CN115996306B

CN115996306B - Drive control circuit and method, drive module, camera module and electronic device

Info

Publication number: CN115996306B
Application number: CN202111208239.4A
Authority: CN
Inventors: 李飞; 靳浩楠; 何雨航; 高翔宇; 夏颂; 辛本坚; 任凯乐; 徐卓; 陈伟
Original assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Current assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Priority date: 2021-10-18
Filing date: 2021-10-18
Publication date: 2024-12-31
Anticipated expiration: 2041-10-18
Also published as: CN115996306A; WO2023065857A1

Abstract

The application relates to a drive control circuit and method, a drive module, a camera module, electronic equipment and a storage medium. The driving control circuit comprises a signal generating module and a frequency tracking module, wherein the signal generating module is used for being connected with the piezoelectric motor and generating a driving signal to drive the piezoelectric motor to work, the frequency tracking module is connected with the signal generating module and also used for being connected with the piezoelectric motor, the frequency tracking module is used for detecting an operating electric signal of the piezoelectric motor and outputting an adjusting signal to the signal generating module according to the operating electric signal so that the signal generating module generates the driving signal according to the received adjusting signal, and if the frequency tracking module outputs the adjusting signal corresponding to the maximum operating electric signal, the signal generating module generates a target driving signal with a target frequency to drive the piezoelectric motor to work at a mechanical resonance frequency, and the frequency tracking of the piezoelectric motor can be realized.

Description

Drive control circuit and method, drive module, camera module and electronic equipment

Technical Field

The present application relates to the field of electromechanical control, and in particular, to a driving control circuit and method, a driving module, a camera module, an electronic device, and a storage medium.

Background

The piezoelectric motor is a new type driving motor, which uses the inverse piezoelectric effect of piezoelectric material to convert electric energy into vibration mechanical energy, and then uses friction force to drive the piezoelectric rotor to make rotation or linear motion. Compared with an electromagnetic motor, the piezoelectric motor has unique excitation and motion transmission mechanisms, so that the piezoelectric motor has the characteristics of no magnetic field, strong self-locking capability, quick response, high efficiency, high motion precision, miniaturization and the like, which are incomparable with the traditional electromagnetic motor. As such, research on piezoelectric motors and driving control circuits thereof has become one of research hotspots in the fields of micromachining and motor engineering.

In general, a piezoelectric motor driving control technology adopts an open-loop driving control circuit or a closed-loop driving control circuit, but the closed-loop driving control circuit in the related art is mostly used for controlling the frequency and the phase of the piezoelectric motor, and realizes the speed control of the piezoelectric motor through frequency modulation and phase modulation, and the closed-loop driving control circuit is more complex.

Disclosure of Invention

The application provides a driving control circuit and method, a driving module, a camera module, electronic equipment and a storage medium, which can realize frequency tracking of a piezoelectric motor and have simple structure and low cost.

In a first aspect, an embodiment of the present application provides a drive control circuit including:

The signal generation module is used for being connected with the piezoelectric motor, and the generation module is used for generating a driving signal so as to drive the piezoelectric motor to work;

The frequency tracking module is connected with the signal generation module and is also used for being connected with the piezoelectric motor, the frequency tracking module is used for detecting an operation electric signal of the piezoelectric motor, outputting an adjusting signal to the signal generation module according to the operation electric signal, enabling the signal generation module to generate a driving signal according to the received adjusting signal so as to drive the piezoelectric motor to work at a mechanical resonance frequency, wherein the frequency of the driving signal generated according to the adjusting signal is related to the adjusting signal, and if the frequency tracking module outputs the adjusting signal corresponding to the maximum operation electric signal, the signal generation module generates a target driving signal which is used for driving the piezoelectric motor to work at the mechanical resonance frequency.

The driving control circuit comprises a signal generation module and a frequency tracking module, wherein the signal generation module and the frequency tracking module can be respectively connected with the piezoelectric motor, the signal generation module can generate a driving signal to drive the piezoelectric motor to work, the frequency tracking module can detect an operating electric signal when the piezoelectric motor responds to the current driving signal to work, and output an adjusting signal to the signal generation module according to the operating electric signal, so that the signal generation module adjusts the frequency of the current driving signal according to the received adjusting signal to generate a new driving signal. If the frequency tracking module outputs an adjusting signal corresponding to the maximum working electric signal, the signal generating module generates a target driving signal with a target frequency so as to drive the piezoelectric motor to work at a mechanical resonance frequency. The driving control circuit can carry out closed-loop control on the piezoelectric motor, realizes the frequency tracking of the piezoelectric motor, can track the mechanical resonance frequency point of the piezoelectric motor at any time, and controls the piezoelectric motor to work at the optimal working frequency, namely, to keep at the maximum speed point, thereby ensuring the stability of the performance of the piezoelectric motor. Meanwhile, compared with the isolated pole voltage feedback and phase-locked loop in the related technology, the drive control circuit provided by the embodiment of the application has the advantages of simple circuit structure and low cost.

In a second aspect, an embodiment of the present application provides a drive control method including:

the control signal generation module generates a driving signal to drive the piezoelectric motor to work;

acquiring an operating electric signal of a piezoelectric motor, and outputting an adjusting signal to the signal generating module according to the operating electric signal until a target adjusting signal is output, wherein the target adjusting signal is an adjusting signal corresponding to the maximum operating electric signal, and the frequency of the driving signal is related to the adjusting signal;

and controlling the signal generating module to generate a target driving signal with a target frequency according to the target adjusting signal so as to drive the piezoelectric motor to work at a mechanical resonance frequency.

The driving control method provided by the application can control the signal generation module to generate a driving signal so as to drive the piezoelectric motor to work, acquire the working electric signal of the piezoelectric motor, output the adjusting signal to the signal generation module according to the working electric signal until the target adjusting signal is output, and control the signal generation module to output the target driving signal with the target frequency according to the target adjusting signal so as to drive the piezoelectric motor to work at the mechanical resonance frequency. The driving control method can realize the frequency tracking of the piezoelectric motor, and can track the mechanical resonance frequency point of the piezoelectric motor at any time, so that the frequency tracking is more reliable and stable.

In a third aspect, an embodiment of the present application provides a driving module, including:

A piezoelectric motor is provided with a plurality of electrodes,

The driving control circuit is connected with the piezoelectric motor and used for driving the piezoelectric motor to work at a mechanical resonance frequency.

In a fourth aspect, an embodiment of the present application provides a camera module, including:

The lens seat is of a hollow cavity structure;

A lens including a barrel and a lens mounted to the barrel;

The driving module is connected with the lens base and used for driving the lens cone to move along the optical axis of the lens.

In a fifth aspect, an embodiment of the present application provides an electronic device including a memory storing a computer program and a processor implementing the following steps when the processor executes the computer program:

the control signal generating module generates a driving signal to drive the piezoelectric motor to work;

Acquiring an operating electric signal of a piezoelectric motor, and outputting an adjusting signal to the signal generating module according to the operating electric signal until a target adjusting signal is output, wherein the target adjusting signal is an adjusting signal corresponding to the maximum operating electric signal;

And controlling the signal generating module to output a target driving signal with a target frequency according to the target adjusting signal so as to drive the piezoelectric motor to work at a mechanical resonance frequency.

In a sixth aspect, embodiments of the present application provide a computer readable storage medium having stored thereon a computer program which when executed by a processor performs the steps of:

It may be appreciated that the above-mentioned advantages achieved by the driving module set according to the third aspect and the camera module set according to the fourth aspect may refer to the advantages of the driving control circuit according to the first aspect and any one of the embodiments thereof, which are not described herein.

It will be appreciated that the advantages achieved by the electronic device according to the fifth aspect and the computer readable storage medium according to the sixth aspect may refer to the advantages of the driving control method according to the second aspect and any one of the embodiments, which are not described herein.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments or the conventional techniques of the present application, the drawings required for the descriptions of the embodiments or the conventional techniques will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present application, and other drawings may be obtained according to the drawings without inventive effort for those skilled in the art.

FIG. 1 is a schematic diagram of a driving control circuit according to an embodiment;

FIG. 2 is a second schematic diagram of a driving control circuit according to an embodiment;

FIG. 3 is a third schematic diagram of a driving control circuit according to one embodiment;

FIG. 4 is a schematic diagram of a driving control circuit according to one embodiment;

FIG. 5 is a schematic diagram of a driving control circuit according to an embodiment;

FIG. 6 is a schematic diagram of a driving control circuit according to one embodiment;

FIG. 7 is a schematic diagram of a driving control circuit according to one embodiment;

FIG. 8 is a schematic diagram of a driving control circuit according to an embodiment;

FIG. 9 is a flow chart of a driving control method in one embodiment;

FIG. 10 is a flow chart of detecting an operating electrical signal of a piezoelectric motor and outputting a regulating signal to the signal generating module according to the operating electrical signal until a target regulating signal is output according to an embodiment;

FIG. 11 is a flow chart of detecting an operation electric signal of a piezoelectric motor and outputting a regulating signal to the signal generating module according to the operation electric signal until a target regulating signal is output according to another embodiment;

FIG. 12 is a flow chart of generating the adjustment signal from an electrical signal of operation of the piezoelectric motor in one embodiment;

FIG. 13 is a block diagram of a driving module according to an embodiment.

Detailed Description

In order that the application may be readily understood, a more complete description of the application will be rendered by reference to the appended drawings. Embodiments of the application are illustrated in the accompanying drawings. This application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

It is to be understood that the terms "first," "second," and the like, as used herein, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or number of technical features being indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. The terms "first," "second," and the like may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another element. Furthermore, in the description of the present application, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise. In the description of the present application, the meaning of "several" means at least one, such as one, two, etc., unless specifically defined otherwise.

It will be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element or be connected to the other element through intervening elements. Further, "connection" in the following embodiments should be understood as "electrical connection", "communication connection", and the like if there is transmission of electrical signals or data between objects to be connected.

As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," and/or the like, specify the presence of stated features, integers, steps, operations, elements, components, or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or groups thereof. Also, the term "and/or" as used in this specification includes any and all combinations of the associated listed items.

The piezoelectric motor can be regarded as a complex time-varying system with multiple variables and strong coupling, and shows special dynamics phenomenon and strong nonlinearity, and modeling is difficult. The actual performance of the piezoelectric motor is affected by factors such as load size, pressure between the stator and the rotor, working temperature, rotating speed, steering change and the like. Thus, the inventors have found that it is difficult to control the piezoelectric motor as it is to control a conventional electromagnetic motor. The piezoelectric motor can be applied to a camera module comprising a lens base and a lens. The lens comprises a lens barrel and a lens arranged on the lens barrel. The piezoelectric motor is connected with the lens base and used for driving the lens cone to move along the optical axis of the lens.

In the related art, most of the piezoelectric motor driving technologies adopt relatively mature open-loop driving control circuits. The power amplifier mainly comprises a frequency generation module, a split-phase frequency division module and a power amplifier matching module. The frequency generation module can send out simple harmonic driving signals with certain frequency, the frequency division and phase separation module divides the excitation driving signals into multiphase signals and different signals should have certain phase difference, and the power amplification matching module further processes the signals so that the power of the excitation signals can drive the piezoelectric motor. In general, an open-loop driving control circuit outputs a fixed driving frequency, and the mechanical characteristics of the piezoelectric motor are changed to a certain extent due to the loss caused by long-term operation of the piezoelectric motor, so that an optimum frequency point (a mechanical resonance frequency point) is shifted, and when the optimum frequency point is shifted, the output of the piezoelectric motor becomes smaller and smaller (including driving force, driving speed, etc.).

In the related art, a relatively closed-loop driving control circuit is used for controlling the frequency and the speed phase of the piezoelectric motor. The closed-loop control circuit of the piezoelectric motor in the related art is mostly used for controlling the frequency and the phase of the piezoelectric motor, and the speed control of the piezoelectric motor is realized through frequency modulation and phase modulation. In the design of a closed-loop control circuit, a driving control circuit mostly adopts a bridge push-pull circuit controlled by pulse width modulation (Pulse width modulation, PWM), and a loop control mostly adopts a lone voltage loop and a Phase Lock Loop (PLL) to realize frequency loop. However, for the piezoelectric motor (L1B 2 piezoelectric motor for short) with the coupling mode of the first-order extension and the second-order bending, the piezoelectric motor always works at the maximum speed point and has no speed regulation requirement, so for the closed loop isolated pole voltage and the phase-locked loop circulation control in the related technology, the complexity of the closed loop control circuit is high, the relative speed is low, and the cost is high.

Based on the above analysis, the inventor researches and discovers that aiming at the driving control of the L1B2 piezoelectric motor, the application provides a driving control circuit which can realize closed-loop control of the piezoelectric motor, realize frequency tracking of the piezoelectric motor, can track the mechanical resonance frequency point of the piezoelectric motor at any time and control the piezoelectric motor to work at the optimal working frequency, namely, to keep at the maximum speed point. Meanwhile, compared with the isolated pole voltage feedback and phase-locked loop in the related technology, the drive control circuit provided by the embodiment of the application has the advantages of simple circuit structure, high drive speed and low cost.

In one embodiment, as shown in fig. 1, an embodiment of the present application provides a drive control circuit for implementing the driving of the piezoelectric motor 200. Specifically, the drive control circuit 100 includes a signal generation module 110 and a frequency tracking module 120. The signal generating module 110 is connected to the piezoelectric motor 200, and the signal generating module 110 is configured to generate a driving signal and output the driving signal to the piezoelectric motor 200 to drive the piezoelectric motor 200 to work. The driving signal may be a high-frequency sinusoidal voltage signal, and when the high-frequency sinusoidal voltage signal acts on the piezoelectric stator of the piezoelectric motor 200, the piezoelectric stator is driven to generate elliptical motion, so as to drive the piezoelectric motor 200.

The frequency tracking module 120 is respectively connected to the signal generating module 110 and the piezoelectric motor 200, and the frequency tracking module 120 is configured to detect an operating electrical signal of the piezoelectric motor 200, and output an adjusting signal to the signal generating module 110 according to the operating electrical signal, so that the signal generating module 110 generates a driving signal according to the received adjusting signal. Wherein the frequency of the driving signal generated from the adjustment signal is related to the adjustment signal. The signal generation module 110 generates a driving signal before receiving the adjustment signal at a frequency different from that of the driving signal generated according to the received adjustment signal. Specifically, when the piezoelectric motor 200 starts to operate under the action of the driving signal (e.g., the first driving signal), the frequency tracking module 120 may collect the operating electrical signal of the piezoelectric motor 200, and further may output the adjusting signal to the signal generating module 110 according to the collected operating electrical signal, so that the signal generating module 110 adjusts the frequency of the first driving signal according to the received adjusting signal to generate the second driving signal, and drives the piezoelectric motor 200 based on the second driving signal. In this manner, the signal generation module 110 may continuously generate a new driving signal to drive the piezoelectric motor 200 according to the adjustment signal. If the frequency tracking module 120 outputs an adjustment signal corresponding to the maximum operating electric signal, the signal generating module 110 generates a target driving signal having a target frequency. The target drive signal is for use where the target frequency of the drive signal is the same as the mechanical resonant frequency of the piezoelectric motor 200. That is, the target drive signal generated by the signal generation module 110 may drive the piezoelectric motor 200 to operate at a mechanical resonant frequency.

The driving control circuit 100 provided in the embodiment of the application includes a signal generating module 110 and a frequency tracking module 120, where the signal generating module 110 and the frequency tracking module 120 may be respectively connected to the piezoelectric motor 200, the signal generating module 110 may generate a driving signal to drive the piezoelectric motor 200 to work, the frequency tracking module 120 may detect an operating electric signal when the piezoelectric motor 200 operates in response to a current driving signal, and output an adjusting signal to the signal generating module 110 according to the operating electric signal, so that the signal generating module 110 generates a new driving signal according to the received adjusting signal. If the frequency tracking module 120 outputs an adjustment signal corresponding to the maximum operating electric signal, the signal generating module 110 generates a target driving signal having a target frequency to drive the piezoelectric motor to operate at the mechanical resonance frequency. The drive control circuit 100 realizes closed-loop control of the piezoelectric motor 200 through the signal generating module 110 and the frequency tracking module 120, realizes frequency tracking of the piezoelectric motor 200, can track the mechanical resonance frequency point of the piezoelectric motor 200 at any time, and controls the piezoelectric motor 200 to work at an optimal working frequency, namely, to keep at a maximum speed point, thereby ensuring the stability of the performance of the piezoelectric motor 200. Meanwhile, compared with the isolated pole voltage feedback and the phase-locked loop in the related art, the drive control circuit 100 provided by the embodiment of the application has the advantages of simple circuit structure and low cost.

In one embodiment, as shown in fig. 2, the frequency tracking module 120 includes a detection unit 121, a conversion unit 122, and a processing unit 123 electrically connected in sequence. Wherein, the detection unit 121 is configured to be connected to the piezoelectric motor 200, and the detection unit 121 is configured to detect the operation electric signal of the piezoelectric motor 200 and output a voltage signal corresponding to the operation electric signal. Among them, the detection unit 121 may be used to detect an operation electric signal of the piezoelectric motor 200 in response to a driving signal. The working electric signal can be a current signal or a voltage signal.

The detection unit 121 may include a current detection unit, which may be used to detect a current signal of the piezoelectric motor 200. The current detection unit may include a current hall detector, and may also include a sampling resistor. For convenience of explanation, the current detection unit is taken as a sampling resistor for illustration. In the embodiment of the present application, a sampling resistor (a resistor of about several hundred ohms) may be used to collect a current signal of the piezoelectric stator in the piezoelectric motor 200, and convert the current signal into a voltage signal and output the voltage signal to the conversion unit 122 for conversion processing. The current signal of the piezoelectric stator is an alternating current signal, and the converted voltage signal is also an alternating voltage signal. In the embodiment of the present application, an operation electric signal of a piezoelectric motor is taken as an operation electric signal of a piezoelectric stator as an example.

In the embodiment of the application, the current signal of the piezoelectric stator is weak, and the sampling resistor with smaller resistance is adopted to collect the current signal, so that the collection accuracy of the current signal can be improved, and the accuracy of the target driving signal can be further improved.

Alternatively, the detecting unit 121 may be a voltage detecting unit for detecting a voltage signal of the piezoelectric motor 200. The voltage detecting unit may be a voltage hall detector, which is configured to detect an ac voltage signal of the piezoelectric stator in the piezoelectric motor 200, and send the detected ac voltage signal to the converting unit 122 for conversion processing.

And a conversion unit 122 connected to the detection unit 121, for receiving the voltage signal and converting the voltage signal into a digital signal. As shown in fig. 3, the conversion unit 122 may include an analog-to-digital converter (Analog digital converter, ADC) 1222 for converting an analog signal corresponding to the voltage signal into a digital signal to output the digital signal to the processing unit 123. The analog-to-digital converter 1222 may be a high-speed ADC sampling circuit, among other things.

Further, the conversion unit 122 further includes a Root Mean Square (RMS) converter 1221, wherein an input terminal of the RMS converter 1221 is connected to the detection unit 121, and an output terminal of the RMS converter 1221 is connected to the analog-to-digital converter 1222. The effective value converter 1221 may be configured to perform effective value RMS calculation on the received ac voltage signal to obtain an effective value voltage. It will be appreciated that the active value converter 1221 is capable of converting an ac voltage signal to a dc voltage signal, i.e. the active value converter 1221 may convert a high frequency sinusoidal ac voltage signal to an active value voltage signal. Meanwhile, the significand converter 1221 may transmit its significand voltage signal to the analog-to-digital converter 1222 to convert the significand voltage signal into a digital signal to output the digital signal to the processing unit 123. In particular, the active value converter 1221 may include, but is not limited to, an active value-to-direct current converter.

The processing unit 123 can track the frequency of the piezoelectric motor 200 according to the data signal, so that real-time tracking of the resonant frequency of the piezoelectric motor 200 can be realized. Specifically, the processing unit 123 is connected to the converting unit 122 and the signal generating module 110, and is configured to receive the digital signal, and output the adjustment signal according to the digital signal, so as to control the signal generating module 110 to generate the driving signal according to the received adjustment signal. Wherein, the adjusting signal corresponding to the maximum current signal of the piezoelectric motor 200 is a target adjusting signal, and the signal generating module 110 may generate the target driving signal with the frequency at the mechanical resonance frequency according to the received target adjusting signal. For example, if the current signal is a current signal, the maximum current signal may be understood as a maximum current value. The processing unit 123 is further configured to output the target adjustment signal to the signal generating module 110, so that the signal generating module 110 generates a target driving signal with the target frequency, that is, a high-frequency sinusoidal voltage signal, so as to perform driving control on the piezoelectric motor 200, thereby achieving the purpose of frequency tracking.

The processing unit 123 may be a Single-chip microcomputer (SCM), a field programmable gate array (Field Programmable GATE ARRAY, FPGA), a central processing unit (Central Processing Unit, CPU), or a control processing device capable of performing analysis processing on a digital signal. Further, the processing unit 123 may further include a register, which is connected to the analog-to-digital converter 1222 and is used for receiving the digital signal, and the processing unit 123 may output the adjustment signal based on the digital signal received by the register, so as to control the signal generating module 110 to adjust the frequency of the driving signal until the current value of the current signal of the piezoelectric motor 200 reaches the maximum. Further, the processor may output the adjustment signal based on the mapping relationship between the digital signal and the current signal, which are stored in the register in the processing unit 123.

The processing unit 123 may perform a cyclic operation in which the processing unit 123 may drive the piezoelectric motor 200 to operate according to a current driving signal, and generate an adjustment signal according to a current signal of the piezoelectric motor 200 and output the adjustment signal to the signal generation module 110, so that the signal generation module 110 can adjust a frequency of the current driving signal according to the received adjustment signal to generate a new driving signal, and acquire the current signal of the piezoelectric motor 200 in response to the new driving signal. In this process, the current signal of the piezoelectric motor may be obtained based on the mapping relation stored in advance by the processing unit and the received digital signal.

Specifically, for any two adjacent moments, it is determined whether the difference between the second current signal corresponding to the current moment of the piezoelectric motor 200 and the first current signal corresponding to the previous moment of the piezoelectric motor 200 is smaller than a preset value. And if the difference value is smaller than the preset value, taking the adjusting signal corresponding to the second current signal as the target adjusting signal. According to the impedance spectrum analysis characteristic of the piezoelectric stator, the working current of the piezoelectric stator has a unique maximum value (or a maximum value) in a certain frequency range. Therefore, when the current value of the second circuit signal I (I) corresponding to the current time is compared with the current value of the first current signal I (I-1) corresponding to the previous time (or the previous time), if the current value of the second circuit signal I (I) has a decreasing trend with respect to the current value of the first current signal I (I-1), the current value of the first current signal I (I-1) may be the only maximum value of the operating current of the piezoelectric stator, and the corresponding adjustment signal of the first current signal I (I-1) may be the target adjustment signal. The processing unit 123 outputs the target adjustment signal to the signal generating module 110, so that the signal generating module 110 generates a driving signal with a target frequency according to the target adjustment signal, so that the piezoelectric motor 200 operates at a mechanical resonance frequency, thereby achieving the purpose of frequency tracking.

In one embodiment, if the current value of the second circuit signal I (I) has a tendency to rise relative to the current value of the first current signal I (I-1), it is indicated that the current value of the first current signal I (I-1) of the piezoelectric stator does not reach the maximum value. At this time, the processing unit 123 generates a corresponding adjusting signal according to the second circuit signal I (I), so that the signal generating module 110 adjusts the frequency of the driving signal according to the preset sweep strategy. For example, the processing unit 123 may output a corresponding adjustment signal, so that the signal generating module 110 performs sweep adjustment on the frequency of the driving signal according to the received adjustment signal in one of the following manners:

starting from a first initial frequency, gradually increasing a first preset sweep frequency amount;

starting from a second initial frequency, gradually reducing a second preset sweep frequency amount;

The third mode is that a third preset frequency sweep amount is gradually increased from the first initial frequency until a target frequency sweep interval is determined, and frequency sweep is carried out in the target frequency sweep interval by a fourth preset frequency sweep amount, wherein the second initial frequency is larger than the first initial frequency, and the fourth preset frequency sweep amount is lower than the third preset frequency sweep amount, and the target frequency sweep interval comprises the target frequency.

The first preset frequency sweep amount, the second preset frequency sweep amount and the third preset frequency sweep amount can be the same or different. The preset frequency sweep amount may be set according to the operation property of the piezoelectric motor 200. The first initial frequency may be reasonably designed according to the resonant frequency f_r 'measured by the piezoelectric stator at the impedance spectrum analyzer, for example, the initial frequency f (0) =f_r' -100kHz may be set.

When the signal generating module 110 performs sweep frequency adjustment on the frequency of the driving signal according to the adjustment signal, the frequency tracking module 120 may circularly detect the second working current of the piezoelectric motor 200 at the current time and the first working current corresponding to the previous time until the working current with the maximum value is determined, and then determine the optimal resonant frequency f_r of the piezoelectric motor 200, which is the mechanical resonant frequency of the piezoelectric motor 200. After the resonant frequency of the piezoelectric stator is determined, the resonant frequency is given to the driving signal generating circuit to output a high-frequency sinusoidal alternating current signal with corresponding frequency, so that the aim of frequency tracking is fulfilled.

In the embodiment of the application, by arranging the frequency tracking module 120, the working current of the piezoelectric motor 200 can be monitored in real time, and the resonant frequency of the piezoelectric motor 200 can be corrected, so that the piezoelectric motor 200 works at a mechanical resonant frequency point, and the stability of the performance output of the piezoelectric motor 200 and the stability under long-term working are improved.

In one embodiment, as shown in fig. 4, the signal generating module 110 includes a control unit 111 and a generating unit 112. The control unit 111 is connected to the frequency tracking module 120, and is configured to generate an adjustment instruction according to the received adjustment signal. The control unit 111 is a control core unit of the drive control circuit 100, and can perform operations such as program logic operation control and high-speed a/D conversion. Of course, the control unit 111 may output a driving instruction, may also receive a target adjustment signal output by the processing unit 123 of the frequency tracking module 120, and may generate a target adjustment instruction according to the target adjustment signal. The drive instruction is for instructing the generating unit 112 to generate a drive signal, and the target adjustment instruction is for instructing the generating unit 112 to generate a target drive signal. The driving instruction may be generated autonomously by the control unit 111, or may receive a driving instruction output by another module. In the embodiment of the present application, it should be noted that a specific generation manner of the driving instruction is not further limited.

The generating unit 112 is connected to the control unit 111 and the piezoelectric motor 200, respectively. The generating unit 112 is configured to generate the driving signal according to a driving instruction to drive the piezoelectric motor 200 to operate. In an initial stage of driving the piezoelectric motor 200, the generating unit 112 may generate a driving signal under the control of the driving command of the control unit 111, where the frequency of the driving signal may be a high-frequency sinusoidal voltage signal with a frequency similar to the resonant frequency of the piezoelectric motor 200.

Further, the generating unit 112 may also adjust the frequency of the driving signal according to the adjustment instruction to generate a new driving signal. The generating unit 112 may also adjust the frequency of the driving signal according to the adjustment instruction so that the adjusted frequency can be closer to the mechanical resonance frequency of the piezoelectric motor 200. In addition, the generating unit 112 may further adjust the frequency of the driving signal to the mechanical resonant frequency according to the received target adjustment command, so that the driving frequency of the driving signal is equal to the mechanical resonant frequency, thereby achieving the purpose of frequency tracking, and further improving the driving accuracy of the piezoelectric motor 200.

In one embodiment, the generating unit 112 includes a direct digital synthesis (DIRECT DIGITAL SYNTHESIS, DDS) signal generator for generating a high-frequency sinusoidal voltage signal and adjusting the frequency of the high-frequency sinusoidal voltage signal according to the adjustment instruction. The DDS signal generator adopts a direct digital frequency synthesis technology, improves the frequency stability and accuracy of the signal generator to the same level as the reference frequency, and can carry out fine frequency adjustment in a very wide frequency range. In addition, the DDS signal generator can perform serial and parallel input modes, is simple to control, and generates signals with stable frequency and amplitude.

In the embodiment of the application, the DDS signal generator is adopted, so that the driving signal of the high-frequency sinusoidal voltage signal can be generated, the stability of the output driving signal is extremely high, and the driving stability of the piezoelectric motor 200 can be further improved.

In one embodiment, as shown in FIG. 5, the signal generation module 110 further includes an input unit 113 connected to the control unit 111. Wherein the input unit 113 is used for responding to external operation and generating a driving instruction. The driving command may be output to the control unit 111, and the control unit 111 controls the generating unit 112 to generate a high-frequency sinusoidal signal with a frequency similar to the mechanical resonance frequency of the piezoelectric motor 200 according to the received driving command. Wherein the input unit 113 may optionally include a touch screen, keys, a data port, etc. For example, the user may input a driving instruction to the control unit 111 through the input unit 113.

In the present embodiment, by providing the input unit 113, the generation timing of the driving instruction can be decided by the user to achieve flexible driving of the piezoelectric motor 200.

In one embodiment, as shown in fig. 6, the signal generating module 110 further includes a first filtering unit 114 and a first amplifying unit 115. The first filtering unit 114 is connected to the generating unit 112, and is configured to perform a low-pass filtering process on the driving signal output by the generating unit 112. Specifically, the first filtering unit 114 may include one or more cascaded low-pass filters, which may filter out a portion of the high-frequency interference signal in the driving signal. The input end of the first amplifying unit 115 is connected to the output end of the first filtering unit 114, and the output end of the first amplifying unit 115 is connected to the piezoelectric motor 200, so as to amplify the driving signal output by the first filtering unit 114, and output the amplified driving signal to the piezoelectric motor 200, thereby driving the piezoelectric motor 200. Specifically, the first amplifying unit 115 may be a high-frequency high-speed operational amplifier chip, which amplifies the voltage of the driving signal from mV level to 1V, and thus may increase the voltage value of the driving signal. The processing order of the driving signals by the first filtering unit 114 and the first amplifying unit 115 may also be interchanged. For example, an input of the first amplifying unit 115 is connected to the generating unit 112, an output of the first amplifying unit 115 is connected to an input of the first filtering unit 114, and an output of the first filtering unit 114 is connected to the piezoelectric motor 200.

In this embodiment, the first filtering unit 114 is designed to perform filtering processing on the driving signal, filter out a part of high-frequency interference signals in the driving signal, and amplify the driving signal after the filtering processing to amplify the voltage value of the driving signal, so that the driving signal with high amplitude and no interference can be output to the piezoelectric motor, the influence of the interference signals in the driving signal on the piezoelectric motor 200 can be reduced, and then accurate tracking and accurate driving on the frequency of the piezoelectric motor 200 can be realized.

In one embodiment, as shown in fig. 6, the signal generating module 110 further includes a clock unit 116 connected to the control unit 111 and the generating unit 112, respectively. The clock unit 116 can provide clock signals to the control unit 111 and the generating unit 112, respectively, so that the generating unit 112 and the clock of the control unit 111 are kept synchronous. Specifically, the clock unit 116 may be any one of a global clock unit, a gate clock unit, a multi-stage logic clock unit, and a ripple clock unit. It should be noted that, in the embodiment of the present application, the type of the clock unit is not limited to the above-mentioned example, but may be other types of clock units.

In the embodiment of the present application, by providing the clock unit 116, a clock signal, that is, a reference clock, may be provided to the driving control circuit 100, so that clocks of the control unit 111 and the generating unit 112 may be ensured to be kept synchronous, so that control operation may be performed on the driving control circuit 100, and timeliness of frequency tracking may be improved.

In one embodiment, as shown in fig. 7 and 8, on the basis of any of the foregoing embodiments, the driving control circuit 100 further includes a signal amplifying module 130 respectively connected to the signal generating module 110 and the piezoelectric motor 200. The signal amplifying module 130 may amplify and filter the driving signal output from the signal generating module 110. Specifically, the signal amplifying module 130 may include a second filtering unit 131 and a second amplifying unit 132. The second filtering unit 131 is connected to the signal generating module 110, and is configured to perform filtering processing on the driving signal output by the signal generating module 110. The second filtering unit 131 may be the same as the first filtering unit 114, and is a low-pass filter to filter out spurious high-frequency signals of the driving signal.

The input end of the second amplifying unit 132 is connected to the second filtering unit 131, and the input end of the second amplifying unit 132 is connected to the piezoelectric motor 200, so as to amplify the driving signal filtered by the second filtering unit 131, and output the amplified driving signal to the piezoelectric motor 200. Specifically, the second amplifying unit 132 may amplify the voltage of the driving signal from mV level to above 100V. The second amplifying unit 132 may be a high-frequency high-speed operational amplifier chip, similar to the first amplifying unit 115. The amplification factor (or gain factor, bandwidth, and amplitude of the second amplification unit 132 may be determined according to the operation parameters of the piezoelectric motor 200 to be driven (e.g., simulation results of the piezoelectric stator of the piezoelectric motor 200 when operated), it is to be noted that, for example, an input end of the second amplifying unit 132 is connected to the signal generating module 110, an output end of the second amplifying unit 132 is connected to an input end of the second filtering unit 131, and an output end of the second filtering unit 131 is connected to the piezoelectric motor 200.

In this embodiment, if the driving control circuit 100 includes the first filtering unit 114, the first amplifying unit 115, the second filtering unit 131 and the second amplifying unit 132, the driving signal output by the signal generating module 110 may be subjected to the secondary filtering and secondary amplifying process, so that the driving signal after the secondary filtering and secondary amplifying can better act on the piezoelectric stator of the piezoelectric motor 200, and the piezoelectric stator is driven to generate an elliptical motion, so as to drive the piezoelectric motor 200.

In one embodiment, as shown in fig. 9, a drive control method is provided. The drive control method may be applied to the drive control circuit in any of the foregoing embodiments. Specifically, the driving control method includes steps 902 to 906.

In step 902, the control signal generating module generates a driving signal to drive the piezoelectric motor to operate.

The signal generating module is connected with the piezoelectric motor, and can generate a driving signal under the control of the driving control circuit and output the driving signal to the piezoelectric motor so as to drive the piezoelectric motor to work. The driving signal may be a high-frequency sinusoidal voltage signal, and when the high-frequency sinusoidal voltage signal acts on the piezoelectric stator of the piezoelectric motor, the piezoelectric stator is driven to generate elliptical motion, so as to drive the piezoelectric motor.

Step 904, acquiring an operating electric signal of the piezoelectric motor, and outputting an adjusting signal to the signal generating module according to the operating electric signal until a target adjusting signal is output, wherein the frequency of the driving signal is related to the adjusting signal, and the target adjusting signal is an adjusting signal corresponding to the maximum operating electric signal.

The driving control circuit can detect the working electric signal of the piezoelectric motor based on the detection unit and output an adjusting signal to the signal generating module according to the working electric signal, so that the signal generating module can feedback adjust the frequency of the driving signal according to the adjusting signal to generate a new driving signal until the driving control circuit outputs a target adjusting signal. That is, when the piezoelectric motor starts to operate under the action of the driving signal (e.g., the first driving signal), the driving control circuit may collect the operating electric signal of the piezoelectric motor, and may output the adjusting signal to the signal generating module according to the collected operating electric signal, so that the signal generating module adjusts the frequency of the first driving signal according to the received adjusting signal to generate the second driving signal, and drives the piezoelectric motor based on the second driving signal. In this way, the signal generating module can continuously generate a new driving signal to drive the piezoelectric motor according to the adjusting signal until the driving control circuit determines the target adjusting signal according to the working electric signal of the piezoelectric motor.

Step 906, controlling the signal generating module to generate a target driving signal with a target frequency according to the target adjusting signal, so as to drive the piezoelectric motor to work at a mechanical resonance frequency.

The drive control circuit may transmit the determined target adjustment signal to a signal generation module, which may output a target drive signal having a target frequency according to the target adjustment signal to drive the piezoelectric motor to operate at a mechanical resonance frequency. Wherein the target frequency of the drive signal is the same as the mechanical resonant frequency of the piezoelectric motor.

The driving control method provided by the embodiment of the application can control the signal generation module to generate a driving signal so as to drive the piezoelectric motor to work, acquire the working electric signal of the piezoelectric motor, output the adjusting signal to the signal generation module according to the working electric signal until the target adjusting signal is output, and control the signal generation module to output the target driving signal with the target frequency according to the target adjusting signal so as to drive the piezoelectric motor to work at the mechanical resonance frequency. The driving control method can realize the frequency tracking of the piezoelectric motor, and can track the mechanical resonance frequency point of the piezoelectric motor at any time, so that the frequency tracking is more reliable and stable.

In one embodiment, as shown in fig. 10, the detecting an operation electric signal of the piezoelectric motor and outputting an adjustment signal to the signal generating module according to the operation electric signal until outputting a target adjustment signal includes steps 1002 to 1008.

Step 1002, generating the adjustment signal according to an operating electric signal of the piezoelectric motor.

In the embodiment of the present application, an operation electric signal is described as an example of a current signal. The drive control circuit can detect an alternating current signal of a piezoelectric stator in the piezoelectric motor and generate an adjusting signal according to the detected alternating current signal. The adjustment signal may be used to adjust the frequency of the drive signal.

Step 1004, controlling the signal generating module to adjust the frequency of the driving signal according to the adjusting signal, and detecting the current signal of the piezoelectric motor responding to the adjusted driving signal.

The driving control circuit can control the signal generating module to adjust the frequency of the driving signal according to the adjusting signal. The signal generating module can output a target driving signal with the frequency at the mechanical resonance frequency, namely a high-frequency sinusoidal voltage signal, according to the target adjusting signal, so as to drive and control the piezoelectric motor, thereby achieving the purpose of frequency tracking. The driving control circuit can generate a regulating signal according to the current signal of the piezoelectric motor at the current moment and output the regulating signal to the signal generating module so that the signal generating module can regulate the frequency of the driving signal according to the regulating signal and acquire the current signal of the piezoelectric motor responding to the regulated driving signal.

Step 1006, determining whether a difference value between the second current signal corresponding to the current time of the piezoelectric motor and the first current signal corresponding to the previous time of the piezoelectric motor is smaller than a preset value.

According to the impedance spectrum analysis characteristic of the piezoelectric stator, the working current of the piezoelectric stator has a unique maximum value (or a maximum value) in a certain frequency range. Specifically, for any two adjacent moments, it is determined whether the difference between the current value of the second current signal I (I) corresponding to the current moment of the piezoelectric motor and the current value of the first current signal I (I-1) corresponding to the previous moment of the piezoelectric motor is smaller than a preset value. Wherein the preset value is a value greater than or equal to 0.

And step 1008, if the difference value is smaller than the preset value, taking the adjusting signal corresponding to the second current signal as the target adjusting signal.

If the difference is smaller than the preset value, if the current value of the second circuit signal I (I) has a decreasing trend relative to the current value of the first current signal I (I-1), the current value of the first current signal I (I-1) may be used as the working current of the piezoelectric stator to have a unique maximum value, and the corresponding adjustment signal of the first current signal I (I-1) may be used as the target adjustment signal. The driving control circuit outputs the target adjusting signal to the signal generating module so that the signal generating module adjusts the frequency of the driving signal to the target frequency according to the target adjusting signal, thereby achieving the purpose of frequency tracking.

In one embodiment, as shown in fig. 11, the driving control method further includes executing step 1112 to feedback-adjust the frequency of the driving signal according to a preset sweep strategy if the difference is greater than or equal to the preset value.

If the difference is greater than or equal to the preset value, it may be indicated that the current value of the second circuit signal I (I) has a tendency to rise relative to the current value of the first current signal I (I-1), which indicates that the current value of the first current signal I (I-1) of the piezoelectric stator does not reach the maximum value. At this time, the driving control circuit generates a corresponding adjusting signal according to the second circuit signal I (I), so that the signal generating module adjusts the frequency of the driving signal according to a preset frequency sweep strategy. For example, the drive control circuit may output a corresponding adjustment signal to cause the signal generation module to perform sweep adjustment on the frequency of the drive signal according to the adjustment signal in one of the following manners:

The first mode is that the first preset sweep frequency quantity is gradually increased from the first initial frequency.

The first initial frequency can be reasonably designed according to the resonant frequency f_r' measured by the piezoelectric stator in the impedance spectrum analyzer. For example, the first initial frequency may be set as an initial frequency, where initial frequency f (0) =f_r' -100kHz. In one mode, the signal generating module may gradually increase the first preset frequency sweep δf1 from the initial frequency based on the received adjustment signal, so as to adjust the frequency of the driving signal. For example, the frequencies of the drive signals, f (0), f (0) +δf1, f (0) +2 δf1, f (0) +3 δf1, f (0) +n δf1, may be adjusted in this order.

And secondly, gradually reducing a second preset sweep frequency amount from the second initial frequency.

The second initial frequency may be set as an initial frequency, wherein the initial frequency f (0) =f_r' +100kHz. In a second mode, the signal generating module may gradually decrease the second preset frequency sweep δf2 from the initial frequency based on the received adjustment signal, so as to adjust the frequency of the driving signal. For example, the frequencies of the drive signals, f (0), f (0) - δf2, f (0) -2 δf2, f (0) -3 δf2,..f (0) -n δf2, may be adjusted in this order. Wherein the second initial frequency is greater than the first initial frequency,

And thirdly, gradually increasing or decreasing a third preset frequency sweep amount from the first initial frequency until a target frequency sweep interval is determined, and carrying out frequency sweep in the target frequency sweep interval by a fourth preset frequency sweep amount.

The method of the first or second mode can be referred to determine the target sweep interval first, then sweep is performed in the target sweep interval by the method of the first or second mode with the fourth preset sweep amount until the target frequency point is determined. The fourth preset frequency sweep amount is lower than the third preset frequency sweep amount, wherein the target frequency sweep area comprises target frequency. The first preset frequency sweep amount, the second preset frequency sweep amount and the third preset frequency sweep amount can be the same or different. The preset frequency sweep amount can be set according to the working property of the piezoelectric motor.

In this embodiment, step 1102 corresponds to step 1002 in the foregoing embodiment, steps 1104 to 1106 correspond to step 1004 in the foregoing embodiment, and step 1108 corresponds to step 1006 in the foregoing embodiment, and will not be described again.

In the embodiment of the application, when the driving control circuit controls the signal generating module to carry out sweep frequency adjustment on the frequency of the driving signal according to any mode, the driving control circuit can circularly detect the second working current of the piezoelectric motor at the current moment and the first working current corresponding to the previous moment until the working current with the maximum value is determined, and then the optimal resonant frequency f_r of the piezoelectric motor is determined, wherein the frequency is the mechanical resonant frequency of the piezoelectric motor. After the resonant frequency of the piezoelectric stator is determined, the resonant frequency is given to the driving signal generating circuit to output a high-frequency sinusoidal alternating current signal with corresponding frequency, so that the aim of frequency tracking is fulfilled. When the mode III is adopted, the target frequency sweeping area can be positioned quickly by rough frequency sweeping, then the target frequency point is positioned in the target frequency sweeping area in a frequency sweeping mode, and the frequency sweeping efficiency and the frequency sweeping accuracy of the target frequency point can be improved.

In one embodiment, please continue with fig. 11, the driving control method further includes step 1100 of initializing the driving signal of the piezoelectric motor. The driving signal may include a signal input to the piezoelectric stator, including a voltage amplitude v_in, an initial frequency f (0), and an initial current I (0), where the voltage amplitude v_in is reasonably set according to an amplification factor of the second amplifying unit in the driving control circuit. Specifically, an actual driving voltage can be obtained through simulation according to required performance parameters, and then the amplification factor of the whole circuit is confirmed according to the output voltage of the signal generation module. The initial frequency f (0) is reasonably designed according to the resonant frequency f_r 'measured by the piezoelectric stator in the impedance spectrum analyzer (for example, f (0) =f_r' -100 kHz) and the initial current I (0) is set to be zero.

In the embodiment of the application, the accuracy of tracking frequency can be further improved by carrying out initialization setting on the initial driving signal.

In one embodiment, as shown in fig. 12, the operating electrical signal includes a current signal, and the generating the adjustment signal from the operating electrical signal of the piezoelectric motor includes steps 1202 to 1208.

Step 1202, outputting a voltage signal corresponding to the working electric signal according to the working electric signal.

When the operating electrical signal is a current signal, a sampling resistor (a resistor of about several hundred ohms) may be used to collect a current signal of a piezoelectric stator in the piezoelectric motor and convert the current signal into a voltage signal for output.

Step 1204, converting the voltage signal into a valid value voltage.

And carrying out effective value RMS calculation on the received alternating voltage signal based on the effective value converter to obtain effective value voltage. It will be appreciated that the active value converter is capable of converting an ac voltage signal to a dc voltage signal, i.e. the active value converter is capable of converting a high frequency sinusoidal ac voltage signal to an active value voltage signal.

Step 1206 converts the analog signal of the effective value voltage to a digital signal.

The received effective value voltage signal is converted into a digital signal based on an analog-to-digital converter.

Step 1208, generating the adjustment signal according to the current signal corresponding to the digital signal.

The drive control circuit may correspond to a map between the digital signal and the current signal, in which the effective value voltage signal thereof is stored in advance, and then commonly output the adjustment signal thereof based on the map and the digital signal.

In this embodiment, the driving control circuit may generate the foregoing adjustment signal according to the received digital signal, so as to implement frequency tracking of the piezoelectric motor. The driving control circuit in the embodiment of the application can be applied to a processing unit (such as a singlechip) of the frequency tracking module in the driving control circuit, can improve the efficiency of frequency tracking, and can also enable the frequency tracking to be more reliable and stable.

It should be understood that, although the steps in the flowcharts of fig. 9 to 12 are shown in order as indicated by the arrows, these steps are not necessarily performed in order as indicated by the arrows. The steps are not strictly limited to the order of execution unless explicitly recited herein, and the steps may be performed in other orders. Moreover, at least a portion of the steps of fig. 9-12 may include multiple steps or stages that are not necessarily performed at the same time, but may be performed at different times, nor does the order in which the steps or stages are performed necessarily occur sequentially, but may be performed alternately or alternately with other steps or at least a portion of the steps or stages in other steps.

In one embodiment, as shown in fig. 13, the embodiment of the present application further provides a driving module, which is characterized by comprising a piezoelectric motor 200 and the driving control circuit 100 in any of the foregoing embodiments. The driving control circuit 100 can track the frequency of the piezoelectric motor 200, and further realize accurate driving of the piezoelectric motor 200, so that the piezoelectric motor 200 can always work at an optimal working frequency, namely, keep at a maximum speed point, and further ensure the stability of the performance of the piezoelectric motor. Compared with the isolated pole voltage feedback and the phase-locked loop in the related art, the drive module provided by the embodiment of the application has the advantages of simple circuit structure and low cost.

In one embodiment, the embodiment of the application further provides a camera module. The camera module comprises a lens seat, a lens and the driving module. The lens comprises a lens barrel and a lens arranged on the lens barrel. The driving module is connected with the lens base and used for driving the lens cone to move along the optical axis of the lens.

In the embodiment of the application, when the driving module for driving the lens barrel to move along the optical axis of the lens is arranged, the mechanical resonance frequency point of the piezoelectric motor can be tracked at any time, and the piezoelectric motor is controlled to work at the optimal working frequency, namely, the maximum speed point is kept, so that the stability of the performance of the piezoelectric motor is ensured, and the camera module has better adaptability to extreme conditions such as dropping, collision and the like.

In one embodiment, an electronic device is provided that includes a memory having a computer program stored therein and a processor that when executing the computer program implements the drive control method of any of the foregoing embodiments.

In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored which, when executed by a processor, implements the drive control method of any of the preceding embodiments.

A computer program product comprising instructions which, when run on a computer, cause the computer to perform the drive control method of any of the preceding embodiments.

Those skilled in the art will appreciate that implementing all or part of the above described methods may be accomplished by way of a computer program stored on a non-transitory computer readable storage medium, which when executed, may comprise the steps of the embodiments of the methods described above. Any reference to memory, storage, database, or other medium used in embodiments provided herein may include at least one of non-volatile and volatile memory. The nonvolatile Memory may include Read-Only Memory (ROM), magnetic tape, floppy disk, flash Memory, optical Memory, or the like. Volatile memory can include random access memory (Random Access Memory, RAM) or external cache memory. By way of illustration, and not limitation, RAM can be in various forms such as static random access memory (Static Random Access Memory, SRAM) or dynamic random access memory (Dynamic Random Access Memory, DRAM), etc.

The technical features of the above embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the application, which are described in detail and are not to be construed as limiting the scope of the application. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the application, which are all within the scope of the application. Accordingly, the scope of protection of the present application is to be determined by the appended claims.

Claims

1. A drive control circuit, characterized by comprising:

the signal generation module is used for being connected with the piezoelectric motor and generating a driving signal so as to drive the piezoelectric motor to work;

The frequency tracking module is connected with the signal generating module and is also used for being connected with the piezoelectric motor, the frequency tracking module is used for detecting an operating electric signal of the piezoelectric motor, outputting an adjusting signal to the signal generating module according to the operating electric signal, enabling the signal generating module to generate a driving signal according to the received adjusting signal until the frequency tracking module outputs a target adjusting signal, wherein the frequency of the driving signal generated according to the adjusting signal is related to the adjusting signal, if the frequency tracking module outputs the target adjusting signal corresponding to the maximum operating electric signal, the signal generating module generates a target driving signal with a target frequency, and the target driving signal is used for driving the piezoelectric motor to operate at a mechanical resonance frequency, and the frequency tracking module comprises:

the detection unit is connected with the piezoelectric motor and used for detecting the working electric signal of the piezoelectric motor and outputting a voltage signal corresponding to the working electric signal;

the conversion unit is connected with the detection unit and is used for receiving the voltage signal and converting the voltage signal into a digital signal;

and the processing unit is connected with the conversion unit and is used for receiving the digital signal and outputting the adjusting signal according to the digital signal, so that the signal generating module adjusts the frequency of the driving signal according to the received adjusting signal, detects the current signal of the piezoelectric motor in response to the adjusted driving signal, judges whether the difference value between the second current signal corresponding to the current moment of the piezoelectric motor and the first current signal corresponding to the previous moment of the piezoelectric motor is smaller than a preset value, and takes the adjusting signal corresponding to the second current signal as the target adjusting signal if the difference value is smaller than the preset value.

2. The drive control circuit according to claim 1, wherein the conversion unit includes:

The effective value converter is connected with the detection unit and is used for converting the voltage signal of the working electric signal into effective value voltage;

And the analog-to-digital converter is connected with the effective value converter and is used for converting the analog signal of the effective value voltage into a digital signal.

3. The drive control circuit according to claim 1, wherein the signal generation module includes:

The control unit is connected with the frequency tracking module and used for generating an adjusting instruction according to the received adjusting signal;

and the generating unit is connected with the control unit and the piezoelectric motor and is used for generating the driving signal and adjusting the frequency of the driving signal according to the adjusting instruction.

4. The drive control circuit of claim 3, wherein the signal generation module further comprises:

an input unit for generating a driving instruction in response to an external operation;

The control unit is connected with the input unit and used for receiving the driving instruction and controlling the generating unit to generate the driving signal according to the driving instruction.

5. The drive control circuit of claim 3, wherein the signal generation module further comprises:

A first filtering unit connected with the generating unit and used for filtering the driving signal output by the generating unit;

and the first amplifying unit is connected with the first filtering unit and is used for amplifying the driving signal output by the first filtering unit.

6. The drive control circuit of claim 3, wherein the signal generation module further comprises:

And the clock unit is respectively connected with the control unit and the generating unit and is used for respectively providing clock signals for the control unit and the generating unit so as to keep the clocks of the generating unit and the control unit synchronous.

7. The drive control circuit according to claim 3, wherein the generating unit includes a direct digital synthesis chip for generating a high-frequency sinusoidal signal and adjusting a frequency of the high-frequency sinusoidal signal according to the adjustment instruction.

8. The drive control circuit according to any one of claims 1 to 7, characterized in that the drive control circuit further comprises:

the second filtering unit is connected with the signal generating module and is used for filtering the driving signal output by the signal generating module;

And the second amplifying unit is connected with the second filtering unit and is used for amplifying the driving signal output by the second filtering unit and outputting the driving signal after the amplification to the piezoelectric motor.

9. A drive control method, characterized by comprising:

Acquiring an operating electric signal of a piezoelectric motor, and generating an adjusting signal according to a current signal of the piezoelectric motor;

controlling the signal generation module to adjust the frequency of the driving signal according to the adjusting signal, and detecting a current signal of the piezoelectric motor in response to the adjusted driving signal;

Judging whether the difference value between a second current signal corresponding to the current moment of the piezoelectric motor and a first current signal corresponding to the previous moment of the piezoelectric motor is smaller than a preset value or not;

if the difference value is smaller than the preset value, taking the regulating signal corresponding to the second current signal as a target regulating signal, wherein the target regulating signal is the regulating signal corresponding to the maximum working electric signal, and the frequency of the driving signal is related to the regulating signal;

10. The drive control method according to claim 9, wherein the controlling the signal generation module to adjust the frequency of the drive signal according to the adjustment signal includes:

and if the difference value is larger than or equal to the preset value, feeding back and adjusting the frequency of the driving signal according to a preset frequency sweep strategy.

11. The drive control method of claim 10, wherein the preset sweep strategy comprises at least one of:

Gradually increasing a first preset sweep frequency amount from a first initial frequency;

gradually reducing a second preset sweep frequency amount from a second initial frequency;

gradually increasing the third preset frequency sweep amount from the first initial frequency until a target frequency sweep interval is determined, and carrying out frequency sweep with the fourth preset frequency sweep amount in the target frequency sweep interval,

The second initial frequency is larger than the first initial frequency, the fourth preset frequency sweep amount is smaller than the third preset frequency sweep amount, and the target frequency sweep area comprises a target frequency.

12. The drive control method according to claim 9, wherein the operation electric signal includes a current signal, and the generating the adjustment signal from the operation electric signal of the piezoelectric motor includes:

according to the working electric signal, outputting a voltage signal corresponding to the working electric signal;

Converting the voltage signal into an effective value voltage;

Converting the analog signal of the effective value voltage into a digital signal;

And generating the regulating signal according to the current signal corresponding to the digital signal.

13. A drive module, comprising:

A piezoelectric motor is provided with a plurality of electrodes,

A drive control circuit according to any one of claims 1 to 8, coupled to the piezoelectric motor for driving the piezoelectric motor to operate at a mechanical resonant frequency.

14. A camera module, comprising:

The lens seat is of a hollow cavity structure;

A lens including a barrel and a lens mounted to the barrel;

the driving module of claim 13, connected to the lens holder and configured to drive the lens barrel to move along an optical axis of the lens.

15. An electronic device comprising a memory and a processor, the memory storing a computer program, characterized in that the processor implements the steps of the method of any of claims 9 to 12 when the computer program is executed.

16. A computer readable storage medium, on which a computer program is stored, characterized in that the computer program, when being executed by a processor, implements the steps of the method of any of claims 9 to 12.