WO2018126560A1

WO2018126560A1 - Method for driving a linear resonant actuator, and terminal

Info

Publication number: WO2018126560A1
Application number: PCT/CN2017/081493
Authority: WO
Inventors: 陈建立; 李辉
Original assignee: 华为技术有限公司
Priority date: 2017-01-04
Filing date: 2017-04-21
Publication date: 2018-07-12
Also published as: CN109874398A

Abstract

A method for driving a linear resonant actuator, and a terminal, for use in accurately obtaining a resonance frequency of the linear resonant actuator, thereby driving the linear resonant actuator by using a driving signal having the resonance frequency, and enhancing the vibration strength of the linear resonant actuator. The terminal comprises: a processor, used for generating a first exciting signal and outputting the first exciting signal to a signal amplifier circuit; the signal amplifier circuit, connected to a processor and used for amplifying the first exciting signal by a first set multiple to obtain a second exciting signal and outputting the second exciting signal to the linear resonant actuator; the linear resonant actuator, connected to the signal amplifier circuit and used for storing energy and generating back electromotive force by using the second exciting signal, and converting the back electromotive force into a first sine wave signal for output; and a detection circuit, connected to the linear resonant actuator and used for obtaining the frequency of the first sine wave signal, the frequency of the first sine wave signal being the resonance frequency of the linear resonant actuator. The processor is also used for generating a driving signal having the resonance frequency and driving the linear resonant actuator by using the driving signal.

Description

Linear motor driving method and terminal

This application claims the priority of the Chinese Patent Application, filed on Jan. 4, 2017, filed Jan. In this application.

Technical field

The embodiments of the present invention relate to the field of terminal technologies, and in particular, to a driving method and a terminal for a linear motor.

Background technique

Linear Resonant Actuator (LRA) is a device used in the terminal to generate vibration and has a wide range of applications in terminals. For example, when the user performs a touch operation on the touch screen of the terminal or clicks a virtual button, the touch screen reports a touch event to the processor, and the processor generates a driving signal after receiving the touch event, thereby driving the linear motor to generate vibration and making the user experience To the sense of vibration, that is, tactile feedback. For another example, when the terminal receives a reminder or notification (such as an incoming call reminder, a short message reminder, an alarm reminder, or a notification from an application, etc.), if the terminal turns on the vibration function, the linear motor also gives vibration feedback.

In the above scenario where the drive signal is generated by the processor to drive the linear motor to generate vibration, when the frequency of the drive signal is the resonant frequency of the linear motor, the vibration intensity of the linear motor is maximum; when the frequency of the drive signal is at the resonant frequency of the linear motor When the absolute value of the difference is greater than the bandwidth of the linear motor (for example, 2 Hz), the vibration strength of the linear motor is rapidly weakened.

The linear motor in the terminal has an inherent resonant frequency before the terminal leaves the factory. After the terminal is shipped, the resonant frequency of the linear motor in the terminal may change due to component aging, manufacturing error or ambient temperature. At this time, if the linear motor is also driven at the resonance frequency inherent to the linear motor, the vibration intensity of the linear motor cannot be maximized.

Summary of the invention

The embodiment of the present application provides a driving method and a terminal for a linear motor, which are used for accurately acquiring a resonant frequency of a linear motor, thereby driving a linear motor by using a driving signal having the resonant frequency, enhancing the vibration intensity of the linear motor, and improving the user. Experience.

In a first aspect, an embodiment of the present invention provides a terminal, where the terminal includes a processor, a signal amplifying circuit, a linear motor, and a detecting circuit. The processor is configured to generate a first excitation signal, and output a first excitation signal to the signal amplification circuit; the signal amplification circuit is coupled to the processor, configured to receive the first excitation signal output by the processor, and amplify the first excitation signal by first After the multiple is set, the second excitation signal is obtained, and the second excitation signal is output to the linear motor; the linear motor is connected to the signal amplification circuit for storing energy by using the second excitation signal to generate a counter electromotive force, and converting the counter electromotive force into the first a sine wave signal output; the detection circuit is coupled to the linear motor for acquiring a frequency of the first sine wave signal, the frequency of the first sine wave signal is a resonant frequency of the linear motor; and the processor is further configured to generate the resonant frequency Driving a signal and driving the linear motor with the drive signal.

The meaning of the driving signal having the resonant frequency is that the frequency of the driving signal is the resonant frequency.

It should be noted that, in the embodiment of the present invention, the specific value of the first set multiple is not limited, and the first set multiple may be greater than 1, or may be equal to 1.

The terminal provided by the above first aspect is based on the following principle when acquiring the resonant frequency of the linear motor: an initial energy storage excitation for the linear motor, the linear motor performs energy storage to generate a counter electromotive force; and the linear motor releases the energy storage, The counter electromotive force is released in the form of a sinusoidal signal whose frequency is the resonant frequency of the linear motor.

In the terminal provided in the above first aspect, since the signal amplifying circuit outputs the second excitation signal to the linear motor, the linear motor can store itself by using the second excitation signal to generate a counter electromotive force; the linear motor releases itself. When storing energy, the frequency of the first sine wave signal output by the linear motor is the resonant frequency of the linear motor. After the frequency of the first sine wave signal (the resonant frequency of the linear motor) is obtained by the detecting circuit, the processor configures the frequency of the driving signal of the linear motor to the acquired resonant frequency, which can enhance the vibration intensity of the linear motor. Therefore, when driving the linear motor, the terminal utilizes the inherent characteristics of the linear motor's own energy storage to generate the back electromotive force and release the energy storage, and can accurately and conveniently acquire the resonant frequency of the linear motor, thereby using the obtained resonant frequency as the driving of the linear motor. The frequency of the signal enhances the vibration strength of the linear motor.

Based on the first aspect, in a possible design, when detecting the frequency of the first sine wave signal, the detecting circuit can be specifically implemented by clamping the first sine wave signal to a preset voltage value to obtain a second The sine wave signal is compared with a preset voltage value to obtain a square wave signal; the frequency of the square wave signal is obtained, and the frequency of the square wave signal is the same as the frequency of the first sine wave signal.

Since the frequency of the sine wave signal is not easy to detect in actual implementation, the first sine wave signal can be converted into a square wave signal after being clamped and compared, and the frequency of the converted square wave signal and the first sine wave signal can be converted. The frequency of the square wave signal is the same, and the frequency of the square wave signal is easier to detect. Therefore, the frequency of the first sine wave signal can be more conveniently obtained by the above implementation manner.

Based on the first aspect, in a possible design, the terminal provided by the above first aspect further includes a memory, where the memory is used to store a resonant frequency acquired by the detecting circuit; then, the processor generates a driving having the resonant frequency. In the case of a signal, the resonant frequency stored in the memory can be read first, and then a drive signal having the read resonant frequency is generated.

Based on the first aspect, in a possible design, the terminal provided by the first aspect further includes a switch unit and a control logic unit. Wherein, the switch unit is connected with the linear motor and the detecting circuit for disconnecting or closing the linear motor and the detecting circuit; the control logic unit is connected with the switching unit for controlling the switching unit to make the linear motor and detecting when the linear motor performs energy storage The circuit is disconnected and the switching unit is controlled to close the linear motor and the detection circuit after the linear motor has been stored.

In the terminal provided in the above first aspect, the switch unit and the control logic unit are disposed, and the switch unit can be controlled by the control logic unit to control the opening or closing of the linear motor and the detection circuit. When the linear motor is disconnected from the detection circuit, the linear motor performs energy storage; when the linear motor and the detection circuit are closed, the linear motor releases the energy storage, that is, the linear motor outputs the back electromotive force generated by the energy storage in the form of the first sine wave signal. To the detection circuit.

Based on the first aspect, in one possible design, the detection circuit specifically includes an operational amplification circuit and a comparator. The operational amplifier circuit is configured to amplify the first sine wave signal by a second set multiple and clamp the preset voltage value to obtain a second sine wave signal; the comparator is connected to the operational amplifier circuit for using the second sine wave The signal is compared with a preset voltage value to obtain a square wave signal.

It should be noted that, in the embodiment of the present invention, the specific value of the second set multiple is not limited, and the second set multiple may be greater than 1, or may be equal to 1.

Based on the first aspect, in one possible design, the comparator in the detection circuit is specifically used to: the second sine wave The signal is compared with the preset voltage value, and the high level is output when the amplitude of the second sine wave signal is greater than or equal to the preset voltage value, and the low level is output when the amplitude of the second sine wave signal is less than the preset voltage value. , get a square wave signal.

Based on the first aspect, in one possible design, the signal amplifying circuit includes a first resistor, a second resistor, a third resistor, a fourth resistor, a first capacitor, a second capacitor, and a first fully differential operational amplifier, wherein: The first end of the first resistor is configured to receive a first differential excitation signal in the first excitation signal, the second end of the first resistor is coupled to the negative input terminal of the first fully differential operational amplifier; the first end of the second resistor Receiving a second differential excitation signal in the first excitation signal, the second end of the second resistor is connected to the forward input end of the first fully differential operational amplifier; the third resistor and the first capacitor are connected in parallel and then connected in the first full a differential operational amplifier between the negative input terminal and the positive output terminal; the fourth resistor and the second capacitor are connected in parallel between the forward input terminal and the negative output terminal of the first fully differential operational amplifier; The forward and negative outputs of the operational amplifier are coupled to the first and second ends of the linear motor, respectively.

In order to maintain the balance between the input signal and the output signal of the first fully differential operational amplifier, it may be set that the resistances of the first resistor and the second resistor are the same, the resistances of the third resistor and the fourth resistor are the same, the first capacitor and the first capacitor The capacitance of the two capacitors is the same. At this time, the first set multiple can be set by adjusting the ratio of the third resistance to the first resistance (ie, the ratio of the fourth resistance to the second resistance).

The signal amplifying circuit is in the form of a first fully differential operational amplifier. In addition to amplifying the first excitation signal by a first set multiple to obtain a second excitation signal, the common mode noise in the second excitation signal can be suppressed, and the second is enhanced. The driving ability of the excitation signal.

Based on the first aspect, in one possible design, the operational amplifier circuit in the detection circuit includes a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, and a second fully differential operational amplifier, wherein: the fifth resistor The first end is connected to the forward input end of the second fully differential operational amplifier, the second end of the fifth resistor is connected to the switch unit, and the first end of the sixth resistor is connected to the negative input end of the second fully differential operational amplifier, The second end of the sixth resistor is connected to the switch unit; the seventh resistor is connected between the forward input terminal and the negative output terminal of the second fully differential operational amplifier, and the eighth resistor is connected across the second fully differential operational amplifier Between the negative input and the positive output. Then, the forward input of the comparator in the detection circuit is connected to the negative output or the positive output of the second fully differential operational amplifier, and the negative output of the comparator is used to input the preset voltage value, the comparator The output is used to output a square wave signal.

It should be noted that, in order to maintain the balance between the input signal and the output signal of the second fully differential operational amplifier, it can be set that the resistance values of the fifth resistor and the sixth resistor are the same, and the resistances of the seventh resistor and the eighth resistor are the same. Then, in the operational amplifier circuit, the second set multiple can be set by adjusting the ratio of the seventh resistor to the fifth resistor (ie, the ratio of the eighth resistor to the sixth resistor).

Based on the first aspect, in one possible design, the switch unit may include a first switch, a second switch, a third switch, and a fourth switch, wherein: one end of the first switch is connected to the first end of the linear motor, and One end is connected to the second end of the fifth resistor; one end of the second switch is connected to the second end of the linear motor, and the other end is connected to the second end of the sixth resistor; one end of the third switch and the second end of the fifth resistor Connected, the other end is grounded; one end of the fourth switch is connected to the second end of the sixth resistor, and the other end is grounded; the control logic unit is specifically configured to: control the first switch and the second switch to be disconnected when the linear motor performs energy storage And controlling the third switch and the fourth switch to be closed; controlling the first switch and the second switch to be closed after the linear motor energy storage is completed, and controlling the third switch and the fourth switch to be turned off.

When the switch unit and the control logic unit adopt the above implementation manner, the control logic unit can control the linear motor and the detection by controlling the opening, closing and closing of the first switch, the second switch, the third switch and the fourth switch in the switch unit. The circuit is open or closed.

In a second aspect, an embodiment of the present invention provides a driving method of a linear motor, where the method is applied to a processor, In the terminal of the signal amplifying circuit, the linear motor and the detecting circuit, the method comprises the steps of: the processor generating a first excitation signal and outputting the first excitation signal to the signal amplifying circuit; and the signal amplifying circuit amplifying the first excitation signal After the first set multiple, a second excitation signal is obtained, and the second excitation signal is output to a linear motor, the second excitation signal is used to generate a counter electromotive force after the linear motor is stored; and the linear motor uses the second excitation signal to store energy. Generating a counter electromotive force and converting the counter electromotive force into a first sine wave signal output; the detecting circuit acquires a frequency of the first sine wave signal, the frequency of the first sine wave signal being a resonant frequency of the linear motor; the processor generates the resonance The frequency of the drive signal, and the drive signal is used to drive the linear motor in the terminal.

In the driving method of the linear motor provided by the second aspect, since the signal amplifying circuit outputs the second excitation signal to the linear motor, the linear motor can store itself by using the second excitation signal to generate a counter electromotive force; the linear motor is When releasing its own stored energy, the frequency of the first sine wave signal output by the linear motor is the resonant frequency of the linear motor. After the frequency of the first sine wave signal (the resonant frequency of the linear motor) is obtained by the detecting circuit, the processor configures the frequency of the driving signal of the linear motor to the acquired resonant frequency, which can enhance the vibration intensity of the linear motor. Therefore, when the linear motor is driven by the driving method of the linear motor provided by the second aspect, the inherent characteristics of the back electromotive force generated by the linear motor itself and the energy storage are released, and the resonant frequency of the linear motor can be accurately and conveniently obtained, thereby obtaining The arriving resonant frequency drives the linear motor as the frequency of the drive signal of the linear motor, enhancing the vibration strength of the linear motor.

Based on the second aspect, in a possible design, when detecting the frequency of the first sine wave signal, the detecting circuit can be implemented by clamping the first sine wave signal to a preset voltage value to obtain a second sine The wave signal is obtained by comparing the second sine wave signal with a preset voltage value to obtain a square wave signal; the frequency of the square wave signal is obtained, and the frequency of the square wave signal is the same as the frequency of the first sine wave signal.

Since the frequency of the sine wave signal is not easy to detect in actual implementation, the first sine wave signal can be converted into a square wave signal after being clamped and compared, and the frequency of the converted square wave signal and the first sine wave signal can be converted. The frequency is the same, and the frequency of the square wave signal is easier to detect, so the frequency of the first sine wave signal can be more conveniently obtained by the above implementation.

Based on the second aspect, in a possible design, the second sine wave signal is compared with a preset voltage value to obtain a square wave signal, which can be specifically achieved by: second sinusoidal signal and preset voltage value Comparing, when the amplitude of the second sine wave signal is greater than or equal to the preset voltage value, the high level is output, and when the amplitude of the second sine wave signal is less than the preset voltage value, the low level is output, and the square wave signal is obtained. .

Based on the second aspect, in a possible design, the terminal further includes a memory, and after the detecting circuit acquires the frequency of the first sine wave signal, the frequency of the first sine wave signal (ie, the resonant frequency of the linear motor) may also be stored by the memory. Then, when the processor generates the driving signal having the resonant frequency, the resonant frequency stored in the memory can be read first, and then the driving signal having the read resonant frequency is generated.

Based on the second aspect, in a possible design, the condition that the trigger processor generates the first excitation signal may be: the processor receives the indication information, where the indication information is used to indicate that the terminal receives the power-on signal, and the power-on signal is used by the terminal. The trigger terminal is powered on; or the terminal receives the shutdown signal, the shutdown signal is used to trigger the terminal to shut down; or the terminal receives the vibration function enable signal, the vibration function enable signal is used to indicate the terminal to open the vibration function; or, the terminal A trigger signal is received, the trigger signal is used to instruct the user to trigger the terminal to acquire the resonant frequency of the linear motor.

DRAWINGS

1 is a schematic structural diagram of a haptic feedback system in a tablet computer according to an embodiment of the present invention;

2 is a schematic diagram of a circuit model of a linear motor according to an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a first terminal according to an embodiment of the present disclosure;

4 is a schematic diagram of a conversion process of a first sine wave signal, a second sine wave signal, and a square wave signal according to an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a signal amplifying circuit according to an embodiment of the present invention;

FIG. 6 is a schematic structural diagram of a second terminal according to an embodiment of the present disclosure;

7 is a schematic structural diagram of an operational amplifier circuit and a switch unit according to an embodiment of the present invention;

FIG. 8 is a schematic structural diagram of a fifth resistor according to an embodiment of the present disclosure;

FIG. 9 is a schematic structural diagram of a third terminal according to an embodiment of the present disclosure;

FIG. 10 is a schematic flow chart of a driving method of a linear motor according to an embodiment of the present invention.

detailed description

In mobile phones, tablets, video game devices, car navigation systems and other terminals, linear motors are commonly used vibration devices. There are various scenarios for driving the linear motor to generate vibration by processing the generated driving signal, for example, when the user performs a touch operation on the touch screen of the terminal or clicks a virtual button, or when the terminal receives a reminder or notification (such as an incoming call reminder, When SMS reminders, alarm reminders, or notifications from applications, etc., the processor generates a drive signal that drives the linear motor, giving the linear motor a vibration feedback.

When the user performs a touch operation on the touch screen of the terminal or clicks a virtual button, the touch screen, the processor, the driver and the motor of the terminal constitute a tactile feedback system. In terminals using haptic feedback technology, linear motors are commonly used vibration devices. When the user touches or clicks the virtual button on the screen of the terminal, the linear motor gives vibration feedback, so that the user gets a tactile feedback experience. Taking the tactile feedback system in the tablet as an example, as shown in FIG. 1 , when the user touches or clicks the virtual button in the tablet, the touch screen reports the touch event to the MCU (Micro Control Unit), and the MCU receives the touch event. The reported touch event sends an enable signal (EN) and a duty cycle variable PWM signal to the driver, thereby enabling the driver to cause the driver to drive the linear motor to vibrate, thereby causing the tablet to give a vibration feedback of the touch event.

In addition, when the terminal receives a reminder or notification (such as an incoming call reminder, a short message reminder, an alarm reminder, or a notification from an application, etc.), it also triggers an operation of reporting a reminder or notification event to the MCU, and the MCU receives such an event. A drive signal is then generated to drive the linear motor to generate vibration.

When a linear motor is driven by a driving signal, the vibration intensity of the linear motor is related to the frequency of the driving signal: when the frequency of the driving signal is the resonant frequency of the linear motor, the vibration intensity of the linear motor is maximum; when the frequency of the driving signal is related to the linear motor When the absolute value of the difference in the resonant frequency is greater than the bandwidth of the linear motor, the vibration strength of the linear motor is rapidly weakened. Due to component aging, manufacturing errors, or ambient temperature, the natural resonant frequency of the linear motor changes compared to the natural resonant frequency at the factory, resulting in a decrease in the vibration strength of the linear motor.

For example, the linear motor has a resonant frequency of 235 Hz and the linear motor has a bandwidth of 2 Hz. The resonant frequency of the linear motor changes as components age, manufacturing tolerances, or ambient temperature changes. For example, from 235Hz to 238Hz. At this time, if the linear motor is still driven by the driving signal with the frequency of 235 Hz, since the absolute value of the difference between the frequency of the driving signal (235 Hz) and the resonant frequency of the linear motor (238 Hz) is greater than 2 Hz, the vibration intensity of the linear motor will be Rapidly weakened.

In the embodiment of the present invention, the linear motor can be equivalent to the circuit model shown in FIG. 2. In the circuit model of the linear motor shown in Figure 2, A and B are the inputs of a linear motor, and the input signal to the linear motor is a set of differential input pairs.

In the model of the linear motor shown in Figure 2, the resonant frequency of the linear motor is

In practical applications, the natural resonant frequencies of common linear motors are 175 Hz and 205 Hz.

According to the circuit model of the linear motor shown in Fig. 2, by testing the electrical characteristics of a 175 Hz linear motor, the parameters corresponding to the equivalent model of Fig. 2 are fitted: resistance Rl = 25.7 Ω, inductance Lc = 135 uH, resistance Rd = 6.1 Ω, capacitance Cm = 8.5329 mF, inductance Lm = 91.81 uH. Short-circuit the A terminal to the B terminal, and after simulating the initial excitation energy storage of the capacitance Cm of the linear motor equivalent circuit by 50mV, an attenuated back electromotive force can be tested at the A and B ends of the linear motor, and the inverse The electromotive force is in the form of a sinusoidal signal having a frequency of 175 Hz, and the amplitude of the sinusoidal signal is gradually attenuated.

It can be seen from the above simulation experiment that after the initial energy storage is provided to the linear motor, the resonance frequency information of the linear motor can be extracted by the back electromotive force signal generated in the linear motor.

In order to enhance the vibration intensity of the linear motor when the linear motor is driven by the driving signal, the embodiment of the present invention provides a driving method and terminal for the linear motor to accurately obtain the resonant frequency of the linear motor based on the conclusions obtained by the above simulation experiment. Thus, a drive signal having the resonant frequency is used to drive the linear motor to enhance the vibration strength of the linear motor. The method and the terminal are based on the same inventive concept. Since the method and the terminal solve the problem are similar in principle, the implementation of the terminal and the method can be referred to each other, and the repeated description is not repeated.

It should be noted that in the description of the embodiments of the present invention, the terms "first", "second" and the like are used only to distinguish the purpose of description, and are not to be understood as indicating or implying relative importance, nor can it be understood as an indication. Or suggest the order.

FIG. 3 is a schematic diagram of a terminal 300 according to an embodiment of the present invention. As shown in FIG. 3, the terminal 300 includes a processor 301, a signal amplifying circuit 302, a linear motor 303, and a detecting circuit 304.

In the terminal 300 provided by the embodiment of the present invention, the processor 301 is configured to generate a first excitation signal, and output the first excitation signal to the signal amplifying circuit 302. The signal amplifying circuit 302 is connected to the processor 301 for receiving the processor. The first excitation signal outputted by the second excitation signal is amplified by a first set multiple to obtain a second excitation signal, and the second excitation signal is output to the linear motor 303; the linear motor 303 is connected to the signal amplification circuit 302 for The second excitation signal is used to store energy and generate a counter electromotive force, and the back electromotive force generated by the energy storage is converted into a first sine wave signal output; the detecting circuit 304 is connected to the linear motor 303 for acquiring the frequency of the first sine wave signal, The frequency of the first sine wave signal is the resonant frequency of the linear motor 303; the processor 301 is further configured to generate a driving signal having the resonant frequency, and drive the linear motor 303 with the driving signal.

It can be seen from the circuit model of the linear motor shown in FIG. 2 that the input signal of the linear motor 303 is a set of differential input pairs, the output signal is a set of differential output pairs, and the two inputs of the linear motor also serve as two outputs of the linear motor. end. Therefore, there are two connecting lines between the signal amplifying circuit 302 and the linear motor 303 in FIG. 3 for respectively outputting the two differential components of the second excitation signal to the linear motor 303 by the signal amplifying circuit 302; between the linear motor 303 and the detecting circuit 304 There are two connecting lines for the linear motor 303 to output two differential components of the first sine wave signal to the detecting circuit 304, respectively.

In addition, when the signal amplifying circuit 302 amplifies the first excitation signal, the value of the first set multiple may be greater than 1 or equal to 1. In particular, signal amplifying circuit 302 can be implemented by a fully differential integrating amplifier. When the signal amplifying circuit 302 is implemented by using a fully differential integrating amplifier, in addition to amplifying the first excitation signal, since the fully differential integrating amplifier can suppress common mode noise, the signal amplifying circuit 302 can also suppress the common in the second excitation signal. Modal noise enhances the driving capability of the second excitation signal.

According to the conclusion of the above simulation experiment, in the terminal 300, the frequency of the first sine wave signal output by the linear motor 303 The rate is the resonant frequency of the linear motor 303. However, the frequency of the sine wave signal is not easy to detect in practical applications. Therefore, when the detection circuit 304 in the terminal 300 acquires the frequency of the first sine wave signal, for example, it can be implemented by clamping the first sine wave signal to a preset voltage value to obtain a second sine wave signal; The two sine wave signals are compared with a preset voltage value to obtain a square wave signal; the frequency of the square wave signal is obtained, and the frequency of the square wave signal is the same as the frequency of the first sine wave signal. Since the frequency of the square wave signal is easy to detect, and the frequency of the square wave signal is the same as the frequency of the first sine wave signal, the square wave signal is used as the signal output by the terminal 300, and the frequency of the first sine wave signal is conveniently obtained. Thereby, the resonance frequency of the linear motor 303 is obtained.

In addition, the terminal 300 may further include a memory. This memory can be used to store the resonant frequency of the linear motor 303. Then, when generating the driving signal having the resonant frequency, the processor 301 can be specifically displayed by first reading the resonant frequency stored in the memory; and then generating a driving signal having the read resonant frequency.

It should be noted that the first sine wave signal and the second sine wave signal mentioned in the embodiments of the present invention only refer to the waveform of the signal, and the initial phase of the signal is not limited. For example, the initial phase of the first sinusoidal signal may be 0°, 90°, 180°, 200°, etc., and the initial phase of the second sinusoidal signal may be 0°, 90°, 180°, 200°, and the like.

After the first sine wave signal is clamped by the detecting circuit 304, the first sine wave signal is converted into a second sine wave signal, and then the second sine wave signal is compared with a preset voltage value to obtain a square wave signal, thereby obtaining a square wave signal, thereby The resonant frequency of the linear motor 303 can be obtained by detecting the frequency of the square wave signal. The specific process of comparing the second sine wave signal with the preset voltage value to obtain the square wave signal may be: comparing the second sine wave signal with a preset voltage value, where the amplitude of the second sine wave signal is greater than or When the voltage is equal to the preset voltage value, the output level is high, and when the amplitude of the second sine wave signal is less than the preset voltage value, the low level is output, thereby obtaining a square wave signal.

Assuming that the preset voltage value is Vcm, the conversion process of the first sine wave signal → the second sine wave signal → the square wave signal may be as shown in FIG. 4 . In FIG. 4, the DC offset of the first sine wave signal is 0, the DC offset of the second sine wave signal is the preset voltage value Vcm, and the DC offset of the square wave signal is also 0. As can be seen from FIG. 4, the second sine wave signal is clamped at a preset voltage value Vcm, and the frequencies of the first sine wave signal, the second sine wave signal, and the square wave signal are all the same. The first sine wave signal is finally converted into a square wave signal and output, which is convenient for detecting the frequency of the square wave signal.

In the embodiment of the present invention, the first excitation signal is an original signal for the linear motor 303 to perform energy storage, and the terminal 300 triggers each circuit and unit in the terminal 300 to perform corresponding operations after receiving the first excitation signal, thereby acquiring The resonant frequency of the linear motor 303 and the frequency of the drive signal are configured as the resonant frequency of the linear motor 303. The first excitation signal is output by the processor 301 in the terminal 300. The triggering condition for the processor 301 to output the first excitation signal is different. For example, the processor 301 outputs the first excitation signal when the terminal 300 is powered on, or the processor 301 outputs the first excitation signal when the terminal 300 is powered off, or is turned on by the user. When the vibration function of the terminal 300 (ie, the user sets the terminal 300 to the vibration mode), the processor 301 outputs a first excitation signal, or sets a corresponding operation interface in the terminal, and the user manually triggers an operation of acquiring the resonance frequency of the linear motor 303. The processor 301 outputs a first excitation signal.

In the terminal 300 shown in FIG. 3, after the signal amplifying circuit 302 outputs the second excitation signal to the linear motor 303, the linear motor 303 can store itself by using the second excitation signal to generate a counter electromotive force; It can be seen from the experiment that when the linear motor 303 releases its own energy storage, the frequency of the first sine wave signal output by the linear motor 303 is the resonant frequency of the linear motor. After the frequency of the first sine wave signal (the resonance frequency of the linear motor 303) is acquired by the detection circuit 304, the processor 301 configures the frequency of the drive signal of the linear motor 303 to the acquired resonance frequency, and the vibration intensity of the linear motor can be enhanced. Therefore, when the linear motor 303 is driven, the terminal 300 utilizes the inherent characteristics of the linear motor 303 to generate the counter electromotive force and release the stored energy, so that the resonant frequency of the linear motor 303 can be accurately and conveniently obtained, thereby obtaining the obtained resonant frequency as The frequency of the drive signal of the linear motor 303 enhances the linearity The vibration intensity of the motor 303.

In the embodiment of the present invention, the signal amplifying circuit 302 is configured to amplify the first excitation signal to obtain a second excitation signal, and output the second excitation signal obtained by the amplification to the linear motor 303. In a specific implementation, the specific structure of the signal amplifying circuit 302 is not limited in the embodiment of the present invention, and the signal amplifying circuit 302 can implement amplification of the first excitation signal. One possible implementation of the signal amplifying circuit 302 is given below.

As shown in FIG. 5, the signal amplifying circuit 302 can include a first resistor, a second resistor, a third resistor, a fourth resistor, a first capacitor, a second capacitor, and a first fully differential operational amplifier, wherein: the first resistor One end is configured to receive a first differential excitation signal in the first excitation signal, a second end of the first resistor is coupled to a negative input terminal of the first fully differential operational amplifier; and a first end of the second resistor is configured to receive the first a second differential excitation signal in the excitation signal, the second end of the second resistor is coupled to the forward input of the first fully differential operational amplifier; the third resistor and the first capacitor are connected in parallel and connected across the negative of the first fully differential operational amplifier Between the input terminal and the forward output terminal; the fourth resistor and the second capacitor are connected in parallel between the forward input terminal and the negative output terminal of the first fully differential operational amplifier; the forward direction of the first fully differential operational amplifier The output end and the negative output end are coupled to the first end and the second end of the linear motor 303, respectively.

The first differential excitation signal and the second differential excitation signal are differential input pairs, which together constitute the first excitation signal described in the embodiment of the present invention.

In order to maintain the balance between the input signal and the output signal of the first fully differential operational amplifier, it may be set that the resistances of the first resistor and the second resistor are the same, the resistances of the third resistor and the fourth resistor are the same, the first capacitor and the first capacitor The capacitance of the two capacitors is the same.

In addition, in the implementation of the signal amplifying circuit 302, the first set multiple may be set by adjusting a ratio of the third resistor to the first resistor (ie, a ratio of the fourth resistor to the second resistor).

In the terminal 300, it is first necessary to store the linear motor 303. After the energy storage is completed, the back electromotive force generated by the energy storage needs to be converted into the first sine wave signal output. Then, judging when to store energy to the linear motor 303 and when to release the stored energy of the linear motor 303 can be achieved by cooperation of the switching unit and the control logic unit.

When the terminal 300 includes a switch unit and a control logic unit, a schematic structural diagram of the terminal 300 can be as shown in FIG. 6. In FIG. 6, the switch unit 305 is coupled to the linear motor 303 and the detection circuit 304 for disconnecting or closing the linear motor 303 and the detection circuit 304; the control logic unit 306 is coupled to the switch unit 305 for storage in the linear motor 303. The enabler control switch unit 305 disconnects the linear motor 303 and the detection circuit 304, and controls the switch unit 305 to close the linear motor 303 and the detection circuit 304 after the linear motor 303 is energized.

Specifically, when the control logic unit 306 controls the switch unit 305 to open or close the linear motor 303 and the detection circuit 304, the linear motor 303 and the detection can be realized by controlling the opening or closing of the plurality of switches included in the switch unit 305. The circuit 304 is opened or closed.

The switch unit 305 and the control logic unit 306 are provided in the terminal 300, and the control unit 305 can be controlled by the control logic unit 306 to control the linear motor 303 to be disconnected or closed from the detection circuit 304. When the linear motor 303 is disconnected from the detecting circuit 304, the linear motor 303 performs energy storage; when the linear motor 303 and the detecting circuit 304 are closed, the linear motor 303 releases the energy storage, that is, the linear motor 303 will generate the back electromotive force generated by the energy storage. A form of a sine wave signal is output to the detection circuit 304.

In the terminal 300, the detecting circuit 304 is configured to clamp the first sine wave signal to a preset voltage value to obtain a second sine wave signal, and compare the second sine wave signal with a preset voltage value to obtain a square wave signal. The detection circuit 304 can implement the above functions by using an operational amplification circuit and a comparator included therein. Specifically, the operational amplifier circuit is configured to amplify the first sine wave signal by a second set multiple and clamp the preset voltage value to obtain a second sine wave signal; the comparator and the transport The amplifier circuit is connected to compare the second sine wave signal with a preset voltage value to obtain a square wave signal.

The operational amplifier circuit in the detection circuit 304 can be implemented by a fully differential operational amplifier. The fully differential operational amplifier can suppress the common mode noise in the signal, thereby reducing the interference of the external environment on the detection circuit 304, improving the quality of the square wave signal output by the detection circuit 304, thereby making the frequency of the detected square wave signal more accurate. .

In specific implementation, the structure of the operational amplifier circuit can be as shown in FIG. 7. In FIG. 7, the operational amplifier circuit may include a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, and a second fully differential operational amplifier, wherein: the first end of the fifth resistor and the second fully differential operational amplifier are positive Connecting to the input end, the second end of the fifth resistor is connected to the switch unit; the first end of the sixth resistor is connected to the negative input end of the second fully differential operational amplifier, and the second end of the sixth resistor is connected to the switch unit; The seventh resistor is connected between the forward input terminal and the negative output terminal of the second fully differential operational amplifier, and the eighth resistor is connected between the negative input terminal and the forward output terminal of the second fully differential operational amplifier; The forward input of the comparator is connected to the negative output or the positive output of the second fully differential operational amplifier, the negative output of the comparator is used to input a preset voltage value, and the output of the comparator is used to output a square wave signal.

In addition, FIG. 7 also shows a schematic structural view of the switching unit 305 in the terminal 300 when the operational amplification circuit adopts the above configuration. As shown in FIG. 7, the switch unit 305 can include a first switch, a second switch, a third switch, and a fourth switch, wherein: one end of the first switch is connected to the first end of the linear motor 303, and the other end is connected to the fifth resistor. The second end of the second switch is connected to the second end of the linear motor 303, and the other end is connected to the second end of the sixth resistor; one end of the third switch is connected to the second end of the fifth resistor, and the other end is connected Grounding; one end of the fourth switch is connected to the second end of the sixth resistor, and the other end is grounded.

Then, when the switch unit 305 includes the first switch, the second switch, the third switch, and the fourth switch, the control logic unit 306 controls the switch unit 305 in such a manner that the linear motor 303 and the detection circuit 304 are opened or closed: The first switch and the second switch are controlled to be turned off when the linear motor 303 performs energy storage, and the third switch and the fourth switch are controlled to be closed, thereby causing the linear motor 303 and the detecting circuit 304 to be disconnected; after the linear motor 303 is stored, the control is completed. The first switch and the second switch are closed, controlling the third switch and the fourth switch to open, thereby causing the linear motor 303 and the detection circuit 304 to close.

Specifically, in the actual circuit implementation, the resistance of the seventh resistor can be set to A, and the resistance of the fifth resistor can be modified by register programming to one of A, 2A, 3A, and 4A, and the second The set multiples are set to 1, 2, 3, and 4, respectively, as shown in FIG. When the fifth resistor adopts the structure as shown in FIG. 8, the resistance of the fifth resistor can be changed by the configuration register programming, thereby changing the second set multiple to satisfy the different magnification requirements of the second fully differential operational amplifier. .

It should also be noted that the forward input of the comparator in the detection circuit 304 can be connected to the negative output of the second fully differential operational amplifier or to the forward output of the second fully differential operational amplifier. This is because the output signals of the forward and negative outputs of the second fully differential op amp are a pair of differential signals when the forward input of the comparator is connected to the positive output of the second fully differential op amp. The comparator compares a differential component of the second sine wave signal with a preset voltage value Vcm to obtain a square wave signal; when the forward input and the second of the comparator are When the negative output terminal of the differential operational amplifier is connected, the comparator compares the other differential component of the second sine wave signal with the preset voltage value Vcm to obtain a square wave signal. The square wave signals obtained by the above two connection methods have the same frequency and a phase difference of 180°. Therefore, the frequency of the square wave signal can be realized as the resonance frequency of the linear motor 303 by using the above two connection modes, thereby realizing the detection of the resonance frequency of the linear motor 303.

In addition, the comparator in the detecting circuit 304 compares the second sine wave signal with the preset voltage value to obtain a square wave signal, which can be implemented by comparing the second sine wave signal with a preset voltage value, When the amplitude of the second sine wave signal is greater than or equal to the preset voltage value, the output high level is output, and when the amplitude of the second sine wave signal is less than the preset voltage value, the low level is output, and the square wave signal is obtained.

In conjunction with the above description of the terminal 300, the embodiment of the present invention further provides another terminal, which can be as shown in FIG. The terminal 700 shown in FIG. 9 can be regarded as a specific example of the terminal 300 shown in FIG.

In Fig. 9, OP1 and OP2 are a specific example of the first fully differential operational amplifier and the second fully differential operational amplifier, respectively. Since OP1 is a fully differential operational amplifier, the input resistance of the forward input and the negative input of OP1 are the same, both are Rin, the feedback resistance of OP1 is Rf, and the feedback capacitance is Cf; similarly, due to OP2 It is a fully differential operational amplifier, so the input resistance of the forward input and the negative input of OP2 are the same, both are R1, and the feedback resistance of OP2 is R2.

In FIG. 9, two Rins connected to the negative input terminal and the forward input terminal of the OP1 can be regarded as the first resistor and the second resistor in the embodiment of the present invention; respectively, connected to the negative input terminal and the forward output of the OP1. The Rf and Cf of the terminal can be regarded as the third resistor and the first capacitor in the embodiment of the present invention respectively; Rf and Cf connected to the forward input terminal and the negative output terminal of the OP1 can be regarded as the first embodiment in the embodiment of the present invention, respectively. The fourth switch and the second switch; S11 and S12 are respectively regarded as the first switch and the second switch in the embodiment of the present invention, and S21 and S22 can be regarded as the third switch and the fourth switch in the embodiment of the present invention; and OP2 The two R1s connected to the positive input terminal and the negative input terminal can be regarded as the fifth resistor and the sixth resistor in the embodiment of the present invention, respectively; the R2 across the forward input terminal and the negative output terminal of the OP2 can be visualized. For the seventh resistor in the embodiment of the present invention, R2 across the negative input terminal and the forward output terminal of the OP2 may be regarded as the eighth resistor in the embodiment of the present invention.

In the terminal 900 shown in FIG. 9, the two input signals through the negative input terminal and the forward input terminal of the Rin input OP1 are the first differential excitation signal and the second differential excitation signal, respectively, as shown in FIG. The excitation signal and the second differential excitation signal are differential input pairs, which together constitute the first excitation signal described in the embodiments of the present invention. The signal amplifying circuit is composed of two Rin, two Cf, two Rf and OP1, and the operational amplifying circuit is composed of two R1, two R2 and OP2.

It should be noted that the control logic unit is not shown in the terminal 900 shown in FIG. 9. The control logic unit can control the switching unit to open or close the linear motor and the detection circuit. The control logic unit controls the switch unit to disconnect the linear motor and the detection circuit, which can be realized by controlling the opening of S11 and S12, and the closing of S21 and S22; the control logic unit controls the switching unit to close the linear motor and the detection circuit, and can control S11 and S12 Closed, S21 and S22 are disconnected.

The terminal 900 shown in Fig. 9 is divided into two working phases when driving the linear motor:

The first stage: linear motor energy storage

The processor outputs a first excitation signal when the terminal is triggered to reacquire the resonant frequency of the linear motor under a specific trigger condition (such as when the terminal is turned on or off). The control logic unit controls S11 and S12 to be disconnected, and S21 and S22 are closed. At this time, OP1 is in an enabled state, OP2 is in an disabled state, and the signal amplifying circuit amplifies the first excitation signal by a first set multiple (such as 1) and outputs. To linear motors, linear motor energy storage produces back EMF.

Wherein, the setting of the first set multiple can be realized by changing the ratio of Rin and Rf.

Second stage: linear motor release energy storage

When the linear motor energy storage is completed, that is, when the input signal (first excitation signal) of the signal amplifying circuit is 0, the control logic unit controls S11 and S12 to be disconnected, and S21 and S22 are closed, and both OP1 and OP2 are in an enabled state. OP2 is connected to the linear motor via R1.

Since the input signal of OP1 in the second phase is zero, OP1 corresponds to the voltage follower in the second phase. Due to the clamping action of the operational amplifier circuit, the first sinusoidal signal (ie, the pair of differential input signals VOP and VON) is clamped at Vcm. The linear motor releases the stored energy in the form of a first sine wave signal and outputs it to OP2. OP2 amplifies the first sine wave signal by a second set multiple and clamps it to Vcm to obtain a second sine wave signal; the comparator compares the second sinusoidal signal with Vcm, when the second sine wave signal is greater than or equal to Vcm The output level is high. When the second sine wave signal is less than Vcm, it outputs a low level, and finally the square wave signal is obtained and output. The frequency of the output square wave signal is the resonant frequency of the linear motor.

Wherein, the setting of the second set multiple can be realized by changing the ratio of R2 and R1. Specifically, R1 can be set as a fixed resistor, and R2 can be set as a resistor having a variable resistance, and the setting of the second set multiple can be realized by adjusting the resistance of R2.

It should be noted that in the terminal 900 shown in FIG. 9, the forward input end of the comparator is connected with the negative output end of the OP2, thereby comparing a differential component of the second sine wave signal with a preset voltage value Vcm to obtain a square wave. Signal; since the forward output and the negative output of the OP2 output a pair of differential signals, in actual implementation, the forward input of the comparator can also be connected to the forward output of the OP2, thereby making the second sine Another differential component of the wave signal is compared to a preset voltage value Vcm to obtain a square wave signal.

The terminal 900 shown in FIG. 9 can be regarded as a specific example of the terminal 300 shown in FIG. 3. The implementation of the terminal 300 shown in FIG. 3 can be referred to the related description of the terminal 300 shown in FIG.

Based on the above embodiments, the present application further provides a driving method of a linear motor, which is applicable to a terminal, the terminal includes a processor, a signal amplifying circuit, a linear motor, and a detecting circuit, that is, the terminal may be FIG. Terminal 300 is shown. As shown in FIG. 10, the method includes the following steps:

S1001: The processor generates a first excitation signal, and outputs the first excitation signal to the signal amplification circuit.

S1002: The signal amplifying circuit amplifies the first excitation signal by a first set multiple to obtain a second excitation signal, and outputs the second excitation signal to the linear motor.

Wherein, the excitation signal is used to generate a counter electromotive force after the linear motor stores energy.

S1003: The linear motor uses a second excitation signal to store energy to generate a counter electromotive force.

S1004: The linear motor converts the generated back electromotive force into a first sine wave signal output.

S1005: The detection circuit acquires the frequency of the first sine wave signal.

The frequency of the first sine wave signal is the resonant frequency of the linear motor.

S1006: The processor generates a driving signal having the resonant frequency, and uses the driving signal to drive the linear motor.

Wherein, when the detection circuit acquires the frequency of the first sine wave signal, the method can be implemented by clamping the first sine wave signal to a preset voltage value to obtain a second sine wave signal; and the second sine wave signal and the pre- The voltage value is compared to obtain a square wave signal; the frequency of the square wave signal is obtained, and the frequency of the square wave signal is the same as the frequency of the first sine wave signal.

In addition, the second sine wave signal is compared with a preset voltage value to obtain a square wave signal, which can be specifically as follows Implementation: comparing the second sine wave signal with a preset voltage value, and outputting a high level when the amplitude of the second sine wave signal is greater than or equal to the preset voltage value, and the amplitude of the second sine wave signal is less than When the voltage value is set, a low level is output, thereby obtaining the above square wave signal.

After performing S1005, the frequency of the first sine wave signal (resonance frequency of the linear motor) may also be stored by a memory included in the terminal; then, when the processor generates the driving signal having the resonant frequency, the processor may first read the memory for storage. The resonant frequency then produces a drive signal with the read resonant frequency.

In S1001, the processor generates a first excitation signal. Generally, the condition that the triggering processor generates the first excitation signal is that the processor receives the indication information, where the indication information is used to indicate that the terminal receives the power-on signal, and the power-on signal is used to trigger the terminal to be powered on; or, the terminal receives a shutdown signal, the shutdown signal is used to trigger the terminal to shut down; or the terminal receives the vibration function on signal, the vibration function on signal is used to indicate that the terminal turns on the vibration function; or the terminal receives the trigger signal, the trigger signal is used to indicate The user triggers the terminal to acquire the resonant frequency of the linear motor.

The method shown in FIG. 10 can be regarded as the method performed by the terminal 300. The implementation method not fully explained and described in the driving method of the linear motor shown in FIG. 10 is referred to the related description in the terminal 300 shown in FIG.

In the method shown in FIG. 10, after the signal amplifying circuit outputs the second excitation signal to the linear motor, the linear motor can store itself by using the second excitation signal to generate a counter electromotive force; according to the foregoing simulation experiment, the linear motor can be known. When releasing its own energy storage, the frequency of the first sine wave signal output by the linear motor is the resonant frequency of the linear motor. After the frequency of the first sine wave signal (the resonant frequency of the linear motor) is obtained by the detecting circuit, the processor configures the frequency of the driving signal of the linear motor to the acquired resonant frequency, which can enhance the vibration intensity of the linear motor. Therefore, when the linear motor is driven by the method shown in FIG. 10, the inherent characteristics of the back-EMF and the stored energy storage by the linear motor itself are stored, and the resonant frequency of the linear motor can be accurately and conveniently obtained, thereby taking the obtained resonant frequency as The frequency of the drive signal of the linear motor drives the linear motor, which enhances the vibration strength of the linear motor and enhances the user experience.

In summary, an embodiment of the present invention provides a driving method and a terminal for a linear motor. The driving method and the terminal of the linear motor provided by the embodiment of the invention can accurately acquire the resonant frequency of the linear motor, thereby setting the frequency of the driving signal of the linear motor to the obtained resonant frequency, enhancing the vibration intensity of the linear motor, and improving user experience.

Those skilled in the art will appreciate that embodiments of the present application can be provided as a method, system, or computer program product. Thus, embodiments of the invention may be in the form of an entirely hardware embodiment, an entirely software embodiment, or a combination of software and hardware. Moreover, embodiments of the invention may take the form of a computer program product embodied on one or more computer usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) including computer usable program code.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (system), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flowchart illustrations and/or FIG. These computer program instructions can be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing device to produce a machine for the execution of instructions for execution by a processor of a computer or other programmable data processing device. Means for implementing the functions specified in one or more of the flow or in a block or blocks of the flow chart.

The computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing device to operate in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture comprising the instruction device. The apparatus implements the functions specified in one or more blocks of a flow or a flow and/or block diagram of the flowchart.

These computer program instructions can also be loaded onto a computer or other programmable data processing device such that a series of operational steps are performed on a computer or other programmable device to produce computer-implemented processing for execution on a computer or other programmable device. The instructions provide steps for implementing the functions specified in one or more of the flow or in a block or blocks of a flow diagram.

It is apparent that those skilled in the art can make various modifications and variations to the embodiments of the invention without departing from the spirit and scope of the embodiments of the invention. Thus, it is intended that the present invention cover the modifications and variations of the embodiments of the invention.

Claims

A terminal, comprising:

a processor, configured to generate a first excitation signal, and output the first excitation signal to a signal amplification circuit;

The signal amplifying circuit is connected to the processor, and configured to receive the first excitation signal output by the processor, and amplify the first excitation signal by a first set multiple to obtain a second excitation signal, And outputting the second excitation signal to the linear motor;

The linear motor is connected to the signal amplifying circuit for storing energy by using the second excitation signal and generating a counter electromotive force, and converting the counter electromotive force into a first sine wave signal output;

a detection circuit coupled to the linear motor for acquiring a frequency of the first sine wave signal, the frequency of the first sine wave signal being a resonant frequency of the linear motor;

The processor is further configured to generate a driving signal having the resonant frequency and drive the linear motor with the driving signal.
The terminal according to claim 1, wherein the detecting circuit is configured to: when acquiring the frequency of the first sine wave signal:

Clamping the first sine wave signal to a preset voltage value to obtain a second sine wave signal;

Comparing the second sine wave signal with the preset voltage value to obtain a square wave signal;

Obtaining a frequency of the square wave signal, the frequency of the square wave signal being the same as the frequency of the first sine wave signal.
The terminal according to claim 1 or 2, further comprising: a memory for storing the resonant frequency;

The processor is configured to: read the resonant frequency stored in the memory when generating a driving signal having the resonant frequency; and generate a driving signal having the read resonant frequency.
The terminal according to any one of claims 1 to 3, further comprising:

a switching unit connected to the linear motor and the detecting circuit for disconnecting or closing the linear motor and the detecting circuit;

a control logic unit coupled to the switch unit for controlling the switch unit to disconnect the linear motor and the detection circuit when the linear motor performs energy storage, and controlling the linear motor after energy storage is completed The switching unit closes the linear motor and the detection circuit.
The terminal according to any one of claims 2 to 4, wherein the detecting circuit comprises:

An operation amplifying circuit, configured to amplify the first sine wave signal by a second set multiple and clamp the preset voltage value to obtain a second sine wave signal;

And a comparator connected to the operational amplifier circuit for comparing the second sine wave signal with the preset voltage value to obtain the square wave signal.
The terminal according to claim 5, wherein the comparator is specifically configured to:

Comparing the second sine wave signal with the preset voltage value, and outputting a high level when the amplitude of the second sine wave signal is greater than or equal to the preset voltage value, in the second sine When the amplitude of the wave signal is less than the preset voltage value, a low level is output, and the square wave signal is obtained.
The terminal according to any one of claims 1 to 6, wherein the signal amplifying circuit comprises a first resistor, a second resistor, a third resistor, a fourth resistor, a first capacitor, a second capacitor, and a first Fully differential op amps, where:

a first end of the first resistor is configured to receive a first differential excitation signal in the first excitation signal, and a second end of the first resistor is coupled to a negative input terminal of the first fully differential operational amplifier ;

a first end of the second resistor is configured to receive a second differential excitation signal in the first excitation signal, and a second end of the second resistor is coupled to a forward input end of the first fully differential operational amplifier;

The third resistor and the first capacitor are connected in parallel and connected between the negative input terminal and the forward output terminal of the first fully differential operational amplifier;

The fourth resistor and the second capacitor are connected in parallel and connected between a forward input terminal and a negative output terminal of the first fully differential operational amplifier;

The forward and negative outputs of the first fully differential operational amplifier are coupled to the first and second ends of the linear motor, respectively.
The terminal according to any one of claims 5 to 7, wherein the operational amplifier circuit comprises a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, and a second fully differential operational amplifier, wherein:

a first end of the fifth resistor is connected to a forward input end of the second fully differential operational amplifier, and a second end of the fifth resistor is connected to the switch unit;

a first end of the sixth resistor is connected to a negative input terminal of the second fully differential operational amplifier, and a second end of the sixth resistor is connected to the switch unit;

The seventh resistor is connected across a forward input terminal and a negative output terminal of the second fully differential operational amplifier, and the eighth resistor is connected across a negative input terminal of the second fully differential operational amplifier Between the forward output and the forward output;

a forward input terminal of the comparator is connected to a negative output terminal or a forward output terminal of the second fully differential operational amplifier, and a negative output terminal of the comparator is configured to input the preset voltage value, The output of the comparator is used to output the square wave signal.
The terminal according to claim 8, wherein the switching unit comprises a first switch, a second switch, a third switch, and a fourth switch, wherein:

One end of the first switch is connected to the first end of the linear motor, and the other end is connected to the second end of the fifth resistor; one end of the second switch is connected to the second end of the linear motor, The other end is connected to the second end of the sixth resistor; one end of the third switch is connected to the second end of the fifth resistor, and the other end is grounded; one end of the fourth switch and the sixth resistor The second end is connected and the other end is grounded;

The control logic unit is specifically configured to: control the first switch and the second switch to be turned off when the linear motor performs energy storage, and control the third switch and the fourth switch to be closed; After the motor energy storage is completed, the first switch and the second switch are controlled to be closed, and the third switch and the fourth switch are controlled to be disconnected.
A driving method of a linear motor, characterized in that the method is applied to a terminal, the terminal comprising a processor, a signal amplifying circuit, a linear motor and a detecting circuit, the method comprising:

The processor generates a first excitation signal and outputs the first excitation signal to the signal amplification circuit;

The signal amplifying circuit amplifies the first excitation signal by a first set multiple to obtain a second excitation signal, and outputs the second excitation signal to the linear motor;

The linear motor uses the second excitation signal to store energy and generate a counter electromotive force, and convert the back electromotive force into a first sine wave signal output;

The detecting circuit acquires a frequency of the first sine wave signal, and a frequency of the first sine wave signal is a resonant frequency of the linear motor;

The processor generates a drive signal having the resonant frequency and drives the linear horse with the drive signal Da.
The method of claim 10, wherein acquiring the frequency of the first sine wave signal comprises:

Clamping the first sine wave signal to a preset voltage value to obtain a second sine wave signal;

Comparing the second sine wave signal with the preset voltage value to obtain a square wave signal;

Obtaining a frequency of the square wave signal, the frequency of the square wave signal being the same as the frequency of the first sine wave signal.
The method of claim 11, wherein comparing the second sine wave signal with the preset voltage value to obtain a square wave signal comprises:

Comparing the second sine wave signal with the preset voltage value, and outputting a high level when the amplitude of the second sine wave signal is greater than or equal to the preset voltage value, in the second sine When the amplitude of the wave signal is less than the preset voltage value, a low level is output, and the square wave signal is obtained.
The method according to any one of claims 10 to 12, further comprising: a memory, after the detecting circuit acquires the frequency of the first sine wave signal, further comprising:

The memory stores the resonant frequency;

The processor generates a driving signal having the resonant frequency, specifically comprising: the processor reading the resonant frequency stored in the memory; generating a driving signal having the read resonant frequency.
The method of claim 13 further comprising: before the processor generates the first excitation signal, further comprising:

The processor receives indication information, where the indication information is used to indicate:

The terminal receives a power-on signal, and the power-on signal is used to trigger the terminal to boot; or

Receiving, by the terminal, a shutdown signal, where the shutdown signal is used to trigger the terminal to perform shutdown; or

Receiving, by the terminal, a vibration function on signal, wherein the vibration function on signal is used to indicate that the terminal starts the vibration function; or

The terminal receives a trigger signal, and the trigger signal is used to instruct the user to trigger the terminal to acquire the resonant frequency of the linear motor.