CN109874398A

CN109874398A - A kind of driving method and terminal of linear motor

Info

Publication number: CN109874398A
Application number: CN201780064676.9A
Authority: CN
Inventors: 陈建立; 李辉
Original assignee: Huawei Technologies Co Ltd
Current assignee: Honor Device Co Ltd
Priority date: 2017-01-04
Filing date: 2017-04-21
Publication date: 2019-06-11
Also published as: WO2018126560A1

Abstract

A kind of driving method and terminal of linear motor, to drive linear motor using the driving signal with the resonance frequency, enhance the oscillation intensity of linear motor accurately to obtain the resonance frequency of linear motor.Terminal includes: processor, for generating the first pumping signal, and exports first pumping signal to signal amplification circuit；Signal amplification circuit is connect with processor, for the first pumping signal amplification the first setting multiple to be obtained the second pumping signal, and exports the second pumping signal to linear motor；Linear motor is connect with signal amplification circuit, and for carrying out energy storage using the second pumping signal and generating counter electromotive force, counter electromotive force is converted into the output of primary sinusoid signal；Detection circuit is connect with linear motor, and for obtaining the frequency of primary sinusoid signal, the frequency of the primary sinusoid signal is the resonance frequency of linear motor；Processor is also used to generate the driving signal with the resonance frequency, and drives linear motor using the driving signal.

Description

Linear motor driving method and terminal

The present application claims priority from chinese patent application entitled "a method and apparatus for obtaining resonant frequency of linear motor" filed by the chinese patent office on 4/1/2017 with application number 201710005324.8, the entire contents of which are incorporated herein by reference.

Technical Field

The embodiment of the invention relates to the technical field of terminals, in particular to a driving method of a linear motor and a terminal.

Background

A Linear motor (LRA) is a device for generating vibration in a terminal, and has a wide application in the terminal. For example, when a user performs a touch operation or clicks a virtual key on a touch screen of the terminal, the touch screen reports a touch event to the processor, and the processor generates a driving signal after receiving the touch event, so as to drive the linear motor to generate vibration, so that the user experiences a vibration sense, i.e., a tactile feedback. For another example, when the terminal receives a reminder or a notification (such as an incoming call reminder, a short message reminder, an alarm reminder, or a notification from an application), if the terminal turns on the vibration function, the linear motor may also give a vibration feedback.

In the above scenario that the linear motor is driven to generate vibration by the processor generating 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 absolute value of the difference between the frequency of the driving signal and the resonant frequency of the linear motor is greater than the bandwidth of the linear motor (e.g., 2Hz), the vibration intensity of the linear motor rapidly decreases.

Before the terminal is shipped out, the linear motor in the terminal has a natural resonant frequency. After the terminal is shipped from a factory, the resonant frequency of the linear motor in the terminal may change due to component aging, manufacturing errors, or environmental temperature. At this time, if the linear motor is also driven at the resonance frequency specific to the linear motor, the vibration intensity of the linear motor cannot be maximized.

Disclosure of Invention

The embodiment of the application provides a driving method and a terminal of a linear motor, which are used for accurately obtaining the resonant frequency of the linear motor, so that the linear motor is driven by a driving signal with the resonant frequency, the vibration intensity of the linear motor is enhanced, and the user experience is improved.

In a first aspect, an embodiment of the present invention provides a terminal, which includes a processor, a signal amplification circuit, a linear motor, and a detection circuit. The processor is used for generating a first excitation signal and outputting the first excitation signal to the signal amplification circuit; the signal amplification circuit is connected with the processor and used for receiving the first excitation signal output by the processor, amplifying 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 with the signal amplification circuit and used for storing energy by adopting a second excitation signal so as to generate a counter electromotive force and converting the counter electromotive force into a first sine wave signal for output; the detection circuit is connected with the linear motor and used for acquiring the frequency of a first sine wave signal, wherein the frequency of the first sine wave signal is the resonance frequency of the linear motor; the processor is also used for generating a driving signal with the resonance frequency and driving the linear motor by adopting the driving signal.

Wherein the drive signal having the resonance frequency means: the frequency of the driving signal is the resonant frequency.

It should be noted that, in the embodiment of the present invention, no limitation is imposed on a specific numerical value of the first setting multiple, and the first setting multiple may be greater than 1, and may also be equal to 1.

The terminal provided by the first aspect is based on the following principle when acquiring the resonant frequency of the linear motor: giving an initial energy storage excitation to the linear motor, and storing energy by the linear motor to generate back electromotive force; when the linear motor releases the stored energy, the counter electromotive force is released in the form of a sine wave signal, and the frequency of the sine wave signal is the resonant frequency of the linear motor.

In the terminal provided by the first aspect, after the signal amplification circuit outputs the second excitation signal to the linear motor, the linear motor may store energy for itself by using the second excitation signal, so as to generate a back electromotive force; when the linear motor releases the stored energy of the linear motor, the frequency of the first sine wave signal output by the linear motor is the resonant frequency of the linear motor. After the detection circuit acquires the frequency of the first sine wave signal (the resonant frequency of the linear motor), the processor configures the frequency of the drive signal of the linear motor to the acquired resonant frequency, so that the vibration intensity of the linear motor can be enhanced. Therefore, when the terminal drives the linear motor, the resonance frequency of the linear motor can be accurately and conveniently acquired by utilizing the inherent characteristics of the linear motor that the linear motor stores energy to generate counter electromotive force and releases the stored energy, so that the acquired resonance frequency is used as the frequency of a driving signal of the linear motor, and the vibration intensity of the linear motor is enhanced.

Based on the first aspect, in a possible design, when acquiring the frequency of the first sine wave signal, the detection circuit may specifically be implemented by: clamping the first sine wave signal at a preset voltage value to obtain a second sine wave signal; comparing the second sine wave signal with a preset voltage value to obtain a square wave signal; and acquiring the frequency of the square wave signal, wherein the frequency of the square wave signal is the same as that of the first sine wave signal.

In practical implementation, the frequency of the sine wave signal is not easy to detect, so that the first sine wave signal can be converted into the square wave signal after clamping and comparing operations, the frequency of the converted square wave signal is the same as that of the first sine wave signal, and the frequency of the square wave signal is easy to detect, so that the frequency of the first sine wave signal can be more conveniently obtained by adopting the implementation mode.

Based on the first aspect, in a possible design, the terminal provided in the first aspect further includes a memory, where the memory is used to store the resonant frequency acquired by the detection circuit; then, when generating the driving signal having the resonant frequency, the processor may first read the resonant frequency stored in the memory and then generate the driving signal having the read resonant frequency.

In a possible design based on the first aspect, the terminal provided in the first aspect further includes a switch unit and a control logic unit. The switch unit is connected with the linear motor and the detection circuit and used for enabling the linear motor and the detection circuit to be opened or closed; the control logic unit is connected with the switch unit and used for controlling the switch unit to disconnect the linear motor and the detection circuit when the linear motor stores energy, and controlling the switch unit to close the linear motor and the detection circuit after the linear motor stores energy.

The terminal provided by the first aspect is provided with a switch unit and a control logic unit, and the switch unit can be controlled by the control logic unit to realize the opening or closing of the linear motor and the detection circuit. When the linear motor is disconnected with the detection circuit, the linear motor stores energy; when the linear motor and the detection circuit are closed, the linear motor releases the stored energy, namely the linear motor outputs the counter electromotive force generated by the stored energy to the detection circuit in the form of a first sine wave signal.

Based on the first aspect, in one possible design, the detection circuit specifically includes an operational amplification circuit and a comparator. The operational amplification circuit is used for amplifying the first sine wave signal by a second set multiple and clamping the first sine wave signal at a preset voltage value to obtain a second sine wave signal; the comparator is connected with the operational amplification circuit and used for comparing the second sine wave signal with a preset voltage value to obtain a square wave signal.

It should be noted that, in the embodiment of the present invention, no limitation is imposed on a specific numerical value of the second setting multiple, and the second setting multiple may be greater than 1, and may also be equal to 1.

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

Based on the first aspect, in one possible design, the signal amplification 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, where: the first end of the first resistor is used for receiving a first differential excitation signal in the first excitation signal, and the second end of the first resistor is connected with the negative input end of the first fully differential operational amplifier; the first end of the second resistor is used for receiving a second differential excitation signal in the first excitation signal, and the second end of the second resistor is connected with the positive input end of the first fully differential operational amplifier; the third resistor and the first capacitor are connected in parallel and then bridged between the negative input end and the positive output end of the first fully differential operational amplifier; the fourth resistor and the second capacitor are connected in parallel and then bridged between the positive input end and the negative output end of the first fully differential operational amplifier; the positive output end and the negative output end of the first fully differential operational amplifier are respectively connected with the first end and the second end of the linear motor.

In order to keep the input signal and the output signal of the first fully differential operational amplifier balanced, it may be set that: the first resistor and the second resistor have the same resistance value, the third resistor and the fourth resistor have the same resistance value, and the first capacitor and the second capacitor have the same capacitance value. At this time, the first setting multiple may be set by adjusting a ratio of the third resistor to the first resistor (i.e., a ratio of the fourth resistor to the second resistor).

The signal amplification circuit adopts a form of a first fully differential operational amplifier, can amplify the first excitation signal by a first set multiple to obtain a second excitation signal, and can also inhibit common mode noise in the second excitation signal and enhance the driving capability of the second excitation signal.

Based on the first aspect, in one possible design, the operational amplification 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, where: the first end of the fifth resistor is connected with the positive input end of the second fully differential operational amplifier, and the second end of the fifth resistor is connected with the switch unit; a first end of the sixth resistor is connected with the negative input end of the second fully differential operational amplifier, and a second end of the sixth resistor is connected with the switch unit; the seventh resistor is connected between the positive input end and the negative output end of the second fully differential operational amplifier in a bridging mode, and the eighth resistor is connected between the negative input end and the positive output end of the second fully differential operational amplifier in a bridging mode. Then, a positive input end of a comparator in the detection circuit is connected with a negative output end or a positive output end of the second fully differential operational amplifier, the negative output end of the comparator is used for inputting a preset voltage value, and the output end of the comparator is used for outputting a square wave signal.

In order to keep the balance between the input signal and the output signal of the second fully differential operational amplifier, it is possible to set: the fifth resistor and the sixth resistor have the same resistance value, and the seventh resistor and the eighth resistor have the same resistance value. Then, in the operational amplifier circuit, the second setting factor may be set by adjusting a ratio of the seventh resistor to the fifth resistor (i.e., a 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, where: one end of the first switch is connected with the first end of the linear motor, and the other end of the first switch is connected with the second end of the fifth resistor; one end of the second switch is connected with the second end of the linear motor, and the other end of the second switch is connected with the second end of the sixth resistor; one end of the third switch is connected with the second end of the fifth resistor, and the other end of the third switch is grounded; one end of the fourth switch is connected with the second end of the sixth resistor, and the other end of the fourth switch is grounded; the control logic unit is specifically configured to: when the linear motor stores energy, the first switch and the second switch are controlled to be switched off, and the third switch and the fourth switch are controlled to be switched on; and after the energy storage of the linear motor is finished, the first switch and the second switch are controlled to be closed, and the third switch and the fourth switch are controlled to be opened.

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 circuit to be opened or closed by controlling the first switch, the second switch, the third switch and the fourth switch in the switch unit to be opened or closed.

In a second aspect, an embodiment of the present invention provides a method for driving a linear motor, where the method is applied to a terminal including a processor, a signal amplification circuit, a linear motor, and a detection circuit, and the method includes the following steps: the processor generates a first excitation signal and outputs the first excitation signal to the signal amplification circuit; the signal amplification 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 second excitation signal is used for enabling the linear motor to store energy and then generate back electromotive force; the linear motor stores energy by adopting a second excitation signal, generates back electromotive force, converts the back electromotive force into a first sine wave signal and outputs the first sine wave signal; the detection circuit acquires the frequency of a first sine wave signal, wherein the frequency of the first sine wave signal is the resonant frequency of the linear motor; the processor generates a drive signal having the resonant frequency and uses the drive signal to drive the linear motor in the terminal.

In the driving method of the linear motor provided in the second aspect, after the signal amplification circuit outputs the second excitation signal to the linear motor, the linear motor may store energy for itself by using the second excitation signal, so as to generate a back electromotive force; when the linear motor releases the stored energy of the linear motor, 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 acquired by the detection circuit, the processor configures the frequency of the driving signal of the linear motor to the acquired resonant frequency, and the vibration intensity of the linear motor can be enhanced. Therefore, when the linear motor is driven by the driving method of the linear motor provided by the second aspect, the resonant frequency of the linear motor can be accurately and conveniently acquired by using the inherent characteristics of the linear motor that the linear motor stores energy to generate counter electromotive force and releases the stored energy, so that the acquired resonant frequency is used as the frequency of the driving signal of the linear motor to drive the linear motor, and the vibration intensity of the linear motor is enhanced.

Based on the second aspect, in one possible design, the detection circuit may be implemented by: clamping the first sine wave signal at a preset voltage value to obtain a second sine wave signal; comparing the second sine wave signal with a preset voltage value to obtain a square wave signal; and acquiring the frequency of the square wave signal, wherein the frequency of the square wave signal is the same as that of the first sine wave signal.

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 may be specifically implemented as follows: and comparing the second sine wave signal with a preset voltage value, outputting a high level when the amplitude of the second sine wave signal is greater than or equal to the preset voltage value, and outputting a low level when the amplitude of the second sine wave signal is less than the preset voltage value to obtain the square wave signal.

Based on the second aspect, in a possible design, the terminal further includes a memory, and after the detection circuit acquires the frequency of the first sine wave signal, the frequency of the first sine wave signal (i.e., the resonant frequency of the linear motor) may be further stored by the memory; then, when generating the driving signal having the resonant frequency, the processor may first read the resonant frequency stored in the memory and then generate the driving signal having the read resonant frequency.

In a possible design based on the second aspect, the condition for triggering the processor to generate the first excitation signal may be: the processor receives indication information, and the indication information is used for indicating that: the terminal receives a starting signal, and the starting signal is used for triggering the terminal to start; or the terminal receives a shutdown signal, wherein the shutdown signal is used for triggering the terminal to shut down; or the terminal receives a vibration function starting signal, wherein the vibration function starting signal is used for indicating the terminal to start a vibration function; alternatively, the terminal receives a trigger signal instructing a user to trigger the terminal to acquire the resonant frequency of the linear motor.

Drawings

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

FIG. 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 invention;

FIG. 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 invention;

fig. 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 invention;

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

fig. 10 is a flowchart illustrating a driving method of a linear motor according to an embodiment of the present invention.

Detailed Description

In terminals such as mobile phones, tablet computers, electronic game devices, and car navigation systems, linear motors are commonly used as vibration devices. There are various scenarios for driving the linear motor to generate vibration by processing the generated driving signal, for example, when a user performs a touch operation or clicks a virtual key on a touch screen of the terminal, or when the terminal receives a reminder or a notification (such as an incoming call reminder, a short message reminder, an alarm reminder, or a notification from an application program), the processor generates the driving signal, so as to drive the linear motor, and the linear motor gives a vibration feedback.

When a user performs touch operation or clicks a virtual key on a touch screen of the terminal, the touch screen, the processor, the driver and the motor of the terminal form a tactile feedback system. In terminals employing haptic feedback technology, linear motors are common vibration devices. The linear motor gives vibration feedback after the user touches or clicks the virtual key on the screen of the terminal, so that the user obtains tactile feedback experience. Taking a tactile feedback system in a tablet computer as an example, as shown in fig. 1, after a user touches or clicks a virtual key in the tablet computer, a touch screen reports a touch event to an MCU (Micro Control Unit), and the MCU sends an enable signal (EN) and a PWM signal with a variable duty ratio to a driver after receiving the reported touch event, so as to enable the driver, so that the driver drives a linear motor to generate vibration, thereby enabling the tablet computer to provide vibration feedback of the touch event.

In addition, when the terminal receives a reminder or a notification (such as an incoming call reminder, a short message reminder, an alarm reminder, or a notification from an application program), an operation of reporting a reminder or a notification event to the MCU is also triggered, and the MCU generates a driving signal after receiving the event, so as to drive the linear motor to vibrate.

When driving a linear motor with a drive signal, the vibration intensity of the linear motor is related to the frequency of the drive 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 absolute value of the difference between the frequency of the driving signal and the resonant frequency of the linear motor is greater than the bandwidth of the linear motor, the vibration intensity of the linear motor is rapidly reduced. Due to aging of components, manufacturing errors, or an ambient temperature, the natural resonant frequency of the linear motor may be changed from the natural resonant frequency at the time of shipment, thereby weakening the vibration intensity of the linear motor.

For example, the resonant frequency of a linear motor is 235Hz, and the bandwidth of the linear motor is 2 Hz. As components age, manufacturing errors, or ambient temperature changes, the resonant frequency of the linear motor changes. For example, from 235Hz to 238 Hz. At this time, if the linear motor is driven by the driving signal having the frequency of 235Hz, the absolute value of the difference between the frequency of the driving signal (235Hz) and the resonance frequency of the linear motor (238Hz) is greater than 2Hz, and thus the vibration intensity of the linear motor is rapidly reduced.

In the embodiment of the present invention, the linear motor may be equivalent to a circuit model as shown in fig. 2. In the circuit model of the linear motor shown in fig. 2, a and B are input terminals of the linear motor, and input signals of the linear motor are a set of differential input pairs.

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

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

According to the circuit model of the linear motor shown in fig. 2, the parameters corresponding to the equivalent model of fig. 2 were fitted by testing the electrical characteristics of a 175Hz linear motor: the resistance Rl is 25.7 Ω, the inductance Lc is 135uH, the resistance Rd is 6.1 Ω, the capacitance Cm is 8.5329mF, and the inductance Lm is 91.81 uH. The end A is short-circuited to the end B, after 50mV initial excitation energy storage is provided for a capacitor Cm of an equivalent circuit of the linear motor through simulation, attenuated back electromotive force can be tested at the end A and the end B of the linear motor, the back electromotive force is in a sine wave signal form, the frequency of the sine wave signal is 175Hz, and the amplitude of the sine wave signal is gradually attenuated.

It can be seen from the above simulation experiments that after initial energy storage is provided for the linear motor, the resonant frequency information of the linear motor can be extracted through the back electromotive force signal generated in the linear motor.

In order to enhance the vibration intensity of the linear motor when the driving signal is used to drive the linear motor, based on the conclusion obtained from the simulation experiment, the embodiments of the present invention provide a driving method and a terminal for the linear motor, so as to accurately obtain the resonant frequency of the linear motor, so that the driving signal with the resonant frequency is used to drive the linear motor, thereby enhancing the vibration intensity of the linear motor. The method and the terminal are based on the same inventive concept, and because the principles of solving the problems of the method and the terminal are similar, the implementation of the terminal and the method can be mutually referred, and repeated parts are 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 for distinguishing between the description and the drawings, and are not to be construed as indicating or implying any relative importance or order.

Referring to fig. 3, a terminal 300 according to an embodiment of the present invention is provided. As shown in fig. 3, the terminal 300 includes a processor 301, a signal amplification circuit 302, a linear motor 303, and a detection circuit 304.

In the terminal 300 provided in 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 amplification circuit 302 is connected to the processor 301, and is configured to receive the first excitation signal output by the processor 301, amplify the first excitation signal by a first set multiple to obtain a second excitation signal, and output the second excitation signal to the linear motor 303; the linear motor 303 is connected with the signal amplification circuit 302, and is configured to store energy and generate a back electromotive force by using the second excitation signal, and convert the back electromotive force generated by storing energy into a first sine wave signal for output; the detection circuit 304 is connected to the linear motor 303, and is configured to obtain a frequency of a first sine wave signal, where the frequency of the first sine wave signal is a 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.

As can be seen from the circuit model of the linear motor shown in fig. 2, the input signals of the linear motor 303 are a set of differential input pairs, the output signals are a set of differential output pairs, and the two input terminals of the linear motor are also used as the two output terminals of the linear motor. Therefore, in fig. 3, there are two connection lines between the signal amplifying circuit 302 and the linear motor 303, respectively for the signal amplifying circuit 302 to output two differential components of the second excitation signal to the linear motor 303; there are two connection lines between the linear motor 303 and the detection circuit 304, respectively for the linear motor 303 to output two differential components of the first sine wave signal to the detection circuit 304.

In addition, when the signal amplifying circuit 302 amplifies the first driving signal, the value of the first setting factor may be greater than 1 or equal to 1. Specifically, the signal amplification circuit 302 may be implemented by a fully differential integrating amplifier. When the signal amplifying circuit 302 is implemented by using the fully differential integrating amplifier, in addition to amplifying the first driving signal, the fully differential integrating amplifier can suppress the common mode noise, so that the signal amplifying circuit 302 can also suppress the common mode noise in the second driving signal, thereby enhancing the driving capability of the second driving signal.

According to the results of the simulation experiments, in the terminal 300, the frequency of the first sine wave signal output by the linear motor 303 is the resonant frequency of the linear motor 303. However, the frequency of the sine wave signal is not easily detected in practical applications. Therefore, the detection circuit 304 in the terminal 300 can be implemented, for example, by: clamping the first sine wave signal at a preset voltage value to obtain a second sine wave signal; comparing the second sine wave signal with a preset voltage value to obtain a square wave signal; and acquiring the frequency of the square wave signal, wherein the frequency of the square wave signal is the same as that 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, taking the square wave signal as the signal output by the terminal 300 facilitates obtaining the frequency of the first sine wave signal, thereby obtaining the resonant frequency of the linear motor 303.

In addition, a memory may also be included in the terminal 300. The memory may be used to store the resonant frequency of the linear motor 303. Then, when the processor 301 generates the driving signal with the resonant frequency, it can specifically display the following way: firstly, reading the resonant frequency stored in a memory; then, a drive signal having the read resonant frequency is generated.

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

After the first sine wave signal is clamped by the detection circuit 304, the first sine wave signal is converted into a second sine wave signal, and the second sine wave signal is compared with a preset voltage value to obtain a square wave signal, so that 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: and comparing the second sine wave signal with a preset voltage value, outputting a high level when the amplitude of the second sine wave signal is greater than or equal to the preset voltage value, and outputting a low level when the amplitude of the second sine wave signal is less than the preset voltage value, so as to obtain a square wave signal.

Assuming that the predetermined voltage value is Vcm, the conversion process of the first sinewave signal → the second sinewave signal → the square wave signal can be as shown in fig. 4. In fig. 4, the dc offset of the first sinusoidal signal is 0, the dc offset of the second sinusoidal signal is a predetermined 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 the predetermined voltage value Vcm, and the frequencies of the first sine wave signal, the second sine wave signal and the square wave signal are the same. And finally, the first sine wave signal is converted into a square wave signal and then output, so that the frequency of the square wave signal can be conveniently detected.

In this embodiment of the present invention, the first excitation signal is an original signal for the linear motor 303 to store energy, and the terminal 300 triggers each circuit and unit in the terminal 300 to perform corresponding operations after receiving the first excitation signal, so as to obtain the resonant frequency of the linear motor 303, and configure the frequency of the driving signal as the resonant frequency of the linear motor 303. Wherein the first excitation signal is output by the processor 301 in the terminal 300. The trigger condition for the processor 301 to output the first excitation signal is various, 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 the processor 301 outputs the first excitation signal when a user turns on a vibration function of the terminal 300 (that is, the user sets the terminal 300 to a vibration mode), or a corresponding operation interface is set in the terminal, and an operation of acquiring the resonant frequency of the linear motor 303 is manually triggered by the user, and at this time, the processor 301 outputs the first excitation signal.

In the terminal 300 shown in fig. 3, after the signal amplification circuit 302 outputs the second excitation signal to the linear motor 303, the linear motor 303 can store energy for itself by using the second excitation signal, so as to generate a back electromotive force; as can be seen from the simulation experiment, when the linear motor 303 releases its stored energy, 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 driving 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 terminal 300 drives the linear motor 303, the resonant frequency of the linear motor 303 can be accurately and conveniently acquired by using the inherent characteristics of the linear motor 303 that the linear motor 303 stores energy to generate counter electromotive force and releases the stored energy, so that the acquired resonant frequency is used as the frequency of the driving signal of the linear motor 303, and the vibration intensity of the linear motor 303 is enhanced.

In this embodiment of the present invention, the signal amplifying circuit 302 is configured to amplify the first excitation signal by a first set multiple to obtain a second excitation signal, and output the second excitation signal obtained after 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 may amplify the first driving signal. One possible implementation of the signal amplification circuit 302 is given below.

As shown in fig. 5, the signal amplifying circuit 302 may 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 end of the first resistor is used for receiving a first differential excitation signal in the first excitation signal, and the second end of the first resistor is connected with the negative input end of the first fully differential operational amplifier; the first end of the second resistor is used for receiving a second differential excitation signal in the first excitation signal, and the second end of the second resistor is connected with the positive input end of the first fully differential operational amplifier; the third resistor and the first capacitor are connected in parallel and then bridged between the negative input end and the positive output end of the first fully differential operational amplifier; the fourth resistor and the second capacitor are connected in parallel and then bridged between the positive input end and the negative output end of the first fully differential operational amplifier; the positive and negative output terminals of the first fully differential operational amplifier are connected to the first and second terminals of the linear motor 303, respectively.

Wherein the first differential fire signal and the second differential fire signal are a differential input pair, which together constitute the first fire signal described in the embodiments of the present invention.

In order to keep the input signal and the output signal of the first fully differential operational amplifier balanced, it may be set that: the first resistor and the second resistor have the same resistance value, the third resistor and the fourth resistor have the same resistance value, and the first capacitor and the second capacitor have the same capacitance value.

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

In the terminal 300, the linear motor 303 needs to be stored with energy, and after the energy storage is finished, the counter electromotive force generated by the stored energy needs to be converted into the first sine wave signal to be output. Then, the determination of when to charge the linear motor 303 and when to discharge the linear motor 303 can be realized by the switch unit and the control logic unit.

When the terminal 300 includes a switch unit and a control logic unit, a schematic diagram of the structure of the terminal 300 can be shown in fig. 6. In fig. 6, a switching unit 305 is connected to the linear motor 303 and the detection circuit 304 for opening or closing the linear motor 303 and the detection circuit 304; the control logic unit 306 is connected to the switch unit 305, and is configured to control the switch unit 305 to open the linear motor 303 and the detection circuit 304 when the linear motor 303 stores energy, and control the switch unit 305 to close the linear motor 303 and the detection circuit 304 after the linear motor 303 stores energy.

Specifically, the control logic unit 306 may control the switch unit 305 to open or close the linear motor 303 and the detection circuit 304 by controlling the plurality of switches included in the switch unit 305 to open or close the linear motor 303 and the detection circuit 304.

A switch unit 305 and a control logic unit 306 are arranged in the terminal 300, and the switch unit 305 can be controlled by the control logic unit 306 to control the linear motor 303 to be opened or closed with the detection circuit 304. When the linear motor 303 is disconnected from the detection circuit 304, the linear motor 303 stores energy; when the linear motor 303 and the detection circuit 304 are closed, the linear motor 303 releases the stored energy, that is, the linear motor 303 outputs the back electromotive force generated by the stored energy to the detection circuit 304 in the form of the first sine wave signal.

In the terminal 300, the detection circuit 304 is configured to clamp the first sine wave signal at a preset voltage value to obtain a second sine wave signal, and compare the second sine wave signal with the preset voltage value to obtain a square wave signal. The detection circuit 304 can implement the above functions through its own operational amplifier circuit and comparator. Specifically, the operational amplifier circuit is configured to amplify the first sine wave signal by a second set multiple and clamp the amplified signal at a preset voltage value to obtain a second sine wave signal; the comparator is connected with the operational amplification circuit and used for comparing 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 may be implemented by a fully differential operational amplifier. The fully differential operational amplifier can suppress common mode noise in the signal, thereby reducing the interference of the external environment to the detection circuit 304, improving the quality of the square wave signal output by the detection circuit 304, and enabling the frequency of the detected square wave signal to be more accurate.

In a specific implementation, the structure of the operational amplifier circuit can be as shown in fig. 7. In fig. 7, the operational amplification 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 is connected with the positive input end of the second fully differential operational amplifier, and the second end of the fifth resistor is connected with the switch unit; a first end of the sixth resistor is connected with the negative input end of the second fully differential operational amplifier, and a second end of the sixth resistor is connected with the switch unit; the seventh resistor is bridged between the positive input end and the negative output end of the second fully differential operational amplifier, and the eighth resistor is bridged between the negative input end and the positive output end of the second fully differential operational amplifier; the positive input end of the comparator is connected with the negative output end or the positive output end of the second fully differential operational amplifier, the negative output end of the comparator is used for inputting a preset voltage value, and the output end of the comparator is used for outputting a square wave signal.

Further, fig. 7 also shows a schematic diagram of the structure of the switch unit 305 in the terminal 300 when the operational amplifier circuit adopts the above-described structure. As shown in fig. 7, the switching unit 305 may include a first switch, a second switch, a third switch, and a fourth switch, wherein: one end of the first switch is connected with the first end of the linear motor 303, and the other end of the first switch is connected with the second end of the fifth resistor; one end of the second switch is connected with the second end of the linear motor 303, and the other end of the second switch is connected with the second end of the sixth resistor; one end of the third switch is connected with the second end of the fifth resistor, and the other end of the third switch is grounded; one end of the fourth switch is connected with the second end of the sixth resistor, and the other end of the fourth switch is grounded.

Then, when the switching unit 305 includes the first switch, the second switch, the third switch, and the fourth switch, the control logic unit 306 controls the switching unit 305 in such a manner that the linear motor 303 and the detection circuit 304 are opened or closed: when the linear motor 303 stores energy, the first switch and the second switch are controlled to be opened, and the third switch and the fourth switch are controlled to be closed, so that the linear motor 303 and the detection circuit 304 are opened; after the linear motor 303 finishes storing energy, the first switch and the second switch are controlled to be closed, and the third switch and the fourth switch are controlled to be opened, so that the linear motor 303 and the detection circuit 304 are closed.

Specifically, in an actual circuit implementation, the resistance value of the seventh resistor may be set to a, and the resistance value of the fifth resistor may be modified by programming a register to have one of values a, 2A, 3A and 4A, so as to set the second setting multiple to 1, 2, 3 and 4, respectively, as shown in fig. 8. When the fifth resistor has the structure shown in fig. 8, the resistance of the fifth resistor can be changed by programming the configuration register, so that the second setting multiple is changed, and the requirements of the second fully differential operational amplifier on different amplification factors are met.

It should also be noted that the positive input terminal of the comparator in the detection circuit 304 may be connected to the negative output terminal of the second fully-differential operational amplifier, and may also be connected to the positive output terminal of the second fully-differential operational amplifier, because: when the positive input end of the comparator is connected with the positive output end of the second fully-differential operational amplifier, the comparator compares one differential component in the second sine wave signal with a preset voltage value Vcm to obtain a square wave signal; when the positive input end of the comparator is connected with the negative output end of the second fully-differential operational amplifier, the comparator compares the other differential component in the second sine wave signal with a preset voltage value Vcm to obtain a square wave signal. The frequencies of the square wave signals obtained by adopting the two connection modes are the same, and the phase difference is 180 degrees. Therefore, both of the above-described connection modes can realize that the frequency of the square wave signal is the resonant frequency of the linear motor 303, thereby realizing detection of the resonant frequency of the linear motor 303.

In addition, the process of comparing the second sine wave signal with the preset voltage value by the comparator in the detection circuit 304 to obtain the square wave signal can be implemented as follows: and comparing the second sine wave signal with a preset voltage value, outputting a high level when the amplitude of the second sine wave signal is greater than or equal to the preset voltage value, and outputting a low level when the amplitude of the second sine wave signal is less than the preset voltage value to obtain a square wave signal.

In conjunction with the above description of the terminal 300, the embodiment of the present invention also provides another terminal, which may be as shown in fig. 9. The terminal 700 shown in fig. 9 can be regarded as a specific example of the terminal 300 shown in fig. 3.

In fig. 9, OP1 and OP2 are one specific example of the first fully differential operational amplifier and the second fully differential operational amplifier, respectively. Because the OP1 is a fully differential operational amplifier, the input resistors of the positive input end and the negative input end of the OP1 have the same resistance value, all are Rin, the feedback resistors of the OP1 are Rf, and the feedback capacitors are Cf; similarly, since the OP2 is a fully differential operational amplifier, the input resistors of the positive input terminal and the negative input terminal of the OP2 have the same resistance value, which is R1, and the feedback resistor of the OP2 is R2.

In fig. 9, two Rin connected to the negative input terminal and the positive input terminal of OP1 can be regarded as a first resistor and a second resistor, respectively, in the embodiment of the present invention; rf and Cf connected across the negative input terminal and the positive output terminal of OP1 can be regarded as a third resistor and a first capacitor in the embodiment of the present invention, respectively; rf and Cf connected across the positive input terminal and the negative output terminal of OP1 can be regarded as a fourth resistor and a second capacitor in the embodiment of the present invention, respectively; s11 and S12 may be regarded as a first switch and a second switch, respectively, in the embodiment of the present invention, and S21 and S22 may be regarded as a third switch and a fourth switch, respectively, in the embodiment of the present invention; the two R1 connected to the positive input terminal and the negative input terminal of the OP2 can be regarded as a fifth resistor and a sixth resistor, respectively, in the embodiment of the present invention; r2 connected across the positive input terminal and the negative output terminal of OP2 may be regarded as a seventh resistor in the embodiment of the present invention, and R2 connected across the negative input terminal and the positive output terminal of OP2 may be regarded as an eighth resistor in the embodiment of the present invention.

In the terminal 900 shown in fig. 9, two input signals through the negative-going input terminal and the positive-going input terminal of the Rin input OP1 are the first differential fire signal and the second differential fire signal, respectively, and as shown in fig. 9, the first differential fire signal and the second differential fire signal are differential input pairs, which together constitute the first fire signal described in the embodiment of the present invention. The signal amplification circuit is composed of two Rin, two Cf, two Rf, and OP1, and the operational amplification circuit is composed of two R1, two R2, and OP 2.

It should be noted that the terminal 900 shown in fig. 9 does not show a control logic unit. The control logic unit may control the switching unit to open or close the linear motor and the detection circuit. The control logic unit controls the switch unit to open 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 switch unit to close the linear motor and the detection circuit, which can be realized by controlling the closing of S11 and S12 and the opening of S21 and S22.

The terminal 900 shown in fig. 9 is time divided into two operating phases when driving the linear motor:

the first stage is as follows: 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 certain trigger condition, such as when the terminal is powered on or off. The control logic unit controls the opening of S11 and S12 and the closing of S21 and S22, at this time, OP1 is in an enabled state, OP2 is in an disabled state, the signal amplification circuit amplifies a first excitation signal by a first set multiple (such as 1) and outputs the first excitation signal to the linear motor, and the linear motor stores energy and generates back electromotive force.

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

And a second stage: linear motor releasing stored energy

When the linear motor is completely stored, namely when the input signal (first excitation signal) of the signal amplifying circuit is 0, the control logic unit controls the S11 and the S12 to be opened, and the S21 and the S22 to be closed, wherein both the OP1 and the OP2 are in an enabling state, and the OP2 is connected with the linear motor through the R1.

Since the input signal of OP1 is zero in the second phase, OP1 acts as a voltage follower in the second phase. The first sine wave signal (i.e., the pair of differential input signals VOP and VON) is clamped at Vcm due to the clamping action of the operational amplifier circuit. The linear motor releases the stored energy in the form of a first sine wave signal, and outputs the stored energy to the OP 2. The OP2 amplifies the first sine wave signal by a second set multiple and clamps the first sine wave signal at Vcm to obtain a second sine wave signal; and the comparator compares the second sine signal with Vcm, outputs a high level when the second sine signal is greater than or equal to Vcm, outputs a low level when the second sine signal is less than Vcm, finally obtains a square wave signal and outputs the square wave signal, wherein the frequency of the output square wave signal is the resonant frequency of the linear motor.

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

It should be noted that in the terminal 900 shown in fig. 9, a positive input end of the comparator is connected to a negative output end of the OP2, so as to compare a differential component of the second sine wave signal with the preset voltage value Vcm, and obtain a square wave signal; because the positive output end and the negative output end of the OP2 output a pair of differential signals, in practical implementation, the positive input end of the comparator may also be connected to the positive output end of the OP2, so as to compare the other differential component of the second sine wave signal with the preset voltage value Vcm, and 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, and the implementation manner not explained and described in detail in fig. 9 can be referred to the related description of the terminal 300 shown in fig. 3.

Based on the above embodiments, the present application also provides a driving method of a linear motor, which is applicable to a terminal including a processor, a signal amplifying circuit, a linear motor, and a detection circuit, that is, the terminal may be the terminal 300 shown in fig. 3. As shown in fig. 10, the method includes the steps of:

s1001: the processor generates a first excitation signal and outputs the first excitation signal to the signal amplification circuit.

S1002: the signal amplification 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 excitation signal is used for enabling the linear motor to store energy and then generate back electromotive force.

S1003: the linear motor stores energy by using the second excitation signal to generate back electromotive force.

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

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 drive signal having the resonant frequency and drives the linear motor with the drive signal.

When the detection circuit acquires the frequency of the first sine wave signal, the detection circuit can be realized by the following modes: clamping the first sine wave signal at a preset voltage value to obtain a second sine wave signal; comparing the second sine wave signal with a preset voltage value to obtain a square wave signal; and acquiring the frequency of the square wave signal, wherein the frequency of the square wave signal is the same as that 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, and the square wave signal can be specifically realized in the following way: and comparing the second sine wave signal with a preset voltage value, outputting a high level when the amplitude of the second sine wave signal is greater than or equal to the preset voltage value, and outputting a low level when the amplitude of the second sine wave signal is less than the preset voltage value, so as to obtain the square wave signal.

After S1005 is performed, the frequency of the first sine wave signal (the resonant frequency of the linear motor) may be further 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 resonant frequency stored in the memory and then generate the driving signal having the read resonant frequency.

In S1001, the processor generates a first excitation signal. Generally, the conditions that trigger the processor to generate the first excitation signal are: the processor receives indication information, and the indication information is used for indicating that: the terminal receives a starting signal, and the starting signal is used for triggering the terminal to start; or the terminal receives a shutdown signal, wherein the shutdown signal is used for triggering the terminal to shut down; or the terminal receives a vibration function starting signal, wherein the vibration function starting signal is used for indicating the terminal to start a vibration function; alternatively, the terminal receives a trigger signal instructing a user to trigger the terminal to acquire the resonant frequency of the linear motor.

The method shown in fig. 10 can be regarded as a method performed by the terminal 300, and the implementation manner in the driving method of the linear motor shown in fig. 10, which is not explained and described in detail, is referred to the relevant description in the terminal 300 shown in fig. 3.

In the method shown in fig. 10, after the signal amplification circuit outputs the second excitation signal to the linear motor, the linear motor may store energy for itself by using the second excitation signal, so as to generate a back electromotive force; according to the simulation experiment, when the linear motor releases 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 acquired by the detection circuit, the processor configures the frequency of the driving signal of the linear motor to the acquired resonant frequency, and the vibration intensity of the linear motor can be enhanced. Therefore, when the linear motor is driven by the method shown in fig. 10, the resonant frequency of the linear motor can be accurately and conveniently obtained by using the inherent characteristics of the linear motor that the linear motor stores energy to generate counter electromotive force and releases the stored energy, so that the obtained resonant frequency is used as the frequency of the driving signal of the linear motor to drive the linear motor, the vibration intensity of the linear motor is enhanced, and the user experience is improved.

In summary, the embodiments of the present invention provide a driving method of a linear motor and a terminal. By adopting the linear motor driving method and the terminal provided by the embodiment of the invention, the resonant frequency of the linear motor can be accurately acquired, so that the frequency of the driving signal of the linear motor is set to be the acquired resonant frequency, the vibration intensity of the linear motor is enhanced, and the user experience is improved.

As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, embodiments of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, embodiments of the present 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, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

It will be apparent to those skilled in the art that various modifications and variations can be made in the embodiments of the present invention without departing from the spirit or scope of the embodiments of the invention. Thus, if such modifications and variations of the embodiments of the present invention fall within the scope of the claims of the present application and their equivalents, the present application is also intended to encompass such modifications and variations.

Claims

A terminal, comprising:

the processor is used for generating a first excitation signal and outputting the first excitation signal to the signal amplification circuit;

the signal amplification circuit is connected with the processor and used for receiving the first excitation signal output by the processor, amplifying 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 with the signal amplification circuit and used for storing energy by adopting the second excitation signal, generating counter electromotive force and converting the counter electromotive force into a first sine wave signal to be output;

the detection circuit is connected with the linear motor and is used for acquiring the frequency of the first sine wave signal, and the frequency of the first sine wave signal is the 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 of claim 1, wherein the detection circuit, when acquiring the frequency of the first sine wave signal, is specifically configured to:

clamping the first sine wave signal at 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;

and acquiring the frequency of the square wave signal, wherein the frequency of the square wave signal is the same as that of the first sine wave signal.
The terminal of claim 1 or 2, further comprising: a memory for storing the resonant frequency;

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

a switching unit connected to the linear motor and the detection circuit, for opening or closing the linear motor and the detection circuit;

and the control logic unit is connected with the switch unit and used for controlling the switch unit to disconnect the linear motor and the detection circuit when the linear motor stores energy and controlling the switch unit to close the linear motor and the detection circuit after the linear motor stores energy.
A terminal as claimed in any one of claims 2 to 4, characterised in that the detection circuit comprises:

the operational amplification circuit is used for amplifying the first sine wave signal by a second set multiple and clamping the first sine wave signal at the preset voltage value to obtain a second sine wave signal;

and the comparator is connected with the operational amplification circuit and used for comparing the second sine wave signal with the preset voltage value to obtain the square wave signal.
The terminal of claim 5, wherein the comparator is specifically configured to:

and comparing the second sine wave signal with the preset voltage value, outputting a high level when the amplitude of the second sine wave signal is greater than or equal to the preset voltage value, and outputting a low level when the amplitude of the second sine wave signal is less than the preset voltage value to obtain the square wave signal.
The terminal of any of claims 1-6, wherein the signal amplification 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 operational amplifier, wherein:

a first end of the first resistor is used for receiving a first differential excitation signal in the first excitation signals, and a second end of the first resistor is connected with a negative input end of the first fully differential operational amplifier;

a first end of the second resistor is used for receiving a second differential excitation signal in the first excitation signal, and a second end of the second resistor is connected with a positive input end of the first fully differential operational amplifier;

the third resistor and the first capacitor are connected in parallel and then bridged between the negative input end and the positive output end of the first fully differential operational amplifier;

the fourth resistor and the second capacitor are connected in parallel and then bridged between the positive input end and the negative output end of the first fully differential operational amplifier;

and the positive output end and the negative output end of the first fully differential operational amplifier are respectively connected with the first end and the second end of the linear motor.
The terminal of any of claims 5 to 7, wherein the operational amplification 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 with a positive input end of the second fully differential operational amplifier, and a second end of the fifth resistor is connected with the switch unit;

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

the seventh resistor is connected between the positive input end and the negative output end of the second fully differential operational amplifier in a bridging mode, and the eighth resistor is connected between the negative input end and the positive output end of the second fully differential operational amplifier in a bridging mode;

and the positive input end of the comparator is connected with the negative output end or the positive output end of the second fully differential operational amplifier, the negative output end of the comparator is used for inputting the preset voltage value, and the output end of the comparator is used for outputting the square wave signal.
The terminal of 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 with the first end of the linear motor, and the other end of the first switch is connected with the second end of the fifth resistor; one end of the second switch is connected with the second end of the linear motor, and the other end of the second switch is connected with the second end of the sixth resistor; one end of the third switch is connected with the second end of the fifth resistor, and the other end of the third switch is grounded; one end of the fourth switch is connected with the second end of the sixth resistor, and the other end of the fourth switch is grounded;

the control logic unit is specifically configured to: when the linear motor stores energy, the first switch and the second switch are controlled to be opened, and the third switch and the fourth switch are controlled to be closed; and after the energy storage of the linear motor is finished, controlling the first switch and the second switch to be closed, and controlling the third switch and the fourth switch to be opened.
A method for driving a linear motor, the method being applied to a terminal including a processor, a signal amplification circuit, a linear motor, and a detection circuit, the method comprising:

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

the signal amplification 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 stores energy by adopting the second excitation signal, generates back electromotive force, and converts the back electromotive force into a first sine wave signal for output;

the detection circuit acquires the frequency of the first sine wave signal, wherein the frequency of the first sine wave signal is the resonant frequency of the linear motor;

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

clamping the first sine wave signal at 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;

and acquiring the frequency of the square wave signal, wherein the frequency of the square wave signal is the same as that of the first sine wave signal.
The method of claim 11, wherein comparing the second sinusoidal signal with the predetermined voltage value to obtain a square wave signal comprises:

and comparing the second sine wave signal with the preset voltage value, outputting a high level when the amplitude of the second sine wave signal is greater than or equal to the preset voltage value, and outputting a low level when the amplitude of the second sine wave signal is less than the preset voltage value to obtain the square wave signal.
The method of any of claims 10 to 12, wherein the terminal further comprises a memory, and further comprising, after the detection circuit acquires the frequency of the first sine wave signal:

the memory stores the resonant frequency;

the processor generates a driving signal with the resonant frequency, and specifically includes: the processor reads the resonant frequency stored in the memory; generating a drive signal having the resonant frequency read.
The method of claim 13, prior to the processor generating the first excitation signal, further comprising:

the processor receives indication information, wherein the indication information is used for indicating that:

the terminal receives a starting signal, and the starting signal is used for triggering the terminal to start; or

The terminal receives a shutdown signal, and the shutdown signal is used for triggering the terminal to shut down; or

The terminal receives a vibration function starting signal, and the vibration function starting signal is used for indicating the terminal to start a vibration function; or

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