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

Abstract

The present application relates to a driving control circuit and method, a driving module, a camera module, an electronic device and a storage medium. The driving control circuit includes: a signal generating module, which is used to connect to a piezoelectric motor, and the signal generating module is used to generate a driving signal to drive the piezoelectric motor to work; a frequency tracking module, which is connected to the signal generating module and is also used to connect to the piezoelectric motor, and the frequency tracking module is used to detect the working electrical signal of the piezoelectric motor, and output an adjustment signal to the signal generating module according to the working electrical signal, so that the signal generating module generates a driving signal according to the received adjustment signal. If the frequency tracking module outputs an adjustment signal corresponding to the maximum working electrical signal, the signal generating module generates a target driving signal with a target frequency to drive the piezoelectric motor to work at a mechanical resonant frequency, which can realize frequency tracking of the piezoelectric motor, and has a simple structure and low cost.

Description

Technical Field

[0001] The present application relates to the field of electromechanical control technology, and in particular to a drive control circuit and method, a drive module, a camera module, an electronic device and a storage medium. Background Art

[0002] Piezoelectric motor is a new type of drive motor, which uses the inverse piezoelectric effect of piezoelectric materials to convert electrical energy into vibration mechanical energy, and then relies on friction to drive the piezoelectric rotor to rotate or move linearly. Compared with electromagnetic motors, piezoelectric motors have unique excitation and motion transmission mechanisms. Therefore, piezoelectric motors do not generate magnetic fields, are not affected by magnetic fields, have strong self-locking capabilities, are fast in response, have high efficiency, high motion accuracy, and are miniaturized, which are unmatched by traditional electromagnetic motors. For this reason, the study of piezoelectric motors and their drive control circuits has become one of the research hotspots in the field of micro-mechanics and electrical engineering.

[0003] Generally, piezoelectric motor drive control technology uses an open-loop drive control circuit or a closed-loop drive control circuit. However, the closed-loop drive control circuit in the related technology is mostly used for frequency and phase control of the piezoelectric motor. The speed of the piezoelectric motor is controlled by frequency and phase modulation, and its closed-loop control circuit is relatively complex. Summary of the invention

[0004] The present application provides a drive control circuit and method, a drive module, a camera module, an electronic device and a storage medium, which can realize frequency tracking of a piezoelectric motor, and has a simple structure and low cost.

[0005] In a first aspect, an embodiment of the present application provides a drive control circuit, comprising:

[0006] A signal generating module, used to be connected to the piezoelectric motor, and the generating module is used to generate a driving signal to drive the piezoelectric motor to work;

[0007] A frequency tracking module is connected to the signal generating module and is also used to connect to the piezoelectric motor. The frequency tracking module is used to detect the working electrical signal of the piezoelectric motor and output an adjustment signal to the signal generating module according to the working electrical signal, so that the signal generating module generates a drive signal according to the received adjustment signal to drive the piezoelectric motor to operate at a mechanical resonant frequency, wherein the frequency of the drive signal generated according to the adjustment signal is related to the adjustment signal; wherein, if the frequency tracking module outputs the adjustment signal corresponding to the maximum working electrical signal, the signal generating module generates a target drive signal, and the target drive signal is used to drive the piezoelectric motor to operate at a mechanical resonant frequency.

[0008] The above-mentioned drive control circuit includes a signal generating module and a frequency tracking module, wherein the signal generating module and the frequency tracking module can be connected to the piezoelectric motor respectively, the signal generating module can generate a driving signal to drive the piezoelectric motor to work, and the frequency tracking module can detect the working electrical signal of the piezoelectric motor when it responds to the current driving signal, and output an adjustment signal to the signal generating module according to the working electrical signal, so that the signal generating module adjusts the frequency of the current driving signal according to the received adjustment signal to generate a new driving signal. If the frequency tracking module outputs an adjustment signal corresponding to the maximum working electrical signal, the signal generating module generates a target driving signal with a target frequency to drive the piezoelectric motor to work at a mechanical resonant frequency. The drive control circuit can perform closed-loop control on the piezoelectric motor, realize frequency tracking of the piezoelectric motor, can always track the mechanical resonant frequency point of the piezoelectric motor, and control the piezoelectric motor to work at the optimal working frequency, that is, to maintain it at the maximum speed point, thereby ensuring the stability of the piezoelectric motor performance. At the same time, compared with the isolated voltage feedback and phase-locked loop in the related art, the drive control circuit provided by the embodiment of the present application has a simple circuit structure and low cost.

[0009] In a second aspect, an embodiment of the present application provides a drive control method, comprising:

[0010] The control signal generating module generates a driving signal to drive the piezoelectric motor to work;

[0011] Acquire a working electrical signal of the piezoelectric motor, and output an adjustment signal to the signal generating module according to the working electrical signal until a target adjustment signal is output; wherein the target adjustment signal is an adjustment signal corresponding to the maximum working electrical signal, and the frequency of the driving signal is related to the adjustment signal;

[0012] The signal generating module is controlled to generate a target driving signal having a target frequency according to the target adjustment signal, so as to drive the piezoelectric motor to operate at a mechanical resonant frequency.

[0013] The drive control method provided in the present application can control the signal generating module to generate a drive signal to drive the piezoelectric motor to work; obtain the working electrical signal of the piezoelectric motor, and output an adjustment signal to the signal generating module according to the working electrical signal until the target adjustment signal is output; control the signal generating module to output a target drive signal with a target frequency according to the target adjustment signal to drive the piezoelectric motor to work at a mechanical resonant frequency. The drive control method can realize frequency tracking of the piezoelectric motor, and can always track the mechanical resonant frequency point of the piezoelectric motor, making the frequency tracking more reliable and stable.

[0014] In a third aspect, an embodiment of the present application provides a driving module, including:

[0015] Piezoelectric motors,

[0016] The aforementioned driving control circuit is connected to the piezoelectric motor and is used to drive the piezoelectric motor to operate at a mechanical resonance frequency.

[0017] In a fourth aspect, an embodiment of the present application provides a camera module, including:

[0018] The mirror base is a hollow cavity structure;

[0019] A lens, comprising a lens barrel and a lens mounted on the lens barrel;

[0020] The aforementioned driving module is connected to the lens holder and is used to drive the lens barrel to move along the optical axis of the lens.

[0021] In a fifth aspect, an embodiment of the present application provides an electronic device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the following steps are implemented:

[0022] The control signal generating module generates a driving signal to drive the piezoelectric motor to work;

[0023] Acquire the working electrical signal of the piezoelectric motor, and output the adjustment signal to the signal generating module according to the working electrical signal until the target adjustment signal is output; the target adjustment signal is the adjustment signal corresponding to the maximum working electrical signal;

[0024] The signal generating module is controlled to output a target driving signal having a target frequency according to the target adjustment signal, so as to drive the piezoelectric motor to operate at a mechanical resonance frequency.

[0025] In a sixth aspect, an embodiment of the present application provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the following steps are implemented:

[0026] The control signal generating module generates a driving signal to drive the piezoelectric motor to work;

[0027] Acquire the working electrical signal of the piezoelectric motor, and output the adjustment signal to the signal generating module according to the working electrical signal until the target adjustment signal is output; the target adjustment signal is the adjustment signal corresponding to the maximum working electrical signal;

[0028] The signal generating module is controlled to output a target driving signal having a target frequency according to the target adjustment signal, so as to drive the piezoelectric motor to operate at a mechanical resonance frequency.

[0029] It can be understood that the beneficial effects that can be achieved by the driving module described in the third aspect and the camera module described in the fourth aspect provided above can refer to the beneficial effects of the driving control circuit described in the first aspect and any of its embodiments, and will not be repeated here.

[0030] It can be understood that the beneficial effects that can be achieved by the electronic device described in the fifth aspect and the computer-readable storage medium described in the sixth aspect provided above can refer to the beneficial effects of the driving control method described in the second aspect and any one of its embodiments, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0032] Figure 1 is one of the structural schematic diagrams of a driving control circuit in one embodiment;

[0033] Figure 2 The second structural diagram of a driving control circuit in one embodiment;

[0034] Figure 3 The third structural diagram of a driving control circuit in one embodiment;

[0035] Figure 4 This is a fourth structural diagram of a drive control circuit in one embodiment;

[0036] Figure 5 FIG5 is a fifth structural diagram of a driving control circuit in an embodiment;

[0037] Figure 6 The sixth structural diagram of a driving control circuit in one embodiment;

[0038] Figure 7 FIG7 is a seventh structural diagram of a driving control circuit in an embodiment;

[0039] Figure 8 FIG8 is a structural schematic diagram of a driving control circuit in an embodiment;

[0040] Fig. 9 is a schematic flow chart of a driving control method in one embodiment;

[0041] Fig.10A schematic diagram of a process for detecting a working electrical signal of a piezoelectric motor in an embodiment, and outputting an adjustment signal to the signal generating module according to the working electrical signal until a target adjustment signal is output;

[0042] Fig.11 A schematic diagram of a process for detecting a working electrical signal of a piezoelectric motor in another embodiment, and outputting an adjustment signal to the signal generating module according to the working electrical signal until a target adjustment signal is output;

[0043] Fig.12 It is a schematic diagram of a flow chart of generating the adjustment signal according to the working electrical signal of the piezoelectric motor in one embodiment;

[0044] Fig.13 FIG. 4 is a structural block diagram of a driving module in an embodiment. DETAILED DESCRIPTION

[0045] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0047] It is understood that the terms "first" and "second" used in this application are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. The terms "first", "second", etc. may be used in this article to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from another element. In addition, in the description of this application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. In the description of this application, the meaning of "several" is at least one, such as one, two, etc., unless otherwise clearly and specifically defined.

[0048] It should be noted that when an element is considered to be "connected" to another element, it can be directly connected to the other element, or connected to the other element through an intermediate element. In addition, the "connection" in the following embodiments should be understood as "electrical connection", "communication connection", etc. if there is transmission of electrical signals or data between the connected objects.

[0049] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. At the same time, the term "and / or" used in this specification includes any and all combinations of the relevant listed items.

[0050] The piezoelectric motor can be regarded as a multivariable, strongly coupled, complex time-varying system, which exhibits special dynamic phenomena and strong nonlinearity, and is difficult to model. Factors such as load size, pressure between the stator and rotor, operating temperature, rotation speed and direction change will affect the actual performance of the piezoelectric motor. Therefore, the inventors found that it is difficult to control the piezoelectric motor like a traditional electromagnetic motor. The piezoelectric motor can be used in a camera module including a lens mount and a lens. Among them, the lens mount is a hollow cavity structure; the lens includes a lens barrel and a lens mounted on the lens barrel. The piezoelectric motor is connected to the lens mount and is used to drive the lens barrel to move along the optical axis of the lens.

[0051] In the related technology, the piezoelectric motor driving technology will adopt the more mature open-loop driving control circuit. It mainly consists of three modules: frequency generation module, phase-frequency division module, and power amplifier matching module. The frequency generation module can emit a simple harmonic driving signal of a certain frequency; the frequency-phase division module divides the excitation driving signal into multi-phase signals and there should be a certain phase difference between different signals; the power amplifier matching module further processes the signal so that the power of the excitation signal can drive the piezoelectric motor. Generally speaking, the open-loop driving control circuit outputs a fixed driving frequency. Because the loss caused by the long-term operation of the piezoelectric motor causes a certain change in its mechanical characteristics, the optimal frequency point (mechanical resonance frequency point) is offset. When the optimal frequency point is offset, the output of the piezoelectric motor will become smaller and smaller (including driving force, driving speed, etc.).

[0052] In the related art, a relatively closed-loop drive control circuit is used for the frequency and speed phase control of the piezoelectric motor. The closed-loop control circuit of the piezoelectric motor in the related art is mostly used for the frequency and phase control of the piezoelectric motor, and the speed control of the piezoelectric motor is achieved by frequency modulation and phase modulation. In the design of the closed-loop control circuit, the drive control circuit mostly adopts a bridge push-pull circuit controlled by pulse width modulation (PWM), and the cycle control mostly adopts an isolated voltage cycle and a phase lock loop (PLL) to achieve frequency cycle. However, for the piezoelectric motor whose piezoelectric material is a coupled mode of first-order elongation and second-order bending (referred to as L1B2 piezoelectric motor), it always works at the maximum speed point and there is no need for speed regulation. Therefore, for the closed-loop isolated voltage and phase-locked loop cycle control in the related art, the closed-loop control circuit is highly complex, relatively slow, and has a high cost.

[0053] Based on the above analysis, the inventors have found that for the drive control of the L1B2 piezoelectric motor, the present invention provides a drive control circuit that can achieve closed-loop control of the piezoelectric motor, achieve frequency tracking of the piezoelectric motor, and can always track the mechanical resonance frequency of the piezoelectric motor and control the piezoelectric motor to operate at the optimal operating frequency, that is, to maintain the maximum speed point. At the same time, compared with the isolated voltage feedback and phase-locked loop in the related art, the drive control circuit provided in the embodiment of the present application has a simple circuit structure, fast drive speed, and low cost.

[0054] In one embodiment, Figure 1 As shown, an embodiment of the present application provides a driving control circuit for driving a piezoelectric motor 200. Specifically, the driving control circuit 100 includes a signal generating 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 used 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 can be a high-frequency sinusoidal voltage signal. When the high-frequency sinusoidal voltage signal acts on the piezoelectric stator of the piezoelectric motor 200, the piezoelectric stator is driven to generate an elliptical motion, thereby driving the piezoelectric motor 200.

[0055] The frequency tracking module 120 is connected to the signal generating module 110 and the piezoelectric motor 200 respectively. The frequency tracking module 120 is used to detect the working electrical signal of the piezoelectric motor 200, and output the adjustment signal to the signal generating module 110 according to the working electrical signal, so that the signal generating module 110 generates a driving signal according to the received adjustment signal. Among them, the frequency of the driving signal generated according to the adjustment signal is related to the adjustment signal. The driving signal generated by the signal generating module 110 before receiving the adjustment signal is different from the frequency of the driving signal generated according to the received adjustment signal. Specifically, when the piezoelectric motor 200 starts to work under the action of the driving signal (for example, the first driving signal), the frequency tracking module 120 can collect the working electrical signal of the piezoelectric motor 200, and then can output the adjustment signal to the signal generating module 110 according to the collected working electrical signal, so that the signal generating module 110 adjusts the frequency of the first driving signal according to the received adjustment signal to generate a second driving signal, and drives the piezoelectric motor 200 based on the second driving signal. In this cyclic operation, the signal generating module 110 can continuously generate a new driving signal according to the adjustment signal to drive the piezoelectric motor 200. If the frequency tracking module 120 outputs the adjustment signal corresponding to the maximum working electrical signal, the signal generating module 110 generates a target driving signal with a target frequency. The target driving signal is used in which the target frequency of the driving signal is the same as the mechanical resonant frequency of the piezoelectric motor 200. That is, the target driving signal generated by the signal generating module 110 can drive the piezoelectric motor 200 to operate at the mechanical resonant frequency.

[0056] The driving control circuit 100 provided in the embodiment of the present application includes a signal generating module 110 and a frequency tracking module 120, wherein the signal generating module 110 and the frequency tracking module 120 can be connected to the piezoelectric motor 200 respectively, the signal generating module 110 can generate a driving signal to drive the piezoelectric motor 200 to work, and the frequency tracking module 120 can detect the working electrical signal of the piezoelectric motor 200 when it responds to the current driving signal, and output an adjustment signal to the signal generating module 110 according to the working electrical signal, so that the signal generating module 110 generates a new driving signal according to the received adjustment signal. If the frequency tracking module 120 outputs the adjustment signal corresponding to the maximum working electrical signal, the signal generating module 110 generates a target driving signal with a target frequency to drive the piezoelectric motor to work at the mechanical resonant frequency. The drive control circuit 100 realizes closed-loop control of the piezoelectric motor 200 through the signal generation module 110 and the frequency tracking module 120, realizes frequency tracking of the piezoelectric motor 200, can always track the mechanical resonance frequency point of the piezoelectric motor 200, and control the piezoelectric motor 200 to work at the optimal operating frequency, that is, to maintain it at the maximum speed point, thereby ensuring the stability of the performance of the piezoelectric motor 200. At the same time, compared with the isolated voltage feedback and phase-locked loop in the related art, the drive control circuit 100 provided in the embodiment of the present application has a simple circuit structure and low cost.

[0057] In one embodiment, Figure 2 As shown, the frequency tracking module 120 includes a detection unit 121, a conversion unit 122 and a processing unit 123 which are electrically connected in sequence. The detection unit 121 is used to connect to the piezoelectric motor 200, and the detection unit 121 is used to detect the working electrical signal of the piezoelectric motor 200 and output a voltage signal corresponding to the working electrical signal. The detection unit 121 can be used to detect the working electrical signal of the piezoelectric motor 200 in response to the driving signal. The working electrical signal can be a current signal or a voltage signal.

[0058] Among them, the detection unit 121 may include a current detection unit, which can be used to detect the 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 the sake of convenience, the current detection unit is taken as a sampling resistor for example. In an embodiment of the present application, a sampling resistor (a resistor of about several hundred ohms) can be used to collect the current signal of the piezoelectric stator in the piezoelectric motor 200, and the current signal is converted into a voltage signal and output to the conversion unit 122 for conversion processing. Among them, the current signal of the piezoelectric stator is an AC current signal, and the converted voltage signal is also an AC voltage signal. In an embodiment of the present application, the working electrical signal of the piezoelectric motor is taken as the working electrical signal of the piezoelectric stator for example.

[0059] In the embodiment of the present application, since the current signal of the piezoelectric stator is very weak, a sampling resistor with a smaller resistance is used to collect the current signal, which can improve the collection accuracy of the current signal and further improve the accuracy of the target drive signal.

[0060] Optionally, the detection unit 121 may also be a voltage detection unit for detecting a voltage signal of the piezoelectric motor 200. The voltage detection unit may be a voltage Hall detector for detecting an AC voltage signal of a piezoelectric stator in the piezoelectric motor 200, and outputting the detected AC voltage signal to the conversion unit 122 for conversion processing.

[0061] The conversion unit 122 is connected to the detection unit 121 and is used to receive the voltage signal and convert the voltage signal into a digital signal. Figure 3 As shown, the conversion unit 122 may include an 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 digital converter 1222 may be a high-speed ADC sampling circuit.

[0062] Further, the conversion unit 122 also includes an effective value (Root mean square, RMS) converter 1221, wherein the input end of the effective value converter 1221 is connected to the detection unit 121, and the output end of the effective value converter 1221 is connected to the analog-to-digital converter 1222. Among them, the effective value converter 1221 can be used to perform effective value RMS calculation on the received AC voltage signal to obtain an effective value voltage. It can be understood that the effective value converter 1221 can convert the AC voltage signal into a DC voltage signal, that is, the effective value converter 1221 can convert the high-frequency sinusoidal AC voltage signal into an effective value voltage signal. At the same time, the effective value converter 1221 can transmit its effective value voltage signal to the analog-to-digital converter 1222 to convert the effective value voltage signal into a digital signal to output the digital signal to the processing unit 123. Specifically, the effective value converter 1221 may include but is not limited to an effective value-to-DC converter.

[0063] The processing unit 123 can track the frequency of the piezoelectric motor 200 according to the data signal, and thus can realize real-time tracking of the resonant frequency of the piezoelectric motor 200. Specifically, the processing unit 123 is connected to the conversion unit 122 and the signal generating module 110 respectively, and is used to receive the digital signal, and output the adjustment signal according to the digital signal to control the signal generating module 110 to generate a drive signal according to the received adjustment signal. Among them, the adjustment signal corresponding to the maximum current signal of the piezoelectric motor 200 is the target adjustment signal, and the signal generating module 110 can generate a target drive signal with a frequency at the mechanical resonant frequency according to the received target adjustment signal. Exemplarily, if the current signal is a current signal, the maximum current signal can be understood as the maximum current value. The processing unit 123 is also used to output the target adjustment signal to the signal generating module 110, so that the signal generating module 110 generates a target drive signal with the target frequency, that is, a high-frequency sinusoidal voltage signal, and then drives and controls the piezoelectric motor 200, thereby achieving the purpose of frequency tracking.

[0064] Among them, the processing unit 123 can be a control processing device such as a single-chip microcomputer (SCM), a field programmable gate array (FPGA), a central processing unit (CPU), etc. that can be used to analyze and process digital signals. Further, the processing unit 123 can also include a register, and its register is connected to the analog-to-digital converter 1222 for receiving the digital signal. The processing unit 123 can output the adjustment signal based on the digital signal received by the register 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 register in the processing unit 123 can store the mapping relationship between the digital signal of its effective value voltage signal and the current signal, and the processor can output its adjustment signal based on the mapping relationship and the digital signal.

[0065] The processing unit 123 can perform the following cyclic operation: the processing unit 123 can drive the piezoelectric motor 200 to work according to the current driving signal, and generate an adjustment signal according to the current signal of the piezoelectric motor 200, and output it to the signal generating module 110, so that the signal generating module 110 can adjust the frequency of the current driving signal according to the received adjustment signal to generate a new driving signal, and obtain 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 can be obtained based on the mapping relationship pre-stored by the processing unit and the received digital signal.

[0066] Specifically, for any two adjacent moments, determine 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 less than a preset value. If the difference is less than the preset value, the adjustment signal corresponding to the second current signal is used as the target adjustment signal. According to the impedance spectrum analysis characteristics of the piezoelectric stator, within a certain frequency range, the working current of the piezoelectric stator has a unique maximum value (or maximum value). Therefore, the current value of the second circuit signal I(i) corresponding to the current moment is compared with the current value of the first current signal I(i-1) corresponding to the previous moment (or the last moment). If the current value of the second circuit signal I(i) has a downward 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) can be used as the only maximum value of the working current of the piezoelectric stator, and the adjustment signal corresponding to the first current signal I(i-1) is used as 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 resonant frequency, thereby achieving the purpose of frequency tracking.

[0067] In one embodiment, if the current value of the second circuit signal I(i) has an upward trend relative to the current value of the first current signal I(i-1), it means that the current value of the first current signal I(i-1) of the piezoelectric stator has not reached a maximum value. At this time, the processing unit 123 generates a corresponding adjustment 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 a preset sweep frequency strategy. For example, the processing unit 123 can output a corresponding adjustment signal so that the signal generating module 110 sweeps the frequency of the driving signal according to the received adjustment signal in one of the following ways:

[0068] Method 1: Starting from the first initial frequency, gradually increase the first preset frequency sweep amount;

[0069] Method 2: Starting from the second initial frequency, gradually reduce the second preset frequency sweep amount;

[0070] Method three: starting from the first initial frequency, gradually increase the third preset frequency sweep amount until the target frequency sweep interval is determined, and within the target frequency sweep interval, sweep with a fourth preset frequency sweep amount, wherein the second initial frequency is greater than the first initial frequency, and the fourth preset frequency sweep amount is lower than the third preset frequency sweep amount; wherein the target frequency sweep area includes the target frequency.

[0071] The first preset frequency sweep amount, the second preset frequency sweep amount, and the third preset frequency sweep amount may be the same or different. The preset frequency sweep amount may be set according to the working properties of the piezoelectric motor 200. The first initial frequency may be reasonably designed according to the resonant frequency f_r' of the piezoelectric stator measured by the impedance spectrum analyzer. For example, the initial frequency f(0) may be set to f_r'-100kHz.

[0072] When the signal generating module 110 sweeps and adjusts the frequency of the driving signal according to the adjustment signal, the frequency tracking module 120 can cyclically detect the second working current of the piezoelectric motor 200 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 200 is determined, and this frequency is the mechanical resonant frequency of the piezoelectric motor 200. After the piezoelectric stator resonant frequency is determined, it is given to the driving signal generating circuit to output a high-frequency sinusoidal AC signal of the corresponding frequency, thereby achieving the purpose of frequency tracking.

[0073] In the embodiment of the present application, by setting up a frequency tracking module 120, real-time monitoring of the working current of the piezoelectric motor 200 can be achieved, and the resonant frequency of the piezoelectric motor 200 can be corrected so that it operates at the mechanical resonant frequency point, thereby improving the stability of the performance output of the piezoelectric motor 200 and the stability under long-term operation.

[0074] In one embodiment, Figure 4 As shown, 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 used to generate an adjustment instruction according to the received adjustment signal. The control unit 111 is the control core unit of the drive control circuit 100, which can perform program logic operation control, high-speed A / D conversion and other operations. Of course, the control unit 111 can output a drive instruction, or it can receive a target adjustment signal output by the processing unit 123 of the frequency tracking module 120, and generate a target adjustment instruction according to the target adjustment signal. The drive instruction is used to instruct the generating unit 112 to generate a drive signal, and the target adjustment instruction is used to instruct the generating unit 112 to generate a target drive signal. The drive instruction can be generated autonomously by the control unit 111, or it can receive a drive instruction output by other modules. In the embodiment of the present application, it should be noted that the specific generation method of the drive instruction is not further limited.

[0075] The generating unit 112 is connected to the control unit 111 and the piezoelectric motor 200 respectively. The generating unit 112 is used to generate the driving signal according to the driving instruction to drive the piezoelectric motor 200 to work. In the initial stage of driving the piezoelectric motor 200, the generating unit 112 can generate a driving signal under the control of the driving instruction of the control unit 111, and the frequency of the driving signal can be a high-frequency sinusoidal voltage signal with a frequency approximately equal to the resonant frequency of the piezoelectric motor 200.

[0076] Furthermore, the generation unit 112 can also adjust the frequency of the drive signal according to the adjustment instruction to generate a new drive signal. The generation unit 112 can also adjust the frequency of the drive 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 generation unit 112 can also adjust the frequency of the drive signal to the mechanical resonance frequency according to the received target adjustment instruction so that the drive frequency of the drive signal is equal to the mechanical resonance frequency, thereby achieving the purpose of frequency tracking and improving the driving accuracy of the piezoelectric motor 200.

[0077] In one embodiment, the generating unit 112 includes a direct digital synthesis (DDS) signal generator, which is used to generate a high-frequency sinusoidal voltage signal and adjust the frequency of the high-frequency sinusoidal voltage signal according to the adjustment instruction. The DDS signal generator adopts direct digital frequency synthesis technology to improve the frequency stability and accuracy of the signal generator to the same level as the reference frequency, and can perform fine frequency adjustment within a wide frequency range. In addition, the DDS signal generator can be input in both serial and parallel modes, is simple to control, and generates stable signal frequency and amplitude.

[0078] In the embodiment of the present application, a DDS signal generator is used to generate a driving signal of a high-frequency sinusoidal voltage signal, so that the output driving signal has extremely high stability, thereby improving the driving stability of the piezoelectric motor 200.

[0079] In one embodiment, Figure 5 As shown, the signal generating module 110 further includes: an input unit 113 connected to the control unit 111. The input unit 113 is used to generate a driving instruction in response to an external operation. The driving instruction can 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 approximately equal to the mechanical resonance frequency of the piezoelectric motor 200 according to the received driving instruction. The input unit 113 can optionally include a touch screen, a button, a data port, etc. Exemplarily, the user can input the driving instruction to the control unit 111 via the input unit 113.

[0080] In this embodiment, by providing the input unit 113 , the user can determine the time of generating the driving instruction, so as to achieve flexible driving of the piezoelectric motor 200 .

[0081] In one embodiment, Figure 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 used to perform low-pass filtering 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 can filter out some high-frequency interference signals 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, and is used to amplify the driving signal output by the first filtering unit 114, so as to output it to the piezoelectric motor 200, thereby realizing the driving of the piezoelectric motor 200. Specifically, the first amplifying unit 115 can be a high-frequency and high-speed operational amplifier chip, which can amplify the voltage of the driving signal from the mV level to 1V, thereby increasing the voltage value of the driving signal. It should be noted that the processing order of the driving signal by the first filtering unit 114 and the first amplifying unit 115 can also be interchanged. For example, an input end of the first amplifying unit 115 is connected to the generating unit 112 , an output end of the first amplifying unit 115 is connected to an input end of the first filtering unit 114 , and an output end of the first filtering unit 114 is connected to the piezoelectric motor 200 .

[0082] In this embodiment, the driving signal is filtered by designing the first filtering unit 114, and some high-frequency interference signals in the driving signal are filtered out, and the driving signal after filtering is amplified to amplify the voltage value of the driving signal. An interference-free, high-amplitude driving signal can be output to the piezoelectric motor, which can reduce the impact of the interference signal in the driving signal on the piezoelectric motor 200, and thus can achieve precise tracking and precise driving of the frequency of the piezoelectric motor 200.

[0083] In one embodiment, Figure 6The 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 synchronized. Specifically, the clock unit 116 can be any one of a global clock unit, a gated clock unit, a multi-level logic clock unit and a wave 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 examples, and can also be other types of clock units.

[0084] In an embodiment of the present application, by setting the clock unit 116, a clock signal, that is, a reference clock, can be provided for the drive control circuit 100, which can ensure that the clocks of the control unit 111 and the generation unit 112 remain synchronized, so that the drive control circuit 100 can be controlled and the timeliness of frequency tracking can be improved.

[0085] In one embodiment, Figure 7 and Figure 8 As shown, on the basis of any of the foregoing embodiments, the drive 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 can amplify and filter the drive signal output by the signal generating module 110. Specifically, the signal amplifying module 130 can 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 used to filter the drive signal output by the signal generating module 110. The second filtering unit 131 can be the same as the first filtering unit 114, both of which are low-pass filters to filter out stray high-frequency signals of the drive signal.

[0086] 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, for amplifying the driving signal filtered by the second filtering unit 131, and outputting the amplified driving signal to the piezoelectric motor 200. Specifically, the second amplifying unit 132 can amplify the voltage of the driving signal from the mV level to more than 100V. The second amplifying unit 132 can also be the same as the first amplifying unit 115, and can be a high-frequency and high-speed operational amplifier chip. Among them, the amplification factor (or gain coefficient, bandwidth and amplitude) of the second amplifying unit 132 can be determined and adaptively designed according to the working parameters of the piezoelectric motor 200 to be driven (for example, the simulation results when the piezoelectric stator of the piezoelectric motor 200 is working). It should be noted that the processing order of the driving signal by the second filtering unit 131 and the second amplifying unit 132 can also be interchanged. For example, the input end of the second amplifying unit 132 is connected to the signal generating module 110, the output end of the second amplifying unit 132 is connected to the input end of the second filtering unit 131, and the output end of the second filtering unit 131 is connected to the piezoelectric motor 200.

[0087] In this embodiment, if the drive control circuit 100 simultaneously includes a first filtering unit 114, a first amplifying unit 115, a second filtering unit 131 and a second amplifying unit 132, the drive signal output by the signal generating module 110 can be subjected to secondary filtering and secondary amplification processing, so that the drive signal after secondary filtering and secondary amplification can better act on the piezoelectric stator of the piezoelectric motor 200, drive the piezoelectric stator to produce elliptical motion, and then drive the piezoelectric motor 200.

[0088] In one embodiment, Fig. 9 As shown, a driving control method is provided. The driving control method can be applied to the driving control circuit in any of the above embodiments. Specifically, the driving control method includes steps 902 to 906.

[0089] Step 902: The control signal generating module generates a driving signal to drive the piezoelectric motor to operate.

[0090] The signal generating module is connected to 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 to drive the piezoelectric motor to work. The driving signal can be a high-frequency sinusoidal voltage signal. When the high-frequency sinusoidal voltage signal acts on the piezoelectric stator of the piezoelectric motor, the piezoelectric stator is driven to generate an elliptical motion, thereby driving the piezoelectric motor.

[0091] Step 904, obtain the working electrical signal of the piezoelectric motor, and output the adjustment signal to the signal generating module according to the working electrical signal until the target adjustment signal is output; wherein the frequency of the driving signal is related to the adjustment signal, and the target adjustment signal is the adjustment signal corresponding to the maximum working electrical signal.

[0092] The drive control circuit can detect the working electrical signal of the piezoelectric motor based on the detection unit, and output the adjustment signal to the signal generating module according to the working electrical signal, so that the signal generating module adjusts the frequency of the driving signal according to the feedback of the adjustment signal to generate a new driving signal until the drive control circuit outputs the target adjustment signal. That is, when the piezoelectric motor starts to work under the action of the driving signal (for example, the first driving signal), the drive control circuit can collect the working electrical signal of the piezoelectric motor, and then output the adjustment signal to the signal generating module according to the collected working electrical signal, so that the signal generating module adjusts the frequency of the first driving signal according to the received adjustment signal to generate a second driving signal, and drives the piezoelectric motor based on the second driving signal. In this cyclic operation, the signal generating module can continuously generate a new driving signal according to the adjustment signal to drive the piezoelectric motor until the drive control circuit determines the target adjustment signal according to the working electrical signal of the piezoelectric motor.

[0093] Step 906 : Control the signal generating module to generate a target driving signal having a target frequency according to the target adjustment signal, so as to drive the piezoelectric motor to operate at a mechanical resonant frequency.

[0094] The drive control circuit can transmit the determined target adjustment signal to the signal generation module, and the signal generation module can output a target drive signal with a target frequency according to the target adjustment signal to drive the piezoelectric motor to operate at a mechanical resonance frequency. The target frequency of the drive signal is the same as the mechanical resonance frequency of the piezoelectric motor.

[0095] The drive control method provided in the embodiment of the present application can control the signal generating module to generate a drive signal to drive the piezoelectric motor to work; obtain the working electrical signal of the piezoelectric motor, and output an adjustment signal to the signal generating module according to the working electrical signal until the target adjustment signal is output; control the signal generating module to output a target drive signal with a target frequency according to the target adjustment signal to drive the piezoelectric motor to work at a mechanical resonant frequency. The drive control method can realize frequency tracking of the piezoelectric motor, and can always track the mechanical resonant frequency point of the piezoelectric motor, making the frequency tracking more reliable and stable.

[0096] In one embodiment, Fig.10As shown, the working electrical signal of the piezoelectric motor is detected, and an adjustment signal is output to the signal generating module according to the working electrical signal until a target adjustment signal is output, including steps 1002 to 1008.

[0097] Step 1002: Generate the adjustment signal according to the working electrical signal of the piezoelectric motor.

[0098] In the embodiment of the present application, the working electrical signal is taken as a current signal for example. The drive control circuit can detect the AC current signal of the piezoelectric stator in the piezoelectric motor, and generate an adjustment signal according to the detected AC current signal. The adjustment signal can be used to adjust the frequency of the drive signal.

[0099] Step 1004: Control the signal generating module to adjust the frequency of the driving signal according to the adjustment signal, and detect the current signal of the piezoelectric motor in response to the adjusted driving signal.

[0100] The drive control circuit can control the signal generating module to adjust the frequency of the drive signal according to the adjustment signal. The signal generating module can output a target drive signal at a mechanical resonance frequency according to the target adjustment signal, that is, a high-frequency sinusoidal voltage signal, and then drive and control the piezoelectric motor to achieve the purpose of frequency tracking. The drive control circuit can generate an adjustment signal according to the current signal of the piezoelectric motor at the current moment, and output it to the signal generating module, so that the signal generating module can adjust the frequency of the drive signal according to the adjustment signal, and obtain the current signal of the piezoelectric motor in response to the adjusted drive signal.

[0101] Step 1006, determining whether a difference between a second current signal corresponding to the piezoelectric motor at a current moment and a first current signal corresponding to the piezoelectric motor at a previous moment is less than a preset value.

[0102] According to the impedance spectrum analysis characteristics of the piezoelectric stator, within a certain frequency range, the working current of the piezoelectric stator has a unique maximum value (or maximum value). 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 less than a preset value. The preset value is a value greater than or equal to 0.

[0103] Step 1008: If the difference is less than the preset value, the adjustment signal corresponding to the second current signal is used as the target adjustment signal.

[0104] If the difference is less than the preset value, and if the current value of the second circuit signal I(i) has a downward 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) can be used as the only maximum value of the working current of the piezoelectric stator, and the adjustment signal corresponding to the first current signal I(i-1) is used as the target adjustment signal. The drive control circuit will output the target adjustment signal to the signal generation module, so that the signal generation module adjusts the frequency of the drive signal to the target frequency according to the target adjustment signal, thereby achieving the purpose of frequency tracking.

[0105] In one embodiment, Fig.11 As shown, the drive control method further includes: if the difference is greater than or equal to the preset value, executing step 1112, and adjusting the frequency of the drive signal according to the preset sweep strategy feedback.

[0106] If the difference is greater than or equal to the preset value, it can be indicated that the current value of the second circuit signal I(i) has an upward trend relative to the current value of the first current signal I(i-1), which means that the current value of the first current signal I(i-1) of the piezoelectric stator has not reached a maximum value. At this time, the drive control circuit generates a corresponding adjustment signal according to the second circuit signal I(i), so that the signal generating module adjusts the frequency of the drive signal according to a preset sweep frequency strategy. For example, the drive control circuit can output a corresponding adjustment signal so that the signal generating module sweeps the frequency of the drive signal according to the adjustment signal in one of the following ways:

[0107] Method 1: Starting from the first initial frequency, gradually increase the first preset frequency sweep amount.

[0108] The first initial frequency can be reasonably designed according to the resonant frequency f_r' of the piezoelectric stator measured by the impedance spectrum analyzer. For example, the first initial frequency can be set as the initial frequency, wherein the initial frequency f(0) = f_r'-100kHz. According to the first method, the signal generating module can gradually increase the first preset frequency sweep amount δf1 from the initial frequency based on the received adjustment signal to adjust the frequency of the drive signal. Exemplarily, the frequency of the drive signal can be adjusted in the following order: f(0), f(0)+δf1, f(0)+2*δf1, f(0)+3*δf1, ..., f(0)+n*δf1.

[0109] Method 2: Starting from the second initial frequency, gradually reduce the second preset frequency sweep amount.

[0110] The second initial frequency can be set as the initial frequency, wherein the initial frequency f(0) = f_r' + 100kHz. According to the second method, the signal generating module can gradually reduce the second preset frequency sweep amount δf2 from the initial frequency based on the received adjustment signal to adjust the frequency of the driving signal. Exemplarily, the frequency of the driving signal can be adjusted in the following order: f(0), f(0)-δf2, f(0)-2*δf2, f(0)-3*δf2, ..., f(0)-n*δf2. The second initial frequency is greater than the first initial frequency,

[0111] Method three: starting from the first initial frequency, gradually increase or decrease the third preset frequency sweep amount until a target frequency sweep interval is determined, and perform frequency sweeping with a fourth preset frequency sweep amount within the target frequency sweep interval.

[0112] The target frequency sweep range can be first determined by referring to the method of method 1 or method 2, and then the frequency sweep is performed again in the target frequency sweep range by the method of method 1 or method 2 with a fourth preset frequency 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 range includes 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 can be set according to the working properties of the piezoelectric motor.

[0113] It should be noted that, in this embodiment, step 1102 corresponds to step 1002 in the aforementioned embodiment, steps 1104 to 1106 correspond to step 1004 in the aforementioned embodiment, and step 1108 corresponds to step 1006 in the aforementioned embodiment, which will not be repeated here.

[0114] In an embodiment of the present application, when the drive control circuit control signal generating module performs frequency sweep adjustment on the frequency of the drive signal according to any of the above-mentioned methods, the drive control circuit can cyclically 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, and this frequency is the mechanical resonant frequency of the piezoelectric motor. After the piezoelectric stator resonant frequency is determined, it is given to the drive signal generating circuit to output a high-frequency sinusoidal AC signal of the corresponding frequency, so as to achieve the purpose of frequency tracking. When the third method is adopted, the frequency can be roughly swept first to quickly locate the target frequency sweep area, and then the target frequency point can be located in the target frequency sweep interval by means of frequency sweeping, which can improve the frequency sweep efficiency and frequency sweep accuracy of the target frequency point.

[0115] In one embodiment, please continue to refer to Fig.11, the drive control method also includes step 1100, initializing the drive signal of the piezoelectric motor. The drive 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), wherein the voltage amplitude v_in is reasonably set according to the amplification factor of the second amplification unit in the drive control circuit. Specifically, an actual drive voltage can be simulated according to the required performance parameters, and then the amplification factor of the overall circuit is confirmed according to the output voltage of the signal generating 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 (such as setting f(0) = f_r'-100kHz), and the initial test current I(0) is set to zero.

[0116] In the embodiment of the present application, the accuracy of the tracking frequency can be further improved by initializing the initial driving signal.

[0117] In one embodiment, Fig.12 As shown, the working electrical signal includes a current signal, and generating the adjustment signal according to the working electrical signal of the piezoelectric motor includes steps 1202 to 1208.

[0118] Step 1202: output a voltage signal corresponding to the working electrical signal according to the working electrical signal.

[0119] When the working electrical signal is a current signal, a sampling resistor (a resistor of about several hundred ohms) can be used to collect the current signal of the piezoelectric stator in the piezoelectric motor, and the current signal is converted into a voltage signal for output.

[0120] Step 1204: convert the voltage signal into an effective value voltage.

[0121] The effective value converter calculates the effective value RMS of the received AC voltage signal to obtain the effective value voltage. It can be understood that the effective value converter can convert the AC voltage signal into a DC voltage signal, that is, the effective value converter can convert the high-frequency sinusoidal AC voltage signal into an effective value voltage signal.

[0122] Step 1206: convert the analog signal of the effective value voltage into a digital signal.

[0123] The received effective value voltage signal is converted into a digital signal based on an analog-to-digital converter.

[0124] Step 1208: Generate the adjustment signal according to the current signal corresponding to the digital signal.

[0125] The drive control circuit may pre-store a mapping relationship between a digital signal of its effective value voltage signal and a current signal, and then output its adjustment signal based on the mapping relationship and the digital signal.

[0126] In this embodiment, the drive control circuit can generate the aforementioned adjustment signal according to the received digital signal, thereby realizing the frequency tracking of the piezoelectric motor. The drive control circuit in the embodiment of the present application can be applied to the processing unit (such as a single chip microcomputer) of the frequency tracking module in the drive control circuit, which can improve the efficiency of frequency tracking and make the frequency tracking more reliable and stable.

[0127] It should be understood that although Figure 9-12 The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. Moreover, Figure 9-12 At least part of the steps may include multiple steps or multiple stages. These steps or stages are not necessarily performed at the same time, but can be performed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed in turn or alternately with other steps or at least part of the steps or stages in other steps.

[0128] In one embodiment, if Fig.13 As shown, the embodiment of the present application also provides a driving module, characterized in that it includes a piezoelectric motor 200 and a driving control circuit 100 in any of the aforementioned embodiments. The driving control circuit 100 can realize frequency tracking of the piezoelectric motor 200, and then realize precise driving of the piezoelectric motor 200, so that the piezoelectric motor 200 can always operate at the optimal operating frequency, that is, maintain at the maximum speed point, thereby ensuring the stability of the piezoelectric motor performance. Compared with the isolated voltage feedback and phase-locked loop in the related art, the driving module provided by the embodiment of the present application has a simple circuit structure and low cost.

[0129] In one embodiment, the present application also provides a camera module. The camera module includes: a lens holder, a lens, and the aforementioned driving module. The lens holder is a hollow cavity structure; the lens includes a lens barrel and a lens mounted on the lens barrel. The driving module is connected to the lens holder and is used to drive the lens barrel to move along the optical axis of the lens.

[0130] In an embodiment of the present application, by setting a driving module for driving the lens barrel to move along the optical axis of the lens, the mechanical resonance frequency point of the piezoelectric motor can be tracked at all times, and the piezoelectric motor can be controlled to operate at the optimal operating frequency, that is, maintained at the maximum speed point, thereby ensuring the stability of the piezoelectric motor performance, and thus making the camera module better adaptable to extreme conditions such as falling and bumping.

[0131] In one embodiment, an electronic device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and when the processor executes the computer program, the drive control method in any of the above embodiments is implemented.

[0132] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the drive control method in any of the aforementioned embodiments is implemented.

[0133] A computer program product comprising instructions, when running on a computer, enables the computer to execute the drive control method in any of the aforementioned embodiments.

[0134] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory or optical memory, etc. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0135] The technical features of the above embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0136] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A drive control circuit, characterized in that: include: A signal generating module, used to be connected to the piezoelectric motor, and the signal generating module is used to generate a driving signal to drive the piezoelectric motor to work; A frequency tracking module, connected to the signal generating module, and also used to connect to the piezoelectric motor, the frequency tracking module is used to detect the working electrical signal of the piezoelectric motor, and output an adjustment signal to the signal generating module according to the working electrical signal, so that the signal generating module generates a driving signal according to the received adjustment signal until the frequency tracking module outputs a target adjustment signal, wherein the frequency of the driving signal generated according to the adjustment signal is related to the adjustment signal; if the frequency tracking module outputs the target adjustment signal corresponding to the maximum working electrical signal, the signal generating module generates a target driving signal with a target frequency, and the target driving signal is used to drive the piezoelectric motor to operate at a mechanical resonant frequency; wherein the frequency tracking module includes: a detection unit, connected to the piezoelectric motor, for detecting the working electrical signal of the piezoelectric motor and outputting a voltage signal corresponding to the working electrical signal; a conversion unit, connected to the detection unit, configured to receive the voltage signal and convert the voltage signal into a digital signal; A processing unit is connected to the conversion unit, and is used to receive the digital signal and output the adjustment signal according to the digital signal, so that the signal generating module adjusts the frequency of the driving signal according to the received adjustment signal, detects the current signal of the piezoelectric motor in response to the adjusted driving signal, and determines whether the difference between the second current signal corresponding to the piezoelectric motor at a current moment and the first current signal corresponding to the piezoelectric motor at a previous moment is less than a preset value. If the difference is less than the preset value, the adjustment signal corresponding to the second current signal is used as the target adjustment signal.

2. The drive control circuit according to claim 1, characterized in that: The conversion unit comprises: An effective value converter, connected to the detection unit, and used to convert the voltage signal of the working electrical signal into an effective value voltage; The analog-to-digital converter is connected to the effective value converter and is used to convert the analog signal of the effective value voltage into a digital signal.

3. The drive control circuit according to claim 1, characterized in that: The signal generating module comprises: A control unit, connected to the frequency tracking module, and configured to generate an adjustment instruction according to the received adjustment signal; A generating unit is connected to the control unit and the piezoelectric motor, and is used to generate the driving signal and adjust the frequency of the driving signal according to the adjusting instruction.

4. The drive control circuit according to claim 3, characterized in that: The signal generating module also includes: An input unit, for generating a driving instruction in response to an external operation; The control unit is connected to the input unit, and is used to receive the driving instruction and control the generating unit to generate the driving signal according to the driving instruction.

5. The drive control circuit according to claim 3, characterized in that: The signal generating module also includes: A first filtering unit, connected to the generating unit, and configured to filter the driving signal output by the generating unit; The first amplifying unit is connected to the first filtering unit and is used to amplify the driving signal output by the first filtering unit.

6. The drive control circuit according to claim 3, characterized in that: The signal generating module also includes: The clock unit is connected to the control unit and the generating unit respectively, and is used to provide clock signals to the control unit and the generating unit respectively, so that the clocks of the generating unit and the control unit are kept synchronized.

7. The drive control circuit according to claim 3, characterized in that: The generating unit comprises a direct digital synthesis chip, which is used to generate a high-frequency sinusoidal signal and adjust the 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 also includes: A second filtering unit, connected to the signal generating module, and configured to filter the driving signal output by the signal generating module; The second amplifying unit is connected to the second filtering unit, and is used for amplifying the driving signal output by the second filtering unit, and outputting the amplified driving signal to the piezoelectric motor.

9. A drive control method, characterized in that: include: The control signal generating module generates a driving signal to drive the piezoelectric motor to work; Acquire a working electrical signal of the piezoelectric motor, and generate a regulating signal according to the current signal of the piezoelectric motor; Controlling the signal generating module to adjust the frequency of the driving signal according to the adjustment signal, and detecting the current signal of the piezoelectric motor in response to the adjusted driving signal; Determine whether a difference between a second current signal corresponding to the piezoelectric motor at a current moment and a first current signal corresponding to the piezoelectric motor at a previous moment is less than a preset value; If the difference is less than the preset value, the adjustment signal corresponding to the second current signal is used as the target adjustment signal; wherein the target adjustment signal is the adjustment signal corresponding to the maximum working electrical signal, and the frequency of the driving signal is related to the adjustment signal; The signal generating module is controlled to generate a target driving signal having a target frequency according to the target adjustment signal, so as to drive the piezoelectric motor to operate at a mechanical resonant frequency.

10. The driving control method according to claim 9, characterized in that: The step of controlling the signal generating module to adjust the frequency of the driving signal according to the adjustment signal comprises: If the difference is greater than or equal to the preset value, the frequency of the driving signal is adjusted according to a preset frequency sweep strategy.

11. The driving control method according to claim 10, characterized in that: The preset frequency sweep strategy includes at least one of the following strategies: Starting from a first initial frequency, gradually increasing a first preset frequency sweep amount; Starting from the second initial frequency, gradually reducing the second preset frequency sweep amount; Starting from the first initial frequency, gradually increase the third preset frequency sweep amount until a target frequency sweep interval is determined, and perform frequency sweeping with a fourth preset frequency sweep amount within the target frequency sweep interval, The second initial frequency is greater 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 area includes a target frequency.

12. The driving control method according to claim 9, characterized in that: The working electrical signal includes a current signal, and the step of generating the adjustment signal according to the working electrical signal of the piezoelectric motor includes: According to the working electrical signal, output a voltage signal corresponding to the working electrical signal; Converting the voltage signal into an effective value voltage; Converting the analog signal of the effective value voltage into a digital signal; The regulating signal is generated according to the current signal corresponding to the digital signal.

13. A driving module, characterized in that: include: Piezoelectric motors, The drive control circuit according to any one of claims 1 to 8 is connected to the piezoelectric motor and is used to drive the piezoelectric motor to operate at a mechanical resonant frequency.

14. A camera module, characterized in that: include: The mirror base is a hollow cavity structure; A lens, comprising a lens barrel and a lens mounted on the lens barrel; The driving module as shown in claim 13 is connected to the lens holder and is used to drive the lens barrel to move along the optical axis of the lens.

15. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 9 to 12 are implemented.

16. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 9 to 12 are implemented.

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