SYSTEM, CONTROL DEVICE AND SIGNAL PROCESSING METHOD TO CONVERT VIBRATION TO SOUND SIGNAL

A system to convert vibration to a sound signal includes a vibration sensing device and a control device. The vibration sensing device is disposed on the surface of a device under test (DUT), and detects a time-domain vibration signal when the DUT is in operation. The control device receives the time-domain vibration signal, and converts the time-domain vibration signal into a sound signal. The sound signal is loaded in a computer playable audio file.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of China Patent Application No. 202310644720.0, filed on Jun. 1, 2023, the entirety of which is incorporated by reference herein.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to an electronic device, and, in particular, to an electronic device for converting a vibration signal to a sound signal and the signal processing method thereof.

Description of the Related Art

In the prior art, equipment status monitoring of reactors in the petrochemical industry usually relies on experts in the field to go to the equipment site and use a sound bar to diagnose with the human ear. The reactor uses high-temperature and high-pressure equipment with a high risk factor, and any failure may endanger the lives of experts on site. In addition, due to the continuous shortage of human resources in the petrochemical industry, it is becoming more and more difficult to inspect such resources for equipment status inspection.

BRIEF SUMMARY OF THE INVENTION

An embodiment of the present invention provides a system to convert vibration to a sound signal. The system includes a vibration sensing device and a control device. The vibration sensing device is disposed on the surface of a device under test (DUT), and detects a time-domain vibration signal when the DUT is in operation. The control device receives the time-domain vibration signal, and converts the time-domain vibration signal into a sound signal. The sound signal is loaded in a computer playable audio file.

According to the system described above, the vibration detected by the vibration sensing device is physical vibration on an object instead of air vibration.

According to the system described above, the vibration sensing device includes a first transmission interface, a control unit, a sensor, and a first register. The first transmission interface receives a control instruction from the control device. The control unit outputs an enable signal according to the control instruction. The sensor receives the enable signal and starts to detect the time-domain vibration signal when the DUT is in operation. The first register stores the time-domain vibration signal, and sends the time-domain vibration signal to the first transmission interface, so that the time-domain vibration signal is output to the control device.

According to the system described above, the control device includes a second transmission interface, a second register, and a memory. The second transmission interface receives the time-domain vibration signal from the vibration sensing device. The second register stores the time-domain vibration signal from the second transmission interface, and outputs the time-domain vibration signal. The memory stores the time-domain vibration signal from the second register.

According to the system described above, the control device further includes a processing unit. The processing unit reads the time-domain vibration signal from the second register or the memory, and converts the time-domain vibration signal into a frequency-domain vibration signal. The processing unit performs signal processing on the frequency-domain vibration signal, and converts the frequency-domain vibration signal into a characteristic sound signal in time-domain.

According to the system described above, the control device loads the sound signal into the computer playable audio file, and stores the computer playable audio file into the memory.

According to the system described above, the control device outputs the computer playable audio file through the second transmission interface.

According to the system described above, the control device further includes a user interface and a processing unit. The user interface generates the control instruction according to a user's operation. The processing unit stores the time-domain vibration signal from the vibration sensing device into the memory. When the system is in an offline mode, after the control device receives the control instruction from the user interface, the processing unit converts the time-domain vibration signal into a sound signal.

According to the system described above, the control device further includes a user interface. The user interface generates the control instruction according to a user's operation. The processing unit stores the time-domain vibration signal from the vibration sensing device into the memory. When the system is in an offline mode, after the control device receives the control instruction from the user interface, the processing unit converts the time-domain vibration signal into the frequency-domain vibration signal, performs signal processing on the frequency-domain vibration signal, and converts the frequency-domain vibration signal into a characteristic sound signal in time-domain.

According to the system described above, the processing unit receives the control instruction, and sends the control instruction to the vibration sensing device through the second transmission interface.

According to the system described above, the signal processing includes the following stages. The processing unit amplifies the specific frequency range of the frequency-domain vibration signal to obtain a characteristic signal. The processing unit converts the characteristic signal into the characteristic sound signal in time-domain.

According to the system described above, the signal processing includes the following stage. The control device uses a digital filter to filter the time-domain vibration signal, and converts the time-domain vibration signal into a characteristic sound signal in time-domain.

According to the system described above, the signal processing includes the following stages. The processing unit amplifies the specific frequency range of the frequency-domain vibration signal to obtain a characteristic signal. The processing unit converts the characteristic signal from frequency-domain to time-domain, uses a digital filter to filter the characteristic signal, and converts the characteristic signal into the characteristic sound signal in time-domain.

According to the system described above, the DUT is a high-pressure reactor in the petrochemical industry, and the vibration sensing device is disposed on a surface of a bearing of the DUT.

According to the system described above, the bearing is selected from one or more of a motor bearing, an intermediate bearing, and a bottom bearing.

According to the system described above, the sampling rate of the sensor is equal to the characteristic frequency of the inner and outer rings of a motor shaft of the DUT, or (rpm/60)*N*n. N is a value not less than 5, rpm is the rotation speed of the motor of the DUT, and n is the number of shaft blades of the motor.

An embodiment of the present invention provides a signal processing method. The signal processing method is applicable to an electronic device comprising a vibration sensing device and a control device. The signal processing method includes the following stages. A time-domain vibration signal is detected when a device under test (DUT) is in operation. The time-domain vibration signal is converted into a frequency-domain vibration signal. Signal processing is performed on the frequency-domain vibration signal to generate a characteristic signal. The characteristic signal is converted into a characteristic sound signal. The characteristic sound signal is loaded in a computer playable audio file.

According to the signal processing method described above, the signal processing method includes the following stages. A control instruction from the control device is received. An enable signal is output according to the control instruction. Detecting the time-domain vibration signal according to the enable signal is started when the DUT is in operation. The time-domain vibration signal is stored. The time-domain vibration signal is sent to the control device.

According to the signal processing method described above, the step of performing signal processing on the frequency-domain vibration signal includes the following stages. The specific frequency range of the frequency-domain vibration signal is amplified to obtain the characteristic signal. The characteristic signal is converted into the characteristic sound signal in time-domain.

The signal processing method further includes the following stages. A digital filter is used to filter the characteristic signal after the characteristic signal is converted from frequency-domain to time-domain. The characteristic signal is converted into the characteristic sound signal in time-domain.

An embodiment of the present invention provides a control device. The control device includes a transmission interface and a processing unit. The transmission interface receives a time-domain vibration signal from a vibration sensing device. The processing unit reads the time-domain vibration signal, and converts the time-domain vibration signal into a sound signal. The sound signal is loaded in a computer playable audio file.

DETAILED DESCRIPTION OF THE INVENTION

In order to make the above purposes, features, and advantages of some embodiments of the present invention more comprehensible, the following is a detailed description in conjunction with the accompanying drawing.

Certain terms are used throughout the description and following claims to refer to particular components. As one skilled in the art will understand, electronic equipment manufacturers may refer to a component by different names. This document does not intend to distinguish between components that differ in name but not function. It is understood that the words “comprise”, “have” and “include” are used in an open-ended fashion, and thus should be interpreted to mean “include, but not limited to . . . ”. Thus, when the terms “comprise”, “have” and/or “include” used in the present invention are used to indicate the existence of specific technical features, values, method steps, operations, units and/or components. However, it does not exclude the possibility that more technical features, numerical values, method steps, work processes, units, components, or any combination of the above can be added.

The directional terms used throughout the description and following claims, such as: “on”, “up”, “above”, “down”, “below”, “front”, “rear”, “back”, “left”, “right”, etc., are only directions referring to the drawings. Therefore, the directional terms are used for explaining and not used for limiting the present invention. Regarding the drawings, the drawings show the general characteristics of methods, structures, and/or materials used in specific embodiments. However, the drawings should not be construed as defining or limiting the scope or properties encompassed by these embodiments. For example, for clarity, the relative size, thickness, and position of each layer, each area, and/or each structure may be reduced or enlarged.

When the corresponding component such as layer or area is referred to as being “on another component”, it may be directly on this other component, or other components may exist between them. On the other hand, when the component is referred to as being “directly on another component (or the variant thereof)”, there is no component between them. Furthermore, when the corresponding component is referred to as being “on another component”, the corresponding component and the other component have a disposition relationship along a top-view/vertical direction, the corresponding component may be below or above the other component, and the disposition relationship along the top-view/vertical direction is determined by the orientation of the device.

It should be understood that when a component or layer is referred to as being “connected to” another component or layer, it can be directly connected to this other component or layer, or intervening components or layers may be present. In contrast, when a component is referred to as being “directly connected to” another component or layer, there are no intervening components or layers present.

The electrical connection or coupling described in this disclosure may refer to direct connection or indirect connection. In the case of direct connection, the endpoints of the components on the two circuits are directly connected or connected to each other by a conductor line segment, while in the case of indirect connection, there are switches, diodes, capacitors, inductors, resistors, other suitable components, or a combination of the above components between the endpoints of the components on the two circuits, but the intermediate component is not limited thereto.

The words “first”, “second”, “third”, “fourth”, “fifth”, and “sixth” are used to describe components. They are not used to indicate the priority order of or advance relationship, but only to distinguish components with the same name.

FIG.1is a schematic diagram of an electronic device100in accordance with some embodiments of the present invention. As shown inFIG.1, the electronic device100includes a vibration sensing device102and a control device104. In some embodiments, the vibration sensing device102is disposed on the surface of a device under test (DUT). The vibration sensing device102detects a time-domain vibration signal130when the DUT is in operation. In detail, the vibration sensing device102includes a sensor106, a first register108, a control unit110, and a first transmission interface112. In some embodiments, the first transmission interface112receives a control instruction150from the control device104. In some embodiments, the control instruction150includes but not limited to sampling rate, start condition, end condition, and transmission target address of the time-domain vibration signal130. The control unit110outputs an enable signal152according to the control instruction150. The sensor106receives the enable signal152and starts to detect the time-domain vibration signal130when the DUT is in operation. In some embodiments, the DUT is a high-pressure reactor in the petrochemical industry, but the present invention is not limited thereto. The first register108stores the time-domain vibration signal130, and sends the time-domain vibration signal130to the first transmission interface112, so that the time-domain vibration signal130is output to the control device104.

In some embodiments, the sensor106is a sensor related to a vibration type, such as a velocity gauge, an accelerometer, or a displacement gauge, but the present invention is not limited thereto. In some embodiments, the sampling rate of the sensor106is6400sampling points per second, but the present invention is not limited thereto. In some embodiments, the vibration detected by the vibration sensing device102is physical vibration on an object instead of air vibration. In other words, the vibration sensing device102detects the actual shaking of the DUT, rather than detecting sound waves in the air. In some embodiments, the first register108is a volatile memory, but the present invention is not limited thereto. In some embodiments, the control unit110may be, for example, a central processing unit, a microprocessor, or a microcontroller, but the present invention is not limited thereto. In some embodiments, the first transmission interface112is a Universal Serial Bus (USB), but the present invention is not limited thereto.

In some embodiments ofFIG.1, the control device104receives the time-domain vibration signal130, converts the time-domain vibration signal130into a frequency-domain vibration signal, performs signal processing on the frequency-domain vibration signal, and converts the frequency-domain vibration signal into an audio signal140. In some embodiments, the control device104directly performs signal processing on the time-domain vibration signal130, but the present invention is not limited thereto. In detail, the control device104includes a processing unit114, a second register116, a memory118, a user interface120, and a second transmission interface122. The second transmission interface122receives the time-domain vibration signal130from the vibration sensing device102. The second register116stores the time-domain vibration signal130from the second transmission interface122, and outputs the time-domain vibration signal130. The memory118stores the time-domain vibration signal130from the second register116. In some embodiments ofFIG.1, the processing unit114reads the time-domain vibration signal130from the memory118. In other words, in some embodiments ofFIG.1, the control device104may pre-store the time-domain vibration signal130in the memory118first, and then convert the time-domain vibration signal130into a frequency-domain vibration signal when receiving a user instruction in the online mode or offline mode. Finally, the control device104may convert the frequency-domain vibration signal into the sound signal140. In this way, the computing resources of the control device104can be saved, and the conversion is performed after receiving a user instruction, so that the control device104supports operation in offline-mode, and it can be applied to some work sites without a network environment.

In some embodiments, the memory118is a non-volatile memory, and the second register116is a volatile memory, but the present invention is not limited thereto. In some embodiments, the processing unit114converts the time-domain vibration signal130into the frequency-domain vibration signal, performs signal processing on the frequency-domain vibration signal, and then converts the frequency-domain vibration signal into the audio signal140. In detail, the processing unit114performs Fast Fourier Transform (FFT) on the time-domain vibration signal130to obtain the frequency-domain vibration signal. In some embodiments, the processing unit114amplifies the specific frequency range of the frequency-domain vibration signal to obtain a characteristic signal. The processing unit114uses a digital filter to filter the characteristic signal after the characteristic signal is converted from frequency-domain to time-domain. Next, the processing unit114converts the characteristic signal, which is amplified in the specific frequency range and filtered, into a characteristic sound signal140. The method of converting from frequency-domain to time-domain may be provided. For example, the processing unit114converts the frequency-domain signal into the time-domain signal through inverse Fourier transform. The method of converting the characteristic signal into the characteristic sound signal may be provided. For example, according to the format of the audio source file to be output, fill in the header with a specific format (for example, the wav format needs to add the block number, block size, file format, etc. as the header), and output it as a playable digital audio file, which is referred as the characteristic sound signal142here. Compared with the sound signal140without frequency range amplification and/or filtering, the amplified and/or filtered characteristic sound signal142may greatly improve the diagnostic accuracy of the DUT problems by experts in the field. In some embodiments, the digital filter may be, for example, a high-pass filter, a low-pass filter, a band-pass filter, or a band-stop filter, but the present invention is not limited thereto. It is noted that the characteristic sound signal142can be amplified in specific frequency ranges and filtered, or only amplified or only filtered. That is, one of amplification and filtering can be selectively performed without having to do both.

In some embodiments, the process of converting time-domain vibration signal130or time-domain characteristic signal into the sound signal140is provided. The processing unit114creates a wav (waveform audio file format) audio file through a Soundfile algorithm suite, and generates a header according to the data acquisition conditions of the sensor106and the audio file setting values (such as the number of channels, sampling frequency, etc.). The processing unit114writes the time-domain vibration signal130without signal processing, or the time-domain characteristic signal with signal processing and conversion, and generates the audio file of the computer-playable sound signal140or the characteristic sound signal142. The audio file of the computer-playable sound signal140or the characteristic sound signal142is for the listener to identify the health status of the DUT (such as rotating machinery). In some embodiments, the processing unit114amplifies or reduces the signal within the specific frequency range of the frequency-domain vibration signal, or it performs a noise reduction algorithm to filter out noise. The noise reduction algorithm may be, for example, autoencoder, ICA, or tasnet, but the present invention is not limited thereto.

In some embodiments ofFIG.1, the processing unit114loads the sound signal140or the characteristic sound signal142into a computer-playable audio file, and stores the computer-playable audio file in the memory118. The control device104outputs the computer-playable audio file to an external device or a cloud180through the second transmission interface122. In some embodiments, the second transmission interface122is a Universal Serial Bus (USB), but the present invention is not limited thereto. In some embodiments, the user interface120generates the control instruction150according to the user's operation170. In some embodiments, the user interface120may be, for example, a screen, a keyboard, and a mouse, but the present invention is not limited thereto. In some embodiments, the processing unit114receives the control instruction150and sends the control instruction150to the vibration sensing device102through the second transmission interface122. The vibration sensing device102then receives the control instruction150through its first transmission interface112.

FIG.2is a schematic diagram of an electronic device200in accordance with some embodiments of the present invention. As shown inFIG.2, the electronic device200includes a vibration sensing device102and a control device104. In some embodiments, the vibration sensing device102is disposed on the surface of a device under test (DUT). The vibration sensing device102detects a time-domain vibration signal130when the DUT is in operation. In detail, the vibration sensing device102includes a sensor106, a first register108, a control unit110, and a first transmission interface112. In some embodiments, the first transmission interface112receives a control instruction150from the control device104. The control unit110outputs an enable signal152according to the control instruction150. The sensor106receives the enable signal152and starts to detect the time-domain vibration signal130when the DUT is in operation. The first register108stores the time-domain vibration signal130, and sends the time-domain vibration signal130to the first transmission interface112, so that the time-domain vibration signal130is output to the control device104.

In some embodiments ofFIG.2, the control device104receives the time-domain vibration signal130, converts the time-domain vibration signal130into a frequency-domain vibration signal, performs signal processing on the frequency-domain vibration signal, and converts the frequency-domain vibration signal into a characteristic sound signal142. In some embodiments, the control device104directly performs signal processing on the time-domain vibration signal130, but the present invention is not limited thereto. In detail, the control device104includes a processing unit114, a second register116, a memory118, a user interface120, and a second transmission interface122. The second transmission interface122receives the time-domain vibration signal130from the vibration sensing device102. The second register116stores the time-domain vibration signal130from the second transmission interface122and outputs the time-domain vibration signal130. The memory118stores the time-domain vibration signal130from the second register116. In some embodiments ofFIG.2, the processing unit114reads the time-domain vibration signal130from the second register116. In other words, in some embodiments ofFIG.2, the control device104cannot operate in the offline mode. The time-domain vibration signal130output by the sensor106is stored in the second register116in real time for subsequent signal processing by the processing unit114.

In some embodiments ofFIG.2, the processing unit114converts the time-domain vibration signal130into the frequency-domain vibration signal, performs signal processing on the frequency-domain vibration signal, and converts the frequency-domain vibration signal into a characteristic sound signal142. In detail, the processing unit114performs Fourier transform on the time-domain vibration signal130to obtain a frequency-domain vibration signal. Optionally, the processing unit114amplifies the specific frequency range of the frequency-domain vibration signal to obtain the characteristic signal. In some embodiments, the specific frequency range may be, for example, the audio frequency range audible to the human ear, but the present invention is not limited thereto. Afterwards, optionally, the processing unit114converts the characteristic signal amplified in the specific frequency range from frequency-domain to time-domain (for example, through inverse Fourier transform). The processing unit114then uses a digital filter to filter the characteristic signal that has been converted from frequency-domain to time-domain, and finally converts the filtered characteristic signal into a characteristic sound signal142. In some embodiments, the processing unit114uses a digital filter to directly filter the time-domain vibration signal130, and converts the filtered characteristic signal into a characteristic sound signal142, without the step of amplifying the specific frequency range.

In some embodiments ofFIG.2, the processing unit114loads the sound signal140into a computer-playable audio file, and stores the computer-playable audio file in the memory118. The control device104outputs the computer-playable audio file to an external device or the cloud180through the second transmission interface122. In some embodiments, the user interface120generates a control instruction150according to the user's operation170.

FIG.3is a schematic diagram of disposing a vibration sensing device102inFIG.1andFIG.2in a device under test (DUT)300in accordance with some embodiments of the present invention. In some embodiments, the DUT300is a high-pressure reactor in the petrochemical industry, but the present invention is not limited thereto. As shown inFIG.3, the DUT300includes a motor302and a motor shaft304. When the DUT300is in operation, the motor302may start to rotate, and at the same time drive the rotation of the motor shaft304. In some embodiments, the vibration sensing device102ofFIG.1andFIG.2may be arranged on each bearing of the DUT300, such as the surfaces of the motor bearing306(positions A and B), the middle bearing (position C), and the bottom bearing (position D), but the present invention is not limited thereto. In some embodiments ofFIG.3, the motor bearing306at position A is located on the top of the motor302, and the vibration sensing device102-1can effectively detect the vibration signal generated when the motor302rotates. The motor bearing306at position B is located where the motor302is physically connected to the motor shaft304, and the vibration sensing device102-2can effectively detect the vibration signal generated when the motor302and the motor shaft304rotate. The intermediate bearing308at position

C is located in the middle of the motor shaft304, and the vibration sensing device102-3can effectively detect the vibration signal generated when the motor shaft304rotates. Similarly, the bottom bearing310at position D is located at the bottom of the motor shaft304, and the vibration sensing device102-4can effectively detect the vibration signal generated when the motor shaft304rotates.

In some embodiments ofFIG.3, the vibration sensing devices102-1,102-2,102-3, and102-4respectively convert the vibration signals sensed by positions A, B, C, and D into the time-domain vibration signal130, and respectively sends the time-domain vibration signal130to the control device104. The control device104receives the time-domain vibration signal130from the vibration sensing devices102-1,102-2,102-3, and102-4, and converts the time-domain vibration signal130into an audio signal140. In some embodiments, the vibration sensing devices102-1,102-2,102-3, and102-4can receive the control instruction150from the control device104to start to detect the vibration signal generated when the motor shaft304rotates. In some embodiments ofFIG.3, the control device104may directly convert the time-domain vibration signal130into the audio signal140, or amplify and/or filter and convert the time-domain vibration signal130through the above process to generate a characteristic audio signal142. The control device104further outputs the sound signal140or the characteristic sound signal142to a distributed control system312. In some embodiments, the distributed control system312may store the sound signal140or the characteristic audio signal142from the control device104into a historical database314in the form of a wav file. In some embodiments, the distributed control system312may play the sound signal140or the characteristic sound signal142for on-site experts to listen to and judge the state of the DUT300.

In some embodiments ofFIG.3, the distributed control system312sends the sound signal140or the characteristic sound signal142to an analysis and prediction system316. In some embodiments, the analysis and prediction system316performs a predictive maintenance module318to determine whether the sound signal140or the characteristic sound signal142is normal, and sends an analysis and prediction result320to the distributed control system312. In some embodiments, the predictive maintenance module318is an artificial intelligence module or a machine learning module, but the present invention is not limited thereto. In some embodiments, in the model training procedure, the predictive maintenance module318uses normal sound signals and abnormal sound signals as big data during its training. The normal sound signals and abnormal sound signals are judged and marked by on-site experts after listening. The trained predictive maintenance module318can therefore judge whether the currently received sound signal140or the characteristic sound signal142is normal according to the training data, and output the analysis and prediction result320accordingly. In other words, the predictive maintenance module318in the analysis and prediction system316can compare the waveform and/or frequency of the currently received sound signal140or characteristic sound signal142according to the judgment and marking data of the on-site experts. Finally, the predictive maintenance module318can automatically judge whether the sound signal140or the characteristic sound signal142is normal. In other words, in some embodiments, after the audio signal140or the characteristic audio signal142stored in the historical database314is listened to and the status of the DUT300is judged and marked by experts in the field, the normal sound signal and abnormal sound signal are distinguished, and then the predictive maintenance module318uses the marked sound signal as data to perform the model training procedure.

In some embodiments ofFIG.3, the sampling rate of the sensor106in the vibration sensing device102satisfies the following frequency range. First, the basic frequency is equal to (rpm/60)*N. N is a value not less than 5, and rpm is the rotation speed of the motor302. Second, a characteristic frequency of inner and outer rings of a motor shaft304. Third, the special frequency is equal to (rpm/60)*N*n. N is a value not less than 5, rpm is the rotational speed of the motor302, and n is the number of shaft blades of the motor302. In some embodiments, the sampling rate of the sensor106is6400sampling points per second, but the present invention is not limited thereto.

FIG.4is a flow chart of a signal processing method in accordance with some embodiments of the present invention. The signal processing method of the present invention inFIG.4is applicable to the electronic device100inFIG.1and the electronic device200inFIG.2. The signal processing method includes the following stages. A time-domain vibration signal is detected when a device under test (DUT) is in operation (step S400). The time-domain vibration signal is converted into a frequency-domain vibration signal (step S402). Signal processing is performed on the frequency-domain vibration signal to generate a characteristic signal (step S404). The characteristic signal is converted into a characteristic sound signal. The characteristic sound signal is loaded in a computer playable audio file (step S406). In some embodiments, step S400is performed by the sensor106inFIG.1andFIG.2. Step S402, step S404, and step S406are performed by the processing unit114inFIG.1andFIG.2.

FIG.5is a detail flow chart of a step S400inFIG.4in accordance with some embodiments of the present invention. As shown inFIG.5, step S400inFIG.4includes the following stages. A control instruction from the control device is received (step S500). An enable signal is output according to the control instruction (step S502). It is started to detect the time-domain vibration signal according to the enable signal when the DUT is in operation (step S504). The time-domain vibration signal is stored (step S506). The time-domain vibration signal is sent to the control device (step S508). In some embodiments, step S500is performed by the first transmission interface112inFIG.1andFIG.2. Step S502is performed by the control unit110inFIG.1andFIG.2. Step S504is performed by the sensor106inFIG.1andFIG.2. Step S506is performed by the first register108inFIG.1andFIG.2. Step S508is performed by the first transmission interface112inFIG.1andFIG.2.

FIG.6is a detail flow chart of a step S404inFIG.4in accordance with some embodiments of the present invention. As shown inFIG.6, step S404inFIG.4includes the following stages. The specific frequency range of the frequency-domain vibration signal is amplified (step S600). A digital filter is used to filter the characteristic signal after the characteristic signal is converted from frequency-domain to time-domain, and the characteristic signal is converted into the characteristic sound signal in time-domain (step S602). The characteristic sound signal, which are amplified and filtered in a specific frequency range and combined with a technology for converting the physical vibration signal into a sound signal as described above, may greatly improve the diagnostic accuracy of experts in the field for the problem of the DUT. In some embodiments, step S600and step S602are performed by the processing unit114inFIG.1andFIG.2. In some embodiments, the signal processing method of the present invention further includes the following stages. A user interface is used to generate the control instruction. A digital filter is used to filter to obtain the filtered characteristic signal. In some embodiments, the signal processing method of the present invention converts the characteristic signal into time-domain signal for subsequent conversion into a characteristic sound signal.

FIG.7is a flow chart of the processing method and a waveform diagram or a spectrum diagram thereof in accordance with some embodiments of the present invention. As shown inFIG.7, the signal processing method includes obtaining a vibration signal (step S700), converting into frequency-domain by frame (step S702), locally amplifying the frequency domain (step S704), converting back to time-domain (step S706), and filtering (step S708). In step S700, the signal processing method of the present invention obtains a time-domain waveform diagram710. In some embodiments, step S700may correspond to step S400inFIG.4. In step S702, the signal processing method of the present invention converts the time-domain waveform diagram710into a spectrum diagram712, and further processes the signal in a frequency band720. In some embodiments, step S702may correspond to step $402inFIG.4. In step S704, the signal processing method of the present invention amplifies the signal in the frequency band720to obtain a spectrum diagram714. In some embodiments, step S704may correspond to step S404inFIG.4and step S600inFIG.6. In step S706, the signal processing method of the present invention converts the spectrum diagram714into a time-domain waveform diagram716. In step S708, the signal processing method of the present invention filters the time-domain waveform diagram716to generate a time-domain waveform diagram718, and finally converts the time-domain waveform diagram718into the characteristic sound signal142. In some embodiments, steps S706and S708may correspond to step S602inFIG.6. In some embodiments, step S708may be performed between step S700and step S702, but the present invention is not limited thereto.

FIG.8is a flow chart of the processing method and a waveform diagram or a spectrum diagram thereof in accordance with some embodiments of the present invention. As shown inFIG.8, the signal processing method of the present invention includes obtaining a vibration signal (step S800) and filtering (step S802). In step S800, the signal processing method of the present invention obtains a time-domain waveform diagram810. In step S802, the signal processing method of the present invention filters the time-domain waveform diagram810to generate a time-domain waveform diagram812. In other words, in one embodiments of the present invention, the vibration signal is directly filtered and converted into the characteristic sound signal without frequency-domain conversion or local amplification during the process.

As shown inFIG.8, in some embodiments, the signal processing method of the present invention includes obtaining a vibration signal (step S800), converting into frequency-domain by frame (step S804), locally amplifying the frequency domain (step S806), and converting back to time-domain (step S808). In step S800, the signal processing method of the present invention obtains a time-domain waveform diagram810. In step S804, the signal processing method of the present invention coverts the time-domain waveform diagram810into a spectrum diagram814, and further processes the signal in a frequency band820. In some embodiments, step S804may correspond to step S402inFIG.4. In step S806, the signal processing method of the present invention amplifies the signal in the frequency band820to obtain a spectrum diagram816. In some embodiments, step S806may correspond to step S404inFIG.4and step S600inFIG.6. In step S808, the signal processing method of the present invention converts the spectrum diagram816into a time-domain waveform diagram818, and finally converts the time-domain waveform diagram818into the characteristic sound signal142. In other words, in one embodiments of the present invention, after the frequency-domain conversion (time-domain to frequency-domain) is performed on the vibration signal, the signal is locally amplified, and finally converted into the characteristic sound signal without filtering in the process.

The electronic device100inFIG.1, the electronic device200inFIG.2, and the signal processing method of the present invention have the following four advantages. First, the noise of the physical vibration signal is low. Traditionally, microphones are used to collect sound on the spot, which will be greatly interfered by on-site noise (such as wind cutting sound, human voice, car sound, etc.), which may lead to misjudgment by experts when listening. However, the present invention detects physical vibration signals instead of air vibration signals (that is, the sound waves), thereby reducing the noise interference of field noise. Second, the amount of transmitted data is less than that of voice signals. The vibration signals can obtain data at a lower sampling rate for key frequency acquisition, which has a lower sampling rate than the sound signals. Third, after the vibration signals are converted into the sound signals, the characteristic signals for identifying the status of the DUT still remain. Fourth, the present invention amplifies and filters local/specific frequency sounds to make characteristic sounds more obvious and easy to identify.