Five-degree-of-freedom piezoelectric actuator and multi-axis motion decoupling excitation method thereof

Abstract

The invention discloses a five-degree-of-freedom piezoelectric actuator and a multi-axis motion decoupling excitation method thereof, belongs to the technical field of piezoelectric driving, and particularly relates to the five-degree-of-freedom piezoelectric actuator and the multi-axis motion decoupling excitation method thereof. The problems that an existing piezoelectric actuator is difficult to generate completely-decoupled multi-axis pure translation or rotation motion at the same time, and the flexibility requirements in the fields of microoperation, active optical regulation and control and the like cannot be met are solved. The piezoelectric actuator comprises an upper piezoelectric actuating module, a middle piezoelectric actuating module and a lower piezoelectric actuating module and is used for outputting five-degree-of-freedom decoupling motion on the top end face of the piezoelectric actuator in a motion coupling compensation mode. The five-degree-of-freedom piezoelectric actuator and the multi-axis motion decoupling excitation method thereof are suitable for simultaneously generating completely decoupled five-degree-of-freedom multi-axis pure translation or rotation motion, and can be applied to the fields of microoperation, active optical regulation and control and the like.

Description

Technical Field

[0001] The present invention relates to the field of piezoelectric drive technology, and in particular to a five-degree-of-freedom piezoelectric actuator and a multi-axis motion decoupling excitation method thereof. Background Art

[0002] Piezoelectric drive is an advanced actuation technology that uses the inverse piezoelectric effect of functional materials to convert electrical energy into mechanical energy. It has outstanding advantages such as fast response speed, high motion precision, and no electromagnetic interference. It has gradually been widely used in semiconductor manufacturing, robotics, optics, micro-nano detection, and precision operations.

[0003] Piezoelectric actuators are the core technology carriers for implementing piezoelectric drive technology. Common typical solutions include piezoelectric stack drivers, piezoelectric dual-crystal drivers, and piezoelectric tube drivers. Among them, using the bending of the body to achieve motion output is a typical method. For example, the piezoelectric dual-crystal driver uses piezoelectric elements and elastic bodies to form a composite structure, and uses the expansion and contraction deformation of the piezoelectric elements under the stimulation of external electrical signals to cause overall bending movement; the piezoelectric tube generates bending movement through partitioned polarization processing and reverse excitation in different areas.

[0004] However, when actuators such as piezoelectric bimorphs and piezoelectric tubes are bent, the movement of their free output ends includes both translational and rotational motions, and complete decoupling of translational or rotational motions cannot be achieved.

[0005] Completely decoupled translational and rotational motions can be used in fields such as micro-manipulation and active optical control because of their independence of motion and operation. However, currently commonly used piezoelectric actuators are difficult to simultaneously produce fully decoupled multi-axis pure translational or rotational motions, and cannot meet the flexibility requirements of these fields.

[0006] In summary, how to improve and innovate the existing driver body and excitation method to generate multi-axis decoupled translation or rotation motion is one of the technical problems that urgently need to be solved in the field of piezoelectric drive technology. Summary of the invention

[0007] The present invention proposes a five-degree-of-freedom piezoelectric actuator and a multi-axis motion decoupling excitation method thereof, which solves the problem that existing piezoelectric drivers are difficult to simultaneously generate fully decoupled multi-axis pure translation or rotational motion and cannot meet the flexibility requirements in the fields of micro-manipulation, active optical control, etc.

[0008] The five-degree-of-freedom piezoelectric actuator described in the present invention has the following technical solution:

[0009] The piezoelectric actuator comprises an upper piezoelectric actuation module, a middle piezoelectric actuation module and a lower piezoelectric actuation module;

[0010] The bottom end of the upper piezoelectric actuation module is fixedly connected to the top end of the middle piezoelectric actuation module;

[0011] The bottom end of the middle piezoelectric actuation module is fixedly connected to the top end of the lower piezoelectric actuation module;

[0012] The upper piezoelectric actuator module is used to independently generate bending motion along the X-axis direction or the Y-axis direction under the stimulation of an electrical signal;

[0013] The intermediate piezoelectric actuator module is used to independently generate telescopic motion along the Z-axis direction under the stimulation of an electrical signal;

[0014] The lower piezoelectric actuator module is used to independently generate bending motion along the X-axis direction or the Y-axis direction under the stimulation of an electrical signal;

[0015] The upper piezoelectric actuation module, the middle piezoelectric actuation module and the lower piezoelectric actuation module are used to output five-degree-of-freedom decoupled motion on the top surface of the piezoelectric actuator by means of motion coupling compensation;

[0016] The five-degree-of-freedom decoupling motion includes linear decoupling motion along the X-axis direction, linear decoupling motion along the Y-axis direction, linear decoupling motion along the Z-axis direction, rotational decoupling motion around the X-axis direction, and rotational decoupling motion around the Y-axis direction.

[0017] Furthermore, a preferred embodiment is provided in which the horizontal cross-sectional outer contours of the upper piezoelectric actuating module, the middle piezoelectric actuating module and the lower piezoelectric actuating module are of the same shape and their edges are aligned.

[0018] Furthermore, a preferred embodiment is provided, in which the outer contours of the horizontal cross sections of the upper piezoelectric actuation module, the middle piezoelectric actuation module and the lower piezoelectric actuation module are circular or polygonal.

[0019] Furthermore, a preferred embodiment is provided, wherein any one of the upper piezoelectric actuation module, the middle piezoelectric actuation module and the lower piezoelectric actuation module is a hollow structure.

[0020] Further, a preferred embodiment is provided, wherein the upper piezoelectric actuation module comprises a first upper piezoelectric actuation unit, a second upper piezoelectric actuation unit, a third upper piezoelectric actuation unit and a fourth upper piezoelectric actuation unit, the four being evenly distributed along the circumferential direction and fixedly connected in an end-to-end manner;

[0021] The intermediate piezoelectric actuation module is an integrated piezoelectric actuation unit;

[0022] The lower piezoelectric actuation module includes a first lower piezoelectric actuation unit, a second lower piezoelectric actuation unit, a third lower piezoelectric actuation unit and a fourth lower piezoelectric actuation unit, which are evenly distributed along the circumferential direction and fixedly connected in an end-to-end manner.

[0023] Further, a preferred embodiment is provided, wherein the first upper piezoelectric actuation unit, the second upper piezoelectric actuation unit, the third upper piezoelectric actuation unit and the fourth upper piezoelectric actuation unit are respectively used to independently generate telescopic or bending deformation under the stimulation of an electrical signal, so that the upper piezoelectric actuation module generates a bending motion along the X-axis direction or the Y-axis direction;

[0024] The first lower piezoelectric actuating unit, the second lower piezoelectric actuating unit, the third lower piezoelectric actuating unit and the fourth lower piezoelectric actuating unit are respectively used to independently generate telescopic or bending deformation under the stimulation of electrical signals, so that the lower piezoelectric actuating module generates bending movement along the X-axis direction or the Y-axis direction.

[0025] Furthermore, a preferred embodiment is provided, wherein the upper piezoelectric actuating unit No. 1, the upper piezoelectric actuating unit No. 2, the upper piezoelectric actuating unit No. 3, the upper piezoelectric actuating unit No. 4, the lower piezoelectric actuating unit No. 1, the lower piezoelectric actuating unit No. 2, the lower piezoelectric actuating unit No. 3, the lower piezoelectric actuating unit No. 4 and the intermediate piezoelectric actuating module are structures containing materials with piezoelectric properties.

[0026] The present invention also proposes a multi-axis motion decoupling excitation method for a five-degree-of-freedom piezoelectric actuator, and its technical solution is as follows:

[0027] The method is used to excite the above-mentioned five-degree-of-freedom piezoelectric actuator; the method comprises:

[0028] Steps to achieve linear decoupled motion along the X-axis:

[0029] The upper piezoelectric actuation module, the middle piezoelectric actuation module and the lower piezoelectric actuation module are simultaneously stimulated by multiple electrical signals, so that the upper piezoelectric actuation module and the lower piezoelectric actuation module respectively generate bending motions in opposite directions along the X-axis direction, and the middle piezoelectric actuation module generates telescopic motions along the Z-axis direction;

[0030] Through the bending movement of the upper piezoelectric actuator module and the telescopic movement of the middle piezoelectric actuator module, the deflection angle and Z-direction displacement caused by the bending movement of the lower piezoelectric actuator module are coupled and compensated.

[0031] The end surface produces linear decoupled motion along the X-axis direction;

[0032] Steps to achieve linear decoupled motion along the Y axis:

[0033] The upper piezoelectric actuation module, the middle piezoelectric actuation module and the lower piezoelectric actuation module are simultaneously stimulated by using multiple electrical signals, so that the upper piezoelectric actuation module and the lower piezoelectric actuation module respectively generate bending motions in opposite directions along the Y-axis direction, and the middle piezoelectric actuation module generates telescopic motions along the Z-axis direction;

[0034] Through the bending movement of the upper piezoelectric actuator module and the telescopic movement of the middle piezoelectric actuator module, the deflection angle and Z-direction displacement caused by the bending movement of the lower piezoelectric actuator module are coupled and compensated.

[0035] The top surface produces a linear decoupled motion along the Y-axis direction;

[0036] Steps to achieve linear decoupled motion along the Z axis:

[0037] The upper piezoelectric actuator module, the middle piezoelectric actuator module and the lower piezoelectric actuator module are stimulated simultaneously or separately by multiple electrical signals, so that the upper piezoelectric actuator module, the middle piezoelectric actuator module and the lower piezoelectric actuator module respectively produce telescopic motion along the Z-axis direction, and a linear decoupling along the Z-axis direction is produced on the top surface of the piezoelectric actuator.

[0038] sports;

[0039] Steps to achieve rotational decoupling motion around the Y axis:

[0040] The upper piezoelectric actuation module, the middle piezoelectric actuation module and the lower piezoelectric actuation module are simultaneously stimulated by multiple electrical signals, so that the upper piezoelectric actuation module and the lower piezoelectric actuation module respectively generate bending motions in opposite directions along the X-axis direction, and the bending amplitude generated by the upper piezoelectric actuation module is larger, so that the middle piezoelectric actuation module generates telescopic motions along the Z-axis direction;

[0041] Through the bending movement of the upper piezoelectric actuator module and the telescopic movement of the middle piezoelectric actuator module, the X-direction displacement and Z-direction displacement caused by the bending movement of the lower piezoelectric actuator module are coupled and compensated.

[0042] The top surface produces a rotational decoupled motion around the Y-axis;

[0043] Steps to achieve rotational decoupling motion around the X-axis:

[0044] The upper piezoelectric actuation module, the middle piezoelectric actuation module and the lower piezoelectric actuation module are simultaneously stimulated by multiple electrical signals, so that the upper piezoelectric actuation module and the lower piezoelectric actuation module respectively generate bending motions in opposite directions along the Y-axis direction, and the bending amplitude generated by the upper piezoelectric actuation module is larger, so that the middle piezoelectric actuation module generates telescopic motions along the Z-axis direction;

[0045] Through the bending movement of the upper piezoelectric actuator module and the telescopic movement of the middle piezoelectric actuator module, the Y-direction displacement and the Z-direction displacement caused by the bending movement of the lower piezoelectric actuator module are coupled and compensated, and a rotational decoupling movement around the X-axis direction is generated on the top surface of the piezoelectric actuator.

[0046] Furthermore, a preferred embodiment is provided, in which the timing of the multiple electrical signals for stimulating the upper piezoelectric actuation module, the middle piezoelectric actuation module and the lower piezoelectric actuation module is kept synchronous and the amplitude is kept in a given proportional relationship.

[0047] Furthermore, a preferred embodiment is provided, in which the multi-channel electrical signals used to excite the upper piezoelectric actuation module, the middle piezoelectric actuation module and the lower piezoelectric actuation module are direct current, sinusoidal wave, square wave, triangle wave or other arbitrary waveform signals.

[0048] The present invention has the following beneficial effects:

[0049] 1. The five-degree-of-freedom piezoelectric actuator described in the present invention adopts a structural superposition combination of upper, middle and lower piezoelectric actuator modules. By designing the parameters such as the timing and amplitude of the electrical signals applied to the three piezoelectric actuator modules, the deformation actions of the three piezoelectric actuator modules are coordinated, so that the multi-axis linear and rotational coupled motion generated by the top surface of the piezoelectric actuator can be compensated, and finally pure linear or pure rotational motion is generated, thereby realizing the decoupled generation of multi-degree-of-freedom linear and rotational motion.

[0050] 2. Compared with typical actuator solutions such as traditional single-degree-of-freedom piezoelectric stacks and piezoelectric bicrystalline beams, the five-degree-of-freedom piezoelectric actuator proposed in the present invention has more degrees of freedom of movement and is more flexible in realizing multi-dimensional precision driving, positioning, operation and other applications.

[0051] The five-degree-of-freedom piezoelectric actuator and the multi-axis motion decoupling excitation method thereof described in the present invention are suitable for simultaneously generating fully decoupled five-degree-of-freedom multi-axis pure translation or rotation motion, and can be applied to the fields of micro-manipulation, active optical control, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0053] Figure 1 1 is a schematic diagram of a three-dimensional structure of a five-degree-of-freedom piezoelectric actuator when no motion is generated in one embodiment of the present invention;

[0054] Figure 2 It is a schematic structural diagram of the upper, middle and lower piezoelectric actuation modules in one embodiment of the present invention;

[0055] Figure 3 Schematic diagram of the coupled motion caused by the bending deformation of the lower piezoelectric actuator module along the X-axis direction in one embodiment of the present invention;

[0056] Figure 4 A schematic diagram of the coupled motion caused by the bending deformation of the lower piezoelectric actuator module along the Y-axis direction in one embodiment of the present invention;

[0057] Figure 5 A schematic diagram of the movement caused by the expansion and contraction deformation of the intermediate piezoelectric actuator module along the Z-axis direction in one embodiment of the present invention;

[0058] Figure 6 A schematic diagram of the coupled motion caused by the bending deformation of the upper piezoelectric actuator module along the X-axis direction in one embodiment of the present invention;

[0059] Figure 7 A schematic diagram of the coupled motion caused by the bending deformation of the upper piezoelectric actuator module along the Y-axis direction in one embodiment of the present invention;

[0060] Figure 8 A schematic diagram of the upper, middle and lower piezoelectric actuator modules coordinating to achieve linear decoupled motion in the X-axis direction in one embodiment of the present invention;

[0061] Fig. 9 A schematic diagram of the upper, middle and lower piezoelectric actuator modules coordinating to achieve linear decoupled motion in the Y-axis direction in one embodiment of the present invention;

[0062] Fig.10 A schematic diagram of the upper, middle and lower piezoelectric actuator modules coordinating to achieve linear decoupled motion in the Z-axis direction in one embodiment of the present invention;

[0063] Fig.11 A schematic diagram of the upper, middle and lower piezoelectric actuator modules coordinating to achieve rotational decoupling motion around the X-axis direction in one embodiment of the present invention;

[0064] Fig.12 A schematic diagram of the upper, middle and lower piezoelectric actuator modules coordinating to achieve rotational decoupling motion around the Y-axis direction in one embodiment of the present invention;

[0065] In the above drawings, the XYZ coordinate system is a spatial Cartesian coordinate system, the three coordinate axes are perpendicular to each other, the origin of the coordinate system is located at the center of the bottom end surface of the five-degree-of-freedom piezoelectric actuator, the X-axis coincides with the center line connecting the No. 1 and No. 3 lower piezoelectric actuator units in the lower piezoelectric actuator module, and the Y-axis coincides with the center line connecting the No. 2 and No. 4 lower piezoelectric actuator units in the lower piezoelectric actuator module;

[0066] Reference numerals:

[0067] 1. Upper piezoelectric actuation module; 2. Middle piezoelectric actuation module; 3. Lower piezoelectric actuation module; 1-1. Upper piezoelectric actuation unit No. 1; 1-2. Upper piezoelectric actuation unit No. 2; 1-3. Upper piezoelectric actuation unit No. 3; 1-4. Upper piezoelectric actuation unit No. 4; 3-1. Lower piezoelectric actuation unit No. 1; 3-2. Lower piezoelectric actuation unit No. 2; 3-3. Lower piezoelectric actuation unit No. 3; 3-4. Lower piezoelectric actuation unit No. 4. DETAILED DESCRIPTION

[0068] In order to make the technical solutions and advantages of the present invention more clearly described, the specific implementation methods of the present invention will be further described in detail and completely in conjunction with the accompanying drawings. The various implementation methods described below are only part of the preferred solutions of the present invention, rather than all implementation methods; the various implementation methods described below are intended to explain the present invention and cannot be understood as limitations on the present invention; the reasonable combination of technical features defined in the various implementation methods of the present invention, and all other implementation methods obtained by ordinary technicians in the field without creative work based on the implementation methods of the present invention, are within the scope of protection of the present invention.

[0069] One embodiment provides a five-degree-of-freedom piezoelectric actuator:

[0070] The piezoelectric actuator comprises an upper piezoelectric actuation module 1, a middle piezoelectric actuation module 2 and a lower piezoelectric actuation module 3;

[0071] The bottom end of the upper piezoelectric actuation module 1 is fixedly connected to the top end of the middle piezoelectric actuation module 2;

[0072] The bottom end of the middle piezoelectric actuation module 2 is fixedly connected to the top end of the lower piezoelectric actuation module 3;

[0073] The upper piezoelectric actuator module 1 is used to independently generate bending motion along the X-axis direction or the Y-axis direction under the stimulation of an electrical signal;

[0074] The intermediate piezoelectric actuator module 2 is used to independently generate telescopic movement along the Z-axis direction under the stimulation of an electrical signal;

[0075] The lower piezoelectric actuator module 3 is used to independently generate bending motion along the X-axis direction or the Y-axis direction under the stimulation of an electrical signal;

[0076] The upper piezoelectric actuation module 1, the middle piezoelectric actuation module 2 and the lower piezoelectric actuation module 3 are used to output five-degree-of-freedom decoupled motion on the top surface of the piezoelectric actuator by means of motion coupling compensation;

[0077] The five-degree-of-freedom decoupling motion includes linear decoupling motion along the X-axis direction, linear decoupling motion along the Y-axis direction, linear decoupling motion along the Z-axis direction, rotational decoupling motion around the X-axis direction, and rotational decoupling motion around the Y-axis direction.

[0078] In this embodiment, the Z-axis direction is a vertical direction.

[0079] In this embodiment, the X-axis direction and the Y-axis direction are two directions perpendicular to each other in the horizontal direction.

[0080] In this embodiment, the top surface of the upper piezoelectric actuator module is the top surface of the piezoelectric actuator.

[0081] In this embodiment, the upper piezoelectric actuation module, the middle piezoelectric actuation module and the lower piezoelectric actuation module are fixedly connected to each other by welding, bonding or threaded connection.

[0082] In this embodiment, relying on the integrated coordinated movement of the three piezoelectric actuator modules, the upper and middle piezoelectric actuator modules partially compensate for the linear and rotational coupled motion generated by the lower piezoelectric actuator module, and ultimately the entire piezoelectric actuator can produce completely decoupled five-degree-of-freedom motion, that is, pure multi-axis linear (along the X-axis, along the Y-axis, along the Z-axis) and multi-axis rotation (around the X-axis, around the Y-axis) motion.

[0083] In addition, in one embodiment, the upper piezoelectric actuating module 1 , the middle piezoelectric actuating module 2 , and the lower piezoelectric actuating module 3 have the same shape of their horizontal cross-section outer contours, and their edges are aligned.

[0084] In addition, in one embodiment, the horizontal cross-sectional outer contours of the upper piezoelectric actuating module 1 , the middle piezoelectric actuating module 2 , and the lower piezoelectric actuating module 3 are circular or polygonal.

[0085] In this implementation manner, the number of sides of the polygon is 3 to N.

[0086] In addition, in one embodiment, any one of the upper piezoelectric actuation module 1 , the middle piezoelectric actuation module 2 and the lower piezoelectric actuation module 3 is a hollow structure.

[0087] In this embodiment, the inner contour of the horizontal cross section of the hollow structure is circular or polygonal.

[0088] In this embodiment, the shape of the inner contour of the horizontal cross section of the hollow structure should be the same as the shape of the outer contour of the horizontal cross section.

[0089] In addition, in one embodiment, any one of the upper piezoelectric actuation module 1 , the middle piezoelectric actuation module 2 and the lower piezoelectric actuation module 3 is a solid structure.

[0090] In addition, in one embodiment, the upper piezoelectric actuation module 1 includes a first upper piezoelectric actuation unit 1-1, a second upper piezoelectric actuation unit 1-2, a third upper piezoelectric actuation unit 1-3 and a fourth upper piezoelectric actuation unit 1-4, which are evenly distributed along the circumferential direction and fixedly connected in an end-to-end manner;

[0091] The intermediate piezoelectric actuation module 2 is an integrated piezoelectric actuation unit;

[0092] The lower piezoelectric actuation module 3 includes a first lower piezoelectric actuation unit 3-1, a second lower piezoelectric actuation unit 3-2, a third lower piezoelectric actuation unit 3-3 and a fourth lower piezoelectric actuation unit 3-4, which are evenly distributed along the circumferential direction and fixedly connected in an end-to-end manner.

[0093] In this embodiment, for the upper piezoelectric actuation module or the lower piezoelectric actuation module, the four piezoelectric actuation units may be fixedly connected by integral sintering, bonding or welding.

[0094] In this embodiment, the piezoelectric actuator is composed of three-level piezoelectric actuation modules, namely, an upper part, a middle part and a lower part, which are connected end to end and stacked together; wherein, the upper and lower piezoelectric actuation modules each contain four basic piezoelectric actuation units for generating longitudinal expansion and contraction and lateral bending deformation; the middle piezoelectric actuation module is an integral piezoelectric actuation unit for generating longitudinal expansion and contraction deformation; by coordinating the deformation actions of the three piezoelectric actuation modules, the multi-axis linear and rotational coupled motion generated by the top surface of the piezoelectric actuator can be compensated, and finally pure linear or pure rotational motion is generated, thereby realizing the decoupled generation of multi-degree-of-freedom linear and rotational motion.

[0095] In addition, in one embodiment, the first upper piezoelectric actuation unit 1-1, the second upper piezoelectric actuation unit 1-2, the third upper piezoelectric actuation unit 1-3, and the fourth upper piezoelectric actuation unit 1-4 are respectively used to independently generate expansion or bending deformation under the stimulation of an electrical signal, so that the upper piezoelectric actuation module 1 generates a bending movement along the X-axis direction or the Y-axis direction;

[0096] The first lower piezoelectric actuating unit 3-1, the second lower piezoelectric actuating unit 3-2, the third lower piezoelectric actuating unit 3-3 and the fourth lower piezoelectric actuating unit 3-4 are respectively used to independently generate telescopic or bending deformation under the stimulation of electrical signals, so that the lower piezoelectric actuating module 3 generates bending movement along the X-axis direction or the Y-axis direction.

[0097] In addition, in one embodiment, the upper piezoelectric actuating unit No. 1 1, the upper piezoelectric actuating unit No. 2 1-2, the upper piezoelectric actuating unit No. 3 1-3, the upper piezoelectric actuating unit No. 4 1-4, the lower piezoelectric actuating unit No. 1 3-1, the lower piezoelectric actuating unit No. 2 3-2, the lower piezoelectric actuating unit No. 3 3, the lower piezoelectric actuating unit No. 4 3-4 and the intermediate piezoelectric actuating module 2 are structures containing piezoelectric material.

[0098] In this embodiment, the piezoelectric material may be a typical piezoelectric material such as piezoelectric ceramics and piezoelectric polymers.

[0099] In addition, in one embodiment, the structure including the piezoelectric material is a single structure including the piezoelectric material.

[0100] In addition, in one embodiment, the structure including the piezoelectric material is a composite structure including the piezoelectric material.

[0101] In this embodiment, the composite structure may be a composite structure of a piezoelectric material and other conductive metal or non-metal material.

[0102] In this embodiment, the composite structure may be composited by bonding, welding or inlaying.

[0103] One embodiment provides a multi-axis motion decoupling excitation method for a five-degree-of-freedom piezoelectric actuator:

[0104] The method is used to excite a five-degree-of-freedom piezoelectric actuator as described in the above embodiment; the method comprises:

[0105] Steps to achieve linear decoupled motion along the X-axis:

[0106] The upper piezoelectric actuation module 1, the middle piezoelectric actuation module 2 and the lower piezoelectric actuation module 3 are simultaneously stimulated by multiple electrical signals, so that the upper piezoelectric actuation module 1 and the lower piezoelectric actuation module 3 respectively generate bending motions in opposite directions along the X-axis direction, and the middle piezoelectric actuation module 2 generates telescopic motions along the Z-axis direction;

[0107] Through the bending movement of the upper piezoelectric actuator module 1 and the telescopic movement of the middle piezoelectric actuator module 2, the deflection angle and Z-direction displacement caused by the bending movement of the lower piezoelectric actuator module 3 are coupled and compensated.

[0108] The top surface of the device produces a linear decoupled motion along the X-axis direction;

[0109] Steps to achieve linear decoupled motion along the Y axis:

[0110] The upper piezoelectric actuation module 1, the middle piezoelectric actuation module 2 and the lower piezoelectric actuation module 3 are simultaneously stimulated by using multiple electrical signals, so that the upper piezoelectric actuation module 1 and the lower piezoelectric actuation module 3 respectively generate bending motions in opposite directions along the Y-axis direction, and the middle piezoelectric actuation module 2 generates telescopic motions along the Z-axis direction;

[0111] The deflection angle and Z-direction displacement caused by the bending movement of the lower piezoelectric actuation module 3 are coupled and compensated by the bending movement of the upper piezoelectric actuation module 1 and the telescopic movement of the middle piezoelectric actuation module 2.

[0112] The top surface of the actuator produces a linear decoupled motion along the Y-axis direction;

[0113] Steps to achieve linear decoupled motion along the Z axis:

[0114] The upper piezoelectric actuator module 1, the middle piezoelectric actuator module 2 and the lower piezoelectric actuator module 3 are stimulated simultaneously or separately by multiple electrical signals, so that the upper piezoelectric actuator module 1, the middle piezoelectric actuator module 2 and the lower piezoelectric actuator module 3 respectively generate telescopic motion along the Z-axis direction, and generate a Z-axis motion on the top surface of the piezoelectric actuator.

[0115] Linear decoupled motion;

[0116] Steps to achieve rotational decoupling motion around the Y axis:

[0117] The upper piezoelectric actuation module 1, the middle piezoelectric actuation module 2 and the lower piezoelectric actuation module 3 are simultaneously stimulated by multiple electrical signals, so that the upper piezoelectric actuation module 1 and the lower piezoelectric actuation module 3 respectively generate bending motions in opposite directions along the X-axis direction, and the bending amplitude generated by the upper piezoelectric actuation module 1 is larger, so that the middle piezoelectric actuation module 2 generates telescopic motions along the Z-axis direction;

[0118] The X-direction displacement and Z-direction displacement caused by the bending movement of the lower piezoelectric actuation module 3 are coupled and compensated by the bending movement of the upper piezoelectric actuation module 1 and the telescopic movement of the middle piezoelectric actuation module 2.

[0119] The top surface of the actuator produces a rotational decoupling motion around the Y-axis direction;

[0120] Steps to achieve rotational decoupling motion around the X-axis:

[0121] The upper piezoelectric actuation module 1, the middle piezoelectric actuation module 2 and the lower piezoelectric actuation module 3 are simultaneously stimulated by multiple electrical signals, so that the upper piezoelectric actuation module 1 and the lower piezoelectric actuation module 3 respectively generate bending motions in opposite directions along the Y-axis direction, and the bending amplitude generated by the upper piezoelectric actuation module 1 is larger, so that the middle piezoelectric actuation module 2 generates telescopic motions along the Z-axis direction;

[0122] Through the bending movement of the upper piezoelectric actuator module 1 and the telescopic movement of the middle piezoelectric actuator module 2, the Y-axis displacement and Z-axis displacement caused by the bending movement of the lower piezoelectric actuator module 3 are coupled and compensated, and a rotational decoupling movement around the X-axis direction is generated on the top surface of the piezoelectric actuator.

[0123] In this embodiment, by implementing the step of linear decoupling motion along the X-axis direction, Figure 3 and Figure 6 The coupled motions along the X-axis, along the Z-axis, and around the Y-axis shown are corrected to Figure 8 Linear decoupled motion along the X-axis is shown.

[0124] In this embodiment, by implementing the step of linear decoupling motion along the Y-axis direction, Figure 4 and Figure 7 The coupled motions along the Y axis, along the Z axis, and around the X axis shown are corrected to Fig. 9 Linear decoupled motion along the Y-axis is shown.

[0125] In this embodiment, by implementing the step of linear decoupling motion along the Z-axis direction, it is possible to achieve Figure 5 or Fig.10 Linear decoupled motion along the Z-axis is shown.

[0126] In this embodiment, by implementing the step of rotational decoupling motion around the Y-axis direction, Figure 3 and Figure 6 The coupled motions along the X-axis, along the Z-axis, and around the Y-axis shown are corrected to Fig.12 The rotational decoupled motion around the Y-axis is shown.

[0127] In this embodiment, by implementing the step of rotational decoupling motion around the X-axis direction, Figure 4 and Figure 7 The coupled motions along the Y axis, along the Z axis, and around the X axis shown are corrected to Fig.11 The rotational decoupled motion around the X-axis is shown.

[0128] In this embodiment, in the step of realizing the rotational decoupling motion around the Y-axis direction:

[0129] According to the difference between the bending amplitude of the upper piezoelectric actuating module 1 and the bending amplitude of the lower piezoelectric actuating module 3 , the rotation angle around the Y-axis direction can be obtained.

[0130] In this embodiment, in the step of realizing the rotational decoupling motion around the X-axis direction:

[0131] According to the difference between the bending amplitude of the upper piezoelectric actuation module 1 and the bending amplitude of the lower piezoelectric actuation module 3 , the rotation angle around the X-axis direction can be obtained.

[0132] In this embodiment, a five-degree-of-freedom piezoelectric actuator based on a three-level module combination and an excitation method based on the idea of ​​motion compensation provide a new idea for realizing multi-axis decoupled motion at the same time. It has the unique advantages of multiple degrees of freedom, high precision, and pure decoupling. In the future, it can provide support for applications in semiconductor manufacturing, robotics, optics, precision operations and other fields.

[0133] In addition, in one embodiment, the timing of the multiple electrical signals for stimulating the upper piezoelectric actuation module 1 , the middle piezoelectric actuation module 2 and the lower piezoelectric actuation module 3 is kept synchronous, and the amplitudes are kept in a given proportional relationship.

[0134] In this embodiment, the timing and amplitude proportional relationship of the multiple electrical signals is specifically determined by the size, material and physical parameters of the upper piezoelectric actuation module 1, the middle piezoelectric actuation module 2 and the lower piezoelectric actuation module 3, and the signal proportional coefficient can be established by mechanical solution.

[0135] In addition, in one embodiment, the multi-channel electrical signals used to excite the upper piezoelectric actuation module 1, the middle piezoelectric actuation module 2 and the lower piezoelectric actuation module 3 are direct current, sine wave, square wave, triangle wave or other arbitrary waveform signals.

[0136] The technical solution provided by the present invention is further described in detail above through several specific implementation modes in order to highlight the advantages and benefits of the technical solution provided by the present invention. However, the several specific implementation modes described above are not intended to be used as limitations on the present invention. Any reasonable changes and improvements to the present invention, reasonable combinations of implementation modes and equivalent substitutions based on the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A five-degree-of-freedom piezoelectric actuator, characterized in that: The piezoelectric actuator comprises an upper piezoelectric actuation module (1), a middle piezoelectric actuation module (2) and a lower piezoelectric actuation module (3); The bottom end of the upper piezoelectric actuation module (1) is fixedly connected to the top end of the middle piezoelectric actuation module (2); The bottom end of the middle piezoelectric actuation module (2) is fixedly connected to the top end of the lower piezoelectric actuation module (3); The upper piezoelectric actuator module (1) is used to independently generate bending motion along the X-axis direction or the Y-axis direction under the stimulation of an electrical signal; The intermediate piezoelectric actuator module (2) is used to independently generate telescopic movement along the Z-axis direction under the stimulation of an electrical signal; The lower piezoelectric actuator module (3) is used to independently generate bending motion along the X-axis direction or the Y-axis direction under the stimulation of an electrical signal; The upper piezoelectric actuation module (1), the middle piezoelectric actuation module (2) and the lower piezoelectric actuation module (3) are used to output five-degree-of-freedom decoupled motion on the top surface of the piezoelectric actuator by means of motion coupling compensation; The five-degree-of-freedom decoupling motion includes linear decoupling motion along the X-axis direction, linear decoupling motion along the Y-axis direction, linear decoupling motion along the Z-axis direction, rotational decoupling motion around the X-axis direction, and rotational decoupling motion around the Y-axis direction.

2. A five-degree-of-freedom piezoelectric actuator according to claim 1, characterized in that: The upper piezoelectric actuation module (1), the middle piezoelectric actuation module (2) and the lower piezoelectric actuation module (3) have the same shape of their horizontal cross-section outer contours, and their edges are aligned.

3. A five-degree-of-freedom piezoelectric actuator according to claim 2, characterized in that: The horizontal cross-sectional outer contours of the upper piezoelectric actuation module (1), the middle piezoelectric actuation module (2) and the lower piezoelectric actuation module (3) are circular or polygonal.

4. A five-degree-of-freedom piezoelectric actuator according to claim 3, characterized in that: Any one of the upper piezoelectric actuation module (1), the middle piezoelectric actuation module (2) and the lower piezoelectric actuation module (3) is a hollow structure.

5. The five-degree-of-freedom piezoelectric actuator according to claim 3, characterized in that: The upper piezoelectric actuation module (1) comprises a first upper piezoelectric actuation unit (1-1), a second upper piezoelectric actuation unit (1-2), a third upper piezoelectric actuation unit (1-3) and a fourth upper piezoelectric actuation unit (1-4), the four being evenly distributed along the circumferential direction and fixedly connected in an end-to-end manner; The intermediate piezoelectric actuation module (2) is an integrated piezoelectric actuation unit; The lower piezoelectric actuation module (3) comprises a first lower piezoelectric actuation unit (3-1), a second lower piezoelectric actuation unit (3-2), a third lower piezoelectric actuation unit (3-3) and a fourth lower piezoelectric actuation unit (3-4), the four being evenly distributed along the circumferential direction and fixedly connected in an end-to-end manner.

6. A five-degree-of-freedom piezoelectric actuator according to claim 5, characterized in that: The first upper piezoelectric actuation unit (1-1), the second upper piezoelectric actuation unit (1-2), the third upper piezoelectric actuation unit (1-3) and the fourth upper piezoelectric actuation unit (1-4) are respectively used to independently generate expansion and contraction or bending deformation under the stimulation of an electrical signal, so that the upper piezoelectric actuation module (1) generates bending movement along the X-axis direction or the Y-axis direction; The first lower piezoelectric actuating unit (3-1), the second lower piezoelectric actuating unit (3-2), the third lower piezoelectric actuating unit (3-3) and the fourth lower piezoelectric actuating unit (3-4) are respectively used to independently generate expansion and contraction or bending deformation under the stimulation of an electrical signal, so that the lower piezoelectric actuating module (3) generates bending movement along the X-axis direction or the Y-axis direction.

7. A five-degree-of-freedom piezoelectric actuator according to claim 6, characterized in that: The first upper piezoelectric actuating unit (1-1), the second upper piezoelectric actuating unit (1-2), the third upper piezoelectric actuating unit (1-3), the fourth upper piezoelectric actuating unit (1-4), the first lower piezoelectric actuating unit (3-1), the second lower piezoelectric actuating unit (3-2), the third lower piezoelectric actuating unit (3-3), the fourth lower piezoelectric actuating unit (3-4) and the intermediate piezoelectric actuating module (2) are structures comprising piezoelectric material.

8. A multi-axis motion decoupling excitation method for a five-degree-of-freedom piezoelectric actuator, characterized in that: The method is used to excite a five-degree-of-freedom piezoelectric actuator as claimed in any one of claims 1 to 7; the method comprises: Steps to achieve linear decoupled motion along the X-axis: A plurality of electrical signals are used to simultaneously excite the upper piezoelectric actuation module (1), the middle piezoelectric actuation module (2) and the lower piezoelectric actuation module (3), so that the upper piezoelectric actuation module (1) and the lower piezoelectric actuation module (3) respectively generate bending motions in opposite directions along the X-axis direction, and the middle piezoelectric actuation module (2) generates telescopic motions along the Z-axis direction; Through the bending movement of the upper piezoelectric actuator module (1) and the telescopic movement of the middle piezoelectric actuator module (2), The deflection angle and Z-direction displacement caused by the bending movement of the piezoelectric actuator module (3) are coupled and compensated, and a linear decoupling movement along the X-axis direction is generated on the top surface of the piezoelectric actuator; Steps to achieve linear decoupled motion along the Y axis: A plurality of electrical signals are used to simultaneously excite the upper piezoelectric actuation module (1), the middle piezoelectric actuation module (2) and the lower piezoelectric actuation module (3), so that the upper piezoelectric actuation module (1) and the lower piezoelectric actuation module (3) respectively generate bending motions in opposite directions along the Y-axis direction, and the middle piezoelectric actuation module (2) generates telescopic motions along the Z-axis direction; Through the bending movement of the upper piezoelectric actuator module (1) and the telescopic movement of the middle piezoelectric actuator module (2), The deflection angle and Z-direction displacement caused by the bending movement of the lower piezoelectric actuator module (3) are coupled and compensated, and a linear decoupling movement along the Y-axis direction is generated on the top surface of the piezoelectric actuator; Steps to achieve linear decoupled motion along the Z axis: The upper piezoelectric actuation module (1), the middle piezoelectric actuation module (2) and the lower piezoelectric actuation module (3) are stimulated simultaneously or separately by using multiple electrical signals, so that the upper piezoelectric actuation module (1), the middle piezoelectric actuation module (2) and the lower piezoelectric actuation module (3) respectively generate telescopic motion along the Z-axis direction, and a linear decoupling motion along the Z-axis direction is generated on the top surface of the piezoelectric actuator; Steps to achieve rotational decoupling motion around the Y axis: A multi-channel electrical signal is used to simultaneously excite the upper piezoelectric actuation module (1), the middle piezoelectric actuation module (2) and the lower piezoelectric actuation module (3), so that the upper piezoelectric actuation module (1) and the lower piezoelectric actuation module (3) respectively generate bending motions in opposite directions along the X-axis direction, and the bending amplitude generated by the upper piezoelectric actuation module (1) is larger, so that the middle piezoelectric actuation module (2) generates telescopic motions along the Z-axis direction; Through the bending movement of the upper piezoelectric actuator module (1) and the telescopic movement of the middle piezoelectric actuator module (2), Coupled compensation is performed on the X-direction displacement and the Z-direction displacement caused by the bending movement of the lower piezoelectric actuator module (3). A rotational decoupled motion around the Y-axis direction is generated on the top surface of the piezoelectric actuator; Steps to achieve rotational decoupling motion around the X-axis: A plurality of electrical signals are used to simultaneously excite the upper piezoelectric actuation module (1), the middle piezoelectric actuation module (2) and the lower piezoelectric actuation module (3), so that the upper piezoelectric actuation module (1) and the lower piezoelectric actuation module (3) respectively generate bending motions in opposite directions along the Y-axis direction, and the bending amplitude generated by the upper piezoelectric actuation module (1) is larger, so that the middle piezoelectric actuation module (2) generates telescopic motions along the Z-axis direction; Through the bending movement of the upper piezoelectric actuator module (1) and the telescopic movement of the middle piezoelectric actuator module (2), The Y-direction displacement and the Z-direction displacement caused by the bending movement of the lower piezoelectric actuator module (3) are coupled and compensated. A rotational decoupled motion around the X-axis direction is generated on the top surface of the piezoelectric actuator.

9. The multi-axis motion decoupling excitation method for a five-degree-of-freedom piezoelectric actuator according to claim 8, characterized in that: The timing of the multiple-channel electrical signals used to stimulate the upper piezoelectric actuation module (1), the middle piezoelectric actuation module (2) and the lower piezoelectric actuation module (3) is kept synchronous, and the amplitudes are kept in a given proportional relationship.

10. The multi-axis motion decoupling excitation method for a five-degree-of-freedom piezoelectric actuator according to claim 8, characterized in that: The multi-channel electrical signals used to stimulate the upper piezoelectric actuation module (1), the middle piezoelectric actuation module (2) and the lower piezoelectric actuation module (3) are direct current, sine wave, square wave, triangle wave or other arbitrary waveform signals.

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