A method and device for detecting resonance frequency of a linear motor

Abstract

A linear motor resonant frequency detection method and device are disclosed. According to one embodiment, a linear motor resonant frequency detection method may include: driving a linear motor in a terminal device and acquiring vibration data generated by the terminal device in response to the driving; acquiring motion data of the terminal device; and determining the resonant frequency of the linear motor based on the vibration data and the motion data. The present invention can use existing sensors of the terminal device to quickly determine the resonant frequency of the motor, thereby reducing the cost of the motor driver chip.

Description

Technical Field

[0001] The present application relates to the technical field of electronic equipment, and more specifically, to a method and device for detecting the resonant frequency of a linear motor. Background Art

[0002] At present, in order to improve the tactile experience of users using terminal devices, linear motors are usually installed in terminal devices, which have the advantages of small size, fast startup, and low power consumption. Linear motors mainly include springs, magnetic mass blocks, coils and other components. The spring suspends the mass block inside the motor. The mass block can move on a single axis in the applied changing magnetic field. This vibration is sensed by people to produce a tactile effect.

[0003] During operation, in order to efficiently generate tactile effects, the spring-loaded mass is ideally driven at its natural resonant frequency. For example, the closer the frequency of the driving waveform is to the true resonant frequency of the motor, the shorter the time it takes for the motor to enter resonance and the more obvious the vibration effect. During the braking phase, the closer the frequency of the driving waveform is to the true resonant frequency of the motor, the faster the motor can brake. Therefore, obtaining the accurate motor resonant frequency is an important prerequisite for achieving vibration control.

[0004] When the actual resonant frequency of a smart terminal device deviates from the resonant frequency designed at the factory due to the use environment, physical shock, component aging, etc., the vibration amount of the motor will change. The existing method of detecting the resonant frequency of a linear motor in a terminal generally uses a constructed drive to excite the motor to vibrate, obtains the reverse electromotive force through the data of the motor's built-in voltage sensor and current sensor, and estimates the resonant frequency through the reverse electromotive force. This method must rely on the built-in sensor of the motor driver chip, which is complex to operate and has high cost. Summary of the invention

[0005] In order to solve the above technical problems in the prior art, this application is proposed. The embodiment of this application provides a method and a device for detecting the resonant frequency of a linear motor. The detection method is used in a mobile terminal device, which can use the existing sensors of the terminal device to quickly determine the resonant frequency of the motor, thereby reducing the cost of the motor drive chip, and can detect the resonant frequency of the motor in real time in the terminal.

[0006] According to one aspect of the present application, a method for detecting the resonant frequency of a linear motor is provided, which is applied to a mobile terminal device, comprising: driving a linear motor in the terminal device and acquiring vibration data generated by the terminal device in response to the driving; acquiring motion data of the terminal device; and determining the resonant frequency of the linear motor based on the vibration data and the motion data.

[0007] According to another aspect of the present application, a method for detecting the resonant frequency of a linear motor is provided, which is applied to a mobile terminal device, comprising: driving a linear motor in the terminal device and acquiring vibration data generated by the terminal device in response to the driving; judging a current state of the terminal device; and when determining that the terminal device is in a stationary state, determining the resonant frequency of the linear motor based on the vibration data.

[0008] In some embodiments, obtaining vibration data generated by the terminal device in response to the drive includes: using an acceleration sensor in the terminal device to obtain acceleration data of the terminal device on the motion axis of the linear motor.

[0009] In some embodiments, obtaining the motion data of the terminal device includes: determining a current state of the terminal device, and obtaining the motion data when it is determined that the terminal device is in motion.

[0010] In some embodiments, determining the current state of the terminal device includes: performing a long-term vibration on the linear motor using a preset waveform; obtaining corresponding vibration response data of the terminal device, the vibration response data including at least one of acceleration amplitude, amplitude offset, acceleration zero frequency, and acceleration envelope; determining the deviation between the vibration response data and a preset standard, and determining the current state of the terminal based on the deviation.

[0011] In some embodiments, acquiring the motion data of the terminal device includes: acquiring the posture data of the terminal device using an angular velocity sensor in the terminal device.

[0012] In some embodiments, determining the resonant frequency of the linear motor based on the vibration data and the motion data includes: determining the azimuth of the linear motor motion axis based on the motion data; determining the component of gravity acceleration on the linear motor motion axis based on the azimuth; determining corrected vibration data on the linear motor motion axis based on the vibration data and the component; and determining the resonant frequency of the linear motor based on the corrected vibration data.

[0013] In some embodiments, driving the linear motor in the terminal device includes: generating a continuous drive waveform having N frequency points, the continuous drive waveform having a starting frequency and an ending frequency, the resonant frequency being between the starting frequency and the ending frequency, wherein N is an integer greater than or equal to 2; using the continuous drive waveform to drive the linear motor to vibrate; and determining the resonant frequency of the linear motor based on the corrected vibration data includes: after obtaining N corrected vibration data of the terminal device in response to the continuous drive waveform, determining the frequency point corresponding to the maximum value in the corrected vibration data.

[0014] In some embodiments, obtaining the vibration data generated by the terminal device in response to the drive includes: obtaining the vibration data of the terminal device after the motor is controlled to enter the residual vibration stage; and determining the resonant frequency of the linear motor based on the vibration data and the motion data includes: determining the period of the corrected vibration data according to the obtained corrected vibration data; determining the resonant frequency of the linear motor according to the period of the corrected vibration data.

[0015] In some embodiments, driving the linear motor in the terminal device includes: using each drive signal in the drive signal group to drive the linear motor to vibrate respectively, and the signal group includes at least three drive signals, wherein each drive signal has a different frequency; determining the resonant frequency of the linear motor based on the corrected vibration data includes: after obtaining the corrected vibration data of the terminal device in response to each drive signal in the drive signal group, judging whether the frequency difference between the drive signals corresponding to the maximum value and the second largest value in all the corrected vibration data obtained meets the preset requirements; if the frequency difference does not meet the preset requirements, determining the first frequency for driving the linear motor according to the change trend of the corrected vibration data of each drive signal, using the drive signal with the first frequency to drive the linear motor to vibrate, obtaining the corresponding corrected vibration data of the terminal device, and repeating the above judgment steps; if the frequency difference meets the preset requirements, determining the frequency of the drive signal corresponding to the maximum value in all the corrected vibration data as the resonant frequency of the linear motor.

[0016] Another aspect of the present application provides a device for detecting the resonant frequency of a linear motor, comprising: a driving unit for driving a linear motor in a mobile terminal device; a data acquisition unit for acquiring vibration data generated by the terminal device in response to the driving, and acquiring motion data of the terminal device; and a calculation unit for determining the resonant frequency of the linear motor based on the vibration data and the motion data, or when it is determined that the terminal device is in a stationary state, determining the resonant frequency of the linear motor based on the vibration data.

[0017] Another aspect of the present application provides a terminal device, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the computer program is executed by the processor, the processor executes the detection method described above.

[0018] Another aspect of the present application further provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the processor executes each step in the above detection method.

[0019] Compared with the prior art, the linear motor resonant frequency detection method and device of the embodiment of the present application utilizes the inertial measurement unit and motion encoder and other sensor devices built into the smart terminal device to realize real-time detection of the motor resonant frequency. Therefore, there is no need to build relevant sensor devices into the motor driver chip, thereby reducing the cost of the motor driver chip. By real-time detection and determining the true resonant frequency of the motor, the vibration control effect of the motor is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] By describing the embodiments of the present application in more detail in conjunction with the accompanying drawings, the above and other purposes, features and advantages of the present application will become more apparent. The accompanying drawings are used to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the present application and do not constitute a limitation of the present application. In the accompanying drawings, the same reference numerals generally represent the same components or steps.

[0021] Figure 1 A flow chart showing a linear motor resonant frequency detection method according to an embodiment of the present application is shown;

[0022] Figure 2 A flow chart showing a linear motor resonant frequency detection method according to another embodiment of the present application;

[0023] Figure 3 A flowchart showing a method for determining the current state of the terminal device provided according to an embodiment of the present application;

[0024] Figure 4 A schematic diagram showing the vibration response of the linear motor under long-vibration drive at a frequency of f0 is shown;

[0025] Figure 5 A flow chart showing a method for determining the resonant frequency of the linear motor provided according to an embodiment of the present application;

[0026] Figure 6 A flow chart showing a detection method for determining the resonant frequency of a linear motor based on corrected vibration data according to an embodiment of the present application is shown;

[0027] Figure 7 A flow chart showing a detection method for determining the resonant frequency of a linear motor based on corrected vibration data according to another embodiment of the present application;

[0028] Figure 8 A flow chart showing a detection method for determining the resonant frequency of a linear motor based on corrected vibration data according to another embodiment of the present application is shown;

[0029] Fig. 9 A block diagram showing a linear motor resonant frequency detection device according to an embodiment of the present application;

[0030] Fig.10 A structural block diagram of a terminal device provided according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0031] Below, the example embodiments according to the present application will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. At the same time, it is not necessary to realize all the above advantages at the same time to implement any example of the embodiments of the present application. It should be understood that the present application should not be limited to the specific details of these example embodiments. Instead, the embodiments of the present application can be implemented without these specific details or by adopting other alternatives, without departing from the ideas and principles of the present application defined in the claims.

[0032] The embodiments of this document provide a method for detecting the resonant frequency of a linear motor, which can be applied to a terminal equipped with a linear motor to achieve a tactile effect, for example, it can be used in various occasions such as frequency calibration of the linear motor. The terminal device is usually configured with the resonant frequency corresponding to the linear motor at the factory, but in actual applications, the resonant frequency of the linear motor may shift. At this time, if the resonant frequency configured at the factory continues to be used to drive the linear motor to vibrate, the vibration intensity of the linear motor will deviate from its maximum value, affecting the tactile vibration effect of the terminal. Therefore, in actual applications, it is usually necessary to calibrate and update the resonant frequency of the linear motor.

[0033] The terminal device in this embodiment may be a mobile terminal device, for example, the terminal device may be an electronic device such as a mobile phone, a tablet computer, a personal digital assistant, a game console or a wearable device. The terminal device generally includes a processor component, a memory, a sensor component, various interactive interfaces and a linear motor. Among them, in order to achieve functions such as positioning or measuring motion parameters, the sensor component may include an inertial measurement unit and a motion encoder (including an accelerometer, a gyroscope and a magnetometer, etc.).

[0034] The execution subject of the linear motor resonant frequency detection method provided in this embodiment can be the above-mentioned terminal device (such as a mobile terminal device), or a functional module and / or functional entity in the terminal, which can be determined according to the type of terminal device and actual needs, and this embodiment does not make specific limitations. The following takes the terminal device as an example to exemplify the linear motor resonant frequency detection method of the embodiment of the present invention.

[0035] refer to Figure 1 , which shows a flow chart of a method for detecting the resonant frequency of a linear motor provided by an embodiment of the present application, which is applied to a terminal device, such as Figure 1 As shown, the method 100 may include the following steps:

[0036] Step S110, driving the linear motor in the terminal device, and acquiring vibration data generated by the terminal device in response to the driving.

[0037] In one embodiment, the linear motor driver chip can start implementing the resonant frequency detection method of the present invention after receiving a detection trigger signal. The trigger signal can be triggered by a user who is using the terminal device or automatically triggered according to the driving mode. For example, a corresponding detection trigger signal can be generated according to the current driving state. After receiving the trigger signal, the driver chip generates a control signal to generate a driving signal for detection to drive the linear motor.

[0038] For example, in response to a trigger signal, the driver chip can generate a drive signal with a preset frequency (e.g., a factory resonant frequency), and provide it to the linear motor through the drive circuit to excite the motor to vibrate. The drive signal can be a sine wave, a square wave, etc., and the drive cycle or duration can also be preset. In one embodiment, the linear motor can be driven to vibrate for a long time, that is, the set drive duration can be several resonant cycles.

[0039] During the process of driving the motor to vibrate, the vibration data generated by the terminal device in response to the drive can be synchronously acquired, which may include the vibration data of the terminal device synchronized with the drive, and may also include residual vibration data after the drive is disconnected. As described above, the vibration data can be acquired using a motion sensor built into the terminal device. In one embodiment, an acceleration sensor (e.g., an accelerometer) in the terminal device can be used to acquire acceleration data of the terminal device on the motion axis of the linear motor, thereby facilitating subsequent detection operations of the resonant frequency of the linear motor.

[0040] For the accelerometer, there may be fluctuations such as temperature drift that affect sensitivity, so it is necessary to filter the motion data. In one embodiment, the Kalman filter algorithm can be used to correct the collected acceleration data. At the same time, the motion data obtained is generally acceleration data along three independent coordinate axes of the terminal device coordinate system, as described in detail below. Since mobile terminal devices such as mobile phones may be in motion due to user operations, the acceleration data sensed by the accelerometer has components on the three coordinate axes, among which only the acceleration data on the linear motor motion axis is associated with the vibration data generated by the drive motor. Therefore, this embodiment can process the motion data collected by the accelerometer to obtain the acceleration data on the linear motor motion axis as the vibration data of the terminal device.

[0041] While obtaining the vibration data generated by the motor vibration, step S120 may be performed to obtain the motion data of the terminal device.

[0042] If the terminal device is in motion, for example, when the user operates the device to move or flip it, these actions will affect the vibration data obtained by sensors such as accelerometers, that is, the vibration data may deviate from the actual vibration response of the motor vibration applied to the terminal device. The main source of the deviation is that as the motion state of the terminal device changes, the gravity acceleration will also have a changing impact on the vibration data.

[0043] In order to determine such deviation, for example, in the process of obtaining vibration data generated by the vibration of the driving motor, the motion data of the terminal device can be synchronously obtained. In one embodiment, the angular velocity sensor (e.g., gyroscope) in the terminal device can be used to obtain the posture data of the terminal device. For example, in order to obtain the amount of change in the posture of the terminal device during the motion process, the rotation angle can be obtained by integrating the data obtained by the angular velocity sensor in the directions of the three axes within a predetermined time interval, and the position change of the terminal device during the motor drive can be determined based on the rotation angle. Furthermore, the deviation value between the vibration data obtained by the current motion sensor and the vibration caused by the linear motor due to the gravity acceleration can be determined through the current posture information.

[0044] In one embodiment, when the motion data of the terminal device is obtained, it can be determined that the terminal device is in motion. If the motion data cannot be obtained, it indicates that the sensor or circuit system in the terminal device may be faulty, and the resonant frequency detection operation can be terminated at this time.

[0045] In one embodiment, the current state of the terminal device can also be determined based on parameters such as vibration data, and motion data can be obtained when the terminal device is determined to be in motion. In this embodiment, it can also be determined based on these parameters whether the current state of the terminal device is suitable for resonant frequency detection, which will be described below.

[0046] In step 130 of this embodiment, the resonant frequency of the linear motor may be determined based on the vibration data and the motion data.

[0047] For example, the vibration data obtained by motion sensors such as accelerometers can be corrected through the acquired terminal motion data. The corrected vibration data can represent the tactile vibration data caused by the motor vibration, so that the resonant frequency of the linear motor can be determined based on the information in the corrected vibration data (such as the amplitude and frequency of the acceleration, etc.).

[0048] This embodiment realizes the detection of the resonant frequency of the linear motor by reusing sensors such as accelerometers and gyroscopes in the mobile terminal device. The real resonant frequency can be obtained by real-time detection in the terminal. Compared with the existing method of building voltage and current sensors into the driver chip, the hardware cost is reduced.

[0049] For mobile terminal devices, since they may be in motion or at rest during the process of interacting with the user, if it is determined that the terminal device is at rest, the resonant frequency of the linear motor can be directly determined based on the vibration data. Figure 2 A flow chart of a method for detecting the resonant frequency of a linear motor provided by another embodiment of the present application is shown, which is applied to a terminal device, such as Figure 2 As shown, the method 200 may include the following steps:

[0050] Step 210: drive the linear motor in the terminal device and obtain vibration data generated by the terminal device in response to the driving.

[0051] Step 210 is substantially the same as the aforementioned step 110, for example, utilizing an acceleration sensor (eg, an accelerometer) in the terminal device to obtain acceleration data of the terminal device on the linear motor motion axis, which will not be described in detail herein.

[0052] Step 220, determining the current state of the terminal device.

[0053] In one embodiment, for example, the current state of the terminal device can be determined based on the sensing data obtained by the sensor of the mobile device. For example, the acceleration data obtained by the accelerometer can be used to perform integration operations on three axes to calculate the relative displacement of the terminal within a certain period of time. If the calculated displacement value is zero, it indicates that the terminal device is in a stationary state, otherwise the terminal device is in a moving state.

[0054] In another embodiment, the current state of the terminal device may be determined based on the acquired vibration data itself, which will be described in detail later.

[0055] Step 230: When it is determined that the terminal device is in a stationary state, determine the resonant frequency of the linear motor based on the vibration data.

[0056] Since the terminal device is in a stationary state, it can be assumed that the deviation value between the vibration data obtained by the motion sensor and the vibration caused by the linear motor due to gravity acceleration is constant. Therefore, the resonant frequency of the linear motor can be determined directly based on the vibration data. For example, the motor can be driven to vibrate at multiple frequencies, and multiple vibration data collected by the motion sensor are obtained accordingly. The largest vibration data is selected from the multiple vibration data, and the driving frequency corresponding to the largest vibration data is determined as the resonant frequency of the motor.

[0057] Figure 3 A flow chart of a method for determining the current state of the terminal device provided according to an embodiment of the present application is shown.

[0058] like Figure 3 As shown, determining the current state of the terminal device may include the following steps:

[0059] In step 310, the linear motor is vibrated for a long time using a preset waveform.

[0060] This embodiment determines whether the vibration data during the driving signal, such as the acceleration data obtained by the accelerometer, meets the preset driving expectation. To this end, the linear motor is vibrated for a long time using a preset waveform, and the preset waveform will correspond to the preset driving expectation. For example, the preset driving waveform can be a long vibration drive with a resonant frequency f0.

[0061] Figure 4 Schematic diagram showing the vibration response of a linear motor under long-vibration drive at a frequency of f0, which shows a graph of the vibration acceleration of the motor under the drive signal and after the drive is completed. Figure 4 As shown in FIG. 1 , the vibration acceleration of the linear motor will show an envelope rising trend during the driving period, and after the driving is disconnected, the acceleration will show an envelope falling trend. It should be understood that if the driving frequency deviates from the actual resonant frequency, although the vibration acceleration during the driving period may have a vibration drop, the envelope of the vibration response data still has the same trend characteristics.

[0062] return Figure 3 In step 320, the corresponding vibration response data of the terminal device is obtained, and the vibration response data includes at least one of acceleration amplitude, amplitude offset, acceleration zero crossing frequency, and acceleration envelope.

[0063] For example, an accelerometer can be used to obtain acceleration data of a terminal device, and preprocess the data, such as filtering. By processing and analyzing the acceleration data, response data such as acceleration amplitude, amplitude offset, acceleration zero crossing frequency, and acceleration envelope can be obtained.

[0064] Among them, the acceleration amplitude represents the peak value in the acquired acceleration data, that is, the acceleration when the motor vibration amplitude is the largest. The amplitude offset can represent the deviation between multiple acceleration peaks, which can be determined by the difference between two adjacent peaks. The acceleration zero crossing frequency represents the frequency of acceleration crossing zero, which can be determined by the time interval between two adjacent zero crossings. The acceleration envelope represents the envelope obtained by selecting specific sample points (for example, each extreme point) on the acceleration curve and connecting the sample points.

[0065] In step 330, the deviation between the vibration response data and a preset standard is determined, and the current state of the terminal is determined based on the deviation.

[0066] When the vibration response data meets the driving expectation, the terminal device can be considered to be in a stationary state; on the contrary, if the vibration response data does not meet the driving expectation, the terminal device can be considered to be in a moving state. In some cases, if the vibration response data deviates greatly from the driving expectation, it can be considered that the current state of the terminal device is not suitable for frequency detection.

[0067] When the vibration response data is the acceleration amplitude, the deviation between the amplitude and the preset vibration amount can be determined. If the deviation exceeds the threshold, it is considered that it does not meet the driving expectations, that is, the terminal device is in motion. Otherwise, it can be considered that the terminal device is in a stationary state.

[0068] When the vibration response data is an amplitude offset, it can be determined whether the offset satisfies a specific form. For example, when the amplitude offset is substantially constant over time, or in other words, the vibration envelope after the offset compensation of the acceleration data will have Figure 4 The response curve shown can be considered to meet the driving expectations, that is, the terminal device is in a stationary state. Otherwise, when the amplitude deviation exceeds the preset standard, it can be considered that the terminal device is in a moving state.

[0069] When the vibration response data is the acceleration zero-crossing frequency, the deviation between the zero-crossing frequency and the driving frequency of the preset driving waveform in step 122 can be determined. If the deviation exceeds the threshold, it is considered that it does not meet the driving expectations, that is, the terminal device is in motion. Otherwise, it can be considered that the terminal device is in a stationary state.

[0070] When the vibration response data is an acceleration envelope, the similarity between the acceleration envelope and the preset target acceleration curve envelope can be calculated, and the deviation between the two can be determined by the similarity. If the similarity exceeds a threshold, it is considered that the vibration response meets the driving expectations, that is, the terminal device is in a stationary state. Otherwise, it can be considered that the terminal device is in motion.

[0071] In one embodiment, if it is determined that the terminal device is in a stationary state, Figure 2 The described method detects the resonant frequency. If it is determined that the terminal device is in motion, the Figure 1 The described method performs the detection of the resonance frequency.

[0072] Figure 5 The flowchart of the method for determining the resonant frequency of the linear motor when the terminal device is in motion according to an embodiment of the present application is specifically shown. Figure 5 As shown, determining the resonant frequency of the linear motor based on the vibration data and the motion data may include the following steps:

[0073] In step 410, the azimuth angle of the linear motor motion axis is determined based on the motion data.

[0074] In one embodiment, in the process of driving the motor to vibrate, the motion sensor (e.g., accelerometer) and angular velocity sensor (e.g., gyroscope) in the terminal device can be used to collect vibration data and angular velocity at the same time. Since the terminal device is also in motion, the azimuth of the linear motor motion axis may also be changing. For example, the vibration data and motion data collected by the accelerometer and the gyroscope can be used to determine the azimuth of the linear motor motion axis using a complementary filtering algorithm. It can be understood that motion data at different times correspond to different azimuths. To this end, preferably, the collected vibration data and motion data can be sampled at the same sampling frequency, so that the vibration data collected at the current moment can be associated with the azimuth of the motor motion axis at that moment.

[0075] In step 420, a component of gravity acceleration on the axis of motion of the linear motor is determined based on the azimuth angle.

[0076] For example, the angle between the linear motor motion axis and the gravity acceleration direction can be determined based on the azimuth angle, thereby determining the component of gravity acceleration on the linear motor motion axis. It is understandable that during the movement of the terminal device, the component data calculated at different times are also changing.

[0077] In step 430, corrected vibration data on the linear motor motion axis is determined based on the vibration data and the components.

[0078] For example, the vibration data and the component data may be subtracted to obtain corrected vibration data on the motion axis of the linear motor, and the corrected data may represent tactile vibration data of the terminal device caused by driving the linear motor to vibrate.

[0079] As described in the previous steps, the vibration data collected at any time can be associated with the azimuth of the motor motion axis. Accordingly, for any time, the corrected vibration data at that time can be determined based on the vibration data collected at that time and the calculated component data of the gravity acceleration on the linear motor motion axis at that time.

[0080] In one embodiment, the terminal device may be subjected to external forces such as impacts while in motion, which may also interfere with the vibration data of the linear motor. To this end, the external force exerted on the terminal device and its changes may be detected by sensing devices such as pressure sensors in the terminal device, and the acceleration generated by the terminal device under the external force may be calculated. The acceleration may be further subtracted from the corrected vibration data obtained above to obtain corrected data for determining the resonant frequency of the linear motor.

[0081] In step 440, the resonant frequency of the linear motor is determined based on the modified vibration data.

[0082] During the driving signal that drives the linear motor to vibrate, based on the previous steps, the modified vibration data that changes with time can be determined. The modified vibration data can present information such as amplitude and frequency, and the resonant frequency of the linear motor can be determined based on this information.

[0083] In one embodiment, before determining the resonant frequency of the linear motor based on the amplitude, frequency and other information of the modified vibration data, it is possible to determine whether the modified vibration data meets expectations (acceleration amplitude, amplitude offset, acceleration zero frequency, acceleration envelope, etc.), for example, whether the curve data of the modified acceleration has a predetermined envelope, which may have, for example, Figure 4 The response curve shown shows the envelope characteristics. When the modified vibration data meets the expected requirements, the subsequent resonant frequency determination step can be performed, and if the modified vibration data does not meet the expectations or deviates greatly from the expected requirements, the motor can be driven again and the frequency detection can be performed based on the re-acquired data.

[0084] Figure 6 A flow chart of a method for determining the resonant frequency of a linear motor based on calculated corrected vibration data according to an embodiment of the present application is shown. As shown in the figure, the method for detecting the resonant frequency of a linear motor may include the following steps:

[0085] Step 510: Generate a continuous driving waveform with N frequency points, wherein the continuous driving waveform has a starting frequency and an ending frequency, and the resonant frequency is located between the starting frequency and the ending frequency, wherein N is an integer greater than or equal to 2.

[0086] In one embodiment, the rated resonant frequency f0' (for example, 200 Hz) is used as a reference, and an offset value offset (for example, 10 Hz) is set, the starting frequency is f0'-offset, and the ending frequency is f0'+offset; or the starting frequency is f0'+offset, and the ending frequency is f0'-offset. N frequency values ​​are determined within the frequency range of the starting frequency and the ending frequency with a preset frequency step value (for example, 0.5 Hz), and waveforms of several cycles are generated for each frequency value, and then the waveforms of all frequency values ​​are connected end to end in time sequence, so as to generate a continuous driving waveform with N frequency points.

[0087] Step 520: Use the continuous driving waveform to drive the linear motor to vibrate.

[0088] For example, the driving chip can transmit the generated continuous driving waveform data to a data transmission device, which can cache part or all of the waveform data, and then send it to a digital-to-analog conversion device for digital-to-analog conversion and signal amplification processing, and then provide the amplified driving analog signal to the linear motor to drive the motor to vibrate.

[0089] The aforementioned steps 510 and 520 may be used to implement Figure 1 After the motor is driven, the detection method may proceed to step 530, where N corrected vibration data of the terminal device in response to the continuous driving waveform are obtained (for example, the detection method may be performed using Figure 5 The method shown in the figure is performed), and the frequency point corresponding to the maximum value in the corrected vibration data is determined as the resonant frequency of the linear motor.

[0090] Based on the above description, while the motor is driven to vibrate, sensors such as accelerometers and gyroscopes can be used to collect vibration data and motion data, and N corresponding corrected vibration data at each of the N frequency points can be calculated, such as corrected acceleration data. After the driving waveform data is played, the maximum value in the corrected vibration data and the frequency point corresponding to the maximum value can be determined, and the frequency point corresponding to the maximum value can be determined as the true resonant frequency of the linear motor.

[0091] Figure 7 A flow chart of a method for determining the resonant frequency of a linear motor based on calculated corrected vibration data according to another embodiment of the present application is shown. According to this embodiment, the method for detecting the resonant frequency of a linear motor may include the following steps:

[0092] Step 610, obtaining vibration data of the terminal device after the motor is controlled to enter the residual vibration stage.

[0093] In one embodiment, a preset waveform drive may be used to vibrate the motor and then the drive may be disconnected, so that the motor enters the residual vibration stage, at which time the motor performs damped oscillation. When the terminal device is in motion, the accelerometer and gyroscope in the terminal device can still sense vibration data and motion data, so the corrected vibration data of the terminal device in the residual vibration stage can be obtained. The calculation process can be performed using the method described above, which will not be repeated here.

[0094] Step 610 may be used to implement Figure 1 In the step 110 of obtaining vibration data shown in FIG. 1 , after the motor is driven, the detection method may proceed to step 620 to determine the period of the modified vibration data according to the obtained modified vibration data.

[0095] For example, after calculating the corrected vibration data at each moment of the residual vibration stage (for example, Figure 5The method shown in the figure is performed), and the waveform data of the modified vibration data can be obtained, so that the period of the modified vibration data can be obtained according to the waveform data. For example, one or more time intervals of two or more adjacent zero crossing points of the modified vibration data can be obtained, and then the period of the modified vibration data can be determined according to the one or more time intervals or obtained by weighted calculation.

[0096] Step 630: Determine the resonant frequency of the linear motor according to the period of the modified vibration data.

[0097] The period of the modified vibration data determined in the previous step can be approximated to the damping period of the motor, so the damped oscillation frequency of the motor can be obtained. In one embodiment, the resonant frequency of the linear motor can be determined using the following formula:

[0098]

[0099] Where f0 is the resonant frequency of the linear motor, f d is the damped oscillation frequency of the motor, and ξ is the damping coefficient.

[0100] Figure 8 A flow chart showing a method for determining the resonant frequency of a linear motor based on calculated corrected vibration data according to another embodiment of the present application is shown. According to this embodiment, the method for detecting the resonant frequency of a linear motor may include the following steps:

[0101] Step 710: Use each driving signal in the driving signal group to drive the linear motor to vibrate, wherein the driving signal group includes at least three driving signals, wherein each driving signal has a different frequency.

[0102] In one embodiment, a drive signal group may be pre-constructed, which may include, for example, three drive signals, and the three drive signals may have drive frequencies that increase in sequence, and the three drive signals are respectively used to drive the linear motor to perform long vibration. Generally, since the deviation between the actual resonant frequency of the linear motor and the factory-set frequency may be small, for example, the resonant frequency may only be offset by 2 Hz, the frequencies of the three drive signals may be selected near the factory-set resonant frequency.

[0103] The aforementioned step 710 may be used to implement Figure 1 In the driving step 110 shown in the figure, after the motor is driven, the detection method can proceed to step 720, after obtaining the corrected vibration data of the terminal device in response to each driving signal in the driving signal group, it is determined whether the frequency difference of the driving signal corresponding to the maximum value and the second largest value of all the corrected vibration data obtained meets the preset requirements.

[0104] Based on the above description, while each driving signal is used to drive the motor to vibrate, vibration data and motion data can be collected using sensors such as accelerometers and gyroscopes, and corrected vibration data under each driving signal, such as corrected acceleration data, can be calculated. For example, when the driving signal group includes three driving signals, the maximum value, the second largest value, the minimum value, and the change trend of the corrected vibration data can be determined, wherein the frequency corresponding to the maximum value is the driving frequency of the three driving signals that is closest to the true resonant frequency of the motor.

[0105] The frequency difference in the judgment step may be, for example, the deviation between the frequencies of the driving signals corresponding to the maximum value and the second largest value in the corrected vibration data in the constructed driving signal group. If the deviation between the two is not greater than a preset value, it is considered that the detection accuracy meets the requirements. Otherwise, it can be considered that the detection accuracy does not meet the requirements. The preset value can be set according to the detection accuracy. For example, the preset value can be 0.2Hz-0.5Hz.

[0106] Generally, the frequency difference between the three frequencies of the constructed initial drive signal group will be greater than the preset value, so the detection accuracy of the initial judgment will not meet the requirements. At this time, a new drive signal group can be constructed. For example, it may include the following step 730, determining the first frequency for driving the linear motor according to the change trend of the corrected vibration data of each drive signal.

[0107] In one embodiment, the first frequency may be close to the frequencies corresponding to the maximum and second largest values ​​in the aforementioned modified vibration data, and away from the frequency corresponding to the minimum value in the aforementioned modified vibration data, so that the newly determined first frequency may be closer to the true resonant frequency of the motor. For example, when the modified vibration data of the three drive signals show a trend of first rising and then falling, the first frequency may be determined within the frequency interval of the three drive signals, and the first frequency may be selected between the frequencies corresponding to the maximum and second largest values ​​in the aforementioned modified vibration data, and when the modified vibration data of the three drive signals show a trend of unidirectional increase or decrease, the first frequency may be determined outside the frequency interval of the three drive signals and adjacent to the frequency corresponding to the maximum value in the aforementioned modified vibration data.

[0108] In one embodiment, while adding the driving signal with the first frequency to the newly constructed driving signal group, the driving signal corresponding to the minimum value in the aforementioned corrected vibration data may be removed, that is, the newly constructed driving signal group still has three driving signals.

[0109] like Figure 8 As shown, after constructing a new driving signal group, step 740 can be performed to drive the linear motor to vibrate using a driving signal with a first frequency to obtain corresponding corrected vibration data of the terminal device. Afterwards, the judgment of step 720 is repeated.

[0110] For example, the driving chip can generate a driving signal with a first frequency to drive the linear motor and obtain corresponding corrected vibration data. The calculation and judgment process can be performed using the method described above, which will not be repeated here.

[0111] In one embodiment, if the frequency difference meets the requirement, step 750 may be performed to determine the frequency of the driving signal corresponding to the maximum value in all the corrected vibration data as the resonant frequency of the linear motor.

[0112] Through this embodiment, the driving frequency can be updated by adjusting the driving frequency strategy to approach the resonant frequency of the linear motor, thereby speeding up the detection process.

[0113] The embodiment of the present invention also provides a linear motor resonant frequency detection device. Fig. 9 As shown, according to an embodiment of the present application, a linear motor resonant frequency detection device 800 may include: a driving unit 810, used to drive a linear motor in a mobile terminal device, which may be electrically coupled to the linear motor; a data acquisition unit 820, used to acquire vibration data generated by the terminal device in response to the drive, and to acquire motion data of the terminal device; and a calculation unit 830, used to determine the resonant frequency of the linear motor based on the vibration data and the motion data, or when it is determined that the terminal device is in a stationary state, determine the resonant frequency of the linear motor based on the vibration data.

[0114] In one example, the vibration data is acceleration data, and the data acquisition unit 820 can be configured to use an acceleration sensor in the terminal device to acquire acceleration data of the terminal device on the linear motor motion axis.

[0115] In an example, the motion data is posture data, and the data acquisition unit 820 can be configured to acquire the posture data of the terminal device using an angular velocity sensor in the terminal device.

[0116] In one example, the calculation unit 830 can also be used to determine the current state of the terminal device, which can be done in the following manner: using a preset waveform to perform a long-term vibration on the linear motor; obtaining corresponding vibration response data of the terminal device, the vibration response data including at least one of acceleration amplitude, amplitude offset, acceleration zero frequency, and acceleration envelope; determining the deviation between the vibration response data and a preset standard, and determining the current state of the terminal based on the deviation.

[0117] In one example, the computing unit 830 may be configured to determine the resonant frequency of the linear motor in the following manner: determine the azimuth angle of the linear motor motion axis based on the motion data; determine the component of gravity acceleration on the linear motor motion axis based on the azimuth angle; determine corrected vibration data on the linear motor motion axis based on the vibration data and the component; and determine the resonant frequency of the linear motor based on the corrected vibration data.

[0118] In one example, the driving unit 810 can be configured to drive the linear motor in the terminal device in the following manner: generate a continuous driving waveform with N frequency points, the continuous driving waveform has a starting frequency and an ending frequency, and the resonant frequency is between the starting frequency and the ending frequency, wherein N is an integer greater than or equal to 2; use the continuous driving waveform to drive the linear motor to vibrate; and the calculation unit 830 can be configured to determine the resonant frequency of the linear motor in the following manner: after obtaining N corrected vibration data of the terminal device in response to the continuous driving waveform, determine the frequency point corresponding to the maximum value in the corrected vibration data.

[0119] In one example, the data acquisition unit 820 can be configured to acquire vibration data generated by the terminal device in response to the drive in the following manner: acquiring vibration data of the terminal device after the motor is controlled to enter the residual vibration stage; and the calculation unit 830 can be configured to determine the resonant frequency of the linear motor in the following manner: determining the period of the corrected vibration data based on the obtained corrected vibration data; determining the resonant frequency of the linear motor based on the period of the corrected vibration data.

[0120] In one example, the driving unit 810 can be configured to drive the linear motor in the terminal device in the following manner: each driving signal in the driving signal group is used to drive the linear motor to vibrate respectively, and the driving signal group includes at least three driving signals, wherein each driving signal has a different frequency; and the calculation unit 830 can be configured to determine the resonant frequency of the linear motor in the following manner: after obtaining the corrected vibration data of the terminal device in response to each driving signal in the driving signal group, determine whether the frequency difference of the driving signal corresponding to the maximum value and the second largest value in all the corrected vibration data obtained meets the preset requirements; if the frequency difference does not meet the requirements, determine the first frequency for driving the linear motor according to the change trend of the corrected vibration data of each driving signal, use the driving signal with the first frequency to drive the linear motor to vibrate, obtain the corresponding corrected vibration data of the terminal device, and repeat the above judgment steps; if the frequency difference meets the requirements, determine the frequency of the driving signal corresponding to the maximum value in all the corrected vibration data as the resonant frequency of the linear motor.

[0121] The specific functions and operations of the various units and modules in the above-mentioned resonant frequency detection device 800 have been described in the above reference. Figure 1-8 The detection method described in detail is described in the literature, so it is only briefly introduced here and unnecessary repeated descriptions are omitted.

[0122] The present invention also provides a computer-readable storage medium, wherein a linear motor resonant frequency detection program is stored on the computer-readable storage medium, and the linear motor resonant frequency detection program is executed by a processor to perform the steps of the linear motor resonant frequency detection method as described above. The specific implementation can be referred to Figure 1-8 The steps of the detection method described are not repeated here.

[0123] The embodiments of the present invention may also be terminal devices, such as various electronic devices, wherein the terminal device includes a memory, a processor, and instructions stored in the memory and executable on the processor, wherein the instructions, when executed by the processor, cause the processor to execute the steps of the method for detecting the resonant frequency of the linear motor as described above. For specific implementation, reference may be made to Figure 1-8 The resonant frequency detection method described above will not be repeated here.

[0124] Fig.10 FIG. 1 is a block diagram of a terminal device according to an embodiment of the present application. Fig.10 As shown, the terminal device 900 includes a processor 910 and a memory 920 .

[0125] The processor 910 may be a central processing unit (CPU), a microprocessor, or other forms of processing chips having data processing capabilities and / or instruction execution capabilities, and may control other components in the terminal device 900 to perform desired functions.

[0126] The memory 920 may be an internal storage unit of an electronic device, such as a non-volatile and / or volatile memory. The memory 920 may store various data such as the motor's factory resonant frequency, and may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. One or more computer program instructions may be stored on the computer-readable storage medium, and the processor 910 may execute the program instructions to implement the above-mentioned detection of the resonant frequency of the linear motor and / or other desired functions.

[0127] In one example, the terminal device 900 may also include: an input device 930 and an output device 940, which are interconnected through a bus system and / or other forms of connection mechanisms (not shown). For example, the input device 930 may be a camera, an antenna, or a microphone device. In addition, the input device 930 may also include, for example, a keyboard, a mouse, etc. The output device 940 may output various information to the outside. The output device 940 may include, for example, a display, a speaker, and a communication network and a remote output device connected thereto, etc.

[0128] Of course, to simplify, Fig.10 Only some of the components related to the present application in the terminal device 900 are shown, and components such as a bus, an input / output interface, etc. are omitted. In addition, according to specific application conditions, the terminal device 900 may also include any other appropriate components.

[0129] The basic principles of the present application are described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, effects, etc. mentioned in the present application are only examples and not limitations, and it cannot be considered that these advantages, strengths, effects, etc. are required by each embodiment of the present application. In addition, the specific details disclosed above are only for the purpose of illustration and ease of understanding, not for limitation, and the above details do not limit the present application to being implemented by adopting the above specific details.

[0130] The block diagrams of devices, apparatuses, equipment, and systems involved in this application are only illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. Words such as "including," "comprising," "having," and the like are open words, meaning "including but not limited to," and can be used interchangeably therewith. The words "or" and "and" used herein refer to the words "and / or," and can be used interchangeably therewith, unless the context clearly indicates otherwise. The word "such as" used herein refers to the phrase "such as but not limited to," and can be used interchangeably therewith.

[0131] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of the present application. Therefore, the present application is not intended to be limited to the aspects shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

[0132] The above description has been given for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although multiple example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. A method for detecting the resonant frequency of a linear motor, applied to a terminal device, the method comprising: driving a linear motor in the terminal device, and acquiring vibration data generated by the terminal device in response to the driving; Determining a current state of the terminal device, and when determining that the terminal device is in motion, acquiring motion data of the terminal device; Correcting the vibration data by using the motion data to obtain corrected vibration data; as well as, determining a resonant frequency of the linear motor based on the corrected vibration data, Wherein, the obtaining of vibration data generated by the terminal device in response to the driving includes: Using an acceleration sensor in the terminal device to obtain acceleration data of the terminal device on the motion axis of the linear motor, Wherein, acquiring the motion data of the terminal device includes: Acquiring posture data of the terminal device using an angular velocity sensor in the terminal device, Wherein, the correcting the vibration data by using the motion data to obtain the corrected vibration data comprises: determining an azimuth angle of a motion axis of the linear motor based on the motion data; determining a component of gravity acceleration on the axis of motion of the linear motor based on the azimuth angle; Modified vibration data on the axis of motion of the linear motor is determined based on the vibration data and the components.

2. The detection method according to claim 1, wherein: Determining the current state of the terminal device includes: Long-vibrating the linear motor using a preset waveform; Acquire vibration response data corresponding to the terminal device, wherein the vibration response data includes at least one of acceleration amplitude, amplitude offset, acceleration zero crossing frequency, and acceleration envelope; Determine the deviation between the vibration response data and a preset standard, and determine the current state of the terminal based on the deviation.

3. The detection method according to claim 1, wherein: The driving of the linear motor in the terminal device comprises: Generate a continuous driving waveform with N frequency points, the continuous driving waveform has a starting frequency and an ending frequency, the resonant frequency is between the starting frequency and the ending frequency, wherein N is an integer greater than or equal to 2; Using the continuous drive waveform to drive the linear motor to vibrate; Furthermore, determining the resonant frequency of the linear motor based on the corrected vibration data includes: After acquiring the N modified vibration data of the terminal device in response to the continuous driving waveform, a frequency point corresponding to a maximum value among the N modified vibration data is determined as the resonant frequency of the linear motor.

4. The detection method according to claim 1, wherein: The acquiring of vibration data generated by the terminal device in response to the driving includes: Acquiring vibration data of the terminal device after controlling the linear motor to enter a residual vibration stage; Furthermore, determining the resonant frequency of the linear motor based on the corrected vibration data includes: Determining a period of the corrected vibration data according to the corrected vibration data obtained; The resonance frequency of the linear motor is determined based on the period of the corrected vibration data.

5. The detection method according to claim 3, wherein: The driving of the linear motor in the terminal device comprises: Using each driving signal in the driving signal group to drive the linear motor to vibrate, the driving signal group includes at least three driving signals, wherein each driving signal has a different frequency; Furthermore, determining the resonant frequency of the linear motor based on the corrected vibration data includes: After obtaining the corrected vibration data of the terminal device in response to each drive signal in the drive signal group, determining whether the frequency difference of the drive signal corresponding to the maximum value and the second largest value in all the corrected vibration data obtained meets the preset requirement; If the frequency difference does not meet the preset requirement, determine the first frequency for driving the linear motor according to the change trend of the corrected vibration data of each driving signal, drive the linear motor to vibrate using the driving signal with the first frequency, obtain the corresponding corrected vibration data of the terminal device, and repeat the above determination step; If the frequency difference meets the preset requirement, the frequency of the driving signal corresponding to the maximum value in all the corrected vibration data is determined as the resonant frequency of the linear motor.

6. A linear motor resonant frequency detection device, comprising: A driving unit, used to drive a linear motor in a mobile terminal device; a data acquisition unit, configured to acquire vibration data generated by the terminal device in response to the drive, and determine a current state of the terminal device, and acquire motion data of the terminal device when it is determined that the terminal device is in motion; a calculation unit, configured to modify the vibration data by using the motion data to obtain modified vibration data, and determine a resonant frequency of the linear motor based on the modified vibration data; The data acquisition unit is configured to acquire vibration data generated by the terminal device in response to the driving in the following manner: Using an acceleration sensor in the terminal device to obtain acceleration data of the terminal device on the motion axis of the linear motor, The data acquisition unit is configured to acquire the motion data of the terminal device in the following manner: Acquiring posture data of the terminal device using an angular velocity sensor in the terminal device, The calculation unit is configured to correct the vibration data by using the motion data in the following manner to obtain corrected vibration data: determining an azimuth angle of a motion axis of the linear motor based on the motion data; determining a component of gravity acceleration on the axis of motion of the linear motor based on the azimuth angle; Modified vibration data on the axis of motion of the linear motor is determined based on the vibration data and the components.

7. A terminal device, comprising a processor, a memory, and a computer program stored in the memory and executable on the processor, wherein the computer program implements the detection method according to any one of claims 1 to 5 when executed by the processor.

8. A computer-readable storage medium storing a computer program, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the detection method according to any one of claims 1 to 5 is implemented.

Images