Motor drive circuit, motor system, motor control method, and electronic device

Abstract

The embodiment of the invention provides a motor driving circuit, a motor system, a motor control method and electronic equipment, and the motor system can be applied to a camera module and is used for the zooming and / or anti-shake function of the camera module. The motor system may include a motor drive circuit (dr iver I C) and a motor connected to each other. Wherein a high-frequency PWM (Pulse Width Modulation) wave circuit is introduced into the dr iver I C and is used for outputting high-frequency PWM current to the motor, so that the instantaneous thrust of the motor is improved on the premise that the power consumption is not improved.

Description

Technical Field

[0001] The present application relates to the field of electronic technology, and in particular to a motor drive circuit, a motor system, a motor control method and an electronic device. Background Art

[0002] With the development of electronic technology, mobile phones, tablet computers and other electronic devices are generally equipped with cameras. As an important component of the camera, the motor can be used to drive the lens to change the focal length, thereby realizing the zoom and anti-shake functions in terminal imaging technology. Improving motor thrust has always been a concern for technicians. However, the internal space of electronic devices such as mobile phones is very limited, and it is difficult to increase the motor thrust by increasing the motor size. Summary of the invention

[0003] In a first aspect, an embodiment of the present application provides a motor driving circuit, which may include: a conversion circuit and a first pulse width modulation (PWM) wave circuit. The conversion circuit is coupled to the first PWM wave circuit.

[0004] The conversion circuit is also coupled to the power supply module of the motor drive circuit (such as a power management circuit) to receive the supply voltage output by the power supply module. The conversion circuit can also be connected to a processor, such as an application processor (AP), to receive travel instructions from the processor, and the travel instructions include the target position of the motor.

[0005] The conversion circuit can also be used to convert the supply voltage into a first PWM voltage with a first frequency, a first amplitude, and a first duty cycle according to a target stroke of the motor. The target stroke is determined by the conversion circuit according to the target position and the actual position of the motor.

[0006] The conversion circuit is also used to output the first PWM voltage to the first PWM wave circuit.

[0007] The first PWM wave circuit can be used to convert the first PWM voltage into a first PWM current. The frequency of the first PWM current is close to or equal to the first frequency, and the duty cycle of the first PWM current is close to or equal to the first duty cycle. Here, the frequency is close to each other, which means that the difference between the frequency of the first PWM current and the frequency of the first PWM voltage is very small, for example, the frequency difference is within the level of hundreds of hertz (Hz). The duty cycle is close to each other, which means that the difference between the duty cycle of the first PWM current and the duty cycle of the first PWM voltage is very small, for example, the duty cycle difference is within 2%. In addition, the amplitude A of the first PWM current is i The amplitude A of the first PWM voltage u The following relationship exists: A i =A u / R, where R represents the circuit resistance, which may include load resistance, such as VCM motor coil resistance, and circuit transmission line resistance.

[0008] The first PWM wave circuit can also be connected to a motor to output a first PWM current to the motor to control the motor to generate motor thrust.

[0009] The motor drive circuit provided in the first aspect increases the instantaneous thrust of the motor by introducing a high-frequency pulse width modulation (PWM) current into the motor, so as to quickly overcome the static friction during motor startup without increasing power consumption.

[0010] In combination with the first aspect, in some embodiments, the correspondence between the duty cycle, amplitude or frequency of the first PWM voltage and the motor displacement can be used to record the motor stroke when any two of the three parameters of frequency, amplitude and duty cycle are fixed, and the third parameter takes different values. The mapping relationship includes a first mapping relationship, a second mapping relationship, and a third mapping relationship. Among them, the first mapping relationship can be used to record the motor displacement corresponding to each of the first PWM voltage when the duty cycle takes different values ​​when the frequency and amplitude take fixed values. The second mapping relationship can be used to record the motor displacement corresponding to each of the first PWM voltage when the amplitude takes different values ​​when the frequency and amplitude take fixed values. The third mapping relationship can be used to record the motor displacement corresponding to each of the first PWM voltage when the frequency takes different values ​​when the amplitude and duty cycle take fixed values.

[0011] In combination with the first aspect, in some embodiments, the conversion circuit can be specifically used to determine that the frequency of the first PWM voltage is fixed to the first frequency, the amplitude is fixed to the first amplitude, and the duty cycle corresponding to the target stroke is determined to be the first duty cycle based on the first mapping relationship. The first mapping relationship records the motor strokes corresponding to different duty cycles when the frequency of the first PWM voltage is fixed to the first frequency and the amplitude is fixed to the second amplitude, and the motor strokes corresponding to different duty cycles include the target stroke.

[0012] In combination with the first aspect, in some embodiments, the second mapping relationship records the motor strokes corresponding to different amplitudes of the first PWM voltage when the frequency is fixed to a first frequency and the duty cycle is fixed to a first duty cycle, and the motor strokes corresponding to different amplitudes include the target stroke.

[0013] The conversion circuit can be specifically used to determine that the frequency of the first PWM voltage is fixed to the first frequency, the duty cycle is fixed to the first duty cycle, and based on the second mapping relationship, determine that the amplitude corresponding to the target stroke is the first amplitude.

[0014] In combination with the first aspect, in some embodiments, the third mapping relationship records the motor strokes corresponding to different frequencies when the amplitude of the first PWM voltage is fixed to a first amplitude and the duty cycle is fixed to a first duty cycle, and the motor strokes corresponding to different frequencies include the target stroke.

[0015] In combination with the first aspect, in some embodiments, the conversion circuit can be specifically used to determine that the amplitude of the first PWM voltage is fixed to a first amplitude, the duty cycle is fixed to a first duty cycle, and based on a third mapping relationship, determine that the frequency corresponding to the target stroke is the first frequency.

[0016] Furthermore, in order to reduce storage costs, a segment of data that is close to linear in the mapping relationship can be selected for storage, such as the corresponding relationship between the duty cycle in the range of 20% to 40% and the motor stroke. Moreover, the data of the linear portion can be expressed in the form of a linear function, and only the linear function expression and the linear range can be recorded to significantly reduce the amount of data storage.

[0017] In some embodiments, in the first mapping relationship, the duty cycle and the motor stroke may present a linear relationship.

[0018] In some embodiments, in the second mapping relationship, the amplitude and the motor stroke may present a linear relationship.

[0019] In some embodiments, in the third mapping relationship, the frequency and the motor stroke may present a linear relationship.

[0020] In combination with the first aspect, in some embodiments, the motor drive circuit may further include a control circuit. The control circuit is coupled to the conversion circuit and can be used to output a target stroke to the conversion circuit. The control circuit may also be coupled to the processor for receiving a stroke instruction transmitted by the processor, wherein the stroke instruction carries the target position of the motor. The control circuit may also be coupled to a position detection circuit in the motor for receiving the actual position of the motor mover in the motor transmitted by the position detection circuit, wherein the position detection circuit is used to detect the actual position of the motor mover. The target stroke may be determined based on the target position and the actual position of the motor mover, and the closer the actual position is to the target position, the smaller the target stroke. In this way, by adding a feedback link and a closed-loop control link, unnecessary motion oscillations are eliminated, and the motor mover can move to the specified position more quickly.

[0021] In combination with the first aspect, in some embodiments, the conversion circuit can be specifically used to convert the target stroke into a first frequency, a first amplitude, and a first duty cycle through a proportional integral differential PID control algorithm, and then produce a first PWM voltage according to the first frequency, the first amplitude, and the first duty cycle.

[0022] In combination with the first aspect, in some embodiments, the motor drive circuit may further include a voltage doubling circuit, wherein the input end of the voltage doubling circuit is coupled to the conversion circuit, and the output end of the voltage doubling circuit is coupled to the first PWM wave circuit. The voltage doubling circuit is used to boost the first PWM voltage generated by the conversion circuit and then output it to the first PWM wave circuit to convert it into a first PWM current.

[0023] In combination with the first aspect, in some embodiments, the voltage doubling circuit may include: a capacitor C1, a first unidirectional conduction device, a second unidirectional conduction device and a switch S1, as well as a first input terminal, a second input terminal, a first output terminal and a second output terminal; wherein: the first terminal of the capacitor C1 is coupled to the first input terminal, the second terminal of the capacitor C1 is coupled to the first output terminal, and the second output terminal is coupled to the second input terminal; one end of the first unidirectional conduction device is coupled to the second end of the capacitor C1, and the other end is coupled to the first moving terminal of the switch S1; one end of the second unidirectional conduction device is also coupled to the second end of the capacitor C1, and the other end is coupled to the second moving terminal of the switch S1; the fixed end of the switch S1 is coupled to the second input terminal; the conduction directions of the first unidirectional conduction device and the second unidirectional conduction device are opposite.

[0024] In combination with the first aspect, in some embodiments, the voltage doubler circuit is an n-stage voltage doubler circuit, n≥2, and n is a positive integer; a switch S1 is connected in parallel across the capacitor Cn in the n-th stage charge and discharge circuit in the voltage doubler circuit, and the switch S1 is used to adjust the voltage polarity of the output voltage of the voltage doubler circuit.

[0025] In a second aspect, an embodiment of the present application provides a motor system, which may include a motor drive circuit and a motor. The output circuit of the motor drive circuit is coupled to the motor, and the motor drive circuit may be the motor drive circuit described in the first aspect or any possible implementation of the first aspect.

[0026] In conjunction with the second aspect, in some embodiments, the motor system may further include a position detection circuit, and the motor drive circuit may further include a control circuit. The position detection circuit is coupled to the control circuit in the motor drive circuit, and the position detection circuit is used to detect the actual position of the motor mover and output the detected actual position to the control circuit.

[0027] In a third aspect, an embodiment of the present application provides an electronic device, which may include: a motor system and a processor. The motor system may be the motor system described in the second aspect or any possible implementation of the second aspect; the processor is coupled to a motor drive circuit in the motor system, and the processor is used to transmit a travel instruction to the motor drive circuit in the motor system, and the travel instruction includes a target position of the motor.

[0028] In combination with the third aspect, in some embodiments, the motor system is disposed in a camera module of an electronic device.

[0029] In a fourth aspect, an embodiment of the present application provides a motor control method, which can be applied to an electronic device, which may be the electronic device described in the third aspect or any possible implementation manner of the third aspect.

[0030] The method provided in the fourth aspect may include: the electronic device converts the target stroke of the motor into a first frequency, a first amplitude, and a first duty cycle; the electronic device generates a first PWM voltage according to the first frequency, the first amplitude, and the first duty cycle; the electronic device converts the first PWM voltage into a first PWM current; and the electronic device outputs the first PWM current to the motor.

[0031] In combination with the fourth aspect, in some embodiments, before the electronic device converts the target stroke of the motor into a first frequency, a first amplitude, and a first duty cycle, the method may also include: the electronic device detects an operation of changing the optical zoom ratio of the camera module; and the electronic device determines the target stroke based on the optical zoom ratio.

[0032] In conjunction with the fourth aspect, in some embodiments, a first mapping relationship may be stored in the electronic device, the first mapping relationship recording the motor strokes corresponding to different duty ratios when the frequency of the first PWM voltage is fixed to the first frequency and the amplitude is fixed to the second amplitude, and the motor strokes corresponding to different duty ratios include the target stroke. The electronic device converts the target stroke of the motor into the first frequency, the first amplitude, and the first duty ratio, which may specifically include: the electronic device determines that the frequency of the first PWM voltage is fixed to the first frequency and the amplitude is fixed to the first amplitude, and determines that the duty ratio corresponding to the target stroke is the first duty ratio based on the first mapping relationship.

[0033] In conjunction with the fourth aspect, in some embodiments, a second mapping relationship may be stored in the electronic device, the second mapping relationship recording the motor strokes corresponding to different amplitudes when the frequency of the first PWM voltage is fixed to the first frequency and the duty cycle is fixed to the first duty cycle, and the motor strokes corresponding to the different amplitudes include the target stroke. The electronic device converts the target stroke of the motor into the first frequency, the first amplitude, and the first duty cycle, which may specifically include: the electronic device determines that the frequency of the first PWM voltage is fixed to the first frequency and the duty cycle is fixed to the first duty cycle, and determines that the amplitude corresponding to the target stroke is the first amplitude based on the second mapping relationship.

[0034] In conjunction with the fourth aspect, in some embodiments, a third mapping relationship may be stored in the electronic device, and the third mapping relationship records the motor strokes corresponding to different frequencies when the amplitude of the first PWM voltage is fixed to the first amplitude and the duty cycle is fixed to the first duty cycle, and the motor strokes corresponding to different frequencies include the target stroke. The electronic device converts the target stroke of the motor into the first frequency, the first amplitude, and the first duty cycle, which may specifically include: the electronic device determines that the amplitude of the first PWM voltage is fixed to the first amplitude, and the duty cycle is fixed to the first duty cycle, and determines that the frequency corresponding to the target stroke is the first frequency based on the third mapping relationship.

[0035] In combination with the fourth aspect, in some embodiments, the electronic device converts the target stroke of the motor into a first frequency, a first amplitude, and a first duty cycle, which may specifically include: the electronic device converts the target stroke into the first frequency, the first amplitude, and the first duty cycle through a PID control algorithm.

[0036] In combination with the fourth aspect, in some embodiments, the motor system may further include a position detection circuit and a control circuit. The method provided in the fourth aspect may also include: after the electronic device outputs the first PWM current to the motor, the electronic device determines whether the motor mover is in the target position; if not, the electronic device redetermines the target stroke based on the position deviation between the actual position of the motor mover and the target position, and the electronic device converts the redetermined target stroke into a second frequency, a second amplitude, and a second duty cycle through a PID algorithm; the electronic device generates a second PWM voltage based on the second frequency, the second amplitude, and the second duty cycle; the electronic device converts the second PWM voltage into a second PWM current; and the electronic device outputs the second PWM current to the motor.

[0037] In a fifth aspect, an embodiment of the present application provides a computer-readable storage medium, comprising a coded instruction sequence, which, when executed on an electronic device, enables execution of the method described in the aforementioned fourth aspect or any possible implementation of the fourth aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 A typical motor drive system is shown;

[0039] Figure 2 A motor system provided by an embodiment of the present application is shown;

[0040] Figure 3 Shows Figure 2 The input and output of the high-frequency PWM wave circuit in the motor drive circuit shown;

[0041] Figure 4 Shows Figure 2 The waveform of the first PWM voltage input to the high-frequency PWM wave circuit in the motor drive circuit shown;

[0042] Figure 5 Shows Figure 2 A circuit composition of a motor drive circuit inputted into a high-frequency PWM wave circuit;

[0043] Figure 6 The waveform of the first PWM current generated by the high-frequency PWM wave circuit is exemplarily shown when the frequency and amplitude of the first PWM voltage are fixed and the duty cycle is three different values ​​(20%, 30%, 40%);

[0044] Figure 7 The motor travel time curve corresponding to the duty cycle taking three different values ​​(20%, 30%, 40%) is shown as an example when the frequency and amplitude of the first PWM voltage take fixed values;

[0045] Figure 8 The corresponding curves of duty cycle and motor stroke are shown as an example when the frequency and amplitude are fixed;

[0046] Fig. 9 A motor system simulation model of an embodiment of the present application is shown;

[0047] Fig.10 A closed-loop motor system provided by an embodiment of the present application is shown;

[0048] Fig.11 An open-loop motor system including a voltage doubling circuit provided in an embodiment of the present application is shown;

[0049] Fig. 12A The two-stage voltage doubling circuit provided in the embodiment of the present application is shown;

[0050] Fig. 12B The connection relationship of the two-stage voltage doubling circuit provided in the embodiment of the present application in the motor driving circuit is shown;

[0051] Fig.13A A charging process of a voltage doubler circuit is shown;

[0052] Fig. 13B A discharge process of a voltage doubler circuit is shown;

[0053] Fig. 13C Another charging process of the voltage doubler circuit is shown;

[0054] Fig.13D Another discharge process of the voltage doubler circuit is shown;

[0055] Fig.14A Another two-stage voltage doubling circuit provided in an embodiment of the present application is shown;

[0056] Fig. 14B The two-stage voltage doubling circuit provided in the embodiment of the present application is shown;

[0057] Fig.15A An n-stage voltage multiplier circuit provided in an embodiment of the present application is shown;

[0058] Fig. 15B Shows Fig.15A The structure of the switch S1 in the n-stage voltage multiplier circuit shown;

[0059] Fig.16 Shows Fig. 12BThe waveform timing curves of the voltage of capacitor C1 and the coil current in the circuit shown;

[0060] Fig.17 An electronic device 100 provided in an embodiment of the present application is shown;

[0061] Fig.18 Several motor thrust directions of the camera are shown;

[0062] Fig.19 A motor control method provided by an embodiment of the present application is shown;

[0063] Fig. 20 Another motor control method provided by an embodiment of the present application is shown. DETAILED DESCRIPTION

[0064] The terms used in the following embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application.

[0065] The motor is an important component of the camera, used to move the lens to change the focal length. Depending on whether it is used for anti-shake, the motor can be divided into a motor used only for auto focus (AF) and a motor with optical image stabilization (OIS) function (also known as "optical image stabilization"). The motor drives the lens to move in the direction of the optical axis to achieve zoom, and the motor drives the lens to move in the plane perpendicular to the optical axis to achieve anti-shake.

[0066] According to the different driving forces of the motor, the motor can be divided into: voice coil motor (VCM), shape memory alloy (SMA) motor and ultrasonic motor, etc. Among them, VCM uses the Lorentz force between the energized coil and the magnet to drive the lens movement to achieve zoom or anti-shake function. The SMA motor uses the unique deformation ability of memory metal to pull the lens movement to achieve zoom or anti-shake function. The ultrasonic motor can control the phase difference of two AC voltages to make the piezoelectric ceramic plate reach a preset resonant motion state, and convert this resonant motion into a designed motion state (such as linear motion) through a structural part, driving the lens to move to achieve zoom or anti-shake function.

[0067] Figure 1 A typical motor drive system is shown in FIG. Figure 1As shown in the figure, the motor and the motor driver IC connected to it constitute the most basic motor drive system. The motor driver IC can output DC current to the VCM to drive the VCM to work, thereby driving the lens to move. By adjusting the current amplitude, the motor can be controlled to output different driving forces. In addition, Figure 1 As shown, the driver IC can also be connected to a power management circuit (PMC) to receive power (voltage is shown as VDD) provided by the PMC; the driver IC can also be connected to a power management circuit (PMC) to receive power (voltage is shown as VDD) provided by the PMC; 2 C bus) is connected to the processor, receives the control signal from the processor, and then controls the current of the DC power provided to the motor.

[0068] When starting the motor, the motor first needs to overcome the static friction f it is subjected to. The motor can only be started when the instantaneous thrust of the motor (that is, the Lorentz force exerted on the energized coil) is greater than the static friction f. Referring to the calculation formula of the Lorentz force F, F=B*L*I, it can be seen that when the number of coil turns and the size of the magnet remain unchanged, increasing the instantaneous thrust of the motor requires increasing the current. In the above formula, B represents the magnetic flux density (magnetic induction intensity), L represents the length of the wire in the magnetic field, and I represents the current in the coil. Secondly, during the movement, the Lorentz force exerted on the motor is also needed to overcome the restoring force F1, damping F2 and dynamic friction f' caused by the deformation of the reed, and the remaining force is the actual acceleration force acting on the movement of the lens.

[0069] Therefore, in the scheme of using direct current to drive the motor, if the current is small, in one case, the instantaneous thrust of the motor may be smaller than the static friction f that needs to be overcome when the motor starts, which may cause the lens to be unable to achieve zoom and / or anti-shake functions. In another case, the Lorentz force on the motor can overcome the static friction f, but after overcoming f, the actual acceleration force acting on the movement of the lens is small, which may cause the lens to be unable to achieve fast zoom or poor anti-shake function, affecting the user experience. If this problem is overcome by increasing the instantaneous thrust of the motor, the current needs to be increased, and the overall power consumption of the solution is high, which may cause problems such as heating, which will also affect the user experience.

[0070] To solve the above problems, the embodiments of the present application introduce high-frequency pulse width modulation (PWM) current into the motor to increase the instantaneous thrust of the motor, so as to quickly overcome the static friction during motor startup without increasing power consumption.

[0071] Embodiment 1

[0072] Figure 2A motor system provided in an embodiment of the present application is shown, which can be applied to a camera module for the zoom and / or anti-shake functions of the camera module.

[0073] like Figure 2 As shown, the motor system may include: a motor driving circuit (driver IC) and a motor, which are connected. A high-frequency PWM wave circuit is introduced in the driver IC to output a high-frequency PWM current to the motor to increase the instantaneous thrust of the motor without increasing power consumption. The motor type may be a reed motor, a ball motor, etc.

[0074] Specifically, Figure 2 As shown, the driver IC may include: a conversion circuit and a high-frequency PWM wave circuit.

[0075] The conversion circuit can be connected to the power supply module (such as the power management circuit) of the driver IC to receive the power supply voltage VDD output by the power supply module. Not limited to the power management circuit, other modules can also supply power to the driver IC. The conversion circuit can be used to convert the power supply voltage VDD into a high-frequency periodic voltage of a specific frequency (which can be called a first frequency), a specific amplitude (which can be called a first amplitude), and a specific duty cycle (which can be called a first duty cycle) according to the target stroke of the motor (which can be called the target displacement). The high-frequency periodic voltage is a PWM voltage and can be called a first PWM voltage. In some embodiments, the conversion circuit can also be connected to a processor, such as an application processor (AP), which can be used to receive a stroke instruction from the processor, and the stroke instruction may include the target position of the motor. The target position can be determined by the processor according to the user's zoom operation or determined by the jitter compensation calculated according to the device jitter amplitude detected by the sensor in the electronic device. The conversion circuit can be used to determine the target stroke of the motor according to the target position and the actual position of the motor, that is, in which direction to move and how much distance.

[0076] In order to accurately drive the motor to the specified position, a correspondence between the duty cycle, amplitude or frequency of the first PWM voltage and the motor displacement can be established, and the correspondence can be stored in the driver IC in the form of a correspondence table or other data for the conversion circuit to call. The correspondence can be linear or nonlinear. The subsequent content will introduce the correspondence and its application in detail, so it will not be expanded here.

[0077] The conversion circuit can also be connected to the high-frequency PWM wave circuit to output the first PWM voltage to the high-frequency PWM wave circuit.

[0078] The high-frequency PWM wave circuit can be used to convert the first PWM voltage into a high-frequency PWM current. The PWM current can be referred to as a first PWM current. The high-frequency PWM wave circuit can also be connected to a motor and can be used to output the first PWM current to the motor, such as outputting the first PWM current to a coil of the VCM to generate a corresponding driving force to drive the motor to move.

[0079] In the embodiment of the present application, the high-frequency PWM wave circuit can be referred to as a first PWM wave circuit.

[0080] like Figure 3 As shown, the input of the high-frequency PWM wave circuit is a high-frequency PWM voltage, and the output is a high-frequency PWM current. The frequency of the first PWM current may be equal to or close to the frequency of the first high-frequency PWM voltage, and the duty cycle of the first PWM current may be equal to or close to the duty cycle of the first high-frequency PWM voltage. Here, the frequency is close to each other, which may mean that the difference between the frequency of the first PWM current and the frequency of the first PWM voltage is very small, for example, the frequency difference is within the level of hundreds of Hertz (Hz). The duty cycle is close to each other, which may mean that the difference between the duty cycle of the first PWM current and the duty cycle of the first PWM voltage is very small, for example, the duty cycle difference is within 2%. In addition, the amplitude A of the first PWM current i The amplitude A of the first PWM voltage u The following relationship exists: A i =A u / R, where R represents the circuit resistance, which may include load resistance, such as VCM motor coil resistance, and circuit transmission line resistance.

[0081] By adjusting the duty cycle, frequency, and amplitude of the first PWM voltage, the waveform of the first PWM voltage can be controlled, and then the waveform of the first PWM current output to the motor can be controlled, and finally the motor thrust can be controlled. During the zoom and anti-shake process of the camera, the conversion circuit can receive a travel instruction from the processor, and the target position included in the travel instruction changes due to changes in the zoom ratio and anti-shake displacement. Correspondingly, the duty cycle, frequency, or amplitude of the first PWM voltage output by the conversion circuit will also change, thereby changing the frequency, amplitude, and duty cycle of the first PWM current output by the first PWM wave circuit, and finally changing the motor thrust.

[0082] The waveform of the first PWM voltage input to the high-frequency PWM wave circuit can be as follows: Figure 4 As shown, in Figure 4 Middle,U max represents the voltage amplitude of the first PWM voltage, T represents the period of the first PWM voltage, T work Represents the duration of high level in one cycle. The duty cycle of the first PWM voltage is the duration of high level T work The proportion within a period T can be calculated by the following formula: T work / T. The frequency of the first PWM voltage is the reciprocal of the period T, that is, 1 / T.

[0083] A circuit composition of a high-frequency PWM wave circuit can be as follows Figure 5 As shown in the example, it can be composed of a resistor R1, a capacitor C1, an inductor L1, a diode D1 and a resistor R2. Among them, the voltage input end of the high-frequency PWM wave circuit can be coupled to the voltage output end of the conversion circuit to receive the first PWM voltage output by the conversion circuit; the resistor R1 can be coupled to the voltage input end at one end and coupled to the capacitor C1 at the other end; the resistor R1, the capacitor C1, the inductor L1 and the resistor R2 are connected in series in sequence; the diode D1 can be connected in parallel between the middle position of the capacitor C1 and the inductor L1 and the point reference point (such as the ground); the current flowing through the resistor R2 is used as the output current of the high-frequency PWM wave circuit, that is, the first PWM current. Unlimited Figure 5 The circuit composition of the example, the circuit structure of the high-frequency PWM wave circuit can also be in other forms, and the embodiments of the present application are not limited to this.

[0084] Since the first PWM current output to the motor has a certain duty cycle, the driver IC can output a larger instantaneous current to the motor under the same power consumption, thereby increasing the instantaneous thrust of the motor and successfully overcoming the static friction when the motor starts.

[0085] In the embodiment of the present application, high frequency may refer to a frequency greater than 1000 Hz.

[0086] In an embodiment of the present application, the correspondence between the duty cycle, amplitude or frequency of the first PWM voltage and the motor displacement can be used to record the motor stroke when the third parameter takes different values ​​when any two of the three parameters of frequency, amplitude and duty cycle are fixed.

[0087] Specifically, the mapping relationship includes a first mapping relationship, a second mapping relationship, and a third mapping relationship. The first mapping relationship can be used to record the motor displacement corresponding to each of the first PWM voltage when the duty cycle takes different values ​​when the frequency and amplitude take fixed values. The second mapping relationship can be used to record the motor displacement corresponding to each of the first PWM voltage when the amplitude takes different values ​​when the frequency and amplitude take fixed values. The third mapping relationship can be used to record the motor displacement corresponding to each of the first PWM voltage when the frequency takes different values ​​when the amplitude and duty cycle take fixed values.

[0088] Take a VCM reed motor as an example. Figure 6 The waveform of the first PWM current generated by the high-frequency PWM wave circuit is shown as an example when the frequency and amplitude of the first PWM voltage are fixed and the duty cycle is three different values ​​(20%, 30%, 40%). Figure 6In the example, the amplitude of the first PWM voltage is fixed at 3.2*2V, the frequency of the first PWM voltage is fixed at 30000Hz, and the waveform of the first PWM current changes with the duty cycle. Figure 7 The motor travel time curves corresponding to the three different duty cycle values ​​(20%, 30%, 40%) are shown as an example when the frequency and amplitude of the first PWM voltage are fixed. Figure 7 In the embodiment, the amplitude of the first PWM voltage is fixed at 3.2*2V, the frequency of the first PWM voltage is fixed at 30000Hz, and the motor displacement varies with the duty cycle. When the duty cycle is 20%, the corresponding motor stroke is 70 microns, when the duty cycle is 30%, the corresponding motor stroke is 190 microns, and when the duty cycle is 40%, the corresponding motor stroke is 335 microns.

[0089] Taking the first correspondence as an example, in order to more comprehensively cover the correspondence between duty cycle and motor stroke, the motor stroke corresponding to the first PWM voltage with more different duty cycles can be obtained under the condition of fixed frequency and amplitude, which can form Figure 8 The corresponding curve of duty cycle and motor stroke is shown as an example. The more different values ​​of duty cycle are taken, the smoother the curve is.

[0090] In some embodiments, the conversion circuit converts the supply voltage into a first PWM voltage with a first frequency, a first amplitude, and a first duty cycle according to the target stroke of the motor, which may specifically include: the conversion circuit determines that the frequency of the first PWM voltage is fixed to the first frequency, the amplitude is fixed to the first amplitude, and based on the first mapping relationship, determines that the duty cycle corresponding to the target stroke is the first duty cycle.

[0091] In some embodiments, the conversion circuit converts the supply voltage into a first PWM voltage with a first frequency, a first amplitude, and a first duty cycle according to the target stroke of the motor, which may specifically include: the conversion circuit determines that the amplitude of the first PWM voltage is fixed to the first amplitude, the duty cycle is fixed to the first duty cycle, and based on a third mapping relationship, determines that the frequency corresponding to the target stroke is the first frequency.

[0092] In some embodiments, the conversion circuit converts the supply voltage into a first PWM voltage with a first frequency, a first amplitude, and a first duty cycle according to the target stroke of the motor, which may specifically include: the conversion circuit determines that the frequency of the first PWM voltage is fixed to the first frequency, the duty cycle is fixed to the first duty cycle, and based on the second mapping relationship, determines that the amplitude corresponding to the target stroke is the first amplitude.

[0093] Furthermore, to reduce storage costs, you can choose Figure 8The data of a section close to linearity is stored, such as the corresponding relationship between the duty cycle in the range of 20% to 40% and the motor stroke. Moreover, the data of the linear part can be expressed in the form of a linear function, and only the linear function expression and the linear range can be recorded to significantly reduce the amount of data storage. For example, Figure 8 The linear part of the first mapping relationship shown can be expressed as: s(x)=1300x-190, where x represents the duty cycle, and its value range is 20%-40%, and s(x) represents the motor stroke. When the target stroke of the motor is determined to be 70 microns, the duty cycle of the first PWM voltage can be set to 20%; when the target stroke of the motor is determined to be 330 microns, the duty cycle of the first PWM voltage can be set to 40%.

[0094] In some embodiments, in the first mapping relationship, the duty cycle and the motor stroke may present a linear relationship.

[0095] In some embodiments, in the second mapping relationship, the amplitude and the motor stroke may present a linear relationship.

[0096] In some embodiments, in the third mapping relationship, the frequency and the motor stroke may present a linear relationship.

[0097] When the two input parameters that originally took fixed values ​​change, the mapping relationship between the originally changed third parameter and the motor stroke will also change. Continuing the above example, when the originally fixed frequency changes from 30000Hz to 20000Hz, if the target shape of the motor is still 70um, the duty cycle needs to be changed to a value greater than 20%, no longer 20%. In actual applications, developers can obtain or maximize the linear segment or approximate segment between the third parameter and the motor stroke by adjusting the fixed values ​​of the two parameters. For example, when the amplitude and frequency of the first PWM voltage are fixed at 3.2*2 volts and 10000Hz respectively, the duty cycle of the first PWM current can be linearly corresponding to the motor stroke in the range of 40%-50%; when the amplitude and frequency of the first PWM voltage are fixed at 3.2*2 volts and 40000Hz respectively, the duty cycle of the first PWM current can be linearly corresponding to the motor stroke in the range of 5%-20%. In this way, the driver IC can store multiple sets of linear correspondences between duty cycle and motor stroke for the conversion circuit to call, so as to achieve a linear or approximately linear correspondence between duty cycle and motor stroke in a larger range of 5%-50%.

[0098] In the embodiment of the present application, when the target stroke is not within the linear part of the first mapping relationship (such as the motor stroke range of 70um to 335um corresponding to the duty cycle of 20% to 40%), the conversion circuit can check whether the target stroke is in the linear part of the second mapping relationship or the third mapping relationship. If so, the second mapping relationship or the third mapping relationship can be used to generate the PWM voltage. For example, assuming that the target stroke is 10 microns, it is not Figure 8 The linear part shown; however, when the amplitude and duty cycle of the first PWM voltage are fixed at 3.2*3 volts and 15% respectively, the frequency of the first PWM current can be linearly corresponding to the motor stroke in the range of 20000Hz-45000Hz, and the linear part includes the target stroke of 10 microns. That is, multiple items in the first mapping relationship, the second mapping relationship, and the third mapping relationship can be used to maximize the linear mapping relationship of the motor stroke. In some embodiments, it is also possible to measure in advance which section of the entire motor stroke falls into which linear part of the mapping relationship by conducting experiments, so that after determining the target stroke of the motor, the linear part corresponding to the target stroke can be directly used to determine the amplitude, frequency, and duty cycle of the high-frequency PWM voltage without having to find the linear mapping relationship where the target stroke is located.

[0099] The corresponding relationship between the duty cycle, amplitude or frequency of the first PWM voltage and the motor displacement can be obtained by simulation or actual measurement.

[0100] The above simulation method can be based on Fig. 9 The motor system simulation model is implemented as shown.

[0101] like Fig. 9 As shown, the simulation model of the motor system can be divided into three parts: the circuit part, the electromagnetic part, and the mechanical part. Among them, the circuit part is used to simulate the aforementioned high-frequency PWM wave circuit, and its input is a high-frequency PWM voltage with different parameters (duty cycle, amplitude, frequency), and its output is a high-frequency PWM current. The circuit part outputs a high-frequency PWM current signal to the electromagnetic part. The coil in the electromagnetic part can be used to simulate the electromagnetic device in the motor, and a magnetic field is generated when a high-frequency PWM current is passed through. The mechanical part can be used to simulate the mechanical device in the motor, and a magnetic force is generated by the magnetic field, thereby driving the upper spring sheet and the lower spring sheet module to move, and finally driving the driven component (such as the lens of the camera) to move. The mechanical part may also include a displacement sensor, which can be used to record the movement stroke of the driven component.

[0102] Embodiment 2

[0103] Figure 2 The motor system shown is an open-loop motor system. An open-loop motor system is one in which the motor system is not adjusted by feedback information from the system during operation. Figure 2The motor system shown lacks a feedback mechanism for adjusting the first PWM voltage generated by the conversion circuit according to the actual position of the lens driven by the motor during operation.

[0104] The open-loop motor system has the advantages of being simple and easy to operate. However, in some instances, the motor system needs to be applied to some high-precision equipment, such as camera modules. These high-precision equipment puts forward further requirements on the motion accuracy and speed of the motor mover. The above-mentioned open-loop motor system lacks the above-mentioned feedback mechanism, so it is impossible to adjust the possible errors in the system (for example, the lens is not pushed to the target position) according to the movement status of the motor, and the accuracy is poor.

[0105] The embodiment of the present application eliminates unnecessary motion oscillations by adding a feedback link and a closed-loop control link on the basis of open-loop control, so that the motor can move to the specified position more quickly.

[0106] Fig.10 A closed-loop motor system provided by an embodiment of the present application is shown.

[0107] like Fig.10 As shown, except Figure 2 In addition to the components of the open-loop motor system shown, the closed-loop motor system may further include a control circuit and a position detection circuit. The position detection circuit may be used to detect the actual position of the motor mover and output the actual position to the control circuit. The control circuit may also receive a stroke instruction from the processor and extract the target position contained in the stroke instruction. The control circuit may also be used to calculate the position deviation between the actual position and the target position and output the position deviation to the conversion circuit. The position deviation is used as the target stroke of the motor. Then, the conversion circuit may generate a first PWM voltage input to the high-frequency PWM wave circuit according to the target stroke, and then the high-frequency PWM wave circuit outputs a first PWM current, continues to drive the motor to generate motor thrust, and pushes the driven component closer to the target position.

[0108] The target stroke can be determined based on the target position carried in the stroke instruction from the processor and the actual position of the motor mover, and specifically can be the difference between the two. The closer the actual position is to the target position, the smaller the target stroke is.

[0109] Initially, the motor mover is located at the initial position, and the conversion circuit can directly determine the target stroke according to the target position carried in the stroke instruction from the processor, and generate the corresponding PWM voltage according to the target stroke, and then output the PWM voltage to the high-frequency PWM wave circuit, and then the high-frequency PWM wave circuit outputs the PWM current, and finally drives the motor to generate motor thrust. However, due to the inaccurate correspondence between the duty cycle, amplitude or frequency of the PWM voltage recorded in the aforementioned mapping relationship and the motor displacement, the deviation of the size and other quality parameters during motor manufacturing, or the voltage fluctuation during the actual operation of the motor, the driven component (such as the lens of the camera) may not be accurately pushed to the target position by the motor, that is, there is a position deviation between the actual position of the motor mover (detected by the position detection circuit) and the target position. The control circuit can also be used to calculate the position deviation between the actual position and the target position and output the position deviation to the conversion circuit. The position deviation can be used as the new target stroke of the motor. Then, the conversion circuit can regenerate the PWM voltage input to the high-frequency PWM wave circuit according to the new target stroke, and then the high-frequency PWM wave circuit re-outputs the PWM current, continues to drive the motor to generate motor thrust, and pushes the driven component closer to the target position. This process is repeated many times until the position detection circuit detects that the driven component is actually at the target position.

[0110] The position detection circuit in the closed-loop motor system may include a Hall sensor and / or an infrared sensor, etc., which are used to detect the position of an object pushed by the motor, but the embodiments of the present application are not limited to this.

[0111] The control circuit in the closed-loop motor system may be located in the driver IC. The control circuit may be arranged in the conversion circuit. Not limited thereto, the control circuit may also be a separate circuit independent of the driver IC, and the embodiment of the present application does not limit the arrangement position of the control circuit.

[0112] In some embodiments, the conversion circuit can also use a proportional-integral-derivative (PID) control algorithm to achieve the conversion between the target displacement and the frequency, amplitude, and duty cycle of the PWM voltage (which can be called input parameters), so that the motor mover can stabilize to the target position more quickly and reduce the motion oscillation of the camera module during the anti-shake and zoom functions.

[0113] The conversion circuit can be used to convert the target stroke into a first frequency, a first amplitude, and a first duty cycle through a proportional integral differential PID control algorithm, and generate a first PWM voltage according to the first frequency, the first amplitude, and the first duty cycle.

[0114] Similar to the aforementioned determination of the input parameters of the first PWM voltage according to the mapping relationship, the PID control algorithm can determine the value of the third input parameter according to the target stroke, provided that two of the input parameters have fixed values. Exemplarily, the amplitude and frequency of the first PWM voltage are fixed at 3.2*2V and 30000Hz, respectively. If the target stroke is 190um at this time, the conversion circuit can calculate that the duty cycle of the first PWM voltage should be set to 25% according to the PID control algorithm, and then generate a PWM voltage with an amplitude, frequency, and duty cycle of 3.2*2V, 30000Hz, and 25%, respectively, and output the PWM voltage to the high-frequency PWM wave circuit.

[0115] Specifically, the PID control algorithm is used to calculate the value of a certain input parameter, including three control items - proportional item P, integral item I, and differential item D. When the above PID control algorithm is applied to control the motor stroke, the above three control items are calculated based on the deviation error (t) between the actual position of the object (such as the lens) pushed by the motor at time t and the target position. Taking the application of the motor system to the camera module as an example, the above proportional item P is proportional to the position deviation (i.e., the third stroke), which is used to generate a rapid response of the motor system so that the lens moves to the target position as quickly as possible; the above integral item I is proportional to the accumulation of the position deviation, which is used to eliminate the steady-state error, so that the deviation between the actual position of the lens and the target position is small enough, so that it can stay accurately near the target position; the above differential item D is proportional to the rate of change of position variation, which is used to suppress oscillation and improve the stability of the motor system, ensuring that the lens can be adjusted to the target position quickly and smoothly.

[0116] The output of the above PID control is determined by the combination of these three control items and can be expressed as:

[0117]

[0118] Among them, Kp is the proportional gain, Ki is the integral gain, and Kd is the differential gain. The value of the above gain parameters determines the value of each of the above control items, thereby affecting the PID output result and further affecting the performance of the system. Therefore, training the PID control algorithm is actually to adjust the above gain parameters to appropriate values.

[0119] These three gain parameters are adjusted according to actual needs and performance indicators during system design. Different PID parameter settings are required in different application scenarios and systems. Therefore, in actual applications, the gain parameters can be manually adjusted through experiments and adjustments to determine the appropriate gain parameter values, thereby achieving stable, fast and precise control of the system.

[0120] The PID control algorithm executed by the above conversion circuit should be an accurate control algorithm obtained after a lot of training. The above accurate control algorithm refers to the control algorithm in which the above appropriate gain parameters are determined during the training process. The training of the PID control algorithm can be based on Fig.10 The closed-loop motor system shown is implemented.

[0121] Developers can first determine the values ​​of the input voltage amplitude and current frequency, and then make initial settings for Kp, Ki, and Kd based on experience. After the settings are completed, the above-mentioned conversion circuit can generate corresponding duty cycle values ​​according to the given target position and PID control algorithm. The duty cycle, together with the above-mentioned voltage amplitude and current frequency, constitutes a set of input parameters (frequency, amplitude, duty cycle). The conversion circuit outputs the input parameters to the above-mentioned conversion circuit. The high-frequency PWM voltage generated by the above-mentioned conversion circuit is converted into a high-frequency PWM current that acts on both ends of the motor coil to drive the motor to move. The position detection module can detect the position of the object pushed by the motor in real time. Developers can correct the value of the above-mentioned gain parameter based on the position deviation between the actual position of the object pushed by the motor and the target position. After correction, repeat the above steps until the actual position of the object pushed by the motor matches the target position or there is a reasonable error (for example, the error is within ±0.5um), then the gain parameter is considered to be a suitable gain parameter, and the PID control algorithm is an accurate control algorithm.

[0122] Continuing with the above example, developers can first determine that the input voltage amplitude is set to 3.2*2 volts, the current frequency is 30000Hz, and the target position is 190um. Initially set Kp=0.1, Ki=0.01, and Kd=0.001. Then use the PID control algorithm to obtain the corresponding duty cycle value of 25%, and input this set of input parameters into the driverIC to generate a high-frequency PWM current to drive the motor to achieve the movement of the lens. Then increase the value of Kp and repeat the above process until overshoot (for example, when the motor stroke is 200um) or oscillation (for example, the motor stroke oscillates back and forth between 180um and 195um) occurs. If during this process, the position deviation between the actual position of the lens and the target position (i.e., the third stroke) is large, the value of Ki can be appropriately increased to reduce the above position deviation. If during this process, the motor movement has overshoot or oscillation, the value of Kd can be appropriately increased to increase the stability of the system.

[0123] By iteratively optimizing each gain parameter according to the above operation, the above appropriate gain parameter can be found, thereby obtaining an accurate PID control algorithm.

[0124] When the frequency and voltage amplitude in the above input parameters change, the above gain parameters will also change accordingly. Correspondingly, when the fixed parameters in the above input parameters are frequency and duty cycle, or the fixed parameters are voltage amplitude and duty cycle, the above gain parameters will also be different.

[0125] The driver IC in the closed-loop motor system may also combine the methods in the first embodiment and the second embodiment to generate a high-frequency PWM voltage.

[0126] For example, after receiving the target position indicated by the processor, the conversion circuit can first use the method in Example 1 to determine the duty cycle, amplitude, and frequency of the high-frequency PWM voltage corresponding to the target stroke according to the corresponding relationship between the duty cycle, amplitude or frequency of the first PWM voltage and the motor displacement, generate a high-frequency PWM voltage output, and then convert it into a high-frequency PWM current to drive the motor, driving the lens to quickly approach the above-mentioned target position. Then the above-mentioned position detection circuit can detect the actual position of the lens in real time and output it to the above-mentioned control circuit. The above-mentioned control circuit calculates the above-mentioned third stroke based on the actual position of the above-mentioned lens and the target position and inputs it into the above-mentioned conversion circuit. At this time, the conversion circuit can convert the above-mentioned third stroke into a corresponding high-frequency PWM' voltage according to the above-mentioned PID control algorithm, and then generate a high-frequency PWM' current, thereby realizing precise control of the lens when it is close to the target position.

[0127] In some embodiments, in order to further solve the static friction problem when the motor is started, in addition to the aforementioned circuit structure, the open-loop motor system or the closed-loop motor system may also include a voltage doubling circuit.

[0128] Taking the open-loop motor system as an example, Fig.11 An open-loop motor system including a voltage doubling circuit provided in an embodiment of the present application is shown.

[0129] like Fig.11 As shown, the input end of the voltage doubling circuit is coupled to the conversion circuit, and the output end of the voltage doubling circuit is coupled to the first PWM wave circuit. The voltage doubling circuit can be used to multiply the first PWM voltage generated by the conversion circuit, and then output the multiplied PWM voltage to the first PWM wave circuit to generate a first PWM current, and finally output the first PWM current to the motor, such as outputting it to both ends of the VCM coil load, thereby multiplying the instantaneous current flowing through the VCM coil, and then significantly improving the instantaneous thrust of the motor, so that the motor can overcome static friction more quickly when starting. When the motor system is applied to a camera, users can have faster zoom speeds and better anti-shake performance.

[0130] In the embodiment of the present application, the voltage doubling circuit can also be partially or completely integrated in the driver IC and connected to the conversion circuit and the first PWM wave circuit. Partial integration in the driver IC can mean that the switches and other logic devices in the voltage doubling circuit are integrated in the IC. The voltage doubling circuit can also be integrated in the application module (such as a camera module, a button module, etc.), and can even be integrated in the VCM, for example, etching a voltage doubling circuit welding pad on a part of the flexible printed circuit board (FPCB) built into the VCM or on a metal part.

[0131] A conventional voltage doubling circuit is usually a combination of multiple capacitors and multiple diodes, which generates an average voltage increase by periodically charging and discharging the capacitors. However, this solution will increase the size of the motor and is not suitable for electronic devices 100 with limited body space.

[0132] Based on this, an embodiment of the present application provides a voltage doubling circuit with a more streamlined circuit structure to solve this problem.

[0133] The voltage doubling circuit provided in the embodiments of the present application will be described in detail from multiple aspects below.

[0134] The voltage doubling circuit mentioned in this article may include a two-stage voltage doubling circuit, a three-stage voltage doubling circuit, or even a multi-stage voltage doubling circuit.

[0135] Secondary voltage doubler circuit

[0136] The embodiment of the present application provides a two-stage voltage doubling circuit, which further reduces the circuit size and can change the polarity voltage of the output voltage. When the voltage doubling circuit is applied to a motor system, such as when the input end of the voltage doubling circuit is connected to a conversion circuit and the output end is connected to a first PWM wave circuit, it can change the direction of the current in the final coil, thereby supporting the motor to output motor thrust in two directions, and ultimately controlling the object pushed by the motor (such as the lens of a camera) to move in two directions.

[0137] like Fig. 12AAs shown, the secondary voltage doubler circuit 11 may include a capacitor C1, a diode D1, a diode D2, and a switch S1, input terminals 08A, 08B, and output terminals 09A, 09B. The switch S1 may be a single-pole double-throw switch, including a fixed terminal P1 and two moving terminals T1, T2, which may be used to switch between conducting D1 and conducting D2. Among them, one end of the capacitor C1 is coupled to the input terminal 08A, and the other end is coupled to the output terminal 09A. Of the two ends of the capacitor C1, the end coupled to the input terminal 08A may be referred to as the first end of the capacitor C1, and the other end coupled to the output terminal 09A may be referred to as the second end of the capacitor C1. The cathode of the diode D1 is coupled to the second end of the capacitor C1, and the anode is coupled to the active end T1 of the switch S1; the anode of the diode D2 is also coupled to the second end of the capacitor C1, and the cathode is coupled to the active end T2 of the switch S1; the fixed end P1 of the switch S1 is coupled to the input end 08B; and the input end 08B is also coupled to the output end 09B.

[0138] In the voltage doubler circuit 11, C1 and D1 form a charge-discharge circuit, and C1 and D2 also form a charge-discharge circuit. The two charge-discharge circuits share the same capacitor C1, so that the improved two-stage voltage doubler circuit 11 does not need two capacitors, which can further reduce the circuit size.

[0139] In the voltage doubling circuit 11, the two charge and discharge circuits do not work at the same time, and the switch S1 can be used to select which charge and discharge circuit to work. Specifically, the switch S1 can also include two control terminals C1 and C2 to receive control signals from a control unit such as a processor or a controller. Whether the switch S1 selectively turns on D1 or D2 (i.e., which charge and discharge circuit is selected to work) can be controlled by a control signal input to the control terminal. The control signal can be generated due to the user's zoom action. For example, the action of increasing the zoom ratio will trigger the control unit such as the processor to generate a control signal to select to turn on D1, thereby driving the lens to move in the first direction. For another example, the action of reducing the zoom ratio will trigger the control unit such as the processor to generate a control signal to select to turn on D2, thereby driving the lens to move in the second direction. The first direction can be, for example, a direction close to the object being photographed, and the second direction can be, for example, a direction away from the object being photographed.

[0140] The diodes D1 and D2 are only an example of a unidirectional conduction device, and the voltage doubler circuit 11 may also use other types of unidirectional conduction devices. In the voltage doubler circuit 11, the diodes D1 and D2 may be replaced by two unidirectional conduction devices with opposite conduction directions. Herein, the unidirectional conduction device may be a unidirectional conduction device or a unidirectional conduction circuit that forms a small conduction voltage drop (less than 1V).

[0141] like Fig. 12BAs shown, the secondary voltage doubling circuit 11 provided in the embodiment of the present application can be connected between the conversion circuit 12 and the first PWM wave circuit 13 (the circuit structure details are not shown), and can be used to increase the output voltage of the conversion circuit 12 and further output it to the first PWM wave circuit 13, so that the instantaneous current output to both ends of the coil 14 load is increased. Among them, the output end of the first PWM wave circuit 13 is coupled to the coil 14. The coil is essentially a series connection of an inductor and a resistor. In the figure, "R Z ” may represent the equivalent load of the coil 14. Specifically, one input end of the voltage doubler circuit 11 is coupled to the output end 10A of the conversion circuit 12, and the other input end is coupled to the output end 10B of the conversion circuit 12; one output end of the voltage doubler circuit 11 is coupled to one end of the first PWM wave circuit 13, and the other output end is coupled to the other end of the first PWM wave circuit 13.

[0142] In this article, coupling includes direct electrical connection and indirect electrical connection with a conductive device (such as a resistor) or a conductive circuit in series. Since the first PWM wave circuit 13 does not affect the working principle of the voltage doubler circuit charging and discharging, in order to simplify the description of the charging and discharging process of the improved voltage doubler circuit, in the subsequent description, the output end of the voltage doubler circuit 11 is coupled to the coil 14 for description.

[0143] Charging and discharging of the improved two-stage voltage doubler circuit

[0144] Figure 13A-13B Figure 2 shows a charging and discharging method of a voltage doubler circuit. Figure 13A-13B In the embodiment, switch S1 selectively turns on D1.

[0145] like Fig.13A As shown, when the input voltage signal is in the first half cycle, the voltage polarities of the input terminals 08A and 08B are negative and positive respectively, and the capacitor C1 is charged, with the voltage polarity being positive on the right and negative on the left, and soon after, the capacitor voltage is charged to be close to the input voltage. In this article, this charging process can be referred to as "one-time capacitor charging".

[0146] like Fig. 13B As shown, when the input voltage signal switches to the second half cycle, the voltage polarities of the input terminals 08A and 08B are positive and negative respectively, D1 is not conducting, capacitor C1 is discharged, and the voltage on capacitor C1 is superimposed on the input voltage to form an output voltage. The polarity of the output voltage is the first polarity (positive on top and negative on bottom as shown in the figure), which supplies power to the coil, and the current flowing through the coil is approximately 2*I. Among them, I represents the coil current when the voltage doubling circuit is not used under the same input voltage, I=U in / R z The above U in is the voltage of the input voltage doubler circuit, that is, the PWM voltage generated by the conversion circuit. In this article, this discharge process can be referred to as "one-time capacitance superimposed input voltage discharge".

[0147] Fig. 13B In the embodiment, the direction of the coil current is from the first end of the coil 14 to the second end of the coil 14. The first end of the coil 14 is an end coupled to the output end 09A, and the second end of the coil 14 is an end coupled to the output end 09B.

[0148] When the input voltage signal reaches the next cycle, the voltage doubler circuit 11 repeats Fig.13A The charging process shown Fig. 13B The discharge process is shown.

[0149] Unlike the traditional two-stage voltage doubling circuit, the two-stage voltage doubling circuit provided in the embodiment of the present application can achieve approximately doubling of the VCM supply voltage in one and a half cycles, without taking as long as one cycle. The two-stage voltage doubling circuit provided in the embodiment of the present application only requires one capacitor C1, not two capacitors, which can save size.

[0150] Figure 13C-Figure 13D Another charging and discharging method of the voltage doubler circuit is shown in FIG. Figure 13C-Figure 13D In the embodiment, switch S1 selectively turns on D2.

[0151] like Fig. 13C As shown, when the input voltage signal is in the second half cycle, the voltage polarities of the input terminals 08A and 08B are positive and negative respectively, the capacitor C1 is charged, the voltage polarity is positive on the left and negative on the right, and soon it is charged until the capacitor voltage is close to the input voltage, completing the "one-fold capacitor charging".

[0152] like Fig.13D As shown, when the input voltage signal is switched to the first half cycle, the voltage polarities of the input terminals 08A and 08B are negative and positive respectively, D2 is not conducting, capacitor C1 is discharged, and the voltage on capacitor C1 is superimposed on the input voltage to form an output voltage. The polarity of the output voltage is the second polarity (negative on the top and positive on the bottom as shown in the figure), which supplies power to the coil. The current flowing through the coil is approximately 2*I, completing the "one times capacitance superimposed on input voltage discharge".

[0153] Fig.13D In the embodiment, the direction of the coil current is from the second end of the coil 13 to the first end of the coil 13.

[0154] When the input voltage signal reaches the next cycle, the voltage doubler circuit 11 repeats Fig. 13C The charging process shown Fig.13D The discharge process is shown.

[0155] In addition, according to the right-hand screw rule, when current flows through the coil, the coil can generate an attractive force or a repulsive force relative to its matching magnet, thereby driving the lens or other components to be driven to move. Fig. 13B The coil current and Fig.13DThe coil currents shown in the figure have opposite directions, so they will generate two opposite driving forces, which can drive the lens to move in these two directions.

[0156] The first half cycle and the second half cycle can be respectively the negative half cycle and the positive half cycle, or respectively the positive half cycle and the negative half cycle. That is, the input voltage with positive top and negative bottom shown in the figure can be the input voltage of the positive half cycle or the input voltage of the negative half cycle.

[0157] Adding bias resistors

[0158] Furthermore, a resistor can be connected in series in the charge-discharge circuit to adjust the charge-discharge time of the capacitor C1. Because the time constant of the charge-discharge circuit is τ=R*C, where R represents the circuit resistance, including the power supply internal resistance, the diode conduction resistance, and the transmission line resistance, further connecting resistors of different sizes in series can change the charge-discharge time constant of the circuit.

[0159] like Fig.14A As shown, the two-stage voltage doubler circuit 11 may further include a bias resistor R1, which may be connected in series between the fixed end P1 of the switch S1 and the output end 10B of the driver IC, i.e., constitutes a bias resistor shared by the charge and discharge circuits of the diodes D1 and D2, and adjusts the charge and discharge time of the two charge and discharge circuits together. That is, the fixed end P1 of the switch S1 in the voltage doubler circuit 11 is not directly coupled to the output end 10B of the driver IC, but is indirectly coupled to the output end 10B of the driver IC through the series-connected bias resistor R1.

[0160] like Fig. 14B As shown, the secondary voltage doubler circuit 11 may also include two bias resistors R1 and R2, which may be connected in series in the charge and discharge circuits of the diodes D1 and D2, respectively, to independently adjust the charge and discharge time of the charge and discharge circuits of D1 or D2. Specifically, the bias resistor R1 may be connected in series between the positive electrode of the diode D1 and the moving end T1 of the switch S1, and the bias resistor R2 may be connected in series between the negative electrode of the diode D2 and the moving end T1 of the switch S1. That is, the positive electrode of the diode D1 in the voltage doubler circuit 11 is not directly coupled to the moving end T1 of the switch S1, and the negative electrode of the diode D2 is not directly coupled to the moving end T2 of the switch S1.

[0161] More voltage doubler circuits

[0162] Fig.15A FIG. 2 shows an n-level voltage multiplication circuit provided in an embodiment of the present application, where n≥2. Fig.15AAs shown, the n-stage voltage multiplier circuit can be composed of a traditional n-stage voltage multiplier circuit (including a traditional two-stage voltage multiplier circuit) and a switch S1. The switch S1 is electrically connected between the output end of the traditional n-stage voltage multiplier circuit and the coil load, and can be used to control the polarity of the voltage loaded on both ends of the coil to change the direction of the current flowing through the coil, thereby changing the direction of the motor thrust.

[0163] like Fig. 15B As shown, the switch S1 may be a double-pole double-throw switch or a combination of two single-pole double-throw switches, and may include: two fixed terminals P1 and P2, four moving terminals T1, T2, T3, and T4, and two control terminals C1 and C2. Among them, P1 and P2 are electrically connected to the two ends of the capacitor Cn, respectively, T1 and T4 are electrically connected to the first end of the coil, and T2 and T3 are electrically connected to the second end of the coil.

[0164] When the voltage polarity of the output end of the n-stage voltage doubler circuit (i.e., the two ends of the capacitor Cn) is positive at the top and negative at the bottom, the switch can be controlled to switch so that P1 to T1 is turned on, P1 to T2 is turned off, P2 to T3 is turned on, and P2 to T4 is turned off, thereby controlling the voltage polarity of the coil to be positive at the top and negative at the bottom, and the direction of the coil current is to flow from the first end of the coil to the second end. When the voltage polarity of the output end of the n-stage voltage doubler circuit is positive at the top and negative at the bottom, the switch can be controlled to switch so that P1 to T2 is turned on, P1 to T1 is turned off, P2 to T4 is turned on, and P2 to T3 is turned off, thereby controlling the voltage polarity of the coil to be positive at the bottom and negative at the top, and the direction of the coil current is to flow from the second end of the coil to the first end. In this way, the direction of the coil current can be adjusted by the selective conduction capability of S1, thereby controlling the direction of the motor thrust.

[0165] Similarly, when the voltage polarity of the output end of the n-stage voltage multiplier circuit is negative at the top and positive at the bottom, the direction of the coil current can also be adjusted through the selective conduction capability of S1, thereby controlling the direction of the motor thrust.

[0166] The control signal of the switch switching can be transmitted from a control unit such as a controller or a processor through two control terminals C1 and C2.

[0167] In addition, in order to independently control the time constant τ of each charging circuit, a bias resistor can be connected in series in each charging circuit, such as Fig.15A R1, R2, R3...Rn.

[0168] Fig.16 Shows Fig. 12B The waveform timing curve of the voltage of capacitor C1 and coil current in the circuit shown. C1 Represents the capacitance voltage of capacitor C1, I coil Represents the current flowing through the coil. Fig.16 As shown, after the above two-stage voltage doubling circuit is introduced, U C1 Approximately equal to U in, I coil Approximately equal to 2I.

[0169] By introducing the voltage doubling circuit, the instantaneous thrust of the motor is nearly doubled at the moment of capacitor C1 discharge, which can significantly increase the acceleration of lens movement and improve the efficiency of lens movement to the target position. Moreover, since the PWM voltage generated by the conversion circuit is a high-frequency voltage, generally 10KHz, 20KHz, or even higher, the output of motor thrust is very dense in a short period of time, such as 20,000 times of high thrust output in 1 second, which makes the focusing or anti-shake smooth and the user experience better.

[0170] Fig.17 An electronic device 100 provided in an embodiment of the present application is shown.

[0171] like Fig.17 As shown, the electronic device 100 may include: a processor 110, a memory 120, a motor system 130, a power management circuit 140, a camera 150, a button 160, and a display screen 170. Among them:

[0172] The processor 110 may include an application processor (AP), an image signal processor (ISP). The processor 110 may also include a modem processor, a graphics processing unit (GPU), a video codec, a digital signal processor (DSP), a baseband processor, and / or a neural-network processing unit (NPU). Different processing units may be independent devices or integrated into one or more processors.

[0173] The processor 110 may include one or more interfaces. The interface may include an integrated circuit (IC). 2 C) interface, inter-integrated circuit sound, I 2S) interface, pulse code modulation (PCM) interface, universal asynchronous receiver / transmitter (UART) interface, mobile industry processor interface (MIPI), general-purpose input / output (GPIO) interface, subscriber identity module (SIM) interface, and / or universal serial bus (USB) interface, etc.

[0174] I 2 The I C interface is a bidirectional synchronous serial bus that includes a serial data line (SDA) and a serial clock line (SCL). The processor 110 may include multiple I 2 The processor 110 can be connected to the I 2 The C bus couples the memory 120, the power management circuit 140, the camera 150, the button 160, the display screen 170, etc.

[0175] For example, the processor 110 may 2 The C bus is coupled to the camera 150 to control the driver IC in the camera 150 to adjust the amplitude, duty cycle, and frequency of the voltage signal (the aforementioned high-frequency PWM voltage) generated by it, thereby adjusting the current output to the VCM coil and ultimately adjusting the motor thrust. For another example, the processor 110 can use I 2 The C bus is coupled to the camera 150 to control the controller in the camera 150 to output a switch selection signal, thereby adjusting the current direction of the VCM coil to generate a motor thrust in a specified direction.

[0176] I 2 The S interface can be used for audio communication. The processor 110 can include multiple groups of I 2 The processor 110 can use I 2 The S bus is coupled to the audio module in the electronic device 100 to realize communication between the processor 110 and the audio module. The audio module can be connected to the I 2 The S interface transmits audio signals to the wireless communication module in the electronic device 100, thereby realizing the function of answering calls through a Bluetooth headset.

[0177] The PCM interface can also be used for audio communication, sampling, quantizing and encoding analog signals. The audio module and the wireless communication module can be coupled through the PCM bus interface. The audio module can also transmit audio signals to the wireless communication module through the PCM interface to realize the function of answering calls through Bluetooth headsets.

[0178] The UART interface is a universal serial data bus that converts the data to be transmitted between serial communication and parallel communication. The UART interface is usually used to connect the processor 110 with the wireless communication module. For example, the processor 110 communicates with the Bluetooth module in the wireless communication module through the UART interface to implement the Bluetooth function.

[0179] The MIPI interface can be used to connect the processor 110 with peripheral devices such as a display screen and a camera 150. The MIPI interface includes a camera serial interface (CSI), a display serial interface (DSI), and the like.

[0180] The GPIO interface can be configured by software. The GPIO interface can be configured as a control signal or a data signal. The GPIO interface can be used to connect the processor 110 with the camera 150, a display screen, a wireless communication module, an audio module, and various sensors. The GPIO interface can also be configured as I 2 C interface, I 2 S interface, UART interface, MIPI interface, etc.

[0181] The USB interface may include: Mini USB interface, Micro USB interface, USB Type C interface, etc. The USB interface may be used to connect a charger to charge the electronic device 100, or may be used to transmit data between the electronic device 100 and a peripheral device. The interface may also be used to connect other electronic devices, such as AR devices, etc.

[0182] The memory 120 may include one or more random access memories (RAM) and one or more non-volatile memories (NVM). The random access memory can be directly read and written by the processor 110, and can be used to store executable programs (such as machine instructions) of the operating system or other running programs, and can also be used to store user and application data. The non-volatile memory can also store executable programs and store user and application data, etc., and can be loaded into the random access memory in advance for direct reading and writing by the processor 110.

[0183] The processor 110 may also be provided with a memory for storing instructions and data. The memory in the processor 110 is a high-speed cache memory. The memory may store instructions or data that the processor 110 has just used or cyclically used. If the processor 110 needs to use the instruction or data again, it may be directly called from the memory. This avoids repeated access, reduces the waiting time of the processor 110, and thus improves the efficiency of the electronic device 100.

[0184] The motor system 130 may include a driver IC and a VCM.

[0185] The input end of the driver IC is connected to the power management circuit 140, and the output end is connected to the VCM. In the embodiment of the present application, the driver IC can generate a high-frequency PWM voltage, and then convert the high-frequency PWM voltage into a high-frequency PWM current and load it to both ends of the VCM coil. By adjusting the amplitude, frequency, and duty cycle of the high-frequency PWM voltage generated in the driver IC, the instantaneous current loaded to the VCM coil can be changed, thereby changing the instantaneous thrust of the motor, thereby solving the problem that the instantaneous thrust of the motor is too small to overcome the static friction. Specifically, the driver IC can be used to generate a high-frequency PWM voltage. 2 The C bus communicates with the processor 110 (eg, AP), receives a power supply adjustment signal, and then adaptively changes the voltage signal generated by it according to the power supply adjustment signal.

[0186] The motor system 130 can be applied to one or some components of the electronic device 100, such as the camera 150, the button 160, and the display screen 170. The dotted arrows in the figure represent a hardware-implemented dependency, that is, the camera 150, the button 160, and the display screen 170 can be implemented by relying on the motor system 130.

[0187] When the motor system 130 is applied to the camera 150, the VCM generates mechanical force to drive the lens to move so as to change the zoom ratio; when the motor system 130 is applied to the button 160, the VCM generates mechanical force to drive the rebound mechanism in the button to rebound; when the motor system 130 is applied to the display screen 170 (specifically a touch screen), the VCM generates mechanical force to form force feedback to simulate force tactile sensation.

[0188] The following description will be made by taking the application of the motor system 130 to the camera 150 as an example.

[0189] The camera 150 may include: a lens, a VCM, a light sensor, and a controller. The camera 150 may also include: a driver IC (not shown) connected to the VCM. The driver IC and the controller may be arranged on a flexible printed circuit board (FPCB). The FPCB may also be responsible for connecting some components in the camera 150 to the processor 110, for example, transmitting the raw data output by the light sensor to the processor 110 (specifically, the ISP).

[0190] When taking a photo, the shutter of the camera 150 is opened, and light enters and shines on the photosensitive sensor. The photosensitive sensor converts the light signal into an electrical signal, and then further converts the electrical signal into a digital signal through analog digital convert (ADC) to pass it to the ISP for processing. The ISP can perform the following processing on the output data of the photosensitive sensor: auto exposure control (AEC), auto gain control (AGC), auto white balance (AWB), color correction, removal of bad pixels, etc. The ISP can also be integrated into the camera 150.

[0191] Depending on whether the VCM is used for anti-shake, it can be divided into a motor used only for auto focus (AF) and a motor with optical image stabilization (OIS) function (also known as "optical image stabilization"). AF VCM can be used to drive the lens to move in the direction of the optical axis. OIS VCM can be used to drive the lens to move in a plane perpendicular to the optical axis. The above controller can be used to adjust the current direction of the VCM coil to generate motor thrust in a specified direction to achieve the zoom function of AFVCM and the anti-shake function of OISVCM.

[0192] Generally, such as Fig.18 As shown, OIS requires jitter compensation in at least four directions in the plane perpendicular to the optical axis: x1, x2, y1, y2. In the figure, z1 and z2 represent the direction of the optical axis. When the motor system includes the above-mentioned voltage doubling circuit, a VCM provided in the embodiment of the present application can generate motor thrust in both directions, and can also reduce the number of OIS VCMs.

[0193] In the camera 150, the driver ICs can be provided for the AF VCM and the OIS VCM respectively to independently power the AF VCM and the OIS VCM. The driver ICs of the AF VCM and the OIS VCM can be provided through I 2The C bus communicates with the processor 110 (such as AP), receives the power supply adjustment signal of AFVCM and OIS VCM, and then changes the amplitude, duty cycle and frequency of the voltage signal generated by the conversion circuit in each driver IC accordingly. The driver IC also includes a high-frequency PWM first PWM wave circuit, which is used to introduce a high-frequency PWM current, thereby increasing the instantaneous current output to both ends of the coil load of the VCM under the same power consumption, and then driving the motor to drive the lens to achieve fast zoom and anti-shake functions.

[0194] In a motor system including a voltage doubling circuit, the above-mentioned driver IC can integrate the improved voltage doubling circuit described in the above-mentioned embodiment, which can multiply the PWM voltage, increase the instantaneous current of the coil, and ultimately multiply the instantaneous thrust of the motor.

[0195] In the motor system, the controller can be used to control the selective conduction of the switch S1 in the voltage doubler circuit, thereby adjusting the current direction of the VCM coil and generating the motor thrust in a specified direction. 2 The C bus communicates with the processor 110 (such as AP), receives the automatic zoom command and the optical image stabilization command, and then outputs the switch selection signal to the control terminals C1 and C2 of the switch S1 in the voltage doubling circuit accordingly, adjusts the current direction of the VCM coil to generate the motor thrust in the specified direction, and completes the automatic zoom and optical image stabilization goals.

[0196] The camera 150 may have only one controller for controlling the coil current direction of multiple VCMs, and thus controlling the motor thrust direction of the multiple VCMs. That is, the one controller may be electrically connected to the switch S1 in the multiple VCM voltage doubling circuits, specifically connected to the control terminals C1 and C2 of the switch S1. Of course, the camera 150 may also have multiple controllers, one controller for each VCM, to independently control the motor thrust direction of each VCM.

[0197] The button 160 may be a power button, a volume button, etc. The motor system 130 may be applied to the button 160 to drive the rebound mechanism to rebound, provide significant rebound force, and improve the user's button experience.

[0198] The display screen 170 can be used to display images, videos, etc. The display screen 170 can be a touch screen with a touch panel, and the motor system 130 can be applied to the display screen 170 to generate vibration prompts (such as vibration prompts for incoming calls, alarms, etc.) or provide touch force feedback to the user.

[0199] The power management circuit 140 can be used to connect the battery, charging management module and processor 110 in the electronic device 100. The power management circuit 140 receives input from the battery and / or charging management module to power the processor 110, the memory 120, the camera 150, the display screen, the wireless communication module, etc. Specifically, the power management circuit 140 can be connected to the driver IC that matches each VCM in the camera 150 to control the power supply to the camera through the driver IC. The power management circuit 140 can also be used to monitor parameters such as battery capacity, battery cycle number, battery health status (leakage, impedance), etc. The power management circuit 140 can also be set in the processor 110. The power management circuit 140 can also be integrated with the charging management module.

[0200] The electronic device 100 may also include: a wireless communication module. The wireless communication module may provide wireless communication solutions including wireless local area networks (WLAN) (such as wireless fidelity (Wi-Fi) networks), Bluetooth (BT), global navigation satellite system (GNSS), frequency modulation (FM), nearfield communication technology (NFC), infrared technology (IR), etc., which are applied to the electronic device 100. The wireless communication module may also provide wireless communication solutions including 2G / 3G / 4G / 5G, etc., which are applied to the electronic device 100. The wireless communication module receives electromagnetic waves via an antenna, modulates and filters the electromagnetic wave signals, and sends the processed signals to the processor 110. The wireless communication module may also receive the signal to be sent from the processor 110, modulate the frequency of the signal, amplify it, and convert it into electromagnetic waves for radiation through the antenna.

[0201] The electronic device 100 may further include: an audio module, a speaker, a receiver, a microphone, and an earphone interface.

[0202] Among them, the electronic device can realize audio functions through an audio module, a speaker, a receiver, a microphone, a headphone interface, and an application processor (AP). For example, music playback, recording, etc. The audio module is used to convert digital audio information into an analog audio signal output, and is also used to convert analog audio input into a digital audio signal. The audio module can also be used to encode and decode audio signals. The audio module can be set in the processor 110, or some functional modules of the audio module can be set in the processor 110. The speaker, also known as a "speaker", is used to convert audio electrical signals into sound signals. The electronic device can listen to music or listen to hands-free calls through the speaker. The receiver, also known as a "handset", is used to convert audio electrical signals into sound signals. When the electronic device answers a call or voice message, the voice can be answered by placing the receiver close to the human ear. The microphone, also known as a "microphone" or a "microphone", is used to convert sound signals into electrical signals. When making a call or sending a voice message, the user can make a sound by approaching the microphone with the human mouth to input the sound signal into the microphone. The headphone interface is used to connect wired headphones. The headphone interface can be a USB interface, or a 3.5 mm open mobile terminal platform (OMTP) standard interface, or a cellular telecommunications industry association of the USA (CTIA) standard interface.

[0203] The electronic device 100 may also include sensors such as a gyroscope, an accelerometer, a pressure sensor, a distance sensor, a proximity light sensor, an ambient light sensor, a Hall sensor, etc. Among them, a gyroscope and an accelerometer are very necessary for OIS. Sensors such as a distance sensor and a Hall sensor that can directly or indirectly reflect the actual position of an object pushed by a motor can be used in a position detection circuit of the motor system 130.

[0204] Fig.17 The illustrated structure does not constitute a specific limitation on the electronic device, and the electronic device may include more or fewer components than shown in the figure, or combine some components, or separate some components, or arrange the components differently. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

[0205] In addition, based on the above Figure 2 The open-loop motor system described in the embodiment is applied to the camera 150 , and the embodiment of the present application also provides a motor control method.

[0206] like Fig.19 As shown, the method may include:

[0207] S103, the electronic device 100 converts the target stroke of the motor into a first frequency, a first amplitude, and a first duty cycle.

[0208] S104: The electronic device 100 generates a first PWM voltage according to a first frequency, a first amplitude, and a first duty cycle.

[0209] S105 , the electronic device 100 converts the first PWM voltage into a first PWM current.

[0210] S106 , the electronic device 100 outputs a first PWM current to the motor.

[0211] Further, such as Fig.19 As shown, before the electronic device converts the target stroke of the motor into the first frequency, the first amplitude, and the first duty cycle, the motor control method may further include:

[0212] S101, the electronic device 100 detects an operation of changing the optical zoom ratio of the camera module;

[0213] S102: The electronic device 100 determines a target travel distance according to the optical zoom ratio.

[0214] In some embodiments, the electronic device may store a first mapping relationship. As mentioned above, the first mapping relationship may record the motor strokes corresponding to different duty ratios when the frequency of the first PWM voltage is fixed to the first frequency and the amplitude is fixed to the second amplitude, and the motor strokes corresponding to different duty ratios include the target stroke.

[0215] The electronic device converts the target stroke of the motor into a first frequency, a first amplitude, and a first duty cycle, which may specifically include: the electronic device determines that the frequency of the first PWM voltage is fixed to the first frequency, the amplitude is fixed to the first amplitude, and based on the first mapping relationship, determines that the duty cycle corresponding to the target stroke is the first duty cycle.

[0216] In some embodiments, the electronic device may store a second mapping relationship. As mentioned above, the second mapping relationship records the motor strokes corresponding to different amplitudes of the first PWM voltage when the frequency is fixed to the first frequency and the duty cycle is fixed to the first duty cycle, and the motor strokes corresponding to different amplitudes include the target stroke.

[0217] The electronic device converts the target stroke of the motor into a first frequency, a first amplitude, and a first duty cycle, which may specifically include: the electronic device determines that the frequency of the first PWM voltage is fixed to the first frequency, the duty cycle is fixed to the first duty cycle, and based on the second mapping relationship, determines that the amplitude corresponding to the target stroke is the first amplitude.

[0218] In some embodiments, the electronic device may store a third mapping relationship. As mentioned above, the third mapping relationship records the motor strokes corresponding to different frequencies when the amplitude of the first PWM voltage is fixed to the first amplitude and the duty cycle is fixed to the first duty cycle, and the motor strokes corresponding to different frequencies include the target stroke.

[0219] The electronic device converts the target stroke of the motor into a first frequency, a first amplitude, and a first duty cycle, which may specifically include: the electronic device determines that the amplitude of the first PWM voltage is fixed to the first amplitude, the duty cycle is fixed to the first duty cycle, and based on a third mapping relationship determines that the frequency corresponding to the target stroke is the first frequency.

[0220] In some embodiments, the electronic device may also convert the target stroke into a first frequency, a first amplitude, and a first duty cycle for generating a first PWM through a PID control algorithm.

[0221] Furthermore, under the premise that the motor system further includes a position detection circuit and a control circuit to form a closed-loop motor system, the motor control method may further include:

[0222] S107, after the electronic device 100 outputs the first PWM current to the motor, the electronic device determines whether the motor mover is at a target position;

[0223] S108, if not, the electronic device 100 redetermines the target stroke according to the position deviation between the actual position of the motor mover and the target position, and the electronic device 100 converts the redetermined target stroke into a second frequency, a second amplitude, and a second duty cycle through a PID algorithm;

[0224] S109, the electronic device 100 generates a second PWM voltage according to the second frequency, the second amplitude, and the second duty cycle;

[0225] S110, the electronic device 100 converts the second PWM voltage into a second PWM current;

[0226] S111 , the electronic device 100 outputs a second PWM current to the motor.

[0227] In addition, based on the above Fig. 12B , Figure 15A-15B The motor system described in the embodiment is applied to the camera 150 . The embodiment of the present application also provides another motor control method to control the motor to output motor thrust in a specified direction.

[0228] like Fig. 20 As shown, the method may include:

[0229] S201 , the electronic device 100 detects an operation of increasing the optical zoom ratio of the camera 150 .

[0230] S202, the electronic device 100 switches the switch S1 in the AF VCM voltage doubling circuit in the camera 150 to the first active end to be turned on.

[0231] When the switch S1 is turned to the first moving end to be turned on, the direction of the AF VCM coil current is from the first end of the coil to the second end of the coil. At this time, the lens of the camera 150 moves away from the object being photographed on the optical axis.

[0232] S203 , the electronic device detects an operation of reducing the optical zoom ratio of the camera 150 .

[0233] S204, the electronic device 100 switches the switch S1 in the AF VCM voltage doubling circuit in the camera 150 to the second active end to be turned on.

[0234] When the switch S1 is turned to the second moving end to be turned on, the direction of the AF VCM coil current is from the second end of the coil to the first end of the coil. At this time, the lens of the camera 150 moves on the optical axis toward the direction of the object being photographed.

[0235] In the AF VCM voltage doubler circuit, Figure 12A-12B In the case described in the embodiment, the first moving end may refer to the moving end T1, and the second moving end may refer to the moving end T2. Figure 15A-15B In the case described in the embodiment, the first moving end may refer to a group of moving ends T1 and T3, and the second moving end may refer to a group of moving ends T2 and T4.

[0236] Furthermore, the method may also include:

[0237] S205 , when the camera 150 is turned on to capture images, the electronic device 100 detects device shaking in a third direction.

[0238] The third direction may be an OIS direction of the camera 150. Herein, the OIS direction refers to the direction in which the OIS VCM provides jitter compensation. Fig.11 The four directions represented by x1, y1, x2, and y2 provide jitter compensation, and these four directions are OIS directions. Of course, the OIS VCM can also provide jitter compensation in more (such as 8) directions, that is, have more OIS directions. This embodiment is described by taking the camera 150 having four OIS directions as an example.

[0239] S206 , the electronic device 100 switches the switch S1 in the OIS VCM voltage doubling circuit in the camera 150 to the first active end to be turned on.

[0240] When the switch S1 is turned on to the first moving end, the direction of the OIS VCM coil current flows from the first end of the coil to the second end of the coil. At this time, the lens of the camera 150 moves in the fourth direction on the optical axis plane. The fourth direction is the opposite direction of the third direction and is also another OIS direction of the camera 150. The third direction and the fourth direction can be respectively Fig.18 x1, x2, or y1, y2 in .

[0241] S207, when the camera 150 is turned on to capture images, the electronic device 100 detects device shaking in a fourth direction.

[0242] S208 , the electronic device 100 switches the switch S1 in the OIS VCM voltage doubling circuit in the camera 150 to the second active end to be turned on.

[0243] When the switch S1 is turned on to the second moving end, the direction of the current of the OIS VCM coil is from the second end of the coil to the first end of the coil. At this time, the lens of the camera 150 moves in the third direction on the optical axis plane.

[0244] An actual device jitter may not be simply a device jitter in a certain OIS direction. In this case, the actual device jitter can be decomposed into two device jitters in two mutually perpendicular OIS directions, for example Fig.11 After performing this decomposition, anti-shake compensation is performed on the device jitter in a single OIS direction.

[0245] In the above method, the execution order of S201-S202, S203-S204, S205-S206, and S207-S208 is not particularly limited. S203-S204 can be executed before S201-S202, such as when the user first reduces the zoom ratio and then increases the zoom ratio. S207-S208 can also be executed before S205-S206. S205-S206 and S207-S208 can be executed before S201-S202 and S203-S204, such as when the device shakes before the user adjusts the focus. S205-S206 and S207-S208 can also be executed simultaneously with S201-S202 and S203-S204, such as when the device shakes when the user adjusts the focus.

[0246] A VCM control method provided by an embodiment of the present application is further described below based on the internal architecture of the electronic device 100 .

[0247] S301, after detecting an operation of increasing the optical zoom ratio of the camera 150 through an input device such as a touch screen, the processor may send a first autofocus instruction to a controller in the camera 150, which may indicate a direction for the lens to move away from the object being photographed.

[0248] S302, the controller outputs a first control signal to the control end of the switch S1 in the AF VCM voltage doubling circuit.

[0249] S303, in response to the first control signal, the switch S1 in the AF VCM voltage doubler circuit is switched to the first active end to be turned on. The first control signal may be a level signal.

[0250] S304, after detecting an operation of reducing the optical zoom ratio of the camera 150 through an input device such as a touch screen, the processor may send a second autofocus instruction to a controller in the camera 150, which may indicate a moving direction of the lens: moving closer to the object being photographed.

[0251] S305, the controller outputs a second control signal to the control end of the switch S1 in the AF VCM voltage doubling circuit.

[0252] S306, in response to the second control signal, the switch S1 in the AF VCM voltage doubler circuit is switched to the second active end to be turned on. The second control signal may be a level signal.

[0253] In addition, when device shaking is detected, the processor may also send an OIS instruction to OIS VCM 1 or OIS VCM 2, and the OIS instruction may indicate the anti-shake compensation direction.

[0254] S307, after detecting device shaking in the x1 direction through input devices such as a gyroscope and an accelerometer, the processor may send an OIS instruction to the controller in the camera 150, and the OIS instruction may indicate that the anti-shake compensation direction is: x2 direction.

[0255] S308 , the controller outputs a first control signal to the control terminal of the switch S1 in the voltage doubling circuit of the OIS VCM 1 .

[0256] S309 , in response to the first control signal, the switch S1 in the voltage doubler circuit of the OIS VCM 1 is switched to the first active end to be turned on.

[0257] S310, after detecting device shaking in the x2 direction through an input device such as a gyroscope or an accelerometer, the processor may send an OIS instruction to a controller in the camera 150, and the OIS instruction may indicate that the anti-shake compensation direction is: the x1 direction.

[0258] S311 , the controller outputs a second control signal to the control terminal of the switch S1 in the voltage doubling circuit of the OIS VCM 1 .

[0259] S312, in response to the second control signal, the switch S1 in the voltage doubler circuit of the OIS VCM 1 is switched to the second active end to be turned on.

[0260] By controlling the conduction of the switch S1 in the voltage doubling circuit of the OIS VCM 1, the OIS VCM 1 can be controlled to push the lens to move in the anti-shake compensation direction, thereby achieving anti-shake compensation.

[0261] Similarly, after detecting device shaking in the y1 or y2 direction through input devices such as a gyroscope and an accelerometer, the processor may also send an OIS instruction to the controller in the camera 150 and indicate the direction of anti-shake compensation; the controller may control the conduction of the switch S1 in the voltage doubling circuit of the OIS VCM 2 according to the OIS instruction to control the OIS VCM 2 to push the lens to move in the anti-shake compensation direction to achieve anti-shake compensation.

[0262] Each step in the above method embodiment provided by the present application can be completed by an integrated logic circuit of hardware in a processor or by instructions in the form of software. The method steps disclosed in the embodiments of the present application can be directly embodied as being executed by a hardware processor, or by a combination of hardware and software modules in a processor.

[0263] The present application also provides an electronic device, which may include: a memory and a processor, wherein the memory may be used to store a computer program; and the processor may be used to call the computer program in the memory so that the electronic device executes the method in any one of the above embodiments.

[0264] The present application also provides a chip system, which includes at least one processor for implementing the functions involved in the method executed by the electronic device in any of the above embodiments.

[0265] In one possible design, the chip system also includes a memory, which is used to store program instructions and data, and the memory is located inside or outside the processor.

[0266] The chip system may be composed of the chip, or may include the chip and other discrete devices.

[0267] Optionally, the processor in the chip system may be one or more. The processor may be implemented by hardware or by software. When implemented by hardware, the processor may be a logic circuit, an integrated circuit, etc. When implemented by software, the processor may be a general-purpose processor implemented by reading software code stored in a memory.

[0268] Optionally, the memory in the chip system may also be one or more. The memory may be integrated with the processor or may be separately arranged with the processor, which is not limited in the embodiments of the present application. Exemplarily, the memory may be a non-transient processor, such as a read-only memory ROM, which may be integrated with the processor on the same chip or may be arranged on different chips respectively. The embodiments of the present application do not specifically limit the type of memory and the arrangement of the memory and the processor.

[0269] Exemplarily, the chip system can be a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), a system on chip (SoC), a central processor unit (CPU), a network processor (NP), a digital signal processor (DSP), a microcontroller unit (MCU), a programmable logic device (PLD) or other integrated chips.

[0270] The present application also provides a computer program product, which includes: a computer program (also referred to as code, or instruction), which enables a computer to execute the method executed by the electronic device in any of the above embodiments when the computer program is executed.

[0271] The present application also provides a computer-readable storage medium, which stores a computer program (also referred to as code or instruction). When the computer program is executed, the computer executes the method executed by the electronic device in any of the above embodiments.

[0272] The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on the computer, the process or function according to the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from a website site, a computer, a server or a data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, server or data center. The computer-readable storage medium can be any available medium that the computer can access or a data storage device such as a server or a data center that includes one or more available media integrations. Available media can be magnetic media, (e.g., floppy disk, hard disk, tape), optical media (e.g., DVD), or semiconductor media (e.g., solid-state drive Solid State Disk), etc.

[0273] Those skilled in the art can understand that to implement all or part of the processes in the above-mentioned embodiments, the processes can be completed by computer programs to instruct related hardware, and the programs can be stored in computer-readable storage media. When the programs are executed, they can include the processes of the above-mentioned method embodiments. The aforementioned storage media include: ROM or random access memory RAM, magnetic disk or optical disk and other media that can store program codes.

[0274] In short, the above are only embodiments of the technical solution of the present invention, and are not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made according to the disclosure of the present invention shall be included in the protection scope of the present invention.

Claims

1. A motor drive circuit, characterized in that: The motor drive circuit comprises: a conversion circuit and a first pulse width modulation (PWM) wave circuit; wherein the conversion circuit is coupled to the first PWM wave circuit, and the conversion circuit is also coupled to a power supply module of the motor drive circuit for receiving power from the power supply module, and the conversion circuit is also connected to a processor for receiving a travel instruction from the processor, and the travel instruction includes a target position of the motor; The conversion circuit is used to convert the supply voltage into a first PWM voltage with a first frequency, a first amplitude and a first duty cycle according to the target stroke of the motor; the target stroke is determined by the conversion circuit according to the target position and the actual position of the motor; The conversion circuit is also used to output the first PWM voltage to the first PWM wave circuit; The first PWM wave circuit is used to convert the first PWM voltage into a first PWM current; the frequency of the first PWM current is close to or equal to the first frequency, and the duty cycle of the first PWM current is close to or equal to the first duty cycle; The first PWM wave circuit is also connected to the motor, and is used to output the first PWM current to the motor, so as to control the motor to generate motor thrust.

2. The motor driving circuit according to claim 1, characterized in that: The conversion circuit is used to convert the supply voltage into a first PWM voltage with a first frequency, a first amplitude, and a first duty cycle according to the target stroke of the motor, and specifically includes: The conversion circuit is used to determine that the frequency of the first PWM voltage is fixed to the first frequency, the amplitude is fixed to the first amplitude, and based on the first mapping relationship, determine that the duty cycle corresponding to the target stroke is the first duty cycle; The first mapping relationship records the motor strokes corresponding to different duty cycles when the frequency of the first PWM voltage is fixed to the first frequency and the amplitude is fixed to the second amplitude, and the motor strokes corresponding to the different duty cycles include the target stroke.

3. The motor driving circuit according to claim 2, characterized in that: In the first mapping relationship, the duty cycle and the motor stroke present a linear relationship.

4. The motor driving circuit according to claim 1, characterized in that: The second mapping relationship records the motor strokes corresponding to different amplitudes of the first PWM voltage when the frequency is fixed to the first frequency and the duty cycle is fixed to the first duty cycle, and the motor strokes corresponding to the different amplitudes include the target stroke; The conversion circuit is used to convert the supply voltage into a first PWM voltage with a first frequency, a first amplitude, and a first duty cycle according to the target stroke of the motor, and specifically includes: The conversion circuit is used to determine that the frequency of the first PWM voltage is fixed to the first frequency, the duty cycle is fixed to the first duty cycle, and based on the second mapping relationship, determine that the amplitude corresponding to the target stroke is the first amplitude.

5. The motor driving circuit according to claim 4, characterized in that: In the second mapping relationship, the amplitude and the motor stroke present a linear relationship.

6. The motor driving circuit according to claim 1, characterized in that: The third mapping relationship records the motor strokes corresponding to different frequencies when the amplitude of the first PWM voltage is fixed to the first amplitude and the duty cycle is fixed to the first duty cycle, and the motor strokes corresponding to the different frequencies include the target stroke; The conversion circuit is used to convert the supply voltage into a first PWM voltage with a first frequency, a first amplitude, and a first duty cycle according to the target stroke of the motor, and specifically includes: The conversion circuit is used to determine that the amplitude of the first PWM voltage is fixed to the first amplitude, the duty cycle is fixed to the first duty cycle, and based on the third mapping relationship, determine that the frequency corresponding to the target stroke is the first frequency.

7. The motor driving circuit according to claim 6, characterized in that: In the third mapping relationship, the frequency and the motor stroke present a linear relationship.

8. The motor driving circuit according to any one of claims 1 to 7, characterized in that: The motor drive circuit further comprises a control circuit; the control circuit is coupled to the conversion circuit, and is used to output the target stroke to the conversion circuit; the control circuit is also coupled to a processor, and is used to receive a stroke instruction transmitted by the processor, wherein the stroke instruction carries the target position of the motor; the control circuit is also coupled to a position detection circuit in the motor, and is used to receive the actual position of the motor mover in the motor transmitted by the position detection circuit; The position detection circuit is used to detect the actual position of the motor mover; The target stroke is determined based on the target position and the actual position of the motor mover. The closer the actual position is to the target position, the smaller the target stroke is.

9. The motor driving circuit according to claim 8, characterized in that: The conversion circuit is used to convert the supply voltage into a first PWM voltage with a first frequency, a first amplitude, and a first duty cycle according to the target stroke of the motor, and specifically includes: The conversion circuit is used to convert the target stroke into the first frequency, the first amplitude, and the first duty cycle through a proportional integral differential PID control algorithm; The conversion circuit is further configured to generate the first PWM voltage according to the first frequency, the first amplitude, and the first duty cycle.

10. The motor driving circuit according to any one of claims 1 to 9, characterized in that: The motor driving circuit further comprises a voltage doubling circuit, an input end of the voltage doubling circuit is coupled to the conversion circuit, and an output end of the voltage doubling circuit is coupled to the first PWM wave circuit; The voltage doubling circuit is used to boost the first PWM voltage generated by the conversion circuit and then output it to the first PWM wave circuit to convert it into the first PWM current.

11. The motor driving circuit according to claim 10, characterized in that: The voltage doubling circuit includes: a capacitor C1, a first unidirectional conduction device, a second unidirectional conduction device and a switch S1, as well as a first input terminal, a second input terminal, a first output terminal and a second output terminal; wherein: the first terminal of the capacitor C1 is coupled to the first input terminal, the second terminal of the capacitor C1 is coupled to the first output terminal, and the second output terminal is coupled to the second input terminal; one terminal of the first unidirectional conduction device is coupled to the second terminal of the capacitor C1, and the other terminal is coupled to the first moving terminal of the switch S1; one terminal of the second unidirectional conduction device is also coupled to the second terminal of the capacitor C1, and the other terminal is coupled to the second moving terminal of the switch S1; the fixed terminal of the switch S1 is coupled to the second input terminal; the conduction directions of the first unidirectional conduction device and the second unidirectional conduction device are opposite.

12. The motor driving circuit according to claim 11, characterized in that: The voltage doubler circuit is an n-stage voltage doubler circuit, n≥2, and n is a positive integer; a switch S1 is connected in parallel across the capacitor Cn in the n-stage charge and discharge circuit in the voltage doubler circuit, and the switch S1 is used to adjust the voltage polarity of the output voltage of the voltage doubler circuit.

13. A motor system, characterized in that: It comprises a motor driving circuit and a motor; wherein the output circuit of the motor driving circuit is coupled to the motor, and the motor driving circuit is the motor driving circuit according to any one of claims 1-12.

14. The motor system according to claim 13, characterized in that The motor system further includes a position detection circuit, and the motor drive circuit further includes a control circuit; The position detection circuit is coupled to the control circuit in the motor drive circuit, and the position detection circuit is used to detect the actual position of the motor mover and output the detected actual position to the control circuit.

15. An electronic device, characterized in that: include: A motor system and a processor; wherein the motor system is the motor system according to claim 13 or 14; The processor is coupled to the motor drive circuit in the motor system, and the processor is used to transmit a travel instruction to the motor drive circuit in the motor system, wherein the travel instruction includes a target position of the motor.

16. The electronic device according to claim 15, characterized in that: The motor system is arranged in the camera module of the electronic device.

17. A motor control method, the method being applied to an electronic device, characterized in that: The electronic device is the electronic device according to claim 15 or 16; The method comprises: The electronic device converts the target stroke of the motor into the first frequency, the first amplitude, and the first duty cycle; The electronic device generates the first PWM voltage according to the first frequency, the first amplitude, and the first duty cycle; The electronic device converts the first PWM voltage into a first PWM current; The electronic device outputs the first PWM current to the motor.

18. The method according to claim 17, characterized in that Before the electronic device converts the target stroke of the motor into the first frequency, the first amplitude, and the first duty cycle, the method further includes: The electronic device detects an operation of changing the optical zoom ratio of the camera module; The electronic device determines the target travel distance according to the optical zoom ratio.

19. The method according to claim 17 or 18, characterized in that The electronic device stores a first mapping relationship, wherein the first mapping relationship records motor strokes corresponding to different duty ratios when the frequency of the first PWM voltage is fixed to the first frequency and the amplitude is fixed to the second amplitude, and the motor strokes corresponding to the different duty ratios include the target stroke; The electronic device converts the target stroke of the motor into the first frequency, the first amplitude, and the first duty cycle, specifically including: The electronic device determines that the frequency of the first PWM voltage is fixed to the first frequency, the amplitude is fixed to the first amplitude, and determines that the duty cycle corresponding to the target stroke is the first duty cycle based on a first mapping relationship.

20. The method according to claim 17 or 18, characterized in that The electronic device stores a second mapping relationship, wherein the second mapping relationship records motor strokes corresponding to different amplitudes of the first PWM voltage when the frequency is fixed to the first frequency and the duty cycle is fixed to the first duty cycle, and the motor strokes corresponding to the different amplitudes include the target stroke; The electronic device converts the target stroke of the motor into the first frequency, the first amplitude, and the first duty cycle, specifically including: The electronic device determines that the frequency of the first PWM voltage is fixed to the first frequency, the duty cycle is fixed to the first duty cycle, and determines that the amplitude corresponding to the target stroke is the first amplitude based on the second mapping relationship.

21. The method according to claim 17 or 18, characterized in that The electronic device stores a third mapping relationship, wherein the third mapping relationship records motor strokes corresponding to different frequencies when the amplitude of the first PWM voltage is fixed to the first amplitude and the duty cycle is fixed to the first duty cycle, and the motor strokes corresponding to the different frequencies include the target stroke; The electronic device converts the target stroke of the motor into the first frequency, the first amplitude, and the first duty cycle, specifically including: The electronic device determines that the amplitude of the first PWM voltage is fixed to the first amplitude, the duty cycle is fixed to the first duty cycle, and determines that the frequency corresponding to the target stroke is the first frequency based on the third mapping relationship.

22. The method according to claim 17 or 18, characterized in that The electronic device converts the target stroke of the motor into the first frequency, the first amplitude, and the first duty cycle, specifically including: The electronic device converts the target stroke into the first frequency, the first amplitude, and the first duty cycle through a PID control algorithm.

23. The method according to any one of claims 17 to 22, characterized in that: The motor system further includes a position detection circuit and a control circuit, and the method further includes: After the electronic device outputs the first PWM current to the motor, the electronic device determines whether the motor mover is at a target position; If not, the electronic device redetermines the target stroke according to the position deviation between the actual position of the motor mover and the target position, and the electronic device converts the redetermined target stroke into a second frequency, a second amplitude, and a second duty cycle through a PID algorithm; The electronic device generates a second PWM voltage according to the second frequency, the second amplitude, and the second duty cycle; The electronic device converts the second PWM voltage into a second PWM current; The electronic device outputs the second PWM current to the motor.

24. A computer-readable storage medium comprising a coded instruction sequence, characterized in that: When the coded instruction sequence is run on an electronic device, the method according to any one of claims 17 to 23 is executed.

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