CN-121984377-A - Inchworm type piezoelectric motor transverse disturbance suppression method and system

CN121984377ACN 121984377 ACN121984377 ACN 121984377ACN-121984377-A

Abstract

The invention relates to the technical field of mechanical and electronic engineering, and discloses a inchworm type piezoelectric motor transverse disturbance suppression method and system, which are mainly used for measuring and suppressing motor rotor transverse disturbance caused by inconsistent inherent characteristics of piezoelectric stacks. The method comprises the steps of firstly, respectively establishing kinematic models of the inchworm piezoelectric motor in the clamping stack and the shearing stack in the actuating process, secondly, obtaining input and output data of the motion models of the inchworm piezoelectric motor in the clamping stack and the shearing stack in the actuating process through direct measurement and calculation deduction, thirdly, identifying inherent attribute parameters of each piezoelectric stack in the two piezoelectric stack motion models, and fourthly, inhibiting transverse disturbance of the motor based on the inchworm piezoelectric motor motion models and the specific attribute parameters of each piezoelectric stack. The invention maintains the advantage of small volume of the inchworm piezoelectric motor, improves the performance of the inchworm motor, and promotes the application of the inchworm piezoelectric motor in the field with strict requirements in the non-working direction.

Inventors

XUE CHAO
DING YANWEI
WANG WEI
XU YIYAN
HUANG SHENGPING
Cai Bingwei
CHANG JIE
YANG HENGXU
XIE ZIQING
ZHANG JINXIU

Assignees

中山大学

Dates

Publication Date: 20260505
Application Date: 20251224

Claims (10)

1. A inchworm type piezoelectric motor transverse disturbance suppression method is characterized in that the inchworm type piezoelectric motor comprises a shell (200) and a rotor (100), a flexible pre-tightening mechanism (300) and at least two driving units (400) which are arranged in the shell (200), wherein two groups of driving units (400) are symmetrically arranged relative to the rotor (100), each driving unit (400) comprises a clamping piezoelectric stack (420) and a shearing piezoelectric stack (410) which are connected, the flexible pre-tightening mechanism (300) is arranged between the clamping piezoelectric stack (420) and the shell (200), the shearing piezoelectric stack (410) acts on the rotor (100), The method comprises the following steps: According to the structure of the inchworm-type piezoelectric motor, a clamping stack motion model and a shearing stack motion model are established, wherein the clamping stack motion model represents a dynamic relationship between an electrical input and a motion output of the clamping piezoelectric stack, the shearing stack motion model represents a dynamic relationship between the electrical input and the motion output of the shearing piezoelectric stack, and the clamping stack motion model and the shearing stack motion model both comprise at least one inherent attribute parameter to be identified; Applying a preset first electrical input to the clamping piezoelectric stack, and synchronously collecting a first actual motion output generated by the inchworm type piezoelectric motor under the action of the first electrical input; applying a preset second electrical input to the shearing piezoelectric stack, and synchronously collecting a second actual motion output generated by the inchworm type piezoelectric motor under the action of the second electrical input; substituting the first electrical input and the first actual motion output into the clamping stack motion model to identify inherent attribute parameters of the clamping stack motion model; substituting the second electrical input and the second actual motion output into the shear stack motion model, and identifying inherent attribute parameters of the shear stack motion model; And applying corresponding electrical input to each clamping piezoelectric stack when the motion output of each clamping piezoelectric stack at the symmetrical position is consistent based on the inherent attribute parameters of each shearing stack motion model, and applying corresponding electrical input to each shearing piezoelectric stack when the motion output of each shearing piezoelectric stack at the symmetrical position is consistent based on the inherent attribute parameters of each shearing stack motion model, thereby inhibiting transverse disturbance to the mover caused by parasitic moment of inconsistent driving force.
2. The method of claim 1, wherein the electrical input of the clamp stack motion model is an excitation voltage of the clamp piezoelectric stack, the motion output is an elongation of the clamp piezoelectric stack, a rotation angle of the flexible pretensioning mechanism, and a rotation angle of the mover, and the electrical input of the shear stack motion model is an excitation voltage of the shear piezoelectric stack, and the motion output is a displacement of the mover, and a rotation angle of the mover.
3. The method of claim 2, wherein the clamped stack motion model and the sheared stack motion model are built based on a constitutive model of a piezoelectric stack that equates each piezoelectric stack of the inchworm-type piezoelectric motor to one electromechanical system, wherein a mechanical part is simplified to a mass-spring-damping system, and considering that a motor mover is effectively driven by the piezoelectric stack without involving reciprocation of the piezoelectric stack, ignoring hysteresis effects of the piezoelectric stack, the constitutive model of the piezoelectric stack is expressed as: , Wherein, the In order to apply a voltage to the piezoelectric stack, For the total charge stored on the piezoelectric stack, Is the equivalent capacitance of the piezoelectric stack, Is the piezoelectric conversion ratio of the piezoelectric stack, In order to apply a force to the electricity, For the equivalent stiffness of the piezoelectric stack, For the damping of the piezoelectric stack, For the displacement of the piezoelectric stack, For the piezoelectric stack speed, The acceleration of the piezoelectric stack is such that, Is the mass of the piezoelectric stack.
4. A method according to claim 3, wherein in the construction of the clamp stack motion model, the clamp piezoelectric stack is used only to compress the mover, and no complex relative motion process is involved, so that analyzing the clamp piezoelectric stack takes into account steady state conditions before and after actuation, including: analyzing the change of the output force of each clamping piezoelectric stack before and after electrifying; , In the formula, Is the first The amount of change in output force before and after energizing the piezoelectric stacks is clamped, Is the first The excitation voltage of the piezoelectric stack is clamped, Is the first The piezoelectric conversion ratio of each clamping piezoelectric stack, Is the first The equivalent stiffness of each clamped piezoelectric stack, Is the first The output force variation amounts of the clamping piezoelectric stacks at symmetrical positions are the same; Analyzing displacement change of the flexible pre-tightening mechanism, namely, equivalent the flexible pre-tightening mechanism to a linear spring in the displacement direction, wherein the extension of the clamping piezoelectric stack can lead the flexible pre-tightening mechanism to be further compressed, and the elastic force increment generated by the compression of the flexible pre-tightening mechanism is equal to the sum of the output force change of the clamping piezoelectric stack which is extended at the same side of the rotor, then , In the formula, Is the compression amount of the flexible pre-tightening mechanism, Is the linear rigidity of the flexible pre-tightening mechanism, Output force variation of clamping piezoelectric stacks positioned on the same side of the rotor; The rotation of the flexible pre-tightening mechanism around the eta axis and the phi axis is analyzed, namely the rotation of the flexible pre-tightening mechanism around the eta axis and the phi axis is respectively equivalent to a hinge with a certain rotation rigidity, the moment for causing the rotation of the flexible pre-tightening mechanism is derived from the difference value of output forces of two driving units acting on the flexible pre-tightening mechanism, and therefore, for the rotation of the flexible pre-tightening mechanism around the eta axis and the phi axis, the relation between the rotation moment and the rotation rigidity is as follows: , In the formula, For the distance of the drive unit from the motor centre in the y-direction and in the z-direction, The rotation angle of the flexible pre-tightening mechanism around the eta axis is adopted, The rotation angle of the flexible pre-tightening mechanism around the phi axis, And The rotation rigidity of the flexible pre-tightening mechanism around the eta axis and the phi axis is respectively, And The rotation moment expressed by the output force of the piezoelectric stack is respectively born by the flexible pre-tightening mechanism on the eta axis and the phi axis; Analyzing the geometric relationship between the displacement variation of the contact part of the flexible pre-tightening mechanism and the clamping piezoelectric stack and the self corner of the flexible pre-tightening mechanism: , In the formula, And The displacement variation amounts of the contact positions of the flexible pre-tightening mechanism and the clamping piezoelectric stack are respectively the same side of the rotor; analyzing the relation between the compression amount of the flexible pre-tightening mechanism and the elongation amount of each clamping piezoelectric stack, namely defining the displacement at the center of the flexible pre-tightening mechanism as the equivalent deformation amount of the flexible mechanism Expressed as: , In the formula, To be positioned at the same side of the rotor The amount of elongation of the piezoelectric stack is clamped, The number of clamping stacks is elongated for the same side of the mover; Analyzing the relation between the displacement of the rotor in the direction parallel to the driving unit and the rotation angle of the rotor when the rotor contacts with the clamping piezoelectric stack, wherein the relation comprises the following steps: , In the formula, And Respectively the displacement of the contact positions of the rotor and the driving unit at the same side of the rotor, And The corners of the rotor around the eta axis and the phi axis are respectively; the displacement of the rotation center of the mover in the direction of the piezoelectric stack can be expressed by the elongation of each clamping piezoelectric stack: , In the formula, The piezoelectric stack elongation is clamped for one side of the mover, Clamping the elongation of the piezoelectric stack for the other side of the mover; the above formulas are combined to obtain the clamping stack motion model, wherein the input of the clamping stack motion model is the excitation voltage of the clamping piezoelectric stack The output is the elongation of the clamping piezoelectric stack Corner of flexible pre-tightening mechanism Corner of rotor Wherein =1,2。
5. The method of claim 4, wherein substituting the first electrical input, the first actual motion output into the clamped stack motion model identifies intrinsic property parameters of the clamped stack motion model, comprising: substituting the first electrical input and the first actual motion output into the clamping stack motion model, and setting a normalized objective function as follows: , In the formula, In order to make the number of outputs, For the number of data points in each output, Is the first The outputs are based on a normalization factor of the maximum value, Is the first Output number 1 An estimate of the data point is obtained, Is the first Output number 1 The actual values of the data points are calculated, Is the first All data output; Then nonlinear optimization is carried out by using fimincon functions to obtain the piezoelectric conversion ratio of each clamping piezoelectric stack And stiffness(s) Estimates of these intrinsic parameters.
6. The method of claim 5, wherein said applying a corresponding electrical input to each of said clamping piezo-stacks while ensuring consistent motion output of each of said clamping piezo-stacks at symmetrical locations based on said intrinsic property parameters of each of said clamping stack motion models comprises: In order to ensure that the rotor deflection caused by the inherent parameter inconsistency is not generated in the actuation process of the clamping piezoelectric stack, the following relationship needs to be satisfied: , In the formula, For the desired amount of elongation set for the clamped stack, In order to clamp the number of piezo-stacks, Is the first The piezoelectric conversion ratio of each clamping piezoelectric stack, The voltage corresponding to each clamping piezoelectric stack is used under the condition that the mover does not deflect; when the inchworm type piezoelectric motor is driven, the calculated non-deflection clamping voltage is calculated Applied to the corresponding clamping piezo-stack.
7. The method of claim 3, wherein the shear stack motion model is constructed such that during actuation of the shear piezoelectric stack, the mover is driven by friction between the shear piezoelectric stack and the mover, the process being more complex, the dynamic model containing more information is considered to represent the actuation of the shear piezoelectric stack, and the friction between the shear piezoelectric stack and the mover is characterized by using a pre-slip friction model: , In the formula, To shear the equivalent stiffness of the elastic deformation of the piezoelectric stack-mover interface, For shearing the relative displacement between the piezoelectric stack and the mover; Analyzing the movement of the mover along the working direction under the action of tangential friction force of the shearing piezoelectric stack, and establishing a kinetic equation in the working direction: , In the formula, In order to shear the mass of the piezoelectric stack, Is the mass of the rotor, and is the mass of the rotor, Is the first The equivalent damping of the individual shear piezoelectric stacks, Is the first The equivalent stiffness of the individual shear piezoelectric stacks, Is the first The friction force between the shearing piezoelectric stack and the mover, Is the first The displacement of the piezoelectric stack is sheared off, For the displacement of the mover(s), Is the first The excitation voltage of the shear piezoelectric stack, Is the first Piezoelectric conversion ratios of the individual shear piezoelectric stacks; Analyzing the rotation of the mover around the eta axis, wherein the inconsistent driving forces of friction on two sides of the mover are caused by the inherent property difference of the shearing piezoelectric stack, and the inconsistent driving forces form moment for causing the mover to rotate around the eta axis The kinetic equation of the mover rotation about the eta axis is: , In the formula, For the rotation angle of the mover around the eta axis, For the angular velocity at which the mover rotates about the eta axis, For the angular acceleration of the mover rotation about the eta axis, For the moment of inertia of the mover about the eta axis, And Equivalent damping and equivalent rigidity of the rotor rotating around the eta axis and the rotation moment are respectively By the displacement of each shear piezoelectric stack in the driving unit And pre-slip friction stiffness The characteristics of the product are characterized in that, And analyzing the rotation of the rotor around the theta axis, wherein a kinetic equation of the rotation of the rotor around the theta axis is as follows: , In the formula, For the rotation angle of the mover around the theta axis, For the angular velocity of the mover rotation about the theta axis, For the angular acceleration of the mover rotation about the theta axis, For the moment of inertia of the mover about the theta axis, And Respectively equivalent damping and equivalent rigidity of the rotor rotating around the theta axis, Simultaneously, the shear stack motion model is obtained, and the input of the shear stack motion model is the excitation voltage on the shear piezoelectric stack The output is the displacement of the rotor along the z direction The rotation angle theta of the mover around the theta axis and the rotation angle eta of the mover around the eta axis.
8. The method of claim 7, wherein substituting the second electrical input, the second actual motion output into the shear stack motion model identifies intrinsic property parameters of the shear stack motion model, comprising; Substituting the second electrical input, the second actual motion output into the shear stack motion model, considering a weighted normalized objective function as: In the formula, For the number of shear stack motion model outputs, And The total number of data points of the actuation measurement data of the shear piezoelectric stack in the positive and negative polarity driving units are respectively represented, And Respectively represent the first of the measured data of the positive and negative polarity stacks The first output A data point is provided for each of the data points, And Respectively represent the calculated first of the positive and negative polarity shearing stack models The first output Data point, max term indicates The outputs are based on a normalization factor of the maximum value, Then using particle swarm algorithm to obtain the inherent attribute parameters in the shear stack motion model, namely the piezoelectric conversion ratio of the shear piezoelectric stack Equivalent stiffness of shear piezoelectric stack And equivalent damping of shear piezoelectric stacks And (5) identifying.
9. The method of claim 8, wherein said applying a corresponding electrical input to each of said shear piezoelectric stacks while ensuring consistent motion output of each of said shear piezoelectric stacks at symmetrical locations based on said intrinsic property parameters of each of said shear stack motion models comprises: in order to prevent the rotor from being transversely disturbed due to inconsistent inherent parameters of the shearing piezoelectric stack in the actuating process, the following relation needs to be satisfied by the shearing voltage: , In the formula, The desired amount of elongation set for the shear piezoelectric stack, In order to shear the number of piezoelectric stacks, The voltage corresponding to each shearing piezoelectric stack under the condition that the rotor does not deflect; When the inchworm type piezoelectric motor is driven, the calculated non-deflection shearing voltage is calculated Applied to the corresponding shear piezoelectric stack.
10. The inchworm type piezoelectric motor transverse disturbance suppression system is characterized in that the inchworm type piezoelectric motor comprises a shell (200) and a rotor (100), a flexible pre-tightening mechanism (300) and at least two driving units (400), wherein the rotor (100) is arranged in the shell (200), the two driving units (400) are symmetrically arranged about the rotor (100), each driving unit (400) comprises a clamping piezoelectric stack (420) and a shearing piezoelectric stack (410) which are connected, the flexible pre-tightening mechanism (300) is arranged between the clamping piezoelectric stack (420) and the shell (200), and the shearing piezoelectric stack (410) acts on the rotor (100), and the inchworm type piezoelectric motor transverse disturbance suppression system further comprises: The modeling module is used for establishing a clamping stack motion model and a shearing stack motion model according to the structure of the inchworm type piezoelectric motor, wherein the clamping stack motion model represents the dynamic relationship between the electrical input and the motion output of the clamping piezoelectric stack, the shearing stack motion model represents the dynamic relationship between the electrical input and the motion output of the shearing piezoelectric stack, and the clamping stack motion model and the shearing stack motion model both comprise at least one inherent attribute parameter to be identified; The measuring module is used for applying a preset first electrical input to the clamping piezoelectric stack and synchronously collecting a first actual motion output generated by the inchworm type piezoelectric motor under the action of the first electrical input; applying a preset second electrical input to the shearing piezoelectric stack, and synchronously collecting a second actual motion output generated by the inchworm type piezoelectric motor under the action of the second electrical input; The identification module is used for substituting the first electrical input and the first actual motion output into the clamping stack motion model to identify inherent attribute parameters of the clamping stack motion model; substituting the second electrical input and the second actual motion output into the shear stack motion model, and identifying inherent attribute parameters of the shear stack motion model; and the driving module is used for applying corresponding electrical input to each clamping piezoelectric stack when the motion output of each clamping piezoelectric stack at the symmetrical position is consistent based on the inherent attribute parameters of each clamping piezoelectric stack motion model, and applying corresponding electrical input to each shearing piezoelectric stack when the motion output of each shearing piezoelectric stack at the symmetrical position is consistent based on the inherent attribute parameters of each shearing piezoelectric stack motion model, so as to inhibit transverse disturbance to the mover caused by parasitic moment of inconsistent driving force.

Description

Inchworm type piezoelectric motor transverse disturbance suppression method and system Technical Field The invention relates to the technical field of mechanical and electronic engineering, in particular to a inchworm type piezoelectric motor transverse disturbance suppression method and system. Background The inchworm type piezoelectric motor is a precise driver imitating the creeping principle of inchworm in nature, has the advantages of high displacement resolution, high response speed, small volume, no magnetism and the like, and is widely applied to the fields of precise optics, biomedicine, IC manufacture and aerospace. The inchworm piezoelectric motor has excellent motion performance in the working direction and theoretically does not generate motion in the non-working direction. However, consistency of the intrinsic parameters of the piezoelectric stack as the inchworm-type piezoelectric motor driving element is difficult to ensure, which results in that under the conventional driving mode, the piezoelectric stack generates different output forces/displacements under the same exciting voltage, and the inconsistent output forces act on the mover through friction to cause the mover to generate a rotation moment, so that the mover rotates, and the transverse displacement is shown in a non-working direction. Such a transverse disturbance will lead to fatal consequences in the second-stage release of the spatial inertial reference in the spatial gravitational wave detection. In addition, the mover cannot be limited by constraint and guide, and the mover and the guide mechanism slide relatively, so that the excessive constraint force can cause excessive friction force on the mover to greatly reduce the driving efficiency, and the too small constraint force cannot form effective transverse constraint on the mover. Therefore, an active inhibition method of the lateral disturbance of the inchworm-type piezoelectric motor caused by parasitic moment needs to be designed. Disclosure of Invention The invention aims to provide a inchworm type piezoelectric motor transverse disturbance suppression method and system, which can reduce the influence of parasitic moment caused by piezoelectric stack variability on the inchworm type piezoelectric motor transverse disturbance. In order to achieve the above object, the present invention provides the following technical solutions: In a first aspect, the invention provides a method for suppressing lateral disturbance of an inchworm-type piezoelectric motor, the inchworm-type piezoelectric motor comprises a housing, a rotor arranged in the housing, a flexible pre-tightening mechanism, at least two driving units, wherein the two driving units are symmetrically arranged about the rotor, each driving unit comprises a clamping piezoelectric stack and a shearing piezoelectric stack which are connected, the flexible pre-tightening mechanism is arranged between the clamping piezoelectric stack and the housing, the shearing piezoelectric stack acts on the rotor, The method comprises the following steps: According to the structure of the inchworm-type piezoelectric motor, a clamping stack motion model and a shearing stack motion model are established, wherein the clamping stack motion model represents a dynamic relationship between an electrical input and a motion output of the clamping piezoelectric stack, the shearing stack motion model represents a dynamic relationship between the electrical input and the motion output of the shearing piezoelectric stack, and the clamping stack motion model and the shearing stack motion model both comprise at least one inherent attribute parameter to be identified; Applying a preset first electrical input to the clamping piezoelectric stack, and synchronously collecting a first actual motion output generated by the inchworm type piezoelectric motor under the action of the first electrical input; applying a preset second electrical input to the shearing piezoelectric stack, and synchronously collecting a second actual motion output generated by the inchworm type piezoelectric motor under the action of the second electrical input; substituting the first electrical input and the first actual motion output into the clamping stack motion model to identify inherent attribute parameters of the clamping stack motion model; substituting the second electrical input and the second actual motion output into the shear stack motion model, and identifying inherent attribute parameters of the shear stack motion model; And applying corresponding electrical input to each clamping piezoelectric stack when the motion output of each clamping piezoelectric stack at the symmetrical position is consistent based on the inherent attribute parameters of each shearing stack motion model, and applying corresponding electrical input to each shearing piezoelectric stack when the motion output of each shearing piezoelectric stack at the symmetrical position is consistent based