise output of the mechanical motion of the mover. However, a major challenge faced by existing piezoelectric stick-slip drives in the "sliding" stage is the large friction force, which not only causes the mechanism to retreat, but also limits the increase in drive speed, making it difficult to quickly reach the ideal performance in high-speed driving. Summary of the invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the problem of easy retreat of the piezoelectric stick-slip actuator in the prior art, and to provide a spatial orthogonal pressure-torsion coupled flexible piezoelectric stick-slip actuator and a driving method thereof.

[0005] In order to solve the above technical problems, the present invention provides a spatial orthogonal pressure-torsion coupled flexible piezoelectric stick-slip actuator, which includes: a fixed base; a stator, the stator includes a piezoelectric stack and a flexible driving component, wherein the piezoelectric stack is connected to the fixed base, and it is lifted and moved by driving an electrical signal, and the flexible driving component includes a first hinge, a second hinge and a third hinge, wherein the first hinge and the second hinge are symmetrically arranged with the piezoelectric stack as the center, and the first hinge and the second hinge are configured to be connected to the piezoelectric stack at both ends, and the middle part faces away from the The structure is protruding in the direction of the piezoelectric stack, and the third hinge includes a first connecting part and a second connecting part which are connected to each other, the first connecting part is connected to the first hinge, and the second connecting part is connected to the second hinge, and a driving foot is formed at the junction of the first connecting part and the second connecting part, and the driving foot moves along the first direction and / or the second direction through the piezoelectric stack; a mover, the mover includes a fixed guide rail and a movable guide rail, the fixed guide rail is connected to the fixed base, the movable guide rail can contact the driving foot and move along the second direction through the driving foot.

[0006] In one embodiment of the present invention, the radius of curvature of the curved surface where the first hinge is located is the same as the radius of curvature of the curved surface where the second hinge is located, and both are R; the spacing distance between the two ends of the first hinge in the third direction is the same as the spacing distance between the two ends of the first hinge in the third direction, and both are L; the axial stiffness distribution of the flexible drive component is ∝L / R, where 1<L / R<10.

[0007] In one embodiment of the present invention, the acute angle formed by the first connection portion and the second connection portion is α, and 30°<α<60°.

[0008] In one embodiment of the present invention, the thickness of the driving foot in the third direction is smaller than the thickness of the moving guide rail in the third direction, so as to increase the effective contact area between the driving foot and the mover.

[0009] In one embodiment of the present invention, the stator also includes a connecting component, which includes an assembly body, a preload gasket and an adjusting member. The assembly body is arranged at both ends of the piezoelectric stack, both ends of the first hinge and the second hinge are connected to the assembly body, the preload gasket is arranged between the piezoelectric stack and the assembly body, and the adjusting member is connected through the assembly body, the preload gasket and the piezoelectric stack to adjust the axial preload force of the piezoelectric stack.

[0010] In one embodiment of the present invention, the spatial orthogonal pressure-torsion coupled flexible piezoelectric stick-slip actuator also includes a pre-tensioning mechanism, which includes: a base, which is connected to the fixed base and has at least one adjustment rail provided thereon, and the at least one adjustment rail extends along a first direction; a mobile platform, which is slidably connected to the base and fixedly connected to the stator.

[0011] In one embodiment of the present invention, the pre-tightening mechanism also includes an adjusting screw rod and a fastening screw. The adjusting screw rod is arranged on the base and is threadedly connected to the mobile platform to adjust the relative position of the mobile platform and the base. The fastening screw can be passed through to fix the base and the mobile platform.

[0012] In one embodiment of the present invention, the fixed base includes a first mounting portion and a second mounting portion which are vertically connected to each other, wherein the first mounting portion extends in a horizontal direction and is connected to the stator, and the second mounting portion is arranged on one side of the first mounting portion, and its top includes a connecting table and an avoidance step, wherein the connecting table is detachably connected to the fixed guide rail, the avoidance step is recessed downward from the connecting table, and the movable guide rail moves above the avoidance step and is spaced apart from the avoidance step.

[0013] The present invention also provides a driving method for a spatial orthogonal pressure-torsion coupled flexible piezoelectric stick-slip actuator, which is used to perform a stick-slip driving process on the above-mentioned spatial orthogonal pressure-torsion coupled flexible piezoelectric stick-slip actuator, and comprises: step S1, assembling and connecting a stator and a mover so that the stator contacts the mover; step S2, inputting a uniformly increasing voltage signal to the piezoelectric stack so that the driving piezoelectric stack extends along its height direction, and at the same time, through a flexible driving component, converting the lifting and lowering movement trend of the piezoelectric stack into a horizontal movement trend of the driving foot along the surface of the mover to drive the mover to move; step S3, when the voltage signal reaches a maximum, causing the driving foot to contract until it is detached from the surface of the mover to inhibit the mover from retreating; step S4, inputting a uniformly decreasing voltage signal to the piezoelectric stack so that the piezoelectric stack returns to its initial position, and the driving foot contacts the surface of the mover again; step S5, repeating steps S3 to S4 to drive the mover to move continuously.

[0014] In one embodiment of the present invention, the voltage signal in step S2 to step S5 is a sawtooth waveform voltage signal, the voltage signal fluctuation period T is between 0.001 and 1.000 s, the voltage signal strength is between 60 and 120 V, and the sawtooth waveform voltage signal symmetry is between 50.00 and 99.99%.

[0015] The above technical solution of the present invention has the following advantages compared with the prior art: The spatial orthogonal pressure-torsion coupling flexible piezoelectric stick-slip actuator and its driving method described in the present invention realizes precise driving of the mover through the contact between the piezoelectric stack and the flexible driving component. During the lifting process of the piezoelectric stack, based on the mutual cooperation and linkage between the first hinge, the second hinge and the third hinge with a special structure, the strain of the piezoelectric stack in the height direction is efficiently converted into the horizontal lateral displacement output. The unique characteristics of the pressure-torsion coupling are combined to accurately control the friction between the stator and the mover, effectively eliminating the phenomenon of the mover's retreat movement. Compared with the conventional stick-slip actuator at this stage, the present application has the significant advantages of ingenious structure, high controllability, effective prevention of retreat, fast response speed, precise driving process and wide range of use, showing broad application potential and prospects in the fields of micro-nano precision driving and positioning such as aerospace, optical precision instruments, and semiconductor processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to make the contents of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings.

[0017] Figure 1 3D schematic diagram of the structure of a spatial orthogonal pressure-torsion coupled flexible piezoelectric stick-slip actuator in a preferred embodiment of the present invention; Figure 2 yes Figure 1 A schematic diagram of the three-dimensional structure of a fixed base in a spatial orthogonal pressure-torsion coupled flexible piezoelectric stick-slip actuator is shown; Figure 3 yes Figure 1 A schematic diagram of the three-dimensional structure of the preload mechanism in the spatial orthogonal pressure-torsion coupled flexible piezoelectric stick-slip actuator is shown; Figure 4 yes Figure 1 Schematic diagram of the three-dimensional structure of the stator in the spatial orthogonal pressure-torsion coupled flexible piezoelectric stick-slip actuator shown; Figure 5 yes Figure 4 A schematic diagram of the three-dimensional structure of the flexible drive assembly shown; Figure 6 yes Figure 1 Schematic diagram of the three-dimensional structure of the mover in the spatial orthogonal pressure-torsion coupled flexible piezoelectric stick-slip actuator; Figure 7 It is a schematic diagram of the structure and the change process of the electrical signal waveform of the driving method of the spatial orthogonal pressure-torsion coupling flexible piezoelectric stick-slip actuator in the initial state in another embodiment of the present invention; Figure 8 yes Figure 7 The schematic diagram of the structure and the change process of the electrical signal waveform of the driving method of the spatial orthogonal pressure-torsion coupling flexible piezoelectric stick-slip actuator during the process of inputting a uniformly increasing voltage signal; Fig. 9 yes Figure 7 The schematic diagram of the change process of the structure and the electrical signal waveform of the driving method of the spatial orthogonal pressure-torsion coupling flexible piezoelectric stick-slip actuator when the voltage signal reaches the maximum; Fig.10 yes Figure 7 The schematic diagram of the structure and electrical signal waveform change process of the spatial orthogonal pressure-torsion coupled flexible piezoelectric stick-slip actuator driving method during the input of a uniformly decreasing voltage signal is shown.

[0018] Description of the accompanying drawings in the specification: 100, fixed base; 110, first mounting portion; 120, second mounting portion; 121, connecting table; 122, avoidance step; 200, pre-tightening mechanism; 210, base; 211, adjustment guide rail; 220, moving platform; 230, adjustment screw rod; 240, fastening screw; 300, stator; 310, flexible drive assembly; 311, first hinge; 312, second hinge ; 313, third hinge; 3131, first connecting part; 3132, second connecting part; 320, piezoelectric stack; 330, connecting assembly; 331, preload gasket; 332, adjusting member; 333, assembly body; 340, mounting plate; 400, mover; 410, fixed guide rail; 420, movable guide rail; 430, retaining frame; 440, limit member; X, first direction; Y, second direction; Z, third direction. DETAILED DESCRIPTION

[0019] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention. Embodiment 1

[0020] See also Figure 1As shown, the present embodiment provides a spatial orthogonal pressure-torsion coupled flexible piezoelectric stick-slip actuator, which includes: a fixed base 100; a stator 300, wherein the stator 300 includes a piezoelectric stack 320 and a flexible driving component 310, wherein the piezoelectric stack 320 is connected to the fixed base 100, and is lifted and moved by a driving electrical signal, and the flexible driving component 310 includes a first hinge 311, a second hinge 312 and a third hinge 313, wherein the first hinge 311 and the second hinge 312 are symmetrically arranged with the piezoelectric stack 320 as the center, and the first hinge 311 and the second hinge 312 are both configured to be connected to the piezoelectric stack 320 at both ends, and the middle part faces away from the piezoelectric stack 320. The protruding structure, the third hinge 313 includes a first connecting part 3131 and a second connecting part 3132 which are connected to each other, the first connecting part 3131 is connected to the first hinge 311, the second connecting part 3132 is connected to the second hinge 312, and the junction of the first connecting part 3131 and the second connecting part 3132 forms a driving foot, and the driving foot moves along the first direction X and / or the second direction Y through the piezoelectric stack 320; the mover 400, the mover 400 includes a fixed guide rail 410 and a movable guide rail 420, the fixed guide rail 410 is connected to the fixed base 100, the movable guide rail 420 can contact the driving foot and move along the second direction Y through the driving foot.

[0021] The spatial orthogonal pressure-torsion coupled flexible piezoelectric stick-slip actuator described in this embodiment realizes precise driving of the mover 400 through the contact between the piezoelectric stack 320 and the flexible driving component 310. During the lifting and lowering process of the piezoelectric stack 320, based on the mutual coordination and linkage between the first hinge 311, the second hinge 312 and the third hinge 313 with a special structure, the strain of the piezoelectric stack 320 in the height direction is efficiently converted into a horizontal lateral displacement output. In this way, the friction between the stator 300 and the mover 400 is precisely controlled in combination with the unique characteristics of the pressure-torsion coupling, thereby effectively eliminating the retreat movement phenomenon of the mover 400.

[0022] It should be noted that, for the sake of ease of expression, this embodiment defines the arrangement direction of the stator 300 and the mover 400 in the spatial orthogonal pressure-torsion coupled flexible piezoelectric stick-slip actuator as a first direction X, the moving direction of the mover 400 is defined as a second direction Y, and the height direction of the orthogonal pressure-torsion coupled flexible piezoelectric stick-slip actuator is defined as a third direction Z, wherein the first direction X, the second direction Y and the third direction Z are arranged perpendicular to each other in pairs, and the first direction X and the second direction Y are located in the same plane.

[0023] See also Figure 1 and Figure 2As shown, in this embodiment, the fixed base 100 is used to provide an installation and connection platform for other structures, and specifically includes a first installation portion 110 and a second installation portion 120 that are vertically connected to each other, wherein the first installation portion 110 extends in a horizontal direction and is connected to the stator 300, and the second installation portion 120 is arranged on one side of the first installation portion 110, and its top includes a connecting table 121 and an avoidance step 122, wherein the connecting table 121 is detachably connected to the fixed guide rail 410, and the avoidance step 122 is recessed downward by the connecting table 121, and the movable guide rail 420 moves above the avoidance step 122 and is spaced apart from the avoidance step 122, thereby ensuring that the mover 400 is connected and fixed while avoiding the second installation portion 120 causing friction interference to the movement process of the movable guide rail 420.

[0024] See also Figure 3 As shown, in order to achieve the adjustment of the preload force between the stator 300 and the mover 400, the spatial orthogonal compression-torsion coupled flexible piezoelectric stick-slip actuator in this embodiment also includes a preload mechanism 200. The operator can change the specific position of the stator 300 on the first mounting portion 110 through the preload mechanism 200. The preload mechanism 200 specifically includes: a base 210, the base 210 is connected to the fixed base 100, and at least one adjustment guide rail 211 is provided thereon, and the at least one adjustment guide rail 211 extends along the first direction X; a mobile platform 220, the mobile platform 220 is slidably connected to the base 210, and is fixedly connected to the stator 300.

[0025] Furthermore, the base 210 in this embodiment is used to realize the connection between the preload mechanism 200 and the fixed base 100, and is provided with four adjustment rails 211 arranged at intervals along the second direction Y, and any adjustment rail 211 extends along the first direction X, so that the mobile platform 220 can adjust its specific fixed position along the second direction Y. The mobile platform 220 is used to realize the fixed connection between it and the stator 300, so that it can drive the stator 300 to move along the first direction X, so as to achieve the purpose of adjusting the initial contact pressure between it and the mover 400. In different embodiments, the specific type, quantity and installation position of the adjustment rail 211 can be adaptively adjusted according to actual use requirements, and the present invention does not impose specific restrictions on this.

[0026] Furthermore, the pre-tightening mechanism 200 further includes an adjusting screw rod 230 and a fastening screw 240, wherein the adjusting screw rod 230 is disposed on the base 210 and is threadedly connected to the mobile platform 220 to adjust the relative position of the mobile platform 220 and the base 210, and the fastening screw 240 can be passed through to fix the base 210 and the mobile platform 220. The adjusting screw rod 230 is used for the operator to adjust the mobile platform 220, and the fastening screw 240 is used to fix the position of the mobile platform 220 after adjustment.

[0027] See also Figure 4 and Figure 5 As shown, in this embodiment, the piezoelectric stack is a cubic structure as a whole, and the first hinge 311 and the second hinge 312 are respectively connected to the diagonal edges of the piezoelectric stack. Further, a symmetrical spatial hexagonal prism structure can be formed between the first hinge 311 and the second hinge 312 in this embodiment, and its substrate is preferably an aluminum alloy material. Specifically, the radius of curvature of the curved surface where the first hinge 311 in this embodiment is located is the same as the radius of curvature of the curved surface where the second hinge 312 is located, and both are R; the spacing distance between the two ends of the first hinge 311 in the third direction Z is the same as the spacing distance between the two ends of the first hinge 311 in the third direction Z, and both are L; the axial stiffness distribution of the flexible drive component 310 is ∝L / R, where 1<L / R<10. It should be noted that the radius of curvature is a key parameter in the axial stiffness of the flexible hinge. A smaller radius of curvature will result in a higher local stiffness, while a larger radius of curvature will reduce the stiffness. In this embodiment, when R increases relative to L, the overall stiffness of the corresponding hinge will decrease, which will result in a more uniform distribution of axial stiffness, but the overall axial stiffness will decrease. On the contrary, when R decreases relative to L, the overall stiffness of the corresponding hinge will increase, which may result in an uneven distribution of axial stiffness, but the driving foot will have a higher stiffness, thereby inducing a horizontal lateral displacement at the driving foot end, thereby achieving the purpose of dynamically adjusting the positive pressure of the contact between the stator 300 and the mover 400. Specifically, the ratio of R to any hinge thickness in this embodiment is limited to 0.02~0.90, thereby achieving better stiffness control.

[0028] Based on the above structure, the third hinge 313 in this embodiment is preferably a "human" shaped structure, which includes a relatively short first connection part 3131 and a relatively long second connection part 3132, and the first connection part 3131 and the second connection part 3132 are mutually orthogonal structures in space. It can use the compression-torsion coupling characteristics to realize the spatial deformation of the third hinge 313, so that it produces lateral displacement, thereby increasing the friction driving force during the slow deformation driving stage and reducing the friction resistance during the fast deformation driving stage, thereby achieving comprehensive regulation of the friction force. Specifically, in this embodiment, the acute angle formed by the first connection part 3131 and the second connection part 3132 is α, and 30°<α<60°, so that the actual strain of the driving foot can be changed by adjusting the angle range, thereby achieving different effects of suppressing retreat.

[0029] Further, in order to increase the effective contact area between the driving foot and the mover 400, the thickness of the driving foot in the third direction Z in this embodiment is less than the thickness of the moving guide rail 420 in the third direction Z. Specifically, the thickness of the driving foot in the third direction Z in this embodiment is 7 mm, and the thickness of the moving guide rail 420 in the third direction Z is 8 mm. In addition, the surface of the driving foot is coated with a ceramic or glass fiber friction material layer to improve its friction driving effect.

[0030] Furthermore, the stator 300 in this embodiment further includes a connecting assembly 330, which includes an assembly body 333, a preload washer 331 and an adjusting member 332. The assembly body 333 is disposed at both ends of the piezoelectric stack 320, both ends of the first hinge 311 and the second hinge 312 are connected to the assembly body 333, the preload washer 331 is disposed between the piezoelectric stack 320 and the assembly body 333, and the adjusting member 332 is connected through the assembly body 333, the preload washer 331 and the piezoelectric stack 320 to adjust the axial preload force of the piezoelectric stack 320. In addition, the stator 300 further includes a mounting plate 340, which is detachably connected to the mobile platform 220 through bolts and other connecting members, and the flexible drive assembly 310, the piezoelectric stack 320 and the connecting assembly 330 are all disposed on the mounting plate 340.

[0031] See also Figure 6 As shown, the mover 400 in this embodiment further includes a retainer 430 and a stopper 440, wherein the movable guide rail 420 is slidably connected to the fixed guide rail 410 through the retainer 430, and the stopper 440 is disposed at both ends of the movable guide rail 420 and the fixed guide rail 410 to limit the maximum moving distance of the movable guide rail 420. In addition, the outer surface of the movable guide rail 420 in this embodiment is also coated with a ceramic or glass fiber friction material. Embodiment 2

[0032] See also Figure 7 As shown, this embodiment provides a driving method of a spatial orthogonal pressure-torsion coupled flexible piezoelectric stick-slip actuator, which is used to perform a stick-slip driving process through the above-mentioned spatial orthogonal pressure-torsion coupled flexible piezoelectric stick-slip actuator, which can comprehensively control the friction between the stator 300 and the mover 400 under the excitation of the sawtooth voltage signal, thereby improving the mechanical output characteristics of the piezoelectric stick-slip actuator, specifically including: Step S1, assembling and connecting the stator 300 and the mover 400 so that the stator 300 is in contact with the mover 400; Step S2, input a uniformly increasing voltage signal to the piezoelectric stack 320, so that the piezoelectric stack 320 is driven to extend along its height direction, and at the same time, the lifting movement trend of the piezoelectric stack 320 is converted into a horizontal movement trend of the driving foot along the surface of the mover 400 through the flexible driving component 310, so as to drive the mover 400 to move; further, see Figure 7 and Figure 8 As shown, step S2 is represented by t 0 ~t 1 The change process within the time period, at this time, the piezoelectric stack 320 gradually extends along its height direction under the driving action of the voltage signal to promote the flexible driving component 310 to amplify the displacement and transform the direction of the force. Specifically, during the process, the contact positive pressure between the stator 300 and the mover 400 gradually increases, and the friction driving force between the two gradually increases, thereby prompting the movable guide rail 420 to move slightly along the second direction Y under the action of the static friction force.

[0033] Step S3: when the voltage signal reaches the maximum, the driving foot is contracted until it is separated from the surface of the mover 400 to inhibit the mover 400 from retreating; further, see Fig. 9 As shown, t 1 The voltage signal at the moment reaches the highest peak value. At this time, the driving foot can be retracted and separated from the surface of the mover 400 while maintaining the continued movement of the movable guide rail 420 by means of the compression-torsion coupling principle and the precise control of the preload force, thereby effectively reducing the contact area and contact time between the stator 300 and the mover 400, thereby reducing the friction resistance between the two during the rapid deformation driving stage, and effectively suppressing the retreat movement.

[0034] Step S4, input a uniformly decreasing voltage signal to the piezoelectric stack 320, so that the piezoelectric stack 320 returns to its initial position, and the driving foot contacts the surface of the mover 400 again; further, see Fig.10 As shown, at t 1 to 2During the time period, the piezoelectric stack 320 contracts rapidly, and each structure in the stator 300 quickly resets to an initial state, thus completing a driving process.

[0035] Step S5, repeating steps S3 to S4 to drive the mover 400 to move continuously.

[0036] In summary, the contact between the electric stack and the flexible drive assembly 310 realizes the precise driving of the mover 400. During the lifting process of the piezoelectric stack 320, based on the mutual cooperation and linkage between the first hinge 311, the second hinge 312 and the third hinge 313 with a special structure, the strain of the piezoelectric stack 320 in the height direction is efficiently converted into the horizontal lateral displacement output. The unique characteristics of the compression-torsion coupling are combined to precisely control the friction between the stator 300 and the mover 400, effectively eliminating the retreat movement of the mover 400. Compared with the conventional stick-slip actuator at this stage, the present application has the significant advantages of ingenious structure, high controllability, effective prevention of retreat, fast response speed, precise driving process and wide range of use.

[0037] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A spatial orthogonal pressure-torsion coupled flexible piezoelectric stick-slip actuator, characterized in that: include: Fixed base; A stator, the stator comprising a piezoelectric stack and a flexible driving component, wherein the piezoelectric stack is connected to the fixed base and moves up and down by driving an electrical signal, the flexible driving component comprising a first hinge, a second hinge and a third hinge, wherein the first hinge and the second hinge are symmetrically arranged with the piezoelectric stack as the center, the first hinge and the second hinge are both configured as structures with two ends connected to the piezoelectric stack and a middle portion protruding in a direction away from the piezoelectric stack, the third hinge comprises a first connecting portion and a second connecting portion connected to each other, the first connecting portion is connected to the first hinge, the second connecting portion is connected to the second hinge, the junction of the first connecting portion and the second connecting portion forms a driving foot, and the driving foot moves along the first direction and / or the second direction through the piezoelectric stack; The mover comprises a fixed guide rail and a movable guide rail, wherein the fixed guide rail is connected to the fixed base, and the movable guide rail can contact the driving foot and move along the second direction through the driving foot.

2. The spatial orthogonal pressure-torsion coupled flexible piezoelectric stick-slip actuator according to claim 1, characterized in that: The radius of curvature of the curved surface where the first hinge is located is the same as the radius of curvature of the curved surface where the second hinge is located, and both are R; the spacing distance between the two ends of the first hinge in the third direction is the same as the spacing distance between the two ends of the first hinge in the third direction, and both are L; the axial stiffness distribution of the flexible drive component is ∝L / R, where 1<L / R<10.

3. The spatial orthogonal pressure-torsion coupled flexible piezoelectric stick-slip actuator according to claim 1, characterized in that: The acute angle formed by the first connection portion and the second connection portion is α, and 30°<α<60°.

4. The spatial orthogonal pressure-torsion coupled flexible piezoelectric stick-slip actuator according to claim 1, characterized in that: The thickness of the driving foot in the third direction is smaller than the thickness of the moving guide rail in the third direction, so as to increase the effective contact area between the driving foot and the mover.

5. The spatial orthogonal pressure-torsion coupled flexible piezoelectric stick-slip actuator according to claim 1, characterized in that: The stator also includes a connecting component, which includes an assembly body, a preload washer and an adjusting member. The assembly body is arranged at both ends of the piezoelectric stack, both ends of the first hinge and the second hinge are connected to the assembly body, the preload washer is arranged between the piezoelectric stack and the assembly body, and the adjusting member is connected through the assembly body, the preload washer and the piezoelectric stack to adjust the axial preload force of the piezoelectric stack.

6. The spatial orthogonal pressure-torsion coupled flexible piezoelectric stick-slip actuator according to claim 1, characterized in that: The spatial orthogonal pressure-torsion coupling flexible piezoelectric stick-slip actuator further includes a pre-tightening mechanism, and the pre-tightening mechanism includes: A base, the base is connected to the fixed base and is provided with at least one adjustment rail, the at least one adjustment rail extending along a first direction; A mobile platform is slidably connected to the base and fixedly connected to the stator.

7. The spatial orthogonal pressure-torsion coupled flexible piezoelectric stick-slip actuator according to claim 6, characterized in that: The pre-tightening mechanism also includes an adjusting screw rod and a fastening screw. The adjusting screw rod is arranged on the base and is threadedly connected to the mobile platform to adjust the relative position of the mobile platform and the base. The fastening screw can be passed through and fixed to the base and the mobile platform.

8. The spatial orthogonal pressure-torsion coupled flexible piezoelectric stick-slip actuator according to claim 1, characterized in that: The fixed base includes a first mounting portion and a second mounting portion which are vertically connected to each other, wherein the first mounting portion extends in a horizontal direction and is connected to the stator, and the second mounting portion is arranged on one side of the first mounting portion, and its top includes a connecting table and an avoidance step, wherein the connecting table is detachably connected to the fixed guide rail, the avoidance step is recessed downward from the connecting table, and the movable guide rail moves above the avoidance step and is spaced apart from the avoidance step.

9. A driving method of a spatial orthogonal pressure-torsion coupled flexible piezoelectric stick-slip actuator, characterized in that: The method is used to perform a stick-slip driving process through the spatial orthogonal pressure-torsion coupled flexible piezoelectric stick-slip actuator according to any one of claims 1 to 8, comprising: Step S1, assembling and connecting the stator and the mover so that the stator is in contact with the mover; Step S2, inputting a uniformly increasing voltage signal to the piezoelectric stack to drive the piezoelectric stack to extend in its height direction, and at the same time converting the lifting movement trend of the piezoelectric stack into a horizontal movement trend of the driving foot along the surface of the mover through the flexible driving component to drive the mover to move; Step S3, when the voltage signal reaches a maximum, the driving foot is contracted until it is separated from the surface of the mover to inhibit the mover from retreating; Step S4, inputting a uniformly decreasing voltage signal to the piezoelectric stack, so that the piezoelectric stack returns to an initial position, and the driving foot contacts the surface of the mover again; Step S5, repeating steps S3 to S4 to drive the mover to move continuously.

10. The driving method of the spatial orthogonal pressure-torsion coupled flexible piezoelectric stick-slip actuator according to claim 9, characterized in that: The voltage signal in step S2 to step S5 is a sawtooth waveform voltage signal, the voltage signal fluctuation period T is between 0.001 and 1.000 s, the voltage signal strength is between 60 and 120 V, and the sawtooth waveform voltage signal symmetry is between 50.00 and 99.99%.

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