CN217087797U

CN217087797U - Driving device of piezoelectric actuator

Info

Publication number: CN217087797U
Application number: CN202220918371.8U
Authority: CN
Inventors: 王学亮; 郭抗; 隋永新; 杨怀江
Original assignee: Changchun National Extreme Precision Optics Co ltd
Current assignee: Changchun National Extreme Precision Optics Co ltd
Priority date: 2022-04-20
Filing date: 2022-04-20
Publication date: 2022-07-29
Anticipated expiration: 2032-04-20

Abstract

The application discloses piezoelectric actuator's drive arrangement includes: a processor and a multi-path driving circuit; the multi-path driving circuits comprise digital-to-analog converters, controllable voltage reference sources and amplifiers, and the digital-to-analog converters output voltages applied to the piezoelectric ceramics after amplifying respective analog signals through the amplifiers; the voltage reference value of each path of digital-to-analog converter is regulated and controlled by a controllable voltage reference source or the amplification factor of each output voltage is regulated by an amplifier, so that the minimum displacement variation of each piezoelectric ceramic is the same. In the calibration process, the range of the input digital code does not need to be adjusted, so that each path can keep the designed dynamic range, and the problem of inconsistent displacement resolution of the prior art can be solved, thereby ensuring that the extension and retraction amount of each piezoelectric ceramic is the same when the piezoelectric driver carries out linear displacement.

Description

Driving device of piezoelectric actuator

Technical Field

The present application relates to the field of piezoelectric actuators, and in particular, to a driving device of a piezoelectric actuator.

Background

Piezoelectric ceramics are widely used in many fields due to their precise output capability, and in practical applications, it is usually necessary to assemble a plurality of piezoelectric ceramics into an integral system, such as a zRxRy three-dimensional adjusting table shown in FIG. 1.

In the three-dimensional adjusting table shown in fig. 1, three

piezoelectric ceramics

102, 103, 104 are firmly mounted on a base 101, and after a driving voltage signal is applied, the piezoelectric ceramics will extend to jack up a workpiece table 108, so that the workpiece table generates z-direction translation and rotation around x and y by respectively controlling the extension displacement of the three

piezoelectric ceramics

102, 103, 104. Springs 105, 106, 107 are mounted between the base 101 and the stage 108 to provide pre-load to the

piezoceramics

102, 103, 104. The workpiece table 108 has mounting

holes

109, 110, 111 on its upper surface for mounting a workpiece.

Since there is necessarily a difference in characteristics between the plurality of piezoelectric ceramics, there is a difference in the amount of elongation displacement even when the same driving voltage is applied. For example, the

piezoelectric ceramics

102, 103, 104 shown in FIG. 1 ideally have input/output characteristics of 0.1 μm/V, but actually, the input/output characteristics of 3 piezoelectric ceramics are 0.098 μm/V, 0.106 μm/V and 0.084 μm/V, respectively. The

piezoelectric ceramics

102, 103, 104 are applied with drive voltages V1, V2, and V3, respectively, and when V1 ═ V2 ═ V3 ═ 100V, the amount of elongation displacement is D1 ═ 9.8 μm, D2 ═ 10.6 μm, and D3 ═ 8.4 μm, respectively. Ideally, the stage 108 should only move in translation in the z-direction, and in practice, the stage 108 generates z-, Rx-, and Ry-motions in three dimensions.

In the prior art, in order to make the displacement of the three-way DAC input digital code consistent, only the input digital code can be changed, so that after calibration, the input digital code is wasted, that is, the dynamic range is poor, and further the displacement range of the piezoelectric ceramic is reduced.

SUMMERY OF THE UTILITY MODEL

The purpose of the application is to provide a control device of a piezoelectric driver, which can ensure that the dynamic range of DAC input codes of each path keeps the original design value and can ensure that the displacement resolution of each path is consistent.

In order to solve the technical problem, the application provides the following technical scheme:

the utility model provides a drive arrangement of piezoelectric actuator, piezoelectric actuator includes stator, active cell and a plurality of piezoceramics, and is a plurality of piezoceramics set up in on the stator for the drive the active cell is according to predetermineeing the orbit motion, drive arrangement includes:

a processor and a multi-path driving circuit;

the drive circuits comprise digital-to-analog converters, controllable voltage reference sources and amplifiers, and the digital-to-analog converters output voltages applied to the piezoelectric ceramics after amplifying respective analog signals through the amplifiers;

and regulating the voltage reference value of each path of digital-to-analog converter through the controllable voltage reference source or regulating the amplification factor of each output voltage through the amplifier so as to ensure that the minimum displacement variation of each piezoelectric ceramic is the same.

Preferably, the controllable voltage reference source comprises a voltage regulating digital-to-analog converter.

Preferably, the controllable voltage reference source comprises a digital potentiometer.

Preferably, the controllable voltage reference source comprises a digital programmable gain amplifier.

Preferably, a digital programmable gain amplifier is also included in series with the amplifier.

Preferably, the feedback circuit is connected with the amplifier and comprises a digital potentiometer and a fixed resistance resistor connected with the digital potentiometer.

Compared with the prior art, the technical scheme has the following advantages:

the present application provides a drive device of a piezoelectric actuator, including: a processor and a multi-path driving circuit; the multi-path driving circuits comprise digital-to-analog converters, controllable voltage reference sources and amplifiers, and the digital-to-analog converters output voltages applied to the piezoelectric ceramics after amplifying respective analog signals through the amplifiers; the voltage reference value of each path of digital-to-analog converter is regulated and controlled by a controllable voltage reference source or the amplification factor of each output voltage is regulated by an amplifier, so that the minimum displacement variation of each piezoelectric ceramic is the same. In the calibration process, the range of the input digital code does not need to be adjusted, so that each path can keep the designed dynamic range, and the problem of inconsistent displacement resolution of the prior art can be solved, thereby ensuring that the extension and retraction amount of each piezoelectric ceramic is the same when the piezoelectric driver carries out linear displacement.

Drawings

In order to more clearly illustrate the technical solutions in the present application or the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a schematic structural diagram of a conventional three-dimensional adjustment table;

fig. 2 is a schematic diagram of a driving principle of a conventional piezoelectric actuator;

fig. 3 is a schematic diagram illustrating a driving principle of a piezoelectric actuator according to an embodiment of the present application;

FIG. 4 is a schematic diagram of a controllable voltage reference source formed by a voltage regulating digital-to-analog converter;

FIG. 5 is a schematic diagram of a controllable voltage reference source consisting of a digital potentiometer;

FIG. 6 is a schematic diagram of a controllable voltage reference source formed by a digital programmable gain amplifier;

FIG. 7 is a schematic diagram of a digital programmable gain amplifier in series with an original amplifier;

fig. 8 is a schematic diagram of a feedback circuit of the amplifier.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present application more comprehensible, embodiments accompanying the present application are described in detail below with reference to the accompanying drawings.

In the following description, specific details are set forth in order to provide a thorough understanding of the present application. This application is capable of implementation in many different ways than those herein set forth and of similar import to those skilled in the art without departing from the spirit and scope of this application. The present application is therefore not limited to the specific embodiments disclosed below.

Referring to fig. 2, fig. 2 is a schematic diagram of a driving principle of a conventional piezoelectric driver, in which an 8-bit DAC is used, a 10V reference voltage is used, and an amplifier amplification factor is 10, so that a system output voltage Vout applied to a piezoelectric ceramic is DAC input number/(2 ^8-1) × 10V ^ 10. At this time, the relationship between the input digital code and the ideal displacement and the actual displacement is shown in table 1, and it can be known from table 1 that when the three DACs all input the digital code 255, the displacements are 9.8um, 10.6um and 8.4um, respectively.

Calibrating the front three-way drive: the minimum voltage variation is 0.39V, the maximum voltage range is 100V, and the dynamic range is 100/0.39 is 256; the displacement resolution (i.e., the minimum amount of displacement change of each piezoelectric ceramic) was 0.04 μm, and 0.03 μm, respectively.

TABLE 1 System input-output conditions before calibration in the prior art

In order to make the displacements of the three-way DAC input code 255 (i.e., full stroke) consistent, the input code can only be changed, and thus the input-output conditions of the calibrated system of the prior art are shown in table 2.

Table 2 shows the input-output conditions of the system after calibration in the prior art

As can be seen from table 2 above, the driving method of the prior art has the following disadvantages after calibration:

1. the input number is wasted, i.e. the dynamic range is degraded: the first route 256 becomes 220 and the second route 256 becomes 203. The expression of the displacement is that the three piezoelectric ceramics stretch by about 8.4 mu m, but the third path keeps the original design idea and is divided into 256 parts, the first path is divided into 220 parts, and the second path is divided into 203 parts.

2. The problem of inconsistent resolution (still 0.04 μm, 0.04 μm and 0.03 μm) existing before calibration is still not solved, i.e. the third path can be adjusted to a small amplitude of 0.03 μm, but the first path and the second path can only be adjusted to an amplitude of 0.04 μm, thus being not beneficial to the displacement output of the piezoelectric driver.

Referring to fig. 3, fig. 3 is a schematic diagram illustrating a driving principle of a piezoelectric actuator according to an embodiment of the present disclosure.

A specific embodiment of the present application provides a piezoelectric actuator's drive arrangement, and piezoelectric actuator includes stator, active cell and a plurality of piezoceramics, and a plurality of piezoceramics set up on the stator for drive active cell is according to predetermineeing the orbit motion, and drive arrangement includes: the number of the drive circuits is the same as that of the piezoelectric ceramics; the multi-path driving circuit comprises digital-to-analog converters, controllable voltage reference sources and amplifiers, for example, three driving circuits, which are respectively marked as A, B, C, wherein the A driving circuit is connected with the piezoelectric ceramic A, the B driving circuit is connected with the piezoelectric ceramic B, and the C driving circuit is connected with the piezoelectric ceramic C, wherein the A driving circuit comprises the digital-to-analog converters A, the controllable voltage reference sources A and the amplifiers A, the B driving circuit comprises the digital-to-analog converters B, the controllable voltage reference sources B and the amplifiers B, the C driving circuit comprises the digital-to-analog converters C, the controllable voltage reference sources C and the amplifiers C, and the digital-to-analog converters amplify respective analog signals through the amplifiers and then output voltages applied to the piezoelectric ceramics; the voltage reference value of each digital-to-analog converter is regulated and controlled by a controllable voltage reference source or the amplification factor of each output voltage is regulated by an amplifier, so that the minimum displacement variation of each piezoelectric ceramic is the same, wherein the controllable voltage reference source can be realized by the following schemes including but not limited to the following three schemes, the controllable voltage reference source comprises a voltage-regulating digital-to-analog converter which is different from the digital-to-analog converter, and as shown in fig. 4, the voltage-regulating digital-to-analog converter and the voltage-regulating voltage reference source can output controllable voltage values by inputting digital signals. The controllable voltage reference source can also be realized by a digital potentiometer, as shown in fig. 5. The controllable voltage reference source can also be realized by a digital programmable gain amplifier, as shown in fig. 6. Therefore, in the calibration process, the range of the input digital code does not need to be adjusted, so that each path can keep the designed dynamic range, and the problem of inconsistent displacement resolution of the prior art can be solved, thereby ensuring that the extension and retraction amount of each piezoelectric ceramic is the same when the piezoelectric driver carries out linear displacement.

For example, an embodiment of the present application still provides a driving apparatus of a piezoelectric driver using an 8-bit DAC, with controllable reference voltages Vref1, Vref2, and Vref3, respectively, and with a subsequent amplifier amplification factor of 10. After testing, when the three DACs are all input with the digital code 255 before calibration, the displacements are respectively 9.8um, 10.6um and 8.4 um. When Vref1 is controlled to be 8.57V, Vref2 to be 7.92V and Vref3 is controlled to be 10V, the calibrated system input-output conditions are shown in table 3.

Table 3 shows the input-output conditions of the system after calibration of the driving device of the present application

The system outputs the input code/(2 ^ DAC digit-1) reference voltage amplification factor. It can be seen from the above formula of system output that besides changing the reference voltage, the amplification factor can also be changed, and the amplification factor of the amplifier can be realized by connecting a digital programmable gain amplifier in series on the basis of the original amplifier, as shown in fig. 7. The feedback circuit is realized by connecting a digital potentiometer and a fixed resistance resistor, and is connected with an amplifier, as shown in fig. 8.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. The utility model provides a drive arrangement of piezoelectric actuator, piezoelectric actuator includes stator, active cell and a plurality of piezoceramics, and is a plurality of piezoceramics set up in on the stator for the drive the active cell is according to the motion of predetermineeing the orbit, its characterized in that, drive arrangement includes:

a processor and a multi-path driving circuit;

2. The drive of claim 1, wherein the controllable voltage reference source comprises a voltage regulating digital-to-analog converter.

3. The driving apparatus as claimed in claim 1, wherein the controllable voltage reference source comprises a digital potentiometer.

4. The driving apparatus as claimed in claim 1, wherein the controllable voltage reference source comprises a digital programmable gain amplifier.

5. The driving apparatus of claim 1, further comprising a digital programmable gain amplifier in series with the amplifier.

6. The driving apparatus as claimed in claim 1, further comprising a feedback circuit connected to the amplifier, the feedback circuit comprising a digital potentiometer and a fixed resistance resistor connected to the digital potentiometer.