Acceleration sensor, air purification device and filter screen detection method of air purification device

Abstract

The invention discloses an acceleration sensor, an air purification device and a filter screen detection method thereof, and the acceleration sensor comprises an acceleration induction sheet which is used for generating a charge signal under the action of acceleration; the charge conversion circuit is connected with the acceleration induction sheet and is used for converting the charge signal into a voltage signal; and the voltage amplification circuit is connected with the charge conversion circuit and is used for amplifying the voltage signal and then outputting the amplified voltage signal to a signal processing unit for processing so as to calculate the acceleration. The acceleration sensor provided by the invention is higher in acceleration detection precision in a low-frequency application scene.

Description

Technical Field

[0001] The present invention relates to the technical field of acceleration sensors, and in particular to an acceleration sensor, an air purification device and a filter detection method thereof. Background Art

[0002] An accelerometer is a sensor device that measures the linear or angular acceleration of an object. It is widely used in aerospace, automotive, consumer electronics, and other fields. Because low-frequency signals have good anti-interference capabilities and minimal energy loss during transmission, an increasing number of accelerometers are being developed for low frequencies. However, due to the weak signals in the low-frequency range, existing accelerometers typically require the use of separate charge amplifiers, resulting in limited use cases and low detection accuracy, making it difficult to accurately detect acceleration in low-frequency applications. Summary of the Invention

[0003] The embodiments of the present invention provide an acceleration sensor, an air purification device, and a filter detection method thereof, which solve the problem of low detection accuracy of the acceleration sensor in low-frequency application scenarios.

[0004] In a first aspect, an embodiment of the present invention provides an acceleration sensor, comprising: Acceleration sensor, used to generate charge signal under the action of acceleration; a charge conversion circuit, connected to the acceleration sensor, for converting the charge signal into a voltage signal; The voltage amplifying circuit is connected to the charge conversion circuit and is used to amplify the voltage signal and output it to the signal processing unit for processing to calculate the acceleration.

[0005] In the acceleration sensor provided in an embodiment of the present invention, the voltage amplification circuit includes a primary voltage amplification module and a secondary voltage amplification module. The primary voltage amplification module is connected to the output end of the charge conversion circuit and is used to amplify the voltage signal output by the charge conversion circuit. The secondary voltage amplification module is connected to the output end of the primary voltage amplification module and is used to amplify the voltage signal amplified by the primary voltage amplification module again and output it to the signal processing unit for processing to calculate acceleration.

[0006] In the acceleration sensor provided in an embodiment of the present invention, the first-level voltage amplification module includes a first operational amplifier, a first resistor and a second resistor, the non-phase input terminal of the first operational amplifier is connected to the charge conversion circuit through the first resistor, the inverting input terminal of the first operational amplifier is grounded through the second resistor, and the output terminal of the first operational amplifier is connected to the input terminal of the second-level voltage amplification module.

[0007] In the acceleration sensor provided by the embodiment of the present invention, the first-stage voltage amplification module further includes a first capacitor, one end of the first capacitor is connected to the non-inverting input terminal of the first operational amplifier, and the other end is grounded.

[0008] In the acceleration sensor provided in an embodiment of the present invention, the secondary voltage amplification module includes a second operational amplifier, a third resistor and a fourth resistor, the non-inverting input terminal of the second operational amplifier is connected to the primary voltage amplification module through the third resistor, the inverting input terminal of the second operational amplifier is grounded through the fourth resistor, and the output terminal of the second operational amplifier is connected to the signal processing unit.

[0009] In the acceleration sensor provided by the embodiment of the present invention, the voltage amplification circuit further includes a second capacitor, one end of the second capacitor is connected to the non-inverting input terminal of the second operational amplifier, and the other end is grounded.

[0010] In the acceleration sensor provided by an embodiment of the present invention, the charge conversion circuit includes a third operational amplifier and a fifth resistor, the non-inverting input terminal of the third operational amplifier is connected to the acceleration sensing piece through the fifth resistor, the inverting input terminal of the third operational amplifier is grounded, and the output terminal of the third operational amplifier is connected to the voltage amplification circuit.

[0011] In a second aspect, an embodiment of the present invention provides an air purification device, which includes: a filter, a signal processing unit and the acceleration sensor described in the first aspect above, the acceleration sensor is arranged on the air outlet side of the filter, and the signal processing unit is connected to the acceleration sensor.

[0012] In the third aspect, an embodiment of the present invention also provides a filter detection method for an air purifier, which is applied to the air purification device described in the second aspect above, and the method includes: obtaining a voltage signal output by an acceleration sensor; obtaining a filter detection result based on the frequency and amplitude of the voltage signal output by the acceleration sensor; and outputting an alarm signal when the filter detection result shows that the filter is abnormal.

[0013] An embodiment of the present invention provides an acceleration sensor, an air purification device, and a filter detection method thereof, wherein the acceleration sensor includes: an acceleration sensing piece for generating a charge signal under the action of acceleration; a charge conversion circuit connected to the acceleration sensing piece for converting the charge signal into a voltage signal; and a voltage amplification circuit connected to the charge conversion circuit for amplifying the voltage signal and outputting it to a signal processing unit for processing to calculate acceleration. The acceleration sensor of the present application converts the charge signal generated by the acceleration sensing piece into a voltage signal through the charge conversion circuit, and then amplifies and outputs the voltage signal through the voltage amplification circuit, so that the signal processing unit can more accurately obtain the voltage signal for processing, thereby accurately calculating the acceleration. In low-frequency application scenarios, the acceleration detection accuracy is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0015] Figure 1 A structural block diagram of an acceleration sensor provided by an embodiment of the present invention; Figure 2 An exploded diagram of an acceleration sensor provided by an embodiment of the present invention; Figure 3 Another structural block diagram of an acceleration sensor provided by an embodiment of the present invention; Figure 4 A circuit diagram of an acceleration sensor provided by an embodiment of the present invention; Figure 5 A simplified structural diagram of an air purification device provided in an embodiment of the present invention; Figure 6 A schematic flow chart of the steps of the method provided in an embodiment of the present invention; Figure 7 A schematic flow chart of the sub-steps of the method provided in an embodiment of the present invention.

[0016] The reference numerals in the figures are: 10. Acceleration sensor; 1. Housing; 2. Circuit board; 11. Acceleration sensor; 12. Charge conversion circuit; 13. Voltage amplification circuit; 131. Primary voltage amplification module; 132. Secondary voltage amplification module; 20. Air purification device; 21. Filter; 22. Signal processing unit. DETAILED DESCRIPTION

[0017] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0018] It will be understood that when used in this specification and the appended claims, the terms “comprises” and “comprising” indicate the presence of described features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0019] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the present invention. As used in the specification and appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0020] It should be further understood that the term "and / or" used in the present description and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0021] As used in this specification and the appended claims, the term "if" can be interpreted as "when" or "upon" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrase "if it is determined" or "if [described condition or event] is detected" can be interpreted as meaning "upon determination" or "in response to determining" or "upon detection of [described condition or event]" or "in response to detecting [described condition or event]," depending on the context.

[0022] Reference Figures 1 to 4 , see Figure 1 , which shows an embodiment of the acceleration sensor 10 provided by the present invention, the structure and working principle of the acceleration sensor 10 are described in detail below in conjunction with the accompanying drawings. Figure 1 As shown, the acceleration sensor 10 includes: an acceleration sensing piece 11, which is used to generate a charge signal under the action of acceleration; a charge conversion circuit 12, connected to the acceleration sensing piece 11, which is used to convert the charge signal into a voltage signal; a voltage amplification circuit 13, connected to the charge conversion circuit 12, which is used to amplify the voltage signal and output it to the signal processing unit 22 for processing to calculate the acceleration.

[0023] In a specific implementation, the acceleration sensor 10 mainly includes an acceleration sensor 11, a charge conversion circuit 12, and a voltage amplifier circuit 13. In addition, the acceleration sensor 10 also includes a housing 1, a circuit board 2, a mass block, and other components. The charge conversion circuit 12 and the voltage amplifier circuit 13 are integrated on the circuit board 2. The acceleration sensor 11 is the core structure of the acceleration sensor 10. The acceleration sensor 11 is a three-layer structure, in which the upper and lower materials are piezoelectric ceramics and the middle layer is a metal base. The acceleration sensor 11 can generate a charge signal under the action of acceleration. The essence of its charge signal generation is the piezoelectric effect. Specifically, in an acceleration scenario, the acceleration sensor 11 is subjected to acceleration, which is manifested as the mass block exerting a mechanical external force on the acceleration sensor 11 due to inertia, causing the piezoelectric ceramic to deform and generate a charge signal through the piezoelectric effect of the piezoelectric ceramic. The input end of the charge conversion circuit 12 is connected to the acceleration sensing piece 11 and is used to convert the charge signal generated by the acceleration sensing piece 11 into a voltage signal. Specifically, the charge signal generated by the acceleration sensing piece 11 is a very weak electrical signal. The charge conversion circuit 12 converts the weak signal into an electrical signal with a certain voltage and outputs it. The input end of the voltage amplifier circuit 13 is connected to the output end of the charge conversion circuit 12 and is used to amplify the voltage signal and output it to the signal processing unit 22 for processing to calculate the acceleration. Specifically, the voltage amplifier circuit 13 amplifies the voltage signal output by the charge conversion circuit 12 and outputs it to obtain a voltage signal with a larger voltage value. The amplified voltage signal is output to the signal processing unit 22 for signal processing. The signal processing unit 22 is set in conjunction with the acceleration sensor 10 in actual application scenarios. For example, when the acceleration sensor 10 is used in a certain device, the signal processing unit 22 can be an MCU chip or other chip that can perform signal processing inside the device. The applications of the acceleration sensor 10 can be divided into low-frequency scenarios and high-frequency application scenarios. The high-frequency application scenario is mainly for measuring high-frequency vibrations or dynamic signals, such as automobile safety monitoring, aviation safety and other scenarios. The low-frequency application scenario is mainly for measuring low-frequency vibrations or dynamic signals, such as bridge building vibration monitoring, mechanical equipment vibration monitoring, earthquake monitoring, etc. In actual low-frequency application scenarios, the acceleration effect is weak, and the charge signal generated by the acceleration sensing piece 11 through the piezoelectric effect is weak, and the weak charge signal is converted into a voltage signal by the charge conversion circuit 12. The voltage signal is amplified by the voltage amplifier circuit 13 and the amplitude becomes larger. The specific amplification factor can be determined according to the actual circuit structure design. The amplified voltage signal is output to the signal processing unit 22 for processing. The signal processing unit 22 can more accurately capture the signal changes output by the acceleration sensor 10 in the low-frequency application scenario, thereby more accurately calculating the acceleration.

[0024] In one embodiment, referring to Figure 3The voltage amplification circuit 13 includes a primary voltage amplification module 131 and a secondary voltage amplification module 132. The primary voltage amplification module 131 is connected to the output of the charge conversion circuit 12 and is used to amplify the voltage signal output by the charge conversion circuit 12. The secondary voltage amplification module 132 is connected to the output of the primary voltage amplification module 131 and is used to further amplify the voltage signal amplified by the primary voltage amplification module 131 and output it to the signal processing unit 22 for processing to calculate acceleration. In a specific implementation, the voltage amplification circuit 13 is mainly composed of the primary voltage amplification module 131 and the secondary voltage amplification module 132. Both the primary voltage amplification module 131 and the secondary voltage amplification module 132 are circuit modules with signal amplification functions. The input of the primary voltage amplification module 131 is connected to the output of the charge conversion circuit 12, and the input of the secondary voltage amplification module 132 is connected to the output of the primary voltage amplification module 131. The output of the secondary voltage amplification module 132 is connected to the signal processing unit 22. In actual applications, the first-level voltage amplification module 131 is used to amplify the voltage signal output by the charge conversion circuit 12, so that the amplitude of the voltage signal increases. The second-level voltage amplification module 132 is used to amplify the voltage signal amplified by the first-level voltage amplification module 131 for a second time, so that the amplitude of the voltage signal increases again. The second-level voltage amplification module 132 outputs the amplified voltage signal to the signal processing unit 22 through the output end. Since the voltage signal output by the charge conversion circuit 12 has undergone two-stage amplification, the signal obtained by the signal processing unit 22 is more accurate, and the acceleration can be calculated more accurately.

[0025] Further, refer to Figure 4The primary voltage amplification module 131 includes a first operational amplifier U1, a first resistor R1, and a second resistor R2. The non-inverting input of the first operational amplifier U1 is connected to the charge conversion circuit 12 via the first resistor R1, the inverting input of the first operational amplifier U1 is grounded via the second resistor R2, and the output of the first operational amplifier U1 is connected to the input of the secondary voltage amplification module 132. In a specific implementation, the primary voltage amplification module 131 mainly comprises the first operational amplifier U1, the first resistor R1, and the second resistor R2. The non-inverting input of the first operational amplifier U1 is connected to the output of the charge conversion circuit 12 via the first resistor R1, the inverting input of the first operational amplifier U1 is connected to ground via the second resistor R2, and the output of the first operational amplifier U1 is connected to the secondary voltage amplification module 132. In actual applications, the charge signal generated by the acceleration sensor 11 is converted into a voltage signal via the charge conversion circuit 12. The voltage signal is then input to the non-inverting input of the first operational amplifier U1 via the first resistor R1. The inverting input of the first operational amplifier U1 is grounded via the second resistor R2, providing a stable reference voltage. The first resistor R1 is used to match the impedance between the first operational amplifier U1 and the input signal source, thereby improving signal transmission efficiency. Theoretically, the higher the input impedance, the less interference the signal source will experience with external noise. The voltage signal output by the charge conversion circuit 12 is amplified by the first operational amplifier U1, increasing its amplitude and enhancing the voltage signal. The amplified voltage signal is then amplified by the secondary voltage amplification module 132 and then output to the signal processing unit 22, allowing the signal processing unit 22 to accurately calculate acceleration.

[0026] Furthermore, refer to Figure 4 The first-level voltage amplification module 131 also includes a first capacitor C1, one end of which is connected to the non-inverting input terminal of the first operational amplifier U1, and the other end is grounded. In a specific implementation, the first-level voltage amplification module 131 is further composed of a first capacitor C1, one end of which is connected to the non-inverting input terminal of the first operational amplifier U1, and the other end of which is connected to ground. In actual applications, when the voltage signal output by the charge conversion circuit 12 passes through the first capacitor C1, noise reduction is achieved by the first capacitor C1, making the signal input to the first operational amplifier U1 more stable, and ultimately the signal processing unit 22 calculates the acceleration more accurately.

[0027] In one embodiment, referring to Figure 4The secondary voltage amplification module 132 includes a second operational amplifier U2, a third resistor R3, and a fourth resistor R4. The non-inverting input of the second operational amplifier U2 is connected to the primary voltage amplification module 131 through the third resistor R3, the inverting input of the second operational amplifier U2 is grounded through the fourth resistor R4, and the output of the second operational amplifier U2 is connected to the signal processing unit 22. In a specific implementation, the secondary voltage amplification module 132 is mainly composed of the second operational amplifier U2, the third resistor R3, and the fourth resistor R4. The non-inverting input of the second operational amplifier U2 is connected to the output of the primary voltage amplification module 131 through the third resistor R3, the inverting input of the first operational amplifier U1 is connected to ground through the fourth resistor R4, and the output of the second operational amplifier U2 is used to connect to the signal processing unit 22. In actual applications, the voltage signal output by the primary voltage amplification module 131 is input to the non-inverting input of the second operational amplifier U2 via the third resistor R3. The inverting input of the second operational amplifier U2 is grounded via the fourth resistor R4, providing a stable reference voltage. The third resistor R3 is used to match the impedance between the first operational amplifier U1 and the input signal source, thereby improving signal transmission efficiency. In theory, the higher the input impedance, the less interference the signal source will have with external noise. The voltage signal output by the primary voltage amplification module 131 is further amplified by the second operational amplifier U2, further enhancing the voltage signal. After a second amplification, the voltage signal is output to the signal processing unit 22 via the output of the second operational amplifier U2, allowing the signal processing unit 22 to accurately calculate the acceleration.

[0028] Further, refer to Figure 4 , the voltage amplifier circuit 13 also includes a second capacitor C2, one end of which is connected to the non-inverting input terminal of the second operational amplifier U2, and the other end is grounded. In a specific implementation, the voltage amplifier circuit 13 is also composed of a second capacitor C2, one end of which is connected to the non-inverting input terminal of the first operational amplifier, and the other end of the second capacitor C2 is connected to the ground. In actual application, when the voltage signal output from the output end of the charge conversion unit passes through the second capacitor C2, noise reduction is achieved by the second capacitor C2, making the input signal of the first operational amplifier U1 more stable, and the voltage signal output from the output end of the first operational amplifier U1 to the signal processing unit 22 more stable, so that the signal processing unit 22 calculates the acceleration more accurately.

[0029] In one embodiment, referring to Figure 4The charge conversion circuit 12 includes a third operational amplifier U3, a fifth resistor R5, and a third capacitor C3. The non-inverting input of the third operational amplifier U3 is connected to the acceleration sensing plate 11 via the fifth resistor R5. One end of the third capacitor C3 is connected to the non-inverting input of the third operational amplifier U3 and the other end is grounded. The inverting input of the third operational amplifier U3 is grounded, and the output of the third operational amplifier U3 is connected to the voltage amplifier circuit 13. Specifically, the charge conversion circuit 12 primarily comprises the third operational amplifier U3, the fifth resistor R5, and the third capacitor C3. The non-inverting input of the third operational amplifier U3 is connected to the acceleration sensing plate 11 via the fifth resistor R5, receiving the charge signal V0 generated by the acceleration sensing plate 11. One end of the third capacitor C3 is connected to the non-inverting input of the first integrated operational amplifier and is also connected to one end of the fifth resistor R5. The other end of the third capacitor C3 is connected to ground. The inverting input of the third operational amplifier U3 is connected to ground, and the output of the third operational amplifier U3 is connected to the input of the voltage amplifier circuit 13. In actual applications, the acceleration sensor 11 generates a weak charge signal, which is filtered and noise-reduced by the third capacitor C3 after passing through the fifth resistor R5 and input to the non-inverting input terminal of the third operational amplifier U3. The signal is amplified by the third operational amplifier U3, and a voltage signal of a certain frequency and amplitude is formed at the output terminal of the third operational amplifier U3, thereby converting the charge signal into a voltage signal. The voltage signal is then amplified by the voltage amplifier circuit 13 to obtain a voltage signal with a larger amplitude, which is output to the signal processing unit 22, so that the signal processing unit 22 can accurately calculate the acceleration.

[0030] The acceleration sensor provided in the embodiment of the present application converts the charge signal generated by the acceleration sensing plate into a voltage signal through a charge conversion circuit, and then amplifies and outputs the voltage signal through a voltage amplification circuit, so that the signal processing unit can more accurately obtain the voltage signal for processing, thereby accurately calculating the acceleration. In low-frequency application scenarios, the acceleration detection accuracy is higher.

[0031] like Figure 5As shown, an embodiment of the present invention provides another air purification device 20, which includes a filter 21, a signal processing unit 22 and the acceleration sensor 10 described in the above embodiment. In addition, it also includes components such as a fan. The acceleration sensor 10 is arranged on the air outlet side of the filter 21, and the signal processing unit 22 is connected to the acceleration sensor 10. The air purification device 20 can remove pollutants in the air by filtering, adsorption, and ionization. The filter 21 is mainly arranged at the air inlet of the air purification device 20 to capture and remove pollutants, particulate matter and harmful gases in the air. The signal processing unit 22 is an MCU or other control chip inside the air purification device 20. The acceleration sensor 10 is arranged inside the air inlet of the air purification device 20, on the air outlet side of the filter 21, and on the same axis as the filter 21. It is used to cooperate with the signal processing unit 22 of the device to detect whether the filter 21 is blocked or damaged or other abnormal conditions. Specifically, when the air purifier 20 is operating normally, the fan draws air into the air inlet. If there is no abnormality in the filter 21, a normal amount of air can be blown directly from the air inlet through the filter 21 to the acceleration sensor 10, and the voltage signal of the acceleration sensor 10 is normal. However, when an abnormality occurs in the filter 21, such as when the filter 21 is blocked or damaged, most of the air cannot pass through the filter 21 to blow toward the acceleration sensor 10. The acceleration sensing piece 11 is less affected by the acceleration, and the voltage signal output by the acceleration sensor 10 is weak. If the filter 21 is damaged, the blocking effect of the filter 21 is weakened, and a large amount of air is blown directly toward the acceleration sensor 10. The acceleration sensing piece 11 is more strongly affected by the acceleration, and the voltage signal output by the acceleration sensor 10 is stronger. Therefore, the signal processing unit 22 of the air purifier 20 can determine whether there is an abnormality in the filter 21 based on the voltage signal output by the acceleration sensor 10, thereby prompting the user.

[0032] The air purification device of this embodiment uses the acceleration sensor provided in the above embodiment to be set in conjunction with the filter. The voltage signal output by the acceleration sensor is processed by the signal processing unit, which can accurately detect abnormal conditions of the filter and improve the user experience.

[0033] like Figure 6 As shown, an embodiment of the present application also provides a filter detection method for an air purification device, which is mainly used in the air purification device described in the above embodiment, and is mainly used to detect whether the filter of the air purification device is blocked. The method includes steps: S110-S130.

[0034] S110: Acquire a voltage signal output by the acceleration sensor.

[0035] In specific implementation, the acceleration sensor is arranged on the air outlet side of the filter of the air purification device and is on the same axis as the filter. When the air purification device is operating normally, the air inlet draws in air and the air blows towards the acceleration sensor, so that the voltage signal output by the acceleration sensor is transmitted to the signal processing unit of the air purification device. The system determines whether there is an abnormality in the filter by processing and analyzing the voltage signal.

[0036] S120 , obtaining a filter detection result according to the frequency and amplitude of the voltage signal output by the acceleration sensor.

[0037] In a specific implementation, the signal processing unit of the air purification device processes the voltage signal to obtain two parameters: the frequency and amplitude of the voltage signal output by the acceleration sensor. The system then uses the frequency and amplitude of the voltage signal to determine the filter detection result. Specifically, the filter detection result can include two results: abnormal filter and normal filter. An abnormal filter indicates that the filter is clogged or damaged. When the filter is normal, a normal amount of air passes through the filter and blows toward the acceleration sensor. The airflow acts on the sensor's mass, which generates mechanical vibrations of a certain frequency that act on the acceleration sensing plate, causing the acceleration sensor to output a voltage signal within a normal frequency and amplitude range. However, when the filter is abnormal, such as when the filter is clogged or damaged, most of the air cannot pass through the filter and blow toward the acceleration sensor, resulting in a smaller voltage signal amplitude. When the filter is damaged, the filter's blocking effect is weakened, allowing a large amount of air to blow directly toward the acceleration sensor, resulting in a larger voltage signal amplitude. Therefore, the system can determine whether the filter is abnormal based on the frequency and amplitude of the voltage signal output by the acceleration sensor.

[0038] In one embodiment, if Figure 7 As shown, the step S120 includes steps: S121-S127.

[0039] S121 . Compare the frequency of the voltage signal output by the acceleration sensor with a preset frequency range.

[0040] In a specific implementation, the system compares the frequency of the output voltage of the sensor with a preset frequency range, which is a frequency value range set by the system as one of the conditions for determining whether an abnormality occurs in the filter.

[0041] S122: Determine whether the frequency of the voltage signal output by the acceleration sensor is within the preset frequency range.

[0042] In a specific implementation, the system compares the frequency of the output voltage of the sensor with a preset frequency range to determine whether the frequency of the output voltage of the sensor is within the preset frequency range, thereby determining whether the frequency of the output voltage of the sensor is normal.

[0043] S123: If the frequency of the voltage signal output by the acceleration sensor is within the preset frequency range, return to step S121 of comparing the frequency of the voltage signal output by the acceleration sensor with the preset frequency range.

[0044] In a specific implementation, when the air purification device system determines that the frequency of the acceleration sensor's output voltage is within the preset frequency range, the frequency of the voltage signal output by the acceleration sensor is normal and the filter is operating normally. Therefore, the system returns to the step of comparing the frequency of the acceleration sensor's output voltage signal with the preset frequency range.

[0045] S124: If the frequency of the voltage signal output by the acceleration sensor is not within the preset frequency range, compare the amplitude of the voltage signal output by the acceleration sensor with a preset amplitude range.

[0046] In a specific implementation, when the air purification system determines that the frequency of the acceleration sensor's output voltage is not within a preset frequency range, the voltage signal frequency of the acceleration sensor output is abnormal, which may be due to a signal error caused by external interference to the acceleration sensor. If the frequency of the acceleration sensor's output voltage is not within the preset frequency range, the system needs to further verify whether the external interference caused it. Therefore, the system compares the amplitude of the voltage signal output by the acceleration sensor with the preset amplitude range, and verifies whether the abnormal frequency of the acceleration sensor's output voltage is caused by external interference based on the preset amplitude range.

[0047] S125. Determine whether the amplitude of the voltage signal output by the acceleration sensor is within the preset amplitude range.

[0048] In specific implementation, the air purification device system compares the amplitude of the sensor's output voltage with the preset amplitude range to determine whether the amplitude of the sensor's output voltage is within the preset amplitude range, thereby determining whether the amplitude of the sensor's output voltage is normal, and then obtaining the filter detection result.

[0049] S126: If the amplitude of the voltage signal output by the acceleration sensor is within the preset amplitude range, return to step S121 of comparing the frequency of the voltage signal output by the acceleration sensor with the preset frequency range.

[0050] In a specific implementation, if the air purification system determines that the amplitude of the acceleration sensor's output voltage is within a preset amplitude range, the amplitude of the voltage signal output by the acceleration sensor is normal, and the previous determination that the abnormal frequency of the acceleration sensor's output voltage signal was due to external interference is considered abnormal. Therefore, the system returns to the step of comparing the frequency of the acceleration sensor's output voltage signal with the preset frequency range and retests.

[0051] S127: If the amplitude of the voltage signal output by the acceleration sensor is not within the preset amplitude range, determine that the filter detection result is a filter abnormality.

[0052] In specific implementations, when the amplitude of the voltage signal output by the acceleration sensor is not within the preset amplitude range, it means that the frequency and amplitude of the output voltage of the acceleration sensor are abnormal, which is not caused by external interference, but by the blockage or damage of the filter. At this time, the system determines that the filter detection result is a filter abnormality, and the user needs to clean or replace the filter to eliminate the abnormality.

[0053] S130: When the filter detection result shows that the filter is abnormal, an alarm signal is output.

[0054] In practice, if the system determines that the filter is abnormal, it will output an alarm signal to inform the user that the filter is clogged or damaged. Specifically, the output alarm signal may include LED lighting, screen display, buzzer alarm, etc. By outputting the alarm signal, the user is reminded to check, clean, or replace the filter, thereby ensuring the normal function of the air purification device.

[0055] The method of the embodiment of the present application obtains the voltage signal output by the acceleration sensor, obtains the filter detection result according to the frequency and amplitude of the voltage signal output by the acceleration sensor, and outputs an alarm signal when the filter detection result shows that the filter is abnormal, thereby reminding the user to check and clean the filter or replace the filter, thereby ensuring the normal function of the air purification device and improving the user experience.

[0056] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and such modifications or substitutions are intended to be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. An acceleration sensor, characterized in that include: Acceleration sensor, used to generate charge signal under the action of acceleration; a charge conversion circuit, connected to the acceleration sensor, for converting the charge signal into a voltage signal; The voltage amplifying circuit is connected to the charge conversion circuit and is used to amplify the voltage signal and output it to the signal processing unit for processing to calculate the acceleration.

2. The acceleration sensor according to claim 1, wherein The voltage amplification circuit includes a primary voltage amplification module and a secondary voltage amplification module. The primary voltage amplification module is connected to the output end of the charge conversion circuit and is used to amplify the voltage signal output by the charge conversion circuit. The secondary voltage amplification module is connected to the output end of the primary voltage amplification module and is used to amplify the voltage signal amplified by the primary voltage amplification module again and output it to the signal processing unit for processing to calculate acceleration.

3. The acceleration sensor according to claim 2, wherein: The first-level voltage amplification module includes a first operational amplifier, a first resistor and a second resistor. The non-inverting input terminal of the first operational amplifier is connected to the charge conversion circuit through the first resistor, the inverting input terminal of the first operational amplifier is grounded through the second resistor, and the output terminal of the first operational amplifier is connected to the input terminal of the second-level voltage amplification module.

4. The acceleration sensor according to claim 3, wherein: The first-stage voltage amplification module further includes a first capacitor, one end of which is connected to the non-inverting input terminal of the first operational amplifier, and the other end of which is grounded.

5. The acceleration sensor according to claim 2, wherein: The secondary voltage amplification module includes a second operational amplifier, a third resistor and a fourth resistor. The non-inverting input terminal of the second operational amplifier is connected to the primary voltage amplification module through the third resistor, the inverting input terminal of the second operational amplifier is grounded through the fourth resistor, and the output terminal of the second operational amplifier is connected to the signal processing unit.

6. The acceleration sensor according to claim 5, wherein: The voltage amplifying circuit further includes a second capacitor, one end of the second capacitor is connected to the non-inverting input terminal of the second operational amplifier, and the other end is grounded.

7. The acceleration sensor according to any one of claims 1 to 6, characterized in that: The charge conversion circuit includes a third operational amplifier, a fifth resistor and a third capacitor. The non-inverting input of the third operational amplifier is connected to the acceleration sensor through the fifth resistor. One end of the third capacitor is connected to the non-inverting input of the third operational amplifier and the other end is grounded. The inverting input of the third operational amplifier is grounded, and the output of the third operational amplifier is connected to the voltage amplification circuit.

8. An air purification device, characterized in that: include: A filter, a signal processing unit, and the acceleration sensor according to any one of claims 1 to 7, wherein the acceleration sensor is arranged on the air outlet side of the filter, and the signal processing unit is connected to the acceleration sensor.

9. A filter detection method for an air purification device, characterized in that: Applied to the air purification device according to claim 8, the method comprises: Obtain the voltage signal output by the acceleration sensor; Obtaining a filter detection result according to the frequency and amplitude of the voltage signal output by the acceleration sensor; When the filter detection result shows that the filter is abnormal, an alarm signal is output.

10. The method according to claim 9, characterized in that The obtaining of the filter detection result according to the frequency and amplitude of the voltage signal output by the acceleration sensor includes: comparing the frequency of the voltage signal output by the acceleration sensor with a preset frequency range; Determining whether the frequency of the voltage signal output by the acceleration sensor is within the preset frequency range; If the frequency of the voltage signal output by the acceleration sensor is within the preset frequency range, returning to the step of comparing the frequency of the voltage signal output by the acceleration sensor with the preset frequency range; If the frequency of the voltage signal output by the acceleration sensor is not within the preset frequency range, comparing the amplitude of the voltage signal output by the acceleration sensor with the preset amplitude range; Determining whether the amplitude of the voltage signal output by the acceleration sensor is within the preset amplitude range; If the amplitude of the voltage signal output by the acceleration sensor is within the preset amplitude range, returning to the step of comparing the frequency of the voltage signal output by the acceleration sensor with the preset frequency range; If the amplitude of the voltage signal output by the acceleration sensor is not within the preset amplitude range, the filter detection result is determined to be a filter abnormality.

Images