Elastic wave sensor self-checking method and device, computer storage medium and terminal

Abstract

According to the elastic wave sensor self-checking method and device, the computer storage medium and the terminal, when interference exists, signal features of original waveform signals output by an elastic wave sensor can change, and self-checking results within access within a certain time when the signal features change are all incredible, so that the self-checking accuracy of the elastic wave sensor is improved. The time interval in which the self-inspection result is not credible is determined; determining at least one acquisition moment of the converted wave signal corresponding to the original waveform signal, and when the determined acquisition moment is in the time interval when the self-inspection result is not credible, excluding the self-inspection result of the acquisition moment in the time interval when the self-inspection result is not credible based on the frequency of the self-inspection dependent on the converted wave signal; the frequency of the converted wave signal is prevented from influencing whether the elastic wave sensor is effective or not when interference exists, and the self-inspection quality of the elastic wave sensor is improved.

Description

Technical Field

[0001] This article relates to electronic circuit technology, and in particular to a method, device, computer storage medium and terminal for self-testing of an elastic wave sensor. Background Technology

[0002] Elastic wave sensors belong to the piezoelectric sensor category. They are intelligent modules that use elastic waves (such as sound waves or mechanical waves) to sense and convert physical signals such as external touch and pressure. The module is usually composed of multiple elastic wave sensors, flexible circuits, and integrated circuits. It can detect elastic wave signals on the touch panel and convert them into electrical signals to achieve high-precision touch and pressure monitoring functions.

[0003] In related technologies, the self-test of elastic wave sensors relies on acquiring the frequency of the square wave generated by the self-excited circuit of the elastic wave sensor. Currently, the self-test of elastic wave sensors only detects the frequency of the square wave generated after waveform conversion circuit. In practical applications, the frequency of the square wave generated by the elastic wave sensor may change due to external interference, such as shaking, knocking, or deformation. Even if the frequencies of multiple square waves are continuously acquired and processed by a certain algorithm, the frequency of the acquired square wave may no longer be equal to its factory calibration value due to continuous external interference. This can cause the voltage of the elastic wave sensor detected during the self-test to change, resulting in unreliable self-test results.

[0004] In summary, how to avoid the impact of external interference on the self-test of elastic wave sensors and improve the quality of the self-test has become a problem to be solved. Summary of the Invention

[0005] This application provides a method for self-testing an elastic wave sensor, including: Based on at least one signal characteristic of the original waveform signal output by the elastic wave sensor, determine the time interval in which the self-test result of the elastic wave sensor is unreliable; Determine at least one acquisition time of the converted wave signal corresponding to the original waveform signal, wherein the converted wave signal is a waveform conversion performed on the original waveform signal during self-testing of the elastic wave sensor to determine the self-test result; If the acquisition time is determined to be within the unreliable time interval, then the self-test results for that acquisition time are excluded.

[0006] On the other hand, embodiments of this application also provide a computer storage medium storing a computer program, which, when executed by a processor, implements the above-described method for self-testing of an elastic wave sensor.

[0007] Furthermore, embodiments of this application also provide a terminal, including: a memory and a processor, wherein the memory stores a computer program; wherein, The processor is configured to execute computer programs in memory; When the computer program is executed by the processor, it implements the self-testing method for the elastic wave sensor as described above.

[0008] Furthermore, embodiments of this application also provide a device for self-testing of an elastic wave sensor, comprising: a sampling circuit, a self-excited oscillation circuit, and a microcontroller unit (MCU); wherein, The sampling circuit is configured to acquire the raw waveform signal output by the elastic wave sensor; The self-excited oscillation circuit is configured to convert the original waveform signal into a converted waveform signal. The MCU is configured to: determine the time interval in which the self-test result of the elastic wave sensor is unreliable based on at least one signal characteristic of the original waveform signal; determine at least one acquisition time of the converted wave signal corresponding to the original waveform signal, wherein the converted wave signal is a waveform conversion performed on the original waveform signal during the self-test of the elastic wave sensor to determine the self-test result; if the acquisition time is determined to be within the unreliable time interval, then the self-test result at that acquisition time is excluded.

[0009] This embodiment of the disclosure is based on the fact that when interference is present, the signal characteristics of the original waveform signal output by the elastic wave sensor will change. By utilizing the fact that the self-test results within a certain time period of signal characteristic change are all unreliable, the time interval of the self-test results being unreliable is determined. At least one acquisition time of the converted wave signal corresponding to the original waveform signal is determined. When the determined acquisition time is within the time interval of the unreliable self-test results, since the self-test depends on the frequency of the converted wave signal, the self-test results acquired at the acquisition time within the time interval of the unreliable self-test results are excluded. This avoids the frequency of the converted wave signal under interference affecting the determination of whether the elastic wave sensor is effective, thus improving the quality of the elastic wave sensor self-test.

[0010] Other features and advantages of this application will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the application. Other advantages of this application can be realized and obtained by means of the solutions described in the description and the accompanying drawings. Attached Figure Description

[0011] The accompanying drawings are used to provide an understanding of the technical solutions of this application and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of this application and do not constitute a limitation on the technical solutions of this application.

[0012] Figure 1 This is a flowchart of a self-testing method for an elastic wave sensor according to an embodiment of this disclosure; Figure 2 This is a schematic diagram of the original waveform signal in an embodiment of this disclosure; Figure 3 This is a schematic diagram of a square wave according to an embodiment of the present disclosure; Figure 4 This is a schematic flowchart of the self-testing method for an elastic wave sensor according to an embodiment of this disclosure; Figure 5 This is a structural block diagram of the self-testing device for an elastic wave sensor according to an embodiment of this disclosure. Detailed Implementation

[0013] This application describes several embodiments, but these descriptions are exemplary and not restrictive, and it will be apparent to those skilled in the art that many more embodiments and implementations are possible within the scope of the embodiments described herein. Although many possible combinations of features are shown in the drawings and discussed in the detailed description, many other combinations of the disclosed features are also possible. Unless specifically limited, any feature or element of any embodiment may be used in combination with, or may replace, any feature or element of any other embodiment.

[0014] This application includes and contemplates combinations of features and elements known to those skilled in the art. The embodiments, features, and elements disclosed in this application can also be combined with any conventional features or elements to form unique inventive solutions. Any feature or element of any embodiment can also be combined with features or elements from other inventive solutions to form another unique inventive solution. Therefore, it should be understood that any feature shown and / or discussed in this application can be implemented individually or in any suitable combination. Therefore, the embodiments are not limited except by the limitations imposed by the appended claims and their equivalents. Furthermore, various modifications and changes can be made within the scope of the appended claims.

[0015] Furthermore, in describing representative embodiments, the specification may have presented methods and / or processes as a specific sequence of steps. However, the method or process should not be limited to the specific order of steps described herein, to the extent that it does not depend on such a specific order. As will be understood by those skilled in the art, other sequences of steps are also possible. Therefore, the specific order of steps set forth in the specification should not be construed as a limitation of the claims. Moreover, the claims concerning the method and / or process should not be limited to the steps performed in the written order, and those skilled in the art will readily understand that these orders can be varied and still remain within the spirit and scope of the embodiments of this application.

[0016] Figure 1 This is a flowchart of a self-testing method for an elastic wave sensor according to an embodiment of this disclosure, as follows: Figure 1 As shown, it includes: Step 101: Based on at least one signal characteristic of the original waveform signal output by the elastic wave sensor, determine the time interval in which the self-test result of the elastic wave sensor is unreliable. Step 102: Determine at least one acquisition time of the converted wave signal corresponding to the original waveform signal. The converted wave signal is the waveform conversion performed on the original waveform signal when the elastic wave sensor performs a self-test to determine the self-test result. Step 103: If it is determined that the collection time is within an unreliable time interval, then exclude the self-test results of that collection time.

[0017] This embodiment of the disclosure is based on the fact that when interference is present, the signal characteristics of the original waveform signal output by the elastic wave sensor will change. By utilizing the fact that the self-test results within a certain time period of signal characteristic change are all unreliable, the time interval of the self-test results being unreliable is determined. At least one acquisition time of the converted wave signal corresponding to the original waveform signal is determined. When the determined acquisition time is within the time interval of the unreliable self-test results, since the self-test depends on the frequency of the converted wave signal, the self-test results acquired at the acquisition time within the time interval of the unreliable self-test results are excluded. This avoids the frequency of the converted wave signal under interference affecting the determination of whether the elastic wave sensor is effective, thus improving the quality of the elastic wave sensor self-test.

[0018] In one exemplary embodiment, this disclosure determines the time interval in which the self-test result of the elastic wave sensor is unreliable based on at least one signal feature of the original waveform signal output by the elastic wave sensor, including: Based on the amplitude of the original waveform signal (also known as the original oscillation waveform) output by the elastic wave sensor, the time interval in which the self-test result of the elastic wave sensor is unreliable is determined.

[0019] In one exemplary embodiment, the converted wave signal of this disclosure is a square wave, and determining at least one acquisition time of the converted wave signal corresponding to the original waveform signal includes: The acquisition time for capturing the rising or falling edge of the square wave is determined each time. The square wave is obtained by converting the original waveform signal through a self-excited oscillation circuit.

[0020] The Input Capture (IC) method in this embodiment is a working mode of a microcontroller timer. It captures data at each rising / falling edge of a square wave, storing the current timer value (count) into a register. For example, if two captures store value2 and value1 respectively, assuming no overflow occurs, the signal period is: (value2 - value1) * timer count period (seconds / count); the frequency is the reciprocal of the signal period.

[0021] In one exemplary instance, embodiments of this disclosure may acquire raw waveform signals via an analog-to-digital converter (ADC). Figure 2 This is a schematic diagram of the original waveform signal in an embodiment of this disclosure, as shown below. Figure 2 As shown, when there is no interference, the original waveform signal in box 2-1 presents a stable and uniform sawtooth wave shape. When there is interference, the amplitude and frequency of the original waveform signal in box 2-2 change due to the interference.

[0022] Based on the original waveform signal, and referring to relevant techniques, a square wave corresponding to the original waveform signal can be generated by a self-excited circuit. Figure 2 The original waveform signal is used as an example. Figure 3 This is a schematic diagram of a square wave according to an embodiment of the present disclosure, as shown below. Figure 3 As shown in the figure, the square waves in boxes 3-1 and 3-2 correspond to the original waveform signal. When interference is present, the frequency of the square waves obtained by converting the original waveform signal changes, which can lead to unreliable self-test results from the elastic wave sensor.

[0023] In one exemplary embodiment, this disclosure determines the time interval in which the self-test result of the elastic wave sensor is unreliable based on the amplitude of the original waveform signal output by the elastic wave sensor, including: The amplitude of the original waveform signal output by the elastic wave sensor for each cycle is compared with the preset maximum amplitude threshold and minimum amplitude threshold respectively. When it is determined that the amplitude of the original waveform signal in the i-th cycle is greater than the maximum amplitude threshold or less than the minimum amplitude threshold, it is determined that there is interference in the original waveform signal in the i-th cycle. The time interval from the start time of the in-th cycle to the end time of the i+n-th cycle is determined as the time interval in which the self-test result is unreliable, where i is the sequence number of the output cycle of the original waveform signal and n is the preset time interval parameter.

[0024] In one exemplary instance, the maximum amplitude threshold and minimum amplitude threshold of this disclosure embodiment can be set by a technician based on the original waveform signals of several elastic wave sensors when they are not interfered with. For example, 100 elastic wave sensors with normal indicators are selected and placed on a test platform without interference according to relevant technologies for testing. The maximum and minimum amplitude values ​​of the original waveform signals output by these 100 elastic wave sensors are measured and obtained. The maximum value is used as the maximum amplitude threshold and the minimum value is used as the minimum amplitude threshold. This disclosure embodiment can set and adjust the maximum amplitude threshold and minimum amplitude threshold in other ways, and this disclosure embodiment does not limit this.

[0025] In one exemplary embodiment, n can take any value between 10 and 40. This embodiment assumes the period of the output original waveform signal is 0.25 milliseconds. When interference is determined in the original waveform signal of the i-th period based on the amplitude of the original waveform signal output by the elastic wave sensor, at least the 10 periods before and after the i-th period are defined as the time interval where the self-test result is unreliable. That is, 2.5 milliseconds before and after the i-th period constitute the time interval where the self-test result is unreliable. Furthermore, to ensure the detection time does not affect other functions, n can be larger, for example, n can be 40, meaning 10 milliseconds before and after the i-th period constitute the time interval where the self-test result is unreliable.

[0026] In one exemplary instance, when the acquisition time determined in this embodiment of the disclosure falls within a time interval where the self-test result is unreliable, the self-test result for that acquisition time is excluded, including: The frequency of the converted wave signal acquired during the time interval when the self-test result is unreliable is not used to perform the self-test of the elastic wave sensor.

[0027] In one exemplary instance, when the acquisition time determined in this embodiment of the disclosure falls within a time interval where the self-test result is unreliable, the self-test result for that acquisition time is excluded, including: The self-test result determined based on the frequency of the converted wave signal within the time interval where the self-test result is unreliable at the time of acquisition is judged as unreliable.

[0028] When the self-test result is determined to be unreliable in this embodiment of the present disclosure, the relevant technology can be used to remove that part of the data.

[0029] In one exemplary instance, after determining the time interval where the self-test result is unreliable, assuming the period of the original waveform signal is 0.25 milliseconds and n is 40, that is, 10 milliseconds before and 10 milliseconds after the i-th period is the time interval where the self-test result is unreliable; then, when the acquisition time is first determined to be within the time interval where the self-test result is unreliable, theoretically, from 20 milliseconds after that acquisition time, the self-test of the elastic wave sensor can be omitted (by removing the frequency of the square wave at the acquisition time from the data used to determine whether the elastic wave sensor is valid), or the self-test result of the elastic wave sensor can be set to unreliable.

[0030] Figure 4 This is a schematic flowchart of the self-testing method for the elastic wave sensor according to an embodiment of this disclosure, as shown below. Figure 4 As shown, it includes: Step 4010: The ADC acquires the original waveform signal output by the elastic wave sensor; Step 4011: Determine whether the amplitude of the original waveform signal in the i-th cycle is greater than the preset maximum amplitude threshold or less than the minimum amplitude threshold, where i is the sequence number of the output cycle of the currently acquired original waveform signal; if the amplitude of the original waveform signal in the i-th cycle is greater than the maximum amplitude threshold or less than the minimum amplitude threshold, proceed to step 4012; if the amplitude of the original waveform signal in the i-th cycle is less than or equal to the maximum amplitude threshold and greater than or equal to the minimum amplitude threshold, proceed to step 4010 to acquire the original waveform signal of the next cycle, i.e., the acquisition of the original waveform signal of the (i+1)-th cycle. Step 4012: Determine that there is interference in the original waveform signal of the i-th cycle, and determine the time interval from the start time of the in-th cycle to the end time of the i+n-th cycle as the time interval where the self-test result is unreliable. Step 4020: Determine the acquisition time for each input capture of the rising or falling edge of the square wave, wherein the square wave is obtained by converting the original waveform signal through a self-excited oscillation circuit; Step 4021: Check if the determined collection time is within the time interval where the self-test result is unreliable; if the determined collection time is within the time interval where the self-test result is unreliable, proceed to step 4022; if the determined collection time is outside the time interval where the self-test result is unreliable, proceed to step 4023. Step 4022: After the acquisition time, for 2n cycles, stop executing the process of determining the acquisition time for each rising or falling edge of the square wave for input capture; in this embodiment of the present disclosure, after 2n cycles, continue executing step 4020. Step 4023: Determine whether the elastic wave sensor is effective based on the frequency of the square wave, and complete the self-test.

[0031] This disclosure also provides a computer storage medium storing a computer program, which, when executed by a processor, implements the above-described method for self-testing of an elastic wave sensor.

[0032] This disclosure also provides a terminal, including: a memory and a processor, wherein the memory stores a computer program; wherein, The processor is configured to execute computer programs in memory; When a computer program is executed by a processor, it implements the self-testing method for elastic wave sensors as described above.

[0033] Figure 5 This is a structural block diagram of the self-testing device for the elastic wave sensor according to an embodiment of this disclosure, as shown below. Figure 5 As shown, it includes: a sampling circuit, a self-oscillating circuit, and a microcontroller unit (MCU); wherein, The sampling circuit is configured to acquire the raw waveform signal output by the elastic wave sensor; The self-excited oscillation circuit is configured to convert the original waveform signal into a converted waveform signal. The MCU is configured to: determine the time interval in which the self-test result of the elastic wave sensor is unreliable based on at least one signal characteristic of the original waveform signal; determine at least one acquisition time of the converted wave signal corresponding to the original waveform signal, wherein the converted wave signal is the waveform conversion performed on the original waveform signal when the elastic wave sensor performs a self-test to determine the self-test result; if the acquisition time is determined to be within the unreliable time interval, then exclude the self-test result at that acquisition time.

[0034] This embodiment of the disclosure is based on the fact that when interference is present, the signal characteristics of the original waveform signal output by the elastic wave sensor will change. By utilizing the fact that the self-test results within a certain time period of signal characteristic change are all unreliable, the time interval of the self-test results being unreliable is determined. At least one acquisition time of the converted wave signal corresponding to the original waveform signal is determined. When the determined acquisition time is within the time interval of the unreliable self-test results, since the self-test depends on the frequency of the converted wave signal, the self-test results acquired at the acquisition time within the time interval of the unreliable self-test results are excluded. This avoids the frequency of the converted wave signal under interference affecting the determination of whether the elastic wave sensor is effective, thus improving the quality of the elastic wave sensor self-test.

[0035] In one exemplary instance, the MCU of this disclosure embodiment is configured to determine the time interval in which the self-test result of the elastic wave sensor is unreliable based on at least one signal feature of the original waveform signal, including: Based on the amplitude of the original waveform signal output by the elastic wave sensor, the time interval in which the self-test result of the elastic wave sensor is unreliable is determined.

[0036] In one exemplary instance, the converted wave signal in this embodiment of the disclosure is a square wave, and the MCU is configured to determine at least one acquisition time of the converted wave signal corresponding to the original waveform signal, including: The acquisition time for capturing the rising or falling edge of the square wave is determined each time. The square wave is obtained by converting the original waveform signal through a self-excited oscillation circuit.

[0037] In one exemplary instance, the converted wave signal in this embodiment of the disclosure is a square wave, and the MCU is configured to determine the time interval in which the self-test result of the elastic wave sensor is unreliable based on the amplitude of the original waveform signal output by the elastic wave sensor: The amplitude of the original waveform signal output by the elastic wave sensor for each cycle is compared with the preset maximum amplitude threshold and minimum amplitude threshold respectively. When it is determined that the amplitude of the original waveform signal in the i-th cycle is greater than the maximum amplitude threshold or less than the minimum amplitude threshold, it is determined that there is interference in the original waveform signal in the i-th cycle. The time interval from the start time of the in-th cycle to the end time of the i+n-th cycle is determined as the time interval in which the self-test result is unreliable, where i is the sequence number of the output cycle of the original waveform signal and n is the preset time interval parameter.

[0038] In one exemplary instance, the value of n in this disclosure includes any value between 10 and 40.

[0039] In one exemplary instance, the MCU of this disclosure embodiment is configured to exclude the self-test result of the acquisition time if it is determined that the acquisition time is within an unreliable time interval, including: Set the frequency of the converted wave signal acquired during the time interval when the self-test result is unreliable, so that it is not used to perform the self-test of the elastic wave sensor; or, The self-test result determined based on the frequency of the converted wave signal within the time interval where the self-test result is unreliable at the time of acquisition is judged as unreliable.

[0040] It will be understood by those skilled in the art that all or some of the steps, systems, or apparatuses disclosed above, and their functional modules / units, can be implemented as software, firmware, hardware, or suitable combinations thereof. In hardware implementations, the division between functional modules / units mentioned above does not necessarily correspond to the division of physical components; for example, a physical component may have multiple functions, or a function or step may be performed collaboratively by several physical components. Some or all components may be implemented as software executed by a processor, such as a digital signal processor or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit (ASIC). Such software may be distributed on a computer-readable medium, which may include computer storage media (or non-transitory media) and communication media (or transient media). As is known to those skilled in the art, the term "computer storage medium" includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disc (DVD) or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and can be accessed by a computer. Furthermore, it is well known to those skilled in the art that communication media typically contain computer-readable instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium.

Claims

1. A method of elastic wave sensor self-test, comprising: The method comprises: determining a time interval in which the self-checking result of the elastic wave sensor is not reliable according to at least one signal feature of a raw waveform signal output by the elastic wave sensor; determining at least one acquisition time of a converted wave signal corresponding to the raw waveform signal, the converted wave signal being a waveform conversion of the raw waveform signal for judging the self-checking result when the elastic wave sensor is self-checked; if it is determined that the acquisition time is in the time interval in which the self-checking result is not reliable, excluding the self-checking result of the acquisition time.

2. The method of claim 1, wherein, The method of determining the time interval in which the self-checking result of the elastic wave sensor is not reliable according to at least one signal feature of a raw waveform signal output by the elastic wave sensor comprises: determining the time interval in which the self-checking result of the elastic wave sensor is not reliable according to the amplitude of the raw waveform signal output by the elastic wave sensor.

3. The method of claim 1, wherein, The converted wave signal is a square wave, and the method of determining the at least one acquisition time of the converted wave signal corresponding to the raw waveform signal comprises: determining the acquisition time at which the rising edge or the falling edge of each square wave is input captured, wherein the square wave is obtained by converting the raw waveform signal through a self-oscillation circuit.

4. The method of claim 2, wherein, The method of determining the time interval in which the self-checking result of the elastic wave sensor is not reliable according to the amplitude of the raw waveform signal output by the elastic wave sensor comprises: comparing the amplitude of the raw waveform signal output by the elastic wave sensor in each period with a preset maximum amplitude threshold and a preset minimum amplitude threshold, respectively; when it is determined that the amplitude of the raw waveform signal in the ith period is greater than the maximum amplitude threshold or less than the minimum amplitude threshold, determining that the raw waveform signal in the ith period is interfered, and determining the time interval from the start time of the ith-nth period to the end time of the ith+nth period as the time interval in which the self-checking result is not reliable, wherein i is the serial number of the output period of the raw waveform signal, and n is a preset time interval parameter.

5. The method of claim 4, wherein, The value of n includes any value between 10 and 40.

6. The method according to any one of claims 1 to 5, characterized in that, When it is determined that the acquisition time is in the time interval in which the self-checking result is not reliable, the method of excluding the self-checking result of the acquisition time comprises at least one of the following: setting the frequency of the converted wave signal of the acquisition time in the time interval in which the self-checking result is not reliable, so as not to be used for performing the self-checking of the elastic wave sensor; when it is determined that the acquisition time is in the time interval in which the self-checking result is not reliable, determining the self-checking result determined based on the frequency of the converted wave signal of the acquisition time in the time interval in which the self-checking result is not reliable as not reliable.

7. A computer storage medium, the computer storage medium storing a computer program, the computer program being executed by a processor to implement the method of self-checking of the elastic wave sensor according to any one of claims 1 to 6.

8. A terminal comprising: A memory and a processor, the memory storing a computer program; wherein the processor is configured to execute the computer program in the memory; the computer program is executed by the processor to implement the method of self-checking of the elastic wave sensor according to any one of claims 1 to 5.

9. An apparatus for elastic wave sensor self-test, comprising: The method comprises: The sampling circuit, the self-oscillation circuit and a micro control unit (MCU); wherein The sampling circuit is configured to collect a raw waveform signal output by the elastic wave sensor; The self-oscillation circuit is configured to convert the raw waveform signal into a converted waveform signal; The MCU is configured to determine a time interval in which the self-checking result of the elastic wave sensor is not credible according to at least one signal feature of the raw waveform signal, determine at least one collection time of the converted waveform signal corresponding to the raw waveform signal, the converted waveform signal being a waveform conversion of the raw waveform signal for judging the self-checking result when the elastic wave sensor is self-checked, and exclude the self-checking result of the collection time if it is determined that the collection time is within the time interval in which the self-checking result is not credible.

10. The apparatus of claim 9, wherein, The MCU is configured to determine a time interval in which the self-checking result of the elastic wave sensor is not credible according to at least one signal feature of the raw waveform signal, comprising: determining the time interval in which the self-checking result of the elastic wave sensor is not credible according to the amplitude of the raw waveform signal output by the elastic wave sensor.

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